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Sample records for profibrinolytic receptor annexin

  1. The Annexin A1 Receptor FPR2 Regulates the Endosomal Export of Influenza Virus

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    Fryad Rahman

    2018-05-01

    Full Text Available The Formyl Peptide Receptor 2 (FPR2 is a novel promising target for the treatment of influenza. During viral infection, FPR2 is activated by annexinA1, which is present in the envelope of influenza viruses; this activation promotes virus replication. Here, we investigated whether blockage of FPR2 would affect the genome trafficking of influenza virus. We found that, upon infection and cell treatment with the specific FPR2 antagonist WRW4 or the anti-FPR2 monoclonal antibody, FN-1D6-AI, influenza viruses were blocked into endosomes. This effect was independent on the strain and was observed for H1N1 and H3N2 viruses. In addition, blocking FPR2signaling in alveolar lung A549 epithelial cells with the monoclonal anti-FPR2 antibody significantly inhibited virus replication. Altogether, these results show that FPR2signaling interferes with the endosomal trafficking of influenza viruses and provides, for the first time, the proof of concept that monoclonal antibodies directed against FPR2 inhibit virus replication. Antibodies-based therapeutics have emerged as attractive reagents in infectious diseases. Thus, this study suggests that the use of anti-FPR2 antibodies against influenza hold great promise for the future.

  2. Annexin A2 is a natural extrahepatic inhibitor of the PCSK9-induced LDL receptor degradation.

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    Nabil G Seidah

    Full Text Available Proprotein convertase subtilisin/kexin-9 (PCSK9 enhances the degradation of hepatic low-density lipoprotein receptor (LDLR. Deletion of PCSK9, and loss-of-function mutants in humans result in lower levels of circulating LDL-cholesterol and a strong protection against coronary heart disease. Accordingly, the quest for PCSK9 inhibitors has major clinical implications. We have previously identified annexin A2 (AnxA2 as an endogenous binding partner and functional inhibitor of PCSK9. Herein, we studied the relevance of AnxA2 in PCSK9 inhibition and lipid metabolism in vivo. Plasma analyses of AnxA2(-/- mice revealed: i a ∼1.4-fold increase in LDL-cholesterol without significant changes in VLDLs or HDLs, and ii a ∼2-fold increase in circulating PCSK9 levels. Western blotting and immunohistochemistry of AnxA2(-/- tissues revealed that the LDLR was decreased by ∼50% in extrahepatic tissues, such as adrenals and colon. We also show that AnxA2-derived synthetic peptides block the PCSK9≡LDLR interaction in vitro, and adenoviral overexpression of AnxA2 in mouse liver increases LDLR protein levels in vivo. These results suggest that AnxA2 acts as an endogenous regulator of LDLR degradation, mostly in extrahepatic tissues. Finally, we identified an AnxA2 coding polymorphism, V98L, that correlates with lower circulating levels of PCSK9 thereby extending our results on the physiological role of AnxA2 in humans.

  3. Yeast two-hybrid screening of proteins interacting with plasmin receptor subunit: C-terminal fragment of annexin A2.

    Science.gov (United States)

    Li, Qun; Laumonnier, Yves; Syrovets, Tatiana; Simmet, Thomas

    2011-11-01

    To identify proteins that interact with the C-terminal fragment of annexin A2 (A2IC), generated by plasmin cleavage of the plasmin receptor, a heterotetramer (AA2t) containing annexin A2. The gene that encodes the A2IC fragment was obtained from PCR-amplified cDNA isolated from human monocytes, and was ligated into the pBTM116 vector using a DNA ligation kit. The resultant plasmid (pBTM116-A2IC) was sequenced with an ABI PRISM 310 Genetic Analyzer. The expression of an A2IC bait protein fused with a LexA-DNA binding domain (BD) was determined using Western blot analysis. The identification of proteins that interact with A2IC and are encoded in a human monocyte cDNA library was performed using yeast two-hybrid screening. The DNA sequences of the relevant cDNAs were determined using an ABI PRISM BigDye terminator cycle sequencing ready reaction kit. Nucleotide sequence databases were searched for homologous sequences using BLAST search analysis (http://www.ncbi.nlm.nih.gov). Confirmation of the interaction between the protein LexA-A2IC and each of cathepsin S and SNX17 was conducted using a small-scale yeast transformation and X-gal assay. The yeast transformed with plasmids encoding the bait proteins were screened with a human monocyte cDNA library by reconstituting full-length transcription factors containing the GAL4-active domain (GAL4-AD) as the prey in a yeast two-hybrid approach. After screening 1×10(7) clones, 23 independent β-Gal-positive clones were identified. Sequence analysis and a database search revealed that 15 of these positive clones matched eight different proteins (SNX17, ProCathepsin S, RPS2, ZBTB4, OGDH, CCDC32, PAPD4, and actin which was already known to interact with annexin A2). A2IC A2IC interacts with various proteins to form protein complexes, which may contribute to the molecular mechanism of monocyte activation induced by plasmin. The yeast two-hybrid system is an efficient approach for investigating protein interactions.

  4. Role of lipoxygenases and lipoxin A(4)/annexin-1 receptor in gastric protection induced by 20% ethanol or sodium salicylate in rats.

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    Peskar, Brigitta M; Ehrlich, Karlheinz; Schuligoi, Rufina; Peskar, Bernhard A

    2009-01-01

    The role of cyclooxygenases and prostaglandins in experimental models of gastroprotection is well established. We investigated the effects of the 5-lipoxygenase inhibitor A63162, the 12-lipoxygenase inhibitor baicalein and the 15-lipoxygenase inhibitor PD146176 as well as the nonspecific lipoxin A(4)/annexin-1 antagonist Boc1 on adaptive protection induced by 20% ethanol against 70% ethanol, and on protection induced by sodium salicylate against the mucosal-damage-aggravating effects of celecoxib and dexamethasone during local ischemia-reperfusion in rats. It was found that both types of gastroprotection were antagonized by the lipoxygenase inhibitors and the lipoxin A(4)/annexin-1 antagonist in doses that have no direct damaging effect on gastric mucosa. The results suggest that not only cyclooxygenases, but also active lipoxygenases and, possibly, annexin-1 are required for these types of gastroprotection to occur. Copyright 2009 S. Karger AG, Basel.

  5. Histones Differentially Modulate the Anticoagulant and Profibrinolytic Activities of Heparin, Heparin Derivatives, and Dabigatran.

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    Ammollo, Concetta Tiziana; Semeraro, Nicola; Carratù, Maria Rosaria; Colucci, Mario; Semeraro, Fabrizio

    2016-02-01

    The antithrombin activity of unfractionated heparin (UFH) is offset by extracellular histones, which, along with DNA, represent a novel mediator of thrombosis and a structural component of thrombi. Here, we systematically evaluated the effect of histones, DNA, and histone-DNA complexes on the anticoagulant and profibrinolytic activities of UFH, its derivatives enoxaparin and fondaparinux, and the direct thrombin inhibitor dabigatran. Thrombin generation was assessed by calibrated automated thrombinography, inhibition of factor Xa and thrombin by synthetic substrates, tissue plasminogen activator-mediated clot lysis by turbidimetry, and thrombin-activatable fibrinolysis inhibitor (TAFI) activation by a functional assay. Histones alone delayed coagulation and slightly stimulated fibrinolysis. The anticoagulant activity of UFH and enoxaparin was markedly inhibited by histones, whereas that of fondaparinux was enhanced. Histones neutralized both the anti-Xa and anti-IIa activities of UFH and preferentially blocked the anti-IIa activity of enoxaparin. The anti-Xa activity of fondaparinux was not influenced by histones when analyzed by chromogenic substrates, but was potentiated in a plasma prothrombinase assay. Histones inhibited the profibrinolytic activity of UFH and enoxaparin and enhanced that of fondaparinux by acting on the modulation of TAFI activation by anticoagulants. Histone H1 was mainly responsible for these effects. Histone-DNA complexes, as well as intact neutrophil extracellular traps, impaired the activities of UFH, enoxaparin, and fondaparinux. Dabigatran was not noticeably affected by histones and/or DNA, whatever the assay performed. In conclusion, histones and DNA present in the forming clot may variably influence the antithrombotic activities of anticoagulants, suggesting a potential therapeutic advantage of dabigatran and fondaparinux over heparins. Copyright © 2016 by The American Society for Pharmacology and Experimental Therapeutics.

  6. Annexin A2 and cancer

    DEFF Research Database (Denmark)

    Christensen, Maria V; Høgdall, Claus K; Jochumsen, Kirsten M

    2018-01-01

    Annexin A2 is a 36-kDa protein interfering with multiple cellular processes especially in cancer progression. The present review aimed to show the relations between Annexin A2 and cancer. A systematic search for studies investigating cancer and Annexin A2 expression was conducted using Pub......Med. Acute lymphoblastic leukaemia, acute promyelocytic leukaemia, clear cell renal cell carcinoma, breast, cervical, colorectal, endometrial, gastric cancer, glioblastoma, hepatocellular carcinoma, lung, multiple myeloma, oesophageal squamous cell carcinoma, ovarian cancer, pancreatic duct adenocarcinoma......, prostate cancer and urothelial carcinoma were evaluated. Annexin A2 expression correlates with resistance to treatment, binding to the bone marrow, histological grade and type, TNM-stage and shortened overall survival. The regulation of Annexin A2 is of interest due to its potential as target for a more...

  7. Role of lipoxygenases and the lipoxin A(4)/annexin 1 receptor in ischemia-reperfusion-induced gastric mucosal damage in rats.

    Science.gov (United States)

    Peskar, Brigitta M; Ehrlich, Karlheinz; Schuligoi, Rufina; Peskar, Bernhard A

    2009-01-01

    Rat gastric mucosal damage was induced by ischemia-reperfusion. The 5-lipoxygenase inhibitors MK886 and A63162, the 12-lipoxygenase inhibitor baicalein, the 15-lipoxygenase inhibitor PD146176 and the lipoxin (LX) A(4)/annexin 1 antagonist Boc1 increased mucosal damage in a dose-dependent manner. Low doses of these compounds, which have no effects on mucosal integrity, cause severe damage when combined with low doses of indomethacin, celecoxib or dexamethasone. 16,16-Dimethylprostaglandin (PG) E(2) and LXA(4) can replace each other in preventing mucosal injury induced by either cyclooxygenase or lipoxygenase inhibitors. The results suggest that not only cyclooxygenases, but also lipoxygenases have a role in limiting gastric mucosal damage during ischemia-reperfusion. Copyright 2009 S. Karger AG, Basel.

  8. Functional interaction of TRPV4 channel protein with annexin A2 in DRG.

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    Ning, Liping; Wang, Chuanwei; Ding, Xinli; Zhang, Yang; Wang, Xuping; Yue, Shouwei

    2012-09-01

    Transient receptor potential vanilloid 4 (TRPV4) is a Ca(2+)-permeable, non-selective cation channel that is involved in the transmission of pain signals mediated by dorsal root ganglion (DRG). Annexin A2 belongs to a class of membrane-binding proteins that plays an important role in the regulation of ion channels. Nevertheless, little is known about the interaction between them in DRG. In this paper, we evaluated the functional interaction of TRPV4 with annexin A2 in DRG. We have used immunocytochemistry and co-immunoprecipitation assays to investigate the interaction between annexin A2 and TRPV4 in DRG. The role of annexin A2 in the regulation of TRPV4 activity in DRG was further verified by measurement of intracellular free calcium concentrations ([Ca(2+)](i)) and substance P (SP) release. First, annexin A2 was showed partial co-localization with TRPV4 in DRG neurons. Then, annexin A2 and TRPV4 were co-precipitated with each other in DRG lysates. Furthermore, the downregulation of annexin A2 using specific small interfering RNA significantly inhibited Ca(2+) influx and SP mediated by TRPV4. Our results provide evidence that annexin A2 is associated with TRPV4 and regulates TRPV4-mediated Ca(2+) influx and SP release in DRG neurons. The objective of this work is to determine the influence of annexin A2 on TRPV4 in DRG neurons, which may be the basis for treatment of pain relief.

  9. Effects of nattokinase, a pro-fibrinolytic enzyme, on red blood cell aggregation and whole blood viscosity.

    Science.gov (United States)

    Pais, Eszter; Alexy, Tamas; Holsworth, Ralph E; Meiselman, Herbert J

    2006-01-01

    The vegetable cheese-like food, natto, is extremely popular in Japan with a history extending back over 1000 years. A fibrinolytic enzyme, termed nattokinase, can be extracted from natto; the enzyme is a subtilisin-like serine protease composed of 275 amino acid residues and has a molecular weight of 27.7 kDa. In vitro and in vivo studies have consistently demonstrated the potent pro-fibrinolytic effect of the enzyme. However, no studies to date have evaluated the effects of nattokinase on various hemorheological parameters and thus we have begun to assess the effects of the enzyme on RBC aggregation and blood viscosity. Blood samples were incubated with nattokinase (final activities of 0, 15.6, 31.3, 62.5 and 125 units/ml) for 30 minutes at 37 degrees C. RBC aggregation was measured using a Myrenne MA-1 aggregometer and blood viscosity assessed over 1-1000 s(-1) with a computer controlled scanning capillary rheometer (Rheolog). Our in vitro results showed a significant, dose-dependent decrease of RBC aggregation and low-shear viscosity, with these beneficial effects evident at concentrations similar to those achieved in previous in vivo animal trials. Our preliminary data thus indicate positive in vitro hemorheological effects of nattokinase, and suggest its potential value as a therapeutic agent and the need for additional studies and clinical trials.

  10. Annexin-Phospholipid Interactions. Functional Implications

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    Javier Turnay

    2013-01-01

    Full Text Available Annexins constitute an evolutionary conserved multigene protein superfamily characterized by their ability to interact with biological membranes in a calcium dependent manner. They are expressed by all living organisms with the exception of certain unicellular organisms. The vertebrate annexin core is composed of four (eight in annexin A6 homologous domains of around 70 amino acids, with the overall shape of a slightly bent ring surrounding a central hydrophilic pore. Calcium- and phospholipid-binding sites are located on the convex side while the N-terminus links domains I and IV on the concave side. The N-terminus region shows great variability in length and amino acid sequence and it greatly influences protein stability and specific functions of annexins. These proteins interact mainly with acidic phospholipids, such as phosphatidylserine, but differences are found regarding their affinity for lipids and calcium requirements for the interaction. Annexins are involved in a wide range of intra- and extracellular biological processes in vitro, most of them directly related with the conserved ability to bind to phospholipid bilayers: membrane trafficking, membrane-cytoskeleton anchorage, ion channel activity and regulation, as well as antiinflammatory and anticoagulant activities. However, the in vivo physiological functions of annexins are just beginning to be established.

  11. In vitro and in vivo characterisation of the profibrinolytic effect of an inhibitory anti-rat TAFI nanobody.

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    Hendrickx, Maarten L V; Zatloukalova, Monika; Hassanzadeh-Ghassabeh, Gholamreza; Muyldermans, Serge; Gils, Ann; Declerck, Paul J

    2014-05-05

    One of the main disadvantages of current t-PA thrombolytic treatment is the increased bleeding risk. Upon activation, thrombin activatable fibrinolysis inhibitor (TAFI) is a very powerful antifibrinolytic enzyme. Therefore, co-administration of a TAFI inhibitor during thrombolysis could reduce the required t-PA dose without compromising the thrombolytic efficacy. In this study we generated and characterised a nanobody that is inhibitory towards rat TAFI and evaluated its profibrinolytic property in vitro and in vivo. Nanobody VHH-rTAFI-i81 inhibits (at a 16-fold molar ratio nanobody over TAFI) the thrombin/thrombomodulin (T/TM)-mediated activation of rat TAFI (rTAFI) by 83 ± 1.8% with an IC50 of 0.46 (molar ratio nanobody over TAFI). The affinity (KA) of VHH-rTAFI-i81 for rTAFI, as determined by surface plasmon resonance (Biacore®), is 2.5 ± 0.2 x 10(10) M(-1) and illustrates a very strong binding. In an in vitro clot lysis assay, administration of VHH-rTAFI-i81 strongly enhances the degree of lysis and reduces time to reach full lysis of t-PA-mediated clot lysis. Epitope mapping discloses that Lys392 is of primary importance for the nanobody/rTAFI interaction besides minor contributions of Tyr175 and Glu183. In vivo application of VHH-rTAFI-i81 in a tissue factor-induced mouse thromboembolism model significantly decreases fibrin deposition in the lungs in the absence of exogenous administered t-PA. Nanobody VHH-rTAFI-i81 is a very potent inhibitor of T/TM-mediated TAFI activation. Co-administration of this nanobody and t-PA enhances the fibrinolytic efficacy. In an in vivo mouse thromboembolism model, VHH-rTAFI-i81 reduces fibrin deposition in the lungs.

  12. Identifying low density lipoprotein cholesterol associated variants in the Annexin A2 (ANXA2) gene

    DEFF Research Database (Denmark)

    Fairoozy, Roaa Hani; Cooper, Jackie; White, Jon

    2017-01-01

    Background and aims: Annexin-A2 (AnxA2) is an endogenous inhibitor of proprotein convertase subtilisin/kexin type-9 (PCSK9). The repeat-one (R1) domain of AnxA2 binds to PCSK9, blocking its ability to promote degradation of low-density lipoprotein cholesterol-receptors (LDL-R) and thereby regulat...

  13. Agrobacterium mediated transformation of annexin gene in tobacco ...

    African Journals Online (AJOL)

    STORAGESEVER

    serves as a selectable marker system in plants and its amplification confirmed the presence of annexin ... annexin signaling to many different physiological pro- ..... Lane 7: pGPTV with annexin gene digested with EcoR1 and XbaI. Lane 8:.

  14. Increased alveolar soluble Annexin V promotes lung inflammation and fibrosis

    OpenAIRE

    Buckley, S.; Shi, W.; Xu, W.; Frey, M.R.; Moats, R.; Pardo, A.; Selman, M.; Warburton, D.

    2015-01-01

    The causes underlying the self-perpetuating nature of idiopathic pulmonary fibrosis (IPF), a progressive and usually lethal disease, remain unknown. We hypothesized that alveolar soluble Annexin V contributes to lung fibrosis, based on the observation that human IPF BALF containing high Annexin V levels promoted fibroblast involvement in alveolar epithelial wound healing that was reduced when Annexin V was depleted from the BALF.

  15. Nuclear localization of Annexin A7 during murine brain development

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    Noegel Angelika A

    2005-04-01

    Full Text Available Abstract Background Annexin A7 is a member of the annexin protein family, which is characterized by its ability to interact with phospholipids in the presence of Ca2+-ions and which is thought to function in Ca2+-homeostasis. Results from mutant mice showed altered Ca2+-wave propagation in astrocytes. As the appearance and distribution of Annexin A7 during brain development has not been investigated so far, we focused on the distribution of Annexin A7 protein during mouse embryogenesis in the developing central nervous system and in the adult mouse brain. Results Annexin A7 is expressed in cells of the developing brain where a change in its subcellular localization from cytoplasm to nucleus was observed. In the adult CNS, the subcellular distribution of Annexin A7 depends on the cell type. By immunohistochemistry analysis Annexin A7 was detected in the cytosol of undifferentiated cells at embryonic days E5–E8. At E11–E15 the protein is still present in the cytosol of cells predominantly located in the ventricular germinative zone surrounding the lateral ventricle. Later on, at embryonic day E16, Annexin A7 in cells of the intermediate and marginal zone of the neopallium translocates to the nucleus. Neuronal cells of all areas in the adult brain present Annexin A7 in the nucleus, whereas glial fibrillary acidic protein (GFAP-positive astrocytes exhibit both, a cytoplasmic and nuclear staining. The presence of nuclear Annexin A7 was confirmed by extraction of the nucleoplasm from isolated nuclei obtained from neuronal and astroglial cell lines. Conclusion We have demonstrated a translocation of Annexin A7 to nuclei of cells in early murine brain development and the presence of Annexin A7 in nuclei of neuronal cells in the adult animal. The role of Annexin A7 in nuclei of differentiating and mature neuronal cells remains elusive.

  16. Annexin A1 N-terminal derived peptide Ac2-26 stimulates fibroblast migration in high glucose conditions.

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    Valentina Bizzarro

    Full Text Available Deficient wound healing in diabetic patients is very frequent, but the cellular and molecular causes are poorly defined. In this study, we have evaluated whether Annexin A1 derived peptide Ac2-26 stimulates fibroblast migration in high glucose conditions. Using normal human skin fibroblasts WS1 in low glucose (LG or high glucose (HG we observed the enrichment of Annexin A1 protein at cell movement structures like lamellipodial extrusions and interestingly, a significant decrease in levels of the protein in HG conditions. The analysis of the translocation of Annexin A1 to cell membrane showed lower levels of Annexin A1 in both membrane pool and supernatants of WS1 cells treated with HG. Wound-healing assays using cell line transfected with Annexin A1 siRNAs indicated a slowing down in migration speed of cells suggesting that Annexin A1 has a role in the migration of WS1 cells. In order to analyze the role of extracellular Annexin A1 in cell migration, we have performed wound-healing assays using Ac2-26 showing that peptide was able to increase fibroblast cell migration in HG conditions. Experiments on the mobilization of intracellular calcium and analysis of p-ERK expression confirmed the activity of the FPR1 following stimulation with the peptide Ac2-26. A wound-healing assay on WS1 cells in the presence of the FPR agonist fMLP, of the FPR antagonist CsH and in the presence of Ac2-26 indicated that Annexin A1 influences fibroblast cell migration under HG conditions acting through FPR receptors whose expression was slightly increased in HG. In conclusion, these data demonstrate that (i Annexin A1 is involved in migration of WS1 cells, through interaction with FPRs; (ii N- terminal peptide of Annexin A1 Ac2-26 is able to stimulate direct migration of WS1 cells in high glucose treatment possibly due to the increased receptor expression observed in hyperglycemia conditions.

  17. Expression of annexin and Annexin-mRNA in rat brain under influence of steroid drugs

    NARCIS (Netherlands)

    Voermans, PH; Go, KG; ter Horst, GJ; Ruiters, MHJ; Solito, E; Parente, L; James, HE; Marshall, LF; Reulen, HJ; Baethmann, A; Marmarou, A; Ito, U; Hoff, JT; Kuroiwa, T; Czernicki, Z

    1997-01-01

    Brain tissue of rats pretreated with methylprednisolone or with the 21-aminosteroid U74389F, and that of untreated control rats, was assessed for the expression of Annexin-l (Anx-1) and the transcription of its mRNA. For this purpose Anx-1 cDNA was amplified and simultaneously a T7-RNA-polymerase

  18. Annexin 1 and Melanocortin Peptide Therapy for Protection Against Ischaemic-Reperfusion Damage in the Heart

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    F.N.E. Gavins

    2006-01-01

    Full Text Available Cardiovascular disease is a major cause of mortality within the western world affecting 2.7 million British people. This review highlights the beneficial effects of naturally occurring hormones and their peptides, in myocardial ischaemic-injury (MI models, a disease pathology in which cytokines and neutrophils play a causal role. Here we discuss two distinct classes of endogenous peptides: the steroid inducible annexin 1 and the melanocortin peptides. Annexin 1 and the melanocortins counteract the most important part of the host inflammatory response, namely, the process of leukocyte extravasation, as well as release of proinflammatory mediators. Their biological effects are mediated via the seven transmembrane G-protein-coupled receptors, the fMLP receptor family (or FPR, and the melanocortin receptors, respectively. Pharmacological analysis has demonstrated that the first 24 amino acids of the N-terminus (termed Ac2-26 are the most active region. Both exogenous annexin 1 and its peptides demonstrate cardioprotectiveness and continuing work is required to understand this annexin 1/FPR relationship fully. The melanocortin peptides are derived from a precursor molecule called the POMC protein. These peptides display potent anti-inflammatory effects in human and animal models of disease. In MI, the MC3R has been demonstrated to play an important role in mediating the protective effects of these peptides. The potential anti-inflammatory role for endogenous peptides in cardiac disease is in its infancy. The inhibition of cell migration and release of cytokines and other soluble mediators appears to play an important role in affording protection in ischaemic injury and thus may lead to potential therapeutic targets.

  19. Determination of autoantibodies to annexin XI in systemic autoimmune diseases

    DEFF Research Database (Denmark)

    Jorgensen, C S; Levantino, G; Houen, Gunnar

    2000-01-01

    Annexin XI, a calcyclin-associated protein, has been shown to be identical to a 56,000 Da antigen recognized by antibodies found in sera from patients suffering from systemic autoimmune diseases. In this work hexahistidine-tagged recombinant annexin XI (His6- rAnn XI) was used as antigen in ELISA...... experiments for determination of autoantibodies to annexin XI in sera of patients with systemic rheumatic autoimmune diseases. Immunoblotting with HeLa cell extract and with His6-rAnn XI as antigen was used for confirmation of positive ELISA results. We found eleven anti-annexin XI positive sera (3.9%) out...... of 282 sera from patients with systemic rheumatic diseases. The highest number of annexin XI positive sera were found in primary antiphospholipid syndrome (3/17), and in subacute lupus erythematosus (1/6), while lower frequencies of positive sera were found in patients with systemic sclerosis (5...

  20. Prognostic significance of annexin A2 and annexin A4 expression in patients with cervical cancer

    International Nuclear Information System (INIS)

    Choi, Chel Hun; Chung, Joon-Yong; Chung, Eun Joo; Sears, John D.; Lee, Jeong-Won; Bae, Duk-Soo; Hewitt, Stephen M.

    2016-01-01

    The annexins (ANXs) have diverse roles in tumor development and progression, however, their clinical significance in cervical cancer has not been elucidated. The present study was to investigate the clinical significance of annexin A2 (ANXA2) and annexin A4 (ANXA4) expression in cervical cancer. ANXA2 and ANXA4 immunohistochemical staining were performed on a cervical cancer tissue microarray consisting of 46 normal cervical epithelium samples and 336 cervical cancer cases and compared the data with clinicopathological variables, including the survival of cervical cancer patients. ANXA2 expression was lower in cancer tissue (p = 0.002), whereas ANXA4 staining increased significantly in cancer tissues (p < 0.001). ANXA2 expression was more prominent in squamous cell carcinoma (p < 0.001), whereas ANXA4 was more highly expressed in adeno/adenosquamous carcinoma (p < 0.001). ANXA2 overexpression was positively correlated with advanced cancer phenotypes, whereas ANXA4 expression was associated with resistance to radiation with or without chemotherapy (p = 0.029). Notably, high ANXA2 and ANXA4 expression was significantly associated with shorter disease-free survival (p = 0.004 and p = 0.033, respectively). Multivariate analysis indicated that ANXA2+ (HR = 2.72, p = 0.003) and ANXA2+/ANXA4+ (HR = 2.69, p = 0.039) are independent prognostic factors of disease-free survival in cervical cancer. Furthermore, a random survival forest model using combined ANXA2, ANXA4, and clinical variables resulted in improved predictive power (mean C-index, 0.76) compared to that of clinical-variable-only models (mean C-index, 0.70) (p = 0.006). These findings indicate that detecting ANXA2 and ANXA4 expression may aid the evaluation of cervical carcinoma prognosis. The online version of this article (doi:10.1186/s12885-016-2459-y) contains supplementary material, which is available to authorized users

  1. Suppression of annexin A2 by prostaglandin E₂ impairs phagocytic ability of peritoneal macrophages in women with endometriosis.

    Science.gov (United States)

    Wu, Meng-Hsing; Chuang, Pei-Chin; Lin, Yiu-Juian; Tsai, Shaw-Jenq

    2013-04-01

    Is annexin A2 involved in the reduced phagocytic ability of macrophages in endometriosis? Data from women with endometriosis and a murine model of the disease show that expression of annexin A2 in peritoneal macrophages is inhibited by prostaglandin E2 (PGE2) and this impairs the phagocytic ability of macrophages. Endometriosis is a chronic inflammatory disease that recruits many immune cells, especially macrophages, to the peritoneal cavity. The phagocytic ability of peritoneal macrophages isolated from women with endometriosis is reduced. A laboratory study. Thirty-five patients (20 with and 15 without endometriosis) of reproductive age with normal menstrual cycles were recruited. Peritoneal macrophages isolated from women with or without endometriosis were cultured and treated with vehicle, PGE2 and different EP receptor agonists, and the expression of annexin A2 was quantified by RT-PCR and western blotting. Annexin A2 was knocked down (by small interfering RNA) in normal macrophages or overexpressed (by treatment with recombinant protein) in endometriotic macrophages and their phagocytic ability was measured by flow cytometry. Peritoneal macrophages were isolated from a mouse model of endometriosis and treated with PGE2 or cyclo-oxygenase (COX) inhibitors, and annexin A2 mRNA was quantified. Levels of annexin A2 were markedly reduced in peritoneal macrophages from women with endometriosis versus controls (mRNA: P endometriosis versus control) via the EP2/EP4 receptor-dependent signaling pathway. Treatment with PGE2 or knockdown of annexin A2 inhibited the phagocytic ability of macrophages (P peritoneal macrophages were markedly reduced in mice treated with PGE2 (P peritoneal macrophages (P peritoneal cells from patients with endometriosis or that their endometriotic fluid contains increased amounts of PGE2 when compared with control subjects. Inhibiting PGE2 signaling, in order to restore or enhance the phagocytic capability of macrophages, may represent a new

  2. 18F-labelled annexin V: a PET tracer for apoptosis imaging

    International Nuclear Information System (INIS)

    Murakami, Yoshihiro; Tatsumi, Mitsuyoshi; Ichise, Rikiya; Nishimura, Shintaro; Takamatsu, Hiroyuki; Noda, Akihiro; Taki, Junichi; Tait, Jonathan F.

    2004-01-01

    Annexin V can be used to detect apoptotic cells in vitro and in vivo, based on its ability to identify extracellular phosphatidylserine, which arises during apoptosis. In the present study, we examined the synthesis of fluorine-18 labelled annexin V as a positron emission tomography tracer for apoptosis imaging. The distribution of [ 18 F]annexin V and technetium-99m labelled annexin V, a well-characterised SPET tracer for apoptosis imaging, was compared. [ 18 F]annexin V was synthesised using N-succinimidyl 4-[ 18 F]fluorobenzoate as an 18 F labelling reagent. Synthesised and purified [ 18 F]annexin V was confirmed by SDS-PAGE. In an ex vivo imaging experiment, [ 18 F]annexin V was intravenously injected into rats 24 h after the induction of myocardial ischaemia, and accumulation in the left ventricle was examined. [ 18 F]annexin V accumulated in the infarct area of the left ventricle, where apoptotic cells were observed. In separate experiments, [ 18 F]annexin V or [ 99m Tc]annexin V was intravenously injected into ischaemic or normal animals, and the distribution of the tracers was compared. In ischaemic animals, accumulation of [ 18 F]annexin V and [ 99m Tc]annexin V in the infarct area was about threefold higher than in the non-infarct area. Furthermore, the ratio of accumulation in the normal heart to the blood radioactivity was not significantly different between the tracers. In normal animals, however, the uptake of [ 18 F]annexin V in the liver, spleen and kidney was much lower than that of [ 99m Tc]annexin V. The low uptake of [ 18 F]annexin V in these organs might represent an advantage over [ 99m Tc]annexin V. (orig.)

  3. Annexin C4 in A. fumigatus: a proteomics approach to understand the function.

    OpenAIRE

    Khalaj , Vahid; Azarian , Bahareh; Enayati , Somayeh; Vaziri , Behrouz

    2011-01-01

    International audience; Annexin C4 has been identified as a new member of fungal annexin family. In search of function, we have generated an annexin C4 disruptant strain of human pathogen, Aspergillus fumigatus. Detailed phenotypic analysis confirmed a non essential role of annexin C4 in the growth and sporulation of this pathogen. We applied a comparative proteomics strategy to understand the possible role of this protein in the fungus. The modification of respiratory chain proteins and stre...

  4. Absence of annexin I expression in B-cell non-Hodgkin's lymphomas and cell lines

    Directory of Open Access Journals (Sweden)

    Gopalakrishnan Velliyur K

    2004-03-01

    Full Text Available Abstract Background Annexin I, one of the 20 members of the annexin family of calcium and phospholipid-binding proteins, has been implicated in diverse biological processes including signal transduction, mediation of apoptosis and immunosuppression. Previous studies have shown increased annexin I expression in pancreatic and breast cancers, while it is absent in prostate and esophageal cancers. Results Data presented here show that annexin I mRNA and protein are undetectable in 10 out of 12 B-cell lymphoma cell lines examined. Southern blot analysis indicates that the annexin I gene is intact in B-cell lymphoma cell lines. Aberrant methylation was examined as a cause for lack of annexin I expression by treating cells 5-Aza-2-deoxycytidine. Reexpression of annexin I was observed after prolonged treatment with the demethylating agent indicating methylation may be one of the mechanisms of annexin I silencing. Treatment of Raji and OMA-BL-1 cells with lipopolysaccharide, an inflammation inducer, and with hydrogen peroxide, a promoter of oxidative stress, also failed to induce annexin I expression. Annexin I expression was examined in primary lymphoma tissues by immunohistochemistry and presence of annexin I in a subset of normal B-cells and absence of annexin I expression in the lymphoma tissues were observed. These results show that annexin I is expressed in normal B-cells, and its expression is lost in all primary B-cell lymphomas and 10 of 12 B-cell lymphoma cell lines. Conclusions Our results suggest that, similar to prostate and esophageal cancers, annexin I may be an endogenous suppressor of cancer development, and loss of annexin I may contribute to B-cell lymphoma development.

  5. The S100A10 subunit of the annexin A2 heterotetramer facilitates L2-mediated human papillomavirus infection.

    Science.gov (United States)

    Woodham, Andrew W; Da Silva, Diane M; Skeate, Joseph G; Raff, Adam B; Ambroso, Mark R; Brand, Heike E; Isas, J Mario; Langen, Ralf; Kast, W Martin

    2012-01-01

    Mucosotropic, high-risk human papillomaviruses (HPV) are sexually transmitted viruses that are causally associated with the development of cervical cancer. The most common high-risk genotype, HPV16, is an obligatory intracellular virus that must gain entry into host epithelial cells and deliver its double stranded DNA to the nucleus. HPV capsid proteins play a vital role in these steps. Despite the critical nature of these capsid protein-host cell interactions, the precise cellular components necessary for HPV16 infection of epithelial cells remains unknown. Several neutralizing epitopes have been identified for the HPV16 L2 minor capsid protein that can inhibit infection after initial attachment of the virus to the cell surface, which suggests an L2-specific secondary receptor or cofactor is required for infection, but so far no specific L2-receptor has been identified. Here, we demonstrate that the annexin A2 heterotetramer (A2t) contributes to HPV16 infection and co-immunoprecipitates with HPV16 particles on the surface of epithelial cells in an L2-dependent manner. Inhibiting A2t with an endogenous annexin A2 ligand, secretory leukocyte protease inhibitor (SLPI), or with an annexin A2 antibody significantly reduces HPV16 infection. With electron paramagnetic resonance, we demonstrate that a previously identified neutralizing epitope of L2 (aa 108-120) specifically interacts with the S100A10 subunit of A2t. Additionally, mutation of this L2 region significantly reduces binding to A2t and HPV16 pseudovirus infection. Furthermore, downregulation of A2t with shRNA significantly decreases capsid internalization and infection by HPV16. Taken together, these findings indicate that A2t contributes to HPV16 internalization and infection of epithelial cells and this interaction is dependent on the presence of the L2 minor capsid protein.

  6. The S100A10 subunit of the annexin A2 heterotetramer facilitates L2-mediated human papillomavirus infection.

    Directory of Open Access Journals (Sweden)

    Andrew W Woodham

    Full Text Available Mucosotropic, high-risk human papillomaviruses (HPV are sexually transmitted viruses that are causally associated with the development of cervical cancer. The most common high-risk genotype, HPV16, is an obligatory intracellular virus that must gain entry into host epithelial cells and deliver its double stranded DNA to the nucleus. HPV capsid proteins play a vital role in these steps. Despite the critical nature of these capsid protein-host cell interactions, the precise cellular components necessary for HPV16 infection of epithelial cells remains unknown. Several neutralizing epitopes have been identified for the HPV16 L2 minor capsid protein that can inhibit infection after initial attachment of the virus to the cell surface, which suggests an L2-specific secondary receptor or cofactor is required for infection, but so far no specific L2-receptor has been identified. Here, we demonstrate that the annexin A2 heterotetramer (A2t contributes to HPV16 infection and co-immunoprecipitates with HPV16 particles on the surface of epithelial cells in an L2-dependent manner. Inhibiting A2t with an endogenous annexin A2 ligand, secretory leukocyte protease inhibitor (SLPI, or with an annexin A2 antibody significantly reduces HPV16 infection. With electron paramagnetic resonance, we demonstrate that a previously identified neutralizing epitope of L2 (aa 108-120 specifically interacts with the S100A10 subunit of A2t. Additionally, mutation of this L2 region significantly reduces binding to A2t and HPV16 pseudovirus infection. Furthermore, downregulation of A2t with shRNA significantly decreases capsid internalization and infection by HPV16. Taken together, these findings indicate that A2t contributes to HPV16 internalization and infection of epithelial cells and this interaction is dependent on the presence of the L2 minor capsid protein.

  7. Function, expression and localization of annexin A7 in platelets and red blood cells: Insights derived from an annexin A7 mutant mouse

    Directory of Open Access Journals (Sweden)

    Zamparelli Carlotta

    2003-08-01

    Full Text Available Abstract Background Annexin A7 is a Ca2+- and phospholipid-binding protein expressed as a 47 and 51 kDa isoform, which is thought to be involved in membrane fusion processes. Recently the 47 kDa isoform has been identified in erythrocytes where it was proposed to be a key component in the process of the Ca2+-dependent vesicle release, a process with which red blood cells might protect themselves against an attack by for example complement components. Results The role of annexin A7 in red blood cells was addressed in erythrocytes from anxA7-/- mice. Interestingly, the Ca2+-mediated vesiculation process was not impaired. Also, the membrane organization appeared not to be disturbed as assessed using gradient fractionation studies. Instead, lack of annexin A7 led to an altered cell shape and increased osmotic resistance of red blood cells. Annexin A7 was also identified in platelets. In these cells its loss led to a slightly slower aggregation velocity which seems to be compensated by an increased number of platelets. The results appear to rule out an important role of annexin A7 in membrane fusion processes occurring in red blood cells. Instead the protein might be involved in the organization of the membrane cytoskeleton. Red blood cells may represent an appropriate model to study the role of annexin A7 in cellular processes. Conclusion We have demonstrated the presence of both annexin A7 isoforms in red blood cells and the presence of the small isoform in platelets. In both cell types the loss of annexin A7 impairs cellular functions. The defects observed are however not compatible with a crucial role for annexin A7 in membrane fusion processes in these cell types.

  8. Annexin A7 suppresses lymph node metastasis of hepatocarcinoma cells in a mouse model

    International Nuclear Information System (INIS)

    Jin, Yanling; Wang, Shaoqing; Chen, Wenjing; Zhang, Jun; Wang, Bo; Guan, Hongwei; Tang, Jianwu

    2013-01-01

    Hepatocellular carcinoma (HCC) is one of the leading causes of cancer death in China. This study investigated the effects of Annexin A7 (ANXA7) on the inhibition of HCC lymph node metastasis in a mouse model. The stable knockup and knockdown of Annexin A7-expressing HCC cells using Annexin A7 cDNA and shRNA vectors, respectively, were injected into a mouse footpad to establish primary and metastatic tumors in mice. On the 14th, 21st, and 28th days after HCC cells inoculation, the mice were sacrificed for inspection of primary and secondary tumors and immunohistochemistry of Annexin A7 expression. The lymph node metastasis rate of the F ANXA7-control group was 77%, and the lymph node metastasis rate of the F ANXA7-down group was 100% (p < 0.05). In contrast, the lymph node metastasis rate of the P ANXA7-up group was 0% and that of the P ANXA7-control group was 36% (p < 0.05). Furthermore, immunohistochemistry experiments revealed that the subcellular localization of Annexin A7 protein in both primary and lymph node-metastasized tumors was mainly in the cytosol. In addition, the expression of the 47 kDa and 51 kDa isoforms of Annexin A7 protein changed during tumor progression. This study indicated that Annexin A7 expression was able to inhibit HCC lymph node metastasis, whereas knockdown of Annexin A7 expression significantly induced HCC metastasis to local lymph nodes

  9. Internalization of annexin A5-functionalized iron oxide particles by apoptotic Jurkat cells

    NARCIS (Netherlands)

    van Tilborg, Geralda A. F.; Geelen, Tessa; Duimel, Hans; Bomans, Paul H. H.; Frederik, Peter M.; Sanders, Honorius M. H. F.; Deckers, Niko M.; Deckers, Roel; Reutelingsperger, Chris P. M.; Strijkers, Gustav J.; Nicolay, Klaas

    2009-01-01

    Apoptosis plays an important role in the etiology of various diseases. Several studies have reported on the use of annexin A5-functionalized iron oxide particles for the detection of apoptosis with MRI, both in vitro and in vivo. The protein annexin A5 binds with high affinity to the phospholipid

  10. Differential Modulation of Annexin I Binding Sites on Monocytes and Neutrophils

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    H. S. Euzger

    1999-01-01

    Full Text Available Specific binding sites for the anti-inflammatory protein annexin I have been detected on the surface of human monocytes and polymorphonuclear leukocytes (PMN. These binding sites are proteinaceous in nature and are sensitive to cleavage by the proteolytic enzymes trypsin, collagenase, elastase and cathepsin G. When monocytes and PMN were isolated independently from peripheral blood, only the monocytes exhibited constitutive annexin I binding. However PMN acquired the capacity to bind annexin I following co-culture with monocytes. PMN incubation with sodium azide, but not protease inhibitors, partially blocked this process. A similar increase in annexin I binding capacity was also detected in PMN following adhesion to endothelial monolayers. We propose that a juxtacrine activation rather than a cleavage-mediated transfer is involved in this process. Removal of annexin I binding sites from monocytes with elastase rendered monocytes functionally insensitive to full length annexin I or to the annexin I-derived pharmacophore, peptide Ac2-26, assessed as suppression of the respiratory burst. These data indicate that the annexin I binding site on phagocytic cells may have an important function in the feedback control of the inflammatory response and their loss through cleavage could potentiate such responses.

  11. An ANNEXIN-like protein from the cereal cyst nematode Heterodera avenae suppresses plant defense.

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    Changlong Chen

    Full Text Available Parasitism genes encoding secreted effector proteins of plant-parasitic nematodes play important roles in facilitating parasitism. An annexin-like gene was isolated from the cereal cyst nematode Heterodera avenae (termed Ha-annexin and had high similarity to annexin 2, which encodes a secreted protein of Globodera pallida. Ha-annexin encodes a predicted 326 amino acid protein containing four conserved annexin domains. Southern blotting revealed that there are at least two homologies in the H. avenae genome. Ha-annexin transcripts were expressed within the subventral gland cells of the pre-parasitic second-stage juveniles by in situ hybridization. Additionally, expression of these transcripts were relatively higher in the parasitic second-stage juveniles by quantitative real-time RT-PCR analysis, coinciding with the time when feeding cell formation is initiated. Knockdown of Ha-annexin by method of barley stripe mosaic virus-based host-induced gene silencing (BSMV-HIGS caused impaired nematode infections at 7 dpi and reduced females at 40 dpi, indicating important roles of the gene in parasitism at least in early stage in vivo. Transiently expression of Ha-ANNEXIN in onion epidermal cells and Nicotiana benthamiana leaf cells showed the whole cell-localization. Using transient expression assays in N. benthamiana, we found that Ha-ANNEXIN could suppress programmed cell death triggered by the pro-apoptotic mouse protein BAX and the induction of marker genes of PAMP-triggered immunity (PTI in N. benthamiana. In addition, Ha-ANNEXIN targeted a point in the mitogen-activated protein kinase (MAPK signaling pathway downstream of two kinases MKK1 and NPK1 in N. benthamiana.

  12. Annexin A1 is elevated in patients with COPD and affects lung fibroblast function

    Directory of Open Access Journals (Sweden)

    Lai TW

    2018-02-01

    Full Text Available Tianwen Lai,1,* Yanyu Li,1,* Zongjiong Mai,2 Xiaoxia Wen,1 Yingying Lv,1 Zhanqing Xie,3 Quanchao Lv,1 Min Chen,1 Dong Wu,1 Bin Wu1 1Department of Respiratory and Critical Care Medicine, 2Department of Oncology, 3Department of Thoracic Surgery, The Affiliated Hospital of Guangdong Medical University, Zhanjiang, People’s Republic of China *These authors contributed equally to this work Purpose: Fibrosis in peripheral airways is responsible for airflow limitation in chronic obstructive pulmonary disease (COPD. Annexin A1 modulates several key biological events during inflammation. However, little is known about its role in airway fibrosis in COPD. We investigated whether levels of Annexin A1 were upregulated in patients with COPD, and whether it promoted airway fibrosis.Methods: We quantified serum Annexin A1 levels in never-smokers (n=12, smokers without COPD (n=11, and smokers with COPD (n=22. Correlations between Annexin A1 expression and clinical indicators (eg, lung function were assessed. In vitro, human bronchial epithelial (HBE cells were exposed to cigarette smoke extract (CSE and Annexin A1 expression was assessed. Primary human lung fibroblasts were isolated from patients with COPD and effects of Annexin A1 on fibrotic deposition of lung fibroblasts were evaluated.Results: Serum Annexin A1 was significantly higher in patients with Global Initiative for Chronic Obstructive Lung Disease (GOLD guidelines stage III or IV than in those with GOLD stages I or II (12.8±0.8 ng/mL versus 9.8±0.7 ng/mL; p=0.016. Annexin A1 expression was negatively associated with airflow obstruction (forced expiratory volume in one second % predicted; r=−0.72, p<0.001. In vitro, Annexin A1 was significantly increased in CSE-exposed HBE cells in a time- and concentration-dependent manner. Annexin A1 promoted lung fibroblasts proliferation, migration, differentiation, and collagen deposition via the ERK1/2 and p38 mitogen-activated protein kinase pathways

  13. Preparation and in vitro evaluation of human recombinant annexin V using for apoptosis

    International Nuclear Information System (INIS)

    Chen Daming; Beijing Univ., Beijing; Qi Benzhong; Yang Hongwei; Luo Zhifu; Zhang Jinrong; Jin Xiaohai; Jia Bing; Xie Hong; Ma Dalong

    2004-01-01

    Human recombinant Annexin V was produced by expression in E coli with high efficiency through genetic engineering. The technique procedure concerned in the temperature and time of vector expression, the basic routine and purification of proteins was established in order to obtain a large quantity of Annexin V. the results of SDS-PAGE analysis and the apoptosis detection of single cell of thymocytes of Balb/c mice using FITC-Annexin V caused by dexamethasone with availableness show that the mature Annexin V with high purity and biologic activity is obtained by ion exchange chromatography. The results of cell binding assay show that its KD is 8.53 nmol/mL and RT is 8.79 nmol/mL. (authors)

  14. Annexin A4 and A6 induce membrane curvature and constriction during cell membrane repair

    DEFF Research Database (Denmark)

    Boye, Theresa Louise; Maeda, Kenji; Pezeshkian, Weria

    2017-01-01

    Efficient cell membrane repair mechanisms are essential for maintaining membrane integrity and thus for cell life. Here we show that the Ca2+- and phospholipid-binding proteins annexin A4 and A6 are involved in plasma membrane repair and needed for rapid closure of micron-size holes. We demonstrate...... that annexin A4 binds to artificial membranes and generates curvature force initiated from free edges, whereas annexin A6 induces constriction force. In cells, plasma membrane injury and Ca2+ influx recruit annexin A4 to the vicinity of membrane wound edges where its homo-trimerization leads to membrane...... that induction of curvature force around wound edges is an early key event in cell membrane repair....

  15. Expression characteristics and diagnostic value of annexin A2 in hepatocellular carcinoma

    OpenAIRE

    Zhang, Hai-Jian; Yao, Deng-Fu; Yao, Min; Huang, Hua; Wu, Wei; Yan, Mei-Juan; Yan, Xiao-Di; Chen, Jie

    2012-01-01

    AIM: To investigate the characteristics and diagnostic value of annexin A2 (ANXA2) expression in cancerous tissues and sera of patients with hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC).

  16. Annexin V–CLIO: A Nanoparticle for Detecting Apoptosis by MRI

    Directory of Open Access Journals (Sweden)

    Eyk A. Schellenberger

    2002-04-01

    Full Text Available Annexin V, which recognizes the phosphatidylserine of apoptotic cells, was conjugated to crosslinked iron oxide (CLIO nanoparticles, a functionalized superparamagnetic preparation developed for target-specific magnetic resonance imaging (MRI. The resulting nanoparticle had an average of 2.7 annexin V proteins linked per CLIO nanoparticle through disulfide bonds. Using camptothecin to induce apoptosis, a mixture of Jurkat T cells (69% healthy and 31% apoptotic was incubated with annexin V–CLIO and was applied to magnetic columns. The result was an almost complete removal of the apoptotic cells (>99%. In a phantom MRI experiment, untreated control cells (12% apoptotic cells, 88% healthy cells and camptothecin-treated cells (65% apoptotic cells, 35% healthy cells were incubated with either annexin V–CLIO (1.0, 0.5, and 0.1 μg Fe/mL or with unlabeled CLIO. A significant signal decrease of camptothecin-treated cells relative to untreated cells was observed even at the lowest concentration tested. Unmodified CLIO failed to cause a significant signal change of apoptotic cells. Hence, annexin V–CLIO allowed the identification of cell suspensions containing apoptotic cells by MRI even at very low concentrations of magnetic substrate. Conjugation of annexin V to CLIO affords a strategy for the development of a MRI imaging probe for detecting apoptosis.

  17. Kit formulation for 99mTc-labeling of recombinant Annexin V molecule with a C-terminally engineered cysteine

    International Nuclear Information System (INIS)

    Chunxiong Lu; Quanfu Jiang; Cheng Tan; Huixin Yu; Minjin Hu; Zichun Hua; Nanjing University, Nanjing

    2015-01-01

    A new formulation of a freeze-dried kit for the labeling of a novel recombinant Annexin V molecules (with a single cysteine residue at its C-terminal, Cys-Annexin V) with technetium-99m has been developed. Effects of the amount range of Cys-Annexin V, stannous chloride, glucoheptonate and disodium edetate on the radiolabeling yield were studied in details. The stabilities of 99m Tc-Cys-Annexin V and freeze-dried kits were performed, respectively. In vitro cell uptake studies showed the binding of 99m Tc-Cys-Annexin V was specific on testing with apoptotic H446 cells. Therefore, 99m Tc-Cys-Annexin V is a potential apoptosis imaging agent and further study is needed. (author)

  18. Role of annexin A5 in cisplatin-induced toxicity in renal cells: molecular mechanism of apoptosis.

    Science.gov (United States)

    Jeong, Jin-Joo; Park, Nahee; Kwon, Yeo-Jung; Ye, Dong-Jin; Moon, Aree; Chun, Young-Jin

    2014-01-24

    Annexin A5 belongs to a large family of calcium-binding and phospholipid-binding proteins and may act as an endogenous regulator of various pathophysiological processes. There is increasing evidence that annexin A5 is related to cytotoxicity, but the precise function of this protein has yet to be elucidated. In this study, we aimed to verify the function of annexin A5 in the apoptosis of renal epithelial cells. Real-time PCR and Western blot analysis, together with immunofluorescence analysis, showed that the expression of annexin A5 significantly increased in the presence of cisplatin in both human and rat renal epithelial cells. With regard to the mechanism of cisplatin-induced apoptosis, apoptosis-inducing factor (AIF) release into the cytosol was observed, and the underlying mechanism was identified as voltage-dependent anion channel (VDAC) oligomerization. Mitochondrial membrane potential (Δψm) was found to be greatly disrupted in cisplatin-treated cells. Moreover, cisplatin strongly induced translocation of annexin A5 into mitochondria. To understand the functional significance of annexin A5 in renal cell death, we used a siRNA-mediated approach to knock down annexin A5. Annexin A5 depletion by siRNA led to decreased annexin A5 translocation into mitochondria and significantly reduced VDAC oligomerization and AIF release. Annexin A5 siRNA also increased cell viability compared with the control. Moreover, expression of annexin A5 was induced by other nephrotoxicants such as CdCl2 and bacitracin. Taken together, our data suggest that annexin A5 may play a crucial role in cisplatin-induced toxicity by mediating the mitochondrial apoptotic pathway via the induction and oligomerization of VDAC.

  19. Leishmania promastigotes lack phosphatidylserine but bind annexin V upon permeabilization or miltefosine treatment.

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    Adrien Weingärtner

    Full Text Available The protozoan parasite Leishmania is an intracellular pathogen infecting and replicating inside vertebrate host macrophages. A recent model suggests that promastigote and amastigote forms of the parasite mimic mammalian apoptotic cells by exposing phosphatidylserine (PS at the cell surface to trigger their phagocytic uptake into host macrophages. PS presentation at the cell surface is typically analyzed using fluorescence-labeled annexin V. Here we show that Leishmania promastigotes can be stained by fluorescence-labeled annexin V upon permeabilization or miltefosine treatment. However, combined lipid analysis by thin-layer chromatography, mass spectrometry and (31P nuclear magnetic resonance (NMR spectroscopy revealed that Leishmania promastigotes lack any detectable amount of PS. Instead, we identified several other phospholipid classes such phosphatidic acid, phosphatidylethanolamine; phosphatidylglycerol and phosphatidylinositol as candidate lipids enabling annexin V staining.

  20. Guanine nucleotide-binding protein subunit beta-2-like 1, a new Annexin A7 interacting protein

    International Nuclear Information System (INIS)

    Du, Yue; Meng, Jinyi; Huang, Yuhong; Wu, Jun; Wang, Bo; Ibrahim, Mohammed M.; Tang, Jianwu

    2014-01-01

    Highlights: • RACK1 formed a complex with Annexin A7. • Depletion of RACK1 inhibited the proliferation, migration and invasion. • RACK1 RNAi abolished RACK1-Annexin A7 interaction. • RACK1-Annexin A7 may play a role in regulating the metastatic potentials. - Abstract: We report for the first time that Guanine nucleotide-binding protein subunit beta-2-like 1 (RACK1) formed a complex with Annexin A7. Hca-F and Hca-P are a pair of syngeneic mouse hepatocarcinoma cell lines established and maintained in our laboratory. Our previous study showed that both Annexin A7 and RACK1 were expressed higher in Hca-F (lymph node metastasis >70%) than Hca-P (lymph node metastasis <30%). Suppression of Annexin A7 expression in Hca-F cells induced decreased migration and invasion ability. In this study, knockdown of RACK1 by RNA interference (RNAi) had the same impact on metastasis potential of Hca-F cells as Annexin A7 down-regulation. Furthermore, by co-immunoprecipitation and double immunofluorescence confocal imaging, we found that RACK1 was in complex with Annexin A7 in control cells, but not in the RACK1-down-regulated cells, indicating the abolishment of RACK1-Annexin A7 interaction in Hca-F cells by RACK1 RNAi. Taken together, these results suggest that RACK1-Annexin A7 interaction may be one of the means by which RACK1 and Annexin A7 influence the metastasis potential of mouse hepatocarcinoma cells in vitro

  1. Biodistribution patterns of native and mutant 99mTc-labelled annexin V in mice

    International Nuclear Information System (INIS)

    Mariani, G.; Erba, P.; Pellegrino, D.; Volterrani, D.; Lazzeri, E.; Freer, G.; Bevilacqua, G.; Blankenberg, F.G.; Tait, J.F.; Strauss, H.W.

    2003-01-01

    Full text: Annexin is a 36 kD protein with high binding affinity to phosphatidylserine (PS), a phospholipid exposed on the membrane surface of cells upon activation of the enzyme caspase, the first step of apoptosis. Radiolabeled annexin V could thus be used for imaging apoptosis in-vivo. When the 319 amino acid protein is made by recombinant techniques and expressed as the human material, it can be radiolabeled with 99mTc after derivatization with a bifunctional agent such as HYNIC. Alternatively, the amino acid structure of the protein can be modified by producing annexin V mutants with an endogenous chelation site for 99mTc, the NH2 residue Ala-Gly-Gly-Cys-Gly-His-Met. Mutant annexin has similar affinity for membrane-bound PS as unmodified annexin. This study was performed to compare the biodistribution of 99mTc-labeled HYNIC annexin (HyA) to mutant annexin (MuA). 99mTc-labeling efficiency of the two annexin preparations was >99% by gel chromatography on Sephadex G10 columns. Groups of adult male mice (n 10, body weight 18-25 grams) were injected iv with either HyA or MuA (1-3 MBq, 3-9 μg/animal). Animals were sacrificed one hour later and dissected for organ biodistribution. Similar biodistribution was performed after pretreatment with cyclophosphamide (150 mg/kg ip 6-15 hr prior to the study). The results of the biodistribution study showed significantly reduced (p<0.05 to p<0.01) uptake of MuA versus HyA in the kidneys (Δ- 81.4%), spleen (Δ- 58.2%), liver (Δ- 56.2%), and bone marrow (Δ- 33.7%), while it was increased in lymph nodes (Δ+ 131%, p<0.001). Pretreatment with the pro-apoptotic agent cyclophosphamide induced significantly increased uptake of MuA (p<0.05) versus baseline in the heart (Δ+ 34.7%), spleen (Δ+ 30.1%) and bowel (Δ+ 44.5%), while uptake of HyA was increased only in the spleen (Δ+ 44.1%). The marked reduction in the renal, splenic, liver, and bone marrow localization of MuA compared to HyA in control animals outlines a pattern of

  2. 99mTc rh-Annexin V for imaging apoptotic cells: Clinical experience

    International Nuclear Information System (INIS)

    Abdel-Dayem, H.M.; Sadek, S.; Heiba, S.; Steinmetz, N.; Cho, J.; Cook, W.; Klein, P.

    2002-01-01

    Introduction: 99m Tc rh-Annexin V (Apomate, Theseus Imaging Corp., Boston, MA), an investigational nuclear medicine agent for imaging apoptotic and necrotic cell death, is currently in Phase II-III clinical trials. Potential applications being evaluated include identification and localization of acute myocardial infarction, non-invasive assessment of cardiac transplant rejection, and early prediction of cancer chemotherapy response. The purposes of this presentation are: 1) To familiarize attendees with the biological basis of 99m Tc-Annexin V localization, the labeling procedure, biodistribution following I.V. injection, and dosimetric data; 2) In patients with acute myocardial infarction (AMI), dual isotope SPECT using 99m Tc-Annexin V and Thallium-201 was performed within 4 days from onset of AMI and 6 weeks later. It demonstrates the increased uptake of 99m Tc-Annexin V in the recent MI area correlating with the perfusion defect in the Thallium study. 99m Tc-Annexin V disappears in the follow-up scan 6 weeks later indicating that 99m Tc-Annexin V will be a clinically useful agent for determining the size and location of recent AMI and for differentiating AMI from myocardial scar. 3) To demonstrate examples of current applications in oncology for predicting chemo- and radiotherapy response in patients with small and non-small cell lung cancer, Hodgkin's and non-Hodgkin's malignant lymphoma and recurrent, metastatic or inoperable breast carcinoma. Early results show significant correlation with treatment response and patient survival. 4) To demonstrate unusual site of 99m Tc-Annexin V uptake in subdural hematoma and non-lactating breast 4 weeks post partum. In light of the current clinical studies of 99m Tc-Annexin V (Apomate) imaging and the potential approval for clinical use in the future, it is important for practicing nuclear medicine physicians to be aware of the normal distribution, expected patterns of uptake in various pathologic conditions, and unusual

  3. Development and evaluation of a novel (99mtc-labeled annexin A5 for early detection of response to chemotherapy.

    Directory of Open Access Journals (Sweden)

    Kazuma Ogawa

    Full Text Available (99mTc-HYNIC-annexin A5 can be considered as a benchmark in the field of apoptosis imaging. However, (99mTc-HYNIC-annexin A5 has characteristics of high uptake and long retention in non-target tissues such as kidney and liver. To minimize this problem, we developed a novel (99mTc-labeled annexin A5 using a bis(hydroxamamide derivative [C3(BHam2] as a bifunctional chelating agent, and evaluated its usefulness as an imaging agent for detecting apoptosis. The amino group of C3(BHam2 was converted to a maleimide group, and was coupled to thiol groups of annexin A5 pretreated with 2-iminothiolane. (99mTc labeling was performed by a ligand exchange reaction with (99mTc-glucoheptonate. Biodistribution experiments for both (99mTc-C3(BHam2-annexin A5 and (99mTc-HYNIC-annexin A5 were performed in normal mice. In addition, in tumor-bearing mice, the relationship between the therapeutic effects of chemotherapy (5-FU and the tumor accumulation of (99mTc-C3(BHam2-annexin A5 just after the first treatment of 5-FU was evaluated. (99mTc-C3(BHam2-annexin A5 was prepared with a radiochemical purity of over 95%. In biodistribution experiments, (99mTc-C3(BHam2-annexin A5 had a much lower kidney accumulation of radioactivity than (99mTc-HYNIC-annexin A5. In the organs for metabolism, such as liver and kidney, radioactivity after the injection of (99mTc-HYNIC-annexin A5 was residual for a long time. On the other hand, radioactivity after the injection of (99mTc-C3(BHam2-annexin A5 gradually decreased. In therapeutic experiments, tumor growth in the mice treated with 5-FU was significantly inhibited. Accumulation of (99mTc-C3(BHam2-annexin A5 in tumors significantly increased after 5-FU treatment. The accumulation of radioactivity in tumor correlated positively with the counts of TUNEL-positive cells. These findings suggest that (99mTc-C3(BHam2-annexin A5 may contribute to the efficient detection of apoptotic tumor response after chemotherapy.

  4. Purification and immunolocalization of an annexin-like protein in pea seedlings

    Science.gov (United States)

    Clark, G. B.; Dauwalder, M.; Roux, S. J.

    1992-01-01

    As part of a study to identify potential targets of calcium action in plant cells, a 35-kDa, annexin-like protein was purified from pea (Pisum sativum L.) plumules by a method used to purify animal annexins. This protein, called p35, binds to a phosphatidylserine affinity column in a calcium-dependent manner and binds 45Ca2+ in a dot-blot assay. Preliminary sequence data confirm a relationship for p35 with the annexin family of proteins. Polyclonal antibodies have been raised which recognize p35 in Western and dot blots. Immunofluorescence and immunogold techniques were used to study the distribution and subcellular localization of p35 in pea plumules and roots. The highest levels of immunostain were found in young developing vascular cells producing wall thickenings and in peripheral root-cap cells releasing slime. This localization in cells which are actively involved in secretion is of interest because one function suggested for the animal annexins is involvement in the mediation of exocytosis.

  5. Methotrexate-Induced Accumulation of Fluorescent Annexin V in Collagen-Induced Arthritis

    Directory of Open Access Journals (Sweden)

    Andreas Wunder

    2005-01-01

    Full Text Available We examined the accumulation of Cy5.5-labeled annexin V in the paws of mice with and without collagen-induced arthritis, with and without methotrexate (MTX treatment, by near-infrared fluorescence imaging. Fluorescence reflectance imaging (FRI of paws was performed 48 hr after MTX injection and at 10 min and 3 hr after the injection of Cy5.5-annexin V (1 nmol dye per mouse. With arthritic paws, MTX treatment caused a 7-fold increase in fluorescence intensity compared with the paws of untreated mice and a 4-fold increase compared to nonarthritic paws of MTX-treated mice (p < .001 each. Tissue samples of paws were examined histologically for Cy5.5 fluorescence and by TUNEL staining for apoptosis. Cy5.5-annexin V was seen in the hyperplastic synovia of MTX-treated mice, and TUNEL staining for apoptosis showed apoptotic cells in the hyperplastic synovia. Monitoring the uptake of Cy5.5-annexin V in arthritic paws by FRI provided a method of assessing a response to MTX, a response that was readily quantitated with simple instrumentation and that occurred before conventional measurements of treatment response.

  6. "Nonclassical" secretion of annexin A2 to the lumenal side of the enterocyte brush border membrane

    DEFF Research Database (Denmark)

    Danielsen, E Michael; van Deurs, Bo; Hansen, Gert H

    2003-01-01

    side of the microvilli, showing an apical secretion by a "nonclassical" mechanism. In addition, annexin A2 was associated with surface-connected, deep apical tubules in the apical terminal web region and with an underlying pleiomorphic, tubulo-vesicular compartment (subapical compartment...

  7. Annexin A1 expression in a pooled breast cancer series : Association with tumor subtypes and prognosis

    NARCIS (Netherlands)

    Sobral-Leite, Marcelo; Wesseling, Jelle; Smit, Vincent T H B M; Nevanlinna, Heli; van Miltenburg, Martine H.; Sanders, Joyce; Hofland, Ingrid; Blows, Fiona M.; Coulson, Penny; Patrycja, Gazinska; Schellens, Jan H M; Fagerholm, Rainer; Heikkilä, Päivi; Aittomäki, Kristiina; Blomqvist, Carl; Provenzano, Elena; Ali, Hamid Raza; Figueroa, Jonine; Sherman, Mark; Lissowska, Jolanta; Mannermaa, Arto; Kataja, Vesa; Kosma, Veli Matti; Hartikainen, Jaana M.; Phillips, Kelly Anne; Couch, Fergus J.; Olson, Janet E.; Vachon, Celine; Visscher, Daniel; Brenner, Hermann; Butterbach, Katja; Arndt, Volker; Holleczek, Bernd; Hooning, Maartje J.; Hollestelle, Antoinette; Martens, John W M; van Deurzen, Carolien H M; van de Water, Bob; Broeks, Annegien; Chang-Claude, Jenny; Chenevix-Trench, Georgia; Easton, Douglas F.; Pharoah, Paul D P; García-Closas, Montserrat; de Graauw, Marjo; Schmidt, Marjanka K.; Aghmesheh, Morteza; Amor, David; Andrews, Lesley; Antill, Yoland; Armitage, Shane; Arnold, Leanne; Balleine, Rosemary; Bankier, Agnes; Bastick, Patti; Beesley, Jonathan; Beilby, John; Bennett, Barbara; Bennett, Ian; Berry, Geoffrey; Blackburn, Anneke; Bogwitz, Michael; Brennan, Meagan; Brown, Melissa; Buckley, Michael; Burgess, Matthew; Burke, Jo; Butow, Phyllis; Byron, Keith; Callen, David; Campbell, Ian; Chauhan, Deepa; Chauhan, Manisha; Christian, Alice; Clarke, Christine; Colley, Alison; Cotton, Dick; Crook, Ashley; Cui, James; Culling, Bronwyn; Cummings, Margaret; Dawson, Sarah Jane; deFazio, Anna; Delatycki, Martin; Dickson, Rebecca; Dixon, Joanne; Dobrovic, Alexander; Dudding, Tracy; Edkins, Ted; Edwards, Stacey; Eisenbruch, Maurice; Farshid, Gelareh; Fawcett, Susan; Fellows, Andrew; Fenton, Georgina; Field, Michael; Firgaira, Frank; Flanagan, James; Fleming, Jean; Fong, Peter; Forbes, John; Fox, Stephen; French, Juliet; Friedlander, Michael; Gaff, Clara; Gardner, Mac; Gattas, Mike; George, Peter; Giles, Graham; Gill, Grantley; Goldblatt, Jack; Greening, Sian; Grist, Scott; Haan, Eric; Hardie, Kate; Harris, Marion; Hart, Stewart; Hayward, Nick; Healey, Sue; Heiniger, Louise; Hopper, John; Humphrey, Evelyn; Hunt, Clare; James, Paul; Jenkins, Mark; Jones, Alison; Kefford, Rick; Kidd, Alexa; Kiely, Belinda; Kirk, Judy; Koehler, Jessica; Kollias, James; Kovalenko, Serguei; Lakhani, Sunil; Leaming, Amanda; Leary, Jennifer; Lim, Jacqueline; Lindeman, Geoff; Lipton, Lara; Lobb, Liz; Mann, Graham; Marsh, Deborah; McLachlan, Sue Anne; Meiser, Bettina; Meldrum, Cliff; Milne, Roger; Mitchell, Gillian; Newman, Beth; Niedermayr, Eveline; Nightingale, Sophie; O'Connell, Shona; O'Loughlin, Imelda; Osborne, Richard; Pachter, Nick; Patterson, Briony; Peters, Lester; Phillips, Kelly; Price, Melanie; Purser, Lynne; Reeve, Tony; Reeve, Jeanne; Richards, Robert; Rickard, Edwina; Robinson, Bridget; Rudzki, Barney; Saleh, Mona; Salisbury, Elizabeth; Sambrook, Joe; Saunders, Christobel; Saunus, Jodi; Sayer, Robyn; Scott, Elizabeth; Scott, Rodney; Scott, Clare; Seshadri, Ram; Sexton, Adrienne; Sharma, Raghwa; Shelling, Andrew; Simpson, Peter; Southey, Melissa; Spurdle, Amanda; Suthers, Graeme; Sykes, Pamela; Tassell, Margaret; Taylor, Donna; Taylor, Jessica; Thierry, Benjamin; Thomas, Susan; Thompson, Ella; Thorne, Heather; Townshend, Sharron; Trainer, Alison; Tran, Lan; Tucker, Kathy; Tyler, Janet; Visvader, Jane; Walker, Logan; Walpole, Ian; Ward, Robin; Waring, Paul; Warner, Bev; Warren, Graham; Williams, Rachael; Wilson, Judy; Winship, Ingrid; Wu, Kathy; Young, Mary Ann; Bowtell, D.; Green, A.; Webb, P.; de Fazio, A.; Gertig, D.

    2015-01-01

    Background: Annexin A1 (ANXA1) is a protein related with the carcinogenesis process and metastasis formation in many tumors. However, little is known about the prognostic value of ANXA1 in breast cancer. The purpose of this study is to evaluate the association between ANXA1 expression, BRCA1/2

  8. Intracellular targeting of annexin A2 inhibits tumor cell adhesion, migration, and in vivo grafting.

    Science.gov (United States)

    Staquicini, Daniela I; Rangel, Roberto; Guzman-Rojas, Liliana; Staquicini, Fernanda I; Dobroff, Andrey S; Tarleton, Christy A; Ozbun, Michelle A; Kolonin, Mikhail G; Gelovani, Juri G; Marchiò, Serena; Sidman, Richard L; Hajjar, Katherine A; Arap, Wadih; Pasqualini, Renata

    2017-06-26

    Cytoskeletal-associated proteins play an active role in coordinating the adhesion and migration machinery in cancer progression. To identify functional protein networks and potential inhibitors, we screened an internalizing phage (iPhage) display library in tumor cells, and selected LGRFYAASG as a cytosol-targeting peptide. By affinity purification and mass spectrometry, intracellular annexin A2 was identified as the corresponding binding protein. Consistently, annexin A2 and a cell-internalizing, penetratin-fused version of the selected peptide (LGRFYAASG-pen) co-localized and specifically accumulated in the cytoplasm at the cell edges and cell-cell contacts. Functionally, tumor cells incubated with LGRFYAASG-pen showed disruption of filamentous actin, focal adhesions and caveolae-mediated membrane trafficking, resulting in impaired cell adhesion and migration in vitro. These effects were paralleled by a decrease in the phosphorylation of both focal adhesion kinase (Fak) and protein kinase B (Akt). Likewise, tumor cells pretreated with LGRFYAASG-pen exhibited an impaired capacity to colonize the lungs in vivo in several mouse models. Together, our findings demonstrate an unrecognized functional link between intracellular annexin A2 and tumor cell adhesion, migration and in vivo grafting. Moreover, this work uncovers a new peptide motif that binds to and inhibits intracellular annexin A2 as a candidate therapeutic lead for potential translation into clinical applications.

  9. Annexins are instrumental for efficient plasma membrane repair in cancer cells.

    Science.gov (United States)

    Lauritzen, Stine Prehn; Boye, Theresa Louise; Nylandsted, Jesper

    2015-09-01

    Plasma membrane stress can cause damage to the plasma membrane, both when imposed by the extracellular environment and by enhanced oxidative stress. Cells cope with these injuries by rapidly activating their plasma membrane repair system, which is triggered by Ca(2+) influx at the wound site. The repair system is highly dynamic, depends on both lipid and protein components, and include cytoskeletal reorganization, membrane replacements, and membrane fusion events. Cancer cells experience enhanced membrane stress when navigating through dense extracellular matrix, which increases the frequency of membrane injuries. In addition, increased motility and oxidative stress further increase the risk of plasma membrane lesions. Cancer cells compensate by overexpressing Annexin proteins including Annexin A2 (ANXA2). Annexin family members can facilitate membrane fusion events and wound healing by binding to negatively charged phospholipids in the plasma membrane. Plasma membrane repair in cancer cells depends on ANXA2 protein, which is recruited to the wound site and forms a complex with the Ca(2+)-binding EF-hand protein S100A11. Here they regulate actin accumulation around the wound perimeter, which is required for wound closure. In this review, we will discuss the requirement for Annexins, S100 proteins and actin cytoskeleton in the plasma membrane repair response of cancer cells, which reveals a novel avenue for targeting metastatic cancers. Copyright © 2015 Elsevier Ltd. All rights reserved.

  10. Tc-99m annexin V imaging and apoptosis staining in rabbit model of osteoarthritis

    International Nuclear Information System (INIS)

    Kang, Do Young; Jeong, Young Jin; Choi, Sun Mee; Lee, Sung Won; Chung, Won Tae; Yoo, Young Hyun

    2004-01-01

    Recent studies showed that, in osteoarthritis (OA), articular chondrocytes appeared to be eliminated by apoptosis. Tc-99mm Annexin V has been successfully used for non-invasive gamma imaging of apoptosis in tumor. myocardial infarction and transplantation. We studied Tc-99m Annexin V imaging and apoptosis staining in rabbit model of osteoarthritis. Osteoarthritis was induced in rabbits by intra-articular injection of 1.0 mg collagenase and surgical transection of leg ligament. Animals were dissected at 2, 4, 6 and 8 weeks after the initiation of the injections. For histological observation, the paraffin sections were stained with hematoxylin and eosin. To confirm that osteoarthritis was induced, immunohistochemistry to TRAIL was conducted on the sections and TRAIL positive cells was revealed by DAB. Tc-99m Annexin V was injected 16 ug/1 mCi/kg and regional images were acquired 10 and 60 min postinjection. A few days later Tc-99m MDP imaging was also acquired. Two weeks after injection, the surface layer of cartilage was lost, chondrocytes in the transitional zone have disappeared, and cleft in the transitional zone were shown. Four weeks after injection, moderate cell cloning in transitional and radial zone was appeared. Six weeks after injection, cell cloning was more apparent in the transitional and radial zones. Whereas TRAIL positive cells were not found in the chondrocytes from the control cartilage, most chondrocytes from the collagenase injected cartilage were TRAIL-positive. Tc-99m Annexin V imaging showed increase uptake in knee area of injuried side to normal side. And Tc-99m MDP imaging also had same findings. In rabbit model of osteoarthritis, apoptosis was detected by Tc-99m Annexin V imaging noninvasively and it was correlated by pathologic staining for apoptosis

  11. Annexin IV (Xanx-4) has a functional role in the formation of pronephric tubules.

    Science.gov (United States)

    Seville, Rachel A; Nijjar, Sarbjit; Barnett, Mark W; Massé, Karine; Jones, Elizabeth A

    2002-04-01

    Vertebrate kidney organogenesis is characterised by the successive formation of the pronephros, the mesonephros and the metanephros. The pronephros is the first to form and is the functional embryonic kidney of lower vertebrates; although it is vestigial in higher vertebrates, it is a necessary precursor for the other kidney types. The Xenopus pronephros is a simple paired organ; each nephron consists of a single large glomus, one set of tubules and a single duct. The simple organisation of the pronephros and the amenability of Xenopus laevis embryos to manipulation make the Xenopus pronephros an attractive system in which to study organogenesis. It has been shown that pronephric tubules can be induced to form in presumptive ectodermal tissue by treatment with RA and activin. We have used this system in a subtractive hybridisation screen that resulted in the cloning of Xenopus laevis annexin IV (Xanx-4). Xanx-4 transcripts are specifically located to the developing pronephric tubules, and the protein to the luminal surface of these tubules. Temporal expression shows zygotic transcription is upregulated at the time of pronephric tubule specification and persists throughout pronephric development. The temporal and spatial expression pattern of Xanx-4 suggests it may have a role in pronephric tubule development. Overexpression of Xanx-4 yields no apparent phenotype, but Xanx-4 depletion, using morpholinos, produces a shortened, enlarged tubule phenotype. The phenotype observed can be rescued by co-injection of Xanx-4 mRNA. Although the function of annexins is not yet clear, studies have suggested a role for annexins in a number of cellular processes. Annexin IV has been shown to have an inhibitory role in the regulation of epithelial calcium-activated chloride ion conductance. The enlarged pronephric tubule phenotype observed may be attributed to incorrect modulation of exocytosis, membrane plasticity or ion channels and/or water homeostasis. In this study, we

  12. Apoptosis imaging with Iodine-124 labeled Annexin V in Fas-mediated hepatic apoptosis model

    International Nuclear Information System (INIS)

    Lee, Tae Sup; Woo, Kwang Sun; Chung, Wee Sup; Kim, Kyung Min; Kim, Jae Hong; Chun, Kwon Soo; Choi, Chang Woon; Lim, Sang Moo; Cheon, Gi Jeong

    2006-01-01

    Healthy cells and, to a lesser extent, malignant cells undergo apoptosis or programmed cell death in response to a variety of stimuli. At an early stage in this process the cell membrane changes so that phosphatidylserine (PS), a lipid normally present on the membrane's inner surface, is exposed on the outer surface. This change in the membrane can be detected by the binding of annexin V to the external PS, and this has formed the basis for an in vitro assay for apoptosis. Blankenberg et al. have applied annexin V to the in vivo imaging of apoptosis by labeling annexin V with 99mTc. With this technique, they have been able to image apoptosis. To extend the use of annexin V to PET, it would be very desirable to iodinate the molecule. The relatively long half-life (4.2 d) of the positron emitting iodine-124 presents several advantages. For example in vivo detection and quantification of longer term biological processes is possible. Also, this cyclotron-generated radionuclide can be prepared well in advance and the established radioiodine labeling techniques can be applied. However, there are some disadvantages such as a relatively low ratio of disintegrations resulting in positrons (23%) and a rather complex decay scheme resulting in several high-energy gamma emissions (0.6- 1.69 MeV). Despite this fact, iodine-124 is still considered to be suitable for positron emission tomography (PET). In this study, we are investigating the feasibility of apoptosis imaging using iodine-124 labeled annexin V in Fas-mediated hepatic apoptosis model

  13. Evaluation of radiolabeling of annexin A5 with technetium-99m: influence of the labeling methods on physico-chemical and biological properties of the compounds

    International Nuclear Information System (INIS)

    Santos, Josefina da Silva

    2009-01-01

    lower lipophilicity for EC-complexes than 99 mTc-HYNIC-ANXA5. The biological activity of radiolabeled annexins was studied in PC-3 cells with radiation induced apoptosis showing that 99 mTc- EC-ANXA5 (ratio 10-2) was the protein with higher percentage of specific binding. In vivo biodistribution of the radiolabeled annexins showed a high uptake in the abdominal region, especially for the HYNIC compound. The results indicated that 99 mTc-EC-ANXA5 (10-2) may be an attractive alternative to 99 mTc-HYNIC-ANXA5 for the in vivo imaging of phosphatidylserine receptors. (author)

  14. Transfer of phagocytosed particles to the parasitophorous vacuole of Leishmania mexicana is a transient phenomenon preceding the acquisition of annexin I by the phagosome.

    Science.gov (United States)

    Collins, H L; Schaible, U E; Ernst, J D; Russell, D G

    1997-01-01

    The eukaryotic intracellular pathogen Leishmania mexicana resides inside macrophages contained within a membrane bound parasitophorous vacuole which, as it matures, acquires the characteristics of a late endosomal compartment. This study reports the selectivity of fusion of this compartment with other particle containing vacuoles. Phagosomes containing zymosan or live Listeria monocytogenes rapidly fused with L. mexicana parasitophorous vacuoles, while those containing latex beads or heat killed L. monocytogenes failed to do so. Fusigenicity of phagosomes was not primarily dependent on the receptor utilized for ingestion, as opsonization with defined ligands could not overcome the exclusion of either latex beads or heat killed organisms. However modulation of intracellular pH by pharmacological agents such as chloroquine and ammonium chloride increased delivery of live Listeria and also induced transfer of previously excluded particles. The absence of fusion correlated with the acquisition of annexin I, a putative lysosomal targeting, molecule, on the phagosome membrane. We propose that the acquisition of cellular membrane constituents such as annexin I during phagosome maturation can ultimately direct the fusion pathway of the vesicles formed and have described a model system to further document changes in vesicle fusigenicity within cells.

  15. receptores

    Directory of Open Access Journals (Sweden)

    Salete Regina Daronco Benetti

    2006-01-01

    Full Text Available Se trata de un estudio etnográfico, que tuvo lo objetivo de interpretar el sistema de conocimiento y del significado atribuidos a la sangre referente a la transfusión sanguínea por los donadores y receptores de un banco de sangre. Para la colecta de las informaciones se observaron los participantes y la entrevista etnográfica se realizó el análisis de dominio, taxonómicos y temáticos. Los dominios culturales fueron: la sangre es vida: fuente de vida y alimento valioso; creencias religiosas: fuentes simbólicas de apoyos; donación sanguínea: un gesto colaborador que exige cuidarse, gratifica y trae felicidad; donación sanguínea: fuente simbólica de inseguridad; estar enfermo es una condición para realizar transfusión sanguínea; transfusión sanguínea: esperanza de vida; Creencias populares: transfusión sanguínea como riesgo para la salud; donadores de sangre: personas benditas; donar y recibir sangre: como significado de felicidad. Temática: “líquido precioso que origina, sostiene, modifica la vida, provoca miedo e inseguridad”.

