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Sample records for 5-hydroxytrytamine 2c receptor

  1. Serotonin 2c receptors in pro-opiomelanocortin neurons regulate energy and glucose homeostasis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Energy and glucose homeostasis are regulated by central serotonin 2C receptors. These receptors are attractive pharmacological targets for the treatment of obesity; however, the identity of the serotonin 2C receptor-expressing neurons that mediate the effects of serotonin and serotonin 2C receptor a...

  2. We Need 2C but Not 2B: Developing Serotonin 2C (5-HT2C) Receptor Agonists for the Treatment of CNS Disorders

    PubMed Central

    Cheng, Jianjun; Kozikowski, Alan P.

    2016-01-01

    The serotonin 2C (5-HT2C) receptor has been identified as a potential drug target for the treatment of a variety of central nervous system (CNS) disorders, such as obesity, substance abuse, and schizophrenia. In this Viewpoint article, recent progress in developing selective 5-HT2C agonists for use in treating these disorders is summarized, including the work of our group. Challenges in this field and the possible future directions are described. Homology modeling as a method to predict the binding modes of 5-HT2C ligands to the receptor is also discussed. Compared to known ligands, the improved pharmacological profiles of the 2-phenylcyclopropylmethylamine-based 5-HT2C agonists make them preferred candidates for further studies. PMID:26507582

  3. 5-HT2C receptors in psychiatric disorders: A review.

    PubMed

    Chagraoui, A; Thibaut, F; Skiba, M; Thuillez, C; Bourin, M

    2016-04-01

    5-HT2Rs have a different genomic organization from other 5-HT2Rs. 5HT2CR undergoes post-transcriptional pre-mRNA editing generating diversity among RNA transcripts. Selective post-transcriptional editing could be involved in the pathophysiology of psychiatric disorders through impairment in G-protein interactions. Moreover, it may influence the therapeutic response to agents such as atypical antipsychotic drugs. Additionally, 5-HT2CR exhibits alternative splicing. Central serotonergic and dopaminergic systems interact to modulate normal and abnormal behaviors. Thus, 5HT2CR plays a crucial role in psychiatric disorders. 5HT2CR could be a relevant pharmacological target in the treatment of neuropsychiatric disorders. The development of drugs that specifically target 5-HT2C receptors will allow for better understanding of their involvement in the pathophysiology of psychiatric disorders including schizophrenia, anxiety, and depression. Among therapeutic means currently available, most drugs used to treat highly morbid psychiatric diseases interact at least partly with 5-HT2CRs. Pharmacologically, 5HT2CRs, have the ability to generate differentially distinct response signal transduction pathways depending on the type of 5HT2CR agonist. Although this receptor property has been clearly demonstrated, in vitro, the eventual beneficial impact of this property opens new perspectives in the development of agonists that could activate signal transduction pathways leading to better therapeutic efficiency with fewer adverse effects.

  4. Impact of RNA Editing on Functions of the Serotonin 2C Receptor in vivo

    PubMed Central

    Olaghere da Silva, Uade B.; Morabito, Michael V.; Canal, Clinton E.; Airey, David C.; Emeson, Ronald B.; Sanders-Bush, Elaine

    2009-01-01

    Transcripts encoding 5-HT2C receptors are modified posttranscriptionally by RNA editing, generating up to 24 protein isoforms. In recombinant cells, the fully edited isoform, 5-HT2C-VGV, exhibits blunted G-protein coupling and reduced constitutive activity. The present studies examine the signal transduction properties of 5-HT2C-VGV receptors in brain to determine the in vivo consequences of altered editing. Using mice solely expressing the 5-HT2C-VGV receptor (VGV/Y), we demonstrate reduced G-protein coupling efficiency and high-affinity agonist binding of brain 5-HT2C-VGV receptors. However, enhanced behavioral sensitivity to a 5-HT2C receptor agonist was also seen in mice expressing 5-HT2C-VGV receptors, an unexpected finding given the blunted G-protein coupling. In addition, mice expressing 5-HT2C-VGV receptors had greater sensitivity to a 5-HT2C inverse agonist/antagonist enhancement of dopamine turnover relative to wild-type mice. These behavioral and biochemical results are most likely explained by increases in 5-HT2C receptor binding sites in the brains of mice solely expressing 5-HT2C-VGV receptors. We conclude that 5-HT2C-VGV receptor signaling in brain is blunted, but this deficiency is masked by a marked increase in 5-HT2C receptor binding site density in mice solely expressing the VGV isoform. These findings suggest that RNA editing may regulate the density of 5-HT2C receptor binding sites in brain. We further caution that the pattern of 5-HT2C receptor RNA isoforms may not reflect the pattern of protein isoforms, and hence the inferred overall function of the receptor. PMID:20582266

  5. Mice with altered serotonin 2C receptor RNA editing display characteristics of Prader-Willi Syndrome

    PubMed Central

    Morabito, Michael V.; Abbas, Atheir I.; Hood, Jennifer L.; Kesterson, Robert A.; Jacobs, Michelle M.; Kump, David S.; Hachey, David L.; Roth, Bryan L.; Emeson, Ronald B.

    2010-01-01

    RNA transcripts encoding the 2C-subtype of serotonin (5HT2C) receptor undergo up to five adenosine-to-inosine editing events to encode twenty-four protein isoforms. To examine the effects of altered 5HT2C editing in vivo, we generated mutant mice solely expressing the fully-edited (VGV) isoform of the receptor. Mutant animals present phenotypic characteristics of Prader-Willi Syndrome (PWS) including a failure to thrive, decreased somatic growth, neonatal muscular hypotonia, and reduced food consumption followed by post-weaning hyperphagia. Though previous studies have identified alterations in both 5HT2C receptor expression and 5HT2C-mediated behaviors in both PWS patients and mouse models of this disorder, to our knowledge the 5HT2C gene is the first locus outside the PWS imprinted region in which mutations can phenocopy numerous aspects of this syndrome. These results not only strengthen the link between the molecular etiology of PWS and altered 5HT2C expression, but also demonstrate the importance of normal patterns of 5HT2C RNA editing in vivo. PMID:20394819

  6. Oligonucleotide-induced alternative splicing of serotonin 2C receptor reduces food intake.

    PubMed

    Zhang, Zhaiyi; Shen, Manli; Gresch, Paul J; Ghamari-Langroudi, Masoud; Rabchevsky, Alexander G; Emeson, Ronald B; Stamm, Stefan

    2016-01-01

    The serotonin 2C receptor regulates food uptake, and its activity is regulated by alternative pre-mRNA splicing. Alternative exon skipping is predicted to generate a truncated receptor protein isoform, whose existence was confirmed with a new antiserum. The truncated receptor sequesters the full-length receptor in intracellular membranes. We developed an oligonucleotide that promotes exon inclusion, which increases the ratio of the full-length to truncated receptor protein. Decreasing the amount of truncated receptor results in the accumulation of full-length, constitutively active receptor at the cell surface. After injection into the third ventricle of mice, the oligonucleotide accumulates in the arcuate nucleus, where it changes alternative splicing of the serotonin 2C receptor and increases pro-opiomelanocortin expression. Oligonucleotide injection reduced food intake in both wild-type and ob/ob mice. Unexpectedly, the oligonucleotide crossed the blood-brain barrier and its systemic delivery reduced food intake in wild-type mice. The physiological effect of the oligonucleotide suggests that a truncated splice variant regulates the activity of the serotonin 2C receptor, indicating that therapies aimed to change pre-mRNA processing could be useful to treat hyperphagia, characteristic for disorders like Prader-Willi syndrome. PMID:27406820

  7. Serotonergic modulation in neuropathy induced by oxaliplatin: effect on the 5HT2C receptor.

    PubMed

    Baptista-de-Souza, Daniela; Di Cesare Mannelli, Lorenzo; Zanardelli, Matteo; Micheli, Laura; Nunes-de-Souza, Ricardo Luiz; Canto-de-Souza, Azair; Ghelardini, Carla

    2014-07-15

    Fluoxetine has been shown to be effective in clinical and experimental studies of neuropathic pain. Besides to increase serotonin levels in the synaptic cleft, fluoxetine is able to block the serotonergic 5-HT2C receptor subtype, which in turn has been involved in the modulation of neuropathic pain. This study investigated the effect of repeated treatments with fluoxetine on the neuropathic nociceptive response induced by oxaliplatin and the effects of both treatments on 5-HT2C receptor mRNA expression and protein levels in the rat spinal cord (SC), rostral ventral medulla (RVM), midbrain periaqueductal gray (PAG) and amygdala (Amy). Nociception was assessed by paw-pressure, cold plate and Von Frey tests. Fluoxetine prevented mechanical hypersensitivity and pain threshold alterations induced by oxaliplatin but did not prevent the impairment in weight gain induced by this anticancer drug. Ex vivo analysis revealed that oxaliplatin increased the 5-HT2C receptor mRNA expression and protein levels in the SC and PAG. Similar effects were observed in fluoxetine-treated animals but only within the PAG. While oxaliplatin decreased the 5-HT2C mRNA expression levels in the Amy, fluoxetine increased their protein levels in this area. Fluoxetine impaired the oxaliplatin effects on the 5-HT2C receptor mRNA expression in the SC and Amy and protein levels in the SC. All treatments increased of 5-HT2C receptor mRNA expression and protein levels in the PAG. These results suggest that the effects of fluoxetine on neuropathic pain induced by oxaliplatin are associated with quantitative changes in the 5-HT2C receptors located within important areas of the nociceptive system.

  8. Dorsal raphe 5-HT(2C) receptor and GABA networks regulate anxiety produced by cocaine withdrawal.

    PubMed

    Craige, Caryne P; Lewandowski, Stacia; Kirby, Lynn G; Unterwald, Ellen M

    2015-06-01

    The serotonin system is intimately linked to both the mediation of anxiety and long-term effects of cocaine, potentially through interaction of inhibitory 5-HT2C receptor and gamma-aminobutyric acid (GABA) networks. This study characterized the function of the dorsal raphe (DR) 5-HT2C receptor and GABA network in anxiety produced by chronic cocaine withdrawal. C57BL/6 mice were injected with saline or cocaine (15 mg/kg) 3 times daily for 10 days, and tested on the elevated plus maze 30 min, 25 h, or 7 days after the last injection. Cocaine-withdrawn mice showed heightened anxiety-like behavior at 25 h of withdrawal, as compared to saline controls. Anxiety-like behavior was not different when mice were tested 30 min or 7 days after the last cocaine injection. Electrophysiology data revealed that serotonin cells from cocaine-withdrawn mice exhibited increased GABA inhibitory postsynaptic currents (IPSCs) in specific DR subregions dependent on withdrawal time (25 h or 7 d), an effect that was absent in cells from non-withdrawn mice (30 min after the last cocaine injection). Increased IPSC activity was restored to baseline levels following bath application of the 5-HT2C receptor antagonist, SB 242084. In a separate cohort of cocaine-injected mice at 25 h of withdrawal, both global and intra-DR blockade of 5-HT2C receptors prior to elevated plus maze testing attenuated anxiety-like behavior. This study demonstrates that DR 5-HT2C receptor blockade prevents anxiety-like behavior produced by cocaine withdrawal, potentially through attenuation of heightened GABA activity, supporting a role for the 5-HT2C receptor in mediating anxiety produced by cocaine withdrawal.

  9. Serotonin(2C) receptors in the ventral pallidum regulate motor function in rats.

    PubMed

    Graves, Steven M; Viskniskki, Annika A; Cunningham, Kathryn A; Napier, T Celeste

    2013-08-01

    The ventral pallidum is a limbic brain region that regulates motor function. This region is extensively innervated by serotoninergic neurons from the dorsal raphe nucleus. Serotonergic receptors, including the 5-HT(2C) receptor subtype, are located in the ventral pallidum. However, little is known regarding the behavioral consequences of serotonergic transmission in the ventral pallidum, and the role of 5-HT(2C) receptors has not been studied. To address this paucity, we measured the motoric consequences of injections of 0.33-10 ng of the 5-HT(2C) receptor agonist MK 212 into the ventral pallidum of adult male Sprague-Dawley rats. We determined that locomotor activity was attenuated by 6.6 ng MK 212, and rearing was attenuated by both 1 and 6.6 ng. The motor suppressant effects of MK 212 were lost at the higher dose of 10 ng, likely reflecting a loss of selectivity of this ligand. These findings indicate negative regulation of motor function by 5-HT(2C) receptors in the ventral pallidum.

  10. Therapeutic Potential of 5-HT2C Receptor Agonists for Addictive Disorders.

    PubMed

    Higgins, Guy A; Fletcher, Paul J

    2015-07-15

    The neurotransmitter 5-hydroxytryptamine (5-HT; serotonin) has long been associated with the control of a variety of motivated behaviors, including feeding. Much of the evidence linking 5-HT and feeding behavior was obtained from studies of the effects of the 5-HT releaser (dex)fenfluramine in laboratory animals and humans. Recently, the selective 5-HT2C receptor agonist lorcaserin received FDA approval for the treatment of obesity. This review examines evidence to support the use of selective 5-HT2C receptor agonists as treatments for conditions beyond obesity, including substance abuse (particularly nicotine, psychostimulant, and alcohol dependence), obsessive compulsive, and excessive gambling disorder. Following a brief survey of the early literature supporting a role for 5-HT in modulating food and drug reinforcement, we propose that intrinsic differences between SSRI and serotonin releasers may have underestimated the value of serotonin-based pharmacotherapeutics to treat clinical forms of addictive behavior beyond obesity. We then highlight the critical involvement of the 5-HT2C receptor in mediating the effect of (dex)fenfluramine on feeding and body weight gain and the evidence that 5-HT2C receptor agonists reduce measures of drug reward and impulsivity. A recent report of lorcaserin efficacy in a smoking cessation trial further strengthens the idea that 5-HT2C receptor agonists may have potential as a treatment for addiction. This review was prepared as a contribution to the proceedings of the 11th International Society for Serotonin Research Meeting held in Hermanus, South Africa, July 9-12, 2014.

  11. Activation of 5-HT2A/2C receptors reduces the excitability of cultured cortical neurons.

    PubMed

    Hu, Lingli; Liu, Chunhua; Dang, Minyan; Luo, Bin; Guo, Yiping; Wang, Haitao

    2016-10-01

    The abundant forebrain serotonergic projections are believed to modulate the activities of cortical neurons. 5-HT2 receptor among multiple subtypes of serotonin receptors contributes to the modulation of excitability, synaptic transmissions and plasticity. In the present study, whole-cell patch-clamp recording was adopted to examine whether activation of 5-HT2A/2C receptors would have any impact on the excitability of cultured cortical neurons. We found that 2,5-Dimethoxy-4-iodoamphetamine (DOI), a selective 5-HT2A/2C receptor agonist, rapidly and reversibly depressed spontaneous action potentials mimicking the effect of serotonin. The decreased excitability was also observed for current-evoked firing. Additionally DOI increased neuronal input resistance. Hyperpolarization-activated cyclic nucleotide-gated cationic channels (HCN) did not account for the inhibition of spontaneous firing. The synaptic contribution was ruled out in that DOI augmented excitation and attenuated inhibition to actually favor an increase in the excitability. Our findings revealed that activation of 5-HT2A/2C receptors reduces neuronal excitability, which would deepen our understanding of serotonergic modulation of cortical activities. PMID:27585751

  12. Design, Synthesis, and Evaluation of Tetrasubstituted Pyridines as Potent 5-HT2C Receptor Agonists

    PubMed Central

    2015-01-01

    A series of pyrido[3,4-d]azepines that are potent and selective 5-HT2C receptor agonists is disclosed. Compound 7 (PF-04781340) is identified as a suitable lead owing to good 5-HT2C potency, selectivity over 5-HT2B agonism, and in vitro ADME properties commensurate with an orally available and CNS penetrant profile. The synthesis of a novel bicyclic tetrasubstituted pyridine core template is outlined, including rationale to account for the unexpected formation of aminopyridine 13 resulting from an ammonia cascade cyclization. PMID:25815155

  13. CRF Type 2 Receptors Mediate the Metabolic Effects of Ghrelin in C2C12 cells

    PubMed Central

    Gershon, Eran; Vale, Wylie W

    2014-01-01

    Objective Ghrelin is known to regulate appetite control and cellular metabolism. The Corticotropin-Releasing Factor (CRF) family is also known to regulate energy balance. In this study, we investigated the links between ghrelin and the CRF family in C2C12 cells, a mouse myoblast cell line. Design and methods C2C12 cells were treated with ghrelin in the presence or absence of CRF receptor antagonists and then subjected to different metabolic analyses. Results Ghrelin enhanced glucose uptake by C2C12 cells, induced GLUT4 translocation to the cell surface and decreased RBP4 expression. A CRF-R2 selective antagonist, anti-sauvagine-30, blocked ghrelin-induced glucose uptake, Ghrelin upregulated CRF-R2 but not CRF-R1 levels. Moreover, ghrelin-treated C2C12 cells displayed a cAMP and pERK activation in response to Ucn3, a CRF-R2 specific ligand, but not in response to CRF or stressin, CRF-R1 specific ligands. Ghrelin also induced UCP2 and UCP3 expression, which were blocked by anti-sauvagine-30. Ghrelin did not induce fatty acids uptake by C2C12 cells or ACC expression. Even though C2C12 cells clearly exhibited responses to ghrelin, the known ghrelin receptor, GHSR1a, was not detectable in C2C12 cells. Conclusion Our results suggest that, ghrelin plays a role in regulating muscle glucose and, raise the possibility that suppression of the CRF-R2 pathway might provide benefits in high ghrelin states. PMID:23804489

  14. SB 242084, a selective and brain penetrant 5-HT2C receptor antagonist.

    PubMed

    Kennett, G A; Wood, M D; Bright, F; Trail, B; Riley, G; Holland, V; Avenell, K Y; Stean, T; Upton, N; Bromidge, S; Forbes, I T; Brown, A M; Middlemiss, D N; Blackburn, T P

    1997-01-01

    SB 242084 has a high affinity (pKi 9.0) for the cloned human 5-HT2C receptor and 100- and 158-fold selectivity over the closely related cloned human 5-HT2B and 5-HT2A subtypes respectively. SB 242084 had over 100-fold selectivity over a range of other 5-HT, dopamine and adrenergic receptors. In studies of 5-HT-stimulated phosphatidylinositol hydrolysis using SH-SY5Y cells stably expressing the cloned human 5-HT2C receptor, SB 242084 acted as an antagonist with a pKb of 9.3, which closely resembled its corresponding receptor binding affinity. SB 242084 potently inhibited m-chlorophenylpiperazine (mCPP, 7 mgkg i.p. 20 min pre-test)-induced hypolocomotion in rats, a model of in vivo central 5-HT2C receptor function, with an ID50 of 0.11 mg/kg i.p., and 2.0 mg/kg p.o. SB 242084 (0.1-1 mg/kg i.p.) exhibited an anxiolytic-like profile in the rat social interaction test, increasing time spent in social interaction, but having no effect on locomotion. SB 242084 (0.1-1 mg/kg i.p.) also markedly increased punished responding in a rat Geller-Seifter conflict test of anxiety, but had no consistent effect on unpunished responding. A large acute dose of SB 242084 (30 mg/kg p.o.) had no effect on seizure susceptibility in the rat maximal electroshock seizure threshold test. Also, while SB 242084 (2 and 6 mg/kg p.o. 1 hr pre-test) antagonized the hypophagic response to mCPP, neither acute nor subchronic administration of the drug, for 5 days at 2 or 6 mg/kg p.o. twice daily, affected food intake or weight gain. The results suggest that SB 242084 is the first reported selective potent and brain penetrant 5-HT2C receptor antagonist and has anxiolytic-like activity, but does not possess either proconvulsant or hyperphagic properties which are characteristic of mutant mice lacking the 5-HT2C receptor. PMID:9225286

  15. Identification of a cys-ser substitution in the 5-HT{sub 2C} (HTR2C) receptor gene and allelic association to violent behavior and alcoholism

    SciTech Connect

    Lappalainen, J.; Ozaki, N.; Goldman, D.

    1994-09-01

    Several lines of evidence suggest that brain serotonergic functions, including behavioral and neurochemical responses to 5-HT{sub 2C} agonist, are abnormal in some individuals with alcoholism and aggressive behaviors. The aim of the present study was to identify coding sequence variants in the human 5-HT{sub 2C} receptor gene which may cause abnormal or variant function of this receptor. Using SSCP analysis, a non-conservative cys-ser substitution was found in the 5-HT{sub 2C} receptor (designated 5-HT{sub 2Ccys} and 5-HT{sub 2Cser}). The polymorphism was typed in CEPH families to genetically map the gene. To test for association of the variant to alcoholism, violent behavior and serotonin function, the 5-HT{sub 2C} genotypes of 151 non-related Finnish male alcoholic violent offenders and impulsive fire setters and 127 Finnish psychiatrically interviewed healthy male volunteers were determined. CSF 5-HIAA concentrations were available for 74 alcoholic violent offenders and 25 healthy volunteers. Linkage analysis placed the 5-HT{sub 2C} gene on Xq21, a region that has been previously shown to contain genes for several mental retardation syndromes. The 5-HT{sub 2Ccys}/5-HT{sub 2Cser} genotype frequencies in alcoholic violent offenders and controls differed significantly (0.90/0.10 and 0.82/0.18, respectively, P=0.048). The association was found to be strongest in the violent offenders who did not fulfill the criteria for antisocial personality disorder (5-HT{sub 2Ccys}/5-HT{sub 2Cser} 0.93/0.07, p=0.021). No association was found between CSF 5-HIAA concentrations and 5-HT{sub 2C} genotype. These results implicate a 5-HT{sub 2C} receptor amino acid substitution in predisposition to alcohol abuse and violent behavior in a subgroup of alcoholics.

  16. Serotonin 2C receptor antagonists induce fast-onset antidepressant effects.

    PubMed

    Opal, M D; Klenotich, S C; Morais, M; Bessa, J; Winkle, J; Doukas, D; Kay, L J; Sousa, N; Dulawa, S M

    2014-10-01

    Current antidepressants must be administered for several weeks to produce therapeutic effects. We show that selective serotonin 2C (5-HT2C) antagonists exert antidepressant actions with a faster-onset (5 days) than that of current antidepressants (14 days) in mice. Subchronic (5 days) treatment with 5-HT2C antagonists induced antidepressant behavioral effects in the chronic forced swim test (cFST), chronic mild stress (CMS) paradigm and olfactory bulbectomy paradigm. This treatment regimen also induced classical markers of antidepressant action: activation of cAMP response element-binding protein (CREB) and induction of brain-derived neurotrophic factor (BDNF) in the medial prefrontal cortex (mPFC). None of these effects were induced by subchronic treatment with citalopram, a prototypical selective serotonin reuptake inhibitor (SSRI). Local infusion of 5-HT2C antagonists into the ventral tegmental area was sufficient to induce BDNF in the mPFC, and dopamine D1 receptor antagonist treatment blocked the antidepressant behavioral effects of 5-HT2C antagonists. 5-HT2C antagonists also activated mammalian target of rapamycin (mTOR) and eukaryotic elongation factor 2 (eEF2) in the mPFC, effects recently linked to rapid antidepressant action. Furthermore, 5-HT2C antagonists reversed CMS-induced atrophy of mPFC pyramidal neurons. Subchronic SSRI treatment, which does not induce antidepressant behavioral effects, also activated mTOR and eEF2 and reversed CMS-induced neuronal atrophy, indicating that these effects are not sufficient for antidepressant onset. Our findings reveal that 5-HT2C antagonists are putative fast-onset antidepressants, which act through enhancement of mesocortical dopaminergic signaling. PMID:24166413

  17. Support for 5-HT2C receptor functional selectivity in vivo utilizing structurally diverse, selective 5-HT2C receptor ligands and the 2,5-dimethoxy-4-iodoamphetamine elicited head-twitch response model

    PubMed Central

    Canal, Clinton E.; Booth, Raymond G.; Morgan, Drake

    2013-01-01

    There are seemingly conflicting data in the literature regarding the role of serotonin (5-HT) 5-HT2C receptors in the mouse head-twitch response (HTR) elicited by the hallucinogenic 5-HT2A/2B/2C receptor agonist 2,5-dimethoxy-4-iodoamphetamine (DOI). Namely, both 5-HT2C receptor agonists and antagonists, regarding 5-HT2C receptor-mediated Gq-phospholipase C (PLC) signaling, reportedly attenuate the HTR response. The present experiments tested the hypothesis that both classes of 5-HT2C receptor compounds could attenuate the DOI-elicited-HTR in a single strain of mice, C57Bl/6J. The expected results were considered in accordance with ligand functional selectivity. Commercially-available 5-HT2C agonists (CP 809101, Ro 60-0175, WAY 161503, mCPP, and 1-methylpsilocin), novel 4-phenyl-2-N,N-dimethyl-aminotetralin (PAT)-type 5-HT2C agonists (with 5-HT2A/2B antagonist activity), and antagonists selective for 5-HT2A (M100907), 5-HT2C (SB-242084), and 5-HT2B/2C (SB-206553) receptors attenuated the DOI-elicited-HTR. In contrast, there were differential effects on locomotion across classes of compounds. The 5-HT2C agonists and M100907 decreased locomotion, SB-242084 increased locomotion, SB-206553 resulted in dose-dependent biphasic effects on locomotion, and the PATs did not alter locomotion. In vitro molecular pharmacology studies showed that 5-HT2C agonists potent for attenuating the DOI-elicited-HTR also reduced the efficacy of DOI to activate mouse 5-HT2C receptor-mediated PLC signaling in HEK cells. Although there were differences in affinities of a few compounds at mouse compared to human 5-HT2A or 5-HT2C receptors, all compounds tested retained their selectivity for either receptor, regardless of receptor species. Results indicate that 5-HT2C receptor agonists and antagonists attenuate the DOI-elicited-HTR in C57Bl/6J mice, and suggest that structurally diverse 5-HT2C ligands result in different 5-HT2C receptor signaling outcomes compared to DOI. PMID:23353901

  18. The serotonin 5-HT2A and 5-HT2C receptors interact with specific sets of PDZ proteins.

    PubMed

    Bécamel, Carine; Gavarini, Sophie; Chanrion, Benjamin; Alonso, Gérard; Galéotti, Nathalie; Dumuis, Aline; Bockaert, Joël; Marin, Philippe

    2004-05-01

    The 5-hydroxytryptamine type 2A (5-HT(2A)) receptor and the 5-HT(2C) receptor are closely related members of the G-protein-coupled receptors activated by serotonin that share very similar pharmacological profiles and cellular signaling pathways. These receptors express a canonical class I PDZ ligand (SXV) at their C-terminal extremity. Here, we have identified proteins that interact with the PDZ ligand of the 5-HT(2A) and 5-HT(2C) receptors by a proteomic approach associating affinity chromatography using immobilized synthetic peptides encompassing the PDZ ligand and mass spectrometry. We report that both receptor C termini interact with specific sets of PDZ proteins in vitro. The 5-HT(2C) receptor but not the 5-HT(2A) receptor binds to the Veli-3.CASK.Mint1 ternary complex and to SAP102. In addition, the 5-HT(2C) receptor binds more strongly to PSD-95 and MPP-3 than the 5-HT(2A) receptor. In contrast, a robust interaction between the 5-HT(2A) receptor and the channel-interacting PDZ protein CIPP was found, whereas CIPP did not significantly associate with the 5-HT(2C) receptor. We also show that residues located at the -1 position and upstream the PDZ ligand in the C terminus of the 5-HT(2A) and 5-HT(2C) receptors are major determinants in their interaction with specific PDZ proteins. Immunofluorescence and electron microscopy studies strongly suggested that these specific interactions also take place in living cells and that the 5-HT(2) receptor-PDZ protein complexes occur in intracellular compartments. The interaction of the 5-HT(2A) and the 5-HT(2C) receptor with specific sets of PDZ proteins may contribute to their different signal transduction properties.

  19. Designed abscisic acid analogs as antagonists of PYL-PP2C receptor interactions.

    PubMed

    Takeuchi, Jun; Okamoto, Masanori; Akiyama, Tomonori; Muto, Takuya; Yajima, Shunsuke; Sue, Masayuki; Seo, Mitsunori; Kanno, Yuri; Kamo, Tsunashi; Endo, Akira; Nambara, Eiji; Hirai, Nobuhiro; Ohnishi, Toshiyuki; Cutler, Sean R; Todoroki, Yasushi

    2014-06-01

    The plant stress hormone abscisic acid (ABA) is critical for several abiotic stress responses. ABA signaling is normally repressed by group-A protein phosphatases 2C (PP2Cs), but stress-induced ABA binds Arabidopsis PYR/PYL/RCAR (PYL) receptors, which then bind and inhibit PP2Cs. X-ray structures of several receptor-ABA complexes revealed a tunnel above ABA's 3' ring CH that opens at the PP2C binding interface. Here, ABA analogs with sufficiently long 3' alkyl chains were predicted to traverse this tunnel and block PYL-PP2C interactions. To test this, a series of 3'-alkylsulfanyl ABAs were synthesized with different alkyl chain lengths. Physiological, biochemical and structural analyses revealed that a six-carbon alkyl substitution produced a potent ABA antagonist that was sufficiently active to block multiple stress-induced ABA responses in vivo. This study provides a new approach for the design of ABA analogs, and the results validated structure-based design for this target class. PMID:24792952

  20. Designed abscisic acid analogs as antagonists of PYL-PP2C receptor interactions.

    PubMed

    Takeuchi, Jun; Okamoto, Masanori; Akiyama, Tomonori; Muto, Takuya; Yajima, Shunsuke; Sue, Masayuki; Seo, Mitsunori; Kanno, Yuri; Kamo, Tsunashi; Endo, Akira; Nambara, Eiji; Hirai, Nobuhiro; Ohnishi, Toshiyuki; Cutler, Sean R; Todoroki, Yasushi

    2014-06-01

    The plant stress hormone abscisic acid (ABA) is critical for several abiotic stress responses. ABA signaling is normally repressed by group-A protein phosphatases 2C (PP2Cs), but stress-induced ABA binds Arabidopsis PYR/PYL/RCAR (PYL) receptors, which then bind and inhibit PP2Cs. X-ray structures of several receptor-ABA complexes revealed a tunnel above ABA's 3' ring CH that opens at the PP2C binding interface. Here, ABA analogs with sufficiently long 3' alkyl chains were predicted to traverse this tunnel and block PYL-PP2C interactions. To test this, a series of 3'-alkylsulfanyl ABAs were synthesized with different alkyl chain lengths. Physiological, biochemical and structural analyses revealed that a six-carbon alkyl substitution produced a potent ABA antagonist that was sufficiently active to block multiple stress-induced ABA responses in vivo. This study provides a new approach for the design of ABA analogs, and the results validated structure-based design for this target class.

  1. Characterization of the NR1, NR2A, and NR2C receptor proteins.

    PubMed Central

    Köpke, A. K.; Bonk, I.; Sydow, S.; Menke, H.; Spiess, J.

    1993-01-01

    N-Methyl-D-aspartate (NMDA) receptor subunits were characterized with seven polyclonal antibodies. The antibodies were directed against NR1-A, NR2A-N1, and NR2C-N1, representing N-terminal sequences of the NR1, NR2A, and NR2C subunits, and against NR1-E, NR2A-C1, and NR2C-C1, derived from C-terminal sequences of these subunits. The anti-NR1-D antibody was raised against the putative internal loop of NR1. A size of 118 kDa was found in sodium dodecyl sulfate-polyacrylamide gel electrophoresis for NR1 (from rat brain) detected by anti-NR1-D and -NR1-E, but not anti-NR1-A. With the anti-NR1-A antibody, a 125-kDa protein was discovered that may represent a glutamate receptor not yet characterized. NR2A and NR2C were identified as proteins with sizes of 175 and 140 kDa, respectively. Enzymatic N-deglycosylation generated a 97-kDa protein from NR1, a 105-kDa protein from the 125-kDa protein, a 162-kDa protein from NR2A, and a 127-kDa protein from NR2C. In contrast to the deglycosylation product of the NR2A, the 97- and 127-kDa proteins derived from NR1 and NR2C, respectively, were found significantly smaller than the molecular masses of 103 and 141 kDa, respectively, predicted on the basis of DNA data. These products may represent truncated proteins. The tissue content of the NR1 and NR2A was high in bovine hippocampus and cortex but lower in the cerebellum. In contrast, NR2C was solely found in the cerebellum. The 125-kDa protein was highest in the cerebellum and cortex. PMID:8298456

  2. Effects of Angiotensin II Receptor Blockers on Metabolism of Arachidonic Acid via CYP2C8.

    PubMed

    Senda, Asuna; Mukai, Yuji; Toda, Takaki; Hayakawa, Toru; Yamashita, Miki; Eliasson, Erik; Rane, Anders; Inotsume, Nobuo

    2015-01-01

    Arachidonic acid (AA) is metabolized to epoxyeicosatrienoic acids (EETs) via cytochrome enzymes such as CYP 2C9, 2C8 and 2J2. EETs play a role in cardioprotection and regulation of blood pressure. Recently, adverse reactions such as sudden heart attack and fatal myocardial infarction were reported among patients taking angiotensin II receptor blockers (ARBs). As some ARBs have affinity for these CYP enzymes, metabolic inhibition of AA by ARBs is a possible cause for the increase in cardiovascular events. In this study, we quantitatively investigated the inhibitory effects of ARBs on the formation of EETs and further metabolites, dihydroxyeicosatrienoic acids (DHETs), from AA via CYP2C8. In incubations with recombinant CYP2C8 in vitro, the inhibitory effects were compared by measuring EETs and DHETs by HPLC-MS/MS. Inhibition of AA metabolism by ARBs was detected in a concentration-dependent manner with IC50 values of losartan (42.7 µM), telmisartan (49.5 µM), irbesartan (55.6 µM), olmesartan (66.2 µM), candesartan (108 µM), and valsartan (279 µM). Losartan, telmisartan and irbesartan, which reportedly accumulate in the liver and kidneys, have stronger inhibitory effects than other ARBs. The lower concentration of EETs leads to less protective action on the cardiovascular system and a higher incidence of adverse effects such as sudden heart attack and myocardial infarction in patients taking ARBs. PMID:26632190

  3. The serotonin 2C receptor potently modulates the head-twitch response in mice induced by a phenethylamine hallucinogen

    PubMed Central

    Canal, Clinton E.; Olaghere da Silva, Uade B.; Gresch, Paul J.; Watt, Erin E.; Sanders-Bush, Elaine

    2010-01-01

    Rationale Hallucinogenic serotonin 2A (5-HT2A) receptor partial agonists, such as (±)-1-(2,5-dimethoxy-4-iodo-phenyl)-2-aminopropane hydrochloride (DOI), induce a frontal cortex-dependent head-twitch response (HTR) in rodents, a behavioral proxy of a hallucinogenic response that is blocked by 5-HT2A receptor antagonists. In addition to 5-HT2A receptors, DOI and most other serotonin-like hallucinogens have high affinity and potency as partial agonists at 5-HT2C receptors. Objectives We tested for involvement of 5-HT2C receptors in the HTR induced by DOI. Results Comparison of 5-HT2C receptor knockout and wild-type littermates revealed an approximately 50% reduction in DOI-induced HTR in knockout mice. Also, pretreatment with either the 5-HT2C receptor antagonist SB206553 or SB242084 eradicated a twofold difference in DOI-induced HTR between the standard inbred mouse strains C57BL/6J and DBA/2J, and decreased the DOI-induced HTR by at least 50% in both strains. None of several measures of 5-HT2A receptors in frontal cortex explained the strain difference, including 5-HT2A receptor density, Gαq or Gαi/o protein levels, phospholipase C activity, or DOI-induced expression of Egr1 and Egr2. 5-HT2C receptor density in the brains of C57BL/6J and DBA/2J was also equivalent, suggesting that 5-HT2C receptor-mediated intracellular signaling or other physiological modulators of the HTR may explain the strain difference in response to DOI. Conclusions We conclude that the HTR to DOI in mice is strongly modulated by 5-HT2C receptor activity. This novel finding invites reassessment of hallucinogenic mechanisms involving 5-HT2 receptors. PMID:20165943

  4. Human alpha 2-adrenergic receptor subtype distribution: widespread and subtype-selective expression of alpha 2C10, alpha 2C4, and alpha 2C2 mRNA in multiple tissues.

    PubMed

    Eason, M G; Liggett, S B

    1993-07-01

    At present, molecular cloning and pharmacological studies have delineated three human alpha 2-adrenergic receptor (alpha 2AR) subtypes, alpha 2C10, alpha 2C4, and alpha 2C2. Assignment of the alpha 2AR subtypes to specific functions has been limited by an unclear definition of tissue alpha 2AR expression outside of the central nervous system. It has been suggested that alpha 2C4 expression is confined to the brain, that alpha 2C2 expression is only in the liver and kidney, and that there is nearly ubiquitous expression of alpha 2C10. However, this is based on studies of a limited number of rat tissues or on studies using non-species-specific approaches. Therefore, to define alpha 2C10, alpha 2C4, and alpha 2C2 tissue expression, we used reverse transcription of total RNA isolated from 20 human tissues, followed by amplification of alpha 2AR cDNA using the polymerase chain reaction. This technique provided two advantages: high sensitivity and, with the use of subtype-specific oligonucleotide primers and probes, differentiation between the alpha 2AR subtypes. The tissues studied were aorta, vena cava, heart (epicardium and endocardium), lung, skeletal muscle, liver, pancreas (head and tail), fat (perinephric and subcutaneous), kidney (cortex and medulla), prostate, stomach, ileum, jejunum, colon, adrenal gland, and spleen. We found that the majority of these tissues expressed alpha 2C10, with the exceptions being the head of the pancreas, subcutaneous fat, colon, and spleen. In marked distinction to other studies, however, we found a prolific expression of the alpha 2C4 and alpha 2C2 subtypes. Expression of alpha 2C4 was found in all tissues with the exception of liver, fat, stomach, and colon, and a virtually ubiquitous expression of alpha 2C2 was found, with the exception of epicardium. Of all tissues studied, only colon and subcutaneous fat expressed a single alpha 2AR subtype, which was alpha 2C2. Thus, the alpha 2AR subtypes do not have a confined expression but

  5. Human alpha 2-adrenergic receptor subtype distribution: widespread and subtype-selective expression of alpha 2C10, alpha 2C4, and alpha 2C2 mRNA in multiple tissues.

    PubMed

    Eason, M G; Liggett, S B

    1993-07-01

    At present, molecular cloning and pharmacological studies have delineated three human alpha 2-adrenergic receptor (alpha 2AR) subtypes, alpha 2C10, alpha 2C4, and alpha 2C2. Assignment of the alpha 2AR subtypes to specific functions has been limited by an unclear definition of tissue alpha 2AR expression outside of the central nervous system. It has been suggested that alpha 2C4 expression is confined to the brain, that alpha 2C2 expression is only in the liver and kidney, and that there is nearly ubiquitous expression of alpha 2C10. However, this is based on studies of a limited number of rat tissues or on studies using non-species-specific approaches. Therefore, to define alpha 2C10, alpha 2C4, and alpha 2C2 tissue expression, we used reverse transcription of total RNA isolated from 20 human tissues, followed by amplification of alpha 2AR cDNA using the polymerase chain reaction. This technique provided two advantages: high sensitivity and, with the use of subtype-specific oligonucleotide primers and probes, differentiation between the alpha 2AR subtypes. The tissues studied were aorta, vena cava, heart (epicardium and endocardium), lung, skeletal muscle, liver, pancreas (head and tail), fat (perinephric and subcutaneous), kidney (cortex and medulla), prostate, stomach, ileum, jejunum, colon, adrenal gland, and spleen. We found that the majority of these tissues expressed alpha 2C10, with the exceptions being the head of the pancreas, subcutaneous fat, colon, and spleen. In marked distinction to other studies, however, we found a prolific expression of the alpha 2C4 and alpha 2C2 subtypes. Expression of alpha 2C4 was found in all tissues with the exception of liver, fat, stomach, and colon, and a virtually ubiquitous expression of alpha 2C2 was found, with the exception of epicardium. Of all tissues studied, only colon and subcutaneous fat expressed a single alpha 2AR subtype, which was alpha 2C2. Thus, the alpha 2AR subtypes do not have a confined expression but

  6. Controversies on the role of 5-HT(2C) receptors in the mechanisms of action of antidepressant drugs.

    PubMed

    Martin, Cedric B P; Hamon, Michel; Lanfumey, Laurence; Mongeau, Raymond

    2014-05-01

    Evidence from the various sources indicates alterations in 5-HT2C receptor functions in anxiety, depression and suicide, and other stress-related disorders treated with antidepressant drugs. Although the notion of a 5-HT2C receptor desensitization following antidepressant treatments is rather well anchored in the literature, this concept is mainly based on in vitro assays and/or behavioral assays (hypolocomotion, hyperthermia) that have poor relevance to anxio-depressive disorders. Our objective herein is to provide a comprehensive overview of the studies that have assessed the effects of antidepressant drugs on 5-HT2C receptors. Relevant molecular (second messengers, editing), neurochemical (receptor binding and mRNA levels), physiological (5-HT2C receptor-induced hyperthermia and hormone release), behavioral (5-HT2C receptor-induced changes in feeding, anxiety, defense and motor activity) data are summarized and discussed. Setting the record straight about drug-induced changes in 5-HT2C receptor function in specific brain regions should help to determine which pharmacotherapeutic strategy is best for affective and anxiety disorders. PMID:24631644

  7. Native Serotonin 5-HT2C Receptors Are Expressed as Homodimers on the Apical Surface of Choroid Plexus Epithelial Cells

    PubMed Central

    Grinde, Ellinor; Lindsley, Tara; Teitler, Milt; Mancia, Filippo; Cowan, Ann; Mazurkiewicz, Joseph E.

    2015-01-01

    G protein–coupled receptors (GPCRs) are a prominent class of plasma membrane proteins that regulate physiologic responses to a wide variety of stimuli and therapeutic agents. Although GPCR oligomerization has been studied extensively in recombinant cells, it remains uncertain whether native receptors expressed in their natural cellular environment are monomers, dimers, or oligomers. The goal of this study was to determine the monomer/oligomer status of a native GPCR endogenously expressed in its natural cellular environment. Native 5-HT2C receptors in choroid plexus epithelial cells were evaluated using fluorescence correlation spectroscopy (FCS) with photon counting histogram (PCH). An anti–5-HT2C fragment antigen binding protein was used to label native 5-HT2C receptors. A known monomeric receptor (CD-86) served as a control for decoding the oligomer status of native 5-HT2C receptors by molecular brightness analysis. FCS with PCH revealed molecular brightness values for native 5-HT2C receptors equivalent to the molecular brightness of a homodimer. 5-HT2C receptors displayed a diffusion coefficient of 5 × 10−9 cm2/s and were expressed at 32 receptors/μm2 on the apical surface of choroid plexus epithelial cells. The functional significance and signaling capabilities of the homodimer were investigated in human embryonic kidney 293 cells using agonists that bind in a wash-resistant manner to one or both protomers of the homodimer. Whereas agonist binding to one protomer resulted in G protein activation, maximal stimulation required occupancy of both protomers. This study is the first to demonstrate the homodimeric structure of 5-HT2C receptors endogenously expressed in their native cellular environment, and identifies the homodimer as a functional signaling unit. PMID:25609374

  8. Genotype-Dependent Difference in 5-HT2C Receptor-Induced Hypolocomotion: Comparison with 5-HT2A Receptor Functional Activity

    PubMed Central

    Bazovkina, Darya V.; Kondaurova, Elena M.; Naumenko, Vladimir S.; Ponimaskin, Evgeni

    2015-01-01

    In the present study behavioral effects of the 5-HT2C serotonin receptor were investigated in different mouse strains. The 5-HT2C receptor agonist MK-212 applied intraperitoneally induced significant dose-dependent reduction of distance traveled in the open field test in CBA/Lac mice. This effect was receptor-specific because it was inhibited by the 5-HT2C receptor antagonist RS102221. To study the role of genotype in 5-HT2C receptor-induced hypolocomotion, locomotor activity of seven inbred mouse strains was measured after MK-212 acute treatment. We found that the 5-HT2C receptor stimulation by MK-212 decreased distance traveled in the open field test in CBA/Lac, C57Bl/6, C3H/He, and ICR mice, whereas it failed to affect locomotor activity in DBA/2J, Asn, and Balb/c mice. We also compared the interstrain differences in functional response to 5-HT2C and 5-HT2A receptors activation measured by the quantification of receptor-mediated head-twitches. These experiments revealed significant positive correlation between 5-HT2C and 5-HT2A receptors functional responses for all investigated mouse strains. Moreover, we found that 5-HT2A receptor activation with DOI did not change locomotor activity in CBA/Lac mice. Taken together, our data indicate the implication of 5-HT2C receptors in regulation of locomotor activity and suggest the shared mechanism for functional responses mediated by 5-HT2C and 5-HT2A receptors. PMID:26380122

  9. Genotype-Dependent Difference in 5-HT2C Receptor-Induced Hypolocomotion: Comparison with 5-HT2A Receptor Functional Activity.

    PubMed

    Bazovkina, Darya V; Kondaurova, Elena M; Naumenko, Vladimir S; Ponimaskin, Evgeni

    2015-01-01

    In the present study behavioral effects of the 5-HT2C serotonin receptor were investigated in different mouse strains. The 5-HT2C receptor agonist MK-212 applied intraperitoneally induced significant dose-dependent reduction of distance traveled in the open field test in CBA/Lac mice. This effect was receptor-specific because it was inhibited by the 5-HT2C receptor antagonist RS102221. To study the role of genotype in 5-HT2C receptor-induced hypolocomotion, locomotor activity of seven inbred mouse strains was measured after MK-212 acute treatment. We found that the 5-HT2C receptor stimulation by MK-212 decreased distance traveled in the open field test in CBA/Lac, C57Bl/6, C3H/He, and ICR mice, whereas it failed to affect locomotor activity in DBA/2J, Asn, and Balb/c mice. We also compared the interstrain differences in functional response to 5-HT2C and 5-HT2A receptors activation measured by the quantification of receptor-mediated head-twitches. These experiments revealed significant positive correlation between 5-HT2C and 5-HT2A receptors functional responses for all investigated mouse strains. Moreover, we found that 5-HT2A receptor activation with DOI did not change locomotor activity in CBA/Lac mice. Taken together, our data indicate the implication of 5-HT2C receptors in regulation of locomotor activity and suggest the shared mechanism for functional responses mediated by 5-HT2C and 5-HT2A receptors. PMID:26380122

  10. Genotype-Dependent Difference in 5-HT2C Receptor-Induced Hypolocomotion: Comparison with 5-HT2A Receptor Functional Activity.

    PubMed

    Bazovkina, Darya V; Kondaurova, Elena M; Naumenko, Vladimir S; Ponimaskin, Evgeni

    2015-01-01

    In the present study behavioral effects of the 5-HT2C serotonin receptor were investigated in different mouse strains. The 5-HT2C receptor agonist MK-212 applied intraperitoneally induced significant dose-dependent reduction of distance traveled in the open field test in CBA/Lac mice. This effect was receptor-specific because it was inhibited by the 5-HT2C receptor antagonist RS102221. To study the role of genotype in 5-HT2C receptor-induced hypolocomotion, locomotor activity of seven inbred mouse strains was measured after MK-212 acute treatment. We found that the 5-HT2C receptor stimulation by MK-212 decreased distance traveled in the open field test in CBA/Lac, C57Bl/6, C3H/He, and ICR mice, whereas it failed to affect locomotor activity in DBA/2J, Asn, and Balb/c mice. We also compared the interstrain differences in functional response to 5-HT2C and 5-HT2A receptors activation measured by the quantification of receptor-mediated head-twitches. These experiments revealed significant positive correlation between 5-HT2C and 5-HT2A receptors functional responses for all investigated mouse strains. Moreover, we found that 5-HT2A receptor activation with DOI did not change locomotor activity in CBA/Lac mice. Taken together, our data indicate the implication of 5-HT2C receptors in regulation of locomotor activity and suggest the shared mechanism for functional responses mediated by 5-HT2C and 5-HT2A receptors.

  11. Mice Lacking Serotonin 2C Receptors Have increased Affective Responses to Aversive Stimuli

    PubMed Central

    Bonasera, Stephen J.; Schenk, A. Katrin; Luxenberg, Evan J.; Wang, Xidao; Basbaum, Allan; Tecott, Laurence H.

    2015-01-01

    Although central serotonergic systems are known to influence responses to noxious stimuli, mechanisms underlying serotonergic modulation of pain responses are unclear. We proposed that serotonin 2C receptors (5-HT2CRs), which are expressed within brain regions implicated in sensory and affective responses to pain, contribute to the serotonergic modulation of pain responses. In mice constitutively lacking 5-HT2CRs (2CKO mice) we found normal baseline sensory responses to noxious thermal, mechanical and chemical stimuli. In contrast, 2CKO mice exhibited a selective enhancement of affect-related ultrasonic afterdischarge vocalizations in response to footshock. Enhanced affect-related responses to noxious stimuli were also exhibited by 2CKO mice in a fear-sensitized startle assay. The extent to which a brief series of unconditioned footshocks produced enhancement of acoustic startle responses was markedly increased in 2CKO mice. As mesolimbic dopamine pathways influence affective responses to noxious stimuli, and these pathways are disinhibited in 2CKO mice, we examined the sensitivity of footshock-induced enhancement of startle to dopamine receptor blockade. Systemic administration of the dopamine D2/D3 receptor antagonist raclopride selectively reduced footshock-induced enhancement of startle without influencing baseline acoustic startle responses. We propose that 5-HT2CRs regulate affective behavioral responses to unconditioned aversive stimuli through mechanisms involving the disinhibition of ascending dopaminergic pathways. PMID:26630489

  12. RNA splicing and editing modulation of 5-HT(2C) receptor function: relevance to anxiety and aggression in VGV mice.

    PubMed

    Martin, C B P; Ramond, F; Farrington, D T; Aguiar, A S; Chevarin, C; Berthiau, A-S; Caussanel, S; Lanfumey, L; Herrick-Davis, K; Hamon, M; Madjar, J J; Mongeau, R

    2013-06-01

    Changes in serotonin(2C) receptor (5-HTR2c) editing, splicing and density were found in conditions such as depression and suicide, but mechanisms explaining the changes in 5-HTR2c function are unknown. Thus, mice expressing only the fully edited VGV isoform of 5-HTR2c, in which clinically relevant behavioral changes are associated with alterations in splicing and receptor density, were studied. VGV mice displayed enhanced anxiety-like behavior in response to a preferential 5-HTR2c agonist in the social interaction test. Nearly half of interactions between pairs of VGV congeners consisted of fighting behaviors, whereas no fighting occurred in wild-type (WT) mice. VGV mice also exhibited a striking increase in freezing behaviors in reaction to an innately aversive ultrasonic stimulus. This behavioral phenotype occurred in conjunction with decreased brain 5-HT turnover during stress. These functional data were put in relation with the 5-HTR2c mRNA splicing process generating a truncated protein (5-HTR2c-Tr) in addition to the full-length receptor (5-HTR2c-Fl). 5-HTR2c-Tr mRNA was less abundant in many brain regions of VGV mice, which concomitantly had more 5-HTR2c than WT mice. Fluorescence resonance energy transfer and bioluminescence resonance energy transfer studies in transfected living HEK293T cells showed that 5-HTR2c-Tr interacts with 5-HTR2c-Fl. The 5-HTR2c-Tr was localized in the endoplasmic reticulum where it retained 5-HTR2c-Fl, preventing the latter to reach the plasma membrane. Consequently, 5-HTR2c-Tr decreased (3)H-mesulergine binding to 5-HTR2c-Fl at the plasma membrane in a concentration-dependent manner and more strongly with edited 5-HTR2c-Fl. These results suggest that 5-HTR2c pre-mRNA editing and splicing are entwined processes determining increased 5-HTR2c levels in pathological conditions through a deficit in 5-HTR2c-Tr.

  13. Upregulation of 5-HT2C receptors in hippocampus of pilocarpine-induced epileptic rats: antagonism by Bacopa monnieri.

    PubMed

    Krishnakumar, Amee; Nandhu, M S; Paulose, C S

    2009-10-01

    Emotional disturbances, depressive mood, anxiety, aggressive behavior, and memory impairment are the common psychiatric features associated with temporal lobe epilepsy (TLE). The present study was carried out to investigate the role of Bacopa monnieri extract in hippocampus of pilocarpine-induced temporal lobe epileptic rats through the 5-HT(2C) receptor in relation to depression. Our results showed upregulation of 5-HT(2C) receptors with a decreased affinity in hippocampus of pilocarpine-induced epileptic rats. Also, there was an increase in 5-HT(2C) gene expression and inositol triphosphate content in epileptic hippocampus. Carbamazepine and B. monnieri treatments reversed the alterations in 5-HT(2C) receptor binding, gene expression, and inositol triphosphate content in treated epileptic rats as compared to untreated epileptic rats. The forced swim test confirmed the depressive behavior pattern during epilepsy that was nearly completely reversed by B. monnieri treatment.

  14. Agonist-directed signaling of serotonin 5-HT2C receptors: differences between serotonin and lysergic acid diethylamide (LSD).

    PubMed

    Backstrom, J R; Chang, M S; Chu, H; Niswender, C M; Sanders-Bush, E

    1999-08-01

    For more than 40 years the hallucinogen lysergic acid diethylamide (LSD) has been known to modify serotonin neurotransmission. With the advent of molecular and cellular techniques, we are beginning to understand the complexity of LSD's actions at the serotonin 5-HT2 family of receptors. Here, we discuss evidence that signaling of LSD at 5-HT2C receptors differs from the endogenous agonist serotonin. In addition, RNA editing of the 5-HT2C receptor dramatically alters the ability of LSD to stimulate phosphatidylinositol signaling. These findings provide a unique opportunity to understand the mechanism(s) of partial agonism.

  15. Optimization of 2-phenylcyclopropylmethylamines as selective serotonin 2C receptor agonists and their evaluation as potential antipsychotic agents.

    PubMed

    Cheng, Jianjun; Giguère, Patrick M; Onajole, Oluseye K; Lv, Wei; Gaisin, Arsen; Gunosewoyo, Hendra; Schmerberg, Claire M; Pogorelov, Vladimir M; Rodriguiz, Ramona M; Vistoli, Giulio; Wetsel, William C; Roth, Bryan L; Kozikowski, Alan P

    2015-02-26

    The discovery of a new series of compounds that are potent, selective 5-HT2C receptor agonists is described herein as we continue our efforts to optimize the 2-phenylcyclopropylmethylamine scaffold. Modifications focused on the alkoxyl substituent present on the aromatic ring led to the identification of improved ligands with better potency at the 5-HT2C receptor and excellent selectivity against the 5-HT2A and 5-HT2B receptors. ADMET studies coupled with a behavioral test using the amphetamine-induced hyperactivity model identified four compounds possessing drug-like profiles and having antipsychotic properties. Compound (+)-16b, which displayed an EC50 of 4.2 nM at 5-HT2C, no activity at 5-HT2B, and an 89-fold selectivity against 5-HT2A, is one of the most potent and selective 5-HT2C agonists reported to date. The likely binding mode of this series of compounds to the 5-HT2C receptor was also investigated in a modeling study, using optimized models incorporating the structures of β2-adrenergic receptor and 5-HT2B receptor. PMID:25633969

  16. Comparative pharmacology of adrenergic alpha(2C) receptors coupled to Ca(2+) signaling through different Galpha proteins.

    PubMed

    Kurko, Dalma; Bekes, Zsófia; Gere, Anikó; Baki, Andrea; Boros, András; Kolok, Sándor; Bugovics, Gyula; Nagy, József; Szombathelyi, Zsolt; Ignácz-Szendrei, Györgyi

    2009-12-01

    Adrenergic alpha(1), alpha(2) and beta receptors are members of the G-protein-coupled receptor families (GPCRs) mediating physiological responses to adrenaline (epinephrine) and noradrenaline (norepinephrine). Since GPCRs are major targets for potential therapeutic agents, development of robust, reliable and cost effective functional screening methods for these receptors is in the focus of pharmacological research. For this reason, the aim of the present study was to develop an intracellular calcium assay for investigating the pharmacology of the alpha(2C) type of adrenergic receptors (alpha(2C)-AR). Although activation of alpha(2C)-AR is not linked to calcium mobilization, co-expression of these receptors with the chimeric Galpha(qi5) protein, containing the five carboxyl-terminal amino acids from G(i), or promiscuosus Galpha(16) protein can divert receptor signaling to the G(q) pathway generating Ca(2+) release from intracellular stores. In order to assess the functional potency of alpha(2)-AR agonists and antagonists, we established a fluorometric Ca(2+) assay using cell lines stably and constitutively co-expressing alpha(2C)-AR and Galpha(qi5) or Galpha(16) proteins (Galpha(qi5)/alpha(2C) and Galpha(16)/alpha(2C)). As part of the pharmacological characterization, we measured the changes in cytoplasmic Ca(2+) levels due to activation of the chimeric Galpha(qi5) or Galpha(16) coupled recombinant alpha(2C) receptors as a function of increasing concentration of several agonists (noradrenaline, brimonidine, oxymetazoline, clonidine, moxonidine) and antagonists (MK912, yohimbine). The binding affinities of alpha(2)-AR agonist and antagonists and the inhibition of the forskolin-stimulated cAMP accumulation in alpha(2C)-AR expressing cells were also measured. These results confirmed that the Galpha(qi5)/alpha(2C) and Galpha(16)/alpha(2C) recombinant systems can be useful for modelling the native G(i)-coupled system. Our results indicate that a plate-reader based

  17. Dissecting G protein-coupled receptor signaling pathways with membrane-permeable blocking peptides. Endogenous 5-HT(2C) receptors in choroid plexus epithelial cells.

    PubMed

    Chang, M; Zhang, L; Tam, J P; Sanders-Bush, E

    2000-03-10

    To determine the intracellular signaling mechanism of the 5-HT(2C) receptor endogenously expressed in choroid plexus epithelial cells, we implemented a strategy of targeted disruption of protein-protein interactions. This strategy entails the delivery of conjugated membrane-permeable peptides that disrupt domain interaction at specific steps in the signaling cascade. As proof of concept, two peptides targeted against receptor-G protein interaction domains were examined. Only G(q)CT, which targets the receptor-G(q) protein interacting domain, disrupted 5-HT(2C) receptor-mediated phosphatidylinositide hydrolysis. G(s)CT, targeting the receptor-G(s) protein, disrupted beta2 adrenergic receptor-mediated activation of cAMP but not 5-HT(2C) receptor-mediated phosphatidylinositide hydrolysis. The peptide MPS-PLCbeta1M, mimicking the domain of phospholipase Cbeta1 (PLCbeta1) interacting with active Galpha(q), also blocked 5-HT(2C) receptor activation. In contrast, peptides PLCbeta2M and Phos that bind to and sequester free Gbetagamma subunits were ineffective at blocking 5-HT(2C) receptor-mediated phosphoinositol turnover. However, both peptides disrupted Gbetagamma-mediated alpha(2A) adrenergic receptor activation of mitogen-activated protein kinase. These results provide the first direct demonstration that active Galpha(q) subunits mediate endogenous 5-HT(2C) receptor activation of PLCbeta and that Gbetagamma subunits released from Galpha(q) heterotrimeric proteins are not involved. Comparable results were obtained with metabotropic glutamate receptor 5 expressed in astrocytes. Thus, conjugated, membrane-permeable peptides are effective tools for the dissection of intracellular signals. PMID:10702266

  18. Sound-induced seizures in serotonin 5-HT2c receptor mutant mice.

    PubMed

    Brennan, T J; Seeley, W W; Kilgard, M; Schreiner, C E; Tecott, L H

    1997-08-01

    The epilepsies are a heterogeneous collection of seizure disorders with a lifetime expectancy risk rate of 2-4%. A convergence of evidence indicates that heritable factors contribute significantly to seizure susceptibility. Genetically epilepsy-prone rodent strains have been frequently used to examine the effect of genetic factors on seizure susceptibility. The most extensively studied of these have been strains that are susceptible to sound-induced convulsions (audiogenic seizures, or AGSs). Early observations of the AGS phenomenon were made in the laboratory of Dr. Ivan Pavlov; in the course of appetite-conditioning experiments in mice, the loud bell used to signal food presentation unexpectedly produced seizures in some animals. In 1947, DBA/2 (D2) mice were found to exhibit a genetic susceptibility to AGSs stimulated by a doorbell mounted in an iron tub. Since this discovery, AGSs have been among the most intensively studied phenotypes in behavioural genetics. Although several genetic loci confer susceptibility to AGSs, the corresponding genes have not been cloned. We report that null mutant mice lacking serotonin 5-HT2C receptors are extremely susceptible to AGSs. The onset of susceptibility is between two and three months of age, with complete penetrance in adult animals. AGS-induced immediate early gene expression indicates that AGSs are subcortical phenomena in auditory circuits. This AGS syndrome is the first produced by a known genetic defect; it provides a robust model for the examination of serotoninergic mechanisms in epilepsy.

  19. Sound-induced seizures in serotonin 5-HT2c receptor mutant mice.

    PubMed

    Brennan, T J; Seeley, W W; Kilgard, M; Schreiner, C E; Tecott, L H

    1997-08-01

    The epilepsies are a heterogeneous collection of seizure disorders with a lifetime expectancy risk rate of 2-4%. A convergence of evidence indicates that heritable factors contribute significantly to seizure susceptibility. Genetically epilepsy-prone rodent strains have been frequently used to examine the effect of genetic factors on seizure susceptibility. The most extensively studied of these have been strains that are susceptible to sound-induced convulsions (audiogenic seizures, or AGSs). Early observations of the AGS phenomenon were made in the laboratory of Dr. Ivan Pavlov; in the course of appetite-conditioning experiments in mice, the loud bell used to signal food presentation unexpectedly produced seizures in some animals. In 1947, DBA/2 (D2) mice were found to exhibit a genetic susceptibility to AGSs stimulated by a doorbell mounted in an iron tub. Since this discovery, AGSs have been among the most intensively studied phenotypes in behavioural genetics. Although several genetic loci confer susceptibility to AGSs, the corresponding genes have not been cloned. We report that null mutant mice lacking serotonin 5-HT2C receptors are extremely susceptible to AGSs. The onset of susceptibility is between two and three months of age, with complete penetrance in adult animals. AGS-induced immediate early gene expression indicates that AGSs are subcortical phenomena in auditory circuits. This AGS syndrome is the first produced by a known genetic defect; it provides a robust model for the examination of serotoninergic mechanisms in epilepsy. PMID:9241279

  20. A subunit-selective potentiator of NR2C- and NR2D-containing NMDA receptors

    PubMed Central

    Mullasseril, Praseeda; Hansen, Kasper B.; Vance, Katie M.; Ogden, Kevin K.; Yuan, Hongjie; Kurtkaya, Natalie L.; Santangelo, Rose; Orr, Anna G.; Le, Phuong; Vellano, Kimberly M.; Liotta, Dennis C.; Traynelis, Stephen F.

    2011-01-01

    NMDA receptors are tetrameric complexes of NR1 and NR2A-D subunits that mediate excitatory synaptic transmission and play a role in neurological disorders. We have identified a novel subunit-selective potentiator of NMDA receptors containing the NR2C or NR2D subunit, which could allow selective modification of circuit function in regions expressing NR2C/D subunits. The substituted tetrahydroisoquinoline CIQ enhances receptor responses two-fold with an EC50 of 3 μM by increasing channel opening frequency without altering mean open time or EC50 values for glutamate or glycine. The actions of CIQ depend on a single residue in the M1 region (NR2D Thr592) and the linker between the amino terminal domain and agonist binding domain. CIQ potentiates native NR2D-containing NMDA receptor currents from subthalamic neurons. Our identification of a subunit-selective NMDA receptor modulator reveals a new class of pharmacological tools with which to probe the role of NR2C- and NR2D-containing NMDA receptors in brain function and disease. PMID:20981015

  1. Peroxisome proliferator-activated receptor alpha, PPARα, directly regulates transcription of cytochrome P450 CYP2C8

    PubMed Central

    Thomas, Maria; Winter, Stefan; Klumpp, Britta; Turpeinen, Miia; Klein, Kathrin; Schwab, Matthias; Zanger, Ulrich M.

    2015-01-01

    The cytochrome P450, CYP2C8, metabolizes more than 60 clinically used drugs as well as endogenous substances including retinoic acid and arachidonic acid. However, predictive factors for interindividual variability in the efficacy and toxicity of CYP2C8 drug substrates are essentially lacking. Recently we demonstrated that peroxisome proliferator-activated receptor alpha (PPARα), a nuclear receptor primarily involved in control of lipid and energy homeostasis directly regulates the transcription of CYP3A4. Here we investigated the potential regulation of CYP2C8 by PPARα. Two linked intronic SNPs in PPARα (rs4253728, rs4823613) previously associated with hepatic CYP3A4 status showed significant association with CYP2C8 protein level in human liver samples (N = 150). Furthermore, siRNA-mediated knock-down of PPARα in HepaRG human hepatocyte cells resulted in up to ∼60 and ∼50% downregulation of CYP2C8 mRNA and activity, while treatment with the PPARα agonist WY14,643 lead to an induction by >150 and >100%, respectively. Using chromatin immunoprecipitation scanning assay we identified a specific upstream gene region that is occupied in vivo by PPARα. Electromobility shift assay demonstrated direct binding of PPARα to a DR-1 motif located at positions –2762/–2775 bp upstream of the CYP2C8 transcription start site. We further validated the functional activity of this element using luciferase reporter gene assays in HuH7 cells. Moreover, based on our previous studies we demonstrated that WNT/β-catenin acts as a functional inhibitor of PPARα-mediated inducibility of CYP2C8 expression. In conclusion, our data suggest direct involvement of PPARα in both constitutive and inducible regulation of CYP2C8 expression in human liver, which is further modulated by WNT/β-catenin pathway. PPARA gene polymorphism could have a modest influence on CYP2C8 phenotype. PMID:26582990

  2. Social Behavioral Deficits Coincide with the Onset of Seizure Susceptibility in Mice Lacking Serotonin Receptor 2c.

    PubMed

    Séjourné, Julien; Llaneza, Danielle; Kuti, Orsolya J; Page, Damon T

    2015-01-01

    The development of social behavior is strongly influenced by the serotonin system. Serotonin 2c receptor (5-HT2cR) is particularly interesting in this context considering that pharmacological modulation of 5-HT2cR activity alters social interaction in adult rodents. However, the role of 5-HT2cR in the development of social behavior is unexplored. Here we address this using Htr2c knockout mice, which lack 5-HT2cR. We found that these animals exhibit social behavior deficits as adults but not as juveniles. Moreover, we found that the age of onset of these deficits displays similar timing as the onset of susceptibility to spontaneous death and audiogenic-seizures, consistent with the hypothesis that imbalanced excitation and inhibition (E/I) may contribute to social behavioral deficits. Given that autism spectrum disorder (ASD) features social behavioral deficits and is often co-morbid with epilepsy, and given that 5-HT2cR physically interacts with Pten, we tested whether a second site mutation in the ASD risk gene Pten can modify these phenotypes. The age of spontaneous death is accelerated in mice double mutant for Pten and Htr2c relative to single mutants. We hypothesized that pharmacological antagonism of 5-HT2cR activity in adult animals, which does not cause seizures, might modify social behavioral deficits in Pten haploinsufficient mice. SB 242084, a 5-HT2cR selective antagonist, can reverse the social behavior deficits observed in Pten haploinsufficient mice. Together, these results elucidate a role of 5-HT2cR in the modulation of social behavior and seizure susceptibility in the context of normal development and Pten haploinsufficiency. PMID:26308619

  3. Serotonin 2C receptor activates a distinct population of arcuate pro-opiomelanocortin neurons via TRPC channels

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Serotonin 2C receptors (5-HT2CRs) expressed by pro-opiomelanocortin (POMC) neurons of hypothalamic arcuate nucleus regulate food intake, energy homeostasis ,and glucose metabolism. However, the cellular mechanisms underlying the effects of 5-HT to regulate POMC neuronal activity via 5-HT2CRs have no...

