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Sample records for a2 mimetic u46619

  1. Activation of CB1receptors by 2-arachidonoylglycerol attenuates vasoconstriction induced by U46619 and angiotensin II in human and rat pulmonary arteries.

    Science.gov (United States)

    Karpińska, Olga; Baranowska-Kuczko, Marta; Kloza, Monika; Ambroz Ewicz, Ewa; Kozłowski, Tomasz; Kasacka, Irena; Malinowska, Barbara; Kozłowska, Hanna

    2017-06-01

    Recent evidence suggests that endocannabinoids acting via cannabinoid CB 1 receptors may modulate vascular responses of various vasoconstrictors in the rodent systemic vasculature. The aim of the study was to investigate whether endocannabinoids modulate the contractile responses evoked by a thromboxane A 2 analog (U46619), angiotensin II (ANG II), serotonin (5-HT), and phenylephrine, which stimulate distinct G q/11 protein-coupled receptors (thromboxane, ANG II type 1, 5-HT 2 , and α 1 -adrenergic receptors) in isolated endothelium-intact human and rat pulmonary arteries (hPAs and rPAs, respectively). The CB 1 receptor antagonist AM251 (1 μM) and diacylglycerol lipase (2-arachidonoylglycerol synthesis enzyme) inhibitor RHC80267 (40 μM) enhanced contractions induced by U46619 in hPAs and rPAs and by ANG II in rPAs in an endothelium-dependent manner. AM251 did not influence vasoconstrictions induced by 5-HT or phenylephrine in rPAs. The monoacylglycerol lipase (2-arachidonoylglycerol degradation enzyme) inhibitor JZL184 (1 μM), but not the fatty acid amide hydrolase (anandamide degradation enzyme) inhibitor URB597 (1 μM), attenuated contractions evoked by U46619 in hPAs and rPAs and ANG II in rPAs. 2-Arachidonoylglycerol concentration-dependently induced relaxation of hPAs, which was inhibited by endothelium denudation or AM251 and enhanced by JZL184. Expression of CB 1 receptors was confirmed in hPAs and rPAs using Western blotting and immunohistochemistry. The present study shows the protective interaction between the endocannabinoid system and vasoconstriction in response to U46619 and ANG II in the human and rat pulmonary circulation. U46619 and ANG II may stimulate rapid endothelial release of endocannabinoids (mainly 2-arachidonoylglycerol), leading to CB 1 receptor-dependent and/or CB 1 receptor-independent vasorelaxation, which in the negative feedback mechanism reduces later agonist-induced vasoconstriction. Copyright © 2017 the American Physiological

  2. TRPA1 and TRPV1 contribute to propofol-mediated antagonism of U46619-induced constriction in murine coronary arteries.

    Directory of Open Access Journals (Sweden)

    Pritam Sinharoy

    Full Text Available Transient receptor potential (TRP ion channels have emerged as key components contributing to vasoreactivity. Propofol, an anesthetic is associated with adverse side effects including hypotension and acute pain upon infusion. Our objective was to determine the extent to which TRPA1 and/or TRPV1 ion channels are involved in mediating propofol-induced vasorelaxation of mouse coronary arterioles in vitro and elucidate the potential cellular signal transduction pathway by which this occurs.Hearts were excised from anesthetized mice and coronary arterioles were dissected from control C57Bl/6J, TRPA1-/-, TRPV1-/- and double-knockout mice (TRPAV-/-. Isolated microvessels were cannulated and secured in a temperature-controlled chamber and allowed to equilibrate for 1 hr. Vasoreactivity studies were performed in microvessels pre-constricted with U46619 to assess the dose-dependent relaxation effects of propofol on coronary microvascular tone.Propofol-induced relaxation was unaffected in vessels obtained from TRPV1-/- mice, markedly attenuated in pre-constricted vessels obtained from TRPA1-/- mice and abolished in vessels obtained from TRPAV-/- mice. Furthermore, NOS inhibition with L-NAME or endothelium denuding abolished the proporfol-induced depressor response in pre-constricted vessels obtained from all mice. In the absence of L-NAME, BKCa inhibition with penitrem A markedly attenuated propofol-mediated relaxation in vessels obtained from wild-type mice and to a lesser extent in vessels obtained from TRPV1-/-, mice with no effect in vessels obtained from TRPA1-/- or TRPAV-/- mice.TRPA1 and TRPV1 appear to contribute to the propofol-mediated antagonism of U46619-induced constriction in murine coronary microvessels that involves activation of NOS and BKCa.

  3. Mimetic Learning

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    Christoph Wulf

    2008-03-01

    Full Text Available Mimetic learning, learning by imitation, constitutes one of the most important forms of learning. Mimetic learning does not, however, just denote mere imitation or copying: Rather, it is a process by which the act of relating to other persons and worlds in a mimetic way leads to an en-hancement of one’s own world view, action, and behaviour. Mimetic learning is productive; it is related to the body, and it establishes a connection between the individual and the world as well as other persons; it creates practical knowledge, which is what makes it constitutive of social, artistic, and practical action. Mimetic learning is cultural learning, and as such it is crucial to teaching and education (Wulf, 2004; 2005.

  4. Partial purification and identification of the thrombozane A2/prostaglandin H2 receptor protein in human platelets

    International Nuclear Information System (INIS)

    Lim, C.T.; Kattelman, E.J.; Arora, S.K.; Venton, D.L.; Le Breton, G.C.

    1986-01-01

    The thromboxane A 2 /prostaglandin H 2 (TXA 2 /PGH 2 ) receptor antagonist [ 3 H]-13-azaprostanoic acid (13-APA) was used to identify and purify the platelet TXA 2 /PGH 2 receptor protein. Optimal solubilization of the 13-APA binding protein was achieved by extraction with 3-[(3-cholamidopropyl)dimethyl-ammonio]-1-propanesulfonate (CHAPS) detergent. Preliminary purification of the crude solubilized membrane fraction was performed by gel filtration chromatography using a Sepharose 4B column. Further purification was accomplished by high performance liquid chromatography (HPLC) using a Synchropak GPC-500 column. The HPLC protein profile revealed two protein peaks, only one of which was enriched in [ 3 H]-13-APA. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) of this peak revealed two bands with molecular weights of 65,000 and 60,000 daltons. In binding studies using the 60,000 dalton-enriched subfraction, unlabelled 13-APA, the TXA 2 /PGH 2 mimetic U46619 and the TXA 2 /PGH 2 antagonist SQ 29,548 all competed for [ 3 H]-13-APA binding whereas TXB 2 did not compete for binding. Heat denaturation of this subfraction resulted in a complete loss of binding activity. These findings indicate that a protein of approximately 60,000 daltons represents the human platelet TXA 2 /PGH 2 receptor

  5. The angiotensin II AT1 receptor antagonist irbesartan prevents thromboxane A2-induced vasoconstriction in the rat hind-limb vascular bed in vivo.

    Science.gov (United States)

    Fukuhara, M; Neves, L A; Li, P; Diz, D I; Ferrario, C M; Brosnihan, K B

    2001-03-01

    We studied the vasoconstrictor effects of the thromboxane A2 (TxA2) analogue U46619 in the perfused hind limb of rats under constant flow before and after intravenous injection of irbesartan, an angiotensin II AT1 receptor antagonist, to test whether irbesartan interacts in vivo with the thromboxane A2/prostaglandin endoperoxidase H2 (TxA2/PGH2) receptor. Male Sprague-Dawley rats (n = 15, body weight 350-420 g) were anesthetized with thiobutabarbital sodium (Inactin, 100 mg/kg intraperitoneally). Regional vascular responses to U46619 (0.5 and 1.0 microg) were investigated in the rat hind quarter under conditions of controlled flow before and after administration of irbesartan (10 mg/kg, intravenously). In addition, to test the specificity of the effect of irbesartan on U46619, phenylephrine (0.5, 1.0 microg) and another AT1 receptor antagonist, candesartan CV11974 (0.3 mg/kg, intravenously) were used. The dose-dependent increases in hind-limb perfusion pressure produced by U46619 were significantly attenuated by prior injection of irbesartan, at a dose that blocked the angiotensin II (Ang II) pressor responses. The specificity for the response was shown with the demonstrations that the increase in vascular resistance produced by phenylephrine was unchanged by irbesartan and, furthermore, that the increase in vascular resistance produced by U46619 was unchanged by another AT1 receptor antagonist, candesartan. This study demonstrates that irbesartan interacts at the TxA2/PGH2 receptor in the rat's hind limb in vivo, to modify changes in local regional vascular resistance. The dual antagonistic actions of irbesartan, acting at both AT1 and TxA2 receptors in blood vessels, may overall enhance its therapeutic profile in the treatment of hypertension.

  6. Effect on human platelet aggregation of phospholipase A2 purified from Heloderma horridum (beaded lizard) venom.

    Science.gov (United States)

    Huang, T F; Chiang, H S

    1994-02-10

    By means of gel filtration, ionic exchange chromatography and DEAE-column HPLC, an acidic phospholipase A2 (PLA2) was purified from beaded lizard (Heloderma horridum) venom. The purified PLA is a single-chain polypeptide, consisting of about 163 amino acid residues with a molecular mass of 19,000 Da as calculated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and amino acid analysis. HHV-PLA showed a rather specific inhibitory effect on platelet aggregation induced by U46619 and epinephrine in human platelet-rich plasma in a dose- and time-dependent manner, whereas it had little effect on collagen- and ADP-induced aggregation. ATP-release reaction induced by various agonists were dose- and time-dependently inhibited by HHV-PLA, even though platelet aggregation was apparently not affected in human washed platelets. When HHV-PLA was chemically modified with p-bromophenacyl bromide, both of its enzymatic activity and antiplatelet activity were lost. Furthermore, exogenous lysophosphatidylcholine and HHV-PLA treated phosphatidylcholine inhibited platelet aggregation induced by U46619 in human washed platelets. In conclusion, PLA enzyme from H. horridum venom inhibits exclusively U46619- or thromboxane-induced platelet aggregation of human platelet-rich plasma probably by virtue of their PLA enzymatic activity on plasma phospholipids, converting phospholipids (e.g., phosphatidylcholine) into lysophospholipids, which in turn interfere with the coupling of TXA2 receptor and its signalling transduction system.

  7. Higher derivative mimetic gravity

    Science.gov (United States)

    Gorji, Mohammad Ali; Mansoori, Seyed Ali Hosseini; Firouzjahi, Hassan

    2018-01-01

    We study cosmological perturbations in mimetic gravity in the presence of classified higher derivative terms which can make the mimetic perturbations stable. We show that the quadratic higher derivative terms which are independent of curvature and the cubic higher derivative terms which come from curvature corrections are sufficient to remove instabilities in mimetic perturbations. The classified higher derivative terms have the same dimensions but they contribute differently in the background and perturbed equations. Therefore, we can control both the background and the perturbation equations allowing us to construct the higher derivative extension of mimetic dark matter and the mimetic nonsingular bouncing scenarios. The latter can be thought as a new higher derivative effective action for the loop quantum cosmology scenario in which the equations of motion coincide with those suggested by loop quantum cosmology. We investigate a possible connection between the mimetic cosmology and the Randall-Sundrum cosmology.

  8. Kinetics of prostaglandin E2 and thromboxane A2 synthesis and suppression of PHA-stimulated peripheral blood mononuclear leucocytes.

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    Awara, W; Hillier, K; Jones, D

    1986-12-01

    The immunomodulatory effects of thromboxane A2 and prostaglandin E2 on peripheral blood mononuclear leucocytes stimulated with PHA in vitro, and the relationship of this to the time-course of their synthesis in culture, were investigated using prostaglandin E2, a thromboxane A2 synthesis inhibitor (UK37248), a thromboxane A2 mimic (U46619) and a thromboxane A2 receptor blocker (EP045). The inhibitory effect of prostaglandin E2 on PHA-induced human peripheral blood mononuclear leucocyte proliferation diminishes if the addition of PGE2 is delayed. If added 4 hr after a maximum concentration of PHA (5 micrograms/ml), the effect of PGE2 was reduced by 60%. If a submaximal concentration of PHA (1 microgram/ml) was used, the effect of PGE2 was not reduced if added 4 hr later but fell by about 60% after 16 hr. UK37248 moderately inhibited PHA-induced activation while substantially inhibiting thromboxane A2 synthesis and simultaneously enhancing PGE2 synthesis. The enhanced accumulation of PGE2 occurs while sensitivity to PGE2 is dropping. U46619, exogenously applied as a thromboxane A2 mimic, inhibited PHA-induced activation at concentrations that did not significantly alter PGE2 synthesis. EP045, which may modulate the effects of endogenous thromboxane A2 by blocking receptors, did not alter PHA-induced activation. We conclude that thromboxane A2 may have a role in inhibiting PHA-induced activation on the basis of the effect of U46619. However, this study highlights difficulties in utilizing prostaglandin and thromboxane receptor and synthesis inhibitors to examine their endogenous role in the modulation of mitogen-induced activation in vitro. If sensitivity to the purported endogenous substance is limited to the early stages of culture and if only low levels are synthesized at this early stage, then blocking drugs would have little effect.

  9. Helix mimetics: Recent developments.

    Science.gov (United States)

    Wilson, Andrew J

    2015-10-01

    The development of protein-protein interaction (PPIs) inhibitors represents a challenging goal in chemical biology and drug discovery. PPIs are problematic targets because they involve large surfaces with less well defined features and recognition motifs that are less amenable to conventional experimental and computational ligand discovery methodologies. α-Helix mediated PPIs represent a sub group with a clearly defined interface and thus may be more amenable to the development of generic ligand discovery methods. Indeed, this is borne out in numerous studies using peptides covalently constrained into a helical conformation resulting in improvement of myriad biophysical and cellular properties. It is however desirable to have small molecule alternatives: a helix mimetic (proteomimetic) is a generic small molecule scaffold that projects functional groups in a similar spatial orientation so as to mimic the presentation of key amino acid side chains from the helix that mediates the PPI. The first true example of a helix mimetic was described over a decade ago however this approach has not yet been elaborated to the extent that it receives similar levels of attention to constrained peptides. This review explores recent significant developments in the area of small molecule α-helix mimetics and provides a critical overview of success stories, potential limitations of the approach, and areas for future development. Copyright © 2015 Elsevier Ltd. All rights reserved.

  10. Pastoral conflict in Kenya: Transforming mimetic violence to mimetic ...

    African Journals Online (AJOL)

    transcending the relationship from mimetic violence to mimetic peace and reconciliation. Ultimately, by empowering local pastoral communities in the. * Ryan Triche is an African regional specialist focusing on governance, conflict mediation, human rights, and the responsibility to protect. He is currently undertaking graduate.

  11. Smac mimetics as IAP antagonists.

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    Fulda, Simone

    2015-03-01

    As the Inhibitor of Apoptosis (IAP) proteins are expressed at high levels in human cancers, they represent promising targets for therapeutic intervention. Small-molecule inhibitors of IAP proteins mimicking the endogenous IAP antagonist Smac, called Smac mimetics, neutralize IAP proteins and thereby promote the induction of cell death. Smac mimetics have been shown in preclinical models of human cancer to directly trigger cancer cell death or to sensitize for cancer cell death induced by a variety of cytotoxic stimuli. Smac mimetics are currently undergoing clinical evaluation in phase I/II trials, demonstrating that therapeutic targeting of IAP proteins has reached the clinical stage. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. Cosmological dynamics of mimetic gravity

    Science.gov (United States)

    Dutta, Jibitesh; Khyllep, Wompherdeiki; Saridakis, Emmanuel N.; Tamanini, Nicola; Vagnozzi, Sunny

    2018-02-01

    We present a detailed investigation of the dynamical behavior of mimetic gravity with a general potential for the mimetic scalar field. Performing a phase-space and stability analysis, we show that the scenario at hand can successfully describe the thermal history of the universe, namely the successive sequence of radiation, matter, and dark-energy eras. Additionally, at late times the universe can either approach a de Sitter solution, or a scaling accelerated attractor where the dark-matter and dark-energy density parameters are of the same order, thus offering an alleviation of the cosmic coincidence problem. Applying our general analysis to various specific potential choices, including the power-law and the exponential ones, we show that mimetic gravity can be brought into good agreement with the observed behavior of the universe. Moreover, with an inverse square potential we find that mimetic gravity offers an appealing unified cosmological scenario where both dark energy and dark matter are characterized by a single scalar field, and where the cosmic coincidence problem is alleviated.

  13. NCAM Mimetic Peptides: An Update

    DEFF Research Database (Denmark)

    Berezin, Vladimir; Bock, Elisabeth

    2008-01-01

    of combinatorial peptide libraries. The C3 and NBP10 peptides target the first Ig module whereas the ENFIN2 and ENFIN11 peptides target fibronectin type III (FN3) modules of NCAM. A number of NCAM mimetics can induce neurite outgrowth and exhibit neuroprotective and synaptic plasticity modulating properties...

  14. Bio-mimetic Flow Control

    Science.gov (United States)

    Choi, Haecheon

    2009-11-01

    Bio-mimetic engineering or bio-mimetics is the application of biological methods and systems found in nature to the study and design of engineering systems and modern technology (from Wikipedia). The concept itself is old, but successful developments have been made recently, especially in the research field of flow control. The objective of flow control based on the bio-mimetic approach is to develop novel concepts for reducing drag, increasing lift and enhancing aerodynamic performance. For skin friction reduction, a few ideas have been suggested such as the riblet from shark, compliant surface from dolphin, microbubble injection and multiple front-body curvature from penguin, and V-shaped protrusion from sailfish. For form drag reduction, several new attempts have been also made recently. Examples include the V-shaped spanwise grooves from saguaro cactus, overall shape of box fish, longitudinal grooves on scallop shell, bill of swordfish, hooked comb on owl wing, trailing-edge protrusion on dragonfly wing, and fillet. For the enhancement of aerodynamic performance, focuses have been made on the birds, fish and insects: e.g., double layered feather of landing bird, leading-edge serration of humpback-whale flipper, pectoral fin of flying fish, long tail on swallowtail-butterfly wing, wing flapping motion of dragonfly, and alula in birds. Living animals adapt their bodies to better performance in multi purposes, but engineering requires single purpose in most cases. Therefore, bio-mimetic approaches often produce excellent results more than expected. However, they are sometimes based on people's wrong understanding of nature and produce unwanted results. Successes and failures from bio-mimetic approaches in flow control will be discussed in the presentation.

  15. Heparin mimetics with anticoagulant activity.

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    Nahain, Abdullah Al; Ignjatovic, Vera; Monagle, Paul; Tsanaktsidis, John; Ferro, Vito

    2018-02-15

    Heparin, a sulfated polysaccharide belonging to the glycosaminoglycan family, has been widely used as an anticoagulant drug for decades and remains the most commonly used parenteral anticoagulant in adults and children. However, heparin has important clinical limitations and is derived from animal sources which pose significant safety and supply problems. The ever growing shortage of the raw material for heparin manufacturing may become a very significant issue in the future. These global limitations have prompted much research, especially following the recent well-publicized contamination scandal, into the development of alternative anticoagulants derived from non-animal and/or totally synthetic sources that mimic the structural features and properties of heparin. Such compounds, termed heparin mimetics, are also needed as anticoagulant materials for use in biomedical applications (e.g., stents, grafts, implants etc.). This review encompasses the development of heparin mimetics of various structural classes, including synthetic polymers and non-carbohydrate small molecules as well as sulfated oligo- and polysaccharides, and fondaparinux derivatives and conjugates, with a focus on developments in the past 10 years. © 2018 Wiley Periodicals, Inc.

  16. Unimodular mimetic F(R) inflation

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    Odintsov, S. D.; Oikonomou, V. K.

    2016-07-01

    We propose the unimodular-mimetic F(R) gravity theory, to resolve cosmological constant problem and dark matter problem in a unified geometric manner. We demonstrate that such a theory naturally admits accelerating universe evolution. Furthermore, we construct unimodular-mimetic F(R) inflationary cosmological scenarios compatible with the Planck and BICEP2/Keck-Array observational data. We also address the graceful exit issue, which is guaranteed by the existence of unstable de Sitter vacua.

  17. Thromboxane A2 Receptor Inhibition Suppresses Multiple Myeloma Cell Proliferation by Inducing p38/c-Jun N-terminal Kinase (JNK) Mitogen-activated Protein Kinase (MAPK)-mediated G2/M Progression Delay and Cell Apoptosis*

    Science.gov (United States)

    Liu, Qian; Tao, Bo; Liu, Guizhu; Chen, Guilin; Zhu, Qian; Yu, Ying; Yu, Yu; Xiong, Hong

    2016-01-01

    Multiple myeloma (MM) is a plasma cell malignancy without effective therapeutics. Thromboxane A2 (TxA2)/TxA2 receptor (T prostanoid receptor (TP)) modulates the progression of some carcinomas; however, its effects on MM cell proliferation remain unclear. In this study, we evaluated cyclooxygenase (COX) enzymes and downstream prostaglandin profiles in human myeloma cell lines RPMI-8226 and U-266 and analyzed the effects of COX-1/-2 inhibitors SC-560 and NS-398 on MM cell proliferation. Our observations implicate COX-2 as being involved in modulating cell proliferation. We further incubated MM cells with prostaglandin receptor antagonists or agonists and found that only the TP antagonist, SQ29548, suppressed MM cell proliferation. TP silencing and the TP agonist, U46619, further confirmed this finding. Moreover, SQ29548 and TP silencing promoted MM cell G2/M phase delay accompanied by reducing cyclin B1/cyclin-dependent kinase-1 (CDK1) mRNA and protein expression. Notably, cyclin B1 overexpression rescued MM cells from G2/M arrest. We also found that the TP agonist activated JNK and p38 MAPK phosphorylation, and inhibitors of JNK and p38 MAPK depressed U46619-induced proliferation and cyclin B1/CDK1 protein expression. In addition, SQ29548 and TP silencing led to the MM cell apoptotic rate increasing with improving caspase 3 activity. The knockdown of caspase 3 reversed the apoptotic rate. Taken together, our results suggest that TxA2/TP promotes MM cell proliferation by reducing cell delay at G2/M phase via elevating p38 MAPK/JNK-mediated cyclin B1/CDK1 expression and hindering cell apoptosis. The TP inhibitor has potential as a novel agent to target kinase cascades for MM therapy. PMID:26724804

  18. [Incretin mimetic drugs: therapeutic positioning].

    Science.gov (United States)

    López Simarro, F

    2014-07-01

    Type 2 diabetes is a chronic and complex disease, due to the differences among affected individuals, which affect choice of treatment. The number of drug families has increased in the last few years, and these families have widely differing mechanisms of action, which contributes greatly to the individualization of treatment according to the patient's characteristics and comorbidities. The present article discusses incretin mimetic drugs. Their development has been based on knowledge of the effects of natural incretin hormones: GLP-1 (glucagon-like peptide 1), GIP (glucose-dependent insulinotropic peptide) and dipeptidyl peptidase enzyme 4 (DPP4), which rapidly degrade them in the systemic circulation. This group is composed of 2 different types of molecules: GLP-1 analogs and DPP4 enzyme inhibitors. The benefits of these molecules include a reduction in plasma glucose without the risk of hypoglycemias or weight gain. There are a series of questions that require new studies to establish a possible association between the use of these drugs and notification of cases of pancreatitis, as well as their relationship with pancreatic and thyroid cancer. Also awaited is the publication of several studies that will provide information on the relationship between these drugs and cardiovascular risk in people with diabetes. All these questions will probably be progressively elucidated with greater experience in the use of these drugs. Copyright © 2014 Elsevier España, S.L.U. y Sociedad Española de Medicina Rural y Generalista (SEMERGEN). All rights reserved.

  19. Cardioprotection by Conditioning Mimetic Drugs.

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    Santillo, Elpidio; Migale, Monica; Postacchini, Demetrio; Balestrini, Fabrizio; Incalzi, Raffaele Antonelli

    2016-01-01

    At present, ischemic heart disease (IHD) is one of the main causes of morbidity and mortality world-wide. An important insight into both IHD pathophysiology and cardioprotection was achieved in 1986 when Murry et al. described for the first time the ischemic preconditioning (IP). IP can be defined as an innate phenomenon by which brief episodes of ischemia confer protection to a tissue from a subsequent more protracted ischemic insult. Suggested mechanisms explaining IP comprise the action of circulating substances (e.g. adenosine, bradykinin, nitric oxide). These mediators are released after a prolonged ischemic stress, causing activation of molecular pathways that induce favorable posttranslational changes of proteins and adaptive modifications in genetic expression. Briefly review evidences from clinical studies on drugs that exert their effects by mimicking IP, discussing their therapeutic properties and the potential clinical employment in order to obtain cardioprotection. Literature regarding IP mimicking pharmacological agents was searched in Medline and Google Scholar. Authors reviewed relevant researches in English language including both clinical studies and reviews of clinical studies published from 1986 to 2016. Several pharmacological agents reproducing IP protective actions have been evaluated in many clinical trials. Examined molecules include adenosine, nicorandil and atrial natriuretic peptide. Interestingly IP mimicking effects of drugs have been also analyzed perioperatively in the context of ischaemia-reperfusion heart injury. Moreover evidences suggest that also some anaesthetic drugs (especially volatile agents) are able to provide myocardial protection by inducing IP. Drugs capable of mimicking IP exhibit a high therapeutic potential because of their properties of eliciting an effective cardioprotective signaling. Future studies should clarify the optimal doses and timing of administration of IP mimetic agents in order to favor the advent of

  20. Mimetic desire and scapegoat mechanism in sport

    Directory of Open Access Journals (Sweden)

    Jernej Pisk

    2012-12-01

    Full Text Available BACKGROUND: The most fundamental question about sport is what is sport, what is its origin and its essence? Because sport is connected with the human being (there is no sport without human beings different anthropological visions of human being result in different understandings of sport. OBJECTIVE: The objective of this paper is to present and explain an anthropological vision of the human being and society as was developed by René Girard. In his view mimetic desire and the scapegoat mechanism have a central role in any culture, religion or other secular institutions. The explanatory power of his theory is presented when it is applied to the world of sport. METHODS: Our methodology is philosophical, involving conceptual analysis and the application of the outcomes to sport. RESULTS: In the paper we show that mimetic desire can be recognized as one of the important origins of recreational and competitive sports. When people recognize what other people are able to do or accomplish in sport this invokes the mimetic desire as a result of which motivation for sport and competiveness can arise. But mimetic rivalry leads to an unstable situation. Therefore a second element is needed: Scapegoating in sport is presented as a mean to preserve the good reputation of sport, to keep peace in sport as well as in society as a whole. Finally, the attempt to overcome mimetic desire and scapegoating in sport is presented and the question if this is worth trying at all is opened. CONCLUSIONS: The theories of mimetic desire and scapegoat mechanism have great explanatory power when they are applied to the field of sport. They could reveal us some hidden motives and forces which drive athletes and sport as a whole. Moreover, they exceed the world of sport and reveal the influence of sport on the whole of society.

  1. Wood mimetic hydrogel beads for enzyme immobilization.

    Science.gov (United States)

    Park, Saerom; Kim, Sung Hee; Won, Keehoon; Choi, Joon Weon; Kim, Yong Hwan; Kim, Hyung Joo; Yang, Yung-Hun; Lee, Sang Hyun

    2015-01-22

    Wood component-based composite hydrogels have potential applications in biomedical fields owing to their low cost, biodegradability, and biocompatibility. The controllable properties of wood mimetic composites containing three major wood components are useful for enzyme immobilization. Here, lipase from Candida rugosa was entrapped in wood mimetic beads containing cellulose, xylan, and lignin by dissolving wood components with lipase in [Emim][Ac], followed by reconstitution. Lipase entrapped in cellulose/xylan/lignin beads in a 5:3:2 ratio showed the highest activity; this ratio is very similar to that in natural wood. The lipase entrapped in various wood mimetic beads showed increased thermal and pH stability. The half-life times of lipase entrapped in cellulose/alkali lignin hydrogel were 31- and 82-times higher than those of free lipase during incubation under denaturing conditions of high temperature and low pH, respectively. Owing to their biocompatibility, biodegradability, and controllable properties, wood mimetic hydrogel beads can be used to immobilize various enzymes for applications in the biomedical, bioelectronic, and biocatalytic fields. Copyright © 2014 Elsevier Ltd. All rights reserved.

  2. Novel Superoxide Dismutase Mimetics for Protection against ...

    African Journals Online (AJOL)

    Paraquat-induced nephrotoxicity involves severe renal damage caused by reactive oxygen species (ROS), specifically by increasing superoxide (O2○-) generation in the kidney. While proven to be of benefit in animal models of organ injury involving O2○-, superoxide dismutase (SOD) and superoxide dismutase mimetics ...

  3. Ac2-26 Mimetic Peptide of Annexin A1 Inhibits Local and Systemic Inflammatory Processes Induced by Bothrops moojeni Venom and the Lys-49 Phospholipase A2 in a Rat Model.

    Directory of Open Access Journals (Sweden)

    Bruna Stuqui

    Full Text Available Annexin A1 (AnxA1 is an endogenous glucocorticoid regulated protein that modulates anti-inflammatory process and its therapeutic potential has recently been recognized in a range of systemic inflammatory disorders. The effect of the N-terminal peptide Ac2-26 of AnxA1 on the toxic activities of Bothrops moojeni crude venom (CV and its myotoxin II (MjTX-II were evaluated using a peritonitis rat model. Peritonitis was induced by the intraperitoneal injection of either CV or MjTX-II, a Lys-49 phospholipase A2. Fifteen minutes after the injection, the rats were treated with either Ac2-26 or PBS. Four hours later, the CV and MjTX-II-induced peritonitis were characterized by neutrophilia (in the peritoneal exudate, blood and mesentery and increased number of mesenteric degranulated mast cells and macrophages. At 24 hours post-injection, the local inflammatory response was attenuated in the CV-induced peritonitis while the MjTX-II group exhibited neutrophilia (peritoneal exudates and blood. Ac2-26 treatment prevented the influx of neutrophils in MjTX-II-induced peritonitis and diminished the proportion of mesenteric degranulated mast cells and macrophages in CV-induced peritonitis. Additionally, CV and MjTX-II promoted increased levels of IL-1β and IL-6 in the peritoneal exudates which were significantly reduced after Ac2-26 treatment. At 4 and 24 hours, the endogenous expression of AnxA1 was upregulated in the mesenteric neutrophils (CV and MjTX-II groups and mast cells (CV group. In the kidneys, CV and MjTX-II administrations were associated with an increased number of macrophages and morphological alterations in the juxtamedullary nephrons in proximal and distal tubules. Ac2-26 promoted significant recovery of the juxtamedullary structures, decreased the number of macrophages and diminished the AnxA1 in epithelial cells from distal tubules and renal capsules. Our results show that Ac2-26 treatment significantly attenuates local and systemic

  4. Oestrogene mimetic isoflavones’ pharmacokinetics and pharmacodynamics

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    Anca Dragomirescu,

    2008-12-01

    Full Text Available Genisteine is the most abundant and the most studied estrogen-mimetic izoflavone. It's chemical formula is 4',5,7 – trihidroxyisoflavone. It has also estrogen-modulated properties by its binding ability to the beta type estrogen receptor. Genisteine presents the following farmacodinamic effects: antiaterogen effect, prevention of estrogen-dependent cancers, especially breast cancer, prevention of skin aging body, osteoprogen effect, prevention of osteoporosis at the menopauses women. Despite all these real benefits, there are also many adverse effects, registered both in humans and animals. Thus, the sheep feeding with some Fabaceae species, containing estrogen-mimetic isoflavones were stopped their reproductive function(isoflavones acted as an oral contraceptive. In humans, phytoestroges influence is still under evaluation, being suspected effects such as cerebral involution - via abusive apoptosis - or disturbance in hormonal status, in male children. All these are added to already known allergies, caused by soy proteins.

  5. NEC violation in mimetic cosmology revisited

    Directory of Open Access Journals (Sweden)

    Anna Ijjas

    2016-09-01

    Full Text Available In the context of Einstein gravity, if the null energy condition (NEC is satisfied, the energy density in expanding space–times always decreases while in contracting space–times the energy density grows and the universe eventually collapses into a singularity. In particular, no non-singular bounce is possible. It is, though, an open question if this energy condition can be violated in a controlled way, i.e., without introducing pathologies, such as unstable negative-energy states or an imaginary speed of sound. In this letter, we will re-examine the claim that the recently proposed mimetic scenario can violate the NEC without pathologies. We show that mimetic cosmology is prone to gradient instabilities even in cases when the NEC is satisfied (except for trivial examples. Most interestingly, the source of the instability is always the Einstein–Hilbert term in the action. The matter stress-energy component does not contribute spatial gradient terms but instead makes the problematic curvature modes dynamical. We also show that mimetic cosmology can be understood as a singular limit of known, well-behaved theories involving higher-derivative kinetic terms and discuss ways of removing the instability.

  6. Direct couplings of mimetic dark matter and their cosmological effects

    Science.gov (United States)

    Shen, Liuyuan; Mou, Yicen; Zheng, Yunlong; Li, Mingzhe

    2018-01-01

    The original mimetic model was proposed to take the role of dark matter. In this paper we consider possible direct interactions of mimetic dark matter with other matter in the universe, especially standard model particles such as baryons and photons. By imposing shift symmetry, the mimetic dark matter field can only have derivative couplings. We discuss the possibilities of generating baryon number asymmetry and cosmic birefringence in the universe based on the derivative couplings of mimetic dark matter to baryons and photons. Supported by NSFC (11422543, 11653002)

  7. Black hole solutions in mimetic Born-Infeld gravity.

    Science.gov (United States)

    Chen, Che-Yu; Bouhmadi-López, Mariam; Chen, Pisin

    2018-01-01

    The vacuum, static, and spherically symmetric solutions in the mimetic Born-Infeld gravity are studied. The mimetic Born-Infeld gravity is a reformulation of the Eddington-inspired-Born-Infeld (EiBI) model under the mimetic approach. Due to the mimetic field, the theory contains non-trivial vacuum solutions different from those in Einstein gravity. We find that with the existence of the mimetic field, the spacelike singularity inside a Schwarzschild black hole could be altered to a lightlike singularity, even though the curvature invariants still diverge at the singularity. Furthermore, in this case, the maximal proper time for a timelike radially-infalling observer to reach the singularity is found to be infinite.

  8. Exercise, fasting, and mimetics: toward beneficial combinations?

    Science.gov (United States)

    Jaspers, Richard T; Zillikens, M Carola; Friesema, Edith C H; delli Paoli, Giuseppe; Bloch, Wilhelm; Uitterlinden, André G; Goglia, Fernando; Lanni, Antonia; de Lange, Pieter

    2017-01-01

    Obesity and type 2 diabetes are associated disorders that involve a multiplicity of tissues. Both fasting and physical exercise are known to counteract dyslipidemia/hyperglycemia. Skeletal muscle plays a key role in the control of blood glucose levels, and the metabolic changes and related signaling pathways in skeletal muscle induced by fasting overlap with those induced by exercise. The reduction of fat disposal has been shown to extend to the liver and to white and brown adipose tissue and to involve an increase in their metabolic activities. In recent years signal transduction pathways related to exercise and fasting/food withdrawal in muscle have been intensively studied, both in animals and in humans. Combining fasting/food withdrawal with exercise in animals as well as in humans causes changes unlike those seen during fasting/food withdrawal or exercise alone, which favor repair of muscle over autophagy. In addition, compounds that mimic exercise have been studied in combination with exercise or fasting/food withdrawal. This review addresses our current knowledge of the mechanisms that underlie the individual and combined effects of fasting/food withdrawal, endurance or resistance exercise, and their mimetics, in muscle vs other organs in rodents and humans, and highlights which combinations may improve metabolic disorders.-Jaspers, R. T., Zillikens, M. C., Friesema, E. C. H., delli Paoli, G., Bloch, W., Uitterlinden, A. G., Goglia, F., Lanni, A., de Lange, P. Exercise, fasting, and mimetics: toward beneficial combinations. © FASEB.

  9. Smac Mimetics to Therapeutically Target IAP Proteins in Cancer.

    Science.gov (United States)

    Fulda, S

    2017-01-01

    Inhibitor of Apoptosis (IAP) proteins are overexpressed in a variety of human cancers. Therefore, they are considered as promising targets for the design of therapeutic strategies. Smac mimetics mimic the endogenous mitochondrial protein Smac that antagonizes IAP proteins upon its release into the cytosol. Multiple preclinical studies have documented the ability of Smac mimetics to either directly induce cell death of cancer cells or to prime them to agents that trigger cell death. At present, several Smac mimetics are being evaluated in early clinical trials. The current review provides an overview on the potential of Smac mimetics as cancer therapeutics to target IAP proteins for cancer therapy. © 2017 Elsevier Inc. All rights reserved.

  10. Promises and Challenges of Smac Mimetics as Cancer Therapeutics.

    Science.gov (United States)

    Fulda, Simone

    2015-11-15

    Inhibitor of Apoptosis (IAP) proteins block programmed cell death and are expressed at high levels in various human cancers, thus making them attractive targets for cancer drug development. Second mitochondrial activator of caspases (Smac) mimetics are small-molecule inhibitors that mimic Smac, an endogenous antagonist of IAP proteins. Preclinical studies have shown that Smac mimetics can directly trigger cancer cell death or, even more importantly, sensitize tumor cells for various cytotoxic therapies, including conventional chemotherapy, radiotherapy, or novel agents. Currently, several Smac mimetics are under evaluation in early clinical trials as monotherapy or in rational combinations (i.e., GDC-0917/CUDC-427, LCL161, AT-406/Debio1143, HGS1029, and TL32711/birinapant). This review discusses the promise as well as some challenges at the translational interface of exploiting Smac mimetics as cancer therapeutics. ©2015 American Association for Cancer Research.

  11. Stereoselective inhibition of thromboxane-induced coronary vasoconstriction by 1,4-dihydropyridine calcium channel antagonists

    International Nuclear Information System (INIS)

    Eltze, M.; Boer, R.; Sanders, K.H.; Boss, H.; Ulrich, W.R.; Flockerzi, D.

    1990-01-01

    The biological activity of the (+)-S- and (-)-R-enantiomers of niguldipine, of the (-)-S- and (+)-R-enantiomers of felodipine and nitrendipine, and of rac-nisoldipine and rac-nimodipine was investigated in vitro and in vivo. Inhibition of coronary vasoconstriction due to the thromboxane A2 (TxA2)-mimetic U-46619 in guinea pig Langendorff hearts, displacement of (+)-[ 3 H]isradipine from calcium channel binding sites of guinea pig skeletal muscle T-tubule membranes, and blood pressure reduction in spontaneously hypertensive rats were determined. The enantiomers were obtained by stereoselective synthesis. Cross-contamination was less than 0.5% for both S- and R-enantiomers of niguldipine and nitrendipine and less than 1% for those of felodipine. From the doses necessary for a 50% inhibition of coronary vasoconstriction, stereoselectivity ratios for (+)-(S)-/(-)-(R)-niguldipine, (-)-(S)-/(+)-(R)-felodipine, and (-)-(S)-/(+)-(R)-nitrendipine of 28, 13, and 7, respectively, were calculated. The potency ratio rac-nisoldipine/rac-nimodipine was 3.5. Ratios obtained from binding experiments and antihypertensive activity were (+)-(S)-/(-)-(R)-niguldipine = 45 and 35, (-)-(S)-/(+)-(R)-felodipine = 12 and 13, (-)-(S)-/(+)-(R)-nitrendipine = 8 and 8, and rac-nisoldipine/rac-nimodipine = 8 and 7, respectively. Highly significant correlations were found between the in vitro potency of the substances to prevent U-46619-induced coronary vasoconstriction and their affinity for calcium channel binding sites as well as their antihypertensive activity

  12. [Insulin-mimetic property of vanadium compounds].

    Science.gov (United States)

    Korbecki, Jan; Baranowska-Bosiacka, Irena; Gutowska, Izabela; Chlubek, Dariusz

    Vanadium is a transition metal which creates a number of inorganic and organic derivatives with various organic substances. Some of these compounds have pharmaceutical significance, e.g. vanadyl cation, vanadate and bis(maltolato) oxovanadium(IV). Vanadium compounds are competence inhibitors of protein tyrosine phosphatases (PTP). They have anti-tumor properties, capable of inhibiting cell proliferation at the concentrations of several micromoles. They also display insulin-mimetic and hypoglycemic properties. As they can increase the activity of the insulin-like growth factor I receptor, they stimulate glycogen synthesis, increase the number of GLUT-4 transporters in the cell membrane and impair gluconeogenesis. In addition to their effects on sugar metabolism, vanadium compounds increase the synthesis of fatty acids, reducing the concentration of glucose in the blood. Thanks to their mitotic properties, low concentrations of vanadium compounds are also able to induce β cell regeneration. Clinical tests have shown that vanadium compounds may be used as antidiabetic drugs with low toxicity. However, the range of therapeutic concentrations is very narrow; at concentrations as low a several micromoles vanadium compounds inhibit cell proliferation and cause apoptosis, necrosis and inflammation.

  13. Energy restriction and potential energy restriction mimetics.

    Science.gov (United States)

    Nikolai, Sibylle; Pallauf, Kathrin; Huebbe, Patricia; Rimbach, Gerald

    2015-12-01

    Energy restriction (ER; also known as caloric restriction) is the only nutritional intervention that has repeatedly been shown to increase lifespan in model organisms and may delay ageing in humans. In the present review we discuss current scientific literature on ER and its molecular, metabolic and hormonal effects. Moreover, criteria for the classification of substances that might induce positive ER-like changes without having to reduce energy intake are summarised. Additionally, the putative ER mimetics (ERM) 2-deoxy-d-glucose, metformin, rapamycin, resveratrol, spermidine and lipoic acid and their suggested molecular targets are discussed. While there are reports on these ERM candidates that describe lifespan extension in model organisms, data on longevity-inducing effects in higher organisms such as mice remain controversial or are missing. Furthermore, some of these candidates produce detrimental side effects such as immunosuppression or lactic acidosis, or have not been tested for safety in long-term studies. Up to now, there are no known ERM that could be recommended without limitations for use in humans.

  14. BSA-boronic acid conjugate as lectin mimetics.

    Science.gov (United States)

    Narla, Satya Nandana; Pinnamaneni, Poornima; Nie, Huan; Li, Yu; Sun, Xue-Long

    2014-01-10

    We report bovine serum albumin (BSA)-boronic acid (BA) conjugates as lectin mimetics and their glyco-capturing capacity. The BSA-BA conjugates were synthesized by amidation of carboxylic acid groups in BSA with aminophenyl boronic acid in the presence of EDC, and were characterized by Alizarin Red S (ARS) assay and SDS-PAGE gel. The BSA-BA conjugates were immobilized onto maleimide-functionalized silica beads and their sugar capturing capacity and specificity were confirmed by ARS displacement assay. Further, surface plasmon resonance (SPR) analysis of the glyco-capturing activity of the BSA-BA conjugates was conducted by immobilizing BSA-BA onto SPR gold chip. Overall, we demonstrated a BSA-BA-based lectin mimetics for glyco-capturing applications. These lectin mimetics are expected to provide an important tool for glycomics and biosensor research and applications. Copyright © 2013 Elsevier Inc. All rights reserved.

  15. Combinatorial solid-phase synthesis of hapalosin mimetics

    DEFF Research Database (Denmark)

    Olsen, Jacob A.; Jensen, Knud J.; Nielsen, John

    2000-01-01

    The solid-phase synthesis of a small library of mimetics of the cyclic depsipeptide hapalosin is described. 3-Amino-4-hydroxy-5-nitrobenzoic acid was anchored through the anilino moiety to a backbone amide linker (BAL) handle support. Using chemoselective reactions and without the need for protec......The solid-phase synthesis of a small library of mimetics of the cyclic depsipeptide hapalosin is described. 3-Amino-4-hydroxy-5-nitrobenzoic acid was anchored through the anilino moiety to a backbone amide linker (BAL) handle support. Using chemoselective reactions and without the need...

  16. Bio-Mimetic Sensors Based on Molecularly Imprinted Membranes

    Directory of Open Access Journals (Sweden)

    Catia Algieri

    2014-07-01

    Full Text Available An important challenge for scientific research is the production of artificial systems able to mimic the recognition mechanisms occurring at the molecular level in living systems. A valid contribution in this direction resulted from the development of molecular imprinting. By means of this technology, selective molecular recognition sites are introduced in a polymer, thus conferring it bio-mimetic properties. The potential applications of these systems include affinity separations, medical diagnostics, drug delivery, catalysis, etc. Recently, bio-sensing systems using molecularly imprinted membranes, a special form of imprinted polymers, have received the attention of scientists in various fields. In these systems imprinted membranes are used as bio-mimetic recognition elements which are integrated with a transducer component. The direct and rapid determination of an interaction between the recognition element and the target analyte (template was an encouraging factor for the development of such systems as alternatives to traditional bio-assay methods. Due to their high stability, sensitivity and specificity, bio-mimetic sensors-based membranes are used for environmental, food, and clinical uses. This review deals with the development of molecularly imprinted polymers and their different preparation methods. Referring to the last decades, the application of these membranes as bio-mimetic sensor devices will be also reported.

  17. The IAP Protein Family, SMAC Mimetics and Cancer Treatment.

    Science.gov (United States)

    Philchenkov, Alex; Miura, Koh

    2016-01-01

    Since the acquired resistance of cells to apoptosis is one of the major hallmarks of cancer, the endogenous inhibitors of apoptosis can be regarded as promising targets in the design of anticancer therapeutics. In addition to their antiapoptotic activity, inhibitor of apoptosis proteins (IAPs) are able to regulate numerous other cell functions, including proliferation, differentiation, and migration, as well as proinflammatory and immune responses. Study of the IAP family as target molecules in targeted therapies has recently focused on SMAC mimetics as synthetic IAP antagonists that have been under development as promising therapeutics. To overview the background of IAP proteins and to focus on the development of SMAC mimetics, the present review first looks at the mechanisms of IAP proteins' antiapoptotic activities and those for controlling those activities; then the SMAC mimetics, including birinapant, LCL161, and DEBIO1143/AT-406, and their clinical trials are introduced. To further clarify the processes to exert the efficacies of SMAC mimetics, it is necessary to determine therapeutic biomarkers that predict and assess them, which may include caspases and factors in the TNFα pathway.

  18. Bio-Mimetic Sensors Based on Molecularly Imprinted Membranes

    Science.gov (United States)

    Algieri, Catia; Drioli, Enrico; Guzzo, Laura; Donato, Laura

    2014-01-01

    An important challenge for scientific research is the production of artificial systems able to mimic the recognition mechanisms occurring at the molecular level in living systems. A valid contribution in this direction resulted from the development of molecular imprinting. By means of this technology, selective molecular recognition sites are introduced in a polymer, thus conferring it bio-mimetic properties. The potential applications of these systems include affinity separations, medical diagnostics, drug delivery, catalysis, etc. Recently, bio-sensing systems using molecularly imprinted membranes, a special form of imprinted polymers, have received the attention of scientists in various fields. In these systems imprinted membranes are used as bio-mimetic recognition elements which are integrated with a transducer component. The direct and rapid determination of an interaction between the recognition element and the target analyte (template) was an encouraging factor for the development of such systems as alternatives to traditional bio-assay methods. Due to their high stability, sensitivity and specificity, bio-mimetic sensors-based membranes are used for environmental, food, and clinical uses. This review deals with the development of molecularly imprinted polymers and their different preparation methods. Referring to the last decades, the application of these membranes as bio-mimetic sensor devices will be also reported. PMID:25196110

  19. Thromboxane A(2 receptor stimulation promotes closure of the rat ductus arteriosus through enhancing neointima formation.

    Directory of Open Access Journals (Sweden)

    Tomohiro Yokota

    Full Text Available Ductus arteriosus (DA closure follows constriction and remodeling of the entire vessel wall. Patent ductus arteriosus occurs when the DA does not close after birth, and this condition is currently treated using cyclooxygenase inhibitors. However, the efficacy of cyclooxygenase inhibitors is often limited. Our previous study demonstrated that low-dose thromboxane A2 receptor (TP stimulation constricted the DA with minimal adverse effects in rat neonates. However, its effect on DA remodeling remains unknown. In this study, we focused on the impact of the exogenous TP stimulation on the DA remodeling, especially intimal thickening. Using DA explants from rat fetuses at embryonic day 19 as a ex vivo model and primary cultured rat DA smooth muscle cells from embryonic day 21 as a in vitro model, we evaluated the effect of TP stimulation on the DA remodeling. The selective TP agonists U46619 and I-BOP promoted neointima formation in the ex vivo DA explants, and TP stimulation increased DA SMC migration in a dose-dependent manner. Both effects were inhibited by the selective TP antagonist SQ29548 or the siRNA against TP. TP stimulation also increased DA SMC proliferation in the presence of 10% fetal bovine serum. LC/MS/MS analysis revealed that TP stimulation increased secretion of several extracellular matrix proteins that may contribute to an increase in neointima formation. In conclusion, we uncovered that exogenous administration of TP agonist promotes neointima formation through the induction of migration and proliferation of DA SMC, which could contribute to DA closure and also to its vasoconstrictive action.

  20. Designing a small molecule erythropoietin mimetic.

    Science.gov (United States)

    Guarnieri, Frank

    2015-01-01

    Erythropoietin (EPO) is a protein made by the kidneys in response to low red blood cell count that is secreted into the bloodstream and binds to a receptor on hematopoietic stem cells in the bone marrow inducing them to become new red blood cells. EPO made with recombinant DNA technology was brought to market in the 1980s to treat anemia caused by kidney disease and cancer chemotherapy. Because EPO infusion was able to replace blood transfusions in many cases, it rapidly became a multibillion dollar per year drug and as the first biologic created with recombinant technology it launched the biotech industry. For many years intense research was focused on creating a small molecule orally available EPO mimetic. The Robert Wood Johnson (RWJ) group seemed to definitively establish that only large peptides with a minimum of 60 residues could replace EPO, as anything less was not a full agonist. An intense study of the published work led me to hypothesize that the size of the mimetic is not the real issue, but the symmetry making and breaking of the EPO receptor induced by the ligand is the key to activating the stem cells. This analysis meant that residues in the binding site of the receptor deemed absolutely essential for ligand binding and activation from mutagenesis experiments, were probably not really that important. My fundamental hypotheses were: (a) the symmetric state of the homodimeric receptor is the most stable state and thus must be the off-state, (b) a highly localized binding site exists at a pivot point where the two halves of the receptor meet, (c) small molecules can be created that have high potency for this site that will be competitive with EPO and thus can displace the protein-protein interaction, (d) small symmetric molecules will stabilize the symmetric off-state of the receptor, and (e) a key asymmetry in the small molecule will stabilize a mirror image asymmetry in the receptor resulting in the stabilization of the on-state and proliferation of

  1. Mechanisms Involved in Thromboxane A2-induced Vasoconstriction of Rat Intracavernous Small Penile Arteries

    DEFF Research Database (Denmark)

    Grann, Martin; Comerma Steffensen, Simon Gabriel; Arcanjo, Daniel Dias Rufino

    2015-01-01

    by activation of thromboxane receptors concentration-dependently increased calcium and contraction. U46619-induced calcium influx was blocked by nifedipine, a blocker of L-type calcium channels, and by 2-aminoethoxydiphenyl borate, a blocker of transient receptor potential (TRP) channels. Inhibitors of ROCK, Y...... relaxation in rat mesenteric arteries. Our findings suggest that U46619 contraction depends on Ca2+ influx through L-type and TRP channels, and ROCKdependent mechanisms in penile arteries. Inhibition of the ROCK pathway is a potential approach for the treatment of erectile dysfunction associated......Diabetes is associated with erectile dysfunction and with hypercontractility in erectile tissue and this is in part ascribed to increased formation of thromboxane. Rho kinase (ROCK) is a key regulator of calcium sensitization and contraction in vascular smooth muscle. This study investigated...

  2. Molecular pathways: targeting death receptors and smac mimetics.

    Science.gov (United States)

    Fulda, Simone

    2014-08-01

    Inhibitor of apoptosis (IAP) proteins are overexpressed in multiple human malignancies, an event that is associated with poor prognosis and treatment resistance. Therefore, IAP proteins represent relevant targets for therapeutic intervention. Second mitochondrial activator of caspases (Smac) is a mitochondrial protein that is released into the cytosol upon the induction of programmed cell death and promotes apoptosis by neutralizing IAP proteins. On the basis of this property, a variety of small-molecule inhibitors have been developed that mimic the binding domain of the native Smac protein to IAP proteins. Evaluation of these Smac mimetics in preclinical studies revealed that they particularly synergize together with agents that trigger the death receptor pathway of apoptosis. Such combinations might therefore be of special interest for being included in the ongoing evaluation of Smac mimetics in early clinical trials. ©2014 American Association for Cancer Research.

  3. Salicylamide and salicylglycine oxidovanadium complexes with insulin-mimetic properties.

    Science.gov (United States)

    Nilsson, Jessica; Shteinman, Albert A; Degerman, Eva; Enyedy, Eva A; Kiss, Tamás; Behrens, Ulrich; Rehder, Dieter; Nordlander, Ebbe

    2011-12-01

    Reaction of N-(2-hydroxybenzyl)-N-(2-picolyl) glycine (H(2)papy) with VOSO(4) in water gives the oxidovanadium(V) oxido-bridged dimer [{(papy)(VO)}(2) μ-O)] (1). Similarly, reaction of N-(2-hydroxybenzyl) glycine (H(2)glysal) with VOSO(4) gives [(glysal)VO(H(2)O)] (2) and reaction of salicylamide (Hsalam) with VOSO(4) in methanol gives [(salam)(2)VO] (3). The crystal structure of the oxido-bridged complex 1 is reported. The insulin-mimetic activity of all three complexes was evaluated with respect to their ability to phosphorylate protein kinase B (PKB). The speciations of complexes 1 and 2 were studied over the pH range 2-10. Complex 1 shows greater stability over the whole pH range but only 2 and 3 exhibit an insulin-mimetic effect. Copyright © 2011 Elsevier Inc. All rights reserved.

  4. A mucosa-mimetic material for the mucoadhesion testing of thermogelling semi-solids

    OpenAIRE

    da Silva, Jéssica Bassi; Khutoryanskiy, Vitaliy V.; Bruschi, Marcos L.; Cook, Michael T.

    2017-01-01

    Mucosa-mimetic materials are synthetic substrates which aim to replace animal tissue in mucoadhesion experiments. One potential mucosa-mimetic material is a hydrogel comprised of N-acryloyl-d-glucosamine and 2-hydroxyethylmethacrylate, which has been investigated as a surrogate for animal mucosae in the mucoadhesion testing of tablets and solution formulations. This study aims to investigate the efficacy of this mucosa-mimetic material in the testing of thermogelling semi-solid formulations, ...

  5. Insulin Reverses D-Glucose–Increased Nitric Oxide and Reactive Oxygen Species Generation in Human Umbilical Vein Endothelial Cells

    Science.gov (United States)

    González, Marcelo; Rojas, Susana; Avila, Pía; Cabrera, Lissette; Villalobos, Roberto; Palma, Carlos; Aguayo, Claudio; Peña, Eduardo; Gallardo, Victoria; Guzmán-Gutiérrez, Enrique; Sáez, Tamara; Salsoso, Rocío; Sanhueza, Carlos; Pardo, Fabián; Leiva, Andrea; Sobrevia, Luis

    2015-01-01

    Vascular tone is controlled by the L-arginine/nitric oxide (NO) pathway, and NO bioavailability is strongly affected by hyperglycaemia-induced oxidative stress. Insulin leads to high expression and activity of human cationic amino acid transporter 1 (hCAT-1), NO synthesis and vasodilation; thus, a protective role of insulin on high D-glucose–alterations in endothelial function is likely. Vascular reactivity to U46619 (thromboxane A2 mimetic) and calcitonin gene related peptide (CGRP) was measured in KCl preconstricted human umbilical vein rings (wire myography) incubated in normal (5 mmol/L) or high (25 mmol/L) D-glucose. hCAT-1, endothelial NO synthase (eNOS), 42 and 44 kDa mitogen-activated protein kinases (p42/44mapk), protein kinase B/Akt (Akt) expression and activity were determined by western blotting and qRT-PCR, tetrahydrobiopterin (BH4) level was determined by HPLC, and L-arginine transport (0–1000 μmol/L) was measured in response to 5–25 mmol/L D-glucose (0–36 hours) in passage 2 human umbilical vein endothelial cells (HUVECs). Assays were in the absence or presence of insulin and/or apocynin (nicotinamide adenine dinucleotide phosphate-oxidase [NADPH oxidase] inhibitor), tempol or Mn(III)TMPyP (SOD mimetics). High D-glucose increased hCAT-1 expression and activity, which was biphasic (peaks: 6 and 24 hours of incubation). High D-glucose–increased maximal transport velocity was blocked by insulin and correlated with lower hCAT-1 expression and SLC7A1 gene promoter activity. High D-glucose–increased transport parallels higher reactive oxygen species (ROS) and superoxide anion (O2•–) generation, and increased U46619-contraction and reduced CGRP-dilation of vein rings. Insulin and apocynin attenuate ROS and O2•– generation, and restored vascular reactivity to U46619 and CGRP. Insulin, but not apocynin or tempol reversed high D-glucose–increased NO synthesis; however, tempol and Mn(III)TMPyP reversed the high D-glucose–reduced BH4

  6. IAP Proteins Antagonist: An Introduction and Chemistry of Smac Mimetics under Clinical Development.

    Science.gov (United States)

    Ali, Rafat; Singh, Shalini; Haq, Wahajul

    2018-03-12

    Smac mimetics (also known as IAP antagonist) are a new class of targeted drugs having a goal to suppress the IAPs, reestablishing the apoptotic pathways and inducing cancer cell death. Therefore, development of Smac mimetics was consideredan attractive strategy for the development of new anticancer drugs. Lots of review has been come in yesteryears which mainly discussed about biology of IAPs and their role in cancer development. But none of these reviews focused on the chemical synthesis of Smac mimetics. Literature study was done by using standard bibliographic search engines like scifinder, pubmed etc. The characteristic features of screened articles were described in the review. The review gives an introduction of IAP proteins and Smac mimetics. Readers will gain an overview of the development of Smac mimetics with representative examples of both monovalent and bivalent Smac mimetics as anticancer agents and an understanding of their structure activity relationships. Chemical synthesis of biologically important Smac mimetics was discussed briefly in this review. Small molecules that mimic Smac are continuously progressing towards clinical development. Smac mimetics are generally well tolerated and have demonstrated rapid suppression of their target (the IAPs), activation of apoptosis and anti-tumor activity. Continuous research has been done to generate even more insight into the function of IAP proteins to significantly enhance the therapeutical potential of Smac mimetics. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  7. Synthesis of Disaccharides Containing 6-Deoxy-a-L-talose as Potential Heparan Sulfate Mimetics

    Directory of Open Access Journals (Sweden)

    Vito Ferro

    2012-08-01

    Full Text Available A 6-deoxy-a-L-talopyranoside acceptor was readily prepared from methyl a-L-rhamnopyranoside and glycosylated with thiogalactoside donors using NIS/TfOH as the promoter to give good yields of the desired a-linked disaccharide (69–90%. Glycosylation with a 2-azido-2-deoxy-D-glucosyl trichloroacetimidate donor was not completely stereoselective (a:b = 6:1, but the desired a-linked disaccharide could be isolated in good overall yield (60% following conversion into its corresponding tribenzoate derivative. The disaccharides were designed to mimic the heparan sulfate (HS disaccharide GlcN(2S,6S-IdoA(2S. However, the intermediates readily derived from these disaccharides were not stable to the sulfonation/deacylation conditions required for their conversion into the target HS mimetics.

  8. Reproductive isolation related to mimetic divergence in the poison frog Ranitomeya imitator

    DEFF Research Database (Denmark)

    Twomey, Evan; Vestergaard, Jacob Schack; Summers, Kyle

    2014-01-01

    study the Peruvian poison frog Ranitomeya imitator, a species that has undergone a mimetic radiation into four distinct morphs. Using a combination of colour–pattern analysis, landscape genetics and mate-choice experiments, we show that a mimetic shift in R. imitator is associated with a narrow...

  9. Late time cosmological dynamics with a nonminimal extension of the mimetic matter scenario

    Science.gov (United States)

    Hosseinkhan, N.; Nozari, K.

    2018-02-01

    We investigate an extension of mimetic gravity in which mimetic matter is nonminimally coupled to the Ricci scalar. We derive the background field equations and show that, as the minimal case, the nonminimal mimetic matter can behave as dark matter or dark energy. By adopting some well-known potentials, we study the dynamics of the scale factor and the equation of state parameter in detail. As the effective mimetic dark energy, this model explains the late time cosmic acceleration and its equation of state parameter crosses the phantom divide. We extend our analysis to the dynamical system approach and the phase space trajectories of the model. We obtain an attractor line which corresponds to the late time cosmic acceleration. By comparing this nonminimal mimetic matter scenario with observational data for the LCDM, we show that the confidence levels of this model overlap with those of Planck 2015 TT, TE, EE + Low P + Lensing + BAO data in the LCDM model.

  10. Mimetic Finite Differences for Flow in Fractures from Microseismic Data

    KAUST Repository

    Al-Hinai, Omar

    2015-01-01

    We present a method for porous media flow in the presence of complex fracture networks. The approach uses the Mimetic Finite Difference method (MFD) and takes advantage of MFD\\'s ability to solve over a general set of polyhedral cells. This flexibility is used to mesh fracture intersections in two and three-dimensional settings without creating small cells at the intersection point. We also demonstrate how to use general polyhedra for embedding fracture boundaries in the reservoir domain. The target application is representing fracture networks inferred from microseismic analysis.

  11. Antifreeze Protein Mimetic Metallohelices with Potent Ice Recrystallization Inhibition Activity.

    Science.gov (United States)

    Mitchell, Daniel E; Clarkson, Guy; Fox, David J; Vipond, Rebecca A; Scott, Peter; Gibson, Matthew I

    2017-07-26

    Antifreeze proteins are produced by extremophile species to control ice formation and growth, and they have potential applications in many fields. There are few examples of synthetic materials which can reproduce their potent ice recrystallization inhibition property. We report that self-assembled enantiomerically pure, amphipathic metallohelicies inhibited ice growth at just 20 μM. Structure-property relationships and calculations support the hypothesis that amphipathicity is the key motif for activity. This opens up a new field of metallo-organic antifreeze protein mimetics and provides insight into the origins of ice-growth inhibition.

  12. Bis(maltolato)vanadium(III)-polypyridyl complexes: synthesis, characterization, DNA cleavage, and insulin mimetic activity.

    Science.gov (United States)

    Islam, Md Nazrul; Kumbhar, Anupa A; Kumbhar, Avinash S; Zeller, Matthias; Butcher, Raymond J; Dusane, Menakshi Bhat; Joshi, Bimba N

    2010-09-20

    Four vanadium(III) complexes of the general formula [V(maltol)(2)(N-N)]ClO(4), where N-N is 2,2'-bipyridine (bpy) (1); 1,10-phenanthroline (phen) (2); dipyrido[3,2-d:2',3'-f]quinoxaline (dpq) (3), and dipyrido[3,2-a:2',3'-c]phenazine (dppz) (4), have been synthesized and characterized by IR, UV-visible, NMR spectroscopies, and electrospray ionization mass spectra (ESI-MS). The complexes exhibit the typical (1)H NMR spectra for paramagnetic V(III) species. The structures of complexes 1, 2, and 3 were characterized by single crystal X-ray diffraction. All complexes are monomeric and cationic containing V(III) species ligated to one neutral polypyridyl ligand and two monoanionic bidentate maltolate ligands with a distorted octahedral geometry. The complexes show an irreversible redox peak around +0.80 V versus Ag/AgCl corresponding to one-electron oxidation of V(III) to V(IV). The time-resolved UV-visible spectral changes for the complexes during the electrolysis in acetonitrile solution at +1.0 V are consistent with one-electron oxidation of the complexes to yield the stable V(IV) species. All complexes cleave plasmid pBR322 DNA without the addition of any external agents. In vitro insulin mimetic activity against insulin responsive RIN 5f cells indicates that complex 1 has similar activity to insulin while the others have moderate insulin mimetic activity.

  13. Small-molecule SMAC mimetics as new cancer therapeutics.

    Science.gov (United States)

    Bai, Longchuan; Smith, David C; Wang, Shaomeng

    2014-10-01

    Apoptosis is a tightly regulated cellular process and faulty regulation of apoptosis is a hallmark of human cancers. Targeting key apoptosis regulators with the goal to restore apoptosis in tumor cells has been pursued as a new cancer therapeutic strategy. XIAP, cIAP1, and cIAP2, members of inhibitor of apoptosis (IAP) proteins, are critical regulators of cell death and survival and are attractive targets for new cancer therapy. The SMAC/DIABLO protein is an endogenous antagonist of XIAP, cIAP1, and cIAP2. In the last decade, intense research efforts have resulted in the design and development of several small-molecule SMAC mimetics now in clinical trials for cancer treatment. In this review, we will discuss the roles of XIAP, cIAP1, and cIAP2 in regulation of cell death and survival, and the design and development of small-molecule SMAC mimetics as novel cancer treatments. Copyright © 2014 Elsevier Inc. All rights reserved.

  14. Effects of canola and corn oil mimetic on Jurkat cells

    Directory of Open Access Journals (Sweden)

    Akinsete Juliana A

    2011-06-01

    Full Text Available Abstract Background The Western diet is high in omega-6 fatty acids and low in omega-3 fatty acids. Canola oil contains a healthier omega 3 to omega 6 ratio than corn oil. Jurkat T leukemia cells were treated with free fatty acids mixtures in ratios mimicking that found in commercially available canola oil (7% α-linolenic, 30% linoleic, 54% oleic or corn oil (59% linoleic, 24% oleic to determine the cell survival or cell death and changes in expression levels of inflammatory cytokines and receptors following oil treatment. Methods Fatty acid uptake was assessed by gas chromatography. Cell survival and cell death were evaluated by cell cycle analyses, propidium-iodide staining, trypan blue exclusion and phosphatidylserine externalization. mRNA levels of inflammatory cytokines and receptors were assessed by RT-PCR. Results There was a significant difference in the lipid profiles of the cells after treatment. Differential action of the oils on inflammatory molecules, following treatment at non-cytotoxic levels, indicated that canola oil mimetic was anti-inflammatory whereas corn oil mimetic was pro-inflammatory. Significance These results indicate that use of canola oil in the diet instead of corn oil might be beneficial for diseases promoted by inflammation.

  15. The mimetic repertoire of the spotted bowerbird Ptilonorhynchus maculatus

    Science.gov (United States)

    Kelley, Laura A.; Healy, Susan D.

    2011-06-01

    Although vocal mimicry in songbirds is well documented, little is known about the function of such mimicry. One possibility is that the mimic produces the vocalisations of predatory or aggressive species to deter potential predators or competitors. Alternatively, these sounds may be learned in error as a result of their acoustic properties such as structural simplicity. We determined the mimetic repertoires of a population of male spotted bowerbirds Ptilonorhynchus maculatus, a species that mimics predatory and aggressive species. Although male mimetic repertoires contained an overabundance of vocalisations produced by species that were generally aggressive, there was also a marked prevalence of mimicry of sounds that are associated with alarm such as predator calls, alarm calls and mobbing calls, irrespective of whether the species being mimicked was aggressive or not. We propose that it may be the alarming context in which these sounds are first heard that may lead both to their acquisition and to their later reproduction. We suggest that enhanced learning capability during acute stress may explain vocal mimicry in many species that mimic sounds associated with alarm.

  16. Modular protein switches derived from antibody mimetic proteins.

    Science.gov (United States)

    Nicholes, N; Date, A; Beaujean, P; Hauk, P; Kanwar, M; Ostermeier, M

    2016-02-01

    Protein switches have potential applications as biosensors and selective protein therapeutics. Protein switches built by fusion of proteins with the prerequisite input and output functions are currently developed using an ad hoc process. A modular switch platform in which existing switches could be readily adapted to respond to any ligand would be advantageous. We investigated the feasibility of a modular protein switch platform based on fusions of the enzyme TEM-1 β-lactamase (BLA) with two different antibody mimetic proteins: designed ankyrin repeat proteins (DARPins) and monobodies. We created libraries of random insertions of the gene encoding BLA into genes encoding a DARPin or a monobody designed to bind maltose-binding protein (MBP). From these libraries, we used a genetic selection system for β-lactamase activity to identify genes that conferred MBP-dependent ampicillin resistance to Escherichia coli. Some of these selected genes encoded switch proteins whose enzymatic activity increased up to 14-fold in the presence of MBP. We next introduced mutations into the antibody mimetic domain of these switches that were known to cause binding to different ligands. To different degrees, introduction of the mutations resulted in switches with the desired specificity, illustrating the potential modularity of these platforms. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  17. Mimetic Gravity: A Review of Recent Developments and Applications to Cosmology and Astrophysics

    Directory of Open Access Journals (Sweden)

    Lorenzo Sebastiani

    2017-01-01

    Full Text Available Mimetic gravity is a Weyl-symmetric extension of General Relativity, related to the latter by a singular disformal transformation, wherein the appearance of a dust-like perfect fluid can mimic cold dark matter at a cosmological level. Within this framework, it is possible to provide a unified geometrical explanation for dark matter, the late-time acceleration, and inflation, making it a very attractive theory. In this review, we summarize the main aspects of mimetic gravity, as well as extensions of the minimal formulation of the model. We devote particular focus to the reconstruction technique, which allows the realization of any desired expansionary history of the universe by an accurate choice of potential or other functions defined within the theory (as in the case of mimetic f(R gravity. We briefly discuss cosmological perturbation theory within mimetic gravity. As a case study within which we apply the concepts previously discussed, we study a mimetic Hořava-like theory, of which we explore solutions and cosmological perturbations in detail. Finally, we conclude the review by discussing static spherically symmetric solutions within mimetic gravity and apply our findings to the problem of galactic rotation curves. Our review provides an introduction to mimetic gravity, as well as a concise but self-contained summary of recent findings, progress, open questions, and outlooks on future research directions.

  18. Affinity column for purification of the human platelet thromboxane A2/prostaglandin H2 (TXA2/PGH2) receptor

    International Nuclear Information System (INIS)

    Venton, D.L.; Arora, S.K.; Kim, S.O.; Lim, C.T.; Le Breton, G.C.

    1987-01-01

    The TXA 2 /PGH 2 receptor antagonist, 13-azaprostanoic acid (13-APA), was synthesized and used as the immobilized ligand in the affinity column purification of the 13-APA/U46619 binding component in human platelets. Diazo coupling of the ligand to the phenol of this tyr-gly-gly-NH-(CO)-O-Sepharose gave the affinity column material. Isolated platelet membranes were solubilized with detergent, applied directly to the affinity column and the eluate collected as 6 x 70 ml fractions. For each fraction, protein concentration and specific 3 H-13-APA/numberH-U46619 binding were determined. The majority of the applied protein (>98%) eluted in fraction number1. However, the specific 13-APA/U46619 binding per mg of protein was localized in fractions number4 and number5, representing approximately a 500-fold purification of this binding component. These results suggest that the platelet TXA 2 /PGH 2 receptor protein is retarded by this column, and that starting from crude, solubilized platelet membranes, a single pass through the column provides a 500-fold purification of the receptor

  19. Metformin + Sodium-glucose Co-transporter-2 Inhibitor: Salutogenic Lifestyle Mimetics in a Tablet?

    Directory of Open Access Journals (Sweden)

    Sanjay Kalra

    2018-01-01

    Full Text Available Salutogenesis is an accepted approach for chronic disease management. Calorie restriction and exercise are two evidence based salutogenic interventions in diabetes treatment. Calorie restriction mimetics and exercise mimetics may be used as pharmacological tools to help manage diabetes in a sulutogenic manner. This article discusses the biochemical basis and pharmacology of metformin and sodium glucose cotransporter 2 inhibitors. It describes how a combination of these drugs can be used as a calories restriction and exercise mimetic, to help improve diabetes control.

  20. Moth eye mimetic cytocompatible bactericidal nanotopography: A convergent design.

    Science.gov (United States)

    Viela, Felipe; Navarro-Baena, Iván; Hernández, Jaime J; Osorio, Manuel R; Rodriguez, Isabel

    2018-01-19

    The rapid emergence of antibiotic resistant bacteria has prompted the need for radically different approaches to combat bacterial infections. Among these, bioinspired surface topographies have emerged as an effective sustainable strategy to deter bacterial infection. This study demonstrates the bactericidal activity and cytocompatibility of the moth eye mimetic topography produced by thermal polymer nanoimprinting. The moth eye topography was found to have bactericidal capabilities against Gram negative and Gram positive bacteria. Electron microscopy imaging revealed the bactericidal effect caused by mechanical rupture of the bacteria wall inflicted by the topography on the adhered cells. The cytocompatibility of the surfaces was evidenced by assessing the proliferation and morphology of keratinocytes cultured on the nanotopography. The technology meets important needs in medical implant technology for materials that not only have good biocompatibility but also antibacterial properties for reducing the risk of infections and related health complications. © 2018 IOP Publishing Ltd.

  1. A multilevel multiscale mimetic method for an anisotropic infiltration problem

    Energy Technology Data Exchange (ETDEWEB)

    Lipnikov, Konstantin [Los Alamos National Laboratory; Moulton, David [Los Alamos National Laboratory; Svyatskiy, Daniil [Los Alamos National Laboratory

    2009-01-01

    Modeling of multiphase flow and transport in highly heterogeneous porous media must capture a broad range of coupled spatial and temporal scales. Recently, a hierarchical approach dubbed the Multilevel Multiscale Mimetic (M3) method, was developed to simulate two-phase flow in porous media. The M{sup 3} method is locally mass conserving at all levels in its hierarchy, it supports unstructured polygonal grids and full tensor permeabilities, and it can achieve large coarsening factors. In this work we consider infiltration of water into a two-dimensional layered medium. The grid is aligned with the layers but not the coordinate axes. We demonstrate that with an efficient temporal updating strategy for the coarsening parameters, fine-scale accuracy of prominent features in the flow is maintained by the M{sup 3} method.

  2. New diketone based vanadium complexes as insulin mimetics.

    Science.gov (United States)

    Sheela, A; Roopan, S Mohana; Vijayaraghavan, R

    2008-10-01

    Since 1985, when Heyliger et al. first reported the in vivo insulin mimetic activity of oral vanadate, extensive studies exploring vanadium chemistry, including the synthesis of novel complexes and their biological effects both in vitro and in vivo have been pursued. Such complexes have emerged as possible potential agents for diabetes therapy. Among the several existing compounds, diketone based vanadium complexes have been chosen for the current study. Two new complexes namely bisdimethylmalonatooxovanadium(IV) and bisdiethylmalonatooxovanadium(IV) have been synthesized and characterized by UV-visible, FTIR and mass spectral studies. The antidiabetic activity of the complexes was proved by animal study. The results show that the above complexes have comparable antidiabetic potential with respect to the standard drug as well as with bisacetylacetonatooxovanadium(IV) which has been studied earlier by Reul et al.

  3. Self-assembly of fibronectin mimetic peptide-amphiphile nanofibers

    Science.gov (United States)

    Rexeisen, Emilie Lynn

    Many therapeutic strategies incorporate peptides into their designs to mimic the natural protein ligands found in vivo. A few examples are the short peptide sequences RGD and PHSRN that mimic the primary and synergy-binding domains of the extracellular matrix protein, fibronectin, which is recognized by the cell surface receptor, alpha5beta 1 integrin. Even though scaffold modification with biomimetic peptides remains one of the most promising approaches for tissue engineering, the use of these peptides in therapeutic tissue-engineered products and drug delivery systems available on the commercial market is limited because the peptides are not easily able to mimic the natural protein. The design of a peptide that can effectively target the alpha5beta1 integrin would greatly increase biomimetic scaffold therapeutic potential. A novel peptide containing both the RGD primary binding domain and PHSRN synergy-binding domain for fibronectin joined with the appropriate linker should bind alpha 5beta1 integrin more efficiently and lead to greater cell adhesion over RGD alone. Several fibronectin mimetic peptides were designed and coupled to dialkyl hydrocarbon tails to make peptide-amphiphiles. The peptides contained different linkers connecting the two binding domains and different spacers separating the hydrophobic tails from the hydrophilic headgroups. The peptide-amphiphiles were deposited on mica substrates using the Langmuir-Blodgett technique. Langmuir isotherms indicated that the peptide-amphiphiles that contained higher numbers of serine residues formed a more tightly packed monolayer, but the increased number of serines also made transferring the amphiphiles to the mica substrate more difficult. Atomic force microscopy (AFM) images of the bilayers showed that the headgroups might be bent, forming small divots in the surface. These divots may help expose the PHSRN synergy-binding domain. Parallel studies undertaken by fellow group members showed that human

  4. Improved Oxidase Mimetic Activity by Praseodymium Incorporation into Ceria Nanocubes.

    Science.gov (United States)

    Jiang, Lei; Fernandez-Garcia, Susana; Tinoco, Miguel; Yan, Zhaoxia; Xue, Qi; Blanco, Ginesa; Calvino, Jose J; Hungria, Ana B; Chen, Xiaowei

    2017-06-07

    Ceria nanocubes (NC) modified with increasing concentrations of praseodymium (5, 10, 15, and 20 mol %) have been successfully synthesized by a hydrothermal method. The as-synthesized Pr-modified ceria nanocubes exhibit an enhanced oxidase-like activity on the organic dye TMB within a wide range of concentrations and durations. The oxidase activity increases with increasing Pr amounts in Pr-modified ceria nanocubes within the investigated concentration range. Meanwhile, these Pr-modified ceria nanocubes also show higher reducibility than pure ceria nanocubes. The kinetics of their oxidase mimetic activity is fitted with the Michaelis-Menten equation. A mechanism has been proposed on how the Pr incorporation could affect the energy level of the bands in ceria and hence facilitate the TMB oxidation reaction. The presence of Pr 3+ species on the surface also contributes to the increasing activity of the Pr-modified ceria nanocubes present higher oxidase activity than pure ceria nanocubes.

  5. Ancient homology underlies adaptive mimetic diversity across butterflies

    Science.gov (United States)

    Gallant, Jason R.; Imhoff, Vance E.; Martin, Arnaud; Savage, Wesley K.; Chamberlain, Nicola L.; Pote, Ben L.; Peterson, Chelsea; Smith, Gabriella E.; Evans, Benjamin; Reed, Robert D.; Kronforst, Marcus R.; Mullen, Sean P.

    2014-01-01

    Convergent evolution provides a rare, natural experiment with which to test the predictability of adaptation at the molecular level. Little is known about the molecular basis of convergence over macro-evolutionary timescales. Here we use a combination of positional cloning, population genomic resequencing, association mapping and developmental data to demonstrate that positionally orthologous nucleotide variants in the upstream region of the same gene, WntA, are responsible for parallel mimetic variation in two butterfly lineages that diverged >65 million years ago. Furthermore, characterization of spatial patterns of WntA expression during development suggests that alternative regulatory mechanisms underlie wing pattern variation in each system. Taken together, our results reveal a strikingly predictable molecular basis for phenotypic convergence over deep evolutionary time. PMID:25198507

  6. Impact of the erythropoietin-derived peptide mimetic Epotris on the histopathological consequences of status epilepticus

    DEFF Research Database (Denmark)

    Zellinger, Christina; Seeger, Natalie; Hadamitzky, Martin

    2011-01-01

    The design of peptide mimetics offers interesting opportunities to selectively include beneficial and exclude undesirable effects of a parent molecule. Epotris represents a novel erythropoietin mimetic, which lacks an erythropoietic activity. The present study evaluates the potential of this pept......The design of peptide mimetics offers interesting opportunities to selectively include beneficial and exclude undesirable effects of a parent molecule. Epotris represents a novel erythropoietin mimetic, which lacks an erythropoietic activity. The present study evaluates the potential...... exert limited in vivo effects on the cellular consequences of prolonged seizure activity. When considering further testing it should be taken in mind that Epotris administration only attenuated selected cellular consequences of status epilepticus and did not completely prevent cellular alterations....

  7. A mucosa-mimetic material for the mucoadhesion testing of thermogelling semi-solids.

    Science.gov (United States)

    da Silva, Jéssica Bassi; Khutoryanskiy, Vitaliy V; Bruschi, Marcos L; Cook, Michael T

    2017-08-07

    Mucosa-mimetic materials are synthetic substrates which aim to replace animal tissue in mucoadhesion experiments. One potential mucosa-mimetic material is a hydrogel comprised of N-acryloyl-d-glucosamine and 2-hydroxyethylmethacrylate, which has been investigated as a surrogate for animal mucosae in the mucoadhesion testing of tablets and solution formulations. This study aims to investigate the efficacy of this mucosa-mimetic material in the testing of thermogelling semi-solid formulations, which transition from solution to gel upon warming. Two methods for assessing mucoadhesion have been used; tensile testing and a flow-through system, which allow for investigation under dramatically different conditions. It was found that the mucosa-mimetic material was a good surrogate for buccal mucosa using both testing methods. This material may be used to replace animal tissue in these experiments, potentially reducing the number of laboratory animals used in studies of this type. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. A non-linear constrained optimization technique for the mimetic finite difference method

    Energy Technology Data Exchange (ETDEWEB)

    Manzini, Gianmarco [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Svyatskiy, Daniil [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Bertolazzi, Enrico [Univ. of Trento (Italy); Frego, Marco [Univ. of Trento (Italy)

    2014-09-30

    This is a strategy for the construction of monotone schemes in the framework of the mimetic finite difference method for the approximation of diffusion problems on unstructured polygonal and polyhedral meshes.

  9. Photochemical solar energy conversion utilizing semiconductors localized in membrane-mimetic systems

    Energy Technology Data Exchange (ETDEWEB)

    Fendler, J.H.

    1991-08-31

    Extending the frontiers of colloidal photochemistry and colloidal electrochemistry to solar photochemistry research had been the main objective of this research. More specific objectives of this proposal include the examination of semiconductor-particle-mediated photoelectron transfer and photoelectric effects in different membrane mimetic systems. Emphasis had been placed on developing bilayer lipid membranes and Langmuir-Blodgett films as new membrane-mimetic systems, as well as on the characterization and utilization of these systems.

  10. The Benefits of Calorie Restriction and Calorie Restriction Mimetics as Related to the Eye

    OpenAIRE

    Anekonda, T.S.

    2009-01-01

    The effects of calorie restriction without malnutrition seem to possess many beneficial effects in numerous disease states. Recently, studies related to calorie restriction mimetics that biochemically mimic the effects of calorie restriction are also becoming increasingly popular. Both calorie restriction and calorie restriction mimetics trigger an adaptive response reminiscent of mild-stress or low-dose toxic response, which is frequently referred to as hormesis in the toxicology literature....

  11. How sound symbolism is processed in the brain: a study on Japanese mimetic words.

    Directory of Open Access Journals (Sweden)

    Junko Kanero

    Full Text Available Sound symbolism is the systematic and non-arbitrary link between word and meaning. Although a number of behavioral studies demonstrate that both children and adults are universally sensitive to sound symbolism in mimetic words, the neural mechanisms underlying this phenomenon have not yet been extensively investigated. The present study used functional magnetic resonance imaging to investigate how Japanese mimetic words are processed in the brain. In Experiment 1, we compared processing for motion mimetic words with that for non-sound symbolic motion verbs and adverbs. Mimetic words uniquely activated the right posterior superior temporal sulcus (STS. In Experiment 2, we further examined the generalizability of the findings from Experiment 1 by testing another domain: shape mimetics. Our results show that the right posterior STS was active when subjects processed both motion and shape mimetic words, thus suggesting that this area may be the primary structure for processing sound symbolism. Increased activity in the right posterior STS may also reflect how sound symbolic words function as both linguistic and non-linguistic iconic symbols.

  12. Smac mimetics and oncolytic viruses synergize in driving anticancer T-cell responses through complementary mechanisms.

    Science.gov (United States)

    Kim, Dae-Sun; Dastidar, Himika; Zhang, Chunfen; Zemp, Franz J; Lau, Keith; Ernst, Matthias; Rakic, Andrea; Sikdar, Saif; Rajwani, Jahanara; Naumenko, Victor; Balce, Dale R; Ewanchuk, Ben W; Taylor, Pankaj; Yates, Robin M; Jenne, Craig; Gafuik, Chris; Mahoney, Douglas J

    2017-08-24

    Second mitochondrial activator of caspase (Smac)-mimetic compounds and oncolytic viruses were developed to kill cancer cells directly. However, Smac-mimetic compound and oncolytic virus therapies also modulate host immune responses in ways we hypothesized would complement one another in promoting anticancer T-cell immunity. We show that Smac-mimetic compound and oncolytic virus therapies synergize in driving CD8 + T-cell responses toward tumors through distinct activities. Smac-mimetic compound treatment with LCL161 reinvigorates exhausted CD8 + T cells within immunosuppressed tumors by targeting tumor-associated macrophages for M1-like polarization. Oncolytic virus treatment with vesicular stomatitis virus (VSV ΔM51 ) promotes CD8 + T-cell accumulation within tumors and CD8 + T-cell activation within the tumor-draining lymph node. When combined, LCL161 and VSV ΔM51 therapy engenders CD8 + T-cell-mediated tumor control in several aggressive mouse models of cancer. Smac-mimetic compound and oncolytic virus therapies are both in clinical development and their combination therapy represents a promising approach for promoting anticancer T-cell immunity.Oncolytic viruses (OV) and second mitochondrial activator of caspase (Smac)-mimetic compounds (SMC) synergistically kill cancer cells directly. Here, the authors show that SMC and OV therapies combination also synergize in vivo by promoting anticancer immunity through an increase in CD8 + T-cell response.