  16. Amino acid sequence analysis of the annexin super-gene family of proteins.

    Science.gov (United States)

    Barton, G J; Newman, R H; Freemont, P S; Crumpton, M J

    1991-06-15

    The annexins are a widespread family of calcium-dependent membrane-binding proteins. No common function has been identified for the family and, until recently, no crystallographic data existed for an annexin. In this paper we draw together 22 available annexin sequences consisting of 88 similar repeat units, and apply the techniques of multiple sequence alignment, pattern matching, secondary structure prediction and conservation analysis to the characterisation of the molecules. The analysis clearly shows that the repeats cluster into four distinct families and that greatest variation occurs within the repeat 3 units. Multiple alignment of the 88 repeats shows amino acids with conserved physicochemical properties at 22 positions, with only Gly at position 23 being absolutely conserved in all repeats. Secondary structure prediction techniques identify five conserved helices in each repeat unit and patterns of conserved hydrophobic amino acids are consistent with one face of a helix packing against the protein core in predicted helices a, c, d, e. Helix b is generally hydrophobic in all repeats, but contains a striking pattern of repeat-specific residue conservation at position 31, with Arg in repeats 4 and Glu in repeats 2, but unconserved amino acids in repeats 1 and 3. This suggests repeats 2 and 4 may interact via a buried saltbridge. The loop between predicted helices a and b of repeat 3 shows features distinct from the equivalent loop in repeats 1, 2 and 4, suggesting an important structural and/or functional role for this region. No compelling evidence emerges from this study for uteroglobin and the annexins sharing similar tertiary structures, or for uteroglobin representing a derivative of a primordial one-repeat structure that underwent duplication to give the present day annexins. The analyses performed in this paper are re-evaluated in the Appendix, in the light of the recently published X-ray structure for human annexin V. The structure confirms most of

  17. Dietary flavonoids bind to mono-ubiquitinated annexin A1 in nuclei, and inhibit chemical induced mutagenesis

    Energy Technology Data Exchange (ETDEWEB)

    Hirata, Fusao, E-mail: fhirata@wayne.edu; Harada, Takasuke; Corcoran, George B.; Hirata, Aiko

    2014-01-15

    Highlight: • Nuclear mono-ubiquitinated annexin A1 is involved in DNA damage induced mutagenesis. • Dietary flavonoids bind to and inhibit purified mono-ubiquitinated annexin A1 helicase. • Dietary flavonoids show anti-mutagenic action. • Annexin A1 may serve as a putative target of cancer chemoprevention by flavonoids. - Abstract: In order to investigate the mechanisms of anti-mutagenic action by dietary flavonoids, we investigated if they inhibit mutation of the thymidine kinase (tk) gene in L5178Ytk(±) lymphoma cells. Silibinin, quercetin and genistein suppressed mutation of the tk gene induced in L5178Ytk(±) lymphoma cells by methyl methanesulfonate (MMS) and As{sup 3+}. Flavone and flavonol were less effective. To establish that mutation of the tk gene in L5178Ytk(±) lymphoma cells by MMS and As{sup 3+} is mediated through mono-ubiquitinated annexin A1, L5178Ytk(±) lymphoma cells were treated with annexin A1 anti-sense oligonucleotide. The treatment reduced mRNA as well as protein levels of annexin A1, and suppressed mutation of the tk gene. Nuclear extracts from L5178Ytk(±) lymphoma cells catalyzed translesion DNA synthesis with an oligonucleotide template containing 8-oxo-guanosine in an annexin A1 dependent manner. This translesion DNA synthesis was inhibited by the anti-mutagenic flavonoids, silibinin, quercetin and genistein, in a concentration dependent manner, but only slightly by flavone and flavonol. Because these observations implicate involvement of annexin A1 in mutagenesis, we examined if flavonoids suppress nuclear annexin A1 helicase activity. Silibinin, quercetin and genistein inhibited ssDNA binding, DNA chain annealing and DNA unwinding activities of purified nuclear mono-ubiquitinated annexin A1. Flavone and flavonol were ineffective. The apparent direct binding of anti-mutagenic flavonoids to the annexin A1 molecule was supported by fluorescence quenching. Taken together, these findings illustrate that nuclear annexin A1 may be

  18. Dietary flavonoids bind to mono-ubiquitinated annexin A1 in nuclei, and inhibit chemical induced mutagenesis

    International Nuclear Information System (INIS)

    Hirata, Fusao; Harada, Takasuke; Corcoran, George B.; Hirata, Aiko

    2014-01-01

    Highlight: • Nuclear mono-ubiquitinated annexin A1 is involved in DNA damage induced mutagenesis. • Dietary flavonoids bind to and inhibit purified mono-ubiquitinated annexin A1 helicase. • Dietary flavonoids show anti-mutagenic action. • Annexin A1 may serve as a putative target of cancer chemoprevention by flavonoids. - Abstract: In order to investigate the mechanisms of anti-mutagenic action by dietary flavonoids, we investigated if they inhibit mutation of the thymidine kinase (tk) gene in L5178Ytk(±) lymphoma cells. Silibinin, quercetin and genistein suppressed mutation of the tk gene induced in L5178Ytk(±) lymphoma cells by methyl methanesulfonate (MMS) and As 3+ . Flavone and flavonol were less effective. To establish that mutation of the tk gene in L5178Ytk(±) lymphoma cells by MMS and As 3+ is mediated through mono-ubiquitinated annexin A1, L5178Ytk(±) lymphoma cells were treated with annexin A1 anti-sense oligonucleotide. The treatment reduced mRNA as well as protein levels of annexin A1, and suppressed mutation of the tk gene. Nuclear extracts from L5178Ytk(±) lymphoma cells catalyzed translesion DNA synthesis with an oligonucleotide template containing 8-oxo-guanosine in an annexin A1 dependent manner. This translesion DNA synthesis was inhibited by the anti-mutagenic flavonoids, silibinin, quercetin and genistein, in a concentration dependent manner, but only slightly by flavone and flavonol. Because these observations implicate involvement of annexin A1 in mutagenesis, we examined if flavonoids suppress nuclear annexin A1 helicase activity. Silibinin, quercetin and genistein inhibited ssDNA binding, DNA chain annealing and DNA unwinding activities of purified nuclear mono-ubiquitinated annexin A1. Flavone and flavonol were ineffective. The apparent direct binding of anti-mutagenic flavonoids to the annexin A1 molecule was supported by fluorescence quenching. Taken together, these findings illustrate that nuclear annexin A1 may be a novel

  19. CELL DEATH DIFFERENTIATION IN BLACK HEADED RAMS SPERMATOZOA, USING FLUORESCENT LABELED ANNEXIN V

    Directory of Open Access Journals (Sweden)

    M Ivanova-Kicheva

    2008-11-01

    Full Text Available Double staining kit of Annexin V Cy3.18/6-CFDA was used to investigate the changes in phospholipide asymmetry after treating sperm cells with dexamethasone. The % of spermatozoa with registered translocation of PS in treated with dexamethazone groups at the 10-th min and in control no treated varied from 2.74%±0.65 to 2.30%±0.89. After the 5 hour of incubation these % increased to 39.83±3.33 for the treated group and 23.44±1.12 for the control. It was concluded that Annexin V binding assay is more sensitive in the detection of deterioration in membrane function than other conventional methods such as motility analysis and supravital techniques.

  20. Quantitative Proteomic Profiling the Molecular Signatures of Annexin A5 in Lung Squamous Carcinoma Cells

    OpenAIRE

    Sun, Bing; Bai, Yuxin; Zhang, Liyuan; Gong, Linlin; Qi, Xiaoyu; Li, Huizhen; Wang, Faming; Chi, Xinming; Jiang, Yulin; Shao, Shujuan

    2016-01-01

    Lung cancer remains the leading cancer killer around the world. It's crucial to identify newer mechanism-based targets to effectively manage lung cancer. Annexin A5 (ANXA5) is a protein kinase C inhibitory protein and calcium dependent phospholipid-binding protein, which may act as an endogenous regulator of various pathophysiological processes. However, its molecular mechanism in lung cancer remains poorly understood. This study was designed to determine the mechanism of ANXA5 in lung cancer...

  1. Impact of Annexin A 7 Deficiency on FGF23 Plasma Concentrations

    Directory of Open Access Journals (Sweden)

    Anja T. Umbach

    2016-11-01

    Full Text Available Background/Aims: The release of fibroblast growth factor FGF23, a powerful regulator of 1,25(OH2D3 formation and mineral metabolism, is stimulated by store-operated Ca2+ entry (SOCE, which is accomplished by the pore forming Ca2+ release activated channel protein Orai1. Regulators of Orai1 and thus FGF23 release include serum & glucocorticoid inducible kinase SGK1, a kinase up-regulated by glucocorticosteroids. Some effects of glucocorticoids require the presence of annexin A7, such as suppression of prostaglandin E2 in gastric glands. The present study thus explored whether annexin A7 impacts on FGF23 plasma levels. Methods: Comparisons were made between gene targeted mice lacking functional annexin A7 (Anx7-/- and their wild type littermates (Anx7+/+. Serum C-terminal-FGF23, intact FGF23, 1,25(OH2D3 and PTH concentrations were measured by ELISA or EIA. The serum and urinary phosphate concentrations were measured by colorimetry, the serum Ca2+ concentration and the urinary Ca2+ concentration by flame photometry. Results: Serum C-terminal FGF23 levels and corticosterone levels were significantly higher and serum 1,25(OH2 D3 and PTH levels were significantly lower in Anx7-/- than in Anx7+/+ mice. Water intake was slightly but significantly higher in Anx7-/- mice than in Anx7+/+ mice. No significant difference was observed between Anx7-/- and Anx7+/+ mice in urinary fluid excretion, plasma Ca2+ concentration, plasma phosphate concentration and urinary Ca2+ output. The urinary phosphate output was significantly lower in Anx7-/- mice than in Anx7+/+ mice. Conclusion: Annexin A7 deficiency upregulates FGF23 plasma levels, an effect paralleled by increased corticosterone plasma levels, as well as decreased 1,25(OH2 D3 and PTH plasma levels.

  2. Towards an easy access to Annexin-A5 protein binding block copolymer micelles

    International Nuclear Information System (INIS)

    Schmidt, Vanessa; Giacomelli, Cristiano; Brisson, Alain R.; Borsali, Redouane

    2008-01-01

    The formation of Annexin-A5 decorated (bio-functionalized) nanoparticles is of particular interest in micelle-mediated target drug delivery, in vivo magnetic resonance imaging, and controlled fabrication of biochips. This work describes an easy access to the synthesis and manipulation of block copolymer nano-objects exhibiting Annexin-A5 protein binding ability. Well-defined spherical micelles containing negatively charged phosphonic diacid groups - which are potential binding sites for Annexin-A5 proteins - at their hydrophilic periphery originate from the self-assembly of polystyrene-b-poly(2-phosphatethyl methacrylate-stat-2-hydroxyethyl methacrylate) (PS-b-P(PEMA-stat-HEMA)) amphiphilic macromolecules in aqueous media. PS-b-P(PEMA-stat-HEMA) can be prepared in a three-step phosphorylation/silylation/methanolysis procedure applied to PS-b-PHEMA precursors synthesized via Atom Transfer Radical Polymerization (ATRP). The herein discussed approach allows precise control over micellar dimensions and properties such as core radius (i.e., loading capacity), corona width, and density of phosphate groups at the micelle periphery

  3. Annexin A2 in amniotic fluid: correlation with histological chorioamnionitis, preterm premature rupture of membranes, and subsequent preterm delivery.

    Science.gov (United States)

    Namba, Fumihiko; Ina, Shihomi; Kitajima, Hiroyuki; Yoshio, Hiroyuki; Mimura, Kazuya; Saito, Shigeru; Yanagihara, Itaru

    2012-01-01

    The aim of this study was to determine whether amniotic fluid levels of annexin A2, a phospholipid-binding protein that is abundant in amnion and regulates fibrin homeostasis, are associated with histological chorioamnionitis, preterm premature rupture of the membranes, and subsequent preterm delivery. Amniotic fluid was obtained from 55 pregnant women with preterm labor and/or preterm premature rupture of the membranes before 32weeks of gestation, and amniotic fluid levels of annexin A2 were measured with a sandwich enzyme-linked immunosorbent assay. Amniotic fluid levels of annexin A2 in patients with histological chorioamnionitis was higher than that in the remainder (P=0.053), whereas amniotic fluid levels of annexin A2 in patients with preterm premature rupture of the membranes was significantly higher than that in the remainder (P=0.002). Amniotic levels of annexin A2 was a fair test (area under receiver-operator characteristic curve=0.679), and amniotic fluid levels of annexin A2>878.2ng/mL had a sensitivity of 68.8%, a specificity of 65.2%, a positive predictive value of 73.3%, and a negative predictive value of 60.0% for predicting delivery within 2weeks after amniotic fluid sampling. Furthermore, the combined use of amniotic fluid cut-off levels of 878.2ng/mL for annexin A2 and 13.3ng/mL for interleukin-8 improved the specificity (91.3%) and the positive predictive value (89.5%). We identified amniotic fluid levels of annexin A2, especially in combination with amniotic fluid levels of interleukin-8, as a novel predictive marker for preterm delivery. © 2011 The Authors. Journal of Obstetrics and Gynaecology Research © 2011 Japan Society of Obstetrics and Gynecology.

  4. Annexins as organizers of cholesterol- and sphingomyelin-enriched membrane microdomains in Niemann-Pick type C disease.

    Science.gov (United States)

    Domon, Magdalena; Nasir, Mehmet Nail; Matar, Gladys; Pikula, Slawomir; Besson, Françoise; Bandorowicz-Pikula, Joanna

    2012-06-01

    Growing evidence suggests that membrane microdomains enriched in cholesterol and sphingomyelin are sites for numerous cellular processes, including signaling, vesicular transport, interaction with pathogens, and viral infection, etc. Recently some members of the annexin family of conserved calcium and membrane-binding proteins have been recognized as cholesterol-interacting molecules and suggested to play a role in the formation, stabilization, and dynamics of membrane microdomains to affect membrane lateral organization and to attract other proteins and signaling molecules onto their territory. Furthermore, annexins were implicated in the interactions between cytosolic and membrane molecules, in the turnover and storage of cholesterol and in various signaling pathways. In this review, we focus on the mechanisms of interaction of annexins with lipid microdomains and the role of annexins in membrane microdomains dynamics including possible participation of the domain-associated forms of annexins in the etiology of human lysosomal storage disease called Niemann-Pick type C disease, related to the abnormal storage of cholesterol in the lysosome-like intracellular compartment. The involvement of annexins and cholesterol/sphingomyelin-enriched membrane microdomains in other pathologies including cardiac dysfunctions, neurodegenerative diseases, obesity, diabetes mellitus, and cancer is likely, but is not supported by substantial experimental observations, and therefore awaits further clarification.

  5. In vivo99mTc-HYNIC-annexin V imaging of early tumor apoptosis in mice after single dose irradiation

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    He Yong-bo

    2009-10-01

    Full Text Available Abstract Background Apoptosis is a major mode of hematological tumor death after radiation. Early detection of apoptosis may be beneficial for cancer adaptive treatment. 99mTc-HYNIC-annexinV has been reported as a promising agent for in vivo apoptosis imaging. The purpose of this study is to evaluate the feasibility of in vivo99mTc-HYNIC-annexinV imaging of radiation- induced apoptosis, and to investigate its correlation with radiosensitivity. Methods Ten days after inoculation of tumor cells in the right upper limbs, the mice were randomly divided into two groups. The imaging group (4 mice each level, 4 dose levels was injected with 4-8 MBq 99mTc-HYNIC-annexinV 24 hours after irradiation and imaged 1 hr post-injection, and the mice were sacrificed immediately after imaging for biodistribution analysis of annexin V. The observation group (4 mice each level, 2 dose levels was only observed for tumor regression post-radiation. The number of apoptotic cells in a tumor was estimated with TUNEL assay. Results The 99mTc-HYNIC-annexin V uptake in E14 lymphoma significantly increased as the radiation dose escalated from 0 to 8 Gy, and significantly correlated with the number of TUNEL-positive cells (r = 0.892, P Conclusion 99mTc-HYNIC-annexinV in vivo imaging is a feasible method to detect early radiation-induced apoptosis in different tumors, and might be predictive for radiation sensitivity.

  6. Annexin A4 fucosylation enhances its interaction with the NF-kB p50 and promotes tumor progression of ovarian clear cell carcinoma.

    Science.gov (United States)

    Wang, Huimin; Deng, Lu; Cai, Mingbo; Zhuang, Huiyu; Zhu, Liancheng; Hao, Yingying; Gao, Jian; Liu, Juanjuan; Li, Xiao; Lin, Bei

    2017-12-08

    To study the structural relationship between annexin A4 and the Lewis y antigen and compare their expression and significance in ovarian clear cell carcinoma, and to explore how annexin A4 fucose glycosylation effects the interaction between annexin A4 and NF-kB p50, and how it promotes tumour progression of ovarian clear cell carcinoma. Structural relationships between annexin A4 and Lewis y antigen were detected using immunoprecipitation. Annexin A4 and Lewis y antigen expression in various subtypes of ovarian cancer tissues was detected by immunohistochemistry, and the relation between their expression was examined. Any interactions between annexin A4 and NF-kB p50 in ovarian clear cell carcinoma were detected by co-immunoprecipitation. Then looked for changes in expression of Lewis y antigen, annexin A4, NF-kB p50 and a number of downstream related molecules before and after transfection annexin A4 or FUT1, and also analyzed changes in biological processes. Lewis y antigen is a part of annexin A4 structure. The expression rate of both annexin A4 and Lewis y antigen was significantly higher in ovarian clear cell carcinoma than in other subtypes of epithelial ovarian cancer, and are associated with the clinical stages, chemotherapy resistance and poor prognostic. The interaction between annexin A4 and NF-kB p50 promoted cell proliferation, adhesion, invasion, metastasis ability and autophagy, and inhibits apoptosis, Lewis y enhanced this interaction. Annexin A4 contains Lewis y structure, Lewis y antigen modification of annexin A4 enhances its interaction with NF-kB p50, which promotes ovarian clear cell carcinoma malignancy progression.

  7. Annexin-1 Mediates Microglial Activation and Migration via the CK2 Pathway during Oxygen–Glucose Deprivation/Reperfusion

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    Shuangxi Liu

    2016-10-01

    Full Text Available Annexin-1 (ANXA1 has shown neuroprotective effects and microglia play significant roles during central nervous system injury, yet the underlying mechanisms remain unclear. This study sought to determine whether ANXA1 regulates microglial response to oxygen–glucose deprivation/reperfusion (OGD/R treatment and to clarify the downstream molecular mechanism. In rat hippocampal slices, OGD/R treatment enhanced the ANXA1 expression in neuron, the formyl peptide receptor (FPRs expression in microglia, and the microglial activation in the CA1 region (cornu ammonis 1. These effects were reversed by the FPRs antagonist Boc1. The cell membrane currents amplitude of BV-2 microglia (the microglial like cell-line was increased when treated with Ac2-26, the N-terminal peptide of ANXA1. Ac2-26 treatment enhanced BV-2 microglial migration whereas Boc1 treatment inhibited the migration. In BV-2 microglia, both the expression of the CK2 target phosphorylated α-E-catenin and the binding of casein kinase II (CK2 with α-E-catenin were elevated by Ac2-26, these effects were counteracted by the CK2 inhibitor TBB and small interfering (si RNA directed against transcripts of CK2 and FPRs. Moreover, both TBB and siRNA-mediated inhibition of CK2 blocked Ac2-26-mediated BV-2 microglia migration. Our findings indicate that ANXA1 promotes microglial activation and migration during OGD/R via FPRs, and CK2 target α-E-catenin phosphorylation is involved in this process.

  8. Annexin A2 Mediates the Localization of Measles Virus Matrix Protein at the Plasma Membrane.

    Science.gov (United States)

    Koga, Ritsuko; Kubota, Marie; Hashiguchi, Takao; Yanagi, Yusuke; Ohno, Shinji

    2018-02-28

    Annexins are a family of structurally related proteins that bind negatively charged membrane phospholipids in a Ca 2+ -dependent manner. Annexin A2 (AnxA2), a member of the family, has been implicated in a variety of cellular functions including the organization of membrane domains, vesicular trafficking and cell-cell adhesion. AnxA2 generally forms the heterotetrameric complex with a small Ca 2+ -binding protein S100A10. Measles virus (MV), a member of the family Paramyxoviridae , is an enveloped virus with a nonsegmented negative strand RNA genome. Knockdown of AnxA2 greatly reduced MV growth in cells, without affecting its entry and viral RNA production. In MV-infected, AnxA2-knockdown cells, the expression level of the matrix (M) protein, but not other viral proteins, was reduced compared with that in control cells, and the distribution of the M protein at the plasma membrane was decreased. The M protein lines the inner surface of the envelope and plays an important role in virus assembly by connecting the nucleocapsid to the envelope proteins. The M protein bound to AnxA2 independently of AnxA2's phosphorylation or its association with S100A10, and was co-localized with AnxA2 within cells. Truncation of the N-terminal 10 amino acid residues, but not the N-terminal 5 residues, compromised the ability of the M protein to interact with AnxA2 and localize at the plasma membrane. These results indicate that AnxA2 mediates the localization of the MV M protein at the plasma membrane by interacting with its N-terminal region (especially residues at positions 6-10), thereby aiding in MV assembly. IMPORTANCE Measles virus (MV) is an important human pathogen, still claiming ∼ 100,000 lives per year despite the presence of effective vaccines, and causes occasional outbreaks even in developed countries. Replication of viruses largely relies on the functions of host cells. Our study revealed that the reduction of the host protein annexin A2 compromises the replication of

  9. Study of 99Tcm-annexin V distribution in inferior vena cava thrombus models of rabbits

    International Nuclear Information System (INIS)

    Wu Dayong; Zhang Wenyan; Bian Yanzhu; Hu Yujing

    2013-01-01

    To study 99 Tc m -Annexin V distribution in inferior vena cava thrombus models of rabbits and uptake of 99 Tc m -Annexin V in fresh and old venous thrombus. Rabbits (n=15) were randomly grouped into 3 groups (the fresh thrombus group, old thrombus group, and control group). The rabbits of two thrombus groups developed inferior vena cava thrombus models by operations. The control group received sham operation. The fresh thrombus group and control group rabbits were injected 99 Tc m -Annexin V after operating 1 d; the old thrombus group 14 d. After 1 h all rabbits were killed by injecting overdose pentobarbital sodium. The thrombus (or the inferior vena cava about 3 cm below inferior pole of right kidney level in the control group rabbits), blood, thrombus area inferior vena cava, head lateral inferior vena cava (except the control group), thigh muscle, stomach, myocardium, pulmonary, liver, kidney, spleen, bone and small intestine were obtained from all group rabbits. The ex tissue and blood were weighed and measured by a Well-type detector. The percentage of the injected dose per gram of ex tissue (or blood) was calculated by the above data. The thrombus to blood, thrombus area inferior vena cava, head lateral inferior vena cava and thigh muscle ratios were calculated by percentage of the injected dose per gram of ex tissue (or blood). The test was used to compare the fresh thrombus group and old thrombus group by SPSS 17.0. The percentage of' the injected dose per gram of thrombi (0.01894± 0.002 16% ID/g) in the fresh thrombus group was higher than the old thrombus group (0.00473±0.001 28% ID/g), P<0.05. The thrombus to blood, thrombus area inferior vena cava, head lateral inferior vena cava and muscle ratios (3.42±1.06, 26.32±13.60, 31.23 ±16.00, 111.62±52.23) in the fresh thrombus group were higher than the old thrombus group (0.98±0.09, 5.12±2.01, 6.25±2.38, 21.82±5.93), P<0.05 for all. All the thrombi of the fresh thrombus group were confirmed

  10. Advance of apoptosis imaging with radiolabeled annexin V in tumor research

    International Nuclear Information System (INIS)

    Huang Daijuan

    2003-01-01

    One of the most important reasons that cause tumor is decrease or complete absence of apoptosis of tumor cells. Conversely successful anti-tumor therapy is correlated with the introduction of apoptosis into tumor cells. Radiolabeled annexin V is used to image in vivo the phosphatidylserine (PS) that explode on the outer surface of cell membrane after apoptosis so that apoptosis can be detected on the early stage. This imaging method can be introduced into the research of tumor in order to help direct the choose of tumor therapy, inspect the effect and evaluate the prognosis

  11. Diagnostic value of anti-annexin A5 antibodies in seropositive versus seronegative antiphospholipid syndrome patients

    Directory of Open Access Journals (Sweden)

    Gihan Omar

    2018-04-01

    Full Text Available Background: Current laboratory criteria for antiphospholipid syndrome (APS classification recommend testing positive for antiphospholipid (aPL antibodies. However, there appears to be a subset of patients with classical APS manifestations who test negative. Aim of the work: To analyze the potential clinical usefulness of testing for anti-annexin A5 antibodies in patients with APS and to study the effectiveness of testing for non-criteria aPLs in an attempt to increase the diagnostic yield, particularly in seronegative APS. Patients and methods: 60 APS patients were divided into two groups; 30 seropositive (SP-APS (group I and 30 age and sex matched seronegative (sN-APS testing negative for aPL antibodies. Serum assay for detection of isotypes of anti-annexin A5 antibodies (IgG and IgM were conducted. Results: The mean age of the patients was 32.9 ± 5.8 years, female:male 57:3 and disease duration in SP-APS versus sN-APS (10.17 ± 4.9 years versus 9.6 ± 5.5 years respectively. Secondary APS was present in 16(53.3% patients in group I compared to 3(10% in group II (p < 0.0001. The mean anti-AnxA5 IgG level was 10.7 ± 5.6 U/ml and IgM was 11.2 ± 7.1 U/ml and were comparable between the 2 groups. The obstetric and thrombotic morbidity had no significant differences between SP and sN-APS. The IgG and IgM levels significantly correlated with the pregnancy morbidity, venous and arterial thrombosis events and showed reasonable sensitivities in their prediction (IgG:71.2%,72.8% and 75.8%; IgM: 68%,67.8% and 71.4% respectively and specificities (IgG:75.9%,77.8% and 81.5%; IgM: 70.9%,73.1% and 73.7% respectively. Conclusion: anti-annexinA5 antibodies are promising for detecting obstetric and thrombotic morbidity in both SP- and sN-APS patients. Keywords: Antiphospholipid syndrome, Seropositive APS (SP-APS, Seronegative APS (sN-APS, Anti-annexin A5 antibodies

  12. From Ugly Duckling to Swan: Unexpected Identification from Cell-SELEX of an Anti-Annexin A2 Aptamer Targeting Tumors

    Science.gov (United States)

    Cibiel, Agnes; Nguyen Quang, Nam; Gombert, Karine; Thézé, Benoit; Garofalakis, Anikitos; Ducongé, Frédéric

    2014-01-01

    Background Cell-SELEX is now widely used for the selection of aptamers against cell surface biomarkers. However, despite negative selection steps using mock cells, this method sometimes results in aptamers against undesirable targets that are expressed both on mock and targeted cells. Studying these junk aptamers might be useful for further applications than those originally envisaged. Methodology/Principal Findings Cell-SELEX was performed to identify aptamers against CHO-K1 cells expressing human Endothelin type B receptor (ETBR). CHO-K1 cells were used for negative selection of aptamers. Several aptamers were identified but no one could discriminate between both cell lines. We decided to study one of these aptamers, named ACE4, and we identified that it binds to the Annexin A2, a protein overexpressed in many cancers. Radioactive binding assays and flow cytometry demonstrated that the aptamer was able to bind several cancer cell lines from different origins, particularly the MCF-7 cells. Fluorescence microscopy revealed it could be completely internalized in cells in 2 hours. Finally, the tumor targeting of the aptamer was evaluated in vivo in nude mice xenograft with MCF-7 cells using fluorescence diffuse optical tomography (fDOT) imaging. Three hours after intravenous injection, the aptamer demonstrated a significantly higher uptake in the tumor compared to a scramble sequence. Conclusions/Significance Although aptamers could be selected during cell-SELEX against other targets than those initially intended, they represent a potential source of ligands for basic research, diagnoses and therapy. Here, studying such aptamers, we identify one with high affinity for Annexin A2 that could be a promising tool for biomedical application. PMID:24489826

  13. Anti-Annexin V Antibodies: Association with Vascular Involvement and Disease Outcome in Patients with Systemic Sclerosis

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    Iman A. Hassan

    2010-04-01

    Full Text Available Background: Systemic Sclerosis (SSc is characterized by skin thickening, fibrosis and vascular obliteration. The onset and course are heterogeneous. Prominent features include autoimmunity, inflammation and vascular damage. Aim of study: To measure the level of serum Anti-Annexin V antibodies in SSc patients and to study its significance in relation to vascular damage in these patients. Patients and methods: Twenty patients with SSc (12 with diffuse SSc and 8 with the limited form and 10 healthy age and sex matched volunteers as controls were all subjected to routine laboratory testing and immunological profiling including antinuclear, anti-Scl-70, anticentomere, anticardiolipin antibodies and anti-annexin V antibodies titres. Vascular damage was assessed by clinical examination and assessment of the disease activity score, nailfold capillaroscopy and colour flow Doppler of the renal arteries; Doppler echocardiography was used for assessing pulmonary hypertension. Results: Anti-annexin V antibodies were detected in 75% of patients. Comparisons between anti-annexin V in diffuse and limited subgroups showed no significance; however a statistically significant positive correlation was found between Anti-annexin V titre and the degree of vascular damage in SSc patients. Anti-annexin V increased significantly in patients with severe vascular damage in comparison with those less affected (15.3 ± 6.6 vs. 11.25 ± 3.6, P , 0.05. A significant positive correlation was found between Anti-annexin V titre and both the ACL titre (r = 0.79, P , 0.001 and the resistive index of the main renal artery (r = 0.42, P , 0.05. Conclusion: Anti-annexin V antibodies were significantly present in sera of patients with SSc. Patients with more severe forms of vascular damage had higher titres of these antibodies. Anti-annexin V antibodies are a sensitive predictor of vascular damage in SSc and could serve as a useful parameter in discriminating patients with a higher

  14. Anti-Annexin V Antibodies: Association with Vascular Involvement and Disease Outcome in Patients with Systemic Sclerosis

    Directory of Open Access Journals (Sweden)

    Reem A. Habeeb

    2010-01-01

    Full Text Available Background Systemic Sclerosis (SSc is characterized by skin thickening, fibrosis and vascular obliteration. The onset and course are heterogeneous. Prominent features include autoimmunity, inflammation and vascular damage. Aim of Study To measure the level of serum Anti-Annexin V antibodies in SSc patients and to study its significance in relation to vascular damage in these patients. Patients and Methods Twenty patients with SSc (12 with diffuse SSc and 8 with the limited form and 10 healthy age and sex matched volunteers as controls were all subjected to routine laboratory testing and immunological profiling including antinuclear, anti-Scl-70, anticentomere, anticardiolipin antibodies and anti-annexin V antibodies titres. Vascular damage was assessed by clinical examination and assessment of the disease activity score, nailfold capillaroscopy and colour flow Doppler of the renal arteries; Doppler echocardiography was used for assessing pulmonary hypertension. Results Anti-annexin V antibodies were detected in 75% of patients. Comparisons between anti-annexin V in diffuse and limited subgroups showed no significance; however a statistically significant positive correlation was found between Anti-annexin V titre and the degree of vascular damage in SSc patients. Anti-annexin V increased significantly in patients with severe vascular damage in comparison with those less affected (15.3 ± 6.6 vs. 11.25 ± 3.6, P < 0.05. A significant positive correlation was found between Anti-annexin V titre and both the ACL titre (r = 0.79, P < 0.001 and the resistive index of the main renal artery (r = 0.42, P < 0.05. Conclusion Anti-annexin V antibodies were significantly present in sera of patients with SSc. Patients with more severe forms of vascular damage had higher titres of these antibodies. Anti-annexin V antibodies are a sensitive predictor of vascular damage in SSc and could serve as a useful parameter in discriminating patients with a higher risk of

  15. The MiR-495/Annexin A3/P53 Axis Inhibits the Invasion and EMT of Colorectal Cancer Cells

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    Zhigang Bai

    2017-12-01

    Full Text Available Background/Aims: More and more reports have shown that the dysregulation of miRNAs can contribute to the progression and metastasis of human cancers. Many studies have shown that the down-regulation of the miR-495 level occurs in a variety of cancers, including colorectal cancer (CRC. However, the precise molecular mechanisms of miR-495 in CRC have not been well clarified. In the current study, we investigated the biological functions and molecular mechanisms of miR-495 in CRC cell lines. Methods: qRT-PCR was used to determine the level of miR-495 in CRC cell lines and tissues. A miR-495 mimic and inhibitor were transfected into CRC cells, and the effects of miR-495 on the invasion and EMT were explored by qRT-PCR as well as transwell and Western blot assays. Meanwhile, luciferase assays were performed to validate Annexin A3 as a miR-495 target in CRC cells. Results: In our study, we found that miR-495 is down-regulated in CRC tissues and cell lines. Moreover, the low level of miR-495 was associated with increased expression of Annexin A3 in CRC tissues and cell lines. The invasion and EMT of CRC cells were suppressed by the overexpression of miR-495. However, the down-regulation of miR-495 promoted the invasion and EMT of CRC cells. Bioinformatics analysis predicted that Annexin A3 was a potential target gene of miR-495. Next, the luciferase reporter assay confirmed that miR-495 could directly target Annexin A3. Consistent with the effect of miR-495, the down-regulation of Annexin A3 by siRNA inhibited the invasion and EMT of CRC cells through the up-regulation of p53. The introduction of Annexin A3 in CRC cells partially blocked the effects of the miR-495 mimic. Conclusion: The introduction of miR-495 directly targeted Annexin A3 to inhibit the invasion and EMT of CRC cells by up-regulating p53, and the down-regulation of Annexin A3 was essential for inhibiting the invasion and EMT of CRC cells by overexpressing miR-495. Overall, the re

  16. Preparation and bioevaluation of 99Tcm-HYNIC-Annexin B1 as a novel radiotracer for apoptosis detection

    International Nuclear Information System (INIS)

    Luo Quanyong; Luo Qiong; Lu Hankui; Zhu Ruisen; Wang Fang; Zhang Yi; Sun Shuhan; Zhang Zhiyong; Liu Xingfeng

    2008-01-01

    Objective: Annexin B1, a novel Ca 2+ -dependent phosphatidylserine (PS)-binding protein, has been shown to have a high affinity for PS exposed on the surface of apoptotic cells or activated platelets. The aim of this study was to develop and bioevaluate an Annexin B1 based PS-targeting radiotracer labeled with 99 Tc m . Methods: Annexin B1 was indirectly labeled with 99 Tc m using hydrazinonicotinamide (HYNIC) as a bifunctional chelator agent. Binding assay with human activated platelets was used to evaluate the biological activity of 99 Tc m -HYNIC-Annexin B1 in vitro. The potential of 99 Tc m -HYNIC-Annexin B1 to detect apoptosis in vivo was evaluated in mice models with dexamethasone-inducecd thymus apoptosis and anti-Fas antibody induced liver apoptosis. The paired t-test was used to analyse the data. Results: The labeling procedure yielded a compound with radiochemical purity higher than 96% and good in vitro stability. Plate- lets binding assay indicated that 99 Tc m -HYNIC-Annexin B1 retained their PS binding activity in vitro. The percentage activity of injection dose per gram of tissue (% ID/g) of mouse thymus showed a 3.50-fold increase at 18 h after administration of dexamethasone compared with control mice (t=5.234, P 99 Tc m -HYNIC-Annexin B1 in the liver of anti-Fas antibody treated mice. The %ID/g of apoptotic murine liver showed a 2.02-fo1d increase at 2 h after the administration of anti-Fas antibody compared with control mice (t=6.178, P 99 Tc m -HYNIC-Annexin B1 can be prepared with high radiochemical purity and in vitro stability. These da- ta also suggest that 99 Tc m -HYNIC-Annexin B1 retains its in vitro and in vivo biological activities. It may therefore be useful as a novel radioligand for the noninvasive imaging of PS externalization associated with apoptosis. (authors)

  17. Quantitative analysis of self-association and mobility of annexin A4 at the plasma membrane.

    Science.gov (United States)

    Crosby, Kevin C; Postma, Marten; Hink, Mark A; Zeelenberg, Christiaan H C; Adjobo-Hermans, Merel J W; Gadella, Theodorus W J

    2013-05-07

    Annexins, found in most eukaryotic species, are cytosolic proteins that are able to bind negatively-charged phospholipids in a calcium-dependent manner. Annexin A4 (AnxA4) has been implicated in diverse cellular processes, including the regulation of exocytosis and ion-transport; however, its precise mechanistic role is not fully understood. AnxA4 has been shown to aggregate on lipid layers upon Ca(2+) binding in vitro, a characteristic that may be critical for its function. We have utilized advanced fluorescence microscopy to discern details on the mobility and self-assembly of AnxA4 after Ca(2+) influx at the plasma membrane in living cells. Total internal reflection microscopy in combination with Förster resonance energy transfer reveals that there is a delay between initial plasma membrane binding and the beginning of self-assembly and this process continues after the cytoplasmic pool has completely relocated. Number-and-brightness analysis suggests that the predominant membrane bound mobile form of the protein is trimeric. There also exists a pool of AnxA4 that forms highly immobile aggregates at the membrane. Fluorescence recovery after photobleaching suggests that the relative proportion of these two forms varies and is correlated with membrane morphology. Copyright © 2013 Biophysical Society. Published by Elsevier Inc. All rights reserved.

  18. Low Annexin A1 expression predicts benefit from induction chemotherapy in oral cancer patients with moderate or poor pathologic differentiation grade

    International Nuclear Information System (INIS)

    Zhu, Dong-wang; Zhang, Chen-ping; Zhang, Zhi-yuan; Zhong, Lai-ping; Liu, Ying; Yang, Xiao; Yang, Cheng-zhe; Ma, Jie; Yang, Xi; Qiao, Jin-ke; Wang, Li-zhen; Li, Jiang

    2013-01-01

    The benefit of induction chemotherapy in locally advanced oral squamous cell carcinoma (OSCC) remains to be clearly defined. Induction chemotherapy is likely to be effective for biologically distinct subgroups of patients and biomarker development might lead to identification of the patients whose tumors are to respond to a particular treatment. Annexin A1 may serve as a biomarker for responsiveness to induction chemotherapy. The aim of this study was to investigate Annexin A1 expression in pre-treatment biopsies from a cohort of OSCC patients treated with surgery and post-operative radiotherapy or docetaxel, cisplatin and 5-fluorouracil (TPF) induction chemotherapy followed by surgery and post-operative radiotherapy. Furthermore we sought to assess the utility of Annexin A1 as a prognostic or predictive biomarker. Immunohistochemical staining for Annexin A1 was performed in pre-treatment biopsies from 232 of 256 clinical stage III/IVA OSCC patients. Annexin A1 index was estimated as the proportion of tumor cells (low and high, <50% and ≥50% of stained cells, respectively) to Annexin A1 cellular membrane and cytoplasm staining. There was a significant correlation between Annexin A1 expression and pathologic differentiation grade (P=0.015) in OSCC patients. The proportion of patients with low Annexin A1 expression was significantly higher amongst those with moderate/poorly differentiated tumor (78/167) compared to those with well differentiated tumor (18/65). Multivariate Cox model analysis showed clinical stage (P=0.001) and Annexin A1 expression (P=0.038) as independent prognostic risk factors. Furthermore, a low Annexin A1 expression level was predictive of longer disease-free survival (P=0.036, HR=0.620) and locoregional recurrence-free survival (P=0.031, HR=0.607) compared to high Annexin A1 expression. Patients with moderate/poorly differentiated tumor and low Annexin A1 expression benefited from TPF induction chemotherapy as measured by distant metastasis

  19. 99mTc-Hynic-annexin V imaging to evaluate inflammation and apoptosis in rats with autoimmune myocarditis

    International Nuclear Information System (INIS)

    Tokita, Naoki; Izumi, Tohru; Hasegawa, Shinji; Maruyama, Kaoru; Blankenberg, Francis G.; Tait, Jonathan F.; Strauss, William H.; Nishimura, Tsunehiko

    2003-01-01

    Inflammation and cell death are two important components of myocarditis. We evaluated the distribution of inflammation and apoptotic cell death in rats with autoimmune myocarditis using two radiotracers - technetium-99m Hynic-annexin V ( 99m Tc-annexin) as a marker of apoptotic cell death and carbon-14 deoxyglucose ( 14 C-DG) as a marker of inflammation - in comparison with histologic findings. Three, 7 and 14 weeks after immunization with porcine cardiac myosin (acute, subacute, and chronic phases, respectively) 99m Tc-annexin and 14 C-DG were injected. The uptake in the total heart was determined as the percentage of injected dose per gram (% ID/g) by tissue counting. Dual-tracer autoradiography with 99m Tc-annexin and 14 C-DG was performed. The distribution of each of these agents was compared with the results of hematoxylin and eosin staining to identify areas of inflammation, and TUNEL staining to identify areas of apoptosis. Total cardiac uptake of 99m Tc-annexin in the acute phase of myocarditis was significantly higher than that in normal rats (1.28%±0.30% vs 0.46%±0.01%; P 14 C-DG in the acute phase of myocarditis was significantly higher than that in normal rats (2.78%±0.95% vs 1.02%±0.25%; P 14 C-DG uptake; some also corresponded to areas of high 99m Tc-annexin uptake in the acute phase of myocarditis. 99m Tc-annexin localization was strongly correlated with the number of TUNEL-positive cells (P 14 C-DG showed no relationship with it. There is a marked difference in the distribution of inflammation and apoptotic cell death in the myocardium of animals with immune myocarditis. These changes are mirrored by the localization of 14 C-DG and 99m Tc-annexin. Sites of inflammation and zones of apoptotic cell death change over the course of immune myocarditis. (orig.)

  20. Regulation of annexins following infection like tissue damage – investigated by 2-dimensional gel electrophoresis

    DEFF Research Database (Denmark)

    Wulff, Tune; Nielsen, Michael Engelbrecht

    are regulated after tissue damaged on the protein level. These proteins have been assign to functions like regulation of coagulation, apoptosis, and exocytosis, indicating their importance following infection and subsequent repair in fish. In addition the regulation observed in this study are supported...... an established model. In the model infection is mimicked by a well-defined tissue damage allowing each fish to be equally affected. Samples were taken 7 days after tissue damage and included samples from the damaged tissue, internal control and an external control. Changes in protein expression between the wound...... by previous findings on the mRNA level, where both proteins are regulated following infection. In conclusion this study show regulation on the protein level of two members of the annexin protein family after infection like tissue damage....

  1. Endothelial microparticles released by activated protein C protect beta cells through EPCR/PAR1 and annexin A1/FPR2 pathways in islets.

    Science.gov (United States)

    Kreutter, Guillaume; Kassem, Mohamad; El Habhab, Ali; Baltzinger, Philippe; Abbas, Malak; Boisrame-Helms, Julie; Amoura, Lamia; Peluso, Jean; Yver, Blandine; Fatiha, Zobairi; Ubeaud-Sequier, Geneviève; Kessler, Laurence; Toti, Florence

    2017-11-01

    Islet transplantation is associated with early ischaemia/reperfusion, localized coagulation and redox-sensitive endothelial dysfunction. In animal models, islet cytoprotection by activated protein C (aPC) restores islet vascularization and protects graft function, suggesting that aPC triggers various lineages. aPC also prompts the release of endothelial MP that bear EPCR, its specific receptor. Microparticles (MP) are plasma membrane procoagulant vesicles, surrogate markers of stress and cellular effectors. We measured the cytoprotective effects of aPC on endothelial and insulin-secreting Rin-m5f β-cells and its role in autocrine and paracrine MP-mediated cell crosstalk under conditions of oxidative stress. MP from aPC-treated primary endothelial (EC) or β-cells were applied to H 2 O 2 -treated Rin-m5f. aPC activity was measured by enzymatic assay and ROS species by dihydroethidium. The capture of PKH26-stained MP and the expression of EPCR were probed by fluorescence microscopy and apoptosis by flow cytometry. aPC treatment enhanced both annexin A1 (ANXA1) and PAR-1 expression in EC and to a lesser extent in β-cells. MP from aPC-treated EC (eM aPC ) exhibited high EPCR and annexin A1 content, protected β-cells, restored insulin secretion and were captured by 80% of β cells in a phosphatidylserine and ANXA1-dependent mechanism. eMP activated EPCR/PAR-1 and ANXA1/FPR2-dependent pathways and up-regulated the expression of EPCR, and of FPR2/ALX, the ANXA1 receptor. Cytoprotection was confirmed in H 2 O 2 -treated rat islets with increased viability (62% versus 48% H 2 O 2 ), reduced apoptosis and preserved insulin secretion in response to glucose elevation (16 versus 5 ng/ml insulin per 10 islets). MP may prove a promising therapeutic tool in the protection of transplanted islets. © 2017 The Authors. Journal of Cellular and Molecular Medicine published by John Wiley & Sons Ltd and Foundation for Cellular and Molecular Medicine.

  2. Inflammation and cancer: role of annexin A1 and FPR2/ALX in proliferation and metastasis in human laryngeal squamous cell carcinoma.

    Directory of Open Access Journals (Sweden)

    Thaís Santana Gastardelo

    Full Text Available The anti-inflammatory protein annexin A1 (ANXA1 has been associated with cancer progression and metastasis, suggesting its role in regulating tumor cell proliferation. We investigated the mechanism of ANXA1 interaction with formylated peptide receptor 2 (FPR2/ALX in control, peritumoral and tumor larynx tissue samples from 20 patients, to quantitate the neutrophils and mast cells, and to evaluate the protein expression and co-localization of ANXA1/FPR2 in these inflammatory cells and laryngeal squamous cells by immunocytochemistry. In addition, we performed in vitro experiments to further investigate the functional role of ANXA1/FPR2 in the proliferation and metastasis of Hep-2 cells, a cell line from larynx epidermoid carcinoma, after treatment with ANXA1(2-26 (annexin A1 N-terminal-derived peptide, Boc2 (antagonist of FPR and/or dexamethasone. Under these treatments, the level of Hep-2 cell proliferation, pro-inflammatory cytokines, ANXA1/FPR2 co-localization, and the prostaglandin signalling were analyzed using ELISA, immunocytochemistry and real-time PCR. An influx of neutrophils and degranulated mast cells was detected in tumor samples. In these inflammatory cells of peritumoral and tumor samples, ANXA1/FPR2 expression was markedly exacerbated, however, in laryngeal carcinoma cells, this expression was down-regulated. ANXA1(2-26 treatment reduced the proliferation of the Hep-2 cells, an effect that was blocked by Boc2, and up-regulated ANXA1/FPR2 expression. ANXA1(2-26 treatment also reduced the levels of pro-inflammatory cytokines and affected the expression of metalloproteinases and EP receptors, which are involved in the prostaglandin signalling. Overall, this study identified potential roles for the molecular mechanism of the ANXA1/FPR2 interaction in laryngeal cancer, including its relationship with the prostaglandin pathway, providing promising starting points for future research. ANXA1 may contribute to the regulation of tumor growth

  3. Annexin A7 deficiency potentiates cardiac NFAT activity promoting hypertrophic signaling

    International Nuclear Information System (INIS)

    Voelkl, Jakob; Alesutan, Ioana; Pakladok, Tatsiana; Viereck, Robert; Feger, Martina; Mia, Sobuj; Schönberger, Tanja; Noegel, Angelika A.; Gawaz, Meinrad; Lang, Florian

    2014-01-01

    Highlights: • Cardiac Anxa7 expression was up-regulated following TAC. • The hypertrophic response following TAC was augmented in Anxa7-deficient mice. • Silencing of Anxa7 increased indicators of HL-1 cardiomyocytes hypertrophy. • Silencing of Anxa7 induced Nfatc1 nuclear translocation. • Silencing of Anxa7 enhanced NFAT-dependent transcriptional activity. - Abstract: Annexin A7 (Anxa7) is a cytoskeletal protein interacting with Ca 2+ signaling which in turn is a crucial factor for cardiac remodeling following cardiac injury. The present study explored whether Anxa7 participates in the regulation of cardiac stress signaling. To this end, mice lacking functional Anxa7 (anxa7 −/− ) and wild-type mice (anxa7 +/+ ) were investigated following pressure overload by transverse aortic constriction (TAC). In addition, HL-1 cardiomyocytes were silenced with Anxa7 siRNA and treated with isoproterenol. Transcript levels were determined by quantitative RT-PCR, transcriptional activity by luciferase reporter assay and protein abundance by Western blotting and confocal microscopy. As a result, TAC treatment increased the mRNA and protein levels of Anxa7 in wild-type mice. Moreover, TAC increased heart weight to body weight ratio and the cardiac mRNA levels of αSka, Nppb, Col1a1, Col3a1 and Rcan1, effects more pronounced in anxa7 −/− mice than in anxa7 +/+ mice. Silencing of Anxa7 in HL-1 cardiomyocytes significantly increased nuclear localization of Nfatc1. Furthermore, Anxa7 silencing increased NFAT-dependent transcriptional activity as well as αSka, Nppb, and Rcan1 mRNA levels both, under control conditions and following β-adrenergic stimulation by isoproterenol. These observations point to an important role of annexin A7 in the regulation of cardiac NFAT activity and hypertrophic response following cardiac stress conditions

  4. Biochemical and immunological characterization of annexin B30 from Clonorchis sinensis excretory/secretory products.

    Science.gov (United States)

    He, Lei; Ren, Mengyu; Chen, Xueqing; Wang, Xiaoyun; Li, Shan; Lin, Jinsi; Liang, Chi; Liang, Pei; Hu, Yue; Lei, Huali; Bian, Meng; Huang, Yan; Wu, Zhongdao; Li, Xuerong; Yu, Xinbing

    2014-07-01

    Clonorchis sinensis has been classified as group I biological carcinogen for cholangiocarcinoma by the World Health Organization. Biological studies on excretory/secretory products (ESPs) enabled us to understand the pathogenesis mechanism of C. sinensis and develop new strategies for the prevention of clonorchiasis. In this study, sequence analysis showed that annexin B30 from C. sinensis (CsANXB30) is composed of four annexin repeats which were characterized by type II and III Ca(2+)-binding sites or KGD motif with the capability of Ca(2+)-binding. In addition, immunoblot assay revealed that recombinant CsANXB30 (rCsANXB30) could be recognized by the sera from rats infected with C. sinensis and the sera from rats immunized by CsESPs. Real-time PCR showed that its transcriptional level was the highest at the stage of metacercaria. Immunofluorescence assay was employed to confirm that CsANXB30 was distributed in the tegument, intestine, and egg of adult worms, as well as the tegument and vitellarium of metacercaria. rCsANXB30 was able to bind phospholipid in a Ca(2+)-dependent manner and human plasminogen in a dose-dependent manner. Moreover, cytokine and antibody measurements indicated that rats subcutaneously immunized with rCsANXB30 developed a strong IL-10 production in spleen cells and a high level of IgG1 isotype, indicating that rCsANXB30 could trigger specific humoral and cellular immune response in rats. The present results implied that CsANXB30 might be involved in a host-parasite interaction and affected the immune response of the host during C. sinensis infection.

  5. Annexin A7 deficiency potentiates cardiac NFAT activity promoting hypertrophic signaling

    Energy Technology Data Exchange (ETDEWEB)

    Voelkl, Jakob; Alesutan, Ioana; Pakladok, Tatsiana; Viereck, Robert; Feger, Martina; Mia, Sobuj [Department of Physiology, University of Tübingen, Tübingen (Germany); Schönberger, Tanja [Department of Cardiology and Cardiovascular Medicine, University of Tübingen, Tübingen (Germany); Noegel, Angelika A. [Center for Biochemistry, Institute of Biochemistry I, University of Cologne, Köln (Germany); Gawaz, Meinrad [Department of Cardiology and Cardiovascular Medicine, University of Tübingen, Tübingen (Germany); Lang, Florian, E-mail: florian.lang@uni-tuebingen.de [Department of Physiology, University of Tübingen, Tübingen (Germany)

    2014-02-28

    Highlights: • Cardiac Anxa7 expression was up-regulated following TAC. • The hypertrophic response following TAC was augmented in Anxa7-deficient mice. • Silencing of Anxa7 increased indicators of HL-1 cardiomyocytes hypertrophy. • Silencing of Anxa7 induced Nfatc1 nuclear translocation. • Silencing of Anxa7 enhanced NFAT-dependent transcriptional activity. - Abstract: Annexin A7 (Anxa7) is a cytoskeletal protein interacting with Ca{sup 2+} signaling which in turn is a crucial factor for cardiac remodeling following cardiac injury. The present study explored whether Anxa7 participates in the regulation of cardiac stress signaling. To this end, mice lacking functional Anxa7 (anxa7{sup −/−}) and wild-type mice (anxa7{sup +/+}) were investigated following pressure overload by transverse aortic constriction (TAC). In addition, HL-1 cardiomyocytes were silenced with Anxa7 siRNA and treated with isoproterenol. Transcript levels were determined by quantitative RT-PCR, transcriptional activity by luciferase reporter assay and protein abundance by Western blotting and confocal microscopy. As a result, TAC treatment increased the mRNA and protein levels of Anxa7 in wild-type mice. Moreover, TAC increased heart weight to body weight ratio and the cardiac mRNA levels of αSka, Nppb, Col1a1, Col3a1 and Rcan1, effects more pronounced in anxa7{sup −/−} mice than in anxa7{sup +/+} mice. Silencing of Anxa7 in HL-1 cardiomyocytes significantly increased nuclear localization of Nfatc1. Furthermore, Anxa7 silencing increased NFAT-dependent transcriptional activity as well as αSka, Nppb, and Rcan1 mRNA levels both, under control conditions and following β-adrenergic stimulation by isoproterenol. These observations point to an important role of annexin A7 in the regulation of cardiac NFAT activity and hypertrophic response following cardiac stress conditions.

  6. Technetium 99m-labeled annexin v scintigraphy of platelet activation in vegetations of experimental endocarditis

    Energy Technology Data Exchange (ETDEWEB)

    Rouzet, F.; Sarda-Mantel, L.; Le Guludec, D. [Nucl Med Serv, Grp Hosp Bichat Claude Bernard, AP-HP, Paris (France); Rouzet, F.; Sarda-Mantel, L.; LeGuludec, D. [Univ Denis Diderot Paris 7, UMR S773, Paris (France); Rouzet, F.; Sarda-Mantel, L.; Le Guludec, D. [INSERM, U773, Paris (France); Hernandez, M.D.; Louedec, L.; Michel, J.B. [Univ Paris 07, CHU Xavier Bichat, INSERM, U698, Paris (France); Hervatin, F. [CEA, DSV, DRM, SHFJ, Orsay (France); Lefort, A.; Fantin, B. [Univ Denis Diderot Paris 7, EA 3964, Paris (France); Duval, X. [Univ Denis Diderot Paris 7, INSERM, CIC 007, Paris (France); Duval, X. [Univ Denis Diderot Paris 7, AP-HP, Grp Hosp Bichat Claude Bernard, Ctr Invest Clin, Paris (France); Hernandez, M.D. [Univ Guadalajara, DeptPathol, Guadalajara 44430, Jalisco (Mexico)

    2008-07-01

    Background: The pathophysiology of infective endocarditis involves a pathogen/host tissue interaction, leading to formation of infected thrombotic vegetations. Annexin V is a ligand of phosphatidyl-serines exposed by activated platelets and apoptotic cells. Because vegetations are platelet-fibrin clots in which platelet pro-aggregant activity is enhanced by bacterial colonization, we investigated the ability of annexin V labeled with technetium {sup 99m}Tc ({sup 99m}Tc-ANX) to provide functional imaging of these vegetations in experimental models of infective endocarditis. This ability was assessed in rabbits and rats because of the different interest of these 2 species in preclinical analysis. Methods and Results: Non-bacterial thrombotic endocarditis was induced with the use of a catheter left indwelling through the aortic or tricuspid valve, and animals were injected with either a bacterial inoculum or saline. Scintigraphic investigations were performed 5 days later and showed a higher {sup 99m}Tc-ANX uptake by vegetations in infected versus non-infected animals (ratio,1.3 for in vivo acquisitions and 2 for autoradiography; P {<=} 0.0001 for all), whereas no significant uptake was present in controls. Right-sided endocarditis was associated with pulmonary uptake foci corresponding to emboli. Histological analysis of vegetations showed a specific uptake of {sup 99m}Tc-ANX at the interface between circulating blood and vegetation. In parallel, underlying myocardial tissue showed myocyte apoptosis and mucoid degeneration, without extracellular matrix degradation at this stage. Conclusions: {sup 99m}Tc-ANX is suitable for functional imaging of platelet-fibrin vegetations in endocarditis, as well as embolic events. {sup 99m}Tc-ANX uptake reflects mainly platelet activation in the luminal layer of vegetations. This uptake is enhanced by bacterial colonization. (authors)

  7. Small molecule inhibitors of the annexin A2 heterotetramer prevent human papillomavirus type 16 infection.

    Science.gov (United States)

    Woodham, Andrew W; Taylor, Julia R; Jimenez, Andrew I; Skeate, Joseph G; Schmidt, Thomas; Brand, Heike E; Da Silva, Diane M; Kast, W Martin

    2015-01-01

    High-risk human papillomavirus (HPV) infection leads to the development of several human cancers that cause significant morbidity and mortality worldwide. HPV type 16 (HPV16) is the most common of the cancer-causing genotypes and gains entry to the basal cells of the epithelium through a non-canonical endocytic pathway that involves the annexin A2/S100A10 heterotetramer (A2t). A2t is composed of two annexin A2 monomers bound to an S100A10 dimer and this interaction is a potential target to block HPV16 infection. Here, recently identified small molecule inhibitors of A2t (A2ti) were investigated for their ability to prevent HPV16 infection in vitro. A2ti were added to HeLa cells in increasing concentrations prior to the addition of HPV16. Cytotoxicity was evaluated via trypan blue exclusion. HPV16 pseudovirion infection and fluorescently labelled HPV16 capsid internalization was measured with flow cytometry. A2ti blocked HPV16 infection by 100% without substantial cellular toxicity or reduction in cell growth. Furthermore, A2ti blocked HPV16 entry into epithelial cells by 65%, indicating that the observed inhibition of HPV16 infection is in part due to a block in entry and that non-infectious entry may occur in the absence of A2t binding. These results demonstrate that targeting A2t may be an effective strategy to prevent HPV16 infection. © The Author 2015. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  8. Technetium 99m-labeled annexin v scintigraphy of platelet activation in vegetations of experimental endocarditis

    International Nuclear Information System (INIS)

    Rouzet, F.; Sarda-Mantel, L.; Le Guludec, D.; Rouzet, F.; Sarda-Mantel, L.; LeGuludec, D.; Rouzet, F.; Sarda-Mantel, L.; Le Guludec, D.; Hernandez, M.D.; Louedec, L.; Michel, J.B.; Hervatin, F.; Lefort, A.; Fantin, B.; Duval, X.; Duval, X.; Hernandez, M.D.

    2008-01-01

    Background: The pathophysiology of infective endocarditis involves a pathogen/host tissue interaction, leading to formation of infected thrombotic vegetations. Annexin V is a ligand of phosphatidyl-serines exposed by activated platelets and apoptotic cells. Because vegetations are platelet-fibrin clots in which platelet pro-aggregant activity is enhanced by bacterial colonization, we investigated the ability of annexin V labeled with technetium 99m Tc ( 99m Tc-ANX) to provide functional imaging of these vegetations in experimental models of infective endocarditis. This ability was assessed in rabbits and rats because of the different interest of these 2 species in preclinical analysis. Methods and Results: Non-bacterial thrombotic endocarditis was induced with the use of a catheter left indwelling through the aortic or tricuspid valve, and animals were injected with either a bacterial inoculum or saline. Scintigraphic investigations were performed 5 days later and showed a higher 99m Tc-ANX uptake by vegetations in infected versus non-infected animals (ratio,1.3 for in vivo acquisitions and 2 for autoradiography; P ≤ 0.0001 for all), whereas no significant uptake was present in controls. Right-sided endocarditis was associated with pulmonary uptake foci corresponding to emboli. Histological analysis of vegetations showed a specific uptake of 99m Tc-ANX at the interface between circulating blood and vegetation. In parallel, underlying myocardial tissue showed myocyte apoptosis and mucoid degeneration, without extracellular matrix degradation at this stage. Conclusions: 99m Tc-ANX is suitable for functional imaging of platelet-fibrin vegetations in endocarditis, as well as embolic events. 99m Tc-ANX uptake reflects mainly platelet activation in the luminal layer of vegetations. This uptake is enhanced by bacterial colonization. (authors)

  9. Potato Annexin STANN1 Promotes Drought Tolerance and Mitigates Light Stress in Transgenic Solanum tuberosum L. Plants

    Czech Academy of Sciences Publication Activity Database

    Szalonek, M.; Sierpien, B.; Rymaszewski, W.; Gieczewska, K.; Vaňková, Radomíra; Dobrev, Petre; Szczesny, P.; Marczewski, W.; Krusiewicz, D.; Strzelczyk-Zyta, D.; Konopka-Postupolska, D.

    2015-01-01

    Roč. 10, č. 7 (2015), e0132683 E-ISSN 1932-6203 Institutional support: RVO:61389030 Keywords : MEDIATED OXIDATIVE STRESS * VIOLAXANTHIN DE-EPOXIDASE * BRASSICA-JUNCEA ANNEXIN-3 Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 3.057, year: 2015

  10. Intraoperative Detection of Cell Injury and Cell Death with an 800 nm Near-Infrared Fluorescent Annexin V Derivative

    Science.gov (United States)

    Ohnishi, Shunsuke; Vanderheyden, Jean-Luc; Tanaka, Eiichi; Patel, Bhavesh; De Grand, Alec; Laurence, Rita G.; Yamashita, Kenichiro; Frangioni, John V.

    2008-01-01

    The intraoperative detection of cell injury and cell death is fundamental to human surgeries such as organ transplantation and resection. Because of low autofluorescence background and relatively high tissue penetration, invisible light in the 800 nm region provides sensitive detection of disease pathology without changing the appearance of the surgical field. In order to provide surgeons with real-time intraoperative detection of cell injury and death after ischemia/reperfusion (I/R), we have developed a bioactive derivative of human annexin V (annexin800), which fluoresces at 800 nm. Total fluorescence yield, as a function of bioactivity, was optimized in vitro, and final performance was assessed in vivo. In liver, intestine and heart animal models of I/R, an optimal signal to background ratio was obtained 30 min after intravenous injection of annexin800, and histology confirmed concordance between planar reflectance images and actual deep tissue injury. In summary, annexin800 permits sensitive, real-time detection of cell injury and cell death after I/R in the intraoperative setting, and can be used during a variety of surgeries for rapid assessment of tissue and organ status. PMID:16869796

  11. Radiolabeled annexin V for imaging apoptosis in radiated human follicular thyroid carcinomas - is an individualized protocol necessary?

    Energy Technology Data Exchange (ETDEWEB)

    Grosse, Jirka [Department of Nuclear Medicine, University of Regensburg, 93042 Regensburg (Germany); Department of Clinical Pharmacology and Toxicology, Charite-Universitaetsmedizin Berlin, Campus Benjamin Franklin, 14195 Berlin (Germany)], E-mail: jirka.grosse@klinik.uni-regensburg.de; Grimm, Daniela [Department of Clinical Pharmacology and Toxicology, Charite-Universitaetsmedizin Berlin, Campus Benjamin Franklin, 14195 Berlin (Germany); Department of Pharmacology, University of Aarhus, 8000 Aarhus (Denmark); Westphal, Kriss; Ulbrich, Claudia [Department of Clinical Pharmacology and Toxicology, Charite-Universitaetsmedizin Berlin, Campus Benjamin Franklin, 14195 Berlin (Germany); Moosbauer, Jutta [Department of Nuclear Medicine, University of Regensburg, 93042 Regensburg (Germany); Pohl, Fabian; Koelbl, Oliver [Department of Radiooncology, University of Regensburg, 93042 Regensburg (Germany); Infanger, Manfred [Department of Reconstructive Surgery, Charite-Universitaetsmedizin Berlin, Campus Benjamin Franklin, 12203 Berlin (Germany); Eilles, Christoph; Schoenberger, Johann [Department of Nuclear Medicine, University of Regensburg, 93042 Regensburg (Germany)

    2009-01-15

    Introduction: Induction of apoptosis is a widely used strategy for cancer therapy, but evaluating the degree and success of this therapy still poses a problem. Radiolabeled annexin V has been proposed to be a promising candidate for detecting apoptotic cells in tumors following chemotherapy in vivo. In order to see whether radiolabeled annexin V could be a suitable substance for the noninvasive in vivo detection of apoptosis in thyroid tissue and to establish an optimized study protocol, we investigated two poorly differentiated thyroid carcinoma cell lines: ML-1 and FTC-133. Methods: Apoptosis was evaluated before as well as 2 and 4 days after in vitro irradiation with 30 Gy X-rays. In this study, binding of FITC- and of {sup 125}I-labeled annexin V was measured in comparison to other apoptosis markers such as Bax, caspase-3 and Fas, which were determined by flow cytometry and Western blot analysis with densitometric evaluation. Results: ML-1 and FTC-133 cells showed a significant increase in annexin V binding 48 h after irradiation. Ninety-six hours after irradiation, the annexin V absorption capability of ML-1 cells was still maximal, while the living fraction of FTC-133 increased significantly. The amount of caspase-3 and Bax was clearly increased 48 h after irradiation and had normalized after 96 h in both cell lines. Fas protein concentrations remained unchanged in ML-1 cells but were significantly enhanced in FTC-133 cells. Conclusion: The binding of FITC- and {sup 125}I-labeled annexin V showed a significant accordance. A reliable evaluation of apoptosis induced by radiotherapy in thyroid tumors was possible 48 h after irradiation, when binding of radiolabeled annexin V is most significantly enhanced. Using two poorly differentiated cell lines of thyroid carcinoma, one may expect to find a nearly similar response to external irradiation. In contrast, the cell lines showed a completely contrary response. However, an individualized study protocol for each

  12. Potato Annexin STANN1 Promotes Drought Tolerance and Mitigates Light Stress in Transgenic Solanum tuberosum L. Plants

    Science.gov (United States)

    Szalonek, Michal; Sierpien, Barbara; Rymaszewski, Wojciech; Gieczewska, Katarzyna; Garstka, Maciej; Lichocka, Malgorzata; Sass, Laszlo; Paul, Kenny; Vass, Imre; Vankova, Radomira; Dobrev, Peter; Szczesny, Pawel; Marczewski, Waldemar; Krusiewicz, Dominika; Strzelczyk-Zyta, Danuta; Hennig, Jacek; Konopka-Postupolska, Dorota

    2015-01-01

    Annexins are a family of calcium- and membrane-binding proteins that are important for plant tolerance to adverse environmental conditions. Annexins function to counteract oxidative stress, maintain cell redox homeostasis, and enhance drought tolerance. In the present study, an endogenous annexin, STANN1, was overexpressed to determine whether crop yields could be improved in potato (Solanum tuberosum L.) during drought. Nine potential potato annexins were identified and their expression characterized in response to drought treatment. STANN1 mRNA was constitutively expressed at a high level and drought treatment strongly increased transcription levels. Therefore, STANN1 was selected for overexpression analysis. Under drought conditions, transgenic potato plants ectopically expressing STANN1 were more tolerant to water deficit in the root zone, preserved more water in green tissues, maintained chloroplast functions, and had higher accumulation of chlorophyll b and xanthophylls (especially zeaxanthin) than wild type (WT). Drought-induced reductions in the maximum efficiency and the electron transport rate of photosystem II (PSII), as well as the quantum yield of photosynthesis, were less pronounced in transgenic plants overexpressing STANN1 than in the WT. This conferred more efficient non-photochemical energy dissipation in the outer antennae of PSII and probably more efficient protection of reaction centers against photooxidative damage in transgenic plants under drought conditions. Consequently, these plants were able to maintain effective photosynthesis during drought, which resulted in greater productivity than WT plants despite water scarcity. Although the mechanisms underlying this stress protection are not yet clear, annexin-mediated photoprotection is probably linked to protection against light-induced oxidative stress. PMID:26172952

  13. Potato Annexin STANN1 Promotes Drought Tolerance and Mitigates Light Stress in Transgenic Solanum tuberosum L. Plants.

    Science.gov (United States)

    Szalonek, Michal; Sierpien, Barbara; Rymaszewski, Wojciech; Gieczewska, Katarzyna; Garstka, Maciej; Lichocka, Malgorzata; Sass, Laszlo; Paul, Kenny; Vass, Imre; Vankova, Radomira; Dobrev, Peter; Szczesny, Pawel; Marczewski, Waldemar; Krusiewicz, Dominika; Strzelczyk-Zyta, Danuta; Hennig, Jacek; Konopka-Postupolska, Dorota

    2015-01-01

    Annexins are a family of calcium- and membrane-binding proteins that are important for plant tolerance to adverse environmental conditions. Annexins function to counteract oxidative stress, maintain cell redox homeostasis, and enhance drought tolerance. In the present study, an endogenous annexin, STANN1, was overexpressed to determine whether crop yields could be improved in potato (Solanum tuberosum L.) during drought. Nine potential potato annexins were identified and their expression characterized in response to drought treatment. STANN1 mRNA was constitutively expressed at a high level and drought treatment strongly increased transcription levels. Therefore, STANN1 was selected for overexpression analysis. Under drought conditions, transgenic potato plants ectopically expressing STANN1 were more tolerant to water deficit in the root zone, preserved more water in green tissues, maintained chloroplast functions, and had higher accumulation of chlorophyll b and xanthophylls (especially zeaxanthin) than wild type (WT). Drought-induced reductions in the maximum efficiency and the electron transport rate of photosystem II (PSII), as well as the quantum yield of photosynthesis, were less pronounced in transgenic plants overexpressing STANN1 than in the WT. This conferred more efficient non-photochemical energy dissipation in the outer antennae of PSII and probably more efficient protection of reaction centers against photooxidative damage in transgenic plants under drought conditions. Consequently, these plants were able to maintain effective photosynthesis during drought, which resulted in greater productivity than WT plants despite water scarcity. Although the mechanisms underlying this stress protection are not yet clear, annexin-mediated photoprotection is probably linked to protection against light-induced oxidative stress.

  14. Technetium-99m-labeled annexin V imaging for detecting prosthetic joint infection in a rabbit model.

    Science.gov (United States)

    Tang, Cheng; Wang, Feng; Hou, Yanjie; Lu, Shanshan; Tian, Wei; Xu, Yan; Jin, Chengzhe; Wang, Liming

    2015-05-01

    Accurate and timely diagnosis of prosthetic joint infection is essential to initiate early treatment and achieve a favorable outcome. In this study, we used a rabbit model to assess the feasibility of technetium-99m-labeled annexin V for detecting prosthetic joint infection. Right knee arthroplasty was performed on 24 New Zealand rabbits. After surgery, methicillin-susceptible Staphylococcus aureus was intra-articularly injected to create a model of prosthetic joint infection (the infected group, n = 12). Rabbits in the control group were injected with sterile saline (n = 12). Seven and 21 days after surgery, technetium-99m-labeled annexin V imaging was performed in 6 rabbits of each group. Images were acquired 1 and 4 hours after injection of technetium-99m-labeled annexin V (150 MBq). The operated-to-normal-knee activity ratios were calculated for quantitative analysis. Seven days after surgery, increased technetium-99m-labeled annexin V uptake was observed in all cases. However, at 21 days a notable decrease was found in the control group, but not in the infected group. The operated-to-normal-knee activity ratios of the infected group were 1.84 ± 0.29 in the early phase and 2.19 ± 0.34 in the delay phase, both of which were significantly higher than those of the control group (P = 0.03 and P = 0.02). The receiver operator characteristic curve analysis showed that the operated-to-normal-knee activity ratios of the delay phase at 21 days was the best indicator, with an accuracy of 80%. In conclusion, technetium-99m-labeled annexin V imaging could effectively distinguish an infected prosthetic joint from an uninfected prosthetic joint in a rabbit model.

  15. Potato Annexin STANN1 Promotes Drought Tolerance and Mitigates Light Stress in Transgenic Solanum tuberosum L. Plants.

    Directory of Open Access Journals (Sweden)

    Michal Szalonek

    Full Text Available Annexins are a family of calcium- and membrane-binding proteins that are important for plant tolerance to adverse environmental conditions. Annexins function to counteract oxidative stress, maintain cell redox homeostasis, and enhance drought tolerance. In the present study, an endogenous annexin, STANN1, was overexpressed to determine whether crop yields could be improved in potato (Solanum tuberosum L. during drought. Nine potential potato annexins were identified and their expression characterized in response to drought treatment. STANN1 mRNA was constitutively expressed at a high level and drought treatment strongly increased transcription levels. Therefore, STANN1 was selected for overexpression analysis. Under drought conditions, transgenic potato plants ectopically expressing STANN1 were more tolerant to water deficit in the root zone, preserved more water in green tissues, maintained chloroplast functions, and had higher accumulation of chlorophyll b and xanthophylls (especially zeaxanthin than wild type (WT. Drought-induced reductions in the maximum efficiency and the electron transport rate of photosystem II (PSII, as well as the quantum yield of photosynthesis, were less pronounced in transgenic plants overexpressing STANN1 than in the WT. This conferred more efficient non-photochemical energy dissipation in the outer antennae of PSII and probably more efficient protection of reaction centers against photooxidative damage in transgenic plants under drought conditions. Consequently, these plants were able to maintain effective photosynthesis during drought, which resulted in greater productivity than WT plants despite water scarcity. Although the mechanisms underlying this stress protection are not yet clear, annexin-mediated photoprotection is probably linked to protection against light-induced oxidative stress.

  16. Reciprocal regulation of annexin A2 and EGFR with Her-2 in Her-2 negative and herceptin-resistant breast cancer.

    Directory of Open Access Journals (Sweden)

    Praveenkumar K Shetty

    Full Text Available Alternative survival pathways are commonly seen to be upregulated upon inhibition of receptor tyrosine kinases (RTK, including Her-2. It is established that treatment with Herceptin leads to selective overexpression and activation of epidermal growth factor receptor (EGFR and Src which further contributes to oncogenesis in Herceptin resistant and triple negative breast cancer (TNBC patients. Here, we show a co-regulated upregulation in the expression of Annexin A2 (AnxA2, a known substrate of Src and one of the regulators of EGFR receptor endocytosis, in Herceptin resistant and Her-2 negative breast cancer. Immunohistochemical expression analysis revealed a reciprocal regulation between Her-2 and AnxA2 in breast cancer clinical samples as well as in cell lines as confirmed by protein and RNA analysis. The siRNA and Herceptin mediated downregulation/inhibition of Her-2 in Her-2 amplified cells induced AnxA2 expression and membrane translocation. In this study we report a possible involvement of AnxA2 in maintaining constitutively activated EGFR downstream signaling intermediates and hence in cell proliferation, migration and viability. This effect was consistent in Herceptin resistant JIMT-1 cells as well as in Her-2 negative breast cancer. The siRNA mediated AnxA2 downregulation leads to increased apoptosis, decreased cell viability and migration. Our studies further indicate the role of AnxA2 in EGFR-Src membrane bound signaling complex and ligand induced activation of downstream signaling pathways. Targeting this AnxA2 dependent positive regulation of EGFR signaling cascade may be of therapeutic value in Her-2 negative breast cancer.

  17. Dexamethasone-induced and estradiol-induced CREB activation and annexin 1 expression in CCRF-CEM lymphoblastic cells: evidence for the involvement of cAMP and p38 MAPK

    Directory of Open Access Journals (Sweden)

    M. Castro-caldas

    2003-01-01

    Full Text Available Aims: Annexin 1 (ANXA1, a member of the annexin family of calcium-binding and phospholipid-binding proteins, is a key mediator of the anti-inflammatory actions of steroid hormones. We have previously demonstrated that, in the human lymphoblastic CCRF-CEM cell line, both the synthetic glucocorticoid hormone, dexamethasone (Dex, and the estrogen hormone, 17β-estradiol (E2β, induce the synthesis of ANXA1, by a mechanism independent of the activation of their nuclear receptors. Recently, it was reported that the gene coding for ANXA1 contains a cAMP-responsive element (CRE. In this work, we investigated whether Dex and E2β were able to induce the activation of CRE binding proteins (CREB in the CCRF-CEM cells. Moreover, we studied the intracellular signalling pathways involved in CREB activation and ANXA1 synthesis in response to Dex and E2β; namely, the role of cAMP and the p38 mitogen-activated protein kinase (MAPK.

  18. Value of amniotic fluid IL-8 and Annexin A2 in prediction of preterm delivery in preterm labor and preterm premature rupture of membranes.

    Science.gov (United States)

    Jia, Xiaohui

    2014-01-01

    To investigate the clinical significance and value in the prediction of preterm delivery of combined amniotic fluid IL-8 and Annexin A2 levels in preterm premature rupture of membranes (PPROM) and preterm labor (PTL). Sixty pregnant women at < 32 gestational weeks who developed PTL were divided into a PPROM group and a non-PPROM group. Ten normal pregnant women served as a control group. IL-8 and Annexin A2 levels were measured in amniotic fluid samples from each patient. Amniotic fluid IL-8 and Annexin-A2 levels in PTL (PPROM and non-PPROM groups) were significantly higher than those of the controls (p < 0.05). The PPROM group displayed higher amniotic fluid Annexin-A2 levels than did the non-PPROM group, with a statistically significant difference (p < 0.05). The PPROM group showed higher amniotic fluid IL-8 levels than did the non-PPROM group; however, this was statistically insignificant (p = 0.56). Combined detection of amniotic fluid IL-8 and Annexin-A2 in the prediction of preterm delivery within 2 weeks of measurement showed sensitivity of 81.25%, specificity of 88.89% and PPV of 92.86%. Amniotic fluid IL-8 and Annexin-A2 levels are associated with the occurrence of PPROM and PTL. Combined detection of IL-8 and Annexin-A2 levels in identifying preterm delivery within 2 weeks in PTL and PPROM is of possible clinical and predictive value.

  19. Proteins Annexin A2 and PSA in Prostate Cancer Biopsies Do Not Predict Biochemical Failure.

    Science.gov (United States)

    Lamb, David S; Sondhauss, Sven; Dunne, Jonathan C; Woods, Lisa; Delahunt, Brett; Ferguson, Peter; Murray, Judith; Nacey, John N; Denham, James W; Jordan, T William

    2017-12-01

    We previously reported the use of mass spectrometry and western blotting to identify proteins from tumour regions of formalin-fixed paraffin-embedded biopsies from 16 men who presented with apparently localized prostate cancer, and found that annexin A2 (ANXA2) appeared to be a better predictor of subsequent biochemical failure than prostate-specific antigen (PSA). In this follow-up study, ANXA2 and PSA were measured using western blotting of proteins extracted from biopsies from 37 men from a subsequent prostate cancer trial. No significant differences in ANXA2 and PSA levels were observed between men with and without biochemical failure. The statistical effect sizes were small, d=0.116 for ANXA2, and 0.266 for PSA. ANXA2 and PSA proteins measured from biopsy tumour regions are unlikely to be good biomarkers for prediction of the clinical outcome of prostate cancer presenting with apparently localized disease. Copyright© 2017, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

  20. Quantitative Proteomic Profiling the Molecular Signatures of Annexin A5 in Lung Squamous Carcinoma Cells.

    Science.gov (United States)

    Sun, Bing; Bai, Yuxin; Zhang, Liyuan; Gong, Linlin; Qi, Xiaoyu; Li, Huizhen; Wang, Faming; Chi, Xinming; Jiang, Yulin; Shao, Shujuan

    Lung cancer remains the leading cancer killer around the world. It's crucial to identify newer mechanism-based targets to effectively manage lung cancer. Annexin A5 (ANXA5) is a protein kinase C inhibitory protein and calcium dependent phospholipid-binding protein, which may act as an endogenous regulator of various pathophysiological processes. However, its molecular mechanism in lung cancer remains poorly understood. This study was designed to determine the mechanism of ANXA5 in lung cancer with a hope to obtain useful information to provide a new therapeutic target. We used a stable isotope dimethyl labeling based quantitative proteomic method to identify differentially expressed proteins in NSCLC cell lines after ANXA5 transfection. Out of 314 proteins, we identified 26 and 44 proteins that were down- and up-regulated upon ANXA5 modulation, respectively. The IPA analysis revealed that glycolysis and gluconeogenesis were the predominant pathways modulated by ANXA5. Multiple central nodes, namely HSPA5, FN1, PDIA6, ENO1, ALDOA, JUP and KRT6A appeared to occupy regulatory nodes in the protein-protein networks upon ANXA5 modulation. Taken together, ANXA5 appears to have pleotropic effects, as it modulates multiple key signaling pathways, supporting the potential usefulness of ANXA5 as a potential target in lung cancer. This study might provide a new insight into the mechanism of ANXA5 in lung cancer.