  4. Developmental Changes is Expression of Beta-Adrenergic Receptors in Cultures of C2C12 Skeletal Muscle Cells

    NASA Technical Reports Server (NTRS)

    Young, Ronald B.; Bridge, K. Y.; Vaughn, J. R.

    2000-01-01

    beta-Adrenergic receptor (bAR) agonists have been reported to modulate growth in several mammalian and avian species, and bAR agonists presumably exert their physiological action on skeletal muscle cells through this receptor. Because of the importance of bAR regulation on muscle protein metabolism in muscle cells, the objectives of this study were to determine the developmental expression pattern of the bAR population in C2C12 skeletal muscle cells, and to analyze changes in both the quantity and isoform expression of the major muscle protein, myosin. The number of bAR in mononucleated C2C12 cells was approximately 8,000 bAR per cell, which is comparable with the population reported in several other nonmuscle cell types. However, the bar population increased after myoblast fusion to greater than 50,000 bAR per muscle cell equivalent. The reasons for this apparent over-expression of bAR in C2C12 cells is not known. The quantity of myosin also increased after C2C12 myoblast fusion, but the quantity of myosin was less than that reported in primary muscle cell cultures. Finally, at least five different isoforms of myosin heavy chain could be resolved in C2C12 cells, and three of these exhibited either increased or decreased developmental regulation relative to the others. Thus, C2C12 myoblasts undergo developmental regulation of bAR population and myosin heavy chain isoform expression.

  5. Role for serotonin2A (5-HT2A) and 2C (5-HT2C) receptors in experimental absence seizures.

    PubMed

    Venzi, Marcello; David, François; Bellet, Joachim; Cavaccini, Anna; Bombardi, Cristiano; Crunelli, Vincenzo; Di Giovanni, Giuseppe

    2016-09-01

    Absence seizures (ASs) are the hallmark of childhood/juvenile absence epilepsy. Monotherapy with first-line anti-absence drugs only controls ASs in 50% of patients, indicating the need for novel therapeutic targets. Since serotonin family-2 receptors (5-HT2Rs) are known to modulate neuronal activity in the cortico-thalamo-cortical loop, the main network involved in AS generation, we investigated the effect of selective 5-HT2AR and 5-HT2CR ligands on ASs in the Genetic Absence Epilepsy Rats from Strasbourg (GAERS), a well established polygenic rat model of these non-convulsive seizures. GAERS rats were implanted with fronto-parietal EEG electrodes under general anesthesia, and their ASs were later recorded under freely moving conditions before and after intraperitoneal administration of various 5-HT2AR and 5-HT2CR ligands. The 5-HT2A agonist TCB-2 dose-dependently decreased the total time spent in ASs, an effect that was blocked by the selective 5-HT2A antagonist MDL11,939. Both MDL11,939 and another selective 5-HT2A antagonist (M100,907) increased the length of individual seizures when injected alone. The 5-HT2C agonists lorcaserin and CP-809,101 dose-dependently suppressed ASs, an effect blocked by the selective 5-HT2C antagonist SB 242984. In summary, 5-HT2ARs and 5-HT2CRs negatively control the expression of experimental ASs, indicating that selective agonists at these 5-HT2R subtypes might be potential novel anti-absence drugs.

  6. Role for serotonin2A (5-HT2A) and 2C (5-HT2C) receptors in experimental absence seizures.

    PubMed

    Venzi, Marcello; David, François; Bellet, Joachim; Cavaccini, Anna; Bombardi, Cristiano; Crunelli, Vincenzo; Di Giovanni, Giuseppe

    2016-09-01

    Absence seizures (ASs) are the hallmark of childhood/juvenile absence epilepsy. Monotherapy with first-line anti-absence drugs only controls ASs in 50% of patients, indicating the need for novel therapeutic targets. Since serotonin family-2 receptors (5-HT2Rs) are known to modulate neuronal activity in the cortico-thalamo-cortical loop, the main network involved in AS generation, we investigated the effect of selective 5-HT2AR and 5-HT2CR ligands on ASs in the Genetic Absence Epilepsy Rats from Strasbourg (GAERS), a well established polygenic rat model of these non-convulsive seizures. GAERS rats were implanted with fronto-parietal EEG electrodes under general anesthesia, and their ASs were later recorded under freely moving conditions before and after intraperitoneal administration of various 5-HT2AR and 5-HT2CR ligands. The 5-HT2A agonist TCB-2 dose-dependently decreased the total time spent in ASs, an effect that was blocked by the selective 5-HT2A antagonist MDL11,939. Both MDL11,939 and another selective 5-HT2A antagonist (M100,907) increased the length of individual seizures when injected alone. The 5-HT2C agonists lorcaserin and CP-809,101 dose-dependently suppressed ASs, an effect blocked by the selective 5-HT2C antagonist SB 242984. In summary, 5-HT2ARs and 5-HT2CRs negatively control the expression of experimental ASs, indicating that selective agonists at these 5-HT2R subtypes might be potential novel anti-absence drugs. PMID:27085605

  7. The human serotonin 5-HT{sub 2C} receptor: Complete cDNA, genomic structure, and alternatively spliced variant

    SciTech Connect

    Xie, Enzhong; Zhu, Lingyu; Zhao, Lingyun

    1996-08-01

    The complete 4775-nt cDNA encoding the human serotonin 5-HT{sub 2C} receptor (5-HT{sub 2C}R), a G-protein-coupled receptor, has been isolated. It contains a 1377-nt coding region flanked by a 728-nt 5{prime}-untranslated region and a 2670-nt 3{prime}-untranslated region. By using the cloned 5-HT{sub 2C}R cDNA probe, the complete human gene for this receptor has been isolated and shown to contain six exons and five introns spanning at least 230 kb of DNA. The coding region of the human 5-HT{sub 2C}R gene is interrupted by three introns, and the positions of the intron/exon junctions are conserved between the human and the rodent genes. In addition, an alternatively spliced 5-HT{sub 2C}R RNA that contains a 95-nt deletion in the region coding for the second intracellular loop and the fourth transmembrane domain of the receptor has been identified. This deletion leads to a frameshift and premature termination so that the short isoform RNA encodes a putative protein of 248 amino acids. The ratio for the short isoform over the 5-HT{sub 2C}R RNA was found to be higher in choroid plexus tumor than in normal brain tissue, suggesting the possibility of differential regulation of the 5-HT{sub 2C}R gene in different neural tissues or during tumorigenesis. Transcription of the human 5-HT{sub 2C}R gene was found to be initiated at multiple sites. No classical TATA-box sequence was found at the appropriate location, and the 5{prime}-flanking sequence contains many potential transcription factor-binding sites. A 7.3-kb 5{prime}-flanking 5-HT{sub 2C}R DNA directed the efficient expression of a luciferase reported gene in SK-N-SH and IMR32 neuroblastoma cells, indicating that is contains a functional promoter. 69 refs., 8 figs., 1 tab.

  8. CYP2C8 Is a Novel Target of Peroxisome Proliferator-Activated Receptor α in Human Liver

    PubMed Central

    Makia, Ngome L.

    2016-01-01

    Human cytochrome P450 (CYP) 2C enzymes metabolize ∼30% of clinically prescribed drugs and various environmental chemicals. CYP2C8, an important member of this subfamily, metabolizes the anticancer drug paclitaxel, certain antidiabetic drugs, and endogenous substrates, including arachidonic acid, to physiologically active epoxyeicosatrienoic acids. Previous studies from our laboratory showed that microRNA 107 (miR107) and microRNA 103 downregulate CYP2C8 post-transcriptionally. miR107 is located in intron 5 of the pantothenate kinase 1 (PANK1) gene. p53 has been reported to coregulate the induction of PANK1 and miR107. Here, we examine the possible downregulation of CYP2C8 by drugs capable of inducing miR107. Hypolipidemic drugs, such as bezafibrate, known activators of the peroxisome proliferator-activated receptor α (PPARα), induce both the PANK1 gene and miR107 (∼2.5-fold) in primary human hepatocytes. Surprisingly, CYP2C8 mRNA and protein levels were induced by bezafibrate. CYP2C8 promoter activity was increased by ectopic expression of PPARα in HepG2 cells, with a further increase after bezafibrate (∼18-fold), 4-chloro-6-(2,3-xylidino)-2-pyrimidinylthio acetic acid (∼10-fold) treatment, or the antidiabetic drug rosiglitazone, all known PPAR activators. Promoter sequence analyses, deletion studies, mutagenesis studies, and electrophoretic mobility shift assays identified a PPARα response element located at position −2109 base pair relative to the translation start site of CYP2C8. Chromatin immunopreciptation assay analysis confirmed recruitment of PPARα to this PPARα response element after bezafibrate treatment of human hepatocytes. Thus, we show for the first time that CYP2C8 is transcriptionally regulated by PPARα, suggesting the potential for drug-drug interactions due to upregulation of CYP2C8 by PPAR activators. PMID:26467040

  9. CYP2C8 Is a Novel Target of Peroxisome Proliferator-Activated Receptor α in Human Liver.

    PubMed

    Makia, Ngome L; Goldstein, Joyce A

    2016-01-01

    Human cytochrome P450 (CYP) 2C enzymes metabolize ∼30% of clinically prescribed drugs and various environmental chemicals. CYP2C8, an important member of this subfamily, metabolizes the anticancer drug paclitaxel, certain antidiabetic drugs, and endogenous substrates, including arachidonic acid, to physiologically active epoxyeicosatrienoic acids. Previous studies from our laboratory showed that microRNA 107 (miR107) and microRNA 103 downregulate CYP2C8 post-transcriptionally. miR107 is located in intron 5 of the pantothenate kinase 1 (PANK1) gene. p53 has been reported to coregulate the induction of PANK1 and miR107. Here, we examine the possible downregulation of CYP2C8 by drugs capable of inducing miR107. Hypolipidemic drugs, such as bezafibrate, known activators of the peroxisome proliferator-activated receptor α (PPARα), induce both the PANK1 gene and miR107 (∼2.5-fold) in primary human hepatocytes. Surprisingly, CYP2C8 mRNA and protein levels were induced by bezafibrate. CYP2C8 promoter activity was increased by ectopic expression of PPARα in HepG2 cells, with a further increase after bezafibrate (∼18-fold), 4-chloro-6-(2,3-xylidino)-2-pyrimidinylthio acetic acid (∼10-fold) treatment, or the antidiabetic drug rosiglitazone, all known PPAR activators. Promoter sequence analyses, deletion studies, mutagenesis studies, and electrophoretic mobility shift assays identified a PPARα response element located at position -2109 base pair relative to the translation start site of CYP2C8. Chromatin immunopreciptation assay analysis confirmed recruitment of PPARα to this PPARα response element after bezafibrate treatment of human hepatocytes. Thus, we show for the first time that CYP2C8 is transcriptionally regulated by PPARα, suggesting the potential for drug-drug interactions due to upregulation of CYP2C8 by PPAR activators. PMID:26467040

  10. Control of sensory neuron excitability by serotonin involves 5HT2C receptors and Ca(2+)-activated chloride channels.

    PubMed

    Salzer, Isabella; Gantumur, Enkhbileg; Yousuf, Arsalan; Boehm, Stefan

    2016-11-01

    Serotonin (5HT) is a constituent of the so-called "inflammatory soup" that sensitizes nociceptors during inflammation. Nevertheless, receptors and signaling mechanisms that mediate an excitation of dorsal root ganglion (DRG) neurons by 5HT remained controversial. Therefore, capsaicin-sensitive nociceptive neurons dissociated from rat DRGs were used to investigate effects of 5HT on membrane excitability and currents through ligand- as well as voltage-gated ion channels. In 58% of the neurons tested, 5HT increased action potential firing, an effect that was abolished by the 5HT2 receptor antagonist ritanserin, but not by the 5HT3 antagonist tropisetron. Unlike other algogenic mediators, such as PGE2 and bradykinin, 5HT did not affect currents through TTX-resistant Na(+) channels or Kv7 K(+) channels. In all neurons investigated, 5HT potentiated capsaicin-evoked currents through TRPV1 channels, an effect that was attenuated by antagonists at 5HT2A (4 F 4 PP), 5HT2B (SB 204741), as well as 5HT2C (RS 102221) receptors. 5HT triggered slowly arising inward Cl(-) currents in 53% of the neurons. This effect was antagonized by the 5HT2C receptor blocker only, and the current was prevented by an inhibitor of Ca(2+)-activated chloride channels (CaCC). The 5HT-induced increase in action potential firing was also abolished by this CaCC blocker and by the TRPV1 inhibitor capsazepine. Amongst the subtype selective 5HT2 antagonists, only RS 102221 (5HT2C-selectively) counteracted the rise in action potential firing elicited by 5HT. These results show that 5HT excites DRG neurons mainly via 5HT2C receptors which concomitantly mediate a sensitization of TRPV1 channels and an opening of CaCCs.

  11. Statin-activated nuclear receptor PXR promotes SGK2 dephosphorylation by scaffolding PP2C to induce hepatic gluconeogenesis.

    PubMed

    Gotoh, Saki; Negishi, Masahiko

    2015-01-01

    Statin therapy is known to increase blood glucose levels in humans. Statins utilize pregnane X receptor (PXR) and serum/glucocorticoid regulated kinase 2 (SGK2) to activate phosphoenolpyruvate carboxykinase 1 (PEPCK1) and glucose-6-phosphatase (G6Pase) genes, thereby increasing glucose production in human liver cells. Here, the novel statin/PXR/SGK2-mediated signaling pathway has now been characterized for hepatic gluconeogenesis. Statin-activated PXR scaffolds the protein phosphatase 2C (PP2C) and SGK2 to stimulate PP2C to dephosphorylate SGK2 at threonine 193. Non-phosphorylated SGK2 co-activates PXR-mediated trans-activation of promoters of gluconeogenic genes in human liver cells, thereby enhancing gluconeogenesis. This gluconeogenic statin-PXR-SGK2 signal is not present in mice, in which statin treatment suppresses hepatic gluconeogenesis. These findings provide the basis for statin-associated side effects such as an increased risk for Type 2 diabetes. PMID:26392083

  12. Variability of 5-HT2C receptor cys23ser polymorphism among European populations and vulnerability to affective disorder.

    PubMed

    Lerer, B; Macciardi, F; Segman, R H; Adolfsson, R; Blackwood, D; Blairy, S; Del Favero, J; Dikeos, D G; Kaneva, R; Lilli, R; Massat, I; Milanova, V; Muir, W; Noethen, M; Oruc, L; Petrova, T; Papadimitriou, G N; Rietschel, M; Serretti, A; Souery, D; Van Gestel, S; Van Broeckhoven, C; Mendlewicz, J

    2001-09-01

    Substantial evidence supports a role for dysfunction of brain serotonergic (5-HT) systems in the pathogenesis of major affective disorder, both unipolar (recurrent major depression) and bipolar.(1) Modification of serotonergic neurotransmission is pivotally implicated in the mechanism of action of antidepressant drugs(2) and also in the action of mood stabilizing agents, particularly lithium carbonate.(3) Accordingly, genes that code for the multiple subtypes of serotonin receptors that have been cloned and are expressed in brain,(4) are strong candidates for a role in the genetic etiology of affective illness. We examined a structural variant of the serotonin 2C (5-HT2C) receptor gene (HTR2C) that gives rise to a cysteine to serine substitution in the N terminal extracellular domain of the receptor protein (cys23ser),(5) in 513 patients with recurrent major depression (MDD-R), 649 patients with bipolar (BP) affective disorder and 901 normal controls. The subjects were drawn from nine European countries participating in the European Collaborative Project on Affective Disorders. There was significant variation in the frequency of the HT2CR ser23 allele among the 10 population groups included in the sample (from 24.6% in Greek control subjects to 9.2% in Scots, chi(2) = 20.9, df 9, P = 0.01). Logistic regression analysis demonstrated that over and above this inter-population variability, there was a significant excess of HT2CR ser23 allele carriers in patients compared to normal controls that was demonstrable for both the MDD (chi(2) = 7.34, df 1, P = 0.006) and BP (chi(2) = 5.45, df 1, P = 0.02) patients. These findings support a possible role for genetically based structural variation in 5-HT2C receptors in the pathogenesis of major affective disorder.

  13. Effects of RO 60 0175, a 5-HT(2C) receptor agonist, in three animal models of anxiety.

    PubMed

    Kennett, G; Lightowler, S; Trail, B; Bright, F; Bromidge, S

    2000-01-10

    There is some controversy as to whether 5-HT(2C) receptor agonists are anxiogenic or anxiolytic. The effects of the novel 5-HT(2C) receptor agonist, (S)-2-chloro-5-fluoro-indol-1-yl)-1-methyl ethylamine fumarate (RO 60 0175), in three models of anxiety were therefore tested. RO 60 0175 was found to induce hypolocomotion in rats at doses greater than 0.5 mg/kg s.c., an effect reversed by the selective 5-HT(2C) receptor antagonist, SB-242084. RO 60 0175 did not elicit anxiolytic-like responses in the social interaction test under high light unfamiliar conditions, but suppressed both time spent in social interaction and locomotion at doses of 1 and 3 mg/kg s.c., suggesting a sedative response. In the Vogel conflict test, RO 60 0175 had no significant action on the number of shocks taken. In the Geller-Seifter test, RO 60 0175 (0.3 and 1 mg/kg s.c.) simultaneously reduced both unpunished and punished lever pressing, a profile consistent with sedation. Finally, RO 60 0175 was tested in a rat social interaction test under low light familiar conditions optimal for the detection of anxiogenic-like responses. At 1 and 3 mg/kg s.c., RO 60 0175 reduced both time spent in social interaction and concurrent locomotion, a profile more consistent with sedation than anxiogenesis. In conclusion, RO 60 0175 induced sedative-like responses via 5-HT(2C) receptor activation, but was neither anxiolytic, nor clearly anxiogenic at the doses tested. PMID:10650160

  14. Decreased Incentive Motivation Following Knockout or Acute Blockade of the Serotonin Transporter: Role of the 5-HT2C Receptor.

    PubMed

    Browne, Caleb J; Fletcher, Paul J

    2016-09-01

    Acute pharmacological elevation of serotonin (5-hydroxytryptamine; 5-HT) activity decreases operant responding for primary reinforcers, suggesting that 5-HT reduces incentive motivation. The mechanism by which 5-HT alters incentive motivation is unknown, but parallel evidence that 5-HT2C receptor agonists also reduce responding for primary reinforcers implicates this receptor as a potential candidate. These experiments examined whether chronic and acute disruptions of serotonin transporter (SERT) activity altered incentive motivation, and whether the 5-HT2C receptor mediated the effects of elevated 5-HT on behavior. To assess incentive motivation, we measured responding for three different reinforcers: a primary reinforcer (saccharin), a conditioned reinforcer (CRf), and an unconditioned sensory reinforcer (USRf). In the chronic condition, responding was compared between SERT knockout (SERT-KO) mice and their wild-type littermates. In the acute condition, responding was examined in wild-type mice following treatment with 10 or 20 mg/kg citalopram, or its vehicle. The ability of the selective 5-HT2C antagonist SB 242084 to prevent the effects of SERT-KO and citalopram on responding was subsequently examined. Both SERT-KO and citalopram reduced responding for saccharin, a CRf, and a USRf. Treatment with SB 242084 enhanced responding for a CRf and a USRf in SERT-KO mice and blocked the effects of citalopram on CRf and USRf responding. However, SB 242084 was unable to prevent the effects of SERT-KO or citalopram on responding for saccharin. These results support a powerful inhibitory function for 5-HT in the control of incentive motivation, and indicate that the 5-HT2C receptor mediates these effects of 5-HT in a reinforcer-dependent manner. PMID:27125304

  15. Analysis of functional selectivity through G protein-dependent and -independent signaling pathways at the adrenergic α(2C) receptor.

    PubMed

    Kurko, Dalma; Kapui, Zoltán; Nagy, József; Lendvai, Balázs; Kolok, Sándor

    2014-08-01

    Although G protein-coupled receptors (GPCRs) are traditionally categorized as Gs-, Gq-, or Gi/o-coupled, their signaling is regulated by multiple mechanisms. GPCRs can couple to several effector pathways, having the capacity to interact not only with more than one G protein subtype but also with alternative signaling or effector proteins such as arrestins. Moreover, GPCR ligands can have different efficacies for activating these signaling pathways, a characteristic referred to as biased agonism or functional selectivity. In this work our aim was to detect differences in the ability of various agonists acting at the α2C type of adrenergic receptors2C-ARs) to modulate cAMP accumulation, cytoplasmic Ca(2+) release, β-arrestin recruitment and receptor internalization. A detailed comparative pharmacological characterization of G protein-dependent and -independent signaling pathways was carried out using adrenergic agonists (norepinephrine, phenylephrine, brimonidine, BHT-920, oxymetazoline, clonidine, moxonidine, guanabenz) and antagonists (MK912, yohimbine). As initial analysis of agonist Emax and EC50 values suggested possible functional selectivity, ligand bias was quantified by applying the relative activity scale and was compared to that of the endogenous agonist norepinephrine. Values significantly different from 0 between pathways indicated an agonist that promoted different level of activation of diverse effector pathways most likely due to the stabilization of a subtly different receptor conformation from that induced by norepinephrine. Our results showed that a series of agonists acting at the α2C-AR displayed different degree of functional selectivity (bias factors ranging from 1.6 to 36.7) through four signaling pathways. As signaling via these pathways seems to have distinct functional and physiological outcomes, studying all these stages of receptor activation could have further implications for the development of more selective therapeutics with

  16. Analysis of functional selectivity through G protein-dependent and -independent signaling pathways at the adrenergic α(2C) receptor.

    PubMed

    Kurko, Dalma; Kapui, Zoltán; Nagy, József; Lendvai, Balázs; Kolok, Sándor

    2014-08-01

    Although G protein-coupled receptors (GPCRs) are traditionally categorized as Gs-, Gq-, or Gi/o-coupled, their signaling is regulated by multiple mechanisms. GPCRs can couple to several effector pathways, having the capacity to interact not only with more than one G protein subtype but also with alternative signaling or effector proteins such as arrestins. Moreover, GPCR ligands can have different efficacies for activating these signaling pathways, a characteristic referred to as biased agonism or functional selectivity. In this work our aim was to detect differences in the ability of various agonists acting at the α2C type of adrenergic receptors2C-ARs) to modulate cAMP accumulation, cytoplasmic Ca(2+) release, β-arrestin recruitment and receptor internalization. A detailed comparative pharmacological characterization of G protein-dependent and -independent signaling pathways was carried out using adrenergic agonists (norepinephrine, phenylephrine, brimonidine, BHT-920, oxymetazoline, clonidine, moxonidine, guanabenz) and antagonists (MK912, yohimbine). As initial analysis of agonist Emax and EC50 values suggested possible functional selectivity, ligand bias was quantified by applying the relative activity scale and was compared to that of the endogenous agonist norepinephrine. Values significantly different from 0 between pathways indicated an agonist that promoted different level of activation of diverse effector pathways most likely due to the stabilization of a subtly different receptor conformation from that induced by norepinephrine. Our results showed that a series of agonists acting at the α2C-AR displayed different degree of functional selectivity (bias factors ranging from 1.6 to 36.7) through four signaling pathways. As signaling via these pathways seems to have distinct functional and physiological outcomes, studying all these stages of receptor activation could have further implications for the development of more selective therapeutics with

  17. 4-Bromo-2,5-dimethoxyphenethylamine (2C-B) and structurally related phenylethylamines are potent 5-HT2A receptor antagonists in Xenopus laevis oocytes

    PubMed Central

    Villalobos, Claudio A; Bull, Paulina; Sáez, Patricio; Cassels, Bruce K; Huidobro-Toro, J Pablo

    2004-01-01

    We recently described that several 2-(2,5-dimethoxy-4-substituted phenyl)ethylamines (PEAs), including 4-I=2C-I, 4-Br=2C-B, and 4-CH3=2C-D analogs, are partial agonists at 5-HT2C receptors, and show low or even negligible intrinsic efficacy at 5-HT2A receptors. These results raised the proposal that these drugs may act as 5-HT2 antagonists. To test this hypothesis, Xenopus laevis oocytes were microinjected with the rat clones for 5-HT2A or 5-HT2C receptors. The above-mentioned PEAs and its 4-H analog (2C-H) blocked the 5-HT-induced currents at 5-HT2A, but not at the 5-HT2C receptor, revealing 5-HT2 receptor subtype selectivity. The 5-HT2A receptor antagonism required a 2-min preincubation to attain maximum inhibition. All PEAs tested shifted the 5-HT concentration–response curves to the right and downward. Their potencies varied with the nature of the C(4) substituent; the relative rank order of their 5-HT2A receptor antagonist potency was 2C-I>2C-B>2C-D>2C-H. The present results demonstrate that in X. laevis oocytes, a series of 2,5-dimethoxy-4-substituted PEAs blocked the 5-HT2A but not the 5-HT2C receptor-mediated responses. As an alternative hypothesis, we suggest that the psychostimulant activity of the PEAs may not be exclusively associated with partial or full 5-HT2A receptor agonism. PMID:15006903

  18. Discovering the mechanisms underlying serotonin (5-HT)2A and 5-HT2C receptor regulation following nicotine withdrawal in rats.

    PubMed

    Zaniewska, Magdalena; Alenina, Natalia; Wydra, Karolina; Fröhler, Sebastian; Kuśmider, Maciej; McCreary, Andrew C; Chen, Wei; Bader, Michael; Filip, Małgorzata

    2015-08-01

    We have previously demonstrated that nicotine withdrawal produces depression-like behavior and that serotonin (5-HT)2A/2C receptor ligands modulate that mood-like state. In the present study we aimed to identify the mechanisms (changes in radioligand binding, transcription or RNA-editing) related to such a behavioral outcome. Rats received vehicle or nicotine (0.4 mg/kg, s.c.) for 5 days in home cages. Brain 5-HT2A/2C receptors were analyzed on day 3 of nicotine withdrawal. Nicotine withdrawal increased [(3)H]ketanserin binding to 5-HT2A receptors in the ventral tegmental area and ventral dentate gyrus, yet decreased binding in the nucleus accumbens shell. Reduction in [(3)H]mesulergine binding to 5-HT2C receptors was seen in the ventral dentate gyrus. Profound decrease in the 5-HT2A receptor transcript level was noted in the hippocampus and ventral tegmental area. Out of five 5-HT2C receptor mRNA editing sites, deep sequencing data showed a reduction in editing at the E site and a trend toward reduction at the C site in the hippocampus. In the ventral tegmental area, a reduction for the frequency of CD 5-HT2C receptor transcript was seen. These results show that the reduction in the 5-HT2A receptor transcript level may be an auto-regulatory response to the increased receptor density in the hippocampus and ventral tegmental area during nicotine withdrawal, while decreased 5-HT2C receptor mRNA editing may explain the reduction in receptor labeling in the hippocampus. Serotonin (5-HT)2A/2C receptor ligands alleviate depression-like state in nicotine-withdrawn rats. Here, we show that the reduction in 5-HT2A receptor transcript level may be an auto-regulatory response to the increased receptor number in the hippocampus and ventral tegmental area during nicotine withdrawal, while attenuated 5-HT2C receptor mRNA editing in the hippocampus might explain reduced inverse agonist binding to 5-HT2C receptor and suggest a shift toward a population of more active receptors. 5

  19. Identification, expression, and pharmacology of a Cys{sub 23}-Ser{sub 23} substitution in the human 5-HT{sub 2C} receptor gene (HTR2C)

    SciTech Connect

    Lappalainen, J.; Ozaki, N.; Goldman, D.

    1995-05-20

    The function of brain serotonin-2C (5-HT{sub 2C}) receptors, including behavioral and neurochemical responses to 5-HT{sub 2C} agonist challenge, has been suggested to be abnormal in individuals with neuropsychiatric disorders. Thus, it is important to identify polymorphisms and functional variants within this gene. Using SSCP analysis, the authors identified a Cys{sub 23}-Ser{sub 23} substitution (designated 5-HT{sub 2Ccys} and 5-HT{sub 2Cser}) in the first hydrophobic region of the human 5-HT{sub 2C} receptor. Allele frequencies in unrelated Caucasians were 0.13 and 0.87 for 5-HT{sub 2Cser} and 5-HT{sub 2Ccys}, respectively. DNAs from informative CEPH families were typed for this polymorphism and analyzed with respect to 20 linked markers on the X chromosome. Linkage analysis placed the 5-HT{sub 2C} receptor gene (HTR2C) on Xq24. To evaluate whether this amino acid substitution causes a variant function of this receptor, recombinant human 5-HT{sub 2Ccys} and 5-HT{sub 2Cser} receptors were expressed in Xenopus oocytes and tested for responses to 5-HT using electrophysiological techniques. Concentration-response curves for 5-HT were not significantly different in oocytes expressing either form of the receptor, suggesting that the 5-HT{sub 2Ccys} and 5-HT{sub 2Cser} receptor proteins may not differ in their responses to serotonin under baseline physiological conditions. 43 refs., 3 figs., 1 tab.

  20. The effects of pharmacological modulation of the serotonin 2C receptor on goal-directed behavior in mice

    PubMed Central

    Williamson, Cait; Mezias, Chris; Winiger, Vanessa; Silver, Rae; Balsam, Peter D.

    2016-01-01

    Rationale Impaired goal-directed motivation represents a debilitating class of symptoms common to psychological disorders including schizophrenia and some affective disorders. Despite the known negative impact of impaired motivation, there are currently no effective pharmacological interventions to treat these symptoms. Objectives Here, we evaluate the effectiveness of the serotonin 2C (5-HT2C) receptor selective ligand, SB242084, as a potential pharmacological intervention for enhancing goal-directed motivation in mice. The studies were designed to identify not only efficacy but also the specific motivational processes that were affected by the drug treatment. Methods We tested subjects following treatment with SB242084 (0.75 mg/kg) in several operant lever pressing assays including the following: a progressive ratio (PR) schedule of reinforcement, an effort-based choice task, a progressive hold down task (PHD), and various food intake tests. Results Acute SB242084 treatment leads to an increase in instrumental behavior. Using a battery of behavioral tasks, we demonstrate that the major effect of SB242084 is an increase in the amount of responses and duration of effort that subjects will make for food rewards. This enhancement of behavior is not the result of non-specific hyperactivity or arousal nor is it due to changes in food consumption. Conclusions Because of this specificity of action, we suggest that the 5-HT2C receptor warrants further attention as a novel therapeutic target for treating pathological impairments in goal-directed motivation. PMID:26558617

  1. Selective androgen receptor modulator, YK11, regulates myogenic differentiation of C2C12 myoblasts by follistatin expression.

    PubMed

    Kanno, Yuichiro; Ota, Rumi; Someya, Kousuke; Kusakabe, Taichi; Kato, Keisuke; Inouye, Yoshio

    2013-01-01

    The myogenic differentiation of C2C12 myoblast cells is induced by the novel androgen receptor (AR) partial agonist, (17α,20E)-17,20-[(1-methoxyethylidene)bis-(oxy)]-3-oxo-19-norpregna-4,20-diene-21-carboxylic acid methyl ester (YK11), as well as by dihydrotestosterone (DHT). YK11 is a selective androgen receptor modulator (SARM), which activates AR without the N/C interaction. In this study, we further investigated the mechanism by which YK11 induces myogenic differentiation of C2C12 cells. The induction of key myogenic regulatory factors (MRFs), such as myogenic differentiation factor (MyoD), myogenic factor 5 (Myf5) and myogenin, was more significant in the presence of YK11 than in the presence of DHT. YK11 treatment of C2C12 cells, but not DHT, induced the expression of follistatin (Fst), and the YK11-mediated myogenic differentiation was reversed by anti-Fst antibody. These results suggest that the induction of Fst is important for the anabolic effect of YK11. PMID:23995658

  2. A gain-of-function mutation of Fgfr2c demonstrates the roles of this receptor variant in osteogenesis

    PubMed Central

    Eswarakumar, Veraragavan P.; Horowitz, Mark C.; Locklin, Rachel; Morriss-Kay, Gillian M.; Lonai, Peter

    2004-01-01

    The b and c variants of fibroblast growth factor receptor 2 (FGFR2) differ in sequence, binding specificity, and localization. Fgfr2b, expressed in epithelia, is required for limb outgrowth and branching morphogenesis, whereas the mesenchymal Fgfr2c variant is required by the osteocyte lineage for normal skeletogenesis. Gain-of-function mutations in human FGFR2c are associated with craniosynostosis syndromes. To confirm and extend this evidence, we introduced a Cys342Tyr replacement into Fgfr2c to create a gain-of-function mutation equivalent to a mutation in human Crouzon and Pfeiffer syndromes. Fgfr2cC342Y/+ heterozygote mice are viable and fertile with shortened face, protruding eyes, premature fusion of cranial sutures, and enhanced Spp1 expression in the calvaria. Homozygous mutants display multiple joint fusions, cleft palate, and trachea and lung defects, and die shortly after birth. They show enhanced Cbfa1/Runx2 expression without significant change in chondrocyte-specific Ihh, PTHrP, Sox9, Col2a, or Col10a gene expression. Histomorphometric analysis and bone marrow stromal cell culture showed a significant increase of osteoblast progenitors with no change in osteoclastogenic cells. Chondrocyte proliferation was decreased in the skull base at embryonic day 14.5 but not later. These results suggest that long-term aspects of the mutant phenotype, including craniosynostosis, are related to the Fgfr2c regulation of the osteoblast lineage. The effect on early chondrocyte proliferation but not gene expression suggests cooperation of Fgfr2c with Fgfr3 in the formation of the cartilage model for endochondral bone. PMID:15316116

  3. Nucleus accumbens shell excitability is decreased by methamphetamine self-administration and increased by 5-HT2C receptor inverse agonism and agonism

    PubMed Central

    Graves, Steven M.; Clark, Mary J.; Traynor, John R.; Hu, Xiu-Ti; Napier, T. Celeste

    2014-01-01

    Methamphetamine profoundly increases brain monoamines and is a widely abused psychostimulant. The effects of methamphetamine self-administration on neuron function are not known for the nucleus accumbens, a brain region involved in addictive behaviors, including drug-seeking. One therapeutic target showing preclinical promise at attenuating psychostimulant-seeking is 5-HT2C receptors; however, the effects of 5-HT2C receptor ligands on neuronal physiology are unclear. 5-HT2C receptor agonism decreases psychostimulant-mediated behaviors, and the putative 5-HT2C receptor inverse agonist, SB 206553, attenuates methamphetamine-seeking in rats. To ascertain the effects of methamphetamine, and 5-HT2C receptor inverse agonism and agonism, on neuronal function in the nucleus accumbens, we evaluated methamphetamine, SB 206553, and the 5-HT2C receptor agonist and Ro 60-0175, on neuronal excitability within the accumbens shell subregion using whole-cell current-clamp recordings in forebrain slices ex vivo. We reveal that methamphetamine self-administration decreased generation of evoked action potentials. In contrast, SB 206553 and Ro 60-0175 increased evoked spiking, effects that were prevented by the 5-HT2C receptor antagonist, SB 242084. We also assessed signaling mechanisms engaged by 5-HT2C receptors, and determined that accumbal 5-HT2C receptors stimulated Gq, but not Gi/o. These findings demonstrate that methamphetamine-induced decreases in excitability of neurons within the nucleus accumbens shell were abrogated by both 5-HT2C inverse agonism and agonism, and this effect likely involved activation of Gq–mediated signaling pathways. PMID:25229719

  4. Nucleus accumbens shell excitability is decreased by methamphetamine self-administration and increased by 5-HT2C receptor inverse agonism and agonism.

    PubMed

    Graves, Steven M; Clark, Mary J; Traynor, John R; Hu, Xiu-Ti; Napier, T Celeste

    2015-02-01

    Methamphetamine profoundly increases brain monoamines and is a widely abused psychostimulant. The effects of methamphetamine self-administration on neuron function are not known for the nucleus accumbens, a brain region involved in addictive behaviors, including drug-seeking. One therapeutic target showing preclinical promise at attenuating psychostimulant-seeking is 5-HT2C receptors; however, the effects of 5-HT2C receptor ligands on neuronal physiology are unclear. 5-HT2C receptor agonism decreases psychostimulant-mediated behaviors, and the putative 5-HT2C receptor inverse agonist, SB 206553, attenuates methamphetamine-seeking in rats. To ascertain the effects of methamphetamine, and 5-HT2C receptor inverse agonism and agonism, on neuronal function in the nucleus accumbens, we evaluated methamphetamine, SB 206553, and the 5-HT2C receptor agonist and Ro 60-0175, on neuronal excitability within the accumbens shell subregion using whole-cell current-clamp recordings in forebrain slices ex vivo. We reveal that methamphetamine self-administration decreased generation of evoked action potentials. In contrast, SB 206553 and Ro 60-0175 increased evoked spiking, effects that were prevented by the 5-HT2C receptor antagonist, SB 242084. We also assessed signaling mechanisms engaged by 5-HT2C receptors, and determined that accumbal 5-HT2C receptors stimulated Gq, but not Gi/o. These findings demonstrate that methamphetamine-induced decreases in excitability of neurons within the nucleus accumbens shell were abrogated by both 5-HT2C inverse agonism and agonism, and this effect likely involved activation of Gq-mediated signaling pathways.

  5. Role of 5-HT2C Receptors in Effects of Monoamine Releasers on Intracranial Self-Stimulation in Rats

    PubMed Central

    Bauer, Clayton T.; Banks, Matthew L.; Blough, Bruce E.; Negus, S. Stevens

    2015-01-01

    Rationale Many monoamine releasers are abused by humans and produce abuse-related facilitation of intracranial self-stimulation (ICSS) in rats. Facilitation of ICSS in rats can be limited by monoamine releaser-induced serotonin (5-HT) release, but receptors that mediate 5-HT effects of monoamine releasers are unknown. Objectives Investigate whether 5-HT2C receptor activation is necessary for rate-decreasing effects produced in an ICSS procedure in rats by the 5-HT-selective monoamine releaser fenfluramine and the non-selective releasers napthylisopropylamine (PAL-287) and (+)-3,4-methylenedioxymethamphetamine ((+)-MDMA). Methods Adult male Sprague-Dawley rats with electrodes implanted in the medial forebrain bundle were trained to lever press for brain stimulation under a “frequency-rate” ICSS procedure. Effectiveness of the 5-HT2C antagonist SB 242,084 was evaluated to block rate-decreasing effects produced by (1) the 5-HT2C agonist Ro 60-0175, (2) the 5-HT-selective releaser fenfluramine, and (3) the mixed-action dopamine (DA)/norepinephrine (NE)/5-HT releasers PAL-287 (1.0-5.6 mg/kg), and (+)-MDMA (1.0-3.2 mg/kg). For comparison, effectiveness of SB 242,084 to alter rate-decreasing effects of the kappa opioid receptor agonist U69,593 and rate-increasing effects of the DA>5-HT releaser amphetamine were also examined. Results SB 242,084 pretreatment blocked rate-decreasing effects of Ro 60-0175 and fenfluramine, but not the rate-decreasing effects of U69,593 or the rate-increasing effects of amphetamine. SB 242,084 blunted the rate-decreasing effects and enhanced expression of rate-increasing effects of PAL-287 and (+)-MDMA. Conclusions These data suggest that 5-HT2C receptor activation contributes to rate-decreasing effects that are produced by selective and mixed-action 5-HT releasers in rats and that may oppose and limit the expression of abuse-related ICSS facilitation by these compounds. PMID:26041338

  6. Splicing factors control C. elegans behavioural learning in a single neuron by producing DAF-2c receptor

    PubMed Central

    Tomioka, Masahiro; Naito, Yasuki; Kuroyanagi, Hidehito; Iino, Yuichi

    2016-01-01

    Alternative splicing generates protein diversity essential for neuronal properties. However, the precise mechanisms underlying this process and its relevance to physiological and behavioural functions are poorly understood. To address these issues, we focused on a cassette exon of the Caenorhabditis elegans insulin receptor gene daf-2, whose proper variant expression in the taste receptor neuron ASER is critical for taste-avoidance learning. We show that inclusion of daf-2 exon 11.5 is restricted to specific neuron types, including ASER, and is controlled by a combinatorial action of evolutionarily conserved alternative splicing factors, RBFOX, CELF and PTB families of proteins. Mutations of these factors cause a learning defect, and this defect is relieved by DAF-2c (exon 11.5+) isoform expression only in a single neuron ASER. Our results provide evidence that alternative splicing regulation of a single critical gene in a single critical neuron is essential for learning ability in an organism. PMID:27198602

  7. Role of the intracellular domain of the human type I interferon receptor 2 chain (IFNAR2c) in interferon signaling. Expression of IFNAR2c truncation mutants in U5A cells.

    PubMed

    Russell-Harde, D; Wagner, T C; Rani, M R; Vogel, D; Colamonici, O; Ransohoff, R M; Majchrzak, B; Fish, E; Perez, H D; Croze, E

    2000-08-01

    A human cell line (U5A) lacking the type I interferon (IFN) receptor chain 2 (IFNAR2c) was used to determine the role of the IFNAR2c cytoplasmic domain in regulating IFN-dependent STAT activation, interferon-stimulated gene factor 3 (ISGF3) and c-sis-inducible factor (SIF) complex formation, gene expression, and antiproliferative effects. A panel of U5A cells expressing truncation mutants of IFNAR2c on their cell surface were generated for study. Janus kinase (JAK) activation was detected in all mutant cell lines; however, STAT1 and STAT2 activation was observed only in U5A cells expressing full-length IFNAR2c and IFNAR2c truncated at residue 462 (R2.462). IFNAR2c mutants truncated at residues 417 (R2. 417) and 346 (R2.346) or IFNAR2c mutant lacking tyrosine residues in its cytoplasmic domain (R2.Y-F) render the receptor inactive. A similar pattern was observed for IFN-inducible STAT activation, STAT complex formation, and STAT-DNA binding. Consistent with these data, IFN-inducible gene expression was ablated in U5A, R2.Y-F, R2.417, and R2.346 cell lines. The implications are that tyrosine phosphorylation and the 462-417 region of IFNAR2c are independently obligatory for receptor activation. In addition, the distal 53 amino acids of the intracellular domain of IFNAR2c are not required for IFN-receptor mediated STAT activation, ISFG3 or SIF complex formation, induction of gene expression, and inhibition of thymidine incorporation. These data demonstrate for the first time that both tyrosine phosphorylation and a specific domain of IFNAR2c are required in human cells for IFN-dependent coupling of JAK activation to STAT phosphorylation, gene induction, and antiproliferative effects. In addition, human and murine cells appear to require different regions of the cytoplasmic domain of IFNAR2c for regulation of IFN responses.

  8. Down-regulation of cerebellar 5-HT(2C) receptors in pilocarpine-induced epilepsy in rats: therapeutic role of Bacopa monnieri extract.

    PubMed

    Krishnakumar, Amee; Abraham, Pretty Mary; Paul, Jes; Paulose, C S

    2009-09-15

    Epilepsy is a syndrome of episodic brain dysfunction characterized by recurrent unpredictable, spontaneous seizures. Cerebellar dysfunction is a recognized complication of temporal lobe epilepsy and it is associated with seizure generation, motor deficits and memory impairment. Serotonin is known to exert a modulatory action on cerebellar function through 5HT(2C) receptors. 5-HT(2C) receptors are novel targets for developing anti-convulsant drugs. In the present study, we investigated the changes in the 5-HT(2C) receptors binding and gene expression in the cerebellum of control, epileptic and Bacopa monnieri treated epileptic rats. There was a significant down regulation of the 5-HT content (p<0.001), 5-HT(2C) gene expression (p<0.001) and 5-HT(2C) receptor binding (p<0.001) with an increased affinity (p<0.001). Carbamazepine and B. monnieri treatments to epileptic rats reversed the down regulated 5-HT content (p<0.01), 5-HT(2C) receptor binding (p<0.001) and gene expression (p<0.01) to near control level. Also, the Rotarod test confirms the motor dysfunction and recovery by B. monnieri treatment. These data suggest the neuroprotective role of B. monnieri through the upregulation of 5-HT(2C) receptor in epileptic rats. This has clinical significance in the management of epilepsy.

  9. RNA editing of the serotonin 2C receptor and expression of Gαq protein: genetic mouse models do not support a role for regulation or compensation

    PubMed Central

    Canal, Clinton E.; Mahautmr, Kontip C.; Cao, Chike; Sanders-Bush, Elaine; Airey, David C.

    2009-01-01

    The serotonin 2C (5-HT2C) receptor undergoes RNA editing at five bases in a region of the pre-mRNA encoding the second intracellular loop, generating many unique 5-HT2C receptor isoforms. Mechanisms regulating in vivo expression of different edited 5-HT2C receptor isoforms are poorly understood, as are the adaptive consequences of variation in editing profiles. Recent findings suggest a putative relationship between expression levels of Gαq/11 protein and the degree of editing of 5-HT2C receptor transcripts. To elucidate the potential regulatory or adaptive role of Gαq/11 protein levels, we quantified editing of 5-HT2C receptor RNA transcripts in Gαq null mice and protein levels of Gαq and Gα11 in transgenic male mice solely expressing either the non-edited (INI) or the fully edited (VGV) isoforms of the 5-HT2C receptor. Pyrosequencing of RNA isolated from amygdaloid cortex in Gαq null and wild-type mice revealed no significant differences in 5-HT2C receptor mRNA editing profiles. Cortical tissue from INI/y, VGV/y, and wild-type mice was assayed for expression of Gαq and Gα11 subunits by Western blotting. No differences in signal density between wild-type and INI/y or VGV/y groups were found, indicating equivalent levels of Gαq and Gα11 protein. Together, these data do not support a causal or compensatory relationship between 5-HT2C receptor RNA editing and Gq protein levels. PMID:19154337

  10. Clozapine, but not olanzapine, disrupts conditioned avoidance response in rats by antagonizing 5-HT2A/2C receptors.

    PubMed

    Li, Ming; Sun, Tao; Mead, Alexa

    2012-04-01

    The present study was designed to assess the role of 5-HT(2A/2C) receptors in the acute and repeated effect of clozapine and olanzapine in a rat conditioned avoidance response model, a validated model of antipsychotic activity. Male Sprague-Dawley rats that were previously treated with either phencyclidine (0.5-2.0 mg/kg, sc), amphetamine (1.25-5.0 mg/kg, sc), or saline and tested in a prepulse inhibition of acoustic startle study were used. They were first trained to acquire avoidance response to a white noise (CS1) and a pure tone (CS2) that differed in their ability to predict the occurrence of footshock. Those who acquired avoidance response were administered with clozapine (10.0 mg/kg, sc) or olanzapine (1.0 mg/kg, sc) together with either saline or 1-2,5-dimethoxy-4-iodo-amphetamine (DOI, a selective 5-HT(2A/2C) agonist, 1.0 or 2.5 mg/kg, sc), and their conditioned avoidance responses were tested for four consecutive days. After two drug-free retraining days, the long-term repeated effect was assessed in a challenge test during which all rats were injected with a low dose of clozapine (5 mg/kg, sc) or olanzapine (0.5 mg/kg). Results show that pretreatment of DOI dose-dependently reversed the acute disruptive effect of clozapine on both CS1 and CS2 avoidance responses, whereas it had little effect in reversing the acute effect of olanzapine. On the challenge test, pretreatment of DOI did not alter the clozapine-induced tolerance or the olanzapine-induced sensitization effect. These results confirmed our previous findings and suggest that clozapine, but not olanzapine, acts on through 5-HT(2A/2C) receptors to achieve its acute avoidance disruptive effect and likely its therapeutic effects. The long-term clozapine tolerance and olanzapine sensitization effects appear to be mediated by non-5-HT(2A/2C) receptors.

  11. Arecoline inhibits and destabilizes agrin-induced acetylcholine receptor cluster formation in C2C12 myotubes.

    PubMed

    Chang, Yung-Fu; Liu, Ting-Yuan; Liu, Shao-Tung

    2013-10-01

    Areca nut (Areca catechu) is chewed as a medical and psychoactive food by roughly 10% of the world population. Areca nut chewing may lead to low birth weight, premature delivery and impaired muscle development. Our previous study showed that arecoline, a major alkaloid in the areca nut, inhibited the myogenic differentiation of C2C12 myoblastic cells. The clustering of acetylcholine receptors (AChRs) in the postsynaptic membrane at the neuromuscular junction (NMJ) by agrin, a signaling protein released by motor neurons, is critical for the development of functional muscles. Here, we further investigate whether arecoline affects the AChR clustering using cultured C2C12 myotubes. Rhodamine-conjugated α-bungarotoxin was used to detect the presence of AChR clusters. Our results showed that arecoline inhibited the formation of agrin-induced AChR clusters and destabilized agrin-induced or spontaneous AChR cluster formation. In addition, arecoline inhibited the expression of myogenin in C2C12 myotubes. These results shed light on the important role of arecoline on the detrimental effect of areca nut to muscle development. PMID:23933062

  12. Delineation of the complement receptor type 2-C3d complex by site-directed mutagenesis and molecular docking.

    PubMed

    Shaw, Craig D; Storek, Michael J; Young, Kendra A; Kovacs, James M; Thurman, Joshua M; Holers, V Michael; Hannan, Jonathan P

    2010-12-10

    The interactions between the complement receptor type 2 (CR2) and the C3 complement fragments C3d, C3dg, and iC3b are essential for the initiation of a normal immune response. A crystal-derived structure of the two N-terminal short consensus repeat (SCR1-2) domains of CR2 in complex with C3d has previously been elucidated. However, a number of biochemical and biophysical studies targeting both CR2 and C3d appear to be in conflict with these structural data. Previous mutagenesis and heteronuclear NMR spectroscopy studies directed toward the C3d-binding site on CR2 have indicated that the CR2-C3d cocrystal structure may represent an encounter/intermediate or nonphysiological complex. With regard to the CR2-binding site on C3d, mutagenesis studies by Isenman and coworkers [Isenman, D. E., Leung, E., Mackay, J. D., Bagby, S. & van den Elsen, J. M. H. (2010). Mutational analyses reveal that the staphylococcal immune evasion molecule Sbi and complement receptor 2 (CR2) share overlapping contact residues on C3d: Implications for the controversy regarding the CR2/C3d cocrystal structure. J. Immunol. 184, 1946-1955] have implicated an electronegative "concave" surface on C3d in the binding process. This surface is discrete from the CR2-C3d interface identified in the crystal structure. We generated a total of 18 mutations targeting the two (X-ray crystallographic- and mutagenesis-based) proposed CR2 SCR1-2 binding sites on C3d. Using ELISA analyses, we were able to assess binding of mutant forms of C3d to CR2. Mutations directed toward the concave surface of C3d result in substantially compromised CR2 binding. By contrast, targeting the CR2-C3d interface identified in the cocrystal structure and the surrounding area results in significantly lower levels of disruption in binding. Molecular modeling approaches used to investigate disparities between the biochemical data and the X-ray structure of the CR2-C3d cocrystal result in highest-scoring solutions in which CR2 SCR1-2 is

  13. Delineation of the complement receptor type 2-C3d complex by site-directed mutagenesis and molecular docking.

    PubMed

    Shaw, Craig D; Storek, Michael J; Young, Kendra A; Kovacs, James M; Thurman, Joshua M; Holers, V Michael; Hannan, Jonathan P

    2010-12-10

    The interactions between the complement receptor type 2 (CR2) and the C3 complement fragments C3d, C3dg, and iC3b are essential for the initiation of a normal immune response. A crystal-derived structure of the two N-terminal short consensus repeat (SCR1-2) domains of CR2 in complex with C3d has previously been elucidated. However, a number of biochemical and biophysical studies targeting both CR2 and C3d appear to be in conflict with these structural data. Previous mutagenesis and heteronuclear NMR spectroscopy studies directed toward the C3d-binding site on CR2 have indicated that the CR2-C3d cocrystal structure may represent an encounter/intermediate or nonphysiological complex. With regard to the CR2-binding site on C3d, mutagenesis studies by Isenman and coworkers [Isenman, D. E., Leung, E., Mackay, J. D., Bagby, S. & van den Elsen, J. M. H. (2010). Mutational analyses reveal that the staphylococcal immune evasion molecule Sbi and complement receptor 2 (CR2) share overlapping contact residues on C3d: Implications for the controversy regarding the CR2/C3d cocrystal structure. J. Immunol. 184, 1946-1955] have implicated an electronegative "concave" surface on C3d in the binding process. This surface is discrete from the CR2-C3d interface identified in the crystal structure. We generated a total of 18 mutations targeting the two (X-ray crystallographic- and mutagenesis-based) proposed CR2 SCR1-2 binding sites on C3d. Using ELISA analyses, we were able to assess binding of mutant forms of C3d to CR2. Mutations directed toward the concave surface of C3d result in substantially compromised CR2 binding. By contrast, targeting the CR2-C3d interface identified in the cocrystal structure and the surrounding area results in significantly lower levels of disruption in binding. Molecular modeling approaches used to investigate disparities between the biochemical data and the X-ray structure of the CR2-C3d cocrystal result in highest-scoring solutions in which CR2 SCR1-2 is

  14. Serotonin increases ERK1/2 phosphorylation in astrocytes by stimulation of 5-HT2B and 5-HT2C receptors.

    PubMed

    Li, Baoman; Zhang, Shiquen; Li, Min; Hertz, Leif; Peng, Liang

    2010-11-01

    We have previously shown that fluoxetine causes ERK(1/2) phosphorylation in cultured mouse astrocytes mediated exclusively by stimulation of 5-HT(2B) receptors (Li et al., 2008b). This raises the question whether this is also the case for serotonin (5-HT) itself. In the present study serotonin was found to induce ERK(1/2) phosphorylation by stimulation of 5-HT(2B) receptors with high affinity (EC(50): 20-30 pM), and by stimulation of 5-HT(2C) receptor with low affinity (EC(50): 1 microM or higher). ERK(1/2) phosphorylation induced by stimulation of either 5-HT(2B) or 5-HT(2C) receptors was mediated by epidermal growth factor (EGF) receptor transactivation (Peng et al., this issue), shown by the inhibitory effect of AG1478, an inhibitor of the EGF receptor tyrosine kinase, and GM6001, an inhibitor of Zn-dependent metalloproteinases, and thus of 5-HT(2B) receptor-mediated EGF receptor agonist release. It is discussed that the high potency of the 5-HT(2B)-mediated effect is consistent with literature data for binding affinity of serotonin to cloned human 5-HT(2B) receptors and with observations of low extracellular concentrations of serotonin in brain, which would allow a demonstrated moderate and modality-dependent increase in specific brain areas to activate 5-HT(2B) receptors. In contrast the relevance of the observed 5-HT(2C) receptors on astrocytes is questioned.

  15. Activation of serotonin(2C) receptors in the lateral habenular nucleus increases the expression of depression-related behaviors in the hemiparkinsonian rat.

    PubMed

    Han, Ling-Na; Zhang, Li; Li, Li-Bo; Sun, Yi-Na; Wang, Yong; Chen, Li; Guo, Yuan; Zhang, Yu-Ming; Zhang, Qiao-Jun; Liu, Jian

    2015-06-01

    The roles of lateral habenular nucleus (LHb) glutamate neurons and serotonin2C (5-HT2C) receptors in depression are poorly understood, particularly in Parkinson's disease-associated depression. Here we assessed the importance of LHb glutamate neurons and 5-HT2C receptors for depressive-like behaviors in sham-operated rats and rats with unilateral 6-hydroxydopamine lesions of the substantia nigra. The lesion induced depressive-like responses compared to sham-operated rats. Intra-LHb injection of potent, selective 5-HT2C receptor agonist Ro60-0175 decreased sucrose consumption and increased immobility time in sham-operated rats, indicating the induction of depressive-like responses, and intra-LHb injection of Ro60-0175 further increased the expression of depressive-like behaviors in the lesioned rats. Activation of LHb 5-HT2C receptors by the local administration of Ro60-0175 increased the firing rate of EAAC1 (a neuronal glutamate transporter)-positive neurons and percentage of the neurons with burst-firing pattern in the two groups of rats. Compared to sham-operated rats, the duration of Ro60-0175 action on the firing rate of EAAC1-positive neurons was markedly prolonged in the lesioned rats. Intra-LHb injection of Ro60-0175 decreased dopamine, 5-HT and noradrenaline levels in the medial prefrontal cortex, habenula, hippocampus and amygdala in sham-operated and the lesioned rats. The lesion did not change the percentage of EAAC1/5-HT2C receptor co-expressing neurons in the LHb. These findings indicate that activation of 5-HT2C receptors in the LHb increases firing activity of LHb glutamate neurons and then decreases monoamine levels in several brain regions, which increase the expression of depressive-like behaviors. Further, our results also suggest that the lesion leads to hyperfunctionality of 5-HT2C receptors on glutamate neurons of the LHb.

  16. Hydroxylamine enhances glucose uptake in C2C12 skeletal muscle cells through the activation of insulin receptor substrate 1.

    PubMed

    Kimura, Taro; Kato, Eisuke; Machikawa, Tsukasa; Kimura, Shunsuke; Katayama, Shinji; Kawabata, Jun

    2014-02-28

    Diabetes mellitus is a global disease, and the number of patients with it is increasing. Of various agents for treatment, those that directly act on muscle are currently attracting attention because muscle is one of the main tissues in the human body, and its metabolism is decreased in type II diabetes. In this study, we found that hydroxylamine (HA) enhances glucose uptake in C2C12 myotubes. Analysis of HA's mechanism revealed the involvement of IRS1, PI3K and Akt that is related to the insulin signaling pathway. Further investigation about the activation mechanism of insulin receptor or IRS1 by HA may provide a way to develop a novel anti-diabetic agent alternating to insulin.

  17. Functional Divergence of the Nuclear Receptor NR2C1 as a Modulator of Pluripotentiality During Hominid Evolution.

    PubMed

    Baker, Jennifer L; Dunn, Katherine A; Mingrone, Joseph; Wood, Bernard A; Karpinski, Beverly A; Sherwood, Chet C; Wildman, Derek E; Maynard, Thomas M; Bielawski, Joseph P

    2016-06-01

    Genes encoding nuclear receptors (NRs) are attractive as candidates for investigating the evolution of gene regulation because they (1) have a direct effect on gene expression and (2) modulate many cellular processes that underlie development. We employed a three-phase investigation linking NR molecular evolution among primates with direct experimental assessment of NR function. Phase 1 was an analysis of NR domain evolution and the results were used to guide the design of phase 2, a codon-model-based survey for alterations of natural selection within the hominids. By using a series of reliability and robustness analyses we selected a single gene, NR2C1, as the best candidate for experimental assessment. We carried out assays to determine whether changes between the ancestral and extant NR2C1s could have impacted stem cell pluripotency (phase 3). We evaluated human, chimpanzee, and ancestral NR2C1 for transcriptional modulation of Oct4 and Nanog (key regulators of pluripotency and cell lineage commitment), promoter activity for Pepck (a proxy for differentiation in numerous cell types), and average size of embryological stem cell colonies (a proxy for the self-renewal capacity of pluripotent cells). Results supported the signal for alteration of natural selection identified in phase 2. We suggest that adaptive evolution of gene regulation has impacted several aspects of pluripotentiality within primates. Our study illustrates that the combination of targeted evolutionary surveys and experimental analysis is an effective strategy for investigating the evolution of gene regulation with respect to developmental phenotypes. PMID:27075724

  18. Functional selectivity of hallucinogenic phenethylamine and phenylisopropylamine derivatives at human 5-hydroxytryptamine (5-HT)2A and 5-HT2C receptors.

    PubMed

    Moya, Pablo R; Berg, Kelly A; Gutiérrez-Hernandez, Manuel A; Sáez-Briones, Patricio; Reyes-Parada, Miguel; Cassels, Bruce K; Clarke, William P

    2007-06-01

    2,5-Dimethoxy-4-substituted phenylisopropylamines and phenethylamines are 5-hydroxytryptamine (serotonin) (5-HT)(2A/2C) agonists. The former are partial to full agonists, whereas the latter are partial to weak agonists. However, most data come from studies analyzing phospholipase C (PLC)-mediated responses, although additional effectors [e.g., phospholipase A(2) (PLA(2))] are associated with these receptors. We compared two homologous series of phenylisopropylamines and phenethylamines measuring both PLA(2) and PLC responses in Chinese hamster ovary-K1 cells expressing human 5-HT(2A) or 5-HT(2C) receptors. In addition, we assayed both groups of compounds as head shake inducers in rats. At the 5-HT(2C) receptor, most compounds were partial agonists for both pathways. Relative efficacy of some phenylisopropylamines was higher for both responses compared with their phenethylamine counterparts, whereas for others, no differences were found. At the 5-HT(2A) receptor, most compounds behaved as partial agonists, but unlike findings at 5-HT(2C) receptors, all phenylisopropylamines were more efficacious than their phenethylamine counterparts. 2,5-Dimethoxyphenylisopropylamine activated only the PLC pathway at both receptor subtypes, 2,5-dimethoxyphenethylamine was selective for PLC at the 5-HT(2C) receptor, and 2,5-dimethoxy-4-nitrophenethylamine was PLA(2)-specific at the 5-HT(2A) receptor. For both receptors, the rank order of efficacy of compounds differed depending upon which response was measured. The phenylisopropylamines were strong head shake inducers, whereas their phenethylamine congeners were not, in agreement with in vitro results and the involvement of 5-HT(2A) receptors in the head shake response. Our results support the concept of functional selectivity and indicate that subtle changes in ligand structure can result in significant differences in the cellular signaling profile.

  19. A comparison of the behavioural effects of 5-HT2A and 5-HT2C receptor agonists in the pigeon.

    PubMed

    Wolff, M C; Leander, J D

    2000-08-01

    Activity at the 5-HT2A receptor versus that of the 5-HT2C receptor was studied in three behavioural paradigms. In pigeons trained to discriminate 0.32 mg/kg of 1-(2,5-diemethoxy-4-iodophenyl)-2-aminopropane (DOI) (a mixed 5-HT2A/C receptor agonist) from vehicle, quipazine (0.1-1 mg/kg) and m-chlorophenylpiperazine (mCPP) (1-3 mg/kg) substituted for DOI in a dose-related manner, and this generalization was blocked by MDL100907 (0.0001-0.01 mg/kg), a selective 5-HT2A receptor antagonist. RO60-0175 (a relatively selective 5-HT2C agonist) induced partial substitution at 3 mg/kg that was antagonized by both MDL100907 and by 3 mg/kg of SB242084, a relatively selective 5-HT2C antagonist. MK212 (a mixed 5-HT2C/A agonist) induced partial substitution that was antagonized by SB242084, but not by MDL100907. On a progressive ratio 5 operant schedule (PR5) for food reinforcement, DOI, quipazine, mCPP, MK212 and R060-0175 decreased the break point; mCPP, DOI, MK212 and quipazine also induced vomiting. Although MDL100907 antagonized both the reductions of break point and vomiting, SB242084 only partially attenuated the decrease in break point observed with MK212 and DOI, and was unable to eliminate vomiting. Thus pharmacological activity at the 5-HT2A receptor can be behaviourally distinguished from pharmacological activity at the 5-HT2C receptor in the pigeon. Furthermore, the decrease in the break point of a PR5 schedule induced by 5-HT2C receptor agonists may be related to decreased appetite, whereas that induced by 5-HT2A receptor agonists may be due to unrelated factors, such as emesis. PMID:11103887

  20. The influence of 5-HT(2A) activity on a 5-HT(2C) specific in vivo assay used for early identification of multiple acting SERT and 5-HT(2C) receptor ligands.

    PubMed

    Éliás, Olivér; Nógrádi, Katalin; Domány, György; Szakács, Zoltán; Kóti, János; Szántay, Csaba; Tarcsay, Ákos; Keserű, György M; Gere, Anikó; Kiss, Béla; Kurkó, Dalma; Kolok, Sándor; Némethy, Zsolt; Kapui, Zoltán; Hellinger, Éva; Vastag, Mónika; Sághy, Katalin; Kedves, Rita; Gyertyán, István

    2016-02-01

    As a result of our exploratory programme aimed at elaborating dually acting compounds towards the serotonin (5-HT) transporter (SERT) and the 5-HT2C receptor a novel series of 3-amino-1-phenylpropoxy substituted diphenylureas was identified. From that collection two promising compounds (2 and 3) exhibiting highest 5-HT2C receptor affinity strongly inhibited the 5-HT2C receptor agonist 1-(3-chlorophenyl)piperazine (mCPP) induced hypomotility in mice. In further pursuance of that objective (2-aminoethyl)(benzyl)sulfamoyl diphenylureas and diphenylpiperazines have also been elaborated. Herein we report the synthesis of potent multiple-acting compounds from this new class. However, when two optimized representatives (6 and 14) possessing the desired in vitro profile were tested neither reduced the motor activity of mCPP treated animals. Comparative albeit limited in vitro structure-activity relationship (SAR) analysis and detailed in vivo studies are discussed and explanation for their intricate behaviour is proposed.