  13. Effect of tempol on redox homeostasis and stress tolerance in mimetically aged Drosophila.

    Science.gov (United States)

    Aksu, Ugur; Yanar, Karolin; Terzioglu, Duygu; Erkol, Tugçe; Ece, Evrim; Aydin, Seval; Uslu, Ezel; Çakatay, Ufuk

    2014-09-01

    We aimed to test our hypothesis that scavenging reactive oxygen species (ROS) with tempol, a membrane permeable antioxidant, affects the type and magnitude of oxidative damage and stress tolerance through mimetic aging process in Drosophila. Drosophila colonies were randomly divided into three groups: (1) no D-galactose, no tempol; (2) D-galactose without tempol; (3) D-galactose, but with tempol. Mimetic aging was induced by d-galactose administration. The tempol-administered flies received tempol at the concentration of 0.2% in addition to d-galactose. Thiobarbituric acid reacting substance (TBARS) concentrations, advanced oxidation protein products (AOPPs), Cu,Zn-superoxide dismutase (Cu,Zn-SOD), sialic acid (SA) were determined. Additionally, stress tolerances were tested. Mimetically aged group without tempol led to a significant decrease in tolerance to heat, cold, and starvation (P tempol was used for these parameters. The Cu,Zn-SOD activity and SA concentrations were lower in both mimetically aged and tempol-administered Drosophila groups compared to control (P tempol-administered groups. Mimetically aged group without tempol led to a significant increase in tissue TBARS and AOPPs concentrations (P tempol could prevent these alterations. Scavenging ROS using tempol also restores redox homeostasis in mimetically aged group. Tempol partly restores age-related oxidative injury and increases stress tolerance. © 2014 Wiley Periodicals, Inc.

  14. Reissner–Nordström Anti-de Sitter Black Holes in Mimetic F(R Gravity

    Directory of Open Access Journals (Sweden)

    V. K. Oikonomou

    2016-05-01

    Full Text Available In this paper, we study under which conditions the Reissner–Nordström anti-de Sitter black hole can be a solution of the vacuum mimetic F ( R gravity with Lagrange multiplier and mimetic scalar potential. As the author demonstrates, the resulting picture in the mimetic F ( R gravity case is a trivial extension of the standard F ( R approach, and in effect, the metric perturbations in the mimetic F ( R gravity case, for the Reissner–Nordström anti-de Sitter black hole metric, at the first order of the perturbed variables are the same at the leading order.

  15. Determination of superoxide dismutase mimetic activity in common culinary herbs.

    Science.gov (United States)

    Chohan, Magali; Naughton, Declan P; Opara, Elizabeth I

    2014-01-01

    Under conditions of oxidative stress, the removal of superoxide, a free radical associated with chronic inflammation, is catalysed by superoxide dismutase (SOD). Thus in addition to acting as an antioxidant, SOD may also be utilized as an anti-inflammatory agent. Some plant derived foods have been shown to have SOD mimetic (SODm) activity however it is not known if this activity is possessed by culinary herbs which have previously been shown to possess both antioxidant and anti-inflammatory properties. The aim of the study was to ascertain if the culinary herbs rosemary, sage and thyme possess SODm activity, and to investigate the influence of cooking and digestion on this activity. Transition metal ion content was also determined to establish if it could likely contribute to any SODm activity detected. All extracts of uncooked (U), cooked (C) and cooked and digested (C&D) herbs were shown to possess SODm activity, which was significantly correlated with previously determined antioxidant and anti-inflammatory activities of these herbs. SODm activity was significantly increased following (C) and (C&D) for rosemary and sage only. The impact of (C) and (C&D) on the SODm for thyme may have been influenced by its transition metal ion content. SODm activity may contribute to the herbs' antioxidant and anti-inflammatory activities however the source and significance of this activity need to be established.

  16. The therapeutic potential of insulin-mimetic vanadium complexes.

    Science.gov (United States)

    Sakurai, Hiromu; Yasui, Hiroyuki; Adachi, Yusuke

    2003-07-01

    Throughout the world, the number of patients suffering from diabetes mellitus (DM) is increasing on a daily basis, probably due to change in lifestyle. DM is mainly classified as either insulin-dependent Type 1 or non-insulin-dependent Type 2, according to the definition of WHO. To treat DM, which has many severe complications, several types of insulin preparations and synthetic drugs for Type 1 and Type 2 DM, respectively, have been developed and are in clinical use. However, there are several problems concerning the insulin preparations and synthetic drugs, such as physical and mental pain due to daily insulin injections and defects involving side effects, respectively. Consequently, a new class of therapeutic agents is anticipated. For this purpose, vanadium-containing complexes are expected to treat or improve both types of DM by using unique characteristics of the transition metal. In this article, the current state of research on insulin-mimetic vanadium complexes are reviewed, with special focus on the paramagnetic vanadyl (+4 oxidation state of vanadium) complexes with different coordination modes. To analyse the blood glucose-lowering effects of the vanadyl complexes, new results on the organ distribution and pharmacokinetic analysis of the vanadyl state in the blood of rats are also described.

  17. Oral insulin-mimetic compounds that act independently of insulin.

    Science.gov (United States)

    García-Vicente, Silvia; Yraola, Francesc; Marti, Luc; González-Muñoz, Elena; García-Barrado, María José; Cantó, Carles; Abella, Anna; Bour, Sandy; Artuch, Rafael; Sierra, Cristina; Brandi, Nuria; Carpéné, Christian; Moratinos, Julio; Camps, Marta; Palacín, Manuel; Testar, Xavier; Gumà, Anna; Albericio, Fernando; Royo, Miriam; Mian, Alec; Zorzano, Antonio

    2007-02-01

    The hallmarks of insulin action are the stimulation and suppression of anabolic and catabolic responses, respectively. These responses are orchestrated by the insulin pathway and are initiated by the binding of insulin to the insulin receptor, which leads to activation of the receptor's intrinsic tyrosine kinase. Severe defects in the insulin pathway, such as in types A and B and advanced type 1 and 2 diabetes lead to severe insulin resistance, resulting in a partial or complete absence of response to exogenous insulin and other known classes of antidiabetes therapies. We have characterized a novel class of arylalkylamine vanadium salts that exert potent insulin-mimetic effects downstream of the insulin receptor in adipocytes. These compounds trigger insulin signaling, which is characterized by rapid activation of insulin receptor substrate-1, Akt, and glycogen synthase kinase-3 independent of insulin receptor phosphorylation. Administration of these compounds to animal models of diabetes lowered glycemia and normalized the plasma lipid profile. Arylalkylamine vanadium compounds also showed antidiabetic effects in severely diabetic rats with undetectable circulating insulin. These results demonstrate the feasibility of insulin-like regulation in the complete absence of insulin and downstream of the insulin receptor. This represents a novel therapeutic approach for diabetic patients with severe insulin resistance.

  18. Membrane mimetic surface functionalization of nanoparticles: Methods and applications

    Science.gov (United States)

    Weingart, Jacob; Vabbilisetty, Pratima; Sun, Xue-Long

    2013-01-01

    Nanoparticles (NPs), due to their size-dependent physical and chemical properties, have shown remarkable potential for a wide range of applications over the past decades. Particularly, the biological compatibilities and functions of NPs have been extensively studied for expanding their potential in areas of biomedical application such as bioimaging, biosensing, and drug delivery. In doing so, surface functionalization of NPs by introducing synthetic ligands and/or natural biomolecules has become a critical component in regards to the overall performance of the NP system for its intended use. Among known examples of surface functionalization, the construction of an artificial cell membrane structure, based on phospholipids, has proven effective in enhancing biocompatibility and has become a viable alternative to more traditional modifications, such as direct polymer conjugation. Furthermore, certain bioactive molecules can be immobilized onto the surface of phospholipid platforms to generate displays more reminiscent of cellular surface components. Thus, NPs with membrane-mimetic displays have found use in a range of bioimaging, biosensing, and drug delivery applications. This review herein describes recent advances in the preparations and characterization of integrated functional NPs covered by artificial cell membrane structures and their use in various biomedical applications. PMID:23688632

  19. SOCS1 Mimetic Peptide Suppresses Chronic Intraocular Inflammatory Disease (Uveitis

    Directory of Open Access Journals (Sweden)

    Chang He

    2016-01-01

    Full Text Available Uveitis is a potentially sight-threatening disease characterized by repeated cycles of remission and recurrent inflammation. The JAK/STAT pathway regulates the differentiation of pathogenic Th1 and Th17 cells that mediate uveitis. A SOCS1 mimetic peptide (SOCS1-KIR that inhibits JAK2/STAT1 pathways has recently been shown to suppress experimental autoimmune uveitis (EAU. However, it is not clear whether SOCS1-KIR ameliorated uveitis by targeting JAK/STAT pathways of pathogenic lymphocytes or via inhibition of macrophages and antigen-presenting cells that also enter the retina during EAU. To further investigate mechanisms that mediate SOCS1-KIR effects and evaluate the efficacy of SOCS1-KIR as an investigational drug for chronic uveitis, we induced EAU in rats by adoptive transfer of uveitogenic T-cells and monitored disease progression and severity by slit-lamp microscopy, histology, and optical coherence tomography. Topical administration of SOCS1-KIR ameliorated acute and chronic posterior uveitis by inhibiting Th17 cells and the recruitment of inflammatory cells into retina while promoting expansion of IL-10-producing Tregs. We further show that SOCS1-KIR conferred protection of resident retinal cells that play critical role in vision from cytotoxic effects of inflammatory cytokines by downregulating proapoptotic genes. Thus, SOCS1-KIR suppresses uveitis and confers neuroprotective effects and might be exploited as a noninvasive treatment for chronic uveitis.

  20. Promotion of hair growth by newly synthesized ceramide mimetic compound.

    Science.gov (United States)

    Park, Bu-Mahn; Bak, Soon-Sun; Shin, Kyung-Oh; Kim, Minhee; Kim, Daehwan; Jung, Sang-Hun; Jeong, Sekyoo; Sung, Young Kwan; Kim, Hyun Jung

    2017-09-09

    Based on the crucial roles of ceramides in skin barrier function, use of ceramides or their structural mimetic compounds, pseudoceramides, as cosmetic ingredients are getting more popular. While currently used pseudoceramides are intended to substitute the structural roles of ceramides in stratum corneum, development of bioactive pseudoceramides has been repeatedly reported. In this study, based on the potential involvement of sphingolipids in hair cycle regulation, we investigated the effects of newly synthesized pseudoceramide, bis-oleamido isopropyl alcohol (BOI), on hair growth using cultured human hair follicles and animal models. BOI treatment promoted hair growth in cultured human hair follicles ex vivo and induced earlier conversion of telogen into anagen. Although we did not find a significant enhancement of growth factor expression and follicular cell proliferation, BOI treatment resulted in an increased sphinganine and sphingosine contents as well as increased ceramides contents in cultured dermal papilla (DP) cells. Taken together, our data strongly suggest that biologically active pseudoceramide promotes hair growth by stimulating do novo synthesis of sphingolipids in DP cells. Copyright © 2017 Elsevier Inc. All rights reserved.

  1. Metal stabilization of collagen and de novo designed mimetic peptides

    Science.gov (United States)

    Parmar, Avanish S.; Xu, Fei; Pike, Douglas H.; Belure, Sandeep V.; Hasan, Nida F.; Drzewiecki, Kathryn E.; Shreiber, David I.; Nanda, Vikas

    2017-01-01

    We explore the design of metal binding sites to modulate triple-helix stability of collagen and collagen-mimetic peptides. Globular proteins commonly utilize metals to connect tertiary structural elements that are well separated in sequence, constraining structure and enhancing stability. It is more challenging to engineer structural metals into fibrous protein scaffolds, which lack the extensive tertiary contacts seen in globular proteins. In the collagen triple helix, the structural adjacency of the carboxy-termini of the three chains makes this region an attractive target for introducing metal binding sites. We engineered His3 sites based on structural modeling constraints into a series of designed homotrimeric and heterotrimeric peptides, assessing the capacity of metal binding to improve stability and in the case of heterotrimers, affect specificity of assembly. Notable enhancements in stability for both homo and heteromeric systems were observed upon addition of zinc(II) and several other metal ions only when all three histidine ligands were present. Metal binding affinities were consistent with the expected Irving-Williams series for imidazole. Unlike other metals tested, copper(II) also bound to peptides lacking histidine ligands. Acetylation of the peptide N-termini prevented copper binding, indicating proline backbone amide metal-coordination at this site. Copper similarly stabilized animal extracted Type I collagen in a metal specific fashion, highlighting the potential importance of metal homeostasis within the extracellular matrix. PMID:26225466

  2. PKC activation sensitizes basal-like breast cancer cell lines to Smac mimetics.

    Science.gov (United States)

    Cornmark, L; Holmgren, C; Masoumi, K; Larsson, C

    2016-01-01

    There is a need for novel strategies to initiate cancer cell death. One approach is the use of Smac mimetics, which antagonize inhibitor of apoptosis proteins (IAPs). Recent studies have shown that combinations of Smac mimetics such as LBW242 or LCL161 in combination with chemotherapeutic agents increase cancer cell death. Here we show that the protein kinase C (PKC) activator TPA together with the Smac mimetic LBW242 induces cell death in two basal breast cancer cell lines (MDA-MB-468 and BT-549) that are resistant to Smac mimetic as single agent. Ten other LBW242-insensitive cancer cell lines were not influenced by the TPA+LBW242 combination. The TPA+LBW242 effect was suppressed by the PKC inhibitor GF109203X, indicating dependence on PKC enzymatic activity. The PKC effect was mediated via increased synthesis and release of TNFα, which can induce death in the presence of Smac mimetics. The cell death, coinciding with caspase-3 cleavage, was suppressed by caspase inhibition and preceded by the association of RIP1 with caspase-8, as seen in complex II formation. Smac mimetics, but not TPA, induced the non-canonical NF-κB pathway in both MDA-MB-231 and MDA-MB-468 cells. Blocking the canonical NF-κB pathway suppressed TPA induction of TNFα in MDA-MB-468 cells whereas isolated downregulation of either the canonical or non-canonical pathways did not abolish the Smac mimetic induction of the NF-κB driven genes TNFα and BIRC3 in MDA-MB-231 cells although the absolute levels were suppressed. A combined downregulation of the canonical and non-canonical pathways further suppressed TNFα levels and inhibited Smac mimetic-mediated cell death. Our data suggest that in certain basal breast cancer cell lines co-treatment of TPA with a Smac mimetic induces cell death highlighting the potential of using these pathways as molecular targets for basal-like breast cancers.

  3. Elementary dispersion analysis of some mimetic discretizations on triangular C-grids

    Energy Technology Data Exchange (ETDEWEB)

    Korn, P., E-mail: peter.korn@mpimet.mpg.de [Max Planck Institute for Meteorology, Hamburg (Germany); Danilov, S. [Alfred Wegener Institute for Polar and Marine Research, Bremerhaven (Germany); A.M. Obukhov Institute of Atmospheric Physics, Moscow (Russian Federation)

    2017-02-01

    Spurious modes supported by triangular C-grids limit their application for modeling large-scale atmospheric and oceanic flows. Their behavior can be modified within a mimetic approach that generalizes the scalar product underlying the triangular C-grid discretization. The mimetic approach provides a discrete continuity equation which operates on an averaged combination of normal edge velocities instead of normal edge velocities proper. An elementary analysis of the wave dispersion of the new discretization for Poincaré, Rossby and Kelvin waves shows that, although spurious Poincaré modes are preserved, their frequency tends to zero in the limit of small wavenumbers, which removes the divergence noise in this limit. However, the frequencies of spurious and physical modes become close on shorter scales indicating that spurious modes can be excited unless high-frequency short-scale motions are effectively filtered in numerical codes. We argue that filtering by viscous dissipation is more efficient in the mimetic approach than in the standard C-grid discretization. Lumping of mass matrices appearing with the velocity time derivative in the mimetic discretization only slightly reduces the accuracy of the wave dispersion and can be used in practice. Thus, the mimetic approach cures some difficulties of the traditional triangular C-grid discretization but may still need appropriately tuned viscosity to filter small scales and high frequencies in solutions of full primitive equations when these are excited by nonlinear dynamics.

  4. From Dalek half balls to Daft Punk helmets: Mimetic fandom and the crafting of replicas

    Directory of Open Access Journals (Sweden)

    Matt Hills

    2014-06-01

    Full Text Available Mimetic fandom is a surprisingly understudied mode of (culturally masculinized fan activity in which fans research and craft replica props. Mimetic fandom can be considered as (inauthentic and (immaterial, combining noncommercial status with grassroots marketing or brand reinforcement as well as fusing an emphasis on material artifacts with Web 2.0 collective intelligence. Simply analyzing mimetic fandom as part of fannish material culture fails to adequately assess the nonmaterial aspects of this collaborative creativity. Two fan cultures are taken as case studies: Dalek building groups and Daft Punk helmet constructors. These diverse cases indicate that mimetic fandom has a presence and significance that moves across media fandoms and is not restricted to the science fiction, fantasy, and horror followings with which it is most often associated. Mimetic fandom may be theorized as an oscillatory activity that confuses binaries and constructions of (academic/fan authenticity. This fan practice desires and pursues a kind of ontological bridging or unity—from text to reality—that is either absent or less dominant in many other fan activities such as cosplay, screen-used prop collecting, and geographical pilgrimage. Fan studies may benefit from reassessing the place of mimesis, especially in order to theorize fan practices that are less clearly transformative in character.

  5. Reactive oxygen species contribute toward Smac mimetic/temozolomide-induced cell death in glioblastoma cells.

    Science.gov (United States)

    Seyfrid, Mathieu; Marschall, Viola; Fulda, Simone

    2016-11-01

    Small-molecule inhibitors of Inhibitor of Apoptosis proteins such as Smac mimetics have been reported to provide a promising tool to sensitize glioblastoma (GBM) cells to cytotoxic therapies including chemotherapeutic drugs. However, the underlying molecular mechanisms of action have not yet been fully unraveled. In the present study, we therefore investigated the role of reactive oxygen species (ROS) in the regulation of Smac mimetic/temozolomide (TMZ)-induced cell death in GBM cells. Here, we show that the Smac mimetic BV6 and TMZ act in concert to stimulate the production of both cytosolic and mitochondrial ROS. This accumulation of ROS contributes toward the activation of the proapoptotic factor BAX upon BV6/TMZ cotreatment as several ROS scavengers (i.e. N-acetyl-L-cysteine, MnTBAP, or α-tocopherol) protect GBM cells against BV6/TMZ-mediated BAX activation. In addition, ROS scavengers significantly rescue GBM cells from BV6/TMZ-triggered cell death, indicating that ROS generation is required for the induction of cell death. By showing that ROS play an important role in the regulation of Smac mimetic/TMZ-induced cell death, our work sheds light on the crucial role of the oxidative system in the cooperative antitumor activity of Smac mimetic/TMZ combination therapy against GBM cells.

  6. Prey from the eyes of predators: Color discriminability of aposematic and mimetic butterflies from an avian visual perspective.

    Science.gov (United States)

    Su, Shiyu; Lim, Matthew; Kunte, Krushnamegh

    2015-11-01

    Predation exerts strong selection on mimetic butterfly wing color patterns, which also serve other functions such as sexual selection. Therefore, specific selection pressures may affect the sexes and signal components differentially. We tested three predictions about the evolution of mimetic resemblance by comparing wing coloration of aposematic butterflies and their Batesian mimics: (a) females gain greater mimetic advantage than males and therefore are better mimics, (b) due to intersexual genetic correlations, sexually monomorphic mimics are better mimics than female-limited mimics, and (c) mimetic resemblance is better on the dorsal wing surface that is visible to predators in flight. Using a physiological model of avian color vision, we quantified mimetic resemblance from predators' perspective, which showed that female butterflies were better mimics than males. Mimetic resemblance in female-limited mimics was comparable to that in sexually monomorphic mimics, suggesting that intersexual genetic correlations did not constrain adaptive response to selection for female-limited mimicry. Mimetic resemblance on the ventral wing surface was better than that on the dorsal wing surface, implying stronger natural and sexual selection on ventral and dorsal surfaces, respectively. These results suggest that mimetic resemblance in butterfly mimicry rings has evolved under various selective pressures acting in a sex- and wing surface-specific manner. © 2015 The Author(s). Evolution © 2015 The Society for the Study of Evolution.

  7. Dual action Smac mimetics-zinc chelators as pro-apoptotic antitumoral agents.

    Science.gov (United States)

    Manzoni, Leonardo; Gornati, Davide; Manzotti, Mattia; Cairati, Silvia; Bossi, Alberto; Arosio, Daniela; Lecis, Daniele; Seneci, Pierfausto

    2016-10-01

    Dual action compounds (DACs) based on 4-substituted aza-bicyclo[5.3.0]decane Smac mimetic scaffolds (ABDs) linked to a Zn(2+)-chelating moiety (DPA, o-hydroxy, m-allyl, N-acyl (E)-phenylhydrazone) through their 10 position are reported and characterized. Their synthesis, their target affinity (XIAP BIR3, Zn(2+)) in cell-free assays, their pro-apoptotic effects and cytotoxicity in tumor cells with varying sensitivity to Smac mimetics are described. The results are interpreted to evaluate the influence of Zn(2+) chelators on cell-free potency and on cellular permeability of DACs, and to propose novel avenues towards more potent antitumoral DACs based on Smac mimetics and Zn(2+) chelation. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. Healthy imperfect dark matter from effective theory of mimetic cosmological perturbations

    International Nuclear Information System (INIS)

    Hirano, Shin'ichi; Nishi, Sakine; Kobayashi, Tsutomu

    2017-01-01

    We study the stability of a recently proposed model of scalar-field matter called mimetic dark matter or imperfect dark matter. It has been known that mimetic matter with higher derivative terms suffers from gradient instabilities in scalar perturbations. To seek for an instability-free extension of imperfect dark matter, we develop an effective theory of cosmological perturbations subject to the constraint on the scalar field's kinetic term. This is done by using the unifying framework of general scalar-tensor theories based on the ADM formalism. We demonstrate that it is indeed possible to construct a model of imperfect dark matter which is free from ghost and gradient instabilities. As a side remark, we also show that mimetic F (R) theory is plagued with the Ostrogradsky instability.

  9. A review of underwater bio-mimetic propulsion: cruise and fast-start

    Science.gov (United States)

    Chao, Li-Ming; Cao, Yong-Hui; Pan, Guang

    2017-08-01

    This paper reviews recent developments in the understanding of underwater bio-mimetic propulsion. Two impressive models of underwater propulsion are considered: cruise and fast-start. First, we introduce the progression of bio-mimetic propulsion, especially underwater propulsion, where some primary conceptions are touched upon. Second, the understanding of flapping foils, considered as one of the most efficient cruise styles of aquatic animals, is introduced, where the effect of kinematics and the shape and flexibility of foils on generating thrust are elucidated respectively. Fast-start propulsion is always exhibited when predator behaviour occurs, and we provide an explicit introduction of corresponding zoological experiments and numerical simulations. We also provide some predictions about underwater bio-mimetic propulsion.

  10. René Girard and the Mimetic Nature of Eating Disorders.

    Science.gov (United States)

    Strand, Mattias

    2018-03-07

    French historian and literary critic René Girard (1923-2015), most widely known for the concepts of mimetic desire and scapegoating, also engaged in the discussion of the surge of eating disorders in his 1996 essay Eating Disorders and Mimetic Desire. This article explores Girard's ideas on the mimetic nature and origin of eating disorders from a clinical psychiatric perspective and contextualizes them within the field of eating disorders research as well as in relation to broader psychological, sociological and anthropological models of social comparison and non-consumption. Three main themes in Girard's thinking on the topic of eating disorders are identified and explored: the 'end of prohibitions' as a driving force in the emergence of eating disorders, eating disorders as a phenomenon specific to modernity, and the significance of 'conspicuous non-consumption' in the emergence of eating disorders.

  11. Targeting apoptotic machinery as approach for anticancer therapy: Smac mimetics as anticancer agents

    Directory of Open Access Journals (Sweden)

    Nevine M.Y. Elsayed

    2015-06-01

    Full Text Available Apoptosis is a chief regulator of cellular homeostasis. Impairment of apoptotic machinery is a main characteristic of several diseases such as cancer, where the evasion of apoptosis is a cardinal hallmark of cancer. Apoptosis is regulated by contribution of pro- and anti- apoptotic proteins, where caspases are the main executioners of the apoptotic machinery. IAP (inhibitors of apoptosis proteins is a family of endogenous inhibitors of apoptosis, which perform their function through interference with the function of caspases. Smac (second mitochondria-derived activator of caspases is endogenous inhibitor of IAPs, thus it is one of the major proapoptotic endogenous proteins. Thus, the development of Smac mimetics has evolved as an approach for anticancer therapy. Several Smac mimetic agents have been introduced to clinical trial such as birinapanet 12. Herein, the history of development of Smac mimetics along with the recent development in this field is briefly discussed.

  12. Modeling seismic wave propagation using staggered-grid mimetic finite differences

    Directory of Open Access Journals (Sweden)

    Freysimar Solano-Feo

    2017-04-01

    Full Text Available Mimetic finite difference (MFD approximations of continuous gradient and divergence operators satisfy a discrete version of the Gauss-Divergence theorem on staggered grids. On the mimetic approximation of this integral conservation principle, an unique boundary flux operator is introduced that also intervenes on the discretization of a given boundary value problem (BVP. In this work, we present a second-order MFD scheme for seismic wave propagation on staggered grids that discretized free surface and absorbing boundary conditions (ABC with same accuracy order. This scheme is time explicit after coupling a central three-level finite difference (FD stencil for numerical integration. Here, we briefly discuss the convergence properties of this scheme and show its higher accuracy on a challenging test when compared to a traditional FD method. Preliminary applications to 2-D seismic scenarios are also presented and show the potential of the mimetic finite difference method.

  13. Ligand selectivity of a synthetic CXCR4 mimetic peptide.

    Science.gov (United States)

    Groß, Andrea; Brox, Regine; Damm, Dominik; Tschammer, Nuška; Schmidt, Barbara; Eichler, Jutta

    2015-07-15

    The chemokine receptor CXCR4 belongs to the family of seven-transmembrane G-protein coupled receptors (GPCRs). It is activated by its natural ligand SDF-1α. In addition, CXCR4, along with CCR5, serve as coreceptors during HIV-1 entry into its target cell. Recently, we introduced a CXCR4 mimetic peptide, termed CX4-M1, which presents the three extracellular loops (ECLs) of the receptor. CX4-M1 was shown to selectively bind to gp120 of X4-tropic, that is, CXCR4 using, HIV-1, as well as to peptides that present the V3-loops of these gp120 proteins. Furthermore, CX4-M1 selectively inhibits infection of cells with X4-tropic HIV-1. We have now adapted the sequence of the ECLs presented by CX4-M1 to the recently published crystal structure of CXCR4. The binding behavior, as well as the effect on HIV-1 infection, of the resulting peptide (CX4-Mc) was very similar to CX4-M1, validating retrospectively the original design of CX4-M1. A peptide presenting the ECLs of CCR5 (CR5-M), on the other hand, did neither bind to gp120 from X4-tropic HIV-1, nor did it inhibit infection of cells with X4-tropic HIV-1. Furthermore, we could show that CX4-M1, as well as CX4-Mc, but not CR5-M, are selectively recognized by anti-CXCR4 antibodies, bind to SDF-1α, and also inhibit SDF-1α signaling, extending the scope of selective functional CXCR4 mimicry through CX4-M1. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. Novel SMAC-mimetics synergistically stimulate melanoma cell death in combination with TRAIL and Bortezomib.

    Science.gov (United States)

    Lecis, D; Drago, C; Manzoni, L; Seneci, P; Scolastico, C; Mastrangelo, E; Bolognesi, M; Anichini, A; Kashkar, H; Walczak, H; Delia, D

    2010-06-08

    XIAP (X-linked inhibitor of apoptosis protein) is an anti-apoptotic protein exerting its activity by binding and suppressing caspases. As XIAP is overexpressed in several tumours, in which it apparently contributes to chemoresistance, and because its activity in vivo is antagonised by second mitochondria-derived activator of caspase (SMAC)/direct inhibitor of apoptosis-binding protein with low pI, small molecules mimicking SMAC (so called SMAC-mimetics) can potentially overcome tumour resistance by promoting apoptosis. Three homodimeric compounds were synthesised tethering a monomeric SMAC-mimetic with different linkers and their affinity binding for the baculoviral inhibitor repeats domains of XIAP measured by fluorescent polarisation assay. The apoptotic activity of these molecules, alone or in combination with tumour necrosis factor-related apoptosis-inducing ligand (TRAIL) and/or Bortezomib, was tested in melanoma cell lines by MTT viability assays and western blot analysis of activated caspases. We show that in melanoma cell lines, which are typically resistant to chemotherapeutic agents, XIAP knock-down sensitises cells to TRAIL treatment in vitro, also favouring the accumulation of cleaved caspase-8. We also describe a new series of 4-substituted azabicyclo[5.3.0]alkane monomeric and dimeric SMAC-mimetics that target various members of the IAP family and powerfully synergise at submicromolar concentrations with TRAIL in inducing cell death. Finally, we show that the simultaneous administration of newly developed SMAC-mimetics with Bortezomib potently triggers apoptosis in a melanoma cell line resistant to the combined effect of SMAC-mimetics and TRAIL. Hence, the newly developed SMAC-mimetics effectively synergise with TRAIL and Bortezomib in inducing cell death. These findings warrant further preclinical studies in vivo to verify the anticancer effectiveness of the combination of these agents.

  15. LRIG1 modulates cancer cell sensitivity to Smac mimetics by regulating TNFα expression and receptor tyrosine kinase signaling.

    Science.gov (United States)

    Bai, Longchuan; McEachern, Donna; Yang, Chao-Yie; Lu, Jianfeng; Sun, Haiying; Wang, Shaomeng

    2012-03-01

    Smac mimetics block inhibitor of apoptosis proteins to trigger TNFα-dependent apoptosis in cancer cells. However, only a small subset of cancer cells seem to be sensitive to Smac mimetics and even sensitive cells can develop resistance. Herein, we elucidated mechanisms underlying the intrinsic and acquired resistance of cancer cells to Smac mimetics. In vitro and in vivo investigations revealed that the expression of the cell surface protein LRIG1, a negative regulator of receptor tyrosine kinases (RTK), is downregulated in resistant derivatives of breast cancer cells sensitive to Smac mimetics. RNA interference-mediated downregulation of LRIG1 markedly attenuated the growth inhibitory activity of the Smac mimetic SM-164 in drug-sensitive breast and ovarian cancer cells. Furthermore, LRIG1 downregulation attenuated TNFα gene expression induced by Smac mimetics and increased the activity of multiple RTKs, including c-Met and Ron. The multitargeted tyrosine kinase inhibitors Crizotinib and GSK1363089 greatly enhanced the anticancer activity of SM-164 in all resistant cell derivatives, with the combination of SM-164 and GSK1363089 also completely inhibiting the outgrowth of resistant tumors in vivo. Together, our findings show that both upregulation of RTK signaling and attenuated TNFα expression caused by LRIG1 downregulation confers resistance to Smac mimetics, with implications for a rational combination strategy.

  16. The conversion in the René Girard’s mimetic theory

    Directory of Open Access Journals (Sweden)

    Agustín Moreno Fernández

    2014-12-01

    Full Text Available One of the specific peculiarities of René Girard’s mimetic theory is the recovery of the concept of conversion. In this article we expose, in a detailed way, the three senses of the conversion according to his thinking: novelistic, religious and epistemological. There is an interaction between the three senses and also different significations for each other.

  17. A Smac mimetic augments the response of urothelial cancer cells to gemcitabine and cisplatin.

    Science.gov (United States)

    Lee, Eugene K; Jinesh G, Goodwin; Laing, Naomi M; Choi, Woonyoung; McConkey, David J; Kamat, Ashish M

    2013-09-01

    Cisplatin-based chemotherapy is considered the gold standard for patients with advanced bladder cancer. However, despite initial response, many patients will relapse; therefore, novel salvage treatment strategies are desperately needed. Herein, we studied a mechanism based treatment combination using a Smac mimetic with standard chemotherapy. Using a panel of 10 urothelial cancer cell lines, we exposed them to a combination of gemcitabine, cisplatin, and a Smac mimetic. Sensitivity was determined using a DNA fragmentation assay. We determined that three cell lines (UMUC-3, UMUC-13, and RT4v6) were considered sensitive to the combination of gemcitabine and cisplatin and an additional three cell lines were sensitized to gemcitabine and cisplatin with the addition of the Smac mimetic (UMUC-6, UMUC-12, and UMUC-18). We next explored the constitutive expression of selected members of the IAP family (XIAP, cIAP-1, cIAP-2, and Survivin), the BCL family (BCL-2, BCLXL, and BAX) and Smac using gene expression profiling and western blotting. We determined that RNA and protein expression of SMAC, selected members of the IAP family and members of the BCL family did not correlate to drug sensitivity. Lastly, using an in vivo mouse model, we determined that treatment with the Smac mimetic in combination with gemcitabine and cisplatin resulted in increased apoptosis, decreased microvessel density and decreased cellular proliferation. This novel treatment strategy may be effective in patients with advanced urothelial carcinoma and warrants further investigation.

  18. Mimetic Divergence and the Speciation Continuum in the Mimic Poison Frog Ranitomeya imitator

    DEFF Research Database (Denmark)

    Twomey, Evan; Vestergaard, Jacob Schack; Venegas, Pablo J.

    2016-01-01

    While divergent ecological adaptation can drive speciation, understanding the factors that facilitate or constrain this process remains a major goal in speciation research. Here, we study two mimetic transition zones in the poison frog Ranitomeya imitator, a species that has undergone a Mullerian...

  19. Effect of tempol on redox homeostasis and stress tolerance in mimetically aged Drosophila

    NARCIS (Netherlands)

    Aksu, Ugur; Yanar, Karolin; Terzioglu, Duygu; Erkol, Tugçe; Ece, Evrim; Aydin, Seval; Uslu, Ezel; Çakatay, Ufuk

    2014-01-01

    We aimed to test our hypothesis that scavenging reactive oxygen species (ROS) with tempol, a membrane permeable antioxidant, affects the type and magnitude of oxidative damage and stress tolerance through mimetic aging process in Drosophila. Drosophila colonies were randomly divided into three

  20. Apolipoprotein A-I mimetic peptide 4F blocks sphingomyelinase-induced LDL aggregation

    DEFF Research Database (Denmark)

    Nguyen, Su Duy; Javanainen, Matti; Rissanen, Sami

    2015-01-01

    Lipolytic modification of LDL particles by SMase generates LDL aggregates with a strong affinity for human arterial proteoglycans and may so enhance LDL retention in the arterial wall. Here, we evaluated the effects of apoA-I mimetic peptide 4F on structural and functional properties of the SMase...

  1. Smac mimetics in combination with TRAIL selectively target cancer stem cells in nasopharyngeal carcinoma.

    Science.gov (United States)

    Wu, Man-Si; Wang, Guang-Feng; Zhao, Zhi-Qiang; Liang, Yi; Wang, Heng-Bang; Wu, Miao-Yi; Min, Ping; Chen, Li-zhen; Feng, Qi-Sheng; Bei, Jin-Xin; Zeng, Yi-Xin; Yang, Dajun

    2013-09-01

    Nasopharyngeal carcinoma is a common malignancy in Southern China. After radiotherapy and chemotherapy, a considerable proportion of patients with nasopharyngeal carcinoma suffered tumor relapse and metastasis. Cancer stem cells (CSC) have been shown with resistance against therapies and thus considered as the initiator of recurrence and metastasis in tumors, where the antiapoptotic property of CSCs play an important role. Smac/DIABLO is an inverse regulator for the inhibitors of apoptosis protein family (IAP), which have been involved in apoptosis. Here, the effects of Smac mimetics on the CSCs of nasopharyngeal carcinoma were studied both in vitro and in vivo, using two clones of nasopharyngeal carcinoma cell line CNE2 as models. We found that one of the clones, S18, had CSC-like properties and IAPs were overexpressed. The combination of Smac mimetics and TNF-related apoptosis-inducing ligand (TRAIL) can reduce the percentage of SP cells and inhibit the colony- and sphere-forming abilities of S18 cells, indicating their ability to attenuate the CSCs. Moreover, in a nasopharyngeal carcinoma xenograft model, the administration of Smac mimetics in combination with TRAIL also led to the elimination of nasopharyngeal carcinoma stem cells. Furthermore, the Smac mimetics in combination with TRAIL induced the degradation of cIAP1 and XIAP and thus induced apoptosis in vitro and in vivo. Taken together, our data show that Smac mimetics exerted an antitumor effect on nasopharyngeal carcinoma cancer stem cells, and this combination treatment should be considered as a promising strategy for the treatment of nasopharyngeal carcinoma.

  2. Smac-mimetic-induced epithelial cell death reduces the growth of renal cysts.

    Science.gov (United States)

    Fan, Lucy X; Zhou, Xia; Sweeney, William E; Wallace, Darren P; Avner, Ellis D; Grantham, Jared J; Li, Xiaogang

    2013-12-01

    Past efforts to pharmacologically disrupt the development and growth of renal cystic lesions focused primarily on normalizing the activity of a specific signaling molecule, but the effects of stimulating apoptosis in the proliferating epithelial cells have not been well studied. Although benign, ADPKD renal cysts created by the sustained proliferation of epithelial cells resemble tumors, and malignant cell death can be achieved by cotreatment with TNF-α and a mimetic of second mitochondria-derived activator of caspase (Smac). Notably, TNF-α accumulates to high levels in ADPKD cyst fluid. Here, we report that an Smac-mimetic selectively induces TNF-α-dependent cystic renal epithelial cell death, leading to the removal of cystic epithelial cells from renal tissues and delaying cyst formation. In vitro, a Smac-mimetic (GT13072) induced the degradation of cIAP1 that is required but not sufficient for cell death. Cotreatment with TNF-α augmented the formation and activation of the RIPK1-dependent death complex and the degradation and cleavage of FLIP, an inhibitor of caspase-8, in renal cystic epithelial cells. This approach produced death specifically in Pkd1 mutant epithelial cells, with no effect on normal renal epithelial cells. Moreover, treatment with the Smac-mimetic slowed cyst and kidney enlargement and preserved renal function in two genetic strains of mice with Pkd1 mutations. Thus, our mechanistic data characterize an apoptotic pathway, activated by the selective synergy of an Smac-mimetic and TNF-α in renal cyst fluid, that attenuates cyst development, providing an innovative translational platform for the rational development of novel therapeutics for ADPKD.

  3. Social variables exert selective pressures in the evolution and form of primate mimetic musculature.

    Science.gov (United States)

    Burrows, Anne M; Li, Ly; Waller, Bridget M; Micheletta, Jerome

    2016-04-01

    Mammals use their faces in social interactions more so than any other vertebrates. Primates are an extreme among most mammals in their complex, direct, lifelong social interactions and their frequent use of facial displays is a means of proximate visual communication with conspecifics. The available repertoire of facial displays is primarily controlled by mimetic musculature, the muscles that move the face. The form of these muscles is, in turn, limited by and influenced by phylogenetic inertia but here we use examples, both morphological and physiological, to illustrate the influence that social variables may exert on the evolution and form of mimetic musculature among primates. Ecomorphology is concerned with the adaptive responses of morphology to various ecological variables such as diet, foliage density, predation pressures, and time of day activity. We present evidence that social variables also exert selective pressures on morphology, specifically using mimetic muscles among primates as an example. Social variables include group size, dominance 'style', and mating systems. We present two case studies to illustrate the potential influence of social behavior on adaptive morphology of mimetic musculature in primates: (1) gross morphology of the mimetic muscles around the external ear in closely related species of macaque (Macaca mulatta and Macaca nigra) characterized by varying dominance styles and (2) comparative physiology of the orbicularis oris muscle among select ape species. This muscle is used in both facial displays/expressions and in vocalizations/human speech. We present qualitative observations of myosin fiber-type distribution in this muscle of siamang (Symphalangus syndactylus), chimpanzee (Pan troglodytes), and human to demonstrate the potential influence of visual and auditory communication on muscle physiology. In sum, ecomorphologists should be aware of social selective pressures as well as ecological ones, and that observed morphology might

  4. Photochemical solar energy conversion utilizing semiconductors localized in membrane-mimetic systems. Performance report, April 1, 1989--August 31, 1991

    Energy Technology Data Exchange (ETDEWEB)

    Fendler, J.H.

    1991-08-31

    Extending the frontiers of colloidal photochemistry and colloidal electrochemistry to solar photochemistry research had been the main objective of this research. More specific objectives of this proposal include the examination of semiconductor-particle-mediated photoelectron transfer and photoelectric effects in different membrane mimetic systems. Emphasis had been placed on developing bilayer lipid membranes and Langmuir-Blodgett films as new membrane-mimetic systems, as well as on the characterization and utilization of these systems.

  5. What kind of signals do mimetic tiger moths send? A phylogenetic test of wasp mimicry systems (Lepidoptera: Arctiidae: Euchromiini).

    Science.gov (United States)

    Simmons, Rebecca B; Weller, Susan J

    2002-05-22

    Mimicry has been examined in field and laboratory studies of butterflies and its evolutionary dynamics have been explored in computer simulations. Phylogenetic studies examining the evolution of mimicry, however, are rare. Here, the phylogeny of wasp-mimicking tiger moths, the Sphecosoma group, was used to test evolutionary predictions of computer simulations of conventional Müllerian mimicry and quasi-Batesian mimicry dynamics. We examined whether mimetic traits evolved individually, or as suites of characters, using concentrated change tests. The phylogeny of these moth mimics revealed that individual mimetic characters were conserved, as are the three mimetic wasp forms: yellow Polybia, black Polybia and Parachartergus mimetic types. This finding was consistent with a 'supergene' control of linked loci and the Nicholson two-step model of mimicry evolution. We also used a modified permutation-tail probability approach to examine the rate of mimetic-type evolution. The observed topology, hypothetical Müllerian and Batesian scenarios, and 1000 random trees were compared using Kishino-Hasegawa tests. The observed phylogeny was more consistent with the predicted Müllerian distribution of mimetic traits than with that of a quasi-Batesian scenario. We suggest that the range of discriminatory abilities of the predator community plays a key role in shaping mimicry dynamics.

  6. Mimetic Theory for Cell-Centered Lagrangian Finite Volume Formulation on General Unstructured Grids

    Energy Technology Data Exchange (ETDEWEB)

    Sambasivan, Shiv Kumar [Los Alamos National Laboratory; Shashkov, Mikhail J. [Los Alamos National Laboratory; Burton, Donald E. [Los Alamos National Laboratory; Christon, Mark A. [Los Alamos National Laboratory

    2012-07-19

    A finite volume cell-centered Lagrangian scheme for solving large deformation problems is constructed based on the hypo-elastic model and using the mimetic theory. Rigorous analysis in the context of gas and solid dynamics, and arbitrary polygonal meshes, is presented to demonstrate the ability of cell-centered schemes in mimicking the continuum properties and principles at the discrete level. A new mimetic formulation based gradient evaluation technique and physics-based, frame independent and symmetry preserving slope limiters are proposed. Furthermore, a physically consistent dissipation model is employed which is both robust and inexpensive to implement. The cell-centered scheme along with these additional new features are applied to solve solids undergoing elasto-plastic deformation.

  7. The controlled release of insulin-mimetic metal ions by the multifunction of chitosan.

    Science.gov (United States)

    Kofuji, Kyoko; Qian, Chun-Jun; Murata, Yoshifumi; Kawashima, Susumu

    2005-06-01

    Vanadium, which is an insulin-mimetic metal ion, was efficiently adsorbed on chitosan (CS). The adsorption of vanadium on CS was affected by the vanadium/CS ratio and the initial concentration of vanadium in preparative medium under constant pH condition. The vanadium-CS complex was able to control vanadium release. Moreover, a consistent control of vanadium release was achieved by incorporation of the vanadium-CS complex into a CS gel. After implantation of the CS gel retaining the vanadium-CS complex into diabetic mice, insulin-mimetic efficacy was confirmed by observation of a steady reduction in blood glucose levels. The sustained vanadium release also contributed to minimization of the side-effects. Thus, CS gel retaining the vanadium-CS complex appears promising as a vehicle for vanadium with long-term action and a low toxicity leading to its clinical use.

  8. Antitumor Efficacy of a Thrombospondin 1 Mimetic CovX-Body

    OpenAIRE

    Li, Lingna; Leedom, Tom A; Do, Janet; Huang, Hanhua; Lai, JingYu; Johnson, Kim; Osothprarop, Trina F; Rizzo, John D; Doppalapudi, Venkata R; Bradshaw, Curt W; Lappe, Rodney W; Woodnutt, Gary; Levin, Nancy J; Pirie-Shepherd, Steven R

    2011-01-01

    CVX-045 is produced by covalently attaching a thrombospondin 1 (TSP-1) mimetic comprising a peptidic sequence and a linker to the Fab binding site of a proprietary scaffold antibody. CVX-045 possesses the potency of the TSP-1-derived peptide, along with the advantageous pharmacokinetics of an antibody. Antitumor activity of CVX-045 was evaluated in human xenograft models alone and in combination with standard chemotherapies and targeted molecules. In A549 and A431 xenograft models, CVX-045 de...

  9. Smac mimetics and type II interferon synergistically induce necroptosis in various cancer cell lines.

    Science.gov (United States)

    Cekay, Michael John; Roesler, Stefanie; Frank, Tanja; Knuth, Anne-Kathrin; Eckhardt, Ines; Fulda, Simone

    2017-12-01

    Since cancer cells often evade apoptosis, induction of necroptosis as another mode of programmed cell death is considered a promising therapeutic alternative. Here, we identify a novel synergistic interaction of Smac mimetics that antagonize x-linked Inhibitor of Apoptosis (XIAP), cellular Inhibitor of Apoptosis (cIAP) 1 and 2 with interferon (IFN)γ to induce necroptosis in apoptosis-resistant cancer cells in which caspase activation is blocked. This synergism is confirmed by calculation of combination indices (CIs) and found in both solid and hematological cancer cell lines as well as for different Smac mimetics (i.e. BV6, Birinapant), pointing to a broader relevance. Importantly, individual genetic knockdown of key components of necroptosis signaling, i.e. receptor-interacting protein (RIP) 1, RIP3 or mixed lineage kinase domain-like pseudokinase (MLKL), significantly protects from BV6/IFNγ-induced cell death. Similarly, pharmacological inhibitors of RIP1 (necrostatin-1(Nec-1)), RIP3 (GSK'872) or MLKL (necrosulfonamide (NSA)) significantly reduce BV6/IFNγ-stimulated cell death. Of note, IFN-regulatory factor (IRF)1 is required for BV6/IFNγ-mediated necroptosis, as IRF1 silencing provides protection from cell death. By comparison, antibodies blocking tumor necrosis factor (TNF)α, TNF-related apoptosis-inducing ligand (TRAIL) or CD95 ligand fail to inhibit BV6/IFNγ-induced cell death, pointing to a mechanism independently of death receptor ligands. This is the first report showing that Smac mimetics synergize with IFNγ to trigger necroptosis in apoptosis-resistant cancer cells with important implications for Smac mimetic-based strategies for the treatment of cancer. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. Apolipoprotein Mimetic Peptides: A New Approach for the Treatment of Asthma

    Directory of Open Access Journals (Sweden)

    Xianglan eYao

    2012-03-01

    Full Text Available New treatments are needed for severe asthmatics to improve disease control and avoid severe toxicities associated with oral corticosteroids. We have used a murine model of house dust mite (HDM-induced asthma to identify steroid-unresponsive genes that might represent targets for new therapeutic approaches for severe asthma. This strategy identified apolipoprotein E as a steroid-unresponsive gene with increased mRNA expression in the lungs of HDM-challenged mice. Furthermore, apolipoprotein E functioned as an endogenous negative regulator of airway hyperreactivity and goblet cell hyperplasia in experimental HDM-induced asthma. The ability of apolipoprotein E, which is expressed by lung macrophages, to attenuate AHR and goblet cell hyperplasia is mediated by low density lipoprotein (LDL receptors expressed by airway epithelial cells. Consistent with this, administration of an apolipoprotein E mimetic peptide, corresponding to amino acids 130 to 149 of the LDL receptor-binding domain of the holo-apoE protein, significantly reduced AHR and goblet cell hyperplasia in HDM-challenged apoE-/- mice. These findings identified the apolipoprotein E - LDL receptor pathway as a new druggable target for asthma that can be activated by administration of apoE mimetic peptides. Similarly, apolipoprotein A-I may have therapeutic potential in asthma based upon its anti-inflammatory, anti-oxidative and anti-fibrotic properties. Furthermore, administration of apolipoprotein A-I mimetic peptides has attenuated airway inflammation, airway remodeling and airway hyperreactivity in murine models of experimental asthma. Thus, site-directed delivery of inhaled apolipoprotein E or apolipoprotein A-I mimetic peptides may represent novel treatment approaches that can be developed for asthma, including severe disease.

  11. Social variables exert selective pressures in the evolution and form of primate mimetic musculature

    OpenAIRE

    Burrows, Anne M.; Li, Ly; Waller, Bridget M.; Micheletta, Jerome

    2016-01-01

    Mammals use their faces in social interactions more so than any other vertebrates. Primates are an extreme among most mammals in their complex, direct, lifelong social interactions and their frequent use of facial displays is a means of proximate visual communication with conspecifics. The available repertoire of facial displays is primarily controlled by mimetic musculature, the muscles that move the face. The form of these muscles is, in turn, limited by and influenced by phylogenetic inert...

  12. iBodies: Modular Synthetic Antibody Mimetics Based on Hydrophilic Polymers Decorated with Functional Moieties

    Czech Academy of Sciences Publication Activity Database

    Šácha, Pavel; Knedlík, Tomáš; Schimer, Jiří; Tykvart, Jan; Parolek, Jan; Navrátil, Václav; Dvořáková, Petra; Sedlák, František; Ulbrich, Karel; Strohalm, Jiří; Majer, Pavel; Šubr, Vladimír; Konvalinka, Jan

    2016-01-01

    Roč. 55, č. 7 (2016), s. 2356-2360 ISSN 1433-7851 R&D Projects: GA ČR GBP208/12/G016; GA MŠk LO1302 Institutional support: RVO:61388963 ; RVO:61389013 Keywords : antibody mimetics * HPMA * molecular recognition * polymer conjugates * protein targeting Subject RIV: CE - Biochemistry; CD - Macromolecular Chemistry (UMCH-V) Impact factor: 11.994, year: 2016 http://onlinelibrary.wiley.com/doi/10.1002/anie.201508642/full

  13. Smac mimetic-derived augmentation of chemotherapeutic response in experimental pancreatic cancer

    International Nuclear Information System (INIS)

    Awasthi, Niranjan; Kirane, Amanda; Schwarz, Margaret A; Toombs, Jason E; Brekken, Rolf A; Schwarz, Roderich E

    2011-01-01

    Pancreatic ductal adenocarcinoma (PDAC) is highly resistant to conventional chemotherapy, in part due to the overexpression of inhibitors of apoptosis proteins (IAPs). Smac is an endogenous IAP-antagonist, which renders synthetic Smac mimetics attractive anticancer agents. We evaluated the benefits of combining a Smac mimetic, JP1201 (JP), with conventional chemotherapy agents used for PDAC management. Cell viability assays and protein expression analysis were performed using WST-1 reagent and Western blotting, respectively. Apoptosis was detected by annexin V/propidium iodide staining. In vivo tumor growth and survival studies were performed in murine PDAC xenografts. JP and gemcitabine (Gem) inhibited PDAC cell proliferation with additive effects in combination. The percentage of early apoptotic cells in controls, JP, Gem and JP + Gem was 17%, 26%, 26% and 38%, respectively. JP-induced apoptosis was accompanied by PARP-1 cleavage. Similar additive anti-proliferative effects were seen for combinations of JP with doxorubicin (Dox) and docetaxel (DT). The JP + Gem combination caused a 30% decrease in tumor size in vivo compared to controls. Median animal survival was improved significantly in mice treated with JP + Gem (38 d) compared to controls (22 d), JP (28 d) or Gem (32 d) (p = 0.01). Animal survival was also improved with JP + DT treatment (32 d) compared to controls (16 d), JP (21 d) or DT alone (27 d). These results warrant further exploration of strategies that promote chemotherapy-induced apoptosis of tumors and highlight the potential of Smac mimetics in clinical PDAC therapy

  14. Synergistic interaction of Smac mimetic and IFNα to trigger apoptosis in acute myeloid leukemia cells.

    Science.gov (United States)

    Bake, Vanessa; Roesler, Stefanie; Eckhardt, Ines; Belz, Katharina; Fulda, Simone

    2014-12-28

    Therapeutic targeting of inhibitor of apoptosis (IAP) proteins by small-molecule inhibitors such as Smac mimetic is considered as a promising anticancer strategy to elicit apoptosis. Recent advances have renewed the interest in exploiting the antileukemic activity of interferon (IFN)α for the treatment of acute myeloid leukemia (AML). Here, we identify a novel synergistic interaction of the Smac mimetic BV6 and IFNα to trigger cell death in AML cells. Calculation of combination index (CI) confirms the synergism of BV6 and IFNα. In contrast to AML cells, no synergistic toxicity of BV6 and IFNα at equimolar concentrations is found against normal peripheral blood lymphocytes. BV6 and IFNα act in concert to stimulate expression of tumor necrosis factor (TNF)α and its secretion into the supernatant, thereby initiating an autocrine/paracrine TNFα/TNF receptor 1 (TNFR1) loop that drives cell death by BV6 and IFNα. Consistently, pharmacological inhibition of TNFα by the TNFα-blocking antibody Enbrel or genetic silencing of TNFR1 significantly reduces BV6/IFNα-induced cell death. In addition, BV6/IFNα-induced cell death depends on interferon regulatory factor (IRF)1, since RNA interference-imposed knockdown of IRF1 significantly rescues cell death. In conclusion, the identification of a novel synergistic antileukemic combination of Smac mimetic and IFNα has important implications for the development of innovative treatment strategies in AML. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  15. Synergistic Effects of a Smac Mimetic with Doxorubicin Against Human Osteosarcoma.

    Science.gov (United States)

    Kamata, Etsuko; Kawamoto, Teruya; Ueha, Takeshi; Hara, Hitomi; Fukase, Naomasa; Minoda, Masaya; Morishita, Masayuki; Takemori, Toshiyuki; Fujiwara, Shuichi; Nishida, Kotaro; Kuroda, Ryosuke; Kurosaka, Masahiro; Akisue, Toshihiro

    2017-11-01

    Second mitochondria-derived activator of caspase (Smac) is a proapoptogenic mitochondrial protein that antagonizes inhibitors of apoptosis proteins (IAPs), resulting in induction of apoptosis. In the present study we investigated the effects of a Smac mimetic in combination with doxorubicin against osteosarcoma. In vitro effects of the combination of a Smac mimetic AT-406 and doxorubicin on cell proliferation and apoptosis in osteosarcoma cell lines were examined using cell proliferation assays, flow cytometry, and immunoblot analyses. For in vivo experiments, human osteosarcoma xenografts were treated with combination of the two substances, and tumor volume and apoptotic activity in treated tumors were assessed. In vitro studies revealed that combination of the two substances significantly inhibited osteosarcoma proliferation with decreased cIAP1 expression and induced apoptosis in osteosarcoma cells. Combination of the two substances significantly suppressed osteosarcoma growth in vivo. Moreover, decreased cIAP1 expression and increased apoptotic activity were observed in tumors treated by their combination of the substances. The Smac mimetic AT-406 showed an apoptotic effect and a synergistic antitumor effect with doxorubicin on osteosarcoma. The combination of AT-406 and doxorubicin may serve as a novel therapeutic strategy for osteosarcoma treatment. Copyright© 2017, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

  16. A Potent Bivalent Smac Mimetic (SM-1200) Achieving Rapid, Complete and Durable Tumor Regression in Mice

    Science.gov (United States)

    Sheng, Rong; Sun, Haiying; Liu, Liu; Lu, Jianfeng; McEachern, Donna; Wang, Guanfeng; Wen, Jianfeng; Min, Ping; Du, Zhenyun; Lu, Huirong; Kang, Sanmao; Guo, Ming; Yang, Dajun; Wang, Shaomeng

    2013-01-01

    We have designed, synthesized and evaluated a series of new compounds based upon our previously reported bivalent Smac mimetics. This led to the identification of compound 12 (SM-1200), which binds to XIAP, cIAP1 and cIAP2 with Ki values of 0.5 nM, 3.7 nM and 5.4 nM, respectively, inhibits cell growth in the MDA-MB-231 breast cancer and SK-OV-3 ovarian cancer cell lines with IC50 values of 11.0 nM and 28.2 nM, respectively. Compound 12 has a much improved pharmacokinetic profile over our previously reported bivalent Smac mimetics and is highly effective in induction of rapid and durable tumor regression in the MDA-MB-231 xenograft model. These data indicate that compound 12 is a promising Smac mimetic and warrants extensive evaluation as a potential candidate for clinical development. PMID:23651223

  17. Vincristine resistance in relapsed neuroblastoma can be efficiently overcome by Smac mimetic LCL161 treatment.

    Science.gov (United States)

    Frommann, Kristin; Appl, Birgit; Hundsdoerfer, Patrick; Reinshagen, Konrad; Eschenburg, Georg

    2018-01-31

    In spite of good initial therapy response neuroblastomas often spread to distant organs or relapse after periods of remission. Dysregulation of apoptosis, a hallmark of cancer, is often effected by elevated levels of antiapoptotic signals leading to resistance against chemotherapeutic drugs. Inhibitors of apoptosis proteins (IAPs) are crucial cellular apoptosis regulators. Targeting IAPs with Smac mimetics has been demonstrated as a promising strategy for treatment of neuroblastoma and other tumors. In paired neuroblastoma cell lines, obtained from the same patient at time of diagnosis (CHLA-15) and postchemotherapy during progressive disease (CHLA-20), expression of crucial IAPs was determined. Furthermore, effects of vincristine on viability, cytotoxicity, apoptosis induction and caspase-3/7 activation were determined. Cellular IAP-1 (cIAP-1) and X-linked IAP (XIAP) expression was increased in cell line CHLA-20. Moreover, biological effects of vincristine were significantly lower in these cells. Treatment of cells with Smac mimetic LCL161 increased the effects of vincristine in CHLA-15 cells and more importantly was able to overcome vincristine resistance in CHLA-20 cells. These findings demonstrate the potential of Smac mimetics for the development of novel therapeutic approaches for the treatment of relapsed/resistant neuroblastoma. Copyright © 2018. Published by Elsevier Inc.

  18. The reconstruction of f(ϕ)R and mimetic gravity from viable slow-roll inflation

    Science.gov (United States)

    Odintsov, S. D.; Oikonomou, V. K.

    2018-04-01

    In this work, we extend the bottom-up reconstruction framework of F (R) gravity to other modified gravities, and in particular for f (ϕ) R and mimetic F (R) gravities. We investigate which are the important conditions in order for the method to work, and we study several viable cosmological evolutions, focusing on the inflationary era. Particularly, for the f (ϕ) R theory case, we specify the functional form of the Hubble rate and of the scalar-to-tensor ratio as a function of the e-foldings number and accordingly, the rest of the physical quantities and also the slow-roll and the corresponding observational indices can be calculated. The same method is applied in the mimetic F (R) gravity case, and in both cases we thoroughly analyze the resulting free parameter space, in order to show that the viability of the models presented is guaranteed and secondly that there is a wide range of values of the free parameters for which the viability of the models occurs. In addition, the reconstruction method is also studied in the context of mimetic F (R) = R gravity. As we demonstrate, the resulting theory is viable, and also in this case, only the scalar-to-tensor ratio needs to be specified, since the rest follow from this condition. Finally, we discuss in brief how the reconstruction method could function for other modified gravities.

  19. Combining basal insulin analogs with glucagon-like peptide-1 mimetics.

    Science.gov (United States)

    Perfetti, Riccardo

    2011-09-01

    Basal insulin analogs are recognized as an effective method of achieving and maintaining glycemic control for patients with type 2 diabetes. However, the progressive nature of the disease means that some individuals may require additional ways to maintain their glycemic goals. Intensification in these circumstances has traditionally been achieved by the addition of short-acting insulin to cover postprandial glucose excursions that are not targeted by basal insulin. However, intensive insulin regimens are associated with a higher risk of hypoglycemia and weight gain, which can contribute to a greater burden on patients. The combination of basal insulin with a glucagon-like peptide-1 (GLP-1) mimetic is a potentially attractive solution to this problem for some patients with type 2 diabetes. GLP-1 mimetics target postprandial glucose and should complement the activity of basal insulins; they are also associated with a relatively low risk of associated hypoglycemia and moderate, but significant, weight loss. Although the combination has not been approved by regulatory authorities, preliminary evidence from mostly small-scale studies suggests that basal insulins in combination with GLP-1 mimetics do provide improvements in A1c and postprandial glucose with concomitant weight loss and no marked increase in the risk of hypoglycemia. These results are promising, but further studies are required, including comparisons with basal-bolus therapy, before the complex value of this association can be fully appreciated.

  20. Role of phosphate on stability and catalase mimetic activity of cerium oxide nanoparticles.

    Science.gov (United States)

    Singh, Ragini; Singh, Sanjay

    2015-08-01

    Cerium oxide nanoparticles (CeNPs) have been recently shown to scavenge reactive oxygen and nitrogen species (ROS and RNS) in different experimental model systems. CeNPs (3+) and CeNPs (4+) have been shown to exhibit superoxide dismutase (SOD) and catalase mimetic activity, respectively. Due to their nanoscale dimension, CeNPs are expected to interact with the components of biologically relevant buffers and medium, which could alter their catalytic properties. We have demonstrated earlier that CeNPs (3+) interact with phosphate and lose the SOD activity. However, very little is known about the interaction of CeNPs (4+) with the phosphate and other anions, predominantly present in biological buffers and their effects on the catalase mimetic-activity of these nanoparticles. In this study, we report that catalase mimetic-activity of CeNPs (4+) is resistant to the phosphate anions, pH changes and composition of cell culture media. Given the abundance of phosphate anions in the biological system, it is likely that internalized CeNPs would be influenced by cytoplasmic and nucleoplasmic concentration of phosphate. Copyright © 2015 Elsevier B.V. All rights reserved.

  1. Drug delivery vectors based on filamentous bacteriophages and phage-mimetic nanoparticles.

    Science.gov (United States)

    Ju, Zhigang; Sun, Wei

    2017-11-01

    With the development of nanomedicine, a mass of nanocarriers have been exploited and utilized for targeted drug delivery, including liposomes, polymers, nanoparticles, viruses, and stem cells. Due to huge surface bearing capacity and flexible genetic engineering property, filamentous bacteriophage and phage-mimetic nanoparticles are attracting more and more attentions. As a rod-like bio-nanofiber without tropism to mammalian cells, filamentous phage can be easily loaded with drugs and directly delivered to the lesion location. In particular, chemical drugs can be conjugated on phage surface by chemical modification, and gene drugs can also be inserted into the genome of phage by recombinant DNA technology. Meanwhile, specific peptides/proteins displayed on the phage surface are able to conjugate with nanoparticles which will endow them specific-targeting and huge drug-loading capacity. Additionally, phage peptides/proteins can directly self-assemble into phage-mimetic nanoparticles which may be applied for self-navigating drug delivery nanovehicles. In this review, we summarize the production of phage particles, the identification of targeting peptides, and the recent applications of filamentous bacteriophages as well as their protein/peptide for targeting drug delivery in vitro and in vivo. The improvement of our understanding of filamentous bacteriophage and phage-mimetic nanoparticles will supply new tools for biotechnological approaches.

  2. Insulin mimetic effects of macrocyclic binuclear oxovanadium complexes on streptozotocin-induced experimental diabetes in rats.

    Science.gov (United States)

    Ramachandran, B; Kandaswamy, M; Narayanan, V; Subramanian, S

    2003-11-01

    The vanadium complexes so far tested for their insulin mimetic effects are either mono- or binuclear and contain only acyclic ligands. The leaching or hydrolysis of vanadyl ions from these complexes is much easier, and hence they elicit side effects. In the present study, a new binuclear macrocyclic oxovanadium complex was synthesized, and its efficacy was studied on streptozotocin (STZ)-induced diabetic rats over a period of 30 days. The insulin mimetic effect of the complex was tested on the blood sugar level in the STZ-diabetic rats and on the activities of the carbohydrate-metabolizing enzymes present in the liver. Administration of vanadium complex to STZ-induced diabetic rats decreased blood glucose levels from hyperglycaemic to normoglycaemic when compared to diabetic rats. The activity of carbohydrate-metabolizing enzymes such as hexokinase, glucose-6-phosphate dehydrogenase, glycogen synthase and glycogen content were increased to near normal in vanadium complex-administered diabetic rats. The biochemical studies such as assay of blood urea and glutamate oxaloacetate transaminases revealed that the complex is not toxic to the system. The nontoxic nature of this complex may be due to the presence of the vanadyl ions in an intact macrocyclic form. Further, the vanadyl ions present in the macrocyclic binuclear oxovanadium complex are very close to each other, and this may enhance the insulin mimetic activity by synergic effect.

  3. The reconstruction of f(ϕR and mimetic gravity from viable slow-roll inflation

    Directory of Open Access Journals (Sweden)

    S.D. Odintsov

    2018-04-01

    Full Text Available In this work, we extend the bottom-up reconstruction framework of F(R gravity to other modified gravities, and in particular for f(ϕR and mimetic F(R gravities. We investigate which are the important conditions in order for the method to work, and we study several viable cosmological evolutions, focusing on the inflationary era. Particularly, for the f(ϕR theory case, we specify the functional form of the Hubble rate and of the scalar-to-tensor ratio as a function of the e-foldings number and accordingly, the rest of the physical quantities and also the slow-roll and the corresponding observational indices can be calculated. The same method is applied in the mimetic F(R gravity case, and in both cases we thoroughly analyze the resulting free parameter space, in order to show that the viability of the models presented is guaranteed and secondly that there is a wide range of values of the free parameters for which the viability of the models occurs. In addition, the reconstruction method is also studied in the context of mimetic F(R=R gravity. As we demonstrate, the resulting theory is viable, and also in this case, only the scalar-to-tensor ratio needs to be specified, since the rest follow from this condition. Finally, we discuss in brief how the reconstruction method could function for other modified gravities.

  4. Activity of Potent and Selective Host Defense Peptide Mimetics in Mouse Models of Oral Candidiasis

    Science.gov (United States)

    Ryan, Lisa K.; Freeman, Katie B.; Masso-Silva, Jorge A.; Falkovsky, Klaudia; Aloyouny, Ashwag; Markowitz, Kenneth; Hise, Amy G.; Fatahzadeh, Mahnaz; Scott, Richard W.

    2014-01-01

    There is a strong need for new broadly active antifungal agents for the treatment of oral candidiasis that not only are active against many species of Candida, including drug-resistant strains, but also evade microbial countermeasures which may lead to resistance. Host defense peptides (HDPs) can provide a foundation for the development of such agents. Toward this end, we have developed fully synthetic, small-molecule, nonpeptide mimetics of the HDPs that improve safety and other pharmaceutical properties. Here we describe the identification of several HDP mimetics that are broadly active against C. albicans and other species of Candida, rapidly fungicidal, and active against yeast and hyphal cultures and that exhibit low cytotoxicity for mammalian cells. Importantly, specificity for Candida over commensal bacteria was also evident, thereby minimizing potential damage to the endogenous microbiome which otherwise could favor fungal overgrowth. Three compounds were tested as topical agents in two different mouse models of oral candidiasis and were found to be highly active. Following single-dose administrations, total Candida burdens in tongues of infected animals were reduced up to three logs. These studies highlight the potential of HDP mimetics as a new tool in the antifungal arsenal for the treatment of oral candidiasis. PMID:24752272

  5. Design, synthesis, and evaluation of an alpha-helix mimetic library targeting protein-protein interactions.

    Science.gov (United States)

    Shaginian, Alex; Whitby, Landon R; Hong, Sukwon; Hwang, Inkyu; Farooqi, Bilal; Searcey, Mark; Chen, Jiandong; Vogt, Peter K; Boger, Dale L

    2009-04-22

    The design and solution-phase synthesis of an alpha-helix mimetic library as an integral component of a small-molecule library targeting protein-protein interactions are described. The iterative design, synthesis, and evaluation of the candidate alpha-helix mimetic was initiated from a precedented triaryl template and refined by screening the designs for inhibition of MDM2/p53 binding. Upon identifying a chemically and biologically satisfactory design and consistent with the screening capabilities of academic collaborators, the corresponding complete library was assembled as 400 mixtures of 20 compounds (20 x 20 x 20-mix), where the added subunits are designed to mimic all possible permutations of the naturally occurring i, i + 4, i + 7 amino acid side chains of an alpha-helix. The library (8000 compounds) was prepared using a solution-phase synthetic protocol enlisting acid/base liquid-liquid extractions for purification on a scale that insures its long-term availability for screening campaigns. Screening of the library for inhibition of MDM2/p53 binding not only identified the lead alpha-helix mimetic upon which the library was based, but also suggests that a digestion of the initial screening results that accompany the use of such a comprehensive library can provide insights into the nature of the interaction (e.g., an alpha-helix mediated protein-protein interaction) and define the key residues and their characteristics responsible for recognition.

  6. Superstretchable Nacre-Mimetic Graphene/Poly(vinyl alcohol) Composite Film Based on Interfacial Architectural Engineering.

    Science.gov (United States)

    Zhao, Nifang; Yang, Miao; Zhao, Qian; Gao, Weiwei; Xie, Tao; Bai, Hao

    2017-05-23

    Through designing hierarchical structures, particularly optimizing the chemical and architectural interactions at its inorganic/organic interface, nacre has achieved an excellent combination of contradictory mechanical properties such as strength and toughness, which is highly demanded yet difficult to achieve by most synthetic materials. Most techniques applied to develop nacre-mimetic composites have been focused on mimicking the "brick-and-mortar" structure, but the interfacial architectural features, especially the asperities and mineral bridges of "bricks", have been rarely concerned, which are of equal importance for enhancing mechanical properties of nacre. Here, we used a modified bidirectional freezing method followed by uniaxial pressing and chemical reduction to assemble a nacre-mimetic graphene/poly(vinyl alcohol) composite film, with both asperities and bridges introduced in addition to the lamellar layers to mimic the interfacial architectural interactions found in nacre. As such, we have developed a composite film that is not only strong (up to ∼150.9 MPa), but also tough (up to ∼8.50 MJ/m 3 ), and highly stretchable (up to ∼10.44%), difficult to obtain by other methods. This was all achieved by only interfacial architectural engineering within the traditional "brick-and-mortar" structure, without introducing a third component or employing chemical cross-linker as in some other nacre-mimetic systems. More importantly, we believe that the design principles and processing strategies reported here can also be applied to other material systems to develop strong and stretchable materials.

  7. Late-time cosmological approach in mimetic f(R, T) gravity

    Energy Technology Data Exchange (ETDEWEB)

    Baffou, E.H. [Institut de Mathematiques et de Sciences Physiques (IMSP), Porto-Novo (Benin); Houndjo, M.J.S. [Institut de Mathematiques et de Sciences Physiques (IMSP), Porto-Novo (Benin); Faculte des Sciences et Techniques de Natitingou, Natitingou (Benin); Hamani-Daouda, M. [Universite de Niamey, Departement de Physique, Niamey (Niger); Alvarenga, F.G. [Universidade Federal do Espirito Santo, Departamento de Engenharia e Ciencias Naturais, CEUNES, Sao Mateus, ES (Brazil)

    2017-10-15

    In this paper, we investigate the late-time cosmic acceleration in mimetic f(R, T) gravity with the Lagrange multiplier and potential in a Universe containing, besides radiation and dark energy, a self-interacting (collisional) matter. We obtain through the modified Friedmann equations the main equation that can describe the cosmological evolution. Then, with several models from Q(z) and the well-known particular model f(R, T), we perform an analysis of the late-time evolution. We examine the behavior of the Hubble parameter, the dark energy equation of state and the total effective equation of state and in each case we compare the resulting picture with the non-collisional matter (assumed as dust) and also with the collisional matter in mimetic f(R, T) gravity. The results obtained are in good agreement with the observational data and show that in the presence of the collisional matter the dark energy oscillations in mimetic f(R, T) gravity can be damped. (orig.)

  8. Late-time cosmological approach in mimetic f( R, T) gravity

    Science.gov (United States)

    Baffou, E. H.; Houndjo, M. J. S.; Hamani-Daouda, M.; Alvarenga, F. G.

    2017-10-01

    In this paper, we investigate the late-time cosmic acceleration in mimetic f( R, T) gravity with the Lagrange multiplier and potential in a Universe containing, besides radiation and dark energy, a self-interacting (collisional) matter. We obtain through the modified Friedmann equations the main equation that can describe the cosmological evolution. Then, with several models from Q(z) and the well-known particular model f( R, T), we perform an analysis of the late-time evolution. We examine the behavior of the Hubble parameter, the dark energy equation of state and the total effective equation of state and in each case we compare the resulting picture with the non-collisional matter (assumed as dust) and also with the collisional matter in mimetic f( R, T) gravity. The results obtained are in good agreement with the observational data and show that in the presence of the collisional matter the dark energy oscillations in mimetic f( R, T) gravity can be damped.

  9. Eltrombopag, a thrombopoietin mimetic, crosses the blood-brain barrier and impairs iron-dependent hippocampal neuron dendrite development.

    Science.gov (United States)

    Bastian, T W; Duck, K A; Michalopoulos, G C; Chen, M J; Liu, Z-J; Connor, J R; Lanier, L M; Sola-Visner, M C; Georgieff, M K

    2017-03-01

    Essentials Potential neurodevelopmental side effects of thrombopoietin mimetics need to be considered. The effects of eltrombopag (ELT) on neuronal iron status and dendrite development were assessed. ELT crosses the blood-brain barrier and causes iron deficiency in developing neurons. ELT blunts dendrite maturation, indicating a need for more safety studies before neonatal use. Background Thrombocytopenia is common in sick neonates. Thrombopoietin mimetics (e.g. eltrombopag [ELT]) might provide an alternative therapy for selected neonates with severe and prolonged thrombocytopenia, and for infants and young children with different varieties of thrombocytopenia. However, ELT chelates intracellular iron, which may adversely affect developing organs with high metabolic requirements. Iron deficiency (ID) is particularly deleterious during brain development, impairing neuronal myelination, dopamine signaling and dendritic maturation and ultimately impairing long-term neurological function (e.g. hippocampal-dependent learning and memory). Objective To determine whether ELT crosses the blood-brain barrier (BBB), causes neuronal ID and impairs hippocampal neuron dendrite maturation. Methods ELT transport across the BBB was assessed using primary bovine brain microvascular endothelial cells. Embryonic mouse primary hippocampal neuron cultures were treated with ELT or deferoxamine (DFO, an iron chelator) from 7 days in vitro (DIV) through 14 DIV and assessed for gene expression and neuronal dendrite complexity. Results ELT crossed the BBB in a time-dependent manner. 2 and 6 μm ELT increased Tfr1 and Slc11a2 (iron-responsive genes involved in neuronal iron uptake) mRNA levels, indicating neuronal ID. 6 μm ELT, but not 2 μm ELT, decreased BdnfVI, Camk2a and Vamp1 mRNA levels, suggesting impaired neuronal development and synaptic function. Dendrite branch number and length were reduced in 6 μm ELT-treated neurons, resulting in blunted dendritic arbor complexity that

  10. Potent Bivalent Smac Mimetics: Effect of the Linker on Binding to Inhibitor of Apoptosis Proteins (IAPs) and Anticancer Activity

    Science.gov (United States)

    Sun, Haiying; Liu, Liu; Lu, Jianfeng; Bai, Longchuan; Li, Xiaoqin; Nikolovska-Coleska, Zaneta; McEachern, Donna; Yang, Chao-Yie; Qiu, Su; Yi, Han; Sun, Duxin; Wang, Shaomeng

    2011-01-01

    We have synthesized and evaluated a series of non-peptidic, bivalent Smac mimetics as antagonists of the inhibitor of apoptosis proteins and new anticancer agents. All these bivalent Smac mimetics bind to full-length XIAP with low nanomolar affinities and function as ultra-potent antagonists of XIAP. While these Smac mimetics bind to cIAP1/2 with similar low nanomolar affinities, their potencies to induce degradation of cIAP1/2 proteins in cells differ by more than 100-fold. The most potent bivalent Smac mimetics inhibit cell growth with IC50 values from 1–3 nM in the MDA-MB-231 breast cancer cell line and are 100-times more potent than the least potent compounds. Determination of intracellular concentrations for several representative compounds showed that the linkers in these bivalent Smac mimetics significantly affect their intracellular concentrations, hence the overall cellular activity. Compound 27 completely inhibits tumor growth in the MDA-MB-231 xenografts, while causing no signs of toxicity in the animals. PMID:21462933

  11. Second mitochondria-derived activator of caspase (SMAC) mimetic potentiates tumor susceptibility toward natural killer cell-mediated killing.

    Science.gov (United States)

    Brinkmann, Kerstin; Hombach, Andreas; Seeger, Jens Michael; Wagner-Stippich, Diana; Klubertz, Daniela; Krönke, Martin; Abken, Hinrich; Kashkar, Hamid

    2014-03-01

    Resistance to apoptosis is a hallmark of cancer, and represents an important mechanism of how tumor cells resist immune cell destruction. Mitochondria are the central regulators of the apoptotic machinery by releasing pro-apoptotic factors including cytochrome c and second mitochondria-derived activator of caspase (SMAC) upon mitochondrial outer membrane permeabilization (MOMP). Small molecules activating MOMP such as BH3 mimetics or antagonizers of the inhibitor of apoptosis proteins (IAPs) such as SMAC mimetics have recently engendered new optimism for a more individualized and effective cancer therapy. Here we show that a SMAC mimetic potentiates cancer cell killing by natural killer (NK) cells through reactivation of tumor cell apoptosis. Specifically, the SMAC mimetic enhances the susceptibility of tumor cells toward NK cell-mediated effector mechanisms involving death receptors and cytolytic granules containing perforin and granzymes by relieving caspase activity. Our data highlight for the first time the specific use of SMAC mimetics for boosting immune cell-mediated immunotherapy, representing a novel and promising approach in the treatment of cancer.

  12. Differential role of RIP1 in Smac mimetic-mediated chemosensitization of neuroblastoma cells.

    Science.gov (United States)

    Czaplinski, Sebastian; Abhari, Behnaz Ahangarian; Torkov, Alica; Seggewiß, Dominik; Hugle, Manuela; Fulda, Simone

    2015-12-08

    We explored the potential of Smac mimetics, which antagonize Inhibitor of Apoptosis (IAP) proteins, for chemosensitization of neuroblastoma (NB). Here, we report that Smac mimetics, e.g. BV6, prime NB cells for chemotherapeutics including the topoisomerase II inhibitor doxorubicin (DOX) and vinca alkaloids such as Vincristine (VCR), Vinblastine (VBL) and Vinorelbine (VNR). Additionally, BV6 acts in concert with DOX or VCR to suppress long-term clonogenic growth. While BV6 causes rapid downregulation of cellular IAP (cIAP)1 protein and nuclear factor-kappaB (NF-κB) activation, DOX/BV6- or VCR/BV6-induced apoptosis occurs independently of NF-κB or TNFα signaling, since overexpression of dominant-negative IκBα superrepressor or the Tumor Necrosis Factor (TNF)α-blocking antibody Enbrel fail to block cell death. Mechanistic studies reveal that Receptor-interacting protein (RIP)1 is required for DOX/BV6-, but not for VCR/BV6-induced apoptosis, since transient or stable knockdown of RIP1 or the pharmacological RIP1 inhibitor necrostatin-1 significantly reduce apoptosis. By comparison, VCR/BV6-mediated apoptosis critically depends on the mitochondrial pathway. VCR/BV6 cotreatment causes phosphorylation of BCL-2 during mitotic arrest, enhanced activation of BAX and BAK and loss of mitochondrial membrane potential (MMP). Additionally, overexpression of BCL-2 profoundly suppresses VCR/BV6-induced apoptosis. Thus, BV6 sensitizes NB cells to chemotherapy-induced apoptosis via distinct initial signaling mechanisms depending on the chemotherapeutic drug. These findings provide novel mechanistic insights into Smac mimetic-mediated chemosensitization of NB.

  13. Incretin mimetics: a novel therapeutic option for patients with type 2 diabetes – a review

    Directory of Open Access Journals (Sweden)

    Katrine B Hansen

    2010-05-01

    Full Text Available Katrine B Hansen1, Tina Vilsbøll2, Filip K Knop21Department of Clinical Physiology, Glostrup Hospital, University of Copenhagen, Denmark; 2Diabetes Research Division, Department of Internal Medicine F, Gentofte Hospital, University of Copenhagen, DenmarkAbstract: Type 2 diabetes mellitus is a metabolic disease associated with low quality of life and early death. The goal in diabetes treatment is to prevent these outcomes by tight glycemic control and minimizing vascular risk factors. So far, even intensified combination regimen with the traditional antidiabetes agents have failed to obtain these goals. Incretin mimetics are a new class of antidiabetes drugs which involve modulation of the incretin system. They bind to and activate glucagon-like peptide-1 (GLP-1 receptors on pancreatic beta-cells following which insulin secretion and synthesis are initiated. Since the compounds have no insulinotropic activity at lower glucose concentrations the risk of hypoglycemia – a well-known shortcoming of existing antidiabetes treatments – is low. Additionally, incretin mimetics have been shown to be associated with beneficial effects on cardiovascular risk factors such as weight loss, decrease in blood pressure and changes in lipid profile. Current clinical data on the two available incretin mimetics, exenatide and liraglutide, are evaluated in this review, focusing on pharmacology, efficacy, safety and tolerability. The review is built on a systematic PubMed and Medline search for publications with the key words GLP-1 receptor agonist, exenatide, liraglutide and type 2 diabetes mellitus up to January 2009.Keywords: glucagon-like peptide-1 (GLP-1, exenatide, liraglutide, type 2 diabetes

  14. Smac mimetic-derived augmentation of chemotherapeutic response in experimental pancreatic cancer

    Directory of Open Access Journals (Sweden)

    Schwarz Margaret A

    2011-01-01

    Full Text Available Abstract Background Pancreatic ductal adenocarcinoma (PDAC is highly resistant to conventional chemotherapy, in part due to the overexpression of inhibitors of apoptosis proteins (IAPs. Smac is an endogenous IAP-antagonist, which renders synthetic Smac mimetics attractive anticancer agents. We evaluated the benefits of combining a Smac mimetic, JP1201 (JP, with conventional chemotherapy agents used for PDAC management. Methods Cell viability assays and protein expression analysis were performed using WST-1 reagent and Western blotting, respectively. Apoptosis was detected by annexin V/propidium iodide staining. In vivo tumor growth and survival studies were performed in murine PDAC xenografts. Results JP and gemcitabine (Gem inhibited PDAC cell proliferation with additive effects in combination. The percentage of early apoptotic cells in controls, JP, Gem and JP + Gem was 17%, 26%, 26% and 38%, respectively. JP-induced apoptosis was accompanied by PARP-1 cleavage. Similar additive anti-proliferative effects were seen for combinations of JP with doxorubicin (Dox and docetaxel (DT. The JP + Gem combination caused a 30% decrease in tumor size in vivo compared to controls. Median animal survival was improved significantly in mice treated with JP + Gem (38 d compared to controls (22 d, JP (28 d or Gem (32 d (p = 0.01. Animal survival was also improved with JP + DT treatment (32 d compared to controls (16 d, JP (21 d or DT alone (27 d. Conclusions These results warrant further exploration of strategies that promote chemotherapy-induced apoptosis of tumors and highlight the potential of Smac mimetics in clinical PDAC therapy.

  15. Mimetic Theory and the evolutionary paradox of schizophrenia: The archetypal scapegoat hypothesis.

    Science.gov (United States)

    Riordan, Daniel Vincent

    2017-10-01

    Schizophrenia poses an evolutionary paradox, being genetically mediated yet associated with reduced fecundity. Numerous hypotheses have attempted to address this, but few describe how the schizophrenic phenotype itself might constitute an evolutionary adaptation. This paper draws on René Girard's theory on human origins, which claims that humans evolved a tendency to mimic both the desires and the behaviours of each other (mimetic theory). This would have promoted social cohesion and co-operation, but at the cost of intra-group rivalry and conflict. The mimetic dynamic would have escalated such conflicts into reciprocal internecine violence, threatening the survival of the entire group. Girard theorised that the "scapegoat mechanism" emerged, by which means such violence was curtailed by the unanimity of "all against one", thus allowing the mimetic impulse to safely evolve further, making language and complex social behaviours possible. Whereas scapegoating may have emerged in the entire population, and any member of a community could be scapegoated if necessary, this paper proposes that the scapegoat mechanism would have worked better in groups containing members who exhibited traits, recognised by all others, which singled them out as victims. Schizophrenia may be a functional adaptation, similar in evolutionary terms to altruism, in that it may have increased inclusive fitness, by providing scapegoat victims, the choice of whom was likely to be agreed upon unanimously, even during internecine conflict, thus restoring order and protecting the group from self-destruction. This evolutionary hypothesis, uses Girardian anthropology to combine the concept of the schizophrenic as religious shaman with that of the schizophrenic as scapegoat. It may help to reconcile divergent philosophical concepts of mental illness, and also help us to better understand, and thus counter, social exclusion and stigmatisation. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Functional Mimetics of the HIV-1 CCR5 Co-Receptor Displayed on the Surface of Magnetic Liposomes.