  1. Quantitative Proteomic Profiling the Molecular Signatures of Annexin A5 in Lung Squamous Carcinoma Cells.

    Directory of Open Access Journals (Sweden)

    Bing Sun

    Full Text Available Lung cancer remains the leading cancer killer around the world. It's crucial to identify newer mechanism-based targets to effectively manage lung cancer. Annexin A5 (ANXA5 is a protein kinase C inhibitory protein and calcium dependent phospholipid-binding protein, which may act as an endogenous regulator of various pathophysiological processes. However, its molecular mechanism in lung cancer remains poorly understood. This study was designed to determine the mechanism of ANXA5 in lung cancer with a hope to obtain useful information to provide a new therapeutic target. We used a stable isotope dimethyl labeling based quantitative proteomic method to identify differentially expressed proteins in NSCLC cell lines after ANXA5 transfection. Out of 314 proteins, we identified 26 and 44 proteins that were down- and up-regulated upon ANXA5 modulation, respectively. The IPA analysis revealed that glycolysis and gluconeogenesis were the predominant pathways modulated by ANXA5. Multiple central nodes, namely HSPA5, FN1, PDIA6, ENO1, ALDOA, JUP and KRT6A appeared to occupy regulatory nodes in the protein-protein networks upon ANXA5 modulation. Taken together, ANXA5 appears to have pleotropic effects, as it modulates multiple key signaling pathways, supporting the potential usefulness of ANXA5 as a potential target in lung cancer. This study might provide a new insight into the mechanism of ANXA5 in lung cancer.

  2. HYDROXYCHLOROQUINE REDUCES BINDING OF ANTIPHOSPHOLIPID ANTIBODIES TO SYNCYTIOTROPHOBLASTS AND RESTORES ANNEXIN A5 EXPRESSION

    Science.gov (United States)

    Wu, Xiao-Xuan; Guller, Seth; Rand, Jacob H.

    2011-01-01

    Objectives Antibody-mediated disruption of the annexin A5 (AnxA5) anticoagulant shield has been posited to be a thrombogenic mechanism in the antiphospholipid syndrome. We recently showed that the antimalarial drug, hydroxychloroquine, dissociates antiphospholipid immune complexes and restores AnxA5 binding to planar phospholipid bilayer. Using quantitative immunoassays, we demonstrated similar effects on BeWo trophoblasts. We therefore investigated the effects of the drug on localization of AnxA5 in primary cultures of human placental syncytiotrophoblasts (SCTs). Study Laser confocal microscopy with computer-based morphometric analysis was used to localize AnxA5 and antiphospholipid antibodies on SCTs exposed to polyclonal and monoclonal antiphospholipid and control IgGs. Results Hydroxychloroquine reversed the effects of the antiphospholipid antibodies on the SCTs by markedly reducing IgG binding and restoring AnxA5 expression. Conclusions These results provide the first morphologic evidence for this effect of hydroxychloroquine on human placental SCTs and support the possibility of novel treatments that target antiphospholipid antibody binding. PMID:21871597

  3. Prohibitin/annexin 2 interaction regulates fatty acid transport in adipose tissue

    Science.gov (United States)

    Salameh, Ahmad; Daquinag, Alexes C.; Staquicini, Daniela I.; An, Zhiqiang; Pasqualini, Renata; Kolonin, Mikhail G.

    2016-01-01

    We have previously identified prohibitin (PHB) and annexin A2 (ANX2) as proteins interacting on the surface of vascular endothelial cells in white adipose tissue (WAT) of humans and mice. Here, we demonstrate that ANX2 and PHB also interact in adipocytes. Mice lacking ANX2 have normal WAT vascularization, adipogenesis, and glucose metabolism but display WAT hypotrophy due to reduced fatty acid uptake by WAT endothelium and adipocytes. By using cell culture systems in which ANX2/PHB binding is disrupted either genetically or through treatment with a blocking peptide, we show that fatty acid transport efficiency relies on this protein complex. We also provide evidence that the interaction between ANX2 and PHB mediates fatty acid transport from the endothelium into adipocytes. Moreover, we demonstrate that ANX2 and PHB form a complex with the fatty acid transporter CD36. Finally, we show that the colocalization of PHB and CD36 on adipocyte surface is induced by extracellular fatty acids. Together, our results suggest that an unrecognized biochemical interaction between ANX2 and PHB regulates CD36-mediated fatty acid transport in WAT, thus revealing a new potential pathway for intervention in metabolic diseases. PMID:27468426

  4. Molecular cloning and expression analysis of annexin A2 gene in sika deer antler tip

    Directory of Open Access Journals (Sweden)

    Yanling Xia

    2018-04-01

    Full Text Available Objective Molecular cloning and bioinformatics analysis of annexin A2 (ANXA2 gene in sika deer antler tip were conducted. The role of ANXA2 gene in the growth and development of the antler were analyzed initially. Methods The reverse transcriptase polymerase chain reaction (RT-PCR was used to clone the cDNA sequence of the ANXA2 gene from antler tip of sika deer (Cervus Nippon hortulorum and the bioinformatics methods were applied to analyze the amino acid sequence of Anxa2 protein. The mRNA expression levels of the ANXA2 gene in different growth stages were examined by real time reverse transcriptase polymerase chain reaction (real time RT-PCR. Results The nucleotide sequence analysis revealed an open reading frame of 1,020 bp encoding 339 amino acids long protein of calculated molecular weight 38.6 kDa and isoelectric point 6.09. Homologous sequence alignment and phylogenetic analysis indicated that the Anxa2 mature protein of sika deer had the closest genetic distance with Cervus elaphus and Bos mutus. Real time RT-PCR results showed that the gene had differential expression levels in different growth stages, and the expression level of the ANXA2 gene was the highest at metaphase (rapid growing period. Conclusion ANXA2 gene may promote the cell proliferation, and the finding suggested Anxa2 as an important candidate for regulating the growth and development of deer antler.

  5. Role of annexin gene and its regulation during zebrafish caudal fin regeneration.

    Science.gov (United States)

    Saxena, Sandeep; Purushothaman, Sruthi; Meghah, Vuppalapaty; Bhatti, Bhawna; Poruri, Akhila; Meena Lakshmi, Mula G; Sarath Babu, Nukala; Narasimha Murthy, Ch Lakshmi; Mandal, Komal K; Kumar, Arvind; Idris, Mohammed M

    2016-05-01

    The molecular mechanism of epimorphic regeneration is elusive due to its complexity and limitation in mammals. Epigenetic regulatory mechanisms play a crucial role in development and regeneration. This investigation attempted to reveal the role of epigenetic regulatory mechanisms, such as histone H3 and H4 lysine acetylation and methylation during zebrafish caudal fin regeneration. It was intriguing to observe that H3K9,14 acetylation, H4K20 trimethylation, H3K4 trimethylation and H3K9 dimethylation along with their respective regulatory genes, such as GCN5, SETd8b, SETD7/9, and SUV39h1, were differentially regulated in the regenerating fin at various time points of post-amputation. Annexin genes have been associated with regeneration; this study reveals the significant up-regulation of ANXA2a and ANXA2b transcripts and their protein products during the regeneration process. Chromatin immunoprecipitation and PCR analysis of the regulatory regions of the ANXA2a and ANXA2b genes demonstrated the ability to repress two histone methylations, H3K27me3 and H4K20me3, in transcriptional regulation during regeneration. It is hypothesized that this novel insight into the diverse epigenetic mechanisms that play a critical role during the regeneration process may help to strategize the translational efforts, in addition to identifying the molecules involved in vertebrate regeneration. © 2016 by the Wound Healing Society.

  6. First Pregnancy, Somatic and Psychological Status of a 4-Year-Old Child Born following Annexin V TESA Sperm Separation

    Directory of Open Access Journals (Sweden)

    Krzysztof Lukaszuk

    2015-10-01

    Full Text Available Introduction - Sperm DNA integrity is a crucial paternal factor affecting fertilization and pregnancy rates, as well as embryo development. Case - The present case report describes the successful pregnancy after testicular sperm aspiration (TESA combined with intracytoplasmic sperm injection (ICSI (TESA-ICSI in a couple where the male presented high sperm DNA fragmentation. In order to sort damaged sperm presenting DNA fragmentation, magnetic activated cell sorting (MACS with annexin V microbeads (MACS Miltenyi Biotec, Teterow, Germany was used. Conclusion - The authors present the first description of a successful medical case using TESA-ICSI annexin V sperm sorting. Additionally, a follow-up of the child at the age of 4 years old was done.

  7. Insulin receptor substrate 1 expression enhances the sensitivity of 32D cells to chemotherapy-induced cell death

    International Nuclear Information System (INIS)

    Porter, Holly A.; Carey, Gregory B.; Keegan, Achsah D.

    2012-01-01

    The adapters IRS1 and IRS2 link growth factor receptors to downstream signaling pathways that regulate proliferation and survival. Both suppress factor-withdrawal-induced apoptosis and have been implicated in cancer progression. However, recent studies suggest IRS1 and IRS2 mediate differential functions in cancer pathogenesis. IRS1 promoted breast cancer proliferation, while IRS2 promoted metastasis. The role of IRS1 and IRS2 in controlling cell responses to chemotherapy is unknown. To determine the role of IRS1 and IRS2 in the sensitivity of cells to chemotherapy, we treated 32D cells lacking or expressing IRS proteins with various concentrations of chemotherapeutic agents. We found that expression of IRS1, in contrast to IRS2, enhanced the sensitivity of 32D cells to chemotherapy-induced apoptosis. When IRS2 was expressed with IRS1, the cells no longer showed enhanced sensitivity. Expression of IRS1 did not alter the expression of pro- and anti-apoptotic proteins; however, 32D-IRS1 cells expressed higher levels of Annexin A2. In 32D-IRS1 cells, IRS1 and Annexin A2 were both located in cytoplasmic and membrane fractions. We also found that IRS1 coprecipitated with Annexin A2, while IRS2 did not. Decreasing Annexin A2 levels reduced 32D-IRS1 cell sensitivity to chemotherapy. These results suggest IRS1 enhances sensitivity to chemotherapy in part through Annexin A2. -- Highlights: ► IRS1 enhanced the sensitivity of 32D cells to chemotherapy-induced apoptosis. ► This sensitivity is abrogated by the expression of IRS2. ► Expressing IRS1 in 32D cells increased levels of Annexin A2. ► Both IRS1 and Annexin A2 were located in cytoplasmic and membrane fractions. ► Decreasing Annexin A2 in 32D-IRS1 cells abated their sensitivity to chemotherapy.

  8. Evaluation of radiolabelled annexin A5 for scintigraphic imaging of cell processes (necrosis/apoptosis) in cardiovascular diseases

    International Nuclear Information System (INIS)

    Sarda-Mantel, L.

    2007-03-01

    Annexin A5, a 35KDa protein, specifically binds with high affinity to phosphatidylserine (P.S.) which is actively redistributed to the external leaflet of plasmic membranes in apoptotic cells and activated platelets. Annexin A5 radiolabelled with 99m Tc( 99m Tc-ANX5) was developed by Strauss (stanford, Usa) to image apoptosis in vivo: tumours cells apoptosis induced by chemo-radiotherapy, ischemia/reperfusion lesions in animals and patients, graft rejection. Additionally, many in vitro data suggest that annexin A5 also stains necrosis (membrane disruption), which occurs in all types of cell death. This preclinical work aimed to evaluate the potential interest of 99m Tc-ANX5 imaging as a clinical tool in cardiovascular diseases. Four studies performed in rat models of myocardial infarction by coronary ligation and ischemia-reperfusion, and in rat models of subacute and acute (isoproterenol-induced) myocarditis show the ability of 99m Tc-ANX5 to detect in vivo cardio myocytes death by apoptosis and necrosis. Another study demonstrates that 99m Tc-ANX5 is highly accurate to evaluate in vivo the biological activity of parietal thrombus in a rat model of elastase-induced abdominal aortic aneurysm. These results suggest that 99m Tc-ANX5 imaging could be used in patients for non invasive diagnosis, prognostic evaluation in acute myocarditis and in various thrombotic cardiovascular diseases. (author)

  9. 99mTc-HYNIC-Annexin A5 in Oncology: Evaluating Efficacy of Anti-Cancer Therapies

    International Nuclear Information System (INIS)

    Schaper, Frédéric L.W.V.J.; Reutelingsperger, Chris P.

    2013-01-01

    Evaluation of efficacy of anti-cancer therapy is currently performed by anatomical imaging (e.g., MRI, CT). Structural changes, if present, become apparent 1–2 months after start of therapy. Cancer patients thus bear the risk to receive an ineffective treatment, whilst clinical trials take a long time to prove therapy response. Both patient and pharmaceutical industry could therefore profit from an early assessment of efficacy of therapy. Diagnostic methods providing information on a functional level, rather than a structural, could present the solution. Recent technological advances in molecular imaging enable in vivo imaging of biological processes. Since most anti-cancer therapies combat tumors by inducing apoptosis, imaging of apoptosis could offer an early assessment of efficacy of therapy. This review focuses on principles of and clinical experience with molecular imaging of apoptosis using Annexin A5, a widely accepted marker for apoptosis detection in vitro and in vivo in animal models. 99m Tc-HYNIC-Annexin A5 in combination with SPECT has been probed in clinical studies to assess efficacy of chemo- and radiotherapy within 1–4 days after start of therapy. Annexin A5-based functional imaging of apoptosis shows promise to offer a personalized medicine approach, now primarily used in genome-based medicine, applicable to all cancer patients

  10. 99mTc-HYNIC-Annexin A5 in Oncology: Evaluating Efficacy of Anti-Cancer Therapies

    Directory of Open Access Journals (Sweden)

    Chris P. Reutelingsperger

    2013-05-01

    Full Text Available Evaluation of efficacy of anti-cancer therapy is currently performed by anatomical imaging (e.g., MRI, CT. Structural changes, if present, become apparent 1–2 months after start of therapy. Cancer patients thus bear the risk to receive an ineffective treatment, whilst clinical trials take a long time to prove therapy response. Both patient and pharmaceutical industry could therefore profit from an early assessment of efficacy of therapy. Diagnostic methods providing information on a functional level, rather than a structural, could present the solution. Recent technological advances in molecular imaging enable in vivo imaging of biological processes. Since most anti-cancer therapies combat tumors by inducing apoptosis, imaging of apoptosis could offer an early assessment of efficacy of therapy. This review focuses on principles of and clinical experience with molecular imaging of apoptosis using Annexin A5, a widely accepted marker for apoptosis detection in vitro and in vivo in animal models. 99mTc-HYNIC-Annexin A5 in combination with SPECT has been probed in clinical studies to assess efficacy of chemo- and radiotherapy within 1–4 days after start of therapy. Annexin A5-based functional imaging of apoptosis shows promise to offer a personalized medicine approach, now primarily used in genome-based medicine, applicable to all cancer patients.

  11. Preparation, in vitro and in vivo evaluation of 99mTc-Annexin B1: A novel radioligand for apoptosis imaging

    International Nuclear Information System (INIS)

    Luo Quanyong; Zhang Zhiyong; Wang Fang; Lu Hankui; Guo Yuzhi; Zhu Ruisen

    2005-01-01

    To develop a radiopharmaceutical for apoptosis imaging, Annexin B1, a new Ca 2+ -dependent phosphatidylserine (PS)-binding protein, was directly radiolabeled with 99m Tc. This procedure yields up to 96% of radiochemical purity and higher radiolabeling efficiency. The preparation has been found to be sufficiently stable in vitro. Binding assay with human activated platelets indicated that 99m Tc-Annexin B1 retained its PS binding activity. Biodistribution in mice revealed that 99m Tc-Annexin B1 rapidly cleared from the blood and predominantly accumulated in the kidney. The increase in hepatic uptake in anti-Fas antibody treated mice correlated to histologic evidence of fulminant hepatic apoptosis. These data suggest that 99m Tc-Annexin B1 can be used as a novel radiotracer to detect apoptosis in vivo

  12. Evaluation of adenosine preconditioning with 99mTc-His10-annexin V in a porcine model of myocardium ischemia and reperfusion injury: preliminary study

    International Nuclear Information System (INIS)

    Ye Fei; Fang Wei; Wang Feng; Hua Zichun; Wang Zizheng; Yang Xiang

    2011-01-01

    Purpose: The goal of this study was to evaluate the feasibility of 99m Tc-His 10 -annexin V for the detection of acute myocardial cell death and to assess the effect of adenosine preconditioning in a porcine model of myocardium ischemia and reperfusion injury (RI). Materials and Methods: 99m Tc-His 10 -annexin V was prepared by one-step direct labeling, and RCP and radiostability were tested. The binding of 99m Tc-His 10 -annexin V to apoptosis was validated in vitro using camptothecin-induced Jurkat cells. In vivo biodistribution was determined in mice by the dissection method. Ischemia of 20-30 min was induced by balloon occlusion of the epicardial coronary artery of the porcine model (n=14). Adenosine was infused intravenously in six pigs before coronary occlusion. 99m Tc-His 10 -annexin V (n=12) was injected intravenously at 1 h after reperfusion. SPECT/CT was acquired at 3 h postinjection. Myocardial perfusion imaging (MPI) with 99m Tc-MIBI was also performed 1 day after His 10 -annexin V imaging. Cardiac tissues were analyzed postmortem using hematoxylin-and-eosin and TUNEL staining. Caspase-3 activity was measured to confirm the presence of apoptosis. Results: 99m Tc-His 10 -annexin V had a RCP >98% and high stability 2 h after radiolabeling; it could bind to apoptotic cells with high affinity. Biodistribution of 99m Tc-His 10 -annexin V showed a predominant uptake in the kidney and relatively low uptake in the myocardium, liver and gastrointestinal tract; rapid clearance from blood and kidney was observed. In the untreated group, intense uptake of His 10 -annexin V was visualized in the defect which was shown in MPI, whereas in the adenosine group a mild uptake of 99m Tc-His 10 -annexin was found in the risk area which showed no defects in the 99m Tc-MIBI image. TUNEL staining and activated caspase-3 confirmed the ongoing apoptosis in RI. Adenosine preconditioning significantly diminished the level of apoptosis. Uptake of His 10 -annexin V in RI correlated

  13. {sup 99m}Tc Hynic-rh-Annexin V scintigraphy for in vivo imaging of apoptosis in patients with head and neck cancer treated with chemoradiotherapy

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    Hoebers, Frank J.P.; Bois, Josien de; Herk, Marcel van; Rasch, Coen R.N.; Verheij, Marcel [The Netherlands Cancer Institute/Antoni van Leeuwenhoek Hospital, Department of Radiotherapy, Amsterdam (Netherlands); Kartachova, Marina; Valdes Olmos, Renato A. [The Netherlands Cancer Institute/Antoni van Leeuwenhoek Hospital, Department of Nuclear Medicine, Amsterdam (Netherlands); Brekel, Michiel W.M. van den [The Netherlands Cancer Institute/Antoni van Leeuwenhoek Hospital and Academic Medical Center, Department of Head and Neck Oncology and Surgery, Amsterdam (Netherlands); Tinteren, Harm van [The Netherlands Cancer Institute/Antoni van Leeuwenhoek Hospital, Biometrics Department, Amsterdam (Netherlands)

    2008-03-15

    The purpose of this study was to determine the value of {sup 99m}Tc Hynic-rh-Annexin-V-Scintigraphy (TAVS), a non-invasive in vivo technique to demonstrate apoptosis in patients with head and neck squamous cell carcinoma. TAVS were performed before and within 48 h after the first course of cisplatin-based chemoradiation. Radiation dose given to the tumour at the time of post-treatment TAVS was 6-8 Gy. Single-photon emission tomography data were co-registered to planning CT scan. Complete sets of these data were available for 13 patients. The radiation dose at post-treatment TAVS was calculated for several regions of interest (ROI): primary tumour, involved lymph nodes and salivary glands. Annexin uptake was determined in each ROI, and the difference between post-treatment and baseline TAVS represented the absolute Annexin uptake: Delta uptake ({delta}U). In 24 of 26 parotid glands, treatment-induced Annexin uptake was observed. Mean {delta}U was significantly correlated with the mean radiation dose given to the parotid glands (r = 0.59, p = 0.002): Glands that received higher doses showed more Annexin uptake. {delta}U in primary tumour and pathological lymph nodes showed large inter-patient differences. A high correlation was observed on an inter-patient level (r = 0.71, p = 0.006) between the maximum {delta}U in primary tumour and in the lymph nodes. Within the dose range of 0-8 Gy, Annexin-V-scintigraphy showed a radiation-dose-dependent uptake in parotid glands, indicative of early apoptosis during treatment. The inter-individual spread in Annexin uptake in primary tumours could not be related to differences in dose or tumour volume, but the Annexin uptake in tumour and lymph nodes were closely correlated. This effect might represent a tumour-specific apoptotic response. (orig.)

  14. Low Annexin A1 expression predicts benefit from induction chemotherapy in oral cancer patients with moderate or poor pathologic differentiation grade.

    Science.gov (United States)

    Zhu, Dong-wang; Liu, Ying; Yang, Xiao; Yang, Cheng-zhe; Ma, Jie; Yang, Xi; Qiao, Jin-ke; Wang, Li-zhen; Li, Jiang; Zhang, Chen-ping; Zhang, Zhi-yuan; Zhong, Lai-ping

    2013-06-21

    The benefit of induction chemotherapy in locally advanced oral squamous cell carcinoma (OSCC) remains to be clearly defined. Induction chemotherapy is likely to be effective for biologically distinct subgroups of patients and biomarker development might lead to identification of the patients whose tumors are to respond to a particular treatment. Annexin A1 may serve as a biomarker for responsiveness to induction chemotherapy. The aim of this study was to investigate Annexin A1 expression in pre-treatment biopsies from a cohort of OSCC patients treated with surgery and post-operative radiotherapy or docetaxel, cisplatin and 5-fluorouracil (TPF) induction chemotherapy followed by surgery and post-operative radiotherapy. Furthermore we sought to assess the utility of Annexin A1 as a prognostic or predictive biomarker. Immunohistochemical staining for Annexin A1 was performed in pre-treatment biopsies from 232 of 256 clinical stage III/IVA OSCC patients. Annexin A1 index was estimated as the proportion of tumor cells (low and high, benefited from TPF induction chemotherapy as measured by distant metastasis-free survival (P=0.048, HR=0.373) as well as overall survival (P=0.078, HR=0.410). Annexin A1 can be used as a prognostic biomarker for OSCC. Patients with moderate/poorly differentiated OSCC and low Annexin A1 expression can benefit from the addition of TPF induction chemotherapy to surgery and post-operative radiotherapy. Annexin A1 expression can potentially be used as a predictive biomarker to select OSCC patients with moderate/poorly differentiated tumor who may benefit from TPF induction chemotherapy.

  15. The Role of (99m)Tc-Annexin V Apoptosis Scintigraphy in Visualizing Early Stage Glucocorticoid-Induced Femoral Head Osteonecrosis in the Rabbit.

    Science.gov (United States)

    Wang, Xiaolong; Liu, Yu; Wang, Xuemei; Liu, Rui; Li, Jianbo; Zhang, Guoliang; Li, Qiang; Wang, Lei; Bai, Zhigang; Zhao, Jianmin

    2016-01-01

    To validate the ability of (99m)Tc-Annexin V to visualize early stage of glucocorticoid-induced femoral head necrosis by comparing with (99m)Tc-MDP bone scanning. Femoral head necrosis was induced in adult New Zealand white rabbits by intramuscular injection of methylprednisolone. (99m)Tc-Annexin scintigraphy and (99m)Tc-MDP scans were performed before and 5, 6, and 8 weeks after methylprednisolone administration. Rabbits were sacrificed at various time points and conducted for TUNEL and H&E staining. All methylprednisolone treated animals developed femoral head necrosis; at 8 weeks postinjection, destruction of bone structure was evident in H&E staining, and apoptosis was confirmed by the TUNEL assay. This was matched by (99m)Tc-Annexin V images, which showed a significant increase in signal over baseline. Serial (99m)Tc-Annexin V scans revealed that increased (99m)Tc-Annexin V uptake could be observed in 5 weeks. In contrast, there was no effect on (99m)Tc-MDP signal until 8 weeks. The TUNEL assay revealed that bone cell apoptosis occurred at 5 weeks. (99m)Tc-Annexin V is superior to (99m)Tc-MDP for the early detection of glucocorticoid-induced femoral head necrosis in the rabbit and may be a better strategy for the early detection of glucocorticoid-induced femoral head necrosis in patients.

  16. CD147 regulates cancer migration via direct interaction with Annexin A2 and DOCK3-β-catenin-WAVE2 signaling.

    Science.gov (United States)

    Cui, Hong-Yong; Wang, Shi-Jie; Miao, Ji-Yu; Fu, Zhi-Guang; Feng, Fei; Wu, Jiao; Yang, Xiang-Min; Chen, Zhi-Nan; Jiang, Jian-Li

    2016-02-02

    The acquisition of inappropriate migratory feature is crucial for tumor metastasis. It has been suggested that CD147 and Annexin A2 are involved in regulating tumor cell movement, while the regulatory mechanisms are far from clear. In this study, we demonstrated that CD147 physically interacted with the N-terminal domain of Annexin A2 and decreased Annexin A2 phosphorylation on tyrosine 23. In vitro kinase assay showed that the I domain of CD147 was indispensable for CD147-mediated downregulation of Annexin A2 phosphorylation by Src. Furthermore, we determined that p-Annexin A2 promoted the expression of dedicator of cytokinesis 3 (DOCK3) and DOCK3 blocked β-catenin nuclear translocation, resulting in inhibition of β-catenin signaling. In addition, DOCK3 inhibited lamellipodium dynamics and tumor cell movement. Also, we found that β-catenin signaling increased WAVE2 expression. Therefore, DOCK3 was characterized as a negative regulator of WAVE2 expression via inhibiting β-catenin signaling. Our study provides the first evidence that CD147 promotes tumor cell movement and metastasis via direct interaction with Annexin A2 and DOCK3-β-catenin-WAVE2 signaling axis.

  17. Proresolving protein Annexin A1: The role in type 2 diabetes mellitus and obesity.

    Science.gov (United States)

    Pietrani, Nathalia T; Ferreira, Cláudia N; Rodrigues, Kathryna F; Perucci, Luiza O; Carneiro, Fernanda S; Bosco, Adriana A; Oliveira, Marina C; Pereira, Solange S; Teixeira, Antônio L; Alvarez-Leite, Jacqueline I; Ferreira, Adaliene V; Sousa, Lirlândia P; Gomes, Karina B

    2018-04-17

    Annexin A1 (AnxA1) is a protein involved in inflammation resolution that might be altered in obesity-associated type 2 diabetes mellitus (DM), which is a chronic inflammatory disease. The aim of this study was to evaluate AnxA1 serum levels in individuals with and without DM stratified according to the body mass index (BMI), and the dynamic of AnxA1 expression in adipose tissue from humans with obesity and non-obesity. Serum samples were obtained from 41 patients with DM (lean, overweight and obese) and 40 controls, and adipose tissue samples were obtained from 16 individuals with obesity (with or without DM), and 15 controls. DM patients showed similar AnxA1 serum levels when compared to controls. However, when the individuals were stratified according to BMI, AnxA1 levels were higher in individuals with obesity than lean or overweight, and in overweight compared to lean individuals. Moreover, AnxA1 was correlated positively with IL-6 levels. AnxA1 levels were also positively correlated with BMI, waist circumference and waist-to-hip ratio. Furthermore, higher levels of cleaved AnxA1 were observed in adipose tissue from individuals with obesity, independently of DM status. Enhanced levels of AnxA1 in serum of individuals with obesity suggest an attempt to counter-regulate the systemic inflammation process in this disease. However, the higher levels of cleaved AnxA1 in the adipose tissue of individuals with obesity could compromise its anti-inflammatory and proresolving actions, locally. Considering our data, AnxA1 cleavage in the adipose tissue, despite increased serum levels of this protein, and consequently the failure in inflammation resolution, suggests an important pathophysiological mechanism involved in inflammatory status observed in obesity. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

  18. Clinical and prognostic role of annexin A2 in adamantinomatous craniopharyngioma.

    Science.gov (United States)

    Wang, Yuelong; Deng, Jiaojiao; Guo, Gang; Tong, Aiping; Peng, Xirui; Chen, Haifeng; Xu, Jianguo; Liu, Yi; You, Chao; Zhou, Liangxue

    2017-01-01

    Annexin A2 (AnxA2) is a highly conserved Ca2 + -regulated membrane binding protein, which affects cell mobility and tumor progression. Adamantinomatous craniopharyngioma (AdaCP) are a kind of epithelial tumors of the sellar region with high tendency to recur. Robust biomarkers are required to predict tumor behavior and to establish follow-up individualized treatment approaches. In this study, we firstly compared four surgical AdaCP samples with normal brain by two-dimensional gel electrophoresis (2DE) proteomic analysis. Potential prognostic biomarkers were further validated in a large cohort of 65 AdaCPs by immunohistochemistry. The effects of AnxA2 on AdaCP cells proliferation and migration were analyzed in vitro with isolated primary AdaCP cells as well as SV40T-immortalized cells. Finally, the gefitinib sensitivity of AdaCPs with differentially expressed AnxA2 and the potential molecular mechanisms were examined by flow cytometric analysis, Real-time PCR and immunoblot assays. Proteomic analysis indicated that AnxA2 was the protein spot with the most elevated expression in AdaCP samples. Immunohistochemistry assays indicated the expression level of AnxA2 was significantly higher in recurrent AdaCPs compared with primary ones. Moreover, AnxA2 + AdaCP cells exhibited enhanced proliferation and migration ability compared with AnxA2 - AdaCP cells in vitro. Further, we show that AnxA2 + AdaCP cells exhibited elevated expression of EGFR and downstream p-AKT (S308) and p-AKT (S473), and were more sensitive to tyrosine kinase inhibitor gefitinib. Our data suggest that AnxA2 may serve as a promising biomarker for AdaCP progression, recurrence and drug susceptibility. Our data support potential clinical implications for the follow-up treatment of AdaCP patients with high AnxA2 expression.

  19. HPV16 E6 regulates annexin 1 (ANXA1) protein expression in cervical carcinoma cell lines

    Energy Technology Data Exchange (ETDEWEB)

    Calmon, Marilia Freitas [Department of Biology, Institute of Bioscience, Language and Exact Science, São Paulo State University, São Jose do Rio Preto (Brazil); Sichero, Laura [Molecular Biology Laboratory, Centre for Translational Research in Oncology, Instituto do Câncer do Estado de São Paulo (ICESP), São Paulo (Brazil); Boccardo, Enrique [Department of Microbiology, Institute of Biomedical Sciences, University of São Paulo., São Paulo (Brazil); Villa, Luisa Lina [Department of Radiology and Oncology, Faculdade de Medicina, Universidade de São Paulo, São Paulo (Brazil); Rahal, Paula, E-mail: rahalp@yahoo.com.br [Department of Biology, Institute of Bioscience, Language and Exact Science, São Paulo State University, São Jose do Rio Preto (Brazil)

    2016-09-15

    Annexin 1 (ANXA1) is a substrate for E6AP mediated ubiquitylation. It has been hypothesized that HPV 16 E6 protein redirects E6AP away from ANXA1, increasing its stability and possibly contributing to viral pathogenesis. We analyzed ANXA1 expression in HPV-positive and negative cervical carcinoma-derived cells, in cells expressing HPV-16 oncogenes and in cells transduced with shRNA targeting E6AP. We observed that ANXA1 protein expression increased in HPV-16-positive tumor cells, in keratinocytes expressing HPV-16 E6wt (wild-type) or E6/E7 and C33 cells expressing HPV-16 E6wt. ANXA1 protein expression decreased in cells transfected with E6 Dicer-substrate RNAs (DsiRNA) and C33 cells cotransduced with HPV-16 E6wt and E6AP shRNA. Moreover, colony number and proliferation rate decreased in HPV16-positive cells transduced with ANXA1 shRNA. We observed that in cells infected with HPV16, the E6 binds to E6AP to degrade p53 and upregulate ANXA1. We suggest that ANXA1 may play a role in HPV-mediated carcinogenesis. - Highlights: • ANXA1 upregulation requires the presence of E6 and E6AP and is dependent on E6 integrity. • E6 binds to E6AP to degrade p53 and upregulate ANXA1 in cells infected with HPV16. • ANXA1 plays a role in cell proliferation in HPV-positive cervical cells.

  20. HPV16 E6 regulates annexin 1 (ANXA1) protein expression in cervical carcinoma cell lines

    International Nuclear Information System (INIS)

    Calmon, Marilia Freitas; Sichero, Laura; Boccardo, Enrique; Villa, Luisa Lina; Rahal, Paula

    2016-01-01

    Annexin 1 (ANXA1) is a substrate for E6AP mediated ubiquitylation. It has been hypothesized that HPV 16 E6 protein redirects E6AP away from ANXA1, increasing its stability and possibly contributing to viral pathogenesis. We analyzed ANXA1 expression in HPV-positive and negative cervical carcinoma-derived cells, in cells expressing HPV-16 oncogenes and in cells transduced with shRNA targeting E6AP. We observed that ANXA1 protein expression increased in HPV-16-positive tumor cells, in keratinocytes expressing HPV-16 E6wt (wild-type) or E6/E7 and C33 cells expressing HPV-16 E6wt. ANXA1 protein expression decreased in cells transfected with E6 Dicer-substrate RNAs (DsiRNA) and C33 cells cotransduced with HPV-16 E6wt and E6AP shRNA. Moreover, colony number and proliferation rate decreased in HPV16-positive cells transduced with ANXA1 shRNA. We observed that in cells infected with HPV16, the E6 binds to E6AP to degrade p53 and upregulate ANXA1. We suggest that ANXA1 may play a role in HPV-mediated carcinogenesis. - Highlights: • ANXA1 upregulation requires the presence of E6 and E6AP and is dependent on E6 integrity. • E6 binds to E6AP to degrade p53 and upregulate ANXA1 in cells infected with HPV16. • ANXA1 plays a role in cell proliferation in HPV-positive cervical cells.

  1. Endogenous annexin A1 counter-regulates bleomycin-induced lung fibrosis

    Directory of Open Access Journals (Sweden)

    Flower Roderick J

    2011-10-01

    Full Text Available Abstract Background The balancing functions of pro/anti-inflammatory mediators of the complex innate responses have been investigated in a variety of experimental inflammatory settings. Annexin-A1 (AnxA1 is one mediator of endogenous anti-inflammation, affording regulation of leukocyte trafficking and activation in many contexts, yet its role in lung pathologies has been scarcely investigated, despite being highly expressed in lung cells. Here we have applied the bleomycin lung fibrosis model to AnxA1 null mice over a 21-day time-course, to monitor potential impact of this mediator on the control of the inflammatory and fibrotic phases. Results Analyses in wild-type mice revealed strict spatial and temporal regulation of the Anxa1 gene, e.g. up-regulation in epithelial cells and infiltrated granulocytes at day 7, followed by augmented protein levels in alveolar macrophages by day 21. Absence of AnxA1 caused increases in: i the degree of inflammation at day 7; and ii indexes of fibrosis (assessed by deposition of hydroxyproline in the lung at day 7 and 21. These alterations in AnxA1 null mice were paralleled by augmented TGF-β1, IFN-γ and TNF-α generation compared to wild-type mice. Finally, treatment of wild type animals with an AnxA1 peptido-mimetic, given prophylactically (from day 0 to 21 or therapeutically (from day 14 onward, ameliorated both signs of inflammation and fibrosis. Conclusion Collectively these data reveal a pathophysiological relevance for endogenous AnxA1 in lung inflammation and, more importantly, fibrosis, and may open new insights for the pharmacological treatment of lung fibrosis.

  2. Mast cell heterogeneity and anti-inflammatory annexin A1 expression in leprosy skin lesions.

    Science.gov (United States)

    Costa, Maurício B; Mimura, Kallyne K O; Freitas, Aline A; Hungria, Emerith M; Sousa, Ana Lúcia O M; Oliani, Sonia M; Stefani, Mariane M A

    2018-03-29

    Mast cells (MCs) have important immunoregulatory roles in skin inflammation. Annexin A1 (ANXA1) is an endogenous anti-inflammatory protein that can be expressed by mast cells, neutrophils, eosinophils, monocytes, epithelial and T cells. This study investigated MCs heterogeneity and ANXA1 expression in human dermatoses with special emphasis in leprosy. Sixty one skin biopsies from 2 groups were investigated: 40 newly diagnosed untreated leprosy patients (18 reaction-free, 11 type 1 reaction/T1R, 11 type 2 reaction/T2R); 21 patients with other dermatoses. Tryptase/try+ and chymase/chy + phenotypic markers and toluidine blue stained intact/degranulated MC counts/mm 2 were evaluated. Try + /chy + MCs and ANXA1 were identified by streptavidin-biotin-peroxidase immunostaining and density was reported. In leprosy, degranulated MCs outnumbered intact ones regardless of the leprosy form (from tuberculoid/TT to lepromatous/LL), leprosy reactions (reactional/reaction-free) and type of reaction (T1R/T2R). Compared to other dermatoses, leprosy skin lesions showed lower numbers of degranulated and intact MCs. Try + MCs outnumbered chy + in leprosy lesions (reaction-free/reactional, particularly in T2R), but not in other dermatoses. Compared to other dermatoses, ANXA1 expression, which is also expressed in mast cells, was higher in the epidermis of leprosy skin lesions, independently of reactional episode. In leprosy, higher MC degranulation and differential expression of try + /chy + subsets independent of leprosy type and reaction suggest that the Mycobacterium leprae infection itself dictates the inflammatory MCs activation in skin lesions. Higher expression of ANXA1 in leprosy suggests its potential anti-inflammatory role to maintain homeostasis preventing tissue and nerve damage. Copyright © 2018 Elsevier Ltd. All rights reserved.

  3. {sup 99m}Tc-HYNIC-annexin V SPECT imaging of acute stroke and its response to neuroprotective therapy with anti-Fas ligand antibody

    Energy Technology Data Exchange (ETDEWEB)

    Blankenberg, Francis G.; Kalinyak, Judy; Cheng, Danye; Goris, Michael L. [Stanford University Hospital, Division of Pediatric Radiology/Department of Radiology, Palo Alto, CA (United States); Liu, Liping; Koike, Maya; Yenari, Midori Anne [University of California San Francisco and San Francisco Veterans Affairs Medical Center, Department of Neurology, San Francisco, CA (United States); Green, Allan; Vanderheyden, Jean-Luc [Theseus Imaging Corporation, Boston, MA (United States); Tong, David C. [Stanford University Hospital, Neurology and Neurological Sciences, Stanford, CA (United States)

    2006-05-15

    The first aim of the study was to determine whether {sup 99m}Tc-HYNIC-annexin V, a marker of cellular stress and apoptosis, can detect ischemic injury in patients with acute stroke. Secondly, we wished to test radiolabeled annexin's ability to monitor therapy in a rodent model of focal ischemic injury. SPECT imaging of patients was performed between 1 and 2 h after intravenous injection of 30 mCi (1,110 MBq) of tracer. Eight MFL4 (anti-FasL) antibody-treated (400 {mu}g i.p. days 0 and 3) and 21 control adult male Sprague-Dawley rats underwent small animal SPECT imaging with 5-10 mCi (185-370 MBq) of tracer, 1 and 6 days after a 2-h intraluminal thread occlusion of the left middle cerebral artery. Two patients with acute stroke had regions of multifocal annexin uptake that correlated with sites of restricted diffusion on MRI. Anti-FasL antibody treatment significantly reduced annexin uptake by 92% with a 60% decrease in the number of caspase-8 staining (apoptotic) neurons on day 1. On day 6, treated animals had an 80% reduction in tracer uptake with a 75% decrease in infarct size as compared with controls. Annexin uptake in controls and treated animals (day 6) linearly correlated with infarct size (r {sup 2}=0.603, p=0.0036) and the number of TUNEL-positive (apoptotic) nuclei (r {sup 2}=0.728, p=0.00084). Annexin imaging shows foci of increased uptake at sites of ischemic injury in patients with acute stroke. Annexin imaging can assess the effects of therapy for ischemic cerebral injury in rats, suggesting its potential as a non-invasive indicator of drug efficacy in future clinical trials. (orig.)

  4. 99mTc-HYNIC-annexin V SPECT imaging of acute stroke and its response to neuroprotective therapy with anti-Fas ligand antibody

    International Nuclear Information System (INIS)

    Blankenberg, Francis G.; Kalinyak, Judy; Cheng, Danye; Goris, Michael L.; Liu, Liping; Koike, Maya; Yenari, Midori Anne; Green, Allan; Vanderheyden, Jean-Luc; Tong, David C.

    2006-01-01

    The first aim of the study was to determine whether 99m Tc-HYNIC-annexin V, a marker of cellular stress and apoptosis, can detect ischemic injury in patients with acute stroke. Secondly, we wished to test radiolabeled annexin's ability to monitor therapy in a rodent model of focal ischemic injury. SPECT imaging of patients was performed between 1 and 2 h after intravenous injection of 30 mCi (1,110 MBq) of tracer. Eight MFL4 (anti-FasL) antibody-treated (400 μg i.p. days 0 and 3) and 21 control adult male Sprague-Dawley rats underwent small animal SPECT imaging with 5-10 mCi (185-370 MBq) of tracer, 1 and 6 days after a 2-h intraluminal thread occlusion of the left middle cerebral artery. Two patients with acute stroke had regions of multifocal annexin uptake that correlated with sites of restricted diffusion on MRI. Anti-FasL antibody treatment significantly reduced annexin uptake by 92% with a 60% decrease in the number of caspase-8 staining (apoptotic) neurons on day 1. On day 6, treated animals had an 80% reduction in tracer uptake with a 75% decrease in infarct size as compared with controls. Annexin uptake in controls and treated animals (day 6) linearly correlated with infarct size (r 2 =0.603, p=0.0036) and the number of TUNEL-positive (apoptotic) nuclei (r 2 =0.728, p=0.00084). Annexin imaging shows foci of increased uptake at sites of ischemic injury in patients with acute stroke. Annexin imaging can assess the effects of therapy for ischemic cerebral injury in rats, suggesting its potential as a non-invasive indicator of drug efficacy in future clinical trials. (orig.)

  5. Inhibition of Langerhans cell maturation by human papillomavirus type 16: a novel role for the annexin A2 heterotetramer in immune suppression.

    Science.gov (United States)

    Woodham, Andrew W; Raff, Adam B; Raff, Laura M; Da Silva, Diane M; Yan, Lisa; Skeate, Joseph G; Wong, Michael K; Lin, Yvonne G; Kast, W Martin

    2014-05-15

    High-risk human papillomaviruses (HPVs) are sexually transmitted viruses causally associated with several cancers. During its natural life cycle, HPV16, the most common high-risk genotype, infects the epithelial basal cells in a process facilitated through a recently identified receptor, the annexin A2 heterotetramer (A2t). During infection, HPV16 also interacts with Langerhans cells (LC), the APC of the epithelium, inducing immune suppression, which is mediated by the HPV16 L2 minor capsid protein. Despite the importance of these virus-immune cell interactions, the specific mechanisms of HPV16 entry into LC and HPV16-induced immune suppression remain undefined. An N-terminal peptide of HPV16 L2 (aa 108-126) has been shown to specifically interact with A2t. In this study, we show that incubation of human LC with this peptide blocks binding of HPV16. Inhibiting this interaction with an A2t ligand or by small interfering RNA downregulation of A2t significantly decreases HPV16 internalization into LC in an L2-dependent manner. A2t is associated with suppression of LC maturation as demonstrated through attenuated secretion of Th1-associated cytokines and decreased surface expression of MHC class II on LC exposed to A2t. Conversely, small molecule inhibition of A2t prevents HPV16-induced suppression of LC immune function as indicated by significantly increased secretion of inflammatory cytokines and surface expression of CD86 in HPV16 treated LC pre-exposed to A2t inhibitors. These results demonstrate that HPV16 suppresses LC maturation through an interaction with A2t, revealing a novel role for this protein.

  6. Inhibition of Langerhans cell maturation by human papillomavirus type 16: a novel role for the annexin A2 heterotetramer in immune suppression1

    Science.gov (United States)

    Woodham, Andrew W.; Raff, Adam B.; Raff, Laura M.; Da Silva, Diane M.; Yan, Lisa; Skeate, Joseph G.; Wong, Michael K.; Lin, Yvonne G.; Kast, W. Martin

    2014-01-01

    High-risk human papillomaviruses (HPV) are sexually transmitted viruses causally associated with several cancers. During its natural life cycle, HPV16, the most common high-risk genotype, infects the epithelial basal cellsin a process facilitated through a recently identified receptor, the annexin A2 heterotetramer (A2t). During infection, HPV16 also interacts with Langerhans cells (LC), the antigen presenting cells of the epithelium, inducing immune suppression, which is mediated by the HPV16 L2 minor capsid protein. Despite the importance of these virus-immune cell interactions, the specific mechanisms of HPV16 entry into LC and HPV16-induced immune suppression remain undefined. An N-terminal peptide of HPV16 L2 (aa 108-126) has been shown to specifically interact with A2t. Here, we show that incubation of human LC with this peptide blocks binding of HPV16. Inhibiting this interaction with an A2t ligand or by siRNA downregulation of A2t, significantly decreases HPV16 internalization into LC in an L2-dependent manner. A2t is associated with suppression of LC maturation as demonstrated through attenuated secretion of Th1-associated cytokines and decreased surface expression of MHC II on LC exposed to A2t. Conversely, small molecule inhibition of A2t prevents HPV16-induced suppression of LC immune function as indicated by significantly increased secretion of inflammatory cytokines and surface expression of CD86 in HPV16 treated LC pre-exposed to A2t inhibitors. These results demonstrate that HPV16 suppresses LC maturation through an interaction with A2t, revealing a novel role for this protein. PMID:24719459

  7. Annexin A5 binds to lipopolysaccharide and reduces its endotoxin activity.

    Science.gov (United States)

    Rand, Jacob H; Wu, Xiao-Xuan; Lin, Elaine Y; Griffel, Alexander; Gialanella, Philip; McKitrick, John C

    2012-01-01

    Annexin A5 (AnxA5) has a high affinity for phosphatidylserine. The protein is widely used to detect apoptotic cells because phosphatidylserine, a phospholipid that is normally present in the inner leaflets of cytoplasmic membranes, becomes translocated to the outer leaflets during programmed cell death. Here we report the novel observation that AnxA5 binds to Gram-negative bacteria via the lipid A domain of lipopolysaccharide (LPS). Binding of AnxA5 to bacteria was measured quantitatively, confirmed by fluorescence microscopy, and found to be inhibited by antibodies against lipid A. AnxA5 also bound to purified dot-blotted LPS and lipid A. Through ellipsometry, we found that the binding of AnxA5 to purified LPS was calcium dependent and rapid and showed a high affinity-characteristics similar to those of AnxA5 binding to phosphatidylserine. Initial functional studies indicated that AnxA5 can affect LPS activities. AnxA5 inhibited LPS-mediated gelation in the Limulus amebocyte lysate assay. Incubation of LPS with the protein reduced the quantity of tumor necrosis factor alpha (TNF-α) released by cultured monocytes compared to that released upon incubation with LPS alone. Initial in vivo experiments indicated that injection of mice with LPS preincubated with AnxA5 produced serum TNF-α levels lower than those seen after injection of LPS alone. These data demonstrate that AnxA5 binds to LPS and open paths to investigation of the potential biological and therapeutic implications of this interaction. AnxA5 is highly expressed in cells that have a barrier function-including, among others, vascular endothelium, placental trophoblasts, and epithelial cells lining bile ducts, renal tubules, mammary ducts, and nasal epithelium. The protein has been well characterized for its binding to phospholipid bilayers that contain phosphatidylserine. This report of a previously unrecognized activity of AnxA5 opens the door to investigation of the possibility that this binding may have

  8. Apoptotic abscess imaging with {sup 99m}Tc-HYNIC-rh-Annexin-V

    Energy Technology Data Exchange (ETDEWEB)

    Penn, David L.; Kim, Christopher; Zhang, Kaijun; Mukherjee, Archana; Devakumar, Devadhas; Jungkind, Donald [Department of Radiology, Thomas Jefferson University, Philadelphia, PA 19107 (United States); Thakur, Mathew L. [Department of Radiology, Thomas Jefferson University, Philadelphia, PA 19107 (United States)], E-mail: mathew.thakur@jefferson.edu

    2010-01-15

    Abscess formation causes systemic and localized up-regulation of neutrophil [polymorphonuclear leukocytes (PMNs)] signaling pathways. In the abscess, following bacterial ingestion or PMN activation by inflammatory mediators, PMN apoptosis is elevated and leads to the externalization of phosphatidylserine. Annexin-V (AnxV) has been shown to have high affinity to externalized phosphatidylserine. We hypothesized that {sup 99m}Tc-AnxV will target high densities of apoptotic PMNs and image abscesses. AnxV, conjugated with hydrazinenicaotinamide (HYNIC), was labeled with reduced {sup 99m}TcO{sub 4}{sup -} and its purity was determined by instant thin-layer chromatography. Apoptosis was induced in isolated human PMNs by incubation in 2% saline for 17 and 22 h at 37 deg. C. PMNs were then incubated with {sup 99m}Tc-HYNIC-AnxV and associated {sup 99m}Tc was determined. Abscesses were induced in mice by intramuscular injection of bacteria or turpentine. Following intravenous administration of {sup 99m}Tc-HYNIC-AnxV, mice were imaged and tissue distribution studied at 4 and 24 h. Radiochemical purity of {sup 99m}Tc-HYNIC-AnxV was 84.9{+-}8.11%. At 17 h, {sup 99m}Tc-HYNIC-AnxV bound to apoptotic PMNs was 71.6{+-}0.01% and 48.6{+-}0.01% for experimental and control cells, respectively (P=.002). At 22 h, experimental cells retained 74.9{+-}0.02% and control cells retained 47.2{+-}0.02% (P=.005). {sup 99m}Tc-HYNIC-AnxV associated with bacterial abscesses was 1.25{+-}0.09 and 3.75{+-}0.83 percent injected dose per gram (%ID/g) at 4 and 24 h compared to turpentine abscesses which was 1.02{+-}0.16 and 0.72{+-}0.17 %ID/g at 4 (P{<=}.05) and 24 h (P{<=}.01). {sup 99m}Tc-HYNIC-AnxV represents a minimally invasive and promising agent to image and potentially distinguish between infectious and inflammatory abscesses.

  9. New markers of pancreatic cancer identified through differential gene expression analyses: claudin 18 and annexin A8.

    Science.gov (United States)

    Karanjawala, Zarir E; Illei, Peter B; Ashfaq, Raheela; Infante, Jeffrey R; Murphy, Kathleen; Pandey, Akhilesh; Schulick, Richard; Winter, Jordan; Sharma, Rajni; Maitra, Anirban; Goggins, Michael; Hruban, Ralph H

    2008-02-01

    New markers to distinguish benign reactive glands from infiltrating ductal adenocarcinoma of the pancreas are needed. The gene expression patterns of 24 surgically resected primary infiltrating ductal adenocarcinomas of the pancreas were compared with 18 non-neoplastic samples using the Affymetrix U133 Plus 2.0 Arrays and the Gene Logic GeneExpress Software System. Gene fragments from 4 genes (annexin A8, claudin 18, CXCL5, and S100 A2) were selected from the fragments found to be highly expressed in infiltrating adenocarcinomas when compared with normal tissues. The protein expression of these genes was examined using immunohistochemical labeling of tissue microarrays. Claudin 18 labeled infiltrating carcinomas in a membranous pattern. When compared with normal and reactive ducts, claudin 18 was overexpressed, at least focally, in 159 of 166 evaluable carcinomas (96%). Strong and diffuse claudin 18 overexpression was most often seen in well-differentiated carcinomas (P=0.02). Claudin 18 was overexpressed in 51 of 52 cases (98%) of pancreatic intraepithelial neoplasia. Annexin A8 was at least focally overexpressed in 149 of 154 evaluable infiltrating carcinomas (97%). S100 A2 was at least focally overexpressed in 118 of 154 evaluable infiltrating carcinomas (77%). Non-neoplastic glands also frequently expressed S100 A2 diminishing its potential diagnostic utility. Immunolabeling with antibodies directed against CXCL5 did not reveal any significant differences in protein expression between infiltrating adenocarcinomas and normal pancreatic ducts. Claudin 18 and annexin A8 are frequently highly overexpressed in infiltrating ductal adenocarcinomas when compared with normal reactive ducts, suggesting a role for these molecules in pancreatic ductal adenocarcinomas. Furthermore, these may serve as diagnostic markers, as screening tests and as therapeutic targets.

  10. Preclinical Validation of 99mTc–Annexin A5–128 in Experimental Autoimmune Myocarditis and Infective Endocarditis: Comparison with 99mTc–HYNIC–Annexin A5

    Directory of Open Access Journals (Sweden)

    Khadija Benali

    2015-01-01

    Full Text Available Hydrazinonicotinamide–annexin A5 (HYNIC-Anx, a 99m technetium (99mTc-labeled agent targeting phosphatidylserine, proved to be sensitive for the detection of apoptosis and thrombosis but is no longer available for clinical use. A mutant of human annexin designed for direct 99mTc labeling (referred to as Anx A5–128 showed improved binding affinity to phosphatidylserine and is expected to be used in humans. We compared both radiotracers with regard to pharmacokinetics and diagnostic ability in animal models. Biodistribution studies were performed in normal rats. Radiolabeled Anx A5–128 and HYNIC-Anx were compared in cardiovascular settings involving phosphatidylserine expression: experimental autoimmune myocarditis and infective endocarditis. Initial blood clearance was faster for Anx A5–128 than for HYNIC-Anx, and tissue biodistribution was similar overall for both tracers. The diagnostic sensitivity of Anx A5–128 was excellent and comparable to that of HYNIC-Anx. Anx A5–128 showed biodistribution and diagnostic ability similar to those of the HYNIC-Anx derivative, supporting its translation to clinical use.

  11. Distribution of 99Tcm-rh-Annexin vin tumor and expression relationship of bcl-2, bax after a single dose of chemotherapy

    International Nuclear Information System (INIS)

    Zhang Xin; Li Yaming; Zhang Yanjun; Tao Li; Zhu Yi; Yang Chun; Ji Xiaopeng; Zhao Ming; Tian Aijuan; Zhang Jianying; Zhao Zhenzhen

    2007-01-01

    The expression of bcl-2 and bax after the single dose of chemotherapy with 99 Tc m -rh-Annexin V as the tracer of tumor apoptosis imaging is studied. tumor cell apoptosis is examined by TUNEL methods, and the expression of bcl-2 and bax in tumor are determined by immunohistochemical methods. Single dose of chemotherapy significantly increased the tumor uptake of 99 Tc m -rh-annexin V and the positive number of TUNEL, as well as the expression of bax (P 99 Tc m -rh-annexin V in tumor reflectes not only the degree of apoptosis of tumor cells, but also the change of bax expression after the single dose of chemotherapy. (authors)

  12. Annexin A2 and its downstream IL-6 and HB-EGF as secretory biomarkers in the differential diagnosis of Her-2 negative breast cancer.

    Science.gov (United States)

    Shetty, Praveenkumar; Patil, Vidya S; Mohan, Rajashekar; D'souza, Leonard Clinton; Bargale, Anil; Patil, Basavaraj R; Dinesh, U S; Haridas, Vikram; Kulkarni, Shrirang P

    2017-07-01

    Background AnnexinA2 (AnxA2) membrane deposition has a critical role in HB-EGF shedding as well as IL-6 secretion in breast cancer cells. This autocrine cycle has a major role in cancer cell proliferation, migration and metastasis. The objective of the study is to demonstrate annexinA2-mediated autocrine regulation via HB-EGF and IL-6 in Her-2 negative breast cancer progression. Methods Secretory annexinA2, HB-EGF and IL-6 were analysed in the peripheral blood sample of Her-2 negative ( n = 20) and positive breast cancer patients ( n = 16). Simultaneously, tissue expression was analysed by immunohistochemistry. The membrane deposition of these secretory ligands and their autocrine regulation was demonstrated using triple-negative breast cancer cell line model. Results Annexina2 and HB-EGF expression are inversely correlated with Her-2, whereas IL-6 expression is seen in both Her-2 negative and positive breast cancer cells. RNA interference studies and upregulation of annexinA2 proved that annexinA2 is the upstream of this autocrine pathway. Abundant soluble serum annexinA2 is secreted in Her-2 negative breast cancer (359.28 ± 63.73 ng/mL) compared with normal (286.10 ± 70.04 ng/mL, P breast cancer phenotypes as compared with normal ( P breast cancer tissues, increased secretion compared with normal cells, and their major role in the regulation of EGFR downstream signalling makes these molecules as a potential tissue and serum biomarker and an excellent therapeutic target in Her-2 negative breast cancer.

  13. Macrophage migration inhibitory factor counter-regulates dexamethasone-induced annexin 1 expression and influences the release of eicosanoids in murine macrophages.

    Science.gov (United States)

    Sun, Yu; Wang, Yu; Li, Jia-Hui; Zhu, Shi-Hui; Tang, Hong-Tai; Xia, Zhao-Fan

    2013-10-01

    Macrophage migration inhibitory factor (MIF), a pro-inflammatory cytokine and glucocorticoid (GC) counter-regulator, has emerged as an important modulator of inflammatory responses. However, the molecular mechanisms of MIF counter-regulation of GC still remain incomplete. In the present study, we investigated whether MIF mediated the counter-regulation of the anti-inflammatory effect of GC by affecting annexin 1 in RAW 264.7 macrophages. We found that stimulation of RAW 264.7 macrophages with lipopolysaccharide (LPS) resulted in down-regulation of annexin 1, while GC dexamethasone (Dex) or Dex plus LPS led to significant up-regulation of annexin 1 expression. RNA interference-mediated knockdown of intracellular MIF increased annexin 1 expression with or without incubation of Dex, whereas Dex-induced annexin 1 expression was counter-regulated by the exogenous application of recombinant MIF. Moreover, recombinant MIF counter-regulated, in a dose-dependent manner, inhibition of cytosolic phospholipase A2α (cPLA2α) activation and prostaglandin E2 (PGE2 ) and leukotriene B4 (LTB4 ) release by Dex in RAW 264.7 macrophages stimulated with LPS. Endogenous depletion of MIF enhanced the effects of Dex, reflected by further decease of cPLA2α expression and lower PGE2 and LTB4 release in RAW 264.7 macrophages. Based on these data, we suggest that MIF counter-regulates Dex-induced annexin 1 expression, further influencing the activation of cPLA2α and the release of eicosanoids. These findings will add new insights into the mechanisms of MIF counter-regulation of GC. © 2013 John Wiley & Sons Ltd.

  14. Insulin receptor substrate 1 expression enhances the sensitivity of 32D cells to chemotherapy-induced cell death

    Science.gov (United States)

    Porter, Holly A.; Carey, Gregory B.; Keegan, Achsah D.

    2012-01-01

    The adaptors IRS1 and IRS2 link growth factor receptors to downstream signaling pathways that regulate proliferation and survival. Both suppress factor-withdrawal-induced apoptosis and have been implicated in cancer progression. However, recent studies suggest IRS1 and IRS2 mediate differential functions in cancer pathogenesis. IRS1 promoted breast cancer proliferation, while IRS2 promoted metastasis. The role of IRS1 and IRS2 in controlling cell responses to chemotherapy is unknown. To determine the role of IRS1 and IRS2 in the sensitivity of cells to chemotherapy, we treated 32D cells lacking or expressing IRS proteins with various concentrations of chemotherapeutic agents. We found that expression of IRS1, in contrast to IRS2, enhanced the sensitivity of 32D cells to chemotherapy-induced apoptosis. When IRS2 was expressed with IRS1, the cells no longer showed enhanced sensitivity. Expression of IRS1 did not alter the expression of pro- and anti-apoptotic proteins; however, 32D-IRS1 cells expressed higher levels of Annexin A2. In 32D-IRS1 cells, IRS1 and Annexin A2 were both located in cytoplasmic and membrane fractions. We also found that IRS1 coprecipitated with Annexin A2, while IRS2 did not. Decreasing Annexin A2 levels reduced 32D-IRS1 cell sensitivity to chemotherapy. These results suggest IRS1 enhances sensitivity to chemotherapy in part through Annexin A2. PMID:22652453

  15. Comparison of {sup 99m}Tc-annexin A5 with {sup 18}F-FDG for the detection of atherosclerosis in ApoE-/- mice

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Yan; Morita, Koichi; Tamaki, Nagara [Hokkaido University, Department of Nuclear Medicine, Graduate School of Medicine, Sapporo (Japan); Kuge, Yuji [Hokkaido University, Department of Tracer Kinetics, Graduate School of Medicine, Sapporo (Japan); Hokkaido University, Department of Molecular Imaging, Graduate School of Medicine, Sapporo (Japan); Kyoto University, Department of Patho-Functional Bioanalysis, Graduate School of Pharmaceutical Sciences, Kyoto (Japan); Zhao, Songji [Hokkaido University, Department of Nuclear Medicine, Graduate School of Medicine, Sapporo (Japan); Hokkaido University, Department of Tracer Kinetics, Graduate School of Medicine, Sapporo (Japan); Inubushi, Masayuki [Hokkaido University, Department of Molecular Imaging, Graduate School of Medicine, Sapporo (Japan); Strauss, H.W. [Memorial Sloan-Kettering Cancer Center, Department of Nuclear Medicine, New York, NY (United States); Blankenberg, Francis G. [Stanford University School of Medicine, Department of Pediatric Radiology, Palo Alto, CA (United States)

    2007-11-15

    {sup 99m}Tc-annexin A5, a marker of ongoing apoptosis, and {sup 18}F-FDG, a marker of the increased metabolism of inflammatory cells, are supposed to be useful in the detection of metabolically active atheroma. This study reports a comparison of the intralesional distribution of these tracers in relation to lesion development in ApoE-/- mice. Male ApoE-/- mice (n = 12-14/group) were maintained on a Western-type diet after the age of 5 weeks. At 25 weeks, {sup 99m}Tc-annexin A5 or {sup 18}F-FDG was injected and the aortas were harvested for autoradiography (ARG) and Oil Red O staining. Regional radioactivity accumulation was compared in relation to the Oil Red O staining score (ranging from 0 to 3, a semiquantitative parameter for evaluating lesion development). Both {sup 99m}Tc-annexin A5 and {sup 18}F-FDG showed preferential uptake into atherosclerotic lesions, with higher uptake levels for {sup 18}F-FDG (mean, 56.07 %ID x kg/m{sup 2}) than for {sup 99m}Tc-annexin A5 (mean, 10.38 %ID x kg/m{sup 2}). The regional uptake levels of each tracer correlated with the Oil Red O staining score (r = 0.65, p < 0.05 for {sup 99m}Tc-annexin A5; r = 0.56, p < 0.05 for {sup 18}F-FDG). The uptake ratios of advanced lesions (score >0.5) to early lesions (score <0.5) were significantly higher for {sup 99m}Tc-annexin A5 than for {sup 18}F-FDG (f = 4.73, p = 0.03). Both {sup 99m}Tc-annexin A5 and {sup 18}F-FDG accumulate in atherosclerotic lesions and correlate with the severity of each lesion. The higher absolute uptake levels of {sup 18}F-FDG may be advantageous for lesion detection, whereas the preferential uptake of {sup 99m}Tc-annexin A5 in advanced lesions may be a useful indicator of late-stage lesions or vulnerable plaque transformation. (orig.)

  16. Comparison of 99mTc-annexin A5 with 18F-FDG for the detection of atherosclerosis in ApoE-/- mice

    International Nuclear Information System (INIS)

    Zhao, Yan; Morita, Koichi; Tamaki, Nagara; Kuge, Yuji; Zhao, Songji; Inubushi, Masayuki; Strauss, H.W.; Blankenberg, Francis G.

    2007-01-01

    99m Tc-annexin A5, a marker of ongoing apoptosis, and 18 F-FDG, a marker of the increased metabolism of inflammatory cells, are supposed to be useful in the detection of metabolically active atheroma. This study reports a comparison of the intralesional distribution of these tracers in relation to lesion development in ApoE-/- mice. Male ApoE-/- mice (n = 12-14/group) were maintained on a Western-type diet after the age of 5 weeks. At 25 weeks, 99m Tc-annexin A5 or 18 F-FDG was injected and the aortas were harvested for autoradiography (ARG) and Oil Red O staining. Regional radioactivity accumulation was compared in relation to the Oil Red O staining score (ranging from 0 to 3, a semiquantitative parameter for evaluating lesion development). Both 99m Tc-annexin A5 and 18 F-FDG showed preferential uptake into atherosclerotic lesions, with higher uptake levels for 18 F-FDG (mean, 56.07 %ID x kg/m 2 ) than for 99m Tc-annexin A5 (mean, 10.38 %ID x kg/m 2 ). The regional uptake levels of each tracer correlated with the Oil Red O staining score (r = 0.65, p 99m Tc-annexin A5; r = 0.56, p 18 F-FDG). The uptake ratios of advanced lesions (score >0.5) to early lesions (score 99m Tc-annexin A5 than for 18 F-FDG (f = 4.73, p = 0.03). Both 99m Tc-annexin A5 and 18 F-FDG accumulate in atherosclerotic lesions and correlate with the severity of each lesion. The higher absolute uptake levels of 18 F-FDG may be advantageous for lesion detection, whereas the preferential uptake of 99m Tc-annexin A5 in advanced lesions may be a useful indicator of late-stage lesions or vulnerable plaque transformation. (orig.)

  17. Distribution of 99Tcm-rh-Annexin V and its relationship with expression of survivin and Caspase-3 in tumors after a single dose of chemotherapy

    International Nuclear Information System (INIS)

    Zhang Xin; Zhang Yanjun; Tao Li; Zhu Yi; Yang Chun; Li Yaming; Zhang Jianying; Zhao Zhenzhen; Ji Xiaopeng; Zhao Ming; Tian Aijuan

    2008-01-01

    Objective: Recently, molecular imaging for detecting cellular apoptosis is developing rapidly. The aim of the study was to determine the effectiveness of imaging with 99 Tc m labelled recombinant human Annexin V ( 99 Tc m -rh-Annexin V) as a reflection of apoptosis in tumor, and related its distribution with expression of Survivin and Caspase-3 after a single dose of chemotherapy. Methods: Eight days after being inoculated with allogenic hepatoma cells (Hca-F25) into right axillary fossa, the mice (purebred 615) were randomly divided into two groups (control group A, n=9; and treated group B, n=10). Group B was received a single dose of chemotherapy intraperitoneally (cyclophosphamide, 150 mg/kg). Groups A and B were given 99 Tc m -rh-AnnexinV (3.7 MBq·0.5 μg -1 per mouse) intravenously 20 h later. Four hours after 99 Tc m -rh-Annexin V injection, the animals were imaged and sacrificed, and the tumor samples were weighed and the radioactivity was determined in a well-counter. The accumulation of 99 Tc m -rh-Annexin V in tumor was expressed as the percentage activity of injection dose per gram of tissue (% ID/g). Tumor cell apoptosis was examined by terminal deoxynueleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling (TUNEL) method, and the expression of Survivin and Caspase-3 in tumor were determined with immunohistochemical method. SPSS 10.0 was used for data analysis. Results: Single dose chemotherapy tsignificantly increased the tumor uptake of 99 Tc m -rh-Annexin V [(0.478 ± 0.123)% ID/g vs (0.332 ± 0.061)% ID/g] and the positive number of TUNEL [(18.030 ± 5.600) cells/field vs (6.744 ± 2.325) cells/field], as well as the expression of Caspase-3 [(3.266 ± 0.482)% vs (2.387 ± 0.387)%, F was 10.502, 31.507, 18.971, respectively, all P 99 Tc m -rh-Annexin V correlated positively well with the expression of Caspase-3 and negatively with the expression of Survivin (P 99 Tc m -rh-Annexin V can not only reflect the extent of apoptosis

  18. Evaluation of adenosine preconditioning with {sup 99m}Tc-His{sub 10}-annexin V in a porcine model of myocardium ischemia and reperfusion injury: preliminary study

    Energy Technology Data Exchange (ETDEWEB)

    Ye Fei [Department of Cardiology, Nanjing First Hospital Affiliated to Nanjing Medical University, 68 Changle Road, Nanjing 210006 (China); Fang Wei [Cardiovascular Institute and Fuwai Hospital, No. 167 Bei-Li-Shi-Lu, Beijing 100037 (China); Wang Feng, E-mail: fengwang1972cn@gmail.co [Department of Nuclear Medicine, Nanjing First Hospital Affiliated to Nanjing Medical University, 68 Changle Road, Nanjing 210006 (China); State Key Laboratory of Pharmaceutical Biotechnology, Department of Biochemistry, College of Life Sciences, Nanjing University, 22 Hankou Road, Nanjing 210093 (China); Hua Zichun [State Key Laboratory of Pharmaceutical Biotechnology, Department of Biochemistry, College of Life Sciences, Nanjing University, 22 Hankou Road, Nanjing 210093 (China); Wang Zizheng [Department of Nuclear Medicine, Nanjing First Hospital Affiliated to Nanjing Medical University, 68 Changle Road, Nanjing 210006 (China); Yang Xiang [State Key Laboratory of Pharmaceutical Biotechnology, Department of Biochemistry, College of Life Sciences, Nanjing University, 22 Hankou Road, Nanjing 210093 (China)

    2011-05-15

    Purpose: The goal of this study was to evaluate the feasibility of {sup 99m}Tc-His{sub 10}-annexin V for the detection of acute myocardial cell death and to assess the effect of adenosine preconditioning in a porcine model of myocardium ischemia and reperfusion injury (RI). Materials and Methods: {sup 99m}Tc-His{sub 10}-annexin V was prepared by one-step direct labeling, and RCP and radiostability were tested. The binding of {sup 99m}Tc-His{sub 10}-annexin V to apoptosis was validated in vitro using camptothecin-induced Jurkat cells. In vivo biodistribution was determined in mice by the dissection method. Ischemia of 20-30 min was induced by balloon occlusion of the epicardial coronary artery of the porcine model (n=14). Adenosine was infused intravenously in six pigs before coronary occlusion. {sup 99m}Tc-His{sub 10}-annexin V (n=12) was injected intravenously at 1 h after reperfusion. SPECT/CT was acquired at 3 h postinjection. Myocardial perfusion imaging (MPI) with {sup 99m}Tc-MIBI was also performed 1 day after His{sub 10}-annexin V imaging. Cardiac tissues were analyzed postmortem using hematoxylin-and-eosin and TUNEL staining. Caspase-3 activity was measured to confirm the presence of apoptosis. Results: {sup 99m}Tc-His{sub 10}-annexin V had a RCP >98% and high stability 2 h after radiolabeling; it could bind to apoptotic cells with high affinity. Biodistribution of {sup 99m}Tc-His{sub 10}-annexin V showed a predominant uptake in the kidney and relatively low uptake in the myocardium, liver and gastrointestinal tract; rapid clearance from blood and kidney was observed. In the untreated group, intense uptake of His{sub 10}-annexin V was visualized in the defect which was shown in MPI, whereas in the adenosine group a mild uptake of {sup 99m}Tc-His{sub 10}-annexin was found in the risk area which showed no defects in the {sup 99m}Tc-MIBI image. TUNEL staining and activated caspase-3 confirmed the ongoing apoptosis in RI. Adenosine preconditioning significantly

  19. Induction of annexin-1 at transcriptional and posttranscriptional level in rat brain by methylprednisolone and the 21-aminosteroid U74389F

    NARCIS (Netherlands)

    Voermans, PH; Go, KG; TerHorst, GJ; Ruiters, MHJ; Solito, E; Parente, L

    1996-01-01

    BRAIN tissue of rats pretreated with methylprednisolone or with the 21-aminosteroid U74389F, and that of untreated control rats, was assessed for the expression of annexin-l (Anx-1) and the transcription of its mRNA. For this purpose Anx-1 cDNA was amplified and simultaneously a T7-RNA-polymerase

  20. Detection of focal hypoxic-ischemic injury and neuronal stress in a rodent model of unilateral MCA occlusion/reperfusion using radiolabeled annexin V

    Energy Technology Data Exchange (ETDEWEB)

    Mari, Carina; Goris, Michael L. [Division of Nuclear Medicine, Department of Radiology, Stanford University Hospital, CA 94305, Stanford (United States); Karabiyikoglu, Murat; Yenari, Midori Anne [Departments of Neurosurgery and Neurology, Stanford University Hospital, CA 94305, Stanford (United States); Tait, Jonathan F. [Department of Laboratory Medicine, University of Washington Medical Center, WA 98195-7110, Seattle (United States); Blankenberg, Francis G. [Division of Nuclear Medicine, Department of Radiology, Stanford University Hospital, CA 94305, Stanford (United States); Division of Pediatric Radiology, Department of Radiology, Stanford University, Lucile Salter Packard Children' s Hospital, 725 Welch Road, Room 1673, CA 94305, Palo Alto (United States)

    2004-05-01

    In this study we wished to determine whether technetium-99m annexin V, an in vivo marker of cellular injury and death, could be used to noninvasively monitor neuronal injury following focal middle cerebral artery (MCA) occlusion/reperfusion injury. Sixteen adult male Sprague-Dawley rats (along with four controls) underwent left (unilateral) MCA intraluminal beaded thread occlusion for 2 h followed by reperfusion. One hour following tail vein injection of 5-10 mCi of {sup 99m}Tc-annexin V, animals underwent either single-photon emission computerized tomography (SPECT) or autoradiography followed by immunohistochemical analyses. There was abnormal, bilateral, multifocal uptake of {sup 99m}Tc-annexin V in each cerebral hemisphere as seen by both SPECT and autoradiography at 4 h and 1, 3, and 7 days after initiation of occlusion. The average maximal annexin V uptake at 4 h was 310%{+-}85% and 365%{+-}151% above control values (P<0.006) within the right and left hemispheres, respectively, peaking on day 3 with values of 925%{+-}734% and 1,194%{+-}643% (P<0.03) that decreased by day 7 to 489%{+-}233% and 785%{+-}225% (P<0.01). Total lesional volume of the left hemisphere was 226%, 261%, and 451% (P<0.03) larger than the right at 4, 24, and 72 h after injury, respectively. Annexin V localized to the cytoplasm of injured neurons ipsilateral to the site of injury as well as to otherwise normal-appearing neurons of the contralateral hemisphere as confirmed by dual fluorescent microscopy. It is concluded that there is abnormal bilateral, multifocal annexin V uptake, greater on the left than on the right side, within 4 h of unilateral left MCA ischemic injury and that the uptake peaks at 3 days and decreases by 7 days after injury. This pattern suggests that neuronal stress may play a role in the response of the brain to focal injury and be responsible for annexin V uptake outside the region of ischemic insult. (orig.)

  1. sCD30, interleukin-1beta-converting enzyme and anti-Annexin V autoantibodies concentrations in heart transplant recipients.

    Science.gov (United States)

    Zeglen, Sławomir; Zakliczyński, Michał; Nozyński, Jerzy; Rogala, Barbara; Zembala, Marian

    2006-11-01

    sCD30 and ICE/caspase-1 as apoptosis-regulating factors are suspected to be involved in the survival rate of immunocompetent cells during immunosuppression after allotransplantation. Serum CD30 and ICE/caspase-1 concentrations were estimated and associated with unspecific serum apoptosis marker--anti-Annexin V antibodies and myocardial biopsies results. 28 clinically stabile patients--heart transplant recipients at least 3 months after cardiac transplantation performed due to heart failure caused by ischaemic and/or congestive cardiomyopathy or/and primary valvular heart disease (26 men and 2 women, mean age=36.8 years, S.D.=7.6) with normal heart function assessed by use of ultrasound scan--were involved in the trial. The patients were divided and analyzed in two ways: first according to the results of elective endomyocardial biopsies and second to main immunosuppressive agent used. The enzyme immunoassay (CD30, Dako; interleukin-1beta-converting enzyme (ICE)/Caspase-1 ELISA and anti-Annexin V BENDER MedSystem) for soluble CD30, caspase-1 and anti-Annexin V autoantibodies serum levels was used. sCD30 and caspase-1 concentrations were non-significantly up-regulated in all analysed groups--with or without rejection signs or immunosuppressed with cyclosporine or especially tacrolimus. In contrast anti-Annexin V autoantibodies concentration was non-significantly down-regulated also in all studied groups. Moreover in the group with signs of transplant rejection, strong negative correlation between anti-Annexin antibodies and rejection grade was observed (-0.65, psCD30 and caspase-1 as well as the decrease in anti-Annexin V autoantibodies concentrations in heart recipients could be the result of post-transplant apoptosis disturbances. This tendency seems to be inhibited in a greater degree by tacrolimus than by cyclosporine. Anti-Annexin V autoantibodies might be considered as negative rejection markers due to their strong negative correlation with the rejection grade.

  2. Young women with polycystic ovary syndrome have raised levels of circulating annexin V-positive platelet microparticles.

    Science.gov (United States)

    Willis, G R; Connolly, K; Ladell, K; Davies, T S; Guschina, I A; Ramji, D; Miners, K; Price, D A; Clayton, A; James, P E; Rees, D A

    2014-12-01

    Are circulating microparticles (MPs) altered in young women with polycystic ovary syndrome (PCOS)? Women with PCOS have elevated concentrations of circulating platelet-derived MPs, which exhibit increased annexin V binding and altered microRNA (miR) profiles compared with healthy volunteers. Some studies have shown that cardiovascular risk is increased in young women with PCOS but the mechanisms by which this occurs are uncertain. Circulating MPs are elevated in patients with cardiovascular disease but the characteristics of MPs in patients with PCOS are unclear. Case-control study comprising 17 women with PCOS (mean ± SD; age 31 ± 7 years, BMI 29 ± 6 kg/m(2)) and 18 healthy volunteers (age 31 ± 6 years, BMI 30 ± 6 kg/m(2)). The study was conducted in a University hospital. Nanoparticle tracking analysis (NTA) and flow cytometry (CD41 platelet, CD11b monocyte, CD144 endothelial) were used to determine MP size, concentration, cellular origin and annexin V positivity (reflecting phosphatidylserine exposure). Fatty acid analysis was performed by gas chromatography and MP miR expression profiles were compared by microarray. PCOS subjects showed increased MP concentrations compared with healthy volunteers (mean ± SD; 11.5 ± 5 × 10(12)/ml versus 10.0 ± 4 × 10(12)/ml, respectively; P = 0.03), which correlated with the homeostasis model of insulin resistance (r = 0.53, P = 0.03). This difference was predominantly seen in MPs whose size was in the small exosomal range (PCOS patients showed a greater percentage of annexin V(+) MPs compared with healthy volunteers (84 ± 18 versus 74 ± 24%, respectively, P = 0.05) but the cellular origin of MPs, which were predominantly platelet-derived (PCOS: 99 ± 0.9%; controls: 99 ± 2.5%), did not differ. MP fatty acid concentration and composition was similar between groups but 16 miRs were differentially expressed (P PCOS were classified by the Rotterdam criteria, which describes a less severe metabolic phenotype than other

  3. Insulin receptors

    International Nuclear Information System (INIS)

    Kahn, C.R.; Harrison, L.C.

    1988-01-01

    This book contains the proceedings on insulin receptors. Part A: Methods for the study of structure and function. Topics covered include: Method for purification and labeling of insulin receptors, the insulin receptor kinase, and insulin receptors on special tissues

  4. Crystallization of the Membrane-Associated Annexin B1: Roles of Additive Screen, Dynamic Light Scattering, and Bioactivity Assay

    Energy Technology Data Exchange (ETDEWEB)

    Ding, F.; Xu, Y; Azzi, A; Zhu, D; Rehse, D; Chen, C; Sun, S; Lin, S

    2010-01-01

    Annexin B1 (AnxB1) is a calcium-dependent phospholipid binding protein from Taenia solium cysticercus and has been reported to possess anticoagulant activity, to inhibit phospholipase A{sub 2}, and to regulate membrane transport. Native AnxB1 and its selenomethionyl derivative have been overproduced in Escherichia coli and purified. The results of dynamic light scattering analysis showed that Hepes buffer combined with low concentration salts (NaCl or CaCl{sub 2}) was beneficial for preventing aggregation and for AnxB1 stabilization in the storage. After the additive screen, crystals have been yielded in the presence of guanidine hydrochloride (Gn-HCl). We determined that a low concentration of Gn-HCl significantly delayed clotting time and increased anticoagulant activity. Analysis of the crystal showed that in the presence of Gn-HCl, AnxB1 crystallizes in orthorhombic space group, which is modified from the cubic space group for crystals grown in the absence of Gn-HCl. A high quality data set (at 1.9 {angstrom}) has been collected successfully for crystals of L-selenomethionine labeled protein in the presence of Gn-HCl, to solve the structure with the single anomalous dispersion method (SAD). The unit cell parameters are a = 102.35 {angstrom}, b = 103.59 {angstrom}, c = 114.60 {angstrom}, {alpha} = {beta} = {gamma} = 90.00{sup o}.

  5. Annexin V Imaging Detects Diabetes-Accelerated Apoptosis and Monitors the Efficacy of Benfotiamine Treatment in Ischemic Limbs of Mice

    Directory of Open Access Journals (Sweden)

    Kyung-Ho Jung

    2014-05-01

    Full Text Available The role of apoptosis imaging for monitoring treatment response in ischemic limbs has not been properly explored. In this study, we investigated the ability of annexin V (AnxV imaging to assess the efficacy of antiapoptotic treatment in ischemic limbs of diabetic mice. Normal C57BL/6 mice and streptozotocin-induced diabetic mice were subject to hindlimb ischemia. AnxV-conjugated fluorescent streptavidin probes were intravenously injected, and optical imaging was performed. Tissue apoptosis was quantified by histochemistry and Western blotting. The AnxV probes showed specific targeting to apoptotic cells on confocal microscopy and flow cytometry. Intravenous AnxV probes displayed substantially greater accumulation in ischemic limbs of diabetic mice. Benfotiamine (BFT treatment of diabetic mice led to better perfusion recovery on laser Doppler imaging and reduced AnxV binding on optical imaging. TUNEL staining and cleaved caspase-3 Western blots confirmed accelerated apoptosis by diabetes and its suppression by BFT treatment. Furthermore, AnxV-SAv-PEcy5.5 uptake in the ischemic limbs closely correlated to cleaved caspase-3 expression. Thus, AnxV imaging may be useful for monitoring the efficacy of therapeutic agents designed to suppress ischemia-induced apoptosis.