  1. Human Serotonin 5-HT2C G Protein-Coupled Receptor Homology Model from the β2 Adrenoceptor Structure: Ligand Docking and Mutagenesis Studies

    PubMed Central

    RDOVA-SINTJAGO, TANIA CÓ; VILLA, NANCY; CANAL, CLINTON; BOOTH, RAYMOND

    2013-01-01

    Activation of the serotonin (5-hydroxytryptamine, 5-HT) 5HT2C G protein-coupled receptor (GPCR) is proposed as novel pharmacotherapy for obesity and neuropsychiatric disorders. In contrast, activation of the 5-HT2A and 5-HT2B GPCRs is associated with untoward hallucinogenic and cardiopulmonary effects, respectively. There is no crystal structure available to guide design of 5-HT2C receptor-specific ligands. For this reason, a homology model of the 5-HT2C receptor was built based on the crystal structure of the human β2 adrenoceptor GPCR to delineate molecular determinants of ligand–receptor interactions for drug design purposes. Computational and experimental studies were carried out to validate the model. Binding of N(CH3)2-PAT [(1R, 3S)-(−)-trans-1-phenyl-3-N,N-dimethylamino-1,2,3,4-tetrahydronaphthalene], a novel 5-HT2C agonist/5-HT2A/2B inverse agonist, and its secondary [NH(CH3)-PAT] and primary (NH2-PAT) amine analogs were studied at the 5-HT2C wild type (WT) and D3.32A, S3.36A, and Y7.43A 5-HT2C point-mutated receptors. Reference ligands included the tertiary amines lisuride and mesulergine and the primary amine 5-HT. Modeling results indicated that 5-HT2C residues D3.32, S3.36, and Y7.43 play a role in ligand binding. Experimental ligand binding results with WT and point-mutated receptors confirmed the impact of D3.32, S3.36, and Y7.43 on ligand affinity. PMID:24244046

  2. Variation within the serotonin (5-HT) 5-HT2C receptor system aligns with vulnerability to cocaine cue reactivity

    PubMed Central

    Anastasio, N C; Liu, S; Maili, L; Swinford, S E; Lane, S D; Fox, R G; Hamon, S C; Nielsen, D A; Cunningham, K A; Moeller, F G

    2014-01-01

    Cocaine dependence remains a challenging public health problem with relapse cited as a major determinant in its chronicity and severity. Environmental contexts and stimuli become reliably associated with its use leading to durable conditioned responses (‘cue reactivity') that can predict relapse as well as treatment success. Individual variation in the magnitude and influence of cue reactivity over behavior in humans and animals suggest that cue-reactive individuals may be at greater risk for the progression to addiction and/or relapse. In the present translational study, we investigated the contribution of variation in the serotonin (5-HT) 5-HT2C receptor (5-HT2CR) system in individual differences in cocaine cue reactivity in humans and rodents. We found that cocaine-dependent subjects carrying a single nucleotide polymorphism (SNP) in the HTR2C gene that encodes for the conversion of cysteine to serine at codon 23 (Ser23 variant) exhibited significantly higher attentional bias to cocaine cues in the cocaine-word Stroop task than those carrying the Cys23 variant. In a model of individual differences in cocaine cue reactivity in rats, we identified that high cocaine cue reactivity measured as appetitive approach behavior (lever presses reinforced by the discrete cue complex) correlated with lower 5-HT2CR protein expression in the medial prefrontal cortex and blunted sensitivity to the suppressive effects of the selective 5-HT2CR agonist WAY163909. Our translational findings suggest that the functional status of the 5-HT2CR system is a mechanistic factor in the generation of vulnerability to cocaine-associated cues, an observation that opens new avenues for future development of biomarker and therapeutic approaches to suppress relapse in cocaine dependence. PMID:24618688

  3. Stimulation of 5-HT2C Receptors Improves Cognitive Deficits Induced by Human Tryptophan Hydroxylase 2 Loss of Function Mutation

    PubMed Central

    Del'Guidice, Thomas; Lemay, Francis; Lemasson, Morgane; Levasseur-Moreau, Jean; Manta, Stella; Etievant, Adeline; Escoffier, Guy; Doré, François Y; Roman, François S; Beaulieu, Jean-Martin

    2014-01-01

    Polymorphisms in the gene encoding the serotonin synthesis enzyme Tph2 have been identified in mental illnesses, including bipolar disorder, major depression, autism, schizophrenia, and ADHD. Deficits in cognitive flexibility and perseverative behaviors are shared common symptoms in these disorders. However, little is known about the impact of Tph2 gene variants on cognition. Mice expressing a human TPH2 variant (Tph2-KI) were used to investigate cognitive consequences of TPH2 loss of function and pharmacological treatments. We applied a recently developed behavioral assay, the automated H-maze, to study cognitive functions in Tph2-KI mice. This assay involves the consecutive discovery of three different rules: a delayed alternation task, a non-alternation task, and a delayed reversal task. Possible contribution of locomotion, reward, and sensory perception were also investigated. The expression of loss-of-function mutant Tph2 in mice was associated with impairments in reversal learning and cognitive flexibility, accompanied by perseverative behaviors similar to those observed in human clinical studies. Pharmacological restoration of 5-HT synthesis with 5-hydroxytryptophan or treatment with the 5-HT2C receptor agonist CP809.101 reduced cognitive deficits in Tph2-KI mice and abolished perseveration. In contrast, treatment with the psychostimulant methylphenidate exacerbated cognitive deficits in mutant mice. Results from this study suggest a contribution of TPH2 in the regulation of cognition. Furthermore, identification of a role for a 5-HT2 receptor agonist as a cognition-enhancing agent in mutant mice suggests a potential avenue to explore for the personalized treatment of cognitive symptoms in humans with reduced 5-HT synthesis and TPH2 polymorphisms. PMID:24196946

  4. Stimulation of 5-HT2C receptors improves cognitive deficits induced by human tryptophan hydroxylase 2 loss of function mutation.

    PubMed

    Del'Guidice, Thomas; Lemay, Francis; Lemasson, Morgane; Levasseur-Moreau, Jean; Manta, Stella; Etievant, Adeline; Escoffier, Guy; Doré, François Y; Roman, François S; Beaulieu, Jean-Martin

    2014-04-01

    Polymorphisms in the gene encoding the serotonin synthesis enzyme Tph2 have been identified in mental illnesses, including bipolar disorder, major depression, autism, schizophrenia, and ADHD. Deficits in cognitive flexibility and perseverative behaviors are shared common symptoms in these disorders. However, little is known about the impact of Tph2 gene variants on cognition. Mice expressing a human TPH2 variant (Tph2-KI) were used to investigate cognitive consequences of TPH2 loss of function and pharmacological treatments. We applied a recently developed behavioral assay, the automated H-maze, to study cognitive functions in Tph2-KI mice. This assay involves the consecutive discovery of three different rules: a delayed alternation task, a non-alternation task, and a delayed reversal task. Possible contribution of locomotion, reward, and sensory perception were also investigated. The expression of loss-of-function mutant Tph2 in mice was associated with impairments in reversal learning and cognitive flexibility, accompanied by perseverative behaviors similar to those observed in human clinical studies. Pharmacological restoration of 5-HT synthesis with 5-hydroxytryptophan or treatment with the 5-HT(2C) receptor agonist CP809.101 reduced cognitive deficits in Tph2-KI mice and abolished perseveration. In contrast, treatment with the psychostimulant methylphenidate exacerbated cognitive deficits in mutant mice. Results from this study suggest a contribution of TPH2 in the regulation of cognition. Furthermore, identification of a role for a 5-HT(2) receptor agonist as a cognition-enhancing agent in mutant mice suggests a potential avenue to explore for the personalized treatment of cognitive symptoms in humans with reduced 5-HT synthesis and TPH2 polymorphisms.

  5. Weight Loss After RYGB Is Independent of and Complementary to Serotonin 2C Receptor Signaling in Male Mice

    PubMed Central

    Carmody, Jill S.; Ahmad, Nadia N.; Machineni, Sriram; Lajoie, Scott

    2015-01-01

    Roux-en-Y gastric bypass (RYGB) typically leads to substantial, long-term weight loss (WL) and diabetes remission, although there is a wide variation in response to RYGB among individual patients. Defining the pathways through which RYGB works should aid in the development of less invasive anti-obesity treatments, whereas identifying weight-regulatory pathways unengaged by RYGB could facilitate the development of therapies that complement the beneficial effects of surgery. Activation of serotonin 2C receptors (5-HT2CR) by serotonergic drugs causes WL in humans and animal models. 5-HT2CR are located on neurons that activate the melanocortin-4 receptors, which are essential for WL after RYGB. We therefore sought to determine whether 5-HT2CR signaling is also essential for metabolic effects of RYGB or whether it is a potentially complementary pathway, the activation of which could extend the benefits of RYGB. Diet-induced obese male mice deficient for the 5-HT2CR and their wild-type littermates underwent RYGB or sham operation. Both groups lost similar amounts of weight after RYGB, demonstrating that the improved metabolic phenotype after RYGB is 5-HT2CR independent. Consistent with this hypothesis, wild-type RYGB-treated mice lost additional weight after the administration of the serotonergic drugs fenfluramine and meta-chlorophenylpiperazine but not the nonserotonergic agent topiramate. The fact that RYGB does not depend on 5-HT2CR signaling suggests that there are important WL mechanisms not fully engaged by surgery that could potentially be harnessed for medical treatment. These results suggest a rational basis for designing medical-surgical combination therapies to optimize clinical outcomes by exploiting complementary physiological mechanisms of action. PMID:26066076

  6. The RAG2 C-terminus and ATM protect genome integrity by controlling antigen receptor gene cleavage.

    PubMed

    Chaumeil, Julie; Micsinai, Mariann; Ntziachristos, Panagiotis; Roth, David B; Aifantis, Iannis; Kluger, Yuval; Deriano, Ludovic; Skok, Jane A

    2013-01-01

    Tight control of antigen-receptor gene rearrangement is required to preserve genome integrity and prevent the occurrence of leukaemia and lymphoma. Nonetheless, mistakes can happen, leading to the generation of aberrant rearrangements, such as Tcra/d-Igh inter-locus translocations that are a hallmark of ataxia telangiectasia-mutated (ATM) deficiency. Current evidence indicates that these translocations arise from the persistence of unrepaired breaks converging at different stages of thymocyte differentiation. Here we show that a defect in feedback control of RAG2 activity gives rise to bi-locus breaks and damage on Tcra/d and Igh in the same T cell at the same developmental stage, which provides a direct mechanism for generating these inter-locus rearrangements. Both the RAG2 C-terminus and ATM prevent bi-locus RAG-mediated cleavage through modulation of three-dimensional conformation (higher-order loops) and nuclear organization of the two loci. This limits the number of potential substrates for translocation and provides an important mechanism for protecting genome stability. PMID:23900513

  7. The 5-HT2C receptor gene Cys23Ser polymorphism influences the intravaginal ejaculation latency time in Dutch Caucasian men with lifelong premature ejaculation.

    PubMed

    Janssen, Paddy Kc; Schaik, Ron van; Olivier, Berend; Waldinger, Marcel D

    2014-01-01

    It has been postulated that the persistent short intravaginal ejaculation latency time (IELT) of men with lifelong premature ejaculation (LPE) is related to 5-hydroxytryptamine (HT)2C receptor functioning. The aim of this study was to investigate the relationship of Cys23Ser 5-HT2C receptor gene polymorphism and the duration of IELT in men with LPE. Therefore, a prospective study was conducted in 64 Dutch Caucasian men with LPE. Baseline IELT during coitus was assessed by stopwatch over a 1-month period. All men were genotyped for Cys23Ser 5-HT2C receptor gene polymorphism. Allele frequencies and genotypes of Cys and Ser variants of 5-HT2C receptor gene polymorphism were determined. Association between Cys/Cys and Ser/Ser genotypes and the natural logarithm of the IELT in men with LPE were investigated. As a result, the geometric mean, median and natural mean IELT were 25.2, 27.0, 33.9 s, respectively. Of all men, 20.0%, 10.8%, 23.1% and 41.5% ejaculated within 10, 10-20, 20-30 and 30-60 s after vaginal penetration. Of the 64 men, the Cys/Cys and Ser/Ser genotype frequency for the Cys23Ser polymorphism of the 5-HT2C receptor gene was 81% and 19%, respectively. The geometric mean IELT of the wildtypes (Cys/Cys) is significantly lower (22.6 s; 95% CI 18.3-27.8 s) than in male homozygous mutants (Ser/Ser) (40.4 s; 95% CI 20.3-80.4 s) (P = 0.03). It is concluded that Cys23Ser 5-HT2C receptor gene polymorphism is associated with the IELT in men with LPE. Men with Cys/Cys genotype have shorter IELTs than men with Ser/Ser genotypes.

  8. The 5-HT2C receptor gene Cys23Ser polymorphism influences the intravaginal ejaculation latency time in Dutch Caucasian men with lifelong premature ejaculation

    PubMed Central

    Janssen, Paddy KC; van Schaik, Ron; Olivier, Berend; Waldinger, Marcel D

    2014-01-01

    It has been postulated that the persistent short intravaginal ejaculation latency time (IELT) of men with lifelong premature ejaculation (LPE) is related to 5-hydroxytryptamine (HT)2C receptor functioning. The aim of this study was to investigate the relationship of Cys23Ser 5-HT2C receptor gene polymorphism and the duration of IELT in men with LPE. Therefore, a prospective study was conducted in 64 Dutch Caucasian men with LPE. Baseline IELT during coitus was assessed by stopwatch over a 1-month period. All men were genotyped for Cys23Ser 5-HT2C receptor gene polymorphism. Allele frequencies and genotypes of Cys and Ser variants of 5-HT2C receptor gene polymorphism were determined. Association between Cys/Cys and Ser/Ser genotypes and the natural logarithm of the IELT in men with LPE were investigated. As a result, the geometric mean, median and natural mean IELT were 25.2, 27.0, 33.9 s, respectively. Of all men, 20.0%, 10.8%, 23.1% and 41.5% ejaculated within 10, 10–20, 20–30 and 30–60 s after vaginal penetration. Of the 64 men, the Cys/Cys and Ser/Ser genotype frequency for the Cys23Ser polymorphism of the 5-HT2C receptor gene was 81% and 19%, respectively. The geometric mean IELT of the wildtypes (Cys/Cys) is significantly lower (22.6 s; 95% CI 18.3–27.8 s) than in male homozygous mutants (Ser/Ser) (40.4 s; 95% CI 20.3–80.4 s) (P = 0.03). It is concluded that Cys23Ser 5-HT2C receptor gene polymorphism is associated with the IELT in men with LPE. Men with Cys/Cys genotype have shorter IELTs than men with Ser/Ser genotypes. PMID:24799636

  9. The 5-HT2C receptor gene Cys23Ser polymorphism influences the intravaginal ejaculation latency time in Dutch Caucasian men with lifelong premature ejaculation.

    PubMed

    Janssen, Paddy Kc; Schaik, Ron van; Olivier, Berend; Waldinger, Marcel D

    2014-01-01

    It has been postulated that the persistent short intravaginal ejaculation latency time (IELT) of men with lifelong premature ejaculation (LPE) is related to 5-hydroxytryptamine (HT)2C receptor functioning. The aim of this study was to investigate the relationship of Cys23Ser 5-HT2C receptor gene polymorphism and the duration of IELT in men with LPE. Therefore, a prospective study was conducted in 64 Dutch Caucasian men with LPE. Baseline IELT during coitus was assessed by stopwatch over a 1-month period. All men were genotyped for Cys23Ser 5-HT2C receptor gene polymorphism. Allele frequencies and genotypes of Cys and Ser variants of 5-HT2C receptor gene polymorphism were determined. Association between Cys/Cys and Ser/Ser genotypes and the natural logarithm of the IELT in men with LPE were investigated. As a result, the geometric mean, median and natural mean IELT were 25.2, 27.0, 33.9 s, respectively. Of all men, 20.0%, 10.8%, 23.1% and 41.5% ejaculated within 10, 10-20, 20-30 and 30-60 s after vaginal penetration. Of the 64 men, the Cys/Cys and Ser/Ser genotype frequency for the Cys23Ser polymorphism of the 5-HT2C receptor gene was 81% and 19%, respectively. The geometric mean IELT of the wildtypes (Cys/Cys) is significantly lower (22.6 s; 95% CI 18.3-27.8 s) than in male homozygous mutants (Ser/Ser) (40.4 s; 95% CI 20.3-80.4 s) (P = 0.03). It is concluded that Cys23Ser 5-HT2C receptor gene polymorphism is associated with the IELT in men with LPE. Men with Cys/Cys genotype have shorter IELTs than men with Ser/Ser genotypes. PMID:24799636

  10. Serotonin increases ERK1/2 phosphorylation in astrocytes by stimulation of 5-HT2B and 5-HT2C receptors.

    PubMed

    Li, Baoman; Zhang, Shiquen; Li, Min; Hertz, Leif; Peng, Liang

    2010-11-01

    We have previously shown that fluoxetine causes ERK(1/2) phosphorylation in cultured mouse astrocytes mediated exclusively by stimulation of 5-HT(2B) receptors (Li et al., 2008b). This raises the question whether this is also the case for serotonin (5-HT) itself. In the present study serotonin was found to induce ERK(1/2) phosphorylation by stimulation of 5-HT(2B) receptors with high affinity (EC(50): 20-30 pM), and by stimulation of 5-HT(2C) receptor with low affinity (EC(50): 1 microM or higher). ERK(1/2) phosphorylation induced by stimulation of either 5-HT(2B) or 5-HT(2C) receptors was mediated by epidermal growth factor (EGF) receptor transactivation (Peng et al., this issue), shown by the inhibitory effect of AG1478, an inhibitor of the EGF receptor tyrosine kinase, and GM6001, an inhibitor of Zn-dependent metalloproteinases, and thus of 5-HT(2B) receptor-mediated EGF receptor agonist release. It is discussed that the high potency of the 5-HT(2B)-mediated effect is consistent with literature data for binding affinity of serotonin to cloned human 5-HT(2B) receptors and with observations of low extracellular concentrations of serotonin in brain, which would allow a demonstrated moderate and modality-dependent increase in specific brain areas to activate 5-HT(2B) receptors. In contrast the relevance of the observed 5-HT(2C) receptors on astrocytes is questioned. PMID:20450948

  11. Prevention of 5-hydroxytryptamine2C receptor RNA editing and alternate splicing in C57BL/6 mice activates the hypothalamic-pituitary-adrenal axis and alters mood

    PubMed Central

    Bombail, Vincent; Qing, Wei; Chapman, Karen E; Holmes, Megan C

    2014-01-01

    The 5-hydroxytryptamine2C (5-HT)2C receptor is widely implicated in the aetiology of affective and eating disorders as well as regulation of the hypothalamo-pituitary-adrenal axis. Signalling through this receptor is regulated by A-to-I RNA editing, affecting three amino acids in the protein sequence, with unedited transcripts encoding a receptor (INI) that, in vitro, is hyperactive compared with edited isoforms. Targeted alteration (knock-in) of the Htr2c gene to generate ‘INI’ mice with no alternate splicing, solely expressing the full-length unedited isoform, did not produce an overt metabolic phenotype or altered anxiety behaviour, but did display reduced depressive-like and fear-associated behaviours. INI mice exhibited a hyperactive hypothalamo-pituitary-adrenal axis, with increased nadir plasma corticosterone and corticotrophin-releasing hormone expression in the hypothalamus but responded normally to chronic stress and showed normal circadian activity and activity in a novel environment. The circadian patterns of 5-HT2C receptor mRNA and mbii52, a snoRNA known to regulate RNA editing and RNA splicing of 5-HT2C receptor pre-mRNA, were altered in INI mice compared with wild-type control mice. Moreover, levels of 5-HT1A receptor mRNA were increased in the hippocampus of INI mice. These gene expression changes may underpin the neuroendocrine and behavioural changes observed in INI mice. However, the phenotype of INI mice was not consistent with a globally hyperactive INI receptor encoded by the unedited transcript in the absence of alternate splicing. Hence, the in vivo outcome of RNA editing may be neuronal cell type specific. PMID:25257581

  12. Expression of hippocampal serotonin receptors 5-HT2C and 5-HT5A in a rat model of diet-induced obesity supplemented with tryptophan.

    PubMed

    Lopez-Esparza, Sarahi; Berumen, Laura C; Padilla, Karla; Miledi, Ricardo; García-Alcocer, Guadalupe

    2015-05-01

    Food intake regulation is a complex mechanism that involves endogenous substances and central nervous system structures like hypothalamus or even hippocampus. The neurotransmitter serotonin is distinguished as food intake mediator; within its multiples receptors, the 5-HT2C type is characterized by its inhibitory appetite action but there is no information about 5-HT5A receptors involvement in obesity disease. It is also unknown if there are any changes in the receptors expression in rats hippocampus with induced obesity during development through a high energy diet (HED) supplemented with tryptophan (W). To appreciate the receptors expression pattern in the hippocampus, obesity was induced to young Sprague Dawley rats through a HED and supplemented with W. Immunocytochemical and western blot techniques were used to study the receptor distribution and quantify the protein expression. The rats with HED diet developed obesity until week 13 of treatment. The 5-HT2C receptor expression decreased in CA1, CA2, CA3 and DG of HED group; and also in CA2, CA3 and DG for HEDW group. The 5-HT5A receptor expression only decreased in DG for HED group. Variations of the two serotonin receptors subtypes support their potential role in obesity.

  13. Lorcaserin, A 5-HT2C Receptor Agonist, Reduces Body Weight by Decreasing Energy Intake without Influencing Energy Expenditure

    PubMed Central

    Martin, Corby K.; Redman, Leanne M.; Zhang, Jinkun; Sanchez, Matilde; Anderson, Christen M.; Smith, Steven R.

    2011-01-01

    Context: Lorcaserin, a selective 5-hydroxytryptamine (5-HT)2C receptor agonist, reduces body weight. It is unclear whether weight loss is due to reduced energy intake (EI) or also to enhanced energy expenditure (EE). Objective: This study tested the effect of lorcaserin on EI and EE. Design, Participants, and Intervention: In a double-blind, randomized, placebo-controlled trial, 57 (39 women) overweight and obese (body mass index, 27–45 kg/m2) adults were randomized to placebo (n = 28) or 10 mg twice daily lorcaserin (n = 29) for 56 d. Weight maintenance was imposed during d 1–7. Beginning on d 8, participants followed a diet and exercise plan targeting a 600 kcal/d deficit. Outcomes: At baseline and after 7 and 56 d of treatment, we measured body weight, body composition (dual x-ray absorptiometry), blood pressure, heart rate, EI at lunch and dinner, subjective appetite ratings, and 24-h EE and 24-h-respiratory quotient (RQ), measured by indirect calorimetry in a respiratory chamber. Results: After 7 d of weight maintenance, EI was significantly (P < 0.01) reduced with lorcaserin but not placebo (mean ± sem for lorcaserin, −286 ± 86 kcal; placebo, −147 ± 89 kcal). After 56 d, lorcaserin resulted in significantly larger reductions in body weight (lorcaserin, −3.8 ± 0.4 kg; placebo, −2.2 ± 0.5 kg; P < 0.01), EI (lorcaserin, −470 ± 87 kcal; placebo, −205 ± 91 kcal; P < .05), and appetite ratings than in placebo. Changes in 24-h EE and 24-h RQ did not differ between groups, even after 24-h EE was adjusted for body weight and composition. Compared with placebo, lorcaserin had no effect on systolic or diastolic blood pressure or heart rate after 56 d. Conclusions: Lorcaserin reduces body weight through reduced EI, not altered EE or RQ. PMID:21190985

  14. Nicotinic receptor-dependent and -independent effects of galantamine, an acetylcholinesterase inhibitor, on the non-neuronal acetylcholine system in C2C12 cells.

    PubMed

    Oikawa, Shino; Mano, Asuka; Iketani, Mitsue; Kakinuma, Yoshihiko

    2015-11-01

    We previously reported that satellite cells possess the ability to produce angiogenic factors, including fibroblast growth factor (FGF)-2 and vascular endothelial growth factor (VEGF) in vivo. However, whether C2C12 cells possess a non-neuronal cholinergic system (NNCS) or non-neuronal ACh (NNA) remains to be studied; therefore, we investigated the system using C2C12 cells and its regulatory mechanisms. C2C12 cells synthesized ACh, the level of which was comparable with that of cardiomyocytes, and the synthesis was augmented by the acetylcholinesterase inhibitor galantamine. The ChAT promoter activity was upregulated by nicotine or galantamine, partly through nicotinic receptors for both agents as well as through a non-nicotinic receptor pathway for galantamine. Further, VEGF secretion by C2C12 cells was also increased by nicotine or galantamine through nicotinic receptors as well as partly through non-nicotinic pathways in the case of galantamine. These results suggest that C2C12 cells are equipped with NNCS or NNA, which is positively regulated through nicotinic or non-nicotinic pathways, particularly in the case of galantamine. These results provide a novel concept that myogenic cells expressing NNA can be a therapeutic target for regulating angiogenic factor synthesis. PMID:25979761

  15. Serotonin 5-HT2C receptor-independent expression of hypothalamic NOR1, a novel modulator of food intake and energy balance, in mice

    SciTech Connect

    Nonogaki, Katsunori; Kaji, Takao; Ohba, Yukie; Sumii, Makiko; Wakameda, Mamoru; Tamari, Tomohiro

    2009-08-21

    NOR1, Nur77 and Nurr1 are orphan nuclear receptors and members of the NR4A subfamily. Here, we report that the expression of hypothalamic NOR1 was remarkably decreased in mildly obese {beta}-endorphin-deficient mice and obese db/db mice with the leptin receptor mutation, compared with age-matched wild-type mice, whereas there were no genotypic differences in the expression of hypothalamic Nur77 or Nurr1 in these animals. The injection of NOR1 siRNA oligonucleotide into the third cerebral ventricle significantly suppressed food intake and body weight in mice. On the other hand, the decreases in hypothalamic NOR1 expression were not found in non-obese 5-HT2C receptor-deficient mice. Moreover, systemic administration of m-chlorophenylpiperazine (mCPP), a 5-HT2C/1B receptor agonist, had no effect on hypothalamic NOR1 expression, while suppressing food intake in {beta}-endorphin-deficient mice. These findings suggest that 5-HT2C receptor-independent proopiomelanocortin-derived peptides regulate the expression of hypothalamic NOR1, which is a novel modulator of feeding behavior and energy balance.

  16. 5-HT2C Receptor Desensitization Moderates Anxiety in 5-HTT Deficient Mice: From Behavioral to Cellular Evidence

    PubMed Central

    Martin, Cédric BP; Martin, Vincent S.; Trigo, José M.; Chevarin, Caroline; Maldonado, Rafael; Fink, Latham H.; Cunningham, Kathryn A.; Hamon, Michel; Lanfumey, Laurence

    2015-01-01

    Background: Desensitization and blockade of 5-HT2C receptors (5-HT2CR) have long been thought to be central in the therapeutic action of antidepressant drugs. However, besides behavioral pharmacology studies, there is little in vivo data documenting antidepressant-induced 5-HT2CR desensitization in specific brain areas. Methods: Mice lacking the 5-HT reuptake carrier (5-HTT-/-) were used to model the consequences of chronic 5-HT reuptake inhibition with antidepressant drugs. The effect of this mutation on 5-HT2CR was evaluated at the behavioral (social interaction, novelty-suppressed feeding, and 5-HT2CR–induced hypolocomotion tests), the neurochemical, and the cellular (RT-qPCR, mRNA editing, and c-fos–induced expression) levels. Results: Although 5-HTT-/- mice had an anxiogenic profile in the novelty-suppressed feeding test, they displayed less 5-HT2CR–mediated anxiety in response to the agonist m-chlorophenylpiperazine in the social interaction test. In addition, 5-HT2CR–mediated inhibition of a stress-induced increase in 5-HT turnover, measured in various brain areas, was markedly reduced in 5-HTT-/- mutants. These indices of tolerance to 5-HT2CR stimulation were associated neither with altered levels of 5-HT2CR protein and mRNA nor with changes in pre-mRNA editing in the frontal cortex. However, basal c-fos mRNA production in cells expressing 5-HT2CR was higher in 5-HTT-/- mutants, suggesting an altered basal activity of these cells following sustained 5-HT reuptake carrier inactivation. Furthermore, the increased c-fos mRNA expression in 5-HT2CR–like immune-positive cortical cells observed in wild-type mice treated acutely with the 5-HT2CR agonist RO-60,0175 was absent in 5-HTT-/- mutants. Conclusions: Such blunted responsiveness of the 5-HT2CR system, observed at the cell signaling level, probably contributes to the moderation of the anxiety phenotype in 5-HTT-/- mice. PMID:25522398

  17. Aromatic interactions impact ligand binding and function at serotonin 5-HT2C G protein-coupled receptors: receptor homology modelling, ligand docking, and molecular dynamics results validated by experimental studies

    NASA Astrophysics Data System (ADS)

    Córdova-Sintjago, Tania; Villa, Nancy; Fang, Lijuan; Booth, Raymond G.

    2014-02-01

    The serotonin (5-hydroxytryptamine, 5-HT) 5-HT2 G protein-coupled receptor (GPCR) family consists of types 2A, 2B, and 2C that share ∼75% transmembrane (TM) sequence identity. Agonists for 5-HT2C receptors are under development for psychoses; whereas, at 5-HT2A receptors, antipsychotic effects are associated with antagonists - in fact, 5-HT2A agonists can cause hallucinations and 5-HT2B agonists cause cardiotoxicity. It is known that 5-HT2A TM6 residues W6.48, F6.51, and F6.52 impact ligand binding and function; however, ligand interactions with these residues at the 5-HT2C receptor have not been reported. To predict and validate molecular determinants for 5-HT2C-specific activation, results from receptor homology modelling, ligand docking, and molecular dynamics simulation studies were compared with experimental results for ligand binding and function at wild type and W6.48A, F6.51A, and F6.52A point-mutated 5-HT2C receptors.

  18. Effect of alkyl glycerophosphate on the activation of peroxisome proliferator-activated receptor gamma and glucose uptake in C2C12 cells

    SciTech Connect

    Tsukahara, Tamotsu; Haniu, Hisao; Matsuda, Yoshikazu

    2013-04-12

    Highlights: •Alkyl-LPA specifically interacts with PPARγ. •Alkyl-LPA treatments induces lipid accumulation in C2C12 cells. •Alkyl-LPA enhanced glucose uptake in C2C12 cells. •Alkyl-LPA-treated C2C12 cells express increased amounts of GLUT4 mRNA. •Alkyl-LPA is a novel therapeutic agent that can be used for the treatment of obesity and diabetes. -- Abstract: Studies on the effects of lipids on skeletal muscle cells rarely examine the effects of lysophospholipids. Through our recent studies, we identified select forms of phospholipids, such as alkyl-LPA, as ligands for the intracellular receptor peroxisome proliferator-activated receptor gamma (PPARγ). PPARγ is a nuclear hormone receptor implicated in many human diseases, including diabetes and obesity. We previously showed that alkyl-LPA is a specific agonist of PPARγ. However, the mechanism by which the alkyl-LPA–PPARγ axis affects skeletal muscle cells is poorly defined. Our objective in the present study was to determine whether alkyl-LPA and PPARγ activation promotes glucose uptake in skeletal muscle cells. Our findings indicate that PPARγ1 mRNA is more abundant than PPARγ2 mRNA in C2C12 cells. We showed that alkyl-LPA (3 μM) significantly activated PPARγ and increased intracellular glucose levels in skeletal muscle cells. We also showed that incubation of C2C12 cells with alkyl-LPA led to lipid accumulation in the cells. These findings suggest that alkyl-LPA activates PPARγ and stimulates glucose uptake in the absence of insulin in C2C12 cells. This may contribute to the plasma glucose-lowering effect in the treatment of insulin resistance.

  19. Activation of serotonin 5-HT(2C) receptor suppresses behavioral sensitization and naloxone-precipitated withdrawal symptoms in morphine-dependent mice.

    PubMed

    Zhang, Gongliang; Wu, Xian; Zhang, Yong-Mei; Liu, Huan; Jiang, Qin; Pang, Gang; Tao, Xinrong; Dong, Liuyi; Stackman, Robert W

    2016-02-01

    Opioid abuse and dependence have evolved into an international epidemic as a significant clinical and societal problem with devastating consequences. Repeated exposure to the opioid, for example morphine, can induce profound, long-lasting behavioral sensitization and physical dependence, which are thought to reflect neuroplasticity in neural circuitry. Central serotonin (5-HT) neurotransmission participates in the development of dependence on and the expression of withdrawal from morphine. Serotonin 5-HT(2C) receptor (5-HT(2C)R) agonists suppress psychostimulant nicotine or cocaine-induced behavioral sensitization and drug-seeking behavior; however, the impact of 5-HT(2C)R agonists on behaviors relevant to opioid abuse and dependence has not been reported. In the present study, the effects of 5-HT(2C)R activation on the behavioral sensitization and naloxone-precipitated withdrawal symptoms were examined in mice underwent repeated exposure to morphine. Male mice received morphine (10 mg/kg, s.c.) to develop behavioral sensitization. Lorcaserin, a 5-HT(2C)R agonist, prevented the induction and expression, but not the development, of morphine-induced behavioral sensitization. Another cohort of mice received increasing doses of morphine over a 7-day period to induce morphine-dependence. Pretreatment of lorcaserin, or the positive control clonidine (an alpha 2-adrenoceptor agonist), ameliorated the naloxone-precipitated withdrawal symptoms. SB 242084, a selective 5-HT(2C)R antagonist, prevented the lorcaserin-mediated suppression of behavioral sensitization and withdrawal. Chronic morphine treatment was associated with an increase in the expression of 5-HT(2C)R protein in the ventral tegmental area, locus coeruleus and nucleus accumbens. These findings suggest that 5-HT(2C)R can modulate behavioral sensitization and withdrawal in morphine-dependent mice, and the activation of 5-HT(2C)R may represent a new avenue for the treatment of opioid addiction.

  20. The role of the 5-HT2A and 5-HT2C receptors in the stimulus effects of hallucinogenic drugs. I: Antagonist correlation analysis.

    PubMed

    Fiorella, D; Rabin, R A; Winter, J C

    1995-10-01

    Investigations conducted over the past 3 decades have demonstrated that serotonergic receptors, specifically the 5-HT2A and 5-HT2C subtypes, play an important role in the behavioral effects of hallucinogenic compounds. The present study was designed to determine the respective significance of these two receptors in the stimulus effects of LSD and (-)DOM in the rat. Specifically, the interactions of a series of serotonergic antagonists (risperidone, pirenpirone, metergoline, ketanserin, loxapine, LY53857, pizotyline, spiperone, cyprohepatadine, mesulergine, promethazine, and thioridazine) with the LSD stimulus and the (-)DOM stimulus in LSD-trained subjects was defined. From these data, IC50 values were determined for the inhibition of the LSD-appropriate responding elicited by either 0.1 mg/kg LSD (15-min pretreatment time) or 0.4 mg/kg (-)DOM (75-min pretreatment). In addition, the affinities of these antagonists for 5-HT2A and 5-HT2C receptors were determined in radioligand competition studies, 5-HT2A affinity correlated significantly with IC50 values for the blockade of the LSD (r = +0.75, P < 0.05) and (-)DOM (r = +0.95, P < 0.001) stimuli in the LSD trained subjects. 5-HT2C affinity did not correlate significantly with either series of IC50 values. These data indicate that (1) the stimulus effects of LSD, and (2) the substitution of (-)DOM for the LSD stimulus are mediated by agonist activity at 5-HT2A receptors.

  1. Methylation of the Constitutive Androstane Receptor Is Involved in the Suppression of CYP2C19 in Hepatitis B Virus-Associated Hepatocellular Carcinoma.

    PubMed

    Tang, Xiaojing; Ge, Lele; Chen, Zhongjian; Kong, Sisi; Liu, Wenhui; Xu, Yingchun; Zeng, Su; Chen, Shuqing

    2016-10-01

    Hepatocellular carcinoma (HCC), one of the most dangerous malignancies with an increasing incidence and a high mortality rate, represents a major international health problem. HCC progression is known to involve genome-wide alteration of epigenetic modifications, leading to aberrant gene expression patterns. The activity of CYP2C19, an important member of the cytochrome P450 superfamily, was reported to be compromised in HCC, but the underlying mechanism remains unclear. To understand whether epigenetic modification in HCC is associated with a change in CYP2C19 activity, we evaluated the expression levels of CYP2C19 and its transcription factors by quantitative real-time polymerase chain reaction using mRNA extracted from both primary hepatocytes and paired tumor versus nontumor liver tissues of patients infected with hepatitis B virus (HBV). DNA methylation was examined by bisulfite sequencing and methylation-specific polymerase chain reaction. Our results indicated that CYP2C19 could be regulated by e-box methylation of the constitutive androstane receptor (CAR). Decreased CYP2C19 expression in tumorous tissues of HBV-infected patients with HCC was highly correlated with suppressed expression and promoter hypermethylation of CAR. Our study demonstrates that aberrant CAR methylation is involved in CYP2C19 regulation in HBV-related HCC and may play a role in liver tumorigenesis.

  2. FCGR2C Polymorphisms Associated with HIV-1 Vaccine Protection Are Linked to Altered Gene Expression of Fc-γ Receptors in Human B Cells.

    PubMed

    Peng, Xinxia; Li, Shuying S; Gilbert, Peter B; Geraghty, Daniel E; Katze, Michael G

    2016-01-01

    The phase III Thai RV144 vaccine trial showed an estimated vaccine efficacy (VE) to prevent HIV-1 infection of 31.2%, which has motivated the search for immune correlates of vaccine protection. In a recent report, several single nucleotide polymorphisms (SNPs) in FCGR2C were identified to associate with the level of VE in the RV144 trial. To investigate the functional significance of these SNPs, we utilized a large scale B cell RNA sequencing database of 462 individuals from the 1000 Genomes Project to examine associations between FCGR2C SNPs and gene expression. We found that the FCGR2C SNPs that associated with vaccine efficacy in RV144 also strongly associated with the expression of FCGR2A/C and one of them also associated with the expression of Fc receptor-like A (FCRLA), another Fc-γ receptor (FcγR) gene that was not examined in the previous report. These results suggest that the expression of FcγR genes is influenced by these SNPs either directly or in linkage with other causal variants. More importantly, these results motivate further investigations into the potential for a causal association of expression and alternative splicing of FCGR2C and other FcγR genes with the HIV-1 vaccine protection in the RV144 trial and other similar studies. PMID:27015273

  3. Synthesis and in vitro evaluation of [18F]FECIMBI-36: A potential agonist PET ligand for 5-HT2A/2C receptors

    PubMed Central

    Prabhakaran, Jaya; Underwood, Mark D.; Dileep Kumar, J. S.; Simpson, Norman R.; Kassir, Suham A.; Bakalian, Mihran J.; Mann, J. John; Arango, Victoria

    2016-01-01

    Radiosynthesis and in vitro evaluation of [18F]-2-(4-bromo-2,5-dimethoxyphenyl)-N-(2-(2-fluoroethoxy)benzyl)ethanamine, ([18F]FECIMBI-36) or ([18F]1), a potential agonist PET imaging agent for 5-HT2A/2C receptors is described. Syntheses of reference standard 1 and the corresponding des-fluoroethyl radiolabeling precursor (2) were achieved with 75% and 65% yields, respectively. In vitro pharmacology assay of FECIMBI-36 by [3H]-ketanserin competition binding assay obtained from NIMH-PDSP showed high affinities to 5-HT2AR (Ki = 1 nM) and 5-HT2CR (Ki = 1.7 nM). Radiolabeling of FECIMBI-36 was achieved from the boc-protected precursor 2 using [18F]-fluoroethyltosylate in presence of Cs2CO3 in DMSO followed by removal of the protective group. [18F]1 was isolated using RP-HPLC in 25 ± 5% yield, purity ≥95% and specific activity 1–2 Ci/μmol (N = 6). In vitro autoradiography studies demonstrate that [18F]1 selectively label 5-HT2A and 5-HT2C receptors in slide-mounted sections of postmortem human brain using phosphor imaging. Our results indicate the potential of [18F]1 for imaging 5-HT2A/2C receptors in the high affinity state in vivo using PET imaging. PMID:26253634

  4. Effect of alkyl glycerophosphate on the activation of peroxisome proliferator-activated receptor gamma and glucose uptake in C2C12 cells.

    PubMed

    Tsukahara, Tamotsu; Haniu, Hisao; Matsuda, Yoshikazu

    2013-04-12

    Studies on the effects of lipids on skeletal muscle cells rarely examine the effects of lysophospholipids. Through our recent studies, we identified select forms of phospholipids, such as alkyl-LPA, as ligands for the intracellular receptor peroxisome proliferator-activated receptor gamma (PPARγ). PPARγ is a nuclear hormone receptor implicated in many human diseases, including diabetes and obesity. We previously showed that alkyl-LPA is a specific agonist of PPARγ. However, the mechanism by which the alkyl-LPA-PPARγ axis affects skeletal muscle cells is poorly defined. Our objective in the present study was to determine whether alkyl-LPA and PPARγ activation promotes glucose uptake in skeletal muscle cells. Our findings indicate that PPARγ1 mRNA is more abundant than PPARγ2 mRNA in C2C12 cells. We showed that alkyl-LPA (3 μM) significantly activated PPARγ and increased intracellular glucose levels in skeletal muscle cells. We also showed that incubation of C2C12 cells with alkyl-LPA led to lipid accumulation in the cells. These findings suggest that alkyl-LPA activates PPARγ and stimulates glucose uptake in the absence of insulin in C2C12 cells. This may contribute to the plasma glucose-lowering effect in the treatment of insulin resistance.

  5. Synthesis and in vitro evaluation of [18F]FECIMBI-36: A potential agonist PET ligand for 5-HT2A/2C receptors.

    PubMed

    Prabhakaran, Jaya; Underwood, Mark D; Kumar, J S Dileep; Simpson, Norman R; Kassir, Suham A; Bakalian, Mihran J; Mann, J John; Arango, Victoria

    2015-09-15

    Radiosynthesis and in vitro evaluation of [(18)F]-2-(4-bromo-2,5-dimethoxyphenyl)-N-(2-(2-fluoroethoxy)benzyl)ethanamine, ([(18)F]FECIMBI-36) or ([(18)F]1), a potential agonist PET imaging agent for 5-HT2A/2C receptors is described. Syntheses of reference standard 1 and the corresponding des-fluoroethyl radiolabeling precursor (2) were achieved with 75% and 65% yields, respectively. In vitro pharmacology assay of FECIMBI-36 by [(3)H]-ketanserin competition binding assay obtained from NIMH-PDSP showed high affinities to 5-HT2AR (Ki = 1nM) and 5-HT2CR (Ki=1.7 nM). Radiolabeling of FECIMBI-36 was achieved from the boc-protected precursor 2 using [(18)F]-fluoroethyltosylate in presence of Cs2CO3 in DMSO followed by removal of the protective group. [(18)F]1 was isolated using RP-HPLC in 25 ± 5% yield, purity > 95% and specific activity 1-2Ci/μmol (N = 6). In vitro autoradiography studies demonstrate that [(18)F]1 selectively label 5-HT2A and 5-HT2C receptors in slide-mounted sections of postmortem human brain using phosphor imaging. Our results indicate the potential of [(18)F]1 for imaging 5-HT2A/2C receptors in the high affinity state in vivo using PET imaging.

  6. Rat exposure in mice with neuropathic pain induces fear and antinociception that is not reversed by 5-HT2C receptor activation in the dorsal periaqueductal gray.

    PubMed

    Furuya-da-Cunha, Elke Mayumi; Souza, Rimenez Rodrigues de; Canto-de-Souza, Azair

    2016-07-01

    Previous studies have demonstrated that serotonin 5-HT2C receptors in the dorsal periaqueductal gray (dPAG) mediate both anxiety and antinociception in mice submitted to the elevated plus maze. The present study examined the effects of intra-dPAG infusion of the serotonin 5-HT2C receptor agonist (MK-212) in the defensive reactions and antinociception in mice with neurophatic pain confronted by a predator. Neuropathic pain was induced by chronic constriction injury (CCI) of the sciatic nerve, and predator confrontation was performed using the rat exposure test (RET). Our results demonstrated that both sham-operated and CCI mice exhibited intense defensive reactions when confronted by rats. However, rat-exposed CCI mice showed reduced pain reactivity in comparison to CCI mice exposed to a toy rat. Intra-dPAG infusion of MK-212 prior to predator exposure did not significantly alter defensive or antinociceptive responses. To our knowledge, our results represent the first evidence of RET-induced antinociception in mice. Moreover, the results of the present study suggest that 5-HT2C receptor activation in the dPAG is not critically involved in the control of predator-evoked fearful or antinociceptive responses. PMID:27059332

  7. m-CPP, a 5-HT2C receptor agonist that modifies the perfusion pressure of the hindquarter vascular bed of anesthetized rat.

    PubMed

    Calama, E; Morán, A; Ortiz de Urbina, A V; Martín, M L; San Román, L

    2005-02-01

    In the present work we studied the actions of the intra-arterial administration of meta-chlorophenylpiperazine (m-CPP - a 5-HT(2C) receptor agonist) in the hindquarters of the anesthetized rat. The lowest doses used (0.001, 0.01, 0.1, 0.25 and 0.5 microg/kg) induced vasodilatation whereas the highest doses produced vasoconstriction (1, 6.25, 12.5 and 25 microg/kg). Both vasodilatation and vasoconstriction were inhibited by the 5-HT(1,2 )receptor antagonist methiothepin, whereas the 5-HT(2 )receptor antagonist ritanserin blocked only the vasoconstrictor responses. 1-[4-(1-Adamantanecarboxamido)butyl]-4-(2-methoxyphenyl)piperazine (a 5-HT(1A) receptor antagonist) and ICI 118,551 (a beta(2)-receptor antagonist) failed to modify the vasodilator responses of m-CPP. Both BRL 15572 (a 5-HT(1D) receptor antagonist) and GR 55562 (a 5-HT(1B) receptor antagonist) only partially inhibited this action. Our data reveal that m-CPP induces the 5-HT(1 )and/or non-specific vasodilator effect and 5-HT(2) vasoconstrictor effects in the hindquarter vascular bed of the rat.

  8. 5-HT2C receptors in the basolateral amygdala and dorsal striatum are a novel target for the anxiolytic and antidepressant effects of exercise.

    PubMed

    Greenwood, Benjamin N; Strong, Paul V; Loughridge, Alice B; Day, Heidi E W; Clark, Peter J; Mika, Agnieszka; Hellwinkel, Justin E; Spence, Katie G; Fleshner, Monika

    2012-01-01

    Physical activity reduces the incidence and severity of psychiatric disorders such as anxiety and depression. Similarly, voluntary wheel running produces anxiolytic- and antidepressant-like effects in rodent models. The specific neurobiological mechanisms underlying the beneficial properties of exercise, however, remain unclear. One relevant pharmacological target in the treatment of psychiatric disorders is the 5-HT(2C) receptor (5-HT(2C)R). Consistent with data demonstrating the anxiogenic consequences of 5-HT(2C)R activation in humans and rodents, we have previously reported that site-specific administration of the selective 5-HT(2C)R agonist CP-809101 in the lateral/basolateral amygdala (BLA) increases shock-elicited fear while administration of CP-809101 in the dorsal striatum (DS) interferes with shuttle box escape learning. These findings suggest that activation of 5-HT(2C)R in discrete brain regions contributes to specific anxiety- and depression-like behaviors and may indicate potential brain sites involved in the anxiolytic and antidepressant effects of exercise. The current studies tested the hypothesis that voluntary wheel running reduces the behavioral consequences of 5-HT(2C)R activation in the BLA and DS, specifically enhanced shock-elicited fear and interference with shuttle box escape learning. After 6 weeks of voluntary wheel running or sedentary conditions, the selective 5-HT(2C)R agonist CP-809101 was microinjected into either the BLA or the DS of adult Fischer 344 rats, and shock-elicited fear and shuttle box escape learning was assessed. Additionally, in-situ hybridization was used to determine if 6 weeks of voluntary exercise changed levels of 5-HT(2C)R mRNA. We found that voluntary wheel running reduced the behavioral effects of CP-809101 and reduced levels of 5-HT(2C)R mRNA in both the BLA and the DS. The current data indicate that expression of 5-HT(2C)R mRNA in discrete brain sites is sensitive to physical activity status of the organism

  9. 5-HT2C and GABAB receptors influence handling-induced convulsion severity in chromosome 4 congenic and DBA/2J background strain mice.

    PubMed

    Reilly, Matthew T; Milner, Lauren C; Shirley, Renee L; Crabbe, John C; Buck, Kari J

    2008-03-10

    Progress towards elucidating the underlying genetic variation for susceptibility to complex central nervous system (CNS) hyperexcitability states has just begun. Genetic mapping analyses suggest that a gene(s) on mid-chromosome 4 has pleiotropic effects on multiple CNS hyperexcitability states in mice, including alcohol and barbiturate withdrawal and convulsions elicited by chemical and audiogenic stimuli. We recently identified Mpdz within this chromosomal region as a gene that influences alcohol and barbiturate withdrawal convulsions. Mpdz encodes the multi-PDZ domain protein (MPDZ). Currently, there is limited information available about the mechanism by which MPDZ influences drug withdrawal and/or other CNS hyperexcitability states, but may involve its interaction with 5-HT2C and/or GABAB receptors. One of the most useful tools we have developed thus far is a congenic strain that possesses a segment of chromosome 4 from the C57BL/6J (donor) mouse strain superimposed on a genetic background that is >99% from the DBA/2J strain. The introduced segment spans the Mpdz gene. Here, we demonstrate that handling-induced convulsions are less severe in congenic vs. background strain mice in response to either a 5-HT2C receptor antagonist (SB242084) or a GABAB receptor agonist (baclofen), but not a GABAA receptor channel blocker (pentylenetetrazol). These data suggest that allelic variation in Mpdz, or a linked gene, influences SB242084- and baclofen-enhanced convulsions. Our results are consistent with the hypothesis that Mpdz's effects on CNS hyperexcitability, including alcohol and barbiturate withdrawal, involve MPDZ interaction with 5-HT2C and/or GABAB receptors. However, additional genes reside within the congenic interval and may also influence CNS hyperexcitability.

  10. Comparison of the enantiomers of (+/-)-doxanthrine, a high efficacy full dopamine D(1) receptor agonist, and a reversal of enantioselectivity at D(1) versus alpha(2C) adrenergic receptors.

    PubMed

    Przybyla, Julie A; Cueva, Juan P; Chemel, Benjamin R; Hsu, K Joseph; Riese, David J; McCorvy, John D; Chester, Julia A; Nichols, David E; Watts, Val J

    2009-02-01

    Parkinson's disease is a neurodegenerative condition involving the death of dopaminergic neurons in the substantia nigra. Dopamine D(1) receptor agonists are potential alternative treatments to current therapies that employ L-DOPA, a dopamine precursor. We evaluated the pharmacological profiles of the enantiomers of a novel dopamine D(1) receptor full agonist, doxanthrine (DOX) at D(1) and alpha(2C) adrenergic receptors. (+)-DOX displayed greater potency and intrinsic activity than (-)-DOX in porcine striatal tissue and in a heterologous D(1) receptor expression system. Studies in MCF7 cells, which express an endogenous human dopamine D(1)-like receptor, revealed that (-)-DOX was a weak partial agonist/antagonist that reduced the functional activity of (+)-DOX and dopamine. (-)-DOX had 10-fold greater potency than (+)-DOX at alpha(2C) adrenergic receptors, with an EC50 value of 4 nM. These findings demonstrate a reversed stereoselectivity for the enantiomers of DOX at D(1) and alpha(2C) receptors and have implications for the therapeutic utility of doxanthrine.

  11. Exploration of synthetic approaches and pharmacological evaluation of PNU-69176E and its stereoisomer as 5-HT2C receptor allosteric modulators.

    PubMed

    Ding, Chunyong; Bremer, Nicole M; Smith, Thressa D; Seitz, Patricia K; Anastasio, Noelle C; Cunningham, Kathryn A; Zhou, Jia

    2012-07-18

    Allosteric modulators of the serotonin (5-HT) 5-HT(2C) receptor (5-HT(2C)R) present a unique drug design strategy to augment the response to endogenous 5-HT in a site- and event-specific manner with great potential as novel central nervous system probes and therapeutics. To date, PNU-69176E is the only reported selective positive allosteric modulator for the 5-HT(2C)R. For the first time, an optimized synthetic route to readily access PNU-69176E (1) and its diastereomer 2 has been established in moderate to good overall yields over 10 steps starting from commercially available picolinic acid. This synthetic approach not only enables a feasible preparation of a sufficient amount of 1 for use as a reference compound for secondary pharmacological studies, but also provides an efficient synthesis of key intermediates to develop novel and simplified 5-HT(2C)R allosteric modulators. Compound 1 and its diastereomer 2 were functionally characterized in Chinese hamster ovary (CHO) cells stably transfected with the 5-HT(2C)R using an intracellular calcium (Ca(i) (2+)) release assay. Compound 1 demonstrated efficacy and potency as an allosteric modulator for the 5-HT(2C)R with no intrinsic agonist activity. Compound 1 did not alter 5-HT-evoked Ca(i) (2+) in CHO cells stably transfected with the highly homologous 5-HT(2A)R. In contrast, the diastereomer 2 did not alter 5-HT-evoked Ca(i) (2+) release in 5-HT(2A)R-CHO or 5-HT(2C)R-CHO cells or exhibit intrinsic agonist activity.

  12. Activation of 5-HT(2C) receptors in the dorsal periaqueductal gray increases antinociception in mice exposed to the elevated plus-maze.

    PubMed

    Baptista, Daniela; Nunes-de-Souza, Ricardo Luiz; Canto-de-Souza, Azair

    2012-11-01

    Several findings have pointed to the role of the dorsal periaqueductal gray (dPAG) serotonin 5-HT(1A) and 5-HT(2A-C) receptor subtypes in the modulation of defensive behavior in animals exposed to the elevated plus-maze (EPM). Besides displaying anxiety-like behavior, rodents also exhibit antinociception in the EPM. This study investigated the effects of intra-dPAG injections of 5-HT(1A) and 5-HT(2B/2C) receptor ligands on EPM-induced antinociception in mice. Male Swiss mice received 0.1 μl intra-dPAG injections of vehicle, 5.6 and 10 nmol of 8-OHDPAT, a 5-HT(1A) receptor agonist (Experiment 1), or 0.01, 0.03 and 0.1 nmol of mCPP, a 5-HT(2B/2C) receptor agonist (Experiment 2). Five minutes later, each mouse received an intraperitoneal injection of 0.6% acetic acid (0.1 ml/10 g body weight; nociceptive stimulus) and was individually confined in the open (OA) or enclosed (EA) arms of the EPM for 5 min, during which the number of abdominal writhes induced by the acetic acid was recorded. While intra-dPAG injection of 8-OHDPAT did not change open-arm antinociception (OAA), mCPP (0.01 nmol) enhanced it. Combined injections of ketanserin (10 nmol/0.1 μl), a 5-HT(2A/2C) receptor antagonist, and 0.01 nmol of mCPP (Experiment 3), selectively and completely blocked the OAA enhancement induced by mCPP. Although intra-dPAG injection of mCPP (0.01 nmol) also produced antinociception in EA-confined mice (Experiment 2), this effect was not confirmed in Experiment 3. Moreover, no other compound changed the nociceptive response in EA-confined animals. These results suggest that the 5-HT(2C) receptors located within the PAG play a role in this type of environmentally induced pain inhibition in mice.

  13. A double dissociation in the effects of 5-HT2A and 5-HT2C receptors on the acquisition and expression of conditioned defeat in Syrian hamsters

    PubMed Central

    Harvey, Marquinta L.; Swallows, Cody L.; Cooper, Matthew A.

    2012-01-01

    Previous research indicates that serotonin enhances the development of stress-induced changes in behavior, although it is unclear which serotonin receptors mediate this effect. 5-HT2 receptors are potential candidates because activation at these receptors is associated with increased fear and anxiety. In this study we investigated whether pharmacological treatments targeting 5-HT2 receptors would alter the acquisition and expression of conditioned defeat. Conditioned defeat is a social defeat model in Syrian hamsters in which individuals display increased submissive and defensive behavior and a loss of territorial aggression when tested with a novel intruder 24 hours after an acute social defeat. The nonselective 5-HT2 receptor agonist mCPP (0.0, 0.3, 1.0 or 3.0 mg/kg) was injected either prior to social defeat training or prior to conditioned defeat testing. Also, the 5-HT2A receptor antagonist MDL 11,939 (0.0, 0.5 or 2.0 mg/kg) was injected either prior to social defeat training or prior to conditioned defeat testing. Injection of mCPP prior to testing increased the expression of conditioned defeat, but injection of mCPP prior to training did not alter the acquisition of conditioned defeat. Conversely, injection of MDL 11,939 prior to training reduced the acquisition of conditioned defeat, but injection of MDL 11,939 prior to testing did not alter the expression of conditioned defeat. Our data suggest that mCPP activates 5-HT2C receptors during testing to enhance the display of submissive and defensive behavior, whereas MDL 11,939 blocks 5-HT2A receptors during social defeat to disrupt the development of the conditioned defeat response. In sum, these results suggest that serotonin acts at separate 5-HT2 receptors to facilitate the acquisition and expression of defeat-induced changes in social behavior. PMID:22708954

  14. Involvement of 5-HT(2C) receptors in the anti-immobility effects of antidepressants in the forced swimming test in mice.

    PubMed

    Clenet, F; De Vos, A; Bourin, M

    2001-04-01

    Several recent studies have demonstrated that 5-HT(1A), 5-HT(1B) and 5-HT(3) receptors were implicated in the mechanism of action of antidepressants in the mouse forced swimming test. Despite extensive evidence for a role of 5-HT(2C) receptors in depression, the precise role of these receptors in the effects of clinically established antidepressants was not directly investigated in the mouse forced swimming test. This work was aimed at exploring interactions between several doses of Ro 60-0175, a recently available, full and selective 5-HT(2C) agonist, and antidepressant drugs in the mouse forced swimming test. Spontaneous locomotor activity was measured as an index of intact sensorimotor functions and the dose-effect of Ro 60-0175 alone, as well as interactions with several antidepressants, such as tricyclic antidepressants (imipramine, desipramine and maprotiline) and selective serotonin reuptake inhibitors (paroxetine, citalopram, fluoxetine, fluvoxamine and sertraline), were studied in the mouse forced swimming test. There was no intrinsic antidepressant-like effect of Ro 60-0175, but an impairment in locomotor function was detected when using doses higher than 4 mg/kg in the mouse. There was a synergistic effect of low doses of Ro 60-0175 with sub-active doses of imipramine, paroxetine, citalopram and fluvoxamine; an antagonism between the highest dose of Ro 60-0175 and the active doses of paroxetine and fluoxetine was also detected. There is evidence that 5-HT(2C) receptors may be involved in the action of antidepressants which are able to boost the concentration of serotonin in the synapse, i.e. SSRIs and imipramine

  15. 5-HT(2C) serotonin receptor blockade prevents tau protein hyperphosphorylation and corrects the defect in hippocampal synaptic plasticity caused by a combination of environmental stressors in mice.

    PubMed

    Busceti, Carla Letizia; Di Pietro, Paola; Riozzi, Barbara; Traficante, Anna; Biagioni, Francesca; Nisticò, Robert; Fornai, Francesco; Battaglia, Giuseppe; Nicoletti, Ferdinando; Bruno, Valeria

    2015-09-01

    Exposure to multimodal sensory stressors is an everyday occurrence and sometimes becomes very intense, such as during rave parties or other recreational events. A growing body of evidence suggests that strong environmental stressors might cause neuronal dysfunction on their own in addition to their synergistic action with illicit drugs. Mice were exposed to a combination of physical and sensory stressors that are reminiscent of those encountered in a rave party. However, this is not a model of rave because it lacks the rewarding properties of rave. A 14-h exposure to environmental stressors caused an impairment of hippocampal long-term potentiation (LTP) and spatial memory, and an enhanced phosphorylation of tau protein in the CA1 and CA3 regions. These effects were transient and critically depended on the activation of 5-HT2C serotonin receptors, which are highly expressed in the CA1 region. Acute systemic injection of the selective 5-HT2C antagonist, RS-102,221 (2 mg/kg, i.p., 2 min prior the onset of stress), prevented tau hyperphosphorylation and also corrected the defects in hippocampal LTP and spatial memory. These findings suggest that passive exposure to a combination of physical and sensory stressors causes a reversible hippocampal dysfunction, which might compromise mechanisms of synaptic plasticity and spatial memory for a few days. Drugs that block 5-HT2C receptors might protect the hippocampus against the detrimental effect of environmental stressors. PMID:26145279

  16. Serotonin2C receptor stimulation inhibits cocaine-induced Fos expression and DARPP-32 phosphorylation in the rat striatum independently of dopamine outflow.

    PubMed

    Devroye, Céline; Cathala, Adeline; Maitre, Marlène; Piazza, Pier Vincenzo; Abrous, Djoher Nora; Revest, Jean-Michel; Spampinato, Umberto

    2015-02-01

    The serotonin(2C) receptor (5-HT(2C)R) is known to control dopamine (DA) neuron function by modulating DA neuronal firing and DA exocytosis at terminals. Recent studies assessing the influence of 5-HT(2C)Rs on cocaine-induced neurochemical and behavioral responses have shown that 5-HT2CRs can also modulate mesoaccumbens DA pathway activity at post-synaptic level, by controlling DA transmission in the nucleus accumbens (NAc), independently of DA release itself. A similar mechanism has been proposed to occur at the level of the nigrostriatal DA system. Here, using in vivo microdialysis in freely moving rats and molecular approaches, we assessed this hypothesis by studying the influence of the 5-HT(2C)R agonist Ro 60-0175 on cocaine-induced responses in the striatum. The intraperitoneal (i.p.) administration of 1 mg/kg Ro 60-0175 had no effect on the increase in striatal DA outflow induced by cocaine (15 mg/kg, i.p.). Conversely, Ro 60-0175 inhibited cocaine-induced Fos immunoreactivity and phosphorylation of the DA and c-AMP regulated phosphoprotein of Mr 32 kDa (DARPP-32) at threonine 75 residue in the striatum. Finally, the suppressant effect of Ro 60-0175 on cocaine-induced DARPP-32 phosphorylation was reversed by the selective 5-HT(2C)R antagonist SB 242084 (0.5 mg/kg, i.p.). In keeping with the key role of DARPP-32 in DA neurotransmission, our results demonstrate that 5-HT(2C)Rs are capable of modulating nigrostriatal DA pathway activity at post-synaptic level, by specifically controlling DA signaling in the striatum. PMID:25446572

  17. Polymorphisms of Serotonin Receptor 2A and 2C Genes and COMT in Relation to Obesity and Type 2 Diabetes

    PubMed Central

    Kring, Sofia I. I.; Werge, Thomas; Holst, Claus; Toubro, Søren; Astrup, Arne; Hansen, Torben; Pedersen, Oluf; Sørensen, Thorkild I. A.

    2009-01-01

    Background Candidate genes of psychological importance include 5HT2A, 5HT2C, and COMT, implicated in the serotonin, noradrenaline and dopamine pathways, which also may be involved in regulation of energy balance. We investigated the associations of single nucleotide polymorphisms (SNPs) of these genes with obesity and metabolic traits. Methodology/Principal Findings In a population of 166 200 young men examined at the draft boards, obese men (n = 726, BMI≥31.0 kg/m2) and a randomly selected group (n = 831) were re-examined at two surveys at mean ages 46 and 49 years (S-46, S-49). Anthropometric, physiological and biochemical measures were available. Logistic regression analyses were used to assess age-adjusted odds ratios. No significant associations were observed of 5HT2A rs6311, 5HT2C rs3813929 and COMT rs4680 with obesity, except that COMT rs4680 GG-genotype was associated with fat-BMI (OR = 1.08, CI = 1.01–1.16). The SNPs were associated with a number of physiological variables; most importantly 5HT2C rs3813929 T-allele was associated with glucose (OR = 4.56, CI = 1.13–18.4) and acute insulin response (OR = 0.65, CI = 0.44–0.94) in S-49. COMT rs4680 GG-genotype was associated with glucose (OR = 1.04, CI = 1.00–1.09). Except for an association between 5HT2A rs6311 and total-cholesterol at both surveys, significant in S-46 (OR = 2.66, CI = 1.11–6.40), no significant associations were observed for the other phenotypes. Significant associations were obtained when combined genotype of 5HT2C rs3813929 and COMT rs4680 were examined in relation to BMI (OR = 1.12, CI = 1.03–1.21), fat-BMI (OR = 1.22, CI = 1.08–1.38), waist (OR = 1.13, CI = 1.04–1.22), and cholesterol (OR = 5.60, CI = 0.99–31.4). Analyses of impaired glucose tolerance (IGT) and type 2 diabetes (T2D) revealed, a 12.3% increased frequency of 5HT2C rs3813929 T-allele and an 11.6% increased frequency of COMT

  18. Multiple conformations of 5-HT2A and 5-HT 2C receptors in rat brain: an autoradiographic study with [125I](±)DOI.

    PubMed

    López-Giménez, Juan F; Vilaró, M Teresa; Palacios, José M; Mengod, Guadalupe

    2013-10-01

    Earlier autoradiographic studies with the 5-HT2 receptor agonist [(125)I](±)DOI in human brain showed unexpected biphasic competition curves for various 5-HT2A antagonists. We have performed similar studies in rat brain regions with selective 5-HT2A (M100907) and 5-HT2C (SB242084) antagonists together with ketanserin and mesulergine. The effect of GTP analogues on antagonist competition was also studied. Increasing concentrations of Gpp(NH)p or GTPγS resulted in a maximal inhibition of [(125)I](±)DOI-specific binding of approximately 50 %. M100907 competed biphasically in all regions. In the presence of 100 μM Gpp(NH)p, M100907 still displaced biphasically the remaining [(125)I](±)DOI binding. Ketanserin showed biphasic curves in some regions and monophasic curves in others. In the latter, Gpp(NH)p evidenced an additional high-affinity site. SB242084 competed biphasically in brainstem nuclei and monophasically in the other regions. In most areas, SB242084 affinities were not notably altered by Gpp(NH)p. Mesulergine competed monophasically in all regions without alteration by Gpp(NH)p. These results conform with the extended ternary complex model of receptor action: receptor exists as an equilibrium of multiple conformations, i.e. ground (R), partly activated (R*) and activated G-protein-coupled (R*G) conformation/s. Thus, [(125)I](±)DOI would label multiple conformations of both 5-HT2A and 5-HT2C receptors in rat brain, and M100907 and ketanserin would recognise these conformations with different affinities.

  19. Mechanism for Noncompetitive Inhibition by Novel GluN2C/D N-Methyl-d-aspartate Receptor Subunit-Selective ModulatorsS⃞

    PubMed Central

    Acker, Timothy M.; Yuan, Hongjie; Hansen, Kasper B.; Vance, Katie M.; Ogden, Kevin K.; Jensen, Henrik S.; Burger, Pieter B.; Mullasseril, Praseeda; Snyder, James P.; Liotta, Dennis C.

    2011-01-01

    The compound 4-(5-(4-bromophenyl)-3-(6-methyl-2-oxo-4-phenyl-1,2-dihydroquinolin-3-yl)-4,5-dihydro-1H-pyrazol-1-yl)-4-oxobutanoic acid (DQP-1105) is a representative member of a new class of N-methyl-d-aspartate (NMDA) receptor antagonists. DQP-1105 inhibited GluN2C- and GluN2D-containing receptors with IC50 values that were at least 50-fold lower than those for recombinant GluN2A-, GluN2B-, GluA1-, or GluK2-containing receptors. Inhibition was voltage-independent and could not be surmounted by increasing concentrations of either coagonist, glutamate or glycine, consistent with a noncompetitive mechanism of action. DQP-1105 inhibited single-channel currents in excised outside-out patches without significantly changing mean open time or single-channel conductance, suggesting that DQP inhibits a pregating step without changing the stability of the open pore conformation and thus channel closing rate. Evaluation of DQP-1105 inhibition of chimeric NMDA receptors identified two key residues in the lower lobe of the GluN2 agonist binding domain that control the selectivity of DQP-1105. These data suggest a mechanism for this new class of inhibitors and demonstrate that ligands can access, in a subunit-selective manner, a new site located in the lower, membrane-proximal portion of the agonist-binding domain. PMID:21807990

  20. The 5-HT(2C) receptor agonist lorcaserin reduces cocaine self-administration, reinstatement of cocaine-seeking and cocaine induced locomotor activity.