    Science.gov (United States)

    Kuzmina, Alona; Vaknin, Karin; Gdalevsky, Garik; Vyazmensky, Maria; Marks, Robert S; Taube, Ran; Engel, Stanislav

    2015-01-01

    Chemokine G protein coupled receptors, principally CCR5 or CXCR4, function as co-receptors for HIV-1 entry into CD4+ T cells. Initial binding of the viral envelope glycoprotein (Env) gp120 subunit to the host CD4 receptor induces a cascade of structural conformational changes that lead to the formation of a high-affinity co-receptor-binding site on gp120. Interaction between gp120 and the co-receptor leads to the exposure of epitopes on the viral gp41 that mediates fusion between viral and cell membranes. Soluble CD4 (sCD4) mimetics can act as an activation-based inhibitor of HIV-1 entry in vitro, as it induces similar structural changes in gp120, leading to increased virus infectivity in the short term but to virus Env inactivation in the long term. Despite promising clinical implications, sCD4 displays low efficiency in vivo, and in multiple HIV strains, it does not inhibit viral infection. This has been attributed to the slow kinetics of the sCD4-induced HIV Env inactivation and to the failure to obtain sufficient sCD4 mimetic levels in the serum. Here we present uniquely structured CCR5 co-receptor mimetics. We hypothesized that such mimetics will enhance sCD4-induced HIV Env inactivation and inhibition of HIV entry. Co-receptor mimetics were derived from CCR5 gp120-binding epitopes and functionalized with a palmitoyl group, which mediated their display on the surface of lipid-coated magnetic beads. CCR5-peptidoliposome mimetics bound to soluble gp120 and inhibited HIV-1 infectivity in a sCD4-dependent manner. We concluded that CCR5-peptidoliposomes increase the efficiency of sCD4 to inhibit HIV infection by acting as bait for sCD4-primed virus, catalyzing the premature discharge of its fusion potential.

  17. Characterization of Potent SMAC Mimetics that Sensitize Cancer Cells to TNF Family-Induced Apoptosis.

    Directory of Open Access Journals (Sweden)

    Kate Welsh

    Full Text Available Members of the Inhibitor of APoptosis (IAP protein family suppress apoptosis within tumor cells, particularly in the context of immune cell-mediated killing by the tumor necrosis factor (TNF superfamily cytokines. Most IAPs are opposed endogenously by the second mitochondrial activator of caspases (SMAC, which binds to selected baculovirus IAP repeat (BIR domains of IAPs to displace interacting proteins. The development of SMAC mimetics as novel anticancer drugs has gained impetus, with several agents now in human clinical trials. To further understand the cellular mechanisms of SMAC mimetics, we focused on IAP family members cIAP1 and cIAP2, which are recruited to TNF receptor complexes where they support cell survival through NF-κB activation while suppressing apoptosis by preventing caspase activation. We established fluorescence polarization (FP assays for the BIR2 and BIR3 domains of human cIAP1 and cIAP2 using fluorochrome-conjugated SMAC peptides as ligands. A library of SMAC mimetics was profiled using the FP assays to provide a unique structure activity relationship (SAR analysis compared to previous assessments of binding to XIAP. Potent compounds displayed mean inhibitory binding constants (Ki of 9 to 27 nM against the BIR3 domains of cIAP1 and cIAP2, respectively. Selected compounds were then characterized using cytotoxicity assays in which a cytokine-resistant human tumor cell line was sensitized to either TNF or lymphotoxin-α (LT-α. Cytotoxicity correlated closely with cIAP1 and cIAP2 BIR3 binding activity with the most potent compounds able to reduce cell viability by 50%. Further testing demonstrated that active compounds also inhibit RIP1 binding to BIR3 of cIAP1 and cIAP2 in vitro and reduce steady-state cIAP1 protein levels in cells. Altogether, these data inform the SAR for our SMAC mimetics with respect to cIAP1 and cIAP2, suggesting that these IAP family members play an important role in tumor cell resistance to

  18. Characterization of Potent SMAC Mimetics that Sensitize Cancer Cells to TNF Family-Induced Apoptosis.

    Science.gov (United States)

    Welsh, Kate; Milutinovic, Snezana; Ardecky, Robert J; Gonzalez-Lopez, Marcos; Ganji, Santhi Reddy; Teriete, Peter; Finlay, Darren; Riedl, Stefan; Matsuzawa, Shu-Ichi; Pinilla, Clemencia; Houghten, Richard; Vuori, Kristiina; Reed, John C; Cosford, Nicholas D P

    2016-01-01

    Members of the Inhibitor of APoptosis (IAP) protein family suppress apoptosis within tumor cells, particularly in the context of immune cell-mediated killing by the tumor necrosis factor (TNF) superfamily cytokines. Most IAPs are opposed endogenously by the second mitochondrial activator of caspases (SMAC), which binds to selected baculovirus IAP repeat (BIR) domains of IAPs to displace interacting proteins. The development of SMAC mimetics as novel anticancer drugs has gained impetus, with several agents now in human clinical trials. To further understand the cellular mechanisms of SMAC mimetics, we focused on IAP family members cIAP1 and cIAP2, which are recruited to TNF receptor complexes where they support cell survival through NF-κB activation while suppressing apoptosis by preventing caspase activation. We established fluorescence polarization (FP) assays for the BIR2 and BIR3 domains of human cIAP1 and cIAP2 using fluorochrome-conjugated SMAC peptides as ligands. A library of SMAC mimetics was profiled using the FP assays to provide a unique structure activity relationship (SAR) analysis compared to previous assessments of binding to XIAP. Potent compounds displayed mean inhibitory binding constants (Ki) of 9 to 27 nM against the BIR3 domains of cIAP1 and cIAP2, respectively. Selected compounds were then characterized using cytotoxicity assays in which a cytokine-resistant human tumor cell line was sensitized to either TNF or lymphotoxin-α (LT-α). Cytotoxicity correlated closely with cIAP1 and cIAP2 BIR3 binding activity with the most potent compounds able to reduce cell viability by 50%. Further testing demonstrated that active compounds also inhibit RIP1 binding to BIR3 of cIAP1 and cIAP2 in vitro and reduce steady-state cIAP1 protein levels in cells. Altogether, these data inform the SAR for our SMAC mimetics with respect to cIAP1 and cIAP2, suggesting that these IAP family members play an important role in tumor cell resistance to cytotoxicity

  19. Molecular Design, Structures, and Activity of Antimicrobial Peptide-Mimetic Polymers

    Science.gov (United States)

    Takahashi, Haruko; Palermo, Edmund F.; Yasuhara, Kazuma; Caputo, Gregory A.

    2014-01-01

    There is an urgent need for new antibiotics which are effective against drug-resistant bacteria without contributing to resistance development. We have designed and developed antimicrobial copolymers with cationic amphiphilic structures based on the mimicry of naturally occurring antimicrobial peptides. These copolymers exhibit potent antimicrobial activity against a broad spectrum of bacteria including methicillin-resistant Staphylococcus aureus with no adverse hemolytic activity. Notably, these polymers also did not result in any measurable resistance development in E. coli. The peptide-mimetic design principle offers significant flexibility and diversity in the creation of new antimicrobial materials and their potential biomedical applications. PMID:23832766

  20. Original nerve growth factor mimetic dipeptide GK-2 limits the manifestations of hemorrhagic stroke in rats.

    Science.gov (United States)

    Kraineva, V A; Gudasheva, T A; Kotelnikova, S O; Antipova, T A; Seredenin, S B

    2013-03-01

    The protective effects of a new low-molecular-weight mimetic of nerve growth factor hexamethylene diamide bis-(N-monosuccinyl-L-glutamine-L-lysine; GK-2) were studied on the experimental model of hemorrhagic stroke (intracerebral posttraumatic hematoma) in rats. Intraperitoneal injections of GK-2 in a dose of 1 mg/kg 4 and 24 h after surgery and 24 h before testing the CNS function on days 3, 7, and 14 prevent death of experimental animals, reduce the neurological deficit, and normalized behavior.

  1. Peroxynitrite formed during a transient episode of brain ischaemia increases endothelium-derived hyperpolarization-type dilations in thromboxane/prostaglandin receptor-stimulated rat cerebral arteries.

    Science.gov (United States)

    Onetti, Y; Dantas, A P; Pérez, B; McNeish, A J; Vila, E; Jiménez-Altayó, F

    2017-05-01

    Increased thromboxane A 2 and peroxynitrite are hallmarks of cerebral ischaemia/reperfusion (I/R). Stimulation of thromboxane/prostaglandin receptors (TP) attenuates endothelium-derived hyperpolarization (EDH). We investigated whether EDH-type middle cerebral artery (MCA) relaxations following TP stimulation are altered after I/R and the influence of peroxynitrite. Vascular function was determined by wire myography after TP stimulation with the thromboxane A 2 mimetic 9,11-dideoxy-9α, 11α -methano-epoxy prostaglandin F2α (U46619) in MCA of Sprague Dawley rats subjected to MCA occlusion (90 min)/reperfusion (24 h) or sham operation, and in non-operated (control) rats. Some rats were treated with saline or the peroxynitrite decomposition catalyst 5,10,15,20-tetrakis(4-sulfonatophenyl)porphyrinato iron (III) (20 mg kg -1 ). Protein expression was evaluated in MCA and in human microvascular endothelial cells submitted to hypoxia (overnight)/reoxygenation (24 h) (H/R) using immunofluorescence and immunoblotting. In U46619-pre-constricted MCA, EDH-type relaxation by the proteinase-activated receptor 2 agonist serine-leucine-isoleucine-glycine-arginine-leucine-NH 2 (SLIGRL) was greater in I/R than sham rats due to an increased contribution of small-conductance calcium-activated potassium channels (SK C a ), which was confirmed by the enlarged relaxation to the SK C a activator N-cyclohexyl-N-2-(3,5-dimethyl-pyrazol-1-yl)-6-methyl-4-pyrimidinamine. I/R and H/R induced endothelial protein tyrosine nitration and filamentous-actin disruption. In control MCA, either cytochalasin D or peroxynitrite disrupted endothelial filamentous-actin and augmented EDH-type relaxation. Furthermore, peroxynitrite decomposition during I/R prevented the increase in EDH-type responses. Following TP stimulation in MCA, EDH-type relaxation to SLIGRL is greater after I/R due to endothelial filamentous-actin disruption by peroxynitrite, which prevents TP-induced block of SK C a input to EDH

  2. Glycosides from Stevia rebaudiana Bertoni Possess Insulin-Mimetic and Antioxidant Activities in Rat Cardiac Fibroblasts

    Science.gov (United States)

    Prata, Cecilia; Zambonin, Laura; Rizzo, Benedetta; Vieceli Dalla Sega, Francesco

    2017-01-01

    Stevia rebaudiana Bertoni is a shrub having a high content of sweet diterpenoid glycosides in its leaves, mainly stevioside and rebaudioside A, which are used as noncaloric, natural sweeteners. The aim of this study was to deepen the knowledge about the insulin-mimetic effect exerted by four different mixtures of steviol glycosides, rich in stevioside and rebaudioside A, in neonatal rat cardiac fibroblasts. The potential antioxidant activity of these steviol glycosides was also assessed, as oxidative stress is associated with diabetes. Likewise the insulin effect, steviol glycosides caused an increase in glucose uptake into rat fibroblasts by activating the PI3K/Akt pathway, thus inducing Glut4 translocation to the plasma membrane. The presence of S961, an insulin antagonist, completely abolished these effects, allowing to hypothesize that steviol glycosides could act as ligands of the same receptor engaged by insulin. Moreover, steviol glycosides counteracted oxidative stress by increasing reduced glutathione intracellular levels and upregulating expression and activity of the two antioxidant enzymes superoxide dismutase and catalase. The present work unravels the insulin-mimetic effect and the antioxidant property exerted by steviol glycosides, suggesting their potential beneficial role in the cotreatment of diabetes and in health maintenance. PMID:28947927

  3. Methods and Experimental Protocols to Design a Simulated Bio-Mimetic Quadruped Robot

    Directory of Open Access Journals (Sweden)

    Hadi El Daou

    2013-05-01

    Full Text Available Abstract This paper presents a bio-mimetic approach to design and simulate a tortoise-like virtual robot. This study takes a multidisciplinary approach: from in vivo and in vitro experiments on animals, data are collected and used to design, control and simulate a bio-mimetic virtual robot using MD ADAMS platform. From the in vitro experiments, the geometrical and inertial properties of body limbs are measured, and a model of tortoise kinematics is derived. From the in vivo experiments the contact forces between each limb and the ground are measured. The contributions of hind and forelimbs in the generation of propelling and braking forces are studied. The motion of the joints between limb segments are recorded and used to solve the inverse kinematics problem. A virtual model of a tortoise-like robot is built; it is a linkage of 15 rigid bodies articulated by 22 degrees of freedom. This model is referred to as TATOR II. It has the inertial and geometrical properties measured during the in vitro experiments. TATOR II motion is achieved using a Proportional-Derivative controller copying the joint angle trajectories calculated from the in vivo experiments.

  4. Stick-slip friction of gecko-mimetic flaps on smooth and rough surfaces.

    Science.gov (United States)

    Das, Saurabh; Cadirov, Nicholas; Chary, Sathya; Kaufman, Yair; Hogan, Jack; Turner, Kimberly L; Israelachvili, Jacob N

    2015-03-06

    The discovery and understanding of gecko 'frictional-adhesion' adhering and climbing mechanism has allowed researchers to mimic and create gecko-inspired adhesives. A few experimental and theoretical approaches have been taken to understand the effect of surface roughness on synthetic adhesive performance, and the implications of stick-slip friction during shearing. This work extends previous studies by using a modified surface forces apparatus to quantitatively measure and model frictional forces between arrays of polydimethylsiloxane gecko footpad-mimetic tilted microflaps against smooth and rough glass surfaces. Constant attachments and detachments occur between the surfaces during shearing, as described by an avalanche model. These detachments ultimately result in failure of the adhesion interface and have been characterized in this study. Stick-slip friction disappears with increasing velocity when the flaps are sheared against a smooth silica surface; however, stick-slip was always present at all velocities and loads tested when shearing the flaps against rough glass surfaces. These results demonstrate the significance of pre-load, shearing velocity, shearing distances, commensurability and shearing direction of gecko-mimetic adhesives and provide us a simple model for analysing and/or designing such systems. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

  5. Stick–slip friction of gecko-mimetic flaps on smooth and rough surfaces

    Science.gov (United States)

    Das, Saurabh; Cadirov, Nicholas; Chary, Sathya; Kaufman, Yair; Hogan, Jack; Turner, Kimberly L.; Israelachvili, Jacob N.

    2015-01-01

    The discovery and understanding of gecko ‘frictional-adhesion’ adhering and climbing mechanism has allowed researchers to mimic and create gecko-inspired adhesives. A few experimental and theoretical approaches have been taken to understand the effect of surface roughness on synthetic adhesive performance, and the implications of stick–slip friction during shearing. This work extends previous studies by using a modified surface forces apparatus to quantitatively measure and model frictional forces between arrays of polydimethylsiloxane gecko footpad-mimetic tilted microflaps against smooth and rough glass surfaces. Constant attachments and detachments occur between the surfaces during shearing, as described by an avalanche model. These detachments ultimately result in failure of the adhesion interface and have been characterized in this study. Stick–slip friction disappears with increasing velocity when the flaps are sheared against a smooth silica surface; however, stick–slip was always present at all velocities and loads tested when shearing the flaps against rough glass surfaces. These results demonstrate the significance of pre-load, shearing velocity, shearing distances, commensurability and shearing direction of gecko-mimetic adhesives and provide us a simple model for analysing and/or designing such systems. PMID:25589569

  6. Copper Complexes of Nicotinic-Aromatic Carboxylic Acids as Superoxide Dismutase Mimetics

    Directory of Open Access Journals (Sweden)

    Virapong Prachayasittikul

    2008-12-01

    Full Text Available Nicotinic acid (also known as vitamin B3 is a dietary element essential for physiological and antihyperlipidemic functions. This study reports the synthesis of novel mixed ligand complexes of copper with nicotinic and other select carboxylic acids (phthalic, salicylic and anthranilic acids. The tested copper complexes exhibited superoxide dismutase (SOD mimetic activity and antimicrobial activity against Bacillus subtilis ATCC 6633, with a minimum inhibition concentration of 256 μg/mL. Copper complex of nicotinic-phthalic acids (CuNA/Ph was the most potent with a SOD mimetic activity of IC50 34.42 μM. The SOD activities were observed to correlate well with the theoretical parameters as calculated using density functional theory (DFT at the B3LYP/LANL2DZ level of theory. Interestingly, the SOD activity of the copper complex CuNA/Ph was positively correlated with the electron affinity (EA value. The two quantum chemical parameters, highest occupied molecular orbital (HOMO and lowest unoccupied molecular orbital (LUMO, were shown to be appropriate for understanding the mechanism of the metal complexes as their calculated energies show good correlation with the SOD activity. Moreover, copper complex with the highest SOD activity were shown to possess the lowest HOMO energy. These findings demonstrate a great potential for the development of value-added metallovitamin-based therapeutics.

  7. The action of mimetic peptides on connexins protects fibroblasts from the negative effects of ischemia reperfusion.

    Science.gov (United States)

    Glass, Beverley J; Hu, Rebecca G; Phillips, Anthony R J; Becker, David L

    2015-10-15

    Connexins have been proposed as a target for therapeutic treatment of a variety of conditions. The main approaches have been by antisense or small peptides specific against connexins. Some of these peptides enhance communication while others interfere with connexin binding partners or bind to the intracellular and extracellular loops of connexins. Here, we explored the mechanism of action of a connexin mimetic peptide by evaluating its effect on gap junction channels, connexin protein levels and hemichannel activity in fibroblast cells under normal conditions and following ischemia reperfusion injury which elevates Cx43 levels, increases hemichannel activity and causes cell death. Our results showed that the effects of the mimetic peptide were concentration-dependent. High concentrations (100-300 μM) significantly reduced Cx43 protein levels and GJIC within 2 h, while these effects did not appear until 6 h when using lower concentrations (10-30 μM). Cell death can be reduced when hemichannel opening and GJIC were minimised. © 2015. Published by The Company of Biologists Ltd.

  8. BH3 Mimetics Reactivate Autophagic Cell Death in Anoxia-Resistant Malignant Glioma Cells

    Directory of Open Access Journals (Sweden)

    Holger Hetschko

    2008-08-01

    Full Text Available Here, we investigated the specific roles of Bcl-2 family members in anoxia tolerance of malignant glioma. Flow cytometry analysis of cell death in 17 glioma cell lines revealed drastic differences in their sensitivity to oxygen withdrawal (<0.1% O2. Cell death correlated with mitochondrial depolarization, cytochrome C release, and translocation of green fluorescent protein (GFP-tagged light chain 3 to autophagosomes but occurred in the absence of caspase activation or phosphatidylserine exposure. In both sensitive and tolerant glioma cell lines, anoxia caused a significant up-regulation of BH3-only genes previously implicated in mediating anoxic cell death in other cell types (BNIP3, NIX, PUMA, and Noxa. In contrast, we detected a strong correlation between anoxia resistance and high expression levels of antiapoptotic Bcl-2 family proteins Bcl-xL, Bcl-2, and Mcl-1 that function to neutralize the proapoptotic activity of BH3-only proteins. Importantly, inhibition of both Bcl-2 and Bcl-xL with the small-molecule BH3 mimetics HA14-1 and BH3I-2′ and by RNA interference reactivated anoxia-induced autophagic cell death in previously resistant glioma cells. Our data suggest that endogenous BH3-only protein induction may not be able to compensate for the high expression of antiapoptotic Bcl-2 family proteins in anoxia-resistant astrocytomas. They also support the conjecture that BH3 mimetics may represent an exciting new approach for the treatment of malignant glioma.

  9. Fabrication of cell outer membrane mimetic polymer brush on polysulfone surface via RAFT technique

    International Nuclear Information System (INIS)

    Ma Qian; Zhang Hui; Zhao Jiang; Gong Yongkuan

    2012-01-01

    Highlights: ► Cell membrane mimetic antifouling polymer brush was grown on polysulfone surface. ► Graft density and polymerization degree were calculated from XPS results. ► Water contact angle measurements showed an extremely hydrophilic surface. ► Platelet adhesion and protein adsorption results suggested excellent antifouling ability. - Abstract: Cell membrane mimetic antifouling polymer brush was grown on polysulfone (PSF) membrane by surface-induced reversible addition–fragmentation chain transfer (RAFT) polymerization of 2-methacryloyloxyethyl phosphorylcholine (MPC). The RAFT agent immobilized PSF substrate was prepared by successive chloromethylation, amination with ethylenediamine (EDA) and amidation of the amine group of grafted EDA with the carboxylic group of 4-cyanopentanoic acid dithiobenzoate (CPAD). The surface RAFT polymerization of MPC was initiated in aqueous solution by 4,4′-azobis-4-cyanopentanoic acid (ACPA). The formation of PMPC brush coating is evidenced by X-ray photoelectron spectroscopy and water contact angle measurements. The degree of polymerization of PMPC and the polymer grafting density were calculated from the high resolution XPS spectra. The platelet adhesion and protein adsorption results showed that the PMPC-grafted PSF surface has excellent antifouling ability to resist platelet adhesion completely and suppress protein adsorption significantly. This biomimetic and bio-friendly surface RAFT polymerization strategy could be promising for a variety of biomedical applications.

  10. Modulating Mimetic Preference with Theta Burst Stimulation of the Inferior Parietal Cortex

    Directory of Open Access Journals (Sweden)

    Luca F. Ticini

    2017-12-01

    Full Text Available We like an object more when we see someone else reaching for it. To what extent is action observation causally linked to object valuation? In this study, we set out to answer to this question by applying continuous theta burst stimulation (cTBS over the left inferior parietal lobule (IPL. Previous studies pointed to this region as critical in the representation of others' actions and in tool manipulation. However, it is unclear to what extent IPL's involvement simply reflects action observation, rather than a casual role in objects' valuation. To clarify this issue, we measured cTBS-dependent modulations of participants' “mimetic preference ratings”, i.e., the difference between the ratings of pairs of familiar objects that were (vs. were not reached out for by other individuals. Our result shows that cTBS increased mimetic preference ratings for tools, when compared to a control condition without stimulation. This effect was selective for items that were reached for or manipulated by another individual, whilst it was not detected in non-tool objects. Although preliminary, this finding suggests that the automatic and covert simulation of an observed action, even when there is no intention to act on an object, influences explicit affective judgments for objects. This work supports embodied cognition theories by substantiating that our subjective preference is grounded in action.

  11. Glycosides from Stevia rebaudiana Bertoni Possess Insulin-Mimetic and Antioxidant Activities in Rat Cardiac Fibroblasts

    Directory of Open Access Journals (Sweden)

    Cecilia Prata

    2017-01-01

    Full Text Available Stevia rebaudiana Bertoni is a shrub having a high content of sweet diterpenoid glycosides in its leaves, mainly stevioside and rebaudioside A, which are used as noncaloric, natural sweeteners. The aim of this study was to deepen the knowledge about the insulin-mimetic effect exerted by four different mixtures of steviol glycosides, rich in stevioside and rebaudioside A, in neonatal rat cardiac fibroblasts. The potential antioxidant activity of these steviol glycosides was also assessed, as oxidative stress is associated with diabetes. Likewise the insulin effect, steviol glycosides caused an increase in glucose uptake into rat fibroblasts by activating the PI3K/Akt pathway, thus inducing Glut4 translocation to the plasma membrane. The presence of S961, an insulin antagonist, completely abolished these effects, allowing to hypothesize that steviol glycosides could act as ligands of the same receptor engaged by insulin. Moreover, steviol glycosides counteracted oxidative stress by increasing reduced glutathione intracellular levels and upregulating expression and activity of the two antioxidant enzymes superoxide dismutase and catalase. The present work unravels the insulin-mimetic effect and the antioxidant property exerted by steviol glycosides, suggesting their potential beneficial role in the cotreatment of diabetes and in health maintenance.

  12. Eltrombopag, a thrombopoietin mimetic, crosses the blood-brain-barrier and impairs iron-dependent hippocampal neuron dendrite development

    Science.gov (United States)

    Bastian, Thomas W.; Duck, Kari A.; Michalopoulos, George C.; Chen, Michael J.; Liu, Zhi-Jian; Connor, James R.; Lanier, Lorene M.; Sola-Visner, Martha C.; Georgieff, Michael K.

    2017-01-01

    Background Thrombocytopenia is common in sick neonates. Thrombopoietin mimetics (e.g., eltrombopag (ELT)) might provide an alternative therapy for selected neonates with severe and prolonged thrombocytopenia, and for infants and young children with different varieties of thrombocytopenia. However, ELT chelates intracellular iron, which may adversely affect developing organs with high metabolic requirements. Iron deficiency (ID) is particularly deleterious during brain development, impairing neuronal myelination, dopamine signaling, and dendritic maturation and ultimately impairing long-term neurological function (e.g. hippocampal-dependent learning and memory). Objective Determine whether ELT crosses the blood-brain barrier (BBB), causes neuronal ID and impairs hippocampal neuron dendrite maturation. Methods ELT transport across the BBB was assessed using primary bovine brain microvascular endothelial cells. Embryonic mouse primary hippocampal neuron cultures were treated with ELT or deferoxamine (DFO, an iron chelator) from 7 days in vitro (DIV) through 14DIV and assessed for gene expression and neuronal dendrite complexity. Results ELT crossed the BBB in a time-dependent manner. 2 and 6 μM ELT increased Tfr1 and Slc11a2 (iron-responsive genes involved in neuronal iron uptake) mRNA levels, indicating neuronal ID. 6 μM ELT, but not 2 μM ELT, decreased BdnfVI, Camk2a, and Vamp1 mRNA levels, suggesting impaired neuronal development and synaptic function. Dendrite branch number and length was reduced in 6 μM ELT-treated neurons, resulting in blunted dendritic arbor complexity that was similar to DFO-treated neurons. Conclusions ELT treatment during development may impair neuronal structure due to neuronal ID. Pre-clinical in vivo studies are warranted to assess ELT safety during periods of rapid brain development. PMID:28005311

  13. Intrinsic and chemo-sensitizing activity of SMAC-mimetics on high-risk childhood acute lymphoblastic leukemia.

    Science.gov (United States)

    Schirmer, M; Trentin, L; Queudeville, M; Seyfried, F; Demir, S; Tausch, E; Stilgenbauer, S; Eckhoff, S M; Meyer, L H; Debatin, K-M

    2016-01-14

    SMAC-mimetics represent a targeted therapy approach to overcome apoptosis resistance in many tumors. Here, we investigated the efficacy of the SMAC-mimetic BV6 in B-cell precursor acute lymphoblastic leukemia (BCP-ALL). In ALL cell lines, intrinsic apoptosis sensitivity was associated with rapid cIAP degradation, NF-κB activation, TNF-α secretion and induction of an autocrine TNF-α-dependent cell death loop. This pattern of responsiveness was also observed upon ex vivo analysis of 40 primograft BCP-ALL samples. Treatment with BV6 induced cell death in the majority of ALL primografts including leukemias with high-risk and poor-prognosis features. Inhibition of cell death by the TNF receptor fusion protein etanercept demonstrated that BV6 activity is dependent on TNF-α. In a preclinical NOD/SCID/huALL model of high-risk ALL, marked anti-leukemia effectivity and significantly prolonged survival were observed upon BV6 treatment. Interestingly, also in vivo, intrinsic SMAC-mimetic activity was mediated by TNF-α. Importantly, BV6 increased the effectivity of conventional induction therapy including vincristine, dexamethasone and asparaginase leading to prolonged remission induction. These data suggest SMAC-mimetics as an important addendum to efficient therapy of pediatric BCP-ALL.

  14. Efficacy and safety of canagliflozin when used in conjunction with incretin-mimetic therapy in patients with type 2 diabetes

    NARCIS (Netherlands)

    Fulcher, G.; Matthews, D. R.; Perkovic, V.; de Zeeuw, D.; Mahaffey, K. W.; Mathieu, C.; Woo, V.; Wysham, C.; Capuano, G.; Desai, M.; Shaw, W.; Vercruysse, F.; Meininger, G.; Neal, B.

    Aims: To assess the efficacy and safety of canagliflozin, a sodium glucose co-transporter 2 (SGLT2) inhibitor, in patients with type 2 diabetes enrolled in the CANagliflozin cardioVascular Assessment Study (CANVAS) who were on an incretin mimetic [dipeptidyl peptidase-4 (DPP-4) inhibitor or

  15. Diabetes-impaired wound healing is improved by matrix therapy with heparan sulfate glycosaminoglycan mimetic OTR4120 in rats

    NARCIS (Netherlands)

    M. Tong (Miao); B. Tuk (Bastiaan); P. Shang (Peng); J.M. Hekking-Weijma (Ineke); E.M.G. Fijneman (Esther ); M. Guijt (Marnix); S.E.R. Hovius (Steven); J.W. van Neck (Han)

    2012-01-01

    textabstractWound healing in diabetes is frequently impaired, and its treatment remains a challenge. We tested a therapeutic strategy of potentiating intrinsic tissue regeneration by restoring the wound cellular environment using a heparan sulfate glycosaminoglycan mimetic, OTR4120. The effect of

  16. The 5A apolipoprotein A-I (apoA-I) mimetic peptide ameliorates experimental colitis by regulating monocyte infiltration

    NARCIS (Netherlands)

    Nowacki, Tobias M.; Remaley, Alan T.; Bettenworth, Dominik; Eisenblaetter, Michel; Vowinkel, Thorsten; Becker, Felix; Vogl, Thomas; Roth, Johannes; Tietge, Uwe J.; Luegering, Andreas; Heidemann, Jan; Nofer, Jerzy-Roch

    Background and PurposeNew therapies for inflammatory bowel disease (IBD) are highly desirable. As apolipoprotein (apo)A-I mimetic peptides are beneficial in several animal models of inflammation, we hypothesized that they might be effective at inhibiting murine colitis. Experimental ApproachDaily

  17. RSL3 and Erastin differentially regulate redox signaling to promote Smac mimetic-induced cell death.

    Science.gov (United States)

    Dächert, Jasmin; Schoeneberger, Hannah; Rohde, Katharina; Fulda, Simone

    2016-09-27

    Redox mechanisms play an important role in the control of various signaling pathways. Here, we report that Second mitochondrial activator of caspases (Smac) mimetic-induced cell death is regulated by redox signaling. We show that RSL3, a glutathione (GSH) peroxidase (GPX) 4 inhibitor, or Erastin, an inhibitor of the cystine/glutamate antiporter, cooperate with the Smac mimetic BV6 to induce reactive oxygen species (ROS)-dependent cell death in acute lymphoblastic leukemia (ALL) cells. Addition of the caspase inhibitor N-benzyloxycarbonyl-Val-Ala-Asp-fluoromethylketone (zVAD.fmk) fails to rescue ROS-induced cell death, demonstrating that RSL3/BV6- or Erastin/BV6-induced cell death occurs in a caspase-independent manner. Interestingly, the iron chelator Deferoxamine (DFO) significantly inhibits RSL3/BV6-induced cell death, whereas it is unable to rescue cell death by Erastin/BV6, showing that RSL3/BV6-, but not Erastin/BV6-mediated cell death depends on iron. ROS production is required for both RSL3/BV6- and Erastin/BV6-induced cell death, since the ROS scavenger α-tocopherol (α-Toc) rescues RSL3/BV6- and Erastin/BV6-induced cell death. By comparison, genetic or pharmacological inhibition of lipid peroxidation by GPX4 overexpression or ferrostatin (Fer)-1 significantly decreases RSL3/BV6-, but not Erastin/BV6-induced cell death, despite inhibition of lipid peroxidation upon exposure to RSL3/BV6 or Erastin/BV6. Of note, inhibition of lipid peroxidation by Fer-1 protects from RSL3/BV6-, but not from Erastin/BV6-stimulated ROS production, indicating that other forms of ROS besides lipophilic ROS occur during Erastin/BV6-induced cell death. Taken together, RSL3/BV6 and Erastin/BV6 differentially regulate redox signaling and cell death in ALL cells. While RSL3/BV6 cotreatment induces ferroptotic cell death, Erastin/BV6 stimulates oxidative cell death independently of iron. These findings have important implications for the therapeutic targeting of redox signaling to

  18. Digital scenography and the mimetic aporia of Richard Wagner's Ring Cycle

    Directory of Open Access Journals (Sweden)

    Jason R. D’Aoust

    2015-12-01

    Full Text Available This article explores the visual friction between the concealment of technology and the need to stage mimetic scenes in Richard Wagner's Der Ring des Nibelungen. The article relies on the critical reception of the Wagnerian Gesamtkunstwerk in musicology, as well as in media, performance, and theatre studies. Drawing on productions and commentaries critical of the iconic Gesamtkunstwerk's attempted retrieval of a lost natural state, the article examines correlations between phantasmagoria, special effects, movement detection technology, and the interactive devices of multimedia and digital scenography. These correlations are framed within a theoretical methodology of historical discourse and media archaeologies. Three specific productions of the Ring are discussed, namely the inaugural and centenary productions at the Bayreuth Festspielhaus, as well as Robert Lepage's production for the Metropolitan Opera of New York in 2010–2012.

  19. Advances in the design and higher-order assembly of collagen mimetic peptides for regenerative medicine.

    Science.gov (United States)

    Strauss, Kevin; Chmielewski, Jean

    2017-08-01

    Regenerative medicine makes use of cell-supporting biomaterials to replace lost or damaged tissue. Collagen holds great potential in this regard caused by its biocompatibility and structural versatility. While natural collagen has shown promise for regenerative medicine, collagen mimetic peptides (CMPs) have emerged that allow far higher degrees of customization and ease of preparation. A wide range of two and three-dimensional assemblies have been generated from CMPs, many of which accommodate cellular adhesion and encapsulation, through careful sequence design and the exploitation of electrostatic and hydrophobic forces. But the methodology that has generated the greatest plethora of viable biomaterials is metal-promoted assembly of CMP triple helices-a rapid process that occurs under physiological conditions. Architectures generated in this manner promote cell growth, enable directed attachment of bioactive cargo, and produce living tissue. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Triple Effect of Mimetic Peptides Interfering with Neural Cell Adhesion Molecule Homophilic Cis Interactions

    DEFF Research Database (Denmark)

    Li, S. Z.; Kolkova, Kateryna; Rudenko, Olga

    2005-01-01

    on neurite extension and adhesion. To evaluate how interference of these mimetic peptides with NCAM homophilic interactions in cis influences NCAM binding in trans, we employed a coculture system in which PC12-E2 cells were grown on monolayers of fibroblasts with or without NCAM expression and the rate...... of neurite outgrowth subsequently was analyzed. P2, but not P1-B, induced neurite outgrowth in the absence of NCAM binding in trans. When PC12-E2 cells were grown on monolayers of NCAM-expressing fibroblasts, the effect of both P1-B and P2 on neurite outgrowth was dependent on peptide concentrations. P1-B......The neural cell adhesion molecule (NCAM) is pivotal in neural development, regeneration, and learning. Here we characterize two peptides, termed P1-B and P2, derived from the homophilic binding sites in the first two N-terminal immunoglobulin (Ig) modules of NCAM, with regard to their effects...

  1. Application of membrane-mimetic chemistry to environmental and energy related engineering

    International Nuclear Information System (INIS)

    Yen, T.F.; Chen, J.; Chen, J.R.; Lian, H.J.; Lin, J.R.

    1991-01-01

    Membrane-mimetic chemistry principles can be applied to both decontamination and beneficiation processes where impurities must be separated from host molecules by a micellar change. These changes are dependent on the geometrical patterns and assemblages of micelles, vesicles or large liquid crystals (gels). They can be affected by radical transfer initiated by ultrasound irradiation or other microwave sources. Reactions proceed in a submicro environment of compression, rarefaction or cavitation with localized instantaneous high pressure and temperature flux or microstreaming. The following results are achieved through utilization of new technological concept: (1) decontamination of oily soils and upgrading of fossil fuels, (2) destruction of halogenated compounds in water, (3) desulfurization of coal by multiphase biocatalysis, (4) peptization and mesophase transition for geomacromolecules

  2. Bioinspired Interface Engineering for Moisture Resistance in Nacre-Mimetic Cellulose Nanofibrils/Clay Nanocomposites.

    Science.gov (United States)

    Yao, Kun; Huang, Shu; Tang, Hu; Xu, Yeping; Buntkowsky, Gerd; Berglund, Lars A; Zhou, Qi

    2017-06-14

    The interfacial adhesion design between "mortar" and "bricks" is essential for mechanical and barrier performance of nanocellulose-based nacre-mimetic nanocomposites, especially at high moisture conditions. To address this fundamental challenge, dopamine (DA) has been conjugated to cellulose nanofibrils (CNFs) and subsequently assembled with montmorillonite (MTM) to generate layered nanocomposite films inspired by the strong adhesion of mussel adhesive proteins to inorganic surfaces under water. The selective formation of catechol/metal ion chelation and hydrogen bonding at the interface between MTM platelets and CNFs bearing DA renders transparent films with strong mechanical properties, particularly at high humidity and in wet state. Increasing the amount of conjugated DA on CNFs results in nanocomposites with increased tensile strength and modulus, up to 57.4 MPa and 1.1 GPa, respectively, after the films are swollen in water. The nanocomposites also show excellent gas barrier properties at high relative humidity (95%), complementing the multifunctional property profile.

  3. Activation and Inactivation of Primary Human Immunodeficiency Virus Envelope Glycoprotein Trimers by CD4-Mimetic Compounds

    Science.gov (United States)

    Madani, Navid; Princiotto, Amy M.; Zhao, Connie; Jahanbakhshsefidi, Fatemeh; Mertens, Max; Herschhorn, Alon; Melillo, Bruno; Smith, Amos B.

    2016-01-01

    ABSTRACT Human immunodeficiency virus type 1 (HIV-1) entry into cells is mediated by the viral envelope glycoproteins (Env), a trimer of three gp120 exterior glycoproteins, and three gp41 transmembrane glycoproteins. The metastable Env is triggered to undergo entry-related conformational changes when gp120 binds sequentially to the receptors, CD4 and CCR5, on the target cell. Small-molecule CD4-mimetic compounds (CD4mc) bind gp120 and act as competitive inhibitors of gp120-CD4 engagement. Some CD4mc have been shown to trigger Env prematurely, initially activating Env function, followed by rapid and irreversible inactivation. Here, we study CD4mc with a wide range of anti-HIV-1 potencies and demonstrate that all tested CD4mc are capable of activating as well as inactivating Env function. Biphasic dose-response curves indicated that the occupancy of the protomers in the Env trimer governs viral activation versus inactivation. One CD4mc bound per Env trimer activated HIV-1 infection. Envs with two CD4mc bound were activated for infection of CD4-negative, CCR5-positive cells, but the infection of CD4-positive, CCR5-positive cells was inhibited. Virus was inactivated when all three Env protomers were occupied by the CD4mc, and gp120 shedding from the Env trimer was increased in the presence of some CD4mc. Env reactivity and the on rates of CD4mc binding to the Env trimer were found to be important determinants of the potency of activation and entry inhibition. Cross-sensitization of Env protomers that do not bind the CD4mc to neutralization by an anti-V3 antibody was not evident. These insights into the mechanism of antiviral activity of CD4mc should assist efforts to optimize their potency and utility. IMPORTANCE The trimeric envelope glycoproteins of human immunodeficiency virus type 1 (HIV-1) mediate virus entry into host cells. Binding to the host cell receptors, CD4 and CCR5, triggers changes in the conformation of the HIV-1 envelope glycoprotein trimer important

  4. Structure-activity studies of heparan mimetic polyanions for anti-prion therapies.

    Science.gov (United States)

    Ouidja, Mohand-Ouidir; Petit, Emmanuel; Kerros, Marie-Emmanuelle; Ikeda, Yasunori; Morin, Christophe; Carpentier, Gilles; Barritault, Denis; Brugère-Picoux, Jeanne; Deslys, Jean-Philippe; Adjou, Karim; Papy-Garcia, Dulce

    2007-11-09

    Polysulfated molecules, as the family of heparan mimetics (HMs) and pentosan polysulfate, are considered among the more promising drugs used in experimental models of prion diseases. Regardless of their therapeutic potential, structure-function studies on these polyanions are still missing. Here, we report the syntheses of a library of HMs of different molecular sizes, containing various sulfation and carboxylation levels, and substituted or not by different hydrophobic cores. The HMs capacities to inhibit the accumulation of PrPres in chronically infected cells (ScGT1-7) and their PrPc binding abilities were examined. Our results showed that an optimal size and sulfation degree are needed for optimum activity, that incorporation of hydrophobic moieties increases compounds efficacy and that the presence of carboxymethyl moieties decreases it. These structural features should be considered on the modelling of polyanionic compounds for optimum anti-prion activities and for advancing in the understanding the mechanisms involved in their biological actions.

  5. Collagen mimetic peptide engineered M13 bacteriophage for collagen targeting and imaging in cancer.

    Science.gov (United States)

    Jin, Hyo-Eon; Farr, Rebecca; Lee, Seung-Wuk

    2014-11-01

    Collagens are over-expressed in various human cancers and subsequently degraded and denatured by proteolytic enzymes, thus making them a target for diagnostics and therapeutics. Genetically engineered bacteriophage (phage) is a promising candidate for the development of imaging or therapeutic materials for cancer collagen targeting due to its promising structural features. We genetically engineered M13 phages with two functional peptides, collagen mimetic peptide and streptavidin binding peptide, on their minor and major coat proteins, respectively. The resulting engineered phage functions as a therapeutic or imaging material to target degraded and denatured collagens in cancerous tissues. We demonstrated that the engineered phages are able to target and label abnormal collagens expressed on A549 human lung adenocarcinoma cells after the conjugation with streptavidin-linked fluorescent agents. Our engineered collagen binding phage could be a useful platform for abnormal collagen imaging and drug delivery in various collagen-related diseases. Published by Elsevier Ltd.

  6. Pharmacology of smac mimetics; chemotype differentiation based on physical association with caspase regulators and cellular transport.

    Science.gov (United States)

    Talbott, Randy L; Borzilleri, Robert M; Chaudhry, Charu; Fargnoli, Joseph; Shen, Henry; Fairchild, Craig; Barnhart, Bryan; Ortega, Marie; McDonagh, Thomas E; Vuppugalla, Ragini; Vite, Gregory D; Hunt, John T; Gottardis, Marco; Naglich, Joseph G

    2015-11-01

    Cellular levels of inhibitor of apoptosis (IAP) proteins are elevated in multiple human cancers and their activities often play a part in promoting cancer cell survival by blocking apoptotic pathways, controlling signal transduction pathways and contributing to resistance. These proteins function through interactions of their BIR (baculoviral IAP repeat) protein domains with pathway components and these interactions are endogenously antagonized by Smac/Diablo (second mitochondrial activator of caspases/direct IAP binding protein with low isoelectric point). This report describes development of synthetic smac mimetics (SM) and compares their binding, antiproliferative and anti-tumor activities. All dimeric antagonists inhibit in vitro smac tetrapeptide binding to recombinant IAP proteins, rescue IAP-bound caspase-3 activity and show anti-proliferative activity against human A875 melanoma cells. One heterodimeric SM, SM3, binds tightly to IAP proteins in vitro and slowly dissociates (greater than two hours) from these protein complexes compared to the other antagonists. In addition, in vitro SM anti-proliferation potency is influenced by ABCB1 transporter (ATP-binding cassette, sub-family B; MDR1, P-gp) activities and one antagonist, SM5, does not appear to be an ABCB1 efflux pump substrate. All dimeric smac mimetics inhibit the growth of human melanoma A875 tumors implanted in athymic mice at well-tolerated doses. One antagonist, SM4, shows broad spectrum in vivo anti-tumor activity and modulates known pharmacodynamic markers of IAP antagonism. These data taken together demonstrate the range of diverse dimeric IAP antagonist activities and supports their potential as anticancer agents. Copyright © 2015 Elsevier Inc. All rights reserved.

  7. Cytotoxic effects of SMAC-mimetic compound LCL161 in head and neck cancer cell lines.

    Science.gov (United States)

    Brands, Roman C; Herbst, Franziska; Hartmann, Stefan; Seher, Axel; Linz, Christian; Kübler, Alexander C; Müller-Richter, Urs D A

    2016-12-01

    Head and neck squamous cell carcinoma (HNSCC) is one of the most common tumor entities worldwide. Unfortunately, recent drug developments in other fields of oncology have yielded no efficacy in the treatment of oral squamous cell carcinoma. As a new starting point, we investigated the impact of Fas ligand (FasL) and the SMAC-mimetic compound LCL161 in mono- and combination treatment in HNSCC cell lines. Five different cell lines of HNSCC were treated with FasL and LCL161 in mono- and combination treatment. Cytotoxicity was measured via a crystal violet assay. The cell lines were characterized for CD95 (FasL receptor) expression via flow cytometry. The degradation of cellular inhibitor of apoptosis protein 1 (cIAP1) was detected via Western blot. Incubation with FasL led to a significant decrease in three out of five cell lines. Combination treatment with LCL161 enhanced cytotoxicity significantly. Two cell lines were FasL resistant, but one of them could be resensitized with LCL161. In all cell lines, Western blot analysis showed degradation of cIAP1 after LCL161 application. However, one cell line showed only minor vulnerability to the FasL and LCL161 combination. This is the first study investigating combination treatment of FasL and LCL161 in head and neck cancer cell lines. Pro-apoptotic effects of the combination were detected in the majority of the cell lines. Interestingly, one of two FasL-resistant cell lines was sensitive to the combination therapy with FasL and LCL161. SMAC-mimetic compounds show promising results in the treatment of other tumor entities in vitro and might be useful drugs to improve HNSCC therapy.

  8. Smac mimetic triggers necroptosis in pancreatic carcinoma cells when caspase activation is blocked.

    Science.gov (United States)

    Hannes, Sabine; Abhari, Behnaz Ahangarian; Fulda, Simone

    2016-09-28

    Evasion of apoptosis represents a key mechanism of treatment resistance of pancreatic cancer (PC) and contributes to the poor prognosis of this cancer type. Here, we report that induction of necroptosis is an alternative strategy to trigger programmed cell death in apoptosis-resistant PC cells. We show that the second mitochondrial activator of caspases (Smac) mimetic BV6 that antagonizes inhibitor of apoptosis (IAP) proteins induces necroptosis in PC cells in which apoptosis is blocked by the caspase inhibitor zVAD.fmk. Intriguingly, BV6 switches autocrine/paracrine production of tumor necrosis factor (TNF)α by PC cells into a death signal and also acts in concert with exogenously supplied TNFα to trigger necroptosis, when caspase activation is simultaneously blocked. BV6 stimulates TNFα production and formation of the receptor-interacting protein (RIP)1/RIP3-containing necrosome complex in PC cells. Knockdown of TNF receptor 1 (TNFR1) protects PC cells from BV6- or BV6/TNFα-mediated cell death, demonstrating that TNFα autocrine/paracrine signaling by PC cells contributes to BV6-induced necroptosis. Importantly, genetic silencing of receptor interacting protein kinase 3 (RIPK3) or mixed lineage kinase domain-like protein (MLKL) significantly rescues PC cells from BV6- or BV6/TNFα-induced cell death. Similarly, pharmacological inhibition of RIP1, RIP3 or MLKL significantly reduces BV6- or BV6/TNFα-stimulated cell death. By demonstrating that Smac mimetics can bypass resistance to apoptosis by triggering necroptosis as an alternative form of programmed cell death, our findings have important implications for the design of new treatment concepts for PC. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  9. Apolipoprotein A-I and A-I mimetic peptides: a role in atherosclerosis

    Directory of Open Access Journals (Sweden)

    Getz GS

    2011-06-01

    Full Text Available Godfrey S Getz, Catherine A ReardonThe University of Chicago, Department of Pathology, Chicago, IL, USAAbstract: Cardiovascular disease remains a major cause of morbidity and mortality in the westernized world. Atherosclerosis is the underlying cause of most cardiovascular diseases. Atherosclerosis is a slowly evolving chronic inflammatory disorder involving the intima of large and medium sized arteries that is initiated in response to high plasma lipid levels, especially LDL. Cells of both the innate and adaptive immunity are involved in this chronic inflammation. Although high plasma LDL levels are a major contributor to most stages of the evolution of atherosclerosis, HDL and its major protein apoA-I possess properties that attenuate and may even reverse atherosclerosis. Two major functions are the ability to induce the efflux of cholesterol from cells, particularly lipid-loaded macrophages, in the artery wall for transfer to the liver, a process referred to as reverse cholesterol transport, and the ability to attenuate the pro-inflammatory properties of LDL. The removal of cellular cholesterol from lipid-loaded macrophages may also be anti-inflammatory. One of the most promising therapies to enhance the anti-atherogenic, anti-inflammatory properties of HDL is apoA-I mimetic peptides. Several of these peptides have been shown to promote cellular cholesterol efflux, attenuate the production of pro-inflammatory cytokines by macrophages, and to attenuate the pro-inflammatory properties of LDL. This latter effect may be related to their high affinity for oxidized lipids present in LDL. This review discusses the functional properties of the peptides and their effect on experimental atherosclerosis and the results of initial clinical studies in humans.Keywords: apoA-I, mimetic peptides, HDL, anti-inflammatory, atherosclerosis

  10. Metabolic effects of the incretin mimetic exenatide in the treatment of type 2 diabetes

    Directory of Open Access Journals (Sweden)

    Catherine A Schnabel

    2006-03-01

    Full Text Available Catherine A Schnabel, Matthew Wintle, Orville KoltermanAmylin Pharmaceuticals, Inc, 9360 Towne Centre Drive, Suite 110, San Diego, CA 92121, USAAbstract: Interventional studies have demonstrated the impact of hyperglycemia on the development of vascular complications associated with type 2 diabetes, which underscores the importance of safely lowering glucose to as near-normal as possible. Among the current challenges to reducing the risk of vascular disease associated with diabetes is the management of body weight in a predominantly overweight patient population, and in which weight gain is likely with many current therapies. Exenatide is the first in a new class of agents termed incretin mimetics, which replicate several glucoregulatory effects of the endogenous incretin hormone, glucagon-like peptide-1 (GLP-1. Currently approved in the US as an injectable adjunct to metformin and/or sulfonylurea therapy, exenatide improves glycemic control through multiple mechanisms of action including: glucose-dependent enhancement of insulin secretion that potentially reduces the risk of hypoglycemia compared with insulin secretagogues; restoration of first-phase insulin secretion typically deficient in patients with type 2 diabetes; suppression of inappropriately elevated glucagon secretion to reduce postprandial hepatic output; and slowing the rate of gastric emptying to regulate glucose appearance into the circulation. Clinical trials in patients with type 2 diabetes treated with subcutaneous exenatide twice daily demonstrated sustained improvements in glycemic control, evidenced by reductions in postprandial and fasting glycemia and glycosylated hemoglobin (HbA1c levels. Notably, improvements in glycemic control with exenatide were coupled with progressive reductions in body weight, which represents a distinct therapeutic benefit for patients with type 2 diabetes. Acute effects of exenatide on beta-cell responsiveness along with significant reductions

  11. Cooperative TRAIL production mediates IFNα/Smac mimetic-induced cell death in TNFα-resistant solid cancer cells.

    Science.gov (United States)

    Roesler, Stefanie; Eckhardt, Ines; Wolf, Sebastian; Fulda, Simone

    2016-01-26

    Smac mimetics antagonize IAP proteins, which are highly expressed in several cancers. Recent reports indicate that Smac mimetics trigger a broad cytokine response and synergize with immune modulators to induce cell death. Here, we identify a differential requirement of TRAIL or TNFα as mediators of IFNα/Smac mimetic-induced cell death depending on the cellular context. Subtoxic concentrations of Smac mimetics cooperate with IFNα to induce cell death in various solid tumor cell lines in a highly synergistic manner as determined by combination index. Mechanistic studies show that IFNα/BV6 cotreatment promotes the formation of a caspase-8-activating complex together with the adaptor protein FADD and RIP1. Assembly of this RIP1/FADD/caspase-8 complex represents a critical event, since RIP1 silencing inhibits IFNα/BV6-induced cell death. Strikingly, pharmacological inhibition of paracrine/autocrine TNFα signaling by the TNFα scavenger Enbrel rescues HT-29 colon carcinoma cells, but not A172 glioblastoma cells from IFNα/BV6-induced cell death. By comparison, A172 cells are significantly protected against IFNα/BV6 treatment by blockage of TRAIL signaling through genetic silencing of TRAIL or its cognate receptor TRAIL receptor 2 (DR5). Despite this differential requirement of TNFα and TRAIL signaling, mRNA and protein expression is increased by IFNα/BV6 cotreatment in both cell lines. Interestingly, A172 cells turn out to be resistant to exogenously added recombinant TNFα even in the presence of BV6, whereas they display a high sensitivity towards TRAIL/BV6. In contrast, BV6 efficiently sensitizes HT-29 cells to TNFα while TRAIL only had limited efficacy. This demonstrates that a differential sensitivity towards TRAIL or TNFα determines the dependency on either death receptor ligand for IFNα/Smac mimetic-induced cell death. Thus, by concomitant stimulation of both death receptor systems IFNα/Smac mimetic combination treatment is an effective strategy to

  12. Cholesterol depletion blocks redistribution of lipid raft components and insulin-mimetic signaling by glimepiride and phosphoinositolglycans in rat adipocytes.

    Science.gov (United States)

    Müller, Gunter; Hanekop, Nils; Wied, Susanne; Frick, Wendelin

    2002-01-01

    Glycosylphosphatidylinositol-anchored plasma membrane (GPI) proteins, such as Gce1, the dually acylated nonreceptor tyrosine kinases (NRTKs), such as pp59(Lyn), and the membrane protein, caveolin, together with cholesterol are typical components of detergent/carbonate-insoluble glycolipid-enriched raft domains (DIGs) in the plasma membrane of most eucaryotes. Previous studies demonstrated the dissociation from caveolin and concomitant redistribution from DIGs of Gce1 and pp59(Lyn) in rat adipocytes in response to four different insulin-mimetic stimuli, glimepiride, phosphoinositolglycans, caveolin-binding domain peptide, and trypsin/NaCl-treatment. We now characterized the structural basis for this dynamic of DIG components. MATERIALS AND METHODS: Carbonate extracts from purified plasma membranes of basal and stimulated adipocytes were analyzed by high-resolution sucrose gradient centrifugation. RESULTS: This process revealed the existence of two distinct species of detergent/carbonate-insoluble complexes floating at higher buoyant density and harboring lower amounts of cholesterol, caveolin, GPI proteins, and NRTKs (lcDIGs) compared to typical DIGs of high cholesterol content (hcDIGs). The four insulin-mimetic stimuli decreased by 40-70% and increased by 2.5- to 5-fold the amounts of GPI proteins and NRTKs at hcDIGs and lcDIGs, respectively. Cholesterol depletion of adipocytes per se by incubation with methyl-beta-cyclodextrin or cholesterol oxidase also caused translocation of GPI proteins and NRTKs from hcDIGs to lcDIGs and their release from caveolin in reversible fashion without concomitant induction of insulin-mimetic signaling. Cholesterol depletion, however, reduced by 50-60% the stimulus-induced translocation as well as dissociation from hcDIGs-associated caveolin of GPI proteins and NRTKs, activation of NRTKs as well as insulin-mimetic signaling and metabolic action. In contrast, insulin-mimetic signaling induced by vanadium compounds was not

  13. Cholesterol depletion blocks redistribution of lipid raft components and insulin-mimetic signaling by glimepiride and phosphoinositolglycans in rat adipocytes.

    Science.gov (United States)

    Müller, Gunter; Hanekop, Nils; Wied, Susanne; Frick, Wendelin

    2002-03-01

    Glycosylphosphatidylinositol-anchored plasma membrane (GPI) proteins, such as Gce1, the dually acylated nonreceptor tyrosine kinases (NRTKs), such as pp59(Lyn), and the membrane protein, caveolin, together with cholesterol are typical components of detergent/carbonate-insoluble glycolipid-enriched raft domains (DIGs) in the plasma membrane of most eucaryotes. Previous studies demonstrated the dissociation from caveolin and concomitant redistribution from DIGs of Gce1 and pp59(Lyn) in rat adipocytes in response to four different insulin-mimetic stimuli, glimepiride, phosphoinositolglycans, caveolin-binding domain peptide, and trypsin/NaCl-treatment. We now characterized the structural basis for this dynamic of DIG components. Carbonate extracts from purified plasma membranes of basal and stimulated adipocytes were analyzed by high-resolution sucrose gradient centrifugation. This process revealed the existence of two distinct species of detergent/carbonate-insoluble complexes floating at higher buoyant density and harboring lower amounts of cholesterol, caveolin, GPI proteins, and NRTKs (lcDIGs) compared to typical DIGs of high cholesterol content (hcDIGs). The four insulin-mimetic stimuli decreased by 40-70% and increased by 2.5- to 5-fold the amounts of GPI proteins and NRTKs at hcDIGs and lcDIGs, respectively. Cholesterol depletion of adipocytes per se by incubation with methyl-beta-cyclodextrin or cholesterol oxidase also caused translocation of GPI proteins and NRTKs from hcDIGs to lcDIGs and their release from caveolin in reversible fashion without concomitant induction of insulin-mimetic signaling. Cholesterol depletion, however, reduced by 50-60% the stimulus-induced translocation as well as dissociation from hcDIGs-associated caveolin of GPI proteins and NRTKs, activation of NRTKs as well as insulin-mimetic signaling and metabolic action. In contrast, insulin-mimetic signaling induced by vanadium compounds was not significantly diminished by cholesterol

  14. Smac Mimetic Bypasses Apoptosis Resistance in FADD- or Caspase-8-Deficient Cells by Priming for Tumor Necrosis Factor α-Induced Necroptosis

    Directory of Open Access Journals (Sweden)

    Bram Laukens

    2011-10-01

    Full Text Available Searching for new strategies to bypass apoptosis resistance, we investigated the potential of the Smac mimetic BV6 in Jurkat leukemia cells deficient in key molecules of the death receptor pathway. Here, we demonstrate for the first time that Smac mimetic primes apoptosis-resistant, FADD- or caspase-8-deficient leukemia cells for TNFα-induced necroptosis in a synergistic manner. In contrast to TNFα, Smac mimetic significantly enhances CD95-induced apoptosis in wild-type but not in FADD-deficient cells. Interestingly, Smac mimetic- and TNFα-mediated cell death occurs without characteristic features of apoptosis (i.e., caspase activation, DNA fragmentation in FADD-deficient cells. By comparison, Smac mimetic and TNFα trigger activation of caspase-8, -9, and -3 and DNA fragmentation in wild-type cells. Consistently, the caspase inhibitor zVAD.fmk fails to block Smac mimetic- and TNFα-triggered cell death in FADD- or caspase-8-deficient cells, while it confers protection in wild-type cells. By comparison, necrostatin-1, an RIP1 kinase inhibitor, abolishes Smac mimetic- and TNFα-induced cell death in FADD- or caspase-8-deficient. Thus, Smac mimetic enhances TNFα-induced cell death in leukemia cells via two distinct pathways in a context-dependent manner: it primes apoptosis-resistant cells lacking FADD or caspase-8 to TNFα-induced, RIP1-dependent and caspase-independent necroptosis, whereas it sensitizes apoptosis-proficient cells to TNFα-mediated, caspase-dependent apoptosis. These findings have important implications for the therapeutic exploitation of necroptosis as an alternative cell death program to overcome apoptosis resistance.

  15. Smac Mimetic Bypasses Apoptosis Resistance in FADD- or Caspase-8-Deficient Cells by Priming for Tumor Necrosis Factor α-Induced Necroptosis12

    Science.gov (United States)

    Laukens, Bram; Jennewein, Claudia; Schenk, Barbara; Vanlangenakker, Nele; Schier, Alexander; Cristofanon, Silvia; Zobel, Kerry; Deshayes, Kurt; Vucic, Domagoj; Jeremias, Irmela; Bertrand, Mathieu JM; Vandenabeele, Peter; Fulda, Simone

    2011-01-01

    Searching for new strategies to bypass apoptosis resistance, we investigated the potential of the Smac mimetic BV6 in Jurkat leukemia cells deficient in key molecules of the death receptor pathway. Here, we demonstrate for the first time that Smac mimetic primes apoptosis-resistant, FADD- or caspase-8-deficient leukemia cells for TNFα-induced necroptosis in a synergistic manner. In contrast to TNFα, Smac mimetic significantly enhances CD95-induced apoptosis in wild-type but not in FADD-deficient cells. Interestingly, Smac mimetic- and TNFα-mediated cell death occurs without characteristic features of apoptosis (i.e., caspase activation, DNA fragmentation) in FADD-deficient cells. By comparison, Smac mimetic and TNFα trigger activation of caspase-8, -9, and -3 and DNA fragmentation in wild-type cells. Consistently, the caspase inhibitor zVAD.fmk fails to block Smac mimetic- and TNFα-triggered cell death in FADD- or caspase-8-deficient cells, while it confers protection in wild-type cells. By comparison, necrostatin-1, an RIP1 kinase inhibitor, abolishes Smac mimetic- and TNFα-induced cell death in FADD- or caspase-8-deficient. Thus, Smac mimetic enhances TNFα-induced cell death in leukemia cells via two distinct pathways in a context-dependent manner: it primes apoptosis-resistant cells lacking FADD or caspase-8 to TNFα-induced, RIP1-dependent and caspase-independent necroptosis, whereas it sensitizes apoptosis-proficient cells to TNFα-mediated, caspase-dependent apoptosis. These findings have important implications for the therapeutic exploitation of necroptosis as an alternative cell death program to overcome apoptosis resistance. PMID:22028622

  16. Smac mimetic bypasses apoptosis resistance in FADD- or caspase-8-deficient cells by priming for tumor necrosis factor α-induced necroptosis.

    Science.gov (United States)

    Laukens, Bram; Jennewein, Claudia; Schenk, Barbara; Vanlangenakker, Nele; Schier, Alexander; Cristofanon, Silvia; Zobel, Kerry; Deshayes, Kurt; Vucic, Domagoj; Jeremias, Irmela; Bertrand, Mathieu J M; Vandenabeele, Peter; Fulda, Simone

    2011-10-01

    Searching for new strategies to bypass apoptosis resistance, we investigated the potential of the Smac mimetic BV6 in Jurkat leukemia cells deficient in key molecules of the death receptor pathway. Here, we demonstrate for the first time that Smac mimetic primes apoptosis-resistant, FADD- or caspase-8-deficient leukemia cells for TNFα-induced necroptosis in a synergistic manner. In contrast to TNFα, Smac mimetic significantly enhances CD95-induced apoptosis in wild-type but not in FADD-deficient cells. Interestingly, Smac mimetic- and TNFα-mediated cell death occurs without characteristic features of apoptosis (i.e., caspase activation, DNA fragmentation) in FADD-deficient cells. By comparison, Smac mimetic and TNFα trigger activation of caspase-8, -9, and -3 and DNA fragmentation in wild-type cells. Consistently, the caspase inhibitor zVAD.fmk fails to block Smac mimetic- and TNFα-triggered cell death in FADD- or caspase-8-deficient cells, while it confers protection in wild-type cells. By comparison, necrostatin-1, an RIP1 kinase inhibitor, abolishes Smac mimetic- and TNFα-induced cell death in FADD- or caspase-8-deficient. Thus, Smac mimetic enhances TNFα-induced cell death in leukemia cells via two distinct pathways in a context-dependent manner: it primes apoptosis-resistant cells lacking FADD or caspase-8 to TNFα-induced, RIP1-dependent and caspase-independent necroptosis, whereas it sensitizes apoptosis-proficient cells to TNFα-mediated, caspase-dependent apoptosis. These findings have important implications for the therapeutic exploitation of necroptosis as an alternative cell death program to overcome apoptosis resistance.

  17. Novel use of fluorescent glucose analogues to identify a new class of triazine-based insulin mimetics possessing useful secondary effects.

    Science.gov (United States)

    Jung, Da-Woon; Ha, Hyung-Ho; Zheng, Xuexiu; Chang, Young-Tae; Williams, Darren R

    2011-02-01

    There is an urgent need to discover new compounds that effectively treat diabetes by mimicking the action of insulin (insulin mimetics). Traditional approaches to studying anti-diabetic agents in cells are inconvenient for screening chemical libraries to identify insulin mimetics. 2-(N-(7-Nitrobenz-2-oxa-1,3-diazol-4-yl)amino)-2-deoxyglucose (2-NBDG) and 6-NBDG are fluorescent analogues of glucose that could be employed in screening. However, there are no published data about the use of these analogues to identify new insulin mimetics. We have developed a screening system based on 6-NBDG using 3T3-L1 adipocytes in a 96-well culture plate format. 6-NBDG was found to produce a larger signal than 2-NBDG in this screening system. 6-NBDG uptake in 3T3-L1 adipocytes was sensitive to insulin, known insulin mimetics, inhibitors of glucose transport and insulin-sensitizing compounds. To validate our screening system, a chemical library of 576 tagged, triazine-based small molecules was screened. The screening results were identical to that obtained from a commercial enzyme-based glucose assay. Two inducers of glucose uptake were shown to be non-cytotoxic and confirmed as insulin mimetic compounds by their inhibition of epinephrine-stimulated free fatty acid release from adipocytes. These novel insulin mimetics functioned at a markedly lower concentration than two widely studied insulin mimetics, zinc(ii) complexes and vanadium compounds, and also showed novel, beneficial effects on endothelial cell function (a key determinant of secondary complications in diabetes). The discovery of new insulin mimetics using 6-NBDG validates the use of this probe in the development of large-scale, cell-based screening systems based on the uptake of fluorescent-tagged glucose analogues. This research should aid the development of novel strategies to discover new drugs and drug targets for combating the increasing prevalence of diabetes.

  18. 4-Connected azabicyclo[5.3.0]decane Smac mimetics-Zn2+ chelators as dual action antitumoral agents.

    Science.gov (United States)

    Manzoni, Leonardo; Samela, Alessandro; Barbini, Stefano; Cairati, Silvia; Penconi, Marta; Arosio, Daniela; Lecis, Daniele; Seneci, Pierfausto

    2017-06-01

    Putative dual action compounds (DACs 3a-d) based on azabicyclo[5.3.0]decane (ABD) Smac mimetic scaffolds linked to Zn 2+ -chelating 2,2'-dipicolylamine (DPA) through their 4 position are reported and characterized. Their synthesis, their target affinity (cIAP1 BIR3, Zn 2+ ) in cell-free assays, their pro-apoptotic effects, and their cytotoxicity in tumor cells with varying sensitivity to Smac mimetics are described. A limited influence of Zn 2+ chelation on in vitro activity of DPA-substituted DACs 3a-d was sometimes perceivable, but did not lead to strong cellular synergistic effects. In particular, the linker connecting DPA with the ABD scaffold seems to influence cellular Zn 2+ -chelation, with longer lipophilic linkers/DAC 3c being the optimal choice. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. A Small Molecule Mimetic of the Humanin Peptide as a Candidate for Modulating NMDA-Induced Neurotoxicity.

    Science.gov (United States)

    Alam, Mohammad Parvez; Bilousova, Tina; Spilman, Patricia; Vadivel, Kanagasabai; Bai, Dongsheng; Elias, Chris J; Evseenko, Denis; John, Varghese

    2018-03-21

    Humanin (HN), a 24-amino acid bioactive peptide, has been shown to increase cell survival of neurons after exposure to Aβ and NMDA-induced toxicity and thus could be beneficial in the treatment of Alzheimer's disease (AD). The neuroprotection by HN is reported to be primarily through its agonist binding properties to the gp130 receptor. However, the peptidic nature of HN presents challenges in its development as a therapeutic for AD. We report here for the first time the elucidation of the binding site of Humanin (HN) peptide to the gp130 receptor extracellular domain through modeling and the synthesis of small molecule mimetics that interact with the HN binding site on the gp130 receptor and provide protection against NMDA-induced neurotoxicity in primary hippocampal neurons. A brain permeable small molecule mimetic was identified through exploratory medicinal chemistry using microfluidic flow chemistry to facilitate the synthesis of new analogues for screening and SAR optimization.

  20. Targeting of apoptotic pathways by SMAC or BH3 mimetics distinctly sensitizes paclitaxel-resistant triple negative breast cancer cells.

    Science.gov (United States)

    Panayotopoulou, Effrosini G; Müller, Anna-Katharina; Börries, Melanie; Busch, Hauke; Hu, Guohong; Lev, Sima

    2017-07-11

    Standard chemotherapy is the only systemic treatment for triple-negative breast cancer (TNBC), and despite the good initial response, resistance remains a major therapeutic obstacle. Here, we employed a High-Throughput Screen to identify targeted therapies that overcome chemoresistance in TNBC. We applied short-term paclitaxel treatment and screened 320 small-molecule inhibitors of known targets to identify drugs that preferentially and efficiently target paclitaxel-treated TNBC cells. Among these compounds the SMAC mimetics (BV6, Birinapant) and BH3-mimetics (ABT-737/263) were recognized as potent targeted therapy for multiple paclitaxel-residual TNBC cell lines. However, acquired paclitaxel resistance through repeated paclitaxel pulses result in desensitization to BV6, but not to ABT-263, suggesting that short- and long-term paclitaxel resistance are mediated by distinct mechanisms. Gene expression profiling of paclitaxel-residual, -resistant and naïve MDA-MB-231 cells demonstrated that paclitaxel-residual, as opposed to -resistant cells, were characterized by an apoptotic signature, with downregulation of anti-apoptotic genes (BCL2, BIRC5), induction of apoptosis inducers (IL24, PDCD4), and enrichment of TNFα/NF-κB pathway, including upregulation of TNFSF15, coupled with cell-cycle arrest. BIRC5 and FOXM1 downregulation and IL24 induction was also evident in breast cancer patient datasets following taxane treatment. Exposure of naïve or paclitaxel-resistant cells to supernatants of paclitaxel-residual cells sensitized them to BV6, and treatment with TNFα enhanced BV6 potency, suggesting that sensitization to BV6 is mediated, at least partially, by secreted factor(s). Our results suggest that administration of SMAC or BH3 mimetics following short-term paclitaxel treatment could be an effective therapeutic strategy for TNBC, while only BH3-mimetics could effectively overcome long-term paclitaxel resistance.

  1. The Targeted SMAC Mimetic SW IV-134 is a strong enhancer of standard chemotherapy in pancreatic cancer.

    Science.gov (United States)

    Hashim, Yassar M; Vangveravong, Suwanna; Sankpal, Narendra V; Binder, Pratibha S; Liu, Jingxia; Goedegebuure, S Peter; Mach, Robert H; Spitzer, Dirk; Hawkins, William G

    2017-01-17

    Pancreatic cancer is a lethal malignancy that frequently acquires resistance to conventional chemotherapies often associated with overexpression of inhibitors of apoptosis proteins (IAPs). We have recently described a novel means to deliver second mitochondria-derived activator of caspases (SMAC) mimetics selectively to cancer cells employing the sigma-2 ligand/receptor interaction. The intrinsic death pathway agonist SMAC offers an excellent opportunity to counteract the anti-apoptotic activity of IAPs. SMAC mimetics have been used to sensitize several cancer types to chemotherapeutic agents but cancer-selective delivery and appropriate cellular localization have not yet been considered. In our current study, we tested the ability of the sigma-2/SMAC drug conjugate SW IV-134 to sensitize pancreatic cancer cells to gemcitabine. Using the targeted SMAC mimetic SW IV-134, inhibition of the X-linked inhibitor of apoptosis proteins (XIAP) was induced pharmacologically and its impact on cell viability was studied alone and in combination with gemcitabine. Pathway analyses were performed by assessing caspase activation, PARP cleavage and membrane blebbing (Annexin-V), key components of apoptotic cell death. Single-agent treatment regimens were compared with combination therapy in a preclinical mouse model of pancreatic cancer. The sensitizing effect of XIAP interference toward gemcitabine was confirmed via pharmacological intervention using our recently designed, targeted SMAC mimetic SW IV-134 across a wide range of commonly used pancreatic cancer cell lines at concentrations where the individual drugs showed only minimal activity. On a mechanistic level, we identified involvement of key components of the apoptosis machinery during cell death execution. Furthermore, combination therapy proved superior in decreasing the tumor burden and extending the lives of the animals in a preclinical mouse model of pancreatic cancer. We believe that the strong sensitizing capacity of

  2. A highly efficient type I β-turn mimetic simulating an Asx-Pro-turn-like structure.

    Science.gov (United States)

    Pinsker, Andrea; Einsiedel, Jürgen; Härterich, Steffen; Waibel, Reiner; Gmeiner, Peter

    2011-07-01

    Asx-Pro-turns have been identified with high frequency in protein structures nucleating type I β-turns. By bridging the amino acid side chain in position i with a nitrogen substituent in position i+2 by ring-closing olefin metathesis (RCM), peptide mimetics of type 1 could be developed. NMR based conformational investigations indicated a stable intramolecular H-bond constraining a U-turn conformation that was predicted to simulate a type I β-turn.

  3. Effect of the Nerve Growth Factor Mimetic GK-2 on Brain Structural and Functional State in the Early Postresuscitation Period

    Directory of Open Access Journals (Sweden)

    M. Sh. Avrushchenko

    2012-01-01

    Full Text Available Objective: to evaluate the efficacy of the nerve growth factor mimetic GK-2 used to improve the structural and functional state of the brain in the early postresuscitation period. Material and methods. Cardiac arrest was induced in mature male albino rats for 12 minutes, followed by resuscitation. The neurological state of the resuscitated animals was assessed by a scoring scale. On postresuscitation day 7, the density and composition of neuronal populations of Purkinje cells in the lateral cerebellar region and pyramidal neurons in the hippocampal CA1 sector were determined by a differential morphometric analysis. The results were statistically processed using the ANOVA method. Results. The use of GK-2 was found to accelerate neurological recovery in the resuscitated animals. On day 7 after 12-minute cardiac arrest, the resuscitated animals showed neuronal dystrophic changes and death in the neuronal populations highly susceptible to ischemia. It was shown that the systemic administration of the nerve growth factor mimetic GK-2 contributed to a reduction in the magnitude and depth of postresuscitation changes in the cerebellar Purkinje cells and prevented dystrophic changes in the pyramidal cells of the hippocampal CA1 sector. The findings suggest that GK-2 has a neuroprotective effect in the recovery period after total body ischemia. Conclusion. The results of this study indicate the efficiency of the systemic administration of the nerve growth factor mimetic GK-2 in improving the brain structural and functional state in the early postresuscitation period. This determines perspectives for the use of GK-2 to prevent and correct posthypoxic encephalopathies. Key words: the nerve growth factor mimetic GK-2, postresuscitation period, neuronal dystrophic changes and death, neurological status.

  4. Can mimetics, a theatre based practice, open possibilities for young people with learning disabilities - a capability approach?

    OpenAIRE

    Trowsdale, Jo; Hayhow, Richard

    2013-01-01

    Whilst the significance of the social model of disability for articulating inclusive approaches in education is recognised, the application of capability theory to education is less developed. We consider how a particular theatre based practice, here described as ‘mimetics’, can alter and extend the aspirations and achievements of children and young people with learning disabilities, and might be understood as applied capability theory or ‘capability practice’. Mimetics has been crafted from ...

  5. SOD mimetics: A Novel Class of Androgen Receptor Inhibitors that Suppresses Castration-Resistant Growth of Prostate Cancer

    Science.gov (United States)

    Thomas, Rusha; Sharifi, Nima

    2011-01-01

    Advanced prostate cancer (PCa) is the second-leading cause of cancer-related deaths among American men. The androgen receptor (AR) is vital for PCa progression, even in the face of castrate levels of serum testosterone following androgen ablation therapy, a mainstay therapy for advanced PCa. Downregulation of superoxide dismutase 2 (SOD2), a major intracellular antioxidant enzyme, occurs progressively during PCa progression to advanced states, and is known to promote AR activity in PCa. Therefore, this study investigated the effects of SOD mimetics on AR expression and function in AR-dependent LNCaP, CWR22Rv1, and LAPC-4AD PCa cells. Treatment with Tempol, a SOD mimetic, not only lowered cellular superoxide levels, but also concomitantly attenuated AR transcriptional activity and AR target gene expression in a dose- and time-dependent manner, in the presence and absence of dihydrotestosterone, the major endogenous AR agonist. Tempol's inhibition of AR was mediated, in large part, by its ability to decrease AR protein via increased degradation, in the absence of any inhibitory effects on other nuclear receptors. Tempol's inhibitory effects on AR were also reproducible with other SOD mimetics, MnTBAP and MnTMPyP. Importantly, Tempol's effects on AR function were accompanied by significant in vitro and in vivo reduction in castration-resistant PCa survival and growth. Collectively, this study has demonstrated for the first time that SOD mimetics, by virtue of their ability to suppress AR function, may be beneficial in treating the currently incurable castration-resistant PCa in which SOD2 expression is highly suppressed. PMID:22172488

  6. SMAC mimetic BV6 induces cell death in monocytes and maturation of monocyte-derived dendritic cells.

    Directory of Open Access Journals (Sweden)

    Nicole Müller-Sienerth

    Full Text Available BACKGROUND: Compounds mimicking the inhibitory effect of SMAC/DIABLO on X-linked inhibitor of apoptosis (XIAP have been developed with the aim to achieve sensitization for apoptosis of tumor cells resistant due to deregulated XIAP expression. It turned out that SMAC mimetics also have complex effects on the NFκB system and TNF signaling. In view of the overwhelming importance of the NFκB transcription factors in the immune system, we analyzed here the effects of the SMAC mimetic BV6 on immune cells. PRINCIPAL FINDINGS: BV6 induced apoptotic and necrotic cell death in monocytes while T-cells, dendritic cells and macrophages were largely protected against BV6-induced cell death. In immature dendritic cells BV6 treatment resulted in moderate activation of the classical NFκB pathway, but it also diminished the stronger NFκB-inducing effect of TNF and CD40L. Despite its inhibitory effect on TNF- and CD40L signaling, BV6 was able to trigger maturation of immature DCs as indicated by upregulation of CD83, CD86 and IL12. SIGNIFICANCE: The demonstrated effects of SMAC mimetics on immune cells may complicate the development of tumor therapeutic concepts based on these compounds but also arise the possibility to exploit them for the development of immune stimulatory therapies.

  7. Deleterious Effects of High Dose Connexin 43 Mimetic Peptide Infusion After Cerebral Ischaemia in Near-Term Fetal Sheep

    Directory of Open Access Journals (Sweden)

    Alistair J. Gunn

    2012-05-01

    Full Text Available Hypoxic-ischaemic brain injury at birth is associated with 1–3/1000 cases of moderate to severe encephalopathy. Previously, we have shown that connexin 43 hemichannel blockade, with a specific mimetic peptide, reduced the occurrence of seizures, improved recovery of EEG power and sleep state cycling, and improved cell survival following global cerebral ischaemia. In the present study, we examined the dose response for intracerebroventricular mimetic peptide infusion (50 µmol/kg/h for 1 h, followed by 50 µmol/kg/24 h (low dose or 50 µmol/kg/h for 25 h (high dose or vehicle only (control group, starting 90 min after the end of ischaemia, following global cerebral ischaemia, induced by 30 min bilateral carotid artery occlusion, in near-term fetal sheep (128 ± 1 days gestation. Both peptide infusion groups were associated with a transient significant increase in EEG power between 2–12 h after ischaemia. The ischaemia-low dose group showed a significant recovery of EEG power from day five compared to the ischaemia-vehicle and -high dose groups. In contrast, the high dose infusion was associated with greater secondary increase in impedance (brain cell swelling, as well as a trend towards a greater increase in lactate concentration and mortality. These data suggest that higher doses of connexin mimetic peptide are not beneficial and may be associated with adverse outcomes, most likely attributable to uncoupling of connexin 43 gap junctions leading to dysfunction of the astrocytic syncytium.

  8. Interaction of a Cyclic, Bivalent Smac Mimetic with the X-Linked Inhibitor of Apoptosis Protein

    Energy Technology Data Exchange (ETDEWEB)

    Nikolovska-Coleska, Zaneta; Meagher, Jennifer L.; Jiang, Sheng; Yang, Chao-Yie; Qiu, Su; Roller, Peter P.; Stuckey, Jeanne A.; Wang, Shaomeng (Michigan); (NIH)

    2009-02-25

    We have designed and synthesized a cyclic, bivalent Smac mimetic (compound 3) and characterized its interaction with the X-linked inhibitor of apoptosis protein (XIAP). Compound 3 binds to XIAP containing both BIR2 and BIR3 domains with a biphasic dose-response curve representing two binding sites with IC{sub 50} values of 0.5 and 406 nM, respectively. Compound 3 binds to XIAPs containing the BIR3-only and BIR2-only domain with K{sub i} values of 4 nM and 4.4 {mu}M, respectively. Gel filtration experiments using wild-type and mutated XIAPs showed that 3 forms a 1:2 stoichiometric complex with XIAP containing the BIR3-only domain. However, it forms a 1:1 stoichiometric complex with XIAP containing both BIR2 and BIR3 domains, and both BIR domains are involved in the binding. Compound 3 efficiently antagonizes inhibition of XIAP in a cell-free functional assay and is >200 times more potent than its corresponding monovalent compound 2. Determination of the crystal structure of 3 in complex with the XIAP BIR3 domain confirms that 3 induces homodimerization of the XIAP BIR3 domain and provides a structural basis for the cooperative binding of one molecule of compound 3 to two XIAP BIR3 molecules. On the basis of this crystal structure, a binding model of XIAP containing both BIR2 and BIR3 domains and 3 was constructed, which sheds light on the ability of 3 to relieve the inhibition of XIAP with not only caspase-9 but also caspase-3/-7. Compound 3 is cell-permeable, effectively activates caspases in whole cells, and potently inhibits cancer cell growth. Compound 3 is a useful biochemical and pharmacological tool for further elucidating the role of XIAP in regulation of apoptosis and represents a promising lead compound for the design of potent, cell-permeable Smac mimetics for cancer treatment.

  9. Using superoxide dismutase/catalase mimetics to manipulate the redox environment of neural precursor cells

    International Nuclear Information System (INIS)

    Limoli, C. L.; Giedzinski, E.; Baure, J.; Doctrow, S. R.; Rola, R.; Fike, J. R.

    2006-01-01

    Past work has shown that neural precursor cells are predisposed to redox sensitive changes, and that oxidative stress plays a critical role in the acute and persistent changes that occur within the irradiated CNS. Irradiation leads to a marked rise in reactive oxygen species (ROS) that correlates with oxidative endpoints in vivo and reductions in neuro-genesis. To better understand the impact of oxidative stress on neural precursor cells, and to determine if radiation-induced oxidative damage and precursor cell loss after irradiation could be reduced, a series of antioxidant compounds (EUK-134, EUK-163, EUK-172, EUK-189) were tested, three of which possess both superoxide dismutase (SOD) and catalase activities and one (EUK-163) whose only significant activity is SOD. Our results show that these SOD/catalase mimetics apparently increase the oxidation of a ROS-sensitive fluorescent indicator dye, particularly after short (12 h) treatments, but that longer treatments (24 h) decrease oxidation attributable to radiation-induced ROS. Similarly, other studies found that cells incubated with CuZnSOD showed some increase in intracellular ROS levels. Subsequent data suggested that the dye-oxidising capabilities of the EUK compounds were linked to differences in their catalase activity and, most likely, their ability to catalyse per-oxidative pathways. In unirradiated mice, the EUK-134 analogue induced some decrease of proliferating precursor cells and immature neurons 48 h after radiation, an effect that may be attributable to cytotoxicity and/or inhibition of precursor proliferation. In irradiated mice, a single injection of EUK-134 was not found to be an effective radioprotector at acute times (48 h). The present results support continued development of our in vitro model as a tool for predicting certain in vivo responses, and suggest that in some biological systems the capability to scavenge superoxide but produce excess H 2 O 2 , as is known for CuZnSOD, may be

  10. Collagen-binding VEGF mimetic peptide: Structure, matrix interaction, and endothelial cell activation

    Science.gov (United States)

    Chan, Tania R.