  6. Annexin V imaging detects diabetes-accelerated apoptosis and monitors the efficacy of benfotiamine treatment in ischemic limbs of mice.

    Science.gov (United States)

    Jung, Kyung-Ho; Lee, Jin Hee; Park, Jin Won; Paik, Jin Young; Quach, Cung Hoa Thien; Lee, Eun Jeong; Lee, Kyung-Han

    2014-01-01

    The role of apoptosis imaging for monitoring treatment response in ischemic limbs has not been properly explored. In this study, we investigated the ability of annexin V (AnxV) imaging to assess the efficacy of antiapoptotic treatment in ischemic limbs of diabetic mice. Normal C57BL/6 mice and streptozotocin-induced diabetic mice were subject to hindlimb ischemia. AnxV-conjugated fluorescent streptavidin probes were intravenously injected, and optical imaging was performed. Tissue apoptosis was quantified by histochemistry and Western blotting. The AnxV probes showed specific targeting to apoptotic cells on confocal microscopy and flow cytometry. Intravenous AnxV probes displayed substantially greater accumulation in ischemic limbs of diabetic mice. Benfotiamine (BFT) treatment of diabetic mice led to better perfusion recovery on laser Doppler imaging and reduced AnxV binding on optical imaging. TUNEL staining and cleaved caspase-3 Western blots confirmed accelerated apoptosis by diabetes and its suppression by BFT treatment. Furthermore, AnxV-SAv-PEcy5.5 uptake in the ischemic limbs closely correlated to cleaved caspase-3 expression. Thus, AnxV imaging may be useful for monitoring the efficacy of therapeutic agents designed to suppress ischemia-induced apoptosis.

  7. (99m)Tc-Annexin A5 quantification of apoptotic tumor response: a systematic review and meta-analysis of clinical imaging trials.

    Science.gov (United States)

    Belhocine, Tarik Z; Blankenberg, Francis G; Kartachova, Marina S; Stitt, Larry W; Vanderheyden, Jean-Luc; Hoebers, Frank J P; Van de Wiele, Christophe

    2015-12-01

    (99m)Tc-Annexin A5 has been used as a molecular imaging probe for the visualization, characterization and measurement of apoptosis. In an effort to define the quantitative (99m)Tc-annexin A5 uptake criteria that best predict tumor response to treatment, we performed a systematic review and meta-analysis of the results of all clinical imaging trials found in the literature or publicly available databases. Included in this review were 17 clinical trials investigating quantitative (99m)Tc-annexin A5 (qAnx5) imaging using different parameters in cancer patients before and after the first course of chemotherapy and/or radiation therapy. Qualitative assessment of the clinical studies for diagnostic accuracy was performed using the QUADAS-2 criteria. Of these studies, five prospective single-center clinical trials (92 patients in total) were included in the meta-analysis after exclusion of one multicenter clinical trial due to heterogeneity. Pooled positive predictive values (PPV) and pooled negative predictive values (NPV) (with 95% CI) were calculated using Meta-Disc software version 1.4. Absolute quantification and/or relative quantification of (99m)Tc-annexin A5 uptake were performed at baseline and after the start of treatment. Various quantitative parameters have been used for the calculation of (99m)Tc-annexin A5 tumor uptake and delta (Δ) tumor changes post-treatment compared to baseline including: tumor-to-background ratio (TBR), ΔTBR, tumor-to-noise ratio, relative tumor ratio (TR), ΔTR, standardized tumor uptake ratio (STU), ΔSTU, maximum count per pixel within the tumor volume (Cmax), Cmax%, absolute ΔU and percentage (ΔU%), maximum ΔU counts, semiquantitative visual scoring, percent injected dose (%ID) and %ID/cm(3). Clinical trials investigating qAnx5 imaging have included patients with lung cancer, lymphoma, breast cancer, head and neck cancer and other less common tumor types. In two phase I/II single-center clinical trials, an increase of ≥25% in

  8. An immune response manifested by the common occurrence of annexins I and II autoantibodies and high circulating levels of IL-6 in lung cancer

    Science.gov (United States)

    Brichory, Franck M.; Misek, David E.; Yim, Anne-Marie; Krause, Melissa C.; Giordano, Thomas J.; Beer, David G.; Hanash, Samir M.

    2001-01-01

    The identification of circulating tumor antigens or their related autoantibodies provides a means for early cancer diagnosis as well as leads for therapy. The purpose of this study was to identify proteins that commonly induce a humoral response in lung cancer by using a proteomic approach and to investigate biological processes that may be associated with the development of autoantibodies. Aliquots of solubilized proteins from a lung adenocarcinoma cell line (A549) and from lung tumors were subjected to two-dimensional PAGE, followed by Western blot analysis in which individual sera were tested for primary antibodies. Sera from 54 newly diagnosed patients with lung cancer and 60 patients with other cancers and from 61 noncancer controls were analyzed. Sera from 60% of patients with lung adenocarcinoma and 33% of patients with squamous cell lung carcinoma but none of the noncancer controls exhibited IgG-based reactivity against proteins identified as glycosylated annexins I and/or II. Immunohistochemical analysis showed that annexin I was expressed diffusely in neoplastic cells in lung tumor tissues, whereas annexin II was predominant at the cell surface. Interestingly, IL-6 levels were significantly higher in sera of antibody-positive lung cancer patients compared with antibody-negative patients and controls. We conclude that an immune response manifested by annexins I and II autoantibodies occurs commonly in lung cancer and is associated with high circulating levels of an inflammatory cytokine. The proteomic approach we have implemented has utility for the development of serum-based assays for cancer diagnosis as we report in this paper on the discovery of antiannexins I and/or II in sera from patients with lung cancer. PMID:11504947

  9. A low molecular weight zinc{sup 2+}-dipicolylamine-based probe detects apoptosis during tumour treatment better than an annexin V-based probe

    Energy Technology Data Exchange (ETDEWEB)

    Palmowski, Karin [RWTH-Aachen University, Department of Experimental Molecular Imaging, Aachen (Germany); University of Heidelberg, Department of Pneumology, Thoraxklinik Heidelberg, Heidelberg (Germany); Rix, Anne; Lederle, Wiltrud; Kiessling, Fabian [RWTH-Aachen University, Department of Experimental Molecular Imaging, Aachen (Germany); Behrendt, Florian F. [RWTH-Aachen University, Department of Nuclear Medicine, Aachen (Germany); Mottaghy, Felix M. [RWTH-Aachen University, Department of Nuclear Medicine, Aachen (Germany); Maastricht University Medical Center, Department of Nuclear Medicine, Maastricht (Netherlands); Gray, Brian D. [Molecular Targeting Technologies, Inc., West Chester, PA (United States); Pak, Koon Y. [University Medical Center Heidelberg, Academic Radiology Baden-Baden, Diagnostic and Interventional Radiology, Heidelberg (Germany); Palmowski, Moritz [RWTH-Aachen University, Department of Experimental Molecular Imaging, Aachen (Germany); RWTH-Aachen University, Department of Nuclear Medicine, Aachen (Germany); University Medical Center Heidelberg, Academic Radiology Baden-Baden, Diagnostic and Interventional Radiology, Heidelberg (Germany)

    2014-02-15

    Molecular imaging of apoptosis is frequently discussed for monitoring cancer therapies. Here, we compare the low molecular weight phosphatidylserine-targeting ligand zinc{sup 2+}-dipicolylamine (Zn{sup 2+}-DPA) with the established but reasonably larger protein annexin V. Molecular apoptosis imaging with the fluorescently labelled probes annexin V (750 nm, 36 kDa) and Zn{sup 2+}-DPA (794 nm, 1.84 kDa) was performed in tumour-bearing mice (A431). Three animal groups were investigated: untreated controls and treated tumours after 1 or 4 days of anti-angiogenic therapy (SU11248). Additionally, μPET with {sup 18} F-FDG was performed. Imaging data were displayed as tumour-to-muscle ratio (TMR) and validated by quantitative immunohistochemistry. Compared with untreated control tumours, TUNEL staining indicated significant apoptosis after 1 day (P < 0.05) and 4 days (P < 0.01) of treatment. Concordantly, Zn{sup 2+}-DPA uptake increased significantly after 1 day (P < 0.05) and 4 days (P < 0.01). Surprisingly, annexin V failed to detect significant differences between control and treated animals. Contrary to the increasing uptake of Zn{sup 2+}-DPA, {sup 18} F-FDG tumour uptake decreased significantly at days 1 (P < 0.05) and 4 (P < 0.01). Increase in apoptosis during anti-angiogenic therapy was detected significantly better with the low molecular weight probe Zn{sup 2+}-DPA than with the annexin V-based probe. Additionally, significant treatment effects were detectable as early using Zn{sup 2+}-DPA as with measurements of the glucose metabolism using {sup 18} F-FDG. (orig.)

  10. A low molecular weight zinc2+-dipicolylamine-based probe detects apoptosis during tumour treatment better than an annexin V-based probe

    International Nuclear Information System (INIS)

    Palmowski, Karin; Rix, Anne; Lederle, Wiltrud; Kiessling, Fabian; Behrendt, Florian F.; Mottaghy, Felix M.; Gray, Brian D.; Pak, Koon Y.; Palmowski, Moritz

    2014-01-01

    Molecular imaging of apoptosis is frequently discussed for monitoring cancer therapies. Here, we compare the low molecular weight phosphatidylserine-targeting ligand zinc 2+ -dipicolylamine (Zn 2+ -DPA) with the established but reasonably larger protein annexin V. Molecular apoptosis imaging with the fluorescently labelled probes annexin V (750 nm, 36 kDa) and Zn 2+ -DPA (794 nm, 1.84 kDa) was performed in tumour-bearing mice (A431). Three animal groups were investigated: untreated controls and treated tumours after 1 or 4 days of anti-angiogenic therapy (SU11248). Additionally, μPET with 18 F-FDG was performed. Imaging data were displayed as tumour-to-muscle ratio (TMR) and validated by quantitative immunohistochemistry. Compared with untreated control tumours, TUNEL staining indicated significant apoptosis after 1 day (P 2+ -DPA uptake increased significantly after 1 day (P 2+ -DPA, 18 F-FDG tumour uptake decreased significantly at days 1 (P 2+ -DPA than with the annexin V-based probe. Additionally, significant treatment effects were detectable as early using Zn 2+ -DPA as with measurements of the glucose metabolism using 18 F-FDG. (orig.)

  11. The Assessment of Parameters Affecting the Quality of Cord Blood by the Appliance of the Annexin V Staining Method and Correlation with CFU Assays

    Directory of Open Access Journals (Sweden)

    Teja Falk Radke

    2013-01-01

    Full Text Available The assessment of nonviable haematopoietic cells by Annexin V staining method in flow cytometry has recently been published by Duggleby et al. Resulting in a better correlation with the observed colony formation in methylcellulose assays than the standard ISHAGE protocol, it presents a promising method to predict cord blood potency. Herein, we applied this method for examining the parameters during processing which potentially could affect cord blood viability. We could verify that the current standards regarding time and temperature are sufficient, since no significant difference was observed within 48 hours or in storage at 4°C up to 26°C. However, the addition of DMSO for cryopreservation alone leads to an inevitable increase in nonviable haematopoietic stem cells from initially 14.8% ± 4.3% to at least 30.6% ± 5.5%. Furthermore, CFU-assays with varied seeding density were performed in order to evaluate the applicability as a quantitative method. The results revealed that only in a narrow range reproducible clonogenic efficiency (ClonE could be assessed, giving at least a semiquantitative estimation. We conclude that both Annexin V staining method and CFU-assays with defined seeding density are reliable means leading to a better prediction of the final potency. Especially Annexin V, due to its fast readout, is a practical tool for examining and optimising specific steps in processing, while CFU-assays add a functional confirmation.

  12. Arabidopsis annexin1 mediates the radical-activated plasma membrane Ca²+- and K+-permeable conductance in root cells.

    Science.gov (United States)

    Laohavisit, Anuphon; Shang, Zhonglin; Rubio, Lourdes; Cuin, Tracey A; Véry, Anne-Aliénor; Wang, Aihua; Mortimer, Jennifer C; Macpherson, Neil; Coxon, Katy M; Battey, Nicholas H; Brownlee, Colin; Park, Ohkmae K; Sentenac, Hervé; Shabala, Sergey; Webb, Alex A R; Davies, Julia M

    2012-04-01

    Plant cell growth and stress signaling require Ca²⁺ influx through plasma membrane transport proteins that are regulated by reactive oxygen species. In root cell growth, adaptation to salinity stress, and stomatal closure, such proteins operate downstream of the plasma membrane NADPH oxidases that produce extracellular superoxide anion, a reactive oxygen species that is readily converted to extracellular hydrogen peroxide and hydroxyl radicals, OH•. In root cells, extracellular OH• activates a plasma membrane Ca²⁺-permeable conductance that permits Ca²⁺ influx. In Arabidopsis thaliana, distribution of this conductance resembles that of annexin1 (ANN1). Annexins are membrane binding proteins that can form Ca²⁺-permeable conductances in vitro. Here, the Arabidopsis loss-of-function mutant for annexin1 (Atann1) was found to lack the root hair and epidermal OH•-activated Ca²⁺- and K⁺-permeable conductance. This manifests in both impaired root cell growth and ability to elevate root cell cytosolic free Ca²⁺ in response to OH•. An OH•-activated Ca²⁺ conductance is reconstituted by recombinant ANN1 in planar lipid bilayers. ANN1 therefore presents as a novel Ca²⁺-permeable transporter providing a molecular link between reactive oxygen species and cytosolic Ca²⁺ in plants.

  13. Dysferlin, annexin A1, and mitsugumin 53 are upregulated in muscular dystrophy and localize to longitudinal tubules of the T-system with stretch.

    Science.gov (United States)

    Waddell, Leigh B; Lemckert, Frances A; Zheng, Xi F; Tran, Jenny; Evesson, Frances J; Hawkes, Joanne M; Lek, Angela; Street, Neil E; Lin, Peihui; Clarke, Nigel F; Landstrom, Andrew P; Ackerman, Michael J; Weisleder, Noah; Ma, Jianjie; North, Kathryn N; Cooper, Sandra T

    2011-04-01

    Mutations in dysferlin cause an inherited muscular dystrophy because of defective membrane repair. Three interacting partners of dysferlin are also implicated in membrane resealing: caveolin-3 (in limb girdle muscular dystrophy type 1C), annexin A1, and the newly identified protein mitsugumin 53 (MG53). Mitsugumin 53 accumulates at sites of membrane damage, and MG53-knockout mice display a progressive muscular dystrophy. This study explored the expression and localization of MG53 in human skeletal muscle, how membrane repair proteins are modulated in various forms of muscular dystrophy, and whether MG53 is a primary cause of human muscle disease. Mitsugumin 53 showed variable sarcolemmal and/or cytoplasmic immunolabeling in control human muscle and elevated levels in dystrophic patients. No pathogenic MG53 mutations were identified in 50 muscular dystrophy patients, suggesting that MG53 is unlikely to be a common cause of muscular dystrophy in Australia. Western blot analysis confirmed upregulation of MG53, as well as of dysferlin, annexin A1, and caveolin-3 to different degrees, in different muscular dystrophies. Importantly, MG53, annexin A1, and dysferlin localize to the t-tubule network and show enriched labeling at longitudinal tubules of the t-system in overstretch. Our results suggest that longitudinal tubules of the t-system may represent sites of physiological membrane damage targeted by this membrane repair complex.

  14. PET imaging of apoptosis with 64Cu-labeled streptavidin following pretargeting of phosphatidylserine with biotinylated annexin-V

    International Nuclear Information System (INIS)

    Cauchon, Nicole; Langlois, Rejean; Rousseau, Jacques A.; Tessier, Guillaume; Cadorette, Jules; Lecomte, Roger; Hunting, Darel J.; Lier, Johan E. van; Pavan, Roberto A.; Zeisler, Stefan K.

    2007-01-01

    In vivo detection of apoptosis is a diagnostic tool with potential clinical applications in cardiology and oncology. Radiolabeled annexin-V (anxV) is an ideal probe for in vivo apoptosis detection owing to its strong affinity for phosphatidylserine (PS), the molecular flag on the surface of apoptotic cells. Most clinical studies performed to visualize apoptosis have used 99m Tc-anxV; however, its poor distribution profile often compromises image quality. In this study, tumor apoptosis after therapy was visualized by positron emission tomography (PET) using 64 Cu-labeled streptavidin (SAv), following pre-targeting of apoptotic cells with biotinylated anxV. Apoptosis was induced in tumor-bearing mice by photodynamic therapy (PDT) using phthalocyanine dyes as photosensitizers, and red light. After PDT, mice were injected i.v. with biotinylated anxV, followed 2 h later by an avidin chase, and after another 2 h with 64 Cu-DOTA-biotin-SAv. PET images were subsequently recorded up to 13 h after PDT. PET images delineated apoptosis in treated tumors as early as 30 min after 64 Cu-DOTA-biotin-SAv administration, with tumor-to-background ratios reaching a maximum at 3 h post-injection, i.e., 7 h post-PDT. Omitting the administration of biotinylated anxV or the avidin chase failed to provide a clear PET image, confirming that all three steps are essential for adequate visualization of apoptosis. Furthermore, differences in action mechanisms between photosensitizers that target tumor cells directly or via initial vascular stasis were clearly recognized through differences in tracer uptake patterns detecting early or delayed apoptosis. This study demonstrates the efficacy of a three-step 64 Cu pretargeting procedure for PET imaging of apoptosis. Our data also confirm the usefulness of small animal PET to evaluate cancer treatment protocols. (orig.)

  15. Domains I and IV of annexin A2 affect the formation and integrity of in vitro capillary-like networks.

    Directory of Open Access Journals (Sweden)

    Aase M Raddum

    Full Text Available Annexin A2 (AnxA2 is a widely expressed multifunctional protein found in different cellular compartments. In spite of lacking a hydrophobic signal peptide, AnxA2 is found at the cell surface of endothelial cells, indicative of a role in angiogenesis. Increased extracellular levels of AnxA2 in tumours correlate with neoangiogenesis, metastasis and poor prognosis. We hypothesised that extracellular AnxA2 may contribute to angiogenesis by affecting endothelial cell-cell interactions and motility. To address this question, we studied the effect of heterotetrameric and monomeric forms of AnxA2, as well as its two soluble domains on the formation and maintenance of capillary-like structures by using an in vitro co-culture system consisting of endothelial and smooth muscle cells. In particular, addition of purified domains I and IV of AnxA2 potently inhibited the vascular endothelial growth factor (VEGF-dependent formation of the capillary-like networks in a dose-dependent manner. In addition, these AnxA2 domains disrupted endothelial cell-cell contacts in preformed capillary-like networks, resulting in the internalisation of vascular endothelial (VE-cadherin and the formation of VE-cadherin-containing filopodia-like structures between the endothelial cells, suggesting increased cell motility. Addition of monoclonal AnxA2 antibodies, in particular against Tyr23 phosphorylated AnxA2, also strongly inhibited network formation in the co-culture system. These results suggest that extracellular AnxA2, most likely in its Tyr phosphorylated form, plays a pivotal role in angiogenesis. The exogenously added AnxA2 domains most likely mediate their effects by competing with endogenous AnxA2 for extracellular factors necessary for the initiation and maintenance of angiogenesis, such as those involved in the formation/integrity of cell-cell contacts.

  16. Evaluation of the clinical relevance of anti-annexin-A5 antibodies in Chinese patients with antiphospholipid syndrome.

    Science.gov (United States)

    Zhang, Shulan; Wu, Ziyan; Li, Jing; Wen, Xiaoting; Li, Liubing; Zhang, Wen; Zhao, Jiuliang; Zhang, Fengchun; Li, Yongzhe

    2017-02-01

    A hallmark feature of antiphospholipid syndrome (APS) is the presence of antiphospholipid antibodies (aPLs). Few studies have addressed the clinical relevance of anti-annexin A5 antibodies (aANXA5) in Chinese patients with APS. In this study, we evaluated the clinical performance of aANXA5 in the diagnosis of APS. Sera from 313 subjects were tested, including 170 samples from patients with APS, 104 samples from patients with non-APS diseases as disease controls (DC), and 39 healthy controls (HC). Serum IgG and IgM aANXA5 were determined by ELISA. Overall, the levels of both IgG and IgM aANXA5 were significantly increased in patients with primary APS (PAPS) and APS associated to other diseases (APSAOD) compared with DC and HC. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) for IgG and IgM aANXA5 in the diagnosis of APS were 33.5 and 15.3, 99.0 and 99.0, 98.3 and 96.3, and 47.7 and 41.7%, respectively. Significant associations between IgG aANXA5 and arterial thrombotic events (OR, 2.60; 95% CI, 1.44-4.71) and between IgG aANXA5 and venous thrombotic events (OR, 2.80; 95% CI, 1.55-5.06) were identified. No correlations were identified between IgG or IgM aANXA5 and obstetric complications. Our data suggest that aANXA5 could serve as a diagnosis biomarker for patients with APS. More importantly, our data highlighted a potential role of IgG aANXA5 in identifying APS patients with high risk of thrombosis.

  17. Comparative pharmacokinetics and biodistribution studies of {sup 99m}Tc-annexin V produced by different radiolabeling methods

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Josefina da Silva; Pujatti, Priscilla Brunelli; Couto, Renata Martinussi; Mengatti, Jair; Araujo, Elaine Bortoleti de, E-mail: jssantos@usp.b, E-mail: priscillapujatti@yahoo.com.b, E-mail: renatamartinussicouto@yahoo.com.b, E-mail: jmengatti@ipen.b, E-mail: ebaraujo@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2009-07-01

    The use of radiolabeled annexin A5 (ANXA5) to detect cell death in vivo has increased in the last years. Several {sup 99m}Tc-labeling techniques were reported using different cores, such as [{sup 99m}Tc=O]{sup +3}, [{sup 99m}Tc]HYNIC, [{sup 99m}Tcident toN]{sup +2} and [Tc(CO{sub 3})]{sup +1}. The goal of the present work was to evaluate the influence of {sup 99m}Tc cores in the biological behavior of radiolabeled ANXA5 in Swiss mice using [{sup 99m}Tc=O]{sup +3}, [{sup 99m}Tc]HYNIC cores. Ethylenedicysteine (EC) was applied to obtain [Tc=O]{sup +3} core, N,N,N',N'-tetramethyl(succinimide) uranium tetrafluoroborate (TSTU) was employed to transfer the carboxyl group to their corresponding hydroxysuccinimide ester and HYNIC-ANXA5 was provided by National Cancer Institute-Frederick. ITLC-SG and HPLC analysis were applied to determine non-desirable products and the stability of preparations was evaluated after incubation at room temperature, 4 deg C and in human serum at 37 deg C. In vivo biodistribution and kinetics studies were performed after the intravenous injection of {sup 99m}Tc-HYNIC-ANXA5 and {sup 99m}Tc-EC-ANXA5 and pharmacokinetic parameters were calculated using Biexp software. ANXA5 was radiolabeled at room temperature with high yield (> 95%). The results of biodistribution in mice showed, as expected, higher renal uptake of {sup 99m}Tc-HYNICANXA5 and higher liver uptake of {sup 99m}Tc-EC-ANXA5. The percent injected activity per gram (% IA/g) in liver at 0.5 hours were 6.52 and 1.09 and in kidneys were 1.59 and 32.2 for {sup 99m}Tc-EC-ANXA5 and {sup 99m}Tc-HYNICANXA5, respectively. The results of radioactivity in blood showed that both HYNIC- and EC- radiolabeled ANXA5 presented fast blood clearance. In this study two {sup 99m}Tc-ANXA5 obtained from three different available radiolabeling methods presently were investigated. Each labeling method possesses unique advantages and disadvantages. (author)

  18. 99mTc-Annexin-V uptake in a rat model of variable ischemic severity and reperfusion time

    International Nuclear Information System (INIS)

    Taki, Junichi; Higuchi, Takahiro; Kawashima, Atsuhiro; Muramori, Akira; Nakajima, Kenichi; Tait, J.F.; Matsunari, Ichiro; Vanderheyden, J.L.; Strauss, H.W.

    2007-01-01

    The background of this study was to determine whether mild to moderate ischemia that is not severe enough to induce myocardial infarction will cause myocardial cell damage or apoptosis, the 99m Tc-Annexin-V (Tc-A) uptake was studied in groups of rats with various intervals of coronary occlusion and reperfusion times. After left coronary artery occlusion for 15 min (n=23), 10 min (n=23), or 5 min (n=12), Tc-A (80-150 MBq) was injected at 0.5, 1.5, 6, or 24 h after reperfusion. One hour later, to verify the area at risk, 201 Tl (0.74 MBq) was injected just after left coronary artery re-occlusion and the rats were killed 1 min later. Dual tracer autoradiography was performed to assess Tc-A uptake and area at risk. In all 5-min occlusion and reperfusion models, no significant Tc-A uptake was observed in the area at risk. Tc-A uptake ratios in the 15-min and 10-min ischemia models were 4.46±3.16 and 2.02±0.47 (p=0.078) at 0.5 h after reperfusion, 3.49±1.78 and 1.47±0.11 (p<0.05) at 1.5 h after reperfusion, 1.60±0.43 and 1.34±0.23 (p=0.24) at 6 h after reperfusion, 1.50±0.33 and 1.28±0.33 (p=0.099) at 24 h after reperfusion, respectively. With 15-min ischemia, in 3 of the 5 rats there were a few micro-foci of myocardial cell degeneration and cell infiltration in less than 1% of the ischemic area at 24 h after reperfusion. No significant histological change was observed in rats with 10-min or 5-min ischemia. The data indicate that Tc-A binding depends on the severity of ischemia even without a significant amount of histological change or infarction. (author)

  19. 99mTc-annexin V and 111In-antimyosin antibody uptake in experimental myocardial infarction in rats

    International Nuclear Information System (INIS)

    Sarda-Mantel, Laure; Rouzet, Francois; Martet, Genevieve; Raguin, Olivier; Vrigneaud, Jean-Marc; Guludec, Dominique Le; Michel, Jean-Baptiste; Louedec, Liliane; Vanderheyden, Jean-Luc; Hervatin, Florence; Khaw, Ban An

    2006-01-01

    99m Tc-annexin V (ANX) allows scintigraphic detection of apoptotic cells via specific binding to exposed phosphatidylserine. In myocardial infarction, apoptosis of myocytes is variable and depends especially on the presence or absence of coronary reperfusion. In this study, ANX uptake in non-reperfused experimental myocardial infarcts was compared with uptake of a marker of myocyte necrosis ( 111 In-antimyosin antibodies, AM) and an immunohistochemical marker of apoptosis (Apostain). The left anterior coronary artery was ligated in 47 Wistar rats, which were then injected with ANX (n=20), AM (n=21) or both (n=6). Myocardial uptake of ANX and AM was determined at 2 h (n=14), 4 h (n=14) and 24 h (n=19) after coronary ligation (CL), by quantitative autoradiography with (n=23) or without (n=24) gamma imaging. Heart-to-lung ratios (HLRs) and infarct-to-remote myocardium activity ratios (INRs) were calculated on the scintigrams and autoradiograms respectively. Cardiac sections were stained with haematoxylin-eosin and Apostain. The above studies were repeated in 12 normal rats. All rats with CL showed increased ANX and AM uptake in cardiac areas on scintigrams 24 h after CL, with HLRs higher than in controls: 3.1±0.6 versus 1.5±0.3 (p=0.001) for ANX and 1.99±0.44 versus 1.01±0.05 (p<0.0005) for AM. Autoradiography showed intense ANX and AM uptake in infarcts, with comparable topography and INRs at 2 h, 4 h and 24 h after CL (4.6±0.9 versus 5.0±1.8 at 24 h), while Apostain staining was very low (0.06±0.06% of cells). In this model of persistent CL, we observed increased ANX uptake in injured myocardium, comparable in intensity, topography and kinetics to that of AM. There was only minimal Apostain staining in the same areas. (orig.)

  20. Comparative pharmacokinetics and biodistribution studies of 99mTc-annexin V produced by different radiolabeling methods

    International Nuclear Information System (INIS)

    Santos, Josefina da Silva; Pujatti, Priscilla Brunelli; Couto, Renata Martinussi; Mengatti, Jair; Araujo, Elaine Bortoleti de

    2009-01-01

    The use of radiolabeled annexin A5 (ANXA5) to detect cell death in vivo has increased in the last years. Several 99m Tc-labeling techniques were reported using different cores, such as [ 99m Tc=O] +3 , [ 99m Tc]HYNIC, [ 99m Tc≡N] +2 and [Tc(CO 3 )] +1 . The goal of the present work was to evaluate the influence of 99m Tc cores in the biological behavior of radiolabeled ANXA5 in Swiss mice using [ 99m Tc=O] +3 , [ 99m Tc]HYNIC cores. Ethylenedicysteine (EC) was applied to obtain [Tc=O] +3 core, N,N,N',N'-tetramethyl(succinimide) uranium tetrafluoroborate (TSTU) was employed to transfer the carboxyl group to their corresponding hydroxysuccinimide ester and HYNIC-ANXA5 was provided by National Cancer Institute-Frederick. ITLC-SG and HPLC analysis were applied to determine non-desirable products and the stability of preparations was evaluated after incubation at room temperature, 4 deg C and in human serum at 37 deg C. In vivo biodistribution and kinetics studies were performed after the intravenous injection of 99m Tc-HYNIC-ANXA5 and 99m Tc-EC-ANXA5 and pharmacokinetic parameters were calculated using Biexp software. ANXA5 was radiolabeled at room temperature with high yield (> 95%). The results of biodistribution in mice showed, as expected, higher renal uptake of 99m Tc-HYNICANXA5 and higher liver uptake of 99m Tc-EC-ANXA5. The percent injected activity per gram (% IA/g) in liver at 0.5 hours were 6.52 and 1.09 and in kidneys were 1.59 and 32.2 for 99m Tc-EC-ANXA5 and 99m Tc-HYNICANXA5, respectively. The results of radioactivity in blood showed that both HYNIC- and EC- radiolabeled ANXA5 presented fast blood clearance. In this study two 99m Tc-ANXA5 obtained from three different available radiolabeling methods presently were investigated. Each labeling method possesses unique advantages and disadvantages. (author)

  1. Monitoring Cell Death in Regorafenib-Treated Experimental Colon Carcinomas Using Annexin-Based Optical Fluorescence Imaging Validated by Perfusion MRI.

    Directory of Open Access Journals (Sweden)

    Philipp M Kazmierczak

    Full Text Available To investigate annexin-based optical fluorescence imaging (OI for monitoring regorafenib-induced early cell death in experimental colon carcinomas in rats, validated by perfusion MRI and multiparametric immunohistochemistry.Subcutaneous human colon carcinomas (HT-29 in athymic rats (n = 16 were imaged before and after a one-week therapy with regorafenib (n = 8 or placebo (n = 8 using annexin-based OI and perfusion MRI at 3 Tesla. Optical signal-to-noise ratio (SNR and MRI tumor perfusion parameters (plasma flow PF, mL/100mL/min; plasma volume PV, % were assessed. On day 7, tumors underwent immunohistochemical analysis for tumor cell apoptosis (TUNEL, proliferation (Ki-67, and microvascular density (CD31.Apoptosis-targeted OI demonstrated a tumor-specific probe accumulation with a significant increase of tumor SNR under therapy (mean Δ +7.78±2.95, control: -0.80±2.48, p = 0.021. MRI detected a significant reduction of tumor perfusion in the therapy group (mean ΔPF -8.17±2.32 mL/100 mL/min, control -0.11±3.36 mL/100 mL/min, p = 0.036. Immunohistochemistry showed significantly more apoptosis (TUNEL; 11392±1486 vs. 2921±334, p = 0.001, significantly less proliferation (Ki-67; 1754±184 vs. 2883±323, p = 0.012, and significantly lower microvascular density (CD31; 107±10 vs. 182±22, p = 0.006 in the therapy group.Annexin-based OI allowed for the non-invasive monitoring of regorafenib-induced early cell death in experimental colon carcinomas, validated by perfusion MRI and multiparametric immunohistochemistry.

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

    International Nuclear Information System (INIS)

    Sakwe, Amos M.; Koumangoye, Rainelli; Guillory, Bobby; Ochieng, Josiah

    2011-01-01

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

  3. Annexin A10 optimally differentiates between intrahepatic cholangiocarcinoma and hepatic metastases of pancreatic ductal adenocarcinoma: a comparative study of immunohistochemical markers and panels.

    Science.gov (United States)

    Kälsch, Julia; Padden, Juliet; Bertram, Stefanie; Pott, Leona L; Reis, Henning; Westerwick, Daniela; Schaefer, Christoph M; Sowa, Jan-P; Möllmann, Dorothe; Fingas, Christian; Dechȇne, Alexander; Sitek, Barbara; Eisenacher, Martin; Canbay, Ali; Ahrens, Maike; Baba, Hideo A

    2017-05-01

    Discriminating intrahepatic cholangiocarcinoma (ICC) from hepatic metastases of pancreatic ductal adenocarcinoma (mPDAC) can be challenging. While pathologists might depend on clinical information regarding a primary tumor, their diagnosis will lead the patient either to potentially curative surgery (for ICC) or to palliation (for mPDAC). Beyond the validation of recently published potential biomarkers for PDAC (primary or metastatic) in a large cohort, we assessed diagnostic performance of the most promising candidates in the challenging task of discriminating metastatic PDAC (mPDAC) from ICC. In a training set of 87 ICC and 88 pPDAC, our previously identified biomarkers Annexin A1 (ANXA1), ANXA10, and ANXA13 were tested and compared with 11 published biomarkers or panels (MUCIN 1, Agrin, S100P, MUC5 AC, Laminin, VHL, CK 17, N-Cadherin, ELAC2, PODXL and HSPG2). Biomarkers with best results were further tested in an independent series of biopsies of 27 ICC and 36 mPDAC. Highest AUC values (between 0.72 and 0.84) for the discrimination between ICC and pPDAC were found in the training set for Annexin A1, Annexin A10, MUC5 AC, CK17, and N-Cadherin. These markers were further tested on an independent series of liver biopsies containing ICC or mPDAC. Diagnostic characteristics were evaluated for individual markers as well as for 3× panels. ANXA 10 showed the highest diagnostic potential of all single markers, correctly classifying 75% of mPDAC and 85% of ICC. Our results suggest that ANXA10 may be useful to differentiate between ICC and mPDAC, when only a tissue specimen is available.

  4. Expression of Annexin-A1 and Galectin-1 Anti-Inflammatory Proteins and mRNA in Chronic Gastritis and Gastric Cancer

    Directory of Open Access Journals (Sweden)

    Yvana Cristina Jorge

    2013-01-01

    Full Text Available Objective. The anti-inflammatory proteins annexin-A1 and galectin-1 have been associated with tumor progression. This scenario prompted us to investigate the relationship between the gene and protein expression of annexin-A1 (ANXA1/AnxA1 and galectin-1 (LGALS1/Gal-1 in an inflammatory gastric lesion as chronic gastritis (CG and gastric adenocarcinoma (GA and its association with H. pylori infection. Methods. We analyzed 40 samples of CG, 20 of GA, and 10 of normal mucosa (C by the quantitative real-time PCR (qPCR technique and the immunohistochemistry assay. Results. High ANXA1 mRNA expression levels were observed in 90% (36/40 of CG cases (mean relative quantification RQ = 4.26 ± 2.03 and in 80% (16/20 of GA cases (mean RQ = 4.38 ± 4.77. However, LGALS1 mRNA levels were high (mean RQ = 2.44 ± 3.26 in 60% (12/20 of the GA cases, while low expression was found in CG (mean RQ = 0.43±3.13; P<0.01. Normal mucosa showed modest immunoreactivity in stroma but not in epithelium, while stroma and epithelium displayed an intense immunostaining in CG and GA for both proteins. Conclusion. These results have provided evidence that galectin-1 and mainly annexin-A1 are overexpressed in both gastritis and gastric cancer, suggesting a strong association of these proteins with chronic gastric inflammation and carcinogenesis.

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

    Energy Technology Data Exchange (ETDEWEB)

    Sakwe, Amos M., E-mail: asakwe@mmc.edu [Department of Biochemistry and Cancer Biology, Meharry Medical College, Nashville, TN 37208 (United States); Koumangoye, Rainelli; Guillory, Bobby [Department of Biochemistry and Cancer Biology, Meharry Medical College, Nashville, TN 37208 (United States); Ochieng, Josiah [Department of Biochemistry and Cancer Biology, Meharry Medical College, Nashville, TN 37208 (United States); Center for Aids Health Disparity Research, Meharry Medical College, Nashville, TN 37208 (United States); Department of Cancer Biology, Vanderbilt University, Nashville, TN (United States)

    2011-04-01

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

  6. In vivo prediction of anti-tumor effect of 3-bromopyruvate in hepatocellular carcinoma using Tc-99m labeled annexin-v imaging

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Won; Yoon, Jung Hwan; Kim, Chung Yang [Seoul National University College of Medicine, Seoul (Korea, Republic of); Cheon, Gi Jeoog; Lee, Tae Sup; Woo, Kwang Sun; Chung, Wee Sup [Korea Institute of Radiological and Medical Sciences, Seoul (Korea, Republic of)

    2005-07-01

    We have recently demonstrated that hypoxia stimulates hepatocellular carcinoma (HCC) cell growth through hexokinase II induction, and its inhibition induces apoptotic cell death through activating mitochondrial apoptotic signaling cascades. In this study, we were apt to evaluate the antitumoral effect of 3-bromopyruvate (3-BP) on in vivo model of HCC by apoptotic imaging using Tc-99m labeled annexin V. In vivo model of HCC was established in C3H mice intradermally implanted with MH134 cells, a mouse HCC cell line, and 3-BP (0, 5, 10 mg/kg) was subsequently administered intraperitoneally. Tc-99m-HYNIC-annexin V (185 KBq) was injected via tail vein at one and three days after the 3-BP treatment, planar scan was acquired at a hour after the injection using gamma camera. The anti-tumor effect was evaluated by measuring tumor volumes and quantification of apoptotic cells using terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) staining. Tumor volume was significantly reduced in mice treated with 3-BP in a dose-dependent manner (mean tumor volume 1.07 vs. 0.58 vs. 0.39 cm{sup 3} in 3-BP 0, 5, 10 mg/kg, respectively: p=0.047). The percentage of TUNEL staining-positive cells was significantly increased in 3-BP-treated mice (0.53 vs. 1.40 vs. 1.84% in 3-BP 0, 5, 10 mg/kg, respectively; p=0.018). On Tc-99m-HYNIC annexin V imaging, tumor-to-background uptake ratio (UR) was 1.92 at one day and 4.23 at three days after 3-BP treatment of 5 mg/kg (non-treated tumor showed UR of 2.93). Apoptosis-inducing anti-tumor effect of 3-BP was able to be demonstrated in in vivo model of HCC by apoptotic in vivo imaging using Tc-99m-HYNIC annexin V.

  7. In vivo prediction of anti-tumor effect of 3-bromopyruvate in hepatocellular carcinoma using Tc-99m labeled annexin-v imaging

    International Nuclear Information System (INIS)

    Kim, Won; Yoon, Jung Hwan; Kim, Chung Yang; Cheon, Gi Jeoog; Lee, Tae Sup; Woo, Kwang Sun; Chung, Wee Sup

    2005-01-01

    We have recently demonstrated that hypoxia stimulates hepatocellular carcinoma (HCC) cell growth through hexokinase II induction, and its inhibition induces apoptotic cell death through activating mitochondrial apoptotic signaling cascades. In this study, we were apt to evaluate the antitumoral effect of 3-bromopyruvate (3-BP) on in vivo model of HCC by apoptotic imaging using Tc-99m labeled annexin V. In vivo model of HCC was established in C3H mice intradermally implanted with MH134 cells, a mouse HCC cell line, and 3-BP (0, 5, 10 mg/kg) was subsequently administered intraperitoneally. Tc-99m-HYNIC-annexin V (185 KBq) was injected via tail vein at one and three days after the 3-BP treatment, planar scan was acquired at a hour after the injection using gamma camera. The anti-tumor effect was evaluated by measuring tumor volumes and quantification of apoptotic cells using terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) staining. Tumor volume was significantly reduced in mice treated with 3-BP in a dose-dependent manner (mean tumor volume 1.07 vs. 0.58 vs. 0.39 cm 3 in 3-BP 0, 5, 10 mg/kg, respectively: p=0.047). The percentage of TUNEL staining-positive cells was significantly increased in 3-BP-treated mice (0.53 vs. 1.40 vs. 1.84% in 3-BP 0, 5, 10 mg/kg, respectively; p=0.018). On Tc-99m-HYNIC annexin V imaging, tumor-to-background uptake ratio (UR) was 1.92 at one day and 4.23 at three days after 3-BP treatment of 5 mg/kg (non-treated tumor showed UR of 2.93). Apoptosis-inducing anti-tumor effect of 3-BP was able to be demonstrated in in vivo model of HCC by apoptotic in vivo imaging using Tc-99m-HYNIC annexin V

  8. Evaluation of radiolabelled annexin A5 for scintigraphic imaging of cell processes (necrosis/apoptosis) in cardiovascular diseases; Evaluation de radiotraceurs derives de l'annexine A5 pour l'imagerie scintigraphique de processus cellulaires (apoptose/necrose/thrombose) en pathologie cardiovasculaire (Ressource electronique)

    Energy Technology Data Exchange (ETDEWEB)

    Sarda-Mantel, L

    2007-03-15

    Annexin A5, a 35KDa protein, specifically binds with high affinity to phosphatidylserine (P.S.) which is actively redistributed to the external leaflet of plasmic membranes in apoptotic cells and activated platelets. Annexin A5 radiolabelled with {sup 99m}Tc({sup 99m}Tc-ANX5) was developed by Strauss (stanford, Usa) to image apoptosis in vivo: tumours cells apoptosis induced by chemo-radiotherapy, ischemia/reperfusion lesions in animals and patients, graft rejection. Additionally, many in vitro data suggest that annexin A5 also stains necrosis (membrane disruption), which occurs in all types of cell death. This preclinical work aimed to evaluate the potential interest of {sup 99m}Tc-ANX5 imaging as a clinical tool in cardiovascular diseases. Four studies performed in rat models of myocardial infarction by coronary ligation and ischemia-reperfusion, and in rat models of subacute and acute (isoproterenol-induced) myocarditis show the ability of {sup 99m}Tc-ANX5 to detect in vivo cardio myocytes death by apoptosis and necrosis. Another study demonstrates that {sup 99m}Tc-ANX5 is highly accurate to evaluate in vivo the biological activity of parietal thrombus in a rat model of elastase-induced abdominal aortic aneurysm. These results suggest that {sup 99m}Tc-ANX5 imaging could be used in patients for non invasive diagnosis, prognostic evaluation in acute myocarditis and in various thrombotic cardiovascular diseases. (author)

  9. Somatostatin receptors

    DEFF Research Database (Denmark)

    Møller, Lars Neisig; Stidsen, Carsten Enggaard; Hartmann, Bolette

    2003-01-01

    functional units, receptors co-operate. The total receptor apparatus of individual cell types is composed of different-ligand receptors (e.g. SRIF and non-SRIF receptors) and co-expressed receptor subtypes (e.g. sst(2) and sst(5) receptors) in characteristic proportions. In other words, levels of individual......-peptides, receptor agonists and antagonists. Relatively long half lives, as compared to those of the endogenous ligands, have been paramount from the outset. Motivated by theoretical puzzles or the shortcomings of present-day diagnostics and therapy, investigators have also aimed to produce subtype...

  10. Expression of annexin-A1 and galectin-1 anti-inflammatory proteins and mRNA in chronic gastritis and gastric cancer.

    Science.gov (United States)

    Jorge, Yvana Cristina; Mataruco, Mayra Mioto; Araújo, Leandro Pires; Rossi, Ana Flávia Teixeira; de Oliveira, Juliana Garcia; Valsechi, Marina Curado; Caetano, Alaor; Miyazaki, Kenji; Fazzio, Célia Sebastiana de Jesus; Thomé, Jorge Alberto; Rahal, Paula; Oliani, Sonia Maria; Silva, Ana Elizabete

    2013-01-01

    The anti-inflammatory proteins annexin-A1 and galectin-1 have been associated with tumor progression. This scenario prompted us to investigate the relationship between the gene and protein expression of annexin-A1 (ANXA1/AnxA1) and galectin-1 (LGALS1/Gal-1) in an inflammatory gastric lesion as chronic gastritis (CG) and gastric adenocarcinoma (GA) and its association with H. pylori infection. We analyzed 40 samples of CG, 20 of GA, and 10 of normal mucosa (C) by the quantitative real-time PCR (qPCR) technique and the immunohistochemistry assay. High ANXA1 mRNA expression levels were observed in 90% (36/40) of CG cases (mean relative quantification RQ = 4.26  ±  2.03) and in 80% (16/20) of GA cases (mean RQ = 4.38  ±  4.77). However, LGALS1 mRNA levels were high (mean RQ = 2.44  ±  3.26) in 60% (12/20) of the GA cases, while low expression was found in CG (mean RQ = 0.43 ± 3.13; P gastritis and gastric cancer, suggesting a strong association of these proteins with chronic gastric inflammation and carcinogenesis.

  11. {sup 99m}Tc-Annexin A5 quantification of apoptotic tumor response: a systematic review and meta-analysis of clinical imaging trials

    Energy Technology Data Exchange (ETDEWEB)

    Belhocine, Tarik Z. [Western University, Biomedical Imaging Research Centre (BIRC), London, Ontario (Canada); Blankenberg, Francis G. [Lucile Salter Packard Children' s Hospital, Stanford, Division of Pediatric Radiology, Department of Radiology, Palo Alto, CA (United States); Kartachova, Marina S. [Medical Center Alkmaar, Department of Nuclear Medicine, Alkmaar (Netherlands); Stitt, Larry W. [LW Stitt Statistical Services, London, Ontario (Canada); Vanderheyden, Jean-Luc [JLVMI Consulting LLC, Waukesha, WI (United States); Hoebers, Frank J.P. [Maastricht University Medical Centre, Department of Radiation Oncology (MAASTRO Clinic), GROW School for Oncology and Developmental Biology, Maastricht (Netherlands); Wiele, Christophe van de [University Hospital Ghent, Department of Nuclear Medicine and Radiology, Ghent (Belgium)

    2015-12-15

    {sup 99m}Tc-Annexin A5 has been used as a molecular imaging probe for the visualization, characterization and measurement of apoptosis. In an effort to define the quantitative {sup 99m}Tc-annexin A5 uptake criteria that best predict tumor response to treatment, we performed a systematic review and meta-analysis of the results of all clinical imaging trials found in the literature or publicly available databases. Included in this review were 17 clinical trials investigating quantitative {sup 99m}Tc-annexin A5 (qAnx5) imaging using different parameters in cancer patients before and after the first course of chemotherapy and/or radiation therapy. Qualitative assessment of the clinical studies for diagnostic accuracy was performed using the QUADAS-2 criteria. Of these studies, five prospective single-center clinical trials (92 patients in total) were included in the meta-analysis after exclusion of one multicenter clinical trial due to heterogeneity. Pooled positive predictive values (PPV) and pooled negative predictive values (NPV) (with 95 % CI) were calculated using Meta-Disc software version 1.4. Absolute quantification and/or relative quantification of {sup 99m}Tc-annexin A5 uptake were performed at baseline and after the start of treatment. Various quantitative parameters have been used for the calculation of {sup 99m}Tc-annexin A5 tumor uptake and delta (Δ) tumor changes post-treatment compared to baseline including: tumor-to-background ratio (TBR), ΔTBR, tumor-to-noise ratio, relative tumor ratio (TR), ΔTR, standardized tumor uptake ratio (STU), ΔSTU, maximum count per pixel within the tumor volume (Cmax), Cmax%, absolute ΔU and percentage (ΔU%), maximum ΔU counts, semiquantitative visual scoring, percent injected dose (%ID) and %ID/cm{sup 3}. Clinical trials investigating qAnx5 imaging have included patients with lung cancer, lymphoma, breast cancer, head and neck cancer and other less common tumor types. In two phase I/II single-center clinical trials

  12. ¹¹¹In-DOTA-Annexin V for imaging of apoptosis during HSV1-tk/GCV prodrug activation gene therapy in mice with NG4TL4 sarcoma.

    Science.gov (United States)

    Lin, Ming-Hsien; Wu, Shih-Yen; Wang, Hsin-Ell; Liu, Ren-Shyan; Chen, Jyh-Cheng

    2016-02-01

    Apoptosis has been suggested as a cytocidal mechanism of the HSV1-tk-expressing cells when exposed to ganciclovir (GCV). This study evaluated the efficacy of (111)In-labeled Annexin V for monitoring tumor responses during prodrug activation gene therapy with HSV1-tk and GCV. Annexin V was conjugated to DOTA using N-hydroxysulfosuccinimide (sulfo-NHS) and 1-ethyl-3-[3-(dimethylamino)propyl]carbodiimide (EDC), labeled with (111)In-InCl3 and purified using size exclusion chromatography to give (111)In-DOTA-Annexin V conjugate. The radiochemical yield and the radiochemical purity of (111)In-DOTA-Annexin V were 74±12% and 98±3%, respectively (n=10). (111)In-DOTA-BSA was prepared similarly. An in vitro study to demonstrate the apoptosis of NG4TL4-STK cells after GCV treatment has been performed. Mice bearing NG4TL4-STK and NG4TL4-WT tumors were treated with GCV (10 mg/kg daily) by i.p. injection for 7 consecutive days. Before and during the GCV treatment, biodistribution studies and scintigraphic imaging were performed at 2h post injection of the radiotracers. The uptake of (111)In-DOTA-Annexin V in treated cells (13.41±1.30%) was 4.1 times higher than that in untreated cells (3.21±0.37%). The GCV-induced cell apoptosis in NG4TL4-STK tumor resulted in a significantly increasing accumulation of (111)In-DOTA-Annexin V (1.92±0.32%ID/g at day 0, 4.79±0.86%ID/g at day 2, 4.56±0.58%ID/g at day 4) was observed, but not for that of (111)In-DOTA-BSA. During consecutive GCV treatment, scintigraphic imaging with (111)In-DOTA-Annexin V revealed high uptake in NG4TL4-STK tumor compared with that in NG4TL4-WT tumor. However, no specific (111)In-DOTA-BSA accumulation in NG4TL4-STK and NG4TL4-WT tumors was observed throughout the course of GCV treatment. This study demonstrated that (111)In-DOTA-Annexin V can be used for monitoring tumor cell apoptosis during prodrug activation gene therapy with HSV1-tk and GCV for cancer treatment. Copyright © 2015 Elsevier Ltd. All rights

  13. Receptor assay

    Energy Technology Data Exchange (ETDEWEB)

    Kato, K; Ibayashi, H [Kyushu Univ., Fukuoka (Japan). Faculty of Medicine

    1975-05-01

    This paper summarized present status and problems of analysis of hormone receptor and a few considerations on clinical significance of receptor abnormalities. It was pointed that in future clinical field quantitative and qualitative analysis of receptor did not remain only in the etiological discussion, but that it was an epoch-making field of investigation which contained the possiblity of artificial change of sensitivity of living body on drugs and the development connected directly with treatment of various diseases.

  14. In vitro and in vivo evaluation of [{sup 99m}Tc]-labeled tricarbonyl His-annexin A5 as an imaging agent for the detection of phosphatidylserine-expressing cells

    Energy Technology Data Exchange (ETDEWEB)

    Vangestel, Christel, E-mail: christel.vangestel@ugent.b [Department of Gastroenterology, Ghent University Hospital, 9000-B Ghent (Belgium); Peeters, Marc [Department of Gastroenterology, Ghent University Hospital, 9000-B Ghent (Belgium); Oltenfreiter, Ruth; D' Asseler, Yves [Department of Nuclear Medicine and Radiology, Ghent University Hospital, 9000-B Ghent (Belgium); Staelens, Steven [Department of Medical Signal and Image Processing Group, Faculty of Engineering, Ghent University-IBBT, 9000-B Ghent (Belgium); Van Steenkiste, Magali [Department of Radiopharmacy, Ghent University, 9000-B Ghent (Belgium); Philippe, Jan [Department of Clinical Biology, Microbiology and Immunology, Ghent University, 9000-B Ghent (Belgium); Kusters, Dennis; Reutelingsperger, Chris [Department of Biochemistry, Cardiovascular Research Institute, University of Maastricht, 6200 MD Maastricht (Netherlands); Van Damme, Nancy [Department of Gastroenterology, Ghent University Hospital, 9000-B Ghent (Belgium); Van de Wiele, Christophe [Department of Nuclear Medicine and Radiology, Ghent University Hospital, 9000-B Ghent (Belgium)

    2010-11-15

    Introduction: Apoptosis is one of the mechanisms behind successful chemotherapy and radiation treatment. Radiolabeled annexin A5 has been demonstrated to be a successful tool in the detection of apoptosis following chemotherapy in vivo. Methods: His-tagged annexin A5 was labeled with [{sup 99m}Tc]-tricarbonyl and evaluated as apoptosis imaging radiotracer in vitro and in vivo. The binding of the radiotracer was evaluated in Colo205 cells stimulated with 5-FU (1 mM) for 4 and 24 h, and confirmed by flow cytometry. Biodistribution and dosimetric studies were performed in healthy nude mice (n=5) via planar scintigraphy. [{sup 99m}Tc]-(CO){sub 3} His-annexin A5 was also evaluated for in vivo imaging of spontaneous apoptosis in Colo205-bearing mice (n=12). Results: The labeling procedure yielded a compound with 95-99% radiochemical purity and good in vitro stability. In vitro binding experiments indicated that the radiotracer retained its PS-binding activity. [{sup 99m}Tc]-(CO){sub 3} His-annexin A5 rapidly cleared from the blood and predominantly accumulated in the kidneys. Absorbed dose (per organ) was found to be 116{+-}64 {mu}Gy/MBq for the kidneys and 10.38{+-}0.50 {mu}Gy/MBq for the liver. The effective dose was 7.00{+-}0.28 {mu}Sv/MBq. Spontaneous apoptosis in Colo205-bearing mice was visualised by [{sup 99m}Tc]-(CO){sub 3} His-annexin A5 SPECT and correlated well with caspase-3 immunostaining (R=0.867, P<.01). Conclusion: [{sup 99m}Tc]-(CO){sub 3} His-annexin A5 may be a useful novel radioligand for the in vivo detection of cell death associated with PS expression. A simple, noninvasive way of detecting apoptosis in vivo could have many applications including a better understanding of the extent and timing of apoptosis in response to cancer therapies and assessment of early tumor response.

  15. Annexin A2 promotes the migration and invasion of human hepatocellular carcinoma cells in vitro by regulating the shedding of CD147-harboring microvesicles from tumor cells.

    Directory of Open Access Journals (Sweden)

    Wei Zhang

    Full Text Available It has been reported that Annexin A2 (ANXA2 is up-regulated in hepatocellular carcinoma (HCC, but the roles of ANXA2 in the migration and invasion of HCC cells have not been determined. In this study, we found that ANXA2-specific siRNA (si-ANXA2 significantly inhibited the migration and invasion of HCC cells co-cultured with fibroblasts in vitro. In addition, the production of MMP-2 by fibroblasts cultured in supernatant collected from si-ANXA2-transfected HCC cells was notably down-regulated. ANXA2 was also found to be co-localized and co-immunoprecipitated with CD147. Further investigation revealed that the expression of ANXA2 in HCC cells affected the shedding of CD147-harboring membrane microvesicles, acting as a vehicle for CD147 in tumor-stromal interactions and thereby regulating the production of MMP-2 by fibroblasts. Together, these results suggest that ANXA2 enhances the migration and invasion potential of HCC cells in vitro by regulating the trafficking of CD147-harboring membrane microvesicles.

  16. Proteomic Identification of an Upregulated Isoform of Annexin A3 in the Spinal Cords of Rats in a Neuropathic Pain Model

    Directory of Open Access Journals (Sweden)

    Wangyuan Zou

    2017-09-01

    Full Text Available Neuropathic pain (NP is induced by nerve damage or a disturbance in the peripheral or central nervous systems. Nerve damage causes the activation of sensitizing mechanisms in the peripheral and central nervous systems, which induces transcriptional and post-transcriptional alterations in sensory nerves. However, the underlying mechanisms of NP remain elusive. In the study, Two-dimensional gel electrophoresis (2DGE-based comparative proteomics identified 38 differential gel spots, and 15 differentially expressed proteins (DEPs between the sham and the chronic constriction injury (CCI-induced neuropathic pain rats. Of them, Annexin A3 (ANXA3 was significantly increased after CCI with Western blot analysis and immunofluorescence imaging. A lentivirus delivering ANXA3 shRNA (LV-shANXA3 was administered intrathecally to determine the analgesic effects of ANXA3 on allodynia and hyperalgesia in a CCI-induced neuropathic pain model in rats. Further study showed that LV-shANXA3 reversed the upregulation of ANXA3, alleviated CCI-induced mechanical allodynia and thermal hyperalgesia. The study indicated that ANXA3 may play an important role in neuropathic pain.

  17. Distinct Signaling Cascades Elicited by Different Formyl Peptide Receptor 2 (FPR2 Agonists

    Directory of Open Access Journals (Sweden)

    Fabio Cattaneo

    2013-04-01

    Full Text Available The formyl peptide receptor 2 (FPR2 is a remarkably versatile transmembrane protein belonging to the G-protein coupled receptor (GPCR family. FPR2 is activated by an array of ligands, which include structurally unrelated lipids and peptide/proteins agonists, resulting in different intracellular responses in a ligand-specific fashion. In addition to the anti-inflammatory lipid, lipoxin A4, several other endogenous agonists also bind FPR2, including serum amyloid A, glucocorticoid-induced annexin 1, urokinase and its receptor, suggesting that the activation of FPR2 may result in potent pro- or anti-inflammatory responses. Other endogenous ligands, also present in biological samples, include resolvins, amyloidogenic proteins, such as beta amyloid (Aβ-42 and prion protein (Prp106–126, the neuroprotective peptide, humanin, antibacterial peptides, annexin 1-derived peptides, chemokine variants, the neuropeptides, vasoactive intestinal peptide (VIP and pituitary adenylate cyclase activating polypeptide (PACAP-27, and mitochondrial peptides. Upon activation, intracellular domains of FPR2 mediate signaling to G-proteins, which trigger several agonist-dependent signal transduction pathways, including activation of phospholipase C (PLC, protein kinase C (PKC isoforms, the phosphoinositide 3-kinase (PI3K/protein kinase B (Akt pathway, the mitogen-activated protein kinase (MAPK pathway, p38MAPK, as well as the phosphorylation of cytosolic tyrosine kinases, tyrosine kinase receptor transactivation, phosphorylation and nuclear translocation of regulatory transcriptional factors, release of calcium and production of oxidants. FPR2 is an attractive therapeutic target, because of its involvement in a range of normal physiological processes and pathological diseases. Here, we review and discuss the most significant findings on the intracellular pathways and on the cross-communication between FPR2 and tyrosine kinase receptors triggered by different FPR2

  18. Nattokinase, profibrinolytic enzyme, effectively shrinks the nasal polyp tissue and decreases viscosity of mucus.

    Science.gov (United States)

    Takabayashi, Tetsuji; Imoto, Yoshimasa; Sakashita, Masafumi; Kato, Yukinori; Tokunaga, Takahiro; Yoshida, Kanako; Narita, Norihiko; Ishizuka, Tamotsu; Fujieda, Shigeharu

    2017-10-01

    Chronic rhinosinusitis with nasal polyps (CRSwNP) is often comorbid with asthma and resistant to therapeutic interventions. We recently reported that excessive fibrin deposition caused by impairment of fibrinolysis might play pivotal role in forming nasal polyp. Nattokinase (NK), a serine protease produced by Bacillus subtilis, has been reported to be a strong fibrinolytic enzyme. NK could be a promising drug candidate for use in the treatment of both CRSwNP and asthma. The objective of this study was to investigate the effects of NK on nasal polyp tissues from patients with CRSwNP. The nasal discharge from patients with CRSwNP and sputum from subjects with asthma were also used to investigate whether NK influences the viscosity of mucus. To examine the effects on NK on nasal polyp tissues, pieces of nasal polyps were incubated either with saline or NK (10-1000 FU/ml) at 37 °C for 24 h. We assessed the presence of fibrin in nasal polyp tissue incubated with NK by means of immunohistochemistry. To examine the effects of NK on nasal discharge and sputum from patients with CRSwNP and asthma, respectively, were incubated with NK solution at 37 °C for 1 h. NK effectively shrinks the nasal polyp tissue through fibrin degradation. We also found that the viscosity of the nasal discharge and sputum from patients with CRSwNP and asthma, respectively, was significantly reduced by incubation with NK solution. NK may be an effective alternative therapeutic option in patients with CRSwNP and comorbid asthma by causing fibrin degradation. Copyright © 2017 Japanese Society of Allergology. Production and hosting by Elsevier B.V. All rights reserved.

  19. The role of MAPK in CD4+ T cells toll-like receptor 9-mediated signaling following HHV-6 infection

    International Nuclear Information System (INIS)

    Chi, Jing; Wang, Fang; Li, Lingyun; Feng, Dongju; Qin, Jian; Xie, Fangyi; Zhou, Feng; Chen, Yun; Wang, Jinfeng; Yao, Kun

    2012-01-01

    Human herpesvirus-6 (HHV-6) is an important immunosuppressive and immunomodulatory virus that primarily infects immune cells (mainly CD4 + T cells) and strongly suppresses the proliferation of infected cells. Toll-like receptors are pattern-recognition receptors essential for the development of an appropriate innate immune defense against infection. To understand the role of CD4 + T cells in the innate response to HHV-6 infection and the involvement of TLRs, we used an in vitro infection model and observed that the infection of CD4 + T cells resulted in the activation of JNK/SAPK via up-regulation of toll-like receptor 9 (TLR9). Associated with JNK activation, annexin V-PI staining indicated that HHV-6A was a strong inducer of apoptosis. Apoptotic response associated cytokines, IL-6 and TNF-α also induced by HHV-6A infection.

  20. Biological studies in animal models using [99mTc](CO)3 recombinant annexin V as diagnostic agent of apoptotic processes

    International Nuclear Information System (INIS)

    Teran, Mariella Adriana; Martinez, Elena; Reyes, Ana L.; Paolino, Andrea; Vital, Marcelo; Esperon, Patricia; Pacheco, Jose P.; Savio, Eduardo

    2011-01-01

    Introduction: There are many diseases associated with variations in the expression of apoptosis such as organ rejection after transplantation, myocardial ischemia or infarct and neurodegenerative diseases. For this reason, the early visualization of this process is relevant to set fast and effective therapeutic strategies. Methods: The precursor was prepared according to the procedure reported by R. Alberto, R. Schibli, P. Schubiger, U. Abram, and T. Kaden [Reactions with the technetium and rhenium carbonyl complexes (NEt 4 )[MX 3 (CO) 3 ]. Synthesis and structure of Tc(CN-But) 3 (CO) 3 ](NO 3 ) and (Net 4 )[Tc 2 (μ-SCH 2 CH 2 OH) 3 (CO) 3 ], Polyhedron 1996;15: 1079-89]. Recombinant annexin V was incubated with [ 99m Tc](H 2 O)3(CO) 3 + solution, previously neutralized with buffer. Biodistribution studies were performed in 8-week-old female Wistar rats. Animals were housed and treated in compliance with institutional guidelines related to animal experimentation. Work protocol was previously approved by the Animal Ethics Committee of the university. Two groups of rats were defined. One was used as control and the other group was previously injected with 150 mg/kg ip of cyclophosphamide to induce apoptosis. Results: The synthesis of carbonyl precursor achieved yields higher than 90%, and the radiolabeled protein was obtained with 92% of radiochemical purity and high stability in vitro. An important uptake in apoptotic tissues was confirmed by biodistributions, scintigraphic images and histological studies. Conclusions: Biodistribution studies revealed hepatobiliary elimination, high stability in vivo and important uptake in the reticuloendothelial system. In the pathologic model, higher uptake values correspond to the liver, spleen, lungs and femur. Histological studies confirmed the development of apoptosis at 8 and 24 h postinduction in the spleen and lymphocyte bulks in the peribronchial area. Scintigraphic images confirmed high uptake both the spleen and the

  1. {sup 99m}Tc-annexin V and {sup 111}In-antimyosin antibody uptake in experimental myocardial infarction in rats

    Energy Technology Data Exchange (ETDEWEB)

    Sarda-Mantel, Laure; Rouzet, Francois; Martet, Genevieve; Raguin, Olivier; Vrigneaud, Jean-Marc; Guludec, Dominique Le [Bichat Hospital AP-HP, EA 3512, Nuclear Medicine Department, Paris (France); Michel, Jean-Baptiste; Louedec, Liliane [INSERM U460, UFR Bichat, Paris (France); Vanderheyden, Jean-Luc [Theseus Imaging Corporation, Boston, MA (United States); Hervatin, Florence [Bichat Hospital AP-HP, EA 3512, Nuclear Medicine Department, Paris (France); CGA/SHFS, Orsay (France); Khaw, Ban An [Bouve College of Pharmacy and Health Sciences, Center for Drug Targeting and Analysis, Boston, MA (United States)

    2006-03-15

    {sup 99m}Tc-annexin V (ANX) allows scintigraphic detection of apoptotic cells via specific binding to exposed phosphatidylserine. In myocardial infarction, apoptosis of myocytes is variable and depends especially on the presence or absence of coronary reperfusion. In this study, ANX uptake in non-reperfused experimental myocardial infarcts was compared with uptake of a marker of myocyte necrosis ({sup 111}In-antimyosin antibodies, AM) and an immunohistochemical marker of apoptosis (Apostain). The left anterior coronary artery was ligated in 47 Wistar rats, which were then injected with ANX (n=20), AM (n=21) or both (n=6). Myocardial uptake of ANX and AM was determined at 2 h (n=14), 4 h (n=14) and 24 h (n=19) after coronary ligation (CL), by quantitative autoradiography with (n=23) or without (n=24) gamma imaging. Heart-to-lung ratios (HLRs) and infarct-to-remote myocardium activity ratios (INRs) were calculated on the scintigrams and autoradiograms respectively. Cardiac sections were stained with haematoxylin-eosin and Apostain. The above studies were repeated in 12 normal rats. All rats with CL showed increased ANX and AM uptake in cardiac areas on scintigrams 24 h after CL, with HLRs higher than in controls: 3.1{+-}0.6 versus 1.5{+-}0.3 (p=0.001) for ANX and 1.99{+-}0.44 versus 1.01{+-}0.05 (p<0.0005) for AM. Autoradiography showed intense ANX and AM uptake in infarcts, with comparable topography and INRs at 2 h, 4 h and 24 h after CL (4.6{+-}0.9 versus 5.0{+-}1.8 at 24 h), while Apostain staining was very low (0.06{+-}0.06% of cells). In this model of persistent CL, we observed increased ANX uptake in injured myocardium, comparable in intensity, topography and kinetics to that of AM. There was only minimal Apostain staining in the same areas. (orig.)

  2. Anti-inflammatory effects of Tat-Annexin protein on ovalbumin-induced airway inflammation in a mouse model of asthma

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Sun Hwa; Kim, Dae Won; Kim, Hye Ri; Woo, Su Jung; Kim, So Mi; Jo, Hyo Sang [Department of Biomedical Science and Research Institute of Bioscience and Biotechnology, Hallym University, Chunchon 200-702 (Korea, Republic of); Jeon, Seong Gyu [Department of Life Science, Pohang University of Science and Technology, Pohang 790-784 (Korea, Republic of); Cho, Sung-Woo [Department of Biochemistry and Molecular Biology, University of Ulsan, College of Medicine, Seoul 138-736 (Korea, Republic of); Park, Jong Hoon [Department of Biological Science, Sookmyung Women' s University, Seoul 140-742 (Korea, Republic of); Won, Moo Ho [Department of Neurobiology, School of Medicine, Kangwon National University, Chuncheon 200-701 (Korea, Republic of); Park, Jinseu [Department of Biomedical Science and Research Institute of Bioscience and Biotechnology, Hallym University, Chunchon 200-702 (Korea, Republic of); Eum, Won Sik, E-mail: wseum@hallym.ac.kr [Department of Biomedical Science and Research Institute of Bioscience and Biotechnology, Hallym University, Chunchon 200-702 (Korea, Republic of); Choi, Soo Young, E-mail: sychoi@hallym.ac.kr [Department of Biomedical Science and Research Institute of Bioscience and Biotechnology, Hallym University, Chunchon 200-702 (Korea, Republic of)

    2012-01-20

    Highlights: Black-Right-Pointing-Pointer We construct a cell permeable Tat-ANX1 fusion protein. Black-Right-Pointing-Pointer We examined the protective effects of Tat-ANX1 protein on OVA-induced asthma in animal models. Black-Right-Pointing-Pointer Transduced Tat-ANX1 protein protects from the OVA-induced production of cytokines and eosinophils in BAL fluid. Black-Right-Pointing-Pointer Tat-ANX1 protein markedly reduced OVA-induced MAPK in lung tissues. Black-Right-Pointing-Pointer Tat-ANX1 protein could be useful as a therapeutic agent for lung disorders including asthma. -- Abstract: Chronic airway inflammation is a key feature of bronchial asthma. Annexin-1 (ANX1) is an anti-inflammatory protein that is an important modulator and plays a key role in inflammation. Although the precise action of ANX1 remains unclear, it has emerged as a potential drug target for inflammatory diseases such as asthma. To examine the protective effects of ANX1 protein on ovalbumin (OVA)-induced asthma in animal models, we used a cell-permeable Tat-ANX1 protein. Mice sensitized and challenged with OVA antigen had an increased amount of cytokines and eosinophils in their bronchoalveolar lavage (BAL) fluid. However, administration of Tat-ANX1 protein before OVA challenge significantly decreased the levels of cytokines (interleukin (IL)-4, IL-5, and IL-13) and BAL fluid in lung tissues. Furthermore, OVA significantly increased the activation of mitogen-activated protein kinase (MAPK) in lung tissues, whereas Tat-ANX1 protein markedly reduced phosphorylation of MAPKs such as extracellular signal-regulated protein kinase, p38, and stress-activated protein kinase/c-Jun N-terminal kinase. These results suggest that transduced Tat-ANX1 protein may be a potential protein therapeutic agent for the treatment of lung disorders including asthma.

  3. Biological studies in animal models using [{sup 99m}Tc](CO){sub 3} recombinant annexin V as diagnostic agent of apoptotic processes

    Energy Technology Data Exchange (ETDEWEB)

    Teran, Mariella Adriana, E-mail: mteran@fq.edu.u [Catedra de Radioquimica, Departamento Estrella Campos, Facultad de Quimica, Universidad de la Republica, P.O. 11800, Montevideo (Uruguay); Martinez, Elena; Reyes, Ana L.; Paolino, Andrea [Catedra de Radioquimica, Departamento Estrella Campos, Facultad de Quimica, Universidad de la Republica, P.O. 11800, Montevideo (Uruguay); Vital, Marcelo; Esperon, Patricia [Catedra de Biologia Molecular, Departamento de Bioquimica Clinica, Facultad de Quimica, Universidad de la Republica, Montevideo (Uruguay); Pacheco, Jose P. [Instituto de Patobiologia, Facultad de Veterinaria, Universidad de la Republica, Montevideo (Uruguay); Savio, Eduardo [Catedra de Radioquimica, Departamento Estrella Campos, Facultad de Quimica, Universidad de la Republica, P.O. 11800, Montevideo (Uruguay)

    2011-02-15

    Introduction: There are many diseases associated with variations in the expression of apoptosis such as organ rejection after transplantation, myocardial ischemia or infarct and neurodegenerative diseases. For this reason, the early visualization of this process is relevant to set fast and effective therapeutic strategies. Methods: The precursor was prepared according to the procedure reported by R. Alberto, R. Schibli, P. Schubiger, U. Abram, and T. Kaden [Reactions with the technetium and rhenium carbonyl complexes (NEt{sub 4})[MX{sub 3}(CO){sub 3}]. Synthesis and structure of Tc(CN-But){sub 3}(CO){sub 3}](NO{sub 3}) and (Net{sub 4})[Tc{sub 2}({mu}-SCH{sub 2}CH{sub 2}OH){sub 3}(CO){sub 3}], Polyhedron 1996;15: 1079-89]. Recombinant annexin V was incubated with [{sup 99m}Tc](H{sub 2}O)3(CO){sub 3}{sup +} solution, previously neutralized with buffer. Biodistribution studies were performed in 8-week-old female Wistar rats. Animals were housed and treated in compliance with institutional guidelines related to animal experimentation. Work protocol was previously approved by the Animal Ethics Committee of the university. Two groups of rats were defined. One was used as control and the other group was previously injected with 150 mg/kg ip of cyclophosphamide to induce apoptosis. Results: The synthesis of carbonyl precursor achieved yields higher than 90%, and the radiolabeled protein was obtained with 92% of radiochemical purity and high stability in vitro. An important uptake in apoptotic tissues was confirmed by biodistributions, scintigraphic images and histological studies. Conclusions: Biodistribution studies revealed hepatobiliary elimination, high stability in vivo and important uptake in the reticuloendothelial system. In the pathologic model, higher uptake values correspond to the liver, spleen, lungs and femur. Histological studies confirmed the development of apoptosis at 8 and 24 h postinduction in the spleen and lymphocyte bulks in the peribronchial area

  4. A strategy for isolation of cDNAs encoding proteins affecting human intestinal epithelial cell growth and differentiation: characterization of a novel gut-specific N-myristoylated annexin.

    Science.gov (United States)

    Wice, B M; Gordon, J I

    1992-01-01

    The human intestinal epithelium is rapidly and perpetually renewed as the descendants of multipotent stem cells located in crypts undergo proliferation, differentiation, and eventual exfoliation during a very well organized migration along the crypt to villus axis. The mechanisms that establish and maintain this balance between proliferation and differentiation are largely unknown. We have utilized HT-29 cells, derived from a human colon adenocarcinoma, as a model system for identifying gene products that may regulate these processes. Proliferating HT-29 cells cultured in the absence of glucose (e.g., using inosine as the carbon source) have some of the characteristics of undifferentiated but committed crypt epithelial cells while postconfluent cells cultured in the absence of glucose resemble terminally differentiated enterocytes or goblet cells. A cDNA library, constructed from exponentially growing HT-29 cells maintained in inosine-containing media, was sequentially screened with a series of probes depleted of sequences encoding housekeeping functions and enriched for intestine-specific sequences that are expressed in proliferating committed, but not differentiated, epithelial cells. Of 100,000 recombinant phage surveyed, one was found whose cDNA was derived from an apparently gut-specific mRNA. It encodes a 316 residue, 35,463-D protein that is a new member of the annexin/lipocortin family. Other family members have been implicated in regulation of cellular growth and in signal transduction pathways. RNA blot and in situ hybridization studies indicate that the gene encoding this new annexin exhibits region-specific expression along both axes of the human gut: (a) highest levels of mRNA are present in the jejunum with marked and progressive reductions occurring distally; (b) its mRNA appears in crypt-associated epithelial cells and increases in concentration as they exit the crypt. Villus-associated epithelial cells continue to transcribe this gene during their

  5. Relationship of {sup 99m}Tc-HYNIC annexin V uptake to microvessel density, FasL and MMP-9 expression, and the number of tumour-infiltrating lymphocytes in head and neck carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Vermeersch, Hubert; Loose, David [Department of Head and Neck Surgery, University Hospital Ghent (Belgium); Mervillie, Kris; Cuvelier, Claude [Department of Pathology, University Hospital Ghent (Belgium); Lahorte, Christophe; Slegers, Guido [Department of Radiopharmacy, Ghent University (Belgium); Dierck, Rudi Andre; Van de Wiele, Christophe [Division of Nuclear Medicine, University Hospital Ghent, De Pintelaan 185B, 9000, Ghent (Belgium); Steinmetz, Neil [Theseus Imaging Corporation, Cambridge, Massachusetts (United States)

    2004-07-01

    This study reports on the relationship between quantitative {sup 99m}Tc-HYNIC radiolabelled annexin V tumour uptake measurements, Fas ligand (FasL) expression, matrix metalloproteinase-9 (MMP-9) expression, microvessel density (MVD) and the number of tumour-infiltrating lymphocytes in squamous cell carcinoma of the head and neck (SCCHN) patients. Twenty-eight patients (24 men and 4 women; mean age 59 years, range 43-83 years) suffering from a primary (n, number of patients=22) or locally recurrent (n=6) SCCHN were studied. All patients underwent a spiral CT scan, allowing estimation of lesion size in three dimensions, and {sup 99m}Tc-HYNIC annexin V scintigraphy within 1 week of each other. Biopsies or resection of the suspected primary tumour or local recurrence for histopathological analysis were performed on all patients within a period of 10 days following {sup 99m}Tc-HYNIC annexin V scintigraphy. The percentage uptake of the injected dose of {sup 99m}Tc-HYNIC annexin V in visible tumour lesions on scintigrams divided by the tumour volume, derived from CT, was related to MVD and to histological score (HSCORE) values for MMP-9 and FasL expression as well as to the number of tumour-infiltrating lymphocytes (CD45 staining). Median percentage absolute tumour uptake of the injected dose/cm{sup 3} tumour volume derived from tomographic images was 0.0001% (SD 0.0001%) at 5-6 h p.i. (range: 0.000007-0.0003%). Mean HSCORE for MMP-9 tumour staining was 2.1 (SD 0.84). Mean HSCORE for FasL tumour staining was 2.49 (SD 0.92). At the sites of tumour containing the highest number of vessels, the mean MVD was 20 vessels/field at the hot spot (range 1-73). The median number of tumour-infiltrating lymphocytes was 500 (range 100-5,000). The percentage absolute tumour uptake of the injected dose/cm{sup 3} tumour volume derived from tomographic images correlated linearly with FasL HSCORES(r=0.47, P=0.02). No correlation was found between the percentage absolute tumour uptake of the

  6. Relationship of 99mTc-HYNIC annexin V uptake to microvessel density, FasL and MMP-9 expression, and the number of tumour-infiltrating lymphocytes in head and neck carcinoma

    International Nuclear Information System (INIS)

    Vermeersch, Hubert; Loose, David; Mervillie, Kris; Cuvelier, Claude; Lahorte, Christophe; Slegers, Guido; Dierck, Rudi Andre; Van de Wiele, Christophe; Steinmetz, Neil

    2004-01-01

    This study reports on the relationship between quantitative 99m Tc-HYNIC radiolabelled annexin V tumour uptake measurements, Fas ligand (FasL) expression, matrix metalloproteinase-9 (MMP-9) expression, microvessel density (MVD) and the number of tumour-infiltrating lymphocytes in squamous cell carcinoma of the head and neck (SCCHN) patients. Twenty-eight patients (24 men and 4 women; mean age 59 years, range 43-83 years) suffering from a primary (n, number of patients=22) or locally recurrent (n=6) SCCHN were studied. All patients underwent a spiral CT scan, allowing estimation of lesion size in three dimensions, and 99m Tc-HYNIC annexin V scintigraphy within 1 week of each other. Biopsies or resection of the suspected primary tumour or local recurrence for histopathological analysis were performed on all patients within a period of 10 days following 99m Tc-HYNIC annexin V scintigraphy. The percentage uptake of the injected dose of 99m Tc-HYNIC annexin V in visible tumour lesions on scintigrams divided by the tumour volume, derived from CT, was related to MVD and to histological score (HSCORE) values for MMP-9 and FasL expression as well as to the number of tumour-infiltrating lymphocytes (CD45 staining). Median percentage absolute tumour uptake of the injected dose/cm 3 tumour volume derived from tomographic images was 0.0001% (SD 0.0001%) at 5-6 h p.i. (range: 0.000007-0.0003%). Mean HSCORE for MMP-9 tumour staining was 2.1 (SD 0.84). Mean HSCORE for FasL tumour staining was 2.49 (SD 0.92). At the sites of tumour containing the highest number of vessels, the mean MVD was 20 vessels/field at the hot spot (range 1-73). The median number of tumour-infiltrating lymphocytes was 500 (range 100-5,000). The percentage absolute tumour uptake of the injected dose/cm 3 tumour volume derived from tomographic images correlated linearly with FasL HSCORES(r=0.47, P=0.02). No correlation was found between the percentage absolute tumour uptake of the injected dose/cm 3 tumour

  7. The role of MAPK in CD4{sup +} T cells toll-like receptor 9-mediated signaling following HHV-6 infection

    Energy Technology Data Exchange (ETDEWEB)

    Chi, Jing [Department of Microbiology and Immunology, Nanjing Medical University, Nanjing 210029, Jiangsu Province (China); Wang, Fang [Department of Laboratory Medicine, the First Affiliated Hospital of Nanjing Medical University, 300 Guangzhou Road, Nanjing 210029, Jiangsu Province (China); Li, Lingyun [Department of Developmental Genetics, Nanjing Medical University, Nanjing 210029, Jiangsu Province (China); Feng, Dongju [Department of Microbiology and Immunology, Nanjing Medical University, Nanjing 210029, Jiangsu Province (China); Qin, Jian [College of Foreign Languages, Hehai University, Nanjing 210029, Jiangsu Province (China); Xie, Fangyi; Zhou, Feng; Chen, Yun; Wang, Jinfeng [Department of Microbiology and Immunology, Nanjing Medical University, Nanjing 210029, Jiangsu Province (China); Yao, Kun, E-mail: yaokun@njmu.edu.cn [Department of Microbiology and Immunology, Nanjing Medical University, Nanjing 210029, Jiangsu Province (China)

    2012-01-05

    Human herpesvirus-6 (HHV-6) is an important immunosuppressive and immunomodulatory virus that primarily infects immune cells (mainly CD4{sup +} T cells) and strongly suppresses the proliferation of infected cells. Toll-like receptors are pattern-recognition receptors essential for the development of an appropriate innate immune defense against infection. To understand the role of CD4{sup +} T cells in the innate response to HHV-6 infection and the involvement of TLRs, we used an in vitro infection model and observed that the infection of CD4{sup +} T cells resulted in the activation of JNK/SAPK via up-regulation of toll-like receptor 9 (TLR9). Associated with JNK activation, annexin V-PI staining indicated that HHV-6A was a strong inducer of apoptosis. Apoptotic response associated cytokines, IL-6 and TNF-{alpha} also induced by HHV-6A infection.