    PubMed

    Harvey-Lewis, Colin; Li, Zhaoxia; Higgins, Guy A; Fletcher, Paul J

    2016-02-01

    Lorcaserin (Lorqess, Belviq(®)) is a selective 5-HT(2C) receptor agonist that has received FDA approval for the treatment of obesity. 5-HT(2C) receptor agonists are also efficacious in decreasing multiple aspects of cocaine motivation and reward in preclinical models. This would suggest that lorcaserin is a clinically available therapeutic with the potential to treat cocaine addiction. Here we report the effects of lorcaserin (0.1 mg/kg-1.0 mg/kg) on multiple aspects of cocaine-related behaviours in rats. We find that lorcaserin dose-dependently decreases cocaine self-administration on progressive and fixed ratio schedules of reinforcement. Lorcaserin also reduces reinstatement of cocaine-seeking behaviour in response to priming injections of cocaine and/or reintroduction of cocaine-associated cues. Finally, lorcaserin dose-dependently decreases cocaine-induced hyperlocomotion. Our results, when considered in concert with similar emergent findings in non-human primates, strongly support continued research into the potential of lorcaserin as a clinical treatment for cocaine addiction.

  1. Region-specific alterations of A-to-I RNA editing of serotonin 2c receptor in the cortex of suicides with major depression.

    PubMed

    Weissmann, D; van der Laan, S; Underwood, M D; Salvetat, N; Cavarec, L; Vincent, L; Molina, F; Mann, J J; Arango, V; Pujol, J F

    2016-01-01

    Brain region-specific abnormalities in serotonergic transmission appear to underlie suicidal behavior. Alterations of RNA editing on the serotonin receptor 2C (HTR2C) pre-mRNA in the brain of suicides produce transcripts that attenuate 5-HT2CR signaling by impairing intracellular G-protein coupling and subsequent intracellular signal transduction. In brain, the distribution of RNA-editing enzymes catalyzing deamination (A-to-I modification) shows regional variation, including within the cerebral cortex. We tested the hypothesis that altered pre-mRNA 5-HT2CR receptor editing in suicide is region-specific. To this end, we investigated the complete 5-HT2CR mRNA-editing profile in two architectonically distinct cortical areas involved in mood regulation and decision-making in a clinically well-characterized cohort of age- and sex-matched non-psychiatric drug-free controls and depressed suicides. By using an original biochemical detection method, that is, capillary electrophoresis single-stranded conformational polymorphism (CE-SSCP), we corroborated the 5-HT2CR mRNA-editing profile previously described in the dorsolateral prefrontal cortex (Brodmann area 9 (BA9)). Editing of 5-HT2CR mRNA displayed clear regional difference when comparing dorsolateral prefrontal cortex (BA9) and anterior cingulate cortex (BA24). Compared with non-psychiatric control individuals, alterations of editing levels of 5-HT2CR mRNA were detected in both cortical areas of depressed suicides. A marked increase in editing on 5-HT2CR was especially observed in the anterior cingulate cortex in suicides, implicating this cortical area in suicide risk. The results suggest that region-specific changes in RNA editing of 5-HT2CR mRNA and deficient receptor function likely contribute to the etiology of major depressive disorder or suicide. PMID:27576167

  2. Region-specific alterations of A-to-I RNA editing of serotonin 2c receptor in the cortex of suicides with major depression

    PubMed Central

    Weissmann, D; van der Laan, S; Underwood, M D; Salvetat, N; Cavarec, L; Vincent, L; Molina, F; Mann, J J; Arango, V; Pujol, J F

    2016-01-01

    Brain region-specific abnormalities in serotonergic transmission appear to underlie suicidal behavior. Alterations of RNA editing on the serotonin receptor 2C (HTR2C) pre-mRNA in the brain of suicides produce transcripts that attenuate 5-HT2CR signaling by impairing intracellular G-protein coupling and subsequent intracellular signal transduction. In brain, the distribution of RNA-editing enzymes catalyzing deamination (A-to-I modification) shows regional variation, including within the cerebral cortex. We tested the hypothesis that altered pre-mRNA 5-HT2CR receptor editing in suicide is region-specific. To this end, we investigated the complete 5-HT2CR mRNA-editing profile in two architectonically distinct cortical areas involved in mood regulation and decision-making in a clinically well-characterized cohort of age- and sex-matched non-psychiatric drug-free controls and depressed suicides. By using an original biochemical detection method, that is, capillary electrophoresis single-stranded conformational polymorphism (CE-SSCP), we corroborated the 5-HT2CR mRNA-editing profile previously described in the dorsolateral prefrontal cortex (Brodmann area 9 (BA9)). Editing of 5-HT2CR mRNA displayed clear regional difference when comparing dorsolateral prefrontal cortex (BA9) and anterior cingulate cortex (BA24). Compared with non-psychiatric control individuals, alterations of editing levels of 5-HT2CR mRNA were detected in both cortical areas of depressed suicides. A marked increase in editing on 5-HT2CR was especially observed in the anterior cingulate cortex in suicides, implicating this cortical area in suicide risk. The results suggest that region-specific changes in RNA editing of 5-HT2CR mRNA and deficient receptor function likely contribute to the etiology of major depressive disorder or suicide. PMID:27576167

  3. 5-HT2A and 5-HT2C receptors as hypothalamic targets of developmental programming in male rats

    PubMed Central

    Martin-Gronert, Malgorzata S.; Stocker, Claire J.; Wargent, Edward T.; Cripps, Roselle L.; Garfield, Alastair S.; Jovanovic, Zorica; D'Agostino, Giuseppe; Yeo, Giles S. H.; Cawthorne, Michael A.; Arch, Jonathan R. S.; Heisler, Lora K.; Ozanne, Susan E.

    2016-01-01

    ABSTRACT Although obesity is a global epidemic, the physiological mechanisms involved are not well understood. Recent advances reveal that susceptibility to obesity can be programmed by maternal and neonatal nutrition. Specifically, a maternal low-protein diet during pregnancy causes decreased intrauterine growth, rapid postnatal catch-up growth and an increased risk for diet-induced obesity. Given that the synthesis of the neurotransmitter 5-hydroxytryptamine (5-HT) is nutritionally regulated and 5-HT is a trophic factor, we hypothesised that maternal diet influences fetal 5-HT exposure, which then influences development of the central appetite network and the subsequent efficacy of 5-HT to control energy balance in later life. Consistent with our hypothesis, pregnant rats fed a low-protein diet exhibited elevated serum levels of 5-HT, which was also evident in the placenta and fetal brains at embryonic day 16.5. This increase was associated with reduced levels of 5-HT2CR, the primary 5-HT receptor influencing appetite, in the fetal, neonatal and adult hypothalamus. As expected, a reduction of 5-HT2CR was associated with impaired sensitivity to 5-HT-mediated appetite suppression in adulthood. 5-HT primarily achieves effects on appetite by 5-HT2CR stimulation of pro-opiomelanocortin (POMC) peptides within the arcuate nucleus of the hypothalamus (ARC). We show that 5-HT2ARs are also anatomically positioned to influence the activity of ARC POMC neurons and that mRNA encoding 5-HT2AR is increased in the hypothalamus of in utero growth-restricted offspring that underwent rapid postnatal catch-up growth. Furthermore, these animals at 3 months of age are more sensitive to appetite suppression induced by 5-HT2AR agonists. These findings not only reveal a 5-HT-mediated mechanism underlying the programming of susceptibility to obesity, but also provide a promising means to correct it, by treatment with a 5-HT2AR agonist. PMID:26769798

  4. Synthesis and structure-affinity relationships of novel small molecule natural product derivatives capable of discriminating between serotonin 5-HT1A, 5-HT2A, 5-HT2C receptor subtypes

    PubMed Central

    Cummings, David F.; Canseco, Diana C.; Sheth, Pratikkumar; Johnson, James E.; Schetz, John A.

    2010-01-01

    Efforts to develop ligands that distinguish between clinically relevant 5-HT2A and 5-HT2C serotonin receptor subtypes have been challenging, because their sequences have high homology. Previous studies reported that a novel aplysinopsin belonging to a chemical class of natural products isolated from a marine sponge was selective for the 5-HT2C over the 5-HT2A receptor subtype. Our goal was to explore the 5-HT2A/2C receptor structure-affinity relationships of derivatives based on the aplysinopsin natural product pharmacophore. Twenty aplysinopsin derivatives were synthesized, purified and tested for their affinities for cloned human serotonin 5-HT1A, 5-HT2A and 5-HT2C receptor subtypes. Four compounds in this series had >30-fold selectivity for 5-HT2A or 5-HT2C receptors. The compound (E)-5-((5,6-dichloro-1H-indol-3-yl)methylene)-2-imino-1,3-dimethylimidazolidin-4-one (UNT-TWU-22, 16) had approximately 2100-fold selectivity for the serotonin 5-HT2C receptor subtype: an affinity for 5-HT2C equal to 46 nM and no detectable affinity for the 5-HT1A or 5-HT2A receptor subtypes. The two most important factors controlling 5-HT2A or 5-HT2C receptor subtype selectivity were the combined R1, R3-alkylation of the imidazolidinone ring and the type and number of halogens on the indole ring of the aplysinopsin pharmacophore. PMID:20570529

  5. Role of 5-HT2A and 5-HT2C receptors in the stimulus effects of hallucinogenic drugs. II: Reassessment of LSD false positives.

    PubMed

    Fiorella, D; Rabin, R A; Winter, J C

    1995-10-01

    In the context of animal studies of hallucinogens, an LSD-false positive is defined as a drug known to be devoid of hallucinogenic activity in humans but which nonetheless fully mimics LSD in animals. Quipazine, MK-212, lisuride, and yohimbine have all been reported to be LSD false positives. The present study was designed to determine whether these compounds also substitute for the stimulus effects of the more pharmacologically selective hallucinogen (-)DOM (0.56 mg/kg, 75-min pretreatment time). The LSD and (-)DOM stimuli fully generalized to quipazine (3.0 mg/kg) and lisuride (0.2 mg/kg), but only partially generalized to MK-212 (0.1-1.0 mg/kg) and yohimbine (2-20 mg/kg). In combination tests, pirenpirone (0.08 mg/kg), a compound with both D2 and 5-HT2A affinity, blocked the substitution of quipazine and lisuride for the (-)DOM stimulus. Ketanserin (2.5 mg/kg), an antagonist with greater than 1 order of magnitude higher affinity for 5-HT2A receptors than either 5-HT2C or D2 receptors, also fully blocked the substitution of these compounds for the (-)DOM stimulus, while the selective D2 antagonist thiothixene (0.1-1.0 mg/kg) failed to block the substitution of lisuride for the (-)DOM stimulus. These results suggest that quipazine and lisuride substitute for the stimulus properties of the phenylalkglamine hallucinogen (-)DOM via agonist activity at 5-HT2A receptors. In addition, these results suggest that 5-HT2A agonist activity may be required, but is not in itself sufficient, for indolamine and phenylalkglamine compounds to elicit hallucinations in humans. Finally, it is concluded that MK-212 and yohimbine are neither LSD nor (-)DOM false positives.

  6. Characterisation of human 5-hydroxytryptamine2A and 5-hydroxytryptamine2C receptors expressed in the human neuroblastoma cell line SH-SY5Y: comparative stimulation by hallucinogenic drugs.

    PubMed

    Newton, R A; Phipps, S L; Flanigan, T P; Newberry, N R; Carey, J E; Kumar, C; McDonald, B; Chen, C; Elliott, J M

    1996-12-01

    Stable transfection of the human neuroblastoma cell line SH-SY5Y with the human 5-hydroxytryptamine2A (5-HT2A) or 5-HT2C receptor cDNA produced cell lines demonstrating ligand affinities that correlated closely with those for the corresponding endogenous receptors in human frontal cortex and choroid plexus, respectively. Stimulation of the recombinant receptors by 5-HT induced phosphoinositide hydrolysis with higher potency but lower efficacy at the 5-HT2C receptor (pEC50 = 7.80 +/- 0.06) compared with the 5-HT2A receptor (pEC50 = 7.30 +/- 0.08). Activation of the 5-HT2A receptor caused a transient fourfold increase in intracellular Ca2+ concentration. Whole-cell recordings of cells clamped at -50 mV demonstrated a small inward current (2 pA) in response to 10 microM 5-HT for both receptors. There were no differences in potency or efficacy of phosphoinositide hydrolysis among four hallucinogenic [d-lysergic acid diethylamide (LSD), 1-(4-iodo-2,5-dimethoxyphenyl)-2-aminopropane (DOI), 5-methoxy-N,N-dimethyltryptamine, and mescaline] and three nonhallucinogenic drugs (m-chlorophenylpiperazine, quipazine, and ergotamine). Comparison of equipotent doses producing 20% of the maximal response induced by 5-HT revealed selective activation of the 5-HT2A receptor by LSD and to a lesser degree by DOI, mescaline, and ergotamine. Quipazine and 5-methoxy-N,N-dimethyltryptamine were relatively nonselective, whereas m-chlorophenylpiperazine selectively activated the 5-HT2C receptor. It is unlikely therefore that hallucinosis is mediated primarily by activity at the 5-HT2C receptor, whereas activity at the 5-HT2A receptor may represent an important but not unique mechanism associated with hallucinogenic drug action.

  7. Functional Status of the Serotonin 5-HT2C Receptor (5-HT2CR) Drives Interlocked Phenotypes that Precipitate Relapse-Like Behaviors in Cocaine Dependence

    PubMed Central

    Anastasio, Noelle C; Stutz, Sonja J; Fox, Robert G; Sears, Robert M; Emeson, Ronald B; DiLeone, Ralph J; O'Neil, Richard T; Fink, Latham H; Li, Dingge; Green, Thomas A; Gerard Moeller, F; Cunningham, Kathryn A

    2014-01-01

    Relapse vulnerability in cocaine dependence is rooted in genetic and environmental determinants, and propelled by both impulsivity and the responsivity to cocaine-linked cues (‘cue reactivity'). The serotonin (5-hydroxytryptamine, 5-HT) 5-HT2C receptor (5-HT2CR) within the medial prefrontal cortex (mPFC) is uniquely poised to serve as a strategic nexus to mechanistically control these behaviors. The 5-HT2CR functional capacity is regulated by a number of factors including availability of active membrane receptor pools, the composition of the 5-HT2CR macromolecular protein complex, and editing of the 5-HT2CR pre-mRNA. The one-choice serial reaction time (1-CSRT) task was used to identify impulsive action phenotypes in an outbred rat population before cocaine self-administration and assessment of cue reactivity in the form of lever presses reinforced by the cocaine-associated discrete cue complex during forced abstinence. The 1-CSRT task reliably and reproducibly identified high impulsive (HI) and low impulsive (LI) action phenotypes; HI action predicted high cue reactivity. Lower cortical 5-HT2CR membrane protein levels concomitant with higher levels of 5-HT2CR:postsynaptic density 95 complex distinguished HI rats from LI rats. The frequency of edited 5-HT2CR mRNA variants was elevated with the prediction that the protein population in HI rats favors those isoforms linked to reduced signaling capacity. Genetic loss of the mPFC 5-HT2CR induced aggregate impulsive action/cue reactivity, suggesting that depressed cortical 5-HT2CR tone confers vulnerability to these interlocked behaviors. Thus, impulsive action and cue reactivity appear to neuromechanistically overlap in rodents, with the 5-HT2CR functional status acting as a neural rheostat to regulate, in part, the intersection between these vulnerability behaviors. PMID:23939424

  8. Effects of the 5-HT2C receptor agonist CP809101 in the amygdala on reinstatement of cocaine-seeking behavior and anxiety-like behavior.

    PubMed

    Pockros-Burgess, Lara A; Pentkowski, Nathan S; Der-Ghazarian, Taleen; Neisewander, Janet L

    2014-11-01

    Serotonin 2C receptor (5-HT2CR) agonists attenuate reinstatement of cocaine-seeking behavior. These receptors are found throughout the limbic system, including the basolateral amygdala (BlA), which is involved in forming associations between emotional stimuli and environmental cues, and the central amygdala (CeA), which is implicated in the expression of conditioned responding to emotional stimuli. This study investigated whether 5-HT2CRs in the amygdala are involved in cue and cocaine-primed reinstatement of cocaine-seeking behavior. Rats were trained to self-administer cocaine (0.75 mg/kg, i.v.) which that was paired with light and tone cues, and then subsequently they underwent daily extinction training. Rats then received bilateral microinfusions of the 5-HT2CR agonist CP809101 (0.01-1.0 μg/0.2 μl/side) into either the BlA or CeA prior to tests for cue or cocaine-primed (10 mg/kg, i.p.) reinstatement. Rats were also tested for CP809101 effects on anxiety-like behavior on the elevated plus-maze (EPM). Surprisingly, intra-BlA CP809101 had no effect on cue reinstatement, though it did increase anxiety-like behavior on the EPM. Intra-CeA infusions of CP809101 attenuated cocaine-primed reinstatement, an effect that was prevented with concurrent administration of the 5-HT2CR antagonist SB242084 (0.1 μg/0.2 μl/side). CP809101 had no effect on cue reinstatement or anxiety-like behavior on the EPM. These findings suggest that 5-HT2CRs in the BlA modulate anxiety, whereas those in the CeA modulate incentive motivational effects induced by cocaine priming injections.

  9. Activation of serotonin 5-HT(2C) receptor suppresses behavioral sensitization and naloxone-precipitated withdrawal symptoms in heroin-treated mice.

    PubMed

    Wu, Xian; Pang, Gang; Zhang, Yong-Mei; Li, Guangwu; Xu, Shengchun; Dong, Liuyi; Stackman, Robert W; Zhang, Gongliang

    2015-10-21

    Abuse and dependence to heroin has evolved into a global epidemic as a significant clinical and societal problem with devastating consequences. Repeated exposure to heroin can induce long-lasting behavioral sensitization and withdrawal. Pharmacological activation of 5-HT2C receptors (5-HT2CRs) suppresses psychostimulant-induced drug-seeking and behavioral sensitization. The present study examined the effect of a selective 5-HT2CR agonist lorcaserin on behavioral sensitization and naloxone-precipitated withdrawal symptoms in heroin-treated mice. Male mice received heroin (1.0 mg/kg, s.c.) twice a day for 3 days and then drug treatment was suspended for 5 days. On day 9, a challenge dose of heroin (1.0 mg/kg) was administered to examine the expression of behavioral sensitization. Lorcaserin administered during the development, withdrawal or expression stage suppressed heroin-induced behavioral sensitization on day 9. Another cohort of mice received increasing doses of heroin over a 4.5-day period. Lorcaserin, or the positive control clonidine (an α2-adrenoceptor agonist) suppressed naloxone-precipitated withdrawal symptoms in heroin-treated mice. These findings suggest that activation of 5-HT2CRs suppresses behavioral sensitization and withdrawal in heroin-treated mice. Thus, pharmacological activation of 5-HT2CRs may represent a new avenue for the treatment of heroin addiction.

  10. Activation of serotonin 5-HT(2C) receptor suppresses behavioral sensitization and naloxone-precipitated withdrawal symptoms in heroin-treated mice.

    PubMed

    Wu, Xian; Pang, Gang; Zhang, Yong-Mei; Li, Guangwu; Xu, Shengchun; Dong, Liuyi; Stackman, Robert W; Zhang, Gongliang

    2015-10-21

    Abuse and dependence to heroin has evolved into a global epidemic as a significant clinical and societal problem with devastating consequences. Repeated exposure to heroin can induce long-lasting behavioral sensitization and withdrawal. Pharmacological activation of 5-HT2C receptors (5-HT2CRs) suppresses psychostimulant-induced drug-seeking and behavioral sensitization. The present study examined the effect of a selective 5-HT2CR agonist lorcaserin on behavioral sensitization and naloxone-precipitated withdrawal symptoms in heroin-treated mice. Male mice received heroin (1.0 mg/kg, s.c.) twice a day for 3 days and then drug treatment was suspended for 5 days. On day 9, a challenge dose of heroin (1.0 mg/kg) was administered to examine the expression of behavioral sensitization. Lorcaserin administered during the development, withdrawal or expression stage suppressed heroin-induced behavioral sensitization on day 9. Another cohort of mice received increasing doses of heroin over a 4.5-day period. Lorcaserin, or the positive control clonidine (an α2-adrenoceptor agonist) suppressed naloxone-precipitated withdrawal symptoms in heroin-treated mice. These findings suggest that activation of 5-HT2CRs suppresses behavioral sensitization and withdrawal in heroin-treated mice. Thus, pharmacological activation of 5-HT2CRs may represent a new avenue for the treatment of heroin addiction. PMID:26375926

  11. Food intake inhibition in rainbow trout induced by activation of serotonin 5-HT2C receptors is associated with increases in POMC, CART and CRF mRNA abundance in hypothalamus.

    PubMed

    Pérez-Maceira, Jorge J; Otero-Rodiño, Cristina; Mancebo, María J; Soengas, José L; Aldegunde, Manuel

    2016-04-01

    In rainbow trout, the food intake inhibition induced by serotonin occurs through 5-HT2C and 5-HT1A receptors, though the mechanisms involved are still unknown. Therefore, we assessed if a direct stimulation of 5-HT2C and 5-HT1A serotonin receptors (resulting in decreased food intake in rainbow trout), affects gene expression of neuropeptides involved in the control of food intake, such as pro-opiomelanocortin (POMC), cocaine- and amphetamine-regulated transcript (CART), corticotrophin releasing factor (CRF), and agouti-related peptide (AgRP). In a first set of experiments, the injection of the 5-HT2C receptor agonists MK212 (60 μg kg(-1) icv) and WAY 161503 (1 mg kg(-1) ip), and of the 5-HT1A receptor agonist 8-OH-DPAT (1 mg kg(-1) ip and 30 μg kg(-1) icv) induced food intake inhibition. In a second set of experiments, we observed that the injection of MK212 or WAY 161503 (1 and 3 mg kg(-1)) significantly increased hypothalamic POMC mRNA abundance. CART mRNA abundance in hypothalamus was enhanced by treatment with MK212 and unaffected by WAY 161503. The administration of the 5-HT1A receptor agonist 8-OH-DPAT did not induce any significant variation in the hypothalamic POMC or CART mRNA levels. CRF mRNA abundance was only affected by MK212 that increased hypothalamic values. Finally, hypothalamic AgRP mRNA abundance was only evaluated with the agonist 5-HT2C MK212 resulting in no significant effects. The results show that the reduction in food intake mediated by 5-HT2C receptors is associated with increases in hypothalamic POMC, CART and CRF mRNA abundance.

  12. Proteasomal Degradation of γ-Aminobutyric AcidB Receptors Is Mediated by the Interaction of the GABAB2 C Terminus with the Proteasomal ATPase Rtp6 and Regulated by Neuronal Activity*

    PubMed Central

    Zemoura, Khaled; Benke, Dietmar

    2014-01-01

    Regulation of cell surface expression of neurotransmitter receptors is crucial for determining synaptic strength and plasticity, but the underlying mechanisms are not well understood. We previously showed that proteasomal degradation of GABAB receptors via the endoplasmic reticulum (ER)-associated protein degradation (ERAD) machinery determines the number of cell surface GABAB receptors and thereby GABAB receptor-mediated neuronal inhibition. Here, we show that proteasomal degradation of GABAB receptors requires the interaction of the GABAB2 C terminus with the proteasomal AAA-ATPase Rpt6. A mutant of Rpt6 lacking ATPase activity prevented degradation of GABAB receptors but not the removal of Lys48-linked ubiquitin from GABAB2. Blocking ERAD activity diminished the interaction of Rtp6 with GABAB receptors resulting in increased total as well as cell surface expression of GABAB receptors. Modulating neuronal activity affected proteasomal activity and correspondingly the interaction level of Rpt6 with GABAB2. This resulted in altered cell surface expression of the receptors. Thus, neuronal activity-dependent proteasomal degradation of GABAB receptors by the ERAD machinery is a potent mechanism regulating the number of GABAB receptors available for signaling and is expected to contribute to homeostatic neuronal plasticity. PMID:24482233

  13. Pannexin channels mediate the acquisition of myogenic commitment in C2C12 reserve cells promoted by P2 receptor activation

    PubMed Central

    Riquelme, Manuel A.; Cea, Luis A.; Vega, José L.; Puebla, Carlos; Vargas, Aníbal A.; Shoji, Kenji F.; Subiabre, Mario; Sáez, Juan C.

    2015-01-01

    The acquisition of myoblast commitment to the myogenic linage requires rises in intracellular free Ca2+ concentration ([Ca2+]i). Putative cell membrane pathways involved in these [Ca2+]i increments are P2 receptors (P2Rs) as well as connexin (Cx) and/or pannexin (Panx) hemichannels and channels (Cx HChs and Panx Chs), respectively, which are known to permeate Ca2+. Reserve cells (RCs) are uncommitted myoblasts obtained from differentiated C2C12 cell cultures, which acquire commitment upon replating. Regarding these cells, we found that extracellular ATP increases the [Ca2+]i via P2Rs. Moreover, ATP increases the plasma membrane permeability to small molecules and a non-selective membrane current, both of which were inhibited by Cx HCh/Panx1Ch blockers. However, RCs exposed to divalent cation-free saline solution, which is known to activate Cx HChs (but not Panx Chs), did not enhance membrane permeability, thus ruling out the possible involvement of Cx HChs. Moreover, ATP-induced membrane permeability was inhibited with blockers of P2Rs that activate Panx Chs. In addition, exogenous ATP induced the expression of myogenic commitment and increased MyoD levels, which was prevented by the inhibition of P2Rs or knockdown of Panx1 Chs. Similarly, increases in MyoD levels induced by ATP released by RCs were inhibited by Panx Ch/Cx HCh blockers. Myogenic commitment acquisition thus requires a feed-forward mechanism mediated by extracellular ATP, P2Rs, and Panx Chs. PMID:26000275

  14. ( sup 125 I)-2-(2,5-dimethoxy-4-iodophenyl)aminoethane (( sup 125 I)-2C-I) as a label for the 5-HT2 receptor in rat frontal cortex

    SciTech Connect

    Johnson, M.P.; Mathis, C.A.; Shulgin, A.T.; Hoffman, A.J.; Nichols, D.E. )

    1990-01-01

    Recent studies of 5-HT2 receptor binding have involved the use of radiolabeled agonists. This report describes the use of ({sup 125}I)-2-(2,5-dimethoxy-4-iodophenyl)aminoethane (({sup 125}I)-2C-I) as a label for low-density 5-HT2 agonist binding sites. A nonhydrolyzable analog of GTP, GppNHp, was found to inhibit the high affinity binding of ({sup 125}I)-2C-I. 5-HT and several 5-HT2 agonists and antagonists displayed high affinity for this site. In addition, a significant decrease in the Bmax value, but not the KD for ({sup 125}I)-2C-I was observed at 37 degrees C as compared to that observed at 24 degrees C. Several structure-activity relationships were investigated for displacement of ({sup 125}I)-2C-I, and the results are consistent with the importance of this receptor in the mechanism of action of hallucinogens. This study demonstrates the utility of ({sup 125}I)-2C-I as a novel radioligand and provides further data that the 5-HT2 receptor is significantly linked to hallucinogenic activity for several compounds.

  15. Molecular interactions of agonist and inverse agonist ligands at serotonin 5-HT2C G protein-coupled receptors: computational ligand docking and molecular dynamics studies validated by experimental mutagenesis results

    NASA Astrophysics Data System (ADS)

    Córdova-Sintjago, Tania C.; Liu, Yue; Booth, Raymond G.

    2015-02-01

    To understand molecular determinants for ligand activation of the serotonin 5-HT2C G protein-coupled receptor (GPCR), a drug target for obesity and neuropsychiatric disorders, a 5-HT2C homology model was built according to an adrenergic β2 GPCR (β2AR) structure and validated using a 5-HT2B GPCR crystal structure. The models were equilibrated in a simulated phosphatidyl choline membrane for ligand docking and molecular dynamics studies. Ligands included (2S, 4R)-(-)-trans-4-(3'-bromo- and trifluoro-phenyl)-N,N-dimethyl-1,2,3,4-tetrahydronaphthalene-2-amine (3'-Br-PAT and 3'-CF3-PAT), a 5-HT2C agonist and inverse agonist, respectively. Distinct interactions of 3'-Br-PAT and 3'-CF3-PAT at the wild-type (WT) 5-HT2C receptor model were observed and experimental 5-HT2C receptor mutagenesis studies were undertaken to validate the modelling results. For example, the inverse agonist 3'-CF3-PAT docked deeper in the WT 5-HT2C binding pocket and altered the orientation of transmembrane helices (TM) 6 in comparison to the agonist 3'-Br-PAT, suggesting that changes in TM orientation that result from ligand binding impact function. For both PATs, mutation of 5-HT2C residues S3.36, T3.37, and F5.47 to alanine resulted in significantly decreased affinity, as predicted from modelling results. It was concluded that upon PAT binding, 5-HT2C residues T3.37 and F5.47 in TMs 3 and 5, respectively, engage in inter-helical interactions with TMs 4 and 6, respectively. The movement of TMs 5 and 6 upon agonist and inverse agonist ligand binding observed in the 5-HT2C receptor modelling studies was similar to movements reported for the activation and deactivation of the β2AR, suggesting common mechanisms among aminergic neurotransmitter GPCRs.

  16. Characterization of the 5-HT2C receptor agonist lorcaserin on efficacy and safety measures in a rat model of diet-induced obesity.

    PubMed

    Higgins, Guy A; Desnoyer, Jill; Van Niekerk, Annalise; Silenieks, Leo B; Lau, Winnie; Thevarkunnel, Sandy; Izhakova, Julia; DeLannoy, Ines Am; Fletcher, Paul J; DeLay, Josepha; Dobson, Howard

    2015-02-01

    The 5-HT2C receptor agonist lorcaserin (Belviq®) has been Food and Drug Administration (FDA) approved for the treatment of obesity. The present study is a back translational investigation into the effect of 28-day lorcaserin treatment in a diet-induced obesity (DIO) model using male, Sprague-Dawley rats. An assessment of drug effect on efficacy and multiple safety endpoints including cardiac function was undertaken. Lorcaserin (1-2 mg/kg SC b.i.d.) significantly reduced percentage body weight gain compared to vehicle-treated controls (VEH: 10.6 ± 0.4%; LOR 1: 7.6 ± 1.2%; LOR 2: 5.4 ± 0.6%). Measurement of body composition using quantitative magnetic resonance (QMR) imaging indicated this change was due to the selective reduction in body fat mass. Modest effects on food intake were recorded. At the completion of the treatment phase, echocardiography revealed no evidence for valvulopathy, that is, no aortic or mitral valve regurgitation. The pharmacokinetics of the present treatment regimen was determined over a 7-day treatment period; plasma C min and C max were in the range 13-160 ng/mL (1 mg/kg b.i.d.) and 34-264 ng/mL (2 mg/kg b.i.d.) with no evidence for drug accumulation. In sum, these studies show an effect of lorcaserin in the DIO model, that in the context of the primary endpoint measure of % body weight change was similar to that reported clinically (i.e., 3.0-5.2% vs. 3.2%). The present studies highlight the translational value of obesity models such as DIO, and suggest that assuming consideration is paid to nonspecific drug effects such as malaise, the DIO model has reasonable forward translational value to help predict clinical outcomes of a new chemical entity.

  17. Investigation of drug-drug interactions caused by human pregnane X receptor-mediated induction of CYP3A4 and CYP2C subfamilies in chimeric mice with a humanized liver.

    PubMed

    Hasegawa, Maki; Tahara, Harunobu; Inoue, Ryo; Kakuni, Masakazu; Tateno, Chise; Ushiki, Junko

    2012-03-01

    The induction of cytochrome P450 (P450) enzymes is one of the risk factors for drug-drug interactions (DDIs). To date, the human pregnane X receptor (PXR)-mediated CYP3A4 induction has been well studied. In addition to CYP3A4, the expression of CYP2C subfamily is also regulated by PXR, and the DDIs caused by the induction of CYP2C enzymes have been reported to have a major clinical impact. The purpose of the present study was to investigate whether chimeric mice with a humanized liver (PXB mice) can be a suitable animal model for investigating the PXR-mediated induction of CYP2C subfamily, together with CYP3A4. We evaluated the inductive effect of rifampicin (RIF), a typical human PXR ligand, on the plasma exposure to the four P450 substrate drugs (triazolam/CYP3A4, pioglitazone/CYP2C8, (S)-warfarin/CYP2C9, and (S)-(-)-mephenytoin/CYP2C19) by cassette dosing in PXB mice. The induction of several drug-metabolizing enzymes and transporters in the liver was also examined by measuring the enzyme activity and mRNA expression levels. Significant reductions in the exposure to triazolam, pioglitazone, and (S)-(-)-mephenytoin, but not to (S)-warfarin, were observed. In contrast to the in vivo results, all the four P450 isoforms, including CYP2C9, were elevated by RIF treatment. The discrepancy in the (S)-warfarin results between in vivo and in vitro studies may be attributed to the relatively small contribution of CYP2C9 to (S)-warfarin elimination in the PXB mice used in this study. In summary, PXB mice are a useful animal model to examine DDIs caused by PXR-mediated induction of CYP2C and CYP3A4. PMID:22126990

  18. The role of the 5-HT2A and 5-HT2C receptors in the stimulus effects of hallucinogenic drugs. III: The mechanistic basis for supersensitivity to the LSD stimulus following serotonin depletion.

    PubMed

    Fiorella, D; Helsley, S; Lorrain, D S; Rabin, R A; Winter, J C

    1995-10-01

    The present study was designed to determine the effects of p-chlorophenylalanine (PCPA) and p-chloroamphetamine (PCA) administration on (1) the levels of serotonin (5-hydroxytryptamine, 5-HT) and 5-hydroxyindoleacetic acid (5-HIAA) in rat brain, (2) the sensitivity of LSD-trained rats to the stimulus effects of LSD, and (3) the maximal levels of 5-HT2A and 5-HT2C receptor mediated phosphoinositide (PI) hydrolysis in rat brain. PCA and PCPA both produced a significant depletion of whole brain 5-HT and 5-HIAA concentrations. The depletion of serotonin with PCPA, but not PCA, resulted in supersensitivity of LSD-trained subjects to the stimulus effects of LSD. Neither PCPA nor PCA treatment altered the maximal level of 5-HT2A receptor-mediated PI hydrolysis. However, PCPA, but not PCA, treatment resulted in a significant upregulation (46%, P < 0.05) of the maximal level of 5-HT2C receptor mediated PI hydrolysis. These data suggest that upregulation of the 5-HT2C receptor mediates the supersensitivity to LSD discriminative stimulus which follows the depletion of central nervous system serotonin by PCPA.

  19. Drug discovery targeting human 5-HT2C receptors: Residues S3.36 and Y7.43 impact ligand—binding pocket structure via hydrogen bond formation

    PubMed Central

    Canal, Clinton E.; Cordova-Sintjago, Tania C.; Villa, Nancy Y.; Fang, Li-Juan; Booth, Raymond G.

    2011-01-01

    Specific activation of serotonin (5-HT) 5-HT2C G protein-coupled receptors may be therapeutic for obesity and neuropsychiatric disorders. Mutagenesis coupled with computational and molecular modeling experiments based on the human β2 adrenergic receptor structure were employed to delineate the interactions of different ligands at human 5-HT2C residues D3.32, S3.36 and Y7.43. No binding of the tertiary amine radioligand ([3H]-mesulergine) could be detected when the 5-HT2C D3.32 residue was mutated to alanine (D3.32A). The S3.36A point-mutation greatly reduced affinity of primary amine ligands, modestly reduced affinity of a secondary amine, and except for the 5-HT2C-specific agonist N(CH3)2-PAT, affinity of tertiary amines was unaffected. Molecular modeling results indicated that the primary amines form hydrogen bonds with the S3.36 residue, whereas, with the exception of N(CH3)2-PAT, tertiary amines do not interact considerably with this residue. The Y7.43A point-mutation greatly reduced affinity of 5-HT, yet reduced to a lesser extent the affinity of tryptamine that lacks the 5-hydroxy moiety present in 5-HT; modeling results indicated that the 5-HT 5-hydroxy moiety hydrogen bonds with Y7.43 at the 5-HT2C receptor. Additional modeling results showed that 5-HT induced a hydrogen bond between Y7.43 and D3.32. Finally, modeling results revealed two low-energy binding modes for 5-HT in the 5-HT2C binding pocket, supporting the concept that multiple agonist binding modes may stabilize different receptor active conformations to influence signaling. Ligand potencies for modulating WT and point-mutated 5-HT2C receptor-mediated phospholipase C activity were in accordance with the affinity data. Ligand efficacies, however, were altered considerably by the S3.36A mutation only. PMID:22020288

  20. A Novel Aminotetralin-Type Serotonin (5-HT) 2C Receptor-Specific Agonist and 5-HT2A Competitive Antagonist/5-HT2B Inverse Agonist with Preclinical Efficacy for Psychoses

    PubMed Central

    Morgan, Drake; Felsing, Daniel; Kondabolu, Krishnakanth; Rowland, Neil E.; Robertson, Kimberly L.; Sakhuja, Rajeev; Booth, Raymond G.

    2014-01-01

    Development of 5-HT2C agonists for treatment of neuropsychiatric disorders, including psychoses, substance abuse, and obesity, has been fraught with difficulties, because the vast majority of reported 5-HT2C selective agonists also activate 5-HT2A and/or 5-HT2B receptors, potentially causing hallucinations and/or cardiac valvulopathy. Herein is described a novel, potent, and efficacious human 5-HT2C receptor agonist, (−)-trans-(2S,4R)-4-(3′[meta]-bromophenyl)-N,N-dimethyl-1,2,3,4-tetrahydronaphthalen-2-amine (−)-MBP), that is a competitive antagonist and inverse agonist at human 5-HT2A and 5-HT2B receptors, respectively. (−)-MBP has efficacy comparable to the prototypical second-generation antipsychotic drug clozapine in three C57Bl/6 mouse models of drug-induced psychoses: the head-twitch response elicited by [2,5]-dimethoxy-4-iodoamphetamine; hyperlocomotion induced by MK-801 [(5R,10S)-(+)-5-methyl-10,11-dihydro-5H-dibenzo[a,d]cyclohepten-5,10-imine hydrogen maleate (dizocilpine maleate)]; and hyperlocomotion induced by amphetamine. (−)-MBP, however, does not alter locomotion when administered alone, distinguishing it from clozapine, which suppresses locomotion. Finally, consumption of highly palatable food by mice was not increased by (−)-MBP at a dose that produced at least 50% maximal efficacy in the psychoses models. Compared with (−)-MBP, the enantiomer (+)-MBP was much less active across in vitro affinity and functional assays using mouse and human receptors and also translated in vivo with comparably lower potency and efficacy. Results indicate a 5-HT2C receptor-specific agonist, such as (−)-MBP, may be pharmacotherapeutic for psychoses, without liability for obesity, hallucinations, heart disease, sedation, or motoric disorders. PMID:24563531

  1. Association of Polymorphisms within the Serotonin Receptor Genes 5-HTR1A, 5-HTR1B, 5-HTR2A and 5-HTR2C and Migraine Susceptibility in a Turkish Population

    PubMed Central

    Yücel, Yavuz; Coşkun, Salih; Cengiz, Beyhan; Özdemir, Hasan H.; Uzar, Ertuğrul; Çim, Abdullah; Camkurt, M. Akif; Aluclu, M. Ufuk

    2016-01-01

    Objective Migraine, a highly prevelant headache disorder, is regarded as a polygenic multifactorial disease. Serotonin (5-HT) and their respective receptors have been implicated in the patogenesis. Methods We investigated the 5-HT1A, 5-HT1B, 5-HT2A, and 5-HT2C receptor gene polymorphisms and their association with migraine in Turkish patients. The rs6295, rs1300060, rs1228814, rs6311, rs6313, rs6314, rs6318, rs3813929 (−759C/T) and rs518147 polymorphisms were analyzed in 135 patients with migraine and 139 healthy subjects, using a BioMark 96.96 dynamic array system. Results We found no difference in the frequency of the analyzed eight out of nine polymorpisms between migraine and control groups. However, a significant association was found between the rs3813929 polymorphism in the promoter region of 5-HTR2C gene and migraine. Also, the allele of rs3813929 was more common in the migraine group. Conclusion This result suggests that the 5-HTR2C rs3813929 polymorphism can be a genetic risk factor for migraine in a Turkish population. PMID:27489378

  2. AKAP79, PKC, PKA and PDE4 participate in a Gq-linked muscarinic receptor and adenylate cyclase 2 cAMP signalling complex

    PubMed Central

    Shen, Jia X.; Cooper, Dermot M. F.

    2014-01-01

    AC2 (adenylate cyclase 2) is stimulated by activation of Gq-coupled muscarinic receptors through PKC (protein kinase C) to generate localized cAMP in HEK (human embryonic kidney)-293 cells. In the present study, we utilized a sensitive live-cell imaging technique to unravel the proteins that play essential roles in a Gq-coupled muscarinic receptor-mediated cAMP signalling complex. We reveal that, upon agonist binding to the Gq-coupled muscarinic receptor, AKAP79 (A-kinase-anchoring protein 79) recruits PKC to activate AC2 to produce cAMP. The cAMP formed is degraded by PDE4 (phosphodiesterase 4) activated by an AKAP-anchored PKA (protein kinase A). Calcineurin, a phosphatase bound to AKAP79, is not involved in this regulation. Overall, a transient cAMP increase is generated from AC2 by Gq-coupled muscarinic receptor activation, subject to sophisticated regulation through AKAP79, PKC, PDE4 and PKA, which significantly enhances acetylcholine-mediated signalling. PMID:23889134

  3. Synthesis and Structure Activity Relationship of Tetrahydroisoquinoline-based Potentiators of GluN2C and GluN2D Containing N-Methyl-D-Aspartate Receptors

    PubMed Central

    Santangelo Freel, Rose M.; Ogden, Kevin K.; Strong, Katie L.; Khatri, Alpa; Chepiga, Kathryn M.; Jensen, Henrik S.; Traynelis, Stephen F.; Liotta, Dennis C.

    2015-01-01

    We describe here the synthesis and evaluation of a series of tetrahydroisoquinolines that show subunit-selective potentiation of NMDA receptors containing the GluN2C or GluN2D subunits. Bischler-Napieralski conditions were employed in the key step for the conversion of acyclic amides to the corresponding tetrahydroisoquinoline containing analogs. Compounds were evaluated using both two electrode voltage clamp recordings from Xenopus laevis oocytes and imaging of mammalian BHK cells loaded with Ca2+-sensitive dyes. The most potent analogues had EC50 values of 300 nM and showed over 2-fold potentiation of the response to maximally effective concentrations of glutamate and glycine, but had no effect on responses from NMDA receptors containing the GluN2A or GluN2B subunits, AMPA, kainate, GABA, or glycine receptors or a variety of other potential targets. These compounds represent a potent class of small molecule subunit-selective potentiators of NMDA receptors. PMID:23627311

  4. Variation of hormonal receptor, pS2, c-erbB-2 and GSTpi contents in breast carcinomas under tamoxifen: a study of 74 cases.

    PubMed Central

    Soubeyran, I.; Quénel, N.; Mauriac, L.; Durand, M.; Bonichon, F.; Coindre J-M

    1996-01-01

    Seventy-four post menopausal patients with primary non-metastatic invasive ductal carcinomas of the breast were first treated with tamoxifen alone (30 mg p.o. daily) for 5 months. To study changes induced by tamoxifen, core biopsies before treatment and surgical specimens after hormonal therapy were assayed by immunohistochemistry for oestrogen (ER) and progesterone receptors (PR), pS2, GSTpi and c-erbB2. After tamoxifen, ER and PR significantly decreased in 60 and 44 cases respectively, whereas 11 and 19 cases showed no variation and 2 and 11 cases showed an increase (P<10(-4)). GSTpi and pS2 showed a significant increase in 43 and 41 cases, a decrease in 2 and 21 cases and no variation in 29 and 12 cases (P<10(-4) and P=0.04 respectively). c-erbB-2 showed no significant variation under tamoxifen, increased in only three cases and decreased in 13 cases. No relation was found between these variations and efficiency of hormone therapy. Our results allow a better knowledge of protein expression modifications occurring in breast cancer cells under tamoxifen therapy. They are also more consistent with clone selection rather than with phenotype modification. Images Figure 1 PMID:8611373

  5. Effects of central activation of serotonin 5-HT2A/2C or dopamine D2/3 receptors on the acute and repeated effects of clozapine in the conditioned avoidance response test

    PubMed Central

    Feng, Min; Gao, Jun; Sui, Nan; Li, Ming

    2014-01-01

    Rationale: Acute administration of clozapine (a gold standard of atypical antipsychotics) disrupts avoidance response in rodents, while repeated administration often causes a tolerance effect. Objective: The present study investigated the neuroanatomical basis and receptor mechanisms of acute and repeated effects of clozapine treatment in the conditioned avoidance response test in male Sprague-Dawley rats. Methods: DOI (2,5-dimethoxy-4-iodo-amphetamine, a preferential 5-HT2A/2C agonist) or quinpirole (a preferential dopamine D2/3 agonist) was microinjected into the medial prefrontal cortex (mPFC) or nucleus accumbens shell (NAs), and their effects on the acute and long-term avoidance-disruptive effect of clozapine were tested. Results: Intra-mPFC microinjection of quinpirole enhanced the acute avoidance disruptive effect of clozapine (10 mg/kg, sc), while DOI microinjections reduced it marginally. Repeated administration of clozapine (10 mg/kg, sc) daily for 5 days caused a progressive decrease in its inhibition of avoidance responding, indicating tolerance development. Intra-mPFC microinjection of DOI at 25.0 (but not 5.0) μg/side during this period completely abolished the expression of clozapine tolerance. This was indicated by the finding that clozapine-treated rats centrally infused with 25.0 μg/side DOI did not show higher levels of avoidance responses than the vehicle-treated rats in the clozapine challenge test. Microinjection of DOI into the mPFC immediately before the challenge test also decreased the expression of clozapine tolerance. Conclusions: Acute behavioral effect of clozapine can be enhanced by activation of the D2/3 receptors in the mPFC. Clozapine tolerance expression relies on the neuroplasticity initiated by its antagonist action against 5-HT2A/2C receptors in the mPFC. PMID:25288514

  6. Boehmeria nivea Stimulates Glucose Uptake by Activating Peroxisome Proliferator-Activated Receptor Gamma in C2C12 Cells and Improves Glucose Intolerance in Mice Fed a High-Fat Diet

    PubMed Central

    Kim, Sung Hee; Sung, Mi Jeong; Park, Jae Ho; Yang, Hye Jeong; Hwang, Jin-Taek

    2013-01-01

    We examined the antidiabetic property of Boehmeria nivea (L.) Gaud. Ethanolic extract of Boehmeria nivea (L.) Gaud. (EBN) increased the uptake of 2-[N-(nitrobenz-2-oxa-1,3-diazol-4-yl)amino]-2-deoxy-d-glucose in C2C12 myotubes. To examine the mechanisms underlying EBN-mediated increase in glucose uptake, we examined the transcriptional activity and expression of peroxisome proliferator-activated receptor gamma (PPAR-γ), a pivotal target for glucose metabolism in C2C12 myotubes. We found that the EBN increased both the transcriptional activity and mRNA expression levels of PPAR-γ. In addition, we measured phosphorylation and expression levels of other targets of glucose metabolism, such as AMP-activated protein kinase (AMPK) and protein kinase B (Akt/PKB). We found that EBN did not alter the phosphorylation or expression levels of these proteins in a time- or dose-dependent manner, which suggested that EBN stimulates glucose uptake through a PPAR-γ-dependent mechanism. Further, we investigated the antidiabetic property of EBN using mice fed a high-fat diet (HFD). Administration of 0.5% EBN reduced the HFD-induced increase in body weight, total cholesterol level, and fatty liver and improved the impaired fasting glucose level, blood insulin content, and glucose intolerance. These results suggest that EBN had an antidiabetic effect in cell culture and animal systems and may be useful for preventing diabetes. PMID:23690860

  7. Embryonic morphogenesis in Caenorhabditis elegans integrates the activity of LET-502 Rho-binding kinase, MEL-11 myosin phosphatase, DAF-2 insulin receptor and FEM-2 PP2c phosphatase.

    PubMed Central

    Piekny, A J; Wissmann, A; Mains, P E

    2000-01-01

    let-502 rho-binding kinase and mel-11 myosin phosphatase regulate Caenorhabditis elegans embryonic morphogenesis. Genetic analysis presented here establishes the following modes of let-502 action: (i) loss of only maternal let-502 results in abnormal early cleavages, (ii) loss of both zygotic and maternal let-502 causes elongation defects, and (iii) loss of only zygotic let-502 results in sterility. The morphogenetic function of let-502 and mel-11 is apparently redundant with another pathway since elimination of these two genes resulted in progeny that underwent near-normal elongation. Triple mutant analysis indicated that unc-73 (Rho/Rac guanine exchange factor) and mlc-4 (myosin light chain) act in parallel to or downstream of let-502/mel-11. In contrast mig-2 (Rho/Rac), daf-2 (insulin receptor), and age-1 (PI3 kinase) act within the let-502/mel-11 pathway. Mutations in the sex-determination gene fem-2, which encodes a PP2c phosphatase (unrelated to the MEL-11 phosphatase), enhanced mutations of let-502 and suppressed those of mel-11. fem-2's elongation function appears to be independent of its role in sexual identity since the sex-determination genes fem-1, fem-3, tra-1, and tra-3 had no effect on mel-11 or let-502. By itself, fem-2 affects morphogenesis with low penetrance. fem-2 blocked the near-normal elongation of let-502; mel-11 indicating that fem-2 acts in a parallel elongation pathway. The action of two redundant pathways likely ensures accurate elongation of the C. elegans embryo. PMID:11102366

  8. Extending David Horrobin's membrane phospholipid theory of schizophrenia: overactivity of cytosolic phospholipase A(2) in the brain is caused by overdrive of coupled serotonergic 5HT(2A/2C) receptors in response to stress.

    PubMed

    Eggers, Arnold E

    2012-12-01

    David Horrobin's membrane phospholipid theory of schizophrenia has held up well over time because his therapeutic prediction that dietary supplementation with eicosapentaenoic acid (EPA) would have a therapeutic effect has been partially verified and undergoes continued testing. In the final version of his theory, he hypothesized that there was hyperactivity of phosphoslipase A(2) (PLA(2)) or a related enzyme but did not explain how the hyperactivity came about. It is known that serotonergic 5HT(2A/2C) receptors are coupled to PLA(2), which hydrolyzes both arachidonic acid (AA) and EPA from diacylglycerides at the sn-2 position. In this paper, Horrobin's theory is combined with a previously published theory of chronic stress in which it was hypothesized that a disinhibited dorsal raphe nucleus, the principal nucleus of the serotonergic system, can organize the neuropathology of diseases such as migraine, hypertension, and the metabolic syndrome. The new or combined theory is that schizophrenia is a disease of chronic stress in which a disinhibited DRN causes widespread serotonergic overdrive in the cerebral cortex. This in turn causes overdrive of cPLA(2) and both central and peripheral depletion of AA and EPA. Because EPA is present in smaller amounts, it falls below threshold for maintaining an intracellular balance between AA-derived and EPA-derived second messenger cascades, which leads to abnormal patterns of neuronal firing. There are two causes of neuronal dysfunction: the disinhibited DRN and EPA depletion. Schizophrenia is statistically associated with metabolic syndrome, hypertension, and migraine because they form a cluster of diseases with similar pathophysiology. The theory provides an explanation for both the central and peripheral phospholipid abnormalities in schizophrenia. It also explains the role of stress in schizophrenia, elevated serum PLA(2) activity in schizophrenia, the relationship between untreated schizophrenia and metabolic syndrome

  9. A critical review of both the synthesis approach and the receptor profile of the 8-chloro-1-(2',4'-dichlorophenyl)-N-piperidin-1-yl-1,4,5,6-tetrahydrobenzo[6,7]cyclohepta[1,2-c]pyrazole-3-carboxamide and analogue derivatives.

    PubMed

    Lazzari, Paolo; Distinto, Rita; Manca, Ilaria; Baillie, Gemma; Murineddu, Gabriele; Pira, Marilena; Falzoi, Matteo; Sani, Monica; Morales, Paula; Ross, Ruth; Zanda, Matteo; Jagerovic, Nadine; Pinna, Gérard Aimè

    2016-10-01

    8-Chloro-1-(2',4'-dichlorophenyl)-N-piperidin-1-yl-1,4,5,6-tetrahydrobenzo[6,7]cyclohepta[1,2-c]pyrazole-3-carboxamide 9a was discovered as potent and selective CB1 antagonist by part of our group few years ago. In particular it was reported to have an affinity towards the CB1 cannabinoid receptor (CB1R), expressed as Ki, of 0.00035 nM. Nevertheless significantly divergent data were reported for the same compound from other laboratories. To unequivocally define the receptor profile of 9a, we have critically reviewed both its synthesis approach and binding data. Here we report that, in contrast to our previously reported data, 9a showed a Ki value for CB1R in the order of nanomolar rather than of fentomolar range. The new determined receptor profile of 9a was also ascertained for analogue derivatives 9b-i, as well as for 12. Moreover, the structural features of the synthesized compounds necessary for CB1R were investigated. Amongst the novel series, effects on CB1R intrinsic activity was highlighted due to the substituents at the position 3 of the pyrazole ring of the 1,4,5,6-tetrahydrobenzo[6,7]cyclohepta[1,2-c]pyrazole scaffold. Although the cannabinoid receptor profile of 9a was reviewed in this work, the relevance of this compound in CB1R antagonist based drug discovery is confirmed.

  10. Spectroscopic and structural study of Y 2C 2 carbide encapsulating endohedral metallofullerene: (Y 2C 2)@C 82

    NASA Astrophysics Data System (ADS)

    Inoue, Takashi; Tomiyama, Tetsuo; Sugai, Toshiki; Shinohara, Hisanori

    2003-12-01

    The first di-yttrium carbide endohedral metallofullerene has been produced and spectroscopically and structurally characterized. 13C NMR structural analyses reveal that di-yttrium endohedral metallofullerene having a molecular formula of Y 2C 84 has been found to possess an endohedral yttrium carbide structure, (Y 2C 2)@C 82, in which a Y 2C 2 species is encaged by a C 82-C 3v(8) fullerene. The encaged Y 2C 2 species should rapidly rotate in order to maintain the entire (Y 2C 2)@C 82 molecular symmetry unchanged at room temperature.

  11. Meconium Ileus Caused by Mutations in GUCY2C, Encoding the CFTR-Activating Guanylate Cyclase 2C

    PubMed Central

    Romi, Hila; Cohen, Idan; Landau, Daniella; Alkrinawi, Suliman; Yerushalmi, Baruch; Hershkovitz, Reli; Newman-Heiman, Nitza; Cutting, Garry R.; Ofir, Rivka; Sivan, Sara; Birk, Ohad S.

    2012-01-01

    Meconium ileus, intestinal obstruction in the newborn, is caused in most cases by CFTR mutations modulated by yet-unidentified modifier genes. We now show that in two unrelated consanguineous Bedouin kindreds, an autosomal-recessive phenotype of meconium ileus that is not associated with cystic fibrosis (CF) is caused by different homozygous mutations in GUCY2C, leading to a dramatic reduction or fully abrogating the enzymatic activity of the encoded guanlyl cyclase 2C. GUCY2C is a transmembrane receptor whose extracellular domain is activated by either the endogenous ligands, guanylin and related peptide uroguanylin, or by an external ligand, Escherichia coli (E. coli) heat-stable enterotoxin STa. GUCY2C is expressed in the human intestine, and the encoded protein activates the CFTR protein through local generation of cGMP. Thus, GUCY2C is a likely candidate modifier of the meconium ileus phenotype in CF. Because GUCY2C heterozygous and homozygous mutant mice are resistant to E. coli STa enterotoxin-induced diarrhea, it is plausible that GUCY2C mutations in the desert-dwelling Bedouin kindred are of selective advantage. PMID:22521417

  12. Molecular Mimicry Regulates ABA Signaling by SnRK2 Kinases and PP2C Phosphatases

    SciTech Connect

    Soon, Fen-Fen; Ng, Ley-Moy; Zhou, X. Edward; West, Graham M.; Kovach, Amanda; Tan, M.H. Eileen; Suino-Powell, Kelly M.; He, Yuanzheng; Xu, Yong; Chalmers, Michael J.; Brunzelle, Joseph S.; Zhang, Huiming; Yang, Huaiyu; Jiang, Hualiang; Li, Jun; Yong, Eu-Leong; Cutler, Sean; Zhu, Jian-Kang; Griffin, Patrick R.; Melcher, Karsten; Xu, H. Eric

    2014-10-02

    Abscisic acid (ABA) is an essential hormone for plants to survive environmental stresses. At the center of the ABA signaling network is a subfamily of type 2C protein phosphatases (PP2Cs), which form exclusive interactions with ABA receptors and subfamily 2 Snfl-related kinase (SnRK2s). Here, we report a SnRK2-PP2C complex structure, which reveals marked similarity in PP2C recognition by SnRK2 and ABA receptors. In the complex, the kinase activation loop docks into the active site of PP2C, while the conserved ABA-sensing tryptophan of PP2C inserts into the kinase catalytic cleft, thus mimicking receptor-PP2C interactions. These structural results provide a simple mechanism that directly couples ABA binding to SnRK2 kinase activation and highlight a new paradigm of kinase-phosphatase regulation through mutual packing of their catalytic sites.

  13. Molecular Mimicry Regulates ABA Signaling by SnRK2 Kinases and PP2C Phosphatases

    PubMed Central

    Soon, Fen-Fen; Ng, Ley-Moy; Zhou, X. Edward; West, Graham M.; Kovach, Amanda; Tan, M. H. Eileen; Suino-Powell, Kelly M.; He, Yuanzheng; Xu, Yong; Chalmers, Michael J.; Brunzelle, Joseph S.; Zhang, Huiming; Yang, Huaiyu; Jiang, Hualiang; Li, Jun; Yong, Eu-Leong; Cutler, Sean; Zhu, Jian-Kang; Griffin, Patrick R.; Melcher, Karsten; Xu, H. Eric

    2013-01-01

    Abscisic acid (ABA) is an essential hormone for plants to survive environmental stresses. At the center of the ABA signaling network is a subfamily of type 2C protein phosphatases (PP2Cs), which form exclusive interactions with ABA receptors and subfamily 2 Snfl-related kinase (SnRK2s). Here, we report a SnRK2-PP2C complex structure, which reveals marked similarity in PP2C recognition by SnRK2 and ABA receptors. In the complex, the kinase activation loop docks into the active site of PP2C, while the conserved ABA-sensing tryptophan of PP2C inserts into the kinase catalytic cleft, thus mimicking receptor-PP2C interactions. These structural results provide a simple mechanism that directly couples ABA binding to SnRK2 kinase activation and highlight a new paradigm of kinase-phosphatase regulation through mutual packing of their catalytic sites. PMID:22116026

  14. B2C graphene, nanotubes, and nanoribbons.

    PubMed

    Wu, Xiaojun; Pei, Yong; Zeng, Xiao Cheng

    2009-04-01

    We report a first-principles prediction of a new two-dimensional inorganic material, namely, the B(2)C graphene in which the boron and carbon atoms are packed into a mosaic of hexagons and rhombuses. In the B(2)C graphene, each carbon atom is bonded with four boron atoms, forming a planar-tetracoordinate carbon (ptC) moiety, a notion first conceived by Hoffmann et al. The B(2)C graphene is possibly a metal with a small overlap in the energy of conduction and valence bands. Like the carbon graphene and nanotubes, a B(2)C graphene sheet can be rolled into various forms of B(2)C nanotubes as well. Depending on the roll-up vector, the B(2)C nanotubes may become either a metal or a semiconductor. All B(2)C graphene nanoribbons are predicted to be uniformly metallic, regardless of their width and edge structure.

  15. STM and STS Observation on Titanium-Carbide Metallofullerenes:. TI2C2@C78

    NASA Astrophysics Data System (ADS)

    Fukui, N.; Moribe, H.; Umemoto, H.; Shinohara, H.; Suwa, Y.; Heike, S.; Fujimori, M.; Hashizume, T.

    2009-06-01

    A metallofullerene Ti2C2@C78, in which two titanium atoms and C2 cluster are encapsulated, is studied by scanning tunneling microscopy and spectroscopy. Measurements of Ti2C2@C78 on Cu(111) surface reveal that their cage symmetry is C78-D3h. There is a preferential orientation of Ti2C2@C78 resulting from electrostatic interaction same as other metallofullerene.

  16. Curtiss SB2C-1 Helldiver

    NASA Technical Reports Server (NTRS)

    1944-01-01

    Curtiss SB2C-1 Helldiver: This Curtiss SB2C-1 Helldiver was flown by the NACA at Langley with an early radio-control system. Flying controls such as a spring tab were also examined with this airframe. Helldivers were also operated by the U. S. Army as A-25 Shrikes.

  17. Global variation in CYP2C8–CYP2C9 functional haplotypes

    PubMed Central

    Speed, William C; Kang, Soonmo Peter; Tuck, David P; Harris, Lyndsay N; Kidd, Kenneth K

    2009-01-01

    We have studied the global frequency distributions of 10 single nucleotide polymorphisms (SNPs) across 132 kb of CYP2C8 and CYP2C9 in ∼2500 individuals representing 45 populations. Five of the SNPs were in noncoding sequences; the other five involved the more common missense variants (four in CYP2C8, one in CYP2C9) that change amino acids in the gene products. One haplotype containing two CYP2C8 coding variants and one CYP2C9 coding variant reaches an average frequency of 10% in Europe; a set of haplotypes with a different CYP2C8 coding variant reaches 17% in Africa. In both cases these haplotypes are found in other regions of the world at <1%. This considerable geographic variation in haplotype frequencies impacts the interpretation of CYP2C8/CYP2C9 association studies, and has pharmacogenomic implications for drug interactions. PMID:19381162

  18. Curtiss SB2C-1 Helldiver

    NASA Technical Reports Server (NTRS)

    1943-01-01

    Curtiss SB2C-1 Helldiver: The front canopy came off this Curtiss SB2C-1 Helldiver while it was in flight, injuring pilot Herbert H. Hoover, but he recovered the plane back to the NACA at Langley Field. SB2Cs were license-built by Fairchild as SBFs and by Canadian Car and Foundry as SBWs. Helldivers were also flown by the British and Australians.

  19. Design, Synthesis, and Structure–Activity Relationship of a Novel Series of GluN2C-Selective Potentiators

    PubMed Central

    2015-01-01

    NMDA receptors are tetrameric complexes composed of GluN1 and GluN2A–D subunits that mediate a slow Ca2+-permeable component of excitatory synaptic transmission. NMDA receptors have been implicated in a wide range of neurological diseases and thus represent an important therapeutic target. We herein describe a novel series of pyrrolidinones that selectively potentiate only NMDA receptors that contain the GluN2C subunit. The most active analogues tested were over 100-fold selective for recombinant GluN2C-containing receptors over GluN2A/B/D-containing NMDA receptors as well as AMPA and kainate receptors. This series represents the first class of allosteric potentiators that are selective for diheteromeric GluN2C-containing NMDA receptors. PMID:24512267

  20. Photoelectron spectra of thulium atoms encapsulated C82 fullerene, Tm2@C82 (III) and Tm2C2@C82 (III)

    NASA Astrophysics Data System (ADS)

    Miyazaki, Takafumi; Tokumoto, Youji; Sumii, Ryohei; Yagi, Hajime; Izumi, Noriko; Shinohara, Hisanori; Hino, Shojun

    2014-03-01

    Ultraviolet photoelectron spectra (UPS) and X-ray photoelectron spectra (XPS) of two thulium atoms and thulium-carbide cluster entrapped fullerenes, Tm2@C82 (III) and Tm2C2@C82 (III), were measured using synchrotron radiation and MgKα X-ray light sources. The UPS spectral onset energy of these endohedral fullerenes is around 0.9 eV, which is smaller than that of 1.2 eV of empty C82. The UPS of Tm2@C82 (III) and Tm2C2@C82 (III) resemble each other. Further, the UPS of Tm2@C82 (III), Y2@C82-C3v and Er2@C82-C3v are almost identical and as well as are Tm2C2@C82 (III), Y2C2@C82-C3v and Er2C2@C82-C3v. The XPS Tm4d5/2 peaks of Tm2@C82 and Tm2C2@C82 appear at higher binding energy region than that of Tm@C82, which suggests the oxidation states of Tm atoms in Tm2@C82 (III) and Tm2C2@C82 are higher than that in Tm@C82.

  1. Nanosegregation in Na2C60

    SciTech Connect

    Klupp, G.; Kamaras, K.; Matus, P.; Kiss, L.F.; Kovats, E.; Pekker, S.; Nemes, N.M.; Quintavalle, D.; Janossy, A.

    2005-09-27

    There is continuous interest in the nature of alkali metal fullerides containing C{sub 60}{sup 4-} and C{sub 60}{sup 2-}, because these compounds are believed to be nonmagnetic Mott-Jahn-Teller insulators. This idea could be verified in the case of A4C60, but Na2C60 is more controversial. By comparing the results of infrared spectroscopy and X-ray diffraction, we found that Na2C60 is segregated into 3-10 nm large regions. The two main phases of the material are insulating C60 and metallic Na3C60. We found by neutron scattering that the diffusion of sodium ions becomes faster on heating. Above 470 K Na2C60 is homogeneous and we show IR spectroscopic evidence of a Jahn-Teller distorted C{sub 60}{sup 2-} anion.

  2. SAR of psilocybin analogs: discovery of a selective 5-HT 2C agonist.

    PubMed

    Sard, Howard; Kumaran, Govindaraj; Morency, Cynthia; Roth, Bryan L; Toth, Beth Ann; He, Ping; Shuster, Louis

    2005-10-15

    An SAR study of psilocybin and psilocin derivatives reveals that 1-methylpsilocin is a selective agonist at the h5-HT(2C) receptor. The corresponding phosphate derivative, 1-methylpsilocybin, shows efficacy in an animal model for obsessive-compulsive disorder, as does 4-fluoro-N,N-dimethyltryptamine. These results suggest a new area for development of novel 5-HT(2C) agonists with applications for drug discovery.

  3. Ultraviolet photoelectron spectra of (YC)2 @ C82 and Y2 @ C82

    NASA Astrophysics Data System (ADS)

    Hino, Shojun; Wanita, Norihiko; Iwasaki, Kentaro; Yoshimura, Daisuke; Akachi, Takao; Inoue, Takeshi; Ito, Yasuhiro; Sugai, Toshiki; Shinohara, Hisanori

    2005-11-01

    Ultraviolet photoelectron spectra (UPS) of metallofullerenes, (YC)2@C82 (III) and Y2@C82 (III) were measured using a synchrotron radiation light source. The spectral onset energy of (YC)2@C82 (III) was determined to be 0.8 eV below the Fermi level, and that of Y2@C82 (III) was 0.45eV , indicating the semiconductive nature of these metallofullerenes. The UPS consisted of numerous crests and troughs. Further, a change in intensity upon tuning the excitation energy was observed; however, the intensity of the change was not as large as those observed for other fullerenes. The UPS of two metallofullerenes basically resemble each other, although there are minute differences between them. The UPS of (YC)2@C82 (III) was easily reproduced by a simulated spectrum obtained by molecular orbital calculations assuming a C3v (8) cage structure with four additional electrons on the cage. A difference spectrum between the UPS of (YC)2@C82 (III) and Y2@C82 (III) indicates the existence of additional electrons on the cage of Y2@C82 .