    Long term survival of artificial tissue constructs depends greatly on proper vascularization. In nature, differentiation of endothelial cells and formation of vasculature are directed by dynamic spatio-temporal cues in the extracellular matrix that are difficult to reproduce in vitro. In this dissertation, we present a novel bifunctional peptide that mimics matrix-bound vascular endothelial growth factor (VEGF), which can be used to encode spatially controlled angiogenic signals in collagen-based scaffolds. The peptide, QKCMP, contains a collagen mimetic domain (CMP) that binds to type I collagen by a unique triple helix hybridization mechanism and a VEGF mimetic domain (QK) with pro-angiogenic activity. We demonstrate QKCMP's ability to hybridize with native and heat denatured collagens through a series of binding studies on collagen and gelatin substrates. Circular dichroism experiments show that the peptide retains the triple helical structure vital for collagen binding, and surface plasmon resonance study confirms the molecular interaction between the peptide and collagen strands. Cell culture studies demonstrate QKCMP's ability to induce endothelial cell morphogenesis and network formation as a matrix-bound factor in 2D and 3D collagen scaffolds. We also show that the peptide can be used to spatially modify collagen-based substrates to promote localized endothelial cell activation and network formation. To probe the biological events that govern these angiogenic cellular responses, we investigated the cell signaling pathways activated by collagen-bound QKCMP and determined short and long-term endothelial cell response profiles for p38, ERK1/2, and Akt signal transduction cascades. Finally, we present our efforts to translate the peptide's in vitro bioactivity to an in vivo burn injury animal model. When implanted at the wound site, QKCMP functionalized biodegradable hydrogels induce enhanced neovascularization in the granulation tissue. The results show QKCMP

  11. Design and facile synthesis of neoglycolipids as lactosylceramide mimetics and their transformation into glycoliposomes.

    Science.gov (United States)

    Harada, Yoichiro; Murata, Takeomi; Totani, Kazuhide; Kajimoto, Tetsuya; Masum, Shah Md; Tamba, Yukihiro; Yamazaki, Masahito; Usui, Taichi

    2005-01-01

    Neoglycolipids composed of disaccharide glycoside and phospholipid were designed and prepared as mimetics of lactosylceramide. The lactosyl- and N-acetyllactosaminyl-phospholipids (Lac-DPPA and LacNAc-DPPA) were enzymatically synthesized from lactose and LacNAc respectively by cellulase-mediated condensation with 1,6-hexanediol, followed by conjugation of the resulting glycosides and dipalmitoylphosphatidyl choline (DPPC) mediated by Streptomyces phospholipase D. Alternatively, allyl beta-lactoside was ozonolyzed to give an aldehyde, which was condensed with dipalmytoyl phosphatidyl ethanolamine to afford a second type of glycolipid (Lac-DPPE). NMR spectroscopy indicated that the neoglycolipids behave differently in different solvent systems. X-ray diffraction clearly showed that multilamellar vesicles (MLVs) of Lac-DPPE and Lac-DPPA-MLV are in the bilayer gel phase at 20 degrees C, whereas those of Lac-DPPE-MLV were in the lamellar liquid-crystalline phase at 50 degrees C. Differential scanning calorimetry showed that Lac-DPPE-MLV had complex thermotropic behavior depending on the incubation conditions. After a long incubation at 10 degrees C, endothermic transitions are observed at 39.6, 42.3 degrees C, and 42.9 degrees C. These neoglycolipids have the ability to trap calcein, a chelating derivative of fluorescein, in MLVs and showed specific binding to lectin in plate assays using fluorescently labeled compounds.

  12. Antitumor efficacy of a thrombospondin 1 mimetic CovX-body.

    Science.gov (United States)

    Li, Lingna; Leedom, Tom A; Do, Janet; Huang, Hanhua; Lai, JingYu; Johnson, Kim; Osothprarop, Trina F; Rizzo, John D; Doppalapudi, Venkata R; Bradshaw, Curt W; Lappe, Rodney W; Woodnutt, Gary; Levin, Nancy J; Pirie-Shepherd, Steven R

    2011-08-01

    CVX-045 is produced by covalently attaching a thrombospondin 1 (TSP-1) mimetic comprising a peptidic sequence and a linker to the Fab binding site of a proprietary scaffold antibody. CVX-045 possesses the potency of the TSP-1-derived peptide, along with the advantageous pharmacokinetics of an antibody. Antitumor activity of CVX-045 was evaluated in human xenograft models alone and in combination with standard chemotherapies and targeted molecules. In A549 and A431 xenograft models, CVX-045 demonstrated significant (P CVX-045 in combination with 5-fluorouracil significantly (P CVX-045, or 5-fluorouracil alone. Cotreatment of CVX-045 plus CPT-11 delayed progression of tumor growth from day 28 to 60. In contrast CVX-045 alone treatment did not delay the progression of tumor growth, and CPT-11 alone delayed progression of tumor growth to day 39. Cotreatment of CVX-045 with sunitinib extended the time to reach tumor load from day 26 to 40. In summary, CVX-045 exhibits significant antiangiogenic activity in several tumor models and enhances antitumor activity in combination with chemotherapy or targeted therapies. These data suggest future avenues for effective combination therapy in treating solid tumors. CVX-045 has recently completed a phase 1 trial in solid tumors where it has been well tolerated.

  13. Synergistic Interactions of a Synthetic Lubricin-Mimetic with Fibronectin for Enhanced Wear Protection

    Directory of Open Access Journals (Sweden)

    Roberto C. Andresen Eguiluz

    2017-06-01

    Full Text Available Lubricin (LUB, a major mucinous glycoprotein of mammalian synovial fluids, is believed to provide excellent lubrication to cartilage surfaces. Consequently, when joint disease or replacement leads to increased friction and surface damage in the joint, robust synthetic LUB alternatives that could be used therapeutically to improve lubrication and surface protection are needed. Here, we report the characterization of a lubricating multiblock bottlebrush polymer whose architecture was inspired by LUB, and we investigate the role of fibronectin (FN, a glycoprotein found in the superficial zone of cartilage, in mediating the tribological properties of the polymer upon shear between mica surfaces. Our surface forces apparatus (SFA normal force measurements indicate that the lubricin-mimetic (mimLUB could be kept anchored between mica surfaces, even under high contact pressures, when an intermediate layer of FN was present. Additional SFA friction measurements show that FN would also extend the wearless friction regime of the polymer up to pressures of 3.4 MPa while ensuring stable friction coefficients (μ ≈ 0.28. These results demonstrate synergistic interactions between mimLUB and FN in assisting the lubrication and wear protection of ideal (mica substrates upon shear. Collectively, these findings suggest that our proposed mimLUB might be a promising alternative to LUB, as similar mechanisms could potentially facilitate the interaction between the polymer and cartilage surfaces in articular joints and prosthetic implants in vivo.

  14. Data assimilation method for fractured reservoirs using mimetic finite differences and ensemble Kalman filter

    KAUST Repository

    Ping, Jing

    2017-05-19

    Optimal management of subsurface processes requires the characterization of the uncertainty in reservoir description and reservoir performance prediction. For fractured reservoirs, the location and orientation of fractures are crucial for predicting production characteristics. With the help of accurate and comprehensive knowledge of fracture distributions, early water/CO 2 breakthrough can be prevented and sweep efficiency can be improved. However, since the rock property fields are highly non-Gaussian in this case, it is a challenge to estimate fracture distributions by conventional history matching approaches. In this work, a method that combines vector-based level-set parameterization technique and ensemble Kalman filter (EnKF) for estimating fracture distributions is presented. Performing the necessary forward modeling is particularly challenging. In addition to the large number of forward models needed, each model is used for sampling of randomly located fractures. Conventional mesh generation for such systems would be time consuming if possible at all. For these reasons, we rely on a novel polyhedral mesh method using the mimetic finite difference (MFD) method. A discrete fracture model is adopted that maintains the full geometry of the fracture network. By using a cut-cell paradigm, a computational mesh for the matrix can be generated quickly and reliably. In this research, we apply this workflow on 2D two-phase fractured reservoirs. The combination of MFD approach, level-set parameterization, and EnKF provides an effective solution to address the challenges in the history matching problem of highly non-Gaussian fractured reservoirs.

  15. Mimetic finite difference method for the stokes problem on polygonal meshes

    Energy Technology Data Exchange (ETDEWEB)

    Lipnikov, K [Los Alamos National Laboratory; Beirao Da Veiga, L [DIPARTIMENTO DI MATE; Gyrya, V [PENNSYLVANIA STATE UNIV; Manzini, G [ISTIUTO DI MATEMATICA

    2009-01-01

    Various approaches to extend the finite element methods to non-traditional elements (pyramids, polyhedra, etc.) have been developed over the last decade. Building of basis functions for such elements is a challenging task and may require extensive geometry analysis. The mimetic finite difference (MFD) method has many similarities with low-order finite element methods. Both methods try to preserve fundamental properties of physical and mathematical models. The essential difference is that the MFD method uses only the surface representation of discrete unknowns to build stiffness and mass matrices. Since no extension inside the mesh element is required, practical implementation of the MFD method is simple for polygonal meshes that may include degenerate and non-convex elements. In this article, we develop a MFD method for the Stokes problem on arbitrary polygonal meshes. The method is constructed for tensor coefficients, which will allow to apply it to the linear elasticity problem. The numerical experiments show the second-order convergence for the velocity variable and the first-order for the pressure.

  16. Carbohydrate Mimetic Peptides Augment Carbohydrate-Reactive Immune Responses in the Absence of Immune Pathology

    Energy Technology Data Exchange (ETDEWEB)

    Hennings, Leah; Artaud, Cecile; Jousheghany, Fariba; Monzavi-Karbassi, Behjatolah; Pashov, Anastas; Kieber-Emmons, Thomas, E-mail: tke@uams.edu [Winthrop P. Rockefeller Cancer Institute and Department of Pathology, University of Arkansas for Medical Sciences, Little Rock, AR 72205 (United States)

    2011-11-11

    Among the most challenging of clinical targets for cancer immunotherapy are Tumor Associated Carbohydrate Antigens (TACAs). To augment immune responses to TACA we are developing carbohydrate mimetic peptides (CMPs) that are sufficiently potent to activate broad-spectrum anti-tumor reactivity. However, the activation of immune responses against terminal mono- and disaccharide constituents of TACA raises concerns regarding the balance between “tumor destruction” and “tissue damage”, as mono- and disaccharides are also expressed on normal tissue. To support the development of CMPs for clinical trial testing, we demonstrate in preclinical safety assessment studies in mice that vaccination with CMPs can enhance responses to TACAs without mediating tissue damage to normal cells expressing TACA. BALB/c mice were immunized with CMPs that mimic TACAs reactive with Griffonia simplicifolia lectin 1 (GS-I), and tissue reactivity of serum antibodies were compared with the tissue staining profile of GS-I. Tissues from CMP immunized mice were analyzed using hematoxylin and eosin stain, and Luxol-fast blue staining for myelination. Western blots of membranes from murine mammary 4T1 cells, syngeneic with BALB/c mice, were also compared using GS-I, immunized serum antibodies, and naive serum antibodies. CMP immunization enhanced glycan reactivities with no evidence of pathological autoimmunity in any immunized mice demonstrating that tissue damage is not an inevitable consequence of TACA reactive responses.

  17. Evidences for diabetes and insulin mimetic activity of medicinal plants: Present status and future prospects.

    Science.gov (United States)

    Manukumar, H M; Shiva Kumar, J; Chandrasekhar, B; Raghava, Sri; Umesha, S

    2017-08-13

    Diabetes mellitus (DM) is a considerable systemic metabolic disorder to exhibit various metabolic and cardiovascular disorders, mainly hyperglycemia. The global projected estimate of diabetes in 2030 will be about 439 million adults, out of which 300 million expected are of type-2 diabetes mellitus (T2DM). The present knowledge revealed responsible factors, occurrence and mechanism of these factors involved in the DM diseases. Hence, the aim of this review is to address and summarize the causes, plant resources, importance, present status and future programmes for diabetes control. The present review answers the contemporary present questions raised in the scientific field on DM. Two major problems are explained in detail about the autoimmune attack or dysfunction of β-cell and insulin resistance involved for Type 1 and Type 2 DM, respectively. Though there are various approaches to reduce the ill effects of diabetes and its secondary complications, many preferred herbal formulations due to lesser side effects and low cost. For this reason still it is getting increased attention in searching antidiabetic medicinal plants for hot research and to develop targeted medicine. Recurrence of islet autoimmunity lesson from pancreatic islet cell transplantation to cure T1D was outlined. With these highlights, the review summarizes the current knowledge on diabetes occurrence, factors (environmental and genetics), and types (I, II, gestation, and secondary DM), antidiabetic plants, sources for insulin mimetic plant principle compounds and their target mechanism with current and future trusted research areas for controlling of DM.

  18. Gene Transcriptional and Metabolic Profile Changes in Mimetic Aging Mice Induced by D-Galactose.

    Science.gov (United States)

    Zhou, Yue-Yue; Ji, Xiong-Fei; Fu, Jian-Ping; Zhu, Xiao-Juan; Li, Rong-Hua; Mu, Chang-Kao; Wang, Chun-Lin; Song, Wei-Wei

    2015-01-01

    D-galactose injection has been shown to induce many changes in mice that represent accelerated aging. This mouse model has been widely used for pharmacological studies of anti-aging agents. The underlying mechanism of D-galactose induced aging remains unclear, however, it appears to relate to glucose and 1ipid metabolic disorders. Currently, there has yet to be a study that focuses on investigating gene expression changes in D-galactose aging mice. In this study, integrated analysis of gas chromatography/mass spectrometry-based metabonomics and gene expression profiles was used to investigate the changes in transcriptional and metabolic profiles in mimetic aging mice injected with D-galactose. Our findings demonstrated that 48 mRNAs were differentially expressed between control and D-galactose mice, and 51 potential biomarkers were identified at the metabolic level. The effects of D-galactose on aging could be attributed to glucose and 1ipid metabolic disorders, oxidative damage, accumulation of advanced glycation end products (AGEs), reduction in abnormal substance elimination, cell apoptosis, and insulin resistance.

  19. Discrete conservation properties for shallow water flows using mixed mimetic spectral elements

    Science.gov (United States)

    Lee, D.; Palha, A.; Gerritsma, M.

    2018-03-01

    A mixed mimetic spectral element method is applied to solve the rotating shallow water equations. The mixed method uses the recently developed spectral element histopolation functions, which exactly satisfy the fundamental theorem of calculus with respect to the standard Lagrange basis functions in one dimension. These are used to construct tensor product solution spaces which satisfy the generalized Stokes theorem, as well as the annihilation of the gradient operator by the curl and the curl by the divergence. This allows for the exact conservation of first order moments (mass, vorticity), as well as higher moments (energy, potential enstrophy), subject to the truncation error of the time stepping scheme. The continuity equation is solved in the strong form, such that mass conservation holds point wise, while the momentum equation is solved in the weak form such that vorticity is globally conserved. While mass, vorticity and energy conservation hold for any quadrature rule, potential enstrophy conservation is dependent on exact spatial integration. The method possesses a weak form statement of geostrophic balance due to the compatible nature of the solution spaces and arbitrarily high order spatial error convergence.

  20. Extreme Mechanical Behavior of Nacre-Mimetic Graphene-Oxide and Silk Nanocomposites.

    Science.gov (United States)

    Xie, Wanting; Tadepalli, Sirimuvva; Park, Sang Hyun; Kazemi-Moridani, Amir; Jiang, Qisheng; Singamaneni, Srikanth; Lee, Jae-Hwang

    2018-02-14

    Biological materials have the ability to withstand extreme mechanical forces due to their unique multilevel hierarchical structure. Here, we fabricated a nacre-mimetic nanocomposite comprised of silk fibroin and graphene oxide that exhibits hybridized dynamic responses arising from alternating high-contrast mechanical properties of the components at the nanoscale. Dynamic mechanical behavior of these nanocomposites is assessed through a microscale ballistic characterization using a 7.6 μm diameter silica sphere moving at a speed of approximately 400 m/s. The volume fraction of graphene oxide in these composites is systematically varied from 0 to 32 vol % to quantify the dynamic effects correlating with the structural morphologies of the graphene oxide flakes. Specific penetration energy of the films rapidly increases as the distribution of graphene oxide flakes evolves from noninteracting, isolated sheets to a partially overlapping continuous sheet. The specific penetration energy of the nanocomposite at the highest graphene oxide content tested here is found to be significantly higher than that of Kevlar fabrics and close to that of pure multilayer graphene. This study evidently demonstrates that the morphologies of nanoscale constituents and their interactions are critical to realize scalable high-performance nanocomposites using typical nanomaterial constituents having finite dimensions.

  1. Inhibition of human amylin fibril formation by insulin-mimetic vanadium complexes.

    Science.gov (United States)

    He, Lei; Wang, Xuesong; Zhao, Cong; Zhu, Dengsen; Du, Weihong

    2014-05-01

    The toxicity of amyloid-forming proteins can be linked to many degenerative and systemic diseases. Human islet amyloid polypeptide (hIAPP, amylin) has been associated with type II diabetes. Methods for efficient inhibition of amyloid fibril formation are highly clinically important. This study demonstrated the significant inhibitory effects of six vanadium complexes on hIAPP aggregation. Vanadium complexes, such as bis(maltolato)-oxovanadium (BMOV), have been used as insulin-mimetic agents for the treatment of diabetes for many years. Different biophysical methods were applied to investigate the interaction between V complexes and hIAPP. The results indicated that the selected compounds affected the peptide aggregation by different action modes and protected the cells from the cytotoxicity induced by hIAPP. Both the high binding affinity and the ligand spatial effect on inhibiting hIAPP aggregation are significant. Although some of these compounds undergo biotransformation under the conditions of the experiments, and the active species are not identified, it is understood that the effect results from a particular compound and its conversion products. Importantly, our work provided information on the effects of the selected V complexes on hIAPP and demonstrated multiple levels of effects of V complexes against amyloid-related diseases.

  2. Structurally Ordered Nanowire Formation from Co-Assembly of DNA Origami and Collagen-Mimetic Peptides

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, Tao [Department; Meyer, Travis A. [Wallace; Modlin, Charles [Department; Zuo, Xiaobing [X-ray; Conticello, Vincent P. [Department; Ke, Yonggang [Wallace

    2017-10-02

    We describe the co-assembly of two different building units: collagen-mimetic peptides and DNA origami. Two peptides CP++ and sCP(++) are designed with a sequence comprising a central block (Pro-Hyp-Gly) and two positively charged domains (Pro-Arg-Gly) at both N- and C-termini. Co-assembly of peptides and DNA origami two-layer (TL) nanosheets affords the formation of one-dimensional nanowires with repeating periodicity of similar to 10 nm. Structural analyses suggest a face-to-face stacking of DNA nanosheets with peptides aligned perpendicularly to the sheet surfaces. We demonstrate the potential of selective peptide-DNA association between face-to-face and edge-to-edge packing by tailoring the size of DNA nanostructures. This study presents an attractive strategy to create hybrid biomolecular assemblies from peptide and DNA-based building blocks that takes advantage of the intrinsic chemical and physical properties of the respective components to encode structural and, potentially, functional complexity within readily accessible biomimetic materials.

  3. Carbohydrate Mimetic Peptides Augment Carbohydrate-Reactive Immune Responses in the Absence of Immune Pathology

    International Nuclear Information System (INIS)

    Hennings, Leah; Artaud, Cecile; Jousheghany, Fariba; Monzavi-Karbassi, Behjatolah; Pashov, Anastas; Kieber-Emmons, Thomas

    2011-01-01

    Among the most challenging of clinical targets for cancer immunotherapy are Tumor Associated Carbohydrate Antigens (TACAs). To augment immune responses to TACA we are developing carbohydrate mimetic peptides (CMPs) that are sufficiently potent to activate broad-spectrum anti-tumor reactivity. However, the activation of immune responses against terminal mono- and disaccharide constituents of TACA raises concerns regarding the balance between “tumor destruction” and “tissue damage”, as mono- and disaccharides are also expressed on normal tissue. To support the development of CMPs for clinical trial testing, we demonstrate in preclinical safety assessment studies in mice that vaccination with CMPs can enhance responses to TACAs without mediating tissue damage to normal cells expressing TACA. BALB/c mice were immunized with CMPs that mimic TACAs reactive with Griffonia simplicifolia lectin 1 (GS-I), and tissue reactivity of serum antibodies were compared with the tissue staining profile of GS-I. Tissues from CMP immunized mice were analyzed using hematoxylin and eosin stain, and Luxol-fast blue staining for myelination. Western blots of membranes from murine mammary 4T1 cells, syngeneic with BALB/c mice, were also compared using GS-I, immunized serum antibodies, and naive serum antibodies. CMP immunization enhanced glycan reactivities with no evidence of pathological autoimmunity in any immunized mice demonstrating that tissue damage is not an inevitable consequence of TACA reactive responses

  4. M402, a novel heparan sulfate mimetic, targets multiple pathways implicated in tumor progression and metastasis.

    Directory of Open Access Journals (Sweden)

    He Zhou

    Full Text Available Heparan sulfate proteoglycans (HSPGs play a key role in shaping the tumor microenvironment by presenting growth factors, cytokines, and other soluble factors that are critical for host cell recruitment and activation, as well as promoting tumor progression, metastasis, and survival. M402 is a rationally engineered, non-cytotoxic heparan sulfate (HS mimetic, designed to inhibit multiple factors implicated in tumor-host cell interactions, including VEGF, FGF2, SDF-1α, P-selectin, and heparanase. A single s.c. dose of M402 effectively inhibited seeding of B16F10 murine melanoma cells to the lung in an experimental metastasis model. Fluorescent-labeled M402 demonstrated selective accumulation in the primary tumor. Immunohistological analyses of the primary tumor revealed a decrease in microvessel density in M402 treated animals, suggesting anti-angiogenesis to be one of the mechanisms involved in-vivo. M402 treatment also normalized circulating levels of myeloid derived suppressor cells in tumor bearing mice. Chronic administration of M402, alone or in combination with cisplatin or docetaxel, inhibited spontaneous metastasis and prolonged survival in an orthotopic 4T1 murine mammary carcinoma model. These data demonstrate that modulating HSPG biology represents a novel approach to target multiple factors involved in tumor progression and metastasis.

  5. Tempol, a Superoxide Dismutase Mimetic Agent, Inhibits Superoxide Anion-Induced Inflammatory Pain in Mice.

    Science.gov (United States)

    Bernardy, Catia C F; Zarpelon, Ana C; Pinho-Ribeiro, Felipe A; Calixto-Campos, Cássia; Carvalho, Thacyana T; Fattori, Victor; Borghi, Sergio M; Casagrande, Rubia; Verri, Waldiceu A

    2017-01-01

    The present study evaluated the anti-inflammatory and analgesic effects of the superoxide dismutase mimetic agent tempol in superoxide anion-induced pain and inflammation. Mice were treated intraperitoneally with tempol (10-100 mg/kg) 40 min before the intraplantar injection of a superoxide anion donor, potassium superoxide (KO 2 , 30  μ g). Mechanical hyperalgesia and thermal hyperalgesia, paw edema, and mRNA expression of peripheral and spinal cord mediators involved in inflammatory pain, TNF α , IL-1 β , IL-10, COX-2, preproET-1, gp91 phox , Nrf2, GFAP, and Iba-1, were evaluated. Peripheral and spinal cord reductions of antioxidant defenses and superoxide anion were also assessed. Tempol reduced KO 2 -induced mechanical hyperalgesia and thermal hyperalgesia and paw edema. The increased mRNA expression of the evaluated mediators and oxidative stress in the paw skin and spinal cord and increased mRNA expression of glial markers in the spinal cord induced by KO 2 were successfully inhibited by tempol. KO 2 -induced reduction in Nrf2 mRNA expression in paw skin and spinal cord was also reverted by tempol. Corroborating the effect of tempol in the KO 2 model, tempol also inhibited carrageenan and CFA inflammatory hyperalgesia. The present study demonstrates that tempol inhibits superoxide anion-induced molecular and behavioral alterations, indicating that tempol deserves further preclinical studies as a promising analgesic and anti-inflammatory molecule for the treatment of inflammatory pain.

  6. Tempol, a Superoxide Dismutase-Mimetic Drug, Ameliorates Progression of Renal Disease in CKD Mice

    Directory of Open Access Journals (Sweden)

    Wei Ding

    2015-07-01

    Full Text Available Background: Oxidative stress has been implicated in the pathogenesis of chronic kidney disease (CKD and antioxidants may ameliorate disease progression. We investigate the beneficial effect of Tempol, a superoxide dismutase-mimetic drug, on progression of disease in a mouse model of CKD. Methods: CKD was surgically induced in c57BL/6 mice by 5/6 nephrectomy. Mice were randomly divided into 3 groups: sham group, 5/6 nephrectomized group (Nx and Nx+Tempol (2 mmol/l in drinking water. Mice were sacrificed at the end of 12 weeks. Renal function, structure as well as expression of key molecules involved in the pathogenesis of inflammation, fibrosis and progression in mice were measured. Results: Reduced body weight and impaired renal function (elevation on serum creatinine, blood urea nitrogen, urine albumin, segmental sclerosis and tubulointerstitial damage was demonstrated in Nx mice but was significantly improved by Tempol administration. Nx animals exhibited significantly elevated proinflammatory and profibrotic factors, activation of NF-κB, increased expression of NADPH oxidase related subunits (p47phox, p67phox, gp91phox, and elevated activation of TGF-ß/Smad3, EGFR, MAPK signaling pathway. Tempol inhibited NF-κB mediated inflammation, TGF-ß/Smad3-induced renal fibrosis as well as EGFR and MAPK signaling pathway activation. Conclusions: Tempol administration attenuated renal injury in CKD mice through NF-κB, TGF-ß/Smad3, redox-senstive EGFR activation and c-Raf/MEK/ERK pathways.

  7. Tempol, a Superoxide Dismutase Mimetic Agent, Inhibits Superoxide Anion-Induced Inflammatory Pain in Mice

    Directory of Open Access Journals (Sweden)

    Catia C. F. Bernardy

    2017-01-01

    Full Text Available The present study evaluated the anti-inflammatory and analgesic effects of the superoxide dismutase mimetic agent tempol in superoxide anion-induced pain and inflammation. Mice were treated intraperitoneally with tempol (10–100 mg/kg 40 min before the intraplantar injection of a superoxide anion donor, potassium superoxide (KO2, 30 μg. Mechanical hyperalgesia and thermal hyperalgesia, paw edema, and mRNA expression of peripheral and spinal cord mediators involved in inflammatory pain, TNFα, IL-1β, IL-10, COX-2, preproET-1, gp91phox, Nrf2, GFAP, and Iba-1, were evaluated. Peripheral and spinal cord reductions of antioxidant defenses and superoxide anion were also assessed. Tempol reduced KO2-induced mechanical hyperalgesia and thermal hyperalgesia and paw edema. The increased mRNA expression of the evaluated mediators and oxidative stress in the paw skin and spinal cord and increased mRNA expression of glial markers in the spinal cord induced by KO2 were successfully inhibited by tempol. KO2-induced reduction in Nrf2 mRNA expression in paw skin and spinal cord was also reverted by tempol. Corroborating the effect of tempol in the KO2 model, tempol also inhibited carrageenan and CFA inflammatory hyperalgesia. The present study demonstrates that tempol inhibits superoxide anion-induced molecular and behavioral alterations, indicating that tempol deserves further preclinical studies as a promising analgesic and anti-inflammatory molecule for the treatment of inflammatory pain.

  8. Tempol, a Superoxide Dismutase-Mimetic Drug, Ameliorates Progression of Renal Disease in CKD Mice.

    Science.gov (United States)

    Ding, Wei; Wang, Bin; Zhang, Minmin; Gu, Yong

    2015-01-01

    Oxidative stress has been implicated in the pathogenesis of chronic kidney disease (CKD) and antioxidants may ameliorate disease progression. We investigate the beneficial effect of Tempol, a superoxide dismutase-mimetic drug, on progression of disease in a mouse model of CKD. CKD was surgically induced in c57BL/6 mice by 5/6 nephrectomy. Mice were randomly divided into 3 groups: sham group, 5/6 nephrectomized group (Nx) and Nx+Tempol (2 mmol/l in drinking water). Mice were sacrificed at the end of 12 weeks. Renal function, structure as well as expression of key molecules involved in the pathogenesis of inflammation, fibrosis and progression in mice were measured. Reduced body weight and impaired renal function (elevation on serum creatinine, blood urea nitrogen, urine albumin, segmental sclerosis and tubulointerstitial damage) was demonstrated in Nx mice but was significantly improved by Tempol administration. Nx animals exhibited significantly elevated proinflammatory and profibrotic factors, activation of NF-κB, increased expression of NADPH oxidase related subunits (p47phox, p67phox, gp91phox), and elevated activation of TGF-β/Smad3, EGFR, MAPK signaling pathway. Tempol inhibited NF-κB mediated inflammation, TGF-β/Smad3-induced renal fibrosis as well as EGFR and MAPK signaling pathway activation. Tempol administration attenuated renal injury in CKD mice through NF-κB, TGF-β/Smad3, redox-senstive EGFR activation and c-Raf/MEK/ERK pathways. © 2015 S. Karger AG, Basel.

  9. Efficacy of the superoxide dismutase mimetic tempol in animal hypertension models: a meta-analysis.

    Science.gov (United States)

    Dornas, Waleska C; Silva, Maísa; Tavares, Ricardo; de Lima, Wanderson G; dos Santos, Rinaldo C; Pedrosa, Maria L; Silva, Marcelo E

    2015-01-01

    Considering the growing body of evidence that indicates the contribution of superoxide anions (O2) and other reactive oxygen species (ROS) to the development of hypertension, we assessed whether animal models of hypertension have a benefic effect with tempol, a superoxide dismutase mimetic, to help augment the design of future studies. Studies published between July 1998 and December 2012 on blood pressure (BP) in different hypertensive models were obtained after an electronic and manual search of PubMed. In-depth analyses of the methodological quality of the studies and the mean arterial pressure (MAP) changes after treatment with tempol were performed, as well as the subgroup analyses on the route of tempol delivery. Out of the 144 identified studies, 28 were included after screening. The data showed that tempol reduced MAP by computing the standardized mean difference with the value of 4.622 (95% confidence interval 3.24-5.99). The quality of studies included in the meta-analysis was category II; however, omission of details in the trials might have biased the results. There was substantial heterogeneity in the results with an I of 94.45%, which persisted after stratifying for the route of tempol delivery. In conclusion, this analysis shows that antioxidant treatment with tempol can reduce BP, suggesting that ROS plays a role in the pathogenesis of increased BP in the hypertension models used in the current research practice.

  10. A novel generation of heparan sulfate mimetics for the treatment of prion diseases.

    Science.gov (United States)

    Adjou, Karim Tarik; Simoneau, Steve; Salès, Nicole; Lamoury, François; Dormont, Dominique; Papy-Garcia, Dulce; Barritault, Denis; Deslys, Jean-Philippe; Lasmézas, Corinne Ida

    2003-09-01

    The accumulation of PrP(res), the protease-resistant abnormal form of the host-encoded cellular prion protein, PrP(C), plays a central role in transmissible spongiform encephalopathies. Human contamination by bovine spongiform encephalopathy (BSE) has propelled many scientific teams on a highway for anti-prion drug development. This study reports that heparan sulfate mimetics (HMs), developed originally for their effect on tissue regeneration, abolish prion propagation in scrapie-infected GT1 cells. PrP(res) does not reappear for up to 50 days post-treatment. When tested in vivo, one of these compounds, HM2602, hampered PrP(res) accumulation in scrapie- and BSE-infected mice and prolonged significantly the survival time of 263K scrapie-infected hamsters. Interestingly, HM2602 is an apparently less toxic and more potent inhibitor of PrP(res) accumulation than dextran sulfate 500, a molecule known to exhibit anti-prion properties in vivo. Kinetics of PrP(res) disappearance in vitro and unaffected PrP(C) levels during treatment suggest that HMs are able to block the conversion of PrP(C) into PrP(res). It is speculated that HMs act as competitors of endogenous heparan sulfates known to act as co-receptors for the prion protein. Since these molecules are particularly amenable to drug design, their anti-prion potential could be developed further and optimized for the treatment of prion diseases.

  11. Non-Covalent Photo-Patterning of Gelatin Matrices Using Caged Collagen Mimetic Peptides

    Science.gov (United States)

    Li, Yang; Hoa San, Boi; L. Kessler, Julian; Hwan Kim, Jin; Xu, Qingguo; Hanes, Justin; Yu, Seungju Michael

    2015-01-01

    Advancements in photolithography have enabled us to spatially encode biochemical cues in biocompatible platforms such as synthetic hydrogels. Conventional patterning works through photo-activated chemical reactions on inert polymer networks. However, these techniques cannot be directly applied to protein hydrogels without chemically altering the protein scaffolds. To this end, we developed a non-covalent photo-patterning strategy for gelatin (denatured collagen) hydrogels utilizing a caged collagen mimetic peptide (caged CMP) which binds to gelatin strands through UV activated, triple helix hybridization. Here we present 2D and 3D photo-patterning of gelatin hydrogels enabled by the caged CMPs as well as creation of concentration gradients of CMPs. We show that photo-patterning of PEG-conjugated caged CMPs can be used to spatially control cell adhesion on gelatin films. CMP’s specificity for binding to gelatin allows patterning of almost any synthetic or natural gelatin-containing matrix, such as zymograms, gelatin-methacrylate hydrogels, and even a corneal tissue. Since the CMP is a chemically and biologically inert peptide which is proven to be an ideal carrier for bioactive molecules, our patterning method provides a radically new tool for immobilizing drugs to natural tissues and for functionalizing scaffolds for complex tissue formation. PMID:25476588

  12. Design and synthesis of collagen mimetic peptide derivatives for studying triple helix assembly and collagen mimetic peptide-collagen binding interaction

    Science.gov (United States)

    Mo, Xiao

    2008-10-01

    Collagen is the principal tensile clement of the extra-cellular matrix in mammals and is the basic scaffold for cells and tissues. Collagen molecules are comprised of homo-trimeric helices (e.g. collagen type II and type III), ABB type hetero-trimeric helices (e.g. collagen type I, type IV, and type V), or ABC type hetero-trimeric helices (e.g. type V). Mimicry of collagen structures can help elucidate collagen triple helical conformation and provide insights into making novel collagen-like biomaterials. Our group previously reported a new physical collagen modification method, which was based on non-covalent interaction between collagen mimetic peptide (CMP: -(Pro-Hyp-Gly) x-) and natural collagen. We hypothesized that CMP binds to collagen through a process involving both strand invasion and triple helix assembly. The aim of this dissertation is to study structural formation and stability of collagen triple helix, and to investigate CMP-collagen binding interactions using two types of CMP derivatives: covalently templated CMP trimer and CMP-nanoparticle conjugates. We demonstrated that covalently templated ABB type CMP hetero-trimers could be prepared by a versatile synthetic strategy involving both solid phase and solution peptide coupling. Our thermal melting studies showed that the templated CMP hetero-trimers formed collagen-like triple helices and their folding kinetics correlated with the amino acid compositions of the individual CMP strands. We also studied the thermal melting behavior and folding kinetics of a templated hetero-trimer complex comprised of CMP and a peptide derived from collagen. This synthetic strategy can be readily extended to synthesize other ABB type hetero-trimers to investigate their local melting behavior and biological activity. We also prepared colloidally stable CMP functionalized gold nanoparticles (Au-CMPs) as a TEM marker for investigating the CMP-collagen interaction. Au-CMP showed preferential binding to collagen fiber's gap

  13. Continuous volatile fatty acid production from lignocellulosic biomass by a novel rumen-mimetic bioprocess.

    Science.gov (United States)

    Agematu, Hitosi; Takahashi, Takehiko; Hamano, Yoshio

    2017-11-01

    Lignocellulosic biomass is an attractive source of biofuels and biochemicals, being abundant in various plant sources. However, processing this type of biomass requires hydrolysis of cellulose. The proposed rumen-mimetic bioprocess consists of dry-pulverization of lignocellulosic biomass and pH-controlled continuous cultivation of ruminal bacteria using ammonium as a nitrogen source. In this study, ruminal bacteria were continuously cultivated for over 60 days and used to digest microcrystalline cellulose, rice straw, and Japanese cedar to produce volatile fatty acids (VFAs). The ruminal bacteria grew well in the chemically defined medium. The amounts of VFAs produced from 20 g of cellulose, rice straw, and Japanese cedar were 183 ± 29.7, 69.6 ± 12.2, and 21.8 ± 12.9 mmol, respectively. Each digestion completed within 24 h. The carbon yield was 60.6% when 180 mmol of VFAs was produced from 20 g of cellulose. During the cultivation, the bacteria were observed to form flocs that enfolded the feed particles. These flocs likely contain all of the bacterial species necessary to convert lignocellulosic biomass to VFAs and microbial protein symbiotically. Denaturing gradient gel electrophoresis (DGGE) analysis of PCR-amplified 16S rDNA fragments revealed that the bacterial community was relatively stable after 1 week in cultivation, though it was different from the original community structure. Furthermore, sequence analysis of the DGGE bands indicates that the microbial community includes a cellulolytic bacterium, a bacterium acting synergistically with cellulolytic bacteria, and a propionate-producing bacterium, as well as other anaerobic bacteria. Copyright © 2017 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  14. Structure of the nociceptin/orphanin FQ receptor in complex with a peptide mimetic

    Energy Technology Data Exchange (ETDEWEB)

    Thompson, Aaron A.; Liu, Wei; Chun, Eugene; Katritch, Vsevolod; Wu, Huixian; Vardy, Eyal; Huang, Xi-Ping; Trapella, Claudio; Guerrini, Remo; Calo, Girolamo; Roth, Bryan L.; Cherezov, Vadim; Stevens, Raymond C. (Ferrara); (Scripps); (UNC)

    2012-07-11

    Members of the opioid receptor family of G-protein-coupled receptors (GPCRs) are found throughout the peripheral and central nervous system, where they have key roles in nociception and analgesia. Unlike the 'classical' opioid receptors, {delta}, {kappa} and {mu} ({delta}-OR, {kappa}-OR and {mu}-OR), which were delineated by pharmacological criteria in the 1970s and 1980s, the nociceptin/orphanin FQ (N/OFQ) peptide receptor (NOP, also known as ORL-1) was discovered relatively recently by molecular cloning and characterization of an orphan GPCR. Although it shares high sequence similarity with classical opioid GPCR subtypes ({approx}60%), NOP has a markedly distinct pharmacology, featuring activation by the endogenous peptide N/OFQ, and unique selectivity for exogenous ligands. Here we report the crystal structure of human NOP, solved in complex with the peptide mimetic antagonist compound-24 (C-24) (ref. 4), revealing atomic details of ligand-receptor recognition and selectivity. Compound-24 mimics the first four amino-terminal residues of the NOP-selective peptide antagonist UFP-101, a close derivative of N/OFQ, and provides important clues to the binding of these peptides. The X-ray structure also shows substantial conformational differences in the pocket regions between NOP and the classical opioid receptors {kappa} (ref. 5) and {mu} (ref. 6), and these are probably due to a small number of residues that vary between these receptors. The NOP-compound-24 structure explains the divergent selectivity profile of NOP and provides a new structural template for the design of NOP ligands.

  15. Size Control and Fluorescence Labeling of Polydopamine Melanin-Mimetic Nanoparticles for Intracellular Imaging

    Directory of Open Access Journals (Sweden)

    Devang R. Amin

    2017-09-01

    Full Text Available As synthetic analogs of the natural pigment melanin, polydopamine nanoparticles (NPs are under active investigation as non-toxic anticancer photothermal agents and as free radical scavenging therapeutics. By analogy to the widely adopted polydopamine coatings, polydopamine NPs offer the potential for facile aqueous synthesis and incorporation of (biofunctional groups under mild temperature and pH conditions. However, clear procedures for the convenient and reproducible control of critical NP properties such as particle diameter, surface charge, and loading with functional molecules have yet to be established. In this work, we have synthesized polydopamine-based melanin-mimetic nanoparticles (MMNPs with finely controlled diameters spanning ≈25 to 120 nm and report on the pH-dependence of zeta potential, methodologies for PEGylation, and the incorporation of fluorescent organic molecules. A comprehensive suite of complementary techniques, including dynamic light scattering (DLS, cryogenic transmission electron microscopy (cryo-TEM, X-ray photoelectron spectroscopy (XPS, zeta-potential, ultraviolet–visible (UV–Vis absorption and fluorescence spectroscopy, and confocal microscopy, was used to characterize the MMNPs and their properties. Our PEGylated MMNPs are highly stable in both phosphate-buffered saline (PBS and in cell culture media and exhibit no cytotoxicity up to at least 100 µg mL−1 concentrations. We also show that a post-functionalization methodology for fluorophore loading is especially suitable for producing MMNPs with stable fluorescence and significantly narrower emission profiles than previous reports, suggesting they will be useful for multimodal cell imaging. Our results pave the way towards biomedical imaging and possibly drug delivery applications, as well as fundamental studies of MMNP size and surface chemistry dependent cellular interactions.

  16. Endothelial targeting of liposomes encapsulating SOD/catalase mimetic EUK-134 alleviates acute pulmonary inflammation.

    Science.gov (United States)

    Howard, Melissa D; Greineder, Colin F; Hood, Elizabeth D; Muzykantov, Vladimir R

    2014-03-10

    Production of excessive levels of reactive oxygen species (ROS) in the vascular endothelium is a common pathogenic pathway in many dangerous conditions, including acute lung injury, ischemia-reperfusion, and inflammation. Ineffective delivery of antioxidants to the endothelium limits their utility for management of these conditions. In this study, we devised a novel translational antioxidant intervention targeted to the vascular endothelium using PEG-liposomes loaded with EUK-134 (EUK), a potent superoxide dismutase/catalase mimetic. EUK loaded into antibody-coated liposomes (size 197.8±4.5 nm diameter, PDI 0.179±0.066) exerted partial activity in the intact carrier, while full activity was recovered upon liposome disruption. For targeting we used antibodies (Abs) to platelet-endothelial cell adhesion molecule (PECAM-1). Both streptavidin-biotin and SATA/SMCC conjugation chemistries provided binding of 125-150 Ab molecules per liposome. Ab/EUK/liposomes, but not IgG/EUK/liposomes: i) bound to endothelial cells and inhibited cytokine-induced inflammatory activation in vitro; and, ii) accumulated in lungs after intravascular injection, providing >60% protection against pulmonary edema in endotoxin-challenged mice (vs <6% protection afforded by IgG/liposome/EUK counterpart). Since the design elements of this drug delivery system are already in clinical use (PEG-liposomes, antibodies, SATA/SMCC conjugation), it is an attractive candidate for translational interventions using antioxidant molecules such as EUK and other clinically acceptable drugs. Copyright © 2014 Elsevier B.V. All rights reserved.

  17. Bio-Mimetics of Disaster Anticipation-Learning Experience and Key-Challenges.

    Science.gov (United States)

    Tributsch, Helmut

    2013-03-19

    Anomalies in animal behavior and meteorological phenomena before major earthquakes have been reported throughout history. Bio-mimetics or bionics aims at learning disaster anticipation from animals. Since modern science is reluctant to address this problem an effort has been made to track down the knowledge available to ancient natural philosophers. Starting with an archaeologically documented human sacrifice around 1700 B.C. during the Minoan civilization immediately before a large earthquake, which killed the participants, earthquake prediction knowledge throughout antiquity is evaluated. Major practical experience with this phenomenon has been gained from a Chinese earthquake prediction initiative nearly half a century ago. Some quakes, like that of Haicheng, were recognized in advance. However, the destructive Tangshan earthquake was not predicted, which was interpreted as an inherent failure of prediction based on animal phenomena. This is contradicted on the basis of reliable Chinese documentation provided by the responsible earthquake study commission. The Tangshan earthquake was preceded by more than 2,000 reported animal anomalies, some of which were of very dramatic nature. They are discussed here. Any physical phenomenon, which may cause animal unrest, must involve energy turnover before the main earthquake event. The final product, however, of any energy turnover is heat. Satellite based infrared measurements have indeed identified significant thermal anomalies before major earthquakes. One of these cases, occurring during the 2001 Bhuj earthquake in Gujarat, India, is analyzed together with parallel animal anomalies observed in the Gir national park. It is suggested that the time window is identical and that both phenomena have the same geophysical origin. It therefore remains to be demonstrated that energy can be released locally before major earthquake events. It is shown that by considering appropriate geophysical feedback processes, this is

  18. Mechanisms of vanadium action: insulin-mimetic or insulin-enhancing agent?

    Science.gov (United States)

    Cam, M C; Brownsey, R W; McNeill, J H

    2000-10-01

    The demonstration that the trace element vanadium has insulin-like properties in isolated cells and tissues and in vivo has generated considerable enthusiasm for its potential therapeutic value in human diabetes. However, the mechanisms by which vanadium induces its metabolic effects in vivo remain poorly understood, and whether vanadium directly mimics or rather enhances insulin effects is considered in this review. It is clear that vanadium treatment results in the correction of several diabetes-related abnormalities in carbohydrate and lipid metabolism, and in gene expression. However, many of these in vivo insulin-like effects can be ascribed to the reversal of defects that are secondary to hyperglycemia. The observations that the glucose-lowering effect of vanadium depends on the presence of endogenous insulin whereas metabolic homeostasis in control animals appears not to be affected, suggest that vanadium does not act completely independently in vivo, but augments tissue sensitivity to low levels of plasma insulin. Another crucial consideration is one of dose-dependency in that insulin-like effects of vanadium in isolated cells are often demonstrated at high concentrations that are not normally achieved by chronic treatment in vivo and may induce toxic side effects. In addition, vanadium appears to be selective for specific actions of insulin in some tissues while failing to influence others. As the intracellular active forms of vanadium are not precisely defined, the site(s) of action of vanadium in metabolic and signal transduction pathways is still unknown. In this review, we therefore examine the evidence for and against the concept that vanadium is truly an insulin-mimetic agent at low concentrations in vivo. In considering the effects of vanadium on carbohydrate and lipid metabolism, we conclude that vanadium acts not globally, but selectively and by enhancing, rather than by mimicking the effects of insulin in vivo.

  19. Perylene Diimide as a Precise Graphene-like Superoxide Dismutase Mimetic

    Energy Technology Data Exchange (ETDEWEB)

    Jalilov, Almaz S.; Nilewski, Lizanne G.; Berka, Vladimir [Hematology,; Zhang, Chenhao; Yakovenko, Andrey A. [Argonne National Laboratory, X-ray Science Division,; Wu, Gang [Hematology,; Kent, Thomas A. [Department; Center for Translational Research in Inflammatory Diseases, Michel E. DeBakey VA Medical Center, Houston, Texas 77030, United States; Tsai, Ah-Lim [Hematology,; Tour, James M.

    2017-01-31

    Here we show that the active portion of a graphitic nanoparticle can be mimicked by a perylene diimide (PDI) to explain the otherwise elusive biological and electrocatalytic activity of the nanoparticle construct. Development of molecular analogues that mimic the antioxidant properties of oxidized graphenes, in this case the poly(ethylene glycolated) hydrophilic carbon clusters (PEG–HCCs), will afford important insights into the highly efficient activity of PEG–HCCs and their graphitic analogues. PEGylated perylene diimides (PEGn–PDI) serve as well-defined molecular analogues of PEG–HCCs and oxidized graphenes in general, and their antioxidant and superoxide dismutase-like (SOD-like) properties were studied. PEGn–PDIs have two reversible reduction peaks, which are more positive than the oxidation peak of superoxide (O2•–). This is similar to the reduction peak of the HCCs. Thus, as with PEG–HCCs, PEGn–PDIs are also strong single-electron oxidants of O2•–. Furthermore, reduced PEGn–PDI, PEGn–PDI•–, in the presence of protons, was shown to reduce O2•– to H2O2 to complete the catalytic cycle in this SOD analogue. The kinetics of the conversion of O2•– to O2 and H2O2 by PEG8–PDI was measured using freeze-trap EPR experiments to provide a turnover number of 133 s–1; the similarity in kinetics further supports that PEG8–PDI is a true SOD mimetic. Finally, PDIs can be used as catalysts in the electrochemical oxygen reduction reaction in water, which proceeds by a two-electron process with the production of H2O2, mimicking graphene oxide nanoparticles that are otherwise difficult to study spectroscopically.

  20. An Independent Evaluation of a Novel Peptide Mimetic, Brilacidin (PMX30063), for Ocular Anti-Infective

    Science.gov (United States)

    Romanowski, Eric G.; Yates, Kathleen A.; Mah, Francis S.

    2016-01-01

    Abstract Purpose: Brilacidin (BRI), a novel defensin mimetic, was evaluated as an ocular anti-infective. Methods: In vitro: Potency based on MIC90s was compared for 50 Staphylococcus aureus (SA), 50 Staphylococcus epidermidis (SE), and 25 each of Streptococcus pneumonia (SP), Streptococcus viridans (SV), Moraxella (MS), Haemophilus influenzae (HI), Pseudomonas aeruginosa (PA), and Serratia marcescens (SM). In vivo: Using established methods, ocular toxicity was graded with Draize testing. For efficacy testing, both corneas of 24 rabbits were infected with methicillin-resistant S. aureus (MRSA), whereas the corneal epithelium was removed in the left eye. After 4 h, 21 topical drops over 5 h were administered to 4 groups: BRI 0.5%, vancomycin (VAN) 5%, saline, and no treatment. The eyes were clinically graded and the corneas were harvested for colony counts. Results: In vitro: Both SA and SE had the lowest minimum inhibitory concentrations among the bacterial groups. The MIC90s to BRI for SP, SV, MS, HI, PA, and SM were 4, 32, 256, 32, 16, and 128-fold higher, respectively, than SA and SE. In vivo: Draize testing determined BRI 0.5% to be minimally irritating. For abraded corneas, BRI was not statistically different from VAN for reducing MRSA. BRI was bactericidal. For intact corneas, VAN reduced more CFU than BRI. BRI reduced CFU in abraded corneas more than intact corneas suggesting poor corneal penetration. Conclusions: BRI has Gram-positive in vitro activity; topical BRI 0.5% was minimally irritating; and BRI 0.5% was equally efficacious as VAN in a MRSA keratitis model when the corneal epithelium was removed. PMID:26501484

  1. Size Control and Fluorescence Labeling of Polydopamine Melanin-Mimetic Nanoparticles for Intracellular Imaging.

    Science.gov (United States)

    Amin, Devang R; Sugnaux, Caroline; Lau, King Hang Aaron; Messersmith, Phillip B

    2017-09-01

    As synthetic analogs of the natural pigment melanin, polydopamine nanoparticles (NPs) are under active investigation as non-toxic anticancer photothermal agents and as free radical scavenging therapeutics. By analogy to the widely adopted polydopamine coatings, polydopamine NPs offer the potential for facile aqueous synthesis and incorporation of (bio)functional groups under mild temperature and pH conditions. However, clear procedures for the convenient and reproducible control of critical NP properties such as particle diameter, surface charge, and loading with functional molecules have yet to be established. In this work, we have synthesized polydopamine-based melanin-mimetic nanoparticles (MMNPs) with finely controlled diameters spanning ≈25 to 120 nm and report on the pH-dependence of zeta potential, methodologies for PEGylation, and the incorporation of fluorescent organic molecules. A comprehensive suite of complementary techniques, including dynamic light scattering (DLS), cryogenic transmission electron microscopy (cryo-TEM), X-ray photoelectron spectroscopy (XPS), zeta-potential, ultraviolet-visible (UV-Vis) absorption and fluorescence spectroscopy, and confocal microscopy, was used to characterize the MMNPs and their properties. Our PEGylated MMNPs are highly stable in both phosphate-buffered saline (PBS) and in cell culture media and exhibit no cytotoxicity up to at least 100 μg mL -1 concentrations. We also show that a post-functionalization methodology for fluorophore loading is especially suitable for producing MMNPs with stable fluorescence and significantly narrower emission profiles than previous reports, suggesting they will be useful for multimodal cell imaging. Our results pave the way towards biomedical imaging and possibly drug delivery applications, as well as fundamental studies of MMNP size and surface chemistry dependent cellular interactions.

  2. Three-Dimensional Elastomeric Scaffolds Designed with Cardiac-Mimetic Structural and Mechanical Features

    Science.gov (United States)

    Neal, Rebekah A.; Jean, Aurélie; Park, Hyoungshin; Wu, Patrick B.; Hsiao, James; Engelmayr, George C.; Langer, Robert

    2013-01-01

    Tissue-engineered constructs, at the interface of material science, biology, engineering, and medicine, have the capacity to improve outcomes for cardiac patients by providing living cells and degradable biomaterials that can regenerate the native myocardium. With an ultimate goal of both delivering cells and providing mechanical support to the healing heart, we designed three-dimensional (3D) elastomeric scaffolds with (1) stiffnesses and anisotropy mimicking explanted myocardial specimens as predicted by finite-element (FE) modeling, (2) systematically varied combinations of rectangular pore pattern, pore aspect ratio, and strut width, and (3) structural features approaching tissue scale. Based on predicted mechanical properties, three scaffold designs were selected from eight candidates for fabrication from poly(glycerol sebacate) by micromolding from silicon wafers. Large 20×20 mm scaffolds with high aspect ratio features (5:1 strut height:strut width) were reproducibly cast, cured, and demolded at a relatively high throughput. Empirically measured mechanical properties demonstrated that scaffolds were cardiac mimetic and validated FE model predictions. Two-layered scaffolds providing fully interconnected pore networks were fabricated by layer-by-layer assembly. C2C12 myoblasts cultured on one-layered scaffolds exhibited specific patterns of cell elongation and interconnectivity that appeared to be guided by the scaffold pore pattern. Neonatal rat heart cells cultured on two-layered scaffolds for 1 week were contractile, both spontaneously and in response to electrical stimulation, and expressed sarcomeric α-actinin, a cardiac biomarker. This work not only demonstrated several scaffold designs that promoted functional assembly of rat heart cells, but also provided the foundation for further computational and empirical investigations of 3D elastomeric scaffolds for cardiac tissue engineering. PMID:23190320

  3. A model for population dynamics of the mimetic butterfly Papilio polytes in the Sakishima Islands, Japan.

    Science.gov (United States)

    Sekimura, Toshio; Fujihashi, Yuta; Takeuchi, Yasuhiro

    2014-11-21

    We present a mathematical model for population dynamics of the mimetic swallowtail butterfly Papilio polytes in the Sakishima Islands, Japan. The model includes four major variables, that is, population densities of three kinds of butterflies (two female forms f. cyrus, f. polytes and the unpalatable butterfly Pachliopta aristolochiae) and their predator. It is well-known that the non-mimic f. cyrus resembles and attracts the male most, and the mimic f. polytes mimics the model butterfly P. aristolochiae. Based on experimental evidence, we assume that two forms f. cyrus and f. polytes interact under intraspecific competition for resources including the male, and the growth rate of f. cyrus is higher than that of f. polytes. We further assume that both the benefit of mimicry for the mimic f. polytes and the cost for the model are dependent on their relative frequencies, i.e. the motality of the mimic by predation decreases with increase in frequency of the model, while the motality of the model increases as the frequency of the mimic increases. Taking the density-dependent effect through carrying capacity into account, we set up a model system consisting of three ordinary differential equations (ODEs), analyze it mathematically and provide computer simulations that confirm the analytical results. Our results reproduce field records on population dynamics of P. polytes in the Miyako-jima Island. They also explain the positive dependence of the relative abundance (RA) of the mimic on the advantage index (AI) of the mimicry in the Sakishima Islands defined in Section 2. Copyright © 2014 Elsevier Ltd. All rights reserved.

  4. Smac mimetic SM-164 potentiates APO2L/TRAIL- and doxorubicin-mediated anticancer activity in human hepatocellular carcinoma cells.

    Directory of Open Access Journals (Sweden)

    Shuijun Zhang

    Full Text Available The members of inhibitor of apoptosis proteins (IAPs family are key negative regulators of apoptosis. Overexpression of IAPs are found in hepatocellular carcinoma (HCC, and can contribute to chemotherapy resistance and recurrence of HCC. Small-molecule Second mitochondria-derived activator of caspases (Smac mimetics have recently emerged as novel anticancer drugs through targeting IAPs. The specific aims of this study were to 1 examine the anticancer activity of Smac mimetics as a single agent and in combination with chemotherapy in HCC cells, and 2 investigate the mechanism of anticancer action of Smac mimetics.Four HCC cell lines, including SMMC-7721, BEL-7402, HepG2 and Hep3B, and 12 primary HCC cells were used in this study. Smac mimetic SM-164 was used to treat HCC cells. Cell viability, cell death induction and clonal formation assays were used to evaluate the anticancer activity. Western blotting analysis and a pancaspase inhibitor were used to investigate the mechanisms.Although SM-164 induced complete cIAP-1 degradation, it displayed weak inhibitory effects on the viability of HCC cells. Nevertheless, SM-164 considerably potentiated Apo2 ligand or TNF-related apoptosis-inducing ligand (APO2L/TRAIL- and Doxorubicin-mediated anticancer activity in HCC cells. Mechanistic studies demonstrated that SM-164 in combination with chemotherapeutic agents resulted in enhanced activation of caspases-9, -3 and cleavage of poly ADP-ribose polymerase (PARP, and also led to decreased AKT activation.Smac mimetics can enhance chemotherapeutic-mediated anticancer activity by enhancing apoptosis signaling and suppressing survival signaling in HCC cells. This study suggests Smac mimetics are potential therapeutic agents for HCC.

  5. Antibodies Elicited by Multiple Envelope Glycoprotein Immunogens in Primates Neutralize Primary Human Immunodeficiency Viruses (HIV-1) Sensitized by CD4-Mimetic Compounds.

    Science.gov (United States)

    Madani, Navid; Princiotto, Amy M; Easterhoff, David; Bradley, Todd; Luo, Kan; Williams, Wilton B; Liao, Hua-Xin; Moody, M Anthony; Phad, Ganesh E; Vázquez Bernat, Néstor; Melillo, Bruno; Santra, Sampa; Smith, Amos B; Karlsson Hedestam, Gunilla B; Haynes, Barton; Sodroski, Joseph

    2016-05-15

    The human immunodeficiency virus (HIV-1) envelope glycoproteins (Env) mediate virus entry through a series of complex conformational changes triggered by binding to the receptors CD4 and CCR5/CXCR4. Broadly neutralizing antibodies that recognize conserved Env epitopes are thought to be an important component of a protective immune response. However, to date, HIV-1 Env immunogens that elicit broadly neutralizing antibodies have not been identified, creating hurdles for vaccine development. Small-molecule CD4-mimetic compounds engage the CD4-binding pocket on the gp120 exterior Env and induce Env conformations that are highly sensitive to neutralization by antibodies, including antibodies directed against the conserved Env region that interacts with CCR5/CXCR4. Here, we show that CD4-mimetic compounds sensitize primary HIV-1 to neutralization by antibodies that can be elicited in monkeys and humans within 6 months by several Env vaccine candidates, including gp120 monomers. Monoclonal antibodies directed against the gp120 V2 and V3 variable regions were isolated from the immunized monkeys and humans; these monoclonal antibodies neutralized a primary HIV-1 only when the virus was sensitized by a CD4-mimetic compound. Thus, in addition to their direct antiviral effect, CD4-mimetic compounds dramatically enhance the HIV-1-neutralizing activity of antibodies that can be elicited with currently available immunogens. Used as components of microbicides, the CD4-mimetic compounds might increase the protective efficacy of HIV-1 vaccines. Preventing HIV-1 transmission is a high priority for global health. Eliciting antibodies that can neutralize transmitted strains of HIV-1 is difficult, creating problems for the development of an effective vaccine. We found that small-molecule CD4-mimetic compounds sensitize HIV-1 to antibodies that can be elicited in vaccinated humans and monkeys. These results suggest an approach to prevent HIV-1 sexual transmission in which a virus

  6. Antibodies Elicited by Multiple Envelope Glycoprotein Immunogens in Primates Neutralize Primary Human Immunodeficiency Viruses (HIV-1) Sensitized by CD4-Mimetic Compounds

    Science.gov (United States)

    Madani, Navid; Princiotto, Amy M.; Easterhoff, David; Bradley, Todd; Luo, Kan; Williams, Wilton B.; Liao, Hua-Xin; Moody, M. Anthony; Phad, Ganesh E.; Vázquez Bernat, Néstor; Melillo, Bruno; Santra, Sampa; Smith, Amos B.; Karlsson Hedestam, Gunilla B.; Haynes, Barton

    2016-01-01

    ABSTRACT The human immunodeficiency virus (HIV-1) envelope glycoproteins (Env) mediate virus entry through a series of complex conformational changes triggered by binding to the receptors CD4 and CCR5/CXCR4. Broadly neutralizing antibodies that recognize conserved Env epitopes are thought to be an important component of a protective immune response. However, to date, HIV-1 Env immunogens that elicit broadly neutralizing antibodies have not been identified, creating hurdles for vaccine development. Small-molecule CD4-mimetic compounds engage the CD4-binding pocket on the gp120 exterior Env and induce Env conformations that are highly sensitive to neutralization by antibodies, including antibodies directed against the conserved Env region that interacts with CCR5/CXCR4. Here, we show that CD4-mimetic compounds sensitize primary HIV-1 to neutralization by antibodies that can be elicited in monkeys and humans within 6 months by several Env vaccine candidates, including gp120 monomers. Monoclonal antibodies directed against the gp120 V2 and V3 variable regions were isolated from the immunized monkeys and humans; these monoclonal antibodies neutralized a primary HIV-1 only when the virus was sensitized by a CD4-mimetic compound. Thus, in addition to their direct antiviral effect, CD4-mimetic compounds dramatically enhance the HIV-1-neutralizing activity of antibodies that can be elicited with currently available immunogens. Used as components of microbicides, the CD4-mimetic compounds might increase the protective efficacy of HIV-1 vaccines. IMPORTANCE Preventing HIV-1 transmission is a high priority for global health. Eliciting antibodies that can neutralize transmitted strains of HIV-1 is difficult, creating problems for the development of an effective vaccine. We found that small-molecule CD4-mimetic compounds sensitize HIV-1 to antibodies that can be elicited in vaccinated humans and monkeys. These results suggest an approach to prevent HIV-1 sexual transmission in

  7. Relaxing Responses to Hydrogen Peroxide and Nitric Oxide in Human Pericardial Resistance Arteries Stimulated with Endothelin-1

    DEFF Research Database (Denmark)

    Leurgans, Thomas M; Bloksgaard, Maria; Irmukhamedov, Akhmadjon

    2018-01-01

    In human pericardial resistance arteries, effects of the endothelium-dependent vasodilator bradykinin are mediated by NO during contraction induced by K(+) or the TxA2 analogue U46619 and by H2 O2 during contraction by endothelin-1 (ET-1), respectively. We tested the hypotheses that ET-1 reduces...... relaxing effects of NO and increases those of H2 O2 in resistance artery smooth muscle of patients with cardiovascular disease. Arterial segments, dissected from the parietal pericardium of 39 cardiothoracic surgery patients, were studied by myography during amplitude-matched contractions induced by K......(+) , the TXA2 analogue U46619 or ET-1. Effects of the NO-donor Na-nitroprusside (SNP) and of exogenous H2 O2 were recorded in absence and presence of inhibitors of cyclooxygenases, NO-synthases and small and intermediate conductance calcium-activated K(+) channels. During contractions induced by either...

  8. Study on distribution of terminal branches of the facial nerve in mimetic muscles (orbicularis oculi muscle and orbicularis oris muscle).

    Science.gov (United States)

    Mitsukawa, Nobuyuki; Moriyama, Hiroshi; Shiozawa, Kei; Satoh, Kaneshige

    2014-01-01

    There have been many anatomical reports to date regarding the course of the facial nerve to the mimetic muscles. However, reports are relatively scarce on the detailed distribution of the terminal branches of the facial nerve to the mimetic muscles. In this study, we performed detailed examination of the terminal facial nerve branches to the mimetic muscles, particularly the branches terminating in the orbicularis oculi muscle and orbicularis oris muscle. Examination was performed on 25 Japanese adult autopsy cases, involving 25 hemifaces. The mean age was 87.4 years (range, 60-102 years). There were 12 men and 13 women (12 left hemifaces and 13 right hemifaces). In each case, the facial nerve was exposed through a preauricular skin incision. The main trunk of the facial nerve was dissected from the stylomastoid foramen. A microscope was used to dissect the terminal branches to the periphery and observe them. The course and distribution were examined for all terminal branches of the facial nerve. However, focus was placed on the course and distribution of the zygomatic branch, buccal branch, and mandibular branch to the orbicularis oculi muscle and orbicularis oris muscle. The temporal branch was distributed to the orbicularis oculi muscle in all cases and the marginal mandibular branch was distributed to the orbicularis oris muscle in all cases. The zygomatic branch was distributed to the orbicularis oculi muscle in all cases, but it was also distributed to the orbicularis oris muscle in 10 of 25 cases. The buccal branch was not distributed to the orbicularis oris muscle in 3 of 25 cases, and it was distributed to the orbicularis oculi muscle in 8 cases. There was no significant difference in the variations. The orbicularis oculi muscle and orbicularis oris muscle perform particularly important movements among the facial mimetic muscles. According to textbooks, the temporal branch and zygomatic branch innervate the orbicularis oculi muscle, and the buccal branch

  9. A novel Smac mimetic APG-1387 demonstrates potent antitumor activity in nasopharyngeal carcinoma cells by inducing apoptosis.

    Science.gov (United States)

    Li, Ning; Feng, Lin; Han, Hui-Qiong; Yuan, Jing; Qi, Xue-Kang; Lian, Yi-Fan; Kuang, Bo-Hua; Zhang, Yu-Chen; Deng, Cheng-Cheng; Zhang, Hao-Jiong; Yao, You-Yuan; Xu, Miao; He, Gui-Ping; Zhao, Bing-Chun; Gao, Ling; Feng, Qi-Sheng; Chen, Li-Zhen; Yang, Lu; Yang, Dajun; Zeng, Yi-Xin

    2016-10-10

    Despite advances in the development of radiation against nasopharyngeal carcinoma (NPC), the management of advanced NPC remains a challenge. Smac mimetics are designed to neutralize inhibitor of apoptosis (IAP) proteins, thus reactivating the apoptotic program in cancer cells. In this study, we investigated the effect of a novel bivalent Smac mimetic APG-1387 in NPC. In vitro, APG-1387 in combination with TNF-α potently decreased NPC cell viability by inducing apoptosis in majority of NPC cell lines. The in vitro antitumor effect was RIPK1-dependent, whereas it was independent on IAPs, USP11, or EBV. Of note, the inhibition of NF-κB or AKT pathway rendered resistant NPC cells responsive to the treatment of APG-1387/TNF-α. In vivo, APG-1387 displayed antitumor activity as a single agent at well-tolerated doses, even in an in vitro resistant cell line. In summary, our results demonstrate that APG-1387 exerts a potent antitumor effect on NPC. These findings support clinical evaluation of APG-1387 as a potential treatment for advanced NPC. Copyright © 2016. Published by Elsevier Ireland Ltd.

  10. Effect of Vanadyl Rosiglitazone, a New Insulin-Mimetic Vanadium Complexes, on Glucose Homeostasis of Diabetic Mice.

    Science.gov (United States)

    Jiang, Pingzhe; Dong, Zhen; Ma, Baicheng; Ni, Zaizhong; Duan, Huikun; Li, Xiaodan; Wang, Bin; Ma, Xiaofeng; Wei, Qian; Ji, Xiangzhen; Li, Minggang

    2016-11-01

    Diabetes has been cited as the most challenging health problem in the twenty-first century. Accordingly, it is urgent to develop a new type of efficient and low-toxic antidiabetic medication. Since vanadium compounds have insulin-mimetic and potential hypoglycemic activities for type 1 and type 2 diabetes, a new trend has been developed using vanadium and organic ligands to form a new compound in order to increase the intestinal absorption and reduce the toxicity of vanadium compound. In the current investigation, a new organic vanadium compounds, vanadyl rosiglitazone, was synthesized and determined by infrared spectra. Vanadyl rosiglitazone and three other organic vanadium compounds were administered to the diabetic mice through oral administration for 5 weeks. The results of mouse model test indicated that vanadyl rosiglitazone could regulate the blood glucose level and relieve the symptoms of polydipsia, polyphagia, polyuria, and weight loss without side effects and was more effective than the other three organic vanadium compounds including vanadyl trehalose, vanadyl metformin, and vanadyl quercetin. The study indicated that vanadyl rosiglitazone presents insulin-mimetic activities, and it will be a good potential candidate for the development of a new type of oral drug for type 2 diabetes.

  11. Influence of Block Copolymerization on the Antifreeze Protein Mimetic Ice Recrystallization Inhibition Activity of Poly(vinyl alcohol).

    Science.gov (United States)

    Congdon, Thomas R; Notman, Rebecca; Gibson, Matthew I

    2016-09-12

    Antifreeze (glyco) proteins are produced by many cold-acclimatized species to enable them to survive subzero temperatures. These proteins have multiple macroscopic effects on ice crystal growth which makes them appealing for low-temperature applications-from cellular cryopreservation to food storage. Poly(vinyl alcohol) has remarkable ice recrystallization inhibition activity, but its mode of action is uncertain as is the extent at which it can be incorporated into other high-order structures. Here the synthesis and characterization of well-defined block copolymers containing poly(vinyl alcohol) and poly(vinylpyrrolidone) by RAFT/MADIX polymerization is reported, as new antifreeze protein mimetics. The effect of adding a large second hydrophilic block is studied across a range of compositions, and it is found to be a passive component in ice recrystallization inhibition assays, enabling retention of all activity. In the extreme case, a block copolymer with only 10% poly(vinyl alcohol) was found to retain all activity, where statistical copolymers of PVA lose all activity with very minor changes to composition. These findings present a new method to increase the complexity of antifreeze protein mimetic materials, while retaining activity, and also to help understand the underlying mechanisms of action.

  12. A small molecule glycosaminoglycan mimetic blocks Plasmodium invasion of the mosquito midgut.

    Directory of Open Access Journals (Sweden)

    Derrick K Mathias

    Full Text Available Malaria transmission-blocking (T-B interventions are essential for malaria elimination. Small molecules that inhibit the Plasmodium ookinete-to-oocyst transition in the midgut of Anopheles mosquitoes, thereby blocking sporogony, represent one approach to achieving this goal. Chondroitin sulfate glycosaminoglycans (CS-GAGs on the Anopheles gambiae midgut surface are putative ligands for Plasmodium falciparum ookinetes. We hypothesized that our synthetic polysulfonated polymer, VS1, acting as a decoy molecular mimetic of midgut CS-GAGs confers malaria T-B activity. In our study, VS1 repeatedly reduced midgut oocyst development by as much as 99% (P<0.0001 in mosquitoes fed with P. falciparum and Plasmodium berghei. Through direct-binding assays, we observed that VS1 bound to two critical ookinete micronemal proteins, each containing at least one von Willebrand factor A (vWA domain: (i circumsporozoite protein and thrombospondin-related anonymous protein-related protein (CTRP and (ii vWA domain-related protein (WARP. By immunofluorescence microscopy, we observed that VS1 stains permeabilized P. falciparum and P. berghei ookinetes but does not stain P. berghei CTRP knockouts or transgenic parasites lacking the vWA domains of CTRP while retaining the thrombospondin repeat region. We produced structural homology models of the first vWA domain of CTRP and identified, as expected, putative GAG-binding sites on CTRP that align closely with those predicted for the human vWA A1 domain and the Toxoplasma gondii MIC2 adhesin. Importantly, the models also identified patches of electropositive residues that may extend CTRP's GAG-binding motif and thus potentiate VS1 binding. Our molecule binds to a critical, conserved ookinete protein, CTRP, and exhibits potent malaria T-B activity. This study lays the framework for a high-throughput screen of existing libraries of safe compounds to identify those with potent T-B activity. We envision that such compounds when

  13. Combinational Spinal GAD65 Gene Delivery and Systemic GABA-Mimetic Treatment for Modulation of Spasticity

    Science.gov (United States)

    Kakinohana, Osamu; Hefferan, Michael P.; Miyanohara, Atsushi; Nejime, Tetsuya; Marsala, Silvia; Juhas, Stefan; Juhasova, Jana; Motlik, Jan; Kucharova, Karolina; Strnadel, Jan; Platoshyn, Oleksandr; Lazar, Peter; Galik, Jan; Vinay, Laurent; Marsala, Martin

    2012-01-01

    Background Loss of GABA-mediated pre-synaptic inhibition after spinal injury plays a key role in the progressive increase in spinal reflexes and the appearance of spasticity. Clinical studies show that the use of baclofen (GABAB receptor agonist), while effective in modulating spasticity is associated with major side effects such as general sedation and progressive tolerance development. The goal of the present study was to assess if a combined therapy composed of spinal segment-specific upregulation of GAD65 (glutamate decarboxylase) gene once combined with systemic treatment with tiagabine (GABA uptake inhibitor) will lead to an antispasticity effect and whether such an effect will only be present in GAD65 gene over-expressing spinal segments. Methods/Principal Findings Adult Sprague-Dawley (SD) rats were exposed to transient spinal ischemia (10 min) to induce muscle spasticity. Animals then received lumbar injection of HIV1-CMV-GAD65 lentivirus (LVs) targeting ventral α-motoneuronal pools. At 2–3 weeks after lentivirus delivery animals were treated systemically with tiagabine (4, 10, 20 or 40 mg/kg or vehicle) and the degree of spasticity response measured. In a separate experiment the expression of GAD65 gene after spinal parenchymal delivery of GAD65-lentivirus in naive minipigs was studied. Spastic SD rats receiving spinal injections of the GAD65 gene and treated with systemic tiagabine showed potent and tiagabine-dose-dependent alleviation of spasticity. Neither treatment alone (i.e., GAD65-LVs injection only or tiagabine treatment only) had any significant antispasticity effect nor had any detectable side effect. Measured antispasticity effect correlated with increase in spinal parenchymal GABA synthesis and was restricted to spinal segments overexpressing GAD65 gene. Conclusions/Significance These data show that treatment with orally bioavailable GABA-mimetic drugs if combined with spinal-segment-specific GAD65 gene overexpression can represent a novel

  14. The GLP-1 mimetic exenatide potentiates insulin secretion in healthy cats.

    Science.gov (United States)

    Gilor, C; Graves, T K; Gilor, S; Ridge, T K; Rick, M

    2011-07-01

    The glucagon-like peptide-1 mimetic exenatide has a glucose-dependent insulinotropic effect, and it is effective in controlling blood glucose (BG) with minimal side effects in people with type 2 diabetes. Exenatide also delays gastric emptying, increases satiety, and improves β-cell function. We studied the effect of exenatide on insulin secretion during euglycemia and hyperglycemia in cats. Nine young, healthy, neutered, purpose-bred cats were used in a randomized, cross-over design. BG concentrations during an oral glucose tolerance test were determined in these cats previously. Two isoglycemic glucose clamps (mimicking the BG concentration during the oral glucose tolerance test) were performed in each cat on separate days, one without prior treatment (IGC) and the second with exenatide (1 μg/kg) injected subcutaneously 2 h before (ExIGC). BG, insulin, and exenatide concentrations were measured, and glucose infusion rates were recorded and compared in paired tests between the two experiments. After exenatide injection, insulin serum concentrations increased significantly (2.4-fold; range 1.0- to 9.2-fold; P = 0.004) within 15 min. This was followed by a mild decrease in BG concentration and a return of insulin concentration to baseline despite a continuous increase in serum exenatide concentrations. Insulin area under the curve (AUC) during ExIGC was significantly higher than insulin AUC during IGC (AUC ratio, 2.0 ± 0.4; P = 0.03). Total glucose infused was not significantly different between IGC and ExIGC. Exenatide was detectable in plasma at 15 min after injection. The mean exenatide concentration peaked at 45 min and then returned to baseline by 75 min. Exenatide was still detectable in the serum of three of five cats 8 h after injection. No adverse reactions to exenatide were observed. In conclusion, exenatide affects insulin secretion in cats in a glucose-dependent manner, similar to its effect in other species. Although this effect was not accompanied

  15. Bio-Mimetics of Disaster Anticipation—Learning Experience and Key-Challenges

    Science.gov (United States)

    Tributsch, Helmut

    2013-01-01

    Simple Summary Starting from 1700 B.C. in the old world and up to recent times in China there is evidence of earthquake prediction based on unusual metrological phenomena and animal behavior. The review tries to explore the credibility and to pin down the nature of geophysical phenomena involved. It appears that the concept of ancient Greek philosophers in that a dry gas, pneuma is correlated with earthquakes, is relevant. It is not the cause of earthquakes, as originally thought, but may be an accompanying phenomenon and occasional precursor. This would explain unusual animal behavior as well as thermal anomalies detected from satellites. Abstract Anomalies in animal behavior and meteorological phenomena before major earthquakes have been reported throughout history. Bio-mimetics or bionics aims at learning disaster anticipation from animals. Since modern science is reluctant to address this problem an effort has been made to track down the knowledge available to ancient natural philosophers. Starting with an archaeologically documented human sacrifice around 1700 B.C. during the Minoan civilization immediately before a large earthquake, which killed the participants, earthquake prediction knowledge throughout antiquity is evaluated. Major practical experience with this phenomenon has been gained from a Chinese earthquake prediction initiative nearly half a century ago. Some quakes, like that of Haicheng, were recognized in advance. However, the destructive Tangshan earthquake was not predicted, which was interpreted as an inherent failure of prediction based on animal phenomena. This is contradicted on the basis of reliable Chinese documentation provided by the responsible earthquake study commission. The Tangshan earthquake was preceded by more than 2,000 reported animal anomalies, some of which were of very dramatic nature. They are discussed here. Any physical phenomenon, which may cause animal unrest, must involve energy turnover before the main earthquake

  16. Bio-Mimetics of Disaster Anticipation—Learning Experience and Key-Challenges

    Directory of Open Access Journals (Sweden)

    Helmut Tributsch

    2013-03-01

    Full Text Available Anomalies in animal behavior and meteorological phenomena before major earthquakes have been reported throughout history. Bio-mimetics or bionics aims at learning disaster anticipation from animals. Since modern science is reluctant to address this problem an effort has been made to track down the knowledge available to ancient natural philosophers. Starting with an archaeologically documented human sacrifice around 1700 B.C. during the Minoan civilization immediately before a large earthquake, which killed the participants, earthquake prediction knowledge throughout antiquity is evaluated. Major practical experience with this phenomenon has been gained from a Chinese earthquake prediction initiative nearly half a century ago. Some quakes, like that of Haicheng, were recognized in advance. However, the destructive Tangshan earthquake was not predicted, which was interpreted as an inherent failure of prediction based on animal phenomena. This is contradicted on the basis of reliable Chinese documentation provided by the responsible earthquake study commission. The Tangshan earthquake was preceded by more than 2,000 reported animal anomalies, some of which were of very dramatic nature. They are discussed here. Any physical phenomenon, which may cause animal unrest, must involve energy turnover before the main earthquake event. The final product, however, of any energy turnover is heat. Satellite based infrared measurements have indeed identified significant thermal anomalies before major earthquakes. One of these cases, occurring during the 2001 Bhuj earthquake in Gujarat, India, is analyzed together with parallel animal anomalies observed in the Gir national park. It is suggested that the time window is identical and that both phenomena have the same geophysical origin. It therefore remains to be demonstrated that energy can be released locally before major earthquake events. It is shown that by considering appropriate geophysical feedback

  17. Mechanisms of neuroblastoma cell growth inhibition by CARP-1 functional mimetics.

    Directory of Open Access Journals (Sweden)

    Magesh Muthu

    Full Text Available Neuroblastomas (NBs are a clinically heterogeneous group of extra cranial pediatric tumors. Patients with high-risk, metastatic NBs have a long-term survival rate of below 40%, and are often resistant to current therapeutic modalities. Due to toxic side effects associated with radiation and chemotherapies, development of new agents is warranted to overcome resistance and effectively treat this disease in clinic. CARP-1 functional mimetics (CFMs are an emerging class of small molecule compounds that inhibit growth of diverse cancer cell types. Here we investigated NB inhibitory potential of CFMs and the molecular mechanisms involved. CFM-1, -4, and -5 inhibited NB cell growth, in vitro, independent of their p53 and MYCN status. CFM-4 and -5 induced apoptosis in NB cells in part by activating pro-apoptotic stress-activated kinases (SAPKs p38 and JNK, stimulating CARP-1 expression and cleavage of PARP1, while promoting loss of the oncogenes C and N-myc as well as mitotic cyclin B1. Treatments of NB cells with CFM-4 or -5 also resulted in loss of Inhibitory κB (IκB α and β proteins. Micro-RNA profiling revealed upregulation of XIAP-targeting miR513a-3p in CFM-4-treated NB, mesothelioma, and breast cancer cells. Moreover, exposure of NB and breast cancer cells to CFM-4 or -5 resulted in diminished expression of anti-apoptotic XIAP1, cIAP1, and Survivin proteins. Expression of anti-miR513a-5p or miR513a-5p mimic, however, interfered with or enhanced, respectively, the breast cancer cell growth inhibition by CFM-4. CFMs also impacted biological properties of the NB cells by blocking their abilities to migrate, form colonies in suspension, and invade through the matrix-coated membranes. Our studies indicate anti-NB properties of CFM-4 and 5, and suggest that these CFMs and/or their future analogs have potential as anti-NB agents.

  18. A multilevel multiscale mimetic (M 3) method for two-phase flows in porous media

    Science.gov (United States)

    Lipnikov, K.; Moulton, J. D.; Svyatskiy, D.

    2008-07-01

    We describe a multilevel multiscale mimetic (M 3) method for solving two-phase flow (water and oil) in a heterogeneous reservoir. The governing equations are the elliptic equation for the reservoir pressure and the hyperbolic equation for the water saturation. On each time step, we first solve the pressure equation and then use the computed flux in an explicit upwind finite volume method to update the saturation. To reduce the computational cost, the pressure equation is solved on a much coarser grid than the saturation equation. The coarse-grid pressure discretization captures the influence of multiple scales via the subgrid modeling technique for single-phase flow recently proposed in [Yu. A. Kuznetsov. Mixed finite element method for diffusion equations on polygonal meshes with mixed cells. J. Numer. Math., 14 (4) (2006) 305-315; V. Gvozdev. discretization of the diffusion and Maxwell equations on polyhedral meshes. Technical Report Ph.D. Thesis, University of Houston, 2007; Yu. Kuznetsov. Mixed finite element methods on polyhedral meshes for diffusion equations, in: Computational Modeling with PDEs in Science and Engineering, Springer-Verlag, Berlin, in press]. We extend significantly the applicability of this technique by developing a new robust and efficient method for estimating the flux coarsening parameters. Specifically, with this advance the M 3 method can handle full permeability tensors and general coarsening strategies, which may generate polygonal meshes on the coarse grid. These problem dependent coarsening parameters also play a critical role in the interpolation of the flux, and hence, in the advection of saturation for two-phase flow. Numerical experiments for two-phase flow in highly heterogeneous permeability fields, including layer 68 of the SPE Tenth Comparative Solution Project, demonstrate that the M 3 method retains good accuracy for high coarsening factors in both directions, up to 64 for the considered models. Moreover, we demonstrate

  19. Smac mimetic enables the anticancer action of BCG-stimulated neutrophils through TNF-α but not through TRAIL and FasL

    Science.gov (United States)

    Jinesh G., Goodwin; Chunduru, Srinivas; Kamat, Ashish M.

    2012-01-01

    BCG, the current gold standard immunotherapy for bladder cancer, exerts its activity via recruitment of neutrophils to the tumor microenvironment. Many patients do not respond to BCG therapy, indicating the need to understand the mechanism of action of BCG-stimulated neutrophils and to identify ways to overcome resistance to BCG therapy. Using isolated human neutrophils stimulated with BCG, we found that TNF-α is the key mediator secreted by BCG-stimulated neutrophils. RT4v6 human bladder cancer cells, which express TNFR1, CD95/Fas, CD95 ligand/FasL, DR4, and DR5, were resistant to BCG-stimulated neutrophil conditioned medium but effectively killed by the combination of conditioned medium and Smac mimetic. rhTNF-α and rhFasL, but not rhTRAIL, in combination with Smac mimetic, generated signature molecular events similar to those produced by BCG-stimulated neutrophils in combination with Smac mimetic. However, experiments using neutralizing antibodies to these death ligands showed that TNF-α secreted from BCG-stimulated neutrophils was the key mediator of anticancer action. These findings explain the mechanism of action of BCG and identified Smac mimetics as potential combination therapeutic agents for bladder cancer. PMID:22517918

  20. Synthesis, molecular docking and biological evaluation as HDAC inhibitors of cyclopeptide mimetics by a tandem three-component reaction and intramolecular [3+2] cycloaddition.

    Science.gov (United States)

    Pirali, Tracey; Faccio, Valeria; Mossetti, Riccardo; Grolla, Ambra A; Di Micco, Simone; Bifulco, Giuseppe; Genazzani, Armando A; Tron, Gian Cesare

    2010-02-01

    Novel macrocyclic peptide mimetics have been synthesized by exploiting a three-component reaction and an azide-alkyne [3 + 2] cycloaddition. The prepared compounds were screened as HDAC inhibitors allowing us to identify a new compound with promising biological activity. In order to rationalize the biological results, computational studies have also been performed.