  8. Somatostatin and opioid receptors do not regulate proliferation or apoptosis of the human multiple myeloma U266 cells

    Directory of Open Access Journals (Sweden)

    Allouche Stéphane

    2009-06-01

    Full Text Available Abstract Background opioid and somatostatin receptors (SSTRs that can assemble as heterodimer were individually reported to modulate malignant cell proliferation and to favour apoptosis. Materials and methods: SSTRs and opioid receptors expression were examined by RT-PCR, western-blot and binding assays, cell proliferation was studied by XTT assay and propidium iodide (PI staining and apoptosis by annexin V-PI labelling. Results almost all human malignant haematological cell lines studied here expressed the five SSTRs. Further experiments were conducted on the human U266 multiple myeloma cells, which express also μ-opioid receptors (MOP-R. XTT assays and cell cycle studies provide no evidence for a significant effect upon opioid or somatostatin receptors stimulation. Furthermore, neither direct effect nor potentiation of the Fas-receptor pathway was detected on apoptosis after these treatments. Conclusion these data suggest that SSTRs or opioid receptors expression is not a guaranty for an anti-tumoral action in U266 cell line.

  9. The LDL receptor.

    Science.gov (United States)

    Goldstein, Joseph L; Brown, Michael S

    2009-04-01

    In this article, the history of the LDL receptor is recounted by its codiscoverers. Their early work on the LDL receptor explained a genetic cause of heart attacks and led to new ways of thinking about cholesterol metabolism. The LDL receptor discovery also introduced three general concepts to cell biology: receptor-mediated endocytosis, receptor recycling, and feedback regulation of receptors. The latter concept provides the mechanism by which statins selectively lower plasma LDL, reducing heart attacks and prolonging life.

  10. Role of the Phosphatidylserine Receptor TIM-1 in Enveloped-Virus Entry

    Science.gov (United States)

    Moller-Tank, Sven; Kondratowicz, Andrew S.; Davey, Robert A.; Rennert, Paul D.

    2013-01-01

    The cell surface receptor T cell immunoglobulin mucin domain 1 (TIM-1) dramatically enhances filovirus infection of epithelial cells. Here, we showed that key phosphatidylserine (PtdSer) binding residues of the TIM-1 IgV domain are critical for Ebola virus (EBOV) entry through direct interaction with PtdSer on the viral envelope. PtdSer liposomes but not phosphatidylcholine liposomes competed with TIM-1 for EBOV pseudovirion binding and transduction. Further, annexin V (AnxV) substituted for the TIM-1 IgV domain, supporting a PtdSer-dependent mechanism. Our findings suggest that TIM-1-dependent uptake of EBOV occurs by apoptotic mimicry. Additionally, TIM-1 enhanced infection of a wide range of enveloped viruses, including alphaviruses and a baculovirus. As further evidence of the critical role of enveloped-virion-associated PtdSer in TIM-1-mediated uptake, TIM-1 enhanced internalization of pseudovirions and virus-like proteins (VLPs) lacking a glycoprotein, providing evidence that TIM-1 and PtdSer-binding receptors can mediate virus uptake independent of a glycoprotein. These results provide evidence for a broad role of TIM-1 as a PtdSer-binding receptor that mediates enveloped-virus uptake. Utilization of PtdSer-binding receptors may explain the wide tropism of many of these viruses and provide new avenues for controlling their virulence. PMID:23698310

  11. Phosphatidylserine Sensing by TAM Receptors Regulates AKT-Dependent Chemoresistance and PD-L1 Expression.

    Science.gov (United States)

    Kasikara, Canan; Kumar, Sushil; Kimani, Stanley; Tsou, Wen-I; Geng, Ke; Davra, Viralkumar; Sriram, Ganapathy; Devoe, Connor; Nguyen, Khanh-Quynh N; Antes, Anita; Krantz, Allen; Rymarczyk, Grzegorz; Wilczynski, Andrzej; Empig, Cyril; Freimark, Bruce; Gray, Michael; Schlunegger, Kyle; Hutchins, Jeff; Kotenko, Sergei V; Birge, Raymond B

    2017-06-01

    Tyro3, Axl, and Mertk (collectively TAM receptors) are three homologous receptor tyrosine kinases that bind vitamin K-dependent endogenous ligands, Protein S (ProS), and growth arrest-specific factor 6 (Gas6), and act as bridging molecules to promote phosphatidylserine (PS)-mediated clearance of apoptotic cells (efferocytosis). TAM receptors are overexpressed in a vast array of tumor types, whereby the level of expression correlates with the tumor grade and the emergence of chemo- and radioresistance to targeted therapeutics, but also have been implicated as inhibitory receptors on infiltrating myeloid-derived cells in the tumor microenvironment that can suppress host antitumor immunity. In the present study, we utilized TAM-IFNγR1 reporter lines and expressed TAM receptors in a variety of epithelial cell model systems to show that each TAM receptor has a unique pattern of activation by Gas6 or ProS, as well as unique dependency for PS on apoptotic cells and PS liposomes for activity. In addition, we leveraged this system to engineer epithelial cells that express wild-type TAM receptors and show that although each receptor can promote PS-mediated efferocytosis, AKT-mediated chemoresistance, as well as upregulate the immune checkpoint molecule PD-L1 on tumor cells, Mertk is most dominant in the aforementioned pathways. Functionally, TAM receptor-mediated efferocytosis could be partially blocked by PS-targeting antibody 11.31 and Annexin V, demonstrating the existence of a PS/PS receptor (i.e., TAM receptor)/PD-L1 axis that operates in epithelial cells to foster immune escape. These data provide a rationale that PS-targeting, anti-TAM receptor, and anti-PD-L1-based therapeutics will have merit as combinatorial checkpoint inhibitors. Implications: Many tumor cells are known to upregulate the immune checkpoint inhibitor PD-L1. This study demonstrates a role for PS and TAM receptors in the regulation of PD-L1 on cancer cells. Mol Cancer Res; 15(6); 753-64. ©2017 AACR

  12. Receptor-receptor interactions within receptor mosaics. Impact on neuropsychopharmacology.

    Science.gov (United States)

    Fuxe, K; Marcellino, D; Rivera, A; Diaz-Cabiale, Z; Filip, M; Gago, B; Roberts, D C S; Langel, U; Genedani, S; Ferraro, L; de la Calle, A; Narvaez, J; Tanganelli, S; Woods, A; Agnati, L F

    2008-08-01

    Future therapies for diseases associated with altered dopaminergic signaling, including Parkinson's disease, schizophrenia and drug addiction or drug dependence may substantially build on the existence of intramembrane receptor-receptor interactions within dopamine receptor containing receptor mosaics (RM; dimeric or high-order receptor oligomers) where it is believed that the dopamine D(2) receptor may operate as the 'hub receptor' within these complexes. The constitutive adenosine A(2A)/dopamine D(2) RM, located in the dorsal striato-pallidal GABA neurons, are of particular interest in view of the demonstrated antagonistic A(2A)/D(2) interaction within these heteromers; an interaction that led to the suggestion and later demonstration that A(2A) antagonists could be used as novel anti-Parkinsonian drugs. Based on the likely existence of A(2A)/D(2)/mGluR5 RM located both extrasynaptically on striato-pallidal GABA neurons and on cortico-striatal glutamate terminals, multiple receptor-receptor interactions within this RM involving synergism between A(2A)/mGluR5 to counteract D(2) signaling, has led to the proposal of using combined mGluR5 and A(2A) antagonists as a future anti-Parkinsonian treatment. Based on the same RM in the ventral striato-pallidal GABA pathways, novel strategies for the treatment of schizophrenia, building on the idea that A(2A) agonists and/or mGluR5 agonists will help reduce the increased dopaminergic signaling associated with this disease, have been suggested. Such treatment may ensure the proper glutamatergic drive from the mediodorsal thalamic nucleus to the prefrontal cortex, one which is believed to be reduced in schizophrenia due to a dominance of D(2)-like signaling in the ventral striatum. Recently, A(2A) receptors also have been shown to counteract the locomotor and sensitizing actions of cocaine and increases in A(2A) receptors have also been observed in the nucleus accumbens after extended cocaine self-administration, probably

  13. Acetylcholine receptor antibody

    Science.gov (United States)

    ... medlineplus.gov/ency/article/003576.htm Acetylcholine receptor antibody To use the sharing features on this page, please enable JavaScript. Acetylcholine receptor antibody is a protein found in the blood of ...

  14. Cooperative ethylene receptor signaling

    OpenAIRE

    Liu, Qian; Wen, Chi-Kuang

    2012-01-01

    The gaseous plant hormone ethylene is perceived by a family of five ethylene receptor members in the dicotyledonous model plant Arabidopsis. Genetic and biochemical studies suggest that the ethylene response is suppressed by ethylene receptor complexes, but the biochemical nature of the receptor signal is unknown. Without appropriate biochemical measures to trace the ethylene receptor signal and quantify the signal strength, the biological significance of the modulation of ethylene responses ...

  15. Hepatocyte growth factor enhances death receptor-induced apoptosis by up-regulating DR5

    International Nuclear Information System (INIS)

    Li, Yang; Fan, Xing; Goodwin, C Rory; Laterra, John; Xia, Shuli

    2008-01-01

    Hepatocyte growth factor (HGF) and its receptor c-MET are commonly expressed in malignant gliomas and embryonic neuroectodermal tumors including medulloblastoma and appear to play an important role in the growth and dissemination of these malignancies. Dependent on cell context and the involvement of specific downstream effectors, both pro- and anti-apoptotic effects of HGF have been reported. Human medulloblastoma cells were treated with HGF for 24–72 hours followed by death receptor ligand TRAIL (Tumor necrosis factor-related apoptosis-inducing ligand) for 24 hours. Cell death was measured by MTT and Annexin-V/PI flow cytometric analysis. Changes in expression levels of targets of interest were measured by Northern blot analysis, quantitative reverse transcription-PCR, Western blot analysis as well as immunoprecipitation. In this study, we show that HGF promotes medulloblastoma cell death induced by TRAIL. TRAIL alone triggered apoptosis in DAOY cells and death was enhanced by pre-treating the cells with HGF for 24–72 h prior to the addition of TRAIL. HGF (100 ng/ml) enhanced TRAIL (10 ng/ml) induced cell death by 36% (P < 0.001). No cell death was associated with HGF alone. Treating cells with PHA-665752, a specific c-Met receptor tyrosine kinase inhibitor, significantly abrogated the enhancement of TRAIL-induced cell death by HGF, indicating that its death promoting effect requires activation of its canonical receptor tyrosine kinase. Cell death induced by TRAIL+HGF was predominately apoptotic involving both extrinsic and intrinsic pathways as evidenced by the increased activation of caspase-3, 8, 9. Promotion of apoptosis by HGF occurred via the increased expression of the death receptor DR5 and enhanced formation of death-inducing signal complexes (DISC). Taken together, these and previous findings indicate that HGF:c-Met pathway either promotes or inhibits medulloblastoma cell death via pathway and context specific mechanisms

  16. GABA receptor imaging

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jong Doo [Yonsei University College of Medicine, Seoul (Korea, Republic of)

    2007-04-15

    GABA is primary an inhibitory neurotransmitter that is localized in inhibitory interneurons. GABA is released from presynaptic terminals and functions by binding to GABA receptors. There are two types of GABA receptors, GABA{sub A}-receptor that allows chloride to pass through a ligand gated ion channel and GABA{sub B}-receptor that uses G-proteins for signaling. The GABA{sub A}-receptor has a GABA binding site as well as a benzodiazepine binding sites, which modulate GABA{sub A}-receptor function. Benzodiazepine GABAA receptor imaging can be accomplished by radiolabeling derivates that activates benzodiazepine binding sites. There has been much research on flumazenil (FMZ) labeled with {sup 11}C-FMZ, a benzodiazepine derivate that is a selective, reversible antagonist to GABAA receptors. Recently, {sup 18}F-fluoroflumazenil (FFMZ) has been developed to overcome {sup 11}C's short half-life. {sup 18}F-FFMZ shows high selective affinity and good pharmacodynamics, and is a promising PET agent with better central benzodiazepine receptor imaging capabilities. In an epileptic focus, because the GABA/benzodiazepine receptor amount is decreased, using '1{sup 1}C-FMZ PET instead of {sup 18}F-FDG, PET, restrict the foci better and may also help find lesions better than high resolution MR. GABA{sub A} receptors are widely distributed in the cerebral cortex, and can be used as an viable neuronal marker. Therefore it can be used as a neuronal cell viability marker in cerebral ischemia. Also, GABA-receptors decrease in areas where neuronal plasticity develops, therefore, GABA imaging can be used to evaluate plasticity. Besides these usages, GABA receptors are related with psychological diseases, especially depression and schizophrenia as well as cerebral palsy, a motor-related disorder, so further in-depth studies are needed for these areas.

  17. GABA receptor imaging

    International Nuclear Information System (INIS)

    Lee, Jong Doo

    2007-01-01

    GABA is primary an inhibitory neurotransmitter that is localized in inhibitory interneurons. GABA is released from presynaptic terminals and functions by binding to GABA receptors. There are two types of GABA receptors, GABA A -receptor that allows chloride to pass through a ligand gated ion channel and GABA B -receptor that uses G-proteins for signaling. The GABA A -receptor has a GABA binding site as well as a benzodiazepine binding sites, which modulate GABA A -receptor function. Benzodiazepine GABAA receptor imaging can be accomplished by radiolabeling derivates that activates benzodiazepine binding sites. There has been much research on flumazenil (FMZ) labeled with 11 C-FMZ, a benzodiazepine derivate that is a selective, reversible antagonist to GABAA receptors. Recently, 18 F-fluoroflumazenil (FFMZ) has been developed to overcome 11 C's short half-life. 18 F-FFMZ shows high selective affinity and good pharmacodynamics, and is a promising PET agent with better central benzodiazepine receptor imaging capabilities. In an epileptic focus, because the GABA/benzodiazepine receptor amount is decreased, using '1 1 C-FMZ PET instead of 18 F-FDG, PET, restrict the foci better and may also help find lesions better than high resolution MR. GABA A receptors are widely distributed in the cerebral cortex, and can be used as an viable neuronal marker. Therefore it can be used as a neuronal cell viability marker in cerebral ischemia. Also, GABA-receptors decrease in areas where neuronal plasticity develops, therefore, GABA imaging can be used to evaluate plasticity. Besides these usages, GABA receptors are related with psychological diseases, especially depression and schizophrenia as well as cerebral palsy, a motor-related disorder, so further in-depth studies are needed for these areas

  18. Glucocorticoid receptor modulators.

    Science.gov (United States)

    Meijer, Onno C; Koorneef, Lisa L; Kroon, Jan

    2018-06-01

    The glucocorticoid hormone cortisol acts throughout the body to support circadian processes and adaptation to stress. The glucocorticoid receptor is the target of cortisol and of synthetic glucocorticoids, which are used widely in the clinic. Both agonism and antagonism of the glucocorticoid receptor may be beneficial in disease, but given the wide expression of the receptor and involvement in various processes, beneficial effects are often accompanied by unwanted side effects. Selective glucocorticoid receptor modulators are ligands that induce a receptor conformation that allows activation of only a subset of downstream signaling pathways. Such molecules thereby combine agonistic and antagonistic properties. Here we discuss the mechanisms underlying selective receptor modulation and their promise in treating diseases in several organ systems where cortisol signaling plays a role. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

  19. Dengue virus receptor

    OpenAIRE

    Hidari, Kazuya I.P.J.; Suzuki, Takashi

    2011-01-01

    Dengue virus is an arthropod-borne virus transmitted by Aedes mosquitoes. Dengue virus causes fever and hemorrhagic disorders in humans and non-human primates. Direct interaction of the virus introduced by a mosquito bite with host receptor molecule(s) is crucial for virus propagation and the pathological progression of dengue diseases. Therefore, elucidation of the molecular mechanisms underlying the interaction between dengue virus and its receptor(s) in both humans and mosquitoes is essent...

  20. Involvement of apoptosis and autophagy in the death of RPMI 8226 multiple myeloma cells by two enantiomeric sigma receptor ligands.

    Science.gov (United States)

    Korpis, Katharina; Weber, Frauke; Brune, Stefanie; Wünsch, Bernhard; Bednarski, Patrick J

    2014-01-01

    Over-expression of σ receptors by many tumor cell lines makes ligands for these receptors attractive as potential chemotherapeutic drugs. Enantiomeric piperazines (S)-4 and (R)-4 were prepared as potential σ-receptor ligands in a chiral pool synthesis starting from (S)- and (R)-aspartate. Both compounds showed high affinities for the σ₁ and σ₂ receptors. In the human multiple myeloma cell line RPMI 8226, a line expressing high levels of σ receptors, both compounds inhibited cell proliferation with IC₅₀ values in the low μM range. No chiral differentiation between either the σ receptor binding affinity or the cytotoxicity of the two enantiomers was observed. Both compounds induced apoptosis, which was evidenced by nuclear condensation, binding of annexin-V to phosphatidylserine in the outer leaf of the cell membrane, cleavage products of poly(ADP-ribose) polymerase-1 (PARP-1) and caspase-8 as well as the expression of bcl₂ family members bax, bad and bid. However, apoptosis appeared to be caspase independent. Increased levels of the phosphorylated form of the microtubule associated protein light chain 3-II (LC3-II), an autophagosome marker, gave evidence that both compounds induced autophagy. However, further data (e.g., treatment with wortmannin) indicate that autophagy is incomplete and not cytoprotective. Lipid peroxidation (LPO) was observed in RPMI 8226 cells treated with the two compounds, and the lipid antioxidant α-tocopherol attenuated LPO. Interestingly, α-tocopherol reduced significantly both apoptosis and autophagy induced by the compounds. These results provide evidence that, by initiating LPO and changes in mitochondrial membrane potential, both compounds induce apoptosis and autophagy in RPMI 8226 cells. Copyright © 2013 Elsevier Ltd. All rights reserved.

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

    Science.gov (United States)

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

    2012-01-01

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

  2. Angiotensin type 2 receptors

    DEFF Research Database (Denmark)

    Sumners, Colin; de Kloet, Annette D; Krause, Eric G

    2015-01-01

    In most situations, the angiotensin AT2-receptor (AT2R) mediates physiological actions opposing those mediated by the AT1-receptor (AT1R), including a vasorelaxant effect. Nevertheless, experimental evidence vastly supports that systemic application of AT2R-agonists is blood pressure neutral...

  3. Glutamate receptor agonists

    DEFF Research Database (Denmark)

    Vogensen, Stine Byskov; Greenwood, Jeremy R; Bunch, Lennart

    2011-01-01

    The neurotransmitter (S)-glutamate [(S)-Glu] is responsible for most of the excitatory neurotransmission in the central nervous system. The effect of (S)-Glu is mediated by both ionotropic and metabotropic receptors. Glutamate receptor agonists are generally a-amino acids with one or more...... stereogenic centers due to strict requirements in the agonist binding pocket of the activated state of the receptor. By contrast, there are many examples of achiral competitive antagonists. The present review addresses how stereochemistry affects the activity of glutamate receptor ligands. The review focuses...... mainly on agonists and discusses stereochemical and conformational considerations as well as biostructural knowledge of the agonist binding pockets, which is useful in the design of glutamate receptor agonists. Examples are chosen to demonstrate how stereochemistry not only determines how the agonist...

  4. AMPA receptor ligands

    DEFF Research Database (Denmark)

    Strømgaard, Kristian; Mellor, Ian

    2004-01-01

    Alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA) receptors (AMPAR), subtype of the ionotropic glutamate receptors (IGRs), mediate fast synaptic transmission in the central nervous system (CNS), and are involved in many neurological disorders, as well as being a key player in the f......Alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA) receptors (AMPAR), subtype of the ionotropic glutamate receptors (IGRs), mediate fast synaptic transmission in the central nervous system (CNS), and are involved in many neurological disorders, as well as being a key player...... in the formation of memory. Hence, ligands affecting AMPARs are highly important for the study of the structure and function of this receptor, and in this regard polyamine-based ligands, particularly polyamine toxins, are unique as they selectively block Ca2+ -permeable AMPARs. Indeed, endogenous intracellular...

  5. Xingshentongqiao Decoction Mediates Proliferation, Apoptosis, Orexin-A Receptor and Orexin-B Receptor Messenger Ribonucleic Acid Expression and Represses Mitogen-activated Protein Kinase Signaling

    Directory of Open Access Journals (Sweden)

    Yuanli Dong

    2015-01-01

    Full Text Available Background: Hypocretin (HCRT signaling plays an important role in the pathogenesis of narcolepsy and can be significantly influenced by Chinese herbal therapy. Our previous study showed that xingshentongqiao decoction (XSTQ is clinically effective for the treatment of narcolepsy. To determine whether XSTQ improves narcolepsy by modulating HCRT signaling, we investigated its effects on SH-SY5Y cell proliferation, apoptosis, and HCRT receptor 1/2 (orexin receptor 1 [OX1R] and orexin receptor 2 [OX2R] expression. The signaling pathways involved in these processes were also assessed. Methods: The effects of XSTQ on proliferation and apoptosis in SH-SY5Y cells were assessed using cell counting kit-8 and annexin V-fluorescein isothiocyanate assays. OX1R and OX2R expression was assessed by quantitative real-time polymerase chain reaction analysis. Western blotting for mitogen-activated protein kinase (MAPK pathway activation was performed to further assess the signaling mechanism of XSTQ. Results: XSTQ reduced the proliferation and induced apoptosis of SH-SY5Y cells. This effect was accompanied by the upregulation of OX1R and OX2R expression and the reduced phosphorylation of extracellular signal-regulated kinase (Erk 1/2, p38 MAPK and c-Jun N-terminal kinase (JNK. Conclusions: XSTQ inhibits proliferation and induces apoptosis in SH-SY5Y cells. XSTQ also promotes OX1R and OX2R expression. These effects are associated with the repression of the Erk1/2, p38 MAPK, and JNK signaling pathways. These results define a molecular mechanism for XSTQ in regulating HCRT and MAPK activation, which may explain its ability to treat narcolepsy.

  6. Lipophorin Receptor: The Insect Lipoprotein Receptor

    Indian Academy of Sciences (India)

    IAS Admin

    Director of ... function of the Lp is to deliver lipids throughout the insect body for metabolism ... Lipid is used as a major energy source for development as well as other metabolic .... LpR4 receptor variant was expressed exclusively in the brain and.

  7. Peroxisome proliferator-activated receptor delta (PPARdelta) activation protects H9c2 cardiomyoblasts from oxidative stress-induced apoptosis.

    Science.gov (United States)

    Pesant, Matthieu; Sueur, Stéphanie; Dutartre, Patrick; Tallandier, Mireille; Grimaldi, Paul A; Rochette, Luc; Connat, Jean-Louis

    2006-02-01

    Activation of peroxisome proliferator-activated receptor alpha (PPARalpha) and PPARgamma plays beneficial roles in cardiovascular disorders such as atherosclerosis and heart reperfusion. Although PPARalpha and gamma have been documented to reduce oxidative stress in the vasculature and the heart, the role of PPARdelta remains poorly studied. We focused on PPARdelta function in the regulation of oxidative stress-induced apoptosis in the rat cardiomyoblast cell line H9c2. Using semi-quantitative reverse transcriptase-polymerase chain reaction (RT-PCR), we showed that PPARdelta is the predominantly expressed isotype whereas PPARalpha was weakly detected. By performing cell viability assays, we also showed that the selective PPARdelta agonist GW501516 protected cells from H(2)O(2)-induced cell death. The protective effect of GW501516 was due to an inhibition of H(2)O(2)-triggered apoptosis as shown by annexin-V labeling, DNA fragmentation analysis, and caspase-3 activity measurement. We demonstrated by transient transfection of a dominant negative mutant of PPARdelta that the protection induced by GW501516 was totally dependent on PPARdelta. Semi-quantitative RT-PCR and Western blotting analysis demonstrated that GW501516 treatment upregulated catalase. Moreover, forced overexpression of catalase inhibited H(2)O(2)-triggered apoptosis, as evidenced by annexin-V labeling. Taken together, our results account for an important role of PPARdelta in inhibiting the onset of oxidative stress-induced apoptosis in H9c2 cells. PPARdelta appears to be a new therapeutic target for the regulation of heart reperfusion-associated oxidative stress and stimulation of enzymatic antioxidative defences.

  8. Serotonin Receptors in Hippocampus

    Science.gov (United States)

    Berumen, Laura Cristina; Rodríguez, Angelina; Miledi, Ricardo; García-Alcocer, Guadalupe

    2012-01-01

    Serotonin is an ancient molecular signal and a recognized neurotransmitter brainwide distributed with particular presence in hippocampus. Almost all serotonin receptor subtypes are expressed in hippocampus, which implicates an intricate modulating system, considering that they can be localized as autosynaptic, presynaptic, and postsynaptic receptors, even colocalized within the same cell and being target of homo- and heterodimerization. Neurons and glia, including immune cells, integrate a functional network that uses several serotonin receptors to regulate their roles in this particular part of the limbic system. PMID:22629209

  9. Cytotoxicity of synthetic cannabinoids on primary neuronal cells of the forebrain: the involvement of cannabinoid CB{sub 1} receptors and apoptotic cell death

    Energy Technology Data Exchange (ETDEWEB)

    Tomiyama, Ken-ichi; Funada, Masahiko, E-mail: mfunada@ncnp.go.jp

    2014-01-01

    The abuse of herbal products containing synthetic cannabinoids has become an issue of public concern. The purpose of this paper was to evaluate the acute cytotoxicity of synthetic cannabinoids on mouse brain neuronal cells. Cytotoxicity induced by synthetic cannabinoid (CP-55,940, CP-47,497, CP-47,497-C8, HU-210, JWH-018, JWH-210, AM-2201, and MAM-2201) was examined using forebrain neuronal cultures. These synthetic cannabinoids induced cytotoxicity in the forebrain cultures in a concentration-dependent manner. The cytotoxicity was suppressed by preincubation with the selective CB{sub 1} receptor antagonist AM251, but not with the selective CB{sub 2} receptor antagonist AM630. Furthermore, annexin-V-positive cells were found among the treated forebrain cells. Synthetic cannabinoid treatment induced the activation of caspase-3, and preincubation with a caspase-3 inhibitor significantly suppressed the cytotoxicity. These synthetic cannabinoids induced apoptosis through a caspase-3-dependent mechanism in the forebrain cultures. Our results indicate that the cytotoxicity of synthetic cannabinoids towards primary neuronal cells is mediated by the CB{sub 1} receptor, but not by the CB{sub 2} receptor, and further suggest that caspase cascades may play an important role in the apoptosis induced by these synthetic cannabinoids. In conclusion, excessive synthetic cannabinoid abuse may present a serious acute health concern due to neuronal damage or deficits in the brain. - Highlights: • Synthetic cannabinoids (classical cannabinoids, non-classical cannabinoids, and aminoalkylindole derivatives) induce cytotoxicity in mouse forebrain cultures. • Synthetic cannabinoid-induced cytotoxicity towards forebrain cultures is mediated by the CB{sub 1} receptor, but not by the CB{sub 2} receptor, and involves caspase-dependent apoptosis. • A high concentration of synthetic cannabinoids may be toxic to neuronal cells that express CB{sub 1} receptors.

  10. Cytotoxicity of synthetic cannabinoids on primary neuronal cells of the forebrain: the involvement of cannabinoid CB1 receptors and apoptotic cell death

    International Nuclear Information System (INIS)

    Tomiyama, Ken-ichi; Funada, Masahiko

    2014-01-01

    The abuse of herbal products containing synthetic cannabinoids has become an issue of public concern. The purpose of this paper was to evaluate the acute cytotoxicity of synthetic cannabinoids on mouse brain neuronal cells. Cytotoxicity induced by synthetic cannabinoid (CP-55,940, CP-47,497, CP-47,497-C8, HU-210, JWH-018, JWH-210, AM-2201, and MAM-2201) was examined using forebrain neuronal cultures. These synthetic cannabinoids induced cytotoxicity in the forebrain cultures in a concentration-dependent manner. The cytotoxicity was suppressed by preincubation with the selective CB 1 receptor antagonist AM251, but not with the selective CB 2 receptor antagonist AM630. Furthermore, annexin-V-positive cells were found among the treated forebrain cells. Synthetic cannabinoid treatment induced the activation of caspase-3, and preincubation with a caspase-3 inhibitor significantly suppressed the cytotoxicity. These synthetic cannabinoids induced apoptosis through a caspase-3-dependent mechanism in the forebrain cultures. Our results indicate that the cytotoxicity of synthetic cannabinoids towards primary neuronal cells is mediated by the CB 1 receptor, but not by the CB 2 receptor, and further suggest that caspase cascades may play an important role in the apoptosis induced by these synthetic cannabinoids. In conclusion, excessive synthetic cannabinoid abuse may present a serious acute health concern due to neuronal damage or deficits in the brain. - Highlights: • Synthetic cannabinoids (classical cannabinoids, non-classical cannabinoids, and aminoalkylindole derivatives) induce cytotoxicity in mouse forebrain cultures. • Synthetic cannabinoid-induced cytotoxicity towards forebrain cultures is mediated by the CB 1 receptor, but not by the CB 2 receptor, and involves caspase-dependent apoptosis. • A high concentration of synthetic cannabinoids may be toxic to neuronal cells that express CB 1 receptors

  11. Annexin A2 in Proliferative Vitreoretinopathy

    Science.gov (United States)

    2016-10-01

    normal architecture of the Anxa2+/+ retina with loss of defined cell layers and retraction of the retina to form a mass containing pigmented cells...ectopic presence of RPE cells, and no retraction of the retina. In the Anxa2-/- eye, the normal architecture of the retina and its typical distribution...eyes. For semi-quantitative scoring, we have devised an overall PVR Histology Index ( PHI ) (Figure 2). The PHI is based on the degree of retinal

  12. Annexin A2 in Proliferative Vitreoretinopathy

    Science.gov (United States)

    2017-10-01

    that breaches the blood-retinal barrier, leakage of plasma proteins and circulating blood cells, possibly together with local hypoxia, conspire to...immunofluorescence staining to document the migration of A2-positive cells from the RPE to the surface of the retina in PVR (Fig. 3). We have also detected a few...readily detected (Fig. 9B, 9C). Cells in both groups were also positive for A2. These data indicate that expression of A2 in both RPE cells and

  13. Structure of a C-terminal AHNAK peptide in a 1:2:2 complex with S100A10 and an acetylated N-terminal peptide of annexin A2

    International Nuclear Information System (INIS)

    Ozorowski, Gabriel; Milton, Saskia; Luecke, Hartmut

    2013-01-01

    Structure of a 20-amino-acid peptide of AHNAK bound asymmetrically to the AnxA2–S100A10A heterotetramer (1:2:2 symmetry) provides insights into the atomic level interactions that govern this membrane-repair scaffolding complex. AHNAK, a large 629 kDa protein, has been implicated in membrane repair, and the annexin A2–S100A10 heterotetramer [(p11) 2 (AnxA2) 2 )] has high affinity for several regions of its 1002-amino-acid C-terminal domain. (p11) 2 (AnxA2) 2 is often localized near the plasma membrane, and this C2-symmetric platform is proposed to be involved in the bridging of membrane vesicles and trafficking of proteins to the plasma membrane. All three proteins co-localize at the intracellular face of the plasma membrane in a Ca 2+ -dependent manner. The binding of AHNAK to (p11) 2 (AnxA2) 2 has been studied previously, and a minimal binding motif has been mapped to a 20-amino-acid peptide corresponding to residues 5654–5673 of the AHNAK C-terminal domain. Here, the 2.5 Å resolution crystal structure of this 20-amino-acid peptide of AHNAK bound to the AnxA2–S100A10 heterotetramer (1:2:2 symmetry) is presented, which confirms the asymmetric arrangement first described by Rezvanpour and coworkers and explains why the binding motif has high affinity for (p11) 2 (AnxA2) 2 . Binding of AHNAK to the surface of (p11) 2 (AnxA2) 2 is governed by several hydrophobic interactions between side chains of AHNAK and pockets on S100A10. The pockets are large enough to accommodate a variety of hydrophobic side chains, allowing the consensus sequence to be more general. Additionally, the various hydrogen bonds formed between the AHNAK peptide and (p11) 2 (AnxA2) 2 most often involve backbone atoms of AHNAK; as a result, the side chains, particularly those that point away from S100A10/AnxA2 towards the solvent, are largely interchangeable. While the structure-based consensus sequence allows interactions with various stretches of the AHNAK C-terminal domain, comparison

  14. Structure of a C-terminal AHNAK peptide in a 1:2:2 complex with S100A10 and an acetylated N-terminal peptide of annexin A2

    Energy Technology Data Exchange (ETDEWEB)

    Ozorowski, Gabriel [University of California, Irvine, Irvine, CA 92697-3900 (United States); University of California, Irvine, Irvine, CA 92697-3900 (United States); Milton, Saskia [University of California, Irvine, Irvine, CA 92697-3900 (United States); Luecke, Hartmut, E-mail: hudel@uci.edu [University of California, Irvine, Irvine, CA 92697-3900 (United States); University of California, Irvine, Irvine, CA 92697-3900 (United States); University of California, Irvine, Irvine, CA 92697 (United States); University of California, Irvine, Irvine, CA 92697 (United States)

    2013-01-01

    Structure of a 20-amino-acid peptide of AHNAK bound asymmetrically to the AnxA2–S100A10A heterotetramer (1:2:2 symmetry) provides insights into the atomic level interactions that govern this membrane-repair scaffolding complex. AHNAK, a large 629 kDa protein, has been implicated in membrane repair, and the annexin A2–S100A10 heterotetramer [(p11){sub 2}(AnxA2){sub 2})] has high affinity for several regions of its 1002-amino-acid C-terminal domain. (p11){sub 2}(AnxA2){sub 2} is often localized near the plasma membrane, and this C2-symmetric platform is proposed to be involved in the bridging of membrane vesicles and trafficking of proteins to the plasma membrane. All three proteins co-localize at the intracellular face of the plasma membrane in a Ca{sup 2+}-dependent manner. The binding of AHNAK to (p11){sub 2}(AnxA2){sub 2} has been studied previously, and a minimal binding motif has been mapped to a 20-amino-acid peptide corresponding to residues 5654–5673 of the AHNAK C-terminal domain. Here, the 2.5 Å resolution crystal structure of this 20-amino-acid peptide of AHNAK bound to the AnxA2–S100A10 heterotetramer (1:2:2 symmetry) is presented, which confirms the asymmetric arrangement first described by Rezvanpour and coworkers and explains why the binding motif has high affinity for (p11){sub 2}(AnxA2){sub 2}. Binding of AHNAK to the surface of (p11){sub 2}(AnxA2){sub 2} is governed by several hydrophobic interactions between side chains of AHNAK and pockets on S100A10. The pockets are large enough to accommodate a variety of hydrophobic side chains, allowing the consensus sequence to be more general. Additionally, the various hydrogen bonds formed between the AHNAK peptide and (p11){sub 2}(AnxA2){sub 2} most often involve backbone atoms of AHNAK; as a result, the side chains, particularly those that point away from S100A10/AnxA2 towards the solvent, are largely interchangeable. While the structure-based consensus sequence allows interactions with various

  15. Targeting annexin A7 by a small molecule suppressed the activity of phosphatidylcholine-specific phospholipase C in vascular endothelial cells and inhibited atherosclerosis in apolipoprotein E⁻/⁻mice.

    Science.gov (United States)

    Li, H; Huang, S; Wang, S; Zhao, J; Su, L; Zhao, B; Zhang, Y; Zhang, S; Miao, J

    2013-09-19

    Phosphatidylcholine-specific phospholipase C (PC-PLC) is a key factor in apoptosis and autophagy of vascular endothelial cells (VECs), and involved in atherosclerosis in apolipoprotein E⁻/⁻ (apoE⁻/⁻) mice. But the endogenous regulators of PC-PLC are not known. We recently found a small chemical molecule (6-amino-2, 3-dihydro-3-hydroxymethyl-1, 4-benzoxazine, ABO) that could inhibit oxidized low-density lipoprotein (oxLDL)-induced apoptosis and promote autophagy in VECs, and further identified ABO as an inhibitor of annexin A7 (ANXA7) GTPase. Based on these findings, we hypothesize that ANXA7 is an endogenous regulator of PC-PLC, and targeting ANXA7 by ABO may inhibit atherosclerosis in apoE⁻/⁻ mice. In this study, we tested our hypothesis. The results showed that ABO suppressed oxLDL-induced increase of PC-PLC level and activity and promoted the co-localization of ANXA7 and PC-PLC in VECs. The experiments of ANXA7 knockdown and overexpression demonstrated that the action of ABO was ANXA7-dependent in cultured VECs. To investigate the relation of ANXA7 with PC-PLC in atherosclerosis, apoE⁻/⁻ mice fed with a western diet were treated with 50 or 100 mg/kg/day ABO. The results showed that ABO decreased PC-PLC levels in the mouse aortic endothelium and PC-PLC activity in serum, and enhanced the protein levels of ANXA7 in the mouse aortic endothelium. Furthermore, both dosages of ABO significantly enhanced autophagy and reduced apoptosis in the mouse aortic endothelium. As a result, ABO significantly reduced atherosclerotic plaque area and effectively preserved a stable plaques phenotype, including reduced lipid deposition and pro-inflammatory macrophages, increased anti-inflammatory macrophages, collagen content and smooth muscle cells, and less cell death in the plaques. In conclusion, ANXA7 was an endogenous regulator of PC-PLC, and targeting ANXA7 by ABO inhibited atherosclerosis in apoE⁻/⁻ mice.

  16. Cyclooxygenase inhibitors potentiate receptor tyrosine kinase therapies in bladder cancer cells in vitro

    Directory of Open Access Journals (Sweden)

    Bourn J

    2018-06-01

    Full Text Available Jennifer Bourn,1,2 Maria Cekanova1,2 1Department of Small Animal Clinical Sciences, College of Veterinary Medicine, The University of Tennessee, Knoxville, TN, USA; 2UT-ORNL Graduate School of Genome Science and Technology, The University of Tennessee, Knoxville, TN, USA Purpose: Receptor tyrosine kinase inhibitors (RTKIs are used as targeted therapies for patients diagnosed with cancer with highly expressed receptor tyrosine kinases (RTKs, including the platelet-derived growth factor receptor (PDGFR and c-Kit receptor. Resistance to targeted therapies is partially due to the activation of alternative pro-survival signaling pathways, including cyclooxygenase (COX-2. In this study, we validated the effects of two RTKIs, axitinib and AB1010, in combination with COX inhibitors on the V-akt murine thymoma oncogene homolog 1 (Akt and COX-2 signaling pathways in bladder cancer cells.Methods: The expression of several RTKs and their downstream signaling targets was analyzed by Western blot (WB analysis in human and canine bladder transitional cell carcinoma (TCC cell lines. The effects of RTKIs and COX inhibitors in bladder TCC cells were assessed by MTS for cell viability, by Caspase-3/7 and Annexin V assay for apoptosis, by WB analysis for detection of COX-2 and Akt signaling pathways, and by enzyme-linked immunosorbent assay for detection of prostaglandin E2 (PGE2 levels.Results: All tested TCC cells expressed the c-Kit and PDGFRα receptors, except human 5637 cells that had low RTKs expression. In addition, all tested cells expressed COX-1, COX-2, Akt, extracellular signal regulated kinases 1/2, and nuclear factor kappa-light-chain-enhance of activated B cells proteins, except human UM-UC-3 cells, where no COX-2 expression was detected by WB analysis. Both RTKIs inhibited cell viability and increased apoptosis in a dose-dependent manner in tested bladder TCC cells, which positively correlated with their expression levels of the PDGFRα and c

  17. Ionotropic crustacean olfactory receptors.

    Directory of Open Access Journals (Sweden)

    Elizabeth A Corey

    Full Text Available The nature of the olfactory receptor in crustaceans, a major group of arthropods, has remained elusive. We report that spiny lobsters, Panulirus argus, express ionotropic receptors (IRs, the insect chemosensory variants of ionotropic glutamate receptors. Unlike insects IRs, which are expressed in a specific subset of olfactory cells, two lobster IR subunits are expressed in most, if not all, lobster olfactory receptor neurons (ORNs, as confirmed by antibody labeling and in situ hybridization. Ligand-specific ORN responses visualized by calcium imaging are consistent with a restricted expression pattern found for other potential subunits, suggesting that cell-specific expression of uncommon IR subunits determines the ligand sensitivity of individual cells. IRs are the only type of olfactory receptor that we have detected in spiny lobster olfactory tissue, suggesting that they likely mediate olfactory signaling. Given long-standing evidence for G protein-mediated signaling in activation of lobster ORNs, this finding raises the interesting specter that IRs act in concert with second messenger-mediated signaling.

  18. Hyperoxaluria Requires TNF Receptors to Initiate Crystal Adhesion and Kidney Stone Disease.

    Science.gov (United States)

    Mulay, Shrikant R; Eberhard, Jonathan N; Desai, Jyaysi; Marschner, Julian A; Kumar, Santhosh V R; Weidenbusch, Marc; Grigorescu, Melissa; Lech, Maciej; Eltrich, Nuru; Müller, Lisa; Hans, Wolfgang; Hrabě de Angelis, Martin; Vielhauer, Volker; Hoppe, Bernd; Asplin, John; Burzlaff, Nicolai; Herrmann, Martin; Evan, Andrew; Anders, Hans-Joachim

    2017-03-01

    Intrarenal crystals trigger inflammation and renal cell necroptosis, processes that involve TNF receptor (TNFR) signaling. Here, we tested the hypothesis that TNFRs also have a direct role in tubular crystal deposition and progression of hyperoxaluria-related CKD. Immunohistochemical analysis revealed upregulated tubular expression of TNFR1 and TNFR2 in human and murine kidneys with calcium oxalate (CaOx) nephrocalcinosis-related CKD compared with controls. Western blot and mRNA expression analyses in mice yielded consistent data. When fed an oxalate-rich diet, wild-type mice developed progressive CKD, whereas Tnfr1-, Tnfr2- , and Tnfr1/2- deficient mice did not. Despite identical levels of hyperoxaluria, Tnfr1-, Tnfr2- , and Tnfr1/2 -deficient mice also lacked the intrarenal CaOx deposition and tubular damage observed in wild-type mice. Inhibition of TNFR signaling prevented the induced expression of the crystal adhesion molecules, CD44 and annexin II, in tubular epithelial cells in vitro and in vivo , and treatment with the small molecule TNFR inhibitor R-7050 partially protected hyperoxaluric mice from nephrocalcinosis and CKD. We conclude that TNFR signaling is essential for CaOx crystal adhesion to the luminal membrane of renal tubules as a fundamental initiating mechanism of oxalate nephropathy. Furthermore, therapeutic blockade of TNFR might delay progressive forms of nephrocalcinosis in oxalate nephropathy, such as primary hyperoxaluria. Copyright © 2017 by the American Society of Nephrology.

  19. Inhibition of CPU0213, a Dual Endothelin Receptor Antagonist, on Apoptosis via Nox4-Dependent ROS in HK-2 Cells

    Directory of Open Access Journals (Sweden)

    Qing Li

    2016-06-01

    Full Text Available Background/Aims: Our previous studies have indicated that a novel endothelin receptor antagonist CPU0213 effectively normalized renal function in diabetic nephropathy. However, the molecular mechanisms mediating the nephroprotective role of CPU0213 remain unknown. Methods and Results: In the present study, we first detected the role of CPU0213 on apoptosis in human renal tubular epithelial cell (HK-2. It was shown that high glucose significantly increased the protein expression of Bax and decreased Bcl-2 protein in HK-2 cells, which was reversed by CPU0213. The percentage of HK-2 cells that showed Annexin V-FITC binding was markedly suppressed by CPU0213, which confirmed the inhibitory role of CPU0213 on apoptosis. Given the regulation of endothelin (ET system to oxidative stress, we determined the role of redox signaling in the regulation of CPU0213 on apoptosis. It was demonstrated that the production of superoxide (O2-. was substantially attenuated by CPU0213 treatment in HK-2 cells. We further found that CPU0213 dramatically inhibited expression of Nox4 protein, which gene silencing mimicked the role of CPU0213 on the apoptosis under high glucose stimulation. We finally examined the role of CPU0213 on ET-1 receptors and found that high glucose-induced protein expression of endothelin A and B receptors was dramatically inhibited by CPU0213. Conclusion: Taken together, these results suggest that this Nox4-dependenet O2- production is critical for the apoptosis of HK-2 cells in high glucose. Endothelin receptor antagonist CPU0213 has an anti-apoptosis role through Nox4-dependent O2-.production, which address the nephroprotective role of CPU0213 in diabetic nephropathy.

  20. Assays for calcitonin receptors

    International Nuclear Information System (INIS)

    Teitelbaum, A.P.; Nissenson, R.A.; Arnaud, C.D.

    1985-01-01

    The assays for calcitonin receptors described focus on their use in the study of the well-established target organs for calcitonin, bone and kidney. The radioligand used in virtually all calcitonin binding studies is 125 I-labelled salmon calcitonin. The lack of methionine residues in this peptide permits the use of chloramine-T for the iodination reaction. Binding assays are described for intact bone, skeletal plasma membranes, renal plasma membranes, and primary kidney cell cultures of rats. Studies on calcitonin metabolism in laboratory animals and regulation of calcitonin receptors are reviewed

  1. Angiotensin type 2 receptor (AT2R) and receptor Mas

    DEFF Research Database (Denmark)

    Villela, Daniel; Leonhardt, Julia; Patel, Neal

    2015-01-01

    The angiotensin type 2 receptor (AT2R) and the receptor Mas are components of the protective arms of the renin-angiotensin system (RAS), i.e. they both mediate tissue protective and regenerative actions. The spectrum of actions of these two receptors and their signalling mechanisms display striki...

  2. TLX: An elusive receptor.

    Science.gov (United States)

    Benod, Cindy; Villagomez, Rosa; Webb, Paul

    2016-03-01

    TLX (tailless receptor) is a member of the nuclear receptor superfamily and belongs to a class of nuclear receptors for which no endogenous or synthetic ligands have yet been identified. TLX is a promising therapeutic target in neurological disorders and brain tumors. Thus, regulatory ligands for TLX need to be identified to complete the validation of TLX as a useful target and would serve as chemical probes to pursue the study of this receptor in disease models. It has recently been proved that TLX is druggable. However, to identify potent and specific TLX ligands with desirable biological activity, a deeper understanding of where ligands bind, how they alter TLX conformation and of the mechanism by which TLX mediates the transcription of its target genes is needed. While TLX is in the process of escaping from orphanhood, future ligand design needs to progress in parallel with improved understanding of (i) the binding cavity or surfaces to target with small molecules on the TLX ligand binding domain and (ii) the nature of the TLX coregulators in particular cell and disease contexts. Both of these topics are discussed in this review. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. Glutamate receptor ligands

    DEFF Research Database (Denmark)

    Guldbrandt, Mette; Johansen, Tommy N; Frydenvang, Karla Andrea

    2002-01-01

    Homologation and substitution on the carbon backbone of (S)-glutamic acid [(S)-Glu, 1], as well as absolute stereochemistry, are structural parameters of key importance for the pharmacological profile of (S)-Glu receptor ligands. We describe a series of methyl-substituted 2-aminoadipic acid (AA...

  4. Ginkgolides and glycine receptors

    DEFF Research Database (Denmark)

    Jaracz, Stanislav; Nakanishi, Koji; Jensen, Anders A.

    2004-01-01

    Ginkgolides from the Ginkgo biloba tree are diterpenes with a cage structure consisting of six five-membered rings and a unique tBu group. They exert a variety of biological properties. In addition to being antagonists of the platelet activating factor receptor (PAFR), it has recently been shown ...

  5. adrenergic receptor with preeclampsia

    African Journals Online (AJOL)

    User

    2011-05-09

    May 9, 2011 ... due to a post- receptor defect (Karadas et al., 2007). Several polymorphisms have ... the detection of the Arg16Gly polymorphism, overnight digestion at. 37°C with 10 U ..... DW, Wood AJ, Stein CM (2004). Beta2-adrenoceptor ...

  6. Metformin and insulin receptors

    International Nuclear Information System (INIS)

    Vigneri, R.; Gullo, D.; Pezzino, V.

    1984-01-01

    The authors evaluated the effect of metformin (N,N-dimethylbiguanide), a biguanide known to be less toxic than phenformin, on insulin binding to its receptors, both in vitro and in vivo. Specific 125 I-insulin binding to cultured IM-9 human lymphocytes and MCF-7 human breast cancer cells was determined after preincubation with metformin. Specific 125 I-insulin binding to circulating monocytes was also evaluated in six controls, eight obese subjects, and six obese type II diabetic patients before and after a short-term treatment with metformin. Plasma insulin levels and blood glucose were also measured on both occasions. Metformin significantly increased insulin binding in vitro to both IM-9 lymphocytes and MCF-7 cells; the maximum increment was 47.1% and 38.0%, respectively. Metformin treatment significantly increased insulin binding in vivo to monocytes of obese subjects and diabetic patients. Scatchard analysis indicated that the increased binding was mainly due to an increase in receptor capacity. Insulin binding to monocytes of normal controls was unchanged after metformin as were insulin levels in all groups; blood glucose was significantly reduced after metformin only in diabetic patients. These data indicate that metformin increases insulin binding to its receptors in vitro and in vivo. The effect in vivo is observed in obese subjects and in obese type II diabetic patients, paralleling the clinical effectiveness of this antidiabetic agent, and is not due to receptor regulation by circulating insulin, since no variation in insulin levels was recorded

  7. Profile and regulation of annexin II expression during early embryogenesis in cattle Perfil e regulação da expressão da anexina II durante a embriogênese em bovinos

    Directory of Open Access Journals (Sweden)

    L.F.S. Costa

    2007-12-01

    Full Text Available The presence of annexin II (Ann-II during the initial stages of bovine embryo development and the regulation of Ann-II expression by retinol and insulin-like growth factor I (IGF-I were studied. Bovine embryos at different stages of development were produced in vitro on Synthetic Oviductal Fluid (SOF medium (control group, SOF supplemented with retinol (retinol group; 0.1ng/ml, or IGF-I (IGF-I group; 10ng/ml. The embryos were processed for mRNA extraction, cDNA production and polymerase chain reaction (PCR using Ann-II-specific oligonucleotides. Ann-II was detected in all stages of early embryo development, except for the 16-cell stage. The blastocyst rates were significantly higher (PForam estudadas a presença de anexina II (Ann-II durante a fase inicial do desenvolvimento embrionário bovino e sua regulação pelo retinol e pelo fator de crescimento semelhante à insulina (IGF-I. Embriões bovinos em diferentes estádios de desenvolvimento foram produzidos in vitro em fluido sintético de oviduto (SOF sem suplementação (grupo-controle ou suplementado com retinol (grupo retinol; 0,1ng/ml medium ou IGF-I (grupo IGF-I; 10 ng/ml de meio. Os embriões foram processados para extração de mRNA, produção de cDNA e posterior análise por reação em cadeia da polimerase (PCR com oligonucleotídeos específicos para Ann-II. Em todos os estádios de desenvolvimento embrionário, Ann-II foi detectada, exceto no estádio de 16 células. Os índices de blastocisto foram significativamente maiores (P<0,05 no grupo suplementado com retinol (37,8%, 45/119 durante o cultivo in vitro de embriões (PIV que aqueles obtidos no grupo controle (20,5%, 24/117 ou no IGF-I (25,8%, 24/93. Análise semiquantitativa da expressão de Ann-II em embriões produzidos em meio suplementado com IGF-I ou retinol revelou uma menor expressão desse gene quando comparado com embriões cultivados somente em SOF (P<0,05. A expressão de Ann-II não foi diferente em embri

  8. Olfactory Receptor Database: a sensory chemoreceptor resource

    OpenAIRE

    Skoufos, Emmanouil; Marenco, Luis; Nadkarni, Prakash M.; Miller, Perry L.; Shepherd, Gordon M.

    2000-01-01

    The Olfactory Receptor Database (ORDB) is a WWW-accessible database that has been expanded from an olfactory receptor resource to a chemoreceptor resource. It stores data on six classes of G-protein-coupled sensory chemoreceptors: (i) olfactory receptor-like proteins, (ii) vomeronasal receptors, (iii) insect olfactory receptors, (iv) worm chemoreceptors, (v) taste papilla receptors and (vi) fungal pheromone receptors. A complementary database of the ligands of these receptors (OdorDB) has bee...

  9. Regulation of ITAM adaptor molecules and their receptors by inhibition of calcineurin-NFAT signalling during late stage osteoclast differentiation

    Energy Technology Data Exchange (ETDEWEB)

    Zawawi, M.S.F. [Universiti Sains Malaysia (USM) (Malaysia); Discipline of Anatomy and Pathology, School of Medical Sciences, University of Adelaide, Adelaide, SA 5005 (Australia); Dharmapatni, A.A.S.S.K.; Cantley, M.D. [Discipline of Anatomy and Pathology, School of Medical Sciences, University of Adelaide, Adelaide, SA 5005 (Australia); McHugh, K.P. [University of Florida, College of Dentistry, Fl (United States); Haynes, D.R. [Discipline of Anatomy and Pathology, School of Medical Sciences, University of Adelaide, Adelaide, SA 5005 (Australia); Crotti, T.N., E-mail: tania.crotti@adelaide.edu.au [Discipline of Anatomy and Pathology, School of Medical Sciences, University of Adelaide, Adelaide, SA 5005 (Australia)

    2012-10-19

    Highlights: Black-Right-Pointing-Pointer Calcineurin/NFAT inhibitors FK506 and VIVIT treated human PBMC derived osteoclasts in vitro. Black-Right-Pointing-Pointer Differential regulation of ITAM receptors and adaptor molecules by calcineurin/NFAT inhibitors. Black-Right-Pointing-Pointer FK506 and VIVIT suppress ITAM factors during late phase osteoclast differentiation. -- Abstract: Osteoclasts are specialised bone resorptive cells responsible for both physiological and pathological bone loss. Osteoclast differentiation and activity is dependent upon receptor activator NF-kappa-B ligand (RANKL) interacting with its receptor RANK to induce the transcription factor, nuclear factor of activated T-cells, cytoplasmic, calcineurin-dependent 1 (NFATc1). The immunoreceptor tyrosine-based activation motif (ITAM)-dependent pathway has been identified as a co-stimulatory pathway in osteoclasts. Osteoclast-associated receptor (OSCAR) and triggering receptor expressed in myeloid cells (TREM2) are essential receptors that pair with adaptor molecules Fc receptor common gamma chain (FcR{gamma}) and DNAX-activating protein 12 kDa (DAP12) respectively to induce calcium signalling. Treatment with calcineurin-NFAT inhibitors, Tacrolimus (FK506) and the 11R-VIVIT (VIVIT) peptide, reduces NFATc1 expression consistent with a reduction in osteoclast differentiation and activity. This study aimed to investigate the effects of inhibiting calcineurin-NFAT signalling on the expression of ITAM factors and late stage osteoclast genes including cathepsin K (CathK), Beta 3 integrin ({beta}3) and Annexin VIII (AnnVIII). Human peripheral blood mononuclear cells (PBMCs) were differentiated with RANKL and macrophage-colony stimulating factor (M-CSF) over 10 days in the presence or absence of FK506 or VIVIT. Osteoclast formation (as assessed by tartrate resistant acid phosphatase (TRAP)) and activity (assessed by dentine pit resorption) were significantly reduced with treatment. Quantitative real

  10. Surface TRAIL decoy receptor-4 expression is correlated with TRAIL resistance in MCF7 breast cancer cells

    International Nuclear Information System (INIS)

    Sanlioglu, Ahter D; Dirice, Ercument; Aydin, Cigdem; Erin, Nuray; Koksoy, Sadi; Sanlioglu, Salih

    2005-01-01

    Tumor Necrosis Factor (TNF)-Related Apoptosis-Inducing Ligand (TRAIL) selectively induces apoptosis in cancer cells but not in normal cells. Despite this promising feature, TRAIL resistance observed in cancer cells seriously challenged the use of TRAIL as a death ligand in gene therapy. The current dispute concerns whether or not TRAIL receptor expression pattern is the primary determinant of TRAIL sensitivity in cancer cells. This study investigates TRAIL receptor expression pattern and its connection to TRAIL resistance in breast cancer cells. In addition, a DcR2 siRNA approach and a complementary gene therapy modality involving IKK inhibition (AdIKKβKA) were also tested to verify if these approaches could sensitize MCF7 breast cancer cells to adenovirus delivery of TRAIL (Ad5hTRAIL). TRAIL sensitivity assays were conducted using Molecular Probe's Live/Dead Cellular Viability/Cytotoxicity Kit following the infection of breast cancer cells with Ad5hTRAIL. The molecular mechanism of TRAIL induced cell death under the setting of IKK inhibition was revealed by Annexin V binding. Novel quantitative Real Time RT-PCR and flow cytometry analysis were performed to disclose TRAIL receptor composition in breast cancer cells. MCF7 but not MDA-MB-231 breast cancer cells displayed strong resistance to adenovirus delivery of TRAIL. Only the combinatorial use of Ad5hTRAIL and AdIKKβKA infection sensitized MCF7 breast cancer cells to TRAIL induced cell death. Moreover, novel quantitative Real Time RT-PCR assays suggested that while the level of TRAIL Decoy Receptor-4 (TRAIL-R4) expression was the highest in MCF7 cells, it was the lowest TRAIL receptor expressed in MDA-MB-231 cells. In addition, conventional flow cytometry analysis demonstrated that TRAIL resistant MCF7 cells exhibited substantial levels of TRAIL-R4 expression but not TRAIL decoy receptor-3 (TRAIL-R3) on surface. On the contrary, TRAIL sensitive MDA-MB-231 cells displayed very low levels of surface TRAIL-R4

  11. Prostaglandin Receptor Signaling in Disease

    Directory of Open Access Journals (Sweden)

    Toshiyuki Matsuoka

    2007-01-01

    Full Text Available Prostanoids, consisting of the prostaglandins (PGs and the thromboxanes (TXs, are a group of lipid mediators formed in response to various stimuli. They include PGD2, PGE2, PGF2α, PGI2, and TXA2. They are released outside of the cells immediately after synthesis, and exert their actions by binding to a G-protein coupled rhodopsin-type receptor on the surface of target cells. There are eight types of the prostanoid receptors conserved in mammals from mouse to human. They are the PGD receptor (DP, four subtypes of the PGE receptor (EP1, EP2, EP3, and EP4, the PGF receptor (FP, PGI receptor (IP, and TXA receptor (TP. Recently, mice deficient in each of these prostanoid receptors were generated and subjected to various experimental models of disease. These studies have revealed the roles of PG receptor signaling in various pathological conditions, and suggest that selective manipulation of the prostanoid receptors may be beneficial in treatment of the pathological conditions. Here we review these recent findings of roles of prostanoid receptor signaling and their therapeutic implications.

  12. The interleukin-4 receptor: signal transduction by a hematopoietin receptor.

    Science.gov (United States)

    Keegan, A D; Pierce, J H

    1994-02-01

    Over the last several years, the receptors for numerous cytokines have been molecularly characterized. Analysis of their amino acid sequences shows that some of these receptors bear certain motifs in their extracellular domains that define a family of receptors called the Hematopoietin receptor superfamily. Significant advances in characterizing the structure, function, and mechanisms of signal transduction have been made for several members of this family. The purpose of this review is to discuss the recent advances made for one of the family members, the interleukin (IL) 4 receptor. Other receptor systems have recently been reviewed elsewhere. The IL-4 receptor consists of, at the minimum, the cloned 140 kDa IL-4-binding chain with the potential for associating with other chains. The IL-4 receptor transduces its signal by activating a tyrosine kinase that phosphorylates cellular substrates, including the receptor itself, and the 170 kDa substrate called 4PS. Phosphorylated 4PS interacts with the SH2 domain of the enzyme PI-3'-kinase and increases its enzymatic activity. These early events in the IL-4 receptor initiated signaling pathway may trigger a series of signals that will ultimately lead to an IL-4 specific biologic outcome.

  13. Meeting report: nuclear receptors

    DEFF Research Database (Denmark)

    Tuckermann, Jan; Bourguet, William; Mandrup, Susanne

    2010-01-01

    The biannual European Molecular Biology Organization (EMBO) conference on nuclear receptors was organized by Beatrice Desvergne and Laszlo Nagy and took place in Cavtat near Dubrovnik on the Adriatic coast of Croatia September 25-29, 2009. The meeting brought together researchers from all over...... the world covering a wide spectrum from fundamental mechanistic studies to metabolism, clinical studies, and drug development. In this report, we summarize the recent and exciting findings presented by the speakers at the meeting....

  14. Neurotransmitter receptor imaging

    International Nuclear Information System (INIS)

    Cordes, M.; Hierholzer, J.; Nikolai-Beyer, K.

    1993-01-01

    The importance of neuroreceptor imaging in vivo using single photon emission tomography (SPECT) and positron emission tomography (PET) has increased enormously. The principal neurotransmitters, such as dopamine, GABA/benzodiazepine, acetylcholine, and serotonin, are presented with reference to anatomical, biochemical, and physiological features. The main radioligands for SPECT and PET are introduced, and methodological characteristics of both PET and SPECT presented. Finally, the results of neurotransmitter receptor imaging obtained so far will be discussed. (orig.) [de

  15. Thyroid Stimulating Hormone Receptor

    Directory of Open Access Journals (Sweden)

    Murat Tuncel

    2017-02-01

    Full Text Available Thyroid stimulating hormone receptor (TSHR plays a pivotal role in thyroid hormone metabolism. It is a major controller of thyroid cell function and growth. Mutations in TSHR may lead to several thyroid diseases, most commonly hyperthyroidism. Although its genetic and epigenetic alterations do not directly lead to carcinogenesis, it has a crucial role in tumor growth, which is initiated by several oncogenes. This article will provide a brief review of TSHR and related diseases.

  16. Membrane receptor-mediated apoptosis and caspase activation in the differentiated EoL-1 eosinophilic cell line.

    Science.gov (United States)

    Al-Rabia, Mohammed W; Blaylock, Morgan G; Sexton, Darren W; Walsh, Garry M

    2004-06-01

    Caspases are key molecules in the control of apoptosis, but relatively little is known about their contribution to eosinophil apoptosis. We examined caspase-3, -8, and -9 activities in receptor ligation-dependent apoptosis induction in the differentiated human eosinophilic cell line EoL-1. Differentiated EoL-1 exhibited bi-lobed nuclei, eosinophil-associated membrane receptors, and basic granule proteins. Annexin-V fluorescein isothiocyanate binding to EoL-1 revealed significant (PEoL-1 but had no effect on constitutive (baseline) apoptosis at 16 and 20 h. Caspase activity was analyzed using the novel CaspaTag trade mark technique and flow cytometry. EoL-1 treated with pan-CD45, CD45RA, CD45RB, and CD95 mAb exhibited caspase-3 and -9 activation at 12 h post-treatment, which increased at 16 and 20 h. Activated caspase-8 was detected 12 and 16 h after ligation with CD45, CD45RA, CD45RB, and CD95 mAb followed by a trend toward basal levels at 20 h. CD69 ligation resulted in caspase-3 activation, a modest but significant activation of caspase-8, and a loss in mitochondrial transmembrane potential but had no significant effect on activation of caspase-9. Thus, the intrinsic and extrinsic caspase pathways are involved in controlling receptor ligation-mediated apoptosis induction in human eosinophils, findings that may aid the development of a more targeted, anti-inflammatory therapy for asthma.

  17. Melatonin Receptor Genes in Vertebrates

    Directory of Open Access Journals (Sweden)

    Hua Dong Yin

    2013-05-01

    Full Text Available Melatonin receptors are members of the G protein-coupled receptor (GPCR family. Three genes for melatonin receptors have been cloned. The MT1 (or Mel1a or MTNR1A and MT2 (or Mel1b or MTNR1B receptor subtypes are present in humans and other mammals, while an additional melatonin receptor subtype, Mel1c (or MTNR1C, has been identified in fish, amphibians and birds. Another melatonin related orphan receptor, GPR50, which does not bind melatonin, is found exclusively in mammals. The hormone melatonin is secreted primarily by the pineal gland, with highest levels occurring during the dark period of a circadian cycle. This hormone acts systemically in numerous organs. In the brain, it is involved in the regulation of various neural and endocrine processes, and it readjusts the circadian pacemaker, the suprachiasmatic nucleus. This article reviews recent studies of gene organization, expression, evolution and mutations of melatonin receptor genes of vertebrates. Gene polymorphisms reveal that numerous mutations are associated with diseases and disorders. The phylogenetic analysis of receptor genes indicates that GPR50 is an outgroup to all other melatonin receptor sequences. GPR50 may have separated from a melatonin receptor ancestor before the split between MTNR1C and the MTNR1A/B ancestor.

  18. Flavivirus Entry Receptors: An Update

    Directory of Open Access Journals (Sweden)

    Manuel Perera-Lecoin

    2013-12-01

    Full Text Available Flaviviruses enter host cells by endocytosis initiated when the virus particles interact with cell surface receptors. The current model suggests that flaviviruses use at least two different sets of molecules for infectious entry: attachment factors that concentrate and/or recruit viruses on the cell surface and primary receptor(s that bind to virions and direct them to the endocytic pathway. Here, we present the currently available knowledge regarding the flavivirus receptors described so far with specific attention to C-type lectin receptors and the phosphatidylserine receptors, T-cell immunoglobulin and mucin domain (TIM and TYRO3, AXL and MER (TAM. Their role in flavivirus attachment and entry as well as their implication in the virus biology will be discussed in depth.

  19. Adenosine Receptors and Wound Healing

    Directory of Open Access Journals (Sweden)

    Bruce N. Cronstein

    2004-01-01

    Full Text Available Recent studies have demonstrated that application of topical adenosine A2A receptor agonists promotes more rapid wound closure and clinical studies are currently underway to determine the utility of topical A2A adenosine receptor agonists in the therapy of diabetic foot ulcers. The effects of adenosine A2A receptors on the cells and tissues of healing wounds have only recently been explored. We review here the known effects of adenosine A2A receptor occupancy on the cells involved in wound healing.

  20. Virally encoded 7TM receptors

    DEFF Research Database (Denmark)

    Rosenkilde, M M; Waldhoer, M; Lüttichau, H R

    2001-01-01

    expression of this single gene in certain lymphocyte cell lineages leads to the development of lesions which are remarkably similar to Kaposi's sarcoma, a human herpesvirus 8 associated disease. Thus, this and other virally encoded 7TM receptors appear to be attractive future drug targets.......A number of herpes- and poxviruses encode 7TM G-protein coupled receptors most of which clearly are derived from their host chemokine system as well as induce high expression of certain 7TM receptors in the infected cells. The receptors appear to be exploited by the virus for either immune evasion...

  1. Adenosine receptor desensitization and trafficking.

    Science.gov (United States)

    Mundell, Stuart; Kelly, Eamonn

    2011-05-01

    As with the majority of G-protein-coupled receptors, all four of the adenosine receptor subtypes are known to undergo agonist-induced regulation in the form of desensitization and trafficking. These processes can limit the ability of adenosine receptors to couple to intracellular signalling pathways and thus reduce the ability of adenosine receptor agonists as well as endogenous adenosine to produce cellular responses. In addition, since adenosine receptors couple to multiple signalling pathways, these pathways may desensitize differentially, while the desensitization of one pathway could even trigger signalling via another. Thus, the overall picture of adenosine receptor regulation can be complex. For all adenosine receptor subtypes, there is evidence to implicate arrestins in agonist-induced desensitization and trafficking, but there is also evidence for other possible forms of regulation, including second messenger-dependent kinase regulation, heterologous effects involving G proteins, and the involvement of non-clathrin trafficking pathways such as caveolae. In this review, the evidence implicating these mechanisms is summarized for each adenosine receptor subtype, and we also discuss those issues of adenosine receptor regulation that remain to be resolved as well as likely directions for future research in this field. Copyright © 2010 Elsevier B.V. All rights reserved.

  2. Effects of icotinib, a novel epidermal growth factor receptor tyrosine kinase inhibitor, in EGFR-mutated non-small cell lung cancer.

    Science.gov (United States)

    Yang, Guangdie; Yao, Yinan; Zhou, Jianya; Zhao, Qiong

    2012-06-01

    Epidermal growth factor receptor (EGFR) is one of the most promising targets for non-small cell lung cancer (NSCLC). Our study demonstrated the antitumor effects of icotinib hydrochloride, a highly selective epidermal growth factor receptor tyrosine kinase inhibitor (EGFR TKI), in two EGFR-mutated lung cancer cell lines compared to A549, a cell line without EGFR mutations. We incubated PC-9 and HCC827 human lung cancer cell lines both with (E746-A750) mutations with various concentrations of icotinib and gefitinib for 48 h. Cell proliferation and migration were determined using a real-time cell invasion and migration assay and cytotoxicity assay. Apoptosis was assessed by measuring Annexin V staining using flow cytometry. The antitumor effects of icotinib compared to gefitinib were similar and were most effective in reducing the proliferation of EGFR-mutated cells compared to non-mutated controls. Our results suggest the possibility of icotinib as a new therapeutic agent of EGFR-mutated cancer cells, which has the potential to be used in the first-line treatment of EGFR-mutated NSCLC.

  3. Endothelial microparticle formation by angiotensin II is mediated via Ang II receptor type I/NADPH oxidase/ Rho kinase pathways targeted to lipid rafts.

    Science.gov (United States)

    Burger, Dylan; Montezano, Augusto C; Nishigaki, Nobuhiro; He, Ying; Carter, Anthony; Touyz, Rhian M

    2011-08-01

    Circulating microparticles are increased in cardiovascular disease and may themselves promote oxidative stress and inflammation. Molecular mechanisms underlying their formation and signaling are unclear. We investigated the role of reactive oxygen species (ROS), Rho kinase, and lipid rafts in microparticle formation and examined their functional significance in endothelial cells (ECs). Microparticle formation from angiotensin II (Ang II)-stimulated ECs and apolipoprotein E(-/-) mice was assessed by annexin V or by CD144 staining and electron microscopy. Ang II promoted microparticle formation and increased EC O(2)(-) generation and Rho kinase activity. Ang II-stimulated effects were inhibited by irbesartan (Ang II receptor type I blocker) and fasudil (Rho kinase inhibitor). Methyl-β-cyclodextrin and nystatin, which disrupt lipid rafts/caveolae, blocked microparticle release. Functional responses, assessed in microparticle-stimulated ECs, revealed increased O(2)(-) production, enhanced vascular cell adhesion molecule/platelet-EC adhesion molecule expression, and augmented macrophage adhesion. Inhibition of epidermal growth factor receptor blocked the prooxidative and proinflammatory effects of microparticles. In vitro observations were confirmed in apolipoprotein E(-/-) mice, which displayed vascular inflammation and high levels of circulating endothelial microparticles, effects that were reduced by apocynin. We demonstrated direct actions of Ang II on endothelial microparticle release, mediated through NADPH oxidase, ROS, and Rho kinase targeted to lipid rafts. Microparticles themselves stimulated endothelial ROS formation and inflammatory responses. Our findings suggest a feedforward system whereby Ang II promotes EC injury through its own endothelial-derived microparticles.

  4. Axonal GABAA receptors.

    Science.gov (United States)

    Trigo, Federico F; Marty, Alain; Stell, Brandon M

    2008-09-01

    Type A GABA receptors (GABA(A)Rs) are well established as the main inhibitory receptors in the mature mammalian forebrain. In recent years, evidence has accumulated showing that GABA(A)Rs are prevalent not only in the somatodendritic compartment of CNS neurons, but also in their axonal compartment. Evidence for axonal GABA(A)Rs includes new immunohistochemical and immunogold data: direct recording from single axonal terminals; and effects of local applications of GABA(A)R modulators on action potential generation, on axonal calcium signalling, and on neurotransmitter release. Strikingly, whereas presynaptic GABA(A)Rs have long been considered inhibitory, the new studies in the mammalian brain mostly indicate an excitatory action. Depending on the neuron that is under study, axonal GABA(A)Rs can be activated by ambient GABA, by GABA spillover, or by an autocrine action, to increase either action potential firing and/or transmitter release. In certain neurons, the excitatory effects of axonal GABA(A)Rs persist into adulthood. Altogether, axonal GABA(A)Rs appear as potent neuronal modulators of the mammalian CNS.

  5. Possible Relevance of Receptor-Receptor Interactions between Viral- and Host-Coded Receptors for Viral-Induced Disease

    Directory of Open Access Journals (Sweden)

    Luigi F. Agnati

    2007-01-01

    Full Text Available It has been demonstrated that some viruses, such as the cytomegalovirus, code for G-protein coupled receptors not only to elude the immune system, but also to redirect cellular signaling in the receptor networks of the host cells. In view of the existence of receptor-receptor interactions, the hypothesis is introduced that these viral-coded receptors not only operate as constitutively active monomers, but also can affect other receptor function by interacting with receptors of the host cell. Furthermore, it is suggested that viruses could also insert not single receptors (monomers, but clusters of receptors (receptor mosaics, altering the cell metabolism in a profound way. The prevention of viral receptor-induced changes in host receptor networks may give rise to novel antiviral drugs that counteract viral-induced disease.

  6. Receptor studies in biological psychiatry

    International Nuclear Information System (INIS)

    Fujiwara, Yutaka

    1992-01-01

    Recent advances in the pharmacological treatment of endogenous psychosis have led to the development of biological studies in psychiatry. Studies on neurotransmitter receptors were reviewed in order to apply positron-emission tomograph (PET) for biological psychiatry. The dopamine (DA) hypothesis for schizophrenia was advanced on the basis of the observed effects of neuroleptics and methamphetamine, and DA(D 2 ) receptor supersensitivity measured by PET and receptor binding in the schizophrenic brain. The clinical potencies of neuroleptics for schizophrenia were correlated with their abilities to inhibit the D 2 receptor, and not other receptors. The σ receptor was expected to be a site of antipsychotic action. However, the potency of drugs action on it was not correlated with clinical efficacy. Haloperidol binds with high affinity to the σ receptor, which may mediate acute dystonia, an extrapyramidal side effect of neuroleptics. Behavioral and neurochemical changes induced by methamphetamine treatment were studied as an animal model of schizophrenia, and both a decrease of D 2 receptor density and an increase of DA release were detected. The monoamine hypothesis for manic-depressive psychosis was advanced on the basis of the effect of reserpine, monoamine oxidase inhibitor and antidepressants. 3 H-clonidine binding sites were increased in platelet membranes of depressive patients, 3 H-imipramine binding sites were decreased. The GABA A receptor is the target site for the action of anxiolytics and antiepileptics such as benzodiazepines and barbiturates. Recent developments in molecular biology techniques have revealed the structure of receptor proteins, which are classified into two receptor families, the G-protein coupled type (D 2 ) and the ion-channel type (GABA A ). (J.P.N.)

  7. Quantitative analysis of receptor imaging

    International Nuclear Information System (INIS)

    Fu Zhanli; Wang Rongfu

    2004-01-01

    Model-based methods for quantitative analysis of receptor imaging, including kinetic, graphical and equilibrium methods, are introduced in detail. Some technical problem facing quantitative analysis of receptor imaging, such as the correction for in vivo metabolism of the tracer and the radioactivity contribution from blood volume within ROI, and the estimation of the nondisplaceable ligand concentration, is also reviewed briefly

  8. Coronavirus spike-receptor interactions

    NARCIS (Netherlands)

    Mou, H.

    2015-01-01

    Coronaviruses cause important diseases in humans and animals. Coronavirus infection starts with the virus binding with its spike proteins to molecules present on the surface of host cells that act as receptors. This spike-receptor interaction is highly specific and determines the virus’ cell, tissue

  9. Neurobeachin regulates neurotransmitter receptor trafficking to synapses

    NARCIS (Netherlands)

    Nair, R.; Lauks, J.; Jung, S; Cooke, N.E.; de Wit, H.; Brose, N.; Kilimann, M.W.; Verhage, M.; Rhee, J.

    2013-01-01

    The surface density of neurotransmitter receptors at synapses is a key determinant of synaptic efficacy. Synaptic receptor accumulation is regulated by the transport, postsynaptic anchoring, and turnover of receptors, involving multiple trafficking, sorting, motor, and scaffold proteins. We found

  10. A Novel Mechanism of Androgen Receptor Action

    National Research Council Canada - National Science Library

    Roberts, Jr, Charles T

    2006-01-01

    .... Specifically, the authors had determined that the androgen receptor controls the expression of the cell-surface receptor for the hormone IGF-1 at the level of translation of the IGF-1 receptor mRNA...

  11. Quantitative densitometry of neurotransmitter receptors

    International Nuclear Information System (INIS)

    Rainbow, T.C.; Bleisch, W.V.; Biegon, A.; McEwen, B.S.

    1982-01-01

    An autoradiographic procedure is described that allows the quantitative measurement of neurotransmitter receptors by optical density readings. Frozen brain sections are labeled in vitro with [ 3 H]ligands under conditions that maximize specific binding to neurotransmitter receptors. The labeled sections are then placed against the 3 H-sensitive LKB Ultrofilm to produce the autoradiograms. These autoradiograms resemble those produced by [ 14 C]deoxyglucose autoradiography and are suitable for quantitative analysis with a densitometer. Muscarinic cholinergic receptors in rat and zebra finch brain and 5-HT receptors in rat brain were visualized by this method. When the proper combination of ligand concentration and exposure time are used, the method provides quantitative information about the amount and affinity of neurotransmitter receptors in brain sections. This was established by comparisons of densitometric readings with parallel measurements made by scintillation counting of sections. (Auth.)

  12. Dopamine Receptors and Parkinson's Disease

    Directory of Open Access Journals (Sweden)

    Shin Hisahara

    2011-01-01

    Full Text Available Parkinson's disease (PD is a progressive extrapyramidal motor disorder. Pathologically, this disease is characterized by the selective dopaminergic (DAergic neuronal degeneration in the substantia nigra. Correcting the DA deficiency in PD with levodopa (L-dopa significantly attenuates the motor symptoms; however, its effectiveness often declines, and L-dopa-related adverse effects emerge after long-term treatment. Nowadays, DA receptor agonists are useful medication even regarded as first choice to delay the starting of L-dopa therapy. In advanced stage of PD, they are also used as adjunct therapy together with L-dopa. DA receptor agonists act by stimulation of presynaptic and postsynaptic DA receptors. Despite the usefulness, they could be causative drugs for valvulopathy and nonmotor complication such as DA dysregulation syndrome (DDS. In this paper, physiological characteristics of DA receptor familyare discussed. We also discuss the validity, benefits, and specific adverse effects of pharmaceutical DA receptor agonist.

  13. Molecular characterization of opioid receptors

    Energy Technology Data Exchange (ETDEWEB)

    Howard, A.D.

    1986-01-01

    The aim of this research was to purify and characterize active opioid receptors and elucidate molecular aspects of opioid receptor heterogeneity. Purification to apparent homogeneity of an opioid binding protein from bovine caudate was achieved by solubilization in the non-ionic detergent, digitonin, followed by sequential chromatography on the opiate affinity matrix, ..beta..-naltrexylethylenediamine-CH-Sepharose 4B, and on the lectine affinity matrix, wheat germ agglutinin-agarose. Polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate (SDS-PAGE) followed by autoradiography revealed that radioiodinated purified receptor gave a single band. Purified receptor preparations showed a specific activity of 12,000-15,000 fmol of opiate bound per mg of protein. Radioiodinated human beta-endorphin (/sup 125/I-beta-end/sub H/) was used as a probe to investigate the ligand binding subunits of mu and delta opioid receptors. /sup 125/I-beta-end/sub H/ was shown to bind to a variety of opioid receptor-containing tissues with high affinity and specificity with preference for mu and delta sites, and with little, if any, binding to kappa sites. Affinity crosslinking techniques were employed to covalently link /sup 125/I-beta-end/sub H/ to opioid receptors, utilizing derivatives of bis-succinimidyl esters that are bifunctional crosslinkers with specificities for amino and sulfhydryl groups. This, and competition experiments with high type-selective ligands, permitted the assignment of two labeled peptides to their receptor types, namely a peptide of M/sub r/ = 65,000 for mu receptors and one of M/sub r/ = 53,000 for delta receptors.