  4. Expression of paired-like homeodomain transcription factor 2c (PITX2c) in epidermal keratinocytes

    SciTech Connect

    Shi, Ge; Sohn, Kyung-Cheol; Choi, Tae-Young; Choi, Dae-Kyoung; Lee, Sang-Sin; Ou, Bai-sheng; Kim, Sooil; Lee, Young Ho; Yoon, Tae-Jin; Kim, Seong-Jin; Lee, Young; Seo, Young-Joon; Lee, Jeung-Hoon; Kim, Chang Deok

    2010-11-15

    Paired-like homeodomain transcription factor 2 (PITX2) has been implicated as one of the genes responsible for Rieger syndrome. It has been also shown to play a central role during development. In this study, we investigated the functional role of PITX2 in keratinocyte differentiation. RT-PCR analysis showed that PITX2c isoform was predominantly expressed in a differentiation-dependent manner. Consistent with, immunohistochemical staining showed that PITX2 expression was increased in the upper layer of epidermis. When PITX2c was overexpressed in cultured keratinocytes by a recombinant adenovirus, the differentiation markers such as involucrin and loricrin were significantly increased at both mRNA and protein levels. In addition, PITX2c overexpression led to the decrease of cell growth, concomitantly with the upregulation of cell cycle-related genes p21. To investigate the effect of PITX2c in vivo, we microinjected PITX2c expression vector into zebrafish embryo. Interestingly, overexpression of PITX2c in zebrafish embryo led to the formation of horn-like structure and thickening of epidermis, together with the increase of keratin 8 (K8) expression. These results suggest that PITX2c has a role in proliferation and differentiation of epidermal keratinocytes.

  5. Interferon signaling is dependent on specific tyrosines located within the intracellular domain of IFNAR2c. Expression of IFNAR2c tyrosine mutants in U5A cells.

    PubMed

    Wagner, T Charis; Velichko, Sharlene; Vogel, David; Rani, M R Sandhya; Leung, Stewart; Ransohoff, Richard M; Stark, George R; Perez, H Daniel; Croze, Ed

    2002-01-11

    Type I interferons (IFNs) are cytokines that play a central role in mediating antiviral, antiproliferative, and immunomodulatory activities in virtually all cells. These activities are entirely dependent on the interaction of IFNs with their particular cell surface receptor. In this report, we identify two specific tyrosine residues located within the cytoplasmic domain of IFNAR2c that are obligatory for IFN-dependent signaling. Various IFNAR2c tyrosine mutants were expressed in a human lung fibroscarcoma cell line lacking IFNAR2c (U5A). Stable clones expressing these mutants were analyzed for their ability to induce STAT1 and STAT2 activation, ISGF3 transcriptional complex formation, gene expression, and cell growth regulation in response to stimulation with type I IFNs. The replacement of all seven cytoplasmic tyrosine residues of IFNAR2c with phenylalanine resulted in a receptor unable to respond to IFN stimulation. Substitution of single tyrosines at amino acid residue 269, 316, 318, 337, or 512 with phenylalanine had no effect on IFN-dependent signaling, suggesting that no single tyrosine is essential for IFN receptor-mediated signaling. In addition, IFNAR2c retaining five proximal tyrosines residues (269, 306, 316, 318, and 337) or either two distal tyrosine residues (411 or 512) continued to be responsive to IFN stimulation. Surprisingly, the presence of only a single tyrosine at either position 337 or 512 was sufficient to restore a complete IFN response. These results indicate that IFN-dependent signaling proceeds through the redundant usage of two tyrosine residues in the cytoplasmic domain of IFNAR2c.

  6. Superposition of quantum and classical rotational motions in Sc2C2@C84 fullerite

    NASA Astrophysics Data System (ADS)

    Michel, K. H.; Verberck, B.; Hulman, M.; Kuzmany, H.; Krause, M.

    2007-02-01

    The superposition of the quantum rotational motion (tunneling) of the encapsulated Sc2C2 complex with the classical rotational motion of the surrounding C84 molecule in a powder crystal of Sc2C2@C84 fullerite is investigated by theory. Since the quantum rotor is dragged along by the C84 molecule, any detection method which couples to the quantum rotor (in casu the C2 bond of the Sc2C2 complex) also probes the thermally excited classical motion (uniaxial rotational diffusion and stochastic meroaxial jumps) of the surrounding fullerene. The dynamic rotation-rotation response functions in frequency space are obtained as convolutions of quantum and classical dynamic correlation functions. The corresponding Raman scattering laws are derived, and the overall shape of the spectra and the width of the resonance lines are studied as functions of temperature. The results of the theory are confronted with experimental low-frequency Raman spectra on powder crystals of Sc2C2@C84 [M. Krause et al., Phys. Rev. Lett. 93, 137403 (2004)]. The agreement of theory with experiment is very satisfactory in a broad temperature range.

  7. Polyclonal Expansion of NKG2C+ NK Cells in TAP-Deficient Patients

    PubMed Central

    Béziat, Vivien; Sleiman, Marwan; Goodridge, Jodie P.; Kaarbø, Mari; Liu, Lisa L.; Rollag, Halvor; Ljunggren, Hans-Gustaf; Zimmer, Jacques; Malmberg, Karl-Johan

    2015-01-01

    Adaptive natural killer (NK) cell responses to human cytomegalovirus infection are characterized by the expansion of NKG2C+ NK cells expressing self-specific inhibitory killer-cell immunoglobulin-like receptors (KIRs). Here, we set out to study the HLA class I dependency of such NKG2C+ NK cell expansions. We demonstrate the expansion of NKG2C+ NK cells in patients with transporter associated with antigen presentation (TAP) deficiency, who express less than 10% of normal HLA class I levels. In contrast to normal individuals, expanded NKG2C+ NK cell populations in TAP-deficient patients display a polyclonal KIR profile and remain hyporesponsive to HLA class I-negative target cells. Nonetheless, agonistic stimulation of NKG2C on NK cells from TAP-deficient patients yielded significant responses in terms of degranulation and cytokine production. Thus, while interactions with self-HLA class I molecules likely shape the KIR repertoire of expanding NKG2C+ NK cells during adaptive NK cell responses in normal individuals, they are not a prerequisite for NKG2C+ NK cell expansions to occur. The emergence of NKG2C-responsive adaptive NK cells in TAP-deficient patients may contribute to antiviral immunity and potentially explain these patients’ low incidence of severe viral infections. PMID:26500647

  8. Intestinal GUCY2C prevents TGF-β secretion coordinating desmoplasia and hyperproliferation in colorectal cancer.

    PubMed

    Gibbons, Ahmara V; Lin, Jieru E; Kim, Gilbert W; Marszalowicz, Glen P; Li, Peng; Stoecker, Brian A; Blomain, Erik S; Rattan, Satish; Snook, Adam E; Schulz, Stephanie; Waldman, Scott A

    2013-11-15

    Tumorigenesis is a multistep process that reflects intimate reciprocal interactions between epithelia and underlying stroma. However, tumor-initiating mechanisms coordinating transformation of both epithelial and stromal components are not defined. In humans and mice, initiation of colorectal cancer is universally associated with loss of guanylin and uroguanylin, the endogenous ligands for the tumor suppressor guanylyl cyclase C (GUCY2C), disrupting a network of homeostatic mechanisms along the crypt-surface axis. Here, we reveal that silencing GUCY2C in human colon cancer cells increases Akt-dependent TGF-β secretion, activating fibroblasts through TGF-β type I receptors and Smad3 phosphorylation. In turn, activating TGF-β signaling induces fibroblasts to secrete hepatocyte growth factor (HGF), reciprocally driving colon cancer cell proliferation through cMET-dependent signaling. Elimination of GUCY2C signaling in mice (Gucy2c(-/-)) produces intestinal desmoplasia, with increased reactive myofibroblasts, which is suppressed by anti-TGF-β antibodies or genetic silencing of Akt. Thus, GUCY2C coordinates intestinal epithelial-mesenchymal homeostasis through reciprocal paracrine circuits mediated by TGF-β and HGF. In that context, GUCY2C signaling constitutes a direct link between the initiation of colorectal cancer and the induction of its associated desmoplastic stromal niche. The recent regulatory approval of oral GUCY2C ligands to treat chronic gastrointestinal disorders underscores the potential therapeutic opportunity for oral GUCY2C hormone replacement to prevent remodeling of the microenvironment essential for colorectal tumorigenesis. PMID:24085786

  9. Intestinal GUCY2C Prevents TGF-β Secretion Coordinating Desmoplasia and Hyperproliferation in Colorectal Cancer

    PubMed Central

    Gibbons, Ahmara V.; Lin, Jieru E.; Kim, Gilbert W.; Marszalowicz, Glen P.; Li, Peng; Stoecker, Brian A.; Blomain, Erik S.; Rattan, Satish; Snook, Adam E.; Schulz, Stephanie; Waldman, Scott A.

    2013-01-01

    Tumorigenesis is a multi-step process that reflects intimate reciprocal interactions between epithelia and underlying stroma. However, tumor-initiating mechanisms coordinating transformation of both epithelial and stromal components are not defined. In humans and mice, initiation of colorectal cancer is universally associated with loss of guanylin and uroguanylin, the endogenous ligands for the tumor suppressor guanylyl cyclase C (GUCY2C), disrupting a network of homeostatic mechanisms along the crypt-surface axis. Here, we reveal that silencing GUCY2C in human colon cancer cells increases Akt-dependent TGF-β secretion, activating fibroblasts through TGF-β type I receptors and Smad3 phosphorylation. In turn, activating TGF-β signaling induces fibroblasts to secrete hepatocyte growth factor (HGF), reciprocally driving colon cancer cell proliferation through cMET-dependent signaling. Elimination of GUCY2C signaling in mice (Gucy2c-/-) produces intestinal desmoplasia, with increased reactive myofibroblasts, which is suppressed by anti-TGF-β antibodies or genetic silencing of Akt. Thus, GUCY2C coordinates intestinal epithelial-mesenchymal homeostasis through reciprocal paracrine circuits mediated by TGF-β and HGF. In that context, GUCY2C signaling constitutes a direct link between the initiation of colorectal cancer and the induction of its associated desmoplastic stromal niche. The recent regulatory approval of oral GUCY2C ligands to treat chronic gastrointestinal disorders underscores the potential therapeutic opportunity for oral GUCY2C hormone replacement to prevent remodeling of the microenvironment essential for colorectal tumorigenesis. PMID:24085786

  10. DRAGON, a GPI-anchored membrane protein, inhibits BMP signaling in C2C12 myoblasts.

    PubMed

    Kanomata, Kazuhiro; Kokabu, Shoichiro; Nojima, Junya; Fukuda, Toru; Katagiri, Takenobu

    2009-06-01

    Bone morphogenetic proteins (BMPs) induce osteoblastic differentiation of myoblasts via binding to cell surface receptors. Repulsive guidance molecules (RGMs) have been identified as BMP co-receptors. We report here that DRAGON/RGMb, a member of the RGM family, suppressed BMP signaling in C2C12 myoblasts via a novel mechanism. All RGMs were expressed in C2C12 cells that were differentiated into myocytes and osteoblastic cells, but RGMc was not detected in immature cells. In C2C12 cells, only DRAGON suppressed ALP and Id1 promoter activities induced by BMP-4 or by constitutively activated BMP type I receptors. This inhibition by DRAGON was dependent on the secretory form of the von Willbrand factor type D domain. DRAGON even suppressed BMP signaling induced by constitutively activated Smad1. Over-expression of neogenin did not alter the inhibitory capacity of DRAGON. Taken together, these findings indicate that DRAGON may be an inhibitor of BMP signaling in C2C12 myoblasts. We also suggest that a novel molecule(s) expressed on the cell membrane may mediate the signal transduction of DRAGON in order to suppress BMP signaling in C2C12 myoblasts.

  11. Isolation and characterization of canine parvovirus type 2C (CPV-2C) from symptomatic puppies

    PubMed Central

    Puentes, R; Eliopulos, N; Pérez, R; Franco, G; Sosa, K; Bianchi, P; Furtado, A; Hübner, S.O.; Esteves, P.A.

    2012-01-01

    Canine parvovirus type 2 (CPV-2) is a leading cause of diarrhea in puppies in several parts of the world. In this study CPV-2 was detected and recovered from puppies showing clinical disease from Montevideo, Uruguay. Samples were processed and used to infect CRFK and MDCK cells in order to isolate the virus. Out of twelve, two samples were positive for CPV-2. A genomic region of 583 bp was amplified and the molecular characterization was performed by sequencing, phylogenetic analysis and Restriction Fragment Length Polymorphism (RFLP). Two isolated viruses (UY1 and UY2) were CPV-2c-like viruses. The comparison between the cytophatic effect (CPE) of CPV-2 (vaccinal virus) and CPV-2c (isolated virus) on primary canine cells cultures and on CRFK line cells, demonstrated that CPV-2c is less citopathogenic in CRFK than in primary cultures. Our study represents the first report on isolation and characterization of canine parvovirus type 2c (CPV-2c) in cell cultures from South American dogs. PMID:24031919

  12. Isolation and characterization of canine parvovirus type 2C (CPV-2C) from symptomatic puppies.

    PubMed

    Puentes, R; Eliopulos, N; Pérez, R; Franco, G; Sosa, K; Bianchi, P; Furtado, A; Hübner, S O; Esteves, P A

    2012-07-01

    Canine parvovirus type 2 (CPV-2) is a leading cause of diarrhea in puppies in several parts of the world. In this study CPV-2 was detected and recovered from puppies showing clinical disease from Montevideo, Uruguay. Samples were processed and used to infect CRFK and MDCK cells in order to isolate the virus. Out of twelve, two samples were positive for CPV-2. A genomic region of 583 bp was amplified and the molecular characterization was performed by sequencing, phylogenetic analysis and Restriction Fragment Length Polymorphism (RFLP). Two isolated viruses (UY1 and UY2) were CPV-2c-like viruses. The comparison between the cytophatic effect (CPE) of CPV-2 (vaccinal virus) and CPV-2c (isolated virus) on primary canine cells cultures and on CRFK line cells, demonstrated that CPV-2c is less citopathogenic in CRFK than in primary cultures. Our study represents the first report on isolation and characterization of canine parvovirus type 2c (CPV-2c) in cell cultures from South American dogs.

  13. Isolation and characterization of canine parvovirus type 2C (CPV-2C) from symptomatic puppies.

    PubMed

    Puentes, R; Eliopulos, N; Pérez, R; Franco, G; Sosa, K; Bianchi, P; Furtado, A; Hübner, S O; Esteves, P A

    2012-07-01

    Canine parvovirus type 2 (CPV-2) is a leading cause of diarrhea in puppies in several parts of the world. In this study CPV-2 was detected and recovered from puppies showing clinical disease from Montevideo, Uruguay. Samples were processed and used to infect CRFK and MDCK cells in order to isolate the virus. Out of twelve, two samples were positive for CPV-2. A genomic region of 583 bp was amplified and the molecular characterization was performed by sequencing, phylogenetic analysis and Restriction Fragment Length Polymorphism (RFLP). Two isolated viruses (UY1 and UY2) were CPV-2c-like viruses. The comparison between the cytophatic effect (CPE) of CPV-2 (vaccinal virus) and CPV-2c (isolated virus) on primary canine cells cultures and on CRFK line cells, demonstrated that CPV-2c is less citopathogenic in CRFK than in primary cultures. Our study represents the first report on isolation and characterization of canine parvovirus type 2c (CPV-2c) in cell cultures from South American dogs. PMID:24031919

  14. Telecom 2-B and 2-C (TC2B and TC2C)

    NASA Technical Reports Server (NTRS)

    Dulac, J.; Alvarez, H.

    1991-01-01

    The DSN (Deep Space Network) mission support requirements for Telecom 2-B and 2-C (TC2B and TC2C) are summarized. These Telecom missions will provide high-speed data link applications, telephone, and television service between France and overseas territories as a follow-on to TC2A. Mission objectives are outlined and the DSN support requirements are defined through the presentation of tables and narratives describing the spacecraft flight profile; DSN support coverage; frequency assignments; support parameters for telemetry, command and support systems; and tracking support responsibility.

  15. Design, synthesis, and application of OB2C combinatorial peptide and peptidomimetic libraries.

    PubMed

    Liu, Ruiwu; Shih, Tsung-Chieh; Deng, Xiaojun; Anwar, Lara; Ahadi, Sara; Kumaresan, Pappanaicken; Lam, Kit S

    2015-01-01

    The "one-bead two-compound" (OB2C) combinatorial library is constructed on topologically segregated trifunctional bilayer beads such that each bead has a fixed cell-capturing ligand and a random library compound co-displayed on its surface and a chemical coding tag (bar code) inside the bead. An OB2C library containing thousands to millions of compounds can be synthesized and screened concurrently within a short period of time. When live cells are incubated with such OB2C libraries, every bead will be coated with a monolayer of cells. The cell membranes of the captured cells facing the bead surface are exposed to the library compounds tethered to each bead. A specific biochemical or cellular response can be detected with an appropriate reporter system. The OB2C method enables investigators to rapidly discover synthetic molecules that not only interact with cell-surface receptors but can also stimulate or inhibit downstream cell signaling. To demonstrate this powerful method, one OB2C peptide library and two OB2C peptidomimetic libraries were synthesized and screened against Molt-4 lymphoma cells to discover "death ligands." Apoptosis of the bead-bound cells was detected with immunocytochemistry using horseradish peroxidase (HRP)-conjugated anti-cleaved caspase-3 antibody and 3,3'-diaminobenzidine as a substrate. Two novel synthetic "death ligands" against Molt-4 cells were discovered using this OB2C library approach.

  16. FGFR2c-mediated ERK-MAPK activity regulates coronal suture development.

    PubMed

    Pfaff, Miles J; Xue, Ke; Li, Li; Horowitz, Mark C; Steinbacher, Derek M; Eswarakumar, Jacob V P

    2016-07-15

    Fibroblast growth factor receptor 2 (FGFR2) signaling is critical for proper craniofacial development. A gain-of-function mutation in the 2c splice variant of the receptor's gene is associated with Crouzon syndrome, which is characterized by craniosynostosis, the premature fusion of one or more of the cranial vault sutures, leading to craniofacial maldevelopment. Insight into the molecular mechanism of craniosynostosis has identified the ERK-MAPK signaling cascade as a critical regulator of suture patency. The aim of this study is to investigate the role of FGFR2c-induced ERK-MAPK activation in the regulation of coronal suture development. Loss-of-function and gain-of-function Fgfr2c mutant mice have overlapping phenotypes, including coronal synostosis and craniofacial dysmorphia. In vivo analysis of coronal sutures in loss-of-function and gain-of-function models demonstrated fundamentally different pathogenesis underlying coronal suture synostosis. Calvarial osteoblasts from gain-of-function mice demonstrated enhanced osteoblastic function and maturation with concomitant increase in ERK-MAPK activation. In vitro inhibition with the ERK protein inhibitor U0126 mitigated ERK protein activation levels with a concomitant reduction in alkaline phosphatase activity. This study identifies FGFR2c-mediated ERK-MAPK signaling as a key mediator of craniofacial growth and coronal suture development. Furthermore, our results solve the apparent paradox between loss-of-function and gain-of-function FGFR2c mutants with respect to coronal suture synostosis. PMID:27034231

  17. MEF2C protects bone marrow B-lymphoid progenitors during stress haematopoiesis

    PubMed Central

    Wang, Wenyuan; Org, Tonis; Montel-Hagen, Amélie; Pioli, Peter D.; Duan, Dan; Israely, Edo; Malkin, Daniel; Su, Trent; Flach, Johanna; Kurdistani, Siavash K.; Schiestl, Robert H.; Mikkola, Hanna K. A.

    2016-01-01

    DNA double strand break (DSB) repair is critical for generation of B-cell receptors, which are pre-requisite for B-cell progenitor survival. However, the transcription factors that promote DSB repair in B cells are not known. Here we show that MEF2C enhances the expression of DNA repair and recombination factors in B-cell progenitors, promoting DSB repair, V(D)J recombination and cell survival. Although Mef2c-deficient mice maintain relatively intact peripheral B-lymphoid cellularity during homeostasis, they exhibit poor B-lymphoid recovery after sub-lethal irradiation and 5-fluorouracil injection. MEF2C binds active regulatory regions with high-chromatin accessibility in DNA repair and V(D)J genes in both mouse B-cell progenitors and human B lymphoblasts. Loss of Mef2c in pre-B cells reduces chromatin accessibility in multiple regulatory regions of the MEF2C-activated genes. MEF2C therefore protects B lymphopoiesis during stress by ensuring proper expression of genes that encode DNA repair and B-cell factors. PMID:27507714

  18. HTR1B and HTR2C in autism spectrum disorders in Brazilian families.

    PubMed

    Orabona, G M; Griesi-Oliveira, K; Vadasz, E; Bulcão, V L S; Takahashi, V N V O; Moreira, E S; Furia-Silva, M; Ros-Melo, A M S; Dourado, F; Matioli, S R; Matioli, R; Otto, P; Passos-Bueno, M R

    2009-01-23

    Autism spectrum disorders (ASD) is a group of behaviorally defined neurodevelopmental disabilities characterized by multiple genetic etiologies and a complex presentation. Several studies suggest the involvement of the serotonin system in the development of ASD, but only few have investigated serotonin receptors. We have performed a case-control and a family-based study with 9 polymorphisms mapped to two serotonin receptor genes (HTR1B and HTR2C) in 252 Brazilian male ASD patients of European ancestry. These analyses showed evidence of undertransmission of the HTR1B haplotypes containing alleles -161G and -261A at HTR1B gene to ASD (P=0.003), but no involvement of HTR2C to the predisposition to this disease. Considering the relatively low level of statistical significance and the power of our sample, further studies are required to confirm the association of these serotonin-related genes and ASD.

  19. The Arabidopsis Protein Phosphatase PP2C38 Negatively Regulates the Central Immune Kinase BIK1.

    PubMed

    Couto, Daniel; Niebergall, Roda; Liang, Xiangxiu; Bücherl, Christoph A; Sklenar, Jan; Macho, Alberto P; Ntoukakis, Vardis; Derbyshire, Paul; Altenbach, Denise; Maclean, Dan; Robatzek, Silke; Uhrig, Joachim; Menke, Frank; Zhou, Jian-Min; Zipfel, Cyril

    2016-08-01

    Plants recognize pathogen-associated molecular patterns (PAMPs) via cell surface-localized pattern recognition receptors (PRRs), leading to PRR-triggered immunity (PTI). The Arabidopsis cytoplasmic kinase BIK1 is a downstream substrate of several PRR complexes. How plant PTI is negatively regulated is not fully understood. Here, we identify the protein phosphatase PP2C38 as a negative regulator of BIK1 activity and BIK1-mediated immunity. PP2C38 dynamically associates with BIK1, as well as with the PRRs FLS2 and EFR, but not with the co-receptor BAK1. PP2C38 regulates PAMP-induced BIK1 phosphorylation and impairs the phosphorylation of the NADPH oxidase RBOHD by BIK1, leading to reduced oxidative burst and stomatal immunity. Upon PAMP perception, PP2C38 is phosphorylated on serine 77 and dissociates from the FLS2/EFR-BIK1 complexes, enabling full BIK1 activation. Together with our recent work on the control of BIK1 turnover, this study reveals another important regulatory mechanism of this central immune component. PMID:27494702

  20. The Arabidopsis Protein Phosphatase PP2C38 Negatively Regulates the Central Immune Kinase BIK1

    PubMed Central

    Liang, Xiangxiu; Bücherl, Christoph A.; Sklenar, Jan; Macho, Alberto P.; Ntoukakis, Vardis; Derbyshire, Paul; Altenbach, Denise; Robatzek, Silke; Uhrig, Joachim; Menke, Frank; Zhou, Jian-Min

    2016-01-01

    Plants recognize pathogen-associated molecular patterns (PAMPs) via cell surface-localized pattern recognition receptors (PRRs), leading to PRR-triggered immunity (PTI). The Arabidopsis cytoplasmic kinase BIK1 is a downstream substrate of several PRR complexes. How plant PTI is negatively regulated is not fully understood. Here, we identify the protein phosphatase PP2C38 as a negative regulator of BIK1 activity and BIK1-mediated immunity. PP2C38 dynamically associates with BIK1, as well as with the PRRs FLS2 and EFR, but not with the co-receptor BAK1. PP2C38 regulates PAMP-induced BIK1 phosphorylation and impairs the phosphorylation of the NADPH oxidase RBOHD by BIK1, leading to reduced oxidative burst and stomatal immunity. Upon PAMP perception, PP2C38 is phosphorylated on serine 77 and dissociates from the FLS2/EFR-BIK1 complexes, enabling full BIK1 activation. Together with our recent work on the control of BIK1 turnover, this study reveals another important regulatory mechanism of this central immune component. PMID:27494702

  1. Structural transformations of Li2C2 at high pressures

    NASA Astrophysics Data System (ADS)

    Efthimiopoulos, Ilias; Benson, Daryn E.; Konar, Sumit; Nylén, Johanna; Svensson, Gunnar; Häussermann, Ulrich; Liebig, Stefan; Ruschewitz, Uwe; Vazhenin, Grigory V.; Loa, Ingo; Hanfland, Michael; Syassen, Karl

    2015-08-01

    Structural changes of Li2C2 under pressure were studied by synchrotron x-ray diffraction in a diamond anvil cell under hydrostatic conditions and by using evolutionary search methodology for crystal structure prediction. We show that the high-pressure polymorph of Li2C2 , which forms from the I m m m ground-state structure (Z =2 ) at around 15 GPa, adopts an orthorhombic P n m a structure with Z =4 . Acetylide C2 dumbbells characteristic of I m m m Li2C2 are retained in P n m a Li2C2 . The structure of P n m a Li2C2 relates closely to the anticotunnite-type structure. C2 dumbbell units are coordinated by nine Li atoms, as compared to eight in the antifluorite structure of I m m m Li2C2 . First-principles calculations predict a transition of P n m a Li2C2 at 32 GPa to a topologically identical phase with a higher C m c m symmetry. The coordination of C2 dumbbell units by Li atoms is increased to 11. The structure of C m c m Li2C2 relates closely to the Ni2 In-type structure. It is calculated that C m c m Li2C2 becomes metallic at pressures above 40 GPa. In experiments, however, P n m a Li2C2 is susceptible to irreversible amorphization.

  2. GUCY2C lysosomotropic endocytosis delivers immunotoxin therapy to metastatic colorectal cancer

    PubMed Central

    Marszalowicz, Glen P.; Snook, Adam E.; Magee, Michael S.; Merlino, Dante; Lisa, D. Berman-Booty; Waldman, Scott A.

    2014-01-01

    The emergence of targeted cancer therapy has been limited by the paucity of determinants which are tumor-specific and generally associated with disease, and have cell dynamics which effectively deploy cytotoxic payloads. Guanylyl cyclase C (GUCY2C) may be ideal for targeting because it is normally expressed only in insulated barrier compartments, including intestine and brain, but over-expressed by systemic metastatic colorectal tumors. Here, we reveal that GUCY2C rapidly internalizes from the cell surface to lysosomes in intestinal and colorectal cancer cells. Endocytosis is independent of ligand binding and receptor activation, and is mediated by clathrin. This mechanism suggests a design for immunotoxins comprising a GUCY2C-directed monoclonal antibody conjugated through a reducible disulfide linkage to ricin A chain, which is activated to a potent cytotoxin in lysosomes. Indeed, this immunotoxin specifically killed GUCY2C-expressing colorectal cancer cells in a lysosomal- and clathrin-dependent fashion. Moreover, this immunotoxin reduced pulmonary tumors >80% (p<0.001), and improved survival 25% (p<0.001), in mice with established colorectal cancer metastases. Further, therapeutic efficacy was achieved without histologic evidence of toxicity in normal tissues. These observations support GUCY2C-targeted immunotoxins as novel therapeutics for metastatic tumors originating in the GI tract, including colorectum, stomach, esophagus, and pancreas. PMID:25294806

  3. A role for Sv2c in basal ganglia functions.

    PubMed

    Dardou, D; Monlezun, S; Foerch, P; Courade, J P; Cuvelier, L; De Ryck, M; Schiffmann, S N

    2013-04-24

    SV2C is an isoform of the synaptic vesicle 2 protein family that exhibits a particular pattern of brain expression with enriched expression in several basal ganglia nuclei. In the present study, we have investigated SV2C implication in both normal and pathological basal ganglia functioning with a peculiar attention to dopamine neuron containing regions. In SV2C-/- mice, the expression of tyrosine hydroxylase mRNA in midbrain dopaminergic neurons was largely and significantly increased and enkephalin mRNA expression was significantly decreased in the caudate-putamen and accumbens nucleus. The expression of SV2C was studied in two models of dopaminergic denervation (6-OHDA- and MPTP-induced lesions). In dopamine-depleted animals, SV2C mRNA expression was significant increased in the striatum. In order to further understand the role of SV2C, we performed behavioral experiments on SV2C-/- mice and on knock-down mice receiving an injection of adeno-associated virus expressing SV2C miRNA specifically in the ventral midbrain. These modifications of SV2C expression had little or no impact on behavior in open field and elevated plus maze. However, even if complete loss of SV2C had no impact on conditioned place preference induced by cocaine, the specific knock-down of SV2C expression in the dopaminergic neurons completely abolished the development of a CPP while the reaction to an acute drug injection remains similar in these mice compared to control mice. These results showed that SV2C, a poorly functionally characterized protein is strongly involved in normal operation of the basal ganglia network and could be also involved in system adaptation in basal ganglia pathological conditions. PMID:23458503

  4. Unusual behaviour of (Np,Pu)B2C

    NASA Astrophysics Data System (ADS)

    Klimczuk, Tomasz; Boulet, Pascal; Griveau, Jean-Christophe; Colineau, Eric; Bauer, Ernst; Falmbigl, Matthias; Rogl, Peter; Wastin, Franck

    2015-02-01

    Two transuranium metal boron carbides, NpB2C and PuB2C have been synthesized by argon arc melting. The crystal structures of the {Np,Pu}B2C compounds were determined from single-crystal X-ray data to be isotypic with the ThB2C-type (space group ?, a = 0.6532(2) nm; c = 1.0769(3) nm for NpB2C and a = 0.6509(2) nm; c = 1.0818(3) nm for PuB2C; Z = 9). Physical properties have been derived from polycrystalline bulk material in the temperature range from 2 to 300 K and in magnetic fields up to 9 T. Magnetic susceptibility and heat capacity data indicate the occurrence of antiferromagnetic ordering for NpB2C with a Neel temperature TN = 68 K. PuB2C is a Pauli paramagnet most likely due to a strong hybridization of s(p,d) electrons with the Pu-5f states. A pseudo-gap, as concluded from the Sommerfeld value and the electronic transport, is thought to be a consequence of the hybridization. The magnetic behaviour of {Np,Pu}B2C is consistent with the criterion of Hill.

  5. Synthesis and Structure–Activity Relationships of N-Benzyl Phenethylamines as 5-HT2A/2C Agonists

    PubMed Central

    2014-01-01

    N-Benzyl substitution of 5-HT2A receptor agonists of the phenethylamine structural class of psychedelics (such as 4-bromo-2,5-dimethoxyphenethylamine, often referred to as 2C-B) confer a significant increase in binding affinity as well as functional activity of the receptor. We have prepared a series of 48 compounds with structural variations in both the phenethylamine and N-benzyl part of the molecule to determine the effects on receptor binding affinity and functional activity at 5-HT2A and 5-HT2C receptors. The compounds generally had high affinity for the 5-HT2A receptor with 8b having the highest affinity at 0.29 nM but with several other compounds also exhibiting subnanomolar binding affinities. The functional activity of the compounds was distributed over a wider range with 1b being the most potent at 0.074 nM. Most of the compounds exhibited low to moderate selectivity (1- to 40-fold) for the 5-HT2A receptor in the binding assays, although one compound 6b showed an impressive 100-fold selectivity for the 5-HT2A receptor. In the functional assay, selectivity was generally higher with 1b being more than 400-fold selective for the 5-HT2A receptor. PMID:24397362

  6. Protein-tyrosine-phosphatase 2C is phosphorylated and inhibited by 44-kDa mitogen-activated protein kinase.

    PubMed Central

    Peraldi, P; Zhao, Z; Filloux, C; Fischer, E H; Van Obberghen, E

    1994-01-01

    Protein-tyrosine-phosphatase 2C (PTP2C, also named SHPTP2, SHPTP3, or PTP1D) is a cytosolic enzyme with two Src homology 2 domains. We have investigated its regulation by phosphorylation in PC12 rat pheochromocytoma cells. In untreated cells, PTP2C was phosphorylated predominantly on serine residues. A 5-min treatment with epidermal growth factor (EGF) induced an increase in phosphorylation on threonine and, to a lesser degree, on serine. After 45 min of exposure to EGF, PTP2C phosphorylation returned to basal levels. Using an in vitro kinase assay, we found that the 44-kDa mitogen-activated protein kinase, p44mapk, phosphorylated PTP2C on serine and threonine residues. This phosphorylation resulted in a pronounced inhibition of PTP2C enzyme activity measured with phosphorylated EGF receptors as substrate. Moreover, in intact PC12 cells, PTP2C was also inhibited following a short EGF treatment, but its activity returned to normal when the exposure to EGF was maintained for 45 min. The profile of this response to EGF can be inversely correlated to that of the stimulatory action of EGF on p44mapk. These data suggest that the EGF-induced regulation of PTP2C activity is mediated by p44mapk. These findings provide evidence for an additional role of the mitogen-activated protein kinase cascade--namely, the regulation of a PTP. Images PMID:8197172

  7. Structural, electronic and bonding properties of antifluorite crystals of Be2C, BeMgC and Mg2C

    NASA Astrophysics Data System (ADS)

    Joshi, K. B.; Trivedi, D. K.; Paliwal, U.; Galav, K. L.

    2016-05-01

    Structure prediction methods are coupled with the first-principles linear combination of atomic orbitals method to propose the crystal parameters and bulk modulus of antifluorite BeMgC. The binary antifluorite methanides Be2C, Mg2C are also studied. Electronic structure calculations and Mulliken population analyses (MPA) are performed to unravel bands dispersion and bonding properties. The values of the indirect band gap Γ → X for Be2C, Mg2C and BeMgC, in order, are 2.90, 2.05 and 1.86 eV. The calculated energies of a few occupied bands in Be2C are in very good agreement with the available experimental data. The application of pressure causes change in the band gap of three carbides. The Γ-Γ, Γ-X and Γ-K band gaps exhibit different trends with pressure. Effective charges on the basis of MPA in the three compounds are {(B{e}+1.095)}2{C}-2.19, {(M{g}+1.615)}2{C}-3.23 and B{e}+1.12M{g}+1.682{C}-2.802. It signifies covalent bonding in Be2C, ionic in Mg2C, and intermediate in the BeMgC.

  8. First detection of canine parvovirus type 2c in Brazil

    PubMed Central

    Streck, André Felipe; de Souza, Carine Kunzler; Gonçalves, Karla Rathje; Zang, Luciana; Pinto, Luciane Dubina; Canal, Cláudio Wageck

    2009-01-01

    The presence of canine parvovirus type 2 (CPV-2), 2a and 2b has been described in Brazil, however, the type 2c had not been reported until now. In the current study, seven out of nine samples from dogs with diarrhea were characterized as CPV-2c, indicating that this virus is already circulating in the Brazilian canine population. PMID:24031389

  9. Discovery of Protein Phosphatase 2C Inhibitors by Virtual Screening

    PubMed Central

    Rogers, Jessica P.; Beuscher, Albert E.; Flajolet, Marc; McAvoy, Thomas; Nairn, Angus C.; Olson, Arthur; Greengard, Paul

    2008-01-01

    Protein phosphatase 2C (PP2C) is an archetype of the PPM Ser/Thr phosphatases, characterized by dependence on divalent magnesium or manganese cofactors, absence of known regulatory proteins, and resistance to all known Ser/Thr phosphatase inhibitors. We have used virtual ligand screening with the AutoDock method and the National Cancer Institute Diversity Set to identify small molecule inhibitors of PP2Cα activity at a protein substrate. These inhibitors are active in the micromolar range, and represent the first non-phosphate-based molecules found to inhibit a type 2C phosphatase. The compounds docked to three recurrent binding sites near the PP2Cα active site and displayed novel Ser/Thr phosphatase selectivity profiles. Common chemical features of these compounds may form the basis for development of a PP2C inhibitor pharmacophore and may facilitate investigation of PP2C control and cellular function. PMID:16509582

  10. Leptin rapidly activates PPARs in C2C12 muscle cells

    SciTech Connect

    Bendinelli, Paola; Piccoletti, Roberta . E-mail: Roberta.Piccoletti@unimi.it; Maroni, Paola

    2005-07-08

    Experimental evidence suggests that leptin operates on the tissues, including skeletal muscle, also by modulating gene expression. Using electrophoretic mobility shift assays, we have shown that physiological doses of leptin promptly increase the binding of C2C12 cell nuclear extracts to peroxisome proliferator-activated receptor (PPAR) response elements in oligonucleotide probes and that all three PPAR isoforms participate in DNA-binding complexes. We pre-treated C2C12 cells with AACOCF{sub 3}, a specific inhibitor of cytosolic phospholipase A{sub 2} (cPLA{sub 2}), an enzyme that supplies ligands to PPARs, and found that it abrogates leptin-induced PPAR DNA-binding activity. Leptin treatment significantly increased cPLA{sub 2} activity, evaluated as the release of [{sup 3}H]arachidonic acid from pre-labelled C2C12 cells, as well as phosphorylation. Further, using MEK1 inhibitor PD-98059 we showed that leptin activates cPLA{sub 2} through ERK induction. These results support a direct effect of leptin on skeletal muscle cells, and suggest that the hormone may modulate muscle transcription also by precocious activation of PPARs through ERK-cPLA{sub 2} pathway.

  11. Menthol reduces the anticoagulant effect of warfarin by inducing cytochrome P450 2C expression.

    PubMed

    Hoshino, Motohiro; Ikarashi, Nobutomo; Tsukui, Makoto; Kurokawa, Asako; Naito, Rina; Suzuki, Midori; Yokobori, Kohsuke; Ochiai, Takumi; Ishii, Makoto; Kusunoki, Yoshiki; Kon, Risako; Ochiai, Wataru; Wakui, Nobuyuki; Machida, Yoshiaki; Sugiyama, Kiyoshi

    2014-06-01

    Recently, it was reported that the anticoagulant effect of warfarin was reduced when patients receiving warfarin also took menthol. The purpose of this study is to reveal the mechanism of this reduced anticoagulant effect of warfarin from the pharmacokinetic point of view. Warfarin was orally administered to mice 24h after the administration of menthol for 2 days, and the plasma warfarin concentration was measured. In the menthol administration group, the area under the blood concentration time curve of warfarin was decreased by approximately 25%, while total clearance was increased to 1.3-fold compared to the control group. The hepatic cytochrome P450 (CYP) 2C protein expression level in the menthol administration group was significantly increased compared to that in the control group. An increase in the nuclear translocation of constitutive androstane receptor (CAR) was also observed. The addition of menthol to human hepatic cells, HepaRG cells, caused an increase in the mRNA expression level of CYP2C9. The results of this study revealed that menthol causes an increase in CYP2C expression levels in the liver, which leads to an enhancement of warfarin metabolism, resulting in a decreased anticoagulant effect of warfarin. It was also suggested that menthol acted directly on the liver and increased the expression level of CYP2C by enhancing the nuclear translocation of CAR. PMID:24594507

  12. Allele frequency distribution of CYP2C9 2 and CYP2C9 3 polymorphisms in six Mexican populations.

    PubMed

    Castelán-Martínez, Osvaldo D; Hoyo-Vadillo, Carlos; Sandoval-García, Emmanuel; Sandoval-Ramírez, Lucila; González-Ibarra, Miriam; Solano-Solano, Gloria; Gómez-Díaz, Rita A; Parra, Esteban J; Cruz, Miguel; Valladares-Salgado, Adán

    2013-07-10

    Allele frequency differences of functional CYP2C9 polymorphisms are responsible for some of the variation in drug response observed in human populations. The most relevant CYP2C9 functional variants are CYP2C9*2 (rs1799853) and CYP2C9 3 (rs1057910). These polymorphisms show variation in allele frequencies among different population groups. The present study aimed to analyze these polymorphisms in 947 Mexican-Mestizo from Mexico City and 483 individuals from five indigenous Mexican populations: Nahua, Teenek, Tarahumara, Purepecha and Huichol. The CYP2C9*2 allele frequencies in the Mestizo, Nahua and Teenek populations were 0.051, 0.007 and 0.005, respectively. As for CYP2C9 3, the allelic frequencies in the Mestizo, Nahua and Teenek populations were 0.04, 0.005 and 0.005, respectively. The CYP2C9 2 and CYP2C9 3 alleles were not observed in the Tarahumara, Purepecha and Huichol populations. These findings are in agreement with previous studies reporting very low allele frequencies for these polymorphisms in American Indigenous populations.

  13. Arabidopsis DREB2C modulates ABA biosynthesis during germination.

    PubMed

    Je, Jihyun; Chen, Huan; Song, Chieun; Lim, Chae Oh

    2014-09-12

    Plant dehydration-responsive element binding factors (DREBs) are transcriptional regulators of the APETELA2/Ethylene Responsive element-binding Factor (AP2/ERF) family that control expression of abiotic stress-related genes. We show here that under conditions of mild heat stress, constitutive overexpression seeds of transgenic DREB2C overexpression Arabidopsis exhibit delayed germination and increased abscisic acid (ABA) content compared to untransformed wild-type (WT). Treatment with fluridone, an inhibitor of the ABA biosynthesis abrogated these effects. Expression of an ABA biosynthesis-related gene, 9-cis-epoxycarotenoid dioxygenase 9 (NCED9) was up-regulated in the DREB2C overexpression lines compared to WT. DREB2C was able to trans-activate expression of NCED9 in Arabidopsis leaf protoplasts in vitro. Direct and specific binding of DREB2C to a complete DRE on the NCED9 promoter was observed in electrophoretic mobility shift assays. Exogenous ABA treatment induced DREB2C expression in germinating seeds of WT. Vegetative growth of transgenic DREB2C overexpression lines was more strongly inhibited by exogenous ABA compared to WT. These results suggest that DREB2C is a stress- and ABA-inducible gene that acts as a positive regulator of ABA biosynthesis in germinating seeds through activating NCED9 expression.

  14. The interstellar chemistry of H2C3O isomers

    NASA Astrophysics Data System (ADS)

    Loison, Jean-Christophe; Agúndez, Marcelino; Marcelino, Núria; Wakelam, Valentine; Hickson, Kevin M.; Cernicharo, José; Gerin, Maryvonne; Roueff, Evelyne; Guélin, Michel

    2016-03-01

    We present the detection of two H2C3O isomers, propynal and cyclopropenone, toward various starless cores and molecular clouds, together with upper limits for the third isomer propadienone. We review the processes controlling the abundances of H2C3O isomers in interstellar media showing that the reactions involved are gas-phase ones. We show that the abundances of these species are controlled by kinetic rather than thermodynamic effects.

  15. The interstellar chemistry of H2C3O isomers

    PubMed Central

    Loison, Jean-Christophe; Agúndez, Marcelino; Marcelino, Núria; Wakelam, Valentine; Hickson, Kevin M.; Cernicharo, José; Gerin, Maryvonne; Roueff, Evelyne; Guélin, Michel

    2016-01-01

    We present the detection of two H2C3O isomers, propynal and cyclopropenone, toward various starless cores and molecular clouds, together with upper limits for the third isomer propadienone. We review the processes controlling the abundances of H2C3O isomers in interstellar media showing that the reactions involved are gas-phase ones. We show that the abundances of these species are controlled by kinetic rather than thermodynamic effects. PMID:27013768

  16. Structure-Activity Relationships and Pharmacophore Model of a Non-Competitive Pyrazoline Containing Class of GluN2C/GluN2D Selective Antagonists

    PubMed Central

    Acker, Timothy M.; Khatri, Alpa; Vance, Katie M.; Slabber, Cathryn; Bacsa, John; Snyder, James P.; Traynelis, Stephen F.; Liotta, Dennis C.

    2013-01-01

    Here we describe the synthesis and structure-activity relationship for a class of pyrazoline-containing dihydroquinolone negative allosteric modulators of the NMDA receptor that show strong subunit-selectivity for GluN2C- and GluN2D-containing receptors over GluN2A-and GluN2B-containing receptors. Several members of this class inhibit NMDA receptor responses in the nanomolar range, and are more than 50-fold selective over GluN1/GluN2A and GluN1/GluN2B NMDA receptors, as well as AMPA, kainate, GABA, glycine, nicotinic, serotonin, and purinergic receptors. Analysis of the purified enantiomers of one of the more potent and selective compounds shows that the S-enantiomer is both more potent and more selective than the R-enantiomer. The S-enantiomer had an IC50 value of 0.17–0.22 µM at GluN2D- and GluN2C-containing receptors, respectively, and showed over 70-fold selectivity over other NMDA receptor subunits. The subunit-selectivity of this class of compounds should be useful in defining the role of GluN2C- and GluN2D-containing receptors in specific brain circuits in both physiological and patho-physiological conditions. PMID:23909910

  17. A potential therapeutic effect of CYP2C8 overexpression on anti-TNF-α activity

    PubMed Central

    LIU, WANJUN; WANG, BEI; DING, HU; WANG, DAO WEN; ZENG, HESONG

    2014-01-01

    Epoxyeicosatrienoic acids (EETs) are generated from arachidonic acid catalysed by cytochrome P450 (CYP) epoxygenases. In addition to regulating vascular tone EETs may alleviate inflammation and ROS. The present study was conducted to determine whether CYP2C8 gene overexpression was able to increase the level of EETs, and subsequently prevent TNF-α induced inflammation and reactive oxygen species (ROS) in human umbilical vein endothelial cells (HUVECs) and macrophages. Peroxisome proliferator-activated receptor γ (PPARγ) activation, nuclear factor-κB (NF-κB) activation, endothelial nitric oxide synthase (eNOS) activation, gp-91 activation, and inflammatory cytokine expression were detected by western blot analysis or enzyme-linked immunosorbent assay. Intracellular reactive oxygen species (ROS) was measured by flow cytometry, while the migration of vascular smooth muscle cells (VSMCs) was detected by Transwell assay. pCMV-mediated CYP2C8 overexpression and its metabolites, EETs, markedly suppressed TNF-α induced inflammatory cytokines IL-6 and MCP-1 expression via the activation of NF-κB and degradation of IκBα. Moreover, pretreatment with 11,12-EET significantly blocked TNF-α-induced ROS production. CYP2C8-derived EETs also effectively alleviated the migration of VSMCs and improved the function of endothelial cells through the upregulation of eNOS, which was significantly decreased under the stimulation of TNF-α. Furthermore, these protective effects observed were mediated by PPARγ activation. To the best of our knowledge, the results of the present study demonstrated for the first time that CYP2C8-derived EETs exerted antivascular inflammatory and anti-oxidative effects, at least in part, through the activation of PPARγ. Thus, the CYP2C8 gene may be useful in the prevention and treatment of vascular inflammatory diseases. PMID:25017038

  18. MEF2C regulates outflow tract alignment and transcriptional control of Tdgf1.

    PubMed

    Barnes, Ralston M; Harris, Ian S; Jaehnig, Eric J; Sauls, Kimberly; Sinha, Tanvi; Rojas, Anabel; Schachterle, William; McCulley, David J; Norris, Russell A; Black, Brian L

    2016-03-01

    Congenital heart defects are the most common birth defects in humans, and those that affect the proper alignment of the outflow tracts and septation of the ventricles are a highly significant cause of morbidity and mortality in infants. A late differentiating population of cardiac progenitors, referred to as the anterior second heart field (AHF), gives rise to the outflow tract and the majority of the right ventricle and provides an embryological context for understanding cardiac outflow tract alignment and membranous ventricular septal defects. However, the transcriptional pathways controlling AHF development and their roles in congenital heart defects remain incompletely elucidated. Here, we inactivated the gene encoding the transcription factor MEF2C in the AHF in mice. Loss of Mef2c function in the AHF results in a spectrum of outflow tract alignment defects ranging from overriding aorta to double-outlet right ventricle and dextro-transposition of the great arteries. We identify Tdgf1, which encodes a Nodal co-receptor (also known as Cripto), as a direct transcriptional target of MEF2C in the outflow tract via an AHF-restricted Tdgf1 enhancer. Importantly, both the MEF2C and TDGF1 genes are associated with congenital heart defects in humans. Thus, these studies establish a direct transcriptional pathway between the core cardiac transcription factor MEF2C and the human congenital heart disease gene TDGF1. Moreover, we found a range of outflow tract alignment defects resulting from a single genetic lesion, supporting the idea that AHF-derived outflow tract alignment defects may constitute an embryological spectrum rather than distinct anomalies. PMID:26811383

  19. Structural basis for recognition of synaptic vesicle protein 2C by botulinum neurotoxin A

    NASA Astrophysics Data System (ADS)

    Benoit, Roger M.; Frey, Daniel; Hilbert, Manuel; Kevenaar, Josta T.; Wieser, Mara M.; Stirnimann, Christian U.; McMillan, David; Ceska, Tom; Lebon, Florence; Jaussi, Rolf; Steinmetz, Michel O.; Schertler, Gebhard F. X.; Hoogenraad, Casper C.; Capitani, Guido; Kammerer, Richard A.

    2014-01-01

    Botulinum neurotoxin A (BoNT/A) belongs to the most dangerous class of bioweapons. Despite this, BoNT/A is used to treat a wide range of common medical conditions such as migraines and a variety of ocular motility and movement disorders. BoNT/A is probably best known for its use as an antiwrinkle agent in cosmetic applications (including Botox and Dysport). BoNT/A application causes long-lasting flaccid paralysis of muscles through inhibiting the release of the neurotransmitter acetylcholine by cleaving synaptosomal-associated protein 25 (SNAP-25) within presynaptic nerve terminals. Two types of BoNT/A receptor have been identified, both of which are required for BoNT/A toxicity and are therefore likely to cooperate with each other: gangliosides and members of the synaptic vesicle glycoprotein 2 (SV2) family, which are putative transporter proteins that are predicted to have 12 transmembrane domains, associate with the receptor-binding domain of the toxin. Recently, fibroblast growth factor receptor 3 (FGFR3) has also been reported to be a potential BoNT/A receptor. In SV2 proteins, the BoNT/A-binding site has been mapped to the luminal domain, but the molecular details of the interaction between BoNT/A and SV2 are unknown. Here we determined the high-resolution crystal structure of the BoNT/A receptor-binding domain (BoNT/A-RBD) in complex with the SV2C luminal domain (SV2C-LD). SV2C-LD consists of a right-handed, quadrilateral β-helix that associates with BoNT/A-RBD mainly through backbone-to-backbone interactions at open β-strand edges, in a manner that resembles the inter-strand interactions in amyloid structures. Competition experiments identified a peptide that inhibits the formation of the complex. Our findings provide a strong platform for the development of novel antitoxin agents and for the rational design of BoNT/A variants with improved therapeutic properties.

  20. Computer simulation of the infrared spectra of endohedral metallofullerenes Li2C60 and Na2C60

    NASA Astrophysics Data System (ADS)

    Butyrskaya, E. V.; Zapryagaev, S. A.

    2009-03-01

    Using the Gaussian03 computer software, the infrared spectra of endohedral Li2C60 and Na2C60 are calculated by the Hartree-Fock method in the 3-21 G basis set. The calculation is carried out for three cases: (i) metallofullerenes without a solvent, (ii) metallofullerenes in a toluene solution, and (iii) metallofullerenes in a tetrahydrofuran solution. The effect of a solvent on the energetic, electrical, and spectral characteristics of the metallofullerenes is studied.

  1. The GSTM2 C-Terminal Domain Depresses Contractility and Ca2+ Transients in Neonatal Rat Ventricular Cardiomyocytes.

    PubMed

    Hewawasam, Ruwani P; Liu, Dan; Casarotto, Marco G; Board, Philip G; Dulhunty, Angela F

    2016-01-01

    The cardiac ryanodine receptor (RyR2) is an intracellular ion channel that regulates Ca2+ release from the sarcoplasmic reticulum (SR) during excitation-contraction coupling in the heart. The glutathione transferases (GSTs) are a family of phase II detoxification enzymes with additional functions including the selective inhibition of RyR2, with therapeutic implications. The C-terminal half of GSTM2 (GSTM2C) is essential for RyR2 inhibition, and mutations F157A and Y160A within GSTM2C prevent the inhibitory action. Our objective in this investigation was to determine whether GSTM2C can enter cultured rat neonatal ventricular cardiomyocytes and influence contractility. We show that oregon green-tagged GSTM2C (at 1 μM) is internalized into the myocytes and it reduces spontaneous contraction frequency and myocyte shortening. Field stimulation of myocytes evoked contraction in the same percentage of myocytes treated either with media alone or media plus 15 μM GSTM2C. Myocyte shortening during contraction was significantly reduced by exposure to 15 μM GSTM2C, but not 5 and 10 μM GSTM2C and was unaffected by exposure to 15 μM of the mutants Y160A or F157A. The amplitude of the Ca2+ transient in the 15 μM GSTM2C - treated myocytes was significantly decreased, the rise time was significantly longer and the decay time was significantly shorter than in control myocytes. The Ca2+ transient was not altered by exposure to Y160A or F157A. The results are consistent with GSTM2C entering the myocytes and inhibiting RyR2, in a manner that indicates a possible therapeutic potential for treatment of arrhythmia in the neonatal heart. PMID:27612301

  2. The GSTM2 C-Terminal Domain Depresses Contractility and Ca2+ Transients in Neonatal Rat Ventricular Cardiomyocytes

    PubMed Central

    Hewawasam, Ruwani P.; Liu, Dan; Casarotto, Marco G.; Board, Philip G.; Dulhunty, Angela F.

    2016-01-01

    The cardiac ryanodine receptor (RyR2) is an intracellular ion channel that regulates Ca2+ release from the sarcoplasmic reticulum (SR) during excitation–contraction coupling in the heart. The glutathione transferases (GSTs) are a family of phase II detoxification enzymes with additional functions including the selective inhibition of RyR2, with therapeutic implications. The C-terminal half of GSTM2 (GSTM2C) is essential for RyR2 inhibition, and mutations F157A and Y160A within GSTM2C prevent the inhibitory action. Our objective in this investigation was to determine whether GSTM2C can enter cultured rat neonatal ventricular cardiomyocytes and influence contractility. We show that oregon green-tagged GSTM2C (at 1 μM) is internalized into the myocytes and it reduces spontaneous contraction frequency and myocyte shortening. Field stimulation of myocytes evoked contraction in the same percentage of myocytes treated either with media alone or media plus 15 μM GSTM2C. Myocyte shortening during contraction was significantly reduced by exposure to 15 μM GSTM2C, but not 5 and 10 μM GSTM2C and was unaffected by exposure to 15 μM of the mutants Y160A or F157A. The amplitude of the Ca2+ transient in the 15 μM GSTM2C - treated myocytes was significantly decreased, the rise time was significantly longer and the decay time was significantly shorter than in control myocytes. The Ca2+ transient was not altered by exposure to Y160A or F157A. The results are consistent with GSTM2C entering the myocytes and inhibiting RyR2, in a manner that indicates a possible therapeutic potential for treatment of arrhythmia in the neonatal heart. PMID:27612301

  3. Insights into the influence of 5-HT2c aminoacidic variants with the inhibitory action of serotonin inverse agonists and antagonists.

    PubMed

    Galeazzi, Roberta; Massaccesi, Luca; Piva, Francesco; Principato, Giovanni; Laudadio, Emilioano

    2014-03-01

    Specific modulation of serotonin 5-HT(2C) G protein-coupled receptors may be therapeutic for obesity and neuropsychiatric disorders. The different efficacy of drugs targeting these receptors are due to the presence of genetic variants in population and this variability is still hard to predict. Therefore, in order to administer the more suitable drug, taking into account patient genotype, it is necessary to know the molecular effects of its gene nucleotide variations. In this work, starting from an accurate 3D model of 5-HT(2C), we focus on the prediction of the possible effect of some single nucleotide polymorphisms (SNPs) producing amino acidic changes in proximity of the 5-HT(2C) ligand binding site. Particularly we chose a set of 5-HT(2C) inverse agonists and antagonists which have high inhibitory activity. After prediction of the structures of the receptor-ligand complexes using molecular docking tools, we performed full atom molecular dynamics simulations in explicit lipid bilayer monitoring the interactions between ligands and trans-membrane helices of the receptor, trying to infer relations with their biological activity. Serotonin, as the natural ligand was chosen as reference compound to advance a hypothesis able to explain the receptor inhibition mechanism. Indeed we observed a different behavior between the antagonists and inverse agonist with respect to serotonin or unbounded receptor, which could be responsible, even if not directly, of receptor's inactivation. Furthermore, we analyzed five aminoacidic variants of 5HT(2C) receptor observing alterations in the interactions between ligands and receptor which give rise to changes of free energy values for every complex considered.

  4. The strong selective sweep candidate gene ADRA2C does not explain domestication related changes in the stress response of chickens.

    PubMed

    Elfwing, Magnus; Fallahshahroudi, Amir; Lindgren, Isa; Jensen, Per; Altimiras, Jordi

    2014-01-01

    Analysis of selective sweeps to pinpoint causative genomic regions involved in chicken domestication has revealed a strong selective sweep on chromosome 4 in layer chickens. The autoregulatory α-adrenergic receptor 2C (ADRA2C) gene is the closest to the selective sweep and was proposed as an important gene in the domestication of layer chickens. The ADRA2C promoter region was also hypermethylated in comparison to the non-selected ancestor of all domesticated chicken breeds, the Red Junglefowl, further supporting its relevance. In mice the receptor is involved in the fight-or-flight response as it modulates epinephrine release from the adrenals. To investigate the involvement of ADRA2C in chicken domestication, we measured gene expression in the adrenals and radiolabeled receptor ligand in three brain regions comparing the domestic White Leghorn strain with the wild ancestor Red Junglefowl. In adrenals ADRA2C was twofold greater expressed than the related receptor gene ADRA2A, indicating that ADRA2C is the predominant modulator of epinephrine release but no strain differences were measured. In hypothalamus and amygdala, regions associated with the stress response, and in striatum, receptor binding pIC50 values ranged between 8.1-8.4, and the level was not influenced by the genotyped allele. Because chicken strains differ in morphology, physiology and behavior, differences attributed to a single gene may be lost in the noise caused by the heterogeneous genetic background. Therefore an F10 advanced intercross strain between White Leghorn and Red Junglefowl was used to investigate effects of ADRA2C alleles on fear related behaviors and fecundity. We did not find compelling genotype effects in open field, tonic immobility, aerial predator, associative learning or fecundity. Therefore we conclude that ADRA2C is probably not involved in the domestication of the stress response in chicken, and the strong selective sweep is probably caused by selection of some unknown

  5. The strong selective sweep candidate gene ADRA2C does not explain domestication related changes in the stress response of chickens.

    PubMed

    Elfwing, Magnus; Fallahshahroudi, Amir; Lindgren, Isa; Jensen, Per; Altimiras, Jordi

    2014-01-01

    Analysis of selective sweeps to pinpoint causative genomic regions involved in chicken domestication has revealed a strong selective sweep on chromosome 4 in layer chickens. The autoregulatory α-adrenergic receptor 2C (ADRA2C) gene is the closest to the selective sweep and was proposed as an important gene in the domestication of layer chickens. The ADRA2C promoter region was also hypermethylated in comparison to the non-selected ancestor of all domesticated chicken breeds, the Red Junglefowl, further supporting its relevance. In mice the receptor is involved in the fight-or-flight response as it modulates epinephrine release from the adrenals. To investigate the involvement of ADRA2C in chicken domestication, we measured gene expression in the adrenals and radiolabeled receptor ligand in three brain regions comparing the domestic White Leghorn strain with the wild ancestor Red Junglefowl. In adrenals ADRA2C was twofold greater expressed than the related receptor gene ADRA2A, indicating that ADRA2C is the predominant modulator of epinephrine release but no strain differences were measured. In hypothalamus and amygdala, regions associated with the stress response, and in striatum, receptor binding pIC50 values ranged between 8.1-8.4, and the level was not influenced by the genotyped allele. Because chicken strains differ in morphology, physiology and behavior, differences attributed to a single gene may be lost in the noise caused by the heterogeneous genetic background. Therefore an F10 advanced intercross strain between White Leghorn and Red Junglefowl was used to investigate effects of ADRA2C alleles on fear related behaviors and fecundity. We did not find compelling genotype effects in open field, tonic immobility, aerial predator, associative learning or fecundity. Therefore we conclude that ADRA2C is probably not involved in the domestication of the stress response in chicken, and the strong selective sweep is probably caused by selection of some unknown

  6. Enhanced 1520 nm photoluminescence from Er3+ ions in di-erbium-carbide metallofullerenes (Er2C2)@C82 (isomers I, II, and III).

    PubMed

    Ito, Yasuhiro; Okazaki, Toshiya; Okubo, Shingo; Akachi, Masahiro; Ohno, Yutaka; Mizutani, Takashi; Nakamura, Tetsuya; Kitaura, Ryo; Sugai, Toshiki; Shinohara, Hisanori

    2007-12-01

    Di-erbium and di-erbium-carbide endohedral metallofullerenes with a C(82) cage such as Er(2)@C(82) (isomers I, II, and III) and (Er(2)C(2))@C(82) (isomers I, II, and III) have been synthesized and chromatographically isolated (99%). The structures of Er(2)@C(82) (I, II, III) and (Er(2)C(2))@C(82) (I, II, III) metallofullerenes are characterized by comparison with the UV-vis-NIR absorption spectra of (Y(2)C(2))@C(82) (I, II, III), where molecular symmetries of the structures are determined to be C(s), C(2v) and C(3v), respectively. Furthermore, enhanced near-infrared photoluminescence (PL) at 1520 nm from Er(3+) ions in Er(2)@C(82) (I, III) and (Er(2)C(2))@C(82) (I, III) have been observed at room temperature. The PL intensities have been shown to depend on the symmetry of the C(82) cage. In particular, the PL intensity of (Er(2)C(2))@C(82) (III) has been the strongest among the isomers of Er(2)@C(82) and (Er(2)C(2))@C(82). Optical measurements indicate that the PL properties of Er(2)@C(82) (I, II, III) and (Er(2)C(2))@C(82) (I, II, III) correlate strongly with the absorbance at 1520 nm and the HOMO-LUMO energy gap of the C(82) cage.

  7. Investigation of Encephalopathy Caused by Shiga Toxin 2c-Producing Escherichia coli Infection in Mice

    PubMed Central

    Amran, Muhammad Yunus; Fujii, Jun; Suzuki, Satoshi O.; Kolling, Glynis L.; Villanueva, Sharon Y. A. M.; Kainuma, Mosaburo; Kobayashi, Hideyuki; Kameyama, Hideko; Yoshida, Shin-ichi

    2013-01-01

    A large outbreak of Shiga toxin (Stx)-producing enteroaggregative Escherichia coli (EAEC) O104:H4 occurred in northern Germany. From this outbreak, at least 900 patients developed hemolytic uremic syndrome (HUS), resulting in more than 50 deaths. Thirty percent of the HUS patients showed encephalopathy. We previously established a mouse model with encephalopathy associated with blood brain barrier (BBB) damage after oral infection with the Shiga toxin (Stx) 2c-producing Escherichia coli O157: H- strain E32511 (E32511). In this model, we detected high expression of the Stx receptor synthase enzyme, glycosphingolipid globotriaosylceramide (Gb3) synthase, in endothelial cells (ECs) and neurons in the reticular formation of the medulla oblongata by in situ hybridization. Caspase-3 was activated in neurons in the reticular formation of the medulla oblongata and the anterior horn of the spinal cord. Astrocytes (ASTs) were activated in the medulla oblongata and spinal cord, and a decrease in aquaporin 4 around the ECs suggested that BBB integrity was compromised directly by Stx2c or through the activation of ASTs. We also report the effectiveness of azithromycin (AZM) in our model. Moreover, AZM strongly inhibited the release of Stx2c from E32511 in vitro. PMID:23516588

  8. Thermoelectric performance of functionalized Sc2C MXenes

    NASA Astrophysics Data System (ADS)

    Kumar, S.; Schwingenschlögl, U.

    2016-07-01

    Functionalization of the MXene Sc2C , which has the rare property to realize semiconducting states for various functionalizations including O, F, and OH, is studied with respect to the electronic and thermal behavior. The lowest lattice thermal conductivity is obtained for OH functionalization and an additional 30% decrease can be achieved by confining the phonon mean free path to 100 nm. Despite a relatively low Seebeck coefficient, Sc2C (OH) 2 is a candidate for intermediate-temperature thermoelectric applications due to compensation by a high electrical conductivity and very low lattice thermal conductivity.

  9. Tricyclic pyrazoles. Part 6. Benzofuro[3,2-c]pyrazole: a versatile architecture for CB2 selective ligands.

    PubMed

    Pinna, Giovanni; Loriga, Giovanni; Lazzari, Paolo; Ruiu, Stefania; Falzoi, Matteo; Frau, Simona; Pau, Amedeo; Murineddu, Gabriele; Asproni, Battistina; Pinna, Gerard A

    2014-07-23

    A new series of 1H-benzofuro[3,2-c]pyrazole-3-carboxamides was synthesized. The novel compounds (15-24) were evaluated for their affinity to CB2 and CB1 cannabinoid receptors. The synthesis of the title compounds takes advantage of the acid-catalysed thermal cyclization of bicyclic hydrazone ethyl 2-(2-(2,4-dichlorophenyl)hydrazono)-2-(6-methyl-3-oxo-2,3-dihydrobenzofuran-2-yl)acetate to tricyclic ethyl 1-(2,4-dichlorophenyl)-6-methyl-1H-benzofuro[3,2-c]pyrazol-3-carboxylate. All the obtained derivatives showed high affinity to CB2 receptors. Moreover, significant selectivity for CB2 over CB1 receptors was highlighted for lead derivatives amongst the novel series. The best binding profiles were determined for homologues bearing monocyclic and bicyclic monoterpenic substituents at the carbamoyl group at 3 position of the pyrazole ring (KiCB2 < 4 nM). In particular, the isopinocampheyl-substituted derivative 22 exhibited the highest selectivity for CB2 receptors with Ki values of 3.7 and 2398 nM for CB2 and CB1 receptors, respectively. Preliminary functional assays evidenced CB2 agonism behaviour for all the assayed novel derivatives.

  10. E-2C Loads Calibration in DFRC Flight Loads Lab

    NASA Technical Reports Server (NTRS)

    Schuster, Lawrence S.

    2008-01-01

    Objectives: a) Safely and efficiently perform structural load tests on NAVAIR E-2C aircraft to calibrate strain gage instrumentation installed by NAVAIR; b) Collect load test data and derive loads equations for use in NAVAIR flight tests; and c) Assist flight test team with use of loads equations measurements at PAX River.

  11. Genome Sequence of Enterotoxigenic Escherichia coli Strain B2C.

    PubMed

    Madhavan, T P Vipin; Steen, Jason A; Hugenholtz, Philip; Sakellaris, Harry

    2014-04-10

    Enterotoxigenic Escherichia coli (ETEC) is a major cause of diarrheal disease around the globe, causing an estimated 380,000 deaths annually. The disease is caused by a wide variety of strains. Here, we report the genome sequence of ETEC strain B2C, which was isolated from an American soldier in Vietnam.