  1. A synthetic NCAM-derived mimetic peptide, FGL, exerts anti-inflammatory properties via IGF-1 and interferon-gamma modulation

    DEFF Research Database (Denmark)

    Downer, Eric J; Cowley, Thelma R; Cox, Fionnuala

    2009-01-01

    Microglial cell activity increases in the rat hippocampus during normal brain aging. The neural cell adhesion molecule (NCAM)-derived mimetic peptide, FG loop (FGL), acts as an anti-inflammatory agent in the hippocampus of the aged rat, promoting CD200 ligand expression while attenuating glial cell...

  2. Effect of fat level on the perception of five flavor chemicals in ice cream with or without fat mimetics by using a descriptive test.

    Science.gov (United States)

    Liou, B K; Grün, I U

    2007-10-01

    Fat mimetics are commonly used in the manufacture of low-fat and fat-free ice creams. However, the use of fat mimetics affects flavor and texture characteristics of ice cream, which results in decreased overall acceptability by consumers. The initial objective of this study was to investigate the release behavior of 5 strawberry flavor compounds in ice creams with Simplesse((R)), Litesse((R)), and Litesse((R))/Simplesse((R)) mixes using descriptive analysis. Fat mimetics and flavor formulation significantly influenced the perception of Furaneoltrade mark (cooked sugar flavor), alpha-ionone (violet flavor), and gamma-undecalactone (peach flavor), but there was no interaction between ice cream type and flavor formulation for the 3 flavors. Furaneol and ethyl-3-methyl-3-phenylglycidate (candy flavor) were perceived more strongly in full-fat ice cream, while cis-3-hexen-1-ol (grassy flavor), alpha-ionone, and gamma-undecalactone were perceived more strongly in low-fat ice cream. Ice creams with Simplesse and full-fat ice cream had similar sensory characteristics, while ice creams with Litesse were similar to low-fat ice creams in flavor characteristics, and ice creams with Litesse/Simplesse mixes were closer in flavor profile to low-fat ice cream but had similar texture properties to those of full-fat ice cream. Simplesse was found to be a better fat mimetic for duplicating the flavor profiles and mouthfeel of full-fat ice cream.

  3. iBodies: modular synthetic antibody mimetics based on hydrophilic polymers decorated with functional moieties as tools for molecular recognition, imaging and specific drug delivery

    Czech Academy of Sciences Publication Activity Database

    Šácha, Pavel; Dvořáková, Petra; Knedlík, Tomáš; Schimer, Jiří; Šubr, Vladimír; Ulbrich, Karel; Bušek, P.; Navrátil, Václav; Sedlák, František; Majer, Pavel; Šedo, A.; Konvalinka, Jan

    2017-01-01

    Roč. 284, Suppl 1 (2017), s. 340 ISSN 1742-464X. [FEBS Congress /42./ From Molecules to Cells and Back. 10.09.2017-14.09.2017, Jerusalem] Institutional support: RVO:61388963 ; RVO:61389013 Keywords : antibody mimetics * molecular recognition * polymer conjugates Subject RIV: CE - Biochemistry

  4. Smac mimetic induces cell death in a large proportion of primary acute myeloid leukemia samples, which correlates with defined molecular markers.

    Science.gov (United States)

    Lueck, Sonja C; Russ, Annika C; Botzenhardt, Ursula; Schlenk, Richard F; Zobel, Kerry; Deshayes, Kurt; Vucic, Domagoj; Döhner, Hartmut; Döhner, Konstanze; Fulda, Simone; Bullinger, Lars

    2016-08-02

    Apoptosis is deregulated in most, if not all, cancers, including hematological malignancies. Smac mimetics that antagonize Inhibitor of Apoptosis (IAP) proteins have so far largely been investigated in acute myeloid leukemia (AML) cell lines; however, little is yet known on the therapeutic potential of Smac mimetics in primary AML samples. In this study, we therefore investigated the antileukemic activity of the Smac mimetic BV6 in diagnostic samples of 67 adult AML patients and correlated the response to clinical, cytogenetic and molecular markers and gene expression profiles. Treatment with cytarabine (ara-C) was used as a standard chemotherapeutic agent. Interestingly, about half (51%) of primary AML samples are sensitive to BV6 and 21% intermediate responsive, while 28% are resistant. Notably, 69% of ara-C-resistant samples show a good to fair response to BV6. Furthermore, combination treatment with ara-C and BV6 exerts additive effects in most samples. Whole-genome gene expression profiling identifies cell death, TNFR1 and NF-κB signaling among the top pathways that are activated by BV6 in BV6-sensitive, but not in BV6-resistant cases. Furthermore, sensitivity of primary AML blasts to BV6 correlates with significantly elevated expression levels of TNF and lower levels of XIAP in diagnostic samples, as well as with NPM1 mutation. In a large set of primary AML samples, these data provide novel insights into factors regulating Smac mimetic response in AML and have important implications for the development of Smac mimetic-based therapies and related diagnostics in AML.

  5. Chemistry and insulin-mimetic properties of bis(acetylacetonate)oxovanadium(IV) and derivatives.

    Science.gov (United States)

    Amin, S S; Cryer, K; Zhang, B; Dutta, S K; Eaton, S S; Anderson, O P; Miller, S M; Reul, B A; Brichard, S M; Crans, D C

    2000-02-07

    The syntheses and the solid state structural and spectroscopic solution characterizations of VO(Me-acac)2 and VO(Et-acac)2 (where Me-acac is 3-methyl-2,4-pentanedionato and Et-acac is 3-ethyl-2,4-pentanedionato) have been conducted since both VO(acac)2 and VO(Et-acac)2 have long-term in vivo insulin-mimetic effects in streptozotocin-induced diabetic Wistar rats. X-ray structural characterizations of VO(Me-acac)2 and VO(Et-acac)2 show that both contain five-coordinate vanadium similar to the parent VO(acac)2. The unit cells for VO(Et-acac)2 and VO(Me-acac)2 are both triclinic, P1, with a = 9.29970(10) A, b = 13.6117(2) A, c = 13.6642(2) A, alpha = 94.1770(10) degrees, beta = 106.4770(10) degrees, gamma = 106.6350(10) degrees for VO(Et-acac)2 and a = 7.72969(4) A, b = 8.1856(5) A, c = 11.9029(6) A, alpha = 79.927(2) degrees, beta = 73.988(2)degrees, gamma = 65.1790(10)degrees for VO(Me-acac)2. The total concentration of EPR-observable vanadium(IV) species for VO(acac)2 and derivatives in water solution at 20 degreesC was determined by double integration of the EPR spectra and apportioned between individual species on the basis of computer simulations of the spectra. Three species were observed, and the concentrations were found to be time, pH, temperature, and salt dependent. The three complexes are assigned as the trans-VO(acac)2.H2O adduct, cis-VO(acac)2.H2O adduct, and a hydrolysis product containing one vanadium atom and one R-acac- group. The reaction rate for conversion of species was slower for VO(acac)2 than for VO(malto)2, VO(Et-acac)2, and VO(Me-acac)2; however, in aqueous solution the rates for all of these species are slow compared to those of other vanadium species. The concentration of vanadium(V) species was determined by 51V NMR. The visible spectra were time dependent, consistent with the changes in species concentrations that were observed in the EPR and NMR spectra. EPR and visible spectroscopic studies of solutions prepared as for administration

  6. Conformational assembly and biological properties of collagen mimetic peptides and their thermally responsive polymer conjugates

    Science.gov (United States)

    Krishna, Ohm Divyam

    2011-12-01

    Collagens are one of the most abundant proteins found in body tissues and organs, endowing structural integrity, mechanical strength, and multiple biological functions. Destabilized collagen inside human body leads to various degenerative diseases (ex. osteoarthritis) and ageing. This has continued to motivate the design of synthetic peptides and bio-synthetic polypeptides to closely mimic the native collagens in terms of triple helix structure and stability, potential for higher order assembly, and biological properties. However, the widespread application of de novo collagens has been limited in part by the need for hydroxylated proline in the formation of stable triple helical structures. To address this continued need, a hydroxyproline-free, thermally stable collagen-mimetic peptide (CLP-Cys) was rationally designed via the incorporation of electrostatically stabilized amino acid triplets. CLP-Cys was synthesized via solid phase peptide synthesis. The formation and stability of the triple helical structure were indicated via circular dichroism (CD) experiments and confirmed via differential scanning calorimetry (DSC) results. CLP-Cys also self-assembled into nano-rods and micro-fibrils, as evidenced via a combination of dynamic light scattering and transmission electron microscopy. Given the high thermal stability and its propensity for higher-order assembly, CLP-Cys was further functionalized at both the ends with a thermally responsive polymer, poly(diethylene glycol methyl ether methacrylate), (PDEGMEMA) to synthesize a biohybrid triblock copolymer. The CD results indicated that the triple helical form is retained, the thermal unfolding is sustained and helix to coil transition is reversible in the triblock hybrid context. The LCST of PDEGMEMA homopolymer (26 °C) is increased (to 35 °C) upon conjugation to the hydrophilic collagen peptide domain. Further, a combination of static light scattering, Cryo-SEM, TEM and confocal microscopy elucidated that the

  7. The CNTF-derived peptide mimetic Cintrofin attenuates spatial-learning deficits in a rat post-status epilepticus model

    DEFF Research Database (Denmark)

    Russmann, Vera; Seeger, Natalie; Zellinger, Christina

    2013-01-01

    . Whereas status epilepticus caused a significant disturbance in spatial learning in reversed peptide-treated rats, the performance of Cintrofin-treated rats did not differ from controls. The study confirms that Cintrofin comprises an active sequence mimicking effects of its parent molecule. While the data......Ciliary neurotrophic growth factor is considered a potential therapeutic agent for central nervous system diseases. We report first in vivo data of the ciliary neurotrophic growth factor peptide mimetic Cintrofin in a rat post-status epilepticus model. Cintrofin prevented long-term alterations...... in the number of doublecortin-positive neuronal progenitor cells and attenuated the persistence of basal dendrites. In contrast, Cintrofin did neither affect acute status epilepticus-associated alterations in hippocampal cell proliferation and neurogenesis nor reveal any relevant effect on seizure activity...

  8. A novel insulin mimetic vanadium-flavonol complex: synthesis, characterization and in vivo evaluation in STZ-induced rats.

    Science.gov (United States)

    Pillai, Subramanian Iyyam; Subramanian, Sorimuthu Pillai; Kandaswamy, Muthusamy

    2013-05-01

    Since 1985, when Heyliger et al., first demonstrated a serendipitous discovery that oral administration of 0.8 mg/ml of sodium orthovanadate in drinking water to streptozotocin-induced diabetic rats resulted in normoglycemia, numerous extensive studies have been pursued on the anti-diabetic and insulinomimetic actions of vanadium. The acceptance of vanadium compounds as promising therapeutic antidiabetic agents has been slowed due to the concern for chronic toxicity associated with vanadium accumulation. In order to circumvent the toxic effects of vanadium, we have taken up a combinational approach wherein a novel vanadium-flavonol complex was synthesized, characterized and its toxic as well as insulin mimetic potential was evaluated in STZ-induced experimental diabetes in rats. The results indicate that the complex is non-toxic and possess anti-diabetic activity. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

  9. Peroxide(s) of vanadium: a novel and potent insulin-mimetic agent which activates the insulin receptor kinase.

    Science.gov (United States)

    Kadota, S; Fantus, I G; Deragon, G; Guyda, H J; Hersh, B; Posner, B I

    1987-08-31

    The actions of insulin, vanadate (V) and hydrogen peroxide (H2O2) on IGF-II binding and insulin receptor tyrosine kinase activity were studied in rat adipocytes. Incubating adipocytes with a combination of V plus H2O2 resulted in a potent synergistic effect on both the increase in IGF-II binding and the activation of the insulin receptor kinase. Catalase, which removes H2O2, abolished this synergism if added at the time of mixing of V plus H2O2 but not if added 10 min. later, suggesting that the formation of peroxide(s) of vanadate generated a potent insulin mimicker. The data support a critical role for the insulin receptor kinase in insulin action. The novel insulin-mimetic compound, a presumed peroxide of vanadate, could prove useful for investigating insulin action and may be valuable for treating insulin resistance.

  10. Synthesis of multivalent carbohydrate mimetics with aminopolyol end groups and their evaluation as L-selectin inhibitors

    Directory of Open Access Journals (Sweden)

    Joana Salta

    2015-05-01

    Full Text Available In this article a series of divalent and trivalent carbohydrate mimetics on the basis of an enantiopure aminopyran and of serinol is described. These aminopolyols are connected by amide bonds to carboxylic acid derived spacer units either by Schotten–Baumann acylation or by coupling employing HATU as reagent. The O-sulfation employing the SO3·DMF complex was optimized. It was crucial to follow this process by 700 MHz 1H NMR spectroscopy to ensure full conversion and to use a refined neutralization and purification protocol. Many of the compounds could not be tested as L-selectin inhibitor by SPR due to their insolubility in water, nevertheless, a divalent and a trivalent amide showed surprisingly good activities with IC50 values in the low micromolar range.

  11. TREATMENT OF DIABETES MELLITUS IN A GOLDEN LION TAMARIN (LEONTOPITHECUS ROSALIA) WITH THE GLUCAGON-LIKE PEPTIDE-1 MIMETIC EXENATIDE.

    Science.gov (United States)

    Johnson, James G; Langan, Jennifer N; Gilor, Chen

    2016-09-01

    An 8-yr-old male golden lion tamarin ( Leontopithecus rosalia ) was diagnosed with diabetes mellitus based on hyperglycemia and persistent glycosuria. Initial treatment consisted of the oral antihyperglycemic medications glipizide and metformin that resulted in decreased blood glucose concentrations; however, marked glycosuria persisted. Insufficient improvement on oral antihyperglycemic therapy and poor feasibility of daily subcutaneous insulin therapy led to an investigation into an alternative therapy with extended-release exenatide, a glucagon-like peptide-1 (GLP-1) mimetic, at a dosage of 0.13 mg/kg subcutaneously once per month. Following treatment with exenatide, the persistent glycosuria resolved, the animal maintained normal blood glucose concentrations, and had lower serum fructosamine concentrations compared to pretreatment levels. Based on these findings, extended-release exenatide could be considered as a therapeutic option in nonhuman primates with diabetes mellitus that do not respond to oral antihyperglycemics and in which daily subcutaneous insulin is not feasible.

  12. TDP6, a brain-derived neurotrophic factor-based trkB peptide mimetic, promotes oligodendrocyte myelination.

    Science.gov (United States)

    Wong, Agnes W; Giuffrida, Lauren; Wood, Rhiannon; Peckham, Haley; Gonsalvez, David; Murray, Simon S; Hughes, Richard A; Xiao, Junhua

    2014-11-01

    Brain-derived neurotrophic factor (BDNF) plays critical roles in the development and maintenance of the central (CNS) and peripheral nervous systems (PNS). BDNF exerts its biological effects via tropomyosin-related kinase B (TrkB) and the p75 neurotrophin receptor (p75NTR). We have recently identified that BDNF promotes CNS myelination via oligodendroglial TrkB receptors. In order to selectively target TrkB to promote CNS myelination, we have used a putative TrkB agonist, a small multicyclic peptide (tricyclic dimeric peptide 6, TDP6) previously described by us that structurally mimics a region of BDNF that binds TrkB. We confirmed that TDP6 acts as a TrkB agonist as it provoked autophosphorylation of TrkB and its downstream signalling effector extracellular related-kinase 1 and 2 (Erk1/2) in primary oligodendrocytes. Using an in vitro myelination assay, we show that TDP6 significantly promotes myelination by oligodendrocytes in vitro, as evidenced by enhanced myelin protein expression and an increased number of myelinated axonal segments. In contrast, a second, structurally distinct BDNF mimetic (cyclo-dPAKKR) that targets p75NTR had no effect upon oligodendrocyte myelination in vitro, despite the fact that cyclo-dPAKKR is a very effective promoter of peripheral (Schwann cell) myelination. The selectivity of TDP6 was further verified by using TrkB-deficient oligodendrocytes, in which TDP6 failed to promote myelination, indicating that the pro-myelinating effect of TDP6 is oligodendroglial TrkB-dependent. Together, our results demonstrate that TDP6 is a novel BDNF mimetic that promotes oligodendrocyte myelination in vitro via targeting TrkB.

  13. Metallokinetic analysis of disposition of vanadyl complexes as insulin-mimetics in rats using BCM-ESR method.

    Science.gov (United States)

    Yasui, H; Takechi, K; Sakurai, H

    2000-02-01

    Among vanadium's wide variety of biological functions, its insulin-mimetic effect is the most interesting and important. Recently, the vanadyl ion (+4 oxidation state of vanadium) and its complexes have been shown to normalize the blood glucose levels of streptozotocin-induced diabetic rats (STZ-rats). During our investigations to find more effective and less toxic vanadyl complexes, the vanadyl-methylpicolinate complex (VO-MPA) was found to exhibit higher insulin-mimetic activity and less toxicity than other complexes, as evaluated by both in vitro and in vivo experiments. Electron spin resonance (ESR) is capable of measuring the paramagnetic species in biological samples. We have developed the in vivo blood circulation monitoring-electron spin resonance (BCM-ESR) method to analyze the ESR signals due to stable organic radicals in real time. In the present investigation, we have applied this method to elucidate the relationship between the blood glucose normalizing effect of VO-MPA and the global disposition of paramagnetic vanadyl species. This paper describes the results of vanadyl species in the circulating blood of rats following intravenous administration of vanadyl compounds. ESR spectra due to the presence of vanadyl species were obtained in the circulating blood, and their pharmacokinetic parameters were estimated using compartment models. The results indicate that vanadyl species are distributed considerably to the peripheral tissues, as estimated by BCM-ESR, and eliminated from the body through the urine, as estimated by ESR at 77 K. The exposure of vanadyl species in the blood was found to be enhanced by VO-MPA treatment. Given these results, we concluded that the pharmacokinetic character of vanadyl species is closely related with the structure and antidiabetic activity of the vanadyl compounds.

  14. NiCoBP-doped carbon nanotube hybrid: A novel oxidase mimetic system for highly efficient electrochemical immunoassay

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Bing; He, Yu; Liu, Bingqian; Tang, Dianping, E-mail: dianping.tang@fzu.edu.cn

    2014-12-03

    Highlights: • We report a new oxidase mimetic system for highly efficient electrochemical immunoassay. • NiCoBP-doped carbon nanotube hybrids were used as the nanocatalysts. • NiCoBP-doped carbon nanotube hybrids were used as the mimic oxidase. - Abstract: NiCoBP-doped multi-walled carbon nanotube (NiCoBP–MWCNT) was first synthesized by using induced electroless-plating method and functionalized with the biomolecules for highly efficient electrochemical immunoassay of prostate-specific antigen (PSA, used as a model analyte). We discovered that the as-synthesized NiCoBP–MWCNT had the ability to catalyze the glucose oxidization with a stable and well-defined redox peak. The catalytic current increased with the increment of the immobilized NiCoBP–MWCNT on the electrode. Transmission electron microscope (TEM) and energy dispersive X-ray spectrometry (EDX) were employed to characterize the as-prepared NiCoBP–MWCNT. Using the NiCoBP–MWCNT-conjugated anti-PSA antibody as the signal-transduction tag, a new enzyme-free electrochemical immunoassay protocol could be designed for the detection of target PSA on the capture antibody-functionalized immunosensing interface. Experimental results revealed that the designed immunoassay system could exhibit good electrochemical responses toward target PSA, and allowed the detection of PSA at a concentration as low as 0.035 ng mL{sup −1}. More importantly, the NiCoBP-MWCNT-based oxidase mimetic system could be further extended for the monitoring of other low-abundance proteins or disease-related biomarkers by tuning the target antibody.

  15. A recombinant mimetics of the HIV-1 gp41 prehairpin fusion intermediate fused with human IgG Fc fragment elicits neutralizing antibody response in the vaccinated mice

    International Nuclear Information System (INIS)

    Qi, Zhi; Pan, Chungen; Lu, Hong; Shui, Yuan; Li, Lin; Li, Xiaojuan; Xu, Xueqing; Liu, Shuwen; Jiang, Shibo

    2010-01-01

    Research highlights: → One recombinant mimetics of gp41 prehairpin fusion intermediate (PFI) consisting of gp41 N46 sequence, foldon and IgG Fc, designated N46FdFc, was expressed. → N46FdFc-induced antibodies in mice that neutralized HIV-1 infection, inhibited PIE7 binding to PFI, blocked gp41 six-helix bundle formation, and suppressed HIV-1 mediated cell-cell fusion. → These findings provide an important clue for developing recombinant gp41 PFI mimetics-based HIV vaccines. -- Abstract: HIV-1 gp41 prehairpin fusion intermediate (PFI) composed of three N-terminal heptad repeats (NHR) plays a crucial role in viral fusion and entry and represents an attractive target for anti-HIV therapeutics (e.g., enfuvirtide) and vaccines. In present study, we constructed and expressed two recombinant gp41 PFI mimetics, designated N46Fd and N46FdFc. N46Fd consists of N46 (residues 536-581) in gp41 NHR and foldon (Fd), a trimerization motif. N46FdFc is composed of N46Fd fused with human IgG Fc fragment as an immunoenhancer. We immunized mice with N46 peptide, N46Fd and N46FdFc, respectively, and found that only N46FdFc elicited neutralizing antibody response in mice against infection by HIV-1 strains IIIB (clade B, X4), 92US657 (clade B, R5), and 94UG103 (clade A, X4R5). Anti-N46FdFc antibodies inhibited PIE7 binding to PFI, blocked gp41 six-helix bundle formation, and suppressed HIV-1 mediated cell-cell fusion. These findings provide an important clue for developing recombinant gp41 PFI mimetics-based HIV vaccines.

  16. The SMAC mimetic birinapant attenuates lipopolysaccharide-induced liver injury by inhibiting the tumor necrosis factor receptor-associated factor 3 degradation in Kupffer cells.

    Science.gov (United States)

    Liu, Hongxiang; Liao, Rui; He, Kun; Zhu, Xiwen; Li, Peizhi; Gong, Jianping

    2017-05-01

    It was demonstrated that second mitochondria-derived activator of caspases (SMAC) mimetic inhibites tumor necrosis factor receptor-associated factor 3 (TRAF3) degradation and the mitogen-activated protein kinase (MAPK) signaling pathway activation induced by lipopolysaccharide (LPS) in vitro. However, the effect of Smac mimetic in vivo is not clear. The present study was to investigate the role of Smac mimetic in LPS-induced liver injury in mice and its possible mechanism. An animal model of LPS-induced liver injury was established by intraperitoneally injecting mice with 10mg/kg LPS pretreatment with or without Smac mimetic birinapant (30mg/kg body weight). Birinapant significantly improved the survival rate of endotoxemic mice (P<0.05) and attenuated LPS-induced liver pathologic damage and inflammatory response. IL-1 and TNF-α levels in the serum were markedly decreased in birinapant pretreatment mice compared with control mice (P<0.05).The cellular inhibitor of apoptosis protein 1 (cIAP1) expression in liver resident macrophage (Kupffer cells, KCs) was significantly decreased in the Birinapant group compared to the Vehicle group (P<0.05). At the same time, total TRAF3 protein abundance in KCs rapidly declined after LPS stimulation in the Vehicle group. However, it remained constant in the Birinapant group. Moreover, K48-linked polyubiquitination of TRAF3 in KCs was markedly impressed in the birinapant group compared with the control group. At last, the JNK and p38 MAPK activation in KCs was significantly inhibited by birinapant pretreatment (P<0.05). These results suggested that birinapant attenuated liver injury and improved survival rates in endotoxemic mice by inhibited the expression of cIAP1, degradation of TRAF3 and aviation of MAPK signaling pathway. Copyright © 2017 European Federation of Immunological Societies. Published by Elsevier B.V. All rights reserved.

  17. Smac Mimetic-Induced Upregulation of CCL2/MCP-1 Triggers Migration and Invasion of Glioblastoma Cells and Influences the Tumor Microenvironment in a Paracrine Manner

    Directory of Open Access Journals (Sweden)

    Carina Lindemann

    2015-06-01

    Full Text Available Second mitochondria-derived activator of caspase (Smac mimetics are considered as promising anticancer therapeutics that are currently under investigation in early clinical trials. They induce apoptosis by antagonizing inhibitor of apoptosis proteins, which are frequently overexpressed in cancer. We previously reported that Smac mimetics, such as BV6, additionally exert non-apoptotic functions in glioblastoma (GBM cells by stimulating migration and invasion in a nuclear factor kappa B (NF-κB-dependent manner. Because NF-κB target genes mediating these effects are largely unknown, we performed whole-genome expression analyses. Here, we identify chemokine (C-C motif ligand 2 (CCL2 as the top-listed NF-κB-regulated gene being upregulated upon BV6 treatment in GBM cells. BV6-induced upregulation and secretion of CCL2 are required for migration and invasion of GBM cells because knockdown of CCL2 in GBM cells abolishes these effects. Co-culture experiments of GBM cells with non-malignant astroglial cells reveal that BV6-stimulated secretion of CCL2 by GBM cells into the supernatant triggers migration of astroglial cells toward GBM cells because CCL2 knockdown in BV6-treated GBM cells impedes BV6-stimulated migration of astroglial cells. In conclusion, we identify CCL2 as a BV6-induced NF-κB target gene that triggers migration and invasion of GBM cells and exerts paracrine effects on the GBM's microenvironment by stimulating migration of astroglial cells. These findings provide novel insights into the biological functions of Smac mimetics with important implications for the development of Smac mimetics as cancer therapeutics.

  18. A recombinant mimetics of the HIV-1 gp41 prehairpin fusion intermediate fused with human IgG Fc fragment elicits neutralizing antibody response in the vaccinated mice

    Energy Technology Data Exchange (ETDEWEB)

    Qi, Zhi; Pan, Chungen; Lu, Hong; Shui, Yuan [Lindsley F. Kimball Research Institute, New York Blood Center, New York, NY 10065 (United States); Li, Lin [Lindsley F. Kimball Research Institute, New York Blood Center, New York, NY 10065 (United States); School of Pharmaceutical Sciences, Southern Medical University, Guangzhou, Guangdong 510515 (China); Li, Xiaojuan; Xu, Xueqing; Liu, Shuwen [School of Pharmaceutical Sciences, Southern Medical University, Guangzhou, Guangdong 510515 (China); Jiang, Shibo, E-mail: sjiang@nybloodcenter.org [Lindsley F. Kimball Research Institute, New York Blood Center, New York, NY 10065 (United States); School of Pharmaceutical Sciences, Southern Medical University, Guangzhou, Guangdong 510515 (China)

    2010-07-30

    Research highlights: {yields} One recombinant mimetics of gp41 prehairpin fusion intermediate (PFI) consisting of gp41 N46 sequence, foldon and IgG Fc, designated N46FdFc, was expressed. {yields} N46FdFc-induced antibodies in mice that neutralized HIV-1 infection, inhibited PIE7 binding to PFI, blocked gp41 six-helix bundle formation, and suppressed HIV-1 mediated cell-cell fusion. {yields} These findings provide an important clue for developing recombinant gp41 PFI mimetics-based HIV vaccines. -- Abstract: HIV-1 gp41 prehairpin fusion intermediate (PFI) composed of three N-terminal heptad repeats (NHR) plays a crucial role in viral fusion and entry and represents an attractive target for anti-HIV therapeutics (e.g., enfuvirtide) and vaccines. In present study, we constructed and expressed two recombinant gp41 PFI mimetics, designated N46Fd and N46FdFc. N46Fd consists of N46 (residues 536-581) in gp41 NHR and foldon (Fd), a trimerization motif. N46FdFc is composed of N46Fd fused with human IgG Fc fragment as an immunoenhancer. We immunized mice with N46 peptide, N46Fd and N46FdFc, respectively, and found that only N46FdFc elicited neutralizing antibody response in mice against infection by HIV-1 strains IIIB (clade B, X4), 92US657 (clade B, R5), and 94UG103 (clade A, X4R5). Anti-N46FdFc antibodies inhibited PIE7 binding to PFI, blocked gp41 six-helix bundle formation, and suppressed HIV-1 mediated cell-cell fusion. These findings provide an important clue for developing recombinant gp41 PFI mimetics-based HIV vaccines.

  19. Chimeric design, synthesis, and biological assays of a new nonpeptide insulin-mimetic vanadium compound to inhibit protein tyrosine phosphatase 1B

    Directory of Open Access Journals (Sweden)

    Thomas Scior

    2010-09-01

    Full Text Available Thomas Scior1, José Antonio Guevara-García2, FJ Melendez2, Hassan H Abdallah3, Quoc-Tuan Do4, Philippe Bernard41Facultad de Ciencias Químicas, Universidad Autónoma de Puebla, Pue, Puebla, Mexico; 2Faculty of Basic Sciences, Technology and Engineering, Laboratory of Research in Bioinorganic and Bioremediation, Universidad Autónoma de Tlaxcala, Apizaco, Tlaxcala, México; 3School of Chemical Sciences, Universiti Sains Malaysia, Penang, Malaysia; 4GreenPharma S.A., 3 Allée du Titane, Orléans, FranceAbstract: Prior to its total synthesis, a new vanadium coordination compound, called TSAG0101, was computationally designed to inhibit the enzyme protein tyrosine phosphatase 1B (PTP1B. The PTP1B acts as a negative regulator of insulin signaling by blocking the active site where phosphate hydrolysis of the insulin receptor takes place. TSAG001, [VVO2(OH(picolinamide], was characterized by infrared (IR and nuclear magnetic resonance (NMR spectroscopy; IR: ν/cm-1 3,570 (NH, 1,627 (C=O, coordinated, 1,417 (C-N, 970/842 (O=V=O, 727 δ (pyridine ring; 13C NMR: 5 bands between 122 and 151 ppm and carbonyl C shifted to 180 ppm; and 1H NMR: 4 broad bands from 7.6 to 8.2 ppm and NH2 shifted to 8.8 ppm. In aqueous solution, in presence or absence of sodium citrate as a biologically relevant and ubiquitous chelator, TSAG0101 undergoes neither ligand exchange nor reduction of its central vanadium atom during 24 hours. TSAG0101 shows blood glucose lowering effects in rats but it produced no alteration of basal- or glucose-induced insulin secretion on β cells during in vitro tests, all of which excludes a direct mechanism evidencing the extrapancreatic nature of its activity. The lethal dose (LD50 of TSAG0101 was determined in Wistar mice yielding a value of 412 mg/Kg. This value is one of the highest among vanadium compounds and classifies it as a mild toxicity agent when compared with literature data. Due to its nonsubstituted, small-sized scaffold design

  20. Smac mimetic induces an early wave of gene expression via NF-κB and AP-1 and a second wave via TNFR1 signaling.

    Science.gov (United States)

    Schmidt, Nadine; Haydn, Tinka; Schneider, Ines; Busch, Hauke; Boerries, Melanie; Fulda, Simone

    2018-05-01

    Smac (second mitochondria-derived activator of caspases) mimetics are considered as promising cancer therapeutics, but little is yet known about how they alter gene expression. In this study, we used an unbiased genome-wide expression array to investigate gene regulation induced by the Smac mimetic BV6 in breast cancer cell lines. Here, we discover that tumor necrosis factor (TNF)α/TNF receptor 1 (TNFR1) auto-/paracrine signaling regulates Smac mimetic-stimulated changes in gene expression in a time-dependent manner. TNFR1-independent and -dependent genes account for two subsequent waves of BV6-induced gene expression. While the first wave mostly comprises TNFR1-independent genes and involves nuclear factor-kappa B (NF-κB) and activator protein (AP)-1 transcription factors, the second wave largely depends on TNFR1 signaling. Interestingly, disrupting auto-/paracrine TNFα/TNFR1 signaling by knockdown of TNFR1 strongly attenuates the BV6-induced second wave of gene expression and upregulation of many pathways, including NF-κB, apoptosis and immune signaling, while activation of mitogen-activated protein kinase (MAPK) signaling occurs also in TNFR1 knockdown cells. Thus, BV6 alters gene expression in a time- as well as TNFR1-dependent manner. Copyright © 2018 Elsevier B.V. All rights reserved.

  1. EPOR-Based Purification and Analysis of Erythropoietin Mimetic Peptides from Human Urine by Cys-Specific Cleavage and LC/MS/MS

    Science.gov (United States)

    Vogel, Matthias; Thomas, Andreas; Schänzer, Wilhelm; Thevis, Mario

    2015-09-01

    The development of a new class of erythropoietin mimetic agents (EMA) for treating anemic conditions has been initiated with the discovery of oligopeptides capable of dimerizing the erythropoietin (EPO) receptor and thus stimulating erythropoiesis. The most promising amino acid sequences have been mounted on various different polymeric structures or carrier molecules to obtain highly active EPO-like drugs exhibiting beneficial and desirable pharmacokinetic profiles. Concomitant with creating new therapeutic options, erythropoietin mimetic peptide (EMP)-based drug candidates represent means to artificially enhance endurance performance and necessitate coverage by sports drug testing methods. Therefore, the aim of the present study was to develop a strategy for the comprehensive detection of EMPs in doping controls, which can be used complementary to existing protocols. Three model EMPs were used to provide proof-of-concept data. Following EPO receptor-facilitated purification of target analytes from human urine, the common presence of the cysteine-flanked core structure of EMPs was exploited to generate diagnostic peptides with the aid of a nonenzymatic cleavage procedure. Sensitive detection was accomplished by targeted-SIM/data-dependent MS2 analysis. Method characterization was conducted for the EMP-based drug peginesatide concerning specificity, linearity, precision, recovery, stability, ion suppression/enhancement, and limit of detection (LOD, 0.25 ng/mL). Additionally, first data for the identification of the erythropoietin mimetic peptides EMP1 and BB68 were generated, demonstrating the multi-analyte testing capability of the presented approach.

  2. Phylogeny and evolution of Müllerian mimicry in aposematic Dilophotes: evidence for advergence and size-constraints in evolution of mimetic sexual dimorphism.

    Science.gov (United States)

    Motyka, Michal; Kampova, Lucie; Bocak, Ladislav

    2018-02-27

    Multiple patterns and intraspecific polymorphism should not persist in mutualistic Müllerian systems due to purifying and frequency-dependent selection, but they are commonly identified in nature. We analysed molecular phylogeny and reconstructed dispersal history of 58 species of Dilophotes (Coleoptera: Lycidae) in Asia. Dilophotes colonized the Great Sundas and Malay Peninsula where they joined extensive mimetic communities of net-winged beetles. We identified the brightly bi-coloured males and females which adverged on five occasions to different autochthonous models. This is the first described case of Müllerian sexual dimorphism based on sex-specific body size. We propose that the constraint, i.e. the conservative sexual size dimorphism, forced the unprofitable prey to such complex adaptation in a multi-pattern environment. Although mimetic sexual dimorphism has frequently evolved in Dilophotes, a single pattern has been maintained by both sexes in multiple closely related, sympatrically occurring species. Some patterns may be suboptimal because they are rare, crudely resemble co-mimics, or are newly evolved, but they persist in Müllerian communities for a long time. We assume that failure to closely resemble the most common model can increase the diversity of large Müllerian communities and produce mimetic dimorphism.

  3. Syntheses of vanadyl and zinc(II) complexes of 1-hydroxy-4,5,6-substituted 2(1H)-pyrimidinones and their insulin-mimetic activities.

    Science.gov (United States)

    Yamaguchi, Mika; Wakasugi, Kei; Saito, Ryota; Adachi, Yusuke; Yoshikawa, Yutaka; Sakurai, Hiromu; Katoh, Akira

    2006-02-01

    Control of the glucose level in the blood plasma has been achieved in vitro and in vivo by administration of vanadium and zinc in form of inorganic salts. It has been shown that elements are poorly absorbed in their inorganic forms and required high doses which have been associated with undesirable side effects. Many researchers, therefore, have focused on metal complexes that were prepared from VOSO(4) or ZnSO(4) and low-molecular-weight bidentate ligands. Seven kinds of 1-hydroxy-4,6-disubstituted and 1-hydroxy-4,5,6-trisubstituted-2(1H)-pyrimidinones were synthesized by reaction of N-benzyloxyurea and beta-diketones and subsequent removal of the protecting group. Six kinds of 1-hydroxy-4-(substituted)amino-2(1H)-pyrimidinones were synthesized by the substitution reaction of 1-benzyloxy-4-(1',2',4'-triazol-1'-yl)-2(1H)-pyrimidinone with various alkyl amines or amino acids. Treatment with VOSO(4) and ZnSO(4) or Zn(OAc)(2) afforded vanadyl(IV) and zinc(II) complexes which were characterized by means of (1)H NMR, IR, EPR, and UV-vis spectroscopies, and combustion analysis. The in vitro insulin-mimetic activity of these complexes was evaluated from 50% inhibitory concentrations (IC(50)) on free fatty acid (FFA) release from isolated rat adipocytes treated with epinephrine. Vanadyl complexes of 4,6-disubstituted-2(1H)-pyrimidinones showed higher insulin-mimetic activities than those of 4,5,6-trisubstituted ones. On the other hand, Zn(II) complexes showed lower insulin-mimetic activities than VOSO(4) and ZnSO(4) as positive controls. It was found that the balance of the hydrophilicity and/or hydrophobicity is important for higher insulin-mimetic activity. The in vivo insulin-mimetic activity was evaluated with streptozotocin (STZ)-induced diabetic rats. Blood glucose levels were lowered from hyperglycemic to normal levels after the treatment with bis(1,2-dihydro-4,6-dimethyl-2-oxo-1-pyrimidinolato)oxovanadium(IV) by daily intraperitoneal injections. The improvement in

  4. Synthesis of natural urolithin M6, a galloflavin mimetic, as a potential inhibitor of lactate dehydrogenase A.

    Science.gov (United States)

    Rupiani, Sebastiano; Guidotti, Laura; Manerba, Marcella; Di Ianni, Lorenza; Giacomini, Elisa; Falchi, Federico; Di Stefano, Giuseppina; Roberti, Marinella; Recanatini, Maurizio

    2016-11-22

    Glycolysis is the main route for energy production in tumors. LDH-A is a key enzyme of this process and its inhibition represents an attractive strategy to hamper cancer cell metabolism. Galloflavin is a reliable LDH-A inhibitor as previously identified by us; however, its poor physicochemical properties and chemical tractability render it unsuitable for further development. Therefore, a rational design was undertaken with the aim to reproduce the pharmacophore of galloflavin on simpler, potentially more soluble and synthetic accessible scaffolds. Following a process of structural simplification, natural urolithin M6 (UM6), which is an ellagitannin metabolite produced by gut microbiota, was identified as a putative galloflavin mimetic. In the present study, the synthesis of UM6 is described for the first time. An efficient synthetic pathway has been developed, which involved five steps from readily accessible starting materials. The key reaction steps, a Suzuki coupling and an intramolecular C-H oxygenation, have been optimized to improve the synthetic feasibility and provide the best conditions in terms of reaction time and yield. Moreover, this route would be suitable to obtain other analogs for SAR studies. Preliminary biological tests revealed that UM6 was able to smoothly reproduce the behavior of galloflavin, confirming that our approach was successful in providing a new and accessible structure in the search for new LDH-A inhibitors.

  5. Cell-specific discrimination of desmosterol and desmosterol mimetics confers selective regulation of LXR and SREBP in macrophages.

    Science.gov (United States)

    Muse, Evan D; Yu, Shan; Edillor, Chantle R; Tao, Jenhan; Spann, Nathanael J; Troutman, Ty D; Seidman, Jason S; Henke, Adam; Roland, Jason T; Ozeki, Katherine A; Thompson, Bonne M; McDonald, Jeffrey G; Bahadorani, John; Tsimikas, Sotirios; Grossman, Tamar R; Tremblay, Matthew S; Glass, Christopher K

    2018-04-09

    Activation of liver X receptors (LXRs) with synthetic agonists promotes reverse cholesterol transport and protects against atherosclerosis in mouse models. Most synthetic LXR agonists also cause marked hypertriglyceridemia by inducing the expression of sterol regulatory element-binding protein (SREBP)1c and downstream genes that drive fatty acid biosynthesis. Recent studies demonstrated that desmosterol, an intermediate in the cholesterol biosynthetic pathway that suppresses SREBP processing by binding to SCAP, also binds and activates LXRs and is the most abundant LXR ligand in macrophage foam cells. Here we explore the potential of increasing endogenous desmosterol production or mimicking its activity as a means of inducing LXR activity while simultaneously suppressing SREBP1c-induced hypertriglyceridemia. Unexpectedly, while desmosterol strongly activated LXR target genes and suppressed SREBP pathways in mouse and human macrophages, it had almost no activity in mouse or human hepatocytes in vitro. We further demonstrate that sterol-based selective modulators of LXRs have biochemical and transcriptional properties predicted of desmosterol mimetics and selectively regulate LXR function in macrophages in vitro and in vivo. These studies thereby reveal cell-specific discrimination of endogenous and synthetic regulators of LXRs and SREBPs, providing a molecular basis for dissociation of LXR functions in macrophages from those in the liver that lead to hypertriglyceridemia. Copyright © 2018 the Author(s). Published by PNAS.

  6. Selective activity against proliferating tumor endothelial cells by CVX-22, a thrombospondin-1 mimetic CovX-Body.

    Science.gov (United States)

    Coronella, Julia; Li, Lingna; Johnson, Kimberly; Pirie-Shepherd, Steven; Roxas, Giovanni; Levin, Nancy

    2009-06-01

    CVX-22 is a CovX-Body, produced by covalently attaching a thrombospondin-1 (TSP-1) type 1 repeat peptide mimetic to a humanized IgG1 molecule. To dissect the antiangiogenic mechanism of CVX-22, the numbers and proliferative status of defined tumor endothelial cell (TEC) subsets from the B16 and C32 melanoma models were examined. CVX-22 treatment reduced the numbers of activated, vascular endothelial growth factor receptor 2 (VEGFR2)-positive TECs. Because the vast majority of mitotically active TECs reside in the VEGFR2 subset, a reduction in numbers of this compartment resulted in an 82% overall decrease in BrdU labeling of TEC. However, the rate of proliferation and VEGFR2 receptor density of this VEGFR2-positive subpopulation were unaffected. Instead, CVX-22 induced endothelial cell apoptosis both in vitro and in vivo, indicating that CVX-22 acts by selective deletion of activated, VEGFR2-positive TEC. The overrepresentation of activated cells in sites of tumor angiogenesis may confer a unique specificity of CVX-22 for tumor vasculature.

  7. Development of a novel long-acting antidiabetic FGF21 mimetic by targeted conjugation to a scaffold antibody.

    Science.gov (United States)

    Huang, Jie; Ishino, Tetsuya; Chen, Gang; Rolzin, Paul; Osothprarop, Trina F; Retting, Kelsey; Li, Lingna; Jin, Ping; Matin, Marla J; Huyghe, Bernard; Talukdar, Saswata; Bradshaw, Curt W; Palanki, Moorthy; Violand, Bernard N; Woodnutt, Gary; Lappe, Rodney W; Ogilvie, Kathleen; Levin, Nancy

    2013-08-01

    Fibroblast growth factor (FGF)21 improves insulin sensitivity, reduces body weight, and reverses hepatic steatosis in preclinical species. We generated long-acting FGF21 mimetics by site-specific conjugation of the protein to a scaffold antibody. Linking FGF21 through the C terminus decreased bioactivity, whereas bioactivity was maintained by linkage to selected internal positions. In mice, these CovX-Bodies retain efficacy while increasing half-life up to 70-fold compared with wild-type FGF21. A preferred midlinked CovX-Body, CVX-343, demonstrated enhanced in vivo stability in preclinical species, and a single injection improved glucose tolerance for 6 days in ob/ob mice. In diet-induced obese mice, weekly doses of CVX-343 reduced body weight, blood glucose, and lipids levels. In db/db mice, CVX-343 increased glucose tolerance, pancreatic β-cell mass, and proliferation. CVX-343, created by linkage of the CovX scaffold antibody to the engineered residue A129C of FGF21 protein, demonstrated superior preclinical pharmacodynamics by extending serum half-life of FGF21 while preserving full therapeutic functionality.

  8. Inhibitors of Apoptosis Protein Antagonists (Smac Mimetic Compounds Control Polarization of Macrophages during Microbial Challenge and Sterile Inflammatory Responses

    Directory of Open Access Journals (Sweden)

    Vinod Nadella

    2018-01-01

    Full Text Available Apoptosis is a physiological cell death process essential for development, tissue homeostasis, and for immune defense of multicellular animals. Inhibitors of apoptosis proteins (IAPs regulate apoptosis in response to various cellular assaults. Using both genetic and pharmacological approaches we demonstrate here that the IAPs not only support opportunistic survival of intracellular human pathogens like Chlamydia pneumoniae but also control plasticity of iNOS+ M1 macrophage during the course of infection and render them refractory for immune stimulation. Treatment of Th1 primed macrophages with birinapant (IAP-specific antagonist inhibited NO generation and relevant proteins involved in innate immune signaling. Accordingly, birinapant promoted hypoxia, angiogenesis, and tumor-induced M2 polarization of iNOS+ M1 macrophages. Interestingly, birinapant-driven changes in immune signaling were accompanied with changes in the expression of various proteins involved in the metabolism, and thus revealing the new role of IAPs in immune metabolic reprogramming in committed macrophages. Taken together, our study reveals the significance of IAP targeting approaches (Smac mimetic compounds for the management of infectious and inflammatory diseases relying on macrophage plasticity.

  9. Measuring niacin-associated skin toxicity (NASTy) stigmata along with symptoms to aid development of niacin mimetics.

    Science.gov (United States)

    Dunbar, Richard L; Goel, Harsh; Tuteja, Sony; Song, Wen-Liang; Nathanson, Grace; Babar, Zeeshan; Lalic, Dusanka; Gelfand, Joel M; Rader, Daniel J; Grove, Gary L

    2017-04-01

    Though cardioprotective, niacin monotherapy is limited by unpleasant cutaneous symptoms mimicking dermatitis: niacin-associated skin toxicity (NASTy). Niacin is prototypical of several emerging drugs suffering off-target rubefacient properties whereby agonizing the GPR109A receptor on cutaneous immune cells provokes vasodilation, prompting skin plethora and rubor , as well as dolor , tumor , and calor , and systemically, heat loss, frigor , chills, and rigors. Typically, NASTy effects are described by subjective patient-reported perception, at best semi-quantitative and bias-prone. Conversely, objective, quantitative, and unbiased methods measuring NASTy stigmata would facilitate research to abolish them, motivating development of several objective methods. In early drug development, such methods might better predict clinical tolerability in larger clinical trials. Measuring cutaneous stigmata may also aid investigations of vasospastic, ischemic, and inflammatory skin conditions. We present methods to measure NASTy physical stigmata to facilitate research into novel niacin mimetics/analogs, detailing characteristics of each technique following niacin, and how NASTy stigmata relate to symptom perception. We gave niacin orally and measured rubor by colorimetry and white-light spectroscopy, plethora by laser Doppler flowmetry, and calor / frigor by thermometry. Surprisingly, each stigma's abruptness predicted symptom perception, whereas peak intensity did not. These methods are adaptable to study other rubefacient drugs or dermatologic and vascular disorders. Copyright © 2017 by the American Society for Biochemistry and Molecular Biology, Inc.

  10. Ochre Bathing of the Bearded Vulture: A Bio-Mimetic Model for Early Humans towards Smell Prevention and Health

    Directory of Open Access Journals (Sweden)

    Helmut Tributsch

    2016-01-01

    Full Text Available Since primordial times, vultures have been competing with man for animal carcasses. One of these vultures, the once widespread bearded vulture ( Gypaetus barbatus , has the habit of bathing its polluted feathers and skin in red iron oxide - ochre - tainted water puddles. Why? Primitive man may have tried to find out and may have discovered its advantages. Red ochre, which has accompanied human rituals and everyday life for more than 100,000 years, is not just a simple red paint for decoration or a symbol for blood. As modern experiments demonstrate, it is active in sunlight producing aggressive chemical species. They can kill viruses and bacteria and convert smelly organic substances into volatile neutral carbon dioxide gas. In this way, ochre can in sunlight sterilize and clean the skin to provide health and comfort and make it scentless, a definitive advantage for nomadic meat hunters. This research thus also demonstrates a sanitary reason for the vulture’s habit of bathing in red ochre mud. Prehistoric people have therefore included ochre use into their rituals, especially into those in relation to birth and death. Significant ritual impulses during evolution of man may thus have developed bio-mimetically, inspired from the habits of a vulture. It is discussed how this health strategy could be developed to a modern standard helping to fight antibiotics-resistant bacteria in hospitals.

  11. Maternal viral mimetic administration at the beginning of fetal hypothalamic nuclei development accelerates puberty in female rat offspring.

    Science.gov (United States)

    Cakan, Pınar; Yildiz, Sedat; Ozgocer, Tuba; Yildiz, Azibe; Vardi, Nigar

    2017-08-21

    This study aimed to investigate the effects of maternal viral infection during a critical time window of fetal hypothalamic development on timing of puberty in the female offspring. For that purpose, a viral mimetic (i.e. synthetic double strand RNA, namely, polyinosinic:polycytidylic acid, Poly (I:C)) or saline was injected (i.p.) to the pregnant rats during the beginning (day 12 of pregnancy, n=5 for each group) or at the end of this time window (day 14 of pregnancy, n=5 for each group). Four study groups were formed from the female pups (n=9 or 10 pups/group). Following weaning of pups, vaginal opening and vaginal smearing was studied daily until two sequential estrous cycles were observed. During the second diestrus phase, blood samples were taken for progesterone, leptin, corticosterone, follicle stimulating hormone (FSH) and luteinizing hormone (LH). Maternal poly (I:C) injection on day 12 of pregnancy increased body weight and reduced the time to puberty in the female offspring. Neither poly (I:C) nor timing of injection affected other parameters studied (p > 0.05). In conclusion, it has been shown for the first time that maternal viral infection during the beginning of fetal hypothalamic development might hasten puberty by increasing body weight in rat offspring.

  12. Sera from children with autism induce autistic features which can be rescued with a CNTF small peptide mimetic in rats.

    Science.gov (United States)

    Kazim, Syed Faraz; Cardenas-Aguayo, Maria Del Carmen; Arif, Mohammad; Blanchard, Julie; Fayyaz, Fatima; Grundke-Iqbal, Inge; Iqbal, Khalid

    2015-01-01

    Autism is a neurodevelopmental disorder characterized clinically by impairments in social interaction and verbal and non-verbal communication skills as well as restricted interests and repetitive behavior. It has been hypothesized that altered brain environment including an imbalance in neurotrophic support during early development contributes to the pathophysiology of autism. Here we report that sera from children with autism which exhibited abnormal levels of various neurotrophic factors induced cell death and oxidative stress in mouse primary cultured cortical neurons. The effects of sera from autistic children were rescued by pre-treatment with a ciliary neurotrophic factor (CNTF) small peptide mimetic, Peptide 6 (P6), which was previously shown to exert its neuroprotective effect by modulating CNTF/JAK/STAT pathway and LIF signaling and by enhancing brain derived neurotrophic factor (BDNF) expression. Similar neurotoxic effects and neuroinflammation were observed in young Wistar rats injected intracerebroventricularly with autism sera within hours after birth. The autism sera injected rats demonstrated developmental delay and deficits in social communication, interaction, and novelty. Both the neurobiological changes and the behavioral autistic phenotype were ameliorated by P6 treatment. These findings implicate the involvement of neurotrophic imbalance during early brain development in the pathophysiology of autism and a proof of principle of P6 as a potential therapeutic strategy for autism.

  13. Sera from children with autism induce autistic features which can be rescued with a CNTF small peptide mimetic in rats.

    Directory of Open Access Journals (Sweden)

    Syed Faraz Kazim

    Full Text Available Autism is a neurodevelopmental disorder characterized clinically by impairments in social interaction and verbal and non-verbal communication skills as well as restricted interests and repetitive behavior. It has been hypothesized that altered brain environment including an imbalance in neurotrophic support during early development contributes to the pathophysiology of autism. Here we report that sera from children with autism which exhibited abnormal levels of various neurotrophic factors induced cell death and oxidative stress in mouse primary cultured cortical neurons. The effects of sera from autistic children were rescued by pre-treatment with a ciliary neurotrophic factor (CNTF small peptide mimetic, Peptide 6 (P6, which was previously shown to exert its neuroprotective effect by modulating CNTF/JAK/STAT pathway and LIF signaling and by enhancing brain derived neurotrophic factor (BDNF expression. Similar neurotoxic effects and neuroinflammation were observed in young Wistar rats injected intracerebroventricularly with autism sera within hours after birth. The autism sera injected rats demonstrated developmental delay and deficits in social communication, interaction, and novelty. Both the neurobiological changes and the behavioral autistic phenotype were ameliorated by P6 treatment. These findings implicate the involvement of neurotrophic imbalance during early brain development in the pathophysiology of autism and a proof of principle of P6 as a potential therapeutic strategy for autism.

  14. In situ sequestration of endogenous PDGF-BB with an ECM-mimetic sponge for accelerated wound healing.

    Science.gov (United States)

    Li, Qiu; Niu, Yiming; Diao, Huajia; Wang, Lintao; Chen, Xiuping; Wang, Yitao; Dong, Lei; Wang, Chunming

    2017-12-01

    Recapitulating the typical features of extracellular matrix (ECM) in engineered biomaterials is crucial for preparing a suitable niche to activate endogenous tissue repair. Here, we report the design and evaluation of an ECM-mimetic scaffold that successfully accelerated wound healing through enriching endogenous platelet-derived growth factor-BB (PDGF-BB). Specifically, we prepared a electrospun hydrogel sponge (EGS) comprising a PDGF-BB-binding polysaccharide (EUP3) and gelatin. The two polymers in concert exerted a 'retention-and-release' function: upon the application of EGS in vivo, EUP3 started to bind and sequester endogenous PDGF-BB at the wound site; gradually, gelatin was degraded to free the PDGF-BB/EUP3 complex that acted on the cells in situ. Our serial in vitro and in vivo tests validated the efficacy of EGS in retaining PDGF-BB, releasing PDGF-BB/EUP3 in response to collagenase, and promoting various PDGF-BB-mediated regenerative activities. Particularly, EGS accelerated the repair of a full-thickness skin wound in mice and induced optimal neo-tissue formation, without the addition of any exogenous GFs, cells or genes. Collectively, our results suggest that, by mimicking the distinctive GF-affinitive feature of ECM, EGS as an engineered biomaterial can effectively harness the endogenous regenerative power of the native tissue. Our investigation may inspire the design of new, effective and safer approaches for tissue regeneration. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Molecular phylogenetic evidence for a mimetic radiation in Peruvian poison frogs supports a Müllerian mimicry hypothesis.

    Science.gov (United States)

    Symula, R; Schulte, R; Summers, K

    2001-12-07

    Examples of Müllerian mimicry, in which resemblance between unpalatable species confers mutual benefit, are rare in vertebrates. Strong comparative evidence for mimicry is found when the colour and pattern of a single species closely resemble several different model species simultaneously in different geographical regions. Todemonstrate this, it is necessary to provide compelling evidence that the putative mimics do, in fact, form a monophyletic group. We present molecular phylogenetic evidence that the poison frog Dendrobates imitator mimics three different poison frogs in different geographical regions in Peru. DNA sequences from four different mitochondrial gene regions in putative members of a single species are analysed using parsimony, maximum-likelihood and neighbour-joining methods. The resulting hypotheses of phylogenetic relationships demonstrate that the different populations of D.imitator form a monophyletic group. To our knowledge, these results provide the first evidence for a Müllerian mimetic radiation in amphibians in which a single species mimics different sympatric species in different geographical regions.

  16. A synthetic superoxide dismutase/catalase mimetic EUK-207 mitigates radiation dermatitis and promotes wound healing in irradiated rat skin.

    Science.gov (United States)

    Doctrow, Susan R; Lopez, Argelia; Schock, Ashley M; Duncan, Nathan E; Jourdan, Megan M; Olasz, Edit B; Moulder, John E; Fish, Brian L; Mäder, Marylou; Lazar, Jozef; Lazarova, Zelmira

    2013-04-01

    In the event of a radionuclear attack or nuclear accident, the skin would be the first barrier exposed to radiation, though skin injury can progress over days to years following exposure. Chronic oxidative stress has been implicated as being a potential contributor to the progression of delayed radiation-induced injury to skin and other organs. To examine the causative role of oxidative stress in delayed radiation-induced skin injury, including impaired wound healing, we tested a synthetic superoxide dismutase (SOD)/catalase mimetic, EUK-207, in a rat model of combined skin irradiation and wound injury. Administered systemically, beginning 48 hours after irradiation, EUK-207 mitigated radiation dermatitis, suppressed indicators of tissue oxidative stress, and enhanced wound healing. Evaluation of gene expression in irradiated skin at 30 days after exposure revealed a significant upregulation of several key genes involved in detoxication of reactive oxygen and nitrogen species. This gene expression pattern was primarily reversed by EUK-207 therapy. These results demonstrate that oxidative stress has a critical role in the progression of radiation-induced skin injury, and that the injury can be mitigated by appropriate antioxidant compounds administered 48 hours after exposure.

  17. Structural basis of activation-dependent binding of ligand-mimetic antibody AL-57 to integrin LFA-1

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Hongmin; Liu, Jin-huan; Yang, Wei; Springer, Timothy; Shimaoka, Motomu; Wang, Jia-huai; (CH-Boston); (DFCI)

    2010-09-21

    The activity of integrin LFA-1 ({alpha}{sub L}{beta}{sub 2}) to its ligand ICAM-1 is regulated through the conformational changes of its ligand-binding domain, the I domain of {alpha}{sub L} chain, from an inactive, low-affinity closed form (LA), to an intermediate-affinity form (IA), and then finally, to a high-affinity open form (HA). A ligand-mimetic human monoclonal antibody AL-57 (activated LFA-1 clone 57) was identified by phage display to specifically recognize the affinity-upregulated I domain. Here, we describe the crystal structures of the Fab fragment of AL-57 in complex with IA, as well as in its unligated form. We discuss the structural features conferring AL-57's strong selectivity for the high affinity, open conformation of the I domain. The AL-57-binding site overlaps the ICAM-1 binding site on the I domain. Furthermore, an antibody Asp mimics an ICAM Glu by forming a coordination to the metal-ion dependent adhesion site (MIDAS). The structure also reveals better shape complementarity and a more hydrophobic interacting interface in AL-57 binding than in ICAM-1 binding. The results explain AL-57's antagonistic mimicry of LFA-1's natural ligands, the ICAM molecules.

  18. Improvement of the antihypertensive capacity of candesartan and trityl candesartan by their SOD mimetic copper(II) complexes.

    Science.gov (United States)

    Islas, María S; Rojo, Teófilo; Lezama, Luis; Merino, Mercedes Griera; Cortes, María A; Puyol, Manuel Rodriguez; Ferrer, Evelina G; Williams, Patricia A M

    2013-06-01

    Two new complexes [Cu(Cand)(H2O)4] [1] and [Cu2(TCand)4(H2O)2]·4H2O [2] (Cand = candesartan; TCand = trityl candesartan) have been synthesized and thoroughly characterized. The FTIR, Raman, EPR and diffuse reflectance spectra of the solid compounds show a dimeric complex for [2] with carboxylate bridging of the type found in copper(II) acetate. Both elemental analysis and thermal measurements allow the determination of the total stoichiometries of both complexes. The stability measurements show that the compounds are stable in ethanolic solutions at least for 1h, while the preservation of the overall stochiometry for both species in solution has been determined by spectrophotometric titrations. By metal complexation the absence of antioxidant behavior of both sartans has been improved. Complexes [1] and [2] are strong superoxidedismutase mimetic compounds and complex [2] also behaves as a peroxyl radical scavenger. Furthermore, this higher antioxidant activity works in parallel with the improvement of the expansive activity over the angiotensin II-induced contracted human mesangial cells. These new complexes exhibit even higher efficiency as drugs in comparison with the free non-complexed medication with increased antioxidant ability expressing higher capacity to block the angiotensin II contractile effect. This study provides a new insight into the development of copper(II) complexes as potential drugs. Copyright © 2013 Elsevier Inc. All rights reserved.

  19. CXCR4 Protein Epitope Mimetic Antagonist POL5551 Disrupts Metastasis and Enhances Chemotherapy Effect in Triple-Negative Breast Cancer.

    Science.gov (United States)

    Xiang, Jingyu; Hurchla, Michelle A; Fontana, Francesca; Su, Xinming; Amend, Sarah R; Esser, Alison K; Douglas, Garry J; Mudalagiriyappa, Chidananda; Luker, Kathryn E; Pluard, Timothy; Ademuyiwa, Foluso O; Romagnoli, Barbara; Tuffin, Gérald; Chevalier, Eric; Luker, Gary D; Bauer, Michael; Zimmermann, Johann; Aft, Rebecca L; Dembowsky, Klaus; Weilbaecher, Katherine N

    2015-11-01

    The SDF-1 receptor CXCR4 has been associated with early metastasis and poorer prognosis in breast cancers, especially the most aggressive triple-negative subtype. In line with previous reports, we found that tumoral CXCR4 expression in patients with locally advanced breast cancer was associated with increased metastases and rapid tumor progression. Moreover, high CXCR4 expression identified a group of bone marrow-disseminated tumor cells (DTC)-negative patients at high risk for metastasis and death. The protein epitope mimetic (PEM) POL5551, a novel CXCR4 antagonist, inhibited binding of SDF-1 to CXCR4, had no direct effects on tumor cell viability, but reduced migration of breast cancer cells in vitro. In two orthotopic models of triple-negative breast cancer, POL5551 had little inhibitory effect on primary tumor growth, but significantly reduced distant metastasis. When combined with eribulin, a chemotherapeutic microtubule inhibitor, POL5551 additively reduced metastasis and prolonged survival in mice after resection of the primary tumor compared with single-agent eribulin. Hypothesizing that POL5551 may mobilize tumor cells from their microenvironment and sensitize them to chemotherapy, we used a "chemotherapy framing" dosing strategy. When administered shortly before and after eribulin treatment, three doses of POL5551 with eribulin reduced bone and liver tumor burden more effectively than chemotherapy alone. These data suggest that sequenced administration of CXCR4 antagonists with cytotoxic chemotherapy synergize to reduce distant metastases. ©2015 American Association for Cancer Research.

  20. Superoxide dismutase mimetic, tempol, aggravates renal injury in advanced-stage stroke-prone spontaneously hypertensive rats.

    Science.gov (United States)

    Sugama, Ikuko; Kohagura, Kentaro; Yamazato, Masanobu; Nakamura, Takuto; Shinzato, Tomoko; Ohya, Yusuke

    2014-03-01

    The aim of this study was to determine whether antioxidant therapy could relieve hypertension and retard the progression of renal damage in advanced-stage hypertensive rats. Twenty-four-week-old spontaneously hypertensive stroke-prone rats were treated for 8 weeks with the superoxide dismutase mimetic tempol, low-dose or high-dose candesartan (an angiotensin receptor blocker), or hydralazine, and blood pressure and renal damage were compared. Elevated blood pressure and renal damage with heterogeneity were present after 8 weeks, with greater glomerulosclerosis in the juxtamedullary glomeruli than in the superficial glomeruli. Although both tempol and candesartan effectively reduced reactive oxygen species production in the kidney, tempol did not decrease blood pressure and exacerbated urine protein and histological damage, such as glomerulosclerosis and interstitial fibrosis, particularly in juxtamedullary nephrons (tempol vs. untreated: glomerulosclerosis index, 2.0 vs. 1.5, Ptempol-treated rats, suggesting that changes in glomerular hemodynamics may be responsible for the exacerbation of glomerulosclerosis. Both candesartan- and hydralazine-treated rats had glomeruli that were slightly decreased in size. These results suggest that single-antioxidant therapy starting at an advanced-stage may be ineffective for hypertension and rather exacerbate renal damage in nonsalt loaded SHRSP. Furthermore, lowering blood pressure and inhibiting the renin-angiotensin system could be critical for slowing the progression of hypertensive renal damage at an advanced stage.

  1. Furoxans (1,2,5-Oxadiazole-N-Oxides) as Novel NO Mimetic Neuroprotective and Procognitive Agents

    Energy Technology Data Exchange (ETDEWEB)

    Schiefer, Isaac T.; VandeVrede, Lawren; Fa; , Mauro; Arancio, Ottavio; Thatcher, Gregory R.J. (Columbia); (UIC)

    2012-08-31

    Furoxans (1,2,5-oxadiazole-N-oxides) are thiol-bioactivated NO-mimetics that have not hitherto been studied in the CNS. Incorporation of varied substituents adjacent to the furoxan ring system led to modulation of reactivity toward bioactivation, studied by HPLC-MS/MS analysis of reaction products. Attenuated reactivity unmasked the cytoprotective actions of NO in contrast to the cytotoxic actions of higher NO fluxes reported previously for furoxans. Neuroprotection was observed in primary neuronal cell cultures following oxygen glucose deprivation (OGD). Neuroprotective activity was observed to correlate with thiol-dependent bioactivation to produce NO{sub 2}{sup -}, but not with depletion of free thiol itself. Neuroprotection was abrogated upon cotreatment with a sGC inhibitor, ODQ, thus supporting activation of the NO/sGC/CREB signaling cascade by furoxans. Long-term potentiation (LTP), essential for learning and memory, has been shown to be potentiated by NO signaling, therefore, a peptidomimetic furoxan was tested in hippocampal slices treated with oligomeric amyloid-{beta} peptide (A{beta}) and was shown to restore synaptic function. The novel observation of furoxan activity of potential therapeutic use in the CNS warrants further studies.

  2. Rational Structure-Based Rescaffolding Approach to De Novo Design of Interleukin 10 (IL-10 Receptor-1 Mimetics.

    Directory of Open Access Journals (Sweden)

    Gloria Ruiz-Gómez

    Full Text Available Tackling protein interfaces with small molecules capable of modulating protein-protein interactions remains a challenge in structure-based ligand design. Particularly arduous are cases in which the epitopes involved in molecular recognition have a non-structured and discontinuous nature. Here, the basic strategy of translating continuous binding epitopes into mimetic scaffolds cannot be applied, and other innovative approaches are therefore required. We present a structure-based rational approach involving the use of a regular expression syntax inspired in the well established PROSITE to define minimal descriptors of geometric and functional constraints signifying relevant functionalities for recognition in protein interfaces of non-continuous and unstructured nature. These descriptors feed a search engine that explores the currently available three-dimensional chemical space of the Protein Data Bank (PDB in order to identify in a straightforward manner regular architectures containing the desired functionalities, which could be used as templates to guide the rational design of small natural-like scaffolds mimicking the targeted recognition site. The application of this rescaffolding strategy to the discovery of natural scaffolds incorporating a selection of functionalities of interleukin-10 receptor-1 (IL-10R1, which are relevant for its interaction with interleukin-10 (IL-10 has resulted in the de novo design of a new class of potent IL-10 peptidomimetic ligands.

  3. Fabrics produced mimetically during static metamorphism in retrogressed eclogites from the Zermatt-Saas zone, Western Italian Alps

    Science.gov (United States)

    McNamara, D. D.; Wheeler, J.; Pearce, M.; Prior, D. J.

    2012-11-01

    Lattice preferred orientations (LPOs) are commonly interpreted to form by dislocation creep. Consequently they are used to infer deformation at the metamorphic grade at which the minerals were stable, especially if those minerals show a shape fabric. Here we show that LPOs can occur through mimicry of a pre-existing LPO, so they formed statically, not during deformation. Omphacite and glaucophane LPOs occur in eclogite facies rocks from the Zermatt-Saas Unit of the Northwest Italian Alps. Barroisite grew during greenschist facies retrogression and has an LPO controlled significantly by the eclogite facies omphacite and glaucophane LPOs, rather than directly by deformation. Using spatially resolved lattice orientation data from the three key minerals, collected using electron backscatter diffraction, we deploy a new technique of interphase misorientation distribution analysis to prove this. Barroisite LPO develops by mimicry of omphacite (via a particular lattice orientation relationship) and by direct topotactic and epitactic replacement of glaucophane. LPO in turn influenced anisotropic grain growth, resulting in a barroisite grain shape fabric. Thus regional retrogression during exhumation of the Zermatt-Saas high-pressure rocks was, in large part, static, rather than dynamic as previously interpreted. In general the possibility of mimetic fabrics forming during metamorphic reactions must be borne in mind when interpreting direct structural observations and seismic anisotropy data in terms of deformation, in both crust and mantle.

  4. Mechanism of the G-protein mimetic nanobody binding to a muscarinic G-protein-coupled receptor.

    Science.gov (United States)

    Miao, Yinglong; McCammon, J Andrew

    2018-03-20

    Protein-protein binding is key in cellular signaling processes. Molecular dynamics (MD) simulations of protein-protein binding, however, are challenging due to limited timescales. In particular, binding of the medically important G-protein-coupled receptors (GPCRs) with intracellular signaling proteins has not been simulated with MD to date. Here, we report a successful simulation of the binding of a G-protein mimetic nanobody to the M 2 muscarinic GPCR using the robust Gaussian accelerated MD (GaMD) method. Through long-timescale GaMD simulations over 4,500 ns, the nanobody was observed to bind the receptor intracellular G-protein-coupling site, with a minimum rmsd of 2.48 Å in the nanobody core domain compared with the X-ray structure. Binding of the nanobody allosterically closed the orthosteric ligand-binding pocket, being consistent with the recent experimental finding. In the absence of nanobody binding, the receptor orthosteric pocket sampled open and fully open conformations. The GaMD simulations revealed two low-energy intermediate states during nanobody binding to the M 2 receptor. The flexible receptor intracellular loops contribute remarkable electrostatic, polar, and hydrophobic residue interactions in recognition and binding of the nanobody. These simulations provided important insights into the mechanism of GPCR-nanobody binding and demonstrated the applicability of GaMD in modeling dynamic protein-protein interactions.

  5. Egg white hydrolysate shows insulin mimetic and sensitizing effects in 3T3-F442A pre-adipocytes.

    Directory of Open Access Journals (Sweden)

    Forough Jahandideh

    Full Text Available Insulin resistance and inflammation in adipose tissue is a key mechanism underlying metabolic syndrome, a growing health problem characterized by diabetes, obesity and hypertension. Previous work from our research group has demonstrated the potential of egg white ovotransferrin derived bioactive peptides against hypertension, oxidative stress and inflammation in vitro and in vivo. Egg white hydrolysate (EWH has also shown anti-hypertensive effects in spontaneously hypertensive rats. Given the interplay among hypertension, inflammation, oxidative stress and metabolic syndrome, the objective of the study was to test the EWH on differentiation, insulin signaling and inflammatory responses in 3T3-F442A pre-adipocytes. Our study suggested that EWH could promote adipocyte differentiation as shown by increased lipid accumulation, increased release of adiponectin and upregulation of peroxisome proliferator associated receptor gamma (PPARγ and CCAAT/ enhancer binding protein alpha (C/EBP-α. In addition to enhanced insulin effects on the upregulation of protein kinase B/Akt phosphorylation, EWH treatment increased extracellular signal regulated kinase 1/2 (ERK1/2 phosphorylation to a level similar to that of insulin, indicating insulin sensitizing and mimetic properties of the EWH. EWH further attenuated cytokine induced inflammatory marker; cyclooxygenase -2 (COX-2 by 48.78%, possibly through the AP-1 pathway by down regulating c-Jun phosphorylation in adipocytes. Given the critical role of adipose in the pathogenesis of insulin resistance and metabolic syndrome, EWH may have potential applications in the prevention and management of metabolic syndrome and its complications.

  6. Superoxide dismutase/catalase mimetic EUK-134 prevents diaphragm muscle weakness in monocrotalin-induced pulmonary hypertension.

    Science.gov (United States)

    Himori, Koichi; Abe, Masami; Tatebayashi, Daisuke; Lee, Jaesik; Westerblad, Håkan; Lanner, Johanna T; Yamada, Takashi

    2017-01-01

    Patients with pulmonary hypertension (PH) suffer from inspiratory insufficiency, which has been associated with intrinsic contractile dysfunction in diaphragm muscle. Here, we examined the role of redox stress in PH-induced diaphragm weakness by using the novel antioxidant, EUK-134. Male Wistar rats were randomly divided into control (CNT), CNT + EUK-134 (CNT + EUK), monocrotaline-induced PH (PH), and PH + EUK groups. PH was induced by a single intraperitoneal injection of monocrotaline (60 mg/kg body weight). EUK-134 (3 mg/kg body weight/day), a cell permeable mimetic of superoxide dismutase (SOD) and catalase, was daily intraperitoneally administered starting one day after induction of PH. After four weeks, diaphragm muscles were excised for mechanical and biochemical analyses. There was a decrease in specific tetanic force in diaphragm bundles from the PH group, which was accompanied by increases in: protein expression of NADPH oxidase 2/gp91phox, SOD2, and catalase; 3-nitrotyrosine content and aggregation of actin; glutathione oxidation. Treatment with EUK-134 prevented the force decrease and the actin modifications in PH diaphragm bundles. These data show that redox stress plays a pivotal role in PH-induced diaphragm weakness. Thus, antioxidant treatment can be a promising strategy for PH patients with inspiratory failure.

  7. Functional enhancement of neuronal cell behaviors and differentiation by elastin-mimetic recombinant protein presenting Arg-Gly-Asp peptides

    Directory of Open Access Journals (Sweden)

    Jeon Won

    2012-09-01

    Full Text Available Abstract Background Integrin-mediated interaction of neuronal cells with extracellular matrix (ECM is important for the control of cell adhesion, morphology, motility, and differentiation in both in vitro and in vivo systems. Arg-Gly-Asp (RGD sequence is one of the most potent integrin-binding ligand found in many native ECM proteins. An elastin-mimetic recombinant protein, TGPG[VGRGD(VGVPG6]20WPC, referred to as [RGD-V6]20, contains multiple RGD motifs to bind cell-surface integrins. This study aimed to investigate how surface-adsorbed recombinant protein can be used to modulate the behaviors and differentiation of neuronal cells in vitro. For this purpose, biomimetic ECM surfaces were prepared by isothermal adsorption of [RGD-V6]20 onto the tissue culture polystyrene (TCPS, and the effects of protein-coated surfaces on neuronal cell adhesion, spreading, migration, and differentiation were quantitatively measured using N2a neuroblastoma cells. Results The [RGD-V6]20 was expressed in E. coli and purified by thermally-induced phase transition. N2a cell attachment to either [RGD-V6]20 or fibronectin followed hyperbolic binding kinetics saturating around 2 μM protein concentration. The apparent maximum cell binding to [RGD-V6]20 was approximately 96% of fibronectin, with half-maximal adhesion on [RGD-V6]20 and fibronectin occurring at a coating concentration of 2.4 × 10-7 and 1.4 × 10-7 M, respectively. The percentage of spreading cells was in the following order of proteins: fibronectin (84.3% ± 6.9% > [RGD-V6]20 (42.9% ± 6.5% > [V7]20 (15.5% ± 3.2% > TCPS (less than 10%. The migration speed of N2a cells on [RGD-V6]20 was similar to that of cells on fibronectin. The expression of neuronal marker proteins Tuj1, MAP2, and GFAP was approximately 1.5-fold up-regulated by [RGD-V6]20 relative to TCPS. Moreover, by the presence of both [RGD-V6]20 and RA, the expression levels of NSE, TuJ1, NF68, MAP2, and GFAP

  8. SELF AND THE OTHER: MIMETIC DESIRE AND VIOLENCE IN STEPHEN CRANE’S “MAGGIE: A GIRL OF THE STREETS” AND D. H. LAWRENCE’S “THE PRUSSIAN OFFICER”

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    JOSÉ SANTOS

    2005-01-01

    Full Text Available This essay examines Stephen Crane’s novella Maggie: A Girl of the Streets and D. H. Lawrence’s short story “The Prussian Officer”, in light of Rene Girard’s notion of mimetic desire. Girard argues that at the heart of interpersonal relationships is the desire for that which makes the Other being. In possession of this being, the Other becomes at first the model the subject reveres, and later,the rival the subject detests. For Girard, this is what stands at the heart of violence and disharmony in human societies. Violence or ritual sacrifice become the mechanisms capable of halting mimetic desire and bring back social order. In the two narratives analyzed, mimetic desire stands at the center of the protagonists’ existential crises and violent deaths.

  9. High-resolution NMR characterization of a spider-silk mimetic composed of 15 tandem repeats and a CRGD motif.

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    McLachlan, Glendon D; Slocik, Joseph; Mantz, Robert; Kaplan, David; Cahill, Sean; Girvin, Mark; Greenbaum, Steve

    2009-01-01

    Multidimensional solution NMR spectroscopic techniques have been used to obtain atomic level information about a recombinant spider silk construct in hexafluoro-isopropanol (HFIP). The synthetic 49 kDa silk-like protein mimics authentic silk from Nephila clavipes, with the inclusion of an extracellular matrix recognition motif. 2D (1)H-(15)N HSQC NMR spectroscopy reveals 33 cross peaks, which were assigned to amino acid residues in the semicrystalline repeat units. Signals from the amorphous segments in the primary sequence were weak and broad, suggesting that this region is highly dynamic and undergoing conformational exchange. An analysis of the deviations of the (13)C(alpha), (13)C(beta), and (13)CO chemical shifts relative to the expected random coil values reveals two highly alpha-helical regions from amino acid 12-19 and 26-32, which comprise the polyalanine track and a GGLGSQ sequence. This finding is further supported by phi-value analysis and sequential and medium-range NOE interactions. Pulsed field gradient NMR measurements indicate that the topology of the silk mimetic in HFIP is nonglobular. Moreover, the 3D (15)N-NOESY HSQC spectrum exhibits few long-range NOEs. Similar spectral features have been observed for repeat modules in other polypeptides and are characteristic of an elongated conformation. The results provide a residue-specific description of a silk sequence in nonaqueous solution and may be insightful for understanding the fold and topology of highly concentrated, stable silk before spinning. Additionally, the insights obtained may find application in future design and large-scale production and storage of synthetic silks in organic solvents.

  10. Differential effect triggered by a heparan mimetic of the RGTA family preventing oral mucositis without tumor protection.

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    Mangoni, Monica; Yue, Xiaoli; Morin, Christophe; Violot, Dominique; Frascogna, Valerie; Tao, Yungan; Opolon, Paule; Castaing, Marine; Auperin, Anne; Biti, Giampaolo; Barritault, Denis; Vozenin-Brotons, Marie-Catherine; Deutsch, Eric; Bourhis, Jean

    2009-07-15

    Oral mucositis is a common side effect induced by radio/chemotherapy in patients with head and neck cancer. Although it dramatically impairs patient quality of life, no efficient and safe therapeutic solution is available today. Therefore, we investigated the protective efficacy of a new heparan mimetic biopolymer, RGTA-OTR4131, used alone or in combination with amifostine, for oral mucositis and simultaneously evaluated its effect on tumor growth in vitro and in vivo. A single dose of 16.5 Gy was selectively delivered to the snout of mice, and the effects of OTR4131 or amifostine-OTR4131 were analyzed by macroscopic scoring and histology. The effect of OTR4131 administration on tumor growth was then investigated in vitro and in xenograft models using two cell lines (HEP-2 and HT-29). Amifostine and OTR4131 significantly decreased the severity and duration of lip mucosal reactions. However, amifostine has to be administered before irradiation, whereas the most impressive protection was obtained when OTR4131 was injected 24 h after irradiation. In addition, OTR4131 was well tolerated, and the combination of amifostine and OTR4131 further enhanced mucosal protection. At the tumor level, OTR4131 did not modify HEP-2 cell line clonogenic survival in vitro or protect xenografted tumor cells from radiotherapy. Of interest, high doses of OTR4131 significantly decreased clonogenic survival of HT-29 cells. RGTAs-OTR4131 is a well-tolerated, natural agent that effectively reduces radio-induced mucositis without affecting tumor sensitivity to irradiation. This suggests a possible transfer into the clinic for patients' benefit.

  11. Anti-tumor activity of a novel HS-mimetic-vascular endothelial growth factor binding small molecule.

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    Kazuyuki Sugahara

    Full Text Available The angiogenic process is controlled by variety of factors of which the vascular endothelial growth factor (VEGF pathway plays a major role. A series of heparan sulfate mimetic small molecules targeting VEGF/VEGFR pathway has been synthesized. Among them, compound 8 (2-butyl-5-chloro-3-(4-nitro-benzyl-3H-imidazole-4-carbaldehyde was identified as a significant binding molecule for the heparin-binding domain of VEGF, determined by high-throughput-surface plasmon resonance assay. The data predicted strong binding of compound 8 with VEGF which may prevent the binding of VEGF to its receptor. We compared the structure of compound 8 with heparan sulfate (HS, which have in common the functional ionic groups such as sulfate, nitro and carbaldehyde that can be located in similar positions of the disaccharide structure of HS. Molecular docking studies predicted that compound 8 binds at the heparin binding domain of VEGF through strong hydrogen bonding with Lys-30 and Gln-20 amino acid residues, and consistent with the prediction, compound 8 inhibited binding of VEGF to immobilized heparin. In vitro studies showed that compound 8 inhibits the VEGF-induced proliferation migration and tube formation of mouse vascular endothelial cells, and finally the invasion of a murine osteosarcoma cell line (LM8G7 which secrets high levels of VEGF. In vivo, these effects produce significant decrease of tumor burden in an experimental model of liver metastasis. Collectively, these data indicate that compound 8 may prevent tumor growth through a direct effect on tumor cell proliferation and by inhibition of endothelial cell migration and angiogenesis mediated by VEGF. In conclusion, compound 8 may normalize the tumor vasculature and microenvironment in tumors probably by inhibiting the binding of VEGF to its receptor.

  12. Fisetin as a caloric restriction mimetic protects rat brain against aging induced oxidative stress, apoptosis and neurodegeneration.

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    Singh, Sandeep; Singh, Abhishek Kumar; Garg, Geetika; Rizvi, Syed Ibrahim

    2018-01-15

    In the present study, attempts have been made to evaluate the potential role of fisetin, a caloric restriction mimetic (CRM), for neuroprotection in D-galactose (D-gal) induced accelerated and natural aging models of rat. Fisetin was supplemented (15mg/kg b.w., orally) to young, D-gal induced aged (D-gal 500mg/kg b.w subcutaneously) and naturally aged rats for 6weeks. Standard protocols were employed to measure pro-oxidants, antioxidants and mitochondrial membrane potential in brain tissues. Gene expression analysis with reverse transcriptase-polymerase chain reaction (RT-PCR) was performed to assess the expression of autophagy, neuronal, aging as well as inflammatory marker genes. We have also evaluated apoptotic cell death and synaptosomal membrane-bound ion transporter activities in brain tissues. Our data demonstrated that fisetin significantly decreased the level of pro-oxidants and increased the level of antioxidants. Furthermore, fisetin also ameliorated mitochondrial membrane depolarization, apoptotic cell death and impairments in the activities of synaptosomal membrane-bound ion transporters in aging rat brain. RT-PCR data revealed that fisetin up-regulated the expression of autophagy genes (Atg-3 and Beclin-1), sirtuin-1 and neuronal markers (NSE and Ngb), and down-regulated the expression of inflammatory (IL-1β and TNF-α) and Sirt-2 genes respectively in aging brain. The present study suggests that fisetin supplementation may provide neuroprotection against aging-induced oxidative stress, apoptotic cell death, neuro-inflammation, and neurodegeneration in rat brain. Copyright © 2017 Elsevier Inc. All rights reserved.

  13. The Aryl Hydrocarbon Receptor Nuclear Translocator (ARNT/HIF-1β is Influenced by Hypoxia and Hypoxia-Mimetics

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    Matthias Wolff

    2013-09-01

    Full Text Available Background: The Aryl Hydrocarbon Receptor Nuclear Translocator (ARNT, HIF-1β is a member of the basic-Helix-Loop-Helix PER/ARNT/SIM (bHLH/PAS protein family and a vital transcriptional regulator regarding development and physiological adaptation processes. ARNT is discussed to be linked with cancer, and other diseases. ARNT is known to be translocated into the cell nucleus, where accumulation of the protein takes place. ARNT is a heterodimerisation partner of the xenobiotic ligand activated Aryl Hydrocarbon Receptor (AhR, the Single Minded proteins (SIM, the cardiovascular helix-loop-helix factor 1 and the Hypoxia Inducible Factor proteins (HIF-α. ARNT is obligatory for HIF-1, HIF-2 and HIF-3 binding to DNA. Whereas degradation of the HIF-α subunits is suppressed by hypoxia, ARNT is generally regarded as constitutively expressed in excess within the cell, and stabilisation is commonly thought to be oxygen-independent. However, we provide evidence that the regulation of ARNT is far more complex. The aim of our study was to reevaluate the regulation of ARNT expression. Methods: We examined cell lines of different origin like MCF-7 and T47D (human breast cancer, HeLa (human cervix carcinoma, Hep3B and HepG2 (human hepatoma, Kelly (human neuroblastoma, REPC (human kidney and Cos7 (primary primate kidney cells. We used immunoblot analysis, densitometry, RT-PCR and transient transfection. Results and Conclusion: Our results show that ARNT protein levels are influenced by hypoxia and hypoxia mimetics such as cobalt(II-chloride (CoCl2 and dimethyloxalylglycine (DMOG in a cell line specific manner. We demonstrate that this effect might be triggered by HIF-1α which plays an important role in the process of stabilizing ARNT in hypoxia.