  14. Dopamine-induced apoptosis of lactotropes is mediated by the short isoform of D2 receptor.

    Science.gov (United States)

    Radl, Daniela Betiana; Ferraris, Jimena; Boti, Valeria; Seilicovich, Adriana; Sarkar, Dipak Kumar; Pisera, Daniel

    2011-03-25

    Dopamine, through D2 receptor (D2R), is the major regulator of lactotrope function in the anterior pituitary gland. Both D2R isoforms, long (D2L) and short (D2S), are expressed in lactotropes. Although both isoforms can transduce dopamine signal, they differ in the mechanism that leads to cell response. The administration of D2R agonists, such as cabergoline, is the main pharmacological treatment for prolactinomas, but resistance to these drugs exists, which has been associated with alterations in D2R expression. We previously reported that dopamine and cabergoline induce apoptosis of lactotropes in primary culture in an estrogen-dependent manner. In this study we used an in vivo model to confirm the permissive action of estradiol in the apoptosis of anterior pituitary cells induced by D2R agonists. Administration of cabergoline to female rats induced apoptosis, measured by Annexin-V staining, in anterior pituitary gland from estradiol-treated rats but not from ovariectomized rats. To evaluate the participation of D2R isoforms in the apoptosis induced by dopamine we used lactotrope-derived PR1 cells stably transfected with expression vectors encoding D2L or D2S receptors. In the presence of estradiol, dopamine induced apoptosis, determined by ELISA and TUNEL assay, only in PR1-D2S cells. To study the role of p38 MAPK in apoptosis induced by D2R activation, anterior pituitary cells from primary culture or PR1-D2S were incubated with an inhibitor of the p38 MAPK pathway (SB203850). SB203580 blocked the apoptotic effect of D2R activation in lactotropes from primary cultures and PR1-D2S cells. Dopamine also induced p38 MAPK phosphorylation, determined by western blot, in PR1-D2S cells and estradiol enhanced this effect. These data suggest that, in the presence of estradiol, D2R agonists induce apoptosis of lactotropes by their interaction with D2S receptors and that p38 MAPK is involved in this process.

  15. Dopamine-induced apoptosis of lactotropes is mediated by the short isoform of D2 receptor.

    Directory of Open Access Journals (Sweden)

    Daniela Betiana Radl

    Full Text Available Dopamine, through D2 receptor (D2R, is the major regulator of lactotrope function in the anterior pituitary gland. Both D2R isoforms, long (D2L and short (D2S, are expressed in lactotropes. Although both isoforms can transduce dopamine signal, they differ in the mechanism that leads to cell response. The administration of D2R agonists, such as cabergoline, is the main pharmacological treatment for prolactinomas, but resistance to these drugs exists, which has been associated with alterations in D2R expression. We previously reported that dopamine and cabergoline induce apoptosis of lactotropes in primary culture in an estrogen-dependent manner. In this study we used an in vivo model to confirm the permissive action of estradiol in the apoptosis of anterior pituitary cells induced by D2R agonists. Administration of cabergoline to female rats induced apoptosis, measured by Annexin-V staining, in anterior pituitary gland from estradiol-treated rats but not from ovariectomized rats. To evaluate the participation of D2R isoforms in the apoptosis induced by dopamine we used lactotrope-derived PR1 cells stably transfected with expression vectors encoding D2L or D2S receptors. In the presence of estradiol, dopamine induced apoptosis, determined by ELISA and TUNEL assay, only in PR1-D2S cells. To study the role of p38 MAPK in apoptosis induced by D2R activation, anterior pituitary cells from primary culture or PR1-D2S were incubated with an inhibitor of the p38 MAPK pathway (SB203850. SB203580 blocked the apoptotic effect of D2R activation in lactotropes from primary cultures and PR1-D2S cells. Dopamine also induced p38 MAPK phosphorylation, determined by western blot, in PR1-D2S cells and estradiol enhanced this effect. These data suggest that, in the presence of estradiol, D2R agonists induce apoptosis of lactotropes by their interaction with D2S receptors and that p38 MAPK is involved in this process.

  16. Group I mGlu receptor stimulation inhibits activation-induced cell death of human T lymphocytes

    Science.gov (United States)

    Chiocchetti, Annalisa; Miglio, Gianluca; Mesturini, Riccardo; Varsaldi, Federica; Mocellin, Marco; Orilieri, Elisabetta; Dianzani, Chiara; Fantozzi, Roberto; Dianzani, Umberto; Lombardi, Grazia

    2006-01-01

    The effects of L-glutamate on activation-induced cell death (AICD) of human activated (1 μg ml−1 phytohemagglutinin plus 2 U ml−1 interleukin-2; 8 days) T lymphocytes were studied by measuring anti-CD3 monoclonal antibody (10 μg ml−1; 18 h)-induced cell apoptosis (Annexin V and propidium iodide staining). L-Glutamate (1 × 10−8–1 × 10−4 M) significantly (P⩽0.01) inhibited AICD in a concentration-dependent manner (EC50=6.3 × 10−8 M; maximum inhibition 54.8±6.3% at 1 × 10−6 M). The L-glutamate inhibitory effect was pharmacologically characterized as mediated by group I mGlu receptors, since mGlu receptor agonists reproduced this effect. The EC50 values were: 3.2 × 10−7 M for (1S,3R)-ACPD; 4.5 × 10−8 M for quisqualate; 1.0 × 10−6 M for (S)-3,5-DHPG; 2.0 × 10−5 M for CHPG. Group I mGlu receptor antagonists inhibited the effects of quisqualate 1.0 × 10−6 M. The IC50 values calculated were: 8.7 × 10−5, 4.3 × 10−6 and 6.3 × 10−7 M for AIDA, LY 367385 and MPEP, respectively. L-Glutamate (1 × 10−6 M; 18 h) significantly (P⩽0.05) inhibited FasL expression (40.8±11.3%) (cytofluorimetric analysis), whereas it did not affect Fas signalling. Expression of both mGlu1 and mGlu5 receptor mRNA by T lymphocytes and T-cell lines, as demonstrated by reverse transcriptase–PCR analysis, suggests that L-glutamate-mediated inhibition of AICD was exerted on T cells. These data depict a novel role for L-glutamate in the regulation of the immune response through group I mGlu receptor-mediated mechanisms. PMID:16751798

  17. Stargazin Modulation of AMPA Receptors

    Directory of Open Access Journals (Sweden)

    Sana A. Shaikh

    2016-10-01

    Full Text Available Fast excitatory synaptic signaling in the mammalian brain is mediated by AMPA-type ionotropic glutamate receptors. In neurons, AMPA receptors co-assemble with auxiliary proteins, such as stargazin, which can markedly alter receptor trafficking and gating. Here, we used luminescence resonance energy transfer measurements to map distances between the full-length, functional AMPA receptor and stargazin expressed in HEK293 cells and to determine the ensemble structural changes in the receptor due to stargazin. In addition, we used single-molecule fluorescence resonance energy transfer to study the structural and conformational distribution of the receptor and how this distribution is affected by stargazin. Our nanopositioning data place stargazin below the AMPA receptor ligand-binding domain, where it is well poised to act as a scaffold to facilitate the long-range conformational selection observations seen in single-molecule experiments. These data support a model of stargazin acting to stabilize or select conformational states that favor activation.

  18. Radioiodinated ligands for dopamine receptors

    International Nuclear Information System (INIS)

    Kung, H.F.

    1994-01-01

    The dopamine receptor system is important for normal brain function; it is also the apparent action site for various neuroleptic drugs for the treatment of schizophrenia and other metal disorders. In the past few years radioiodinated ligands for single photon emission tomography (SPECT) have been successfully developed and tested in humans: [ 123 I]TISCH for D1 dopamine receptors; [ 123 I]IBZM, epidepride, IBF and FIDA2, four iodobenzamide derivatives, for D2/D3 dopamine receptors. In addition, [ 123 I]β-CIT (RTI-55) and IPT, cocaine derivatives, for the dopamine reuptake site are potentially useful for diagnosis of loss of dopamine neurons. The first iodinated ligand, (R)trans-7-OH-PIPAT, for D3 dopamine receptors, was synthesized and characterized with cloned cell lines (Spodoptera frugiperda, Sf9) expressing the D2 and D3 dopamine receptors and with rat basal forebrain membrane preparations. Most of the known iodobenzamides displayed similar potency in binding to both D2 and D3 dopamine receptors expressed in the cell lines. Initial studies appear to suggest that by fine tuning the structures it may be possible to develop agents specific for D2 and D3 dopamine receptors. It is important to investigate D2/D3 selectivity for this series of potent ligands

  19. Labeled receptor ligands for spect

    International Nuclear Information System (INIS)

    Kung, H.F.

    1989-01-01

    Receptor specific imaging agents for single photon emission computed tomography (SPECT) can potentially be useful in the understanding of basic biochemistry and pharmacology of receptors. SPECT images may also provide tools for evaluation of density and binding kinetics of a specific receptor, information important for diagnosis and patient management. Basic requirements for receptor imaging agents are: (a) they are labeled with short-lived isotopes, (b) they show high selectivity and specific uptake, (c) they exhibit high target/background ratio, and (d) they can be modeled to obtain quantitative information. Several good examples of CNS receptor specific ligands labeled with I-123 have been developed, including iodoQNB, iodoestrogen iodobenzadiazepine, iodobenazepine, iodobenzamides for muscarinic, estrogen benzadiazepine, D-1 and D-2 dopamine receptors. With the advent of newer and faster SPECT imaging devices, it may be feasible to quantitate the receptor density by in vivo imaging techniques. These new brain imaging agents can provide unique diagnostic information, which may not be available through other imaging modalities, such as CT and MRI

  20. XMRV: usage of receptors and potential co-receptors

    Directory of Open Access Journals (Sweden)

    Gaddam Durga

    2011-09-01

    Full Text Available Abstract Background XMRV is a gammaretrovirus first identified in prostate tissues of Prostate Cancer (PC patients and later in the blood cells of patients with Chronic Fatigue Syndrome (CFS. Although XMRV is thought to use XPR1 for cell entry, it infects A549 cells that do not express XPR1, suggesting usage of other receptors or co-receptors. Methods To study the usage of different receptors and co- receptors that could play a role in XMRV infection of lymphoid cells and GHOST (GFP- Human osteosarcoma cells expressing CD4 along with different chemokine receptors including CCR1, CCR2, etc., were infected with XMRV. Culture supernatants and cells were tested for XMRV replication using real time quantitative PCR. Results Infection and replication of XMRV was seen in a variety of GHOST cells, LNCaP, DU145, A549 and Caski cell lines. The levels of XMRV replication varied in different cell lines showing differential replication in different cell lines. However, replication in A549 which lacks XPR1 expression was relatively higher than DU145 but lower than, LNCaP. XMRV replication varied in GHOST cell lines expressing CD4 and each of the co- receptors CCR1-CCR8 and bob. There was significant replication of XMRV in CCR3 and Bonzo although it is much lower when compared to DU145, A549 and LNCaP. Conclusion XMRV replication was observed in GHOST cells that express CD4 and each of the chemokine receptors ranging from CCR1- CCR8 and BOB suggesting that infectivity in hematopoietic cells could be mediated by use of these receptors.

  1. Quantitative receptor radioautography in the study of receptor-receptor interactions in the nucleus tractus solitarii

    Directory of Open Access Journals (Sweden)

    Fior-Chadi D.R.

    1998-01-01

    Full Text Available The nucleus tractus solitarii (NTS in the dorsomedial medulla comprises a wide range of neuropeptides and biogenic amines. Several of them are related to mechanisms of central blood pressure control. Angiotensin II (Ang II, neuropeptide Y (NPY and noradrenaline (NA are found in the NTS cells, as well as their receptors. Based on this observation we have evaluated the modulatory effect of these peptide receptors on a2-adrenoceptors in the NTS. Using quantitative receptor radioautography, we observed that NPY and Ang II receptors decreased the affinity of a2-adrenoceptors for their agonists in the NTS of the rat. Cardiovascular experiments agreed with the in vitro data. Coinjection of a threshold dose of Ang II or of the NPY agonists together with an ED50 dose of adrenergic agonists such as NA, adrenaline and clonidine counteracted the depressor effect produced by the a2-agonist in the NTS. The results provide evidence for the existence of an antagonistic interaction between Ang II at1 receptors and NPY receptor subtypes with the a2-adrenoceptors in the NTS. This receptor interaction may reduce the transduction over the a2-adrenoceptors which can be important in central cardiovascular regulation and in the development of hypertension

  2. Peripheral adrenergic receptors in hypertension

    NARCIS (Netherlands)

    Michel, M. C.; Brodde, O. E.; Insel, P. A.

    1990-01-01

    Increased sympathoadrenal activity appears to play an important role in the development or maintenance of elevated blood pressure in hypertensive patients and various animal models of hypertension. Alterations of adrenergic receptor number or responsiveness might contribute to this increased

  3. Are olfactory receptors really olfactive?

    DEFF Research Database (Denmark)

    Giorgi, Franco; Maggio, Roberto; Bruni, Luis Emilio

    2011-01-01

    environmental conditions. By adopting this standpoint, the functional attribution as olfactory or chemotactic sensors to these receptors should not be seen neither as a cause conditioning receptor gene expression, nor as a final effect resulting from genetically predetermined programs, but as a direct...... and odor-decoding processes. However, this type of explanation does not entirely justify the role olfactory receptors have played during evolution, since they are also expressed ectopically in different organs and/or tissues. Homologous olfactory genes have in fact been found in such diverse cells and....../or organs as spermatozoa, testis and kidney where they are assumed to act as chemotactic sensors or renin modulators. To justify their functional diversity, homologous olfactory receptors are assumed to share the same basic role: that of conferring a self-identity to cells or tissues under varying...

  4. Nuclear Receptor Signaling Atlas (NURSA)

    Data.gov (United States)

    U.S. Department of Health & Human Services — The Nuclear Receptor Signaling Atlas (NURSA) is designed to foster the development of a comprehensive understanding of the structure, function, and role in disease...

  5. L-glutamate Receptor In Paramecium

    Science.gov (United States)

    Bernal-Martínez, Juan; Ortega-Soto, Arturo

    2004-09-01

    Behavioral, electrophysiological and biochemical experiments were performed in order to establish the presence of a glutamate receptor in the ciliate Paramecium. It was found that an AMPA/KA receptor is functionally expressed in Paramecium and that this receptor is immunologically and fillogenetically related to the AMPA/KA receptor present in vertebrates.

  6. Receptor-targeted metalloradiopharmaceuticals. Final technical report

    International Nuclear Information System (INIS)

    Green, Mark A.

    2000-01-01

    Copper (II) and platinum (II) coordination complexes were prepared and characterized. These complexes were designed to afford structural homology with steroidal and non-steroidal estrogens for possible use as receptor-targeted radiopharmaceuticals. While weak affinity for the estrogen receptor was detectable, none would appear to have sufficient receptor-affinity for estrogen-receptor-targeted imaging or therapy

  7. [The receptor theory of atherosclerosis].

    Science.gov (United States)

    Likhoded, V G; Bondarenko, V M; Gintsburg, A L

    2010-01-01

    Lipopolysaccharides of Gram-negative bacteria can interact with Toll-like receptor 4 (TLR4) and induce atheroma formation. The risk of atherosclerosis is decreased in case of TLR4 mutation. Other bacterial ligands and endogenous ligands of TLRs can also be involved in induction of atherogenesis. The general concept of atherosclerosis pathogentsis is presented. According to this concept atherogenesis can be initiated by some reactions resulting from interaction of exogenous and endogenous microbial ligands with Toll-like receptors.

  8. Xenobiotics and the Glucocorticoid Receptor

    International Nuclear Information System (INIS)

    Gulliver, Linda S M

    2017-01-01

    Glucocorticoid Receptor (GR) is present in virtually every human cell type. Representing a nuclear receptor superfamily, GR has several different isoforms essentially acting as ligand-dependent transcription factors, regulating glucocorticoid-responsive gene expression in both a positive and a negative manner. Although the natural ligand of the Glucocorticoid Receptor, glucocorticoids (GC) represent only some of the multiple ligands for GR. Xenobiotics, ubiquitous in the environment, bind to GR and are also capable of activating or repressing GR gene expression, thereby modulating GR cell and tissue-specific downstream effects in a multitude of ways that include responses to inflammatory, allergic, metabolic, neoplastic and autoimmune processes. Many xenobiotics, if inadequately metabolized by xenobiotic metabolizing enzymes and not wholly eliminated, could have deleterious toxic effects with potentially lethal consequences. This review examines GR, the genomic and non-genomic actions of natural and synthetic GC and the body's handling of xenobiotic compounds, before reviewing what is presently known about GR's interactions with many of the more commonly encountered and some of the less well known GR-associated xenobiotics. GR promiscuity and crosstalk with other signaling pathways is discussed, alongside novel roles for GR that include mood disorder and addiction. A knowledge of GR interactions with xenobiotics is increasingly relevant when considering aging populations and the related prevalence of neoplastic disease, together with growing concerns around human exposure to mixtures of chemicals in the environment. Furthermore, escalating rates of obesity, Type 2 diabetes; autoimmune, allergy, addiction and mood disorder-related pathologies, require novel targeted interventions and GR appears a promising pharmacological candidate. - Highlights: • Biological impact of xenobiotics acting through Glucocorticoid Receptor. • Promiscuity of Glucocorticoid

  9. Xenobiotics and the Glucocorticoid Receptor

    Energy Technology Data Exchange (ETDEWEB)

    Gulliver, Linda S M, E-mail: linda.gulliver@otago.ac.nz

    2017-03-15

    Glucocorticoid Receptor (GR) is present in virtually every human cell type. Representing a nuclear receptor superfamily, GR has several different isoforms essentially acting as ligand-dependent transcription factors, regulating glucocorticoid-responsive gene expression in both a positive and a negative manner. Although the natural ligand of the Glucocorticoid Receptor, glucocorticoids (GC) represent only some of the multiple ligands for GR. Xenobiotics, ubiquitous in the environment, bind to GR and are also capable of activating or repressing GR gene expression, thereby modulating GR cell and tissue-specific downstream effects in a multitude of ways that include responses to inflammatory, allergic, metabolic, neoplastic and autoimmune processes. Many xenobiotics, if inadequately metabolized by xenobiotic metabolizing enzymes and not wholly eliminated, could have deleterious toxic effects with potentially lethal consequences. This review examines GR, the genomic and non-genomic actions of natural and synthetic GC and the body's handling of xenobiotic compounds, before reviewing what is presently known about GR's interactions with many of the more commonly encountered and some of the less well known GR-associated xenobiotics. GR promiscuity and crosstalk with other signaling pathways is discussed, alongside novel roles for GR that include mood disorder and addiction. A knowledge of GR interactions with xenobiotics is increasingly relevant when considering aging populations and the related prevalence of neoplastic disease, together with growing concerns around human exposure to mixtures of chemicals in the environment. Furthermore, escalating rates of obesity, Type 2 diabetes; autoimmune, allergy, addiction and mood disorder-related pathologies, require novel targeted interventions and GR appears a promising pharmacological candidate. - Highlights: • Biological impact of xenobiotics acting through Glucocorticoid Receptor. • Promiscuity of Glucocorticoid

  10. Nuclear Receptors, RXR, and the Big Bang.

    Science.gov (United States)

    Evans, Ronald M; Mangelsdorf, David J

    2014-03-27

    Isolation of genes encoding the receptors for steroids, retinoids, vitamin D, and thyroid hormone and their structural and functional analysis revealed an evolutionarily conserved template for nuclear hormone receptors. This discovery sparked identification of numerous genes encoding related proteins, termed orphan receptors. Characterization of these orphan receptors and, in particular, of the retinoid X receptor (RXR) positioned nuclear receptors at the epicenter of the "Big Bang" of molecular endocrinology. This Review provides a personal perspective on nuclear receptors and explores their integrated and coordinated signaling networks that are essential for multicellular life, highlighting the RXR heterodimer and its associated ligands and transcriptional mechanism. Copyright © 2014 Elsevier Inc. All rights reserved.

  11. Fibroblast growth factor receptors in breast cancer.

    Science.gov (United States)

    Wang, Shuwei; Ding, Zhongyang

    2017-05-01

    Fibroblast growth factor receptors are growth factor receptor tyrosine kinases, exerting their roles in embryogenesis, tissue homeostasis, and development of breast cancer. Recent genetic studies have identified some subtypes of fibroblast growth factor receptors as strong genetic loci associated with breast cancer. In this article, we review the recent epidemiological findings and experiment results of fibroblast growth factor receptors in breast cancer. First, we summarized the structure and physiological function of fibroblast growth factor receptors in humans. Then, we discussed the common genetic variations in fibroblast growth factor receptors that affect breast cancer risk. In addition, we also introduced the potential roles of each fibroblast growth factor receptors isoform in breast cancer. Finally, we explored the potential therapeutics targeting fibroblast growth factor receptors for breast cancer. Based on the biological mechanisms of fibroblast growth factor receptors leading to the pathogenesis in breast cancer, targeting fibroblast growth factor receptors may provide new opportunities for breast cancer therapeutic strategies.

  12. Prognostic Value of Estrogen Receptor alpha and Progesterone Receptor Conversion in Distant Breast Cancer Metastases

    NARCIS (Netherlands)

    Hoefnagel, Laurien D. C.; Moelans, Cathy B.; Meijer, S. L.; van Slooten, Henk-Jan; Wesseling, Pieter; Wesseling, Jelle; Westenend, Pieter J.; Bart, Joost; Seldenrijk, Cornelis A.; Nagtegaal, Iris D.; Oudejans, Joost; van der Valk, Paul; van Gils, Carla H.; van der Wall, Elsken; van Diest, Paul J.

    2012-01-01

    BACKGROUND: Changes in the receptor profile of primary breast cancers to their metastases (receptor conversion) have been described for the estrogen receptor alpha (ER alpha) and progesterone receptor (PR). The purpose of this study was to evaluate the impact of receptor conversion for ER alpha and

  13. Expression of GABAergic receptors in mouse taste receptor cells.

    Directory of Open Access Journals (Sweden)

    Margaret R Starostik

    Full Text Available BACKGROUND: Multiple excitatory neurotransmitters have been identified in the mammalian taste transduction, with few studies focused on inhibitory neurotransmitters. Since the synthetic enzyme glutamate decarboxylase (GAD for gamma-aminobutyric acid (GABA is expressed in a subset of mouse taste cells, we hypothesized that other components of the GABA signaling pathway are likely expressed in this system. GABA signaling is initiated by the activation of either ionotropic receptors (GABA(A and GABA(C or metabotropic receptors (GABA(B while it is terminated by the re-uptake of GABA through transporters (GATs. METHODOLOGY/PRINCIPAL FINDINGS: Using reverse transcriptase-PCR (RT-PCR analysis, we investigated the expression of different GABA signaling molecules in the mouse taste system. Taste receptor cells (TRCs in the circumvallate papillae express multiple subunits of the GABA(A and GABA(B receptors as well as multiple GATs. Immunocytochemical analyses examined the distribution of the GABA machinery in the circumvallate papillae. Both GABA(A-and GABA(B- immunoreactivity were detected in the peripheral taste receptor cells. We also used transgenic mice that express green fluorescent protein (GFP in either the Type II taste cells, which can respond to bitter, sweet or umami taste stimuli, or in the Type III GAD67 expressing taste cells. Thus, we were able to identify that GABAergic receptors are expressed in some Type II and Type III taste cells. Mouse GAT4 labeling was concentrated in the cells surrounding the taste buds with a few positively labeled TRCs at the margins of the taste buds. CONCLUSIONS/SIGNIFICANCE: The presence of GABAergic receptors localized on Type II and Type III taste cells suggests that GABA is likely modulating evoked taste responses in the mouse taste bud.

  14. Toll-like receptors in neonatal sepsis.

    LENUS (Irish Health Repository)

    O'Hare, Fiona M

    2013-06-01

    Toll-like receptors are vital transmembrane receptors that initiate the innate immune response to many micro-organisms. The discovery of these receptors has improved our understanding of host-pathogen interactions, and these receptors play an important role in the pathogenesis of multiple neonatal conditions such as sepsis and brain injury. Toll-like receptors, especially TLRs 2 and 4, are associated with necrotizing enterocolitis, periventricular leukomalacia and sepsis.

  15. Studies on insulin receptor, 2

    International Nuclear Information System (INIS)

    Sakai, Yukio

    1979-01-01

    The present study is to investigate an influence of starvation and high fat diet on insulin receptor of the plasma membrane by means of radioreceptor assay using 125 I-labelled insulin. Male guinea pigs of Hartley strain were employed for the starvation study, and 125 I-insulin binding capacity on the plasma membrane of the liver and kidney was determined at 24, 48 and 72 hours of the fast after the last meal. Male rats of Wistar strain were employed for the high fat study where the diet containing 35% of butter was fed ad libitum for 38 or 68 days. The animals were killed at the fast of 12 hours, and 125 I-insulin binding capacity on the plasma membrane of the liver was determined. The results obtained are summarized as follows: 1) An increase in 125 I-insulin binding capacity on the plasma membrane of the liver and kidney was observed by the starvation for 24 to 72 hours. 2) The mechanism of the increase by starvation was considered to be different by the organs; it was due to an increase in number of insulin receptor in the liver, and due to an increase in affinity of insulin receptor in the kidney. 3) In non-obese rats fed with high fat diet, the number of insulin receptor on the liver plasma membrane showed a decrease, and this observation clearly indicated that the decrease in number of the receptor did not depend on the obesity. 4) Obese rats also fed with high fat diet presented a decrease in number of insulin receptor without an elevation of insulin levels in the circulating blood. This indicated that at least in the obese rats fed with high fat diet, the decrease in number of the receptor was not due to hyperinsulinemia. (author)

  16. Interplay between estrogen receptor and AKT in estradiol-induced alternative splicing.

    Science.gov (United States)

    Bhat-Nakshatri, Poornima; Song, Eun-Kyung; Collins, Nikail R; Uversky, Vladimir N; Dunker, A Keith; O'Malley, Bert W; Geistlinger, Tim R; Carroll, Jason S; Brown, Myles; Nakshatri, Harikrishna

    2013-06-11

    Alternative splicing is critical for generating complex proteomes in response to extracellular signals. Nuclear receptors including estrogen receptor alpha (ERα) and their ligands promote alternative splicing. The endogenous targets of ERα:estradiol (E2)-mediated alternative splicing and the influence of extracellular kinases that phosphorylate ERα on E2-induced splicing are unknown. MCF-7 and its anti-estrogen derivatives were used for the majority of the assays. CD44 mini gene was used to measure the effect of E2 and AKT on alternative splicing. ExonHit array analysis was performed to identify E2 and AKT-regulated endogenous alternatively spliced apoptosis-related genes. Quantitative reverse transcription polymerase chain reaction was performed to verify alternative splicing. ERα binding to alternatively spliced genes was verified by chromatin immunoprecipitation assay. Bromodeoxyuridine incorporation-ELISA and Annexin V labeling assays were done to measure cell proliferation and apoptosis, respectively. We identified the targets of E2-induced alternative splicing and deconstructed some of the mechanisms surrounding E2-induced splicing by combining splice array with ERα cistrome and gene expression array. E2-induced alternatively spliced genes fall into at least two subgroups: coupled to E2-regulated transcription and ERα binding to the gene without an effect on rate of transcription. Further, AKT, which phosphorylates both ERα and splicing factors, influenced ERα:E2 dependent splicing in a gene-specific manner. Genes that are alternatively spliced include FAS/CD95, FGFR2, and AXIN-1. E2 increased the expression of FGFR2 C1 isoform but reduced C3 isoform at mRNA level. E2-induced alternative splicing of FAS and FGFR2 in MCF-7 cells correlated with resistance to FAS activation-induced apoptosis and response to keratinocyte growth factor (KGF), respectively. Resistance of MCF-7 breast cancer cells to the anti-estrogen tamoxifen was associated with ER

  17. Histamine induces microglia activation and dopaminergic neuronal toxicity via H1 receptor activation.

    Science.gov (United States)

    Rocha, Sandra M; Saraiva, Tatiana; Cristóvão, Ana C; Ferreira, Raquel; Santos, Tiago; Esteves, Marta; Saraiva, Cláudia; Je, Goun; Cortes, Luísa; Valero, Jorge; Alves, Gilberto; Klibanov, Alexander; Kim, Yoon-Seong; Bernardino, Liliana

    2016-06-04

    Histamine is an amine widely known as a peripheral inflammatory mediator and as a neurotransmitter in the central nervous system. Recently, it has been suggested that histamine acts as an innate modulator of microglial activity. Herein, we aimed to disclose the role of histamine in microglial phagocytic activity and reactive oxygen species (ROS) production and to explore the consequences of histamine-induced neuroinflammation in dopaminergic (DA) neuronal survival. The effect of histamine on phagocytosis was assessed both in vitro by using a murine N9 microglial cell line and primary microglial cell cultures and in vivo. Cells were exposed to IgG-opsonized latex beads or phosphatidylserine (PS) liposomes to evaluate Fcγ or PS receptor-mediated microglial phagocytosis, respectively. ROS production and protein levels of NADPH oxidases and Rac1 were assessed as a measure of oxidative stress. DA neuronal survival was evaluated in vivo by counting the number of tyrosine hydroxylase-positive neurons in the substantia nigra (SN) of mice. We found that histamine triggers microglial phagocytosis via histamine receptor 1 (H1R) activation and ROS production via H1R and H4R activation. By using apocynin, a broad NADPH oxidase (Nox) inhibitor, and Nox1 knockout mice, we found that the Nox1 signaling pathway is involved in both phagocytosis and ROS production induced by histamine in vitro. Interestingly, both apocynin and annexin V (used as inhibitor of PS-induced phagocytosis) fully abolished the DA neurotoxicity induced by the injection of histamine in the SN of adult mice in vivo. Blockade of H1R protected against histamine-induced Nox1 expression and death of DA neurons in vivo. Overall, our results highlight the relevance of histamine in the modulation of microglial activity that ultimately may interfere with neuronal survival in the context of Parkinson's disease (PD) and, eventually, other neurodegenerative diseases which are accompanied by microglia

  18. Purinergic Receptors in Ocular Inflammation

    Directory of Open Access Journals (Sweden)

    Ana Guzman-Aranguez

    2014-01-01

    Full Text Available Inflammation is a complex process that implies the interaction between cells and molecular mediators, which, when not properly “tuned,” can lead to disease. When inflammation affects the eye, it can produce severe disorders affecting the superficial and internal parts of the visual organ. The nucleoside adenosine and nucleotides including adenine mononucleotides like ADP and ATP and dinucleotides such as P1,P4-diadenosine tetraphosphate (Ap4A, and P1,P5-diadenosine pentaphosphate (Ap5A are present in different ocular locations and therefore they may contribute/modulate inflammatory processes. Adenosine receptors, in particular A2A adenosine receptors, present anti-inflammatory action in acute and chronic retinal inflammation. Regarding the A3 receptor, selective agonists like N6-(3-iodobenzyl-5′-N-methylcarboxamidoadenosine (CF101 have been used for the treatment of inflammatory ophthalmic diseases such as dry eye and uveoretinitis. Sideways, diverse stimuli (sensory stimulation, large intraocular pressure increases can produce a release of ATP from ocular sensory innervation or after injury to ocular tissues. Then, ATP will activate purinergic P2 receptors present in sensory nerve endings, the iris, the ciliary body, or other tissues surrounding the anterior chamber of the eye to produce uveitis/endophthalmitis. In summary, adenosine and nucleotides can activate receptors in ocular structures susceptible to suffer from inflammatory processes. This involvement suggests the possible use of purinergic agonists and antagonists as therapeutic targets for ocular inflammation.

  19. Scavenger receptors in homeostasis and immunity.

    Science.gov (United States)

    Canton, Johnathan; Neculai, Dante; Grinstein, Sergio

    2013-09-01

    Scavenger receptors were originally identified by their ability to recognize and to remove modified lipoproteins; however, it is now appreciated that they carry out a striking range of functions, including pathogen clearance, lipid transport, the transport of cargo within the cell and even functioning as taste receptors. The large repertoire of ligands recognized by scavenger receptors and their broad range of functions are not only due to the wide range of receptors that constitute this family but also to their ability to partner with various co-receptors. The ability of individual scavenger receptors to associate with different co-receptors makes their responsiveness extremely versatile. This Review highlights recent insights into the structural features that determine the function of scavenger receptors and the emerging role that these receptors have in immune responses, notably in macrophage polarization and in the pathogenesis of diseases such as atherosclerosis and Alzheimer's disease.

  20. Photo-antagonism of the GABAA receptor.

    Science.gov (United States)

    Mortensen, Martin; Iqbal, Favaad; Pandurangan, Arun P; Hannan, Saad; Huckvale, Rosemary; Topf, Maya; Baker, James R; Smart, Trevor G

    2014-07-29

    Neurotransmitter receptor trafficking is fundamentally important for synaptic transmission and neural network activity. GABAA receptors and inhibitory synapses are vital components of brain function, yet much of our knowledge regarding receptor mobility and function at inhibitory synapses is derived indirectly from using recombinant receptors, antibody-tagged native receptors and pharmacological treatments. Here we describe the use of a set of research tools that can irreversibly bind to and affect the function of recombinant and neuronal GABAA receptors following ultraviolet photoactivation. These compounds are based on the competitive antagonist gabazine and incorporate a variety of photoactive groups. By using site-directed mutagenesis and ligand-docking studies, they reveal new areas of the GABA binding site at the interface between receptor β and α subunits. These compounds enable the selected inactivation of native GABAA receptor populations providing new insight into the function of inhibitory synapses and extrasynaptic receptors in controlling neuronal excitation.

  1. TAM receptor signaling in development.

    Science.gov (United States)

    Burstyn-Cohen, Tal

    2017-01-01

    TYRO3, AXL and MERTK comprise the TAM family of receptor protein tyrosine kinases. Activated by their ligands, protein S (PROS1) and growth-arrest-specific 6 (GAS6), they mediate numerous cellular functions throughout development and adulthood. Expressed by a myriad of cell types and tissues, they have been implicated in homeostatic regulation of the immune, nervous, vascular, bone and reproductive systems. The loss-of-function of TAM signaling in adult tissues culminates in the destruction of tissue homeostasis and diseased states, while TAM gain-of-function in various tumors promotes cancer phenotypes. Combinatorial ligand-receptor interactions may elicit different molecular and cellular responses. Many of the TAM regulatory functions are essentially developmental, taking place both during embryogenesis and postnatally. This review highlights current knowledge on the role of TAM receptors and their ligands during these developmental processes in the immune, nervous, vascular and reproductive systems.

  2. How calcium makes endocytic receptors attractive

    DEFF Research Database (Denmark)

    Andersen, Christian B F; Moestrup, Søren K

    2014-01-01

    of the receptor. Endosomal acidification and calcium efflux lead to the essential ligand-receptor affinity switch and separation. Recent data, including crystal structures of receptor-ligand complexes, now reveal how calcium, in different types of domain scaffolds, functions in a common way as a removable...... 'lynchpin' that stabilizes favorable positioning of ligand-attractive receptor residues. In addition to explaining how calcium depletion can cause ligand-receptor dissociation, the new data add further insight into how acidification contributes to dissociation through structural changes that affect...... the receptor calcium sites....

  3. Lessons from crystal structures of kainate receptors

    DEFF Research Database (Denmark)

    Møllerud, Stine; Frydenvang, Karla Andrea; Pickering, Darryl S

    2017-01-01

    Kainate receptors belong to the family of ionotropic glutamate receptors. These receptors assemble from five subunits (GluK1-5) into tetrameric ion channels. Kainate receptors are located at both pre- and postsynaptic membranes in the central nervous system where they contribute to excitatory...... synaptic transmission and modulate network excitability by regulating neurotransmitter release. Dysfunction of kainate receptors has been implicated in several neurological disorders such as epilepsy, schizophrenia and depression. Here we provide a review on the current understanding of kainate receptor...

  4. The lactate receptor, G-protein-coupled receptor 81/hydroxycarboxylic acid receptor 1

    DEFF Research Database (Denmark)

    Morland, Cecilie; Lauritzen, Knut Huso; Puchades, Maja

    2015-01-01

    We have proposed that lactate is a “volume transmitter” in the brain and underpinned this by showing that the lactate receptor, G-protein-coupled receptor 81 (GPR81, also known as HCA1 or HCAR1), which promotes lipid storage in adipocytes, is also active in the mammalian brain. This includes......, energy metabolism, and energy substrate availability, including a glucose- and glycogen-saving response. HCAR1 may contribute to optimizing the cAMP concentration. For instance, in the prefrontal cortex, excessively high cAMP levels are implicated in impaired cognition in old age, fatigue, stress...

  5. Stability of solubilized benzodiazepine receptors

    NARCIS (Netherlands)

    Janssen, M.J; Ensing, K; de Zeeuw, R.A

    1997-01-01

    According to the observations of other researchers, benzodiazepine receptors solubilized with sodium deoxycholate are unstable, but stability can be improved by exchanging deoxycholate for Triton X-100. In our experiments we conclude that the choice of detergent is not the restrictive factor for the

  6. Serum transferrin receptor in polycythemia.

    Science.gov (United States)

    Manteiga, R; Remacha, A F; Sardà, M P; Ubeda, J

    1998-10-01

    We measured serum transferrin receptor (sTfR) levels in 22 patients with polycythemia vera and in 26 cases of secondary polycythemia. In our study, raised sTfR levels in both polycythemia groups were related to iron deficiency.

  7. FMRFamide receptors of Helix aspersa

    International Nuclear Information System (INIS)

    Payza, K.

    1988-01-01

    A receptor binding assay and an isolated heart bioassay were used to identify and characterize the FMRFamide receptors in Helix. In the heart bioassay, FMRFamide increased myocardial contraction force. A potent FMRFamide analog, desaminoTyr-Phe-norLeu-arg-Phe-amide (daYFnLRFamide), was used as a radioiodinated receptor ligand. The high affinity binding of 125 I-daYFnLRFamide at 0 degree C to Helix brain membranes was reversible, saturable, pH-dependent and specific, with a K D of 13-14 nM. A lower affinity (245 nM) site was also observed. Radioligand binding sites were also identified in the heart, male reproductive organs and digestive organs. The structure-activity relations (SAR) of cardiostimulation correlated with the specificity of 125 I-daYFnLRFamide binding to brain and heart receptors. The SAR were similar to those of other molluscan FMRFamide bioassays, except that they showed a marked preference for some analogs with blocked amino-terminals

  8. Pharmacological approach of the receptors

    International Nuclear Information System (INIS)

    Puech, A.J.

    1989-01-01

    This paper explains the three main goals for clinical positron emission tomography (PET) studies: detection of receptor abnormalities in groups of patients to propose therapeutic indication of new ligands; validation of current hypothesis of drug effect; rational clinical drug development specially for dose-finding studies. (H.W.)

  9. Uncompetitive antagonism of AMPA receptors

    DEFF Research Database (Denmark)

    Andersen, Trine F; Tikhonov, Denis B; Bølcho, Ulrik

    2006-01-01

    Philanthotoxins are uncompetitive antagonists of Ca2+-permeable AMPA receptors presumed to bind to the pore-forming region, but a detailed molecular mechanism for this interaction is missing. Here a small library of novel philanthotoxins was designed and synthesized using a solid-phase strategy. ...

  10. NMDA receptors and memory encoding.

    Science.gov (United States)

    Morris, Richard G M

    2013-11-01

    It is humbling to think that 30 years have passed since the paper by Collingridge, Kehl and McLennan showing that one of Jeff Watkins most interesting compounds, R-2-amino-5-phosphonopentanoate (d-AP5), blocked the induction of long-term potentiation in vitro at synapses from area CA3 of the hippocampus to CA1 without apparent effect on baseline synaptic transmission (Collingridge et al., 1983). This dissociation was one of the key triggers for an explosion of interest in glutamate receptors, and much has been discovered since that collectively contributes to our contemporary understanding of glutamatergic synapses - their biophysics and subunit composition, of the agonists and antagonists acting on them, and their diverse functions in different networks of the brain and spinal cord. It can be fairly said that Collingridge et al.'s (1983) observation was the stimulus that has led, on the one hand, to structural biological work at the atomic scale describing the key features of NMDA receptors that enables their coincidence function to happen; and, on the other, to work with whole animals investigating the contributions that calcium signalling via this receptor can have on rhythmical activities controlled by spinal circuits, memory encoding in the hippocampus (the topic of this article), visual cortical plasticity, sensitization in pain, and other functions. In this article, I lay out how my then interest in long-term potentiation (LTP) as a model of memory enabled me to recognise the importance of Collingridge et al.'s discovery - and how I and my colleagues endeavoured to take things forward in the area of learning and memory. This is in some respects a personal story, and I tell it as such. The idea that NMDA receptor activation is essential for memory encoding, though not for storage, took time to develop and to be accepted. Along the way, there have been confusions, challenges, and surprises surrounding the idea that activation of NMDA receptors can

  11. Ror receptor tyrosine kinases: orphans no more

    OpenAIRE

    Green, Jennifer L.; Kuntz, Steven G.; Sternberg, Paul W.

    2008-01-01

    Receptor tyrosine kinase-like orphan receptor (Ror) proteins are a conserved family of tyrosine kinase receptors that function in developmental processes including skeletal and neuronal development, cell movement and cell polarity. Although Ror proteins were originally named because the associated ligand and signaling pathway were unknown, recent studies in multiple species have now established that Ror proteins are Wnt receptors. Depending on the cellular context, Ror proteins can either act...

  12. Benzodiazepine receptor antagonists for hepatic encephalopathy

    DEFF Research Database (Denmark)

    Als-Nielsen, B; Gluud, L L; Gluud, C

    2004-01-01

    Hepatic encephalopathy may be associated with accumulation of substances that bind to a receptor-complex in the brain resulting in neural inhibition. Benzodiazepine receptor antagonists may have a beneficial effect on patients with hepatic encephalopathy.......Hepatic encephalopathy may be associated with accumulation of substances that bind to a receptor-complex in the brain resulting in neural inhibition. Benzodiazepine receptor antagonists may have a beneficial effect on patients with hepatic encephalopathy....

  13. Synaptic Bistability Due to Nucleation and Evaporation of Receptor Clusters

    KAUST Repository

    Burlakov, V. M.; Emptage, N.; Goriely, A.; Bressloff, P. C.

    2012-01-01

    interacting receptors and is stabilized against clustering by a high nucleation barrier. The other state contains a receptor gas in equilibrium with a large cluster of immobile receptors, which is stabilized by the turnover rate of receptors into and out

  14. Repeated blockade of mineralocorticoid receptors, but not of glucocorticoid receptors impairs food rewarded spatial learning

    NARCIS (Netherlands)

    Douma, B. R.; Korte, S. M.; Buwalda, B.; La Fleur, S. E.; Bohus, B.; Luiten, P. G.

    1998-01-01

    Corticosteroids from the adrenal cortex influence a variety of behaviours including cognition, learning and memory. These hormones act via two intracellular receptors, the mineralo-corticoid receptor (MR) and the glucocorticoid receptor (GR). These two receptor types display a high concentration and

  15. Repeated blockade of mineralocorticoid receptors, but not of glucocorticoid receptors impairs food rewarded spatial learning

    NARCIS (Netherlands)

    Douma, BRK; Korte, SM; Buwalda, B; la Fleur, SE; Bohus, B; Luiten, PGM

    Corticosteroids from the adrenal cortex influence a variety of behaviours including cognition, learning and memory. These hormones act via two intracellular receptors, the mineralo-corticoid receptor (MR) and the glucocorticoid receptor (GR). These two receptor types display a high concentration and

  16. Receptores de progesterona en meningioma.

    Directory of Open Access Journals (Sweden)

    Herminio Ojeda Di Ninno

    1995-04-01

    Full Text Available Objetivo: Determinar la presencia de los receptores de progesterona en meningiomas y su frecuencia mediante la inmunohistoquímica. Material y Métodos: Se analizaron 24 muestras provenientes de pacientes intervenidos quirúrgicamente en el Instituto Nacional de Enfermedades Neoplásicas entre los años 1990 y 1992 con diagnóstico anatomopatológico de meningioma. La determinación de los receptores se hizo mediante una técnica de inmunohistoquímica rápida que permite el estudio de tejidos fijados previamente en parafina. Resultados: De los 24 casos estudiados, nueve resultaron ser positivos en la determinación de receptores de progesterona (37%. Se pudo observar un marcado predominio dentro del grupo femenino quienes constituyeron 8/9 casos positivos. Conclusiones: El empleo de esta reciente técnica de inmunohistoquímica aplicada a tejido de fijado en parafina, nos ha permitido confirmar la presencia de receptores de progesterona en meningiomas con una frecuencia elevada que creemos amerita un estudio más amplio de manera sistemática que incluya la intervención terapéutica mediante el uso de antiprogestágenos, como el Mifepristone o RU 486. De este estudio podrían beneficiarse no sólo pacientes operados recientemente sino aquellos que, intervenidos en el pasado sean detectados como portadores de receptores de progesterona mediante la aplicación de esta novedosa técnica (Rev Med Hered 1995; 6: 121-130.

  17. A new family of insect tyramine receptors

    DEFF Research Database (Denmark)

    Cazzamali, Giuseppe; Klærke, Dan Arne; Grimmelikhuijzen, Cornelis J P

    2005-01-01

    in the genomic databases from the malaria mosquito Anopheles gambiae and the honeybee Apis mellifera. These four tyramine or tyramine-like receptors constitute a new receptor family that is phylogenetically distinct from the previously identified insect octopamine/tyramine receptors. The Drosophila tyramine...

  18. Imaging of receptors in clinical neurosciences

    NARCIS (Netherlands)

    Korf, J

    This article deals with the question why should one determine receptors in the brain with positron and single photon emission tomography (PET and SPECT, respectively). Radiopharmaceuticals for a wide variety of receptors are available now. Receptors studies with PET and SPECT have thus far focused

  19. Receptor conversion in distant breast cancer metastases

    NARCIS (Netherlands)

    Hoefnagel, L.D.C.

    2013-01-01

    The routine pathological work-up of breast cancer includes the evaluation of the estrogen receptor (ERα), progesterone receptor (PR) and human epidermal growth factor receptor 2 (HER2) which reveals biological information about the tumour as well as provides predictive biomarkers regarding hormonal

  20. Molecular pharmacology of human NMDA receptors

    DEFF Research Database (Denmark)

    Hedegaard, Maiken; Hansen, Kasper Bø; Andersen, Karen Toftegaard

    2012-01-01

    N-methyl-d-aspartate (NMDA) receptors are ionotropic glutamate receptors that mediate excitatory neurotransmission. NMDA receptors are also important drug targets that are implicated in a number of pathophysiological conditions. To facilitate the transition from lead compounds in pre-clinical ani...

  1. Concurrent Autophagy Inhibition Overcomes the Resistance of Epidermal Growth Factor Receptor Tyrosine Kinase Inhibitors in Human Bladder Cancer Cells.

    Science.gov (United States)

    Kang, Minyong; Lee, Kyoung-Hwa; Lee, Hye Sun; Jeong, Chang Wook; Kwak, Cheol; Kim, Hyeon Hoe; Ku, Ja Hyeon

    2017-02-04

    Despite the potential therapeutic efficacy of epithelial growth factor receptor (EGFR) inhibitors in the treatment of advanced stage bladder cancer, there currently is no clear evidence to support this hypothesis. In this study, we investigate whether the concurrent treatment of autophagy-blocking agents with EGFR inhibitors exerts synergistic anti-cancer effects in T24 and J82 human bladder cancer cells. Lapatinib and gefitinib were used as EGFR inhibitors, and bafilomycin A1 (BFA1), chloroquine (CQ) and 3-methyladenine (3-MA) were used as the pharmacologic inhibitors of autophagy activities. To assess the proliferative and self-renewal capabilities, the Cell Counting Kit-8 (CCK-8) assay and a clonogenic assay were performed, respectively. To examine apoptotic cell death, flow cytometry using annexin-V/propidium iodide (PI) was used. To measure the autophagy activities, the expression levels of LC3I and II was determined by Western blot analysis. To validate the synergistic effects of autophagy inhibition with EGFR inhibitors, we specifically blocked key autophagy regulatory gene ATG12 by transfection of small interference RNA and examined the phenotypic changes. Of note, lapatinib and gefitinib triggered autophagy activities in T24 and J82 human bladder cancer cells, as indicated by upregulation of LC3II. More importantly, inhibiting autophagy activities with pharmacologic inhibitors (BFA1, CQ or 3-MA) remarkably reduced the cell viabilities and clonal proliferation of T24 and J82 cells, compared to those treated with either of the agents alone. We also obtained similar results of the enhanced anti-cancer effects of EGFR inhibitors by suppressing the expression of ATG12. Notably, the apoptotic assay showed that synergistic anti-cancer effects were induced via the increase of apoptotic cell death. In summary, concomitant inhibition of autophagy activities potentiated the anti-cancer effects of EGFR inhibitors in human bladder cancer cells, indicating a novel

  2. Concurrent Autophagy Inhibition Overcomes the Resistance of Epidermal Growth Factor Receptor Tyrosine Kinase Inhibitors in Human Bladder Cancer Cells

    Directory of Open Access Journals (Sweden)

    Minyong Kang

    2017-02-01

    Full Text Available Despite the potential therapeutic efficacy of epithelial growth factor receptor (EGFR inhibitors in the treatment of advanced stage bladder cancer, there currently is no clear evidence to support this hypothesis. In this study, we investigate whether the concurrent treatment of autophagy-blocking agents with EGFR inhibitors exerts synergistic anti-cancer effects in T24 and J82 human bladder cancer cells. Lapatinib and gefitinib were used as EGFR inhibitors, and bafilomycin A1 (BFA1, chloroquine (CQ and 3-methyladenine (3-MA were used as the pharmacologic inhibitors of autophagy activities. To assess the proliferative and self-renewal capabilities, the Cell Counting Kit-8 (CCK-8 assay and a clonogenic assay were performed, respectively. To examine apoptotic cell death, flow cytometry using annexin-V/propidium iodide (PI was used. To measure the autophagy activities, the expression levels of LC3I and II was determined by Western blot analysis. To validate the synergistic effects of autophagy inhibition with EGFR inhibitors, we specifically blocked key autophagy regulatory gene ATG12 by transfection of small interference RNA and examined the phenotypic changes. Of note, lapatinib and gefitinib triggered autophagy activities in T24 and J82 human bladder cancer cells, as indicated by upregulation of LC3II. More importantly, inhibiting autophagy activities with pharmacologic inhibitors (BFA1, CQ or 3-MA remarkably reduced the cell viabilities and clonal proliferation of T24 and J82 cells, compared to those treated with either of the agents alone. We also obtained similar results of the enhanced anti-cancer effects of EGFR inhibitors by suppressing the expression of ATG12. Notably, the apoptotic assay showed that synergistic anti-cancer effects were induced via the increase of apoptotic cell death. In summary, concomitant inhibition of autophagy activities potentiated the anti-cancer effects of EGFR inhibitors in human bladder cancer cells, indicating

  3. Some theoretical aspects of hormone receptor determination

    International Nuclear Information System (INIS)

    Sluiter, W.J.

    1981-01-01

    Suitable antisera for determination of hormone receptors are not available for the majority of hormone receptors. Therefore, the determination of hormone receptors is mostly performed in terms of binding capacity for the appropriate hormone, using radioactive hormone labels. Some theoretical aspects of such a receptor determination are discussed including the length of incubation (total or unoccupied receptor concentration), single point or multiple point (Scatchard) analysis (regarding the influence of other specific binders), the correction procedure for non-specific binding and the influence of the circulating hormone level. (Auth.)

  4. [Ceruloplasmin receptor on human erythrocytes].

    Science.gov (United States)

    Saenko, E L; Basevich, V V; Iaropolov, A I

    1988-08-01

    The structural fragments of the human ceruloplasmin (CP) molecule and of erythrocyte receptors which provide for the specific interaction of CP with erythrocytes were identified, and their properties were investigated. The interaction of CP with erythrocytes, both intact and treated with neuroaminidase and proteolytic enzymes (trypsin, chymotrypsin, papaine, pronase E) is described. Experiments with CP reception were performed at 4 degrees C, using [125I]CP and [125I]asialo-CP. The parameters of binding were determined in Scatchard plots. It was demonstrated that the specific binding of CP to erythrocyte receptors is determined by its interaction with two structural sites of the carbohydrate moiety of the CP molecule, i.e., the terminal residues of sialic acids and a site, (formula; see text) located at a large distance from the chain terminus.

  5. NGA/Insulin receptor scanning

    International Nuclear Information System (INIS)

    Kurtaran, A.; Virgolini, I.

    1994-01-01

    Tc-99m-galactosyl-neoglycoalbumin (NGA) is one of the first receptor-based radiopharmaceuticals which specifically recognizes the hepatic binding protein (HBP) located on the surface of the hepatocytes. The exclusive interactin of NGA with HBP provided the basis for a kinetic model for the evaluation hepatocellular function. During the last years we have used NGA in more than 300 patients with various liver diseases including liver cirrhosis (Stages Child A to Child C), viral hepatitis, and carcinomas. In these studies, the calculated HBP densities, after i.v.-injection of Tc-99m-NGA, significantly correlated with the clinical course of the diseases. Furthermore, similar to conventional Tc-colloid, NGA provided excellent demonstration of 'cold spots' for hepatic masses. In a further approach we used another hepatocyte receptor-seeking radioligand, I-123-Tyr-A14- insulin, and found, that its in vitro-binding to hepatocellular carcinomas is greatly enhanced over normal hepatic tissue. On this basis, we developed a double-tracer method using NGA and insulin in a single study. Thus, areas of 'cold spots' identifying hepatic masses on NGA scans, take up I-123-Tyr-A14-insulin immediately after i.v.-injection. This was true for hepatocellular hepatomas, but not for adenocarcinomas. In conclusion, NGA/insulin receptor scanning could be a novel and save method for the demonstration of hepatocellular hepatomas. (author)

  6. PAF receptor structure: a hypothesis.

    Science.gov (United States)

    Godfroid, J J; Dive, G; Lamotte-Brasseur, J; Batt, J P; Heymans, F

    1991-12-01

    Different hypotheses of the structure of platelet-activating factor (PAF) receptor based on structure-activity relationships of agonists and antagonists are reviewed. For an agonistic effect, strong hydrophobic interactions and an ether function are required in position-1 of the glycerol backbone; chain length limitations and steric hindrance demand a small group in position-2. The unusual structural properties of non-PAF-like antagonists required 3-D electrostatic potential calculations. This method applied to seven potent antagonists suggests a strong "Cache-orielles" (ear-muff) effect, i.e., two strong electronegative wells (isocontour at -10 Kcal/mole) are located at 180 degrees to each other and at a relatively constant distance. Initial consideration of the "Cache-oreilles" effect implied the structure of a bipolarized cylinder of 10-12 A diameter for the receptor. However, very recent results on studies with agonists and antagonists structurally similar to PAF suggest that the receptor may in fact be a multi-polarized cylinder.

  7. NGA/Insulin receptor scanning

    Energy Technology Data Exchange (ETDEWEB)

    Kurtaran, A; Virgolini, I [Vienna Univ. (Austria). Abt. fuer Nuklearmedizin; Angelberger, P [Ludwig Boltzmann-Institut fuer Nuklearmedizin, Vienna (Austria)

    1994-10-01

    Tc-99m-galactosyl-neoglycoalbumin (NGA) is one of the first receptor-based radiopharmaceuticals which specifically recognizes the hepatic binding protein (HBP) located on the surface of the hepatocytes. The exclusive interactin of NGA with HBP provided the basis for a kinetic model for the evaluation hepatocellular function. During the last years we have used NGA in more than 300 patients with various liver diseases including liver cirrhosis (Stages Child A to Child C), viral hepatitis, and carcinomas. In these studies, the calculated HBP densities, after i.v.-injection of Tc-99m-NGA, significantly correlated with the clinical course of the diseases. Furthermore, similar to conventional Tc-colloid, NGA provided excellent demonstration of `cold spots` for hepatic masses. In a further approach we used another hepatocyte receptor-seeking radioligand, I-123-Tyr-A14- insulin, and found, that its in vitro-binding to hepatocellular carcinomas is greatly enhanced over normal hepatic tissue. On this basis, we developed a double-tracer method using NGA and insulin in a single study. Thus, areas of `cold spots` identifying hepatic masses on NGA scans, take up I-123-Tyr-A14-insulin immediately after i.v.-injection. This was true for hepatocellular hepatomas, but not for adenocarcinomas. In conclusion, NGA/insulin receptor scanning could be a novel and save method for the demonstration of hepatocellular hepatomas. (author).

  8. Lymphocyte receptors for pertussis toxin

    Energy Technology Data Exchange (ETDEWEB)

    Clark, C.G.; Armstrong, G.D. (Univ. of Alberta, Edmonton (Canada))

    1990-12-01

    We have investigated human T-lymphocyte receptors for pertussis toxin by affinity isolation and photoaffinity labeling procedures. T lymphocytes were obtained from peripheral human blood, surface iodinated, and solubilized in Triton X-100. The iodinated mixture was then passed through pertussis toxin-agarose, and the fractions were analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Autoradiography of the fixed, dried gels revealed several bands in the pertussis toxin-bound fraction that were not observed in fractions obtained from histone or fetuin-agarose. Further investigations employed a photoaffinity labeling reagent, sulfosuccinimidyl 2-(p-azido-salicylamido)-1,3'-dithiopropionate, to identify pertussis toxin receptors in freshly isolated peripheral blood monocytic cells, T lymphocytes, and Jurkat cells. In all three cell systems, the pertussis toxin affinity probe specifically labeled a single protein species with an apparent molecular weight of 70,000 that was not observed when the procedure was performed in the presence of excess unmodified pertussis toxin. A protein comparable in molecular weight to the one detected by the photoaffinity labeling technique was also observed among the species that bound to pertussis toxin-agarose. The results suggest that pertussis toxin may bind to a 70,000-Da receptor in human T lymphocytes.

  9. The two-state dimer receptor model: a general model for receptor dimers.

    Science.gov (United States)

    Franco, Rafael; Casadó, Vicent; Mallol, Josefa; Ferrada, Carla; Ferré, Sergi; Fuxe, Kjell; Cortés, Antoni; Ciruela, Francisco; Lluis, Carmen; Canela, Enric I

    2006-06-01

    Nonlinear Scatchard plots are often found for agonist binding to G-protein-coupled receptors. Because there is clear evidence of receptor dimerization, these nonlinear Scatchard plots can reflect cooperativity on agonist binding to the two binding sites in the dimer. According to this, the "two-state dimer receptor model" has been recently derived. In this article, the performance of the model has been analyzed in fitting data of agonist binding to A(1) adenosine receptors, which are an example of receptor displaying concave downward Scatchard plots. Analysis of agonist/antagonist competition data for dopamine D(1) receptors using the two-state dimer receptor model has also been performed. Although fitting to the two-state dimer receptor model was similar to the fitting to the "two-independent-site receptor model", the former is simpler, and a discrimination test selects the two-state dimer receptor model as the best. This model was also very robust in fitting data of estrogen binding to the estrogen receptor, for which Scatchard plots are concave upward. On the one hand, the model would predict the already demonstrated existence of estrogen receptor dimers. On the other hand, the model would predict that concave upward Scatchard plots reflect positive cooperativity, which can be neither predicted nor explained by assuming the existence of two different affinity states. In summary, the two-state dimer receptor model is good for fitting data of binding to dimeric receptors displaying either linear, concave upward, or concave downward Scatchard plots.

  10. Localization of mineralocorticoid receptors at mammalian synapses.

    Directory of Open Access Journals (Sweden)

    Eric M Prager

    Full Text Available In the brain, membrane associated nongenomic steroid receptors can induce fast-acting responses to ion conductance and second messenger systems of neurons. Emerging data suggest that membrane associated glucocorticoid and mineralocorticoid receptors may directly regulate synaptic excitability during times of stress when adrenal hormones are elevated. As the key neuron signaling interface, the synapse is involved in learning and memory, including traumatic memories during times of stress. The lateral amygdala is a key site for synaptic plasticity underlying conditioned fear, which can both trigger and be coincident with the stress response. A large body of electrophysiological data shows rapid regulation of neuronal excitability by steroid hormone receptors. Despite the importance of these receptors, to date, only the glucocorticoid receptor has been anatomically localized to the membrane. We investigated the subcellular sites of mineralocorticoid receptors in the lateral amygdala of the Sprague-Dawley rat. Immunoblot analysis revealed the presence of mineralocorticoid receptors in the amygdala. Using electron microscopy, we found mineralocorticoid receptors expressed at both nuclear including: glutamatergic and GABAergic neurons and extra nuclear sites including: presynaptic terminals, neuronal dendrites, and dendritic spines. Importantly we also observed mineralocorticoid receptors at postsynaptic membrane densities of excitatory synapses. These data provide direct anatomical evidence supporting the concept that, at some synapses, synaptic transmission is regulated by mineralocorticoid receptors. Thus part of the stress signaling response in the brain is a direct modulation of the synapse itself by adrenal steroids.

  11. Protein Connectivity in Chemotaxis Receptor Complexes.

    Directory of Open Access Journals (Sweden)

    Stephan Eismann

    2015-12-01

    Full Text Available The chemotaxis sensory system allows bacteria such as Escherichia coli to swim towards nutrients and away from repellents. The underlying pathway is remarkably sensitive in detecting chemical gradients over a wide range of ambient concentrations. Interactions among receptors, which are predominantly clustered at the cell poles, are crucial to this sensitivity. Although it has been suggested that the kinase CheA and the adapter protein CheW are integral for receptor connectivity, the exact coupling mechanism remains unclear. Here, we present a statistical-mechanics approach to model the receptor linkage mechanism itself, building on nanodisc and electron cryotomography experiments. Specifically, we investigate how the sensing behavior of mixed receptor clusters is affected by variations in the expression levels of CheA and CheW at a constant receptor density in the membrane. Our model compares favorably with dose-response curves from in vivo Förster resonance energy transfer (FRET measurements, demonstrating that the receptor-methylation level has only minor effects on receptor cooperativity. Importantly, our model provides an explanation for the non-intuitive conclusion that the receptor cooperativity decreases with increasing levels of CheA, a core signaling protein associated with the receptors, whereas the receptor cooperativity increases with increasing levels of CheW, a key adapter protein. Finally, we propose an evolutionary advantage as explanation for the recently suggested CheW-only linker structures.

  12. Characterization of astrocytic and neuronal benzodiazepine receptors

    Energy Technology Data Exchange (ETDEWEB)

    Bender, A.S.

    1988-01-01

    Primary cultures of astrocytes and neurons express benzodiazepine receptors. Neuronal benzodiazepine receptors were of high-affinity, K{sub D} values were 7.5-43 nM and the densities of receptors (B{sub max}) were 924-4131 fmol/mg protein. Astrocytes posses a high-affinity benzodiazepine receptor, K{sub D} values were 6.6-13 nM. The B{sub max} values were 6,033-12,000 fmol/mg protein. The pharmacological profile of the neuronal benzodiazepine receptor was that of the central-type benzodiazepine receptor, where clonazepam has a high-affinity and Ro 5-4864 (4{prime}-chlorodiazepam) has a low-affinity. Whereas astrocytic benzoidazepine receptor was characteristic of the so called peripheral-type benzodiazepine receptors, which shows a high-affinity towards Ro 5-4863, and a low-affinity towards clonazepam. The astrocytic benzodiazepine receptors was functionally correlated with voltage dependent calcium channels, since dihydropyridines and benzodiazepines interacted with ({sup 3}H) diazepam and ({sup 3}H) nitrendipine receptors with the same rank order of potency, showing a statistically significant correlation. No such correlation was observed in neurons.

  13. Cyproterone acetate enhances TRAIL-induced androgen-independent prostate cancer cell apoptosis via up-regulation of death receptor 5.

    Science.gov (United States)

    Chen, Linjie; Wolff, Dennis W; Xie, Yan; Lin, Ming-Fong; Tu, Yaping

    2017-03-07

    Virtually all prostate cancer deaths occur due to obtaining the castration-resistant phenotype after prostate cancer cells escaped from apoptosis and/or growth suppression initially induced by androgen receptor blockade. TNF-related apoptosis-inducing ligand (TRAIL) was an attractive cancer therapeutic agent due to its minimal toxicity to normal cells and remarkable apoptotic activity in tumor cells. However, most localized cancers including prostate cancer are resistant to TRAIL-induced apoptosis, thereby creating a therapeutic challenge of inducing TRAIL sensitivity in cancer cells. Herein the effects of cyproterone acetate, an antiandrogen steroid, on the TRAIL-induced apoptosis of androgen receptor-negative prostate cancer cells are reported. Cell apoptosis was assessed by both annexin V/propidium iodide labeling and poly (ADP-ribose) polymerase cleavage assays. Gene and protein expression changes were determined by quantitative real-time PCR and western blot assays. The effect of cyproterone acetate on gene promoter activity was determined by luciferase reporter assay. Cyproterone acetate but not AR antagonist bicalutamide dramatically increased the susceptibility of androgen receptor-negative human prostate cancer PC-3 and DU145 cells to TRAIL-induced apoptosis but no effects on immortalized human prostate stromal PS30 cells and human embryonic kidney HEK293 cells. Further investigation of the TRAIL-induced apoptosis pathway revealed that cyproterone acetate exerted its effect by selectively increasing death receptor 5 (DR5) mRNA and protein expression. Cyproterone acetate treatment also increased DR5 gene promoter activity, which could be abolished by mutation of a consensus binding domain of transcription factor CCAAT-enhancer-binding protein homologous protein (CHOP) in the DR5 gene promoter. Cyproterone acetate increases CHOP expression in a concentration and time-dependent manner and endoplasmic reticulum stress reducer 4-phenylbutyrate could block

  14. Receptor Tyrosine Kinases in Drosophila Development

    Science.gov (United States)

    Sopko, Richelle; Perrimon, Norbert

    2013-01-01

    Tyrosine phosphorylation plays a significant role in a wide range of cellular processes. The Drosophila genome encodes more than 20 receptor tyrosine kinases and extensive studies in the past 20 years have illustrated their diverse roles and complex signaling mechanisms. Although some receptor tyrosine kinases have highly specific functions, others strikingly are used in rather ubiquitous manners. Receptor tyrosine kinases regulate a broad expanse of processes, ranging from cell survival and proliferation to differentiation and patterning. Remarkably, different receptor tyrosine kinases share many of the same effectors and their hierarchical organization is retained in disparate biological contexts. In this comprehensive review, we summarize what is known regarding each receptor tyrosine kinase during Drosophila development. Astonishingly, very little is known for approximately half of all Drosophila receptor tyrosine kinases. PMID:23732470

  15. Receptor binding studies of the living heart

    International Nuclear Information System (INIS)

    Syrota, A.

    1988-01-01

    Receptors form a class of intrinsic membrane proteins (or glycoproteins) defined by the high affinity and specificity with which they bind ligands. Many receptors are associated directly or indirectly with membrane ion channels that open or close after a conformational change of the receptor induced by the binding of the neurotransmitter. Changes in number and/or affinity of cardiac neurotransmitter receptors have been associated with myocardial ischemia and infarction, congestive heart failure, and cardiomyopathy as well as diabetes or thyroid-induced heart muscle disease. These alterations of cardiac receptors have been demonstrated in vitro on membrane homogenates from samples collected mainly during surgery or postmortem. The disadvantage of these in vitro binding techniques is that receptors lose their natural environment and their relationships with the other components of the tissue

  16. Subtype selective kainic acid receptor agonists

    DEFF Research Database (Denmark)

    Bunch, Lennart; Krogsgaard-Larsen, Povl

    2009-01-01

    (S)-Glutamic acid (Glu) is the major excitatory neurotransmitter in the mammalian central nervous system, activating the plethora of glutamate receptors (GluRs). In broad lines, the GluRs are divided into two major classes: the ionotropic Glu receptors (iGluRs) and the metabotropic Glu receptors (m......GluRs). Within the iGluRs, five subtypes (KA1, KA2, iGluR5-7) show high affinity and express full agonist activity upon binding of the naturally occurring amino acid kainic acid (KA). Thus these receptors have been named the KA receptors. This review describes all-to our knowledge-published KA receptor agonists...

  17. Characteristic molecular vibrations of adenosine receptor ligands.

    Science.gov (United States)

    Chee, Hyun Keun; Yang, Jin-San; Joung, Je-Gun; Zhang, Byoung-Tak; Oh, S June

    2015-02-13

    Although the regulation of membrane receptor activation is known to be crucial for molecular signal transduction, the molecular mechanism underlying receptor activation is not fully elucidated. Here we study the physicochemical nature of membrane receptor behavior by investigating the characteristic molecular vibrations of receptor ligands using computational chemistry and informatics methods. By using information gain, t-tests, and support vector machines, we have identified highly informative features of adenosine receptor (AdoR) ligand and corresponding functional amino acid residues such as Asn (6.55) of AdoR that has informative significance and is indispensable for ligand recognition of AdoRs. These findings may provide new perspectives and insights into the fundamental mechanism of class A G protein-coupled receptor activation. Copyright © 2015 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.

  18. Acetylcholine receptors in the human retina

    International Nuclear Information System (INIS)

    Hutchins, J.B.; Hollyfield, J.G.

    1985-01-01

    Evidence for a population of acetylcholine (ACh) receptors in the human retina is presented. The authors have used the irreversible ligand 3 H-propylbenzilylcholine mustard ( 3 H-PrBCM) to label muscarinic receptors. 3 H- or 125 I-alpha-bungarotoxin (alpha-BTx) was used to label putative nicotinic receptors. Muscarinic receptors are apparently present in the inner plexiform layer of the retina. Autoradiographic grain densities are reduced in the presence of saturating concentrations of atropine, quinuclidinyl benzilate or scopolamine; this indicates that 3 H-PrBCM binding is specific for a population of muscarinic receptors in the human retina. Binding sites for radiolabeled alpha-BTx are found predominantly in the inner plexiform layer of the retina. Grain densities are reduced in the presence of d-tubocurarine, indicating that alpha-BTx may bind to a pharmacologically relevant nicotinic ACh receptor. This study provides evidence for cholinergic neurotransmission in the human retina

  19. Annexin II-Dependent Mechanism of Breast Cancer Progression

    Science.gov (United States)

    2010-11-01

    Guedj N, Zhan Q, Perigny M, et al. Comparative protein expression profiles of hilar and peripheral hepatic cholangiocarcinomas. J Hepatol 2009; 51: 93...Guedj, N., et al., 2009. Comparative protein expression profiles of hilar and peripheral hepatic cholangiocarcinomas. J. Hepatol. 51, 93–101. Hajjar

  20. Studies on insulin receptor, 1

    International Nuclear Information System (INIS)

    Sakai, Yukio

    1979-01-01

    The present study was designed for the purpose of establishing a method of insulin radioreceptor assay using plasma membranes of guinea pigs as receptor sites. The results obtained are as follows: 1) Insulin receptor in the renal plasma membranes of guinea pigs showed a significantly high affinity to porcine insulin compared with that in the plasma membranes of guinea pig liver or rat kidney and liver. 2) In the insulin radioreceptor assay, an optimum condition was observed by the incubation at 4 0 C for 24 - 48 hours with 100 μg membrane protein of guinea pig kidney and 0.08 ng of 125 I-insulin. This assay method was specific for insulin and showed an accurate biological activity of insulin. 3) The recovery rate of insulin radioreceptor assay was 98.4% and dilution check up to 16 times did not influence on the result. An average of coefficient variation was 3.92% within assay. All of these results indicated the method to be satisfactory. 4) Glucose induced insulin release by perfusion method in isolated Langerhans islets of rats showed an identical pattern of reaction curves between radioreceptor assay and radioimmunoassay, although the values of radioreceptor assay was slightly low. 5) Insulin free serum produced by ultra filtration method was added to the standard assay medium. By this procedure, direct measurement of human serum by radioreceptor assay became possible. 6) The value of human serum insulin receptor binding activity by the radioreceptor assay showed a high correlation with that of insulin radioimmunoassay in sera of normal, borderline or diabetic type defined by glucose tolerance test. (author)

  1. Seventh Symposium on Subtypes of Musccarinic Receptors.

    Science.gov (United States)

    1997-01-01

    nociceptive pain, are less than ideal. For mild to moderate pain, the first line of therapy includes aspirin, acetaminophen/ paracetamol , and nonsteroidal...due to receptor degradation triggered by prolonged carbachol occupancy. This down-regulation was accompanied by uncoupling of the M2-receptors after 24...be under control by the m3 mAChR, suggesting a complex receptor regulation of phosphoinositide metabolism, including degradation and synthesis. Future

  2. Molecular identification of the first SIFamide receptor

    DEFF Research Database (Denmark)

    Jørgensen, Lars M; Hauser, Frank; Cazzamali, Giuseppe

    2006-01-01

    , an impressive sequence conservation (67-77% amino acid sequence identities between the seven-transmembrane areas; 82-87% sequence similarities). The identification of well-conserved SIFamide receptor orthologues in all other insects with a sequenced genome, suggests that the SIFamide/receptor couple must have...... an essential function in arthropods. This paper is the first report on the identification of a SIFamide receptor....

  3. Progesterone receptor modulators in breast cancer

    OpenAIRE

    WIEHLE, Ronald D.

    2015-01-01

    Breast cancer has been treated successfully with selective estrogen receptor antagonists (SERMs) such as tamoxifen, receptor-depleting agents such as fulvestrant, and aromatase inhibitors such as anastrozole. Selective progesterone receptor modulators (SPRMs or PRMs) have not been studied as much and are currently under investigation for inhibition of mammary carcinogenesis in animal models and breast cancer prevention trials in women. They might follow tamoxifen and aromatase inhibitors in t...

  4. Androgen Receptor Signaling in Bladder Cancer

    OpenAIRE

    Li, Peng; Chen, Jinbo; Miyamoto, Hiroshi

    2017-01-01

    Emerging preclinical findings have indicated that steroid hormone receptor signaling plays an important role in bladder cancer outgrowth. In particular, androgen-mediated androgen receptor signals have been shown to correlate with the promotion of tumor development and progression, which may clearly explain some sex-specific differences in bladder cancer. This review summarizes and discusses the available data, suggesting the involvement of androgens and/or the androgen receptor pathways in u...

  5. Muscarinic Receptor Agonists and Antagonists

    Directory of Open Access Journals (Sweden)

    David R. Kelly

    2001-02-01

    Full Text Available A comprehensive review of pharmacological and medical aspects of the muscarinic class of acetylcholine agonists and antagonists is presented. The therapeutic benefits of achieving receptor subtype selectivity are outlined and applications in the treatment of Alzheimer’s disease are discussed. A selection of chemical routes are described, which illustrate contemporary methodology for the synthesis of chiral medicinal compounds (asymmetric synthesis, chiral pool, enzymes. Routes to bicyclic intrannular amines and intramolecular Diels-Alder reactions are highlighted.

  6. Hemoglobin and heme scavenger receptors

    DEFF Research Database (Denmark)

    Nielsen, Marianne Jensby; Møller, Holger Jon; Moestrup, Søren Kragh

    2010-01-01

    Heme, the functional group of hemoglobin, myoglobin, and other hemoproteins, is a highly toxic substance when it appears in the extracellular milieu. To circumvent potential harmful effects of heme from hemoproteins released during physiological or pathological cell damage (such as hemolysis...... and rhabdomyolysis), specific high capacity scavenging systems have evolved in the mammalian organism. Two major systems, which essentially function in a similar way by means of a circulating latent plasma carrier protein that upon ligand binding is recognized by a receptor, are represented by a) the hemoglobin...

  7. Combined blockade of angiotensin II and prorenin receptors ameliorates podocytic apoptosis induced by IgA-activated mesangial cells.

    Science.gov (United States)

    Leung, Joseph C K; Chan, Loretta Y Y; Saleem, M A; Mathieson, P W; Tang, Sydney C W; Lai, Kar Neng

    2015-07-01

    Glomerulo-podocytic communication plays an important role in the podocytic injury in IgA nephropathy (IgAN). In this study, we examine the role of podocytic angiotensin II receptor subtype 1 (AT1R) and prorenin receptor (PRR) in podocytic apoptosis in IgAN. Polymeric IgA (pIgA) was isolated from patients with IgAN and healthy controls. Conditioned media were prepared from growth arrested human mesangial cells (HMC) incubated with pIgA from patients with IgAN (IgA-HMC media) or healthy controls (Ctl-HMC media). A human podocyte cell line was used as a model to examine the regulation of the expression of AT1R, PRR, TNF-α and CTGF by IgA-HMC media. Podocytic nephrin expression, annexin V binding and caspase 3 activity were used as the functional readout of podocytic apoptosis. IgA-HMC media had no effect on AngII release by podocytes. IgA-HMC media significantly up-regulated the expression of AT1R and PRR, down-regulated nephrin expression and induced apoptosis in podocytes. Mono-blockade of AT1R, PRR, TNF-α or CTGF partially reduced podocytic apoptosis. IgA-HMC media activated NFκB, notch1 and HEY1 expression by podocytes and dual blockade of AT1R with PRR, or anti-TNF-α with anti-CTGF, effectively rescued the podocytic apoptosis induced by IgA-HMC media. Our data suggests that pIgA-activated HMC up-regulates the expression of AT1R and PRR expression by podocytes and the associated activation of NFκB and notch signalling pathways play an essential role in the podocytic apoptosis induced by glomerulo-podocytic communication in IgAN. Simultaneously targeting the AT1R and PRR could be a potential therapeutic option to reduce the podocytic injury in IgAN.

  8. CERAPP: Collaborative Estrogen Receptor Activity Prediction Project

    Data.gov (United States)

    U.S. Environmental Protection Agency — Data from a large-scale modeling project called CERAPP (Collaborative Estrogen Receptor Activity Prediction Project) demonstrating using predictive computational...

  9. Identification and mechanism of ABA receptor antagonism

    KAUST Repository

    Melcher, Karsten; Xu, Yong; Ng, Ley-Moy; Zhou, X. Edward; Soon, Fen-Fen; Chinnusamy, Viswanathan; Suino-Powell, Kelly M.; Kovach, Amanda; Tham, Fook S.; Cutler, Sean R.; Li, Jun; Yong, Eu-Leong; Zhu, Jian-Kang; Xu, H. Eric

    2010-01-01

    The phytohormone abscisic acid (ABA) functions through a family of fourteen PYR/PYL receptors, which were identified by resistance to pyrabactin, a synthetic inhibitor of seed germination. ABA activates these receptors to inhibit type 2C protein phosphatases, such as ABI1, yet it remains unclear whether these receptors can be antagonized. Here we demonstrate that pyrabactin is an agonist of PYR1 and PYL1 but is unexpectedly an antagonist of PYL2. Crystal structures of the PYL2-pyrabactin and PYL1-pyrabactin-ABI1 complexes reveal the mechanism responsible for receptor-selective activation and inhibition, which enables us to design mutations that convert PYL1 to a pyrabactin-inhibited receptor and PYL2 to a pyrabactin-activated receptor and to identify new pyrabactin-based ABA receptor agonists. Together, our results establish a new concept of ABA receptor antagonism, illustrate its underlying mechanisms and provide a rational framework for discovering novel ABA receptor ligands. © 2010 Nature America, Inc. All rights reserved.

  10. Dehydroepiandrosterone: an ancestral ligand of neurotrophin receptors.

    Science.gov (United States)

    Pediaditakis, Iosif; Iliopoulos, Ioannis; Theologidis, Ioannis; Delivanoglou, Nickoleta; Margioris, Andrew N; Charalampopoulos, Ioannis; Gravanis, Achille

    2015-01-01

    Dehydroepiandosterone (DHEA), the most abundant steroid in humans, affects multiple cellular functions of the endocrine, immune, and nervous systems. However, up to quite recently, no receptor has been described specifically for it, whereas most of its physiological actions have been attributed to its conversion to either androgens or estrogens. DHEA interacts and modulate a variety of membrane and intracellular neurotransmitter and steroid receptors. We have recently reported that DHEA protects neuronal cells against apoptosis, interacting with TrkA, the high-affinity prosurvival receptor of the neurotrophin, nerve growth factor. Intrigued by its pleiotropic effects in the nervous system of a variety of species, we have investigated the ability of DHEA to interact with the other two mammalian neurotrophin receptors, ie, the TrkB and TrkC, as well as their invertebrate counterparts (orthologs) in mollusks Lymnaea and Aplysia and in cephalochordate fish Amphioxus. Amazingly, DHEA binds to all Trk receptors, although with lower affinity by 2 orders of magnitude compared with that of the polypeptidic neurotrophins. DHEA effectively induced the first step of the TrkA and TrkC receptors activation (phosphorylation at tyrosine residues), including the vertebrate neurotrophin nonresponding invertebrate Lymnaea and Aplysia receptors. Based on our data, we hypothesize that early in evolution, DHEA may have acted as a nonspecific neurotrophic factor promoting neuronal survival. The interaction of DHEA with all types of neurotrophin receptors offers new insights into the largely unidentified mechanisms of its actions on multiple tissues and organs known to express neurotrophin receptors.

  11. Characterization of the chicken muscle insulin receptor

    International Nuclear Information System (INIS)

    Adamo, M.; Simon, J.; Rosebrough, R.W.; McMurtry, J.P.; Steele, N.C.; LeRoith, D.