  12. Convenient syntheses and transformations of 2-C-malonyl carbohydrates.

    PubMed

    Yin, Jian; Sommermann, Thomas; Linker, Torsten

    2007-01-01

    2-C-malonyl carbohydrates were synthesized in only few steps and high yields by radical additions of malonates to glycals. For the first time, the undesired formation of nitrates was completely suppressed with anhydrous cerium ammonium nitrate (CAN) as oxidizing agent. A coherent explanation for the high stereoselectivities of the additions to gluco-configured glycals was provided by variation of the substituents in the 3-position. We established steric effects for the face selectivity, and electronic effects strongly influence the reactivity of the double bonds. The scope and limitation of transition-metal-mediated radical reactions in the synthesis of 2-C-branched carbohydrates was thoroughly investigated. Thus, unsaturated disaccharides and benzyl-protected glycals were used as substrates for the first time. Finally, the 2-C-malonyl carbohydrates were transformed into various products by decarboxylation, saponification and reduction, which afforded interesting precursors for C-disaccharides. In this paper we describe the syntheses of more than 40 new 2-C-analogues of carbohydrates, which were isolated in high yields in analytically pure form. Therefore, the transition-metal-mediated radical addition of malonates to glycals offers a simple and convenient entry to such important carbohydrate derivatives.

  13. High-throughput screening assays for the assessment of CYP2C9*1, CYP2C9*2, and CYP2C9*3 metabolism using fluorogenic Vivid substrates.

    PubMed

    Marks, Bryan D; Thompson, David V; Goossens, Tony A; Trubetskoy, Olga V

    2004-08-01

    CYP2C9 is a genetically polymorphic human cytochrome P450 isozyme involved in the oxidative metabolism of many drugs, including nonsteroidal anti-inflammatory compounds. Individuals genotyped heterozygous or homozygous for CYP2C9 allelic variants have demonstrated altered metabolism of some drugs primarily metabolized by CYP2C9. The ability to expand screening of CYP2C9 allelic variants to a larger set of drugs and pharmaceutical agents would contribute to a better understanding of the significance of CYP2C9 polymorphisms in the population and to predictions of possible outcomes. The authors report the development of an in vitro fluorescence-based assay employing recombinant CYP2C9 variants (CYP2C9*1, CYP2C9*2, and CYP2C9*3) and fluorogenic Vivid(R) CYP2C9 substrates to explore the effects of CYP2C9 polymorphisms on drug metabolism, using drugs primarily metabolized by CYP2C9. Several chemically diverse fluorogenic substrates (Vivid(R) CYP2C9 blue, green, and red substrates) were used as prototypic probes to obtain in vitro CYP2C9 metabolic rates and kinetic parameters, such as apparent K(m), V(max), and V(max)/K(m) ratios for each allelic variant. In addition, a diverse panel of drugs was screened as assay modifiers with CYP2C9*1, CYP2C9*2, CYP2C9*3, and the fluorogenic Vivid(R) CYP2C9 substrates. The inhibitory potential of this large group of chemically diverse drugs and compounds has been assessed on the basis of their ability to compete with Vivid(R) CYP2C9 substrates in fluorescent reporter assays, thus providing a sensitive and quick assessment of polymorphism-dependent changes in CYP2C9 metabolism.

  14. Cobalt triggers necrotic cell death and atrophy in skeletal C2C12 myotubes

    SciTech Connect

    Rovetta, Francesca; Stacchiotti, Alessandra; Faggi, Fiorella; Catalani, Simona; Apostoli, Pietro; Fanzani, Alessandro; Aleo, Maria Francesca

    2013-09-01

    Severe poisoning has recently been diagnosed in humans having hip implants composed of cobalt–chrome alloys due to the release of particulate wear debris on polyethylene and ceramic implants which stimulates macrophagic infiltration and destroys bone and soft tissue, leading to neurological, sensorial and muscular impairments. Consistent with this premise, in this study, we focused on the mechanisms underlying the toxicity of Co(II) ions on skeletal muscle using mouse skeletal C2C12 myotubes as an in vitro model. As detected using propidium iodide incorporation, increasing CoCl{sub 2} doses (from 5 to 200 μM) affected the viability of C2C12 myotubes, mainly by cell necrosis, which was attenuated by necrostatin-1, an inhibitor of the necroptotic branch of the death domain receptor signaling pathway. On the other hand, apoptosis was hardly detectable as supported by the lack of caspase-3 and -8 activation, the latter resulting in only faint activation after exposure to higher CoCl{sub 2} doses for prolonged time points. Furthermore, CoCl{sub 2} treatment resulted in atrophy of the C2C12 myotubes which was characterized by the increased expression of HSP25 and GRP94 stress proteins and other typical 'pro-atrophic molecular hallmarks, such as early activation of the NF-kB pathway and down-regulation of AKT phosphorylation, followed by the activation of the proteasome and autophagy systems. Overall, these results suggested that cobalt may impact skeletal muscle homeostasis as an inducer of cell necrosis and myofiber atrophy. - Highlights: • The effects of cobalt on muscle myofibers in vitro were investigated. • Cobalt treatment mainly causes cell necrosis in skeletal C2C12 myotubes. • Cobalt impacts the PI3K/AKT and NFkB pathways and induces cell stress markers. • Cobalt induces atrophy of C2C12 myotubes through the activation of proteasome and autophagy systems. • Co treatment triggers NF-kB and PI3K/AKT pathways in C2C12 myotubes.

  15. Nitric Oxide and Interleukin-1β Stimulate the Proteasome-Independent Degradation of the Retinoic Acid Hydroxylase CYP2C22 in Primary Rat Hepatocytes

    PubMed Central

    Lee, Choon-myung; Lee, Bang-sub; Arnold, Samuel L.; Isoherranen, Nina

    2014-01-01

    CYP2C22 was recently described as a retinoic acid–metabolizing cytochrome P450 enzyme whose transcription is induced by all-trans-retinoic acid (atRA) in hepatoma cells (Qian L, Zolfaghari R, and Ross AC (2010) J Lipid Res 51:1781–1792). We identified CYP2C22 as a putative nitric oxide (NO)–regulated protein in a proteomic screen and raised specific polyclonal antibodies to CYP2C22 to study its protein expression. We found that CYP2C22 is a liver-specific protein that was not significantly induced by activators of the pregnane X receptor, constitutive androstane receptor, or peroxisome proliferator-activated receptor-α, but was downregulated to <25% of control by the aryl hydrocarbon receptor agonist β-naphthoflavone in cultured rat hepatocytes. CYP2C22 protein and its mRNA both were induced by atRA in hepatocytes, with EC50 of 100–300 nM, whereas the maximal extent of mRNA induction was twice that of the protein. CYP2C22 protein, but not its mRNA, was rapidly downregulated in hepatocytes by interleukin-1 (IL-1) or NO-donating compounds, and the downregulation by IL-1 was blocked by inhibition of NO synthases. The NO donor (Z)-1-[N-(3-aminopropyl)-N-(3-ammoniopropyl)amino]diazen-1-ium-1,2-diolate reduced the half-life of CYP2C22 from 8.7 to 3.4 hours in the presence of cycloheximide, demonstrating that NO-dependent downregulation is due to stimulated proteolysis. No intermediate degradation products were detected. However, this degradation was insensitive to inhibitors of calpains or the canonical proteasomal or lysosomal pathways, indicating that NO-dependent degradation of CYP2C22 proceeds via a novel pathway. PMID:24144795

  16. Liver-specific cytochrome P450 CYP2C22 is a direct target of retinoic acid and a retinoic acid-metabolizing enzyme in rat liver.

    PubMed

    Qian, Linxi; Zolfaghari, Reza; Ross, A Catharine

    2010-07-01

    Several cytochrome P450 (CYP) enzymes catalyze the C4-hydroxylation of retinoic acid (RA), a potent inducer of cell differentiation and an agent in the treatment of several diseases. Here, we have characterized CYP2C22, a member of the rat CYP2C family with homology to human CYP2C8 and CYP2C9. CYP2C22 was expressed nearly exclusively in hepatocytes, where it was one of the more abundant mRNAs transcripts. In H-4-II-E rat hepatoma cells, CYP2C22 mRNA was upregulated by all-trans (at)-RA, and Am580, a nonmetabolizable analog of at-RA. In comparison, in primary human hepatocytes, at-RA increased CYP2C9 but not CYP2C8 mRNA. Analysis of the CYP2C22 promoter region revealed a RA response element (5'-GGTTCA-(n)5-AGGTCA-3') in the distal flanking region, which bound the nuclear hormone receptors RAR and RXR and which was required for transcriptional activation response of this promoter to RA in CYP2C22-luciferase-transfected RA-treated HepG2 cells. The cDNA-expressed CYP2C22 protein metabolized [3H]at-RA to more polar metabolites. While long-chain polyunsaturated fatty acids competed, 9-cis-RA was a stronger competitor. Our studies demonstrate that CYP2C22 is a high-abundance, retinoid-inducible, hepatic P450 with the potential to metabolize at-RA, providing additional insight into the role of the CYP2C gene family in retinoid homeostasis.

  17. High-Resolution Infrared Spectroscopy of Ge_2C_3

    NASA Astrophysics Data System (ADS)

    Thorwirth, S.; Lutter, V.; Schlemmer, S.; Giesen, T. F.; Gauss, J.

    2013-06-01

    Carbon-rich systems are of great importance in diverse areas of research like material science as well as astro- and structural chemistry. Despite this relevance, our knowledge of smaller cluster units is still fragmentary, particularly with respect to investigations at high-spectral resolution in the gas phase. Unequivocal assignment of spectral features to their molecular carriers is critically dependent on predictions from high-level quantum-chemical calculations. In turn, high-resolution studies provide useful information to assess the predictive power of quantum-chemical methods. This is particularly interesting for cluster systems harboring heavy elements for which so far relatively little is known from experiment. With this contribution, we would like to present a recent gas-phase study of a polyatomic germanium-carbon cluster, linear Ge_2C_3 (Ge=C=C=C=Ge), which was previously studied in an Ar matrix. The cluster was produced through laser ablation of germanium-graphite sample rods and observed in a free jet at wavelengths around 5μm. Additionally, quantum-chemical calculations of Ge_2C_3 were performed at the CCSD(T) level of theory. The production and observation of Ge_2C_3 suggests that many more binary clusters should be amenable to high-resolution spectroscopic techniques not only in the infrared but also in the microwave region. D. L. Robbins, C. M. L. Rittby, and W. R. M. Graham, J. Chem. Phys. 114, 3570 (2001).

  18. Similar substrate specificity of cynomolgus monkey cytochrome P450 2C19 to reported human P450 2C counterpart enzymes by evaluation of 89 drug clearances.

    PubMed

    Hosaka, Shinya; Murayama, Norie; Satsukawa, Masahiro; Uehara, Shotaro; Shimizu, Makiko; Iwasaki, Kazuhide; Iwano, Shunsuke; Uno, Yasuhiro; Yamazaki, Hiroshi

    2015-12-01

    Cynomolgus monkeys are used widely in preclinical studies as non-human primate species. The amino acid sequence of cynomolgus monkey cytochrome P450 (P450 or CYP) 2C19 is reportedly highly correlated to that of human CYP2C19 (92%) and CYP2C9 (93%). In the present study, 89 commercially available compounds were screened to find potential substrates for cynomolgus monkey CYP2C19. Of 89 drugs, 34 were metabolically depleted by cynomolgus monkey CYP2C19 with relatively high rates. Among them, 30 compounds have been reported as substrates or inhibitors of, either or both, human CYP2C19 and CYP2C9. Several compounds, including loratadine, showed high selectivity to cynomolgus monkey CYP2C19, and all of these have been reported as human CYP2C19 and/or CYP2C9 substrates. In addition, cynomolgus monkey CYP2C19 formed the same loratadine metabolite as human CYP2C19, descarboethoxyloratadine. These results suggest that cynomolgus monkey CYP2C19 is generally similar to human CYP2C19 and CYP2C9 in its substrate recognition functionality.

  19. A Putative PP2C-Encoding Gene Negatively Regulates ABA Signaling in Populus euphratica

    PubMed Central

    Chen, Jinhuan; Zhang, Dongzhi; Zhang, Chong; Xia, Xinli; Yin, Weilun; Tian, Qianqian

    2015-01-01

    A PP2C homolog gene was cloned from the drought-treated cDNA library of Populus euphratica. Multiple sequence alignment analysis suggested that the gene is a potential ortholog of HAB1. The expression of this HAB1 ortholog (PeHAB1) was markedly induced by drought and moderately induced by ABA. To characterize its function in ABA signaling, we generated transgenic Arabidopsis thaliana plants overexpressing this gene. Transgenic lines exhibited reduced responses to exogenous ABA and reduced tolerance to drought compared to wide-type lines. Yeast two-hybrid analyses indicated that PeHAB1 could interact with the ABA receptor PYL4 in an ABA-independent manner. Taken together; these results indicated that PeHAB1 is a new negative regulator of ABA responses in poplar. PMID:26431530

  20. Sc2@C3v(8)-C82 vs. Sc2C2@C3v(8)-C82: drastic effect of C2 capture on the redox properties of scandium metallofullerenes.

    PubMed

    Kurihara, Hiroki; Lu, Xing; Iiduka, Yuko; Mizorogi, Naomi; Slanina, Zdenek; Tsuchiya, Takahiro; Nagase, Shigeru; Akasaka, Takeshi

    2012-01-30

    We describe the first example of scandium dimetallofullerenes, Sc(2)@C(3v)(8)-C(82), which has the same cage as the previously assigned scandium carbide cluster fullerene Sc(2)C(2)@C(3v)(8)-C(82) but they exhibit distinctly different electronic configurations and electronic behaviours, confirming the drastic influence of the internal C(2) unit.

  1. Mg intercalation into Ti2C building block

    NASA Astrophysics Data System (ADS)

    Yu, Xue-fang; Cheng, Jianbo; Liu, Zhenbo; Li, Qingzhong; Li, Wenzuo; Yang, Xin; Xiao, Bo

    2015-06-01

    Generally, intercalation occurs when foreign atoms intercalate into multi-layer structures, while adsorption occurs when foreign atoms interact with monolayer structures or surfaces. We performed an investigation on the Mg intercalation into Ti2C building block (MXene) from first-principles simulation. We found that Mg can favorably intercalate into MXene, forming the stable compound Ti2MgC, which corresponds to the stage I in the Li intercalation into graphite. Based on the evaluation of the average cell potential and the energy barrier of Mg diffusion for the most energetically stable structure, our results suggest that Ti2MgC is a potential anode for Mg ion batteries.

  2. Global structure search and physical properties of Os2C.

    PubMed

    Hong, Feng; Lu, Jian; Gao, Heng; Ren, Wei; Xu, Run; Xu, Fei; Ma, Zhongquan; Yan, Yanfa

    2016-09-14

    The crystal structures of Os2C were extensively investigated using the structure search method from the first-principles calculations. In contrast to the P6 3 /mmc phase previously proposed as the ground state at ambient pressure, an energetically favorable structure with space group P-6m2 was found more stable at ambient condition. The structural stabilities of the new phase are confirmed by the phonon dispersion and elastic constants. Further calculations indicate that the newly predicted P-6m2 phase is ultra-incompressible with a high bulk modulus of 387 GPa and has a larger ideal shear strength than the P6 3 /mmc phase.

  3. Global structure search and physical properties of Os2C

    NASA Astrophysics Data System (ADS)

    Hong, Feng; Lu, Jian; Gao, Heng; Ren, Wei; Xu, Run; Xu, Fei; Ma, Zhongquan; Yan, Yanfa

    2016-09-01

    The crystal structures of Os2C were extensively investigated using the structure search method from the first-principles calculations. In contrast to the P6 3 /mmc phase previously proposed as the ground state at ambient pressure, an energetically favorable structure with space group P-6m2 was found more stable at ambient condition. The structural stabilities of the new phase are confirmed by the phonon dispersion and elastic constants. Further calculations indicate that the newly predicted P-6m2 phase is ultra-incompressible with a high bulk modulus of 387 GPa and has a larger ideal shear strength than the P6 3 /mmc phase.

  4. Interactions between CYP2C9 and CYP2C19 in reconstituted binary systems influence their catalytic activity: possible rationale for the inability of CYP2C19 to catalyze methoxychlor demethylation in human liver microsomes.

    PubMed

    Hazai, Eszter; Kupfer, David

    2005-01-01

    Previous studies in our laboratory showed that among cDNA-expressed human cytochrome P450 (P450) supersomes, CYP2C19 was the most active in methoxychlor-O-demethylation. However, based on the lack of inhibition of methoxychlor-O-demethylation by monoclonal anti-CYP2C19 antibodies in human liver microsomes (HLM), CYP2C19 did not seem to catalyze that reaction in HLM. By contrast, CYP2C9, much less active than CYP2C19 in supersomes, was the most active in HLM. The current study examines whether the lack of methoxychlor-O-demethylation by CYP2C19 in HLM was due to CYP2C19 exhibiting inferior competition for the NADPH-cytochrome P450 reductase (CPR) versus CYP2C9 and explores the interactions between CYP2C9 and CYP2C19 in a singular and binary complex of a reconstituted system. When reconstituted with CPR, cytochrome b(5), and lipid, purified CYP2C19 and CYP2C9 catalyzed methoxychlor-O-demethylation. However, whereas equimolar CPR to CYP2C9 supported maximal rates of methoxychlor demethylation and diclofenac hydroxylation, the rate of methoxychlor demethylation by CYP2C19 was not fully saturated, even with a 9-fold molar excess of CPR over CYP2C19. This behavior of CYP2C19 was also observed with S-mephenytoin as the substrate. When a binary reconstitution system was prepared by mixing CYP2C9 and CYP2C19 enzymes, methoxychlor-O-demethylation and S-mephenytoin hydroxylation by CYP2C19 were dramatically inhibited. Inhibition depended on the amount of CPR and substrate used. By contrast, in the incubation containing CYP2C9, diclofenac hydroxylation was activated by the presence of CYP2C19. These results show that interactions among P450 enzymes can modulate their catalytic rates, which depend on the substrate undergoing metabolism.

  5. The CYP2C19 Intron 2 Branch Point SNP is the Ancestral Polymorphism Contributing to the Poor Metabolizer Phenotype in Livers with CYP2C19*35 and CYP2C19*2 Alleles

    PubMed Central

    Chaudhry, Amarjit S.; Prasad, Bhagwat; Shirasaka, Yoshiyuki; Fohner, Alison; Finkelstein, David; Fan, Yiping; Wang, Shuoguo; Wu, Gang; Aklillu, Eleni; Sim, Sarah C.; Thummel, Kenneth E.

    2015-01-01

    CYP2C19 rs12769205 alters an intron 2 branch point adenine leading to an alternative mRNA in human liver with complete inclusion of intron 2 (exon 2B). rs12769205 changes the mRNA reading frame, introduces 87 amino acids, and leads to a premature stop codon. The 1000 Genomes project (http://browser.1000genomes.org/index.html) indicated rs12769205 is in linkage disequilibrium with rs4244285 on CYP2C19*2, but found alone on CYP2C19*35 in Blacks. Minigenes containing rs12769205 transfected into HepG2 cells demonstrated this single nucleotide polymorphism (SNP) alone leads to exon 2B and decreases CYP2C19 canonical mRNA. A residual amount of CYP2C19 protein was detectable by quantitative proteomics with tandem mass spectrometry in CYP2C19*2/*2 and *1/*35 liver microsomes with an exon 2 probe. However, an exon 4 probe, downstream from rs12769205, but upstream of rs4244285, failed to detect CYP2C19 protein in livers homozygous for rs12769205, demonstrating rs12769205 alone can lead to complete loss of CYP2C19 protein. CYP2C19 genotypes and mephenytoin phenotype were compared in 104 Ethiopians. Poor metabolism of mephenytoin was seen in persons homozygous for both rs12769205 and rs4244285 (CYP2C19*2/*2), but with little effect on mephenytoin disposition of CYP2C19*1/*2, CYP2C19*1/*3, or CYP2C19*1/*35 heterozygous alleles. Extended haplotype homozygosity tests of the HapMap Yorubans (YRI) showed both haplotypes carrying rs12769205 (CYP2C19*35 and CYP2C19*2) are under significant natural selection, with CYP2C19*35 having a higher relative extended haplotype homozygosity score. The phylogenetic tree of the YRI CYP2C19 haplotypes revealed rs12769205 arose first on CYP2C19*35 and that rs4244285 was added later, creating CYP2C19*2. In conclusion, rs12769205 is the ancestral polymorphism leading to aberrant splicing of CYP2C19*35 and CYP2C19*2 alleles in liver. PMID:26021325

  6. The phonon-mediated superconductivity in B2C sheet

    NASA Astrophysics Data System (ADS)

    Drzazga, E. A.; Szczȩśniak, R.; Duda, A. M.

    2014-07-01

    The values of the thermodynamic parameters of the superconducting state induced by the electron-phonon interaction in the B2C sheet have been determined. It has been found that the critical temperature (TC) can change in the range from 20.4 K to 13 K for the Coulomb pseudopotential (μ⋆) ranging from 0.1 to 0.2. Generalization of the results for the atomic layer demonstrated that the maximum value of TC is equal to 25 K. Next for the B2C sheet, the order parameter (Δ), the thermodynamic critical field (HC), and the specific heat for the superconducting (CS) state and the normal (CN) state have been calculated. The obtained results show that the dimensionless thermodynamic ratios, RΔ≡2Δ(0)/kBTC, RH≡TCCN(TC)/HC2(0), and RC≡(CS(TC)-CN(TC))/CN(TC), deviate from the predictions of the classical BCS theory. In particular RΔ(μ⋆)∈<3.87,3.79>, RH(μ⋆)∈<0.155,0.157>, and RC(μ⋆)∈<1.67,1.62>. The numerical calculations have been conducted in the framework of the Eliashberg formalism.

  7. Novel Marmoset Cytochrome P450 2C19 in Livers Efficiently Metabolizes Human P450 2C9 and 2C19 Substrates, S-Warfarin, Tolbutamide, Flurbiprofen, and Omeprazole.

    PubMed

    Uehara, Shotaro; Uno, Yasuhiro; Inoue, Takashi; Kawano, Mirai; Shimizu, Makiko; Toda, Akiko; Utoh, Masahiro; Sasaki, Erika; Yamazaki, Hiroshi

    2015-10-01

    The common marmoset (Callithrix jacchus), a small New World monkey, has the potential for use in human drug development due to its evolutionary closeness to humans. Four novel cDNAs, encoding cytochrome P450 (P450) 2C18, 2C19, 2C58, and 2C76, were cloned from marmoset livers to characterize P450 2C molecular properties, including previously reported P450 2C8. The deduced amino acid sequence showed high sequence identities (>86%) with those of human P450 2Cs, except for marmoset P450 2C76, which has a low sequence identity (∼70%) with any human P450 2Cs. Phylogenetic analysis showed that marmoset P450 2Cs were more closely clustered with those of humans and macaques than other species investigated. Quantitative polymerase chain reaction analysis showed that all of the marmoset P450 2C mRNAs were predominantly expressed in liver as opposed to the other tissues tested. Marmoset P450 2C proteins were detected in liver by immunoblotting using antibodies against human P450 2Cs. Among marmoset P450 2Cs heterologously expressed in Escherichia coli, marmoset P450 2C19 efficiently catalyzed human P450 2C substrates, S-warfarin, diclofenac, tolbutamide, flurbiprofen, and omeprazole. Marmoset P450 2C19 had high Vmax and low Km values for S-warfarin 7-hydroxylation that were comparable to those in human liver microsomes, indicating warfarin stereoselectivity similar to findings in humans. Faster in vivo S-warfarin clearance than R-warfarin after intravenous administration of racemic warfarin (0.2 mg/kg) to marmosets was consistent with the in vitro kinetic parameters. These results indicated that marmoset P450 2C enzymes had functional characteristics similar to those of humans, and that P450 2C-dependent metabolic properties are likewise similar between marmosets and humans.

  8. CMT2C with vocal cord paresis associated with short stature and mutations in the TRPV4 gene

    PubMed Central

    Chen, D.-H.; Sul, Y.; Weiss, M.; Hillel, A.; Lipe, H.; Wolff, J.; Matsushita, M.; Raskind, W.; Bird, T.

    2010-01-01

    Background: Recently, mutations in the transient receptor potential cation channel, subfamily V, member 4 gene (TRPV4) have been reported in Charcot-Marie-Tooth Type 2C (CMT2C) with vocal cord paresis. Other mutations in this same gene have been described in separate families with various skeletal dysplasias. Further clarification is needed of the different phenotypes associated with this gene. Methods: We performed clinical evaluation, electrophysiology, and genetic analysis of the TRPV4 gene in 2 families with CMT2C. Results: Two multigenerational families had a motor greater than sensory axonal neuropathy associated with variable vocal cord paresis. The vocal cord paresis varied from absent to severe, requiring permanent tracheotomy in 2 subjects. One family with mild neuropathy also manifested pronounced short stature, more than 2 SD below the average height for white Americans. There was one instance of dolichocephaly. A novel S542Y mutation in the TRPV4 gene was identified in this family. The other family had a more severe, progressive, motor neuropathy with sensory loss, but less remarkable short stature and an R315W mutation in TRPV4. Third cranial nerve involvement and sleep apnea occurred in one subject in each family. Conclusion: CMT2C with axonal neuropathy, vocal cord paresis, and short stature is a unique syndrome associated with mutations in the TRPV4 gene. Mutations in TRPV4 can cause abnormalities in bone, peripheral nerve, or both and may result in highly variable orthopedic and neurologic phenotypes. GLOSSARY CMAP = compound muscle action potential; CMT = Charcot-Marie-Tooth; CMT2C = Charcot-Marie-Tooth Type 2C; HMSN = hereditary motor and sensory neuropathy; NCV = nerve conduction velocity; RFLP = restriction fragment length polymorphism; SMA = spinal muscular atrophy; SNAP = sensory nerve action potential; SPSMA = scapuloperoneal spinal muscular atrophy. PMID:21115951

  9. P2C-Type ATPases and Their Regulation.

    PubMed

    Retamales-Ortega, Rocío; Vio, Carlos P; Inestrosa, Nibaldo C

    2016-03-01

    P2C-type ATPases are a subfamily of P-type ATPases comprising Na(+)/K(+)-ATPase and H(+)/K(+)-ATPase. Na(+)/K(+)-ATPase is ubiquitously expressed and has been implicated in several neurological diseases, whereas H(+)/K(+)-ATPase is found principally in the colon, stomach, and kidney. Both ATPases have two subunits, α and β, but Na(+)/K(+)-ATPase also has a regulatory subunit called FXYD, which has an important role in cancer. The most important functions of these ATPases are homeostasis, potassium regulation, and maintaining a gradient in different cell types, like epithelial cells. Na(+)/K(+)-ATPase has become a center of attention ever since it was proposed that it might play a crucial role in neurological disorders such as bipolar disorder, mania, depression, familial hemiplegic migraine, rapid-onset dystonia parkinsonism, chronic stress, epileptogenesis, and Alzheimer's disease. On the other hand, it has been reported that lithium could have a neuroprotective effect against ouabain, which is the best known Na(+)/K(+)-ATPase inhibitor, but and high concentrations of lithium could affect negatively H(+)/K(+)-ATPase activity, that has a key role in regulating acidosis and potassium deficiencies. Finally, potassium homeostasis regulation is composed of two main mechanisms, extrarenal and renal. Extrarenal mechanism controls plasma levels, shifting potassium from the extracellular to the intracellular, whereas renal mechanism concerns with body balance and is influenced by potassium intake and its urinary excretion. In this article, we discuss the functions, isoforms, and localization of P2C-type ATPases, describe some of their modulators, and discuss their implications in some diseases.

  10. P2C-Type ATPases and Their Regulation.

    PubMed

    Retamales-Ortega, Rocío; Vio, Carlos P; Inestrosa, Nibaldo C

    2016-03-01

    P2C-type ATPases are a subfamily of P-type ATPases comprising Na(+)/K(+)-ATPase and H(+)/K(+)-ATPase. Na(+)/K(+)-ATPase is ubiquitously expressed and has been implicated in several neurological diseases, whereas H(+)/K(+)-ATPase is found principally in the colon, stomach, and kidney. Both ATPases have two subunits, α and β, but Na(+)/K(+)-ATPase also has a regulatory subunit called FXYD, which has an important role in cancer. The most important functions of these ATPases are homeostasis, potassium regulation, and maintaining a gradient in different cell types, like epithelial cells. Na(+)/K(+)-ATPase has become a center of attention ever since it was proposed that it might play a crucial role in neurological disorders such as bipolar disorder, mania, depression, familial hemiplegic migraine, rapid-onset dystonia parkinsonism, chronic stress, epileptogenesis, and Alzheimer's disease. On the other hand, it has been reported that lithium could have a neuroprotective effect against ouabain, which is the best known Na(+)/K(+)-ATPase inhibitor, but and high concentrations of lithium could affect negatively H(+)/K(+)-ATPase activity, that has a key role in regulating acidosis and potassium deficiencies. Finally, potassium homeostasis regulation is composed of two main mechanisms, extrarenal and renal. Extrarenal mechanism controls plasma levels, shifting potassium from the extracellular to the intracellular, whereas renal mechanism concerns with body balance and is influenced by potassium intake and its urinary excretion. In this article, we discuss the functions, isoforms, and localization of P2C-type ATPases, describe some of their modulators, and discuss their implications in some diseases. PMID:25631710

  11. Genipin stimulates glucose transport in C2C12 myotubes via an IRS-1 and calcium-dependent mechanism.

    PubMed

    Ma, Chan-Juan; Nie, Ai-Fang; Zhang, Zhi-Jian; Zhang, Zhi-Guo; Du, Li; Li, Xiao-Ying; Ning, Guang

    2013-03-01

    Genipin, a compound derived from Gardenia jasminoides Ellis fruits, has been used over the years in traditional Chinese medicine to treat symptoms of type 2 diabetes. However, the molecular basis for its antidiabetic effect has not been fully revealed. In this study, we investigated the effects of genipin on glucose uptake and signaling pathways in C(2)C(12) myotubes. Our study demonstrates that genipin stimulated glucose uptake in a time- and dose-dependent manner. The maximal effect was achieved at 2 h with a concentration of 10 μM. In myotubes, genipin promoted glucose transporter 4 (GLUT4) translocation to the cell surface, which was observed by analyzing their distribution in subcellular membrane fraction, and increased the phosphorylation of insulin receptor substrate-1 (IRS-1), AKT, and GSK3β. Meanwhile, genipin increased ATP levels, closed K(ATP) channels, and then increased the concentration of calcium in the cytoplasm in C(2)C(12) myotubes. Genipin-stimulated glucose uptake could be blocked by both the PI3-K inhibitor wortmannin and calcium chelator EGTA. Moreover, genipin increases the level of reactive oxygen species and ATP in C(2)C(12) myotubes. These results suggest that genipin activates IRS-1, PI3-K, and downstream signaling pathway and increases concentrations of calcium, resulting in GLUT4 translocation and glucose uptake increase in C(2)C(12) myotubes. PMID:23257267

  12. DRD2 C957T polymorphism interacts with the COMT Val158Met polymorphism in human working memory ability.

    PubMed

    Xu, Haiyan; Kellendonk, Christoph B; Simpson, Eleanor H; Keilp, John G; Bruder, Gerard E; Polan, H Jonathan; Kandel, Eric R; Gilliam, T Conrad

    2007-02-01

    The C957T polymorphism in the dopamine D2 receptor (DRD2) gene and the Val158Met polymorphism in the Catechol-O-Methyl-Transferase (COMT) gene affect dopamine transmission and have been found to be associated with schizophrenia. Since DRD2 in mice and the COMT gene in humans modulate working memory, we examined the relationship and possible interaction of both polymorphisms to working memory performance in 188 healthy adults. Subjects having the DRD2 C/C allele showed the poorest performance in a word serial position test. Moreover, the effect of the C957T genotype was strengthened when interaction with the COMT Val158Met polymorphism was included in the analysis. We propose that an interaction of the DRD2 C957T and COMT Val158Met may be involved in the generation of some working memory deficits in schizophrenia.

  13. Identification and mechanism of ABA receptor antagonism

    SciTech Connect

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

    2010-11-11

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

  14. Up-Regulation of CYP2C19 Expression by BuChang NaoXinTong via PXR Activation in HepG2 Cells

    PubMed Central

    Wu, Xiao-Ying; Wang, Huan; Qu, Qiang; Tan, Shen-Lan; Ruan, Jun-Shan; Qu, Jian; Chen, Hui

    2016-01-01

    Background Cytochrome P450 2C19 (CYP2C19) is an important drug-metabolizing enzyme (DME), which is responsible for the biotransformation of several kinds of drugs such as proton pump inhibitors, platelet aggregation inhibitors and antidepressants. Previous studies showed that Buchang NaoXinTong capsules (NXT) increased the CYP2C19 metabolic activity in vitro and enhanced the antiplatelet effect of clopidogrel in vivo. However, the underlying molecular mechanism remained unclear. In the present study, we examined whether Pregnane X receptor (PXR) plays a role in NXT-mediated regulation of CYP2C19 expression. Methods We applied luciferase assays, real-time quantitative PCR (qPCR), Western blotting and cell-based analysis of metabolic activity experiments to investigate the NXT regulatory effects on the CYP2C19 promoter activity, the mRNA/ protein expression and the metabolic activity. Results Our results demonstrated that NXT significantly increased the CYP2C19 promoter activity when co-transfected with PXR in HepG2 cells. Mutations in PXR responsive element abolished the NXT inductive effects on the CYP2C19 promoter transcription. Additionally, NXT incubation (150 and 250μg/mL) also markedly up-regulated endogenous CYP2C19 mRNA and protein levels in PXR-transfected HepG2 cells. Correspondingly, NXT leaded to a significant enhancement of the CYP2C19 catalytic activity in PXR-transfected HepG2 cells. Conclusion In summary, this is the first study to suggest that NXT could induce CYP2C19 expression via PXR activation. PMID:27467078

  15. Regulation of steroid hormone biosynthesis in R2C and MA-10 Leydig tumor cells: role of the cholesterol transfer proteins StAR and PBR.

    PubMed

    Rao, Rekha M; Jo, Youngah; Babb-Tarbox, Michelle; Syapin, Peter J; Stocco, Douglas M

    2002-11-01

    The MA-10 mouse Leydig tumor cell line produces large amounts of steroids only in response to hormonal stimulation while the R2C rat Leydig tumor cell line is constitutively steroidogenic in nature. In an effort to uncover the potential reasons for constitutive steroidogenesis in R2C cells, we have recently shown that compared to MA-10 cells, R2C cells express much higher levels of the Scavenger Receptor Class B type 1 which results in a higher capacity for cholesteryl ester uptake through the selective uptake pathway. We also found an enhanced expression of Hormone Sensitive Lipase and the Steroidogenic Acute Regulatory protein in these cells and reasoned that they may further facilitate the conversion of cholesteryl esters to free cholesterol and its mobilization to the inner mitochondrial membrane, thus rendering them constitutively steroidogenic. Given the proposed role of the peripheral-type benzodiazepine receptor (PBR) in conferring a constitutively steroidogenic phenotype to the R2C cells, the current study was conducted to investigate the relationship between its expression in MA-10 and R2C cells and correlate it with the constitutive nature of R2C cell steroidogenesis. Our studies show that PBR expression as measured by PK 11195 ligand binding and Western analysis is much higher in MA-10 cells than R2C cells. We also determined that the affinity of ligand binding to the PBR is comparable in the two cell lines, suggesting that PBR is unlikely to be solely responsible for the constitutive nature of R2C cell steroidogenesis.

  16. The Strong Selective Sweep Candidate Gene ADRA2C Does Not Explain Domestication Related Changes In The Stress Response Of Chickens

    PubMed Central

    Elfwing, Magnus; Fallahshahroudi, Amir; Lindgren, Isa; Jensen, Per; Altimiras, Jordi

    2014-01-01

    Analysis of selective sweeps to pinpoint causative genomic regions involved in chicken domestication has revealed a strong selective sweep on chromosome 4 in layer chickens. The autoregulatory α-adrenergic receptor 2C (ADRA2C) gene is the closest to the selective sweep and was proposed as an important gene in the domestication of layer chickens. The ADRA2C promoter region was also hypermethylated in comparison to the non-selected ancestor of all domesticated chicken breeds, the Red Junglefowl, further supporting its relevance. In mice the receptor is involved in the fight-or-flight response as it modulates epinephrine release from the adrenals. To investigate the involvement of ADRA2C in chicken domestication, we measured gene expression in the adrenals and radiolabeled receptor ligand in three brain regions comparing the domestic White Leghorn strain with the wild ancestor Red Junglefowl. In adrenals ADRA2C was twofold greater expressed than the related receptor gene ADRA2A, indicating that ADRA2C is the predominant modulator of epinephrine release but no strain differences were measured. In hypothalamus and amygdala, regions associated with the stress response, and in striatum, receptor binding pIC50 values ranged between 8.1–8.4, and the level was not influenced by the genotyped allele. Because chicken strains differ in morphology, physiology and behavior, differences attributed to a single gene may be lost in the noise caused by the heterogeneous genetic background. Therefore an F10 advanced intercross strain between White Leghorn and Red Junglefowl was used to investigate effects of ADRA2C alleles on fear related behaviors and fecundity. We did not find compelling genotype effects in open field, tonic immobility, aerial predator, associative learning or fecundity. Therefore we conclude that ADRA2C is probably not involved in the domestication of the stress response in chicken, and the strong selective sweep is probably caused by selection of some unknown

  17. Enumeration of NKG2C+ natural killer cells early following allogeneic stem cell transplant recipients does not allow prediction of the occurrence of cytomegalovirus DNAemia.

    PubMed

    Giménez, Estela; Solano, Carlos; Amat, Paula; de la Cámara, Rafael; Nieto, José; López, Javier; Garcia-Noblejas, Ana; Navarro, David

    2015-09-01

    The role of Natural killer (NK) cells in the control of cytomegalovirus (CMV) infection in allogeneic stem cell transplant recipients has not been precisely characterized. The current study is aimed at investigating the potential role of NK cells expressing the activating receptor NKG2C in affording protection against the development of CMV DNAemia in patients exhibiting detectable CMV-specific CD8(+) T-cell responses early following transplantation. A total of 61 nonconsecutive patients were included in the study. Peripheral levels of CD56(bright) CD16(-/low) and CD56(dim) CD16(+) NKG2C(+) NK cells and CMV pp65/IE-1-specific IFN-γ-producing CD8(+) T-cells were enumerated by flow cytometry at days +30 and +60 after transplant. Neither the absolute number of NKG2C(+) NK cells, nor that of CD56(bright) CD16(-/low) and CD56(dim) CD16(+) NKG2C(+) NK-cell subsets at day 30 differed significantly between patients with or without subsequent CMV DNAemia. No significant correlation was found between levels of both NKG2C(+) NK-cell populations and the peak CMV DNA load within subsequent episodes of CMV DNAemia. The data indicate that enumeration of NKG2C(+) NK cells early after transplant is unlikely to be helpful in identifying those patients at highest risk of developing CMV DNAemia. Moreover, the data do not support a direct implication of NKG2C(+) NK cells in preventing the development of CMV DNAemia.

  18. Transforming growth factor-beta1 upregulates myostatin expression in mouse C2C12 myoblasts.

    PubMed

    Budasz-Rwiderska, M; Jank, M; Motyl, T

    2005-06-01

    Myostatin (MSTN) and transforming growth factor-beta1 (TGF-beta1) belong to the same TGF-beta superfamily of proteins. They are involved in regulation of skeletal muscle growth and development as well as muscle catabolism. The aim of the present study was to investigate the relationship between MSTN and TGF-beta1 expression in proliferating and differentiating mouse C2C12 myoblasts cultured in normal and catabolic conditions and to evaluate the effect of exogenous TGF-beta1 as well as "knock down" of TGF-beta1 receptor type II on MSTN expression in proliferating and differentiating myogenic cells. The direct effect of TGF-beta1 on myostatin was also examined. Myostatin expression increased gradually with cell confluency in proliferating cultures, while the level of TGF-beta1, detected in the form of a 100 kDa small latent complex diminished. Myostatin expression was accompanied by a partial cell cycle arrest. Three forms of myostatin were found: a 52 kDa precursor, a 40 kDa latency associated propeptide, and a 26 kDa active peptide. A decrease in myostatin and TGF-beta1 levels was observed during the first three days of differentiation, which was subsequently followed by significant increase of their expression during next three to four days of differentiation. Catabolic state induced by dexamethasone significantly increased the level of all forms of myostatin as well as latent (100 kDa) and active (25 kDa) forms of TGF-beta1 in differentiating myoblasts in a dose dependent manner. Exogenous TGF-beta1 (2 ng/ml) significantly increased myostatin levels both in proliferating and differentiating C2C12 myoblasts, whereas silencing of the TGF-beta1 receptor II gene significantly lowered myostatin level in examined cells. The presented results indicate that TGF-beta1 may control myostatin-related regulation of myogenesis through up-regulation of myostatin, predominantly in the course of terminal differentiation and glucocorticoid-dependent catabolic stimulation.

  19. Basic Data Report for Drillhole SNL-2 (C-2948)

    SciTech Connect

    Powers, Dennis W.

    2005-01-19

    SNL-2 was drilled in the northwest quarter of Section 12, T22S, R30E, in eastern Eddy County, New Mexico (Figure 2-1). It is located 574 ft from the north line (fnl) and 859 ft from the west line (fwl) of the section (Figure 2-2). This location places the drillhole east of the Livingston Ridge escarpment among oil wells of the Cabin Lake field. SNL-2 will be used to test hydraulic properties and to monitor ground water levels of the Culebra Dolomite Member of the Permian Rustler Formation. SNL-2 was permitted by the New Mexico State Engineer as C-2948. [Official correspondence regarding permitting and regulatory information must reference this permit number.] In the plan describing the integrated groundwater hydrology program (Sandia National Laboratories, 2003), SNL-2 is also codesignated WTS-1 because the location also satisfies needs for long-term monitoring of water quality and movement in the Culebra Dolomite for RCRA permitting; this program is under the management of Washington TRU Solutions LLC (WTS). In the event that additional wells are established on the SNL-2 drillpad to monitor other hydrological units (e.g., the Magenta Dolomite Member of the Permian Rustler Formation), the current drillhole will likely be referred to as SNL-2C because it is completed in the Culebra. Most drillholes at WIPP have been described after completion to provide an account of the geology, hydrology, or other basic data acquired during drilling and immediate completion of the drillhole. In addition, the basic data report provides an account of the drilling procedures and activities that may be helpful to later interpretations of data or for further work in the drillhole, including test activities and eventual plugging and abandoning activities. The basic data report also provides a convenient means of reporting information about administrative activities necessary to drill the hole.

  20. Analysis of genetic variations in CYP2C9, CYP2C19, CYP2D6 and CYP3A5 genes using oligonucleotide microarray

    PubMed Central

    Dong, Yuanyuan; Xiao, Huasheng; Wang, Qi; Zhang, Chunxiu; Liu, Xiuming; Yao, Na; Sheng, Haihui; Li, Haiyan

    2015-01-01

    The cytochrome P450 enzymes play a critical role in the metabolism of many commonly prescribed drugs. Among them, the most important enzymes are highly polymorphic CYP2C9, CYP2C19, CYP2D6 and CYP3A5, which are responsible for about 40% of the metabolism of clinical used drugs. Here we developed a novel CYP450 oligonucleotide microarray that allow for detection of 32 known variations of CYP genes from a single multiplex reaction, including 19 polymorphisms of CYP2D6 gene, 8 polymorphisms of CYP2C9 gene, 4 polymorphisms of CYP2C19 gene and 1 polymorphism of CYP3A5 gene. 229 genomic DNA samples from unrelated Han subjects were analyzed. The microarray results showed to have high call rate and accuracy according to concordance with genotypes identified by independent bidirectional sequencing. Furthermore, we found that the major CYP2C9, CYP2C19, CYP2D6 and CYP3A5 alleles in Chinese Han population were CYP2C9*3 (allelic frequency of 10.7%), CYP2C9*2 (20.31%), CYP2C19*2 (5.68%), CYP2D6*10 (58.52%), CYP2D6*2 (13.76) and CYP3A5*3 (70.69%). With flexible DNA preparation, the microarray can significantly facilitates the process of detecting genetics variations in CYP2C9, CYP2C19, CYP2D6 and CYP3A5 gene and provide safe and effective therapy for individual patients. PMID:26770516

  1. Isolation and spectroscopic properties of Sc[sub 2]C[sub 74], Sc[sub 2]C[sub 82], and Sc[sub 2]C[sub 84

    SciTech Connect

    Shinohara, Hisanori; Yamaguchi, Hiroki; Hayashi, Naoyuki; Sato, Hiroyasu; Saito, Yahachi ); Ohkohchi, Masato; Ando, Yoshinori )

    1993-04-29

    The endohedral discandium fullerenes, Sc[sub 2]C[sub 74], Sc[sub 2]C[sub 82], and Sc[sub 2]C[sub 84], have been isolated for the first time from soot prepared by the arc burning of Sc[sub 2]O[sub 3]/graphite composite rods. The separation and isolation of the metallofullerenes from various hollow fullerenes have been realized by using a two-stage high-performance liquid chromatography. Laser-desorption time-of-flight mass analyses of the present samples confirm the isolation of the discandium fullerenes. The discandium fullerene, Sc[sub 2]C[sub 74], has been newly found in this study. The UV-vis absorption spectra of the isolated Sc[sub 2]C[sub 74], Sc[sub 2]C[sub 82], and Sc[sub 2]C[sub 84] reveal several salient features which are totally absent in those of the corresponding hollow fullerenes such as C[sub 76], C[sub 78], C[sub 82], and C[sub 84]. 17 refs., 4 figs.

  2. Sprouty-2 Overexpression in C2C12 Cells Confers Myogenic Differentiation Properties in the Presence of FGF2D⃞

    PubMed Central

    de Alvaro, Cristina; Martinez, Natalia; Rojas, Jose M.; Lorenzo, Margarita

    2005-01-01

    Myoblast C2C12 cells cultured in the presence of FGF2 actively proliferate and showed a differentiation-defective phenotype compared with cells cultured in low serum or in the presence of insulin. These FGF2 effects are associated with sustained activation of p44/p42-MAPK and lack of activation of AKT. Here we demonstrate that Sprouty-2, a protein involved in the negative feedback of receptor tyrosine kinase signaling, when stably overexpressed in C2C12 cells and in the presence of FGF2 produces growth arrest (precluding the expression of PCNA and the phosphorylation of retinoblastoma and inducing the expression of p21CIP) and myogenesis (multinucleated myotubes formation, induction of creatine kinase and expression of myosin heavy chain protein). These events were accompanied by repression of p44/p42-MAPK and activation of AKT. When C2C12 cells were stably transfected with a Sprouty-2 (Y55F) mutant defective in inhibiting p44/p42-MAPK activation by FGF, myoblasts in the presence of FGF continue to grow and completely fail to form myotubes. This work is the first evidence of the contribution of sprouty genes to myogenic differentiation in the presence of FGF2. PMID:16000370

  3. Mir-17-92 regulates bone marrow homing of plasma cells and production of immunoglobulin G2c.

    PubMed

    Xu, Shengli; Ou, Xijun; Huo, Jianxin; Lim, Kristen; Huang, Yuhan; Chee, Sheena; Lam, Kong-Peng

    2015-01-01

    The polycistronic mir-17-92 cluster, also known as oncomir-1, was previously shown to be essential for early B lymphopoiesis. However, its role in late-stage B-cell differentiation and function remains unexplored. Here we ablate mir-17-92 in mature B cells and demonstrate that mir-17-92 is dispensable for conventional B-cell development in the periphery. Interestingly, mir-17-92-deficiency in B cells leads to enhanced homing of plasma cells to the bone marrow during T-cell-dependent immune response and selectively impairs IgG2c production. Mechanistically, mir-17-92 directly represses the expression of Sphingosine 1-phosphate receptor 1 and transcription factor IKAROS, which are, respectively, important for plasma cell homing and IgG2c production. We further show that deletion of mir-17-92 could reduce IgG2c anti-DNA autoantibody production and hence mitigate immune complex glomerulonephritis in Shp1-deficient mice prone to autoimmunity. Our results identify important roles for mir-17-92 in the regulation of peripheral B-cell function. PMID:25881561

  4. Isolation and Crystallographic Characterization of La2C2@Cs(574)-C102 and La2C2@C2(816)-C104: Evidence for the Top-Down Formation Mechanism of Fullerenes.

    PubMed

    Cai, Wenting; Li, Fang-Fang; Bao, Lipiao; Xie, Yunpeng; Lu, Xing

    2016-05-25

    Tubular higher fullerenes are prototypes of finite-length end-capped carbon nanotubes (CNTs) whose structures can be accurately characterized by single-crystal X-ray diffraction crystallography. We present here the isolation and crystallographic characterization of two unprecedented higher fullerenes stabilized by the encapsulation of a La2C2 cluster, namely, La2C2@Cs(574)-C102, which has a perfect tubular cage corresponding to a short (10, 0) zigzag carbon nanotube, and La2C2@C2(816)-C104 which has a defective cage with a pyracylene motif inserting into the cage waist. Both cages provide sufficient spaces for the large La2C2 cluster to adopt a stretched and nearly planar configuration, departing from the common butterfly-like configuration which has been frequently observed in midsized carbide metallofullerenes (e.g., Sc2C2@C80-84), to achieve strong metal-cage interactions. More meaningfully, our crystallographic results demonstrate that the defective cage of C2(816)-C104 is a starting point to form the other three tubular cages known so far, i.e., D5(450)-C100, Cs(574)-C102, and D3d(822)-C104, presenting evidence for the top-down formation mechanism of fullerenes. The fact that only the large La2C2 cluster has been found in giant fullerene cages (C>100) and the small clusters M2C2 (M = Sc, Y, Er, etc.) are present in midsized fullerenes (C80-C86) indicates that geometrical matching between the cluster and the cage, which ensures strong metal-cage interactions, is an important factor controlling the stability of the resultant metallofullerenes, in addition to charge transfer.

  5. Isolation and Crystallographic Characterization of La2C2@Cs(574)-C102 and La2C2@C2(816)-C104: Evidence for the Top-Down Formation Mechanism of Fullerenes.

    PubMed

    Cai, Wenting; Li, Fang-Fang; Bao, Lipiao; Xie, Yunpeng; Lu, Xing

    2016-05-25

    Tubular higher fullerenes are prototypes of finite-length end-capped carbon nanotubes (CNTs) whose structures can be accurately characterized by single-crystal X-ray diffraction crystallography. We present here the isolation and crystallographic characterization of two unprecedented higher fullerenes stabilized by the encapsulation of a La2C2 cluster, namely, La2C2@Cs(574)-C102, which has a perfect tubular cage corresponding to a short (10, 0) zigzag carbon nanotube, and La2C2@C2(816)-C104 which has a defective cage with a pyracylene motif inserting into the cage waist. Both cages provide sufficient spaces for the large La2C2 cluster to adopt a stretched and nearly planar configuration, departing from the common butterfly-like configuration which has been frequently observed in midsized carbide metallofullerenes (e.g., Sc2C2@C80-84), to achieve strong metal-cage interactions. More meaningfully, our crystallographic results demonstrate that the defective cage of C2(816)-C104 is a starting point to form the other three tubular cages known so far, i.e., D5(450)-C100, Cs(574)-C102, and D3d(822)-C104, presenting evidence for the top-down formation mechanism of fullerenes. The fact that only the large La2C2 cluster has been found in giant fullerene cages (C>100) and the small clusters M2C2 (M = Sc, Y, Er, etc.) are present in midsized fullerenes (C80-C86) indicates that geometrical matching between the cluster and the cage, which ensures strong metal-cage interactions, is an important factor controlling the stability of the resultant metallofullerenes, in addition to charge transfer. PMID:27157415

  6. p-Si/W2C and p-Si/W2C/Pt photocathodes for the hydrogen evolution reaction.

    PubMed

    Berglund, Sean P; He, Huichao; Chemelewski, William D; Celio, Hugo; Dolocan, Andrei; Mullins, C Buddie

    2014-01-29

    p-Si/W2C photocathodes are synthesized by evaporating tungsten metal in an ambient of ethylene gas to form tungsten semicarbide (W2C) thin films on top of p-type silicon (p-Si) substrates. As deposited the thin films contain crystalline W2C with a bulk W:C atomic ratio of approximately 2:1. The W2C films demonstrate catalytic activity for the hydrogen evolution reaction (HER), and p-Si/W2C photocathodes produce cathodic photocurrent at potentials more positive than 0.0 V vs RHE while bare p-Si photocathodes do not. The W2C films are an effective support for Pt nanoparticles allowing for a considerable reduction in Pt loading. p-Si/W2C/Pt photocathodes with Pt nanoparticles achieve photocurrent onset potentials and limiting photocurrent densities that are comparable to p-Si/Pt photocathodes with Pt loading nine times higher. This makes W2C an earth abundant alternative to pure Pt for use as an electrocatalyst on photocathodes for the HER. PMID:24393053

  7. Omeprazole-induced acute interstitial nephritis is not related to CYP2C19 genotype or CYP2C19 phenotype

    PubMed Central

    Helsby, Nuala A; Lo, Wing-Yee; Simpson, Ian J; Voss, David M; Logan, Kaye E; Searle, Martin; Schollum, John B W; de Zoysa, Janak R

    2010-01-01

    AIM Omeprazole-induced acute interstitial nephritis (OIAIN) is a rare adverse event. It is unknown if this is an idiosyncratic immune mediated reaction or if it relates to direct drug toxicity. Individuals who are homozygous for the variant alleles of CYP2C19 are poor metabolizers of omeprazole and have a greater exposure to the drug. The aim of this study was to determine the prevalence of the CYP2C19 poor metabolizer genotype and phenotype in patients with OIAIN. METHODS Twenty patients were genotyped for the CYP2C19 variant alleles (*2, 681G>A and *3, 636G>A) by RFLP-PCR analysis and eighteen phenotyped for CYP2C19 metabolizer status. RESULTS The frequency of the CYP2C19*2 allelic variant was 12.5%, no *3 allelic variants were detected and no patient was a homozygous variant genotype. This was not different from the expected frequency. 33% of subjects were phenotypically CYP2C19 poor metabolizers. CONCLUSIONS There was discordance between CYP2C19 genotype and phenotype. However, up to 45% of healthy elderly subjects have a poor metabolizer phenotype. Thus neither CYP2C19 poor metabolizer genotype nor phenotype is a risk factor for OIAIN. PMID:20573087

  8. Enhanced tolerance to low temperature in tobacco by over-expression of a new maize protein phosphatase 2C, ZmPP2C2.

    PubMed

    Hu, Xiaoli; Liu, Lixia; Xiao, Beilei; Li, Dapeng; Xing, Xin; Kong, Xiangpei; Li, Dequan

    2010-10-15

    Low temperature is one of the most common environmental stresses affecting plant growth and agricultural production. Serine/threonine protein phosphatases 2C (PP2Cs) have been suggested to play an important role in stress signaling. To identify potential new member of the PP2C proteins in maize and investigate its functions for stress responses, the ZmPP2C2 gene, encoding a new PP2C protein from maize roots, was cloned by RT-PCR and RACE-PCR. Its constitutive expression in roots, stems and leaves of maize seedlings was detected by RNA gel blot, and its regulation in response to cold stress was also examined. To further evaluate its function in the cold stress response, we over-expressed the ZmPP2C2 gene in tobacco under the control of the Cauliflower Mosaic Virus (CaMV) 35S promoter, and assessed a series of physiological changes in wild type and transgenic plants under low temperatures. Compared with wild type tobacco under cold stress, plants that over-expressed ZmPP2C2 displayed higher germination speed and rate, higher antioxidant enzyme (SOD, POD, CAT) activities, with lower cold-induced electrolyte leakage and malondialdehyde (MDA) contents. These results show that over-expression of ZmPP2C2 in tobacco enhanced tolerance to cold stress, suggesting that this new gene, ZmPP2C2, may act as a positive regulator of cold resistance in plants.

  9. Aminergic receptors in astrogliotic plaques from patients with multiple sclerosis.

    PubMed

    Zeinstra, Esther; te Riele, Paula; Langlois, Xavier; Wilczak, Nadine; Leysen, Josée; de Keyser, Jacques

    2002-10-11

    Cultured astrocytes express a spectrum of neurotransmitter receptors. However, little is known about these receptors in situ. We previously reported the absence of beta(2) adrenergic receptors on astrocytes in multiple sclerosis (MS). Here we used [(3)H]-radioligands and receptor autoradiography to screen for a variety of other aminergic receptors in six silent chronic astrogliotic plaques in brain tissue obtained from five patients with MS. Dopamine D(1) and histamine H(1) receptors were absent. We detected specific binding for cholinergic muscarinic receptors > dopamine D(2), alpha(1-) and alpha(2)-adrenergic receptors > 5-HT(1A), 5-HT(1B/D), 5-HT(2A), 5-HT(2c), 5-HT(4), and dopamine D(3) receptors. Radiotracers for these aminergic receptors might be useful for studying astrogliosis in patients with MS, and compounds acting at some of these receptors may have potential to modulate astroglial function in MS. PMID:12361847

  10. Effects of the hallucinogen 2,5-dimethoxy-4-iodophenethylamine (2C-I) and superpotent N-benzyl derivatives on the head twitch response.

    PubMed

    Halberstadt, Adam L; Geyer, Mark A

    2014-02-01

    N-benzyl substitution markedly enhances the affinity of phenethylamine hallucinogens at the 5-HT(2A) receptor. N-benzyl substituted derivatives of 2,5-dimethoxy-4-iodophenethylamine (2C-I), such as N-(2-methoxybenzyl)-2,5-dimethoxy-4-iodophenethylamine (25I-NBOMe) and N-(2,3-methylenedioxybenzyl)-2,5-dimethoxy-4-iodophenethylamine (25I-NBMD), have appeared recently as designer drugs, but have not been characterized behaviorally. The head twitch response (HTR) is induced by 5-HT(2A) receptor activation in rats and mice, and is widely used as a behavioral proxy for hallucinogen effects in humans. Nevertheless, it is not clear whether phenethylamine hallucinogens reliably provoke this behavior. Hence, we investigated whether 2C-I, 25I-NBOMe and 25I-NBMD induce head twitches in C57BL/6J mice. The HTR was assessed using a head-mounted magnet and a magnetometer coil. 2C-I (1-10 mg/kg SC), 25I-NBOMe (0.1-1 mg/kg SC), and 25I-NBMD (1-10 mg/kg SC) induced the HTR. 25I-NBOMe displayed 14-fold higher potency than 2C-I, and the selective 5-HT(2A) antagonist M100,907 completely blocked the HTR induced by all three compounds. These findings show that phenethylamine hallucinogens induce the HTR by activating 5-HT(2A) receptors. Our results demonstrate that 25I-NBOMe is a highly potent derivative of 2C-I, confirming previous in vitro findings that N-benzyl substitution increases 5-HT(2A) affinity. Given the high potency and ease of synthesis of N-benzylphenethylamines, it is likely that the recreational use of these hallucinogens will become more widespread in the future.

  11. Effects of the hallucinogen 2,5-dimethoxy-4-iodophenethylamine (2C-I) and superpotent N-benzyl derivatives on the head twitch response

    PubMed Central

    Halberstadt, Adam L.; Geyer, Mark A.

    2013-01-01

    N -benzyl substitution markedly enhances the affinity of phenethylamine hallucinogens at the 5-HT2A receptor. N-benzyl substituted derivatives of 2,5-dimethoxy-4-iodophenethylamine (2C-I), such as N-(2-methoxybenzyl)-2,5-dimethoxy-4-iodophenethylamine (25I-NBOMe) and N-(2,3-methylenedioxybenzyl)-2,5-dimethoxy-4-iodophenethylamine (25I-NBMD), have appeared recently as designer drugs, but have not been characterized behaviorally. The head twitch response (HTR) is induced by 5-HT2A receptor activation in rats and mice, and is widely used as a behavioral proxy for hallucinogen effects in humans. Nevertheless, it is not clear whether phenethylamine hallucinogens reliably provoke this behavior. Hence, we investigated whether 2C-I, 25I-NBOMe and 25I-NBMD induce head twitches in C57BL/6J mice. The HTR was assessed using a head-mounted magnet and a magnetometer coil. 2C-I (1–10 mg/kg SC), 25I-NBOMe (0.1–1 mg/kg SC), and 25I-NBMD (1–10 mg/kg SC) induced the HTR. 25I-NBOMe displayed 14-fold higher potency than 2C-I, and the selective 5-HT2A antagonist M100,907 completely blocked the HTR induced by all three compounds. These findings show that phenethylamine hallucinogens induce the HTR by activating 5-HT2A receptors. Our results demonstrate that 25I-NBOMe is a highly potent derivative of 2C-I, confirming previous in vitro findings that N-benzyl substitution increases 5-HT2A affinity. Given the high potency and ease of synthesis of N-benzylphenethylamines, it is likely that the recreational use of these hallucinogens will become more widespread in the future. PMID:24012658

  12. Allele and genotype frequencies of CYP2C9, CYP2C19 and CYP2D6 in an Italian population.

    PubMed

    Scordo, Maria Gabriella; Caputi, Achille P; D'Arrigo, Concetta; Fava, Giuseppina; Spina, Edoardo

    2004-08-01

    The polymorphic cytochrome P450 isoenzymes (CYPs) 2C9, 2C19 and 2D6 metabolise many important drugs, as well as other xenobiotics. Their polymorphism gives rise to important interindividual and interethnic variability in the metabolism and disposition of several therapeutic agents and may cause differences in the clinical response to these drugs. In this study, we determined the genotype profile of a random Italian population in order to compare the CYP2C9, CYP2C19 and CYP2D6 allele frequencies among Italians with previous findings in other Caucasian populations. Frequencies for the major CYP2C9, CYP2C19 and CYP2D6 mutated alleles and genotypes have been evaluated in 360 unrelated healthy Italian volunteers (210 males and 150 females, aged 19-52 years). Genotyping has been carried out on peripheral leukocytes DNA by molecular biology techniques (PCR, RFLP, long-PCR). CYP2C9, CYP2C19 and CYP2D6 allele and genotype frequencies resulted in equilibrium with the Hardy-Weinberg equation. One hundred and fourteen subjects (31.7%) carried one and 23 subjects (6.4%) carried two CYP2C9 mutated alleles. Sixty-eight (18.9%) volunteers were found to be heterozygous and six (1.7%) homozygous for the CYP2C19*2, while no CYP2C19*3 was detected in the evaluated population. Volunteers could be divided into four CYP2D6 genotypes groups: 192 subjects (53.3%) with no mutated alleles (homozygous extensive metabolisers, EM), 126 (35.0%) with one mutated allele (heterozygous EM), 12 (3.4%) with two mutated alleles (poor metabolisers, PM) and 30 (8.3%) with extracopies of a functional gene (ultrarapid metabolisers, UM). Frequencies of both CYP2C9 and CYP2C19 allelic variants, as well as CYP2D6 detrimental alleles, in Italian subjects were similar to those of other Caucasian populations. Conversely, the prevalence of CYP2D6 gene duplication among Italians resulted very high, confirming the higher frequency of CYP2D6 UM in the Mediterranean area compared to Northern Europe. PMID:15177309

  13. Cytochrome P450 2C8 pharmacogenetics: a review of clinical studies

    PubMed Central

    Daily, Elizabeth B; Aquilante, Christina L

    2009-01-01

    Cytochrome P450 (CYP) 2C8 is responsible for the oxidative metabolism of many clinically available drugs from a diverse number of drug classes (e.g., thiazolidinediones, meglitinides, NSAIDs, antimalarials and chemotherapeutic taxanes). The CYP2C8 enzyme is encoded by the CYP2C8 gene, and several common nonsynonymous polymorphisms (e.g., CYP2C8*2 and CYP2C8*3) exist in this gene. The CYP2C8*2 and *3 alleles have been associated in vitro with decreased metabolism of paclitaxel and arachidonic acid. Recently, the influence of CYP2C8 polymorphisms on substrate disposition in humans has been investigated in a number of clinical pharmacogenetic studies. Contrary to in vitro data, clinical data suggest that the CYP2C8*3 allele is associated with increased metabolism of the CYP2C8 substrates, rosiglitazone, pioglitazone and repaglinide. However, the CYP2C8*3 allele has not been associated with paclitaxel pharmacokinetics in most clinical studies. Furthermore, clinical data regarding the impact of the CYP2C8*3 allele on the disposition of NSAIDs are conflicting and no definitive conclusions can be made at this time. The purpose of this review is to highlight these clinical studies that have investigated the association between CYP2C8 polymorphisms and CYP2C8 substrate pharmacokinetics and/or pharmacodynamics in humans. In this review, CYP2C8 clinical pharmacogenetic data are provided by drug class, followed by a discussion of the future of CYP2C8 clinical pharmacogenetic research. PMID:19761371

  14. Effect of CYP2C9 genetic polymorphism on the metabolism of flurbiprofen in vitro.

    PubMed

    Wang, Li; Bao, Shi-Hui; Pan, Pei-Pei; Xia, Meng-Ming; Chen, Meng-Chun; Liang, Bing-Qing; Dai, Da-Peng; Cai, Jian-Ping; Hu, Guo-Xin

    2015-01-01

    CYP2C9 is an important member of the cytochrome P450 enzyme superfamily, and 57 cytochrome P450 2C9 alleles have been previously reported. To examine the enzymatic activity of the CYP2C9 alleles, kinetic parameters for 4'-hydroxyflurbiprofen were determined using recombinant human P450s CYP2C9 microsomes from insect cells Sf21 carrying wild-type CYP2C9*1 and other variants. The results showed that the enzyme activity of most of the variants decreased comparing with the wild type as the previous studies reported, while the enzyme activity of some of them increased, which were not in accordance with the previous researches. Of the 36 tested CYP2C9 allelic isoforms, two variants (CYP2C9*53 and CYP2C9*56) showed a higher intrinsic clearance value than the wild-type protein, especially for CYP2C9*56, exhibited much higher intrinsic clearance (197.3%) relative to wild-type CYP2C9*1, while the remaining 33 CYP2C9 allelic isoforms exhibited significantly decreased clearance values (from 0.6 to 83.8%) compared to CYP2C9*1. This study provided the most comprehensive data on the enzymatic activities of all reported CYP2C9 variants in the Chinese population with regard to the commonly used non-steroidal anti-inflammatory drug, flurbiprofen (FP). The results indicated that most of the tested rare alleles decreased the catalytic activity of CYP2C9 variants toward FP hydroxylation in vitro. This is the first report of all these rare alleles for FP metabolism providing fundamental data for further clinical studies on CYP2C9 alleles for FP metabolism in vivo.

  15. Over-expression of a Zea mays L. protein phosphatase 2C gene (ZmPP2C) in Arabidopsis thaliana decreases tolerance to salt and drought.