  14. In vitro permeation and disposition of niacinamide in silicone and porcine skin of skin barrier-mimetic formulations.

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    Haque, Tasnuva; Lane, Majella E; Sil, Bruno C; Crowther, Jonathan M; Moore, David J

    2017-03-30

    Niacinamide (NIA) is an amide form of vitamin B3 which is used in cosmetic formulations to improve various skin conditions and it has also been shown to increase stratum corneum thickness following repeated application. In this study, three doses (5, 20 and 50μL per cm 2 ) of two NIA containing oil-in-water skin barrier-mimetic formulations were evaluated in silicone membrane and porcine ear skin and compared with a commercial control formulation. Permeation studies were conducted over 24h in Franz cells and at the end of the experiment membranes were washed and niacinamide was extracted. For the three doses, retention or deposition of NIA was generally higher in porcine skin compared with silicone membrane, consistent with the hydrophilic nature of the active. Despite the control containing a higher amount of active, comparable amounts of NIA were deposited in skin for all formulations for all doses; total skin absorption values (permeation and retention) of NIA were also comparable across all formulations. For infinite (50μL) and finite (5μL) doses the absolute permeation of NIA from the control formulation was significantly higher in porcine skin compared with both test formulations. This likely reflects differences in formulation components and/or presence of skin penetration enhancers in the formulations. Higher permeation for the 50 and 20μL dose was also evident in porcine skin compared with silicone membrane but the opposite is the case for the finite dose. The findings point to the critical importance of dose and occlusion when evaluating topical formulations in vitro and also the likelihood of exaggerated effects of excipients on permeation at infinite and pseudo-finite dose applications. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Tempol, a superoxide dismutase mimetic agent, ameliorates cisplatin-induced nephrotoxicity through alleviation of mitochondrial dysfunction in mice.

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    Ahmed, Lamiaa A; Shehata, Nagwa I; Abdelkader, Noha F; Khattab, Mahmoud M

    2014-01-01

    Mitochondrial dysfunction is a crucial mechanism by which cisplatin, a potent chemotherapeutic agent, causes nephrotoxicity where mitochondrial electron transport complexes are shifted mostly toward imbalanced reactive oxygen species versus energy production. In the present study, the protective role of tempol, a membrane-permeable superoxide dismutase mimetic agent, was evaluated on mitochondrial dysfunction and the subsequent damage induced by cisplatin nephrotoxicity in mice. Nephrotoxicity was assessed 72 h after a single i.p. injection of cisplatin (25 mg/kg) with or without oral administration of tempol (100 mg/kg/day). Serum creatinine and urea as well as glucosuria and proteinuria were evaluated. Both kidneys were isolated for estimation of oxidative stress markers, adenosine triphosphate (ATP) content and caspase-3 activity. Moreover, mitochondrial oxidative phosphorylation capacity, complexes I-IV activities and mitochondrial nitric oxide synthase (mNOS) protein expression were measured along with histological examinations of renal tubular damage and mitochondrial ultrastructural changes. Tempol was effective against cisplatin-induced elevation of serum creatinine and urea as well as glucosuria and proteinuria. Moreover, pretreatment with tempol notably inhibited cisplatin-induced oxidative stress and disruption of mitochondrial function by restoring mitochondrial oxidative phosphorylation, complexes I and III activities, mNOS protein expression and ATP content. Tempol also provided significant protection against apoptosis, tubular damage and mitochondrial ultrastructural changes. Interestingly, tempol did not interfere with the cytotoxic effect of cisplatin against the growth of solid Ehrlich carcinoma. This study highlights the potential role of tempol in inhibiting cisplatin-induced nephrotoxicity without affecting its antitumor activity via amelioration of oxidative stress and mitochondrial dysfunction.

  16. Tempol, a superoxide dismutase mimetic agent, ameliorates cisplatin-induced nephrotoxicity through alleviation of mitochondrial dysfunction in mice.

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    Lamiaa A Ahmed

    Full Text Available Mitochondrial dysfunction is a crucial mechanism by which cisplatin, a potent chemotherapeutic agent, causes nephrotoxicity where mitochondrial electron transport complexes are shifted mostly toward imbalanced reactive oxygen species versus energy production. In the present study, the protective role of tempol, a membrane-permeable superoxide dismutase mimetic agent, was evaluated on mitochondrial dysfunction and the subsequent damage induced by cisplatin nephrotoxicity in mice.Nephrotoxicity was assessed 72 h after a single i.p. injection of cisplatin (25 mg/kg with or without oral administration of tempol (100 mg/kg/day. Serum creatinine and urea as well as glucosuria and proteinuria were evaluated. Both kidneys were isolated for estimation of oxidative stress markers, adenosine triphosphate (ATP content and caspase-3 activity. Moreover, mitochondrial oxidative phosphorylation capacity, complexes I-IV activities and mitochondrial nitric oxide synthase (mNOS protein expression were measured along with histological examinations of renal tubular damage and mitochondrial ultrastructural changes. Tempol was effective against cisplatin-induced elevation of serum creatinine and urea as well as glucosuria and proteinuria. Moreover, pretreatment with tempol notably inhibited cisplatin-induced oxidative stress and disruption of mitochondrial function by restoring mitochondrial oxidative phosphorylation, complexes I and III activities, mNOS protein expression and ATP content. Tempol also provided significant protection against apoptosis, tubular damage and mitochondrial ultrastructural changes. Interestingly, tempol did not interfere with the cytotoxic effect of cisplatin against the growth of solid Ehrlich carcinoma.This study highlights the potential role of tempol in inhibiting cisplatin-induced nephrotoxicity without affecting its antitumor activity via amelioration of oxidative stress and mitochondrial dysfunction.

  17. The superoxide dismutase mimetic tempol does not alleviate glucocorticoid-mediated rarefaction of rat skeletal muscle capillaries.

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    Mandel, Erin R; Dunford, Emily C; Abdifarkosh, Ghoncheh; Turnbull, Patrick C; Perry, Christopher G R; Riddell, Michael C; Haas, Tara L

    2017-05-01

    Sustained elevations in circulating glucocorticoids elicit reductions in skeletal muscle microvascular content, but little is known of the underlying mechanisms. We hypothesized that glucocorticoid-induced oxidative stress contributes to this phenomenon. In rats that were implanted with corticosterone (CORT) or control pellets, CORT caused a significant decrease in muscle glutathione levels and a corresponding increase in protein carbonylation, an irreversible oxidative modification of proteins. Decreased endothelial nitric oxide synthase and increased endothelin-1 mRNA levels were detected after 9 days of CORT, and blood flow to glycolytic muscles was diminished. Control and CORT rats were treated concurrently with drinking water containing the superoxide dismutase mimetic tempol (172 mg/L) or the α -1 adrenergic receptor antagonist prazosin (50 mg/L) for 6 or 16 days. Both tempol and prazosin alleviated skeletal muscle protein carbonylation. Tempol failed to prevent CORT-mediated capillary rarefaction and was ineffective in restoring skeletal muscle blood flow. In contrast, prazosin blocked capillary rarefaction and restored skeletal muscle blood flow to control levels. The failure of tempol to prevent CORT-induced skeletal muscle microvascular rarefaction does not support a dominant role of superoxide-induced oxidative stress in this process. Although a decrease in protein carbonylation was observed with prazosin treatment, our data suggest that the maintenance of skeletal muscle microvascular content is related more closely with counteracting the CORT-mediated influence on skeletal muscle vascular tone. © 2017 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of The Physiological Society and the American Physiological Society.

  18. Allosteric Inhibition of Factor XIIIa. Non-Saccharide Glycosaminoglycan Mimetics, but Not Glycosaminoglycans, Exhibit Promising Inhibition Profile.

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    Rami A Al-Horani

    Full Text Available Factor XIIIa (FXIIIa is a transglutaminase that catalyzes the last step in the coagulation process. Orthostery is the only approach that has been exploited to design FXIIIa inhibitors. Yet, allosteric inhibition of FXIIIa is a paradigm that may offer a key advantage of controlled inhibition over orthosteric inhibition. Such an approach is likely to lead to novel FXIIIa inhibitors that do not carry bleeding risks. We reasoned that targeting a collection of basic amino acid residues distant from FXIIIa's active site by using sulfated glycosaminoglycans (GAGs or non-saccharide GAG mimetics (NSGMs would lead to the discovery of the first allosteric FXIIIa inhibitors. We tested a library of 22 variably sulfated GAGs and NSGMs against human FXIIIa to discover promising hits. Interestingly, although some GAGs bound to FXIIIa better than NSGMs, no GAG displayed any inhibition. An undecasulfated quercetin analog was found to inhibit FXIIIa with reasonable potency (efficacy of 98%. Michaelis-Menten kinetic studies revealed an allosteric mechanism of inhibition. Fluorescence studies confirmed close correspondence between binding affinity and inhibition potency, as expected for an allosteric process. The inhibitor was reversible and at least 9-fold- and 26-fold selective over two GAG-binding proteins factor Xa (efficacy of 71% and thrombin, respectively, and at least 27-fold selective over a cysteine protease papain. The inhibitor also inhibited the FXIIIa-mediated polymerization of fibrin in vitro. Overall, our work presents the proof-of-principle that FXIIIa can be allosterically modulated by sulfated non-saccharide agents much smaller than GAGs, which should enable the design of selective and safe anticoagulants.

  19. The radiosensitizing activity of the SMAC-mimetic, Debio 1143, is TNFα-mediated in head and neck squamous cell carcinoma.

    Science.gov (United States)

    Matzinger, Oscar; Viertl, David; Tsoutsou, Pelagia; Kadi, Linda; Rigotti, Stefania; Zanna, Claudio; Wiedemann, Norbert; Vozenin, Marie-Catherine; Vuagniaux, Grégoire; Bourhis, Jean

    2015-09-01

    Second mitochondria-derived activator of caspase (SMAC)-mimetics are a new class of targeted drugs that specifically induce apoptotic cancer cell death and block pro-survival signaling by antagonizing selected members of the inhibitor of apoptosis protein (IAP) family. The present study was designed to investigate the radiosensitizing effect and optimal sequence of administration of the novel SMAC-mimetic Debio 1143 in vitro and in vivo. Apoptosis, alteration of DNA damage repair (DDR), and tumor necrosis factor-alpha (TNF-α) signaling were examined. In vitro, Debio 1143 displayed anti-proliferative activity and enhanced intrinsic radiation sensitivity in 5/6 head and neck squamous cell carcinoma (HNSCC) cell lines in a synergistic manner. In vivo, Debio 1143 dose-dependently radio-sensitized FaDu and SQ20B xenografts, resulting in complete tumor regression in 8/10 FaDu-xenografted mice at the high dose level. At the molecular level, Debio 1143 combined with radiotherapy (RT) induced enhancement of caspase-3 activity, increase in Annexin V-positive cells and karyopyknosis, and increase in TNF-α mRNA levels. Finally, in a neutralization experiment using a TNF-α-blocking antibody and a caspase inhibitor, it was shown that the radiosensitizing effect of Debio 1143 is mediated by caspases and TNF-α. These results demonstrate that the novel SMAC-mimetic Debio 1143 is a radiosensitizing agent that is worthy of further investigation in clinical trials in combination with radiotherapy. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  20. Age-related decrease in the mitochondrial sirtuin deacetylase Sirt3 expression associated with ROS accumulation in the auditory cortex of the mimetic aging rat model.

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    Lingling Zeng

    Full Text Available Age-related dysfunction of the central auditory system, also known as central presbycusis, can affect speech perception and sound localization. Understanding the pathogenesis of central presbycusis will help to develop novel approaches to prevent or treat this disease. In this study, the mechanisms of central presbycusis were investigated using a mimetic aging rat model induced by chronic injection of D-galactose (D-Gal. We showed that malondialdehyde (MDA levels were increased and manganese superoxide dismutase (SOD2 activity was reduced in the auditory cortex in natural aging and D-Gal-induced mimetic aging rats. Furthermore, mitochondrial DNA (mtDNA 4834 bp deletion, abnormal ultrastructure and cell apoptosis in the auditory cortex were also found in natural aging and D-Gal mimetic aging rats. Sirt3, a mitochondrial NAD+-dependent deacetylase, has been shown to play a crucial role in controlling cellular reactive oxygen species (ROS homeostasis. However, the role of Sirt3 in the pathogenesis of age-related central auditory cortex deterioration is still unclear. Here, we showed that decreased Sirt3 expression might be associated with increased SOD2 acetylation, which negatively regulates SOD2 activity. Oxidative stress accumulation was likely the result of low SOD2 activity and a decline in ROS clearance. Our findings indicate that Sirt3 might play an essential role, via the mediation of SOD2, in central presbycusis and that manipulation of Sirt3 expression might provide a new approach to combat aging and oxidative stress-related diseases.

  1. Chemomics-based marker compounds mining and mimetic processing for exploring chemical mechanisms in traditional processing of herbal medicines, a continuous study on Rehmanniae Radix.

    Science.gov (United States)

    Zhou, Li; Xu, Jin-Di; Zhou, Shan-Shan; Shen, Hong; Mao, Qian; Kong, Ming; Zou, Ye-Ting; Xu, Ya-Yun; Xu, Jun; Li, Song-Lin

    2017-12-29

    Exploring processing chemistry, in particular the chemical transformation mechanisms involved, is a key step to elucidate the scientific basis in traditional processing of herbal medicines. Previously, taking Rehmanniae Radix (RR) as a case study, the holistic chemome (secondary metabolome and glycome) difference between raw and processed RR was revealed by integrating hyphenated chromatographic techniques-based targeted glycomics and untargeted metabolomics. Nevertheless, the complex chemical transformation mechanisms underpinning the holistic chemome variation in RR processing remain to be extensively clarified. As a continuous study, here a novel strategy by combining chemomics-based marker compounds mining and mimetic processing is proposed for further exploring the chemical mechanisms involved in herbal processing. First, the differential marker compounds between raw and processed herbs were rapidly discovered by untargeted chemomics-based mining approach through multivariate statistical analysis of the chemome data obtained by integrated metabolomics and glycomics analysis. Second, the marker compounds were mimetically processed under the simulated physicochemical conditions as in the herb processing, and the final reaction products were chemically characterized by targeted chemomics-based mining approach. Third, the main chemical transformation mechanisms involved were clarified by linking up the original marker compounds and their mimetic processing products. Using this strategy, a set of differential marker compounds including saccharides, glycosides and furfurals in raw and processed RR was rapidly found, and the major chemical mechanisms involved in RR processing were elucidated as stepwise transformations of saccharides (polysaccharides, oligosaccharides and monosaccharides) and glycosides (iridoid glycosides and phenethylalcohol glycosides) into furfurals (glycosylated/non-glycosylated hydroxymethylfurfurals) by deglycosylation and/or dehydration. The

  2. Synthesis and structure-activity relationships of phosphonic arginine mimetics as inhibitors of the M1 and M17 aminopeptidases from Plasmodium falciparum.

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    Kannan Sivaraman, Komagal; Paiardini, Alessandro; Sieńczyk, Marcin; Ruggeri, Chiara; Oellig, Christine A; Dalton, John P; Scammells, Peter J; Drag, Marcin; McGowan, Sheena

    2013-06-27

    The malaria parasite Plasmodium falciparum employs two metallo-aminopeptidases, PfA-M1 and PfA-M17, which are essential for parasite survival. Compounds that inhibit the activity of either enzyme represent leads for the development of new antimalarial drugs. Here we report the synthesis and structure-activity relationships of a small library of phosphonic acid arginine mimetics that probe the S1 pocket of both enzymes and map the necessary interactions that would be important for a dual inhibitor.

  3. Cellular Fates of Manganese(II) Pentaazamacrocyclic Superoxide Dismutase (SOD) Mimetics: Fluorescently Labeled MnSOD Mimetics, X-ray Absorption Spectroscopy, and X-ray Fluorescence Microscopy Studies.

    Science.gov (United States)

    Weekley, Claire M; Kenkel, Isabell; Lippert, Rainer; Wei, Shengwei; Lieb, Dominik; Cranwell, Tiffanny; Wedding, Jason L; Zillmann, Annika S; Rohr, Robin; Filipovic, Milos R; Ivanović-Burmazović, Ivana; Harris, Hugh H

    2017-06-05

    Manganese(II) pentaazamacrocyclic complexes (MnPAMs) can act as small-molecule mimics of manganese superoxide dismutase (MnSOD) with potential therapeutic application in conditions linked to oxidative stress. Previously, the in vitro mechanism of action has been determined, their activity has been demonstrated in cells, and some representatives of this class of MnSOD mimetics have entered clinical trials. However, MnPAM uptake, distribution, and metabolism in cells are largely unknown. Therefore, we have used X-ray fluorescence microscopy (XFM) and X-ray absorption spectroscopy (XAS) to study the cellular fate of a number of MnPAMs. We have also synthesized and characterized fluorescently labeled (pyrene and rhodamine) manganese(II) pyane [manganese(II) trans-2,13-dimethyl-3,6,9,12,18-pentaazabicyclo[12.3.1]octadeca-1(18),14,16-triene] derivatives and investigated their utility for cellular imaging of MnPAMs. Their SOD activity was determined via a direct stopped-flow technique. XFM experiments show that treatment with amine-based manganese(II) pyane type pentaazamacrocycles leads to a 10-100-fold increase in the overall cellular manganese levels compared to the physiological levels of manganese in control cells. In treated cells in general, manganese was distributed throughout the cell body, with a couple of notable exceptions. The lipophilicity of the MnPAMs, examined by partitioning in octanol-buffer system, was a good predictor of the relative cellular manganese levels. Analysis of the XAS data of treated cells revealed that some fraction of amine-based MnPAMs taken up by the cells remained intact, with the rest transformed into SOD-active manganese(II) phosphate. Higher phosphate binding constants, determined from the effect of the phosphate concentration on in vitro SOD activity, were associated with more extensive metabolism of the amine-based MnPAMs to manganese(II) phosphate. In contrast, the imine-based manganese(II) pydiene complex that is prone to

  4. Coating of Bio-mimetic Minerals-Substituted Hydroxyapatite on Surgical Grade Stainless Steel 316L by Electrophoretic Deposition for Hard tissue Applications

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    Govindaraj, Dharman; Rajan, Mariappan

    2018-02-01

    Third-era bio-implant materials intend to empower particular live cell reactions at the atomic level, these materials represented with a resorbable and biocompatibility that bodies recuperate once they have been embedded. Necessitate to decrease expenses in public health services has required the utilization of surgical grade stainless steel (SS 316L) as the most inexpensive choice for orthodontic and orthopaedic implants. 316L SS is one of the broadly used implant biomaterials in orthodontic and orthopaedic surgeries. Yet, frequently those discharge for toxic metal ions is confirm from the implants and hence a second surgery is required will remove those implant material. One approach to managing the discharge of toxic metal ions is to coat the implant substance with bio-mimetic minerals in hydroxyapatite (HA). Bio-mimetic minerals such as magnesium (Mg), strontium (Sr), also zinc (Zn) were revealed with animate bone growth furthermore restrain bone resorption both in vitro and in vivo. The present work deals with the electrophoretic deposition (EPD) for multi minerals substituted hydroxyapatite (M-HA) on the surface treated 316L SS under distinctive temperatures (27°C, (room temperature), 60 and 80°C). The resultant coatings were characterized by FT-IR, XRD, SEM-EDX, adhesion strength and leach out analysis.

  5. Modeling of arylamide helix mimetics in the p53 peptide binding site of hDM2 suggests parallel and anti-parallel conformations are both stable.

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    Jonathan C Fuller

    Full Text Available The design of novel α-helix mimetic inhibitors of protein-protein interactions is of interest to pharmaceuticals and chemical genetics researchers as these inhibitors provide a chemical scaffold presenting side chains in the same geometry as an α-helix. This conformational arrangement allows the design of high affinity inhibitors mimicking known peptide sequences binding specific protein substrates. We show that GAFF and AutoDock potentials do not properly capture the conformational preferences of α-helix mimetics based on arylamide oligomers and identify alternate parameters matching solution NMR data and suitable for molecular dynamics simulation of arylamide compounds. Results from both docking and molecular dynamics simulations are consistent with the arylamides binding in the p53 peptide binding pocket. Simulations of arylamides in the p53 binding pocket of hDM2 are consistent with binding, exhibiting similar structural dynamics in the pocket as simulations of known hDM2 binders Nutlin-2 and a benzodiazepinedione compound. Arylamide conformations converge towards the same region of the binding pocket on the 20 ns time scale, and most, though not all dihedrals in the binding pocket are well sampled on this timescale. We show that there are two putative classes of binding modes for arylamide compounds supported equally by the modeling evidence. In the first, the arylamide compound lies parallel to the observed p53 helix. In the second class, not previously identified or proposed, the arylamide compound lies anti-parallel to the p53 helix.

  6. A mimetic, semi-implicit, forward-in-time, finite volume shallow water model: comparison of hexagonal–icosahedral and cubed-sphere grids

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    J. Thuburn

    2014-05-01

    Full Text Available A new algorithm is presented for the solution of the shallow water equations on quasi-uniform spherical grids. It combines a mimetic finite volume spatial discretization with a Crank–Nicolson time discretization of fast waves and an accurate and conservative forward-in-time advection scheme for mass and potential vorticity (PV. The algorithm is implemented and tested on two families of grids: hexagonal–icosahedral Voronoi grids, and modified equiangular cubed-sphere grids. Results of a variety of tests are presented, including convergence of the discrete scalar Laplacian and Coriolis operators, advection, solid body rotation, flow over an isolated mountain, and a barotropically unstable jet. The results confirm a number of desirable properties for which the scheme was designed: exact mass conservation, very good available energy and potential enstrophy conservation, consistent mass, PV and tracer transport, and good preservation of balance including vanishing ∇ × ∇, steady geostrophic modes, and accurate PV advection. The scheme is stable for large wave Courant numbers and advective Courant numbers up to about 1. In the most idealized tests the overall accuracy of the scheme appears to be limited by the accuracy of the Coriolis and other mimetic spatial operators, particularly on the cubed-sphere grid. On the hexagonal grid there is no evidence for damaging effects of computational Rossby modes, despite attempts to force them explicitly.

  7. EGFR-targeted TRAIL and a Smac mimetic synergize to overcome apoptosis resistance in KRAS mutant colorectal cancer cells.

    Directory of Open Access Journals (Sweden)

    Yvonne Möller

    Full Text Available TRAIL is a death receptor ligand that induces cell death preferentially in tumor cells. Recombinant soluble TRAIL, however, performs poorly as an anti-cancer therapeutic because oligomerization is required for potent biological activity. We previously generated a diabody format of tumor-targeted TRAIL termed Db(αEGFR-scTRAIL, comprising single-stranded TRAIL molecules (scTRAIL and the variable domains of a humanized variant of the EGFR blocking antibody Cetuximab. Here we define the bioactivity of Db(αEGFR-scTRAIL with regard to both EGFR inhibition and TRAIL receptor activation in 3D cultures of Caco-2 colorectal cancer cells, which express wild-type K-Ras. Compared with conventional 2D cultures, Caco-2 cells displayed strongly enhanced sensitivity toward Db(αEGFR-scTRAIL in these 3D cultures. We show that the antibody moiety of Db(αEGFR-scTRAIL not only efficiently competed with ligand-induced EGFR function, but also determined the apoptotic response by specifically directing Db(αEGFR-scTRAIL to EGFR-positive cells. To address how aberrantly activated K-Ras, which leads to Cetuximab resistance, affects Db(αEGFR-scTRAIL sensitivity, we generated stable Caco-2tet cells inducibly expressing oncogenic K-Ras(G12V. In the presence of doxycycline, these cells showed increased resistance to Db(αEGFR-scTRAIL, associated with the elevated expression of the anti-apoptotic proteins cIAP2, Bcl-xL and FlipS. Co-treatment of cells with the Smac mimetic SM83 restored the Db(αEGFR-scTRAIL-induced apoptotic response. Importantly, this synergy between Db(αEGFR-scTRAIL and SM83 also translated to 3D cultures of oncogenic K-Ras expressing HCT-116 and LoVo colorectal cancer cells. Our findings thus support the notion that Db(αEGFR-scTRAIL therapy in combination with apoptosis-sensitizing agents may be promising for the treatment of EGFR-positive colorectal cancers, independently of their KRAS status.

  8. Potent and selective small-molecule inhibitors of cIAP1/2 proteins reveal that the binding of Smac mimetics to XIAP BIR3 is not required for their effective induction of cell death in tumor cells.

    Science.gov (United States)

    Sun, Haiying; Lu, Jianfeng; Liu, Liu; Yang, Chao-Yie; Wang, Shaomeng

    2014-04-18

    Cellular inhibitor of apoptosis protein 1 and 2 (cIAP1/2) and X-linked inhibitor of apoptosis protein (XIAP) are key apoptosis regulators and promising new cancer therapeutic targets. This study describes a set of non-peptide, small-molecule Smac (second mitochondria-derived activator of caspases) mimetics that are selective inhibitors of cIAP1/2 over XIAP. The most potent and most selective compounds bind to cIAP1/2 with affinities in the low nanomolar range and show >1,000-fold selectivity for cIAP1 over XIAP. These selective cIAP inhibitors effectively induce degradation of the cIAP1 protein in cancer cells at low nanomolar concentrations and do not antagonize XIAP in a cell-free functional assay. They potently inhibit cell growth and effectively induce apoptosis at low nanomolar concentrations in cancer cells with a mechanism of action similar to that of other known Smac mimetics. Our study shows that binding of Smac mimetics to XIAP BIR3 is not required for effective induction of apoptosis in tumor cells by Smac mimetics. These potent and highly selective cIAP1/2 inhibitors are powerful tools in the investigation of the role of these IAP proteins in the regulation of apoptosis and other cellular processes.

  9. Interaction of GABA-mimetics with the taurine transporter (TauT, Slc6a6) in hyperosmotic treated Caco-2, LLC-PK1 and rat renal SKPT cells

    DEFF Research Database (Denmark)

    Rasmussen, Rune Nørgaard; Lagunas, Candela; Plum, Jakob

    2016-01-01

    The aim of the present study was to investigate if basic GABA-mimetics interact with the taurine transporter (TauT, Slc6a6), and to find a suitable cell based model that is robust towards extracellular changes in osmolality during uptake studies. Taurine uptake was measured in human Caco-2 cells...

  10. Beneficial effect of propofol on arterial adenosine triphosphate-sensitive K+ channel function impaired by thromboxane.

    Science.gov (United States)

    Haba, Masanori; Kinoshita, Hiroyuki; Matsuda, Naoyuki; Azma, Toshiharu; Hama-Tomioka, Keiko; Hatakeyama, Noboru; Yamazaki, Mitsuaki; Hatano, Yoshio

    2009-08-01

    It is not known whether thromboxane A2 impairs adenosine triphosphate (ATP)-sensitive K channel function via increased production of superoxide in blood vessels and whether propofol as a nicotinamide adenine dinucleotide phosphate (NADPH) oxidase inhibitor restores this modification. Rat aortas without endothelium were used for isometric force recording, measurements of membrane potential, and superoxide production and Western immunoblotting. Vasorelaxation to an ATP-sensitive K channel opener levcromakalim was obtained during contraction to phenylephrine (3 x 10(-7) M) or a thromboxane A2 analogue U46619 (3 x 10(-7) M). In some experiments, aortas were incubated with an ATP-sensitive K channel antagonist glibenclamide, a superoxide inhibitor Tiron, a nonselective NADPH oxidase inhibitor apocynin, a hydrogen peroxide scavenger catalase, a xanthine oxidase inhibitor allopurinol, a thromboxane receptor antagonist SQ29548 or propofol (3 x 10(-7) to 3 x 10(-6) M). Levcromakalim-induced vasorelaxation was abolished by glibenclamide in rings contracted with either vasoconstrictor agent. Tiron, apocynin, and propofol, but not catalase, augmented the vasodilator response as well as the hyperpolarization by levcromakalim in aortas contracted with U46619. Tiron, apocynin, SQ29548, and propofol, but not allopurinol, similarly reduced in situ levels of superoxide within aortic vascular smooth muscle exposed to U46619. Protein expression of a NADPH oxidase subunit p47phox increased in these arteries, and this augmentation was abolished by propofol. Thromboxane receptor activation induces vascular oxidative stress via NADPH oxidase, resulting in the impairment of ATP-sensitive K channel function. Propofol reduces this stress via inhibition of a NADPH oxidase subunit p47phox and, therefore, restores ATP-sensitive K channel function.

  11. A Smac-mimetic sensitizes prostate cancer cells to TRAIL-induced apoptosis via modulating both IAPs and NF-kappaB

    International Nuclear Information System (INIS)

    Dai, Yao; Liu, Meilan; Tang, Wenhua; Li, Yongming; Lian, Jiqin; Lawrence, Theodore S; Xu, Liang

    2009-01-01

    Although tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is a promising agent for human cancer therapy, prostate cancer still remains resistant to TRAIL. Both X-linked inhibitor of apoptosis (XIAP) and nuclear factor-kappaB function as key negative regulators of TRAIL signaling. In this study, we evaluated the effect of SH122, a small molecule mimetic of the second mitochondria-derived activator of caspases (Smac), on TRAIL-induced apoptosis in prostate cancer cells. The potential of Smac-mimetics to bind XIAP or cIAP-1 was examined by pull-down assay. Cytotoxicity of TRAIL and/or Smac-mimetics was determined by a standard cell growth assay. Silencing of XIAP or cIAP-1 was achieved by transient transfection of short hairpin RNA. Apoptosis was detected by Annexin V-PI staining followed by flow cytometry and by Western Blot analysis of caspases, PARP and Bid. NF-kappaB activation was determined by subcellular fractionation, real time RT-PCR and reporter assay. SH122, but not its inactive analog, binds to XIAP and cIAP-1. SH122 significantly sensitized prostate cancer cells to TRAIL-mediated cell death. Moreover, SH122 enhanced TRAIL-induced apoptosis via both the death receptor and the mitochondrial pathway. Knockdown of both XIAP and cIAP-1 sensitized cellular response to TRAIL. XIAP-knockdown attenuated sensitivity of SH122 to TRAIL-induced cytotoxicity, confirming that XIAP is an important target for IAP-inhibitor-mediated TRAIL sensitization. SH122 also suppressed TRAIL-induced NF-kappaB activation by preventing cytosolic IkappaB-alpha degradation and RelA nuclear translocation, as well as by suppressing NF-kappaB target gene expression. These results demonstrate that SH122 sensitizes human prostate cancer cells to TRAIL-induced apoptosis by mimicking Smac and blocking both IAPs and NF-kappaB. Modulating IAPs may represent a promising approach to overcoming TRAIL-resistance in human prostate cancer with constitutively active NF-kappaB signaling

  12. Spaceflight on the Bion-M1 biosatellite alters cerebral artery vasomotor and mechanical properties in mice.

    Science.gov (United States)

    Sofronova, Svetlana I; Tarasova, Olga S; Gaynullina, Dina; Borzykh, Anna A; Behnke, Bradley J; Stabley, John N; McCullough, Danielle J; Maraj, Joshua J; Hanna, Mina; Muller-Delp, Judy M; Vinogradova, Olga L; Delp, Michael D

    2015-04-01

    Conditions during spaceflight, such as the loss of the head-to-foot gravity vector, are thought to potentially alter cerebral blood flow and vascular resistance. The purpose of the present study was to determine the effects of long-term spaceflight on the functional, mechanical, and structural properties of cerebral arteries. Male C57BL/6N mice were flown 30 days in a Bion-M1 biosatellite. Basilar arteries isolated from spaceflight (SF) (n = 6), habitat control (HC) (n = 6), and vivarium control (VC) (n = 16) mice were used for in vitro functional and mechanical testing and histological structural analysis. The results demonstrate that vasoconstriction elicited through a voltage-gated Ca(2+) mechanism (30-80 mM KCl) and thromboxane A2 receptors (10(-8) - 3 × 10(-5) M U46619) are lower in cerebral arteries from SF mice. Inhibition of Rho-kinase activity (1 μM Y27632) abolished group differences in U46619-evoked contractions. Endothelium-dependent vasodilation elicited by acetylcholine (10 μM, 2 μM U46619 preconstriction) was virtually absent in cerebral arteries from SF mice. The pressure-diameter relation was lower in arteries from SF mice relative to that in HC mice, which was not related to differences in the extracellular matrix protein elastin or collagen content or the elastin/collagen ratio in the basilar arteries. Diameter, medial wall thickness, and medial cross-sectional area of unpressurized basilar arteries were not different among groups. These results suggest that the microgravity-induced attenuation of both vasoconstrictor and vasodilator properties may limit the range of vascular control of cerebral perfusion or impair the distribution of brain blood flow during periods of stress. Copyright © 2015 the American Physiological Society.

  13. NP-184[2-(5-methyl-2-furyl) benzimidazole], a novel orally active antithrombotic agent with dual antiplatelet and anticoagulant activities.

    Science.gov (United States)

    Kuo, Heng-Lan; Lien, Jin-Cherng; Chung, Ching-Hu; Chang, Chien-Hsin; Lo, Shyh-Chyi; Tsai, I-Chun; Peng, Hui-Chin; Kuo, Sheng-Chu; Huang, Tur-Fu

    2010-06-01

    The established antiplatelet and anticoagulant agents show beneficial effects in the treatment of thromboembolic diseases; however, these drugs still have considerable limitations. The effects of NP-184, a synthetic compound, on platelet functions, plasma coagulant activity, and mesenteric venule thrombosis in mice were investigated. NP-184 concentration-dependently inhibited the human platelet aggregation induced by collagen, arachidonic acid (AA), and U46619, a thromboxane (TX)A(2) mimic, with IC(50) values of 4.5 +/- 0.2, 3.9 +/- 0.1, and 9.3 +/- 0.5 microM, respectively. Moreover, NP-184 concentration-dependently suppressed TXA(2) formations caused by collagen and AA. In exploring effects of NP-184 on enzymes involved in TXA(2) synthesis, we found that NP-184 selectively inhibited TXA(2) synthase activity with an IC(50) value of 4.3 +/- 0.2 microM. Furthermore, NP-184 produced a right shift of the concentration-response curve of U46619, indicating a competitive antagonism on TXA(2)/prostaglandin H(2) receptor. Intriguingly, NP-184 also caused a concentration-dependent prolongation of the activated partial thromboplastin time (aPTT) with no changes in the prothrombin and thrombin time, indicating that it selectively impairs the intrinsic coagulation pathway. Oral administration of NP-184 significantly inhibited thrombus formation of the irradiated mesenteric venules in fluorescein sodium-treated mice without affecting the bleeding time induced by tail transection. However, after oral administration, NP-184 inhibited the ex vivo mouse platelet aggregation triggered by collagen and U46619 and also prolonged aPTT. Taken together, the dual antiplatelet and anticoagulant activities of NP-184 may have therapeutic potential as an oral antithrombotic agent in the treatment of thromboembolic disorders.

  14. A cell adhesion molecule mimetic, FGL peptide, induces alterations in synapse and dendritic spine structure in the dentate gyrus of aged rats: a three-dimensional ultrastructural study

    DEFF Research Database (Denmark)

    Popov, Victor I; Medvedev, Nikolay I; Kraev, Igor V

    2008-01-01

    The FGL peptide is a neural cell adhesion molecule (NCAM) mimetic comprising a 15-amino-acid-long sequence of the FG loop region of the second fibronectin type III module of NCAM. It corresponds to the binding site of NCAM for the fibroblast growth factor receptor 1. FGL improves cognitive function...... through enhancement of synaptic function. We examined the effect of FGL on synaptic and dendritic structure in the brains of aged (22-month-old) rats that were injected subcutaneously (8 mg/kg) at 2-day intervals until 19 days after the start of the experiment. Animals were perfused with fixative, brains...... structure of synapses and dendritic spines in hippocampus of aged rats, complementing data showing its effect on cognitive processes....

  15. Modeling the capture rate by a radially oscillating spherical bubble. A bio-mimetic model for studying the mechanically-mediated uptake by cells

    Science.gov (United States)

    Raudino, Antonio; Raciti, Domenica; Grassi, Antonio

    2016-11-01

    The surface of living cells constitutes a dynamic environment submitted to complex oscillatory motions. Oscillations may modify the uptake of incoming molecules. In this study we explored a bio-mimetic system formed by oscillating bubbles suspended in a sea of randomly distributed diffusants. We investigated by a time-dependent Fokker-Planck equation the effect of the periodic motions on the adsorption of a diffusant onto the moving bubble surface. We introduced both direct interactions between the diffusant and the fluctuating surface and indirect interactions due to the hydrodynamic motions around a vibrating surface. Results are expressed in terms of oscillation frequencies and amplitudes. An overall reduction of the bound diffusant at the bubble surface was observed.

  16. Insight into the mechanism revealing the peroxidase mimetic catalytic activity of quaternary CuZnFeS nanocrystals: colorimetric biosensing of hydrogen peroxide and glucose

    Science.gov (United States)

    Dalui, Amit; Pradhan, Bapi; Thupakula, Umamahesh; Khan, Ali Hossain; Kumar, Gundam Sandeep; Ghosh, Tanmay; Satpati, Biswarup; Acharya, Somobrata

    2015-05-01

    Artificial enzyme mimetics have attracted immense interest recently because natural enzymes undergo easy denaturation under environmental conditions restricting practical usefulness. We report for the first time chalcopyrite CuZnFeS (CZIS) alloyed nanocrystals (NCs) as novel biomimetic catalysts with efficient intrinsic peroxidase-like activity. Novel peroxidase activities of CZIS NCs have been evaluated by catalytic oxidation of the peroxidase substrate 3,3',5,5'-tetramethylbenzidine (TMB) in the presence of hydrogen peroxide (H2O2). CZIS NCs demonstrate the synergistic effect of elemental composition and photoactivity towards peroxidase-like activity. The quaternary CZIS NCs show enhanced intrinsic peroxidase-like activity compared to the binary NCs with the same constituent elements. Intrinsic peroxidase-like activity has been correlated with the energy band position of CZIS NCs extracted using scanning tunneling spectroscopy and ultraviolet photoelectron spectroscopy. Kinetic analyses indicate Michaelis-Menten enzyme kinetic model catalytic behavior describing the rate of the enzymatic reaction by correlating the reaction rate with substrate concentration. Typical color reactions arising from the catalytic oxidation of TMB over CZIS NCs with H2O2 have been utilized to establish a simple and sensitive colorimetric assay for detection of H2O2 and glucose. CZIS NCs are recyclable catalysts showing high efficiency in multiple uses. Our study may open up the possibility of designing new photoactive multi-component alloyed NCs as enzyme mimetics in biotechnology applications.Artificial enzyme mimetics have attracted immense interest recently because natural enzymes undergo easy denaturation under environmental conditions restricting practical usefulness. We report for the first time chalcopyrite CuZnFeS (CZIS) alloyed nanocrystals (NCs) as novel biomimetic catalysts with efficient intrinsic peroxidase-like activity. Novel peroxidase activities of CZIS NCs have been

  17. Clinical profiling of BCL-2 family members in the setting of BRAF inhibition offers a rationale for targeting de novo resistance using BH3 mimetics.

    Directory of Open Access Journals (Sweden)

    Dennie T Frederick

    Full Text Available While response rates to BRAF inhibitiors (BRAFi are high, disease progression emerges quickly. One strategy to delay the onset of resistance is to target anti-apoptotic proteins such as BCL-2, known to be associated with a poor prognosis. We analyzed BCL-2 family member expression levels of 34 samples from 17 patients collected before and 10 to 14 days after treatment initiation with either vemurafenib or dabrafenib/trametinib combination. The observed changes in mRNA and protein levels with BRAFi treatment led us to hypothesize that combining BRAFi with a BCL-2 inhibitor (the BH3-mimetic navitoclax would improve outcome. We tested this hypothesis in cell lines and in mice. Pretreatment mRNA levels of BCL-2 negatively correlated with maximal tumor regression. Early increases in mRNA levels were seen in BIM, BCL-XL, BID and BCL2-W, as were decreases in MCL-1 and BCL2A. No significant changes were observed with BCL-2. Using reverse phase protein array (RPPA, significant increases in protein levels were found in BIM and BID. No changes in mRNA or protein correlated with response. Concurrent BRAF (PLX4720 and BCL2 (navitoclax inhibition synergistically reduced viability in BRAF mutant cell lines and correlated with down-modulation of MCL-1 and BIM induction after PLX4720 treatment. In xenograft models, navitoclax enhanced the efficacy of PLX4720. The combination of a selective BRAF inhibitor with a BH3-mimetic promises to be an important therapeutic strategy capable of enhancing the clinical efficacy of BRAF inhibition in many patients that might otherwise succumb quickly to de novo resistance. Trial registrations: ClinicalTrials.gov NCT01006980; ClinicalTrials.gov NCT01107418; ClinicalTrials.gov NCT01264380; ClinicalTrials.gov NCT01248936; ClinicalTrials.gov NCT00949702; ClinicalTrials.gov NCT01072175.

  18. d-Allulose, a stereoisomer of d-fructose, extends Caenorhabditis elegans lifespan through a dietary restriction mechanism: A new candidate dietary restriction mimetic.

    Science.gov (United States)

    Shintani, Tomoya; Sakoguchi, Hirofumi; Yoshihara, Akihide; Izumori, Ken; Sato, Masashi

    2017-12-02

    Dietary restriction (DR) is an effective intervention known to increase lifespan in a wide variety of organisms. DR also delays the onset of aging-associated diseases. DR mimetics, compounds that can mimic the effects of DR, have been intensively explored. d-Allulose (d-Alu), the C3-epimer of d-fructose, is a rare sugar that has various health benefits, including anti-hyperglycemia and anti-obesity effects. Here, we report that d-Alu increased the lifespan of Caenorhabditis elegans both under monoxenic and axenic culture conditions. d-Alu did not further extend the lifespan of the long-lived DR model eat-2 mutant, strongly indicating that the effect is related to DR. However, d-Alu did not reduce the food intake of wild-type C. elegans. To explore the mechanisms of the d-Alu longevity effect, we examined the lifespan of d-Alu-treated mutants deficient for nutrient sensing pathway-related genes daf-16, sir-2.1, aak-2, and skn-1. As a result, d-Alu increased the lifespan of the daf-16, sir-2.1, and skn-1 mutants, but not the aak-2 mutant, indicating that the lifespan extension was dependent on the energy sensor, AMP-activated protein kinase (AMPK). d-Alu also enhanced the mRNA expression and enzyme activities of superoxide dismutase (SOD) and catalase. From these findings, we conclude that d-Alu extends lifespan by increasing oxidative stress resistance through a DR mechanism, making it a candidate DR mimetic. Copyright © 2017 Elsevier Inc. All rights reserved.

  19. The SMAC mimetic BV6 induces cell death and sensitizes different cell lines to TNF-α and TRAIL-induced apoptosis.

    Science.gov (United States)

    El-Mesery, Mohamed; Shaker, Mohamed E; Elgaml, Abdelaziz

    2016-12-01

    The inhibitors of apoptosis proteins are implicated in promoting cancer cells survival and resistance toward immune surveillance and chemotherapy. Second mitochondria-derived activator of caspases (SMAC) mimetics are novel compounds developed to mimic the inhibitory effect of the endogenous SMAC/DIABLO on these IAPs. Here, we examined the potential effects of the novel SMAC mimetic BV6 on different human cancer cell lines. Our results indicated that BV6 was able to induce cell death in different human cancer cell lines. Mechanistically, BV6 dose dependently induced degradation of IAPs, including cIAP1 and cIAP2. This was coincided with activating the non-canonical NF -kappa B (NF-κB) pathway, as indicated by stabilizing NF-κB-inducing kinase (NIK) for p100 processing to p52. More interestingly, BV6 was able to sensitize some of the resistant cancer cell lines to apoptosis induced by the death ligands tumor necrosis factor-α (TNF-α) and TNF-related apoptosis-inducing ligand (TRAIL) that are produced by different cells of the immune system. Such cell death enhancement was mediated by inducing an additional cleavage of caspase-9 to augment that of caspase-8 induced by death ligands. This eventually led to more processing of the executioner caspase-3 and poly (ADP-ribose) polymerase (PARP). In conclusion, therapeutic targeting of IAPs by BV6 might be an effective approach to enhance cancer regression induced by immune system. Our data also open up the future possibility of using BV6 in combination with other antitumor therapies to overcome cancer drug resistance.

  20. SMAC mimetic BV6 enables sensitization of resistant tumor cells but also affects cytokine-induced killer (CIK cells: a potential challenge for combination therapy

    Directory of Open Access Journals (Sweden)

    Eva eRettinger

    2014-07-01

    Full Text Available Allogeneic hematopoietic stem cell transplantation (HSCT is an established treatment option for high-risk hematological malignancies, and may also be offered to patients with solid malignancies refractory to conventional therapies. In case of patients’ relapse, refractory tumor cells may then be targeted by cellular therapy-based combination strategies. Here, we investigated the potential of small molecule IAP inhibitor (SMAC mimetic BV6 in increasing cytokine-induced killer (CIK cell-mediated cytotoxicity against different tumor targets. Four hour pre-incubation with 2.5 μMol BV6 moderately enhanced CIK cell-mediated lysis of hematological (H9, THP-1, Tanoue and solid malignancies (RH1, RH30, TE671. However, BV6 also increased apoptosis of non-malignant cells like peripheral blood mononuclear cells and most notably had an inhibitory effect on immune cells potentially limiting their cytotoxic potential. Hence, cytotoxicity increased in a dose dependent manner when BV6 was removed before CIK cells were added to tumor targets. However, cytotoxic potential was not further increasable by extending BV6 pre-incubation period of target cells from four to 12 hours. Molecular studies revealed that BV6 sensitization of target cells involved activation of caspases. Here we provide evidence that SMAC mimetic may sensitize targets cells for CIK cell-induced cell death. However, BV6 also increased apoptosis of non-malignant cells like CIK cells and peripheral mononuclear cells. These findings may therefore be important for cell- and small molecule IAP inhibitor- based combination therapies of resistant cancers after allogeneic HSCT.

  1. The role of ultraviolet colour in the assessment of mimetic accuracy between Batesian mimics and their models: a case study using ant-mimicking spiders

    Science.gov (United States)

    Corcobado, Guadalupe; Herberstein, Marie E.; Pekár, Stano

    2016-12-01

    The use of ultraviolet (UV) cues for intra- and inter-specific communication is common in many animal species. Still, the role of UV signals under some predator-prey contexts, such as Batesian mimicry, is not clear. Batesian mimicry is a defensive strategy by which a palatable species (the mimic) resembles an unpalatable or noxious species (the model) to avoid predation. This strategy has evolved independently in many different taxa that are predated by species capable of UV perception. Moreover, there is considerable variation in how accurately Batesian mimics resemble their models across species. Our aim was to investigate how UV colour contributed to mimetic accuracy using several ant-mimicking spider species as a case study. We measured the reflectance spectrum (300-700 nm) for several species of mimics and models, and we tested whether they differ in visible and UV colour. We modelled whether two different predators could discriminate between mimics and models using colour information. We found that generally, ant-mimicking spiders differed significantly from their ant models in UV colour and that information from the visible range of light cannot be extrapolated into the UV. Our modelling suggested that wasps should be able to discriminate between mimics and models combining information from visible and the UV light, whereas birds may not discriminate between them. Thus, we show that UV colour can influence mimic accuracy and we discuss its potential role in Batesian mimicry. We conclude that colour, especially in the UV range, should be taken into account when measuring mimetic accuracy.

  2. In vivo coordination structural changes of a potent insulin-mimetic agent, bis(picolinato)oxovanadium(IV), studied by electron spin-echo envelope modulation spectroscopy.

    Science.gov (United States)

    Fukui, K; Fujisawa, Y; OhyaNishiguchi, H; Kamada, H; Sakurai, H

    1999-01-01

    Bis(picolinato)oxovanadium(IV) [VO(pic)2] is one of the most potent insulin-mimetic vanadium complexes. To probe coordination structural changes of this complex in vivo and provide insights into the origin of its high potency, an electron spin-echo envelope modulation (ESEEM) study was performed on organs (kidney, liver and bone) of VO(pic)2- and VOSO4-treated rats. Kidney and liver samples from both types of rats exhibited a 14N ESEEM signal that could be attributed to equatorially coordinating amine nitrogen. The relative intensity of the amine signal was larger for the organs of the rat treated with the less potent VOSO4, suggesting that this amine coordination inhibits the insulin-mimetic activity. The spectra of kidney and liver from the VO(pic)2-treated rat contained a weak signal due to the picolinate imine nitrogen. This suggests that some picolinato species (including both the bispicolinato and a partially decomposed monopicolinato species) still exist in the organs as a minor species, where the proportions of the picolinato species to the total amount of the EPR-detectable VIVO species are estimated as 8-16% in the kidney and 12-24% in the liver. The picolinate ligand presumably serves to prevent VO2+ from being converted into the inactive amine-coordinated species. Bone samples from both types of rats exhibited an ESEEM signal due to 31P nuclei. The VO2+ in bone is therefore most likely incorporated into the hydroxyapatite Ca10(PO4)6(OH)2 matrix, which is consistent with the hypothesis that the bone-accumulated VO2+ is gradually released and transported to other organs as is Ca2+. No 14N signals were observed, even in the bone samples of the VO(pic)2-treated rats, indicating that vanadium uptake by bone requires complete decomposition of the complex.

  3. Absorption, transport and insulin-mimetic properties of bis(maltolato)oxovanadium (IV) in streptozotocin-induced hyperglycemic rats by integrated mass spectrometric techniques.

    Science.gov (United States)

    Iglesias-González, T; Sánchez-González, C; Montes-Bayón, M; Llopis-González, J; Sanz-Medel, A

    2012-01-01

    The use of V(IV) complexes as insulin-enhancing agents has been increasing during the last decade. Among them, 3-hydroxy-2-methyl-4-pyrone and 2-ethyl-3-hydroxy-4-pyrone (maltol and ethyl maltol, respectively) have proven to be especially suitable as ligands for vanadyl ions. In fact, they have passed phase I and phase II clinical trials, respectively. However, the mechanism through which those drugs exert their insulin-mimetic properties is still not fully understood. Thus, the aim of this study is to obtain an integrated picture of the absorption, biodistribution and insulin-mimetic properties of the bis(maltolato)oxovanadium (IV) (BMOV) in streptozotocin-induced hyperglycaemic rats. For this purpose, BMOV hypoglycaemic properties were evaluated by monitoring both the circulating glucose and the glycohemoglobin, biomarkers of diabetes mellitus. In both cases, the results were drug concentration dependent. Using doses of vanadium at 3 mg/day, it was possible to reduce the glycaemia of the diabetic rats to almost control levels. BMOV absorption experiments have been conducted by intestinal perfusion revealing that approximately 35% of V is absorbed by the intestinal cells. Additionally, the transport of the absorbed vanadium (IV) by serum proteins was studied. For this purpose, a speciation strategy using high-performance liquid chromatography (HPLC) for separation and inductively coupled serum mass spectrometry, ICP-MS, for detection has been employed. The obtained HPLC-ICP-MS results, confirmed by MALDI-MS data, showed evidence that V, administered orally, is uniquely bound to transferrin in rat serum.

  4. Trimebutine, a small molecule mimetic agonist of adhesion molecule L1, contributes to functional recovery after spinal cord injury in mice

    Directory of Open Access Journals (Sweden)

    Junping Xu

    2017-09-01

    Full Text Available Curing spinal cord injury (SCI in mammals is a daunting task because of the lack of permissive mechanisms and strong inhibitory responses at and around the lesion. The neural cell adhesion molecule L1CAM (L1 has been shown to favor axonal regrowth and enhance neuronal survival and synaptic plasticity but delivery of full-length L1 or its extracellular domain could encounter difficulties in translation to therapy in humans. We have, therefore, identified several small organic compounds that bind to L1 and stimulate neuronal survival, neuronal migration and neurite outgrowth in an L1-dependent manner. Here, we assessed the functions of two L1 mimetics, trimebutine and honokiol, in regeneration following SCI in young adult mice. Using the Basso Mouse Scale (BMS score, we found that ground locomotion in trimebutine-treated mice recovered better than honokiol-treated or vehicle-receiving mice. Enhanced hindlimb locomotor functions in the trimebutine group were observed at 6 weeks after SCI. Immunohistology of the spinal cords rostral and caudal to the lesion site showed reduced areas and intensities of glial fibrillary acidic protein immunoreactivity in both trimebutine and honokiol groups, whereas increased regrowth of axons was observed only in the trimebutine-treated group. Both L1- and L1 mimetic-mediated intracellular signaling cascades in the spinal cord lesion sites were activated by trimebutine and honokiol, with trimebutine being more effective than honokiol. These observations suggest that trimebutine and, to a lesser extent under the present experimental conditions, honokiol have a potential for therapy in regeneration of mammalian spinal cord injuries.

  5. Fabrication highly dispersed Fe3O4 nanoparticles on carbon nanotubes and its application as a mimetic enzyme to degrade Orange II.

    Science.gov (United States)

    Deng, Jingheng; Wen, Xianghua; Li, Jiaxi

    2016-09-01

    Fe3O4 nanoparticles were grown in situ on carbon nanotubes (CNTs) by a solvothermal method. The Fe3O4/CNTs composites were characterised by the Brunauer-Emmett-Teller method and transmission electron microscopy. The results indicated that the Fe3O4 nanoparticles were uniformly deposited on CNTs, and the average diameter was approximately 7.0 nm. The Fe3O4/CNTs were applied as an enzyme mimetic to decompose Orange II, and the decomposing conditions were optimised. At 500 mg L(-1) of Fe3O4/CNTs in the presence of 15.0 mmol L(-1) of H2O2, at 30°C, it degraded 94.0% of Orange II (0.25 mmol L(-1), pH = 3.5), showing higher catalytic activity than pure Fe3O4 nanoparticles. The high activity was attributed to the uniform Fe3O4 nanoparticles growing on the side walls of the CNTs and the synergetic effect between Fe3O4 and CNTs. The Fe3O4/CNTs maintained their activity at temperatures as high as 65°C. The Fe3O4/CNTs presented high reusability and stability even after eight uses. These data proved that the Fe3O4/CNTs-catalysed degradation is a promising technique for wastewater treatment. Fe3O4 nanoparticles were grown in situ on carbon nanotubes (CNTs) by a solvothermal method. The Fe3O4/CNTs was applied as a mimetic enzyme to decompose Orange II. The Fe3O4/CNTs were collected after the reaction by applying an external magnetic field and can use repeatedly.

  6. Regression of coronary atherosclerosis with infusions of the high-density lipoprotein mimetic CER-001 in patients with more extensive plaque burden.

    Science.gov (United States)

    Kataoka, Yu; Andrews, Jordan; Duong, MyNgan; Nguyen, Tracy; Schwarz, Nisha; Fendler, Jessica; Puri, Rishi; Butters, Julie; Keyserling, Constance; Paolini, John F; Dasseux, Jean-Louis; Nicholls, Stephen J

    2017-06-01

    CER-001 is an engineered pre-beta high-density lipoprotein (HDL) mimetic, which rapidly mobilizes cholesterol. Infusion of CER-001 3 mg/kg exhibited a potentially favorable effect on plaque burden in the CHI-SQUARE (Can HDL Infusions Significantly Quicken Atherosclerosis Regression) study. Since baseline atheroma burden has been shown as a determinant for the efficacy of HDL infusions, the degree of baseline atheroma burden might influence the effect of CER-001. CHI-SQUARE compared the effect of 6 weekly infusions of CER-001 (3, 6 and 12 mg/kg) vs. placebo on coronary atherosclerosis in 369 patients with acute coronary syndrome (ACS) using serial intravascular ultrasound (IVUS). Baseline percent atheroma volume (B-PAV) cutoff associated with atheroma regression following CER-001 infusions was determined by receiver-operating characteristics curve analysis. 369 subjects were stratified according to the cutoff. The effect of CER-001 at different doses was compared to placebo in each group. A B-PAV ≥30% was the optimal cutoff associated with PAV regression following CER-001 infusions. CER-001 induced PAV regression in patients with B-PAV ≥30% but not in those with B-PAV PAV regression was observed with CER-001 3mg/kg in patients with B-PAV ≥30% (-0.96%±0.34% vs. -0.25%±0.31%, P=0.01), whereas there were no differences between placebo (+0.09%±0.36%) versus CER-001 in patients with B-PAV PAV. These findings identify ACS patients with more extensive disease as most likely to benefit from HDL mimetic therapy.

  7. Real-time examination of aminoglycoside activity towards bacterial mimetic membranes using Quartz Crystal Microbalance with Dissipation monitoring (QCM-D).

    Science.gov (United States)

    Joshi, Tanmaya; Voo, Zhi Xiang; Graham, Bim; Spiccia, Leone; Martin, Lisandra L

    2015-02-01

    The rapid increase in multi-drug resistant bacteria has resulted in previously discontinued treatments being revisited. Aminoglycosides are effective "old" antibacterial agents that fall within this category. Despite extensive usage and understanding of their intracellular targets, there is limited mechanistic knowledge regarding how aminoglycosides penetrate bacterial membranes. Thus, the activity of two well-known aminoglycosides, kanamycin A and neomycin B, towards a bacterial mimetic membrane (DMPC:DMPG (4:1)) was examined using a Quartz Crystal Microbalance with Dissipation monitoring (QCM-D). The macroscopic effect of increasing the aminoglycoside concentration showed that kanamycin A exerts a threshold response, switching from binding to the membrane to disruption of the surface. Neomycin B, however, disrupted the membrane at all concentrations examined. At concentrations above the threshold value observed for kanamycin A, both aminoglycosides revealed similar mechanistic details. That is, they both inserted into the bacterial mimetic lipid bilayer, prior to disruption via loss of materials, presumably aminoglycoside-membrane composites. Depth profile analysis of this membrane interaction was achieved using the overtones of the quartz crystal sensor. The measured data is consistent with a two-stage process in which insertion of the aminoglycoside precedes the 'detergent-like' removal of membranes from the sensor. The results of this study contribute to the insight required for aminoglycosides to be reconsidered as active antimicrobial agents/co-agents by providing details of activity at the bacterial membrane. Kanamycin and neomycin still offer potential as antimicrobial therapeutics for the future and the QCM-D method illustrates great promise for screening new antibacterial or antiviral drug candidates. Copyright © 2014 Elsevier B.V. All rights reserved.

  8. Effects of the dual TP receptor antagonist and thromboxane synthase inhibitor EV-077 on human endothelial and vascular smooth muscle cells

    Energy Technology Data Exchange (ETDEWEB)

    Petri, Marcelo H. [Department of Medicine, Karolinska Institutet and Center for Molecular Medicine, Karolinska University Hospital, Stockholm (Sweden); Tellier, Céline; Michiels, Carine [NARILIS, URBC, University of Namur, Namur (Belgium); Ellertsen, Ingvill [Department of Medicine, Karolinska Institutet and Center for Molecular Medicine, Karolinska University Hospital, Stockholm (Sweden); Dogné, Jean-Michel [Department of Pharmacy, Namur Thrombosis and Hemostasis Center, University of Namur, Namur (Belgium); Bäck, Magnus, E-mail: Magnus.Back@ki.se [Department of Medicine, Karolinska Institutet and Center for Molecular Medicine, Karolinska University Hospital, Stockholm (Sweden)

    2013-11-15

    Highlights: •EV-077 reduced TNF-α induced inflammation in endothelial cells. •The thromboxane mimetic U69915 enhanced vascular smooth muscle cell proliferation. •EV-077 inhibited smooth muscle cell proliferation. -- Abstract: The prothrombotic mediator thromboxane A{sub 2} is derived from arachidonic acid metabolism through the cyclooxygenase and thromboxane synthase pathways, and transduces its effect through the thromboxane prostanoid (TP) receptor. The aim of this study was to determine the effect of the TP receptor antagonist and thromboxane synthase inhibitor EV-077 on inflammatory markers in human umbilical vein endothelial cells and on human coronary artery smooth muscle cell proliferation. To this end, mRNA levels of different proinflammatory mediators were studied by real time quantitative PCR, supernatants were analyzed by enzyme immune assay, and cell proliferation was assessed using WST-1. EV-077 significantly decreased mRNA levels of ICAM-1 and PTX3 after TNFα incubation, whereas concentrations of 6-keto PGF1α in supernatants of endothelial cells incubated with TNFα were significantly increased after EV-077 treatment. Although U46619 did not alter coronary artery smooth muscle cell proliferation, this thromboxane mimetic enhanced the proliferation induced by serum, insulin and growth factors, which was significantly inhibited by EV-077. In conclusion, EV-077 inhibited TNFα-induced endothelial inflammation and reduced the enhancement of smooth muscle cell proliferation induced by a thromboxane mimetic, supporting that the thromboxane pathway may be associated with early atherosclerosis in terms of endothelial dysfunction and vascular hypertrophy.

  9. Thromboxane and isoprostanes as inflammatory and vasoactive mediators in black walnut heartwood extract induced equine laminitis.

    Science.gov (United States)

    Noschka, Erik; Moore, James N; Peroni, John F; Lewis, Stephen J; Morrow, Jason D; Robertson, Tom P

    2009-06-15

    Inflammation and vascular dysfunction occur concurrently during the prodromal stages of equine laminitis. The aim of this study was to provide insights into the role that thromboxane and isoprostanes may play in the development of black walnut heartwood extract (BWHE)-induced laminitis. Horses were divided into two groups, either control or BWHE-administered horses. Plasma concentrations of thromboxane increased transiently after administration of BWHE and coincided with the nadir in white blood cell counts, whereas plasma concentrations of iso-prostaglandin PGF(2alpha) (iso-PGF(2alpha)) did not change in either group. At 12h (for the control group) or Obel grade 1 laminitis (for the BWHE group) the horses were euthanized and laminar tissue collected. Laminar arteries and veins were used in functional studies with vasoconstrictor substances and tissue samples were used for the determination of laminar iso-PGF(2alpha) concentrations. Laminar tissue concentrations of iso-PGF(2alpha) were significantly greater in BWHE horses when compared to control horses. In parallel studies concentrations of iso-PGF(2alpha) in laminar tissue samples obtained 1.5 and 3h after administration of BWHE were indistinguishable from those for control horses at 3 or 12h after administration of an equal volume of water. Laminar vessel constrictor responses to either a thromboxane mimetic (U46619), iso-prostaglandin PGE(2) (iso-PGE(2)) or iso-PGF(2alpha) were determined using small vessel myographs. In some vessels, the effects of putative prostanoid and thromboxane receptor antagonists, SQ 29,548, SC-19220 and AH 6809, upon contractile responses were determined. In control horses, U46619, iso-PGF(2alpha) and iso-PGE(2) more potently and efficaciously constricted laminar veins when compared to laminar arteries. Responses of laminar veins from BWHE horses to iso-PGE(2) were similar to those of laminar veins from control horses, whereas iso-PGF(2alpha) elicited significantly greater responses

  10. Endotoxin induced chorioamnionitis prevents intestinal development during gestation in fetal sheep.

    Directory of Open Access Journals (Sweden)

    Tim G A M Wolfs

    Full Text Available Chorioamnionitis is the most significant source of prenatal inflammation and preterm delivery. Prematurity and prenatal inflammation are associated with compromised postnatal developmental outcomes, of the intestinal immune defence, gut barrier function and the vascular system. We developed a sheep model to study how the antenatal development of the gut was affected by gestation and/or by endotoxin induced chorioamnionitis.Chorioamnionitis was induced at different gestational ages (GA. Animals were sacrificed at low GA after 2d or 14d exposure to chorioamnionitis. Long term effects of 30d exposure to chorioamnionitis were studied in near term animals after induction of chorioamnionitis. The cellular distribution of tight junction protein ZO-1 was shown to be underdeveloped at low GA whereas endotoxin induced chorioamnionitis prevented the maturation of tight junctions during later gestation. Endotoxin induced chorioamnionitis did not induce an early (2d inflammatory response in the gut in preterm animals. However, 14d after endotoxin administration preterm animals had increased numbers of T-lymphocytes, myeloperoxidase-positive cells and gammadelta T-cells which lasted till 30d after induction of chorioamnionitis in then near term animals. At early GA, low intestinal TLR-4 and MD-2 mRNA levels were detected which were further down regulated during endotoxin-induced chorioamnionitis. Predisposition to organ injury by ischemia was assessed by the vascular function of third-generation mesenteric arteries. Endotoxin-exposed animals of low GA had increased contractile response to the thromboxane A2 mimetic U46619 and reduced endothelium-dependent relaxation in responses to acetylcholine. The administration of a nitric oxide (NO donor completely restored endothelial dysfunction suggesting reduced NO bioavailability which was not due to low expression of endothelial nitric oxide synthase.Our results indicate that the distribution of the tight

  11. Protease-activated receptor-2 turnover stimulated independently of receptor activation in porcine coronary endothelial cells

    Science.gov (United States)

    Hamilton, Justin R; Chow, Jean M; Cocks, Thomas M

    1999-01-01

    Protease-activated receptors (PARs) are activated by an irreversible proteolytic mechanism which renders cleaved receptors unresponsive to subsequent challenges with activating enzymes. Non-specific proteolysis of PARs downstream of the activation site also prevents subsequent enzymic activation. Therefore, we investigated the effects of non-activating amino-terminal proteolysis with the bacterial protease thermolysin on PAR-mediated relaxation of porcine coronary artery ring preparations contracted with the thromboxane A2 mimetic U46619 (1–10 nM). Treatment of contracted artery ring segments with thermolysin (0.01–1 u ml−1, 20 min) caused no response, but abolished endothelium-dependent relaxations induced by the enzymic activators of PAR-1 and PAR-2, thrombin (0.01–0.3 u ml−1) and trypsin (0.003–0.1 u ml−1) respectively. The same treatment, however, did not affect similar responses to the proteolysis-independent PAR-1 and PAR-2 activating peptides, SFLLRN-NH2 and SLIGRL-NH2 respectively (0.1–10 μM). The inhibition of responsiveness to trypsin after thermolysin treatment recovered in a time-dependent manner, with maximal recovery (77.3±8.0% of time controls) occurring 150 min after thermolysin treatment. No recovery of responsiveness to thrombin after thermolysin treatment was observed within this time, however, the thrombin response returned to control levels after 20 h. The recovery of responsiveness to trypsin was inhibited by the translation inhibitor cycloheximide (100 μM; 17.3±4.7%) and the protein trafficking inhibitor brefeldin A (10 μM; 12.1±4.8%) but was unaffected by the transcription inhibitor actinomycin D (2 μM; 65.1±3.6%), which did, however, abolish upregulation of B1-kinin receptors in this preparation. In conclusion, our findings indicate that activation-independent amino-terminal proteolysis of PARs stimulates selective recovery of endothelial cell PAR-2 responsiveness, which appears to be

  12. A Placebo-Controlled Study on the Effects of the Glucagon-Like Peptide-1 Mimetic, Exenatide, on Insulin Secretion, Body Composition and Adipokines in Obese, Client-Owned Cats

    DEFF Research Database (Denmark)

    Hoelmkjaer, Kirsten M.; Albrechtsen, Nicolai Jacob Wewer; Holst, Jens Juul

    2016-01-01

    Glucagon-like Peptide-1 mimetics increase insulin secretion and reduces body weight in humans. In lean, healthy cats, short-term treatment has produced similar results, whereas the effect in obese cats or with extended duration of treatment is unknown. Here, prolonged (12 weeks) treatment...... with the Glucagon-like Peptide-1 mimetic, exenatide, was evaluated in 12 obese, but otherwise healthy, client-owned cats. Cats were randomized to exenatide (1.0 μg/kg) or placebo treatment twice daily for 12 weeks. The primary endpoint was changes in insulin concentration; the secondary endpoints were glucose...... by exenatide (P>0.05). Twelve weeks of exenatide was well-tolerated, with only two cases of mild, self-limiting gastrointestinal signs and a single case of mild hypoglycemia. The long-term insulinotropic effect of exenatide appeared less pronounced in obese cats compared to previous short-term studies in lean...

  13. A Special Extract of Bacopa monnieri (CDRI-08)-Restored Memory in CoCl2-Hypoxia Mimetic Mice Is Associated with Upregulation of Fmr-1 Gene Expression in Hippocampus

    OpenAIRE

    Rani, Anupama; Prasad, S.

    2015-01-01

    Fragile X mental retardation protein (FMRP) is a neuronal translational repressor and has been implicated in learning, memory, and cognition. However, the role of Bacopa monnieri extract (CDRI-08) in enhancing cognitive abilities in hypoxia-induced memory impairment via Fmr-1 gene expression is not known. Here, we have studied effects of CDRI-08 on the expression of Fmr-1 gene in the hippocampus of well validated cobalt chloride (CoCl2)-induced hypoxia mimetic mice and analyzed the data with...

  14. Oral delivery of [D-Leu-4]-OB3 and MA-[D-Leu-4]-OB3, synthetic peptide leptin mimetics: Immunofluorescent localization in the mouse hypothalamus.

    Science.gov (United States)

    Anderson, Brian M; Jacobson, Lauren; Novakovic, Zachary M; Grasso, Patricia

    2017-06-01

    This study describes the localization of [D-Leu-4]-OB3 and MA-[D-Leu-4]-OB3, synthetic peptide leptin mimetics, in the hypothalamus of Swiss Webster and C57BL/6J wild-type mice, leptin-deficient ob/ob mice, and leptin-resistant diet-induced obese (DIO) mice. The mice were given [D-Leu-4]-OB3 or MA-[D-Leu-4]-OB3 in 0.3% dodecyl maltoside by oral gavage. Once peak serum concentrations were reached, the mice received a lethal dose of pentobarbital and were subjected to intracardiac perfusion fixation. The brains were excised, post-fixed in paraformaldehyde, and cryo-protected in sucrose. Free-floating frozen coronal sections were cut at 25-µm and processed for imaging by immunofluorescence microscopy. In all four strains of mice, dense staining was concentrated in the area of the median eminence, at the base and/or along the inner wall of the third ventricle, and in the brain parenchyma at the level of the arcuate nucleus. These results indicate that [D-Leu-4]-OB3 and MA-[D-Leu-4]-OB3 cross the blood-brain barrier and concentrate in an area of the hypothalamus known to regulate energy balance and glucose homeostasis. Most noteworthy is the localization of [D-Leu-4]-OB3 immunoreactivity within the hypothalamus of DIO mice via a conduit that is closed to leptin in this rodent model, and in most cases of human obesity. Together with our previous studies describing the effects of [D-Leu-4]-OB3 and MA-[D-Leu-4]-OB3 on energy balance, glucose regulation, and signal transduction pathway activation, these findings are consistent with a central mechanism of action for these synthetic peptide leptin mimetics, and suggest their potential usefulness in the management of leptin-resistant obesity and type 2 diabetes in humans. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Gefitinib-induced killing of NSCLC cell lines expressing mutant EGFR requires BIM and can be enhanced by BH3 mimetics.

    Directory of Open Access Journals (Sweden)

    Mark S Cragg

    2007-10-01

    Full Text Available The epidermal growth factor receptor (EGFR plays a critical role in the control of cellular proliferation, differentiation, and survival. Abnormalities in EGF-EGFR signaling, such as mutations that render the EGFR hyperactive or cause overexpression of the wild-type receptor, have been found in a broad range of cancers, including carcinomas of the lung, breast, and colon. EGFR inhibitors such as gefitinib have proven successful in the treatment of certain cancers, particularly non-small cell lung cancers (NSCLCs harboring activating mutations within the EGFR gene, but the molecular mechanisms leading to tumor regression remain unknown. Therefore, we wished to delineate these mechanisms.We performed biochemical and genetic studies to investigate the mechanisms by which inhibitors of EGFR tyrosine kinase activity, such as gefitinib, inhibit the growth of human NSCLCs. We found that gefitinib triggered intrinsic (also called "mitochondrial" apoptosis signaling, involving the activation of BAX and mitochondrial release of cytochrome c, ultimately unleashing the caspase cascade. Gefitinib caused a rapid increase in the level of the proapoptotic BH3-only protein BIM (also called BCL2-like 11 through both transcriptional and post-translational mechanisms. Experiments with pharmacological inhibitors indicated that blockade of MEK-ERK1/2 (mitogen-activated protein kinase kinase-extracellular signal-regulated protein kinase 1/2 signaling, but not blockade of PI3K (phosphatidylinositol 3-kinase, JNK (c-Jun N-terminal kinase or mitogen-activated protein kinase 8, or AKT (protein kinase B, was critical for BIM activation. Using RNA interference, we demonstrated that BIM is essential for gefitinib-induced killing of NSCLC cells. Moreover, we found that gefitinib-induced apoptosis is enhanced by addition of the BH3 mimetic ABT-737.Inhibitors of the EGFR tyrosine kinase have proven useful in the therapy of certain cancers, in particular NSCLCs possessing

  16. The SMAC mimetic BV6 sensitizes colorectal cancer cells to ionizing radiation by interfering with DNA repair processes and enhancing apoptosis

    International Nuclear Information System (INIS)

    Hehlgans, Stephanie; Oppermann, Julius; Reichert, Sebastian; Fulda, Simone; Rödel, Claus; Rödel, Franz

    2015-01-01

    In the present study, we aimed to investigate the effect of counteracting inhibitor of apoptosis (IAP) proteins using the small molecule Second Mitochondria-derived Activator of Caspase (SMAC) mimetic BV6 in combination with ionizing radiation on apoptosis, cell cycle regulation, DNA double-strand break (DSB) repair, three-dimensional (3D) clonogenic survival and expression of IAPs in colorectal carcinoma cells. Colorectal cancer cell lines (HCT-15, HT-29, SW480) were subjected to BV6 treatment (0–4 μM) with or without irradiation (2–8 Gy, single dose) followed by MTT, Caspase 3/7 activity, γH2AX/53BP1 foci assays, AnnexinV staining, cell cycle analysis, 3D colony forming assays and Western blotting (cellular IAP1 (cIAP1) and cIAP2, Survivin, X-linked IAP (XIAP)). BV6 treatment decreased cell viability and significantly increased irradiation-induced apoptosis as analyzed by Caspase 3/7 activity, AnnexinV-positive and subG1 phase cells. While basal 3D clonogenic survival was decreased in a cell line-dependent manner, BV6 significantly enhanced cellular radiosensitivity of all cell lines in a concentration-dependent manner and increased the number of radiation-induced γH2AX/53BP1-positive foci. Western blot analysis revealed a markedly reduced cIAP1 expression at 4 h after BV6 treatment in all cell lines, a substantial reduction of XIAP expression in SW480 and HT-29 cells at 24 h and a slightly decreased cIAP2 expression in HCT-15 cells at 48 h after treatment. Moreover, single or double knockdown of cIAP1 and XIAP resulted in significantly increased residual γH2AX/53BP1-positive foci 24 h after 2 Gy and radiosensitization relative to control small interfering RNA (siRNA)-treated cells. The SMAC mimetic BV6 induced apoptosis and hampered DNA damage repair to radiosensitize 3D grown colorectal cancer cells. Our results demonstrate IAP targeting as a promising strategy to counteract radiation resistance of colorectal cancer cells. The online version of this

  17. Stimulatory (insulin-mimetic) and inhibitory (ouabain-like) action of vanadate on potassium uptake and cellular sodium and potassium in heart cells in culture.

    Science.gov (United States)

    Werdan, K; Bauriedel, G; Fischer, B; Krawietz, W; Erdmann, E; Schmitz, W; Scholz, H

    1982-04-23

    (1) The influence of vanadate (Na3VO4) on sodium and potassium uptake as well as on cellular ion contents of sodium and potassium has been studied in heart muscle and non-muscle cells obtained from various species. An ouabain-like inhibition of potassium uptake (up to 50%), combined with a decrease of cellular potassium (up to 20%) has been observed by vanadate (10(-4)-10(-3) M) in heart non-muscle cells obtained from neonatal guinea pigs and chick embryos. In heart muscle and non-muscle cells prepared from neonatal rats, as well as in Girardi human heart cells, a vanadate-induced stimulation of potassium uptake (up to 100%), combined with a rise in cellular potassium (up to 20%) and without significant alteration of cellular sodium, has been found. A slight increase of 22Na+ influx can be measured in rat heart muscle cells and in Girardi human heart cells in the presence of vanadate (10(-4)--10(-3) M). (2) In beating rat heart muscle cells in culture, detrimental effects of serum deprivation--concerning beating properties, potassium uptake and cellular potassium--can at least in part be overcome by addition of vanadate. Furthermore, this compound prevents ouabain-induced signs of toxicity (contractures) in these cells. (3) The stimulatory effects of vanadate on potassium can be mimicked by insulin (1-10 mU/ml). Furthermore, vanadate produces an insulin-like stimulation of 2-deoxy-D-glucose uptake in rat heart muscle and non-muscle cells as well as in Girardi human heart cells. (4) The experimental data demonstrate an ouabain-like inhibition as well as an insulin-mimetic stimulation of potassium-uptake in various heart cells. The reason for this antagonistic mode of action may be due to the different capabilities of the heart cell types to reduce vanadium in the V-valence state of vanadium in the IV-valence state, thereby favouring either ouabain-like inhibition (vanadium V) or insulin-mimetic stimulation (vanadium IV) of potassium transport.

  18. Cross-Linking of a CD4-Mimetic Miniprotein with HIV-1 Env gp140 Alters Kinetics and Specificities of Antibody Responses against HIV-1 Env in Macaques.

    Science.gov (United States)

    Shen, Xiaoying; Bogers, Willy M; Yates, Nicole L; Ferrari, Guido; Dey, Antu K; Williams, William T; Jaeger, Frederick H; Wiehe, Kevin; Sawant, Sheetal; Alam, S Munir; LaBranche, Celia C; Montefiori, David C; Martin, Loic; Srivastava, Indresh; Heeney, Jonathan; Barnett, Susan W; Tomaras, Georgia D

    2017-10-01

    Evaluation of the epitope specificities, locations (systemic or mucosal), and effector functions of antibodies elicited by novel HIV-1 immunogens engineered to improve exposure of specific epitopes is critical for HIV-1 vaccine development. Utilizing an array of humoral assays, we evaluated the magnitudes, epitope specificities, avidities, and functions of systemic and mucosal immune responses elicited by a vaccine regimen containing Env cross-linked to a CD4-mimetic miniprotein (gp140-M64U1) in rhesus macaques. Cross-linking of gp140 Env to M64U1 resulted in earlier increases of both the magnitude and avidity of the IgG binding response than those with Env protein alone. Notably, IgG binding responses at an early time point correlated with antibody-dependent cellular cytotoxicity (ADCC) function at the peak immunity time point, which was higher for the cross-linked Env group than for the Env group. In addition, the cross-linked Env group developed higher IgG responses against a linear epitope in the gp120 C1 region of the HIV-1 envelope glycoprotein. These data demonstrate that structural modification of the HIV-1 envelope immunogen by cross-linking of gp140 with the CD4-mimetic M64U1 elicited an earlier increase of binding antibody responses and altered the specificity of the IgG responses, correlating with the rise of subsequent antibody-mediated antiviral functions. IMPORTANCE The development of an efficacious HIV-1 vaccine remains a global priority to prevent new cases of HIV-1 infection. Of the six HIV-1 efficacy trials to date, only one has demonstrated partial efficacy, and immune correlate analysis of that trial revealed a role for binding antibodies and antibody Fc-mediated effector functions. New HIV-1 envelope immunogens are being engineered to selectively expose the most vulnerable and conserved sites on the HIV-1 envelope, with the goal of eliciting antiviral antibodies. Evaluation of the humoral responses elicited by these novel immunogen designs in

  19. Structure-based design, synthesis and validation of CD4-mimetic small molecule inhibitors of HIV-1 entry: conversion of a viral entry agonist to an antagonist.

    Science.gov (United States)

    Courter, Joel R; Madani, Navid; Sodroski, Joseph; Schön, Arne; Freire, Ernesto; Kwong, Peter D; Hendrickson, Wayne A; Chaiken, Irwin M; LaLonde, Judith M; Smith, Amos B

    2014-04-15

    This Account provides an overview of a multidisciplinary consortium focused on structure-based strategies to devise small molecule antagonists of HIV-1 entry into human T-cells, which if successful would hold considerable promise for the development of prophylactic modalities to prevent HIV transmission and thereby alter the course of the AIDS pandemic. Entry of the human immunodeficiency virus (HIV) into target T-cells entails an interaction between CD4 on the host T-cell and gp120, a component of the trimeric envelope glycoprotein spike on the virion surface. The resultant interaction initiates a series of conformational changes within the envelope spike that permits binding to a chemokine receptor, formation of the gp41 fusion complex, and cell entry. A hydrophobic cavity at the CD4-gp120 interface, defined by X-ray crystallography, provided an initial site for small molecule antagonist design. This site however has evolved to facilitate viral entry. As such, the binding of prospective small molecule inhibitors within this gp120 cavity can inadvertently trigger an allosteric entry signal. Structural characterization of the CD4-gp120 interface, which provided the foundation for small molecule structure-based inhibitor design, will be presented first. An integrated approach combining biochemical, virological, structural, computational, and synthetic studies, along with a detailed analysis of ligand binding energetics, revealed that modestly active small molecule inhibitors of HIV entry can also promote viral entry into cells lacking the CD4 receptor protein; these competitive inhibitors were termed small molecule CD4 mimetics. Related congeners were subsequently identified with both improved binding affinity and more potent viral entry inhibition. Further assessment of the affinity-enhanced small molecule CD4 mimetics demonstrated that premature initiation of conformational change within the viral envelope spike, prior to cell encounter, can lead to irreversible

  20. Complexes of neutralizing and non-neutralizing affinity matured Fabs with a mimetic of the internal trimeric coiled-coil of HIV-1 gp41.

    Directory of Open Access Journals (Sweden)

    Elena Gustchina

    Full Text Available A series of mini-antibodies (monovalent and bivalent Fabs targeting the conserved internal trimeric coiled-coil of the N-heptad repeat (N-HR of HIV-1 gp41 has been previously constructed and reported. Crystal structures of two closely related monovalent Fabs, one (Fab 8066 broadly neutralizing across a wide panel of HIV-1 subtype B and C viruses, and the other (Fab 8062 non-neutralizing, representing the extremes of this series, were previously solved as complexes with 5-Helix, a gp41 pre-hairpin intermediate mimetic. Binding of these Fabs to covalently stabilized chimeric trimers of N-peptides of HIV-1 gp41 (named (CCIZN363 or 3-H has now been investigated using X-ray crystallography, cryo-electron microscopy, and a variety of biophysical methods. Crystal structures of the complexes between 3-H and Fab 8066 and Fab 8062 were determined at 2.8 and 3.0 Å resolution, respectively. Although the structures of the complexes with the neutralizing Fab 8066 and its non-neutralizing counterpart Fab 8062 were generally similar, small differences between them could be correlated with the biological properties of these antibodies. The conformations of the corresponding CDRs of each antibody in the complexes with 3-H and 5-Helix are very similar. The adaptation to a different target upon complex formation is predominantly achieved by changes in the structure of the trimer of N-HR helices, as well as by adjustment of the orientation of the Fab molecule relative to the N-HR in the complex, via rigid-body movement. The structural data presented here indicate that binding of three Fabs 8062 with high affinity requires more significant changes in the structure of the N-HR trimer compared to binding of Fab 8066. A comparative analysis of the structures of Fabs complexed to different gp41 intermediate mimetics allows further evaluation of biological relevance for generation of neutralizing antibodies, as well as provides novel structural insights into immunogen

  1. A BDNF loop-domain mimetic acutely reverses spontaneous apneas and respiratory abnormalities during behavioral arousal in a mouse model of Rett syndrome

    Directory of Open Access Journals (Sweden)

    Miriam Kron

    2014-09-01

    Full Text Available Reduced levels of brain-derived neurotrophic factor (BDNF are thought to contribute to the pathophysiology of Rett syndrome (RTT, a severe neurodevelopmental disorder caused by loss-of-function mutations in the gene encoding methyl-CpG-binding protein 2 (MeCP2. In Mecp2 mutant mice, BDNF deficits have been associated with breathing abnormalities, a core feature of RTT, as well as with synaptic hyperexcitability within the brainstem respiratory network. Application of BDNF can reverse hyperexcitability in acute brainstem slices from Mecp2-null mice, suggesting that therapies targeting BDNF or its receptor, TrkB, could be effective at acute reversal of respiratory abnormalities in RTT. Therefore, we examined the ability of LM22A-4, a small-molecule BDNF loop-domain mimetic and TrkB partial agonist, to modulate synaptic excitability within respiratory cell groups in the brainstem nucleus tractus solitarius (nTS and to acutely reverse abnormalities in breathing at rest and during behavioral arousal in Mecp2 mutants. Patch-clamp recordings in Mecp2-null brainstem slices demonstrated that LM22A-4 decreases excitability at primary afferent synapses in the nTS by reducing the amplitude of evoked excitatory postsynaptic currents and the frequency of spontaneous and miniature excitatory postsynaptic currents. In vivo, acute treatment of Mecp2-null and -heterozygous mutants with LM22A-4 completely eliminated spontaneous apneas in resting animals, without sedation. Moreover, we demonstrate that respiratory dysregulation during behavioral arousal, a feature of human RTT, is also reversed in Mecp2 mutants by acute treatment with LM22A-4. Together, these data support the hypothesis that reduced BDNF signaling and respiratory dysfunction in RTT are linked, and establish the proof-of-concept that treatment with a small-molecule structural mimetic of a BDNF loop domain and a TrkB partial agonist can acutely reverse abnormal breathing at rest and in response to

  2. Effects of an Aβ-antibody fragment on Aβ aggregation and astrocytic uptake are modulated by apolipoprotein E and J mimetic peptides.