    1987-01-01

    Insulin receptors are present in chicken skeletal muscle. Crude membrane preparations demonstrated specific 125 I-insulin binding. The nonspecific binding was high (36-55% of total binding) and slightly lower affinity receptors were found than are typically observed for crude membrane insulin binding in other chicken tissues. Affinity crosslinking of 125 I-insulin to crude membranes revealed insulin receptor alpha-subunits of Mr 128K, intermediate between those of liver (134K) and brain (124K). When solubilized and partially purified on wheat germ agglutinin (WGA) affinity columns, chicken muscle insulin receptors exhibited typical high affinity binding, with approximately 10(-10) M unlabeled insulin producing 50% inhibition of the specific 125 I-insulin binding. WGA purified chicken muscle insulin receptors also exhibited insulin-stimulated autophosphorylation of the beta-subunit, which appeared as phosphorylated bands of 92- and 81K. Both bands were immunoprecipitated by anti-receptor antiserum (B10). WGA purified membranes also demonstrated dose-dependent insulin-stimulated phosphorylation of the exogenous substrate poly(Glu,Tyr)4:1. However, unlike chicken liver, chicken muscle insulin receptor number and tyrosine kinase activity were unaltered by 48 hr of fasting or 48 hr of fasting and 24 hr of refeeding. Thus, despite the presence of insulin receptors in chicken muscle showing normal coupling to receptor tyrosine kinase activity, nutritional alterations modulate these parameters in a tissue-specific manner in chickens

  12. Human dopamine receptor and its uses

    Energy Technology Data Exchange (ETDEWEB)

    Civelli, Olivier (Portland, OR); Van Tol, Hubert Henri-Marie (Toronto, CA)

    1999-01-01

    The present invention is directed toward the isolation, characterization and pharmacological use of the human D4 dopamine receptor. The nucleotide sequence of the gene corresponding to this receptor and alleleic variant thereof are provided by the invention. The invention also includes recombinant eukaryotic expression constructs capable of expressing the human D4 dopamine receptor in cultures of transformed eukaryotic cells. The invention provides cultures of transformed eukaryotic cells which synthesize the human D4 dopamine receptor, and methods for characterizing novel psychotropic compounds using such cultures.

  13. Chapter 8. Activation mechanisms of chemokine receptors

    DEFF Research Database (Denmark)

    Jensen, Pia C; Rosenkilde, Mette M

    2009-01-01

    binding. Attempts to unravel the activation mechanism of 7TM receptors have led to the conclusion that activation involves movements of the transmembrane segments VI and VII in particular, as recently gathered in the Global Toggle Switch Model. However, to understand the activation mechanism completely......, more research has to be done in this field. Chemokine receptors are interesting tools in this matter. First, the chemokine system has a high degree of promiscuity that allows several chemokines to target one receptor in different ways, as well as a single chemokine ligand to target several receptors...

  14. Identification and mechanism of ABA receptor antagonism

    KAUST Repository

    Melcher, Karsten

    2010-08-22

    The phytohormone abscisic acid (ABA) functions through a family of fourteen PYR/PYL receptors, which were identified by resistance to pyrabactin, a synthetic inhibitor of seed germination. ABA activates these receptors to inhibit type 2C protein phosphatases, such as ABI1, yet it remains unclear whether these receptors can be antagonized. Here we demonstrate that pyrabactin is an agonist of PYR1 and PYL1 but is unexpectedly an antagonist of PYL2. Crystal structures of the PYL2-pyrabactin and PYL1-pyrabactin-ABI1 complexes reveal the mechanism responsible for receptor-selective activation and inhibition, which enables us to design mutations that convert PYL1 to a pyrabactin-inhibited receptor and PYL2 to a pyrabactin-activated receptor and to identify new pyrabactin-based ABA receptor agonists. Together, our results establish a new concept of ABA receptor antagonism, illustrate its underlying mechanisms and provide a rational framework for discovering novel ABA receptor ligands. © 2010 Nature America, Inc. All rights reserved.

  15. Knock-In Mice with NOP-eGFP Receptors Identify Receptor Cellular and Regional Localization.

    Science.gov (United States)

    Ozawa, Akihiko; Brunori, Gloria; Mercatelli, Daniela; Wu, Jinhua; Cippitelli, Andrea; Zou, Bende; Xie, Xinmin Simon; Williams, Melissa; Zaveri, Nurulain T; Low, Sarah; Scherrer, Grégory; Kieffer, Brigitte L; Toll, Lawrence

    2015-08-19

    The nociceptin/orphanin FQ (NOP) receptor, the fourth member of the opioid receptor family, is involved in many processes common to the opioid receptors including pain and drug abuse. To better characterize receptor location and trafficking, knock-in mice were created by inserting the gene encoding enhanced green fluorescent protein (eGFP) into the NOP receptor gene (Oprl1) and producing mice expressing a functional NOP-eGFP C-terminal fusion in place of the native NOP receptor. The NOP-eGFP receptor was present in brain of homozygous knock-in animals in concentrations somewhat higher than in wild-type mice and was functional when tested for stimulation of [(35)S]GTPγS binding in vitro and in patch-clamp electrophysiology in dorsal root ganglia (DRG) neurons and hippocampal slices. Inhibition of morphine analgesia was equivalent when tested in knock-in and wild-type mice. Imaging revealed detailed neuroanatomy in brain, spinal cord, and DRG and was generally consistent with in vitro autoradiographic imaging of receptor location. Multicolor immunohistochemistry identified cells coexpressing various spinal cord and DRG cellular markers, as well as coexpression with μ-opioid receptors in DRG and brain regions. Both in tissue slices and primary cultures, the NOP-eGFP receptors appear throughout the cell body and in processes. These knock-in mice have NOP receptors that function both in vitro and in vivo and appear to be an exceptional tool to study receptor neuroanatomy and correlate with NOP receptor function. The NOP receptor, the fourth member of the opioid receptor family, is involved in pain, drug abuse, and a number of other CNS processes. The regional and cellular distribution has been difficult to determine due to lack of validated antibodies for immunohistochemical analysis. To provide a new tool for the investigation of receptor localization, we have produced knock-in mice with a fluorescent-tagged NOP receptor in place of the native NOP receptor. These

  16. G-protein-coupled receptors for free fatty acids

    DEFF Research Database (Denmark)

    Milligan, Graeme; Ulven, Trond; Murdoch, Hannah

    2014-01-01

    of these receptors. However, ongoing clinical trials of agonists of free fatty acid receptor 1 suggest that this receptor and other receptors for free fatty acids may provide a successful strategy for controlling hyperglycaemia and providing novel approaches to treat diabetes. Receptors responsive to free fatty acid...

  17. Evidence for Heterodimerization and Functional Interaction of the Angiotensin Type 2 Receptor and the Receptor MAS

    DEFF Research Database (Denmark)

    Leonhardt, Julia; Villela, Daniel C.; Teichmann, Anke

    2017-01-01

    The angiotensin type 2 receptor (AT2R) and the receptor MAS are receptors of the protective arm of the renin-angiotensin system. They mediate strikingly similar actions. Moreover, in various studies, AT2R antagonists blocked the effects of MAS agonists and vice versa. Such cross-inhibition may in...

  18. Interaction of epidermal growth factor receptors with the cytoskeleton is related to receptor clustering

    NARCIS (Netherlands)

    van Belzen, N.; Spaargaren, M.; Verkleij, A. J.; Boonstra, J.

    1990-01-01

    Recently it has been established that cytoskeleton-associated epidermal growth factor (EGF) receptors are predominantly of the high-affinity class and that EGF induces a recruitment of low-affinity receptors to the cytoskeleton. The nature of this EGF-induced receptor-cytoskeleton interaction,

  19. Receptor saturation in roentgen films

    Energy Technology Data Exchange (ETDEWEB)

    Strid, K G; Reichmann, S [Sahlgrenska Sjukhuset, Goeteborg (Sweden)

    1980-01-01

    Roentgen-film recording of small object details of low attenuation differences (e.g. pulmonary vessels) is regularly seen to be impaired when the film is exposed to yield high values of optical density (D). This high-density failure is due to receptor saturation, which implies that at high exposure values most silver halide grains of the film are made developable, leaving few grains available to receive additional informative photons. The receptor saturation is analysed by means of a mathematical model of a non-screen film yielding Dsub(max) = 2.0. Optimum recording, defined by maximum signal-to-noise ratio in the image, is found at D approximately 0.64, corresponding to, on an average, 1.6 photons absorbed per grain. On the other hand, maximum contrast occurs at D approximately 1.4, where, on the average, 3.6 photons are absorbed per grain. The detective quantum efficiency of the film, i.e. the fraction of the photons actually contributing to the information content of the image, drops from 41 per cent at maximum signal-to-noise ratio to a mere 10 per cent at maximum contrast.

  20. Androgen receptor drives cellular senescence.

    Directory of Open Access Journals (Sweden)

    Yelena Mirochnik

    Full Text Available The accepted androgen receptor (AR role is to promote proliferation and survival of prostate epithelium and thus prostate cancer progression. While growth-inhibitory, tumor-suppressive AR effects have also been documented, the underlying mechanisms are poorly understood. Here, we for the first time link AR anti-cancer action with cell senescence in vitro and in vivo. First, AR-driven senescence was p53-independent. Instead, AR induced p21, which subsequently reduced ΔN isoform of p63. Second, AR activation increased reactive oxygen species (ROS and thereby suppressed Rb phosphorylation. Both pathways were critical for senescence as was proven by p21 and Rb knock-down and by quenching ROS with N-Acetyl cysteine and p63 silencing also mimicked AR-induced senescence. The two pathways engaged in a cross-talk, likely via PML tumor suppressor, whose localization to senescence-associated chromatin foci was increased by AR activation. All these pathways contributed to growth arrest, which resolved in senescence due to concomitant lack of p53 and high mTOR activity. This is the first demonstration of senescence response caused by a nuclear hormone receptor.

  1. Excitatory amino acid receptor antagonists

    DEFF Research Database (Denmark)

    Johansen, T N; Frydenvang, Karla Andrea; Ebert, B

    1997-01-01

    We have previously shown that (RS)-2-amino-2-(5-tert-butyl-3-hydroxyisoxazol-4-yl)acetic acid (ATAA) is an antagonist at N-methyl-D-aspartic acid (NMDA) and (RS)-2-amino-3-(3-hydroxy-5-methylisoxazol-4-yl)propionic acid (AMPA) receptors. We have now resolved ATAA via diastereomeric salt formation......)-phenylethylamine salt of N-BOC-(R)-ATAA. Like ATAA, neither (R)- nor (S)-ATAA significantly affected (IC50 > 100 microM) the receptor binding of tritiated AMPA, kainic acid, or (RS)-3-(2-carboxypiperazin-4-yl)propyl-1-phosphonic acid, the latter being a competitive NMDA antagonist. Electrophysiological experiments......, using the rat cortical wedge preparation, showed the NMDA antagonist effect as well as the AMPA antagonist effect of ATAA to reside exclusively in the (R)-enantiomer (Ki = 75 +/- 5 microM and 57 +/- 1 microM, respectively). Neither (R)- nor (S)-ATAA significantly reduced kainic acid-induced excitation...

  2. Posttransplant chimeric antigen receptor therapy.

    Science.gov (United States)

    Smith, Melody; Zakrzewski, Johannes; James, Scott; Sadelain, Michel

    2018-03-08

    Therapeutic T-cell engineering is emerging as a powerful approach to treat refractory hematological malignancies. Its most successful embodiment to date is based on the use of second-generation chimeric antigen receptors (CARs) targeting CD19, a cell surface molecule found in most B-cell leukemias and lymphomas. Remarkable complete remissions have been obtained with autologous T cells expressing CD19 CARs in patients with relapsed, chemo-refractory B-cell acute lymphoblastic leukemia, chronic lymphocytic leukemia, and non-Hodgkin lymphoma. Allogeneic CAR T cells may also be harnessed to treat relapse after allogeneic hematopoietic stem cell transplantation. However, the use of donor T cells poses unique challenges owing to potential alloreactivity. We review different approaches to mitigate the risk of causing or aggravating graft-versus-host disease (GVHD), including CAR therapies based on donor leukocyte infusion, virus-specific T cells, T-cell receptor-deficient T cells, lymphoid progenitor cells, and regulatory T cells. Advances in CAR design, T-cell selection and gene editing are poised to enable the safe use of allogeneic CAR T cells without incurring GVHD. © 2018 by The American Society of Hematology.

  3. Microarray-Based Determination of Estrogen Receptor, Progesterone Receptor, and HER2 Receptor Status in Breast Cancer

    NARCIS (Netherlands)

    Roepman, Paul; Horlings, Hugo M.; Krijgsman, Oscar; Kok, Marleen; Bueno-de-Mesquita, Jolien M.; Bender, Richard; Linn, Sabine C.; Glas, Annuska M.; van de Vijver, Marc J.

    2009-01-01

    Purpose: The level of estrogen receptor (ER), progesterone receptor (PR), and HER2 aids in the determination of prognosis and treatment of breast cancer. Immunohistochemistry is currently the predominant method for assessment, but differences in methods and interpretation can substantially affect

  4. Identifying the receptor subtype selectivity of retinoid X and retinoic acid receptors via quantum mechanics.

    Science.gov (United States)

    Tsuji, Motonori; Shudo, Koichi; Kagechika, Hiroyuki

    2017-03-01

    Understanding and identifying the receptor subtype selectivity of a ligand is an important issue in the field of drug discovery. Using a combination of classical molecular mechanics and quantum mechanical calculations, this report assesses the receptor subtype selectivity for the human retinoid X receptor (hRXR) and retinoic acid receptor (hRAR) ligand-binding domains (LBDs) complexed with retinoid ligands. The calculated energies show good correlation with the experimentally reported binding affinities. The technique proposed here is a promising method as it reveals the origin of the receptor subtype selectivity of selective ligands.

  5. Excitatory amino acid receptors and disease.

    Science.gov (United States)

    Meldrum, B S

    1992-08-01

    Recent advances in the molecular biology of excitatory amino acid receptors are reviewed. Evidence that drugs blocking the excitatory action of glutamate at the N-methyl-D-aspartate (NMDA) and non-NMDA receptors may be of clinical use in epilepsy, Parkinson's disease, cerebral ischaemia and trauma, acquired immune deficiency syndrome (AIDS) encephalopathy and neuropathic pain is summarized.

  6. Docking to flexible nicotinic acetylcholine receptors

    DEFF Research Database (Denmark)

    Sander, Tommy; Bruun, Anne T; Balle, Thomas

    2010-01-01

    Computational docking to nicotinic acetylcholine receptors (nAChRs) and other members of the Cys-loop receptor family is complicated by the flexibility of the so-called C-loop. As observed in the large number of published crystal structures of the acetylcholine binding protein (AChBP), a structural...

  7. Structural Studies of Nicotinic Acetylcholine Receptors

    DEFF Research Database (Denmark)

    Shahsavar, Azadeh; Gajhede, Michael; Kastrup, Jette

    2016-01-01

    Nicotinic acetylcholine receptors (nAChRs) are members of the pentameric ligand-gated ion channel superfamily that play important roles in control of neurotransmitter release in the central and peripheral nervous system. These receptors are important therapeutic targets for development of drugs...

  8. In vivo studies of opiate receptors

    International Nuclear Information System (INIS)

    Frost, J.J.; Dannals, R.F.; Duelfer, T.; Burns, H.D.; Ravert, H.T.; Langstroem, B.; Balasubramanian, V.; Wagner, H.N. Jr.

    1984-01-01

    To study opiate receptors noninvasively in vivo using positron emission tomography, techniques for preferentially labeling opiate receptors in vivo can be used. The rate at which receptor-bound ligand clears from the brain in vivo can be predicted by measuring the equilibrium dissociation constant (KD) at 37 degrees C in the presence of 100 mM sodium chloride and 100 microM guanyl-5'-imidodiphosphate, the drug distribution coefficient, and the molecular weight. A suitable ligand for labeling opiate receptors in vivo is diprenorphine, which binds to mu, delta, and kappa receptors with approximately equal affinity in vitro. However, in vivo diprenorphine may bind predominantly to one opiate receptor subtype, possibly the mu receptor. To predict the affinity for binding to the opiate receptor, a Hansch correlation was determined between the 50% inhibitory concentration for a series of halogen-substituted fentanyl analogs and electronic, lipophilic, and steric parameters. Radiochemical methods for the synthesis of carbon-11-labeled diprenorphine and lofentanil are presented

  9. In vivo studies of opiate receptors

    Energy Technology Data Exchange (ETDEWEB)

    Frost, J.J.; Dannals, R.F.; Duelfer, T.; Burns, H.D.; Ravert, H.T.; Langstroem, B.; Balasubramanian, V.; Wagner, H.N. Jr.

    1984-01-01

    To study opiate receptors noninvasively in vivo using positron emission tomography, techniques for preferentially labeling opiate receptors in vivo can be used. The rate at which receptor-bound ligand clears from the brain in vivo can be predicted by measuring the equilibrium dissociation constant (KD) at 37 degrees C in the presence of 100 mM sodium chloride and 100 microM guanyl-5'-imidodiphosphate, the drug distribution coefficient, and the molecular weight. A suitable ligand for labeling opiate receptors in vivo is diprenorphine, which binds to mu, delta, and kappa receptors with approximately equal affinity in vitro. However, in vivo diprenorphine may bind predominantly to one opiate receptor subtype, possibly the mu receptor. To predict the affinity for binding to the opiate receptor, a Hansch correlation was determined between the 50% inhibitory concentration for a series of halogen-substituted fentanyl analogs and electronic, lipophilic, and steric parameters. Radiochemical methods for the synthesis of carbon-11-labeled diprenorphine and lofentanil are presented.

  10. Receptor study of psychiatric disorders using PET

    International Nuclear Information System (INIS)

    Suhara, Tetsuya

    1992-01-01

    Recent receptor studies of psychiatric disorders using PET have been focused on the change in the number of D 2 dopamine receptors in the striatum of drug-naive schizophrenic patients. One study confirmed an increase in D 2 receptors, while another study denied it. Although there were some differences in the approaches of the two groups, the reason for the discrepancy is not clear yet. Looking to psychiatric disorders other than schizophrenia, our recent study revealed a possible role of dopamine D 1 receptors in bipolar mood disorders. However, some problems must be resolved for further receptor studies with PET. For example, our recent study shows that desipamine decreases the in vivo binding of dopramine D 1 and D 2 receptors whereas these is no effect on dopamine D 1 and D 2 receptors in vitro. Additionally significant methodological problems lie in the method of evaluation of the non-specific binding and the effect of endogenous neurotransmitters. Moreover, difficulties in the diagnosis of psychiatric disorders and ethical problems in psychiatric research are critical factors in receptor studies with PET in psychiatric disorders. (author)

  11. P2X receptors in epithelia

    DEFF Research Database (Denmark)

    Leipziger, Jens Georg

    2015-01-01

    P2X receptors are ubiquitously expressed in all epithelial tissues but their functional roles are less well studied. Here we review the current state of knowledge by focusing on functional effects of P2X receptor in secretory and in absorptive tissues. In glandular tissue like the parotid gland...

  12. Structural Mapping of Adenosine Receptor Mutations

    DEFF Research Database (Denmark)

    Jespers, Willem; Schiedel, Anke C; Heitman, Laura H

    2018-01-01

    The four adenosine receptors (ARs), A1, A2A, A2B, and A3, constitute a subfamily of G protein-coupled receptors (GPCRs) with exceptional foundations for structure-based ligand design. The vast amount of mutagenesis data, accumulated in the literature since the 1990s, has been recently supplemente...

  13. Emerging functions for neuropeptide Y5 receptors

    NARCIS (Netherlands)

    Bischoff, A.; Michel, M. C.

    1999-01-01

    The Y5 subtype of neuropeptide Y (NPY) receptors has raised considerable interest as a mediator of NPY-stimulated food intake, but with the advent of recent data, this hypothesis has come into question. Moreover, Y5 receptor-selective drugs might not be specific for food intake because additional

  14. Immunohistochemical assessment of oestrogen and progesterone receptors

    DEFF Research Database (Denmark)

    Grabau, D A; Thorpe, S M; Knoop, A

    2000-01-01

    Two different methods to determine steroid receptors were analysed with respect to their ability to estimate prognosis in primary breast cancer patients. The immunohistochemical assay (IHA) was compared with the dextran-coated charcoal (DCC) method of receptor determination. A random sample of 28...... distinction between benign and malignant tissue is possible using the IHAmethod. Thus, IHAresults appear to be more clinically relevant....

  15. Lipoprotein receptors in cultured bovine endothelial cells

    International Nuclear Information System (INIS)

    Struempfer, A.E.M.

    1983-07-01

    In this study, receptors that may be involved in the uptake of low density lipoproteins (LDL) and low density lipoproteins which have been modified by acetylation (AcLDL), were characterized. Aortic epithelial cells were used and a cell culture system which closely resembled the in vivo monolayer was established. Endothelial cell and lipoprotein interactions were examined by incubating the cells with 125 l-labelled lipoproteins under various conditions. The receptor affinity of bovine aortic endothelial cells was higher for AcLDL than that for LDL. Competition studies demonstrated that there were two distinct receptors for LDL and AcLDL on the endothelial cells. AcLDL did not compete with LDL for the LDL receptor, and conversely LDL did not compete with AcLDL for the AcLDL receptor. The receptor activities for LDL and AcLDL were examined as a function of culture age. Whereas the LDL receptor could be regulated, the AcLDL receptor was not as susceptible to regulation. Upon exposing endothelial cells for 72 h to either LDL or AcLDL, it was found that the total amount of cellular cholesterol increased by about 50%. However, the increase of total cholesterol was largely in the form of free cholesterol. This is in contrast to macrophages, where the increase in total cholesterol upon exposure to AcLDL is largely in the form cholesteryl esters

  16. Thermogenic characterization of ghrelin receptor null mice

    Science.gov (United States)

    Ghrelin is the only known circulating orexigenic hormone that increases food intake and promotes adiposity, and these physiological functions of ghrelin are mediated through its receptor growth hormone secretagogue receptor (GHS-R). Ghrelin/GHS-R signaling plays a crucial role in energy homeostasis....

  17. Complex Pharmacology of Free Fatty Acid Receptors

    DEFF Research Database (Denmark)

    Milligan, Graeme; Shimpukade, Bharat; Ulven, Trond

    2017-01-01

    pharmacology have shaped understanding of the complex pharmacology of receptors that recognize and are activated by nonesterified or "free" fatty acids (FFAs). The FFA family of receptors is a recently deorphanized set of GPCRs, the members of which are now receiving substantial interest as novel targets...

  18. Neutral anion receptors: design and application

    NARCIS (Netherlands)

    Antonisse, M.M.G.; Reinhoudt, David

    1998-01-01

    After the development of synthetic cation receptors in the late 1960s, only in the past decade has work started on the development of synthetic neutral anion receptors. Combination and preorganization of different anion binding groups, like amides, urea moieties, or Lewis acidic metal centers lead

  19. NRSAS: Nuclear Receptor Structure Analysis Servers.

    NARCIS (Netherlands)

    Bettler, E.J.M.; Krause, R.; Horn, F.; Vriend, G.

    2003-01-01

    We present a coherent series of servers that can perform a large number of structure analyses on nuclear hormone receptors. These servers are part of the NucleaRDB project, which provides a powerful information system for nuclear hormone receptors. The computations performed by the servers include

  20. Transient receptor potential channels in essential hypertension

    DEFF Research Database (Denmark)

    Liu, Daoyan; Scholze, Alexandra; Zhu, Zhiming

    2006-01-01

    The role of nonselective cation channels of the transient receptor potential channel (TRPC) family in essential hypertension has not yet been investigated.......The role of nonselective cation channels of the transient receptor potential channel (TRPC) family in essential hypertension has not yet been investigated....

  1. Receptor tyrosine kinase signaling: a view from quantitative proteomics

    DEFF Research Database (Denmark)

    Dengjel, Joern; Kratchmarova, Irina; Blagoev, Blagoy

    2009-01-01

    Growth factor receptor signaling via receptor tyrosine kinases (RTKs) is one of the basic cellular communication principals found in all metazoans. Extracellular signals are transferred via membrane spanning receptors into the cytoplasm, reversible tyrosine phosphorylation being the hallmark of all...

  2. Steroid Hormone Receptor Signals as Prognosticators for Urothelial Tumor

    Directory of Open Access Journals (Sweden)

    Hiroki Ide

    2015-01-01

    Full Text Available There is a substantial amount of preclinical or clinical evidence suggesting that steroid hormone receptor-mediated signals play a critical role in urothelial tumorigenesis and tumor progression. These receptors include androgen receptor, estrogen receptors, glucocorticoid receptor, progesterone receptor, vitamin D receptor, retinoid receptors, peroxisome proliferator-activated receptors, and others including orphan receptors. In particular, studies using urothelial cancer tissue specimens have demonstrated that elevated or reduced expression of these receptors as well as alterations of their upstream or downstream pathways correlates with patient outcomes. This review summarizes and discusses available data suggesting that steroid hormone receptors and related signals serve as biomarkers for urothelial carcinoma and are able to predict tumor recurrence or progression.

  3. Real-Time G-Protein-Coupled Receptor Imaging to Understand and Quantify Receptor Dynamics

    Directory of Open Access Journals (Sweden)

    María S. Aymerich

    2011-01-01

    Full Text Available Understanding the trafficking of G-protein-coupled receptors (GPCRs and their regulation by agonists and antagonists is fundamental to develop more effective drugs. Optical methods using fluorescent-tagged receptors and spinning disk confocal microscopy are useful tools to investigate membrane receptor dynamics in living cells. The aim of this study was to develop a method to characterize receptor dynamics using this system which offers the advantage of very fast image acquisition with minimal cell perturbation. However, in short-term assays photobleaching was still a problem. Thus, we developed a procedure to perform a photobleaching-corrected image analysis. A study of short-term dynamics of the long isoform of the dopamine type 2 receptor revealed an agonist-induced increase in the mobile fraction of receptors with a rate of movement of 0.08 μm/s For long-term assays, the ratio between the relative fluorescence intensity at the cell surface versus that in the intracellular compartment indicated that receptor internalization only occurred in cells co-expressing G protein-coupled receptor kinase 2. These results indicate that the lateral movement of receptors and receptor internalization are not directly coupled. Thus, we believe that live imaging of GPCRs using spinning disk confocal image analysis constitutes a powerful tool to study of receptor dynamics.

  4. β-Adrenergic receptor-mediated suppression of interleukin 2 receptors in human lymphocytes

    International Nuclear Information System (INIS)

    Feldman, R.D.; Hunninghake, G.W.; McArdle, W.L.

    1987-01-01

    Adrenergic receptor agonists are know to attenuate the proliferative response of human lymphocytes after activation; however, their mechanism of action is unknown. Since expression of interleukin 2 (IL-2) receptors is a prerequisite for proliferation, the effect of β-adrenergic receptor agonists on lymphocyte IL-2 receptors was studied on both mitogen-stimulated lymphocytes and IL-2-dependent T lymphocyte cell lines. In both cell types the β-adrenergic receptor agonist isoproterenol blocked the expression of IL-2 receptors, as determined with the IL-2 receptor anti-TAC antibody. To determine the effect of β-adrenergic agonists on expression of the high affinity IL-2 receptors, [ 125 I]IL-2 binding studies were performed at concentrations selective for high affinity sites. No significant effect of β-adrenergic agonists on high affinity IL-2 receptor sites could be detected. The data demonstrate that β-adrenergic receptor agonists down-regulate IL-2 receptors primarily affecting low affinity sites

  5. Gβ promotes pheromone receptor polarization and yeast chemotropism by inhibiting receptor phosphorylation.

    Science.gov (United States)

    Ismael, Amber; Tian, Wei; Waszczak, Nicholas; Wang, Xin; Cao, Youfang; Suchkov, Dmitry; Bar, Eli; Metodiev, Metodi V; Liang, Jie; Arkowitz, Robert A; Stone, David E

    2016-04-12

    Gradient-directed cell migration (chemotaxis) and growth (chemotropism) are processes that are essential to the development and life cycles of all species. Cells use surface receptors to sense the shallow chemical gradients that elicit chemotaxis and chemotropism. Slight asymmetries in receptor activation are amplified by downstream signaling systems, which ultimately induce dynamic reorganization of the cytoskeleton. During the mating response of budding yeast, a model chemotropic system, the pheromone receptors on the plasma membrane polarize to the side of the cell closest to the stimulus. Although receptor polarization occurs before and independently of actin cable-dependent delivery of vesicles to the plasma membrane (directed secretion), it requires receptor internalization. Phosphorylation of pheromone receptors by yeast casein kinase 1 or 2 (Yck1/2) stimulates their internalization. We showed that the pheromone-responsive Gβγ dimer promotes the polarization of the pheromone receptor by interacting with Yck1/2 and locally inhibiting receptor phosphorylation. We also found that receptor phosphorylation is essential for chemotropism, independently of its role in inducing receptor internalization. A mathematical model supports the idea that the interaction between Gβγ and Yck1/2 results in differential phosphorylation and internalization of the pheromone receptor and accounts for its polarization before the initiation of directed secretion. Copyright © 2016, American Association for the Advancement of Science.

  6. The ABA receptors -- we report you decide.

    Science.gov (United States)

    McCourt, Peter; Creelman, Robert

    2008-10-01

    The plant hormone abscisic acid (ABA) has been implicated in a variety of physiological responses ranging from seed dormancy to stomatal conductance. Recently, three groups have reported the molecular identification of three disparate ABA receptors. Unlike the identification of other hormone receptors, in these three cases high affinity binding to ABA rather than the isolation of ABA insensitive mutants led to these receptor genes. Interestingly, two of the receptors encode genes involved in floral timing and chlorophyll biosynthesis, which are not considered traditional ABA responses. And the third receptor has been clouded in issues of its molecular identity. To clearly determine the roles of these genes in ABA perception it will require placing of these ABA-binding proteins into the rich ABA physiological context that has built up over the years.

  7. Sigma-2 receptor ligands QSAR model dataset

    Directory of Open Access Journals (Sweden)

    Antonio Rescifina

    2017-08-01

    Full Text Available The data have been obtained from the Sigma-2 Receptor Selective Ligands Database (S2RSLDB and refined according to the QSAR requirements. These data provide information about a set of 548 Sigma-2 (σ2 receptor ligands selective over Sigma-1 (σ1 receptor. The development of the QSAR model has been undertaken with the use of CORAL software using SMILES, molecular graphs and hybrid descriptors (SMILES and graph together. Data here reported include the regression for σ2 receptor pKi QSAR models. The QSAR model was also employed to predict the σ2 receptor pKi values of the FDA approved drugs that are herewith included.

  8. Computer modeling of Cannabinoid receptor type 1

    Directory of Open Access Journals (Sweden)

    Sapundzhi Fatima

    2018-01-01

    Full Text Available Cannabinoid receptors are important class of receptors as they are involved in various physiological processes such as appetite, pain-sensation, mood, and memory. It is important to design receptor-selective ligands in order to treat a particular disorder. The aim of the present study is to model the structure of cannabinoid receptor CB1 and to perform docking between obtained models and known ligands. Two models of CBR1 were prepared with two different methods (Modeller of Chimera and MOE. They were used for docking with GOLD 5.2. It was established a high correlation between inhibitory constant Ki of CB1 cannabinoid ligands and the ChemScore scoring function of GOLD, which concerns both models. This suggests that the models of the CB1 receptors obtained could be used for docking studies and in further investigation and design of new potential, selective and active cannabinoids with the desired effects.

  9. The AT2 Receptor and Inflammation

    DEFF Research Database (Denmark)

    Esquitino, Veronica Valero; Danyel, Leon Alexander; Steckelings, Ulrike M.

    2015-01-01

    This chapter summarizes current knowledge about the role of the angiotensin type 2 (AT2) receptor in inflammation. The first section provides an overview about molecular mechanisms underlying the anti-inflammatory action of the AT2 receptor. This section is followed...... by a review of the existing literature addressing the role of the AT2 receptor in a wide range of disorders, in which acute or chronic inflammation is an essential contributor to the pathology. These disorders comprise cardiovascular, cerebrovascular, renal, and autoimmune diseases.Taken as a whole......, the vast majority of data support an anti-inflammatory and immunomodulatory role of the AT2 receptor. In light of the current development of AT2 receptor agonists as future drugs for clinical use, diseases with a marked inflammatory component may become a major area of therapeutic use...

  10. Ror receptor tyrosine kinases: orphans no more.

    Science.gov (United States)

    Green, Jennifer L; Kuntz, Steven G; Sternberg, Paul W

    2008-11-01

    Receptor tyrosine kinase-like orphan receptor (Ror) proteins are a conserved family of tyrosine kinase receptors that function in developmental processes including skeletal and neuronal development, cell movement and cell polarity. Although Ror proteins were originally named because the associated ligand and signaling pathway were unknown, recent studies in multiple species have now established that Ror proteins are Wnt receptors. Depending on the cellular context, Ror proteins can either activate or repress transcription of Wnt target genes and can modulate Wnt signaling by sequestering Wnt ligands. New evidence implicates Ror proteins in planar cell polarity, an alternative Wnt pathway. Here, we review the progress made in understanding these mysterious proteins and, in particular, we focus on their function as Wnt receptors.

  11. Role of retinoic receptors in lung carcinogenesis

    Directory of Open Access Journals (Sweden)

    Renyi-Vamos Ferenc

    2008-07-01

    Full Text Available Abstract Several in vitro and in vivo studies have examined the positive and negative effects of retinoids (vitamin A analogs in premalignant and malignant lesions. Retinoids have been used as chemopreventive and anticancer agents because of their pleiotropic regulator function in cell differentiation, growth, proliferation and apoptosis through interaction with two types of nuclear receptors: retinoic acid receptors and retinoid X receptors. Recent investigations have gradually elucidated the function of retinoids and their signaling pathways and may explain the failure of earlier chemopreventive studies. In this review we have compiled basic and recent knowledge regarding the role of retinoid receptors in lung carcinogenesis. Sensitive and appropriate biological tools are necessary for screening the risk population and monitoring the efficacy of chemoprevention. Investigation of retinoid receptors is important and may contribute to the establishment of new strategies in chemoprevention for high-risk patients and in the treatment of lung cancer.

  12. Androgen insensitivity syndrome: gonadal androgen receptor activity

    International Nuclear Information System (INIS)

    Coulam, C.B.; Graham, M.L.; Spelsberg, T.C.

    1984-01-01

    To determine whether abnormalities of the androgen receptor previously observed in skin fibroblasts from patients with androgen insensitivity syndrome also occur in the gonads of affected individuals, androgen receptor activity in the gonads of a patient with testicular feminization syndrome was investigated. Using conditions for optimal recovery of androgen receptor from human testes established by previous studies, we detected the presence of a high-affinity (dissociation constant . 3.2 X 10(-10) mol/L), low-capacity (4.2 X 10(-12) mol/mg DNA), androgen-binding protein when tritium-labeled R1881 was incubated at 4 degrees C with nuclear extracts from the gonads of control patients or from a patient with testicular feminization syndrome but not when incubated at 37 degrees C. Thus this patient has an androgen receptor with a temperature lability similar to that of receptors from normal persons

  13. Functionally biased signalling properties of 7TM receptors - opportunities for drug development for the ghrelin receptor

    DEFF Research Database (Denmark)

    Sivertsen, B; Holliday, N; Madsen, A N

    2013-01-01

    UNLABELLED: The ghrelin receptor is a 7 transmembrane (7TM) receptor involved in a variety of physiological functions including growth hormone secretion, increased food intake and fat accumulation as well as modulation of reward and cognitive functions. Because of its important role in metabolism...... and energy expenditure, the ghrelin receptor has become an important therapeutic target for drug design and the development of anti-obesity compounds. However, none of the compounds developed so far have been approved for commercial use. Interestingly, the ghrelin receptor is able to signal through several...... review, we have described how ligands and mutations in the 7TM receptor may bias the receptors to favour either one G-protein over another or to promote G-protein independent signalling pathways rather than G-protein-dependent pathways. For the ghrelin receptor, both agonist and inverse agonists have...

  14. Activation of glucocorticoid receptors increases 5-HT2A receptor levels

    DEFF Research Database (Denmark)

    Trajkovska, Viktorija; Kirkegaard, Lisbeth; Krey, Gesa

    2009-01-01

    an effect of GR activation on 5-HT2A levels, mature organotypic hippocampal cultures were exposed to corticosterone with or without GR antagonist mifepristone and mineralocorticoid receptor (MR) antagonist spironolactone. In GR under-expressing mice, hippocampal 5-HT2A receptor protein levels were decreased......Major depression is associated with both dysregulation of the hypothalamic pituitary adrenal axis and serotonergic deficiency, not the least of the 5-HT2A receptor. However, how these phenomena are linked to each other, and whether a low 5-HT2A receptor level is a state or a trait marker...... of depression is unknown. In mice with altered glucocorticoid receptor (GR) expression we investigated 5-HT2A receptor levels by Western blot and 3H-MDL100907 receptor binding. Serotonin fibre density was analyzed by stereological quantification of serotonin transporter immunopositive fibers. To establish...

  15. Receptor oligomerization in family B1 of G-protein-coupled receptors

    DEFF Research Database (Denmark)

    Roed, Sarah Norklit; Ørgaard, Anne; Jørgensen, Rasmus

    2012-01-01

    , the glucagon receptor, and the receptors for parathyroid hormone (PTHR1 and PTHR2). The dysregulation of several family B1 receptors is involved in diseases, such as diabetes, chronic inflammation, and osteoporosis which underlines the pathophysiological importance of this GPCR subfamily. In spite of this......, investigation of family B1 receptor oligomerization and especially its pharmacological importance is still at an early stage. Even though GPCR oligomerization is a well-established phenomenon, there is a need for more investigations providing a direct link between these interactions and receptor functionality......The superfamily of the seven transmembrane G-protein-coupled receptors (7TM/GPCRs) is the largest family of membrane-associated receptors. GPCRs are involved in the pathophysiology of numerous human diseases, and they constitute an estimated 30-40% of all drug targets. During the last two decades...

  16. Cocaine Inhibits Dopamine D2 Receptor Signaling via Sigma-1-D2 Receptor Heteromers

    Science.gov (United States)

    Navarro, Gemma; Moreno, Estefania; Bonaventura, Jordi; Brugarolas, Marc; Farré, Daniel; Aguinaga, David; Mallol, Josefa; Cortés, Antoni; Casadó, Vicent; Lluís, Carmen; Ferre, Sergi

    2013-01-01

    Under normal conditions the brain maintains a delicate balance between inputs of reward seeking controlled by neurons containing the D1-like family of dopamine receptors and inputs of aversion coming from neurons containing the D2-like family of dopamine receptors. Cocaine is able to subvert these balanced inputs by altering the cell signaling of these two pathways such that D1 reward seeking pathway dominates. Here, we provide an explanation at the cellular and biochemical level how cocaine may achieve this. Exploring the effect of cocaine on dopamine D2 receptors function, we present evidence of σ1 receptor molecular and functional interaction with dopamine D2 receptors. Using biophysical, biochemical, and cell biology approaches, we discovered that D2 receptors (the long isoform of the D2 receptor) can complex with σ1 receptors, a result that is specific to D2 receptors, as D3 and D4 receptors did not form heteromers. We demonstrate that the σ1-D2 receptor heteromers consist of higher order oligomers, are found in mouse striatum and that cocaine, by binding to σ1 -D2 receptor heteromers, inhibits downstream signaling in both cultured cells and in mouse striatum. In contrast, in striatum from σ1 knockout animals these complexes are not found and this inhibition is not seen. Taken together, these data illuminate the mechanism by which the initial exposure to cocaine can inhibit signaling via D2 receptor containing neurons, destabilizing the delicate signaling balance influencing drug seeking that emanates from the D1 and D2 receptor containing neurons in the brain. PMID:23637801

  17. The repertoire of trace amine G-protein-coupled receptors

    DEFF Research Database (Denmark)

    Gloriam, David E.; Bjarnadóttir, Thóra K; Yan, Yi-Lin

    2005-01-01

    eukaryotic species for receptors similar to the mammalian trace amine (TA) receptor subfamily. We identified 18 new receptors in rodents that are orthologous to the previously known TA-receptors. Remarkably, we found 57 receptors (and 40 pseudogenes) of this type in the zebrafish (Danio rerio), while fugu...... (Takifugu rubripes) had only eight receptors (and seven pseudogenes). We mapped 47 of the zebrafish TA-receptors on chromosomes using radiation hybrid panels and meiotic mapping. The results, together with the degree of conservation and phylogenetic relationships displayed among the zebrafish receptors...

  18. Advanced glycation endproducts alter functions and promote apoptosis in endothelial progenitor cells through receptor for advanced glycation endproducts mediate overpression of cell oxidant stress.

    Science.gov (United States)

    Chen, Jianfei; Song, Minbao; Yu, Shiyong; Gao, Pan; Yu, Yang; Wang, Hong; Huang, Lan

    2010-02-01

    Endothelial progenitor cells (EPCs) play an important role in preventing atherosclerosis. The factors that regulate the function of EPCs are not completely clear. Increased formation of advanced glycation endproducts (AGEs) is generally regarded as one of the main mechanisms responsible for vascular damage in patients with diabetes and atherosclerosis. AGEs lead to the generation of reactive oxygen species (ROS) and part of the regenerative capacity of EPCs seems to be due to their low baseline ROS levels and reduced sensitivity to ROS-induced cell apoptosis. Therefore, we tested the hypothesis that AGEs can alter functions and promote apoptosis in EPCs through overpress cell oxidant stress. EPCs, isolated from bone marrow, were cultured in the absence or presence of AGEs (50, 100, and 200 microg/ml). A modified Boyden's chamber was used to assess the migration of EPCs and the number of recultured EPCs was counted to measure the adhesiveness function. MTT assay was used to determine the proliferation function. ROS were analyzed using the ROS assay kit. A spectrophotometer was used to assess superoxide dismutase (SOD) and glutathione peroxidase (GSH-PX) activity, and PCR was used to test mRNA expression of SOD and GSH-PX. SiRNA was used to block receptor for advanced glycation endproducts (RAGEs) expression. Apoptosis was evaluated by Annexin V immunostaining and TUNEL staining. Co-culturing with AGEs increases ROS production, decreases anti-oxidant defenses, overpresses oxidant stress, inhibits the proliferation, migration, and adhesion of EPCs, and induces EPCs apoptosis. In addition, these effects were attenuated during block RAGE protein expression by siRNA. AGEs may serve to impair EPCs functions through RAGE-mediate oxidant stress, and promote EPCs sensitivity toward oxidative-stress-mediated apoptosis, which indicates a new pathophysiological mechanism of disturbed vascular adaptation in atherosclerosis and suggests that lower levels of AGEs might improve the

  19. Chronic ethanol exposure induces SK-N-SH cell apoptosis by increasing N-methyl-D-aspartic acid receptor expression and intracellular calcium.

    Science.gov (United States)

    Wang, Hongbo; Wang, Xiaolong; Li, Yan; Yu, Hao; Wang, Changliang; Feng, Chunmei; Xu, Guohui; Chen, Jiajun; You, Jiabin; Wang, Pengfei; Wu, Xu; Zhao, Rui; Zhang, Guohua

    2018-04-01

    It has been identified that chronic ethanol exposure damages the nervous system, particularly neurons. There is scientific evidence suggesting that neuronal loss caused by chronic ethanol exposure has an association with neuron apoptosis and intracellular calcium oscillation is one of the primary inducers of apoptosis. Therefore, the present study aimed to investigate the inductive effects of intracellular calcium oscillation on apoptosis in SK-N-SH human neuroblastoma cells and the protective effects of the N-methyl-D-aspartic acid receptor (NMDAR) antagonist, memantine, on SK-N-SH cell apoptosis caused by chronic ethanol exposure. SK-N-SH cells were treated with 100 mM ethanol and memantine (4 µM) for 2 days. Protein expression of NR1 was downregulated by RNA interference (RNAi). Apoptosis was detected by Annexin V/propidium iodide (PI) double-staining and flow cytometry and cell viability was detected using an MTS kit. Fluorescence dual wavelength spectrophotometry was used to determine the intracellular calcium concentration and the levels of NR1 and caspase-3 were detected using western blotting. NR1 mRNA levels were also detected using qPCR. It was found that chronic ethanol exposure reduced neuronal cell viability and caused apoptosis of SK-N-SH cells, and the extent of damage in SK-N-SH cells was associated with ethanol exposure concentration and time. In addition, chronic ethanol exposure increased the concentration of intracellular calcium in SK-N-SH cells by inducing the expression of NMDAR, resulting in apoptosis, and memantine treatment reduced ethanol-induced cell apoptosis. The results of the present study indicate that the application of memantine may provide a novel strategy for the treatment of alcoholic dementia.

  20. Flow Cytometric Quantification of Peripheral Blood Cell β-Adrenergic Receptor Density and Urinary Endothelial Cell-Derived Microparticles in Pulmonary Arterial Hypertension.

    Directory of Open Access Journals (Sweden)

    Jonathan A Rose

    Full Text Available Pulmonary arterial hypertension (PAH is a heterogeneous disease characterized by severe angiogenic remodeling of the pulmonary artery wall and right ventricular hypertrophy. Thus, there is an increasing need for novel biomarkers to dissect disease heterogeneity, and predict treatment response. Although β-adrenergic receptor (βAR dysfunction is well documented in left heart disease while endothelial cell-derived microparticles (Ec-MPs are established biomarkers of angiogenic remodeling, methods for easy large clinical cohort analysis of these biomarkers are currently absent. Here we describe flow cytometric methods for quantification of βAR density on circulating white blood cells (WBC and Ec-MPs in urine samples that can be used as potential biomarkers of right heart failure in PAH. Biotinylated β-blocker alprenolol was synthesized and validated as a βAR specific probe that was combined with immunophenotyping to quantify βAR density in circulating WBC subsets. Ec-MPs obtained from urine samples were stained for annexin-V and CD144, and analyzed by a micro flow cytometer. Flow cytometric detection of alprenolol showed that βAR density was decreased in most WBC subsets in PAH samples compared to healthy controls. Ec-MPs in urine was increased in PAH compared to controls. Furthermore, there was a direct correlation between Ec-MPs and Tricuspid annular plane systolic excursion (TAPSE in PAH patients. Therefore, flow cytometric quantification of peripheral blood cell βAR density and urinary Ec-MPs may be useful as potential biomarkers of right ventricular function in PAH.

  1. Propensity of red blood cells to undergo P2X7 receptor-mediated phosphatidylserine exposure does not alter during in vivo or ex vivo aging.

    Science.gov (United States)

    Sophocleous, Reece A; Mullany, Phillip R F; Winter, Kelly M; Marks, Denese C; Sluyter, Ronald

    2015-08-01

    Phosphatidylserine (PS) exposure facilitates the removal of red blood cells (RBCs) from the circulation, potentially contributing to the loss of stored RBCs after transfusion, as well as senescent RBCs. Activation of the P2X7 receptor by extracellular adenosine 5'-triphosphate (ATP) can induce PS exposure on freshly isolated human RBCs, but whether this process occurs in stored RBCs or changes during RBC aging is unknown. RBCs were processed and stored according to Australian blood banking guidelines. PS exposure was determined by annexin V binding and flow cytometry. Efficacy of P2X antagonists was assessed by flow cytometric measurements of ATP-induced ethidium+ uptake in RPMI 8226 cells. Osmotic fragility was assessed by lysis in hypotonic saline. RBCs were fractionated by discontinuous density centrifugation. ATP (1 mmol/L) induced PS exposure on RBCs stored for less than 1 week. This process was near-completely inhibited by the P2X7 antagonists A438079 and AZ10606120 and the P2X1/P2X7 antagonist MRS2159 but not the P2X1 antagonist NF499. ATP-induced PS exposure on RBCs was not dependent on K+, Na+, or Cl- fluxes. ATP did not alter the osmotic fragility of stored RBCs. ATP-induced PS exposure was similar between RBCs of different densities. ATP-induced PS exposure was also similar between RBCs stored for less than 1 week or for 6 weeks. The propensity of RBCs to undergo P2X7-mediated PS exposure does not alter during in vivo and ex vivo aging. Thus, P2X7 activation is unlikely to be involved in the removal of senescent RBCs or stored RBCs after transfusion. © 2015 AABB.

  2. Antiproliferative and apoptotic effects of a specific anti-insulin-like growth factor I receptor single chain antibody on breast cancer cells.

    Science.gov (United States)

    Motallebnezhad, Morteza; Younesi, Vahid; Aghebati-Maleki, Leili; Nickho, Hamid; Safarzadeh, Elham; Ahmadi, Majid; Movassaghpour, Ali Akbar; Hosseini, Ahmad; Yousefi, Mehdi

    2016-11-01

    Insulin-like growth factor I receptor (IGF-IR) is expressed on breast cancer cells and involves in metastasis, survival, and proliferation. Currently, application of IGF-IR-targeting monoclonal antibodies (mAbs), alone or in combination with other drugs, is a promising strategy for breast cancer therapy. Single-chain fragment variable (scFv) antibodies have been introduced as appropriate tools for tumor-targeting purposes because of their advantages over whole antibodies. In the present study, we employed a naïve phage library and isolated scFvs against a specific epitope from extracellular domain of IGF-IR by panning process. The selected scFvs were further characterized using polyclonal and monoclonal phage ELISA, soluble monoclonal ELISA, and colony PCR and sequencing. Antiproliferative and apoptotic effects of selected scFv antibodies on breast cancer cell lines were also evaluated by MTT and Annexin V/PI assays. The results of ELISA indicated specific reactions of the isolated scFvs against the IGF-IR peptide, and analyses of PCR product and sequencing confirmed the presence of full length V H and Vκ inserts. Treatment of MCF7 and SKBR3 cells with anti-IGF-IR scFv led to a significant growth inhibition. The results also showed that scFv treatment significantly augmented trastuzumab growth inhibitory effects on SKBR3 cells. The percentage of the apoptotic MCF7 and SKBR3 cells after 24-h treatment with scFv was 39 and 30.70 %, respectively. Twenty-four-hour treatment with scFv in combination with trastuzumab resulted in 44.75 % apoptosis of SKBR3 cells. Taken together, our results demonstrate that the targeting of IGF-IR by scFv can be an effective strategy in the treatment of breast cancer and provide further evidence for effectiveness of dual targeting of HER2 and IGF-IR in breast cancer therapy.

  3. Flow Cytometric Quantification of Peripheral Blood Cell β-Adrenergic Receptor Density and Urinary Endothelial Cell-Derived Microparticles in Pulmonary Arterial Hypertension.

    Science.gov (United States)

    Rose, Jonathan A; Wanner, Nicholas; Cheong, Hoi I; Queisser, Kimberly; Barrett, Patrick; Park, Margaret; Hite, Corrine; Naga Prasad, Sathyamangla V; Erzurum, Serpil; Asosingh, Kewal

    2016-01-01

    Pulmonary arterial hypertension (PAH) is a heterogeneous disease characterized by severe angiogenic remodeling of the pulmonary artery wall and right ventricular hypertrophy. Thus, there is an increasing need for novel biomarkers to dissect disease heterogeneity, and predict treatment response. Although β-adrenergic receptor (βAR) dysfunction is well documented in left heart disease while endothelial cell-derived microparticles (Ec-MPs) are established biomarkers of angiogenic remodeling, methods for easy large clinical cohort analysis of these biomarkers are currently absent. Here we describe flow cytometric methods for quantification of βAR density on circulating white blood cells (WBC) and Ec-MPs in urine samples that can be used as potential biomarkers of right heart failure in PAH. Biotinylated β-blocker alprenolol was synthesized and validated as a βAR specific probe that was combined with immunophenotyping to quantify βAR density in circulating WBC subsets. Ec-MPs obtained from urine samples were stained for annexin-V and CD144, and analyzed by a micro flow cytometer. Flow cytometric detection of alprenolol showed that βAR density was decreased in most WBC subsets in PAH samples compared to healthy controls. Ec-MPs in urine was increased in PAH compared to controls. Furthermore, there was a direct correlation between Ec-MPs and Tricuspid annular plane systolic excursion (TAPSE) in PAH patients. Therefore, flow cytometric quantification of peripheral blood cell βAR density and urinary Ec-MPs may be useful as potential biomarkers of right ventricular function in PAH.

  4. Action mechanisms of Liver X Receptors

    Energy Technology Data Exchange (ETDEWEB)

    Gabbi, Chiara; Warner, Margaret [Center for Nuclear Receptors and Cell Signaling, University of Houston, 3056 Cullen Blv, 77204 Houston, Texas (United States); Gustafsson, Jan-Åke, E-mail: jgustafs@central.uh.edu [Center for Nuclear Receptors and Cell Signaling, University of Houston, 3056 Cullen Blv, 77204 Houston, Texas (United States); Department of Biosciences and Nutrition, Karolinska Institutet, Novum S-141 86 (Sweden)

    2014-04-11

    Highlights: • LXRα and LXRβ are ligand-activated nuclear receptors. • They share oxysterol ligands and the same heterodimerization partner, RXR. • LXRs regulate lipid and glucose metabolism, CNS and immune functions, and water transport. - Abstract: The two Liver X Receptors, LXRα and LXRβ, are nuclear receptors belonging to the superfamily of ligand-activated transcription factors. They share more than 78% homology in amino acid sequence, a common profile of oxysterol ligands and the same heterodimerization partner, Retinoid X Receptor. LXRs play crucial roles in several metabolic pathways: lipid metabolism, in particular in preventing cellular cholesterol accumulation; glucose homeostasis; inflammation; central nervous system functions and water transport. As with all nuclear receptors, the transcriptional activity of LXR is the result of an orchestration of numerous cellular factors including ligand bioavailability, presence of corepressors and coactivators and cellular context i.e., what other pathways are activated in the cell at the time the receptor recognizes its ligand. In this mini-review we summarize the factors regulating the transcriptional activity and the mechanisms of action of these two receptors.

  5. Action mechanisms of Liver X Receptors

    International Nuclear Information System (INIS)

    Gabbi, Chiara; Warner, Margaret; Gustafsson, Jan-Åke

    2014-01-01

    Highlights: • LXRα and LXRβ are ligand-activated nuclear receptors. • They share oxysterol ligands and the same heterodimerization partner, RXR. • LXRs regulate lipid and glucose metabolism, CNS and immune functions, and water transport. - Abstract: The two Liver X Receptors, LXRα and LXRβ, are nuclear receptors belonging to the superfamily of ligand-activated transcription factors. They share more than 78% homology in amino acid sequence, a common profile of oxysterol ligands and the same heterodimerization partner, Retinoid X Receptor. LXRs play crucial roles in several metabolic pathways: lipid metabolism, in particular in preventing cellular cholesterol accumulation; glucose homeostasis; inflammation; central nervous system functions and water transport. As with all nuclear receptors, the transcriptional activity of LXR is the result of an orchestration of numerous cellular factors including ligand bioavailability, presence of corepressors and coactivators and cellular context i.e., what other pathways are activated in the cell at the time the receptor recognizes its ligand. In this mini-review we summarize the factors regulating the transcriptional activity and the mechanisms of action of these two receptors

  6. The cellular receptors of exogenous RNA

    Directory of Open Access Journals (Sweden)

    Patryk Reniewicz

    2016-04-01

    Full Text Available One of the key determinants of survival for organisms is proper recognition of exogenous and endogenous nucleic acids. Therefore, high eukaryotes developed a number of receptors that allow for discrimination between friend or foe DNA and RNA. Appearance of exogenous RNA in cytoplasm provides a signal of danger and triggers cellular responses that facilitate eradication of a pathogen. Recognition of exogenous RNA is additionally complicated by fact that large amount of endogenous RNA is present in cytoplasm Thus, number of different receptors, found in eukaryotic cells, is able to recognize that nucleic acid. First group of those receptors consist endosomal Toll like receptors, namely TLR3, TLR7, TLR8 and TLR13. Those receptors recognize RNA released from pathogens that enter the cell by endocytosis. The second group includes cytoplasmic sensors like PKR and the family of RLRs comprised of RIG-I, MDA5 and LGP2. Cytoplasmic receptors recognize RNA from pathogens invading the cell by non-endocytic pathway. In both cases binding of RNA by its receptors results in activation of the signalling cascades that lead to the production of interferon and other cytokines.

  7. Receptor mapping in psychiatric patients with SPECT

    International Nuclear Information System (INIS)

    Schlegel, S.

    1997-01-01

    This paper summarizes some data of our studies with the single-photon-emission-computerized tomography (SPECT), focussing on the dopamine-D2- and the benzodiazepine receptor mapping. Benzodiazepine receptors: Central benzodiazepine receptors (BZr) can be visualized with iomazenil which is an analogue of the benzodiazepine antagonist flumazenil, labeled with 123-iodine. Since the involvement of the BZr system is discussed in the pathogenesis of anxiety and depression, patients with these disorders were investigated. A third study investigated the BZr-occupancy during benzodiazepine treatment (lorazepam). Results: (a) Patients with panic disorders had lower iomazenil uptake values compared to epileptic patients. (b) Depressed patients showed a positive correlation between severity of illness and frontal uptake. (c) BZr occupancy during lorazepam treatment was measurable, but not associated with lorazepam plasma levels. Dopamine-D2-receptors: With 123-I-iodobenzamide (IBZM), and iodine-labeled dopamine receptor ligand, the D2 receptor density can be measured by a semiquantitative approach (striatum/frontal cortex=ST/FC). Therefore, we investigated the D2-receptor occupancy during treatment with typical and atypical neuroleptics in relationship to dosages (normalized with different formulas of chlorpromazine equivalents), side effects, and prolactin plasma levels. Results: Dependent on the selected formula for chlorpromazine equivalents, the ST/FC ratio was correlated with dosages. Side effects and prolactin plasma levels showed a negative association with lower ST/FC ratios. (orig.) [de

  8. Muscarinic Receptor Signaling in Colon Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Rosenvinge, Erik C. von, E-mail: evonrose@medicine.umaryland.edu; Raufman, Jean-Pierre [University of Maryland School of Medicine, Division of Gastroenterology & Hepatology, 22 S. Greene Street, N3W62, Baltimore, MD 21201 (United States); Department of Veterans Affairs, VA Maryland Health Care System, 10 North Greene Street, Baltimore, MD 21201 (United States)

    2011-03-02

    According to the adenoma-carcinoma sequence, colon cancer results from accumulating somatic gene mutations; environmental growth factors accelerate and augment this process. For example, diets rich in meat and fat increase fecal bile acids and colon cancer risk. In rodent cancer models, increased fecal bile acids promote colon dysplasia. Conversely, in rodents and in persons with inflammatory bowel disease, low-dose ursodeoxycholic acid treatment alters fecal bile acid composition and attenuates colon neoplasia. In the course of elucidating the mechanism underlying these actions, we discovered that bile acids interact functionally with intestinal muscarinic receptors. The present communication reviews muscarinic receptor expression in normal and neoplastic colon epithelium, the role of autocrine signaling following synthesis and release of acetylcholine from colon cancer cells, post-muscarinic receptor signaling including the role of transactivation of epidermal growth factor receptors and activation of the ERK and PI3K/AKT signaling pathways, the structural biology and metabolism of bile acids and evidence for functional interaction of bile acids with muscarinic receptors on human colon cancer cells. In murine colon cancer models, deficiency of subtype 3 muscarinic receptors attenuates intestinal neoplasia; a proof-of-concept supporting muscarinic receptor signaling as a therapeutic target for colon cancer.

  9. Muscarinic Receptor Signaling in Colon Cancer

    International Nuclear Information System (INIS)

    Rosenvinge, Erik C. von; Raufman, Jean-Pierre

    2011-01-01

    According to the adenoma-carcinoma sequence, colon cancer results from accumulating somatic gene mutations; environmental growth factors accelerate and augment this process. For example, diets rich in meat and fat increase fecal bile acids and colon cancer risk. In rodent cancer models, increased fecal bile acids promote colon dysplasia. Conversely, in rodents and in persons with inflammatory bowel disease, low-dose ursodeoxycholic acid treatment alters fecal bile acid composition and attenuates colon neoplasia. In the course of elucidating the mechanism underlying these actions, we discovered that bile acids interact functionally with intestinal muscarinic receptors. The present communication reviews muscarinic receptor expression in normal and neoplastic colon epithelium, the role of autocrine signaling following synthesis and release of acetylcholine from colon cancer cells, post-muscarinic receptor signaling including the role of transactivation of epidermal growth factor receptors and activation of the ERK and PI3K/AKT signaling pathways, the structural biology and metabolism of bile acids and evidence for functional interaction of bile acids with muscarinic receptors on human colon cancer cells. In murine colon cancer models, deficiency of subtype 3 muscarinic receptors attenuates intestinal neoplasia; a proof-of-concept supporting muscarinic receptor signaling as a therapeutic target for colon cancer

  10. Muscarinic Receptor Signaling in Colon Cancer

    Directory of Open Access Journals (Sweden)

    Jean-Pierre Raufman

    2011-03-01

    Full Text Available According to the adenoma-carcinoma sequence, colon cancer results from accumulating somatic gene mutations; environmental growth factors accelerate and augment this process. For example, diets rich in meat and fat increase fecal bile acids and colon cancer risk. In rodent cancer models, increased fecal bile acids promote colon dysplasia. Conversely, in rodents and in persons with inflammatory bowel disease, low-dose ursodeoxycholic acid treatment alters fecal bile acid composition and attenuates colon neoplasia. In the course of elucidating the mechanism underlying these actions, we discovered that bile acids interact functionally with intestinal muscarinic receptors. The present communication reviews muscarinic receptor expression in normal and neoplastic colon epithelium, the role of autocrine signaling following synthesis and release of acetylcholine from colon cancer cells, post-muscarinic receptor signaling including the role of transactivation of epidermal growth factor receptors and activation of the ERK and PI3K/AKT signaling pathways, the structural biology and metabolism of bile acids and evidence for functional interaction of bile acids with muscarinic receptors on human colon cancer cells. In murine colon cancer models, deficiency of subtype 3 muscarinic receptors attenuates intestinal neoplasia; a proof-of-concept supporting muscarinic receptor signaling as a therapeutic target for colon cancer.

  11. Psychopharmacology of 5-HT1A receptors

    International Nuclear Information System (INIS)

    Cowen, Philip J.

    2000-01-01

    Serotonin 1A (5-HT 1A ) receptors are located on both 5-HT cell bodies where they act as inhibitory autoreceptors and at postsynaptic sites where they mediate the effects of 5-HT released from nerve terminals. The sensitivity of 5-HT 1A receptors in humans can be measured using the technique of pharmacological challenge. For example, acute administration of a selective 5-HT 1A receptor agonist, such as ipsapirone, decreases body temperature and increases plasma cortisol through activation of pre- and postsynaptic 5-HT 1A receptors, respectively. Use of this technique has demonstrated that unmedicated patients with major depression have decreased sensitivity of both pre- and postsynaptic 5-HT 1A receptors. Treatment with selective serotonin reuptake inhibitors further down-regulates 5-HT 1A receptor activity. Due to the hypotheses linking decreased sensitivity of 5-HT 1A autoreceptors with the onset of antidepressant activity, there is current interest in the therapeutic efficacy of combined treatment with selective serotonin reuptake inhibitors and 5-HT 1A receptor antagonists

  12. Tachykinin receptors in the equine pelvic flexure

    International Nuclear Information System (INIS)

    Sonea, I.M.; Wilson, D.V.; Bowker, R.M.; Robinson, N.E.

    1997-01-01

    Tachykinins, of which substance P (SP) is the prototype, are neuropeptides which are widely distributed in the nervous systems. In the equine gut, SP is present in enteric nerves and is a powerful constrictor of enteric muscle; in other species, SP is also known to have potent vasodilatory and pro-inflammatory effects. The specific effects of SP are determined by the subtype of receptor present in the target tissue. There are 3 known subtypes of tachykinin receptors, distinguished by their relative affinities for SP and other tachykinins. The distribution of SP binding sites in the equine pelvic flexure was determined using 125I-Bolton Hunter SP (I-BHSP) autoradiography. Most I-BHSP binding sites were determined to be saturable and specific, therefore presumably representing tachykinin receptors. The greatest degree of I-BHSP binding occurred over very small vessels, and over the muscularis mucosae; I-BHSP binding was also intense over the circular muscle of the muscularis externa and mucosa, and present, although less intense, over the longitudinal muscle of the muscularis externa. Competition of I-BHSP with specific receptor agonists for binding sites in the equine pelvic flexure were used to determine the subtypes of tachykinin receptors present. The neurokinin-1 receptor subtype predominated in the equine pelvic flexure, followed by the neurokinin-3 receptor subtype

  13. Pharmacological analysis of calcium antagonist receptors

    International Nuclear Information System (INIS)

    Reynolds, I.J.

    1987-01-01

    This work focuses on two aspects of the action of calcium antagonist drugs, namely, the interaction of drugs with receptors for verapamil-like calcium antagonists, and the interactions of drugs with voltage-sensitive calcium fluxes in rat brain synaptosomes. From binding studies I have found that the ligand of choice for labeling the verapamil receptor is (-)[ 3 H]desmethoxy-verapamil. This drug labels potently, reversibly and stereoselectively two receptors in membranes prepared from rat brain and rabbit skeletal muscle tissues. In equilibrium studies dihydropyridine calcium antagonists interact in a non-competitive fashion, while many non-DHPs are apparently competitive. In-depth kinetic studies in skeletal muscle membranes indicate that the two receptors are linked in a negative heterotropic fashion, and that low-affinity binding of (-) [ 3 H]desmethoxy-verapamil may be to the diltiazem receptor. However, these studies were not able to distinguish between the hypothesis that diltiazem binds to spatially separate, allosterically coupled receptors, and the hypothesis that diltiazem binds to a subsite of the verapamil receptor

  14. Andrographolide regulates epidermal growth factor receptor and transferrin receptor trafficking in epidermoid carcinoma (A-431) cells

    Science.gov (United States)

    Tan, Y; Chiow, KH; Huang, D; Wong, SH

    2010-01-01

    Background and purpose: Andrographolide is the active component of Andrographis paniculata, a plant used in both Indian and Chinese traditional medicine, and it has been demonstrated to induce apoptosis in different cancer cell lines. However, not much is known about how it may affect the key receptors implicated in cancer. Knowledge of how andrographolide affects receptor trafficking will allow us to better understand new mechanisms by which andrographolide may cause death in cancer cells. Experimental approach: We utilized the well-characterized epidermal growth factor receptor (EGFR) and transferrin receptor (TfR) expressed in epidermoid carcinoma (A-431) cells as a model to study the effect of andrographolide on receptor trafficking. Receptor distribution, the total number of receptors and surface receptors were analysed by immunofluorescence, Western blot as well as flow-cytometry respectively. Key results: Andrographolide treatment inhibited cell growth, down-regulated EGFRs on the cell surface and affected the degradation of EGFRs and TfRs. The EGFR was internalized into the cell at an increased rate, and accumulated in a compartment that co-localizes with the lysosomal-associated membrane protein in the late endosomes. Conclusion and implications: This study sheds light on how andrographolide may affect receptor trafficking by inhibiting receptor movement from the late endosomes to lysosomes. The down-regulation of EGFR from the cell surface also indicates a new mechanism by which andrographolide may induce cancer cell death. PMID:20233216

  15. Serotonin 5-HT4 receptors and forebrain cholinergic system: receptor expression in identified cell populations.

    Science.gov (United States)

    Peñas-Cazorla, Raúl; Vilaró, M Teresa

    2015-11-01

    Activation of serotonin 5-HT4 receptors has pro-cognitive effects on memory performance. The proposed underlying neurochemical mechanism is the enhancement of acetylcholine release in frontal cortex and hippocampus elicited by 5-HT4 agonists. Although 5-HT4 receptors are present in brain areas related to cognition, e.g., hippocampus and cortex, the cellular localization of the receptors that might modulate acetylcholine release is unknown at present. We have analyzed, using dual label in situ hybridization, the cellular localization of 5-HT4 receptor mRNA in identified neuronal populations of the rat basal forebrain, which is the source of the cholinergic innervation to cortex and hippocampus. 5-HT4 receptor mRNA was visualized with isotopically labeled oligonucleotide probes, whereas cholinergic, glutamatergic, GABAergic and parvalbumin-synthesizing neurons were identified with digoxigenin-labeled oligonucleotide probes. 5-HT4 receptor mRNA was not detected in the basal forebrain cholinergic cell population. In contrast, basal forebrain GABAergic, parvalbumin synthesizing, and glutamatergic cells contained 5-HT4 receptor mRNA. Hippocampal and cortical glutamatergic neurons also express this receptor. These results indicate that 5-HT4 receptors are not synthesized by cholinergic cells, and thus would be absent from cholinergic terminals. In contrast, several non-cholinergic cell populations within the basal forebrain and its target hippocampal and cortical areas express these receptors and are thus likely to mediate the enhancement of acetylcholine release elicited by 5-HT4 agonists.

  16. Calcitonin and calcitonin receptor-like receptors: common themes with family B GPCRs?

    Science.gov (United States)

    Barwell, James; Gingell, Joseph J; Watkins, Harriet A; Archbold, Julia K; Poyner, David R; Hay, Debbie L

    2012-05-01

    The calcitonin receptor (CTR) and calcitonin receptor-like receptor (CLR) are two of the 15 human family B (or Secretin-like) GPCRs. CTR and CLR are of considerable biological interest as their pharmacology is moulded by interactions with receptor activity-modifying proteins. They also have therapeutic relevance for many conditions, such as osteoporosis, diabetes, obesity, lymphatic insufficiency, migraine and cardiovascular disease. In light of recent advances in understanding ligand docking and receptor activation in both the family as a whole and in CLR and CTR specifically, this review reflects how applicable general family B GPCR themes are to these two idiosyncratic receptors. We review the main functional domains of the receptors; the N-terminal extracellular domain, the juxtamembrane domain and ligand interface, the transmembrane domain and the intracellular C-terminal domain. Structural and functional findings from the CLR and CTR along with other family B GPCRs are critically appraised to gain insight into how these domains may function. The ability for CTR and CLR to interact with receptor activity-modifying proteins adds another level of sophistication to these receptor systems but means careful consideration is needed when trying to apply generic GPCR principles. This review encapsulates current thinking in the realm of family B GPCR research by highlighting both conflicting and recurring themes and how such findings relate to two unusual but important receptors, CTR and CLR. © 2011 The Authors. British Journal of Pharmacology © 2011 The British Pharmacological Society.

  17. N-glycosylation of the β2 adrenergic receptor regulates receptor function by modulating dimerization.

    Science.gov (United States)

    Li, Xiaona; Zhou, Mang; Huang, Wei; Yang, Huaiyu

    2017-07-01

    N-glycosylation is a common post-translational modification of G-protein-coupled receptors (GPCRs). However, it remains unknown how N-glycosylation affects GPCR signaling. β 2 adrenergic receptor (β 2 AR) has three N-glycosylation sites: Asn6, Asn15 at the N-terminus, and Asn187 at the second extracellular loop (ECL2). Here, we show that deletion of the N-glycan did not affect receptor expression and ligand binding. Deletion of the N-glycan at the N-terminus rather than Asn187 showed decreased effects on isoproterenol-promoted G-protein-dependent signaling, β-arrestin2 recruitment, and receptor internalization. Both N6Q and N15Q showed decreased receptor dimerization, while N187Q did not influence receptor dimerization. As decreased β 2 AR homodimer accompanied with reduced efficiency for receptor function, we proposed that the N-glycosylation of β 2 AR regulated receptor function by influencing receptor dimerization. To verify this hypothesis, we further paid attention to the residues at the dimerization interface. Studies of Lys60 and Glu338, two residues at the receptor dimerization interface, exhibited that the K60A/E338A showed decreased β 2 AR dimerization and its effects on receptor signaling were similar to N6Q and N15Q, which further supported the importance of receptor dimerization for receptor function. This work provides new insights into the relationship among glycosylation, dimerization, and function of GPCRs. Peptide-N-glycosidase F (PNGase F, EC 3.2.2.11); endo-β-N-acetylglucosaminidase A (Endo-A, EC 3.2.1.96). © 2017 Federation of European Biochemical Societies.

  18. Evolution of endothelin receptors in vertebrates.

    Science.gov (United States)

    Braasch, Ingo; Schartl, Manfred

    2014-12-01

    Endothelin receptors are G protein coupled receptors (GPCRs) of the β-group of rhodopsin receptors that bind to endothelin ligands, which are 21 amino acid long peptides derived from longer prepro-endothelin precursors. The most basal Ednr-like GPCR is found outside vertebrates in the cephalochordate amphioxus, but endothelin ligands are only present among vertebrates, including the lineages of jawless vertebrates (lampreys and hagfishes), cartilaginous vertebrates (sharks, rays, and chimaeras), and bony vertebrates (ray-finned fishes and lobe-finned vertebrates including tetrapods). A bona fide endothelin system is thus a vertebrate-specific innovation with important roles for regulating the cardiovascular system, renal and pulmonary processes, as well as for the development of the vertebrate-specific neural crest cell population and its derivatives. Expectedly, dysregulation of endothelin receptors and the endothelin system leads to a multitude of human diseases. Despite the importance of different types of endothelin receptors for vertebrate development and physiology, current knowledge on endothelin ligand-receptor interactions, on the expression of endothelin receptors and their ligands, and on the functional roles of the endothelin system for embryonic development and in adult vertebrates is very much biased towards amniote vertebrates. Recent analyses from a variety of vertebrate lineages, however, have shown that the endothelin system in lineages such as teleost fish and lampreys is more diverse and is divergent from the mammalian endothelin system. This diversity is mainly based on differential evolution of numerous endothelin system components among vertebrate lineages generated by two rounds of whole genome duplication (three in teleosts) during vertebrate evolution. Here we review current understanding of the evolutionary history of the endothelin receptor family in vertebrates supplemented with surveys on the endothelin receptor gene complement of

  19. Role of adenosine receptors in caffeine tolerance

    Energy Technology Data Exchange (ETDEWEB)

    Holtzman, S.G.; Mante, S.; Minneman, K.P. (Emory Univ. School of Medicine, Atlanta, GA (USA))

    1991-01-01

    Caffeine is a competitive antagonist at adenosine receptors. Receptor up-regulation during chronic drug treatment has been proposed to be the mechanism of tolerance to the behavioral stimulant effects of caffeine. This study reassessed the role of adenosine receptors in caffeine tolerance. Separate groups of rats were given scheduled access to drinking bottles containing plain tap water or a 0.1% solution of caffeine. Daily drug intake averaged 60-75 mg/kg and resulted in complete tolerance to caffeine-induced stimulation of locomotor activity, which could not be surmounted by increasing the dose of caffeine. 5'-N-ethylcarboxamidoadenosine (0.001-1.0 mg/kg) dose dependently decreased the locomotor activity of caffeine-tolerant rats and their water-treated controls but was 8-fold more potent in the latter group. Caffeine (1.0-10 mg/kg) injected concurrently with 5-N-ethylcarboxamidoadenosine antagonized the decreases in locomotor activity comparably in both groups. Apparent pA2 values for tolerant and control rats also were comparable: 5.05 and 5.11. Thus, the adenosine-antagonist activity of caffeine was undiminished in tolerant rats. The effects of chronic caffeine administration on parameters of adenosine receptor binding and function were measured in cerebral cortex. There were no differences between brain tissue from control and caffeine-treated rats in number and affinity of adenosine binding sites or in receptor-mediated increases (A2 adenosine receptor) and decreases (A1 adenosine receptor) in cAMP accumulation. These results are consistent with theoretical arguments that changes in receptor density should not affect the potency of a competitive antagonist. Experimental evidence and theoretical considerations indicate that up-regulation of adenosine receptors is not the mechanism of tolerance to caffeine-induced stimulation of locomotor activity.

  20. Role of adenosine receptors in caffeine tolerance

    International Nuclear Information System (INIS)

    Holtzman, S.G.; Mante, S.; Minneman, K.P.

    1991-01-01

    Caffeine is a competitive antagonist at adenosine receptors. Receptor up-regulation during chronic drug treatment has been proposed to be the mechanism of tolerance to the behavioral stimulant effects of caffeine. This study reassessed the role of adenosine receptors in caffeine tolerance. Separate groups of rats were given scheduled access to drinking bottles containing plain tap water or a 0.1% solution of caffeine. Daily drug intake averaged 60-75 mg/kg and resulted in complete tolerance to caffeine-induced stimulation of locomotor activity, which could not be surmounted by increasing the dose of caffeine. 5'-N-ethylcarboxamidoadenosine (0.001-1.0 mg/kg) dose dependently decreased the locomotor activity of caffeine-tolerant rats and their water-treated controls but was 8-fold more potent in the latter group. Caffeine (1.0-10 mg/kg) injected concurrently with 5-N-ethylcarboxamidoadenosine antagonized the decreases in locomotor activity comparably in both groups. Apparent pA2 values for tolerant and control rats also were comparable: 5.05 and 5.11. Thus, the adenosine-antagonist activity of caffeine was undiminished in tolerant rats. The effects of chronic caffeine administration on parameters of adenosine receptor binding and function were measured in cerebral cortex. There were no differences between brain tissue from control and caffeine-treated rats in number and affinity of adenosine binding sites or in receptor-mediated increases (A2 adenosine receptor) and decreases (A1 adenosine receptor) in cAMP accumulation. These results are consistent with theoretical arguments that changes in receptor density should not affect the potency of a competitive antagonist. Experimental evidence and theoretical considerations indicate that up-regulation of adenosine receptors is not the mechanism of tolerance to caffeine-induced stimulation of locomotor activity

  1. Lactate Transport and Receptor Actions in Retina

    DEFF Research Database (Denmark)

    Kolko, Miriam; Vosborg, Fia; Henriksen, Jens Ulrik Lütken

    2016-01-01

    known as HCAR1, may contribute importantly to the control of retinal cell functions in health and disease. GPR81, a G-protein coupled receptor, is known to downregulate cAMP both in adipose and nervous tissue. The receptor also acts through other down-stream mechanisms to control functions......In retina, like in brain, lactate equilibrates across cell membranes via monocarboxylate transporters and in the extracellular space by diffusion, forming a basis for the action of lactate as a transmitter of metabolic signals. In the present paper, we argue that the lactate receptor GPR81, also...

  2. Transcriptional targets shared by estrogen receptor- related receptors (ERRs) and estrogen receptor (ER) alpha, but not by ERbeta.

    Science.gov (United States)

    Vanacker, J M; Pettersson, K; Gustafsson, J A; Laudet, V

    1999-01-01

    The physiological activities of estrogens are thought to be mediated by specific nuclear receptors, ERalpha and ERbeta. However, certain tissues, such as the bone, that are highly responsive to estrogens only express a low level of these receptors. Starting from this apparent contradiction, we have evaluated the potentials of two related receptors ERRalpha and ERRbeta to intervene in estrogen signaling. ERalpha, ERRalpha and ERRbeta bind to and activate transcription through both the classical estrogen response element (ERE) and the SF-1 response element (SFRE). In contrast, ERbeta DNA-binding and transcriptional activity is restricted to the ERE. Accordingly, the osteopontin gene promoter is stimulated through SFRE sequences, by ERRalpha as well as by ERalpha, but not by ERbeta. Analysis of the cross-talk within the ER/ERR subgroup of nuclear receptors thus revealed common targets but also functional differences between the two ERs. PMID:10428965

  3. Molecular modeling of ligand-receptor interactions in the OR5 olfactory receptor.

    Science.gov (United States)

    Singer, M S; Shepherd, G M

    1994-06-02

    Olfactory receptors belong to the superfamily of seven transmembrane domain, G protein-coupled receptors. In order to begin analysis of mechanisms of receptor activation, a computer model of the OR5 olfactory receptor has been constructed and compared with other members of this superfamily. We have tested docking of the odor molecule lyral, which is known to activate the OR5 receptor. The results point to specific ligand-binding residues on helices III through VII that form a binding pocket in the receptor. Some of these residues occupy sequence positions identical to ligand-binding residues conserved among other superfamily members. The results provide new insights into possible molecular mechanisms of odor recognition and suggest hypotheses to guide future experimental studies using site-directed mutagenesis.

  4. Dynamics of the actin cytoskeleton mediates receptor cross talk: An emerging concept in tuning receptor signaling

    Science.gov (United States)

    Mattila, Pieta K.; Batista, Facundo D.

    2016-01-01

    Recent evidence implicates the actin cytoskeleton in the control of receptor signaling. This may be of particular importance in the context of immune receptors, such as the B cell receptor, where dysregulated signaling can result in autoimmunity and malignancy. Here, we discuss the role of the actin cytoskeleton in controlling receptor compartmentalization, dynamics, and clustering as a means to regulate receptor signaling through controlling the interactions with protein partners. We propose that the actin cytoskeleton is a point of integration for receptor cross talk through modulation of protein dynamics and clustering. We discuss the implication of this cross talk via the cytoskeleton for both ligand-induced and low-level constitutive (tonic) signaling necessary for immune cell survival. PMID:26833785

  5. Receptor binding radiotracers for the angiotensin II receptor: radioiodinated [Sar1, Ile8]angiotensin II

    International Nuclear Information System (INIS)

    Gibson, R.E.; Beauchamp, H.T.; Fioravanti, C.; Brenner, N.; Burns, H.D.

    1994-01-01

    The potential for imaging the angiotensin II receptor was evaluated using the radioiodinated peptide antagonist [ 125 I][Sar 1 , Ile 8 ]angiotensin II. The radioligand provides a receptor-mediated signal in several tissues in rat (kidneys, adrenal and liver). The receptor-mediated signal of 3% ID/g kidney cortex should be sufficient to permit imaging, at least via SPECT. The radiotracer is sensitive to reductions in receptor concentration and can be used to define in vivo dose-occupancy curves of angiotensin II receptor ligands. Receptor-mediated images of [ 123 I][Sar 1 , Ile 8 ]angiotensin II were obtained in the rat kidney and Rhesus monkey liver. (author)

  6. Selective thyroid hormone receptor modulators

    Directory of Open Access Journals (Sweden)

    Girish Raparti

    2013-01-01

    Full Text Available Thyroid hormone (TH is known to have many beneficial effects on vital organs, but its extrapolation to be used therapeutically has been restricted by the fact that it does have concurrent adverse effects. Recent finding of various thyroid hormone receptors (TR isoforms and their differential pattern of tissue distribution has regained interest in possible use of TH analogues in therapeutics. These findings were followed by search of compounds with isoform-specific or tissue-specific action on TR. Studying the structure-activity relationship of TR led to the development of compounds like GC1 and KB141, which preferentially act on the β1 isoform of TR. More recently, eprotirome was developed and has been studied in humans. It has shown to be effective in dyslipidemia by the lipid-lowering action of TH in the liver and also in obesity. Another compound, 3,5-diiodothyropropionic acid (DITPA, binds to both α- and β-type TRs with relatively low affinity and has been shown to be effective in heart failure (HF. In postinfarction models of HF and in a pilot clinical study, DITPA increased cardiac performance without affecting the heart rate. TR antagonists like NH3 can be used in thyrotoxicosis and cardiac arrhythmias. However, further larger clinical trials on some of these promising compounds and development of newer compounds with increased selectivity is required to achieve higher precision of action and avoid adverse effects seen with TH.