    PubMed

    Liu, Lixia; Hu, Xiaoli; Song, Jian; Zong, Xiaojuan; Li, Dapeng; Li, Dequan

    2009-03-15

    ZmPP2C (AY621066) is a protein phosphatase type-2c previously isolated from roots of Zea mays (LD9002). In this study, constitutive expression of ZmPP2C in Arabidopsis thaliana under the control of the Cauliflower Mosaic Virus (CaMV) 35S promoter decreased plant tolerance to salt and drought during seed germination and vegetative growth. When growing on media with NaCl or mannitol, the ZmPP2C-overexpressed plants displayed more severe damages, with weaker growth phenotypes corresponding to a series of physiological changes: lower net photosynthesis rate (Pn) and free proline content, higher malondialdehyde (MDA) level, higher relative membrane permeability (RMP), and water loss. Under these stress conditions, they also showed decreased transcription of the stress-related genes RD29A, RD29B, P5CS1, and P5CS2, and ABA-related genes ABI1 and ABI2. Further, the transgenic plants became less sensitive to abscisic acid (ABA). ZmPP2C over-expression significantly attenuated ABA inhibition on seed germination and root growth of the transgenic plants. These results demonstrate that ZmPP2C is involved in plant stress signal transduction, and ZmPP2C gene over-expression in Arabidopsis thaliana may be exploited to study its potential roles in stress-induced signaling pathway.

  16. TaPP2C1, a Group F2 Protein Phosphatase 2C Gene, Confers Resistance to Salt Stress in Transgenic Tobacco

    PubMed Central

    Hu, Wei; Yan, Yan; Hou, Xiaowan; He, Yanzhen; Wei, Yunxie; Yang, Guangxiao; He, Guangyuan; Peng, Ming

    2015-01-01

    Group A protein phosphatases 2Cs (PP2Cs) are essential components of abscisic acid (ABA) signaling in Arabidopsis; however, the function of group F2 subfamily PP2Cs is currently less known. In this study, TaPP2C1 which belongs to group F2 was isolated and characterized from wheat. Expression of the TaPP2C1-GFP fusion protein suggested its ubiquitous localization within a cell. TaPP2C1 expression was downregulated by abscisic acid (ABA) and NaCl treatments, but upregulated by H2O2 treatment. Overexpression of TaPP2C1 in tobacco resulted in reduced ABA sensitivity and increased salt resistance of transgenic seedlings. Additionally, physiological analyses showed that improved resistance to salt stress conferred by TaPP2C1 is due to the reduced reactive oxygen species (ROS) accumulation, the improved antioxidant system, and the increased transcription of genes in the ABA-independent pathway. Finally, transgenic tobacco showed increased resistance to oxidative stress by maintaining a more effective antioxidant system. Taken together, these results demonstrated that TaPP2C1 negatively regulates ABA signaling, but positively regulates salt resistance. TaPP2C1 confers salt resistance through activating the antioxidant system and ABA-independent gene transcription process. PMID:26057628

  17. Reduced Toxicity of Shiga Toxin (Stx) Type 2c in Mice Compared to Stx2d Is Associated with Instability of Stx2c Holotoxin.

    PubMed

    Bunger, Joshua C; Melton-Celsa, Angela R; Maynard, Ernest L; O'Brien, Alison D

    2015-06-23

    Shiga toxin (Stx) is an AB5 ribotoxin made by Stx-producing Escherichia coli (STEC). These organisms cause diarrhea, hemorrhagic colitis and the hemolytic uremic syndrome. STEC make two types of Stxs, Stx1 and/or Stx2. Stx2 has one prototype (a) and six subtypes (b-g), but only STEC that make Stx2a, and/or Stx2c, or Stx2d are associated with severe disease. However, Stx2c is about 10-fold less toxic than Stx2d in vivo despite only two amino acid differences in the A subunit at positions 291 and 297. We made mutations at these two sites to create intermediate toxins between Stx2c and Stx2d, and determined the 50% cytotoxic dose on Vero cells before and after heat treatment, and the 50% lethal dose in mice of the toxins. We found that serine 291 was associated with increased toxicity in vivo and that either amino acid change from that in Stx2c to that in Stx2d increased heat stability. We also assessed the secondary structure of Stx2c and Stx2d by circular dichroism (CD) spectroscopy. The CD studies suggest that Stx2c has a less-ordered secondary structure than Stx2d. We conclude that both amino acids at positions 291 and 297 in Stx2c contribute to its decreased stability and in vivo toxicity compared to Stx2d.

  18. CYP2C9, CYP2C19, ABCB1 genetic polymorphisms and phenytoin plasma concentrations in Mexican-Mestizo patients with epilepsy.

    PubMed

    Ortega-Vázquez, A; Dorado, P; Fricke-Galindo, I; Jung-Cook, H; Monroy-Jaramillo, N; Martínez-Juárez, I E; Familiar-López, I; Peñas-Lledó, E; LLerena, A; López-López, M

    2016-06-01

    We aimed to explore the possible influence of CYP2C9 (*2, *3 and IVS8-109 A>T), CYP2C19 (*2, *3 and *17) and ABCB1 (1236C>T, 2677G>A/T and 3435C>T) on phenytoin (PHT) plasma concentrations in 64 Mexican Mestizo (MM) patients with epilepsy currently treated with PHT in mono- (n=25) and polytherapy (n=39). Genotype and allele frequencies of these variants were also estimated in 300 MM healthy volunteers. Linear regression models were used to assess associations between the dependent variables (PHT plasma concentration and dose-corrected PHT concentration) with independent variables (CYP2C9, CYP2C19 and ABCB1 genotypes, ABCB1 haplotypes, age, sex, weight, and polytherapy). In multivariate models, CYP2C9 IVS8-109 T was significantly associated with higher PHT plasma concentrations (t(64)=2.27; P=0.03). Moreover, this allele was more frequent in the supratherapeutic group as compared with the subtherapeutic group (0.13 versus 0.03, respectively; P=0.05, Fisher's exact test). Results suggest that CYP2C9 IVS8-109 T allele may decrease CYP2C9 enzymatic activity on PHT. More research is needed to confirm findings.

  19. Establishment of a functional cell line expressing both subunits of H1a and H2c of human hepatocyte surface molecule ASGPR.

    PubMed

    Hu, Bin; Yang, Yan; Liu, Jia; Ma, Zhiyong; Huang, Hongping; Liu, Shenpei; Yu, Yuan; Hao, Youhua; Wang, Baoju; Lu, Mengji; Yang, Dongliang

    2010-10-01

    To better understand the effect of a new split variant of human asialoglycoprotein receptor (ASGPR H1b) on ASGPR ligands' binding ability, we established a functional cell line which expresses ASGPR. The full lengths of ASGPRH1a and H2c fragments from human liver were amplified by reverse transcript PCR (RT-PCR) and inserted into eukaryotic expression vector pIRES2EGFP, pCDNA3.1 (Zeo+) respectively. The recombinants were co-transfected into HeLa cells. After selection by using Neocin and Zeocin, a stably transfected cell line was established, which was designated 4-1-6. The transcription and expression of ASGPRH1a and H2c in 4-1-6 were confirmed by RT-PCR, Western blotting and immunofluorescence. The endocytosis function of the artificial "ASGPR" on the surface of 4-1-6 was tested by FACS. It was found that the cell line 4-1-6 could bind ASGPR natural ligand molecular asialo-orosomucoid (ASOR). After the eukaryotic plasmid H1b/pCDNA3.1 (neo) was transfected into cell line 4-1-6, H1b did not down-regulate the ligand binding ability of ASGPR. The eukaryotic expression plasmid H1b/pcDNA3.1 (neo) and H2c/pcDNA3.1 (neo) were co-transfected transiently into Hela cell. Neither single H1b nor H1b and H2c could bind ASOR. In conclusion, a functional cell line of human asialoglycoprotein receptor (ASGPR) which expresses both H1a and H2c stably was established. The new split variant H1b has no effect on ASGPR binding to ASOR. ASGPRH1b alone can't bind to ASOR, it yet can't form functional complex with ASGPRH2c.

  20. Molecular Determinants for Ligand Binding at Serotonin 5-HT2A and 5-HT2C GPCRs: Experimental Affinity Results Analyzed by Molecular Modeling and Ligand Docking Studies

    PubMed Central

    Sakhuja, Rajeev; Kondabolu, Krishnakanth; Canal, Clinton E.; Booth, Raymond G.

    2013-01-01

    Ligands that activate the serotonin 5-HT2C G protein-coupled receptor (GPCR) may be therapeutic for psychoses, addiction, and other neuropsychiatric disorders. Ligands that are antagonists at the closely related 5-HT2A GPCR also may treat neuropsychiatric disorders; in contrast, 5-HT2A activation may cause hallucinations. 5-HT2C-specific agonist drug design is challenging because 5-HT2 GPCRs share 80% transmembrane (TM) homology, same second messenger signaling, and no crystal structures are reported. To help delineate molecular determinants underlying differential binding and activation of 5-HT2 GPCRs, 5-HT2A, and 5-HT2C homology models were built from the β2-adrenergic GPCR crystal structure and equilibrated in a lipid phosphatidyl choline bilayer performing molecular dynamics simulations. Ligand docking studies at the 5-HT2 receptor models were conducted with the (2R, 4S)- and (2S, 4R)-enantiomers of the novel 5-HT2C agonist/5-HT2A/2B antagonist trans-4-phenyl-N,N-dimethyl-2-aminotetralin (PAT) and its 4′-chlorophenyl congners. Results indicate PAT–5-HT2 molecular interactions especially in TM domain V are important for the (2R, 4S) enantiomer, whereas, TM domain VI and VII interactions are more important for the (2S, 4R) enantiomer. PMID:23913978

  1. Vibrational modes and resonant Raman spectra of new B2C nanoribbons

    NASA Astrophysics Data System (ADS)

    Li, Xiaowei; Xu, Yuehua; Dong, Jinming

    2011-07-01

    The vibrational properties and first-order resonant Raman spectra of new B2C nanoribbons (B2C-NRs) have been studied by the density functional theory. It is found that there is a characteristic radial-breathing-like mode (RBLM) for all the calculated B2C-NRs with their frequency varying in a linear proportion to the inverse square root of the B2C-NR's width, whose slope depends closely on the types of B2C-NRs. The RBLM resonant peak's intensities and positions in the first-order resonant Raman spectra of the B2C-NRs are found to depend greatly on the polarizations of the incident and scattered light, and also the types of B2C-NRs.

  2. "PP2C7s", Genes Most Highly Elaborated in Photosynthetic Organisms, Reveal the Bacterial Origin and Stepwise Evolution of PPM/PP2C Protein Phosphatases.

    PubMed

    Kerk, David; Silver, Dylan; Uhrig, R Glen; Moorhead, Greg B G

    2015-01-01

    Mg+2/Mn+2-dependent type 2C protein phosphatases (PP2Cs) are ubiquitous in eukaryotes, mediating diverse cellular signaling processes through metal ion catalyzed dephosphorylation of target proteins. We have identified a distinct PP2C sequence class ("PP2C7s") which is nearly universally distributed in Eukaryotes, and therefore apparently ancient. PP2C7s are by far most prominent and diverse in plants and green algae. Combining phylogenetic analysis, subcellular localization predictions, and a distillation of publically available gene expression data, we have traced the evolutionary trajectory of this gene family in photosynthetic eukaryotes, demonstrating two major sequence assemblages featuring a succession of increasingly derived sub-clades. These display predominant expression moving from an ancestral pattern in photosynthetic tissues toward non-photosynthetic, specialized and reproductive structures. Gene co-expression network composition strongly suggests a shifting pattern of PP2C7 gene functions, including possible regulation of starch metabolism for one homologue set in Arabidopsis and rice. Distinct plant PP2C7 sub-clades demonstrate novel amino terminal protein sequences upon motif analysis, consistent with a shifting pattern of regulation of protein function. More broadly, neither the major events in PP2C sequence evolution, nor the origin of the diversity of metal binding characteristics currently observed in different PP2C lineages, are clearly understood. Identification of the PP2C7 sequence clade has allowed us to provide a better understanding of both of these issues. Phylogenetic analysis and sequence comparisons using Hidden Markov Models strongly suggest that PP2Cs originated in Bacteria (Group II PP2C sequences), entered Eukaryotes through the ancestral mitochondrial endosymbiosis, elaborated in Eukaryotes, then re-entered Bacteria through an inter-domain gene transfer, ultimately producing bacterial Group I PP2C sequences. A key evolutionary

  3. "PP2C7s", Genes Most Highly Elaborated in Photosynthetic Organisms, Reveal the Bacterial Origin and Stepwise Evolution of PPM/PP2C Protein Phosphatases

    PubMed Central

    Kerk, David; Silver, Dylan; Uhrig, R. Glen; Moorhead, Greg B. G.

    2015-01-01

    Mg+2/Mn+2-dependent type 2C protein phosphatases (PP2Cs) are ubiquitous in eukaryotes, mediating diverse cellular signaling processes through metal ion catalyzed dephosphorylation of target proteins. We have identified a distinct PP2C sequence class (“PP2C7s”) which is nearly universally distributed in Eukaryotes, and therefore apparently ancient. PP2C7s are by far most prominent and diverse in plants and green algae. Combining phylogenetic analysis, subcellular localization predictions, and a distillation of publically available gene expression data, we have traced the evolutionary trajectory of this gene family in photosynthetic eukaryotes, demonstrating two major sequence assemblages featuring a succession of increasingly derived sub-clades. These display predominant expression moving from an ancestral pattern in photosynthetic tissues toward non-photosynthetic, specialized and reproductive structures. Gene co-expression network composition strongly suggests a shifting pattern of PP2C7 gene functions, including possible regulation of starch metabolism for one homologue set in Arabidopsis and rice. Distinct plant PP2C7 sub-clades demonstrate novel amino terminal protein sequences upon motif analysis, consistent with a shifting pattern of regulation of protein function. More broadly, neither the major events in PP2C sequence evolution, nor the origin of the diversity of metal binding characteristics currently observed in different PP2C lineages, are clearly understood. Identification of the PP2C7 sequence clade has allowed us to provide a better understanding of both of these issues. Phylogenetic analysis and sequence comparisons using Hidden Markov Models strongly suggest that PP2Cs originated in Bacteria (Group II PP2C sequences), entered Eukaryotes through the ancestral mitochondrial endosymbiosis, elaborated in Eukaryotes, then re-entered Bacteria through an inter-domain gene transfer, ultimately producing bacterial Group I PP2C sequences. A key

  4. Theoretical study of the C-H bond dissociation energies of CH4, C2H2, C2H4, and H2C2O

    NASA Technical Reports Server (NTRS)

    Bauschlicher, Charles W., Jr.; Langhoff, Stephen R.

    1991-01-01

    The successive C-H bond dissociation energies of CH4, C2H2, C2H4, and H2C2O (ketene) are determined using large-basis sets and a high level of correlation treatment. For CH4, C2H2, and C2H4 the computed values are in excellent agreement with experiment. Using these results, the values 107.9 + or - 2.0 and 96.7 + or - 2.0 kcal/mol are recommended for the C-H bond dissociation energies of H2C2O and HC2O, respectively.

  5. Genotype and allele frequency of CYP2C19*17 in a healthy Iranian population

    PubMed Central

    Payan, Maryam; Tajik, Nader; Rouini, Mohammad Reza; Ghahremani, Mohammad Hossein

    2015-01-01

    Background: Cytochrome P450 2C19 (CYP2C19) is important in metabolism of wide range of drugs. CYP2C19*17 is a novel variant allele which increases gene transcription and therefore results in ultra-rapid metabolizer phenotype (URM). Distribution of this variant allele has not been well studied worldwide. The aim of present study was to investigate allele and genotype frequencies of CYP2C19*17 in a healthy Iranian population and compare them with other ethnic groups. Methods: One hundred eighty healthy unrelated Iranian volunteer took part in this study and were genotyped for CYP2C19 *2, *3, *17 (-3402) by using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and CYP2C19*17 (-806) by a nested-PCR assays. The distribution of CYP2C19*17 polymorphism in Iranian population was then compared with other ethnic groups. Results: The CYP2C19*17 allele frequency was 21.6% in Iranian population. Among studied subjects 5.5% were homozygous for CYP2C19*17 and phenotyped as ultra-rapid metabolizers; 28.8% were genotyped as CYP2C19*1*17 (extensive metabolizers) and 3.3% as CYP2C19*2*17 (intermediate metabolizers). Conclusion: The CYP2C19*17 genetic distribution in Iranian population is similar to Middle East or European countries. The high frequency of CYP2C19*17 in Iranian population highlights the importance of this new variant allele in metabolism of CYP2C19 substrates. Thus, future association studies are required to reveal clinical consequence of this genetic polymorphism in carrier individuals. PMID:26793660

  6. Effect of cage charges on multiphoton absorptions: first-principles study on metallofullerenes Sc(2)C(2)@C(68) and Sc(3)N@C(68).

    PubMed

    Cheng, W-D; Hu, H; Wu, D-S; Wang, J-Y; Huang, S-P; Xe, Z; Zhang, H

    2009-05-21

    A combined method of the time-dependent density functional theory (TDDFT) and sum-overstate (SOS) formula was implemented to model multiphoton absorption spectra, including two-photon absorption (2PA) and three-photon absorption (3PA), of Sc(2)C(2)@C(68) and Sc(3)N@C(68) endohedral metallofullerenes (EMFs). This method has been proved to be effective by comparisons between the calculated and experimental results of trans-4,4'-bis[diphenylamino]stilbene. It was found that the multiphoton absorption cross sections were larger for Sc(2)C(2)@C(68) than that of Sc(3)N@C(68). The electronic origin of multiphoton absorption has been identified with respect to the molecular orbitals involved in charge transfer process. It shows that the increase of pi-charges on the cage of C(68) results in a large multiphoton absorption cross section in EMFs.

  7. Assignment of human myocyte-specific enhancer binding factor 2C (hMEF2C) to human chromosome 5q14 and evidence that MEF2C is evolutionarily conserved

    SciTech Connect

    Krainc, D.; Lipton, S.A.; Haas, M.; Ward, D.C.

    1995-10-10

    Human myocyte-specific enhancer binding factor 2C (hMEF2C) belongs to the MEF2 subfamily of the MADS (MCM1, AGAMOUS, DEF A, serum response factor) family of transcription factors. Members of the MADS family share a conserved domain - the MADS domain - that is necessary for DNA binding. Highly conserved versions of the MADS domain and of an adjacent domain that is known as the MEF2 domain are found in members of the MEF2 subfamily. Both of these domains are necessary for binding to the MEF2 regulatory element. This regulatory element is known to be functionally important in a variety of muscle-specific genes and possibly in the brain creatine kinase gene. The MEF2C gene product activates transcription by binding to the MEF2 element. hMEF2C is expressed at high levels in postmitotic neurons in the brain, where it is most abundant in the cerebral cortex, and is also expressed in differentiated myotubes. Several lines of evidence suggest the existence of a rat homologue of MEF2C, and a mouse homologue has been cloned. The mouse gene was mapped to mouse chromosome 13 in a region that is syntenic to human 5q13-q15. 12 refs., 1 fig.

  8. ABA Receptors: Past, Present and Future

    SciTech Connect

    Guo, Jianjun; Yang, Xiaohan; Weston, David; Chen, Jay

    2011-01-01

    Abscisic acid (ABA) is the key plant stress hormone. Consistent with the earlier studies in support of the presence of both membrane- and cytoplasm-localized ABA receptors, recent studies have identified multiple ABA receptors located in various subcellular locations. These include a chloroplast envelope-localized receptor (the H subunit of Chloroplast Mg2+-chelatase/ABA Receptor), two plasma membrane-localized receptors (G-protein Coupled Receptor 2 and GPCR-type G proteins), and one cytosol/nucleus-localized Pyrabactin Resistant (PYR)/PYR-Like (PYL)/Regulatory Component of ABA Receptor 1 (RCAR). Although the downstream molecular events for most of the identified ABA receptors are currently unknown, one of them, PYR/PYL/RACR was found to directly bind and regulate the activity of a long-known central regulator of ABA signaling, the A-group protein phosphatase 2C (PP2C). Together with the Sucrose Non-fermentation Kinase Subfamily 2 (SnRK2s) protein kinases, a central signaling complex (ABA-PYR-PP2Cs-SnRK2s) that is responsible for ABA signal perception and transduction is supported by abundant genetic, physiological, biochemical and structural evidence. The identification of multiple ABA receptors has advanced our understanding of ABA signal perception and transduction while adding an extra layer of complexity.

  9. Effect of exogenous growth hormone on somatic growth, gonadal development, and hepatic CYP2C11 and CYP2C12 expression in prepubertal intact male rats.

    PubMed

    Kawai, M; Bandiera, S M; Chang, T K; Bellward, G D

    2001-04-01

    The influence of exogenous growth hormone (GH) on pubertal maturation, as assessed by growth, age of preputial separation, testicular development, and hepatic expression of sexually dimorphic cytochrome P450 (CYP) enzymes, was investigated. Treatment of 22-day old prepubertal intact male rats with twice daily subcutaneous (s.c.) injections of rat recombinant GH (0.12 microg/g body weight) for 12 or 21 days did not affect body weight, skeletal growth, or testicular weight. By comparison, GH suppressed hepatic CYP2C1 enzyme activity, protein, and mRNA levels but induced CYP2C12 expression. GH suppressed CYP2C11 expression by approximately 60% in prepubertal rats as compared with 30% in adult rats, whereas it increased CYP2C12 levels to 80% of the normal female levels but had no effect in adult male rats. Twice daily intravenous injections of GH suppressed CYP2C11 only. Increasing the s.c. dose of GH 30-fold produced little or no additional change in CYP2C11 or CYP2C12 expression, whereas it modestly in creased body weight and skeletal growth and reduced testicular weight. Overall, the present study provides the first demonstration that prepubertal administration (22-33 days of age) of GH at a pharmacologically relevant dose (0.12 microg/g twice daily) suppressed hepatic expression of CYP2C11 in 34-day-old intact male rats, suggesting that in this age group the liver is intrinsically responsive to transcription factors involved in the regulation of GH-dependent, sex-specific CYP gene expression. A higher dose (3.6 microg/g) of GH administered during the prepubertal period was required to elicit a modest effect on somatic growth and gonadal development.

  10. Role of Cytochrome P450 2C8 in Drug Metabolism and Interactions.

    PubMed

    Backman, Janne T; Filppula, Anne M; Niemi, Mikko; Neuvonen, Pertti J

    2016-01-01

    During the last 10-15 years, cytochrome P450 (CYP) 2C8 has emerged as an important drug-metabolizing enzyme. CYP2C8 is highly expressed in human liver and is known to metabolize more than 100 drugs. CYP2C8 substrate drugs include amodiaquine, cerivastatin, dasabuvir, enzalutamide, imatinib, loperamide, montelukast, paclitaxel, pioglitazone, repaglinide, and rosiglitazone, and the number is increasing. Similarly, many drugs have been identified as CYP2C8 inhibitors or inducers. In vivo, already a small dose of gemfibrozil, i.e., 10% of its therapeutic dose, is a strong, irreversible inhibitor of CYP2C8. Interestingly, recent findings indicate that the acyl-β-glucuronides of gemfibrozil and clopidogrel cause metabolism-dependent inactivation of CYP2C8, leading to a strong potential for drug interactions. Also several other glucuronide metabolites interact with CYP2C8 as substrates or inhibitors, suggesting that an interplay between CYP2C8 and glucuronides is common. Lack of fully selective and safe probe substrates, inhibitors, and inducers challenges execution and interpretation of drug-drug interaction studies in humans. Apart from drug-drug interactions, some CYP2C8 genetic variants are associated with altered CYP2C8 activity and exhibit significant interethnic frequency differences. Herein, we review the current knowledge on substrates, inhibitors, inducers, and pharmacogenetics of CYP2C8, as well as its role in clinically relevant drug interactions. In addition, implications for selection of CYP2C8 marker and perpetrator drugs to investigate CYP2C8-mediated drug metabolism and interactions in preclinical and clinical studies are discussed. PMID:26721703

  11. Chemical understanding of carbide cluster metallofullerenes: a case study on Sc2C2@C2v(5)-C80 with complete X-ray crystallographic characterizations.

    PubMed

    Kurihara, Hiroki; Lu, Xing; Iiduka, Yuko; Nikawa, Hidefumi; Mizorogi, Naomi; Slanina, Zdenek; Tsuchiya, Takahiro; Nagase, Shigeru; Akasaka, Takeshi

    2012-02-15

    Little is known about the chemical properties of carbide cluster metallofullerenes (CCMFs). Here we report the photochemical reaction of a newly assigned CCMF Sc(2)C(2)@C(2v)(5)-C(80) with 2-adamantane-2,3-[3H]-diazirine (AdN(2), 1), which provides a carbene reagent under irradiation. Five monoadduct isomers (2a-2e), with respective abundances of 20%, 40%, 25%, 5%, and 10%, were isolated and characterized with a combination of experimental techniques including unambiguous single-crystal X-ray crystallography. Results show that the two Sc atoms of the bent Sc(2)C(2) cluster tend to move in most cases, whereas the C(2)-unit is almost fixed. Accordingly, it is difficult to explain the addition patterns by considering the strain and charge density on the cage with a fixed cluster, and thus a moving cluster may account for the addition patterns. These results show that the situation of CCMFs is more complicated than those in other metallofullerenes. Furthermore, a thermal isomerization process from 2b to 2c was observed, confirming that the most abundant isomer 2b is a kinetically favored adduct. Finally, it is revealed that the electronic and electrochemical properties of pristine Sc(2)C(2)@C(2v)(5)-C(80) have been markedly altered by exohedral modification.

  12. Regioselectivity of Sc2C2@C3v(8)-C82: Role of the Sumanene-Type Hexagon in Diels-Alder Reaction.

    PubMed

    Zhao, Pei; Zhao, Xiang; Ehara, Masahiro

    2016-09-16

    Recently, several experiments have demonstrated high chemical reactivity of the sumanene-type hexagon in Sc2C2@C82. To further uncover its reactivity, the Diels-Alder reaction to all the nonequivalent C-C bonds of C82 and Sc2C2@C82 has been investigated by density functional theory calculations. For the free fullerene, the [5,6] bond 7 is the thermodynamically most favored, whereas the addition on the [6,6] bond 3 has the lowest activation energy. Diels-Alder reaction has no preference for addition sites in the sumanene-type hexagon. However, in the case of the endohedral fullerene, the [6,6] bond 19 in the special hexagon becomes the most reactive site according to both kinetic and thermodynamic considerations. Further analyses reveal that bond 19 in Sc2C2@C82 exhibits the shortest bond length and third largest π-orbital axis vector. In addition, the LUMOs of bond 19 are also symmetry-allowed to interact with butadiene. PMID:27538115

  13. Different effects of proton pump inhibitors and famotidine on the clopidogrel metabolic activation by recombinant CYP2B6, CYP2C19 and CYP3A4.

    PubMed

    Ohbuchi, Masato; Noguchi, Kiyoshi; Kawamura, Akio; Usui, Takashi

    2012-07-01

    Inhibitory potential of proton pump inhibitors (PPIs) and famotidine, an H(2) receptor antagonist, on the metabolic activation of clopidogrel was evaluated using recombinant CYP2B6, CYP2C19 and CYP3A4. Formation of the active metabolite from an intermediate metabolite, 2-oxo-clopidogrel, was investigated by liquid chromatography-tandem mass spectrometry and three peaks corresponding to the pharmacologically active metabolite and its stereoisomers were detected. Omeprazole potently inhibited clopidogrel activation by CYP2C19 with an IC(50) of 12.8 μmol/L and more weakly inhibited that by CYP2B6 and CYP3A4. IC(50) of omeprazole for CYP2C19 and CYP3A4 was decreased about two- and three-fold, respectively, by 30-min preincubation with NADPH. Lansoprazole, esomeprazole, pantoprazole, rabeprazole and rabeprazole thioether, a major metabolite, also inhibited metabolic activation by CYP2C19, with an IC(50) of 4.3, 8.9, 48.3, 36.2 and 30.5 μmol/L, respectively. In contrast, famotidine showed no more than 20% inhibition of clopidogrel activation by CYP2B6, CYP2C19 and CYP3A4 at up to 100 μmol/L and had no time-dependent CYP2C19 and CYP3A4 inhibition. These results provide direct evidence that PPIs inhibit clopidogrel metabolic activation and suggest that CYP2C19 inhibition is the main cause of drug-drug interaction between clopidogrel and omeprazole. Famotidine is considered as a safe anti-acid agent for patients taking clopidogrel. PMID:22313038

  14. Permanent uncoupling of male-specific CYP2C11 transcription/translation by perinatal glutamate

    SciTech Connect

    Banerjee, Sarmistha; Das, Rajat Kumar; Giffear, Kelly A.; Shapiro, Bernard H.

    2015-04-01

    Perinatal exposure of rats and mice to the typically reported 4 mg/g bd wt dose of monosodium glutamate (MSG) results in a complete block in GH secretion as well as obesity, growth retardation and a profound suppression of several cytochrome P450s, including CYP2C11, the predominant male-specific isoform — all irreversible effects. In contrast, we have found that a lower dose of the food additive, 2 mg/g bd wt on alternate days for the first 9 days of life results in a transient neonatal depletion of plasma GH, a subsequent permanent overexpression of CYP2C11 as well as subnormal (mini) GH pulse amplitudes in an otherwise normal adult masculine episodic GH profile. The overexpressed CYP2C11 was characterized by a 250% increase in mRNA, but only a 40 to 50% increase in CYP2C11 protein and its catalytic activity. Using freshly isolated hepatocytes as well as primary cultures exposed to the masculine-like episodic GH profile, we observed normal induction, activation, nuclear translocation and binding to the CYP2C11 promoter of the GH-dependent signal transducers required for CYP2C11 transcription. The disproportionately lower expression levels of CYP2C11 protein were associated with dramatically high expression levels of an aberrant, presumably nontranslated CYP2C11 mRNA, a 200% increase in CYP2C11 ubiquitination and a 70–80% decline in miRNAs associated, at normal levels, with a suppression of CYP2C expression. Whereas the GH-responsiveness of CYP2C7 and CYP2C6 as well as albumin was normal in the MSG-derived hepatocytes, the abnormal expression of CYP2C11 was permanent and irreversible. - Highlights: • A “low” neonatal dose of MSG causes an immediate but transient growth hormone depletion. • Adult circulating growth hormone contains mini pulses in an otherwise male profile. • CYP2C11 is permanently overexpressed > 250%; CYP2C6, 2C7 and albumin remain normal. • The bulk of the overexpressed CYP2C11 mRNA consists of an intron-retained form. • SOCS2

  15. Molecular pharmacology of human NMDA receptors

    PubMed Central

    Hedegaard, Maiken K.; Hansen, Kasper B.; Andersen, Karen T.; Bräuner-Osborne, Hans; Traynelis, Stephen F.

    2012-01-01

    N-methyl-D-aspartate (NMDA) receptors are ionotropic glutamate receptors that mediate excitatory neurotransmission. NMDA receptors are also important drug targets that are implicated in a number of pathophysiological conditions. To facilitate the transition from lead compounds in pre-clinical animal models to drug candidates for human use, it is important to establish whether NMDA receptor ligands have similar properties at rodent and human NMDA receptors. Here, we compare amino acid sequences for human and rat NMDA receptor subunits and discuss inter-species variation in the context of our current knowledge of the relationship between NMDA receptor structure and function. We summarize studies on the biophysical properties of human NMDA receptors and compare these properties to those of rat orthologs. Finally, we provide a comprehensive pharmacological characterization that allows side-by-side comparison of agonists, un-competitive antagonists, GluN2B-selective non-competitive antagonists, and GluN2C/D-selective modulators at recombinant human and rat NMDA receptors. The evaluation of biophysical properties and pharmacological probes acting at different sites on the receptor suggest that the binding sites and conformational changes leading to channel gating in response to agonist binding are highly conserved between human and rat NMDA receptors. In summary, the results of this study suggest that no major detectable differences exist in the pharmacological and functional properties of human and rat NMDA receptors. PMID:22197913

  16. Vibrational spectrum of B2C in argon at 10 K

    NASA Astrophysics Data System (ADS)

    Larson, C. William; Domingo Presilla-Márquez, José

    1999-08-01

    The vibrational spectrum of B2C has been observed for the first time in solid argon by Fourier-transform infrared spectroscopy. Absorption frequencies of the three boron isotopomers of cyclic symmetric B2C, previously deduced by ab initio theory, are in accord with measured frequencies, which enables assignment of an absorption at 1392.8 cm-1 to the ν1(a1) fundamental of B2C(1A1).

  17. Conessine Interferes with Oxidative Stress-Induced C2C12 Myoblast Cell Death through Inhibition of Autophagic Flux

    PubMed Central

    Kim, Hyunju; Lee, Kang Il; Jang, Minsu; Namkoong, Sim; Park, Rackhyun; Ju, Hyunwoo; Choi, Inho; Oh, Won Keun

    2016-01-01

    Conessine, a steroidal alkaloid isolated from Holarrhena floribunda, has anti-malarial activity and interacts with the histamine H3 receptor. However, the cellular effects of conessine are poorly understood. Accordingly, we evaluated the involvement of conessine in the regulation of autophagy. We searched natural compounds that modulate autophagy, and conessine was identified as an inhibitor of autophagic flux. Conessine treatment induced the formation of autophagosomes, and p62, an autophagic adapter, accumulated in the autophagosomes. Reactive oxygen species such as hydrogen peroxide (H2O2) result in muscle cell death by inducing excessive autophagic flux. Treatment with conessine inhibited H2O2-induced autophagic flux in C2C12 myoblast cells and also interfered with cell death. Our results indicate that conessine has the potential effect to inhibit muscle cell death by interfering with autophagic flux. PMID:27257813

  18. Frequency of CYP2C9 alleles in Koreans and their effects on losartan pharmacokinetics

    PubMed Central

    Bae, Jung-woo; Choi, Chang-ik; Kim, Mi-jeong; Oh, Da-hee; Keum, Seul-ki; Park, Jung-in; Kim, Bo-hye; Bang, Hye-kyoung; Oh, Sung-gon; Kang, Byung-sung; Park, Hyun-joo; Kim, Hae-deun; Ha, Ji-hey; Shin, Hee-jung; Kim, Young-hoon; Na, Han-sung; Chung, Myeon-woo; Jang, Choon-gon; Lee, Seok-yong

    2011-01-01

    Aim: CYP2C9 enzyme metabolizes numerous clinically important drugs. The aim of this study is to investigate the frequencies of CYP2C9 genotypes and the effects of selected alleles on losartan pharmacokinetics in a large sample of the Korean population. Methods: The CYP2C9 gene was genotyped in 1796 healthy Korean subjects. CYP2C9 alleles (CYP2C9*1, *2, *3 and *13 alleles) were measured using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) assay and direct sequencing assay. The enzymatic activity of each CYP2C9 genotype was evaluated using losartan as the substrate. Results: The frequencies of CYP2C9*1, *3 and *13 allele were 0.952 (95% confidence interval 0.945–0.959), 0.044 (95% CI 0.037–0.051) and 0.005 (95% CI 0.003–0.007), respectively. The frequencies of the CYP2C9*1/*1, *1/*3, *1/*13 and *3/*3 genotypes were 0.904 (95% CI 0.890–0.918), 0.085 (95% CI 0.072–0.098), 0.009 (95% CI 0.005–0.013) and 0.001 (95% CI 0.000–0.002), respectively. In the pharmacokinetics studies, the AUC0–∞ of losartan in CYP2C9*3/*3 subjects was 1.42-fold larger than that in CYP2C9*1/*1 subjects, and the AUC0–∞ of E-3174, a more active metabolite of losartan, in CYP2C9*3/*3 subjects was only 12% of that in CYP2C9*1/*1 subjects. Conclusion: The results confirmed the frequencies of CYP2C9 genotypes in a large cohort of Koreans, and detected the CYP2C9*3/*3 genotype. CYP2C9*3/*3 subjects metabolized much less losartan into E-3174 than CYP2C9*1/*1 subjects. PMID:21841812

  19. Development of Insulin Resistance through Induction of miRNA-135 in C2C12 Cells

    PubMed Central

    Honardoost, Maryam; Arefian, Ehsan; Soleimani, Masoud; Soudi, Sara; Sarookhani, Mohammad Reza

    2016-01-01

    Objective Micro-RNAs (miRNAs) are a class of posttranscriptional regulators that play crucial roles in various biological processes. Emerging evidence suggests a direct link between miRNAs and development of several diseases including type 2 diabetes (T2D). In this study, we aimed to investigate the effect of predicted miRNA and target genes on insulin resistance. Materials and Methods This experimental study was conducted on the C2C12 cell line. Using bioinformatics tools miRNA-135 and two respective target genes-insulin receptor (Insr) and vesicle associated membrane protein 2 (Vamp2)were selected as potential factors involved in insulin resistance process. Levels of glucose uptake miRNA expression and respective gene targets were determined after cell transfaction by miR-135. Results It was determined that Insr gene expression was significantly down-regulated in miR-135 transfected C2C12 cell line (P≤0.05). Interestingly; these transfected cells have shown a significant difference in glucose uptake incomparision the positive control cells, while it was similar to the insulin resistant cell line (P≤0.05). In contrast, no significant alteration of Vamp2 gene expression was observed. Conclusion Our data indicated no change on the Vamp2 expression level after miRNA transfection, while expression level of Insr was reduced and miR-135 expression was contrarily increased leading to poor stimulation of glucose uptake through insulin, and development of insulin resistance phenotype in C2C12 cell line. PMID:27602317

  20. Development of Insulin Resistance through Induction of miRNA-135 in C2C12 Cells

    PubMed Central

    Honardoost, Maryam; Arefian, Ehsan; Soleimani, Masoud; Soudi, Sara; Sarookhani, Mohammad Reza

    2016-01-01

    Objective Micro-RNAs (miRNAs) are a class of posttranscriptional regulators that play crucial roles in various biological processes. Emerging evidence suggests a direct link between miRNAs and development of several diseases including type 2 diabetes (T2D). In this study, we aimed to investigate the effect of predicted miRNA and target genes on insulin resistance. Materials and Methods This experimental study was conducted on the C2C12 cell line. Using bioinformatics tools miRNA-135 and two respective target genes-insulin receptor (Insr) and vesicle associated membrane protein 2 (Vamp2)were selected as potential factors involved in insulin resistance process. Levels of glucose uptake miRNA expression and respective gene targets were determined after cell transfaction by miR-135. Results It was determined that Insr gene expression was significantly down-regulated in miR-135 transfected C2C12 cell line (P≤0.05). Interestingly; these transfected cells have shown a significant difference in glucose uptake incomparision the positive control cells, while it was similar to the insulin resistant cell line (P≤0.05). In contrast, no significant alteration of Vamp2 gene expression was observed. Conclusion Our data indicated no change on the Vamp2 expression level after miRNA transfection, while expression level of Insr was reduced and miR-135 expression was contrarily increased leading to poor stimulation of glucose uptake through insulin, and development of insulin resistance phenotype in C2C12 cell line.

  1. Protein O-fucosyltransferase 1 expression impacts myogenic C2C12 cell commitment via the Notch signaling pathway.

    PubMed

    Der Vartanian, Audrey; Audfray, Aymeric; Al Jaam, Bilal; Janot, Mathilde; Legardinier, Sébastien; Maftah, Abderrahman; Germot, Agnès

    2015-01-01

    The Notch signaling pathway plays a crucial role in skeletal muscle regeneration in mammals by controlling the transition of satellite cells from quiescence to an activated state, their proliferation, and their commitment toward myotubes or self-renewal. O-fucosylation on Notch receptor epidermal growth factor (EGF)-like repeats is catalyzed by the protein O-fucosyltransferase 1 (Pofut1) and primarily controls Notch interaction with its ligands. To approach the role of O-fucosylation in myogenesis, we analyzed a murine myoblastic C2C12 cell line downregulated for Pofut1 expression by short hairpin RNA (shRNA) inhibition during the time course of differentiation. Knockdown of Pofut1 affected the signaling pathway activation by a reduction of the amount of cleaved Notch intracellular domain and a decrease in downstream Notch target gene expression. Depletion in Pax7(+)/MyoD(-) cells and earlier myogenic program entrance were observed, leading to an increase in myotube quantity with a small number of nuclei, reflecting fusion defects. The rescue of Pofut1 expression in knockdown cells restored Notch signaling activation and a normal course in C2C12 differentiation. Our results establish the critical role of Pofut1 on Notch pathway activation during myogenic differentiation.

  2. Lipoic Acid Exerts Antioxidant and Anti-inflammatory Effects in Response to Heat Shock in C2C12 Myotubes.

    PubMed

    Lee, Cheng-Tse; Chang, Li-Ching; Wu, Pei-Fung

    2016-06-01

    This study explored that lipoic acid treatment for 24 h significantly upregulated and promoted heat shock-induced catalase expression and downregulated GPx1 messenger RNA (mRNA) expression, indicating that lipoic acid exhibits antioxidant activity in the decomposition of hydrogen peroxide by upregulating catalase expression. Moreover, lipoic acid treatment for 3 h increased and promoted heat shock-induced interleukin (IL)-6 mRNA and protein levels and that for 24 h downregulated IL-6 mRNA expression, suggesting a dual effect of lipoic acid on IL-6 regulation. Lipoic acid alone failed to increase or reduce tumor necrosis factor (TNF)-α mRNA and protein levels, whereas heat shock alone downregulated TNF-α mRNA and protein expression. These data suggest that lipoic acid does not have a proinflammatory role and that heat shock acts as an anti-inflammatory agent by downregulating TNF-α expression in C2C12 myotubes. Moreover, lipoic acid or heat shock alone upregulated the IL-6 receptor (IL-6R-α) and glycoprotein 130 (gp130) mRNA expression followed by IL-6 expression; these data indicate that the regulation of lipoic acid or heat shock is mediated by IL-6R signaling, thus suggesting that C2C12 myotubes possesses a mechanism for regulating IL-6R and gp130 expression following lipoic acid treatment or heat shock.

  3. Protein O-Fucosyltransferase 1 Expression Impacts Myogenic C2C12 Cell Commitment via the Notch Signaling Pathway

    PubMed Central

    Der Vartanian, Audrey; Audfray, Aymeric; Al Jaam, Bilal; Janot, Mathilde; Legardinier, Sébastien; Maftah, Abderrahman

    2014-01-01

    The Notch signaling pathway plays a crucial role in skeletal muscle regeneration in mammals by controlling the transition of satellite cells from quiescence to an activated state, their proliferation, and their commitment toward myotubes or self-renewal. O-fucosylation on Notch receptor epidermal growth factor (EGF)-like repeats is catalyzed by the protein O-fucosyltransferase 1 (Pofut1) and primarily controls Notch interaction with its ligands. To approach the role of O-fucosylation in myogenesis, we analyzed a murine myoblastic C2C12 cell line downregulated for Pofut1 expression by short hairpin RNA (shRNA) inhibition during the time course of differentiation. Knockdown of Pofut1 affected the signaling pathway activation by a reduction of the amount of cleaved Notch intracellular domain and a decrease in downstream Notch target gene expression. Depletion in Pax7+/MyoD− cells and earlier myogenic program entrance were observed, leading to an increase in myotube quantity with a small number of nuclei, reflecting fusion defects. The rescue of Pofut1 expression in knockdown cells restored Notch signaling activation and a normal course in C2C12 differentiation. Our results establish the critical role of Pofut1 on Notch pathway activation during myogenic differentiation. PMID:25384974

  4. Clonidine potentiates the effects of 5-HT1A, 5-HT1B and 5-HT2A/2C antagonists and 8-OH-DPAT in the mouse forced swimming test.

    PubMed

    Redrobe, J P; Bourin, M

    1998-08-01

    The present study was undertaken to identify the receptor subtypes involved in clonidine's ability to enhance the effects of antidepressant drugs in the mouse forced swimming test. Clonidine (0.06 mg/kg, i.p.) significantly enhanced the antidepressant-like effects of subactive doses of the 5-HT1A receptor agonist, 8-OH-DPAT (1 mg/kg, i.p.; P<0.01); the 5-HT1A receptor antagonist, NAN 190 (0.5 mg/kg, i.p.; P<0.01); the 5-HT1A/1B autoreceptor antagonist, (+/-) pindolol (32 mg/kg, i.p.; P<0.01); the 5-HT2A/2C receptor antagonist, ritanserin (4 mg/kg, i.p.; P<0.01). Pretreatment with clonidine failed to increase mobility when administered in combination with the 5-HT1B receptor agonist, RU 24969 (1 mg/kg, i.p.) or the 5-HT2A receptor antagonist, ketanserin (8 mg/kg, i.p.). In conclusion, clonidine-induced anti-immobility effects are more likely mediated by 5-HT1A and 5-HT2C receptors, as well as alpha-2-adrenergic autoreceptors situated on noradrenergic neurones. The results of the present study also demonstrate that serotonergic receptor function can influence alpha-2-adrenoreceptor mediated responses in the mouse forced swimming test.

  5. Inhibitory effects of phthalimide derivatives on the activity of the hepatic cytochrome P450 monooxygenases CYP2C9 and CYP2C19.

    PubMed

    Kolukisaoglu, Üner; Wendler, Christian; Goerdes, Dirk; Diener, Annette; Thurow, Kerstin

    2010-12-01

    Affecting hepatic cytochrome (CYP) activity is one of the major concerns in drug-drug interaction. Thus the testing of drug candidates on their impact on these enzymes is an essential step in early drug discovery. We tested a collection of 480 in-house phthalimide derivatives against different CYP450s using a high throughput inhibition assay. In initial tests with the isoform CYP2C19 about 57.5% of the tested phthalimide derivatives showed significantly enhanced inhibitory effects against this enzyme. In addition similar patterns of phthalimide inhibition for CYP2C9 and CYP2C19 were found, whereas the unrelated isoforms CYP2D6 and CYP3A4 were not specifically affected. Also less than 10% of randomly chosen substances inhibited CYP2C9. Analyses of structure-function relationships revealed that the substituent at the nitrogen atom in the isoindole ring is of crucial impact for the activity of CYP2C9/19.

  6. TFAP2C Governs the Luminal Epithelial Phenotype in Mammary Development and Carcinogenesis

    PubMed Central

    Cyr, Anthony R; Kulak, Mikhail V.; Park, Jung M.; Bogachek, Maria V.; Spanheimer, Philip M.; Woodfield, George W.; White-Baer, Lola S.; O’Malley, Yunxia Q.; Sugg, Sonia L.; Olivier, Alicia K.; Zhang, Weizhou; Domann, Frederick E.; Weigel, Ronald J.

    2014-01-01

    Molecular subtypes of breast cancer are characterized by distinct patterns of gene expression that are predictive of outcome and response to therapy. The luminal breast cancer subtypes are defined by the expression of ER-alpha (ERα)-associated genes, many of which are directly responsive to the Transcription Factor Activator Protein 2C (TFAP2C). TFAP2C participates in a gene regulatory network controlling cell growth and differentiation during ectodermal development and regulating ESR1/ERα and other luminal cell-associated genes in breast cancer. TFAP2C has been established as a prognostic factor in human breast cancer, however, its role in the establishment and maintenance of the luminal cell phenotype during carcinogenesis and mammary gland development have remained elusive. Herein, we demonstrate a critical role for TFAP2C in maintaining the luminal phenotype in human breast cancer and in influencing the luminal cell phenotype during normal mammary development. Knockdown of TFAP2C in luminal breast carcinoma cells induced EMT with morphological and phenotypic changes characterized by a loss of luminal-associated gene expression and a concomitant gain of basal-associated gene expression. Conditional knockout of the mouse homolog of TFAP2C, Tcfap2c, in mouse mammary epithelium driven by MMTV-Cre promoted aberrant growth of the mammary tree leading to a reduction in the CD24hi/CD49fmid luminal cell population and concomitant gain of the CD24mid/CD49fhi basal cell population at maturity. Our results establish TFAP2C as a key transcriptional regulator for maintaining the luminal phenotype in human breast carcinoma. Furthermore, Tcfap2c influences development of the luminal cell type during mammary development. The data suggest that TFAP2C plays an important role in regulated luminal specific genes and may be a viable therapeutic target in breast cancer. PMID:24469049

  7. Review of magnetic features observed in (A,A')Ni 2B 2C solid solutions

    NASA Astrophysics Data System (ADS)

    Kuznietz, Moshe; Gonçalves, António P.; Almeida, Manuel

    2002-08-01

    The nickel-borocarbides ANi 2B 2C [A=Y, Ln (lanthanide), An(actinide)], crystallizing in the body-centred tetragonal LuNi 2B 2C-type structure, are classified according to the existence or coexistence of superconducting and antiferromagnetic states (AF). The magnetic features observed in polycrystalline (A,A')Ni 2B 2C solid solutions, adopting the same crystal structure, are reviewed and discussed. Published data on the magnetism in (A,Ln)Ni 2B 2C systems (ANi 2B 2C nonmagnetic, A=Y,La,Lu) indicate a gradual rise in the threshold content, x( m), in (Y 1- xLn x)Ni 2B 2C (Ln=Gd,Tb,Dy,Ho,Er) for the establishment of AF states. (A,A')Ni 2B 2C systems with magnetic end compounds show gradual variation in magnetic features when A and A' are both heavy Ln. The behaviour of (A,A')Ni 2B 2C systems of light A (Pr or U) and heavy A' (Dy or Tm) depends on the magnetic structures of the end compounds. In intermediate compositions, incomplete moment compensation in (Pr,Dy)Ni 2B 2C decreases TN, while different moment directions in the end compounds in (U,Dy)Ni 2B 2C lead to a directional frustration of ordered moments. Such a frustration in (U,Tm)Ni 2B 2C is related to different magnetic structures of the end compounds.

  8. 40 CFR Table 2c to Subpart E of... - Reactivity Factors for Aromatic Hydrocarbon Solvent Mixtures

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 6 2013-07-01 2013-07-01 false Reactivity Factors for Aromatic Hydrocarbon Solvent Mixtures 2C Table 2C to Subpart E of Part 59 Protection of Environment ENVIRONMENTAL... Hydrocarbon Solvent Mixtures Bin Boiling range(degrees F) Criteria Reactivityfactor (g O3/g VOC) 21...

  9. 40 CFR Table 2c to Subpart E of... - Reactivity Factors for Aromatic Hydrocarbon Solvent Mixtures

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 5 2011-07-01 2011-07-01 false Reactivity Factors for Aromatic Hydrocarbon Solvent Mixtures 2C Table 2C to Subpart E of Part 59 Protection of Environment ENVIRONMENTAL... Hydrocarbon Solvent Mixtures Bin Boiling range (degrees F) Criteria Reactivityfactor 21 280-290...

  10. 40 CFR Table 2c to Subpart E of... - Reactivity Factors for Aromatic Hydrocarbon Solvent Mixtures

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 5 2010-07-01 2010-07-01 false Reactivity Factors for Aromatic Hydrocarbon Solvent Mixtures 2C Table 2C to Subpart E of Part 59 Protection of Environment ENVIRONMENTAL... Hydrocarbon Solvent Mixtures Bin Boiling range (degrees F) Criteria Reactivityfactor 21 280-290...

  11. 40 CFR Table 2c to Subpart E of... - Reactivity Factors for Aromatic Hydrocarbon Solvent Mixtures

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 6 2014-07-01 2014-07-01 false Reactivity Factors for Aromatic Hydrocarbon Solvent Mixtures 2C Table 2C to Subpart E of Part 59 Protection of Environment ENVIRONMENTAL... Hydrocarbon Solvent Mixtures Bin Boiling range(degrees F) Criteria Reactivityfactor (g O3/g VOC) 21...

  12. 40 CFR Table 2c to Subpart E of... - Reactivity Factors for Aromatic Hydrocarbon Solvent Mixtures

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 6 2012-07-01 2012-07-01 false Reactivity Factors for Aromatic Hydrocarbon Solvent Mixtures 2C Table 2C to Subpart E of Part 59 Protection of Environment ENVIRONMENTAL... Hydrocarbon Solvent Mixtures Bin Boiling range(degrees F) Criteria Reactivityfactor (g O3/g VOC) 21...

  13. Phosphorylation-dependent degradation of MEF2C contributes to regulate G2/M transition

    PubMed Central

    Badodi, Sara; Baruffaldi, Fiorenza; Ganassi, Massimo; Battini, Renata; Molinari, Susanna

    2015-01-01

    The Myocyte Enhancer Factor 2C (MEF2C) transcription factor plays a critical role in skeletal muscle differentiation, promoting muscle-specific gene transcription. Here we report that in proliferating cells MEF2C is degraded in mitosis by the Anaphase Promoting Complex/Cyclosome (APC/C) and that this downregulation is necessary for an efficient progression of the cell cycle. We show that this mechanism of degradation requires the presence on MEF2C of a D-box (R-X-X-L) and 2 phospho-motifs, pSer98 and pSer110. Both the D-box and pSer110 motifs are encoded by the ubiquitous alternate α1 exon. These two domains mediate the interaction between MEF2C and CDC20, a co-activator of APC/C. We further report that in myoblasts, MEF2C regulates the expression of G2/M checkpoint genes (14–3–3γ, Gadd45b and p21) and the sub-cellular localization of CYCLIN B1. The importance of controlling MEF2C levels during the cell cycle is reinforced by the observation that modulation of its expression affects the proliferation rate of colon cancer cells. Our findings show that beside the well-established role as pro-myogenic transcription factor, MEF2C can also function as a regulator of cell proliferation. PMID:25789873

  14. Structural and electronic studies of metal carbide clusterfullerene Sc2C2@Cs-C72

    NASA Astrophysics Data System (ADS)

    Feng, Yongqiang; Wang, Taishan; Wu, Jingyi; Feng, Lai; Xiang, Junfeng; Ma, Yihan; Zhang, Zhuxia; Jiang, Li; Shu, Chunying; Wang, Chunru

    2013-07-01

    We present a metal carbide clusterfullerene Sc2C2@Cs(10528)-C72, whose structure has been baffling for many years. A motional endohedral Sc2C2 cluster, special molecule geometry and electronic structure were found in Sc2C2@Cs(10528)-C72. The paramagnetic Sc2C2@Cs-C72 anion radical was successfully prepared by a chemical reduction method and hyperfine couplings in the ESR spectrum were observed.We present a metal carbide clusterfullerene Sc2C2@Cs(10528)-C72, whose structure has been baffling for many years. A motional endohedral Sc2C2 cluster, special molecule geometry and electronic structure were found in Sc2C2@Cs(10528)-C72. The paramagnetic Sc2C2@Cs-C72 anion radical was successfully prepared by a chemical reduction method and hyperfine couplings in the ESR spectrum were observed. Electronic supplementary information (ESI) available: Experimental details, HPLC chromatogram, and DFT calculations. CCDC 917712. For ESI and crystallographic data in CIF or other electronic format see DOI: 10.1039/c3nr01739g

  15. Acute Effects of the Novel Psychoactive Drug 2C-B on Emotions

    PubMed Central

    González, Débora; Torrens, Marta; Farré, Magí

    2015-01-01

    Background. 2C-B (Nexus) is one of the most widespread novel psychoactive substances. There is limited information about its pharmacological properties, and few studies in humans concern its acute and chronic effects. 2C-B has been classified as a stimulant, hallucinogen, entactogen, and/or empathogen. Objectives. To evaluate the emotional, subjective, and cardiovascular effects of 2C-B. Methods. Twenty healthy recreational 2C-B users (12 women) self-administered a 20 mg dose of 2C-B. Evaluations included emotional (IAPS, FERT, and speech), subjective (visual analog scales, ARCI, VESSPA, HRS, and POMS questionnaires), and cardiovascular effects (blood pressure and heart rate). Results. Positive subjective effects predominated with a reduction of anger under the influence of 2C-B. It did, however, increase reactivity to negative emotional stimuli and decrease the ability to recognize expressions of happiness. Augmented emotionality in speech could be appreciated by others. 2C-B induced euphoria and well-being, changes in perceptions, and slight hallucinogenic states. Mild sympathetic actions were observed. Conclusions. The specific profile that 2C-B exerts on emotions suggests its classification as an entactogen with psychedelic properties. PMID:26543863

  16. MEF2C and EBF1 Co-regulate B Cell-Specific Transcription

    PubMed Central

    Kong, Nikki R.; Davis, Matthew; Chai, Li; Winoto, Astar; Tjian, Robert

    2016-01-01

    Hematopoietic stem cells are capable of self-renewal or differentiation along three main lineages: myeloid, erythroid, and lymphoid. One of the earliest lineage decisions for blood progenitor cells is whether to adopt the lymphoid or myeloid fate. Previous work had shown that myocyte enhancer factor 2C (MEF2C) is indispensable for the lymphoid fate decision, yet the specific mechanism of action remained unclear. Here, we have identified early B cell factor-1 (EBF1) as a co-regulator of gene expression with MEF2C. A genome-wide survey of MEF2C and EBF1 binding sites identified a subset of B cell-specific genes that they target. We also determined that the p38 MAPK pathway activates MEF2C to drive B cell differentiation. Mef2c knockout mice showed reduced B lymphoid-specific gene expression as well as increased myeloid gene expression, consistent with MEF2C’s role as a lineage fate regulator. This is further supported by interaction between MEF2C and the histone deacetylase, HDAC7, revealing a likely mechanism to repress the myeloid transcription program. This study thus elucidates both activation and repression mechanisms, identifies regulatory partners, and downstream targets by which MEF2C regulates lymphoid-specific differentiation. PMID:26900922

  17. Establishing a Research Center: The Minority Male Community College Collaborative (M2C3)

    ERIC Educational Resources Information Center

    Wood, J. Luke; Urias, Marissa Vasquez; Harris, Frank, III

    2016-01-01

    This chapter describes the establishment of the Minority Male Community College Collaborative (M2C3), a research and practice center at San Diego State University. M2C3 partners with community colleges across the United States to enhance access, achievement, and success among men of color. This chapter begins with a description of the national…

  18. Success and pitfalls of the Sin-2C2H2-C2Bn-2Hn isolobal analogy: Depth and breadth of the boron connection

    NASA Astrophysics Data System (ADS)

    Zdetsis, Aristides D.

    2009-02-01

    The extent and depth of the so-called boron connection suggested recently by the present author [J. Chem. Phys. 128, 184305 (2008)] for the Sin-2C2H2-C2Bn-2Hn isovalent species [following similar connection of (Sin)2--(BnHn)2- dianions] are further investigated by considering larger species up to n =12 and additional isovalent moieties. Here we consider, using density functional and coupled clusters theory, isovalent Sin-2C2H2 and Gen-2C2H2 clusters, in comparison to the corresponding C2Bn-2Hn carboranes and to each other for n =3-8, 12. Special attention is given to the n =8 species, where the corresponding carborane is highly fluxional, and to n =12, where the "parent structures" of the corresponding (Si12)2- and (B12H12)2- dianions have drastically different symmetries. The structures generated by substitutions on (Si12)2-, as well as (B12H12)2-, are compared and interrelated for both C2B10H12 and Si10C2H12. The carborane generated from the Cs (Si12)2- dianion provides an illustrative example of carborane rearrangements, reverting after geometry optimization to the second lowest C2B10H12 meta isomer of C2v symmetry, 0.12 eV above the lowest energy para isomer. This demonstrates the amphidirectional character of the boron connection. It is found that n =8 is the upper limit of the n range in which the isolobal Sin-2C2H2-C2Bn-2Hn analogy is fully operative not only for the lowest but also for the second and third lowest energy states. For n ≤8 all three pairs of structures are isovalent, isostructural, and isolobal. For large values of n (n >8) the boron connection, although not fully isolobal, is still valid in a broader and more general sense, still providing deeper and broader fundamental understanding and insight for both species. It was also found that the Gen-2C2H2 clusters are not fully homologous (isolobal) neither to the isovalent Sin-2C2H2 clusters nor to the corresponding C2Bn-2Hn carboranes, preferring structures in which the two carbon atoms are

  19. Dual agonist occupancy of AT1-R–α2C-AR heterodimers results in atypical Gs-PKA signaling

    PubMed Central

    Bellot, Morgane; Galandrin, Ségolène; Boularan, Cédric; Matthies, Heinrich J; Despas, Fabien; Denis, Colette; Javitch, Jonathan; Mazères, Serge; Sanni, Samra Joke; Pons, Véronique; Seguelas, Marie-Hélène; Hansen, Jakob L; Pathak, Atul; Galli, Aurelio; Sénard, Jean-Michel; Galés, Céline

    2015-01-01

    Hypersecretion of norepinephrine (NE) and angiotensin II (AngII) is a hallmark of major prevalent cardiovascular diseases that contribute to cardiac pathophysiology and morbidity. Herein, we explore whether heterodimerization of presynaptic AngII AT1 receptor (AT1-R) and NE α2C-adrenergic receptor2C-AR) could underlie their functional cross-talk to control NE secretion. Multiple bioluminescence resonance energy transfer and protein complementation assays allowed us to accurately probe the structures and functions of the α2C-AR–AT1-R dimer promoted by ligand binding to individual protomers. We found that dual agonist occupancy resulted in a conformation of the heterodimer different from that induced by active individual protomers and triggered atypical Gs-cAMP–PKA signaling. This specific pharmacological signaling unit was identified in vivo to promote not only NE hypersecretion in sympathetic neurons but also sympathetic hyperactivity in mice. Thus, we uncovered a new process by which GPCR heterodimerization creates an original functional pharmacological entity and that could constitute a promising new target in cardiovascular therapeutics. PMID:25706338

  20. Rg3 Improves Mitochondrial Function and the Expression of Key Genes Involved in Mitochondrial Biogenesis in C2C12 Myotubes

    PubMed Central

    Kim, Min Joo; Koo, Young Do; Kim, Min; Lim, Soo; Park, Young Joo; Chung, Sung Soo; Jang, Hak C.

    2016-01-01

    Background Panax ginseng has glucose-lowering effects, some of which are associated with the improvement in insulin resistance in skeletal muscle. Because mitochondria play a pivotal role in the insulin resistance of skeletal muscle, we investigated the effects of the ginsenoside Rg3, one of the active components of P. ginseng, on mitochondrial function and biogenesis in C2C12 myotubes. Methods C2C12 myotubes were treated with Rg3 for 24 hours. Insulin signaling pathway proteins were examined by Western blot. Cellular adenosine triphosphate (ATP) levels and the oxygen consumption rate were measured. The protein or mRNA levels of mitochondrial complexes were evaluated by Western blot and quantitative reverse transcription polymerase chain reaction analysis. Results Rg3 treatment to C2C12 cells activated the insulin signaling pathway proteins, insulin receptor substrate-1 and Akt. Rg3 increased ATP production and the oxygen consumption rate, suggesting improved mitochondrial function. Rg3 increased the expression of peroxisome proliferator-activated receptor γ coactivator 1α, nuclear respiratory factor 1, and mitochondrial transcription factor, which are transcription factors related to mitochondrial biogenesis. Subsequent increased expression of mitochondrial complex IV and V was also observed. Conclusion Our results suggest that Rg3 improves mitochondrial function and the expression of key genes involved in mitochondrial biogenesis, leading to an improvement in insulin resistance in skeletal muscle. Rg3 may have the potential to be developed as an anti-hyperglycemic agent.

  1. Endothelial Aquaporin-1 (AQP1) Expression Is Regulated by Transcription Factor Mef2c

    PubMed Central

    Jiang, Yong; Liu, He; Liu, Wen-jing; Tong, Hai-bin; Chen, Chang-jun; Lin, Fu-gui; Zhuo, Yan-hang; Qian, Xiao-zhen; Wang, Zeng-bin; Wang, Yu; Zhang, Peng; Jia, Hong-liang

    2016-01-01

    Aquaporin 1 (AQP1) is expressed in most microvasculature endothelial cells and forms water channels that play major roles in a variety of physiologic processes. This study aimed to delineate the transcriptional regulation of AQP1 by Mef2c in endothelial cells. Mef2c cooperated with Sp1 to activate human AQP1 transcription by binding to its proximal promoter in human umbilical cord vein endothelial cells (HUVEC). Over-expression of Mef2c, Sp1, or Mef2c/Sp1 increased HUVEC migration and tube-forming ability, which can be abolished AQP1 knockdown. These data indicate that AQP1 is a direct target of Mef2c in regulating angiogenesis and vasculogenesis of endothelial cells. PMID:26923194

  2. High specific surface area Mo2C nanoparticles as an efficient electrocatalyst for hydrogen evolution

    NASA Astrophysics Data System (ADS)

    Tang, Chaoyun; Sun, Aokui; Xu, Yushuai; Wu, Zhuangzhi; Wang, Dezhi

    2015-11-01

    Mo2C nanoparticles with high specific surface area (120 m2 g-1) are successfully synthesized using a typical and low-cost monosaccharide of glucose via a facile calcination and subsequent reduction process. The HER functions of the obtained Mo2C nanoparticles are investigated and the effect of reduction time in hydrogen is also discussed. It is found that η-MoC can be obtained at 800 °C with a reduction time of 10 min, but the formation of β-Mo2C phase requires more than 20 min. Moreover, the β-Mo2C obtained with a reduction time of 20 min exhibits the best HER activity with a small Tafel slope of 55 mV dec-1 and a large current density of 60 mA cm-2 at -200 mV, which is among the best records over Mo2C-based HER catalysts.

  3. Phosphoinositide system-linked serotonin receptor subtypes and their pharmacological properties and clinical correlates.