    Directory of Open Access Journals (Sweden)

    Laia Montoliu-Gaya

    Full Text Available Aβ-Immunotherapy has long been studied in the treatment of Alzheimer's disease (AD, but not how other molecules involved in the disease can affect antibody performance. We previously designed an antibody fragment, scFv-h3D6, and showed that it precludes Aβ-induced cytotoxicity by withdrawing Aβ oligomers from the amyloid pathway towards a non-toxic, worm-like pathway. ScFv-h3D6 was effective at the behavioral, cellular, and molecular levels in the 3xTg-AD mouse model. Because scFv-h3D6 treatment restored apolipoprotein E (apoE and J (apoJ concentrations to non-pathological values, and Aβ internalization by glial cells was found to be decreased in the presence of these apolipoproteins, we now aimed to test the influence of scFv-h3D6 on Aβ aggregation and cellular uptake by primary human astrocytes in the presence of therapeutic apoE and apoJ mimetic peptides (MPs. Firstly, we demonstrated by CD and FTIR that the molecules used in this work were well folded. Next, interactions between apoE or apoJ-MP, scFv-h3D6 and Aβ were studied by CD. The conformational change induced by the interaction of Aβ with apoE-MP was much bigger than the induced with apoJ-MP, in line with the observed formation of protective worm-like fibrils by the scFv-h3D6/Aβ complex in the presence of apoJ-MP, but not of apoE-MP. ScFv-h3D6, apoJ-MP, and apoE-MP to a different extent reduced Aβ uptake by astrocytes, and apoE-MP partially interfered with the dramatic reduction by scFv-h3D6 while apoJ-MP had no effect on scFv-h3D6 action. As sustained Aβ uptake by astrocytes may impair their normal functions, and ultimately neuronal viability, this work shows another beneficence of scFv-h3D6 treatment, which is not further improved by the use of apoE or apoJ mimetic peptides.

  3. Hypoxia and Hypoxia Mimetics Decrease Aquaporin 5 (AQP5) Expression through Both Hypoxia Inducible Factor-1α and Proteasome-Mediated Pathways

    Science.gov (United States)

    Kawedia, Jitesh D.; Yang, Fan; Sartor, Maureen A.; Gozal, David; Czyzyk-Krzeska, Maria; Menon, Anil G.

    2013-01-01

    The alveolar epithelium plays a central role in gas exchange and fluid transport, and is therefore critical for normal lung function. Since the bulk of water flux across this epithelium depends on the membrane water channel Aquaporin 5 (AQP5), we asked whether hypoxia had any effect on AQP5 expression. We show that hypoxia causes a significant (70%) decrease in AQP5 expression in the lungs of mice exposed to hypoxia. Hypoxia and the hypoxia mimetic, cobalt, also caused similar decreases in AQP5 mRNA and protein expression in the mouse lung epithelial cell line MLE-12. The action of hypoxia and cobalt on AQP5 transcription was demonstrated by directly quantifying heternonuclear RNA by real-time PCR. Dominant negative mutants of Hypoxia Inducible Factor (HIF-1α) and HIF-1α siRNA blocked the action of cobalt, showing that HIF-1α is a key component in this mechanism. The proteasome inhibitors, lactacystin or proteasome inhibitor-III completely abolished the effect of hypoxia and cobalt both at the protein and mRNA level indicating that the proteasome pathway is probably involved not only for the stability of HIF-1α protein, but for the stability of unidentified transcription factors that regulate AQP5 transcription. These studies reveal a potentially important physiological mechanism linking hypoxic stress and membrane water channels. PMID:23469202

  4. Apolipoprotein A-1 mimetic peptide 4F promotes endothelial repairing and compromises reendothelialization impaired by oxidized HDL through SR-B1

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    Dan He

    2018-05-01

    Full Text Available Disruption of endothelial monolayer integrity is the primary instigating factor for many cardiovascular diseases. High density lipoprotein (HDL oxidized by heme enzyme myeloperoxidase (MPO is dysfunctional in promoting endothelial repair. Apolipoprotein A-1 mimetic 4F with its pleiotropic benefits has been proven effective in many in vivo models. In this study we investigated whether 4F promotes endothelial repair and restores the impaired function of oxidized HDL (Cl/NO2-HDL in promoting re-endothelialization. We demonstrate that 4F and Cl/NO2-HDL act on scavenger receptor type I (SR-B1 using human aorta endothelial cells (HAEC and SR-B1 (-/- mouse aortic endothelial cells. Wound healing, transwell migration, lamellipodia formation and single cell migration assay experiments show that 4F treatment is associated with a recovery of endothelial cell migration and associated with significantly increased endothelial nitric oxide synthase (eNOS activity, Akt phosphorylation and SR-B1 expression. 4F increases NO generation and diminishes oxidative stress. In vivo, 4F can stimulate cell proliferation and re-endothelialization in the carotid artery after treatment with Cl/NO2-HDL in a carotid artery electric injury model but fails to do so in SR-B1(-/- mice. These findings demonstrate that 4F promotes endothelial cell migration and has a potential therapeutic benefit against early endothelial injury in cardiovascular diseases.

  5. Apolipoprotein E-Mimetic Peptide COG1410 Promotes Autophagy by Phosphorylating GSK-3β in Early Brain Injury Following Experimental Subarachnoid Hemorrhage

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    Xinshen Li

    2018-03-01

    Full Text Available COG1410, a mimetic peptide derived from the apolipoprotein E (apoE receptor binding region, exerts positive effect on neurological deficits in early brain injury (EBI after experimental subarachnoid hemorrhage (SAH. Currently the neuroprotective effect of COG1410 includes inhibiting BBB disruption, reducing neuronal apoptosis, and neuroinflammation. However, the effect and mechanism of COG1410 to subcellular organelles disorder have not been fully investigated. As the main pathway for recycling long-lived proteins and damaged organelles, neuronal autophagy is activated in SAH and exhibits neuroprotective effects by reducing the insults of EBI. Pharmacologically elevated autophagy usually contributes to alleviated brain injury, while few of the agents achieved clinical transformation. In this study, we explored the activation of autophagy during EBI by measuring the Beclin-1 and LC3B-II protein levels. Administration of COG1410 notably elevated the autophagic markers expression in neurons, simultaneously reversed the neurological deficits. Furthermore, the up-regulated autophagy by COG1410 was further promoted by p-GSK-3β agonist, whereas decreased by p-GSK-3β inhibitor. Taken together, these data suggest that the COG1410 might be a promising therapeutic strategy for EBI via promoting autophagy in SAH.

  6. Age-dependent modulation of synaptic plasticity and insulin mimetic effect of lipoic acid on a mouse model of Alzheimer's disease.

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    Harsh Sancheti

    Full Text Available Alzheimer's disease is a progressive neurodegenerative disease that entails impairments of memory, thinking and behavior and culminates into brain atrophy. Impaired glucose uptake (accumulating into energy deficits and synaptic plasticity have been shown to be affected in the early stages of Alzheimer's disease. This study examines the ability of lipoic acid to increase brain glucose uptake and lead to improvements in synaptic plasticity on a triple transgenic mouse model of Alzheimer's disease (3xTg-AD that shows progression of pathology as a function of age; two age groups: 6 months (young and 12 months (old were used in this study. 3xTg-AD mice fed 0.23% w/v lipoic acid in drinking water for 4 weeks showed an insulin mimetic effect that consisted of increased brain glucose uptake, activation of the insulin receptor substrate and of the PI3K/Akt signaling pathway. Lipoic acid supplementation led to important changes in synaptic function as shown by increased input/output (I/O and long term potentiation (LTP (measured by electrophysiology. Lipoic acid was more effective in stimulating an insulin-like effect and reversing the impaired synaptic plasticity in the old mice, wherein the impairment of insulin signaling and synaptic plasticity was more pronounced than those in young mice.

  7. Insight into partial agonism by observing multiple equilibria for ligand-bound and Gs-mimetic nanobody-bound β1-adrenergic receptor.

    Science.gov (United States)

    Solt, Andras S; Bostock, Mark J; Shrestha, Binesh; Kumar, Prashant; Warne, Tony; Tate, Christopher G; Nietlispach, Daniel

    2017-11-27

    A complex conformational energy landscape determines G-protein-coupled receptor (GPCR) signalling via intracellular binding partners (IBPs), e.g., G s and β-arrestin. Using 13 C methyl methionine NMR for the β 1 -adrenergic receptor, we identify ligand efficacy-dependent equilibria between an inactive and pre-active state and, in complex with G s -mimetic nanobody, between more and less active ternary complexes. Formation of a basal activity complex through ligand-free nanobody-receptor interaction reveals structural differences on the cytoplasmic receptor side compared to the full agonist-bound nanobody-coupled form, suggesting that ligand-induced variations in G-protein interaction underpin partial agonism. Significant differences in receptor dynamics are observed ranging from rigid nanobody-coupled states to extensive μs-to-ms timescale dynamics when bound to a full agonist. We suggest that the mobility of the full agonist-bound form primes the GPCR to couple to IBPs. On formation of the ternary complex, ligand efficacy determines the quality of the interaction between the rigidified receptor and an IBP and consequently the signalling level.

  8. Surface Immobilization of pH-Responsive Polymer Brushes on Mesoporous Silica Nanoparticles by Enzyme Mimetic Catalytic ATRP for Controlled Cargo Release

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    Hang Zhou

    2016-08-01

    Full Text Available Peroxidase mimetic catalytic atom transfer radical polymerization (ATRP was first used to install tertiary amine-functionalized polymer brushes on the surface of mesoporous silica nanoparticles (MSNs in a facile and highly efficient manner. Poly(N,N-dimethylaminoethyl methacrylate (PDMAEMA brushes-grafted MSNs were fabricated by biocompatible deuterohemin-β-Ala-His-Thr-Val-Glu-Lys (DhHP-6-catalyzed surface-initiated ATRP (SI-ATRP. The resulting organic–inorganic hybrid nanocarriers were fully characterized by Fourier transform-infrared spectroscopy (FT-IR, thermogravimetric analysis (TGA, X-ray photoelectron spectroscopy (XPS, powder X-ray diffraction (XRD, SEM, TEM, Elemental analysis, Zeta-potential, and N2 adsorption–desorption isotherms, which demonstrated the successful coating of pH-responsive polymers on the MSN surface. Rhodamine 6G (Rh6G dyes were further loaded within the mesopores of this nanocarrier, and the release of Rh6G out of MSNs in a controlled fashion was achieved upon lowing the solution pH. The electrostatic repulsion of positively-charged tertiary ammonium of PDMAEMAs in acidic environments induced the stretching out of polymer brushes on MSN surfaces, thus opening the gates to allow cargo diffusion out of the mesopores of MSNs.

  9. Potentiation of contraction of rabbit airway smooth muscle by some cyclooxygenase products.

    Science.gov (United States)

    Armour, C L; Johnson, P R; Black, J L

    1988-06-01

    An alteration in smooth muscle sensitivity may be one of the mechanisms of the airway hyperresponsiveness observed in asthma. Indomethacin inhibits experimentally induced airway hyperresponsiveness. We thus examined the effects of the cyclooxygenase products PGD2, PGF2 alpha and a thromboxane A2 analogue U46619 on contractile responses of rabbit airway smooth muscle to histamine, carbachol and electrical field stimulation (EFS). PGD2 did not potentiate any contractile responses. When PGF2 alpha (1 microM) was administered 30 min before cumulative concentration-response curves to histamine and carbachol, no potentiation was observed. However, PGF2 alpha (1 microM) added immediately before EFS and bolus doses of histamine potentiated the contractile responses. U46619 increased the cumulative concentration-responses to both histamine and carbachol. The fact that we could alter smooth muscle sensitivity in vitro with PGF2 alpha and a thromboxane analogue suggests that these mediators may be involved in the airway hyperresponsiveness observed in asthma.

  10. Effect of THIP and SL 76002, two clinically experimented GABA-mimetic compounds, on anterior pituitary GABA receptors and prolactin secretion in the rat

    International Nuclear Information System (INIS)

    Apud, J.A.; Masotto, C.; Racagni, G.

    1987-01-01

    In the present study, the ability of three direct GABA agonists, muscimol, THIP and SL 76002 to displace 3 H-GABA binding from anterior pituitary and medio-basal hypothalamus membranes was evaluated. Further, the effect of both THIP and SL 76002 on baseline prolactin levels or after stimulation of hormone release with haloperidol has been also studied. Either muscimol, THIP or SL 76002 have shown to posses 7-, 7- and 3-fold higher affinity, respectively, for the central nervous system than for the anterior pituitary 3 H-GABA binding sites. Moreover, THIP and SL 76002 have demonstrated to be respectively, 25- and 1000- fold less potent than muscimol in inhibiting 3 H- GABA binding at the level of the anterior pituitary and about 25- and 2700-fold less potent at the level of the medio-basal hypothalamus. Under basal conditions, either THIP or SL 76002 were ineffective to reduce prolactin release. However, after stimulation of prolactin secretion through blockade of the dopaminergic neurotransmission with haloperidol (0.1 mg/kg), both THIP (10 mg/kg) and SL 76002 (200 mg/kg) significantly counteracted the neuroleptic-induced prolactin rise with a potency which is in line with their ability to inhibit 3 H-GABA binding in the anterior pituitary. The present results indicate that both compounds inhibit prolactin release under specific experimental situations probably through a GABAergic mechanism. In view of the endocrine effects of these GABA-mimetic compounds, the possibility arises for an application of these type of drugs in clinical neuroendocrinology. 35 references, 3 figures, 2 tables

  11. Experimental shifts in intraclutch egg color variation do not affect egg rejection in a host of a non-egg-mimetic avian brood parasite.

    Directory of Open Access Journals (Sweden)

    Rebecca Croston

    Full Text Available Avian brood parasites lay their eggs in the nests of other birds, and impose the costs associated with rearing parasitic young onto these hosts. Many hosts of brood parasites defend against parasitism by removing foreign eggs from the nest. In systems where parasitic eggs mimic host eggs in coloration and patterning, extensive intraclutch variation in egg appearances may impair the host's ability to recognize and reject parasitic eggs, but experimental investigation of this effect has produced conflicting results. The cognitive mechanism by which hosts recognize parasitic eggs may vary across brood parasite hosts, and this may explain variation in experimental outcome across studies investigating egg rejection in hosts of egg-mimicking brood parasites. In contrast, for hosts of non-egg-mimetic parasites, intraclutch egg color variation is not predicted to co-vary with foreign egg rejection, irrespective of cognitive mechanism. Here we tested for effects of intraclutch egg color variation in a host of nonmimetic brood parasite by manipulating egg color in American robins (Turdus migratorius, hosts of brown-headed cowbirds (Molothrus ater. We recorded robins' behavioral responses to simulated cowbird parasitism in nests where color variation was artificially enhanced or reduced. We also quantified egg color variation within and between unmanipulated robin clutches as perceived by robins themselves using spectrophotometric measures and avian visual modeling. In unmanipulated nests, egg color varied more between than within robin clutches. As predicted, however, manipulation of color variation did not affect rejection rates. Overall, our results best support the scenario wherein egg rejection is the outcome of selective pressure by a nonmimetic brood parasite, because robins are efficient rejecters of foreign eggs, irrespective of the color variation within their own clutch.

  12. Experimental Shifts in Intraclutch Egg Color Variation Do Not Affect Egg Rejection in a Host of a Non-Egg-Mimetic Avian Brood Parasite

    Science.gov (United States)

    Croston, Rebecca; Hauber, Mark E.

    2015-01-01

    Avian brood parasites lay their eggs in the nests of other birds, and impose the costs associated with rearing parasitic young onto these hosts. Many hosts of brood parasites defend against parasitism by removing foreign eggs from the nest. In systems where parasitic eggs mimic host eggs in coloration and patterning, extensive intraclutch variation in egg appearances may impair the host’s ability to recognize and reject parasitic eggs, but experimental investigation of this effect has produced conflicting results. The cognitive mechanism by which hosts recognize parasitic eggs may vary across brood parasite hosts, and this may explain variation in experimental outcome across studies investigating egg rejection in hosts of egg-mimicking brood parasites. In contrast, for hosts of non-egg-mimetic parasites, intraclutch egg color variation is not predicted to co-vary with foreign egg rejection, irrespective of cognitive mechanism. Here we tested for effects of intraclutch egg color variation in a host of nonmimetic brood parasite by manipulating egg color in American robins (Turdus migratorius), hosts of brown-headed cowbirds (Molothrus ater). We recorded robins’ behavioral responses to simulated cowbird parasitism in nests where color variation was artificially enhanced or reduced. We also quantified egg color variation within and between unmanipulated robin clutches as perceived by robins themselves using spectrophotometric measures and avian visual modeling. In unmanipulated nests, egg color varied more between than within robin clutches. As predicted, however, manipulation of color variation did not affect rejection rates. Overall, our results best support the scenario wherein egg rejection is the outcome of selective pressure by a nonmimetic brood parasite, because robins are efficient rejecters of foreign eggs, irrespective of the color variation within their own clutch. PMID:25831051

  13. Experimental shifts in intraclutch egg color variation do not affect egg rejection in a host of a non-egg-mimetic avian brood parasite.

    Science.gov (United States)

    Croston, Rebecca; Hauber, Mark E

    2015-01-01

    Avian brood parasites lay their eggs in the nests of other birds, and impose the costs associated with rearing parasitic young onto these hosts. Many hosts of brood parasites defend against parasitism by removing foreign eggs from the nest. In systems where parasitic eggs mimic host eggs in coloration and patterning, extensive intraclutch variation in egg appearances may impair the host's ability to recognize and reject parasitic eggs, but experimental investigation of this effect has produced conflicting results. The cognitive mechanism by which hosts recognize parasitic eggs may vary across brood parasite hosts, and this may explain variation in experimental outcome across studies investigating egg rejection in hosts of egg-mimicking brood parasites. In contrast, for hosts of non-egg-mimetic parasites, intraclutch egg color variation is not predicted to co-vary with foreign egg rejection, irrespective of cognitive mechanism. Here we tested for effects of intraclutch egg color variation in a host of nonmimetic brood parasite by manipulating egg color in American robins (Turdus migratorius), hosts of brown-headed cowbirds (Molothrus ater). We recorded robins' behavioral responses to simulated cowbird parasitism in nests where color variation was artificially enhanced or reduced. We also quantified egg color variation within and between unmanipulated robin clutches as perceived by robins themselves using spectrophotometric measures and avian visual modeling. In unmanipulated nests, egg color varied more between than within robin clutches. As predicted, however, manipulation of color variation did not affect rejection rates. Overall, our results best support the scenario wherein egg rejection is the outcome of selective pressure by a nonmimetic brood parasite, because robins are efficient rejecters of foreign eggs, irrespective of the color variation within their own clutch.

  14. Elicitation of neutralizing antibodies directed against CD4-induced epitope(s using a CD4 mimetic cross-linked to a HIV-1 envelope glycoprotein.

    Directory of Open Access Journals (Sweden)

    Antu K Dey

    Full Text Available The identification of HIV-1 envelope glycoprotein (Env structures that can generate broadly neutralizing antibodies (BNAbs is pivotal to the development of a successful vaccine against HIV-1 aimed at eliciting effective humoral immune responses. To that end, the production of novel Env structure(s that might induce BNAbs by presentation of conserved epitopes, which are otherwise occluded, is critical. Here, we focus on a structure that stabilizes Env in a conformation representative of its primary (CD4 receptor-bound state, thereby exposing highly conserved "CD4 induced" (CD4i epitope(s known to be important for co-receptor binding and subsequent virus infection. A CD4-mimetic miniprotein, miniCD4 (M64U1-SH, was produced and covalently complexed to recombinant, trimeric gp140 envelope glycoprotein (gp140 using site-specific disulfide linkages. The resulting gp140-miniCD4 (gp140-S-S-M64U1 complex was recognized by CD4i antibodies and the HIV-1 co-receptor, CCR5. The gp140-miniCD4 complex elicited the highest titers of CD4i binding antibodies as well as enhanced neutralizing antibodies against Tier 1 viruses as compared to gp140 protein alone following immunization of rabbits. Neutralization against HIV-2(7312/V434M and additional serum mapping confirm the specific elicitation of antibodies directed to the CD4i epitope(s. These results demonstrate the utility of structure-based approach in improving immunogenic response against specific region, such as the CD4i epitope(s here, and its potential role in vaccine application.

  15. Ex vivo investigation of ocular tissue distribution following intravitreal administration of connexin43 mimetic peptide using the microdialysis technique and LC-MS/MS.

    Science.gov (United States)

    Bisht, Rohit; Mandal, Abhirup; Rupenthal, Ilva D; Mitra, Ashim K

    2016-12-01

    This study aimed to develop and evaluate an ex vivo eye model for intravitreal drug sampling and tissue distribution of connexin43 mimetic peptide (Cx43MP) following intravitreal injection using the microdialysis technique and LC-MS/MS. An LC-MS/MS method was developed, validated, and applied for quantification of Cx43MP in ocular tissues. Microdialysis probes were calibrated for in vitro recovery studies. Bovine eyes were fixed in a customized eye holder and after intravitreal injection of Cx43MP, microdialysis probes were implanted in the vitreous body. Vitreous samples were collected at particular time intervals over 24 h. Moreover, 24 and 48 h after intravitreal injection ocular tissues were collected, processed, and analyzed for Cx43MP concentrations using LC-MS/MS. The LC-MS/MS method showed good linearity (r 2  = 0.9991). The mean percent recovery for lower (LQC), medium (MQC), and higher quality control (HQC) (0.244, 3.906, and 125 μg/mL) was found to be 83.83, 84.92, and 94.52, respectively, with accuracy ranges between 96 and 99 % and limits of detection (LOD) and quantification (LOQ) of 0.122 and 0.412 μg/mL. The in vitro recovery of the probes was found to be over 80 %. As per microdialysis sample analysis, the Cx43MP concentration was found to increase slowly in the vitreous body up to 16 h and thereafter declined. After 48 h, the Cx43MP concentration was higher in vitreous, cornea, and retina compared to lens, iris, and aqueous humor. This ex vivo model may therefore be a useful tool to investigate intravitreal kinetics and ocular disposition of therapeutic molecules after intravitreal injection.

  16. Probing for missing links in the binary and ternary V(V)-citrate-(H2O2) systems: synthetic efforts and in vitro insulin mimetic activity studies.

    Science.gov (United States)

    Gabriel, C; Venetis, J; Kaliva, M; Raptopoulou, C P; Terzis, A; Drouza, C; Meier, B; Voyiatzis, G; Potamitis, C; Salifoglou, A

    2009-04-01

    In a pH-specific fashion, V(2)O(5) and citric acid in the absence and presence of H(2)O(2) reacted and afforded, in the presence of NaOH and (CH(6)N(3))(2)CO(3), two new dinuclear V(V) binary non-peroxo (CH(6)N(3))(6)[V(2)O(4)(C(6)H(4)O(7))(2)].2H(2)O (1) and ternary peroxo (CH(6)N(3))(4)[V(2)O(2)(Omicron(2))(2)(C(6)H(5)O(7))(2)].6Eta(2)Omicron (2) species, respectively. Complexes 1 and 2 were further characterized by elemental analysis, UV/Vis, FT-IR, NMR (solution and solid state Cross Polarization-Magic Angle Spinning (CP-MAS)) and Raman spectroscopies, cyclic voltammetry, and X-ray crystallography. Both 1 and 2 are members of the family of dinuclear V(V)-citrate species bearing citrate with a distinct coordination mode and degree of deprotonation, with 2 being the missing link in the family of pH-structural variants of the ternary V(V)-peroxo-citrate system. Given that 1 and 2 possess distinct structural features, relevant binary V(III), V(IV) and V(V), and ternary V(V) species bearing O- and N-containing ligands were tested in in vitro cell cultures to assess their cellular toxicity and insulin mimetic capacity. The results project a clear profile for all species tested, earmarking the importance of vanadium oxidation state and its ligand environment in influencing further binary and ternary interactions of vanadium arising with variable mass cellular targets, ultimately leading to a specific (non)toxic phenotype and glucose uptake ability.

  17. Analytics of nonpeptidic erythropoietin mimetic agents in sports drug testing employing high-resolution/high-accuracy liquid chromatography-mass spectrometry.

    Science.gov (United States)

    Vogel, Matthias; Dib, Josef; Tretzel, Laura; Piper, Thomas; Thomas, Andreas; Schänzer, Wilhelm; Thevis, Mario

    2016-09-01

    Since its release as anti-anemic drug, recombinant erythropoietin (rEPO) gradually entered the illicit way to sports competitions as endurance-enhancing drug. Novel modifications biopharmaceutically introduced into the rEPO molecule in the form of carbohydrate or polyethylene glycol moieties made robust and sensitive test methods vital to doping controls in order to provide the necessary tools enabling the conviction of dishonest athletes. Modern protein analysis by means of gel electrophoretic separation and western blotting represents the status quo in rEPO anti-doping analysis. However, new therapeutically promising erythropoietin receptor activating compounds have been developed that exhibit cytokine hormone-mimicking properties but lack any protein structure. Progression to evade parenteral application and substitute for rEPO by low molecular mass and orally available compounds is still one of the major objectives in pharmaceutical research. In this approach, four promising in-house synthesized nonpeptidic erythropoietin mimetic agents, namely compound 129, compound 163, A1B10C1, and A5B10C4 were thoroughly evaluated by employing high-resolution/high-accuracy liquid chromatography tandem mass spectrometry experiments. Characteristic product ions were determined supporting the identification of these drugs and putative metabolites as well as related compounds in future doping controls. Test methods employing direct urine injection and receptor affinity purification strategies were assessed, which demonstrated that EPO receptor purification is of limited utility for nonpeptidic EPOR agonists while direct urine injection allowed for comprehensive method characterization. Thereby, achieved limits of detection were 1 ng/mL for compounds 129/163 and 5 ng/mL for A1B10C1/A5B10C4.

  18. EphrinA4 mimetic peptide targeted to EphA binding site impairs the formation of long-term fear memory in lateral amygdala.

    Science.gov (United States)

    Dines, M; Lamprecht, R

    2014-09-30

    Fear conditioning leads to long-term fear memory formation and is a model for studying fear-related psychopathologies conditions such as phobias and posttraumatic stress disorder. Long-term fear memory formation is believed to involve alterations of synaptic efficacy mediated by changes in synaptic transmission and morphology in lateral amygdala (LA). EphrinA4 and its cognate Eph receptors are intimately involved in regulating neuronal morphogenesis, synaptic transmission and plasticity. To assess possible roles of ephrinA4 in fear memory formation we designed and used a specific inhibitory ephrinA4 mimetic peptide (pep-ephrinA4) targeted to EphA binding site. We show that this peptide, composed of the ephrinA4 binding domain, interacts with EphA4 and inhibits ephrinA4-induced phosphorylation of EphA4. Microinjection of the pep-ephrinA4 into rat LA 30 min before training impaired long- but not short-term fear conditioning memory. Microinjection of a control peptide derived from a nonbinding E helix site of ephrinA4, that does not interact with EphA, had no effect on fear memory formation. Microinjection of pep-ephrinA4 into areas adjacent to the amygdala had no effect on fear memory. Acute systemic administration of pep-ephrinA4 1 h after training also impaired long-term fear conditioning memory formation. These results demonstrate that ephrinA4 binding sites in LA are essential for long-term fear memory formation. Moreover, our research shows that ephrinA4 binding sites may serve as a target for pharmacological treatment of fear and anxiety disorders.

  19. Acute effects of the superoxide dismutase mimetic tempol on split kidney function in two-kidney one-clip hypertensive rats.

    Science.gov (United States)

    Guron, Gregor S; Grimberg, Elisabeth S; Basu, Samar; Herlitz, Hans

    2006-02-01

    To investigate the acute effects of the superoxide dismutase mimetic 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl (tempol) on split kidney function, and renal haemodynamics, in two-kidney, one-clip (2K1C) hypertensive rats. Three weeks after clipping, or the sham procedure, the effects of intravenous tempol (200 micromol/kg per h) were evaluated on thiobutabarbital anaesthetized Sprague-Dawley rats. Mean arterial pressure (MAP; 152 +/- 3 versus 122 +/- 3 mmHg, P < 0.001), plasma renin activity (28.7 +/- 3.0 versus 9.5 +/- 0.6 ng/ml per h, P < 0.001) and urinary 8-iso-prostaglandin F2alpha excretion (124 +/- 4 versus 92 +/- 10 pmol/24 h, P = 0.003) were significantly elevated in 2K1C rats compared with sham. Tempol reduced MAP by 15 +/- 1% compared with baseline (P < 0.001) in 2K1C rats. In clipped kidneys, tempol increased the glomerular filtration rate (GFR; +50 +/- 15% from baseline) and the effective renal plasma flow (ERPF; +37 +/- 13%, from baseline), and reduced renal vascular resistance (RVR; -32 +/- 6% from baseline) compared with saline-treated controls (P < 0.05). In non-clipped kidneys, tempol reduced RVR (-24 +/- 5% from baseline) compared with saline-treated controls (P = 0.001). In sham-operated rats, tempol produced a modest reduction in MAP (-8 +/- 2% from baseline, P = 0.003), but did not significantly affect renal haemodynamics or function. Tempol reduced MAP and RVR in both clipped and non-clipped kidneys of 2K1C hypertensive rats. In addition, tempol increased ERPF and GFR in the clipped kidney. These findings suggest important roles for superoxide in the regulation of renal haemodynamics during the early maintenance phase of renovascular hypertension.

  20. Caloric Restriction Mimetic 2-Deoxyglucose Alleviated Inflammatory Lung Injury via Suppressing Nuclear Pyruvate Kinase M2–Signal Transducer and Activator of Transcription 3 Pathway

    Directory of Open Access Journals (Sweden)

    Kai Hu

    2018-03-01

    Full Text Available Inflammation is an energy-intensive process, and caloric restriction (CR could provide anti-inflammatory benefits. CR mimetics (CRM, such as the glycolytic inhibitor 2-deoxyglucose (2-DG, mimic the beneficial effects of CR without inducing CR-related physiologic disturbance. This study investigated the potential anti-inflammatory benefits of 2-DG and the underlying mechanisms in mice with lipopolysaccharide (LPS-induced lethal endotoxemia. The results indicated that pretreatment with 2-DG suppressed LPS-induced elevation of tumor necrosis factor alpha and interleukin 6. It also suppressed the upregulation of myeloperoxidase, attenuated Evans blue leakage, alleviated histological abnormalities in the lung, and improved the survival of LPS-challenged mice. Treatment with 2-DG had no obvious effects on the total level of pyruvate kinase M2 (PKM2, but it significantly suppressed LPS-induced elevation of PKM2 in the nuclei. Prevention of PKM2 nuclear accumulation by ML265 mimicked the anti-inflammatory benefits of 2-DG. In addition, treatment with 2-DG or ML265 suppressed the phosphorylation of nuclear signal transducer and activator of transcription 3 (STAT3. Inhibition of STAT3 by stattic suppressed LPS-induced inflammatory injury. Interestingly, posttreatment with 2-DG at the early stage post-LPS challenge also improved the survival of the experimental animals. This study found that treatment with 2-DG, a representative CRM, provided anti-inflammatory benefits in lethal inflammation. The underlying mechanisms included suppressed nuclear PKM2-STAT3 pathway. These data suggest that 2-DG might have potential value in the early intervention of lethal inflammation.

  1. Caloric Restriction Mimetic 2-Deoxyglucose Alleviated Inflammatory Lung Injury via Suppressing Nuclear Pyruvate Kinase M2-Signal Transducer and Activator of Transcription 3 Pathway.

    Science.gov (United States)

    Hu, Kai; Yang, Yongqiang; Lin, Ling; Ai, Qing; Dai, Jie; Fan, Kerui; Ge, Pu; Jiang, Rong; Wan, Jingyuan; Zhang, Li

    2018-01-01

    Inflammation is an energy-intensive process, and caloric restriction (CR) could provide anti-inflammatory benefits. CR mimetics (CRM), such as the glycolytic inhibitor 2-deoxyglucose (2-DG), mimic the beneficial effects of CR without inducing CR-related physiologic disturbance. This study investigated the potential anti-inflammatory benefits of 2-DG and the underlying mechanisms in mice with lipopolysaccharide (LPS)-induced lethal endotoxemia. The results indicated that pretreatment with 2-DG suppressed LPS-induced elevation of tumor necrosis factor alpha and interleukin 6. It also suppressed the upregulation of myeloperoxidase, attenuated Evans blue leakage, alleviated histological abnormalities in the lung, and improved the survival of LPS-challenged mice. Treatment with 2-DG had no obvious effects on the total level of pyruvate kinase M2 (PKM2), but it significantly suppressed LPS-induced elevation of PKM2 in the nuclei. Prevention of PKM2 nuclear accumulation by ML265 mimicked the anti-inflammatory benefits of 2-DG. In addition, treatment with 2-DG or ML265 suppressed the phosphorylation of nuclear signal transducer and activator of transcription 3 (STAT3). Inhibition of STAT3 by stattic suppressed LPS-induced inflammatory injury. Interestingly, posttreatment with 2-DG at the early stage post-LPS challenge also improved the survival of the experimental animals. This study found that treatment with 2-DG, a representative CRM, provided anti-inflammatory benefits in lethal inflammation. The underlying mechanisms included suppressed nuclear PKM2-STAT3 pathway. These data suggest that 2-DG might have potential value in the early intervention of lethal inflammation.

  2. Investigation of Endogenous Retrovirus Sequences in the Neighborhood of Genes Up-regulated in a Neuroblastoma Model after Treatment with Hypoxia-Mimetic Cobalt Chloride.

    Science.gov (United States)

    Brütting, Christine; Narasimhan, Harini; Hoffmann, Frank; Kornhuber, Malte E; Staege, Martin S; Emmer, Alexander

    2018-01-01

    Human endogenous retroviruses (ERVs) have been found to be associated with different diseases, e.g., multiple sclerosis (MS). Most human ERVs integrated in our genome are not competent to replicate and these sequences are presumably silent. However, transcription of human ERVs can be reactivated, e.g., by hypoxia. Interestingly, MS has been linked to hypoxia since decades. As some patterns of demyelination are similar to white matter ischemia, hypoxic damage is discussed. Therefore, we are interested in the association between hypoxia and ERVs. As a model, we used human SH-SY5Y neuroblastoma cells after treatment with the hypoxia-mimetic cobalt chloride and analyzed differences in the gene expression profiles in comparison to untreated cells. The vicinity of up-regulated genes was scanned for endogenous retrovirus-derived sequences. Five genes were found to be strongly up-regulated in SH-SY5Y cells after treatment with cobalt chloride: clusterin, glutathione peroxidase 3, insulin-like growth factor 2, solute carrier family 7 member 11, and neural precursor cell expressed developmentally down-regulated protein 9. In the vicinity of these genes we identified large (>1,000 bp) open reading frames (ORFs). Most of these ORFs showed only low similarities to proteins from retro-transcribing viruses. However, we found very high similarity between retrovirus envelope sequences and a sequence in the vicinity of neural precursor cell expressed developmentally down-regulated protein 9. This sequence encodes the human endogenous retrovirus group FRD member 1, the encoded protein product is called syncytin 2. Transfection of syncytin 2 into the well-characterized Ewing sarcoma cell line A673 was not able to modulate the low immunostimulatory activity of this cell line. Future research is needed to determine whether the identified genes and the human endogenous retrovirus group FRD member 1 might play a role in the etiology of MS.

  3. Tempol, a superoxide dismutase-mimetic drug, prevents chronic ischemic renal injury in two-kidney, one-clip hypertensive rats.

    Science.gov (United States)

    Nunes, Douglas Vq; Costa, Cristiane A; De Bem, Graziele F; Cordeiro, Viviane Sc; Santos, Izabelle B; Carvalho, Lenize Crm; Jordão, Alessandro K; Cunha, Anna C; Ferreira, Vitor F; Moura, Roberto S; Resende, Angela C; Ognibene, Dayane T

    2018-01-23

    Tempol, a superoxide dismutase-mimetic drug, has been shown to attenuate radical-induced damage, exerting beneficial effects in the animal models of oxidative stress and hypertension. This study evaluated the effect of Tempol on renal structural and functional alterations in two-Kidney, one-Clip hypertensive rats. In this study, young male Wistar rats had the left kidney clipped (2K1C), and sham-operated animals (Sham) were used as controls. Animals received Tempol (1mmol/L in drinking water) or vehicle for 5 weeks. Systolic blood pressure was evaluated once a week. At the end of the experimental protocol, the animals were placed in metabolic cages to collect urine (24h) and then anesthetized with thiopental (70mg/kg i.p.) to collect blood by puncturing the descending aorta for biochemical analysis, and the clipped kidney for morphological and immunohistochemical analyses. The vasodilator effect of Tempol was evaluated in mesenteric arterial bed (MAB) isolated from adult Wistar rats. The chronic treatment with Tempol prevented the development of hypertension and the increased plasma levels of urea, creatinine, and 8-isoprostane in 2K1C animals. Tempol also improved both glomeruli number and kidney volume to normal levels in the 2K1C+Tempol group. In addition, the treatment prevented the increased collagen deposition and immunostaining for renin, caspase-3, and 8-isoprostane in the stenotic kidney of 2K1C animals. Moreover, Tempol induced a dose-dependent vasodilator response in MAB from Wistar rats. These results suggest that Tempol protects the stenotic kidney against chronic ischemic renal injury and prevents renal dysfunction in the 2K1C model, probably through its antioxidant, vasodilator and antihypertensive actions.

  4. CER-001, a HDL-mimetic, stimulates the reverse lipid transport and atherosclerosis regression in high cholesterol diet-fed LDL-receptor deficient mice.

    Science.gov (United States)

    Tardy, Claudine; Goffinet, Marine; Boubekeur, Nadia; Ackermann, Rose; Sy, Gavin; Bluteau, Alice; Cholez, Guy; Keyserling, Constance; Lalwani, Narendra; Paolini, John F; Dasseux, Jean-Louis; Barbaras, Ronald; Baron, Rudi

    2014-01-01

    CER-001 is a novel engineered HDL-mimetic comprised of recombinant human apoA-I and phospholipids that was designed to mimic the beneficial properties of nascent pre-β HDL. In this study, we have evaluated the capacity of CER-001 to perform reverse lipid transport in single dose studies as well as to regress atherosclerosis in LDLr(-/-) mice after short-term multiple-dose infusions. CER-001 induced cholesterol efflux from macrophages and exhibited anti-inflammatory response similar to natural HDL. Studies with HUVEC demonstrated CER-001 at a concentration of 500 μg/mL completely suppressed the secretion of cytokines IL-6, IL-8, GM-CSF and MCP-1. Following infusion of CER-001 (10mg/kg) in C57Bl/6J mice, we observed a transient increase in the mobilization of unesterified cholesterol in HDL particles containing recombinant human apoA-I. Finally we show that cholesterol elimination was stimulated in CER-001 treated animals as demonstrated by the increased cholesterol concentration in liver and feces. In a familial hypercholesterolemia mouse model (LDL-receptor deficient mice), the infusion of CER-001 caused 17% and 32% reductions in plaque size, 17% and 23% reductions in lipid content after 5 and 10 doses given every 2 days, respectively. Also, there was an 80% reduction in macrophage content in the plaque following 5 doses, and decreased VCAM-1 expression by 16% and 22% in the plaque following 5 and 10 intravenous doses of CER-001, respectively. These data demonstrate that CER-001 rapidly enhances reverse lipid transport in the mouse, reducing vascular inflammation and promoting regression of diet-induced atherosclerosis in LDLr(-/-) mice upon a short-term multiple dose treatment. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  5. 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...

  6. Expression, Purification, and Monitoring of Conformational Changes of hCB2 TMH67H8 in Different Membrane-Mimetic Lipid Mixtures Using Circular Dichroism and NMR Techniques

    Directory of Open Access Journals (Sweden)

    Elvis K. Tiburu

    2017-02-01

    Full Text Available This work was intended to develop self-assembly lipids for incorporating G-protein coupled receptors (GPCRs in order to improve the success rate for nuclear magnetic resonance spectroscopy (NMR structural elucidation. We hereby report the expression and purification of uniformly 15N-labeled human cannabinoid receptor-2 domain in insect cell media. The domain was refolded by screening several membrane mimetic environments. Different q ratios of isotropic bicelles were screened for solubilizing transmembrane helix 6, 7 and 8 (TMH67H8. As the concentration of dimyristoylphosphocholine (DMPC was increased such that the q ratio was between 0.16 and 0.42, there was less crowding in the cross peaks with increasing q ratio. In bicelles of q = 0.42, the maximum number of cross peaks were obtained and the cross peaks were uniformly dispersed. The receptor domain in bicelles beyond q = 0.42 resulted in peak crowding. These studies demonstrate that GPCRs folding especially in bicelles is protein-specific and requires the right mix of the longer chain and shorter chain lipids to provide the right environment for proper folding. These findings will allow further development of novel membrane mimetics to provide greater diversity of lipid mixtures than those currently being employed for GPCR stability and folding, which are critical for both X-ray and NMR studies of GPCRs.

  7. Cationic liposome co-encapsulation of SMAC mimetic and zVAD using a novel lipid bilayer fusion loaded with MLKL-pDNA for tumour inhibition in vivo.

    Science.gov (United States)

    Sun, Dan; Zhao, Linshu; Lin, Junzhong; Zhao, Yun; Zheng, Yu

    2018-01-01

    The increase in multidrug resistance among colon cancer cells presents a challenge for the development of effective therapies. Small-molecule analogues of second mitochondria-derived activator of caspase (SMAC) mimetic in association with mixed lineage kinase domain-like protein (MLKL)-pDNA and z-VAD-fmk have shown ideal antitumor effects in colon cancer cells in vitro via induction of RIP3-dependent necroptosis. To achieve synergistic antitumor effects in vivo, liposomes loaded with SMAC mimetic, MLKL-pDNA and z-VAD-fmk have been developed using novel lipid fusion methods to co-localise the molecules of interest within the tumour cells. The co-encapsulation liposome (MLKL-zVAD-BV6-LP) had a high entrapment efficiency of approximately 95% for both zVAD and BV6 and was able to condense MLKL-pDNA very well. The vectors showed good biocompatibility, tumour targeting and small-molecule co-localisation. In a CT26 mouse model, the MLKL-zVAD-BV6-LP exhibited a tumour-suppression rate of over 60% in vivo, which was significantly higher than that of both the null-liposome and coadministration groups. Above all, the co-encapsulation system provided a novel approach to combination tumour therapy.

  8. The effect of sodium thiopental as a GABA mimetic drug in neonatal period on expression of GAD65 and GAD67 genes in hippocampus of newborn and adult male rats

    Directory of Open Access Journals (Sweden)

    Masoud Naseri

    2017-09-01

    Full Text Available Objective(s: Development of the nervous system in human and most animals is continued after the birth. Critical role of this period in generation and specialization of the neuronal circuits is confirmed in numerous studies. Any pharmacological intervention in this period may result in structural, functional or behavioral abnormalities. In this study, sodium thiopental a GABA mimetic drug was administrated to newborn rats and their GAD65 and GAD67 expression in hippocampus was evaluated before and after puberty. Materials and Methods: Newborn male Wistar rats were received sodium thiopental (35 mg/kg daily for 11 days (from 4 to 14 days after birth. Expression of GAD65 and GAD67 in their hippocampus was compared with control groups in 15 and 45 days after birth with RT-qPCR method. Results: Significant down regulation of GAD65 and GAD67 gene expression was observed in treated rats compared with control group in 45 days after birth animals. But no significant difference was shown between experimental and control groups 15 days after birth animals. Conclusion: The effect of sodium thiopental on GAD65 and GAD67 expression only at adult rats showed a latent period of influence which can be attributed to dosage or intension of sodium thiopental neurotoxicity. Significant down regulation of GAD65 and GAD67 showed unwanted effect of sodium thiopental as GABA mimetic drug in critical period of development.

  9. Superoxide dismutase/catalase mimetics but not MAP kinase inhibitors are neuroprotective against oxygen/glucose deprivation-induced neuronal death in hippocampus.

    Science.gov (United States)

    Zhou, Miou; Dominguez, Reymundo; Baudry, Michel

    2007-12-01

    Although oxygen/glucose deprivation (OGD) has been widely used as a model of ischemic brain damage, the mechanisms underlying acute neuronal death in this model are not yet well understood. We used OGD in acute hippocampal slices to investigate the roles of reactive oxygen species and of the mitogen-activated protein kinases (MAPKs) in neuronal death. In particular, we tested the neuroprotective effects of two synthetic superoxide dismutase/catalase mimetics, EUK-189 and EUK-207. Acute hippocampal slices prepared from 2-month-old or postnatal day 10 rats were exposed to oxygen and glucose deprivation for 2 h followed by 2.5 h reoxygenation. Lactate dehydrogenase (LDH) release in the medium and propidium iodide (PI) uptake were used to evaluate cell viability. EUK-189 or EUK-207 applied during the OGD and reoxygenation periods decreased LDH release and PI uptake in slices from 2-month-old rats. EUK-189 or EUK-207 also partly blocked OGD-induced ATP depletion and extracellular signal-regulated kinases 1 and 2 (ERK1/2) dephosphorylation, and completely eliminated reactive oxygen species generation. The MEK inhibitor U0126 applied together with EUK-189 or EUK-207 completely blocked ERK1/2 activation, but had no effect on their protective effects against OGD-induced LDH release. U0126 alone had no effect on OGD-induced LDH release. EUK-207 had no effect on OGD-induced p38 or c-Jun N-terminal kinase dephosphorylation, and when the p38 inhibitor SB203580 was applied together with EUK-207, it had no effect on the protective effects of EUK-207. SB203580 alone had no effect on OGD-induced LDH release either. In slices from p10 rats, OGD also induced high-LDH release that was partly reversed by EUK-207; however, neither OGD nor EUK-207 produced significant changes in ERK1/2 and p38 phosphorylation. OGD-induced spectrin degradation was not modified by EUK-189 or EUK-207 in slices from p10 or 2-month-old rats, suggesting that their protective effects was not mediated through

  10. Chimeric design, synthesis, and biological assays of a new nonpeptide insulin-mimetic vanadium compound to inhibit protein tyrosine phosphatase 1B.

    Science.gov (United States)

    Scior, Thomas; Guevara-García, José Antonio; Melendez, F J; Abdallah, Hassan H; Do, Quoc-Tuan; Bernard, Philippe

    2010-09-24

    Prior to its total synthesis, a new vanadium coordination compound, called TSAG0101, was computationally designed to inhibit the enzyme protein tyrosine phosphatase 1B (PTP1B). The PTP1B acts as a negative regulator of insulin signaling by blocking the active site where phosphate hydrolysis of the insulin receptor takes place. TSAG001, [V(V)O(2)(OH)(picolinamide)], was characterized by infrared (IR) and nuclear magnetic resonance (NMR) spectroscopy; IR: ν/cm(-1) 3,570 (NH), 1,627 (C=O, coordinated), 1,417 (C-N), 970/842 (O=V=O), 727 δ̣ (pyridine ring); (13)C NMR: 5 bands between 122 and 151 ppm and carbonyl C shifted to 180 ppm; and (1)H NMR: 4 broad bands from 7.6 to 8.2 ppm and NH(2) shifted to 8.8 ppm. In aqueous solution, in presence or absence of sodium citrate as a biologically relevant and ubiquitous chelator, TSAG0101 undergoes neither ligand exchange nor reduction of its central vanadium atom during 24 hours. TSAG0101 shows blood glucose lowering effects in rats but it produced no alteration of basal- or glucose-induced insulin secretion on β cells during in vitro tests, all of which excludes a direct mechanism evidencing the extrapancreatic nature of its activity. The lethal dose (LD(50)) of TSAG0101 was determined in Wistar mice yielding a value of 412 mg/kg. This value is one of the highest among vanadium compounds and classifies it as a mild toxicity agent when compared with literature data. Due to its nonsubstituted, small-sized scaffold design, its remarkable complex stability, and low toxicity; TSAG0101 should be considered as an innovative insulin-mimetic principle with promising properties and, therefore, could become a new lead compound for potential nonpeptide PTP1B inhibitors in antidiabetic drug research. In view of the present work, the inhibitory concentration (IC(50)) and extended solution stability will be tested.

  11. Insulin mimetic effect of a tungstate cluster. Effect of oral administration of homo-polyoxotungstates and vanadium-substituted polyoxotungstates on blood glucose level of STZ mice.

    Science.gov (United States)

    Nomiya, K; Torii, H; Hasegawa, T; Nemoto, Y; Nomura, K; Hashino, K; Uchida, M; Kato, Y; Shimizu, K; Oda, M

    2001-10-01

    Aqueous vanadate and aqueous tungstate have been known to mimic all or most of the actions of insulin in intact cell systems with respect to normalization of the blood glucose level. By carrying out oral administration in vivo experiments on the blood glucose level of streptozotocin (STZ)-induced diabetes (STZ mice), the insulin-mimetic (IM) effects of metal-oxide clusters of all-inorganic composition were examined using many types of polyoxometalates (POM) with and without vanadium substitution. Several homo-POM and vanadium-substituted POM showed hypoglycemic effects. The observed hypoglycemic effects indicated that POM with the Dawson structure [[alpha-P(2)W(18)O(62)](6-) (W-2), [alpha-P(2)W(17)V(V)O(62)](7-) (V-19) and [alpha-1,2,3-P(2)W(15)V(V)(3)O(62)](9-) (V-04)] are more effective than those with the Keggin structure [[alpha-PW(12)O(40)](3-) (W-1), [alpha-PW(11)V(V)O(40)](4-) (V-01), [alpha-1,2-PW(10)V(V)(2)O(40)](5-) (V-02), [alpha-1,2,3-PW(9)V(V)(3)O(40)](6-) (V-03) and [alpha-1,4,9-PW(9)V(V)(3)O(40)](6-) (V-13)]. The vanadate cluster [V(10)O(28)](6-) (V-15) also showed a hypoglycemic effect. (31)P and (51)V NMR measurements showed that the Dawson POM (W-2, V-04 and V-19) are stable in aqueous solution under the conditions used. The effect of all POM on the body weight of STZ mice was also examined. The decrease in body weight after administration of W-2 was much less than for V-19, V-04 and V-15. This suggests that not only monomeric tungstate and vanadate, but also the structure factors of tungstate and vanadate clusters, can play a significant role in their biological action.

  12. Canonical Bcl-2 motifs of the Na+/K+ pump revealed by the BH3 mimetic chelerythrine: early signal transducers of apoptosis?

    Science.gov (United States)

    Lauf, Peter K; Heiny, Judith; Meller, Jarek; Lepera, Michael A; Koikov, Leonid; Alter, Gerald M; Brown, Thomas L; Adragna, Norma C

    2013-01-01

    Chelerythrine [CET], a protein kinase C [PKC] inhibitor, is a prop-apoptotic BH3-mimetic binding to BH1-like motifs of Bcl-2 proteins. CET action was examined on PKC phosphorylation-dependent membrane transporters (Na+/K+ pump/ATPase [NKP, NKA], Na+-K+-2Cl+ [NKCC] and K+-Cl- [KCC] cotransporters, and channel-supported K+ loss) in human lens epithelial cells [LECs]. K+ loss and K+ uptake, using Rb+ as congener, were measured by atomic absorption/emission spectrophotometry with NKP and NKCC inhibitors, and Cl- replacement by NO3ˉ to determine KCC. 3H-Ouabain binding was performed on a pig renal NKA in the presence and absence of CET. Bcl-2 protein and NKA sequences were aligned and motifs identified and mapped using PROSITE in conjunction with BLAST alignments and analysis of conservation and structural similarity based on prediction of secondary and crystal structures. CET inhibited NKP and NKCC by >90% (IC50 values ~35 and ~15 μM, respectively) without significant KCC activity change, and stimulated K+ loss by ~35% at 10-30 μM. Neither ATP levels nor phosphorylation of the NKA α1 subunit changed. 3H-ouabain was displaced from pig renal NKA only at 100 fold higher CET concentrations than the ligand. Sequence alignments of NKA with BH1- and BH3-like motifs containing pro-survival Bcl-2 and BclXl proteins showed more than one BH1-like motif within NKA for interaction with CET or with BH3 motifs. One NKA BH1-like motif (ARAAEILARDGPN) was also found in all P-type ATPases. Also, NKA possessed a second motif similar to that near the BH3 region of Bcl-2. Findings support the hypothesis that CET inhibits NKP by binding to BH1-like motifs and disrupting the α1 subunit catalytic activity through conformational changes. By interacting with Bcl-2 proteins through their complementary BH1- or BH3-like-motifs, NKP proteins may be sensors of normal and pathological cell functions, becoming important yet unrecognized signal transducers in the initial phases of apoptosis. CET

  13. Canonical Bcl-2 Motifs of the Na+/K+ Pump Revealed by the BH3 Mimetic Chelerythrine: Early Signal Transducers of Apoptosis?

    Directory of Open Access Journals (Sweden)

    Peter K. Lauf

    2013-02-01

    Full Text Available Background/Aims: Chelerythrine [CET], a protein kinase C [PKC] inhibitor, is a prop-apoptotic BH3-mimetic binding to BH1-like motifs of Bcl-2 proteins. CET action was examined on PKC phosphorylation-dependent membrane transporters (Na+/K+ pump/ATPase [NKP, NKA], Na+-K+-2Cl+ [NKCC] and K+-Cl- [KCC] cotransporters, and channel-supported K+ loss in human lens epithelial cells [LECs]. Methods: K+ loss and K+ uptake, using Rb+ as congener, were measured by atomic absorption/emission spectrophotometry with NKP and NKCC inhibitors, and Cl- replacement by NO3ˉ to determine KCC. 3H-Ouabain binding was performed on a pig renal NKA in the presence and absence of CET. Bcl-2 protein and NKA sequences were aligned and motifs identified and mapped using PROSITE in conjunction with BLAST alignments and analysis of conservation and structural similarity based on prediction of secondary and crystal structures. Results: CET inhibited NKP and NKCC by >90% (IC50 values ∼35 and ∼15 µM, respectively without significant KCC activity change, and stimulated K+ loss by ∼35% at 10-30 µM. Neither ATP levels nor phosphorylation of the NKA α1 subunit changed. 3H-ouabain was displaced from pig renal NKA only at 100 fold higher CET concentrations than the ligand. Sequence alignments of NKA with BH1- and BH3-like motifs containing pro-survival Bcl-2 and BclXl proteins showed more than one BH1-like motif within NKA for interaction with CET or with BH3 motifs. One NKA BH1-like motif (ARAAEILARDGPN was also found in all P-type ATPases. Also, NKA possessed a second motif similar to that near the BH3 region of Bcl-2. Conclusion: Findings support the hypothesis that CET inhibits NKP by binding to BH1-like motifs and disrupting the α1 subunit catalytic activity through conformational changes. By interacting with Bcl-2 proteins through their complementary BH1- or BH3-like-motifs, NKP proteins may be sensors of normal and pathological cell functions, becoming important yet

  14. Identification and characterization of a putative human platelet thromboxane A2/prostaglandin H2 receptor

    International Nuclear Information System (INIS)

    Saussy, D.L. Jr.

    1986-01-01

    The thromboxane A 2 (TXA 2 ) analog, 9,11-dimethylmethano-11,12-methano-16-(3-iodo-4-hydroxyphenyl)-13,14-dihydro-13-aza-15αβ-omega-tetranor TXA 2 (I-PTA-OH) was characterized as a competitive antagonist of TXA 2 mimetic-induced platelet aggregation, with a K/sub d/ of 190 nM in platelet rich plasma. This antagonism was specific for the putative thromboxane A 2 /prostaglandin H 2 (TXA 2 /PGH 2 ) receptor, since I-PTA-OH had no inhibitory effects on platelet aggregation stimulated by agonists which act independently of TXA 2 /PGH 2 , and did not inhibit platelet TXA 2 synthesis. [ 125 I]-PTA-OH binding to a particulate fraction from human platelets was saturable, displaceable, and linear with protein concentration. Scatchard analysis of equilibrium binding revealed a single class of high affinity binding sites, with a K/sub d/ of 30 +/- 4 nM and a B/sub max/ of 1.8 +/- 0.3 pmol/mg protein. Kinetic analysis yielded a k 1 of 1.35 x 10 6 M -1 x min -1 and a k√ 1 of 0.032 min -1 , K/sub d/ = k√ 1 /k 1 = 24 nM. The subcellular localization of the putative TXA 2 /PGH 2 receptor was determined using [ 125 I]-PTA-OH binding as a marker for the receptor. [ 125 I]-PTA-OH binding as a marker for the receptor. [ 125 I]-PTA-OH binding, was coenriched with markers for plasma membranes and dense tubular system; but not with markers for cytoplasmic constituents, mitochondria, or granules

  15. Pastoral conflict in Kenya: Transforming mimetic violence to mimetic ...

    African Journals Online (AJOL)

    Pastoralist communities in East Africa have traditionally been built upon nomadic peoples, migrating along with .... Inter-tribal co-operation ceases and daily social life and economic routines are disrupted. ..... Vern Redekop (2011), however, asserts that pairing spiritual reconciliation with focusing on personal connections.

  16. Pastoral conflict in Kenya: Transforming mimetic violence to mimetic ...

    African Journals Online (AJOL)

    Livestock raiding has been a source of conflict amongst and between pastoral societies in Africa for hundreds of years. However, more recently, these raids have become more violent and have triggered much more organised retaliations. Many times raids themselves are perceived as motivated by ethnic dimensions.

  17. Caloric restriction and its mimetics

    Directory of Open Access Journals (Sweden)

    Shin-Hae Lee

    2013-04-01

    Full Text Available Caloric restriction is the most reliable intervention to preventage-related disorders and extend lifespan. The reduction ofcalories by 10-30% compared to an ad libitum diet is known toextend the longevity of various species from yeast to rodents.The underlying mechanisms by which the benefits of caloricrestriction occur have not yet been clearly defined. However,many studies are being conducted in an attempt to elucidatethese mechanisms, and there are indications that the benefits ofcaloric restriction are related to alteration of the metabolic rateand the accumulation of reactive oxygen species. Duringmolecular signaling, insulin/insulin-like growth factor signaling,target of rapamycin pathway, adenosine monophosphateactivated protein kinase signaling, and Sirtuin are focused asunderlying pathways that mediate the benefits of caloricrestriction. Here, we will review the current status of caloricrestriction. [BMB Reports 2013; 46(4: 181-187

  18. Effects of the high-density lipoprotein mimetic agent CER-001 on coronary atherosclerosis in patients with acute coronary syndromes: a randomized trial†

    Science.gov (United States)

    Tardif, Jean-Claude; Ballantyne, Christie M.; Barter, Philip; Dasseux, Jean-Louis; Fayad, Zahi A.; Guertin, Marie-Claude; Kastelein, John J. P.; Keyserling, Constance; Klepp, Heather; Koenig, Wolfgang; L'Allier, Philippe L.; Lespérance, Jacques; Lüscher, Thomas F.; Paolini, John F.; Tawakol, Ahmed; Waters, David D.; Pfeffer, M.; Brown, V.; Rouleau, J.; Watkins, P.; Wei, L.J.; Gosselin, G.; Chayer, C.; Lanthier, S.; Pelletier, G.B.; Racine, N.; Agarwal, H.; Brilakis, E.; Cannon, L.; Carrié, D.; Corbelli, J.; Coste, P.; de Winter, R.; Diaz, A.; Eisenberg, S.; Ennis, B.; Fajadet, J.; Fam, N.; Fortuin, D.; Gessler, C.; Grines, C.; Guerra, D.; Gum, H.; Haldis, T.; Heestermans, T.; Herrman, J.P.; Huynh, T.; Kedhi, E.; Koren, M.; Kouz, S.; Krolick, M.; Kumkumian, G.; Lavi, S.; Li, R.J.; Masud, ARZ; McAlhany, C.; McGrew, F.A.; O'Shaughnessy, C.; Oude Ophuis, A.J.M.; Parr, K.; Penny, W.; Pesant, Y.; Post, H.; Robinson, S.; Rodes-Cabau, J.; Roy, A.; Schulman, S.; Spence, F.; Stouffer, G.; Stys, T.; Sussex, B.; Tahirkheli, N.; Tardif, J-C.; Grégoire, J.; ten Berg, J.; van Boven, A.J.; von Birgelen, C.; Weinstein, D.

    2014-01-01

    Aim High-density lipoproteins (HDLs) have several potentially protective vascular effects. Most clinical studies of therapies targeting HDL have failed to show benefits vs. placebo. Objective To investigate the effects of an HDL-mimetic agent on atherosclerosis by intravascular ultrasonography (IVUS) and quantitative coronary angiography (QCA). Design and setting A prospective, double-blinded, randomized trial was conducted at 51 centres in the USA, the Netherlands, Canada, and France. Intravascular ultrasonography and QCA were performed to assess coronary atherosclerosis at baseline and 3 (2–5) weeks after the last study infusion. Patients Five hundred and seven patients were randomized; 417 and 461 had paired IVUS and QCA measurements, respectively. Intervention Patients were randomized to receive 6 weekly infusions of placebo, 3 mg/kg, 6 mg/kg, or 12 mg/kg CER-001. Main outcome measures The primary efficacy parameter was the nominal change in the total atheroma volume. Nominal changes in per cent atheroma volume on IVUS and coronary scores on QCA were also pre-specified endpoints. Results The nominal change in the total atheroma volume (adjusted means) was −2.71, −3.13, −1.50, and −3.05 mm3 with placebo, CER-001 3 mg/kg, 6 mg/kg, and 12 mg/kg, respectively (primary analysis of 12 mg/kg vs. placebo: P = 0.81). There was also no difference among groups for the nominal change in per cent atheroma volume (0.02, −0.02, 0.01, and 0.19%; nominal P = 0.53 for 12 mg/kg vs. placebo). Change in the coronary artery score was −0.022, −0.036, −0.022, and −0.015 mm (nominal P = 0.25, 0.99, 0.55), and change in the cumulative coronary stenosis score was −0.51, 2.65, 0.71, and −0.77% (compared with placebo, nominal P = 0.85 for 12 mg/kg and nominal P = 0.01 for 3 mg/kg). The number of patients with major cardiovascular events was 10 (8.3%), 16 (13.3%), 17 (13.7%), and 12 (9.8%) in the four groups. Conclusion CER-001 infusions did not reduce coronary

  19. Synthetic N-Acetyl-D-glucosamine Based Fully Branched Tetrasaccharide, a Mimetic of the Endogenous Ligand for CD69, Activates CD69+ Killer Lymphocytes upon Dimerization via a Hydrophilic Flexible Linker

    Czech Academy of Sciences Publication Activity Database

    Kovalová, Anna; Ledvina, Miroslav; Šaman, David; Zyka, Daniel; Kubíčková, M.; Žídek, L.; Sklenář, V.; Pompach, P.; Kavan, D.; Bílý, J.; Vaněk, O.; Kubínková, Z.; Libigerová, M.; Ivanová, L.; Antolíková, M.; Mrázek, H.; Rozbeský, D.; Hofbauerová, Kateřina; Křen, Vladimír; Bezouška, K.

    2010-01-01

    Roč. 53, č. 10 (2010), s. 4050-4065 ISSN 0022-2623 R&D Projects: GA MŠk 1M0505; GA ČR GA303/09/0477; GA ČR GD305/09/H008; GA ČR GP203/09/P024; GA AV ČR KAN200520703; GA AV ČR KAN200100801 Grant - others:GA MŠk(CZ) LC06030 Program:LC Institutional research plan: CEZ:AV0Z40550506; CEZ:AV0Z50200510 Keywords : CD69 * mimetic * tetrasaccharide Subject RIV: CC - Organic Chemistry Impact factor: 5.207, year: 2010

  20. Chronic stress in adulthood followed by intermittent stress impairs spatial memory and the survival of newborn hippocampal cells in aging animals: prevention by FGL, a peptide mimetic of neural cell adhesion molecule

    DEFF Research Database (Denmark)

    Borcel, Erika; Pérez-Alvarez, Laura; Herrero, Ana Isabel

    2008-01-01

    , a peptide mimetic of neural cell adhesion molecule, during the 4 weeks of continuous stress not only prevented the deleterious effects of chronic stress on spatial memory, but also reduced the survival of the newly generated hippocampal cells in aging animals. FGL treatment did not, however, prevent......In this study, we examined whether chronic stress in adulthood can exert long-term effects on spatial-cognitive abilities and on the survival of newborn hippocampal cells in aging animals. Male Wistar rats were subjected to chronic unpredictable stress at midlife (12 months old) and then reexposed...... each week to a stress stimulus. When evaluated in the water maze at the early stages of aging (18 months old), chronic unpredictable stress accelerated spatial-cognitive decline, an effect that was accompanied by a reduction in the survival of newborn cells and in the number of adult granular cells...

  1. A Placebo-Controlled Study on the Effects of the Glucagon-Like Peptide-1 Mimetic, Exenatide, on Insulin Secretion, Body Composition and Adipokines in Obese, Client-Owned Cats.

    Directory of Open Access Journals (Sweden)

    Kirsten M Hoelmkjaer

    Full Text Available Glucagon-like Peptide-1 mimetics increase insulin secretion and reduces body weight in humans. In lean, healthy cats, short-term treatment has produced similar results, whereas the effect in obese cats or with extended duration of treatment is unknown. Here, prolonged (12 weeks treatment with the Glucagon-like Peptide-1 mimetic, exenatide, was evaluated in 12 obese, but otherwise healthy, client-owned cats. Cats were randomized to exenatide (1.0 μg/kg or placebo treatment twice daily for 12 weeks. The primary endpoint was changes in insulin concentration; the secondary endpoints were glucose homeostasis, body weight, body composition as measured by dual-energy x-ray absorptiometry and overall safety. An intravenous glucose tolerance test (1 g/kg body weight was conducted at week 0 and week 12. Exenatide did not change the insulin concentration, plasma glucose concentration or glucose tolerance (P>0.05 for all. Exenatide tended to reduce body weight on continued normal feeding. Median relative weight loss after 12 weeks was 5.1% (range 1.7 to 8.4% in the exenatide group versus 3.2% (range -5.3 to 5.7% in the placebo group (P = 0.10. Body composition and adipokine levels were unaffected by exenatide (P>0.05. Twelve weeks of exenatide was well-tolerated, with only two cases of mild, self-limiting gastrointestinal signs and a single case of mild hypoglycemia. The long-term insulinotropic effect of exenatide appeared less pronounced in obese cats compared to previous short-term studies in lean cats. Further investigations are required to fully elucidate the effect on insulin secretion, glucose tolerance and body weight in obese cats.

  2. A Placebo-Controlled Study on the Effects of the Glucagon-Like Peptide-1 Mimetic, Exenatide, on Insulin Secretion, Body Composition and Adipokines in Obese, Client-Owned Cats.

    Science.gov (United States)

    Hoelmkjaer, Kirsten M; Wewer Albrechtsen, Nicolai J; Holst, Jens J; Cronin, Anna M; Nielsen, Dorte H; Mandrup-Poulsen, Thomas; Bjornvad, Charlotte R

    2016-01-01

    Glucagon-like Peptide-1 mimetics increase insulin secretion and reduces body weight in humans. In lean, healthy cats, short-term treatment has produced similar results, whereas the effect in obese cats or with extended duration of treatment is unknown. Here, prolonged (12 weeks) treatment with the Glucagon-like Peptide-1 mimetic, exenatide, was evaluated in 12 obese, but otherwise healthy, client-owned cats. Cats were randomized to exenatide (1.0 μg/kg) or placebo treatment twice daily for 12 weeks. The primary endpoint was changes in insulin concentration; the secondary endpoints were glucose homeostasis, body weight, body composition as measured by dual-energy x-ray absorptiometry and overall safety. An intravenous glucose tolerance test (1 g/kg body weight) was conducted at week 0 and week 12. Exenatide did not change the insulin concentration, plasma glucose concentration or glucose tolerance (P>0.05 for all). Exenatide tended to reduce body weight on continued normal feeding. Median relative weight loss after 12 weeks was 5.1% (range 1.7 to 8.4%) in the exenatide group versus 3.2% (range -5.3 to 5.7%) in the placebo group (P = 0.10). Body composition and adipokine levels were unaffected by exenatide (P>0.05). Twelve weeks of exenatide was well-tolerated, with only two cases of mild, self-limiting gastrointestinal signs and a single case of mild hypoglycemia. The long-term insulinotropic effect of exenatide appeared less pronounced in obese cats compared to previous short-term studies in lean cats. Further investigations are required to fully elucidate the effect on insulin secretion, glucose tolerance and body weight in obese cats.

  3. A Placebo-Controlled Study on the Effects of the Glucagon-Like Peptide-1 Mimetic, Exenatide, on Insulin Secretion, Body Composition and Adipokines in Obese, Client-Owned Cats

    Science.gov (United States)

    Hoelmkjaer, Kirsten M.; Wewer Albrechtsen, Nicolai J.; Holst, Jens J.; Cronin, Anna M.; Nielsen, Dorte H.; Mandrup-Poulsen, Thomas; Bjornvad, Charlotte R.

    2016-01-01

    Glucagon-like Peptide-1 mimetics increase insulin secretion and reduces body weight in humans. In lean, healthy cats, short-term treatment has produced similar results, whereas the effect in obese cats or with extended duration of treatment is unknown. Here, prolonged (12 weeks) treatment with the Glucagon-like Peptide-1 mimetic, exenatide, was evaluated in 12 obese, but otherwise healthy, client-owned cats. Cats were randomized to exenatide (1.0 μg/kg) or placebo treatment twice daily for 12 weeks. The primary endpoint was changes in insulin concentration; the secondary endpoints were glucose homeostasis, body weight, body composition as measured by dual-energy x-ray absorptiometry and overall safety. An intravenous glucose tolerance test (1 g/kg body weight) was conducted at week 0 and week 12. Exenatide did not change the insulin concentration, plasma glucose concentration or glucose tolerance (P>0.05 for all). Exenatide tended to reduce body weight on continued normal feeding. Median relative weight loss after 12 weeks was 5.1% (range 1.7 to 8.4%) in the exenatide group versus 3.2% (range -5.3 to 5.7%) in the placebo group (P = 0.10). Body composition and adipokine levels were unaffected by exenatide (P>0.05). Twelve weeks of exenatide was well-tolerated, with only two cases of mild, self-limiting gastrointestinal signs and a single case of mild hypoglycemia. The long-term insulinotropic effect of exenatide appeared less pronounced in obese cats compared to previous short-term studies in lean cats. Further investigations are required to fully elucidate the effect on insulin secretion, glucose tolerance and body weight in obese cats. PMID:27136422

  4. Post-training intrahippocampal injection of synthetic poly-alpha-2,8-sialic acid-neural cell adhesion molecule mimetic peptide improves spatial long-term performance in mice.

    Science.gov (United States)

    Florian, Cédrick; Foltz, Jane; Norreel, Jean-Chrétien; Rougon, Geneviève; Roullet, Pascal

    2006-01-01

    Several data have shown that the neural cell adhesion molecule (NCAM) is necessary for long-term memory formation and might play a role in the structural reorganization of synapses. The NCAM, encoded by a single gene, is represented by several isoforms that differ with regard to their content of alpha-2,8-linked sialic acid residues (PSA) on their extracellular domain. The carbohydrate PSA is known to promote plasticity, and PSA-NCAM isoforms remain expressed in the CA3 region of the adult hippocampus. In the present study, we investigated the effect on spatial memory consolidation of a PSA gain of function by injecting a PSA mimetic peptide (termed pr2) into the dorsal hippocampus. Mice were subjected to massed training in the spatial version of the water maze. Five hours after the last training session, experimental mice received an injection of pr2, whereas control mice received PBS or reverse peptide injections in the hippocampal CA3 region. Memory retention was tested at different time intervals: 24 h, 1 wk, and 4 wk. The results showed that the post-training infusion of pr2 peptide significantly increases spatial performance whenever it was assessed after the training phase. By contrast, administration of the control reverse peptide did not affect retention performance. These findings provide evidence that (1) PSA-NCAM is involved in memory consolidation processes in the CA3 hippocampal region, and (2) PSA mimetic peptides can facilitate the formation of long-term spatial memory when injected during the memory consolidation phase.

  5. HEAO A-2 extragalactic results

    Science.gov (United States)

    Boldt, E. A.

    1979-01-01

    The all-sky surveys made with the A-2 instrument aboard HEAO-1 involved spectroscopy over a broad enough band width, with sufficient resolution, to obtain the basic spectral characteristics for two extreme aspects of the extragalactic X-ray sky. The overall spectrum (above 3 KeV) is remarkably well decribed by a thermal model. At the other extreme, the detailed broad-band observations of individual sources are restricted to objects within the present epoch. The objects include several individual active galaxies studied in detail for the first time as well as clusters of galaxies. Relating these results to the vast spatially unresolved hard X-ray flux measured with this instruments as well as the softer X-rays (at less than 3 keV) spatially resolved to high redshifts with the Einstein Observatory remains a challenge.

  6. Hypersensitivity to thromboxane receptor mediated cerebral vasomotion and CBF oscillations during acute NO-deficiency in rats.

    Directory of Open Access Journals (Sweden)

    Béla Horváth

    Full Text Available BACKGROUND: Low frequency (4-12 cpm spontaneous fluctuations of the cerebrovascular tone (vasomotion and oscillations of the cerebral blood flow (CBF have been reported in diseases associated with endothelial dysfunction. Since endothelium-derived nitric oxide (NO suppresses constitutively the release and vascular effects of thromboxane A(2 (TXA(2, NO-deficiency is often associated with activation of thromboxane receptors (TP. In the present study we hypothesized that in the absence of NO, overactivation of the TP-receptor mediated cerebrovascular signaling pathway contributes to the development of vasomotion and CBF oscillations. METHODOLOGY/PRINCIPAL FINDINGS: Effects of pharmacological modulation of TP-receptor activation and its downstream signaling pathway have been investigated on CBF oscillations (measured by laser-Doppler flowmetry in anesthetized rats and vasomotion (measured by isometric tension recording in isolated rat middle cerebral arteries, MCAs both under physiological conditions and after acute inhibition of NO synthesis. Administration of the TP-receptor agonist U-46619 (1 µg/kg i.v. to control animals failed to induce any changes of the systemic or cerebral circulatory parameters. Inhibition of the NO synthesis by nitro-L-arginine methyl ester (L-NAME, 100 mg/kg i.v. resulted in increased mean arterial blood pressure and a decreased CBF accompanied by appearance of CBF-oscillations with a dominant frequency of 148±2 mHz. U-46619 significantly augmented the CBF-oscillations induced by L-NAME while inhibition of endogenous TXA(2 synthesis by ozagrel (10 mg/kg i.v. attenuated it. In isolated MCAs U-46619 in a concentration of 100 nM, which induced weak and stable contraction under physiological conditions, evoked sustained vasomotion in the absence of NO, which effect could be completely reversed by inhibition of Rho-kinase by 10 µM Y-27632. CONCLUSION/SIGNIFICANCE: These results suggest that hypersensitivity of the TP

  7. Thorium. Suppl. Vol. A2

    International Nuclear Information System (INIS)

    Kirby, H.W.; Moebius, S.; Muenzel, H.; Ritcey, G.M.; Molnar, R.; Pouskouleli, G.

    1986-01-01

    The present volume ''Thorium'' Suppl. Vol. A2 of the Gmelin Handbook covers the history of thorium and the preparation of its scientifically and technologically important isotopes, as well as the nuclear properties (including fission properties) of all its isotopes. The thorium isotopes range from 212 Th to 236 Th. The different types of production of all of these isotopes have been described and, in the following chapter, the decay data and fission characteristics. On the other hand, chemical isolation procedures have been outlined only for the more important isotopes 227 Th to 234 Th. Special emphasis, however, was devoted to 232 Th, the only naturally occurring very long-lived isotope. Despite some other applications the specific importance of 232 Th comes from the fact that its neutron capture reaction product 233 U is a fissile nuclide, which makes 232 Th an important isotope in nuclear technology, especially for the so-called ''Thorium High Temperature Reactor'' (THTR). The other longer-lived isotopes are either used in the laboratory for tracer studies (e.g. 234 Th) or for the production of nuclides for isotope batteries (e.g. 230 Th), whereas 233 Th is the nuclide measured for the neutron activation determination of thorium. In the chapters for the isolation and purification of thorium isotopes only those extraction and other separation procedures were mentioned which are relevant to the given process. Detailed information on these topics has been given in specific volumes of this Handbook, e.g. Volume D2 for ''Extraction of Thorium''. The literature is covered to the end of 1984. In some cases, more recent data have been considered. (orig./RB)

  8. Rac1 is essential for phospholipase C-gamma2 activation in platelets

    DEFF Research Database (Denmark)

    Pleines, Irina; Elvers, Margitta; Strehl, Amrei

    2008-01-01

    regulation are not fully understood. An involvement of small GTPases of the Rho family (Rho, Rac, Cdc42) in PLC activation has been proposed but this has not been investigated in platelets. We here show that murine platelets lacking Rac1 display severely impaired GPVI- or CLEC-2-dependent activation...... and aggregation. This defect was associated with impaired production of inositol 1,4,5-trisphosphate (IP(3)) and intracellular calcium mobilization suggesting inappropriate activation of PLCgamma2 despite normal tyrosine phosphorylation of the enzyme. Rac1 ( -/- ) platelets displayed defective thrombus formation...... on collagen under flow conditions which could be fully restored by co-infusion of ADP and the TxA(2) analog U46619, indicating that impaired GPVI-, but not G-protein signaling, was responsible for the observed defect. In line with this, Rac1 ( -/- ) mice were protected in two collagen-dependent arterial...

  9. The stable prostacyclin-analogue, iloprost, unlike prostanoids and leukotrienes, potently stimulates cyclic adenosine monophosphate synthesis of primary astroglial cell cultures.

    Science.gov (United States)

    Seregi, A; Schobert, A; Hertting, G

    1988-06-01

    The effect of different eicosanoids on adenosine-3', 5'-cyclic-monophosphate (cAMP) accumulation in primary astroglial cell cultures prepared from newborn rat brain was studied. The stable prostacyclin-analogue, iloprost, effectively stimulated cAMP synthesis in a concentration-dependent, saturable manner, the EC50 being about 3 x 10(-8) M. Prostaglandin (PG) E2 was less potent, without reaching plateau even at 10(-5) M. Prostaglandins D2 and F2 alpha, and the stable thromboxane A2-analogue, U 46619, as well as leukotrienes (LT) B4, C4, D4 and E4 were not effective and did not attenuate basal or isoprenaline (10(-8) M)-stimulated astroglial cAMP formation. This is the first indication for the existence of a prostacyclin receptor coupled positively to the adenylate cyclase in astrocytes. Other eicosanoids are unlikely to be involved in receptor-mediated regulation of astroglial cAMP levels.

  10. Acute effects of prostaglandin E1 and E2 on vascular reactivity and blood flow in situ in the chick chorioallantoic membrane.

    Science.gov (United States)

    Harland, D R; Lorenz, L D; Fay, K; Dunn, B E; Gruenloh, S K; Narayanan, J; Jacobs, E R; Medhora, M

    2012-01-01

    The chick chorioallantoic membrane (CAM) subserves gas exchange in the developing embryo and shell-less culture affords a unique opportunity for direct observations over time of individual blood vessels to pharmacologic interventions. We tested a number of lipids including prostaglandins PGE(1&2) for vascular effects and signaling in the CAM. Application of PGE(1&2) induced a decrease in the diameter of large blood vessels and a concentration-dependent, localized, reversible loss of blood flow through small vessels. The loss of flow was also mimicked by misoprostol, an agonist for 3 of 4 known PGE receptors, EP(2-4), and by U46619, a thromboxane mimetic. Selective receptor antagonists for EP(3) and thromboxane each partially blocked the response. This is a first report of the effects of prostaglandins on vasoreactivity in the CAM. Our model allows the unique ability to examine simultaneous responses of large and small vessels in real time and in vivo. Copyright © 2012. Published by Elsevier Ltd.

  11. [D-Leu-4]-OB3 and MA-[D-Leu-4]-OB3, small molecule synthetic peptide leptin mimetics, improve glycemic control in diet-induced obese (DIO) mice.

    Science.gov (United States)

    Wang, Anke; Anderson, Brian M; Novakovic, Zachary M; Grasso, Patricia

    2018-03-01

    We have previously shown that following oral delivery in dodecyl maltoside (DDM), [D-Leu-4]-OB3 and its myristic acid conjugate, MA-[D-Leu-4]-OB3, improved energy balance and glucose homeostasis in genetically obese/diabetic mouse models. More recently, we have provided immunohistochemical evidence indicating that these synthetic peptide leptin mimetics cross the blood-brain barrier and concentrate in the area of the arcuate nucleus of the hypothalamus in normal C57BL/6J and Swiss Webster mice, in genetically obese ob/ob mice, and in diet-induced obese (DIO) mice. In the present study, we describe the effects of oral delivery of [D-Leu-4]-OB3 and MA-[D-Leu-4]-OB3 on glycemic control in diet-induced (DIO) mice, a non-genetic rodent model of obesity and its associated insulin resistance, which more closely recapitulates common obesity and diabetes in humans. Male C57BL/6J and DIO mice, 17, 20, and 28 weeks of age, were maintained on a low-fat or high-fat diet and given vehicle (DDM) alone or [D-Leu-4]-OB3 or MA-[D-Leu-4]-OB3 in DDM by oral gavage for 12 or 14 days. Body weight gain, food and water intake, fasting blood glucose, oral glucose tolerance, and serum insulin levels were measured. Our data indicate that (1) [D-Leu-4]-OB3 and MA-[D-Leu-4]-OB3 restore glucose tolerance in male DIO mice maintained on a high-fat diet to levels comparable to those of non-obese C57BL/6J wild-type mice of the same age and sex maintained on a low-fat diet; and (2) the influence of [D-Leu-4]-OB3 and MA-[D-Leu-4]-OB3 on glycemic control appears to be independent of their effects on energy balance. These results suggest that [D-Leu-4]-OB3 and/or MA-[D-Leu-4]-OB3 may have application to the management of the majority of cases of common obesity in humans, a state characterized at least in part, by leptin resistance resulting from a defect in leptin transport across the blood-brain barrier. They further suggest that these small molecule synthetic peptide leptin mimetics, through their

  12. Antiplatelet effect of phloroglucinol is related to inhibition of cyclooxygenase, reactive oxygen species, ERK/p38 signaling and thromboxane A2 production

    International Nuclear Information System (INIS)

    Chang, Mei-Chi; Chang, Hsiao-Hua; Chan, Chiu-Po; Chou, Han-Yi; Chang, Bei-En; Yeung, Sin-Yuet; Wang, Tong-Mei; Jeng, Jiiang-Huei

    2012-01-01

    Platelet dysfunction is a major risk factor of cardiovascular diseases such as atherosclerosis, stroke and myocardial infarction. Many antiplatelet agents are used for prevention and treatment of these diseases. In this study, phloroglucinol (2.5–25 μM) suppressed AA-induced platelet aggregation and thromboxane B 2 (TXB 2 ) production, but not U46619-induced platelet aggregation. Phloroglucinol (100–250 μM) showed little cytotoxicity to platelets. Phloroglucinol inhibited the COX-1 and COX-2 activities by 45–74% and 49–72% respectively at concentrations of 10–50 μM. At concentrations of 1 and 5 μM, phloroglucinol attenuated the AA-induced ROS production in platelets by 30% and 53%, with an IC 50 of 13.8 μM. Phloroglucinol also inhibited the PMA-stimulated ROS production in PMN. Preincubation of platelets by phloroglucinol (10–25 μM) markedly attenuated the AA-induced ERK and p38 phosphorylation. Intravenous administration of phloroglucinol (2.5 and 5 μmol/mouse) suppressed the ex vivo AA-induced platelet aggregation by 57–71%. Phloroglucinol administration also elevated the mice tail bleeding time. Moreover, phloroglucinol inhibited the IL-1β-induced PGE 2 production in pulp fibroblasts. These results indicate that antiplatelet and anti-inflammatory effects of phloroglucinol are related to inhibition of COX, ROS and TXA2 production as well as ERK/p38 phosphorylation in platelets. Phloroglucinol further suppress PMA-induced ROS production in PMN. The antiplatelet effect of phloroglucinol was confirmed by ex vivo study. Clinically, the consumption of phloroglucinol-containing food/natural products as nutritional supplement may be helpful to cardiovascular health. Phloroglucinol has potential pharmacological use. -- Highlights: ► Phloroglucinol suppressed AA-induced platelet aggregation and thromboxane production. ► Phloroglucinol inhibited COX activity and IL-1b-induced PGE2 production in fibroblast. ► Phloroglucinol declined platelet and

  13. A Special Extract of Bacopa monnieri (CDRI-08-Restored Memory in CoCl2-Hypoxia Mimetic Mice Is Associated with Upregulation of Fmr-1 Gene Expression in Hippocampus

    Directory of Open Access Journals (Sweden)

    Anupama Rani

    2015-01-01

    Full Text Available Fragile X mental retardation protein (FMRP is a neuronal translational repressor and has been implicated in learning, memory, and cognition. However, the role of Bacopa monnieri extract (CDRI-08 in enhancing cognitive abilities in hypoxia-induced memory impairment via Fmr-1 gene expression is not known. Here, we have studied effects of CDRI-08 on the expression of Fmr-1 gene in the hippocampus of well validated cobalt chloride (CoCl2-induced hypoxia mimetic mice and analyzed the data with alterations in spatial memory. Results obtained from Morris water maze test suggest that CoCl2 treatment causes severe loss of spatial memory and CDRI-08 is capable of reversing it towards that in the normal control mice. Our semiquantitative RT-PCR, Western blot, and immunofluorescence microscopic data reveal that CoCl2-induced hypoxia significantly upregulates the expression of Hif-1α and downregulates the Fmr-1 expression in the hippocampus, respectively. Further, CDRI-08 administration reverses the memory loss and this is correlated with significant downregulation of Hif-1α and upregulation of Fmr-1 expression. Our data are novel and may provide mechanisms of hypoxia-induced impairments in the spatial memory and action of CDRI-08 in the recovery of hypoxia led memory impairment involving Fmr-1 gene encoded protein called FMRP.