  7. Endogenous Receptor Agonists: Resolving Inflammation

    Directory of Open Access Journals (Sweden)

    Gerhard Bannenberg

    2007-01-01

    Full Text Available Controlled resolution or the physiologic resolution of a well-orchestrated inflammatory response at the tissue level is essential to return to homeostasis. A comprehensive understanding of the cellular and molecular events that control the termination of acute inflammation is needed in molecular terms given the widely held view that aberrant inflammation underlies many common diseases. This review focuses on recent advances in the understanding of the role of arachidonic acid and ω-3 polyunsaturated fatty acids (PUFA–derived lipid mediators in regulating the resolution of inflammation. Using a functional lipidomic approach employing LC-MS-MS–based informatics, recent studies, reviewed herein, uncovered new families of local-acting chemical mediators actively biosynthesized during the resolution phase from the essential fatty acids eicosapentaenoic acid (EPA and docosahexaenoic acid (DHA. These new families of local chemical mediators are generated endogenously in exudates collected during the resolution phase, and were coined resolvins and protectins because specific members of these novel chemical families control both the duration and magnitude of inflammation in animal models of complex diseases. Recent advances on the biosynthesis, receptors, and actions of these novel anti-inflammatory and proresolving lipid mediators are reviewed with the aim to bring to attention the important role of specific lipid mediators as endogenous agonists in inflammation resolution.

  8. Teleost Chemokines and Their Receptors

    Directory of Open Access Journals (Sweden)

    Steve Bird

    2015-11-01

    Full Text Available Chemokines are a superfamily of cytokines that appeared about 650 million years ago, at the emergence of vertebrates, and are responsible for regulating cell migration under both inflammatory and physiological conditions. The first teleost chemokine gene was reported in rainbow trout in 1998. Since then, numerous chemokine genes have been identified in diverse fish species evidencing the great differences that exist among fish and mammalian chemokines, and within the different fish species, as a consequence of extensive intrachromosomal gene duplications and different infectious experiences. Subsequently, it has only been possible to establish clear homologies with mammalian chemokines in the case of some chemokines with well-conserved homeostatic roles, whereas the functionality of other chemokine genes will have to be independently addressed in each species. Despite this, functional studies have only been undertaken for a few of these chemokine genes. In this review, we describe the current state of knowledge of chemokine biology in teleost fish. We have mainly focused on those species for which more research efforts have been made in this subject, specially zebrafish (Danio rerio, rainbow trout (Oncorhynchus mykiss and catfish (Ictalurus punctatus, outlining which genes have been identified thus far, highlighting the most important aspects of their expression regulation and addressing any known aspects of their biological role in immunity. Finally, we summarise what is known about the chemokine receptors in teleosts and provide some analysis using recently available data to help characterise them more clearly.

  9. Modulating Estrogen Receptor-related Receptor-α Activity Inhibits Cell Proliferation*

    OpenAIRE

    Bianco, Stéphanie; Lanvin, Olivia; Tribollet, Violaine; Macari, Claire; North, Sophie; Vanacker, Jean-Marc

    2009-01-01

    High expression of the estrogen receptor-related receptor (ERR)-α in human tumors is correlated to a poor prognosis, suggesting an involvement of the receptor in cell proliferation. In this study, we show that a synthetic compound (XCT790) that modulates the activity of ERRα reduces the proliferation of various cell lines and blocks the G1/S transition of the cell cycle in an ERR...

  10. Acetylcholine Receptor: Complex of Homologous Subunits

    Science.gov (United States)

    Raftery, Michael A.; Hunkapiller, Michael W.; Strader, Catherine D.; Hood, Leroy E.

    1980-06-01

    The acetylcholine receptor from the electric ray Torpedo californica is composed of five subunits; two are identical and the other three are structurally related to them. Microsequence analysis of the four polypeptides demonstrates amino acid homology among the subunits. Further sequence analysis of both membrane-bound and Triton-solubilized, chromatographically purified receptor gave the stoichiometry of the four subunits (40,000:50,000:60,000:65,000 daltons) as 2:1:1:1, indicating that this protein is a pentameric complex with a molecular weight of 255,000 daltons. Genealogical analysis suggests that divergence from a common ancestral gene occurred early in the evolution of the receptor. This shared ancestry argues that each of the four subunits plays a functional role in the receptor's physiological action.

  11. C-Type Lectin Receptors in Asthma

    Directory of Open Access Journals (Sweden)

    Sabelo Hadebe

    2018-04-01

    Full Text Available Asthma is a heterogeneous disease that affects approximately 300 million people worldwide, largely in developed countries. The etiology of the disease is poorly understood, but is likely to involve specific innate and adaptive responses to inhaled microbial components that are found in allergens. Fungal-derived allergens represent a major contributing factor in the initiation, persistence, exacerbation, and severity of allergic asthma. C-type lectin like receptors, such as dectin-1, dectin-2, DC-specific intercellular adhesion molecule 3-grabbing nonintegrin, and mannose receptor, recognize many fungal-derived allergens and other structurally similar allergens derived from house dust mites (HDM. In some cases, the fungal derived allergens have been structurally and functionally identified alongside their respective receptors in both humans and mice. In this review, we discuss recent understanding on how selected fungal and HDM derived allergens as well as their known or unknown receptors shape allergic airway diseases.

  12. Brain nuclear receptors and body weight regulation

    Science.gov (United States)

    Neural pathways, especially those in the hypothalamus, integrate multiple nutritional, hormonal, and neural signals, resulting in the coordinated control of body weight balance and glucose homeostasis. Nuclear receptors (NRs) sense changing levels of nutrients and hormones, and therefore play essent...

  13. Probing Biased Signaling in Chemokine Receptors

    DEFF Research Database (Denmark)

    Amarandi, Roxana Maria; Hjortø, Gertrud Malene; Rosenkilde, Mette Marie

    2016-01-01

    The chemokine system mediates leukocyte migration during homeostatic and inflammatory processes. Traditionally, it is described as redundant and promiscuous, with a single chemokine ligand binding to different receptors and a single receptor having several ligands. Signaling of chemokine receptors...... of others has been termed signaling bias and can accordingly be grouped into ligand bias, receptor bias, and tissue bias. Bias has so far been broadly overlooked in the process of drug development. The low number of currently approved drugs targeting the chemokine system, as well as the broad range...... of failed clinical trials, reflects the need for a better understanding of the chemokine system. Thus, understanding the character, direction, and consequence of biased signaling in the chemokine system may aid the development of new therapeutics. This review describes experiments to assess G protein...

  14. Tripodal receptors for cation and anion sensors

    NARCIS (Netherlands)

    Kuswandi, Bambang; Nuriman, [Unknown; Verboom, Willem; Reinhoudt, David

    2006-01-01

    This review discusses different types of artificial tripodal receptors for the selectiverecognition and sensing of cations and anions. Examples on the relationship between structure andselectivity towards cations and anions are described. Furthermore, their applications as potentiometricion sensing

  15. Fluctuation correlation models for receptor immobilization

    Science.gov (United States)

    Fourcade, B.

    2017-12-01

    Nanoscale dynamics with cycles of receptor diffusion and immobilization by cell-external-or-internal factors is a key process in living cell adhesion phenomena at the origin of a plethora of signal transduction pathways. Motivated by modern correlation microscopy approaches, the receptor correlation functions in physical models based on diffusion-influenced reaction is studied. Using analytical and stochastic modeling, this paper focuses on the hybrid regime where diffusion and reaction are not truly separable. The time receptor autocorrelation functions are shown to be indexed by different time scales and their asymptotic expansions are given. Stochastic simulations show that this analysis can be extended to situations with a small number of molecules. It is also demonstrated that this analysis applies when receptor immobilization is coupled to environmental noise.

  16. Mediator-dependent Nuclear Receptor Functions

    Science.gov (United States)

    Chen, Wei; Roeder, Robert

    2011-01-01

    As gene-specific transcription factors, nuclear hormone receptors are broadly involved in many important biological processes. Their function on target genes requires the stepwise assembly of different coactivator complexes that facilitate chromatin remodeling and subsequent preinitiation complex (PIC) formation and function. Mediator has proved to be a crucial, and general, nuclear receptor-interacting coactivator, with demonstrated functions in transcription steps ranging from chromatin remodeling to subsequent PIC formation and function. Here we discuss (i) our current understanding of pathways that nuclear receptors and other interacting cofactors employ to recruit Mediator to target gene enhancers and promoters, including conditional requirements for the strong NR-Mediator interactions mediated by the NR AF2 domain and the MED1 LXXLLL motifs and (ii) mechanisms by which Mediator acts to transmit signals from enhancer-bound nuclear receptors to the general transcription machinery at core promoters to effect PIC formation and function. PMID:21854863

  17. Recurrent LDL-receptor mutation causes familial ...

    African Journals Online (AJOL)

    1995-05-05

    May 5, 1995 ... 3. eaudet . New. Recurrent LDL-receptor mutation causes familial hypercholesterolaemia in ... amplification refractory mutation system (ARMS)" and single- strand conformation .... Location. Afrikaner. Mixed race. ApaLl.

  18. Androgen Receptor Signaling in Bladder Cancer

    Science.gov (United States)

    Li, Peng; Chen, Jinbo; Miyamoto, Hiroshi

    2017-01-01

    Emerging preclinical findings have indicated that steroid hormone receptor signaling plays an important role in bladder cancer outgrowth. In particular, androgen-mediated androgen receptor signals have been shown to correlate with the promotion of tumor development and progression, which may clearly explain some sex-specific differences in bladder cancer. This review summarizes and discusses the available data, suggesting the involvement of androgens and/or the androgen receptor pathways in urothelial carcinogenesis as well as tumor growth. While the precise mechanisms of the functions of the androgen receptor in urothelial cells remain far from being fully understood, current evidence may offer chemopreventive or therapeutic options, using androgen deprivation therapy, in patients with bladder cancer. PMID:28241422

  19. Androgen Receptor Signaling in Bladder Cancer

    Directory of Open Access Journals (Sweden)

    Peng Li

    2017-02-01

    Full Text Available Emerging preclinical findings have indicated that steroid hormone receptor signaling plays an important role in bladder cancer outgrowth. In particular, androgen-mediated androgen receptor signals have been shown to correlate with the promotion of tumor development and progression, which may clearly explain some sex-specific differences in bladder cancer. This review summarizes and discusses the available data, suggesting the involvement of androgens and/or the androgen receptor pathways in urothelial carcinogenesis as well as tumor growth. While the precise mechanisms of the functions of the androgen receptor in urothelial cells remain far from being fully understood, current evidence may offer chemopreventive or therapeutic options, using androgen deprivation therapy, in patients with bladder cancer.

  20. Molecular Mechanisms of Dopamine Receptor Mediated Neuroprotection

    National Research Council Canada - National Science Library

    Sealfon, Stuart

    2000-01-01

    ... of the cellular changes characteristic of this process. Evidence from our laboratory and others suggest that activation of dopamine receptors can oppose the induction of apoptosis in dopamine neurons...

  1. Agonism and antagonism at the insulin receptor

    DEFF Research Database (Denmark)

    Knudsen, Louise; Hansen, Bo Falck; Jensen, Pia

    2012-01-01

    Insulin can trigger metabolic as well as mitogenic effects, the latter being pharmaceutically undesirable. An understanding of the structure/function relationships between insulin receptor (IR) binding and mitogenic/metabolic signalling would greatly facilitate the preclinical development of new...... insulin analogues. The occurrence of ligand agonism and antagonism is well described for G protein-coupled receptors (GPCRs) and other receptors but in general, with the exception of antibodies, not for receptor tyrosine kinases (RTKs). In the case of the IR, no natural ligand or insulin analogue has been...... shown to exhibit antagonistic properties, with the exception of a crosslinked insulin dimer (B29-B'29). However, synthetic monomeric or dimeric peptides targeting sites 1 or 2 of the IR were shown to be either agonists or antagonists. We found here that the S961 peptide, previously described to be an IR...

  2. Ecdysteroid receptors in Drosophila melanogaster adult females

    Science.gov (United States)

    Ecdysteroid receptors were identified and partially characterized from total cell extracts of whole animals and dissected tissues from Drosophila melanogaster adult females. Binding studies indicated the presence of two ecdysteroid binding components having high affinity and specificity consistent w...

  3. Dopamine receptors - physiological understanding to therapeutic intervention potential

    NARCIS (Netherlands)

    Emilien, G; Maloteaux, JM; Hoogenberg, K; Cragg, S

    1999-01-01

    There are two families of dopamine (DA) receptors, called D(1) and D(2), respectively. The D(1) family consists of D(1)- and D(5)-receptor subtypes and the D(2) family consists of D(2)-, D(3)-, and D(4)-receptor subtypes. The amino acid sequences of these receptors show that they all belong to a

  4. Dopamine receptors - physiological understanding to therapeutic intervention potential

    NARCIS (Netherlands)

    Emilien, G; Maloteaux, JM; Hoogenberg, K; Cragg, S

    There are two families of dopamine (DA) receptors, called D(1) and D(2), respectively. The D(1) family consists of D(1)- and D(5)-receptor subtypes and the D(2) family consists of D(2)-, D(3)-, and D(4)-receptor subtypes. The amino acid sequences of these receptors show that they all belong to a

  5. NK-1 receptor antagonists as anti-cancer drugs

    Indian Academy of Sciences (India)

    The substance P (SP)/neurokinin (NK)-1 receptor system plays an important role in cancer. SP promotes the proliferation of tumour cells, angiogenesis and the migration of tumour cells. We review the involvement of SP, the NK-1 receptor and NK-1 receptor antagonists in cancer. Tumour cells overexpress NK-1 receptors, ...

  6. The MC4 receptor and control of appetite

    NARCIS (Netherlands)

    Adan, R. A. H.; Tiesjema, B.; Hillebrand, J. J. G.; La Fleur, S. E.; Kas, M. J. H.; de Krom, M.

    2006-01-01

    Mutations in the human melanocortin (MC)4 receptor have been associated with obesity, which underscores the relevance of this receptor as a drug target to treat obesity. Infusion of MC4R agonists decreases food intake, whereas inhibition of MC receptor activity by infusion of an MC receptor

  7. Clinical and Genomic Crosstalk between Glucocorticoid Receptor and Estrogen Receptor α In Endometrial Cancer

    Directory of Open Access Journals (Sweden)

    Jeffery M. Vahrenkamp

    2018-03-01

    Full Text Available Summary: Steroid hormone receptors are simultaneously active in many tissues and are capable of altering each other’s function. Estrogen receptor α (ER and glucocorticoid receptor (GR are expressed in the uterus, and their ligands have opposing effects on uterine growth. In endometrial tumors with high ER expression, we surprisingly found that expression of GR is associated with poor prognosis. Dexamethasone reduced normal uterine growth in vivo; however, this growth inhibition was abolished in estrogen-induced endometrial hyperplasia. We observed low genomic-binding site overlap when ER and GR are induced with their respective ligands; however, upon simultaneous induction they co-occupy more sites. GR binding is altered significantly by estradiol with GR recruited to ER-bound loci that become more accessible upon estradiol induction. Gene expression responses to co-treatment were more similar to estradiol but with additional regulated genes. Our results suggest phenotypic and molecular interplay between ER and GR in endometrial cancer. : Estrogen receptor α (ER and glucocorticoid receptor (GR are expressed in the uterus and have differential effects on growth. Vahrenkamp et al. find that expression of both receptors is associated with poor outcome in endometrial cancer and that simultaneous induction of ER and GR leads to molecular interplay between the receptors. Keywords: estrogen receptor, glucocorticoid receptor, endometrial cancer

  8. Targeting Discoidin Domain Receptors in Prostate Cancer

    Science.gov (United States)

    2017-08-01

    AWARD NUMBER: W81XWH-15-1-0226 TITLE: Targeting Discoidin Domain Receptors in Prostate Cancer PRINCIPAL INVESTIGATOR: Dr. Rafael Fridman...AND SUBTITLE 5a. CONTRACT NUMBER Targeting Discoidin Domain Receptors in Prostate Cancer 5b. GRANT NUMBER W81XWH-15-1-0226 5c. PROGRAM ELEMENT...response to collagen in prostate cancer. The project’s goal is to define the expression and therapeutic potential of DDRs in prostate cancer. During

  9. Agonist discrimination between AMPA receptor subtypes

    DEFF Research Database (Denmark)

    Coquelle, T; Christensen, J K; Banke, T G

    2000-01-01

    The lack of subtype-selective compounds for AMPA receptors (AMPA-R) led us to search for compounds with such selectivity. Homoibotenic acid analogues were investigated at recombinant GluR1o, GluR2o(R), GluR3o and GluR1o + 3o receptors expressed in Sf9 insect cells and affinities determined in [3H...

  10. Selectivity of Odorant Receptors in Insects

    Science.gov (United States)

    2012-07-13

    Luetje, C. W., and Robertson, H. M. (2007). A honey bee odorant receptor for the queen substance 9-oxo-2-decenoic acid. Proc. Natl. Acad. Sci. U.S.A...since they might be exposed to a greater number of pharmacolog- ically active compounds than other conventional ligand-gated ion channels and G- protein ...2008). Drosophila odorant receptors are novel seven transmembrane domain proteins that can signal independently of heterotrimeric G proteins

  11. Moth sex pheromone receptors and deceitful parapheromones.

    Directory of Open Access Journals (Sweden)

    Pingxi Xu

    Full Text Available The insect's olfactory system is so selective that male moths, for example, can discriminate female-produced sex pheromones from compounds with minimal structural modifications. Yet, there is an exception for this "lock-and-key" tight selectivity. Formate analogs can be used as replacement for less chemically stable, long-chain aldehyde pheromones, because male moths respond physiologically and behaviorally to these parapheromones. However, it remained hitherto unknown how formate analogs interact with aldehyde-sensitive odorant receptors (ORs. Neuronal responses to semiochemicals were investigated with single sensillum recordings. Odorant receptors (ORs were cloned using degenerate primers, and tested with the Xenopus oocyte expression system. Quality, relative quantity, and purity of samples were evaluated by gas chromatography and gas chromatography-mass spectrometry. We identified olfactory receptor neurons (ORNs housed in trichoid sensilla on the antennae of male navel orangeworm that responded equally to the main constituent of the sex pheromone, (11Z,13Z-hexadecadienal (Z11Z13-16Ald, and its formate analog, (9Z,11Z-tetradecen-1-yl formate (Z9Z11-14OFor. We cloned an odorant receptor co-receptor (Orco and aldehyde-sensitive ORs from the navel orangeworm, one of which (AtraOR1 was expressed specifically in male antennae. AtraOR1•AtraOrco-expressing oocytes responded mainly to Z11Z13-16Ald, with moderate sensitivity to another component of the sex pheromone, (11Z,13Z-hexadecadien-1-ol. Surprisingly, this receptor was more sensitive to the related formate than to the natural sex pheromone. A pheromone receptor from Heliothis virescens, HR13 ( = HvirOR13 showed a similar profile, with stronger responses elicited by a formate analog than to the natural sex pheromone, (11Z-hexadecenal thus suggesting this might be a common feature of moth pheromone receptors.

  12. Methodological aspects on drug receptor binding analysis

    International Nuclear Information System (INIS)

    Wahlstroem, A.

    1978-01-01

    Although drug receptors occur in relatively low concentrations, they can be visualized by the use of appropriate radioindicators. In most cases the procedure is rapid and can reach a high degree of accuracy. Specificity of the interaction is studied by competition analysis. The necessity of using several radioindicators to define a receptor population is emphasized. It may be possible to define isoreceptors and drugs with selectivity for one isoreceptor. (Author)

  13. Neurokinin-1 receptor activation in globus pallidus

    Directory of Open Access Journals (Sweden)

    Lei Chen

    2009-10-01

    Full Text Available The undecapeptide substance P has been demonstrated to modulate neuronal activity in a number of brain regions by acting on neurokinin-1 receptors. Anatomical studies revealed a moderate level of neurokinin-1 receptor in rat globus pallidus. To determine the electrophysiological effects of neurokinin-1 receptor activation in globus pallidus, whole-cell patch-clamp recordings were performed in the present study. Under current-clamp recordings, neurokinin-1 receptor agonist, [Sar9, Met(O211] substance P (SM-SP at 1 μM, depolarized globus pallidus neurons and increased their firing rate. Consistently, SM-SP induced an inward current under voltage-clamp recording. The depolarization evoked by SM-SP persisted in the presence of tetrodotoxin, glutamate and GABA receptor antagonists, indicating its direct postsynaptic effects. The neurokinin-1 receptor antagonist, SR140333B, could block SM-SP-induced depolarization. Further experiments showed that suppression of potassium conductance was the predominant ionic mechanism of SM-SP-induced depolarization. To determine if neurokinin-1 receptor activation exerts any effects on GABAergic and glutamatergic neurotransmission, the action of SM-SP on synaptic currents was studied. SM-SP significantly increased the frequency of spontaneous inhibitory postsynaptic currents, but only induced a transient increase in the frequency of miniature inhibitory postsynaptic currents. No change was observed in both spontaneous and miniature excitatory postsynaptic currents. Based on the direct excitatory effects of SM-SP on pallidal neurons, we hypothesize that neurokinin-1 receptor activation in globus pallidus may be involved in the beneficial effect of substance P in Parkinson’s disease.

  14. Expression of Plant Receptor Kinases in Tobacco BY-2 Cells.

    Science.gov (United States)

    Shinohara, Hidefumi; Matsubayashi, Yoshikatsu

    2017-01-01

    Although more than 600 single-transmembrane receptor kinase genes have been found in the Arabidopsis genome, only a few of them have known physiological functions, and even fewer plant receptor kinases have known specific ligands. Ligand-binding analysis must be operated using the functionally expressed receptor form. However, the relative abundance of native receptor kinase molecules in the plasma membrane is often quite low. Here, we present a method for stable and functional expression of plant receptor kinases in tobacco BY-2 cells that allows preparation of microsomal fractions containing the receptor. This procedure provides a sufficient amount of receptor proteins while maintaining its ligand-binding activities.

  15. Opioid receptor desensitization: mechanisms and its link to tolerance

    Directory of Open Access Journals (Sweden)

    Stéphane eAllouche

    2014-12-01

    Full Text Available Opioid receptors are part of the class A of G-protein coupled receptors and the target of the opiates, the most powerful analgesic molecules used in clinic. During a protracted use, a tolerance to analgesic effect develops resulting in a reduction of the effectiveness. So understanding mechanisms of tolerance is a great challenge and may help to find new strategies to tackle this side effect. This review will summarize receptor-related mechanisms that could underlie tolerance especially receptor desensitization. We will focus on the latest data obtained on molecular mechanisms involved in opioid receptor desensitization: phosphorylation, receptor uncoupling, internalization and post-endocytic fate of the receptor.

  16. Beta adrenergic receptors in human cavernous tissue

    Energy Technology Data Exchange (ETDEWEB)

    Dhabuwala, C.B.; Ramakrishna, C.V.; Anderson, G.F.

    1985-04-01

    Beta adrenergic receptor binding was performed with /sup 125/I iodocyanopindolol on human cavernous tissue membrane fractions from normal tissue and transsexual procedures obtained postoperatively, as well as from postmortem sources. Isotherm binding studies on normal fresh tissues indicated that the receptor density was 9.1 fmoles/mg. with a KD of 23 pM. Tissue stored at room temperature for 4 to 6 hours, then at 4C in saline solution for 19 to 20 hours before freezing showed no significant changes in receptor density or affinity, and provided evidence for the stability of postmortem tissue obtained within the same time period. Beta receptor density of 2 cavernous preparations from transsexual procedures was not significantly different from normal control tissues, and showed that high concentrations of estrogen received by these patients had no effect on beta adrenergic receptor density. Displacement of /sup 125/iodocyanopindolol by 5 beta adrenergic agents demonstrated that 1-propranolol had the greatest affinity followed by ICI 118,551, zinterol, metoprolol and practolol. When the results of these displacement studies were subjected to Scatfit, non- linear regression line analysis, a single binding site was described. Based on the relative potency of the selective beta adrenergic agents it appears that these receptors were of the beta 2 subtype.

  17. Targeting the TAM Receptors in Leukemia.

    Science.gov (United States)

    Huey, Madeline G; Minson, Katherine A; Earp, H Shelton; DeRyckere, Deborah; Graham, Douglas K

    2016-11-08

    Targeted inhibition of members of the TAM (TYRO-3, AXL, MERTK) family of receptor tyrosine kinases has recently been investigated as a novel strategy for treatment of hematologic malignancies. The physiologic functions of the TAM receptors in innate immune control, natural killer (NK) cell differentiation, efferocytosis, clearance of apoptotic debris, and hemostasis have previously been described and more recent data implicate TAM kinases as important regulators of erythropoiesis and megakaryopoiesis. The TAM receptors are aberrantly or ectopically expressed in many hematologic malignancies including acute myeloid leukemia, B- and T-cell acute lymphoblastic leukemia, chronic lymphocytic leukemia, and multiple myeloma. TAM receptors contribute to leukemic phenotypes through activation of pro-survival signaling pathways and interplay with other oncogenic proteins such as FLT3, LYN, and FGFR3. The TAM receptors also contribute to resistance to both cytotoxic chemotherapeutics and targeted agents, making them attractive therapeutic targets. A number of translational strategies for TAM inhibition are in development, including small molecule inhibitors, ligand traps, and monoclonal antibodies. Emerging areas of research include modulation of TAM receptors to enhance anti-tumor immunity, potential roles for TYRO-3 in leukemogenesis, and the function of the bone marrow microenvironment in mediating resistance to TAM inhibition.

  18. Corticosteroid receptors adopt distinct cyclical transcriptional signatures.

    Science.gov (United States)

    Le Billan, Florian; Amazit, Larbi; Bleakley, Kevin; Xue, Qiong-Yao; Pussard, Eric; Lhadj, Christophe; Kolkhof, Peter; Viengchareun, Say; Fagart, Jérôme; Lombès, Marc

    2018-05-07

    Mineralocorticoid receptors (MRs) and glucocorticoid receptors (GRs) are two closely related hormone-activated transcription factors that regulate major pathophysiologic functions. High homology between these receptors accounts for the crossbinding of their corresponding ligands, MR being activated by both aldosterone and cortisol and GR essentially activated by cortisol. Their coexpression and ability to bind similar DNA motifs highlight the need to investigate their respective contributions to overall corticosteroid signaling. Here, we decipher the transcriptional regulatory mechanisms that underlie selective effects of MRs and GRs on shared genomic targets in a human renal cellular model. Kinetic, serial, and sequential chromatin immunoprecipitation approaches were performed on the period circadian protein 1 ( PER1) target gene, providing evidence that both receptors dynamically and cyclically interact at the same target promoter in a specific and distinct transcriptional signature. During this process, both receptors regulate PER1 gene by binding as homo- or heterodimers to the same promoter region. Our results suggest a novel level of MR-GR target gene regulation, which should be considered for a better and integrated understanding of corticosteroid-related pathophysiology.-Le Billan, F., Amazit, L., Bleakley, K., Xue, Q.-Y., Pussard, E., Lhadj, C., Kolkhof, P., Viengchareun, S., Fagart, J., Lombès, M. Corticosteroid receptors adopt distinct cyclical transcriptional signatures.

  19. Functional reconstitution of the glycine receptor

    Energy Technology Data Exchange (ETDEWEB)

    Garcia-Calvo, M.; Ruiz-Gomez, A.; Vazquez, J.; Morato, E.; Valdivieso, F.; Mayor, F. Jr. (Universidad Autonoma de Madrid (Spain))

    1989-07-25

    The functional reconstitution of the chloride channel coupled glycine receptor is described. Glycine receptors were purified from the cholate extract of rat spinal cord membranes by affinity chromatography and incorporated into phospholipid vesicles by the addition of phosphatidylcholine and removal of detergent by gel filtration. The reconstituted vesicles showed the same polypeptide composition as the purified receptor. The pharmacological characteristics of the glycine receptor were also preserved in the proteoliposomes, as demonstrated by the displacement of ({sup 3}H)strychnine binding by several glycinergic ligands and by photoaffinity labeling experiments. In order to observe functional responses (i.e., specific agonist-induced anion translocation), the authors have developed an assay based on the fluorescence quenching of an anion-sensitive entrapped probe, SPQ (6-methoxy-N-(3-sulfopropyl)quinolinium). Reconstituted vesicles were loaded with the fluorescent probe during a freeze-thaw-sonication cycle in the presence of added liposomes containing cholesterol. In such a reconstituted system, glycine receptor agonists are able to increase the rate of anion influx into the vesicles. The action of agonists is blocked by the simultaneous presence of strychnine or other glycine antagonists. The results show that the purified 48,000- and 58,000-dalton polypeptides reconstituted into phospholipid vesicles can bind ligands and promote specific ion translocation in a way similar to the glycine receptor in its native environment.

  20. Purification of a putative brain somatostatin receptor

    International Nuclear Information System (INIS)

    He, Haitao; Johnson, K.; Thermos, K.; Reisine, T.

    1989-01-01

    The brain somatostatin receptor was purified by affinity chromatographic techniques. A protein of 60 kDa could be purified from rat brain. The protein was eluted from a [D-Trp 8 ]SRIF affinity column with either sodium acetate (pH 5.5) or free [D-Trp 8 ]SRIF. The binding of the protein to the affinity column was prevented by free [D-Trp 8 ]SRIF or the stable SRIF analogue SMS 201-996 but not by the inactive somatostatin 28-(1-14). The purified receptor could be covalently labeled by the 125 I-labeled SRIF analogue CGP 23996. Excess [D-Trp 8 ]SRIF blocked the binding of 125 I-labeled CGP 23996 to the purified receptor, but somatostatin 28-(1-14) did not affect the binding. A 60-kDa protein was also purified from the anterior pituitary cell line AtT-20, which has a high expression of SRIF receptors. In contrast, no 60-kDa protein could be purified from CHO cells, which have no detectable SRIF receptors. These findings present evidence for the purification of the SRIF receptor

  1. Targeting the TAM Receptors in Leukemia

    Directory of Open Access Journals (Sweden)

    Madeline G. Huey

    2016-11-01

    Full Text Available Targeted inhibition of members of the TAM (TYRO-3, AXL, MERTK family of receptor tyrosine kinases has recently been investigated as a novel strategy for treatment of hematologic malignancies. The physiologic functions of the TAM receptors in innate immune control, natural killer (NK cell differentiation, efferocytosis, clearance of apoptotic debris, and hemostasis have previously been described and more recent data implicate TAM kinases as important regulators of erythropoiesis and megakaryopoiesis. The TAM receptors are aberrantly or ectopically expressed in many hematologic malignancies including acute myeloid leukemia, B- and T-cell acute lymphoblastic leukemia, chronic lymphocytic leukemia, and multiple myeloma. TAM receptors contribute to leukemic phenotypes through activation of pro-survival signaling pathways and interplay with other oncogenic proteins such as FLT3, LYN, and FGFR3. The TAM receptors also contribute to resistance to both cytotoxic chemotherapeutics and targeted agents, making them attractive therapeutic targets. A number of translational strategies for TAM inhibition are in development, including small molecule inhibitors, ligand traps, and monoclonal antibodies. Emerging areas of research include modulation of TAM receptors to enhance anti-tumor immunity, potential roles for TYRO-3 in leukemogenesis, and the function of the bone marrow microenvironment in mediating resistance to TAM inhibition.

  2. Cloning the interleukin 1 receptor from human T cells

    International Nuclear Information System (INIS)

    Sims, J.E.; Acres, R.B.; Grubin, C.E.; McMahan, C.J.; Wignall, J.M.; March, C.J.; Dower, S.K.

    1989-01-01

    cDNA clones of the interleukin 1 (IL-1) receptor expressed in a human T-cell clone have been isolated by using a murine IL-1 receptor cDNA as a probe. The human and mouse receptors show a high degree of sequence conservation. Both are integral membrane proteins possessing a single membrane-spanning segment. Similar to the mouse receptor, the human IL-1 receptor contains a large cytoplasmic region and an extracellular, IL-1 binding portion composed of three immunoglobulin-like domains. When transfected into COS cells, the human IL-1 receptor cDNA clone leads to expression of two different affinity classes of receptors, with K a values indistinguishable from those determined for IL-1 receptors in the original T-cell clone. An IL-1 receptor expressed in human dermal fibroblasts has also been cloned and sequenced and found to be identical to the IL-1 receptor expressed in T cells

  3. Characterization of melanocortin receptor ligands on cloned brain melanocortin receptors and on grooming behavior in the rat

    NARCIS (Netherlands)

    Gispen, W.H.; Adan, R.A.H.; Szklarczyk, A.W.; Oosterom, J.; Brakkee, J.H.; Nijenhuis, W.A.; Schaaper, W.M.; Meloen, R.H.

    1999-01-01

    Since the melanocortin MC3 and melanocortin MC4 receptors are the main melanocortin receptor subtypes expressed in rat brain, we characterized the activity and affinity of nine melanocortin receptor ligands using these receptors in vitro, as well as their activity in a well-defined

  4. Receptor autoradiography in the hippocampus of man and rat

    International Nuclear Information System (INIS)

    Zilles, K.

    1988-01-01

    This chapter deals with the following questions: regional distribution of binding sites for 5-HT, glutamate, and acetylcholine in Ammon's horn and the dentate gyrus of rat and human brain; comparison of receptor distribution and neuronal pathways with identified transmitters; correlation of region-specific densities between different receptors and receptor subtypes (colocalization of different receptors on the level of hippocampal layers) and comparison of receptor distribution in human and rat hippocampus

  5. Determination of HIV-1 co-receptor usage.

    Science.gov (United States)

    Cavarelli, Mariangela; Scarlatti, Gabriella

    2014-01-01

    Human immunodeficiency virus type I (HIV-1) infects target cells through interaction with the CD4 molecule and chemokine receptors, mainly the β-chemokine receptor 5 (CCR5) and the α-chemokine receptor 4 (CXCR4). Viral isolates can be phenotypically classified based on the co-receptor they utilize to infect target cells. In this chapter, methods to determine the co-receptor usage of HIV-1 variants are described.

  6. Macrophage sub-populations and the lipoxin A4 receptor implicate active inflammation during equine tendon repair.

    Directory of Open Access Journals (Sweden)

    Stephanie Georgina Dakin

    Full Text Available Macrophages (Mφ orchestrate inflammatory and reparatory processes in injured connective tissues but their role during different phases of tendon healing is not known. We investigated the contribution of different Mφ subsets in an equine model of naturally occurring tendon injury. Post mortem tissues were harvested from normal (uninjured, sub-acute (3-6 weeks post injury and chronically injured (>3 months post injury superficial digital flexor tendons. To determine if inflammation was present in injured tendons, Mφ sub-populations were quantified based on surface antigen expression of CD172a (pan Mφ, CD14(highCD206(low (pro-inflammatory M1Mφ, and CD206(high (anti-inflammatory M2Mφ to assess potential polarised phenotypes. In addition, the Lipoxin A(4 receptor (FPR2/ALX was used as marker for resolving inflammation. Normal tendons were negative for both Mφ and FPR2/ALX. In contrast, M1Mφ predominated in sub-acute injury, whereas a potential phenotype-switch to M2Mφ polarity was seen in chronic injury. Furthermore, FPR2/ALX expression by tenocytes was significantly upregulated in sub-acute but not chronic injury. Expression of the FPR2/ALX ligand Annexin A1 was also significantly increased in sub-acute and chronic injuries in contrast to low level expression in normal tendons. The combination of reduced FPR2/ALX expression and persistence of the M2Mφ phenotype in chronic injury suggests a potential mechanism for incomplete resolution of inflammation after tendon injury. To investigate the effect of pro-inflammatory mediators on lipoxin A(4 (LXA(4 production and FPR2/ALX expression in vitro, normal tendon explants were stimulated with interleukin-1 beta and prostaglandin E(2. Stimulation with either mediator induced LXA(4 release and maximal upregulation of FPR2/ALX expression after 72 hours. Taken together, our data suggests that although tenocytes are capable of mounting a protective mechanism to counteract inflammatory stimuli, this

  7. Central alpha2 adrenergic receptors in the rat cerebral cortex: repopulation kinetics and receptor reserve

    International Nuclear Information System (INIS)

    Adler, C.H.

    1986-01-01

    The alpha 2 adrenergic receptor subtype is thought to play a role in the mechanism of action of antidepressant and antihypertensive drugs. This thesis has attempted to shed light on the regulation of central alpha 2 adrenergic receptors in the rat cerebral cortex. Repopulation kinetics analysis allows for the determination of the rate of receptor production, rate constant of degradation, and half-life of the receptor. This analysis was carried out using both radioligand binding and functional receptor assays at various times following the irreversible inactivation of central alpha 2 adrenergic receptors by in vivo administration of N-ethoxycarbonyl-2-ethyoxy-1,2-dihydroquinoline (EEDQ). Both alpha 2 agonist and antagonist ligand binding sites recovered with a t/sub 1/2/ equal to approximately 4 days. The function of alpha 2 adrenergic autoreceptors, which inhibit stimulation-evoked release of 3 H-norepinephrine ( 3 H-NE) and alpha 2 adrenergic heteroreceptors which inhibit stimulation-evoked release of 3 H-serotonin ( 3 H-5-HT) were assayed. The t/sub 1/2/ for recovery of maximal autoreceptor and heteroreceptor function was 2.4 days and 4.6 days, respectively. The demonstration of a receptor reserve is critical to the interpretation of past and future studies of the alpha 2 adrenergic receptor since it demonstrates that: (1) alterations in the number of alpha 2 adrenergic receptor binding sites cannot be extrapolated to the actual function of the alpha 2 adrenergic receptor; and (2) alterations in the number of alpha 2 receptors is not necessarily accompanied by a change in the maximum function being studied, but may only result in shifting of the dose-response curve

  8. Receptor downregulation and desensitization enhance the information processing ability of signalling receptors

    Directory of Open Access Journals (Sweden)

    Resat Haluk

    2007-11-01

    Full Text Available Abstract Background In addition to initiating signaling events, the activation of cell surface receptors also triggers regulatory processes that restrict the duration of signaling. Acute attenuation of signaling can be accomplished either via ligand-induced internalization of receptors (endocytic downregulation or via ligand-induced receptor desensitization. These phenomena have traditionally been viewed in the context of adaptation wherein the receptor system enters a refractory state in the presence of sustained ligand stimuli and thereby prevents the cell from over-responding to the ligand. Here we use the epidermal growth factor receptor (EGFR and G-protein coupled receptors (GPCR as model systems to respectively examine the effects of downregulation and desensitization on the ability of signaling receptors to decode time-varying ligand stimuli. Results Using a mathematical model, we show that downregulation and desensitization mechanisms can lead to tight and efficient input-output coupling thereby ensuring synchronous processing of ligand inputs. Frequency response analysis indicates that upstream elements of the EGFR and GPCR networks behave like low-pass filters with the system being able to faithfully transduce inputs below a critical frequency. Receptor downregulation and desensitization increase the filter bandwidth thereby enabling the receptor systems to decode inputs in a wider frequency range. Further, system-theoretic analysis reveals that the receptor systems are analogous to classical mechanical over-damped systems. This analogy enables us to metaphorically describe downregulation and desensitization as phenomena that make the systems more resilient in responding to ligand perturbations thereby improving the stability of the system resting state. Conclusion Our findings suggest that in addition to serving as mechanisms for adaptation, receptor downregulation and desensitization can play a critical role in temporal information

  9. The Cannabinoid Receptor CB1 Modulates the Signaling Properties of the Lysophosphatidylinositol Receptor GPR55*

    Science.gov (United States)

    Kargl, Julia; Balenga, Nariman; Parzmair, Gerald P.; Brown, Andrew J.; Heinemann, Akos; Waldhoer, Maria

    2012-01-01

    The G protein-coupled receptor (GPCR) 55 (GPR55) and the cannabinoid receptor 1 (CB1R) are co-expressed in many tissues, predominantly in the central nervous system. Seven transmembrane spanning (7TM) receptors/GPCRs can form homo- and heteromers and initiate distinct signaling pathways. Recently, several synthetic CB1 receptor inverse agonists/antagonists, such as SR141716A, AM251, and AM281, were reported to activate GPR55. Of these, SR141716A was marketed as a promising anti-obesity drug, but was withdrawn from the market because of severe side effects. Here, we tested whether GPR55 and CB1 receptors are capable of (i) forming heteromers and (ii) whether such heteromers could exhibit novel signaling patterns. We show that GPR55 and CB1 receptors alter each others signaling properties in human embryonic kidney (HEK293) cells. We demonstrate that the co-expression of FLAG-CB1 receptors in cells stably expressing HA-GPR55 specifically inhibits GPR55-mediated transcription factor activation, such as nuclear factor of activated T-cells and serum response element, as well as extracellular signal-regulated kinases (ERK1/2) activation. GPR55 and CB1 receptors can form heteromers, but the internalization of both receptors is not affected. In addition, we observe that the presence of GPR55 enhances CB1R-mediated ERK1/2 and nuclear factor of activated T-cell activation. Our data provide the first evidence that GPR55 can form heteromers with another 7TM/GPCR and that this interaction with the CB1 receptor has functional consequences in vitro. The GPR55-CB1R heteromer may play an important physiological and/or pathophysiological role in tissues endogenously co-expressing both receptors. PMID:23161546

  10. Pathophysiological consequences of receptor mistraffic: Tales from the platelet P2Y12 receptor.

    Science.gov (United States)

    Cunningham, Margaret R; Aungraheeta, Riyaad; Mundell, Stuart J

    2017-07-05

    Genetic variations in G protein-coupled receptor (GPCR) genes can disrupt receptor function in a wide variety of human genetic diseases, including platelet bleeding disorders. Platelets are critical for haemostasis with inappropriate platelet activation leading to the development of arterial thrombosis, which can result in heart attack and stroke whilst decreased platelet activity is associated with an increased risk of bleeding. GPCRs expressed on the surface of platelets play key roles in regulating platelet activity and therefore function. Receptors include purinergic receptors (P2Y 1 and P2Y 12 ), proteinase-activated receptor (PAR1 and PAR4) and thromboxane receptors (TPα), among others. Pharmacological blockade of these receptors forms a powerful therapeutic tool in the treatment and prevention of arterial thrombosis. With the advance of genomic technologies, there has been a substantial increase in the identification of naturally occurring rare and common GPCR variants. These variants include single-nucleotide polymorphisms (SNPs) and insertion or deletions that have the potential to alter GPCR expression or function. A number of defects in platelet GPCRs that disrupt receptor function have now been characterized in patients with mild bleeding disorders. This review will focus on rare, function-disrupting variants of platelet GPCRs with particular emphasis upon mutations in the P2Y 12 receptor gene that affect receptor traffic to modulate platelet function. Further this review will outline how the identification and characterization of function-disrupting GPCR mutations provides an essential link in translating our detailed understanding of receptor traffic and function in cell line studies into relevant human biological systems. Copyright © 2017. Published by Elsevier B.V.

  11. Atypical chemokine receptors in cancer: friends or foes?

    Science.gov (United States)

    Massara, Matteo; Bonavita, Ornella; Mantovani, Alberto; Locati, Massimo; Bonecchi, Raffaella

    2016-06-01

    The chemokine system is a fundamental component of cancer-related inflammation involved in all stages of cancer development. It controls not only leukocyte infiltration in primary tumors but also angiogenesis, cancer cell proliferation, and migration to metastatic sites. Atypical chemokine receptors are a new, emerging class of regulators of the chemokine system. They control chemokine bioavailability by scavenging, transporting, or storing chemokines. They can also regulate the activity of canonical chemokine receptors with which they share the ligands by forming heterodimers or by modulating their expression levels or signaling activity. Here, we summarize recent results about the role of these receptors (atypical chemokine receptor 1/Duffy antigen receptor for chemokine, atypical chemokine receptor 2/D6, atypical chemokine receptor 3/CXC-chemokine receptor 7, and atypical chemokine receptor 4/CC-chemokine receptor-like 1) on the tumorigenesis process, indicating that their effects are strictly dependent on the cell type on which they are expressed and on their coexpression with other chemokine receptors. Indeed, atypical chemokine receptors inhibit tumor growth and progression through their activity as negative regulators of chemokine bioavailability, whereas, on the contrary, they can promote tumorigenesis when they regulate the signaling of other chemokine receptors, such as CXC-chemokine receptor 4. Thus, atypical chemokine receptors are key components of the regulatory network of inflammation and immunity in cancer and may have a major effect on anti-inflammatory and immunotherapeutic strategies. © Society for Leukocyte Biology.

  12. Pharmacology and function of melatonin receptors

    International Nuclear Information System (INIS)

    Dubocovich, M.L.

    1988-01-01

    The hormone melatonin is secreted primarily from the pineal gland, with highest levels occurring during the dark period of a circadian cycle. This hormone, through an action in the brain, appears to be involved in the regulation of various neural and endocrine processes that are cued by the daily change in photoperiod. This article reviews the pharmacological characteristics and function of melatonin receptors in the central nervous system, and the role of melatonin in mediating physiological functions in mammals. Melatonin and melatonin agonists, at picomolar concentrations, inhibit the release of dopamine from retina through activation of a site that is pharmacologically different from a serotonin receptor. These inhibitory effects are antagonized by the novel melatonin receptor antagonist luzindole (N-0774), which suggests that melatonin activates a presynaptic melatonin receptor. In chicken and rabbit retina, the pharmacological characteristics of the presynaptic melatonin receptor and the site labeled by 2-[125I]iodomelatonin are identical. It is proposed that 2-[125I]iodomelatonin binding sites (e.g., chicken brain) that possess the pharmacological characteristics of the retinal melatonin receptor site (order of affinities: 2-iodomelatonin greater than 6-chloromelatonin greater than or equal to melatonin greater than or equal to 6,7-di-chloro-2-methylmelatonin greater than 6-hydroxymelatonin greater than or equal to 6-methoxymelatonin greater than N-acetyltryptamine greater than or equal to luzindole greater than N-acetyl-5-hydroxytryptamine greater than 5-methoxytryptamine much greater than 5-hydroxytryptamine) be classified as ML-1 (melatonin 1). The 2-[125I]iodomelatonin binding site of hamster brain membranes possesses different binding and pharmacological characteristics from the retinal melatonin receptor site and should be classified as ML-2. 64 references

  13. Constitutive dimerization of the G-protein coupled receptor, neurotensin receptor 1, reconstituted into phospholipid bilayers.

    Science.gov (United States)

    Harding, Peter J; Attrill, Helen; Boehringer, Jonas; Ross, Simon; Wadhams, George H; Smith, Eleanor; Armitage, Judith P; Watts, Anthony

    2009-02-01

    Neurotensin receptor 1 (NTS1), a Family A G-protein coupled receptor (GPCR), was expressed in Escherichia coli as a fusion with the fluorescent proteins eCFP or eYFP. A fluorophore-tagged receptor was used to study the multimerization of NTS1 in detergent solution and in brain polar lipid bilayers, using fluorescence resonance energy transfer (FRET). A detergent-solubilized receptor was unable to form FRET-competent complexes at concentrations of up to 200 nM, suggesting that the receptor is monomeric in this environment. When reconstituted into a model membrane system at low receptor density, the observed FRET was independent of agonist binding, suggesting constitutive multimer formation. In competition studies, decreased FRET in the presence of untagged NTS1 excludes the possibility of fluorescent protein-induced interactions. A simulation of the experimental data indicates that NTS1 exists predominantly as a homodimer, rather than as higher-order multimers. These observations suggest that, in common with several other Family A GPCRs, NTS1 forms a constitutive dimer in lipid bilayers, stabilized through receptor-receptor interactions in the absence of other cellular signaling components. Therefore, this work demonstrates that well-characterized model membrane systems are useful tools for the study of GPCR multimerization, allowing fine control over system composition and complexity, provided that rigorous control experiments are performed.

  14. The Orphan Nuclear Receptor TR4 Is a Vitamin A-activated Nuclear Receptor

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, X. Edward; Suino-Powell, Kelly M.; Xu, Yong; Chan, Cee-Wah; Tanabe, Osamu; Kruse, Schoen W.; Reynolds, Ross; Engel, James Douglas; Xu, H. Eric (Michigan-Med); (Van Andel)

    2015-11-30

    Testicular receptors 2 and 4 (TR2/4) constitute a subgroup of orphan nuclear receptors that play important roles in spermatogenesis, lipid and lipoprotein regulation, and the development of the central nervous system. Currently, little is known about the structural features and the ligand regulation of these receptors. Here we report the crystal structure of the ligand-free TR4 ligand binding domain, which reveals an autorepressed conformation. The ligand binding pocket of TR4 is filled by the C-terminal half of helix 10, and the cofactor binding site is occupied by the AF-2 helix, thus preventing ligand-independent activation of the receptor. However, TR4 exhibits constitutive transcriptional activity on multiple promoters, which can be further potentiated by nuclear receptor coactivators. Mutations designed to disrupt cofactor binding, dimerization, or ligand binding substantially reduce the transcriptional activity of this receptor. Importantly, both retinol and retinoic acid are able to promote TR4 to recruit coactivators and to activate a TR4-regulated reporter. These findings demonstrate that TR4 is a ligand-regulated nuclear receptor and suggest that retinoids might have a much wider regulatory role via activation of orphan receptors such as TR4.

  15. Soman- or kainic acid-induced convulsions decrease muscarinic receptors but not benzodiazepine receptors

    International Nuclear Information System (INIS)

    Churchill, L.; Pazdernik, T.L.; Cross, R.S.; Nelson, S.R.; Samson, F.E.

    1990-01-01

    [3H]Quinuclidinyl benzilate (QNB) binding to muscarinic receptors decreased in the rat forebrain after convulsions induced by a single dose of either soman, a potent inhibitor of acetylcholinesterase, or kainic acid, an excitotoxin. A Rosenthal plot revealed that the receptors decreased in number rather than affinity. When the soman-induced convulsions were blocked, the decrease in muscarinic receptors at 3 days was less extensive than when convulsions occurred and at 10 days they approached control levels in most of the brain areas. The most prominent decrements in QNB binding were in the piriform cortex where the decline in QNB binding is probably related to the extensive convulsion-associated neuropathology. The decrements in QNB binding after convulsions suggest that the convulsive state leads to a down-regulation of muscarinic receptors in some brain areas. In contrast to the decrease in QNB binding after convulsions, [3H]flunitrazepam binding to benzodiazepine receptors did not change even in the piriform cortex where the loss in muscarinic receptors was most prominent. Thus, it appears that those neuronal processes that bear muscarinic receptors are more vulnerable to convulsion-induced change than those with benzodiazepine receptors

  16. Ligand-independent recruitment of steroid receptor coactivators to estrogen receptor by cyclin D1

    NARCIS (Netherlands)

    Zwijsen, R.M.L.; Buckle, R.S.; Hijmans, E.M.; Loomans, C.J.M.; Bernards, R.A.

    1998-01-01

    The estrogen receptor (ER) is an important regulator of growth and differentiation of breast epithelium. Transactivation by ER depends on a leucine-rich motif, which constitutes a ligand-regulated binding site for steroid receptor coactivators (SRCs). Cyclin D1 is frequently amplified in breast

  17. The WSXWS motif in cytokine receptors is a molecular switch involved in receptor activation

    DEFF Research Database (Denmark)

    Dagil, Robert; Knudsen, Maiken J.; Olsen, Johan Gotthardt

    2012-01-01

    The prolactin receptor (PRLR) is activated by binding of prolactin in a 2:1 complex, but the activation mechanism is poorly understood. PRLR has a conserved WSXWS motif generic to cytokine class I receptors. We have determined the nuclear magnetic resonance solution structure of the membrane...

  18. Lipid raft integrity affects GABAA receptor, but not NMDA receptor modulation by psychopharmacological compounds.

    Science.gov (United States)

    Nothdurfter, Caroline; Tanasic, Sascha; Di Benedetto, Barbara; Uhr, Manfred; Wagner, Eva-Maria; Gilling, Kate E; Parsons, Chris G; Rein, Theo; Holsboer, Florian; Rupprecht, Rainer; Rammes, Gerhard

    2013-07-01

    Lipid rafts have been shown to play an important role for G-protein mediated signal transduction and the function of ligand-gated ion channels including their modulation by psychopharmacological compounds. In this study, we investigated the functional significance of the membrane distribution of NMDA and GABAA receptor subunits in relation to the accumulation of the tricyclic antidepressant desipramine (DMI) and the benzodiazepine diazepam (Diaz). In the presence of Triton X-100, which allowed proper separation of the lipid raft marker proteins caveolin-1 and flotillin-1 from the transferrin receptor, all receptor subunits were shifted to the non-raft fractions. In contrast, under detergent-free conditions, NMDA and GABAA receptor subunits were detected both in raft and non-raft fractions. Diaz was enriched in non-raft fractions without Triton X-100 in contrast to DMI, which preferentially accumulated in lipid rafts. Impairment of lipid raft integrity by methyl-β-cyclodextrine (MβCD)-induced cholesterol depletion did not change the inhibitory effect of DMI at the NMDA receptor, whereas it enhanced the potentiating effect of Diaz at the GABAA receptor at non-saturating concentrations of GABA. These results support the hypothesis that the interaction of benzodiazepines with the GABAA receptor likely occurs outside of lipid rafts while the antidepressant DMI acts on ionotropic receptors both within and outside these membrane microdomains.

  19. Homologous histamine H1 receptor desensitization results in reduction of H1 receptor agonist efficacy

    NARCIS (Netherlands)

    Leurs, R; Smit, M J; Bast, A; Timmerman, H

    1991-01-01

    Prolonged exposure of the guinea-pig intestinal longitudinal smooth muscle to histamine caused homologous desensitization of the H1 receptor, which led to reduced H1 receptor-mediated production of [3H]inositol phosphates as well as to reduced H1 agonist-induced contractions. [3H]Mepyramine binding

  20. Hormonal control of spermatogenesis: expression of FSJH receptor and androgen receptor genes

    NARCIS (Netherlands)

    L.J. Blok (Leen)

    1992-01-01

    textabstractFSH and testosterone are the main hormonal regulators of spermatogenesis. The actions of androgens and FSH are mediated by their respective receptors. Receptor gene expression (mRNA and protein). is an important determinant of hormone action. Biochemical aspects of the regulation of

  1. Arrestin scaffolds NHERF1 to the P2Y12 receptor to regulate receptor internalization.

    Science.gov (United States)

    Nisar, Shaista P; Cunningham, Margaret; Saxena, Kunal; Pope, Robert J; Kelly, Eamonn; Mundell, Stuart J

    2012-07-13

    We have recently shown in a patient with mild bleeding that the PDZ-binding motif of the platelet G protein-coupled P2Y(12) receptor (P2Y(12)R) is required for effective receptor traffic in human platelets. In this study we show for the first time that the PDZ motif-binding protein NHERF1 exerts a major role in potentiating G protein-coupled receptor (GPCR) internalization. NHERF1 interacts with the C-tail of the P2Y(12)R and unlike many other GPCRs, NHERF1 interaction is required for effective P2Y(12)R internalization. In vitro and prior to agonist stimulation P2Y(12)R/NHERF1 interaction requires the intact PDZ binding motif of this receptor. Interestingly on receptor stimulation NHERF1 no longer interacts directly with the receptor but instead binds to the receptor via the endocytic scaffolding protein arrestin. These findings suggest a novel model by which arrestin can serve as an adaptor to promote NHERF1 interaction with a GPCR to facilitate effective NHERF1-dependent receptor internalization.

  2. Multiple kisspeptin receptors in early Osteichthyans provide new insights into the evolution of this receptor family

    DEFF Research Database (Denmark)

    Pasquier, J.; Lafont, A._G.; Jeng, S.-R.

    2012-01-01

    Deorphanization of GPR54 receptor a decade ago led to the characterization of the kisspeptin receptor (Kissr) in mammals and the discovery of its major role in the brain control of reproduction. While a single gene encodes for Kissr in eutherian mammals including human, other vertebrates present ...

  3. Intracellular insulin-receptor dissociation and segregation in a rat fibroblast cell line transfected with a human insulin receptor gene

    International Nuclear Information System (INIS)

    Levy, J.R.; Olefsky, J.M.

    1988-01-01

    The cellular processing of insulin and insulin receptors was studied using a rat fibroblast cell line that had been transfected with a normal human insulin receptor gene, expressing approximately 500 times the normal number of native fibroblasts insulin receptors. These cells bind and internalize insulin normally. Biochemically assays based on the selective precipitation by polyethylene glycol of intact insulin-receptor complexes but not of free intracellular insulin were developed to study the time course of intracellular insulin-receptor dissociation. Fibroblasts were incubated with radiolabeled insulin at 4 0 C, and internalization of insulin-receptor complexes was initiated by warming the cells to 37 0 C. Within 2 min, 90% of the internalized radioactivity was composed of intact insulin-receptor complexes. The dissociation of insulin from internalized insulin-receptor complexes was markedly inhibited by monensin and chloroquine. Furthermore, chloroquine markedly increased the number of cross-linkable intracellular insulin-receptor complexes, as analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis autoradiography. These findings suggest that acidification of intracellular vesicles is responsible for insulin-receptor dissociation. Physical segregation of dissociated intracellular insulin from its receptor was monitored. The results are consistent with the view that segregation of insulin and receptor occurs 5-10 min after initiation of dissociation. These studies demonstrate the intracellular itinerary of insulin-receptor complexes, including internalization, dissociation of insulin from the internalized receptor within an acidified compartment, segregation of insulin from the receptor, and subsequent ligand degradation

  4. Interaction of chemokines with their receptors--from initial chemokine binding to receptor activating steps

    DEFF Research Database (Denmark)

    Thiele, Stefanie; Rosenkilde, Mette Marie

    2014-01-01

    and surveillance. Chemokines are a group of 8-12 kDa large peptides with a secondary structure consisting of a flexible N-terminus and a core-domain usually stabilized by two conserved disulfide bridges. They mainly interact with the extracellular domains of their cognate 7TM receptors. Affinityand activity......-contributing interactions are attributed to different domains and known to occur in two steps. Here, knowledge on chemokine and receptor domains involved in the first binding-step and the second activation-step is reviewed. A mechanism comprising at least two steps seems consistent; however, several intermediate...... interactions possibly occur, resulting in a multi-step process, as recently proposed for other 7TM receptors. Overall, the N-terminus of chemokine receptors is pivotal for binding of all chemokines. During receptor activation, differences between the two major chemokine subgroups occur, as CC-chemokines mainly...

  5. Quantitative autoradiographic mapping of serotonin receptors in the rat brain. II. Serotonin-2 receptors

    International Nuclear Information System (INIS)

    Pazos, A.; Cortes, R.; Palacios, J.M.

    1985-01-01

    The distribution of serotonin-2 (5-HT 2 ) receptors in the rat brain was studied by light microscopic quantitative autoradiography. Receptors were labeled with four ligands: [ 3 H]ketanserin, [ 3 H]mesulergine, [ 3 H]LSD and [ 3 H]spiperone, which are reported to show high affinity for 5-HT 2 receptors. Very high concentrations were localized in the claustrum, olfactory tubercle and layer IV of the neocortex. The anterior olfactory nucleus, piriform cortex and layer I of neocortex were also rich in 5-HT 2 receptors. The specificity of the different ligands used is discussed in terms of the other populations of sites recognized by them. The distribution of 5-HT 2 receptors here reported is discussed in correlation with (a) the known distribution of serotoninergic terminals, (b) the specific anatomical systems and (c) the central effects reported to be mediated by 5-HT 2 -selective drugs. (Auth.)

  6. Novel GABA receptor pesticide targets.

    Science.gov (United States)

    Casida, John E; Durkin, Kathleen A

    2015-06-01

    The γ-aminobutyric acid (GABA) receptor has four distinct but overlapping and coupled targets of pesticide action importantly associated with little or no cross-resistance. The target sites are differentiated by binding assays with specific radioligands, resistant strains, site-directed mutagenesis and molecular modeling. Three of the targets are for non-competitive antagonists (NCAs) or channel blockers of widely varied chemotypes. The target of the first generation (20th century) NCAs differs between the larger or elongated compounds (NCA-IA) including many important insecticides of the past (cyclodienes and polychlorocycloalkanes) or present (fiproles) and the smaller or compact compounds (NCA-IB) highly toxic to mammals and known as cage convulsants, rodenticides or chemical threat agents. The target of greatest current interest is designated NCA-II for the second generation (21st century) of NCAs consisting for now of isoxazolines and meta-diamides. This new and uniquely different NCA-II site apparently differs enough between insects and mammals to confer selective toxicity. The fourth target is the avermectin site (AVE) for allosteric modulators of the chloride channel. NCA pesticides vary in molecular surface area and solvent accessible volume relative to avermectin with NCA-IBs at 20-22%, NCA-IAs at 40-45% and NCA-IIs at 57-60%. The same type of relationship relative to ligand-docked length is 27-43% for NCA-IBs, 63-71% for NCA-IAs and 85-105% for NCA-IIs. The four targets are compared by molecular modeling for the Drosophila melanogaster GABA-R. The principal sites of interaction are proposed to be: pore V1' and A2' for NCA-IB compounds; pore A2', L6' and T9' for NCA-IA compounds; pore T9' to S15' in proximity to M1/M3 subunit interface (or alternatively an interstitial site) for NCA-II compounds; and M1/M3, M2 interfaces for AVE. Understanding the relationships of these four binding sites is important in resistance management and in the discovery and use

  7. G-protein coupling of cannabinoid receptors

    International Nuclear Information System (INIS)

    Glass, M.

    2001-01-01

    Full text: Since the cloning of the cannabinoid CB1 and CB2 receptors in the early 1990's extensive research has focused on understanding their signal transduction pathways. While it has been known for sometime that both receptors can couple to intracellular signalling via pertussis toxin sensitive G-proteins (Gi/Go), the specificity and kinetics of these interactions have only recently been elucidated. We have developed an in situ reconstitution approach to investigating receptor-G-protein interactions. This approach involves chaotropic extraction of receptor containing membranes in order to inactivate or remove endogenous G-proteins. Recombinant or isolated brain G-proteins can then be added back to the receptors, and their activation monitored through the binding of [ 35 S]-GTPγS. This technique has been utilised for an extensive study of cannabinoid receptor mediated activation of G-proteins. In these studies we have established that CB1 couples with high affinity to both Gi and Go type G-proteins. In contrast, CB2 couples strongly to Gi, but has a very low affinity for Go. This finding correlated well with the previous findings that while CB1 and CB2 both couple to the inhibition of adenylate cyclase, CB1 but not CB2 could also inhibit calcium channels. We then examined the ability of a range of cannabinoid agonists to activate the Gi and Go via CB1. Conventional receptor theory suggests that a receptor is either active or inactive with regard to a G-protein and that the active receptor activates all relevant G-proteins equally. However, in this study we found that agonists could produce different degrees of activation, depending on which G-protein was present. Further studies have compared the ability of the two endocannabinoids to drive the activation of Gi or Go. These studies show that agonists can induce multiple forms of activated receptor that differ in their ability to catalyse the activation of Gi or Go. The ability of an agonist to drive a receptor

  8. Radiolabelled GLP-1 receptor antagonist binds to GLP-1 receptor-expressing human tissues

    Energy Technology Data Exchange (ETDEWEB)

    Waser, Beatrice; Reubi, Jean Claude [University of Berne, Division of Cell Biology and Experimental Cancer Research, Institute of Pathology, PO Box 62, Berne (Switzerland)

    2014-06-15

    Radiolabelled glucagon-like peptide 1 (GLP-1) receptor agonists have recently been shown to successfully image benign insulinomas in patients. For the somatostatin receptor targeting of tumours, however, it was recently reported that antagonist tracers were superior to agonist tracers. The present study therefore evaluated various forms of the {sup 125}iodinated-Bolton-Hunter (BH)-exendin(9-39) antagonist tracer for the in vitro visualization of GLP-1 receptor-expressing tissues in rats and humans and compared it with the agonist tracer {sup 125}I-GLP-1(7-36)amide. Receptor autoradiography studies with {sup 125}I-GLP-1(7-36)amide agonist or {sup 125}I-BH-exendin(9-39) antagonist radioligands were performed in human and rat tissues. The antagonist {sup 125}I-BH-exendin(9-39) labelled at lysine 19 identifies all human and rat GLP-1 target tissues and GLP-1 receptor-expressing tumours. Binding is of high affinity and is comparable in all tested tissues in its binding properties with the agonist tracer {sup 125}I-GLP-1(7-36)amide. For comparison, {sup 125}I-BH-exendin(9-39) with the BH labelled at lysine 4 did identify the GLP-1 receptor in rat tissues but not in human tissues. The GLP-1 receptor antagonist exendin(9-39) labelled with {sup 125}I-BH at lysine 19 is an excellent GLP-1 radioligand that identifies human and rat GLP-1 receptors in normal and tumoural tissues. It may therefore be the molecular basis to develop suitable GLP-1 receptor antagonist radioligands for in vivo imaging of GLP-1 receptor-expressing tissues in patients. (orig.)

  9. Radiolabelled GLP-1 receptor antagonist binds to GLP-1 receptor-expressing human tissues

    International Nuclear Information System (INIS)

    Waser, Beatrice; Reubi, Jean Claude

    2014-01-01

    Radiolabelled glucagon-like peptide 1 (GLP-1) receptor agonists have recently been shown to successfully image benign insulinomas in patients. For the somatostatin receptor targeting of tumours, however, it was recently reported that antagonist tracers were superior to agonist tracers. The present study therefore evaluated various forms of the 125 iodinated-Bolton-Hunter (BH)-exendin(9-39) antagonist tracer for the in vitro visualization of GLP-1 receptor-expressing tissues in rats and humans and compared it with the agonist tracer 125 I-GLP-1(7-36)amide. Receptor autoradiography studies with 125 I-GLP-1(7-36)amide agonist or 125 I-BH-exendin(9-39) antagonist radioligands were performed in human and rat tissues. The antagonist 125 I-BH-exendin(9-39) labelled at lysine 19 identifies all human and rat GLP-1 target tissues and GLP-1 receptor-expressing tumours. Binding is of high affinity and is comparable in all tested tissues in its binding properties with the agonist tracer 125 I-GLP-1(7-36)amide. For comparison, 125 I-BH-exendin(9-39) with the BH labelled at lysine 4 did identify the GLP-1 receptor in rat tissues but not in human tissues. The GLP-1 receptor antagonist exendin(9-39) labelled with 125 I-BH at lysine 19 is an excellent GLP-1 radioligand that identifies human and rat GLP-1 receptors in normal and tumoural tissues. It may therefore be the molecular basis to develop suitable GLP-1 receptor antagonist radioligands for in vivo imaging of GLP-1 receptor-expressing tissues in patients. (orig.)

  10. Inhibition of insulin-like growth factor-1 receptor signaling enhances growth-inhibitory and proapoptotic effects of gefitinib (Iressa) in human breast cancer cells

    International Nuclear Information System (INIS)

    Camirand, Anne; Zakikhani, Mahvash; Young, Fiona; Pollak, Michael

    2005-01-01

    Gefitinib (Iressa, ZD 1839, AstraZeneca) blocks the tyrosine kinase activity of the epidermal growth factor receptor (EGFR) and inhibits proliferation of several human cancer cell types including breast cancer. Phase II clinical trials with gefitinib monotherapy showed an objective response of 9 to 19% in non-small-cell lung cancer patients and less than 10% for breast cancer, and phase III results have indicated no benefit of gefitinib in combination with chemotherapy over chemotherapy alone. In order to improve the antineoplastic activity of gefitinib, we investigated the effects of blocking the signalling of the insulin-like growth factor 1 receptor (IGF-1R), a tyrosine kinase with a crucial role in malignancy that is coexpressed with EGFR in most human primary breast carcinomas. AG1024 (an inhibitor of IGF-1R) was used with gefitinib for treatment of MDA468, MDA231, SK-BR-3, and MCF-7 breast cancer lines, which express similar levels of IGF-1R but varying levels of EGFR. Proliferation assays, apoptosis induction studies, and Western blot analyses were conducted with cells treated with AG1024 and gefitinib as single agents and in combination. Gefitinib and AG1024 reduced proliferation in all lines when used as single agents, and when used in combination revealed an additive-to-synergistic effect on cell growth inhibition. Flow cytometry measurements of cells stained with annexin V-propidium iodide and cells stained for caspase-3 activation indicated that adding an IGF-1R-targeting strategy to gefitinib results in higher levels of apoptosis than are achieved with gefitinib alone. Gefitinib either reduced or completely inhibited p42/p44 Erk kinase phosphorylation, depending on the cell line, while Akt phosphorylation was reduced by a combination of the two agents. Overexpression of IGF-1R in SK-BR-3 cells was sufficient to cause a marked enhancement in gefitinib resistance. These results indicate that IGF-1R signaling reduces the antiproliferative effects of

  11. Cocaine Disrupts Histamine H3 Receptor Modulation of Dopamine D1 Receptor Signaling: σ1-D1-H3 Receptor Complexes as Key Targets for Reducing Cocaine's Effects

    Science.gov (United States)

    Moreno, Estefanía; Moreno-Delgado, David; Navarro, Gemma; Hoffmann, Hanne M.; Fuentes, Silvia; Rosell-Vilar, Santi; Gasperini, Paola; Rodríguez-Ruiz, Mar; Medrano, Mireia; Mallol, Josefa; Cortés, Antoni; Casadó, Vicent; Lluís, Carme; Ferré, Sergi; Ortiz, Jordi; Canela, Enric

    2014-01-01

    The general effects of cocaine are not well understood at the molecular level. What is known is that the dopamine D1 receptor plays an important role. Here we show that a key mechanism may be cocaine's blockade of the histamine H3 receptor-mediated inhibition of D1 receptor function. This blockade requires the σ1 receptor and occurs upon cocaine binding to σ1-D1-H3 receptor complexes. The cocaine-mediated disruption leaves an uninhibited D1 receptor that activates Gs, freely recruits β-arrestin, increases p-ERK 1/2 levels, and induces cell death when over activated. Using in vitro assays with transfected cells and in ex vivo experiments using both rats acutely treated or self-administered with cocaine along with mice depleted of σ1 receptor, we show that blockade of σ1 receptor by an antagonist restores the protective H3 receptor-mediated brake on D1 receptor signaling and prevents the cell death from elevated D1 receptor signaling. These findings suggest that a combination therapy of σ1R antagonists with H3 receptor agonists could serve to reduce some effects of cocaine. PMID:24599455

  12. Multiple autophosphorylation sites of the epidermal growth factor receptor are essential for receptor kinase activity and internalization. Contrasting significance of tyrosine 992 in the native and truncated receptors

    DEFF Research Database (Denmark)

    Sorkin, A; Helin, K; Waters, C M

    1992-01-01

    The role of epidermal growth factor (EGF) receptor autophosphorylation sites in the regulation of receptor functions has been studied using cells transfected with mutant EGF receptors. Simultaneous point mutation of 4 tyrosines (Y1068, Y1086, Y1148, Y1173) to phenylalanine, as well as removal of ...

  13. Sex Hormone Receptor Repertoire in Breast Cancer

    Directory of Open Access Journals (Sweden)

    Gerald M. Higa

    2013-01-01

    Full Text Available Classification of breast cancer as endocrine sensitive, hormone dependent, or estrogen receptor (ER positive refers singularly to ERα. One of the oldest recognized tumor targets, disruption of ERα-mediated signaling, is believed to be the mechanistic mode of action for all hormonal interventions used in treating this disease. Whereas ERα is widely accepted as the single most important predictive factor (for response to endocrine therapy, the presence of the receptor in tumor cells is also of prognostic value. Even though the clinical relevance of the two other sex hormone receptors, namely, ERβ and the androgen receptor remains unclear, two discordant phenomena observed in hormone-dependent breast cancers could be causally related to ERβ-mediated effects and androgenic actions. Nonetheless, our understanding of regulatory molecules and resistance mechanisms remains incomplete, further compromising our ability to develop novel therapeutic strategies that could improve disease outcomes. This review focuses on the receptor-mediated actions of the sex hormones in breast cancer.

  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. Medicinal Chemistry of Competitive Kainate Receptor Antagonists

    Science.gov (United States)

    2010-01-01

    Kainic acid (KA) receptors belong to the group of ionotropic glutamate receptors and are expressed throughout in the central nervous system (CNS). The KA receptors have been shown to be involved in neurophysiological functions such as mossy fiber long-term potentiation (LTP) and synaptic plasticity and are thus potential therapeutic targets in CNS diseases such as schizophrenia, major depression, neuropathic pain and epilepsy. Extensive effort has been made to develop subtype-selective KA receptor antagonists in order to elucidate the physiological function of each of the five subunits known (GluK1−5). However, to date only selective antagonists for the GluK1 subunit have been discovered, which underlines the strong need for continued research in this area. The present review describes the structure−activity relationship and pharmacological profile for 10 chemically distinct classes of KA receptor antagonists comprising, in all, 45 compounds. To the medicinal chemist this information will serve as reference guidance as well as an inspiration for future effort in this field. PMID:22778857

  16. Different endothelin receptor affinities in dog tissues

    International Nuclear Information System (INIS)

    Loeffler, B.M.L.; Loehrer, W.

    1991-01-01

    Endothelin (ET) is a long-lasting potent vasoconstrictor-peptide. Here the authors report different binding affinities of endothelin-1 (ET-1) to ET-receptors of various dog tissues. Crude microsomal fractions were prepared after homogenisation of dog tissues in 50 mM Tris/HCl, 20 mM MnCl2, 1 mM EDTA, pH 7.4 by differential centrifugation. Aliquots of microsomal fractions (70 micrograms of protein) were incubated at 25 degrees C for 180 min in the presence of 20 pM 125I-ET-1 and various concentrations of cold ET-1. Four different ET-1 receptor binding affinities were found: adrenals, cerebrum, liver, heart, skeletal muscle and stomach microsomal membranes contained high affinity binding sites (Kd 50 - 80 pM, Bmax 60 - 250 fmol/mg). In cerebellum and spleen medium affinity ET-1 receptors (Kd 350 pM, Bmax 880 and 1200 fmol/mg respectively) were present. In comparison lung and kidney microsomes contained a low affinity ET-1 receptor (Kd 800 and 880 pM, Bmax 1600 and 350 fmol/mg). Receptors of even lower affinity were present in heart, intestine and liver microsomes with Kd values of 3 - 6 nM

  17. Erythropoietin Receptor Signaling Is Membrane Raft Dependent

    Science.gov (United States)

    McGraw, Kathy L.; Fuhler, Gwenny M.; Johnson, Joseph O.; Clark, Justine A.; Caceres, Gisela C.; Sokol, Lubomir; List, Alan F.

    2012-01-01

    Upon erythropoietin (Epo) engagement, Epo-receptor (R) homodimerizes to activate JAK2 and Lyn, which phosphorylate STAT5. Although recent investigations have identified key negative regulators of Epo-R signaling, little is known about the role of membrane localization in controlling receptor signal fidelity. Here we show a critical role for membrane raft (MR) microdomains in creation of discrete signaling platforms essential for Epo-R signaling. Treatment of UT7 cells with Epo induced MR assembly and coalescence. Confocal microscopy showed that raft aggregates significantly increased after Epo stimulation (mean, 4.3±1.4(SE) vs. 25.6±3.2 aggregates/cell; p≤0.001), accompanied by a >3-fold increase in cluster size (p≤0.001). Raft fraction immunoblotting showed Epo-R translocation to MR after Epo stimulation and was confirmed by fluorescence microscopy in Epo stimulated UT7 cells and primary erythroid bursts. Receptor recruitment into MR was accompanied by incorporation of JAK2, Lyn, and STAT5 and their activated forms. Raft disruption by cholesterol depletion extinguished Epo induced Jak2, STAT5, Akt and MAPK phosphorylation in UT7 cells and erythroid progenitors. Furthermore, inhibition of the Rho GTPases Rac1 or RhoA blocked receptor recruitment into raft fractions, indicating a role for these GTPases in receptor trafficking. These data establish a critical role for MR in recruitment and assembly of Epo-R and signal intermediates into discrete membrane signaling units. PMID:22509308

  18. NMDA Receptors in Glial Cells: Pending Questions.

    Science.gov (United States)

    Dzamba, David; Honsa, Pavel; Anderova, Miroslava

    2013-05-01

    Glutamate receptors of the N-methyl-D-aspartate (NMDA) type are involved in many cognitive processes, including behavior, learning and synaptic plasticity. For a long time NMDA receptors were thought to be the privileged domain of neurons; however, discoveries of the last 25 years have demonstrated their active role in glial cells as well. Despite the large number of studies in the field, there are many unresolved questions connected with NMDA receptors in glia that are still a matter of debate. The main objective of this review is to shed light on these controversies by summarizing results from all relevant works concerning astrocytes, oligodendrocytes and polydendrocytes (also known as NG2 glial cells) in experimental animals, further extended by studies performed on human glia. The results are divided according to the study approach to enable a better comparison of how findings obtained at the mRNA level correspond with protein expression or functionality. Furthermore, special attention is focused on the NMDA receptor subunits present in the particular glial cell types, which give them special characteristics different from those of neurons - for example, the absence of Mg(2+) block and decreased Ca(2+) permeability. Since glial cells are implicated in important physiological and pathophysiological roles in the central nervous system (CNS), the last part of this review provides an overview of glial NMDA receptors with respect to ischemic brain injury.

  19. Responses to microbial challenges by SLAMF receptors

    Directory of Open Access Journals (Sweden)

    Boaz Job Van Driel

    2016-01-01

    Full Text Available The SLAMF Family (SLAMF of cell surface glycoproteins is comprised of nine glycoproteins and whilst SLAMF1, 3, 5, 6, 7, 8, 9 are self-ligand receptors, SLAMF2 and SLAMF4 interact with each other. Their interactions induce signal transduction networks in trans, thereby shaping immune cell-cell communications. Collectively, these receptors modulate a wide range of functions, such as myeloid cell and lymphocyte development and, T and B cell responses to microbes and parasites. In addition, several SLAMF receptors serve as microbial sensors, which either positively or negatively modulate the function of macrophages, dendritic cells, neutrophils and NK cells in response to microbial challenges. The SLAMF receptor-microbe interactions contribute both to intracellular microbicidal activity as well as to migration of phagocytes to the site of inflammation. In this review, we describe the current knowledge on how the SLAMF receptors and their specific adapters SAP and EAT-2 regulate innate and adaptive immune responses to microbes.

  20. Phenobarbital Meets Phosphorylation of Nuclear Receptors.

    Science.gov (United States)

    Negishi, Masahiko

    2017-05-01

    Phenobarbital was the first therapeutic drug to be characterized for its induction of hepatic drug metabolism. Essentially at the same time, cytochrome P450, an enzyme that metabolizes drugs, was discovered. After nearly 50 years of investigation, the molecular target of phenobarbital induction has now been delineated to phosphorylation at threonine 38 of the constitutive androstane receptor (NR1I3), a member of the nuclear receptor superfamily. Determining this mechanism has provided us with the molecular basis to understand drug induction of drug metabolism and disposition. Threonine 38 is conserved as a phosphorylation motif in the majority of both mouse and human nuclear receptors, providing us with an opportunity to integrate diverse functions of nuclear receptors. Here, I review the works and accomplishments of my laboratory at the National Institutes of Health National Institute of Environmental Health Sciences and the future research directions of where our study of the constitutive androstane receptor might take us. U.S. Government work not protected by U.S. copyright.

  1. T3 receptors in human pituitary tumors.

    Science.gov (United States)

    Machiavelli, Gloria A; Pauni, Micaela; Heredia Sereno, Gastón M; Szijan, Irene; Basso, Armando; Burdman, José A

    2009-11-01

    The purpose of this work was to investigate the synthesis of T3 receptors in human tumors of the anterior pituitary gland, its relationship with the hormone synthesized and/or secreted by the tumor and the post-surgical evolution of the patient. Patients were evaluated clinically and by magnetic nuclear resonance to classify the adenoma according to their size. Hormonal concentrations in sera were determined by radioimmunoassay. Immunohistochemistry of the pituitary hormones was performed in the tumors. Tumors were obtained at surgery and immediately frozen in ice, transported to the laboratory and stored at -70 degrees C. Reverse transcription was performed with purified RNA from the tumors. Out of 33 pituitary tumors, 29 had RNA for T3 receptors synthesis (88%). They were present in different histological specimens, the tumors were grades 1-4 according to their size, and there was no relationship between the size of the tumor and the presence of T3 receptor RNAs. The post-surgical evolution of the patient was mostly dependent on the size and not on the presence of T3 receptors. The presence of thyroid hormone receptors in pituitary tumors is in line with two important characteristics of these tumors: they are histologically benign and well differentiated.

  2. Neuroactive Steroids: Receptor Interactions and Responses

    Directory of Open Access Journals (Sweden)

    Kald Beshir Tuem

    2017-08-01

    Full Text Available Neuroactive steroids (NASs are naturally occurring steroids, which are synthesized centrally as de novo from cholesterol and are classified as pregnane, androstane, and sulfated neurosteroids (NSs. NASs modulate many processes via interacting with gamma-aminobutyric acid (GABA, N-methyl-d-aspartate, serotonin, voltage-gated calcium channels, voltage-dependent anion channels, α-adrenoreceptors, X-receptors of the liver, transient receptor potential channels, microtubule-associated protein 2, neurotrophin nerve growth factor, a