  14. A Special Extract of Bacopa monnieri (CDRI-08)-Restored Memory in CoCl2-Hypoxia Mimetic Mice Is Associated with Upregulation of Fmr-1 Gene Expression in Hippocampus.

    Science.gov (United States)

    Rani, Anupama; Prasad, S

    2015-01-01

    Fragile X mental retardation protein (FMRP) is a neuronal translational repressor and has been implicated in learning, memory, and cognition. However, the role of Bacopa monnieri extract (CDRI-08) in enhancing cognitive abilities in hypoxia-induced memory impairment via Fmr-1 gene expression is not known. Here, we have studied effects of CDRI-08 on the expression of Fmr-1 gene in the hippocampus of well validated cobalt chloride (CoCl2)-induced hypoxia mimetic mice and analyzed the data with alterations in spatial memory. Results obtained from Morris water maze test suggest that CoCl2 treatment causes severe loss of spatial memory and CDRI-08 is capable of reversing it towards that in the normal control mice. Our semiquantitative RT-PCR, Western blot, and immunofluorescence microscopic data reveal that CoCl2-induced hypoxia significantly upregulates the expression of Hif-1α and downregulates the Fmr-1 expression in the hippocampus, respectively. Further, CDRI-08 administration reverses the memory loss and this is correlated with significant downregulation of Hif-1α and upregulation of Fmr-1 expression. Our data are novel and may provide mechanisms of hypoxia-induced impairments in the spatial memory and action of CDRI-08 in the recovery of hypoxia led memory impairment involving Fmr-1 gene encoded protein called FMRP.

  15. Alleviation of senescence and epithelial-mesenchymal transition in aging kidney by short-term caloric restriction and caloric restriction mimetics via modulation of AMPK/mTOR signaling.

    Science.gov (United States)

    Dong, Dan; Cai, Guang-Yan; Ning, Yi-Chun; Wang, Jing-Chao; Lv, Yang; Hong, Quan; Cui, Shao-Yuan; Fu, Bo; Guo, Ya-Nan; Chen, Xiang-Mei

    2017-03-07

    Renal fibrosis contributes to declining renal function in the elderly. What is unclear however, is whether epithelial-mesenchymal transition (EMT) contributes to this age-related renal fibrosis. Here, we analyzed indicators of EMT during kidney aging and investigated the protective effects and mechanisms of short-term regimens of caloric restriction (CR) or caloric restriction mimetics (CRMs), including resveratrol and metformin. High glucose was used to induce premature senescence and EMT in human primary proximal tubular cells (PTCs) in vitro. To test the role of AMPK-mTOR signaling, siRNA was used to deplete AMPK. Cellular senescence and AMPK-mTOR signaling markers associated with EMT were detected. CR or CRMs treatment alleviated age-related EMT in aging kidneys, which was accompanied by activation of AMPK-mTOR signaling. High glucose induced premature senescence and EMT in PTCs in vitro, which was accompanied by down-regulation of AMPK/mTOR signaling. CRMs alleviated high glucose-induced senescence and EMT via stimulation of AMPK/mTOR signaling. Activation of AMPK/mTOR signaling protected PTCs from high glucose-induced EMT and cellular senescence. Short-term regimens of CR and CRMs alleviated age-related EMT via AMPK-mTOR signaling, suggesting a potential approach to reducing renal fibrosis during aging.

  16. Structural basis for highly effective HIV-1 neutralization by CD4-mimetic miniproteins revealed by 1.5 Å cocrystal structure of gp120 and M48U1.

    Science.gov (United States)

    Acharya, Priyamvada; Luongo, Timothy S; Louder, Mark K; McKee, Krisha; Yang, Yongping; Kwon, Young Do; Mascola, John R; Kessler, Pascal; Martin, Loïc; Kwong, Peter D

    2013-06-04

    The interface between the HIV-1 gp120 envelope glycoprotein and the CD4 receptor contains an unusual interfacial cavity, the "Phe43 cavity", which CD4-mimetic miniproteins with nonnatural extensions can potentially utilize to enhance their neutralization of HIV-1. Here, we report cocrystal structures of HIV-1 gp120 with miniproteins M48U1 and M48U7, which insert cyclohexylmethoxy and 5-hydroxypentylmethoxy extensions, respectively, into the Phe43 cavity. Both inserts displayed flexibility and hydrophobic interactions, but the M48U1 insert showed better shape complementarity with the Phe43 cavity than the M48U7 insert. Subtle alteration in the gp120 conformation played a substantial role in optimizing fit. With M48U1, these translated into a YU2-gp120 affinity of 0.015 nM and neutralization of all 180 circulating HIV-1 strains tested, except clade-A/E isolates with noncanonical Phe43 cavities. Ligand chemistry, shape complementarity, surface burial, and gp120 conformation act in concert to modulate binding of ligands to the gp120-Phe43 cavity and, when optimized, can effect near-pan-neutralization of HIV-1. Copyright © 2013 Elsevier Ltd. All rights reserved.

  17. Insulin induces relaxation and decreases hydrogen peroxide-induced vasoconstriction in human placental vascular bed in a mechanism mediated by calcium-activated potassium channels and L-arginine/nitric oxide pathways.

    Directory of Open Access Journals (Sweden)

    Lissette Cabrera

    2016-11-01

    Full Text Available Insulin induces relaxation in umbilical veins, increasing the expression of human amino acid transporter 1 (hCAT-1 and nitric oxide synthesis (NO in human umbilical vein endothelial cells (HUVECs. Short-term effects of insulin on vasculature have been reported in healthy subjects and cell cultures; however, its mechanisms remain unknown. The aim of this study was to characterize the effect of acute incubation with insulin on the regulation of vascular tone of placental vasculature. HUVECs and chorionic vein rings were isolated from normal pregnancies. The effect of insulin on NO synthesis, L-arginine transport and hCAT-1 abundance was measured in HUVECs. Isometric tension induced by U46619 (thromboxane A2 analogue or hydrogen peroxide (H2O2 were measured in vessels previously incubated 30 min with insulin and/or the following pharmacological inhibitors: tetraethylammonium (KCa channels, iberiotoxin (BKCa channels, genistein (tyrosine kinases and wortmannin (phosphatidylinositol 3-kinase. Insulin increases L-arginine transport and NO synthesis in HUVECs. In the placenta, this hormone caused relaxation of the chorionic vein and reduced perfusion pressure in placental cotyledons. In vessels pre-incubated with insulin, the constriction evoked by H2O2 and U46619 was attenuated and the effect on H2O2-induced constriction was blocked with tetraethylammonium and iberiotoxin, but not with genistein or wortmannin. Insulin rapidly dilates the placental vasculature through a mechanism involving activity of BKCa channels and L-arginine/NO pathway in endothelial cells. This phenomenon is related to quick increases of hCAT-1 abundance and higher capacity of endothelial cells to take up L-arginine and generate NO.

  18. 18 CFR 3a.2 - Authority.

    Science.gov (United States)

    2010-04-01

    ... 18 Conservation of Power and Water Resources 1 2010-04-01 2010-04-01 false Authority. 3a.2 Section 3a.2 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY COMMISSION, DEPARTMENT OF ENERGY GENERAL RULES NATIONAL SECURITY INFORMATION General § 3a.2 Authority. Official information or...

  19. Chimeric design, synthesis, and biological assays of a new nonpeptide insulin-mimetic vanadium compound to inhibit protein tyrosine phosphatase 1B

    OpenAIRE

    Thomas Scior; José Antonio Guevara-García; FJ Melendez; et al

    2010-01-01

    Thomas Scior1, José Antonio Guevara-García2, FJ Melendez2, Hassan H Abdallah3, Quoc-Tuan Do4, Philippe Bernard41Facultad de Ciencias Químicas, Universidad Autónoma de Puebla, Pue, Puebla, Mexico; 2Faculty of Basic Sciences, Technology and Engineering, Laboratory of Research in Bioinorganic and Bioremediation, Universidad Autónoma de Tlaxcala, Apizaco, Tlaxcala, México; 3School of Chemical Sciences, Universiti Sains Malaysia, Pe...

  20. Birinapant (TL32711), a bivalent SMAC mimetic, targets TRAF2-associated cIAPs, abrogates TNF-induced NF-κB activation, and is active in patient-derived xenograft models.

    Science.gov (United States)

    Benetatos, Christopher A; Mitsuuchi, Yasuhiro; Burns, Jennifer M; Neiman, Eric M; Condon, Stephen M; Yu, Guangyao; Seipel, Martin E; Kapoor, Gurpreet S; Laporte, Matthew G; Rippin, Susan R; Deng, Yijun; Hendi, Mukta S; Tirunahari, Pavan K; Lee, Yu-Hua; Haimowitz, Thomas; Alexander, Matthew D; Graham, Martin A; Weng, David; Shi, Yigong; McKinlay, Mark A; Chunduru, Srinivas K

    2014-04-01

    The acquisition of apoptosis resistance is a fundamental event in cancer development. Among the mechanisms used by cancer cells to evade apoptosis is the dysregulation of inhibitor of apoptosis (IAP) proteins. The activity of the IAPs is regulated by endogenous IAP antagonists such as SMAC (also termed DIABLO). Antagonism of IAP proteins by SMAC occurs via binding of the N-terminal tetrapeptide (AVPI) of SMAC to selected BIR domains of the IAPs. Small molecule compounds that mimic the AVPI motif of SMAC have been designed to overcome IAP-mediated apoptosis resistance of cancer cells. Here, we report the preclinical characterization of birinapant (TL32711), a bivalent SMAC-mimetic compound currently in clinical trials for the treatment of cancer. Birinapant bound to the BIR3 domains of cIAP1, cIAP2, XIAP, and the BIR domain of ML-IAP in vitro and induced the autoubiquitylation and proteasomal degradation of cIAP1 and cIAP2 in intact cells, which resulted in formation of a RIPK1:caspase-8 complex, caspase-8 activation, and induction of tumor cell death. Birinapant preferentially targeted the TRAF2-associated cIAP1 and cIAP2 with subsequent inhibition of TNF-induced NF-κB activation. The activity of a variety of chemotherapeutic cancer drugs was potentiated by birinapant both in a TNF-dependent or TNF-independent manner. Tumor growth in multiple primary patient-derived xenotransplant models was inhibited by birinapant at well-tolerated doses. These results support the therapeutic combination of birinapant with multiple chemotherapies, in particular, those therapies that can induce TNF secretion.

  1. METHODS OF DETECTING PREGNANCY-ASSOCIATED PLASMA PROTEIN-A2 (PAPP-A2)

    DEFF Research Database (Denmark)

    2013-01-01

    The present invention provides pregnancy associated plasma protein A2 (PAPP-A2), its nucleotide and amino acid sequences, antisense molecules to the nucleotide sequences which encode PAPP-A2, expression vectors for the production of purified PAPP-A2, antibodies capable of binding specifically...

  2. Annexin A2 Heterotetramer: Structure and Function

    Directory of Open Access Journals (Sweden)

    David Waisman

    2013-03-01

    Full Text Available Annexin A2 is a pleiotropic calcium- and anionic phospholipid-binding protein that exists as a monomer and as a heterotetrameric complex with the plasminogen receptor protein, S100A10. Annexin A2 has been proposed to play a key role in many processes including exocytosis, endocytosis, membrane organization, ion channel conductance, and also to link F-actin cytoskeleton to the plasma membrane. Despite an impressive list of potential binding partners and regulatory activities, it was somewhat unexpected that the annexin A2-null mouse should show a relatively benign phenotype. Studies with the annexin A2-null mouse have suggested important functions for annexin A2 and the heterotetramer in fibrinolysis, in the regulation of the LDL receptor and in cellular redox regulation. However, the demonstration that depletion of annexin A2 causes the depletion of several other proteins including S100A10, fascin and affects the expression of at least sixty-one genes has confounded the reports of its function. In this review we will discuss the annexin A2 structure and function and its proposed physiological and pathological roles.

  3. Synthesis of a new insulin-mimetic anti-diabetic drug containing vitamin A and vanadium(IV) salt: Chemico-biological characterizations.

    Science.gov (United States)

    Adam, Abdel Majid A; Naglah, Ahmed M; Al-Omar, Mohamed A; Refat, Moamen S

    2017-09-01

    Diabetes patients suffer from chronic disorders in the metabolism due to high blood sugar caused by anomalies in insulin excretion. Recently, vanadium compounds have been prepared and functionalized to decrease the level of hyperglycemia. Vitamin A boosts beta cell activity; therefore, the lack of this vitamin plays a role in the development of type 2 diabetes. The aim of this article focused on the synthesis of a new anti-diabetic drug formed from the complexation of a vanadium(IV) salt with vitamin A. Vitamin A acts as a unidentate chelate through the oxygen of its -OH group. The vanadium(IV) compound is surrounded by two vitamin A molecules. The [VO(vitamin A) 2 (H 2 O) 2 ] compound was synthesized in a binary solvent system consisting of MeOH/H 2 O (1:1 ratio) in alkaline media at pH = 8. This compound was characterized using Fourier transform infrared spectra (FT-IR), electronic spectra (UV-vis), effective magnetic moment, electron spin resonance (ESR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and thermal analysis (thermogravimetry (TG)-differential thermal analysis (DTA)). Anti-diabetic efficiency for the vanadium(IV) compound was assessed in streptozotocin (STZ)-induced diabetic mice. The results of the animal studies demonstrate the ability of the vanadium(IV) complex to act as an anti-diabetic agent, as measured by improvements of lipid profile, antioxidant activity (superoxide dismutase), malondialdehyde (MDA), glutathione, methionine synthase, and kidney and liver functions.

  4. METSAT: Advanced Microwave Sounding Unit-A2 (AMSU-A2) structural mathematical model

    Science.gov (United States)

    Ely, Wayne

    1995-01-01

    This plan describes the Structural Mathematical Model of the METSAT AMSU-A2 instrument. The model is used to verify the structural adequacy of the AMSU-A2 instrument for the specified loading environments.

  5. Neuronal damage by secretory phospholipase A2

    DEFF Research Database (Denmark)

    Kolko, Miriam; Rodriguez de Turco, Elena B; Diemer, Nils H

    2003-01-01

    Activation of cytosolic phospholipase A(2) (cPLA(2)) is an early event in brain injury, which leads to the formation and accumulation of bioactive lipids: platelet-activating factor (PAF), free arachidonic acid, and eicosanoids. A cross-talk between secretory PLA(2) (sPLA(2)) and cPLA(2) in neura...

  6. Countering A2/AD with Swarming

    Science.gov (United States)

    2016-04-01

    more novel approaches involve emergent behavior, neural networks , and subsumption architecture. 84 Emergent behavior control models autonomy after...contested environment because the units could still work together within a degraded electromagnetic spectrum (EMS). Neural networks learn behaviors by...the U.S.’s ability to access contested areas.12 Advanced missiles, new fighter aircraft , Anti-access (A2) - Action intended to slow deployment of

  7. Genetic polymorphisms of cytochrome P450-1A2 (CYP1A2 among Emiratis.

    Directory of Open Access Journals (Sweden)

    Mohammad M Al-Ahmad

    Full Text Available Cytochrome P450 1A2 (CYP1A2 is one of the CYP450 mixed-function oxidase system that is of clinical importance due to the large number of drug interactions associated with its induction and inhibition. In addition, significant inter-individual differences in the elimination of drugs metabolized by CYP1A2 enzyme have been observed which are largely due to the highly polymorphic nature of CYP1A2 gene. However, there are limited studies on CYP1A2 phenotypes and CYP1A2 genotypes among Emiratis and thus this study was carried out to fill this gap. Five hundred and seventy six non-smoker Emirati subjects were asked to consume a soft drink containing caffeine (a non-toxic and reliable probe for predicting CYP1A2 phenotype and then provide a buccal swab along with a spot urine sample. Taq-Man Real Time PCR was used to determine the CYP1A2 genotype of each individual. Phenotyping was carried out by analyzing the caffeine metabolites using High Performance Liquid Chromatography (HPLC analysis. We found that 1.4%, 16.3% and 82.3% of the Emirati subjects were slow, intermediate and rapid CYP1A2 metabolizers, respectively. In addition, we found that 1.4% of the subjects were homozygote for derived alleles while 16.1% were heterozygote and 82.5% were homozygote for the ancestral allele. The genotype frequency of the ancestral allele, CYP1A2*1A/*1A, is the highest in this population, followed by CYP1A2 *1A/*1C and CYP1A2 *1A/*1K genotypes, with frequencies of 0.825, 0.102 and 0.058, respectively. The degree of phenotype/genotype concordance was equal to 81.6%. The CYP1A2*1C/*1C and CYP1A2*3/*3 genotypes showed significantly the lowest enzyme phenotypic activity. The frequency of slow activity CYP1A2 enzyme alleles is very low among Emiratis which correlates with the presence of low frequencies of derived alleles in CYP1A2 gene.

  8. Human mimetic forearm mechanism towards bionic arm.

    Science.gov (United States)

    Seo, Minsang; Kim, Hogyun; Choi, Youngjin

    2017-07-01

    The paper presents a mechanical forearm mechanism to extend the pronation and supination (P/S) movement of the trans-radial amputee when he/she is able to conduct the P/S motion partially with his/her remaining forearm. The P/S motions of the existing prostheses and robotic arms developed till now are completely different from those of the human. When we are to develop the robotic prostheses for the amputees, two important issues should be considered such as cosmetic issue to look like normal arm and motion harmony issue between robotic prosthesis and the amputated living arm. Most prostheses do not realize the human-like P/S motion, but the simple rotational motion at the wrist by using the electric motor. In this paper, the well-known spatial four-bar mechanism is adopted in order to mimic human P/S motion as if the person does, because it is one of the best candidates to describe actual human forearm movement. To obtain the design parameters of the mechanism, first, 3D data of the amputated arm as well as the opposite side non-amputated arm are captured by using MRI (Magnetic Resonance Imaging) and 3D scanner. The design parameters such as link lengths, joint locations, and volumetric shape are determined from the measured data. Second, mathematical analysis is performed to simulate one degree-of-freedom P/S motion realized from the spatial four-bar mechanism, and the simulation results are suggested to confirm whether or not it acts like the relative movement between human ulnar and radius bones. Finally the effectiveness of the proposed mechanism is verified through two ADL (activities of daily living) tests.

  9. Can exercise mimetics substitute for exercise?

    DEFF Research Database (Denmark)

    Richter, Erik; Kiens, Bente; Wojtaszewski, Jørgen

    2008-01-01

    Exercise leads to changes in muscle phenotype with important implications for exercise performance and health. A recent paper in Cell by Narkar et al. (2008) shows that many of the adaptations in muscle phenotype elicited by exercise can be mimicked by genetic manipulation and drug treatment...

  10. A2 /A2 B to B Renal Transplantation: Past, Present, and Future Directions.

    Science.gov (United States)

    Bryan, C F; Cherikh, W S; Sesok-Pizzini, D A

    2016-01-01

    One component of the new national kidney allocation system (KAS) in the United States that was implemented on December 4, 2014, was the allocation of kidneys from A2 and A2 B (A, non-A1 and AB, non-A1 B) deceased donors into blood group B candidates (A2 /A2 B → B). In so far as this is an important component of the new KAS that has the potential to further increase the access to transplantation for blood group B candidates on the waiting list, most of whom are minority candidates, we will review the body of evidence and historical perspectives that led to its inclusion in the new KAS. This review will also describe prospects for more widespread use of A2 /A2 B → B transplantation and a novel mechanism of humoral immunosuppression in B patients before and after transplantation with an A2 or A2 B kidney. © Copyright 2015 The American Society of Transplantation and the American Society of Transplant Surgeons.

  11. Annexin A2 in Proliferative Vitreoretinopathy

    Science.gov (United States)

    2017-10-01

    histologic analysis. The eye was enucleated, and a nick created in the cornea with a #11 blade prior to incubation in 4% paraformaldehyde. The cornea and lens...autofluorescence was quenched with NH4Cl, and sections then blocked with normal donkey serum. For A2 staining, incubation with primary and secondary antibodies...n=7-11 mice per group) representing Anxa2-/- or Anxa2+/+ mice at 2, 4, or 6 weeks and were scored using a standard algorithm . Inter-observer

  12. Kuranishi spaces as a 2-category

    OpenAIRE

    Joyce, Dominic

    2015-01-01

    This is a survey of the author's in-progress book arXiv:1409.6908. 'Kuranishi spaces' were introduced in the work of Fukaya, Oh, Ohta and Ono in symplectic geometry (see e.g. arXiv:1503.07631), as the geometric structure on moduli spaces of $J$-holomorphic curves. We propose a new definition of Kuranishi space, which has the nice property that they form a 2-category $\\bf Kur$. Thus the homotopy category Ho$({\\bf Kur})$ is an ordinary category of Kuranishi spaces. Any Fukaya-Oh-Ohta-Ono (FOOO)...

  13. Imbalance in A2 and A2B phenotype frequency of ABO group in South India

    Science.gov (United States)

    Shastry, Shamee; Bhat, Sudha

    2010-01-01

    Background The heterogeneity of A and B alleles results in weak variants of these antigens. Subgroups of A differ from each other quantitatively and qualitatively. The expected frequencies of A1 and A2 subtypes will be in Hardy-Weinberg equilibrium for the Mendelian inheritance of the allelic A1 and A2 genes. The frequency of A subgroups in the population from south India is not known. The aim of our study was to study the frequency of A subtypes and the prevalence of anti-A1 antibody among this population. Methods Over a period of 3 years, patients’ blood group was typed using a standard tube technique. Anti-A1 lectin studies were done for all patients with groups A and AB. Based on serological reactivity the samples were classified into A1/A1B, A2/A2B and weak A subgroups. The prevalence of A subgroups was determined. The significance of differences in proportions was analysed using the chi-square test. Results A total of 40,113 patients’ samples were typed for ABO, Rh group and A subgroups in our blood bank attached to a tertiary care hospital. Among 10,325 group A samples, 98.14% classified as A1, 1.07% as A2, and 0.01% as weak A; the remaining group A samples were from neonates and reacted poorly with anti A1-lectin. The majority of AB samples (n=2,667) were of A1B type (89.28%). However, the proportion of A2B (8.99%) among AB samples was significantly higher than that of A2 in group A samples (p A1 antibodies among A2 and A2B samples was 1.8% and 3.75%, respectively, and none of them showed reactivity at 37°C. Conclusion The results of our study show a significantly higher proportion of A2B subtypes than A2 subgroups. A similar imbalance is seen in blacks and Japanese. The incidence of anti-A1 antibodies is also higher among A2B patients. PMID:20967168

  14. UPWIND 1A2 Metrology. Final Report

    DEFF Research Database (Denmark)

    Eecen, P.J.; Wagenaar, J.W.; Stefanatos, N.

    by metrology problems (measurement problems). Other examples are in the fields of: • Warranty performance measurements • Improvement of aerodynamic codes • Assessment of wind resources In general terms the uncertainties of the testing techniques and methods are typically much higher than the requirements....... Since this problem covers many areas of wind energy, the work package is defined as a crosscutting activity. The objectives of the metrology work package are to develop metrology tools in wind energy to significantly enhance the quality of measurement and testing techniques. The first deliverable...... is a valuable tool for the further assessment and interest has been shown from other work packages, such as Training. This report describes the activities that have been carried out in the Work Package 1A2 Metrology of the UpWind project. Activities from Risø are described in a separate report: T.F. Pedersen...

  15. Final shutdown of Chinon A2

    International Nuclear Information System (INIS)

    Dumont, J.; Pouzac, J.P.

    1987-01-01

    In order to gain a better grasp of the condition of the Chinon plant at shutdown and the problems its operator might have had to deal with had the plant been kept in operation, the authors review: the history of the plant; its technological design; the main problems encountered during its lifetime and how these were solved. In the first instance, the operator took stock of the technical problems which could have affected the safety of the plant or restricted availability in the short and medium term. The analysis did not point to any serious problems for the five years ahead. The periodic economic review of electricity generating capacity carried out in 1983 the Direction de la Production et du Transport d'Electricite de France showed that the optimal date for decommissioning Chinon A2 was July 1985. The fact that this coincided exactly with the transfer date for personnel in this neighbouring units B3 and B4 (2x900 MWe - PWR) was the additional deciding factor for decommissioning in 1985. Taking the decision early enough enabled the operator to optimise the use both of fuel and of reactor staff. The authors then discuss the disposal options for the plant [fr

  16. Skepinone-L, a Novel Potent and Highly Selective Inhibitor of p38 MAP Kinase, Effectively Impairs Platelet Activation and Thrombus Formation

    Directory of Open Access Journals (Sweden)

    Oliver Borst

    2013-06-01

    Full Text Available Background/Aims: Platelets are critically important for primary haemostasis and the major players in thrombotic vascular occlusion. Platelets are activated by agonists, such as thrombin and collagen-related peptide as well as second-wave mediators including thromboxane A2 via different intracellular signaling pathways resulting in degranulation, aggregation and thrombus formation. Platelet activation is paralleled by phosphorylation and activation of p38 MAPK. The limited specificity of hitherto known p38 MAPK inhibitors precluded safe conclusions on the precise role of p38 MAPK in the regulation of platelet function. The present study examined the impact of Skepinone-L, a novel and highly selective inhibitor of p38 mitogen-activated protein kinase (p38 MAPK, on platelet activation and thrombus formation. Methods: Experiments were performed in freshly isolated human platelets. Protein phosphorylation was quantified by Western blotting, thromboxane B2 synthesis by enzyme immunoassay, ATP release by ChronoLume luciferin assay, cytosolic Ca2+ concentration by Fura-2 fluorescence-measurements, platelet aggregation by a light transmissions measurement and in vitro thrombus formation by a flow chamber. Results: Skepinone-L (1 μM virtually abrogated the phosphorylation of platelet p38 MAPK substrate Hsp27 following stimulation with CRP (1 μg/ml, thrombin (5 mU/ml or thromboxane A2 analogue U-46619 (1 μM. Furthermore, Skepinone-L significantly blunted activation-dependent platelet secretion and aggregation following threshold concentrations of CRP, thrombin and thromboxane A2 analogue U-46619. Skepinone-L did not impair platelet Ca2+ signaling but prevented agonist-induced thromboxane A2 synthesis through abrogation of p38 MAPK-dependent phosphorylation of platelet cytosolic phospholipase A2 (cPLA2. Skepinone-L further markedly blunted thrombus formation under low (500-s and high (1700-s arterial shear rates. Conclusions: The present study discloses

  17. Distinct mechanisms of relaxation to bioactive components from chamomile species in porcine isolated blood vessels.

    Science.gov (United States)

    Roberts, R E; Allen, S; Chang, A P Y; Henderson, H; Hobson, G C; Karania, B; Morgan, K N; Pek, A S Y; Raghvani, K; Shee, C Y; Shikotra, J; Street, E; Abbas, Z; Ellis, K; Heer, J K; Alexander, S P H

    2013-11-01

    German chamomile (Matricaria recutita L.), a widely-used herbal medicine, has been reported to have a wide range of biological effects, including smooth muscle relaxation. The aim of this study was to compare the effects of representative compounds from chamomile (apigenin, luteolin, (-)-α-bisabolol, farnesene, umbelliferone; 3-30 μM) on vascular tone using porcine coronary and splenic arteries mounted for isometric tension recording in isolated tissue baths and precontracted with the thromboxane-mimetic U46619. Apigenin, luteolin, and (-)-α-bisabolol produced slow, concentration-dependent relaxations in both the coronary and splenic arteries that were not blocked by inhibition of nitric oxide synthase or potassium channels. Removal of extracellular calcium inhibited the relaxations to all three compounds, and these compounds also inhibited calcium re-addition-evoked contractions, indicating that the relaxation response may be mediated through inhibition of calcium influx. Apigenin and luteolin, but not (-)-α-bisabolol, enhanced the relaxation to the nitric oxide donor sodium nitroprusside, indicating that apigenin and luteolin may act to regulate cyclic GMP levels. Umbelliferone produced a rapid, transient relaxation in the splenic artery, but not the coronary artery, that was inhibited by L-NAME and removal of the endothelium, suggesting an influence on nitric oxide production. Farnesene, at concentrations up to 30 μM, was without effect in either blood vessel. In conclusion, hydroxylated compounds (apigenin, luteolin and (-)-α-bisabolol) found in chamomile all caused a slow relaxation of isolated blood vessels through an effect on calcium influx. Umbelliferone, on the other hand, produced a rapid, transient relaxation dependent upon release of nitric oxide from the endothelium. © 2013.

  18. Iloprost-induced desensitization of the prostacyclin receptor in isolated rabbit lungs

    Directory of Open Access Journals (Sweden)

    Schrör Karsten

    2007-01-01

    Full Text Available Abstract Background The rapid desensitization of the human prostacyclin (IP in response to agonist binding has been shown in cell culture. Phosphorylation of the IP receptor by protein kinase C (PKC has been suggested to be involved in this process. Methods and results In this study we investigated the vasodilatory effects of iloprost, a stable prostacyclin analogue, in perfused rabbit lungs. Continuous infusion of the thromboxane mimetic U46619 was employed to establish stable pulmonary hypertension. A complete loss of the vasodilatory response to iloprost was observed in experiments with continuous iloprost perfusion, maintaining the intravascular concentration of this prostanoid over a 180 min period. When lungs under chronic iloprost infusion were acutely challenged with inhaled iloprost, a corresponding complete loss of vasoreactivity was observed. This desensitization was not dependent on upregulation of cAMP-specific phosphodiesterases or changes in adenylate cyclase activity, as suggested by unaltered dose-response curves to agents directly affecting these enzymes. Application of a prostaglandin E1 receptor antagonist 6-isopropoxy-9-oxoxanthene-2-carboxylic acid (AH 6809 or the PKC inhibitor bisindolylmaleimide I (BIM enhanced the vasodilatory response to infused iloprost and partially prevented tachyphylaxis. Conclusion A three-hour infusion of iloprost in pulmonary hypertensive rabbit lungs results in complete loss of the lung vasodilatory response to this prostanoid. This rapid desensitization is apparently not linked to changes in adenylate cyclase and phosphodiesterase activation, but may involve PKC function and co-stimulation of the EP1 receptor in addition to the IP receptor by this prostacyclin analogue.

  19. Scutellarin inhibits cytochrome P450 isoenzyme 1A2 (CYP1A2) in rats.

    Science.gov (United States)

    Jian, Tun-Yu; He, Jian-Chang; He, Gong-Hao; Feng, En-Fu; Li, Hong-Liang; Bai, Min; Xu, Gui-Li

    2012-08-01

    Scutellarin is the most important flavone glycoside in the herbal drug Erigeron breviscapus (Vant.) Hand.-Mazz. It is used frequently in the clinic to treat ischemic vascular diseases in China. However, the direct relationship between scutellarin and cytochrome P450 (CYP450) is unclear. The present study investigated the in vitro and in vivo effects of scutellarin on cytochrome P450 1A2 (CYP 1A2) metabolism. According to in vitro experiments, scutellarin (10-250 µM) decreased the formation of 4-acetamidophenol in a concentration-dependent manner, with an IC₅₀ value of 108.20 ± 0.657 µM. Furthermore, scutellarin exhibited a weak mixed-type inhibition against the activity of CYP1A2 in rat liver microsomes, with a K(i) value of 95.2 µM. Whereas in whole animal studies, scutellarin treatment for 7 days (at 5, 15, 30 mg/kg, i.p.) decreased the clearance (CL), and increased the T(1/2) (at 15, 30 mg/kg, i.p.), it did not affect the V(d) of phenacetin. Scutellarin treatment (at 5, 15, 30 mg/kg, i.p.) increased the AUC(0-∞) by 14.3%, 67.3% and 159.2%, respectively. Scutellarin at 30 mg/kg also weakly inhibited CYP1A2 activity, in accordance with our in vitro study. Thus, the results indicate that CYP1A2 is inhibited directly, but weakly, by scutellarin in vivo, and provide useful information on the safe and effective use of scutellarin in clinical practice. Copyright © 2012 John Wiley & Sons, Ltd.

  20. Prediction of cross-recognition of peptide-HLA A2 by Melan-A-specific cytotoxic T lymphocytes using three-dimensional quantitative structure-activity relationships.

    Science.gov (United States)

    Fagerberg, Theres; Zoete, Vincent; Viatte, Sebastien; Baumgaertner, Petra; Alves, Pedro M; Romero, Pedro; Speiser, Daniel E; Michielin, Olivier

    2013-01-01

    The cross-recognition of peptides by cytotoxic T lymphocytes is a key element in immunology and in particular in peptide based immunotherapy. Here we develop three-dimensional (3D) quantitative structure-activity relationships (QSARs) to predict cross-recognition by Melan-A-specific cytotoxic T lymphocytes of peptides bound to HLA A*0201 (hereafter referred to as HLA A2). First, we predict the structure of a set of self- and pathogen-derived peptides bound to HLA A2 using a previously developed ab initio structure prediction approach [Fagerberg et al., J. Mol. Biol., 521-46 (2006)]. Second, shape and electrostatic energy calculations are performed on a 3D grid to produce similarity matrices which are combined with a genetic neural network method [So et al., J. Med. Chem., 4347-59 (1997)] to generate 3D-QSAR models. The models are extensively validated using several different approaches. During the model generation, the leave-one-out cross-validated correlation coefficient (q (2)) is used as the fitness criterion and all obtained models are evaluated based on their q (2) values. Moreover, the best model obtained for a partitioned data set is evaluated by its correlation coefficient (r = 0.92 for the external test set). The physical relevance of all models is tested using a functional dependence analysis and the robustness of the models obtained for the entire data set is confirmed using y-randomization. Finally, the validated models are tested for their utility in the setting of rational peptide design: their ability to discriminate between peptides that only contain side chain substitutions in a single secondary anchor position is evaluated. In addition, the predicted cross-recognition of the mono-substituted peptides is confirmed experimentally in chromium-release assays. These results underline the utility of 3D-QSARs in peptide mimetic design and suggest that the properties of the unbound epitope are sufficient to capture most of the information to determine the

  1. Prediction of cross-recognition of peptide-HLA A2 by Melan-A-specific cytotoxic T lymphocytes using three-dimensional quantitative structure-activity relationships.

    Directory of Open Access Journals (Sweden)

    Theres Fagerberg

    Full Text Available The cross-recognition of peptides by cytotoxic T lymphocytes is a key element in immunology and in particular in peptide based immunotherapy. Here we develop three-dimensional (3D quantitative structure-activity relationships (QSARs to predict cross-recognition by Melan-A-specific cytotoxic T lymphocytes of peptides bound to HLA A*0201 (hereafter referred to as HLA A2. First, we predict the structure of a set of self- and pathogen-derived peptides bound to HLA A2 using a previously developed ab initio structure prediction approach [Fagerberg et al., J. Mol. Biol., 521-46 (2006]. Second, shape and electrostatic energy calculations are performed on a 3D grid to produce similarity matrices which are combined with a genetic neural network method [So et al., J. Med. Chem., 4347-59 (1997] to generate 3D-QSAR models. The models are extensively validated using several different approaches. During the model generation, the leave-one-out cross-validated correlation coefficient (q (2 is used as the fitness criterion and all obtained models are evaluated based on their q (2 values. Moreover, the best model obtained for a partitioned data set is evaluated by its correlation coefficient (r = 0.92 for the external test set. The physical relevance of all models is tested using a functional dependence analysis and the robustness of the models obtained for the entire data set is confirmed using y-randomization. Finally, the validated models are tested for their utility in the setting of rational peptide design: their ability to discriminate between peptides that only contain side chain substitutions in a single secondary anchor position is evaluated. In addition, the predicted cross-recognition of the mono-substituted peptides is confirmed experimentally in chromium-release assays. These results underline the utility of 3D-QSARs in peptide mimetic design and suggest that the properties of the unbound epitope are sufficient to capture most of the information to

  2. 21 CFR 864.7400 - Hemoglobin A2 assay.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Hemoglobin A2 assay. 864.7400 Section 864.7400...) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Hematology Kits and Packages § 864.7400 Hemoglobin A2 assay. (a) Identification. A hemoglobin A2 assay is a device used to determine the hemoglobin A2 content...

  3. Vaccination with EphA2-derived T cell-epitopes promotes immunity against both EphA2-expressing and EphA2-negative tumors

    Directory of Open Access Journals (Sweden)

    Hatano Manabu

    2004-11-01

    Full Text Available Abstract Background A novel tyrosine kinase receptor EphA2 is expressed at high levels in advanced and metastatic cancers. We examined whether vaccinations with synthetic mouse EphA2 (mEphA2-derived peptides that serve as T cell epitopes could induce protective and therapeutic anti-tumor immunity. Methods C57BL/6 mice received subcutaneous (s.c. vaccinations with bone marrow-derived dendritic cells (DCs pulsed with synthetic peptides recognized by CD8+ (mEphA2671–679, mEphA2682–689 and CD4+ (mEphA230–44 T cells. Splenocytes (SPCs were harvested from primed mice to assess the induction of cytotoxic T lymphocyte (CTL responses against syngeneic glioma, sarcoma and melanoma cell lines. The ability of these vaccines to prevent or treat tumor (s.c. injected MCA205 sarcoma or B16 melanoma; i.v. injected B16-BL6 establishment/progression was then assessed. Results Immunization of C57BL/6 mice with mEphA2-derived peptides induced specific CTL responses in SPCs. Vaccination with mEPhA2 peptides, but not control ovalbumin (OVA peptides, prevented the establishment or prevented the growth of EphA2+ or EphA2-negative syngeneic tumors in both s.c. and lung metastasis models. Conclusions These data indicate that mEphA2 can serve as an attractive target against which to direct anti-tumor immunity. The ability of mEphA2 vaccines to impact EphA2-negative tumors such as the B16 melanoma may suggest that such beneficial immunity may be directed against alternative EphA2+ target cells, such as the tumor-associated vascular endothelial cells.

  4. Hypoxia-inducible factor-1β (HIF-1β) is upregulated in a HIF-1α-dependent manner in 518A2 human melanoma cells under hypoxic conditions.

    Science.gov (United States)

    Mandl, Markus; Kapeller, Barbara; Lieber, Roman; Macfelda, Karin

    2013-04-26

    Solid tumors include hypoxic areas due to excessive cell proliferation. Adaptation to low oxygen levels is mediated by the hypoxia-inducible factor (HIF) pathway promoting invasion, metastasis, metabolic alterations, chemo-resistance and angiogenesis. The transcription factor HIF-1, the major player within this pathway consists of HIF-1α and HIF-1β. The alpha subunit is continuously degraded under normoxia and becomes stabilized under reduced oxygen supply. In contrast, HIF-1β is generally regarded as constitutively expressed and being present in excess within the cell. However, there is evidence that the expression of this subunit is more complex. The aim of this study was to investigate the role of HIF-1β in human melanoma cells. Among a panel of five different cell lines, in 518A2 cells exposed to the hypoxia-mimetic cobalt chloride HIF-1β was rapidly elevated on protein level. Knockdown experiments performed under cobalt chloride-exposure and hypoxia revealed that this effect was mediated by HIF-1α. The non-canonical relationship between these subunits was further confirmed by pharmacologic inhibition of HIF-1α and by expression of a dominant-negative HIF mutant. Overexpression of HIF-1α showed a time delay in HIF-1β induction, thus arguing for HIF-1β de novo synthesis rather than protein stabilization by heterodimerization. A Hen's egg test-chorioallantoic membrane model of angiogenesis and invasion indicated a local expression of HIF-1β and implies a biological relevance of these findings. In summary, this study demonstrates the HIF-1α-dependent regulation of HIF-1β under hypoxic conditions for the first time. The results indicate a novel cell specific mechanism which might prevent HIF-1β to become a limiting factor. Copyright © 2013 Elsevier Inc. All rights reserved.

  5. Underutilization of A2 ABO incompatible kidney transplantation.

    Science.gov (United States)

    Redfield, Robert R; Parsons, Ronald F; Rodriguez, Eduardo; Mustafa, Moiz; Cassuto, James; Vivek, Kumar; Noorchashm, Hooman; Naji, Ali; Levine, Matthew H; Abt, Peter L

    2012-01-01

    ABO compatibility creates a disadvantage for O and B renal allograft candidates. A2 ABO incompatible transplant may decrease waiting times and generate equivalent graft survival to an ABO compatible transplant. Death-censored graft survival was compared between A recipients and O, B, and AB recipients of an A2 allograft with multivariate Cox regression models utilizing data from the United Network of Organ Sharing (UNOS) between 1997 and 2007. Eighty-five percent of A2 kidneys were transplanted into ABO compatible recipients vs. 15% into ABO incompatible recipients. Rates of A2 incompatible kidney transplants did not increase over the study period (14.8% to 14.6%). Mean wait time for A2→O kidneys was 337 vs. 684 d for O→O and for A2→B kidneys, 542 vs. 734 d for B→B. Adjusted relative risk of graft loss at five-yr was similar between O, B, and AB recipients compared to A recipients of an A2 allograft, corresponding to a five-yr graft survival of 84%, 86.2%, 86.1%, and 86.1%, respectively. A2 incompatible kidney transplantation is underutilized. Graft outcomes are similar among A2 compatible and incompatible recipients. Shorter waiting time and improved access might be achieved if A2 kidneys are considered in all blood groups. © 2011 John Wiley & Sons A/S.

  6. Chromomycin A2 Induces Autophagy in Melanoma Cells

    Science.gov (United States)

    Guimarães, Larissa Alves; Jimenez, Paula Christine; Sousa, Thiciana da Silva; Freitas, Hozana Patrícia S.; Rocha, Danilo Damasceno; Wilke, Diego Veras; Martín, Jesús; Reyes, Fernando; Pessoa, Otília Deusdênia Loiola; Costa-Lotufo, Letícia Veras

    2014-01-01

    The present study highlights the biological effects of chromomycin A2 toward metastatic melanoma cells in culture. Besides chromomycin A2, chromomycin A3 and demethylchromomycin A2 were also identified from the extract derived from Streptomyces sp., recovered from Paracuru Beach, located in the northeast region of Brazil. The cytotoxic activity of chromomycin A2 was evaluated across a panel of human tumor cell lines, which found IC50 values in the nM-range for exposures of 48 and 72 h. MALME-3M, a metastatic melanoma cell line, showed the highest sensitivity to chromomycin A2 after 48h incubation, and was chosen as a model to investigate this potent cytotoxic effect. Treatment with chromomycin A2 at 30 nM reduced cell proliferation, but had no significant effect upon cell viability. Additionally, chromomycin A2 induced accumulation of cells in G0/G1 phase of the cell cycle, with consequent reduction of S and G2/M and unbalanced expression of cyclins. Chromomycin A2 treated cells depicted several cellular fragments resembling autophagosomes and increased expression of proteins LC3-A and LC3-B. Moreover, exposure to chromomycin A2 also induced the appearance of acidic vacuolar organelles in treated cells. These features combined are suggestive of the induction of autophagy promoted by chromomycin A2, a feature not previously described for chromomycins. PMID:25486109

  7. The Role of Adenosine A2BR in Metastatic Melanoma

    Science.gov (United States)

    2017-07-01

    tumors were harvested, digested in collagenase I with DNAse 1 and stained with antibodies for immune cells markers and analyzed on a BD LSR Fortessa...Evidence indicates that adenosine receptor A2AR plays a role in inhibiting immune cells whereas A2BR is likely most critical on tumor cells and tumor ...endothelium. We propose that elimination of adenosine A2B receptor signaling in endothelial cells and tumor cells will result in a decrease of primary

  8. Adenosine A2A receptors and A2A receptor heteromers as key players in striatal function

    Directory of Open Access Journals (Sweden)

    Sergi eFerre

    2011-06-01

    Full Text Available A very significant density of adenosine adenosine A2A receptors (A2ARs is present in the striatum, where they are preferentially localized postsynaptically in striatopallidal medium spiny neurons (MSNs. In this localization A2ARs establish reciprocal antagonistic interactions with dopamine D2 receptors (D2Rs. In one type of interaction, A2AR and D2R are forming heteromers and, by means of an allosteric interaction, A2AR counteracts D2R-mediated inhibitory modulation of the effects of NMDA receptor stimulation in the striato-pallidal neuron. This interaction is probably mostly responsible for the locomotor depressant and activating effects of A2AR agonist and antagonists, respectively. The second type of interaction involves A2AR and D2R that do not form heteromers and takes place at the level of adenylyl-cyclase (AC. Due to a strong tonic effect of endogenous dopamine on striatal D2R, this interaction keeps A2AR from signaling through AC. However, under conditions of dopamine depletion or with blockade of D2R, A2AR-mediated AC activation is unleashed with an increased gene expression and activity of the striato-pallidal neuron and with a consequent motor depression. This interaction is probably the main mechanism responsible for the locomotor depression induced by D2R antagonists. Finally, striatal A2ARs are also localized presynaptically, in cortico-striatal glutamatergic terminals that contact the striato-nigral MSN. These presynaptic A2ARs heteromerize with A1 receptors (A1Rs and their activation facilitates glutamate release. These three different types of A2ARs can be pharmacologically dissected by their ability to bind ligands with different affinity and can therefore provide selective targets for drug development in different basal ganglia disorders.

  9. Secretory Phospholipase A2-IIA and Cardiovascular Disease

    DEFF Research Database (Denmark)

    Holmes, Michael V; Simon, Tabassome; Exeter, Holly J

    2013-01-01

    This study sought to investigate the role of secretory phospholipase A2 (sPLA2)-IIA in cardiovascular disease.......This study sought to investigate the role of secretory phospholipase A2 (sPLA2)-IIA in cardiovascular disease....

  10. Cyclin A2 regulates erythrocyte morphology and numbers.

    Science.gov (United States)

    Jayapal, Senthil Raja; Ang, Heather Yin-Kuan; Wang, Chelsia Qiuxia; Bisteau, Xavier; Caldez, Matias J; Xuan, Gan Xiao; Yu, Weimiao; Tergaonkar, Vinay; Osato, Motomi; Lim, Bing; Kaldis, Philipp

    2016-11-16

    Cyclin A2 is an essential gene for development and in haematopoietic stem cells and therefore its functions in definitive erythropoiesis have not been investigated. We have ablated cyclin A2 in committed erythroid progenitors in vivo using erythropoietin receptor promoter-driven Cre, which revealed its critical role in regulating erythrocyte morphology and numbers. Erythroid-specific cyclin A2 knockout mice are viable but displayed increased mean erythrocyte volume and reduced erythrocyte counts, as well as increased frequency of erythrocytes containing Howell-Jolly bodies. Erythroblasts lacking cyclin A2 displayed defective enucleation, resulting in reduced production of enucleated erythrocytes and increased frequencies of erythrocytes containing nuclear remnants. Deletion of the Cdk inhibitor p27 Kip1 but not Cdk2, ameliorated the erythroid defects resulting from deficiency of cyclin A2, confirming the critical role of cyclin A2/Cdk activity in erythroid development. Loss of cyclin A2 in bone marrow cells in semisolid culture prevented the formation of BFU-E but not CFU-E colonies, uncovering its essential role in BFU-E function. Our data unveils the critical functions of cyclin A2 in regulating mammalian erythropoiesis.

  11. Roles of EphA2 in Development and Disease

    Directory of Open Access Journals (Sweden)

    Renping Zhou

    2013-07-01

    Full Text Available The Eph family of receptor tyrosine kinases (RTKs has been implicated in the regulation of many aspects of mammalian development. Recent analyses have revealed that the EphA2 receptor is a key modulator for a wide variety of cellular functions. This review focuses on the roles of EphA2 in both development and disease.

  12. 15 CFR 4a.2 - Deputy Assistant Secretary for Security.

    Science.gov (United States)

    2010-01-01

    ... 15 Commerce and Foreign Trade 1 2010-01-01 2010-01-01 false Deputy Assistant Secretary for Security. 4a.2 Section 4a.2 Commerce and Foreign Trade Office of the Secretary of Commerce CLASSIFICATION... Security. The Deputy Assistant Secretary for Security (DAS) is responsible for implementing E.O. 12958 and...

  13. A2A Receptor Antagonism and Dyskinesia in Parkinson's Disease

    Science.gov (United States)

    Morelli, Micaela; Blandini, Fabio; Simola, Nicola; Hauser, Robert A.

    2012-01-01

    Dyskinesia, a major complication of treatment of Parkinson's disease (PD), involves two phases: induction, which is responsible for dyskinesia onset, and expression, which underlies its clinical manifestation. The unique cellular and regional distribution of adenosine A2A receptors in basal ganglia areas that are richly innervated by dopamine, and their antagonistic role towards dopamine receptor stimulation, have positioned A2A receptor antagonists as an attractive nondopaminergic target to improve the motor deficits that characterize PD. In this paper, we describe the biochemical characteristics of A2A receptors and the effects of adenosine A2A antagonists in rodent and primate models of PD on L-DOPA-induced dyskinesia, together with relevant biomarker studies. We also review clinical trials of A2A antagonists as adjuncts to L-DOPA in PD patients with motor fluctuations. These studies have generally demonstrated that the addition of an A2A antagonist to a stable L-DOPA regimen reduces OFF time and mildly increases dyskinesia. However, limited clinical data suggest that the addition of an A2A antagonist along with a reduction of L-DOPA might maintain anti-Parkinsonian benefit and reduce dyskinesia. Whether A2A antagonists might reduce the development of dyskinesia has not yet been tested clinically. PMID:22754707

  14. Effect of Antrodia camphorata on Inflammatory Arterial Thrombosis-Mediated Platelet Activation: The Pivotal Role of Protein Kinase C

    Directory of Open Access Journals (Sweden)

    Wan-Jung Lu

    2014-01-01

    Full Text Available Antrodia camphorata is a rare Taiwanese medicinal mushroom. Antrodia camphorata extract has been reported to exhibit antioxidant, anti-inflammation, antimetastasis, and anticancer activities and plays a role in liver fibrosis, vasorelaxation, and immunomodulation. Critical vascular inflammation leads to vascular dysfunction and cardiovascular diseases, including abdominal aortic aneurysms, hypertension, and atherosclerosis. Platelet activation plays a crucial role in intravascular thrombosis, which is involved in a wide variety of cardiovascular diseases. However, the effect of Antrodia camphorata on platelet activation remains unclear. We examined the effects of Antrodia camphorata on platelet activation. In the present study, Antrodia camphorata treatment (56–224 μg/mL inhibited platelet aggregation induced by collagen, but not U46619, an analogue of thromboxane A2, thrombin, and arachidonic acid. Antrodia camphorata inhibited collagen-induced calcium (Ca2+ mobilization and phosphorylation of protein kinase C (PKC and Akt. In addition, Antrodia camphorata significantly reduced the aggregation and phosphorylation of PKC in phorbol-12, 13-dibutyrate (PDBu activated platelets. In conclusion, Antrodia camphorata may inhibit platelet activation by inhibiting of Ca2+ and PKC cascade and the Akt pathway. Our study suggests that Antrodia camphorata may be a potential therapeutic agent for preventing or treating thromboembolic disorders.

  15. Sulforaphane prevents human platelet aggregation through inhibiting the phosphatidylinositol 3-kinase/Akt pathway.

    Science.gov (United States)

    Chuang, Wen-Ying; Kung, Po-Hsiung; Kuo, Chih-Yun; Wu, Chin-Chung

    2013-06-01

    Sulforaphane, a dietary isothiocyanate found in cruciferous vegetables, has been shown to exert beneficial effects in animal models of cardiovascular diseases. However, its effect on platelet aggregation, which is a critical factor in arterial thrombosis, is still unclear. In the present study, we show that sulforaphane inhibited human platelet aggregation caused by different receptor agonists, including collagen, U46619 (a thromboxane A2 mimic), protease-activated receptor 1 agonist peptide (PAR1-AP), and an ADP P2Y12 receptor agonist. Moreover, sulforaphane significantly reduced thrombus formation on a collagen-coated surface under whole blood flow conditions. In exploring the underlying mechanism, we found that sulforaphane specifically prevented phosphatidylinositol 3-kinase (PI3K)/Akt signalling, without markedly affecting other signlaling pathways involved in platelet aggregation, such as protein kinase C activation, calcium mobilisation, and protein tyrosine phosphorylation. Although sulforaphane did not directly inhibit the catalytic activity of PI3K, it caused ubiquitination of the regulatory p85 subunit of PI3K, and prevented PI3K translocation to membranes. In addition, sulforaphane caused ubiquitination and degradation of phosphoinositide-dependent kinase 1 (PDK1), which is required for Akt activation. Therefore, sulforaphane is able to inhibit the PI3K/Akt pathway at two distinct sites. In conclusion, we have demonstrated that sulforaphane prevented platelet aggregation and reduced thrombus formation in flow conditions; our data also support that the inhibition of the PI3K/Akt pathway by sulforaphane contributes it antiplatelet effects.

  16. Further insights into the anti-aggregating activity of NMDA in human platelets

    Science.gov (United States)

    Franconi, Flavia; Miceli, Mauro; Alberti, Luisa; Seghieri, Giuseppe; De Montis, M Graziella; Tagliamonte, Alessandro

    1998-01-01

    In the present study the effect of N-methyl-D-aspartate (NMDA) on thromboxane B2 synthesis and on [Ca2+]i was studied in human platelets.NMDA (10−7 M) completely inhibited the synthesis of thromboxane B2 from exogenous arachidonic acid (AA), while it did not interfere with the aggregating effect of the thromboxane A2 receptor agonist U-46619.NMDA (0.1 μM–10 μM) dose-dependently increased intracellular calcium in washed platelets pre-loaded with fura 2 AM, and this effect was not additive with that of AA.NMDA shifted the dose-response curve of AA to the right. At the highest AA concentrations platelet aggregation was not inhibited.The antiaggregating effect of NMDA was not antagonized by NG-monomethyl-L-arginine (L-NMMA), a nitric oxide synthase (NOS) inhibitor.Finally, NMDA (0.01 nM–100 nM) associated with either aspirin or indomethacin significantly potentiated the antiaggregating activity of both cyclo-oxygenase inhibitors.It was concluded that NMDA is a potent inhibitor of platelet aggregation and thromboxane B2 synthesis in human platelet rich plasma (PRP). PMID:9630340

  17. Potential Therapeutic Applications of Adenosine A2A Receptor Ligands and Opportunities for A2A Receptor Imaging

    NARCIS (Netherlands)

    van Waarde, Aren; Dierckx, Rudi A. J. O.; Zhou, Xiaoyun; Khanapur, Shivashankar; Tsukada, Hideo; Ishiwata, Kiichi; Luurtsema, Gert; de Vries, Erik F. J.; Elsinga, Philip H.

    Adenosine A2A receptors (A2ARs) are highly expressed in the human striatum, and at lower densities in the cerebral cortex, the hippocampus, and cells of the immune system. Antagonists of these receptors are potentially useful for the treatment of motor fluctuations, epilepsy, postischemic brain

  18. Cyclin A2: a genuine cell cycle regulator?

    Science.gov (United States)

    Bendris, Nawal; Loukil, Abdelhalim; Cheung, Caroline; Arsic, Nikola; Rebouissou, Cosette; Hipskind, Robert; Peter, Marion; Lemmers, Bénédicte; Blanchard, Jean Marie

    2012-12-01

    Abstract Cyclin A2 belongs to the core cell cycle regulators and participates in the control of both S phase and mitosis. However, several observations suggest that it is also endowed with other functions, and our recent data shed light on its involvement in cytoskeleton dynamic and cell motility. From the transcription of its gene to its posttranslational modifications, cyclin A2 regulation reveals the complexity of the regulatory network shaping cell cycle progression. We summarize our current knowledge on this cell cycle regulator and discuss recent findings raising the possibility that cyclin A2 might play a much broader role in epithelial tissues homeostasis.

  19. Evaluation the COL9A2 gene with high myopia

    Science.gov (United States)

    Zhang, Dingding; Huang, Maomin

    2017-11-01

    This paper investigates the association of the COL9A2 gene between high myopia and normal controls in the Han Chinese population. It shows that the frameshift mutation (D281fs) in the COL9A2 gene is not associated with high myopia in the Han Chinese population, and the two novel variants(c.143G>C and c.884G>A) may contribute to the development of high myopia.

  20. A2A receptor ligands: past, present and future trends.

    Science.gov (United States)

    Clementina, Manera; Giuseppe, Saccomanni

    2010-01-01

    The adenosine A(2A) receptor is a member of the G protein-coupled receptor family and mediates multiple physiological effects of adenosine, both at the central nervous system and at peripheral tissues. Increasing evidence relates the A(2A) receptor with several pathological conditions such as neurodegenerative disorders, inflammation, pharmacological stress, and wound healing renewing the interest in A(2A) receptor agonists and antagonists as promising leads for drugs. However some of them initially tested in clinical trials presented several side effects, short half-life, lower solubility, and in some cases a lack of effects, perhaps attributable to receptor desensitization or to low receptor density in the targeted tissue. For these reasons it is evident that additional rational chemical modifications of the existing A(2A) receptor ligands to improve their affinity/selectivity and bioavailability as well as further studies to get new template for A(2A)AR ligands are necessary. The purpose of this review is to analyze and summarize the past and the present aspects related to the medicinal chemistry of A(2A) receptor ligands. Moreover their current and possible therapeutic applications have been also highlighted.

  1. Interaction between EGFR and EphA2

    DEFF Research Database (Denmark)

    Larsen, Alice Bjerregaard

    2010-01-01

    Enhanced or altered epidermal growth factor receptor (EGFR) activity has been reported in many human cancers and several molecular targeting therapies has been developed. However, despite intense research, therapies targeting EGFR have shown conflicting results in clinical studies, indicating...... the involvement of other important molecular players. Several different EGFR mutations have been reported in cancer, one of which is the cancer specific type III EGFR deletion mutant (EGFRvIII, de2-7EGFR, ΔEGFR). In a global search for EGFR and EGFRvIII regulated genes we identified the receptor tyrosine kinase...... (RTK) EphA2. EphA2 belongs to the large Eph-receptor family, which has mainly been associated with neuronal development. More recently, expression of several Eph-receptors has been detected in many different cancer types. Elevated EphA2 expression has been reported in a broad range of human cancer...

  2. Interaction between EGFR and EphA2

    DEFF Research Database (Denmark)

    Larsen, Alice Bjerregaard

    2010-01-01

    Enhanced or altered epidermal growth factor receptor (EGFR) activity has been reported in many human cancers and several molecular targeting therapies has been developed. However, despite intense research, therapies targeting EGFR have shown conflicting results in clinical studies, indicating...... the involvement of other important molecular players. Several different EGFR mutations have been reported in cancer, one of which is the cancer specific type III EGFR deletion mutant (EGFRvIII, de2-7EGFR, ¿EGFR). In a global search for EGFR and EGFRvIII regulated genes we identified the receptor tyrosine kinase...... (RTK) EphA2. EphA2 belongs to the large Eph-receptor family, which has mainly been associated with neuronal development. More recently, expression of several Eph-receptors has been detected in many different cancer types. Elevated EphA2 expression has been reported in a broad range of human cancer...

  3. Interaction between EGFR and EphA2

    DEFF Research Database (Denmark)

    Larsen, Alice Bjerregaard

    2010-01-01

    the involvement of other important molecular players. Several different EGFR mutations have been reported in cancer, one of which is the cancer specific type III EGFR deletion mutant (EGFRvIII, de2-7EGFR, ¿EGFR). In a global search for EGFR and EGFRvIII regulated genes we identified the receptor tyrosine kinase......Enhanced or altered epidermal growth factor receptor (EGFR) activity has been reported in many human cancers and several molecular targeting therapies has been developed. However, despite intense research, therapies targeting EGFR have shown conflicting results in clinical studies, indicating...... (RTK) EphA2. EphA2 belongs to the large Eph-receptor family, which has mainly been associated with neuronal development. More recently, expression of several Eph-receptors has been detected in many different cancer types. Elevated EphA2 expression has been reported in a broad range of human cancer...

  4. An Analytic Formula for the A_2 Jack Polynomials

    Directory of Open Access Journals (Sweden)

    Vladimir V. Mangazeev

    2007-01-01

    Full Text Available In this letter I shall review my joint results with Vadim Kuznetsov and Evgeny Sklyanin [Indag. Math. 14 (2003, 451-482] on separation of variables (SoV for the $A_n$ Jack polynomials. This approach originated from the work [RIMS Kokyuroku 919 (1995, 27-34] where the integral representations for the $A_2$ Jack polynomials was derived. Using special polynomial bases I shall obtain a more explicit expression for the $A_2$ Jack polynomials in terms of generalised hypergeometric functions.

  5. Hypoxia-inducible factor-1β (HIF-1β) is upregulated in a HIF-1α-dependent manner in 518A2 human melanoma cells under hypoxic conditions

    Energy Technology Data Exchange (ETDEWEB)

    Mandl, Markus, E-mail: mmandl@mail.austria.com; Kapeller, Barbara; Lieber, Roman; Macfelda, Karin

    2013-04-26

    Highlights: •HIF-1β is a hypoxia-responsive protein in 518A2 human melanoma cells. •HIF-1β is upregulated in a HIF-1α-dependent manner under hypoxic conditions. •HIF-1β is not elevated due to heterodimerization with HIF-1α per se. •HIF-1β inducibility has a biological relevance as judged in Het-CAM model. -- Abstract: Solid tumors include hypoxic areas due to excessive cell proliferation. Adaptation to low oxygen levels is mediated by the hypoxia-inducible factor (HIF) pathway promoting invasion, metastasis, metabolic alterations, chemo-resistance and angiogenesis. The transcription factor HIF-1, the major player within this pathway consists of HIF-1α and HIF-1β. The alpha subunit is continuously degraded under normoxia and becomes stabilized under reduced oxygen supply. In contrast, HIF-1β is generally regarded as constitutively expressed and being present in excess within the cell. However, there is evidence that the expression of this subunit is more complex. The aim of this study was to investigate the role of HIF-1β in human melanoma cells. Among a panel of five different cell lines, in 518A2 cells exposed to the hypoxia-mimetic cobalt chloride HIF-1β was rapidly elevated on protein level. Knockdown experiments performed under cobalt chloride-exposure and hypoxia revealed that this effect was mediated by HIF-1α. The non-canonical relationship between these subunits was further confirmed by pharmacologic inhibition of HIF-1α and by expression of a dominant-negative HIF mutant. Overexpression of HIF-1α showed a time delay in HIF-1β induction, thus arguing for HIF-1β de novo synthesis rather than protein stabilization by heterodimerization. A Hen’s egg test-chorioallantoic membrane model of angiogenesis and invasion indicated a local expression of HIF-1β and implies a biological relevance of these findings. In summary, this study demonstrates the HIF-1α-dependent regulation of HIF-1β under hypoxic conditions for the first time. The

  6. Hypoxia-inducible factor-1β (HIF-1β) is upregulated in a HIF-1α-dependent manner in 518A2 human melanoma cells under hypoxic conditions

    International Nuclear Information System (INIS)

    Mandl, Markus; Kapeller, Barbara; Lieber, Roman; Macfelda, Karin

    2013-01-01

    Highlights: •HIF-1β is a hypoxia-responsive protein in 518A2 human melanoma cells. •HIF-1β is upregulated in a HIF-1α-dependent manner under hypoxic conditions. •HIF-1β is not elevated due to heterodimerization with HIF-1α per se. •HIF-1β inducibility has a biological relevance as judged in Het-CAM model. -- Abstract: Solid tumors include hypoxic areas due to excessive cell proliferation. Adaptation to low oxygen levels is mediated by the hypoxia-inducible factor (HIF) pathway promoting invasion, metastasis, metabolic alterations, chemo-resistance and angiogenesis. The transcription factor HIF-1, the major player within this pathway consists of HIF-1α and HIF-1β. The alpha subunit is continuously degraded under normoxia and becomes stabilized under reduced oxygen supply. In contrast, HIF-1β is generally regarded as constitutively expressed and being present in excess within the cell. However, there is evidence that the expression of this subunit is more complex. The aim of this study was to investigate the role of HIF-1β in human melanoma cells. Among a panel of five different cell lines, in 518A2 cells exposed to the hypoxia-mimetic cobalt chloride HIF-1β was rapidly elevated on protein level. Knockdown experiments performed under cobalt chloride-exposure and hypoxia revealed that this effect was mediated by HIF-1α. The non-canonical relationship between these subunits was further confirmed by pharmacologic inhibition of HIF-1α and by expression of a dominant-negative HIF mutant. Overexpression of HIF-1α showed a time delay in HIF-1β induction, thus arguing for HIF-1β de novo synthesis rather than protein stabilization by heterodimerization. A Hen’s egg test-chorioallantoic membrane model of angiogenesis and invasion indicated a local expression of HIF-1β and implies a biological relevance of these findings. In summary, this study demonstrates the HIF-1α-dependent regulation of HIF-1β under hypoxic conditions for the first time. The

  7. Familial Hemiplegic Migraine With ATP1A2 Mutations

    Directory of Open Access Journals (Sweden)

    J Gordon Millichap

    2007-05-01

    Full Text Available Three children with prolonged hemiplegia following severe unilateral headache and having mutations in ATP1A2 are reported from UCLA School of Medicine, Los Angeles, CA; University Children’s Hospital, Zurich, Switzerland; and Wake Forest University School of Medicine, Winston-Salem, NC.

  8. PET imaging of adenosine A2A receptors

    NARCIS (Netherlands)

    Zhou, Xiaoyun

    2017-01-01

    This thesis describes the development and evaluation of [11C]preladenant as a novel radioligand for in vivo imaging of adenosine A2A receptors in the brain with positron-emission tomography (PET). The 11C-labeled drug [11C]preladenant was produced with high radiochemical yield and specific activity.

  9. Secretory Phospholipase A(2)-IIA and Cardiovascular Disease

    NARCIS (Netherlands)

    Holmes, Michael V.; Simon, Tabassome; Exeter, Holly J.; Folkersen, Lasse; Asselbergs, Folkert W.; Guardiola, Montse; Cooper, Jackie A.; Palmen, Jutta; Hubacek, Jaroslav A.; Carruthers, Kathryn F.; Horne, Benjamin D.; Brunisholz, Kimberly D.; Mega, Jessica L.; Van Iperen, Erik P. A.; Li, Mingyao; Leusink, Maarten; Trompet, Stella; Verschuren, Jeffrey J. W.; Hovingh, G. Kees; Dehghan, Abbas; Nelson, Christopher P.; Kotti, Salma; Danchin, Nicolas; Scholz, Markus; Haase, Christiane L.; Rothenbacher, Dietrich; Swerdlow, Daniel I.; Kuchenbaecker, Karoline B.; Staines-Urias, Eleonora; Goel, Anuj; van 't Hooft, Ferdinand; Gertow, Karl; de Faire, Ulf; Panayiotou, Andrie G.; Tremoli, Elena; Baldassarre, Damiano; Veglia, Fabrizio; Holdt, Lesca M.; Beutner, Frank; Gansevoort, Ron T.; Navis, Gerjan J.; Mateo Leach, Irene; Breitling, Lutz P.; Brenner, Hermann; Thiery, Joachim; Dallmeier, Dhayana; Franco-Cereceda, Anders; Boer, Jolanda M. A.; Stephens, Jeffrey W.; Hofker, Marten H.; Tedgui, Alain; Hofman, Albert; Uitterlinden, Andre G.; Adamkova, Vera; Pitha, Jan; Onland-Moret, N. Charlotte; Cramer, Maarten J.; Nathoe, Hendrik M.; Spiering, Wilko; Klungel, Olaf H.; Kumari, Meena; Whincup, Peter H.; Morrow, David A.; Braund, Peter S.; Hall, Alistair S.; Olsson, Anders G.; Doevendans, Pieter A.; Trip, Mieke D.; Tobin, Martin D.; Hamsten, Anders; Watkins, Hugh; Koenig, Wolfgang; Nicolaides, Andrew N.; Teupser, Daniel; Day, Ian N. M.; Carlquist, John F.; Gaunt, Tom R.; Ford, Ian; Sattar, Naveed; Tsimikas, Sotirios; Schwartz, Gregory G.; Lawlor, Debbie A.; Morris, Richard W.; Sandhu, Manjinder S.; Poledne, Rudolf; Maitland-van der Zee, Anke H.; Khaw, Kay-Tee; Keating, Brendan J.; van der Harst, Pim; Price, Jackie F.; Mehta, Shamir R.; Yusuf, Salim; Witteman, Jaqueline C. M.; Franco, Oscar H.; Jukema, J. Wouter; de Knijff, Peter; Tybjaerg-Hansen, Anne; Rader, Daniel J.; Farrall, Martin; Samani, Nilesh J.; Kivimaki, Mika; Fox, Keith A. A.; Humphries, Steve E.; Anderson, Jeffrey L.; Boekholdt, S. Matthijs; Palmer, Tom M.; Eriksson, Per; Pare, Guillaume; Hingorani, Aroon D.; Sabatine, Marc S.; Mallat, Ziad; Casas, Juan P.; Talmud, Philippa J.

    2013-01-01

    Objectives This study sought to investigate the role of secretory phospholipase A(2) (sPLA(2))-IIA in cardiovascular disease. Background Higher circulating levels of sPLA(2)-IIA mass or sPLA(2) enzyme activity have been associated with increased risk of cardiovascular events. However, it is not

  10. A 2-dimensional finite element simulation of cooling in castings ...

    African Journals Online (AJOL)

    In this work we present a 2 dimensional finite element simulation of the cooling process in castings. A one way coupling +technique was used to predict the behavior of thermal strains and stresses from the temperature history of casting. The temperature distribution across the casting at different times, the cooling pattern of ...

  11. Activation of phospholipase A2 by Hsp70 in vitro

    DEFF Research Database (Denmark)

    Mahalka, Ajay K; Code, Christian; Rezaijahromi, Behnam

    2011-01-01

    We recently suggested a novel mechanism for the activation of phospholipase A2 (PLA2), with a (catalytically) highly active oligomeric state, which subsequently becomes inactivated by conversion into amyloid. This process can be activated by lysophosphatidylcholine which promotes both oligomeriza...

  12. Phospholipases A2 in ocular homeostasis and diseases

    DEFF Research Database (Denmark)

    Wang, Jinmei; Kolko, Miriam; Kolko, Miriam

    2010-01-01

    Phospholipases A(2) (PLA(2)s) and its generation of second messengers play an important role in signal transduction, cell proliferation, cell survival and gene expression. At low concentrations mediators of PLA(2) activity have a variety of physiological effects whereas high levels of PLA(2) and ...

  13. 26 CFR 1.167(a)-2 - Tangible property.

    Science.gov (United States)

    2010-04-01

    ... Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) INCOME TAX (CONTINUED) INCOME TAXES (CONTINUED) Itemized Deductions for Individuals and Corporations § 1.167(a)-2 Tangible... solely as his residence, or on furniture or furnishings therein, personal effects, or clothing; but...

  14. 17 CFR 270.3a-2 - Transient investment companies.

    Science.gov (United States)

    2010-04-01

    ... 17 Commodity and Securities Exchanges 3 2010-04-01 2010-04-01 false Transient investment companies... (CONTINUED) RULES AND REGULATIONS, INVESTMENT COMPANY ACT OF 1940 § 270.3a-2 Transient investment companies... which an issuer owns or proposes to acquire investment securities (as defined in section 3(a) of the Act...

  15. Automated proton titrations of pancreatic phospholipase A2

    NARCIS (Netherlands)

    Donné-Op den Kelder, G.M.; Haas, G.H. de; Egmond, M.R.

    1982-01-01

    A computer-controlled titration system has been developed, tested, and used for analysis of the proton-titration behavior of pancreatic phospholipase A2 from ox, horse, and pig. The results revealed an error in the reported amino acid composition of the equine enzyme. A simple interface for the

  16. A 2D particle velocity sensor with minimal flow disturbance

    NARCIS (Netherlands)

    Pjetri, O.; Wiegerink, Remco J.; Krijnen, Gijsbertus J.M.

    2016-01-01

    A 2D sound particle velocity sensor, consisting of a cross of two connected, heated wires is presented. We developed a fabrication process by which the wires become freely suspended 350 micrometer above the chip surface. This largely eliminates the influence of boundary layer effects and increases

  17. Drug delivery by phospholipase A(2) degradable liposomes

    DEFF Research Database (Denmark)

    Davidsen, Jesper; Vermehren, C.; Frøkjær, S.

    2001-01-01

    The effect of poly(ethylene glycol)-phospholipid (PE-PEG) lipopolymers on phospholipase A(2) (PLA(2)) hydrolysis of liposomes composed of stearoyl-oleoylphosphatidylcholine (SOPC) was investigated. The PLA(2) lag-time, which is inversely related to the enzymatic activity, was determined by fluore...

  18. 26 CFR 6a.103A-2 - Qualified mortgage bond.

    Science.gov (United States)

    2010-04-01

    ... includes the cost of materials provided and work performed by subcontractors (whether or not related to the... unfinished third floor and which lacks a garage. Normally, a completed recreation room, a finished third... work after A receives title to the unit from B. Under § 6a.103A-2(b)(8)(i)(A), the acquisition cost of...

  19. Ankle fusion using a 2-incision, 3-screw technique

    NARCIS (Netherlands)

    Hendrickx, R. P. M.; Kerkhoffs, G. M. M. J.; Stufkens, S. A. S.; van Dijk, C. N.; Marti, R. K.

    2011-01-01

    Reliable fusion and optimal correction of the alignment of the ankle joint using a 2-incision, 3-screw technique. Symptomatic osteoarthritis of the ankle joint after insufficient other treatment, severe deformity of the osteoarthritic ankle joint, or salvation procedure after failed arthroplasty.

  20. Secretory phospholipase A(2) in newborn infants with sepsis

    NARCIS (Netherlands)

    Schrama, A. J. J.; De Beaufort, A. J.; Poorthuis, B. J. H. M.; Berger, H. M.; Walther, F. J.

    2008-01-01

    Objective: To investigate secretory phospholipase A(2) ( sPLA(2)) activity in neonatal sepsis. Study Design: Plasma sPLA(2) activity, C- reactive protein ( CRP) concentration, leukocyte count and immature/ total neutrophil ( I/ T) ratio were assessed in a group of 156 infants admitted for neonatal

  1. Les femmes américaines et la guerre du Vietnam : mise en place et utilisation d’un processus de mimétisme American Women, the Vietnam War and Mimetism:  Constructing and Developing an Unconscious Imitation of the Soldier

    Directory of Open Access Journals (Sweden)

    Alexandra Boudet-Brugal

    2009-10-01

    Full Text Available By and large, women have been maintained at a “reasonable” distance from the war. Their historic identity has mainly been that of mother, and therefore that of those who do not make war. They are not to belong to this sphere; it is to remain masculine, a men’s world. The Vietnam War (1964-1973 is no exception to the rule. This characteristic may be even more visible in the context of Vietnam given the power granted to authenticity: “having been there” has been essential. However, it seems that, just as Vietnam was a confused war, the border between genders has been sometimes blurred as well. We have thus found that some women have constructed and developed a strange process, a(n (unconscious strategy, in order to enter the world of war while not “having been there” really, while not knowing physically what war is and was. If “Vietnam is the land of [their] imagination”, as Barbara Sonneborn put it (Regret to inform, 1999, mimetism has allowed them to fill out the blanks, to uncover and discover their man’s reality, to “see what it was he saw […] to be in the field with him”, says Gail Gilberg (Snake’s Daugher, 1997. I will therefore expose and study this phenomenon that appears in various women’s stories, written or told, by themselves or others, through their own narrative styles and speeches. In doing so, I intend to examine whether the use of this mechanism reinforces the traditional representations of men and women in war: Does it allow a re-writing of these excluded female voices, while putting forward the specificities of women’s experiences in war? Does it grant women a voice and a visible presence? Considering that “societies are, in some sense, the sum total of the war stories” (Jean B. Elshtain, it seems interesting to examine to what extent this strategy allows the American women to find their place in the story of the Vietnam war, in a very specific way.

  2. Mechanism of A2 adenosine receptor activation. I. Blockade of A2 adenosine receptors by photoaffinity labeling

    International Nuclear Information System (INIS)

    Lohse, M.J.; Klotz, K.N.; Schwabe, U.

    1991-01-01

    It has previously been shown that covalent incorporation of the photoreactive adenosine derivative (R)-2-azido-N6-p-hydroxy-phenylisopropyladenosine [(R)-AHPIA] into the A1 adenosine receptor of intact fat cells leads to a persistent activation of this receptor, resulting in a reduction of cellular cAMP levels. In contrast, covalent incorporation of (R)-AHPIA into human platelet membranes, which contain only stimulatory A2 adenosine receptors, reduces adenylate cyclase stimulation via these receptors. This effect of (R)-AHPIA is specific for the A2 receptor and can be prevented by the adenosine receptor antagonist theophylline. Binding studies indicate that up to 90% of A2 receptors can be blocked by photoincorporation of (R)-AHPIA. However, the remaining 10-20% of A2 receptors are sufficient to mediate an adenylate cyclase stimulation of up to 50% of the control value. Similarly, the activation via these 10-20% of receptors occurs with a half-life that is only 2 times longer than that in control membranes. This indicates the presence of a receptor reserve, with respect to both the extent and the rate of adenylate cyclase stimulation. These observations require a modification of the models of receptor-adenylate cyclase coupling

  3. Solute Carrier Family 26 Member a2 (slc26a2 Regulates Otic Development and Hair Cell Survival in Zebrafish.

    Directory of Open Access Journals (Sweden)

    Fei Liu

    Full Text Available Hearing loss is one of the most prevalent human birth defects. Genetic factors contribute to the pathogenesis of deafness. It is estimated that one-third of deafness genes have already been identified. The current work is an attempt to find novel genes relevant to hearing loss using guilt-by-profiling and guilt-by-association bioinformatics analyses of approximately 80 known non-syndromic hereditary hearing loss (NSHL genes. Among the 300 newly identified candidate deafness genes, slc26a2 were selected for functional studies in zebrafish. The slc26a2 gene was knocked down using an antisense morpholino (MO, and significant defects were observed in otolith patterns, semicircular canal morphology, and lateral neuromast distributions in morphants. Loss-of-function defects are caused primarily by apoptosis, and morphants are insensitive to sound stimulation and imbalanced swimming behaviours. Morphant defects were found to be partially rescued by co-injection of human SLC26A2 mRNA. All the results suggest that bioinformatics is capable of predicting new deafness genes and this showed slc26a2 is to be a critical otic gene whose dysfunction may induce hearing impairment.

  4. Antitumoral Potential of Tunisian Snake Venoms Secreted Phospholipases A2

    Directory of Open Access Journals (Sweden)

    Raoudha Zouari-Kessentini

    2013-01-01

    Full Text Available Phospholipases type A2 (PLA2s are the most abundant proteins found in Viperidae snake venom. They are quite fascinating from both a biological and structural point of view. Despite similarity in their structures and common catalytic properties, they exhibit a wide spectrum of pharmacological activities. Besides being hydrolases, secreted phospholipases A2 (sPLA2 are an important group of toxins, whose action at the molecular level is still a matter of debate. These proteins can display toxic effects by different mechanisms. In addition to neurotoxicity, myotoxicity, hemolytic activity, antibacterial, anticoagulant, and antiplatelet effects, some venom PLA2s show antitumor and antiangiogenic activities by mechanisms independent of their enzymatic activity. This paper aims to discuss original finding against anti-tumor and anti-angiogenic activities of sPLA2 isolated from Tunisian vipers: Cerastes cerastes and Macrovipera lebetina, representing new tools to target specific integrins, mainly, and integrins.

  5. Motor pathway excitability in ATP13A2 mutation carriers

    DEFF Research Database (Denmark)

    Zittel, S; Kroeger, J; van der Vegt, J P M

    2012-01-01

    OBJECTIVE: To describe excitability of motor pathways in Kufor-Rakeb syndrome (PARK9), an autosomal recessive nigro-striatal-pallidal-pyramidal neurodegeneration caused by a mutation in the ATP13A2 gene, using transcranial magnetic stimulation (TMS). METHODS: Five members of a Chilean family...... with an ATP13A2 mutation (one affected mutation carrier (MC) with a compound heterozygous mutation, 4 asymptomatic MC with a single heterozygous mutation) and 11 healthy subjects without mutations were studied. We measured motor evoked potentials (MEP), the contralateral silent period (cSP), short interval...... intracortical inhibition (SICI), intracortical facilitation (ICF), short latency afferent inhibition (SAI) as markers of intracortical intrahemispheric inhibition/facilitation and the ipsilateral silent period (iSP) and paired-pulse interhemispheric inhibition (IHI) to probe interhemispheric motor interactions...

  6. A2e High Fidelity Modeling: Strategic Planning Meetings

    Energy Technology Data Exchange (ETDEWEB)

    Hammond, Steven W. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Sprague, Michael A. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Womble, David [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Barone, Matt [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2015-11-01

    Atmosphere to electrons (A2e) is a multi-year U.S. Department of Energy (DOE) research initiative targeting significant reductions in the cost of wind energy through an improved understanding of the complex physics governing wind flow into and through whole wind farms. Better insight into the flow physics of large multi-turbine arrays will address the plant-level energy losses, is likely to reduce annual operational costs by hundreds of millions of dollars, and will improve project financing terms to more closely resemble traditional capital projects. In support of this initiative, two planning meetings were convened, bringing together professionals from universities, national laboratories, and industry to discuss wind plant modeling challenges, requirements, best practices, and priorities. This report documents the combined work of the two meetings and serves as a key part of the foundation for the A2e/HFM effort for predictive modeling of whole wind plant physics.

  7. Irradiation creep induced anisotropy in a/2 dislocation populations

    International Nuclear Information System (INIS)

    Gelles, D.S.

    1984-05-01

    The contribution of anisotropy in Burgers vector distribution to irradiation creep behavior has been largely ignored in irradiation creep models. However, findings on Frank loops suggest that it may be very important. Procedures are defined to identify the orientations of a/2 Burgers vectors for dislocations in face-centered cubic crystals. By means of these procedures the anisotropy in Burgers vector populations was determined for three Nimonic PE16 pressurized tube specimens irradiated under stress. Considerable anisotropy in Burgers vector population develops during irradiation creep. It is inferred that dislocation motion during irradiation creep is restricted primarily to a climb of a/2 dislocations on 100 planes. Effect of these results on irradiation creep modeling and deformation induced irradiation growth is considered

  8. A 2:1 MUX Based on Multiple MEMS Resonators

    KAUST Repository

    Hafiz, Md Abdullah Al

    2017-01-09

    Micro/nano-electromechanical resonator based mechanical computing has recently attracted significant attention. This paper reports a realization of a 2:1 MUX, a concatenable digital logic element, based on electrothermal frequency tuning of electrically connected multiple arch resonators. Toward this, shallow arch shaped microresonators are electrically connected and their resonance frequencies are tuned based on an electrothermal frequency modulation scheme. This study demonstrates that by reconfiguring the same basic building block, the arch microresonator, complex logic circuits can be realized.

  9. Energy level transitions of gas in a 2D nanopore

    Energy Technology Data Exchange (ETDEWEB)

    Grinyaev, Yurii V., E-mail: grn@ispms.tsc.ru [Institute of Strength Physics and Materials Science SB RAS, Tomsk, 634055 (Russian Federation); National Research Tomsk State University, Tomsk, 634050 (Russian Federation); Chertova, Nadezhda V., E-mail: chertova@ispms.tsc.ru [Institute of Strength Physics and Materials Science SB RAS, Tomsk, 634055 (Russian Federation); Psakhie, Sergei G., E-mail: sp@ispms.tsc.ru [Institute of Strength Physics and Materials Science SB RAS, Tomsk, 634055 (Russian Federation); National Research Tomsk Polytechnic University, Tomsk, 634050 (Russian Federation)

    2015-10-27

    An analytical study of gas behavior in a 2D nanopore was performed. It is shown that the temperature dependence of gas energy can be stepwise due to transitions from one size-quantized subband to another. Taking into account quantum size effects results in energy level transitions governed by the nanopore size, temperature and gas density. This effect leads to an abrupt change of gas heat capacity in the nanopore at the above varying system parameters.

  10. Novel dire