    PubMed Central

    Pandey, S C; Davis, J M; Pandey, G N

    1995-01-01

    Serotonergic neurotransmission represents a complex mechanism involving pre- and post-synaptic events and distinct 5-HT receptor subtypes. Serotonin (5-HT) receptors have been classified into several categories, and they are termed as 5-HT1, 5-HT2, 5-HT3, 5-HT4, 5-HT5, 5-HT6 and 5-HT7 type receptors. 5-HT1 receptors have been further subdivided into 5-HT1A, 5-HT1B, 5-HT1D, 5-HT1E and 5-HT1F. 5-HT2 receptors have been divided into 5-HT2A, 5-HT2B and 5-HT2C receptors. All 5-HT2 receptor subtypes are linked to the multifunctional phosphoinositide (PI) signalling system. 5-HT3 receptors are considered ion-gated receptors and are also linked to the PI signalling system by an unknown mechanism. The 5-HT2A receptor subtype is the most widely studied of the 5-HT receptors in psychiatric disorders (for example, suicide, depression and schizophrenia) as well as in relation to the mechanism of action of antidepressant drugs. The roles of 5-HT2C and 5-HT3 receptors in psychiatric disorders are less clear. These 5-HT receptors also play an important role in alcoholism. It has been shown that 5-HT2A, 5-HT2C and 5-HT3 antagonists cause attenuation of alcohol intake in animals and humans. However, the exact mechanisms are unknown. The recent cloning of the cDNAs for 5-HT2A, 5-HT2C and 5-HT3 receptors provides the opportunity to explore the molecular mechanisms responsible for the alterations in these receptors during illness as well as pharmacotherapy. This review article will focus on the current research into the pharmacological properties, molecular biology, and clinical correlates of 5-HT2A, 5-HT2C and 5-HT3 receptors. PMID:7786883

  4. Transcriptional regulation of SlPYL, SlPP2C, and SlSnRK2 gene families encoding ABA signal core components during tomato fruit development and drought stress

    PubMed Central

    Sun, Liang; Wang, Yan-Ping; Chen, Pei; Ren, Jie; Ji, Kai; Li, Qian; Li, Ping; Dai, Sheng-Jie; Leng, Ping

    2011-01-01

    In order to characterize the potential transcriptional regulation of core components of abscisic acid (ABA) signal transduction in tomato fruit development and drought stress, eight SlPYL (ABA receptor), seven SlPP2C (type 2C protein phosphatase), and eight SlSnRK2 (subfamily 2 of SNF1-related kinases) full-length cDNA sequences were isolated from the tomato nucleotide database of NCBI GenBank. All SlPYL, SlPP2C, and SlSnRK2 genes obtained are homologous to Arabidopsis AtPYL, AtPP2C, and AtSnRK2 genes, respectively. Based on phylogenetic analysis, SlPYLs and SlSnRK2s were clustered into three subfamilies/subclasses, and all SlPP2Cs belonged to PP2C group A. Within the SlPYL gene family, SlPYL1, SlPYL2, SlPYL3, and SlPYL6 were the major genes involved in the regulation of fruit development. Among them, SlPYL1 and SlPYL2 were expressed at high levels throughout the process of fruit development and ripening; SlPYL3 was strongly expressed at the immature green (IM) and mature green (MG) stages, while SlPYL6 was expressed strongly at the IM and red ripe (RR) stages. Within the SlPP2C gene family, the expression of SlPP2C, SlPP2C3, and SlPP2C4 increased after the MG stage; SlPP2C1 and SlPP2C5 peaked at the B3 stage, while SlPP2C2 and SlPP2C6 changed little during fruit development. Within the SlSnRK2 gene family, the expression of SlSnRK2.2, SlSnRK2.3, SlSnRK2.4, and SlSnRK2C was higher than that of other members during fruit development. Additionally, most SlPYL genes were down-regulated, while most SlPP2C and SlSnRK2 genes were up-regulated by dehydration in tomato leaf. PMID:21873532

  5. In silico description of differential enantioselectivity in methoxychlor O-demethylation by CYP2C enzymes.

    PubMed

    Bikádi, Zsolt; Hazai, Eszter

    2008-09-01

    Methoxychlor undergoes metabolism by cytochrome P450 (CYP) enzymes forming a chiral mono-phenolic derivative (Mono-OH-M) as main metabolite. In the current study, members of the CYP2C family were examined for their chiral preference in Mono-OH-M formation. CYP2C9 and CYP2C19 possessed high enantioselectivity favoring the formation of S-Mono-OH-M; CYP2C3 showed no enantioselectivity, whereas CYP2C5 slightly favored the formation of R-Mono-OH-M. Molecular modeling calculations were utilized in order to explain the observed differences in chiral preference of CYP2C enzymes. Molecular docking calculations could describe neither the existence of chiral preference in metabolism, nor the enantiomer which is preferentially formed. Molecular dynamic calculations were also carried out and were found to be useful for accurate description of chiral preference in biotransformation of methoxychlor by CYP2C enzymes. An in silico model capable of predicting chiral preference in cytochrome P450 enzymes in general can be developed based on the analysis of the stability and rigidity parameters of interacting partners during molecular dynamic simulation.

  6. MEF2C regulates cortical inhibitory and excitatory synapses and behaviors relevant to neurodevelopmental disorders

    PubMed Central

    Harrington, Adam J; Raissi, Aram; Rajkovich, Kacey; Berto, Stefano; Kumar, Jaswinder; Molinaro, Gemma; Raduazzo, Jonathan; Guo, Yuhong; Loerwald, Kris; Konopka, Genevieve; Huber, Kimberly M; Cowan, Christopher W

    2016-01-01

    Numerous genetic variants associated with MEF2C are linked to autism, intellectual disability (ID) and schizophrenia (SCZ) – a heterogeneous collection of neurodevelopmental disorders with unclear pathophysiology. MEF2C is highly expressed in developing cortical excitatory neurons, but its role in their development remains unclear. We show here that conditional embryonic deletion of Mef2c in cortical and hippocampal excitatory neurons (Emx1-lineage) produces a dramatic reduction in cortical network activity in vivo, due in part to a dramatic increase in inhibitory and a decrease in excitatory synaptic transmission. In addition, we find that MEF2C regulates E/I synapse density predominantly as a cell-autonomous, transcriptional repressor. Analysis of differential gene expression in Mef2c mutant cortex identified a significant overlap with numerous synapse- and autism-linked genes, and the Mef2c mutant mice displayed numerous behaviors reminiscent of autism, ID and SCZ, suggesting that perturbing MEF2C function in neocortex can produce autistic- and ID-like behaviors in mice. DOI: http://dx.doi.org/10.7554/eLife.20059.001 PMID:27779093

  7. Common variants in the CYP2C19 gene are associated with susceptibility to endometriosis

    PubMed Central

    Painter, Jodie N; Nyholt, Dale R; Krause, Lutz; Zhao, Zhen Z; Chapman, Brett; Zhang, Christine; Medland, Sarah; Martin, Nicholas G; Kennedy, Stephen; Treloar, Susan; Zondervan, Krina; Montgomery, Grant W

    2014-01-01

    Objective To follow-up previous studies highlighting a possible role for cytochrome P450, family 2, subfamily C, 19 (CYP2C19) in susceptibility to endometriosis by searching for additional variants in the CYP2C19 gene that may be associated with the disease. Design Case-control study. Setting Academic research. Subject(s) Cases = 2,271 women with surgically confirmed endometriosis; Controls = 939 women with self-report of no endometriosis and 1,770 unscreened population samples. Intervention(s) Sequencing of the CYP2C19 region and follow-up of 80 SNPs in two case-control samples. Main outcome measure(s) Allele frequency differences between cases and controls. Results Sequencing of the CYP2C19 gene region resulted in the detection of a large number of known and novel SNPs. Genotyping of 80 polymorphic SNPs in 901 endometriosis cases and 939 controls resulted in study-wide significant association signals for SNPs in moderate or complete LD with rs4244285, a functional SNP in exon 5 that abrogates CYP2C19 function through the creation of an alternative splice site. Evidence of association was also detected for another functional SNP in the CYP2C19 promoter, rs12248560, highlighted in our previous study. Conclusion(s) Functional variants in CYP2C19 may contribute to endometriosis susceptibility in both familial and sporadic cases. PMID:24796765

  8. The role of CYP2C9 genetic polymorphism in carvedilol O-desmethylation in vitro.

    PubMed

    Pan, Pei-Pei; Weng, Qing-Hua; Zhou, Chen-Jian; Wei, Yan-Li; Wang, Li; Dai, Da-Peng; Cai, Jian-Ping; Hu, Guo-Xin

    2016-02-01

    We aimed at investigating the role of CYP2C9 in carvedilol O-desmethylation and identifying the effect of 35 CYP2C9 allelic variants we found in Chinese Han population on the in vitro metabolism of carvedilol. Recombinant CYP2C9 and CYP2D6 microsomes of the wild type were used to test and verify the enzymes involved in carvedilol O-desmethylation. Recombinant CYP2C9 microsomes of distinguished genotypes were used to characterize the corresponding enzyme activity toward carvedilol. 2-100 μM carvedilol was incubated for 30 min at 37 °C. The products were detected using high-performance liquid chromatography. CYP2C9 plays a certain role in carvedilol metabolism. Compared with wild-type CYP2C9*1, the intrinsic clearance (V max/K m) values of all variants toward carvedilol O-desmethylation were significantly altered. The variants exhibited significantly decreased values (from 30 to 99.8 %) due to increased K m and/or decreased V max values. We conclude that recombinant system could be used to investigate the enzymes involved in drug metabolism and these findings complement the database where CYP2C9 polymorphism interacts with biotransformation of exogenous substances like drugs and toxins.

  9. Mechanism of CYP2C9 inhibition by flavones and flavonols.

    PubMed

    Si, Dayong; Wang, Ying; Zhou, Yi-Han; Guo, Yingjie; Wang, Juan; Zhou, Hui; Li, Ze-Sheng; Fawcett, J Paul

    2009-03-01

    This article describes an in vitro investigation of the inhibition of cytochrome P450 (P450) 2C9 by a series of flavonoids made up of flavones (flavone, 6-hydroxyflavone, 7-hydroxyflavone, chrysin, baicalein, apigenin, luteolin, scutellarein, and wogonin) and flavonols (galangin, fisetin, kaempferol, morin, and quercetin). With the exception of flavone, all flavonoids were shown to inhibit CYP2C9-mediated diclofenac 4'-hydroxylation in the CYP2C9 RECO system, with K(i) value 2C9, whereas the other flavonoids were competitive inhibitors. Computer docking simulation and constructed mutants substituted at residue 100 of CYP2C9.1 indicate that the noncompetitive binding site of 6-hydroxyflavone lies beside Phe100, similar to the reported allosteric binding site of warfarin. The other flavonoids exert competitive inhibition through interaction with the substrate binding site of CYP2C9 accessed by flurbiprofen. These results suggest flavonoids can participate in interactions with drugs that act as substrates for CYP2C9 and provide a possible molecular basis for understanding cooperativity in human P450-mediated drug-drug interactions. PMID:19074529

  10. Identification of cytochrome P450 2C2 protein complexes in mouse liver.

    PubMed

    Li, Bin; Yau, Peter; Kemper, Byron

    2011-08-01

    Interactions of microsomal cytochromes P450 (CYPs) with other proteins in the microsomal membrane are important for their function. In addition to their redox partners, CYPs have been reported to interact with other proteins not directly involved in their enzymatic function. In this study, proteins were identified that interact with CYP2C2 in vivo in mouse liver. Flag-tagged CYP2C2 was expressed exogenously in mouse liver and was affinity purified, along with associated proteins which were identified by MS and confirmed by Western blotting. Over 20 proteins reproducibly copurified with CYP2C2. The heterogeneous sedimentation velocity of CYP2C2 and associated proteins by centrifugation in sucrose gradients and sequential immunoprecipitation analysis were consistent with multiple CYP2C2 complexes of differing composition. The abundance of CYPs and other drug metabolizing enzymes and NAD/NADP requiring enzymes associated with CYP2C2 suggest that complexes of these proteins may improve enzymatic efficiency or facilitate sequential metabolic steps. Chaperones, which may be important for maintaining CYP function, and reticulons, endoplasmic reticulum proteins that shape the morphology of the endoplasmic reticulum and are potential endoplasmic reticulum retention proteins for CYPs, were also associated with CYP2C2.

  11. Ab initio calculations of optical properties of B2C graphene sheet

    NASA Astrophysics Data System (ADS)

    Shahrokhi, Masoud; Naderi, Sirvan; Fathalian, Ali

    2012-06-01

    The electronic and the linear optical properties of a monolayer B2C graphene sheet are investigated through the density functional theory. The dielectric tensor is derived within the random phase approximation (RPA). Specifically, the dielectric function, absorption coefficient, optical conductivity, extinction index, loss function, reflectivity, and the refraction index of the monolayer B2C graphene sheet are calculated for both parallel and perpendicular electric field polarizations. The results show that the optical spectra are anisotropic along these two polarizations. For the electric field parallel to monolayer B2C graphene E∥x, adding the intraband transitions contribution, will change the optical spectra of a monolayer B2C graphene sheet significantly, while in the electric field perpendicular to monolayer B2C graphene E∥z did not change. Adding the intraband transitions contribution shows that the dielectric function has singularity at zero frequency because of the metallic behavior of a monolayer B2C graphene sheet. Also by considering the intraband transitions contribution for energy loss function in the electric field parallel to monolayer B2C graphene, the first plasmon frequency peak has been shifted from 2.76 eV to 4 eV.

  12. Nek2C functions as a tumor promoter in human breast tumorigenesis.

    PubMed

    Liu, Ziyu; Wang, Yahong; Wang, Shuling; Zhang, Jing; Zhang, Fei; Niu, Yun

    2012-10-01

    The serine⁄threonine kinase Nek2 has been proposed as a requirement for the progression of breast cancer. The aim of this study was to investigate the expression of Nek2C, which is a splice variant of Nek2, and the role it plays in the different stages of breast cancer. We investigated the role of Nek2C in the MCF10 breast cancer cell lines, MCF10A, MCF10AT, MCF10DCIS.com and MCF10CA1a, using RNA interference and plasmid transfection, as well as breast tissue samples of normal breast tissue (NBT), atypical ductal hyperplasia (ADH), ductal carcinoma in situ (DCIS) and invasive ductal carcinoma (IDC). We detected the mRNA Nek2C expression levels in the MCF10 cell lines and in human breast samples. Our results revealed that the mRNA expression of Nek2C was significantly upregulated in the MCF10DCIS.com and MCF10CA1a cell lines as well as in human primary breast cancer tissue (DCIS and IDC). As expected, the Nek2C downregulation, using RNA interference, decreased the survival, invasion and migration of MCF10DCIS.com and MCF10CA1a cells. Consistent with these results, the Nek2C upregulation in MCF10A and MCF10AT cells using plasmid transfection increased the survival ability of these cells. Our results also revealed a correlation between Nek2C mRNA expression levels and tumor grade. Taken together, our findings suggest that Nek2C plays a signicficant role in breast cancer development and that Nek2C inhibition may be a useful therapeutic approach to targeting human breast tumors.

  13. A Case of Intolerance to Warfarin Dosing in an Intermediate Metabolizer of CYP2C9

    PubMed Central

    Lee, Soo-Youn; Kim, June Soo

    2005-01-01

    We report a case of intolerance to warfarin dosing due to impaired drug metabolism in a patient heterozygous for the CYP2C9*3 allele. A 30-year-old woman with an artificial cardiac pacemaker was taking warfarin to prevent thromboembolism. This patient had an extremely elevated international normalized ratio (INR) of prothrombin time (PT) following standard doses of warfarin and experienced difficulties during the induction of anticoagulation. Genotyping for CYP2C9 revealed that this patient was an intermediate metabolizer with genotype CYP2C9*1/*3. This case suggests the clinical usefulness of pharmacogenetic testing for individualized dosage adjustments of warfarin. PMID:16385662

  14. Tumor Radiation Therapy Creates Therapeutic Vaccine Responses to the Colorectal Cancer Antigen GUCY2C

    SciTech Connect

    Witek, Matthew; Blomain, Erik S.; Magee, Michael S.; Xiang, Bo; Waldman, Scott A.; Snook, Adam E.

    2014-04-01

    Purpose: Radiation therapy (RT) is thought to produce clinical responses in cancer patients, not only through direct toxicity to cancer cells and supporting tumor stroma cells, but also through activation of immunologic effectors. More recently, RT has potentiated the local and systemic effects of cancer immunotherapy (IT). However, combination regimens that maximize immunologic and clinical efficacy remain undefined. Methods and Materials: We evaluated the impact of local RT on adenoviral-mediated vaccination against the colorectal cancer antigen GUCY2C (Ad5-GUCY2C) in a murine subcutaneous tumor model using mouse CT26 colon cancer cells (CT26-GUCY2C). Immune responses were assessed by ELISpot, and clinical responses were assessed by tumor size and incidence. Results: The specific sequence of tumor-directed RT preceding Ad5-GUCY2C IT transformed inactive therapeutic Ad5-GUCY2C vaccination into a curative vaccine. GUCY2C-specific T cell responses were amplified (P<.05), tumor eradication was maximized (P<.01), and tumor volumes were minimized (P<.001) in mice whose tumors were irradiated before, compared with after, Ad5-GUCY2C vaccination. The immunologic and antitumor efficacy of Ad5-GUCY2C was amplified comparably by unfractionated (8 Gy × 1), or biologically equivalent doses of fractionated (3.5 Gy × 3), RT. The antitumor effects of sequential RT and IT (RT-IT) depended on expression of GUCY2C by tumor cells and the adenoviral vaccine vector, and tumor volumes were inversely related to the magnitude of GUCY2C-specific T cell responses. Moreover, mice cured of CT26-GUCY2C tumors by RT-IT showed long-lasting antigen-dependent protection, resisting tumors formed by GUCY2C-expressing 4T1 breast cancer cells inoculated 50 days after CT26 cells. Conclusions: Optimal sequencing of RT and IT amplifies antigen-specific local and systemic immune responses, revealing novel acute and long-term therapeutic antitumor protection. These observations underscore the importance

  15. Inactive alleles of cytochrome P450 2C19 may be positively selected in human evolution

    PubMed Central

    2014-01-01

    Background Cytochrome P450 CYP2C19 metabolizes a wide range of pharmacologically active substances and a relatively small number of naturally occurring environmental toxins. Poor activity alleles of CYP2C19 are very frequent worldwide, particularly in Asia, raising the possibility that reduced metabolism could be advantageous in some circumstances. The evolutionary selective forces acting on this gene have not previously been investigated. We analyzed CYP2C19 genetic markers from 127 Gambians and on 120 chromosomes from Yoruba, Europeans and Asians (Japanese + Han Chinese) in the Hapmap database. Haplotype breakdown was explored using bifurcation plots and relative extended haplotype homozygosity (REHH). Allele frequency differentiation across populations was estimated using the fixation index (FST) and haplotype diversity with coalescent models. Results Bifurcation plots suggested conservation of alleles conferring slow metabolism (CYP2C19*2 and *3). REHH was high around CYP2C19*2 in Yoruba (REHH 8.3, at 133.3 kb from the core) and to a lesser extent in Europeans (3.5, at 37.7 kb) and Asians (2.8, at −29.7 kb). FST at the CYP2C19 locus was low overall (0.098). CYP2C19*3 was an FST outlier in Asians (0.293), CYP2C19 haplotype diversity < = 0.037, p <0.001. Conclusions We found some evidence that the slow metabolizing allele CYP2C19*2 is subject to positive selective forces worldwide. Similar evidence was also found for CYP2C19*3 which is frequent only in Asia. FST is low at the CYP2C19 locus, suggesting balancing selection overall. The biological factors responsible for these selective pressures are currently unknown. One possible explanation is that early humans were exposed to a ubiquitous novel toxin activated by CYP2C19. The genetic adaptation took place within the last 10,000 years which coincides with the development of systematic agricultural practices. PMID:24690327

  16. First-principles study of hydrogen storage on Ti-decorated B2C sheet

    NASA Astrophysics Data System (ADS)

    Guo, Y. H.; Xu, B.; Xia, Y. D.; Yin, J.; Liu, Z. G.

    2012-06-01

    The hydrogen storage capacity of Ti decorated B2C sheet has been investigated by first-principles plane-wave calculation. It is revealed that a single Ti atom adsorbed on the B2C sheet can strongly bind up to four hydrogen molecules. The adsorption energy is in the range of -0.36--0.82 eV/H2, which is suitable for ambient temperature hydrogen storage. Considering the fact that Ti can be loaded on both sides of B2C sheet, corresponding gravimetric storage capacity of Ti/B2C system was also calculated and it can reach to about 7.0 wt%, exceeding the minimum requirement of 6.0 wt% for applications.

  17. Somatostatin receptors.

    PubMed

    Srikant, C B; Patel, Y C

    1985-01-01

    It is now well established that the biological actions of tetradecapeptide somatostatin (somatostatin-14, S-14) are receptor-mediated. These receptors were first quantified in GH4C pituitary tumor cells using [125I-Tyr1] S-14 as radioligand which was found to exhibit high non-specific binding to membrane receptor preparations from normal tissues. Our studies have shown that [125I-Tyr11] S-14 in which the radiolabel is situated away from the N-terminus exhibits significantly lower non-specific binding and therefore is more suitable for S-14 receptor studies. In the CNS, highest concentration of S-14 receptors was found in the cerebral cortex, followed by thalamus, hypothalamus, striatum, amygdala and hippocampus while medulla-pons, cerebellum and spinal cord exhibited negligible binding. Outside the CNS membrane receptors for S-14 have been characterized in pituitary, adrenal cortex and pancreatic acini. In all these tissues a single class of high affinity binding sites for S-14 were present, the receptors in pancreatic acinar cells exhibiting significantly greater affinity for binding S-14 than in other tissues.

  18. Engineering Macaca fascicularis cytochrome P450 2C20 to reduce animal testing for new drugs.

    PubMed

    Rua, Francesco; Sadeghi, Sheila J; Castrignanò, Silvia; Di Nardo, Giovanna; Gilardi, Gianfranco

    2012-12-01

    In order to develop in vitro methods as an alternative to P450 animal testing in the drug discovery process, two main requisites are necessary: 1) gathering of data on animal homologues of the human P450 enzymes, currently very limited, and 2) bypassing the requirement for both the P450 reductase and the expensive cofactor NADPH. In this work, P450 2C20 from Macaca fascicularis, homologue of the human P450 2C8 has been taken as a model system to develop such an alternative in vitro method by two different approaches. In the first approach called "molecular Lego", a soluble self-sufficient chimera was generated by fusing the P450 2C20 domain with the reductase domain of cytochrome P450 BM3 from Bacillus megaterium (P450 2C20/BMR). In the second approach, the need for the redox partner and also NADPH were both obviated by the direct immobilization of the P450 2C20 on glassy carbon and gold electrodes. Both systems were then compared to those obtained from the reconstituted P450 2C20 monooxygenase in presence of the human P450 reductase and NADPH using paclitaxel and amodiaquine, two typical drug substrates of the human P450 2C8. The K(M) values calculated for the 2C20 and 2C20/BMR in solution and for 2C20 immobilized on electrodes modified with gold nanoparticles were 1.9 ± 0.2, 5.9 ± 2.3, 3.0 ± 0.5 μM for paclitaxel and 1.2 ± 0.2, 1.6±0.2 and 1.4 ± 0.2 μM for amodiaquine, respectively. The data obtained not only show that the engineering of M. fascicularis did not affect its catalytic properties but also are consistent with K(M) values measured for the microsomal human P450 2C8 and therefore show the feasibility of developing alternative in vitro animal tests.

  19. An ANFIS-based on B2C electronic commerce transaction

    SciTech Connect

    Lin, Juan; Liu, Chenlian; Guo, Yongning

    2014-10-06

    The purpose of this study is to use an adaptive-network-based fuzzy inference system to model a fuzzy logic-based system (FIS) for supporting decision-making process in B2C electronic commerce transaction. Firstly we introduce FIS in B2C electronic commerce transaction and ANFIS. Then we use ANFIS to model FIS with different membership functions(MF). Lastly we give a conclusion.

  20. An ANFIS-based on B2C electronic commerce transaction

    NASA Astrophysics Data System (ADS)

    Lin, Juan; Liu, Chenlian; Guo, Yongning

    2014-10-01

    The purpose of this study is to use an adaptive-network-based fuzzy inference system to model a fuzzy logic-based system (FIS) for supporting decision-making process in B2C electronic commerce transaction. Firstly we introduce FIS in B2C electronic commerce transaction and ANFIS. Then we use ANFIS to model FIS with different membership functions(MF). Lastly we give a conclusion.

  1. Electronic structure and geometry optimization of nanoparticles Fe 2C, FeC 2, Fe 3C, FeC 3 and Fe 2C 2

    NASA Astrophysics Data System (ADS)

    Ryzhkov, Mikhail V.; Ivanovskii, Alexander L.; Delley, Bernard T.

    2005-03-01

    The geometry optimization of the beginning of the row of Fe nC m nanoparticles was carried out using the DFT based DMol 3 method. For FeC 2 and Fe 2C the triangular configurations are found to have the lowest binding energy. The most stable planar structures for FeC 3 and Fe 2C 2 are favored over the three-dimensional isomers, whereas for Fe 3C the pyramidal configuration appeared to be the ground state. The effective charges and total spin densities on the atoms were calculated using integral and Mulliken schemes incorporated in DVM and Hirshfeld procedure of DMol 3. The most reasonable values were obtained with the use of integral method.

  2. Pharmacokinetic assessment of a five-probe cocktail for CYPs 1A2, 2C9, 2C19, 2D6 and 3A

    PubMed Central

    Turpault, Sandrine; Brian, William; Van Horn, Robert; Santoni, Alix; Poitiers, Franck; Donazzolo, Yves; Boulenc, Xavier

    2009-01-01

    AIMS To assess the pharmacokinetics (PK) of selective substrates of CYP1A2 (caffeine), CYP2C9 (S-warfarin), CYP2C19 (omeprazole), CYP2D6 (metoprolol) and CYP3A (midazolam) when administered orally and concurrently as a cocktail relative to the drugs administered alone. METHODS This was an open-label, single-dose, randomized, six-treatment six-period six-sequence William's design study with a wash-out of 7 or 14 days. Thirty healthy male subjects received 100 mg caffeine, 100 mg metoprolol, 0.03 mg kg−1 midazolam, 20 mg omeprazole and 10 mg warfarin individually and in combination (cocktail). Poor metabolizers of CYP2C9, 2C19 and 2D6 were excluded. Plasma samples were obtained up to 48 h for caffeine, metoprolol and omeprazole, 12 h for midazolam, 312 h for warfarin and the cocktail. Three different validated liquid chromatography tandem mass spectrometry methods were used. Noncompartmental PK parameters were calculated. Log-transformed Cmax, AUClast and AUC for each analyte were analysed with a linear mixed effects model with fixed term for treatment, sequence and period, and random term for subject within sequence. Point estimates (90% CI) for treatment ratios (individual/cocktail) were computed for each analyte Cmax, AUClast and AUC. RESULTS There was no PK interaction between the probe drugs when administered in combination as a cocktail, relative to the probes administered alone, as the 90% CI of the PK parameters was within the prespecified bioequivalence limits of 0.80, 1.25. CONCLUSION The lack of interaction between probes indicates that this cocktail could be used to evaluate the potential for multiple drug–drug interactions in vivo. PMID:20002088

  3. A new 2D monolayer BiXene, M2C (M = Mo, Tc, Os).

    PubMed

    Sun, Weiwei; Li, Yunguo; Wang, Baotian; Jiang, Xue; Katsnelson, Mikhail I; Korzhavyi, Pavel; Eriksson, Olle; Di Marco, Igor

    2016-08-25

    The existence of BiXenes, a new family of 2D monolayers, is hereby predicted. Theoretically, BiXenes have 1H symmetry (P6[combining macron]m2) and can be formed from the 4d/5d binary carbides. As the name suggests, they are close relatives of MXenes, which instead have 1T symmetry (P3[combining macron]m1). The newly found BiXenes, as well as some new MXenes, are shown to have formation energies close to that of germanene, which suggests that these materials should be possible to be synthesised. Among them, we illustrate that 1H-Tc2C and 1T-Mo2C are dynamically stable at 0 K, while 1H-Mo2C, 1T-Tc2C, 1H-Os2C, and 1T-Rh2C are likely to be stabilised via strain or temperature. In addition, the nature of the chemical bonding is analysed, emphasizing that the covalency between the transition metal ions and carbon is much stronger in BiXenes than in MXenes. The emergence of BiXenes can not only open up a new era of conducting 2D monolayers, but also provide good candidates for carrier materials aimed at energy storage and spintronic devices that have already been unveiled in MXenes. PMID:27528499

  4. First astronomical detection of the cumulene carbon chain molecule H2C6 in TMC-1

    NASA Technical Reports Server (NTRS)

    Langer, W. D.; Velusamy, T.; Kuiper, T. B.; Peng, R.; McCarthy, M. C.; Travers, M. J.; Kovacs, A.; Gottlieb, C. A.; Thaddeus, P.; Levin, S. M. (Principal Investigator)

    1997-01-01

    The cumulene carbenes are important components of hydrocarbon chemistry in low-mass star-forming cores. Here we report the first astronomical detection of the long-chain cumulene carbene H2C6 in the interstellar cloud TMC-1, from observations of two of its rotational transitions: J(K,K') = 7(1,7) --> 6(1,6) at 18.8 GHz and 8(1,8) --> 7(1,7) at 21.5 GHz, using NASA's Deep Space Network 70 m antenna at Goldstone, California. In addition we also observed the shorter cumulene carbene H2C4 at the same position. The fractional abundance of H2C6 relative to H2 is about 4.7 x 10(-11) and that of H2C4 is about 4.1 x 10(-9). The abundance of H2C6 is in fairly good agreement with gas-phase chemical models for young molecular cloud cores, but the abundance of H2C4 is significantly larger than predicted.

  5. The transcription factor MEF2C mediates cardiomyocyte hypertrophy induced by IGF-1 signaling

    SciTech Connect

    Munoz, Juan Pablo; Collao, Andres; Chiong, Mario; Maldonado, Carola; Adasme, Tatiana; Carrasco, Loreto; Ocaranza, Paula; Bravo, Roberto; Gonzalez, Leticia; Diaz-Araya, Guillermo; Hidalgo, Cecilia; Lavandero, Sergio

    2009-10-09

    Myocyte enhancer factor 2C (MEF2C) plays an important role in cardiovascular development and is a key transcription factor for cardiac hypertrophy. Here, we describe MEF2C regulation by insulin-like growth factor-1 (IGF-1) and its role in IGF-1-induced cardiac hypertrophy. We found that IGF-1 addition to cultured rat cardiomyocytes activated MEF2C, as evidenced by its increased nuclear localization and DNA binding activity. IGF-1 stimulated MEF2 dependent-gene transcription in a time-dependent manner, as indicated by increased MEF2 promoter-driven reporter gene activity; IGF-1 also induced p38-MAPK phosphorylation, while an inhibitor of p38-MAPK decreased both effects. Additionally, inhibitors of phosphatidylinositol 3-kinase and calcineurin prevented IGF-1-induced MEF2 transcriptional activity. Via MEF2C-dependent signaling, IGF-1 also stimulated transcription of atrial natriuretic factor and skeletal {alpha}-actin but not of fos-lux reporter genes. These novel data suggest that MEF2C activation by IGF-1 mediates the pro-hypertrophic effects of IGF-1 on cardiac gene expression.

  6. The transcription factor MEF2C mediates cardiomyocyte hypertrophy induced by IGF-1 signaling.

    PubMed

    Muñoz, Juan Pablo; Collao, Andres; Chiong, Mario; Maldonado, Carola; Adasme, Tatiana; Carrasco, Loreto; Ocaranza, Paula; Bravo, Roberto; Gonzalez, Leticia; Díaz-Araya, Guillermo; Hidalgo, Cecilia; Lavandero, Sergio

    2009-10-01

    Myocyte enhancer factor 2C (MEF2C) plays an important role in cardiovascular development and is a key transcription factor for cardiac hypertrophy. Here, we describe MEF2C regulation by insulin-like growth factor-1 (IGF-1) and its role in IGF-1-induced cardiac hypertrophy. We found that IGF-1 addition to cultured rat cardiomyocytes activated MEF2C, as evidenced by its increased nuclear localization and DNA binding activity. IGF-1 stimulated MEF2 dependent-gene transcription in a time-dependent manner, as indicated by increased MEF2 promoter-driven reporter gene activity; IGF-1 also induced p38-MAPK phosphorylation, while an inhibitor of p38-MAPK decreased both effects. Additionally, inhibitors of phosphatidylinositol 3-kinase and calcineurin prevented IGF-1-induced MEF2 transcriptional activity. Via MEF2C-dependent signaling, IGF-1 also stimulated transcription of atrial natriuretic factor and skeletal alpha-actin but not of fos-lux reporter genes. These novel data suggest that MEF2C activation by IGF-1 mediates the pro-hypertrophic effects of IGF-1 on cardiac gene expression. PMID:19654000

  7. Influence of CYP2C8 polymorphisms on the hydroxylation metabolism of paclitaxel, repaglinide and ibuprofen enantiomers in vitro.

    PubMed

    Yu, Lushan; Shi, Da; Ma, Liping; Zhou, Quan; Zeng, Su

    2013-07-01

    CYP2C8 plays an important role in the metabolism of various drugs, such as paclitaxel, repaglinide and ibuprofen. Polymorphisms in the CYP2C8 gene were shown to influence interindividual differences in the pharmacokinetics of paclitaxel, repaglinide and ibuprofen enantiomers. In this study, three CYP2C8 allelic variants (CYP2C8.2, CYP2C8.3 and CYP2C8.4) and wild-type CYP2C8 (CYP2C8.1) were co-expressed for the first time with human cytochrome P450 oxidoreductase (POR) and cytochrome b5 by using a baculovirus-assisted insect cell expression system. Further, the effects of genotype-phenotype correlations of CYP2C8 alleles on the metabolism of paclitaxel, repaglinide and ibuprofen enantiomers were evaluated. The CLint values of CYP2C8.2, CYP2C8.3 and CYP2C8.4 for paclitaxel were 47.7%, 64.3% and 30.2% of that of CYP2C8.1 (p<0.01). The CLint values of CYP2C8.2 and CYP2C8.4 for repaglinide were 77.9% and 80.2% of that of CYP2C8.1 (p<0.05), respectively, while the CLint value of CYP2C8.3 was 1.31-fold higher than that of CYP2C8.1 (p<0.05). The relative CLint values of CYP2C8.2, CYP2C8.3 and CYP2C8.4 were 110.5%, 72.3% and 49.7% of that of CYP2C8.1 and were 124.6%, 83.4% and 47.4% of that of CYP2C8.1 for R-ibuprofen and S-ibuprofen, respectively. Comparing hydroxylation by CYP2C8.1 and CYP2C8.3 resulted in higher and lower intrinsic clearance of repaglinide and ibuprofen enantiomers, respectively. These in vitro findings were consistent with the pharmacokinetics in volunteers who were heterozygous or homozygous carriers of CYP2C8*3. The results of this study provide useful information for predicting CYP2C8 phenotypes and may contribute to individualized drug therapy in the future.

  8. Dehydroepiandrosterone activates AMP kinase and regulates GLUT4 and PGC-1α expression in C2C12 myotubes

    SciTech Connect

    Yokokawa, Takumi; Sato, Koji; Iwanaka, Nobumasa; Honda, Hiroki; Higashida, Kazuhiko; Iemitsu, Motoyuki; Hayashi, Tatsuya; Hashimoto, Takeshi

    2015-07-17

    Exercise and caloric restriction (CR) have been reported to have anti-ageing, anti-obesity, and health-promoting effects. Both interventions increase the level of dehydroepiandrosterone (DHEA) in muscle and blood, suggesting that DHEA might partially mediate these effects. In addition, it is thought that either 5′-adenosine monophosphate-activated protein kinase (AMPK) or peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α) mediates the beneficial effects of exercise and CR. However, the effects of DHEA on AMPK activity and PGC-1α expression remain unclear. Therefore, we explored whether DHEA in myotubes acts as an activator of AMPK and increases PGC-1α. DHEA exposure increased glucose uptake but not the phosphorylation levels of Akt and PKCζ/λ in C2C12 myotubes. In contrast, the phosphorylation levels of AMPK were elevated by DHEA exposure. Finally, we found that DHEA induced the expression of the genes PGC-1α and GLUT4. Our current results might reveal a previously unrecognized physiological role of DHEA; the activation of AMPK and the induction of PGC-1α by DHEA might mediate its anti-obesity and health-promoting effects in living organisms. - Highlights: • We assessed whether dehydroepiandrosterone (DHEA) activates AMPK and PGC-1α. • DHEA exposure increased glucose uptake in C2C12 myotubes. • The phosphorylation levels of AMPK were elevated by DHEA exposure. • DHEA induced the expression of the genes PGC-1α and GLUT4. • AMPK might mediate the anti-obesity and health-promoting effects of DHEA.

  9. Overexpression of a novel Arabidopsis PP2C isoform, AtPP2CF1, enhances plant biomass production by increasing inflorescence stem growth.

    PubMed

    Sugimoto, Hiroki; Kondo, Satoshi; Tanaka, Tomoko; Imamura, Chie; Muramoto, Nobuhiko; Hattori, Etsuko; Ogawa, Ken'ichi; Mitsukawa, Norihiro; Ohto, Chikara

    2014-10-01

    In contrast to mammals, higher plants have evolved to express diverse protein phosphatase 2Cs (PP2Cs). Of all Arabidopsis thaliana PP2Cs, members of PP2C subfamily A, including ABI1, have been shown to be key negative regulators of abscisic acid (ABA) signalling pathways, which regulate plant growth and development as well as tolerance to adverse environmental conditions. However, little is known about the enzymatic and signalling roles of other PP2C subfamilies. Here, we report a novel Arabidopsis subfamily E PP2C gene, At3g05640, designated AtPP2CF1. AtPP2CF1 was dramatically expressed in response to exogenous ABA and was expressed in vascular tissues and guard cells, similar to most subfamily A PP2C genes. In vitro enzymatic activity assays showed that AtPP2CF1 possessed functional PP2C activity. However, yeast two-hybrid analysis revealed that AtPP2CF1 did not interact with PYR/PYL/RCAR receptors or three SnRK2 kinases, which are ABI1-interacting proteins. This was supported by homology-based structural modelling demonstrating that the putative active- and substrate-binding site of AtPP2CF1 differed from that of ABI1. Furthermore, while overexpression of ABI1 in plants induced an ABA-insensitive phenotype, Arabidopsis plants overexpressing AtPP2CF1 (AtPP2CF1oe) were weakly hypersensitive to ABA during seed germination and drought stress. Unexpectedly, AtPP2CF1oe plants also exhibited increased biomass yield, mainly due to accelerated growth of inflorescence stems through the activation of cell proliferation and expansion. Our results provide new insights into the physiological significance of AtPP2CF1 as a candidate gene for plant growth production and for potential application in the sustainable supply of plant biomass.

  10. Overexpression of a novel Arabidopsis PP2C isoform, AtPP2CF1, enhances plant biomass production by increasing inflorescence stem growth.

    PubMed

    Sugimoto, Hiroki; Kondo, Satoshi; Tanaka, Tomoko; Imamura, Chie; Muramoto, Nobuhiko; Hattori, Etsuko; Ogawa, Ken'ichi; Mitsukawa, Norihiro; Ohto, Chikara

    2014-10-01

    In contrast to mammals, higher plants have evolved to express diverse protein phosphatase 2Cs (PP2Cs). Of all Arabidopsis thaliana PP2Cs, members of PP2C subfamily A, including ABI1, have been shown to be key negative regulators of abscisic acid (ABA) signalling pathways, which regulate plant growth and development as well as tolerance to adverse environmental conditions. However, little is known about the enzymatic and signalling roles of other PP2C subfamilies. Here, we report a novel Arabidopsis subfamily E PP2C gene, At3g05640, designated AtPP2CF1. AtPP2CF1 was dramatically expressed in response to exogenous ABA and was expressed in vascular tissues and guard cells, similar to most subfamily A PP2C genes. In vitro enzymatic activity assays showed that AtPP2CF1 possessed functional PP2C activity. However, yeast two-hybrid analysis revealed that AtPP2CF1 did not interact with PYR/PYL/RCAR receptors or three SnRK2 kinases, which are ABI1-interacting proteins. This was supported by homology-based structural modelling demonstrating that the putative active- and substrate-binding site of AtPP2CF1 differed from that of ABI1. Furthermore, while overexpression of ABI1 in plants induced an ABA-insensitive phenotype, Arabidopsis plants overexpressing AtPP2CF1 (AtPP2CF1oe) were weakly hypersensitive to ABA during seed germination and drought stress. Unexpectedly, AtPP2CF1oe plants also exhibited increased biomass yield, mainly due to accelerated growth of inflorescence stems through the activation of cell proliferation and expansion. Our results provide new insights into the physiological significance of AtPP2CF1 as a candidate gene for plant growth production and for potential application in the sustainable supply of plant biomass. PMID:25038254

  11. Somatostatin receptors.

    PubMed

    Patel, Y C; Srikant, C B

    1997-12-01

    The diverse biological effects of somatostatin (SRIF) are mediated by a family of G protein-coupled receptors (termed sst) that are encoded by five nonallelic genes located on separate chromosomes. The receptors can be further divided into two subfamilies: sst(2,3,5) react with octapeptide and hexapeptide SRIF analogues and belong to one subclass; sst(1,4) react poorly with these compounds and fall into another subclass. This review focuses on the molecular pharmacology and function of these receptors, with particular emphasis on the ligand-binding domain, subtype-selective analogues, agonist-dependent receptor regulation and desensitization responses, subtype-specific effector coupling, and signal transduction pathways responsible for inhibiting cell secretion and cell growth or induction of apoptosis.

  12. Impact of CYP2C9 genetic polymorphism on warfarin dose requirements in Pakistani population.

    PubMed

    Siddiqi, Aisha; Khan, Dilshad Ahmad; Khan, Farooq Ahmed; Naveed, Abdul Khaliq

    2010-10-01

    Variations of cytochrome-P450 enzyme system (CYP2CP) are associated with impaired metabolism of warfarin. The objective of our study was to estimate the frequency of genetic and allelic variants of CYP2C9 in Punjabi population of Pakistan and their effects on warfarin dose requirement. One hundred and twenty unrelated Pakistani subjects belong to Punjab province, were randomly included from the registry of National Institute of Heart Disease Rawalpindi, Pakistan. The patients had stable international normalized ratio (INR) of 2 to 3 for last 3 months with warfarin therapy after heart valves replacement. The detection of CYP2C9 variant was done on polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) assay. Total 120 patients (73 males; 47 females) of mean age of 37 years participated in the study. Nine patients had mutant allele CYP2C9*3 (7.5%), one CYP2C9*2 (0.8%) and 110 patients exhibited wild type CYP2C9*1 (91.7%). The frequency of CYP2C9 genotype was *1/*1 (0.858) ; *1/*3 (0.117) ; 2/*20 (0.08 ) and *3/*3 (0.017) in our study population. A high dose of warfarin (42.2+9.56) mg/week is required for patients with *1/*1 genotype as compared to patients with *2/*2 (17.5+1.9) and *1/*3 (16.6+2.3) allele (p<0.001). Individuals with CYP2C9*3/3* need lowest (8.75±1.76 mg/week) daily warfarin dose. In conclusion, the genetic variations in the CYP2C9 occur in 14% of Punjabi ethnic group in Pakistan. Presence of CYP2C9*2 or *3 variants is an independent predictor of low warfarin dose requirement in our patients. CYP2C9 variants assay may be used in high risk groups for appropriate dose adjustment to avoid complications on long term basis.

  13. Lipoxin receptors.

    PubMed

    Romano, Mario; Recchia, Irene; Recchiuti, Antonio

    2007-01-01

    Lipoxins (LXs) represent a class of arachidonic acid (AA) metabolites that carry potent immunoregulatory and anti-inflammatory properties, LXA4 and LXB4 being the main components of this series. LXs are generated by cooperation between 5-lipoxygenase (LO) and 12- or 15-LO during cell-cell interactions or by single cell types. LX epimers at carbon 15, the 15-epi-LXs, are formed by aspirin-acetylated cyclooxygenase-2 (COX-2) in cooperation with 5-LO. 15-epi-LXA4 is also termed aspirin-triggered LX (ATL). In vivo studies with stable LX and ATL analogs have established that these eicosanoids possess potent anti-inflammatory activities. A LXA4 receptor has been cloned. It belongs to the family of chemotactic receptors and clusters with formyl peptide receptors on chromosome 19. Therefore, it was initially denominated formyl peptide receptor like 1 (FPRL1). This receptor binds with high affinity and stereoselectivity LXA4 and ATL. It also recognizes a variety of peptides, synthetic, endogenously generated, or disease associated, but with lower affinity compared to LXA4. For this reason, this receptor has been renamed ALX. This review summarizes the current knowledge on ALX expression, signaling, and potential pathophysiological role. The involvement of additional recognition sites in LX bioactions is also discussed. PMID:17767357

  14. Association between cytochrome P450 (CYP) 2C19 polymorphisms and harm avoidance in Japanese.

    PubMed

    Yasui-Furukori, Norio; Kaneda, Ayako; Iwashima, Kumiko; Saito, Manabu; Nakagami, Taku; Tsuchimine, Shoko; Kaneko, Sunao

    2007-09-01

    Polymorphic enzyme cytochrome P450 (CYP) 2C19 is expressed not only in the liver but also in the brain and mediates the biotransformation of 5-hydroxytriptamine (5-HT). We investigated possible association between genetic polymorphism of CYP2C19 and individual personality traits, possibly influenced by neurotransmitters. Mentally and physically healthy Japanese subjects were enrolled in this study (n = 352). Temperament and Character Inventory (TCI) and CYP2C19 genotyping were performed in all subjects. We detected CYP2C19*2 and *3 (http://www.imm.ki.se/CYPalleles/) using Amplichip CYP450 DNA tip. The number of genotypes classified as homozygous extensive metabolizer (EM), heterozygous EM, and poor metabolizer were 113, 181, and 58, respectively. Significant difference was found in TCI score in harm avoidance (HA; F = 3.138, P < 0.05). Post hoc analysis showed that TCI score in harm avoidance in homozygous EM was significantly lower than that in heterozygous EM (P < 0.05) or PM (P < 0.05). In sub-item analyses, HA3 (shyness with strangers, P < 0.01) and HA1 (anticipatory worry, P < 0.05) of TCI scores were significantly different among CYP2C19 genotypes. Meanwhile, there were no differences in TCI scores of novelty seeking (NS; F = 0.350, n.s.), reward dependence (RD; F = 1.080, n.s.), or persistence (P; F = 0.786, n.s.) among CYP2C19 genotypes. This study demonstrated that a significant association between CYP2C19 activity and HA is present in Japanese. PMID:17357148

  15. Photoelectron spectroscopy of the hydroxymethoxide anion, H2C(OH)O-

    NASA Astrophysics Data System (ADS)

    Oliveira, Allan M.; Lehman, Julia H.; McCoy, Anne B.; Lineberger, W. Carl

    2016-09-01

    We report the negative ion photoelectron spectroscopy of the hydroxymethoxide anion, H2C(OH)O-. The photoelectron spectra show that 3.49 eV photodetachment produces two distinct electronic states of the neutral hydroxymethoxy radical (H2C(OH)Oṡ). The H2C(OH)Oṡ ground state (X ˜ 2A) photoelectron spectrum exhibits a vibrational progression consisting primarily of the OCO symmetric and asymmetric stretches, the OCO bend, as well as combination bands involving these modes with other, lower frequency modes. A high-resolution photoelectron spectrum aids in the assignment of several vibrational frequencies of the neutral H2C(OH)Oṡ radical, including an experimental determination of the H2C(OH)Oṡ 2ν12 overtone of the H-OCO torsional vibration as 220(10) cm-1. The electron affinity of H2C(OH)Oṡ is determined to be 2.220(2) eV. The low-lying A ˜ 2A excited state is also observed, with a spectrum that peaks ˜0.8 eV above the X ˜ 2A state origin. The A ˜ 2A state photoelectron spectrum is a broad, partially resolved band. Quantum chemical calculations and photoelectron simulations aid in the interpretation of the photoelectron spectra. In addition, the gas phase acidity of methanediol is calculated to be 366(2) kcal mol-1, which results in an OH bond dissociation energy, D0(H2C(OH)O-H), of 104(2) kcal mol-1, using the experimentally determined electron affinity of the hydroxymethoxy radical.

  16. Phenotype-genotype analysis of CYP2C19 in Colombian mestizo individuals

    PubMed Central

    Isaza, Carlos; Henao, Julieta; Martínez, José H Isaza; Arias, Juan C Sepúlveda; Beltrán, Leonardo

    2007-01-01

    Background Omeprazole is metabolized by the hepatic cytochrome P450 (CYP) 2C19 enzyme to 5-hydroxyomeprazole. CYP2C19 exhibits genetic polymorphisms responsible for the presence of poor metabolizers (PMs), intermediate metabolizers (IMs) and extensive metabolizers (EMs). The defective mutations of the enzyme and their frequencies change between different ethnic groups; however, the polymorphism of the CYP2C19 gene has not been studied in Colombian mestizos. The aim of this study was to evaluate the genotype and phenotype status of CYP2C19 in Colombian mestizos, in order to contribute to the use of appropriate strategies of drug therapy for this population. Methods 189 subjects were genotyped using the multiplex SNaPshot technique and a subgroup of 44 individuals received 20 mg of omeprazole followed by blood collection at 3 hours to determine the omeprazole hydroxylation index by HPLC. Results 83.6%, 15.3% and 1.1% of the subjects were genotyped as EMs, IMs and PMs, respectively. The frequencies of the CYP2C29*1 and CYP2C19*2 alleles were 91.3% and 8.7% respectively whereas the *3, *4, *5, *6 and *8 alleles were not found. No discrepancies were found between the genotype and phenotype of CYP2C19. Conclusion The frequency of poor metabolizers (1.1%) in the Colombian mestizos included in this study is similar to that in Bolivian mestizos (1%) but lower than in Mexican-Americans (3.2%), West Mexicans (6%), Caucasians (5%) and African Americans (5.4%). The results of this study will be useful for drug dosage recommendations in Colombian mestizos. PMID:17623107

  17. Cytochrome P450 2C epoxygenases mediate photochemical stress-induced death of photoreceptors.

    PubMed

    Chang, Qing; Berdyshev, Evgeny; Cao, Dingcai; Bogaard, Joseph D; White, Jerry J; Chen, Siquan; Shah, Ravi; Mu, Wenbo; Grantner, Rita; Bettis, Sam; Grassi, Michael A

    2014-03-21

    Degenerative loss of photoreceptors occurs in inherited and age-related retinal degenerative diseases. A chemical screen facilitates development of new testing routes for neuroprotection and mechanistic investigation. Herein, we conducted a mouse-derived photoreceptor (661W cell)-based high throughput screen of the Food and Drug Administration-approved Prestwick drug library to identify putative cytoprotective compounds against light-induced, synthetic visual chromophore-precipitated cell death. Different classes of hit compounds were identified, some of which target known genes or pathways pathologically associated with retinitis pigmentosa. Sulfaphenazole (SFZ), a selective inhibitor of human cytochrome P450 (CYP) 2C9 isozyme, was identified as a novel and leading cytoprotective compound. Expression of CYP2C proteins was induced by light. Gene-targeted knockdown of CYP2C55, the homologous gene of CYP2C9, demonstrated viability rescue to light-induced cell death, whereas stable expression of functional CYP2C9-GFP fusion protein further exacerbated light-induced cell death. Mechanistically, SFZ inhibited light-induced necrosis and mitochondrial stress-initiated apoptosis. Light elicited calcium influx, which was mitigated by SFZ. Light provoked the release of arachidonic acid from membrane phospholipids and production of non-epoxyeicosatrienoic acid metabolites. Administration of SFZ further stimulated the production of non-epoxyeicosatrienoic acid metabolites, suggesting a metabolic shift of arachidonic acid under inhibition of the CYP2C pathway. Together, our findings indicate that CYP2C genes play a direct causative role in photochemical stress-induced death of photoreceptors and suggest that the CYP monooxygenase system is a risk factor for retinal photodamage, especially in individuals with Stargardt disease and age-related macular degeneration that deposit condensation products of retinoids. PMID:24519941

  18. Promiscuous Dimerization of the Growth Hormone Secretagogue Receptor (GHS-R1a) Attenuates Ghrelin-mediated Signaling*

    PubMed Central

    Schellekens, Harriët; van Oeffelen, Wesley E. P. A.; Dinan, Timothy G.; Cryan, John F.

    2013-01-01

    G protein-coupled receptors (GPCRs), such as the ghrelin receptor (GHS-R1a), the melanocortin 3 receptor (MC3), and the serotonin 2C receptor (5-HT2C), are well known for their key role in the homeostatic control of food intake and energy balance. Ghrelin is the only known gut peptide exerting an orexigenic effect and has thus received much attention as an anti-obesity drug target. In addition, recent data have revealed a critical role for ghrelin in dopaminergic mesolimbic circuits involved in food reward signaling. This study investigates the downstream signaling consequences and ligand-mediated co-internalization following heterodimerization of the GHS-R1a receptor with the dopamine 1 receptor, as well as that of the GHS-R1a-MC3 heterodimer. In addition, a novel heterodimer between the GHS-R1a receptor and the 5-HT2C receptor was identified. Interestingly, dimerization of the GHS-R1a receptor with the unedited 5-HT2C-INI receptor, but not with the partially edited 5-HT2C-VSV isoform, significantly reduced GHS-R1a agonist-mediated calcium influx, which was completely restored following pharmacological blockade of the 5-HT2C receptor. These results combined suggest a potential novel mechanism for fine-tuning GHS-R1a receptor-mediated activity via promiscuous dimerization of the GHS-R1a receptor with other G protein-coupled receptors involved in appetite regulation and food reward. These findings may uncover novel mechanisms of significant relevance for the future pharmacological targeting of the GHS-R1a receptor in the homeostatic regulation of energy balance and in hedonic appetite signaling, both of which play a significant role in the development of obesity. PMID:23161547

  19. CYP2C19 polymorphisms in acute coronary syndrome patients undergoing clopidogrel therapy in Zhengzhou population.

    PubMed

    Guo, Y M; Zhao, Z C; Zhang, L; Li, H Z; Li, Z; Sun, H L

    2016-01-01

    The goal of this study was to explore the polymorphisms of CYP2C19 (CYP2C19*2, CYP2C19*3) in patients with acute coronary syndrome (ACS) undergoing percutaneous coronary intervention (PCI) on clopidogrel therapy in Zhengzhou city for guidance on clinical medication and reduction in the incidence of thromboembolic events. Two hundred and thirty-four ACS patients undergoing PCI were included in the study, including 171 males (average age = 64.13 ± 12 years) and 63 females (average age = 67.86 ± 10.20 years). Pyrosequencing analysis detected CYP2C19*2/*3 genotypes, which were divided into wild-type homozygous C/C, mutant heterozygous C/T, and mutant homozygous T/T. This study further explored the relationship between CYP2C19 polymorphisms and clopidogrel resistance in ACS patients. Gene frequencies of C/C, C/T, and T/T for CYP2C19*2 were 39.74, 50, and 10.26%, respectively, while the frequencies of C/C, C/T, and T/T for CYP2C19*3 were 94.02, 5.55, and 0.43%, respectively. According to platelet aggregation analysis, 203 cases normally responded to clopidogrel (86.8%) and 31 cases were clopidogrel resistant (13.2%). There was a correlation between gender and genotype distribution but none between age and genotype. In addition, patients with clopidogrel resistance were treated with ticagrelor antiplatelet therapy instead of clopidogrel, and only 1 case in all patients suffered thrombotic events during a 3-12 month follow-up. In conclusion, CYP2C19*2/*3 polymorphisms may be associated with clopidogrel resistance. Wild-type homozygote and single mutant heterozygote of CYP2C19*2/*3 can be given a normal dose of clopidogrel, while carriers with single mutant homozygote or double mutant heterozygote require ticagrelor antiplatelet therapy as an alternative. PMID:27323099

  20. Critical behavior and magnetocaloric effect in layered structure Tb2C

    NASA Astrophysics Data System (ADS)

    Zhang, Xiao; Matsuishi, Satoru; Hosono, Hideo

    2016-08-01

    The critical behavior and magnetocaloric effects of the layered structure Tb2C have been investigated using magnetization measurements around the Curie temperature. Analyzing temperature and field dependence of magnetization reveals that the Tb2C system undergoes a second-order magnetic phase transition at T C  =  266 K. Critical exponents obtained from modified Arrott, Kouvel–Fisher (KF) and scaling plots are consistent with each other. The critical exponents suggest that the magnetic phase transition in Tb2C can be described by the mean-field model. The exchange energy declines as J(r) ~ r ‑4.547, indicating that long-range interaction dominates the exchange interaction. Consequently, the field dependence magnetic entropy change (ΔS M) of Tb2C, calculated using the Maxwell relation, clearly demonstrates that the relationship between  ‑ΔS M and (H/T C)2/3 obeys the mean-field theory, supporting our conclusion of the ferromagnetism phase transition in Tb2C following the mean-field theory.

  1. Inhibitory effects of fruit juices on cytochrome P450 2C9 activity in vitro.

    PubMed

    Hidaka, Muneaki; Nagata, Masashi; Kawano, Yohei; Sekiya, Hiroshi; Kai, Hirofumi; Yamasaki, Keishi; Okumura, Manabu; Arimori, Kazuhiko

    2008-02-01

    There is limited information on the effect of fruits on human cytochrome P450 (CYP) 2C9 activity. The objective of this study was to determine the effect of fruit juice on CYP2C9-mediated drug metabolism. Nine citrus fruits and eight tropical fruits were chosen. We investigated effects of the fruits on diclofenac 4'-hydroxylation and tolbutamide hydroxylation by human liver microsomes. Among the fruits, pineapple juice showed potent inhibition of CYP2C9 activity. The addition of 25 microl (5.0% v/v) of pineapple juice resulted in almost complete inhibition. Next we examined the inhibitory effect of bromelain, a cysteine protease in pineapple. Bromelain also strongly inhibited CYP2C9 activity. In addition, E-64, a cysteine protease inhibitor, almost entirely blocked inhibition by pineapple juice and bromelain. Thus we found that pineapple juice was a potent inhibitor of CYP2C9, and that the inhibitory effect might be due to the bromelain contained in pineapple.

  2. Lrrc75b is a novel negative regulator of C2C12 myogenic differentiation

    PubMed Central

    Zhong, Yuechun; Zou, Liyi; Wang, Zonggui; Pan, Yaqiong; Dai, Zhong; Liu, Xinguang; Cui, Liao; Zuo, Changqing

    2016-01-01

    Many transcription factors and signaling molecules involved in the guidance of myogenic differentiation have been investigated in previous studies. However, the precise molecular mechanisms of myogenic differentiation remain largely unknown. In the present study, by performing a meta-analysis of C2C12 myogenic differentiation microarray data, we found that leucine-rich repeat-containing 75B (Lrrc75b), also known as AI646023, a molecule of unknown biological function, was downregulated during C2C12 myogenic differentiation. The knockdown of Lrrc75b using specific siRNA in C2C12 myoblasts markedly enhanced the expression of muscle-specific myogenin and increased myoblast fusion and the myotube diameter. By contrast, the adenovirus-mediated overexpression of Lrrc75b in C2C12 cells markedly inhibited myoblast differentiation accompanied by a decrease in myogenin expression. In addition, the phosphorylation of extracellular signal-regulated kinase 1/2 (Erk1/2) was suppressed in the cells in which Lrrc75b was silenced. Taken together, our results demonstrate that Lrrc75b is a novel suppressor of C2C12 myogenic differentiation by modulating myogenin and Erk1/2 signaling. PMID:27633041

  3. Re-engineering of CYP2C9 to probe acid-base substrate selectivity.

    PubMed

    Tai, Guoying; Dickmann, Leslie J; Matovic, Nicholas; DeVoss, James J; Gillam, Elizabeth M J; Rettie, Allan E

    2008-10-01

    A common feature of many CYP2C9 ligands is their weak acidity. As revealed by crystallography, the structural basis for this behavior involves a charge-pairing interaction between an anionic moiety on the substrate and an active site R108 residue. In the present study we attempted to re-engineer CYP2C9 to better accept basic ligands by charge reversal at this key residue. We expressed and purified the R108E and R108E/D293N mutants and compared their ability with that of native CYP2C9 to interact with (S)-warfarin, diclofenac, pyrene, propranolol, and ibuprofen amine. As expected, the R108E mutant maintained all the native enzyme's pyrene 1-hydroxylation activity, but catalytic activity toward diclofenac and (S)-warfarin was abrogated. In contrast, the double mutant displayed much less selectivity in its behavior toward these control ligands. Neither of the mutants displayed significant enhancement of propranolol metabolism, and all three preparations exhibited a type II (inhibitor) rather than type I (substrate) spectrum with ibuprofen amine, although binding became progressively weaker with the single and double mutants. Collectively, these data underscore the importance of the amino acid at position 108 in the acid substrate selectivity of CYP2C9, highlight the accommodating nature of the CYP2C9 active site, and provide a cautionary note regarding facile re-engineering of these complex cytochrome P450 active sites.

  4. Proliferative effect of Hachimijiogan, a Japanese herbal medicine, in C2C12 skeletal muscle cells

    PubMed Central

    Takeda, Takashi; Tsuiji, Kenji; Li, Bin; Tadakawa, Mari; Yaegashi, Nobuo

    2015-01-01

    Background Hachimijiogan (HJG), Ba-Wei-Di-Huang-Wan in Chinese, is one of the most popular herbal medicines in Japanese Kampo. HJG is often prescribed for the prevention and treatment of age-related diseases. Muscle atrophy plays an important role in aging-related disabilities such as sarcopenia. The purpose of this study was to investigate the possible beneficial effect of HJG on skeletal muscle. Methods Cells of murine skeletal muscle myoblast cell line C2C12 were used as an in vitro model of muscle cell proliferation and differentiation. The effect of HJG on C2C12 cell proliferation and differentiation was assessed. We counted the number of myotubes morphologically to assess the degree of differentiation. Results HJG treatment (200 μg/mL) for 3 days significantly increased C2C12 cell number by 1.23-fold compared with that of the control. HJG promoted the proliferation of C2C12 cells through activation of the ERK1/2 signaling pathway without affecting the Akt signaling pathway. HJG did not affect the differentiation of C2C12 cells. Conclusion HJG had beneficial effects on skeletal muscle myoblast proliferation. These findings may provide a useful intervention for the prevention and treatment of sarcopenia. PMID:25709418

  5. Canine parvovirus type 2c infection in a kitten associated with intracranial abscess and convulsions.

    PubMed

    Decaro, Nicola; Desario, Costantina; Amorisco, Francesca; Losurdo, Michele; Colaianni, Maria Loredana; Greco, Maria Fiorella; Buonavoglia, Canio

    2011-04-01

    A case of canine parvovirus type 2c (CPV-2c) infection in a 3-month-old feral kitten with a cerebral abscess and neurological disease is reported. The cat displayed ataxia and convulsions together with signs of gastroenteritis and profound alteration of the total and differential white blood cell counts. A parvovirus strain was detected by a TaqMan assay in the blood and faeces of the affected kitten, which was characterised as CPV by means of molecular assays but did not react with any of the CPV type-specific probes. By sequence and phylogenetic analyses of the VP2-protein gene, the CPV-2c strain displayed a non-coding mutation in the probe-binding region. Although the role of CPV-2c in this particular case is unclear, it is possible that it predisposed the kitten to the clinical signs seen. Continuous surveillance is needed to monitor future spreading of this CPV-2c mutant, and any associated clinical signs, in the dog and cat population.

  6. Ultrasmall and phase-pure W2C nanoparticles for efficient electrocatalytic and photoelectrochemical hydrogen evolution

    PubMed Central

    Gong, Qiufang; Wang, Yu; Hu, Qi; Zhou, Jigang; Feng, Renfei; Duchesne, Paul N.; Zhang, Peng; Chen, Fengjiao; Han, Na; Li, Yafei; Jin, Chuanhong; Li, Yanguang; Lee, Shuit-Tong

    2016-01-01

    Earlier research has been primarily focused on WC as one of the most promising earth-abundant electrocatalysts for hydrogen evolution reaction (HER), whereas the other compound in this carbide family—W2C—has received far less attention. Our theoretical calculations suggest that such a focus is misplaced and W2C is potentially more HER-active than WC. Nevertheless, the preparation of phase pure and sintering-free W2C nanostructures represents a formidable challenge. Here we develop an improved carburization method and successfully prepare ultrasmall and phase-pure W2C nanoparticles. When evaluated for HER electrocatalysis, W2C nanoparticles exhibit a small onset overpotential of 50 mV, a Tafel slope of 45 mV dec−1 and outstanding long-term cycling stability, which are dramatically improved over all existing WC-based materials. In addition, the integration of W2C nanoparticles with p-type Si nanowires enables highly active and sustainable solar-driven hydrogen production. Our results highlight the great potential of this traditionally non-popular material in HER electrocatalysis. PMID:27752046

  7. Notch pathway activation contributes to inhibition of C2C12 myoblast differentiation by ethanol.

    PubMed

    Arya, Michelle A; Tai, Albert K; Wooten, Eric C; Parkin, Christopher D; Kudryavtseva, Elena; Huggins, Gordon S

    2013-01-01

    The loss of muscle mass in alcoholic myopathy may reflect alcohol inhibition of myogenic cell differentiation into myotubes. Here, using a high content imaging system we show that ethanol inhibits C2C12 myoblast differentiation by reducing myogenic fusion, creating smaller and less complex myotubes compared with controls. Ethanol administration during C2C12 differentiation reduced MyoD and myogenin expression, and microarray analysis identified ethanol activation of the Notch signaling pathway target genes Hes1 and Hey1. A reporter plasmid regulated by the Hes1 proximal promoter was activated by alcohol treatment in C2C12 cells. Treatment of differentiating C2C12 cells with a gamma secretase inhibitor (GSI) abrogated induction of Hes1. On a morphological level GSI treatment completely rescued myogenic fusion defects and partially restored other myotube parameters in response to alcohol. We conclude that alcohol inhibits C2C12 myoblast differentiation and the inhibition of myogenic fusion is mediated by Notch pathway activation.

  8. Serum from patients with systemic vasculitis induces alternatively activated macrophage M2c polarization.

    PubMed

    Ohlsson, Susanne M; Linge, Carl Petrus; Gullstrand, Birgitta; Lood, Christian; Johansson, Asa; Ohlsson, Sophie; Lundqvist, Andrea; Bengtsson, Anders A; Carlsson, Fredric; Hellmark, Thomas

    2014-01-01

    Anti-neutrophil cytoplasmic antibody associated vasculitides (AAV) are conditions defined by an autoimmune small vessel inflammation. Dying neutrophils are found around the inflamed vessels and the balance between infiltrating neutrophils and macrophages is important to prevent autoimmunity. Here we investigate how sera from AAV patients may regulate macrophage polarization and function. Macrophages from healthy individuals were differentiated into M0, M1, M2a, M2b or M2c macrophages using a standardized protocol, and phenotyped according to their expression surface markers and cytokine production. These phenotypes were compared with those of macrophages stimulated with serum from AAV patients or healthy controls. While the healthy control sera induced a M0 macrophage, AAV serum promoted polarization towards the M2c subtype. No sera induced M1, M2a or M2b macrophages. The M2c subtype showed increased phagocytosis capacity compared with the other subtypes. The M2c polarization found in AAV is consistent with previous reports of increased levels of M2c-associated cytokines.

  9. HDAC5 controls MEF2C-driven sclerostin expression in osteocytes

    PubMed Central

    Wein, Marc N.; Spatz, Jordan; Nishimori, Shigeki; Doench, John; Root, David; Babij, Philip; Nagano, Kenichi; Baron, Roland; Brooks, Daniel; Bouxsein, Mary; Pajevic, Paola Divieti; Kronenberg, Henry M.

    2014-01-01

    Osteocytes secrete paracrine factors that regulate the balance between bone formation and destruction. Among these molecules, sclerostin (encoded by the gene SOST) inhibits osteoblastic bone formation, and is an osteoporosis drug target. The molecular mechanisms underlying SOST expression remain largely unexplored. Here we report that histone deacetylase 5 (HDAC5) negatively regulates sclerostin levels in osteocytes in vitro and in vivo. HDAC5 shRNA increases, whereas HDAC5 overexpression decreases SOST expression in the novel murine Ocy454 osteocytic cell line. HDAC5 knockout mice show increased levels of SOST mRNA, more sclerostin-positive osteocytes, decreased Wnt activity, low trabecular bone density, and reduced bone formation by osteoblasts. In osteocytes, HDAC5 binds and inhibits the function of MEF2C, a crucial transcription factor for SOST expression. Using chromatin immunoprecipitation, we have mapped endogenous MEF2C binding in the SOST gene to a distal intergenic enhancer 45 kB downstream from the transcription start site. HDAC5 deficiency increases SOST enhancer MEF2C chromatin association and H3K27 acetylation and decreases recruitment of co-repressors NCoR and HDAC3. HDAC5 associates with and regulates the transcriptional activity of this enhancer, suggesting direct regulation of SOST gene expression by HDAC5 in osteocytes. Finally, increased sclerostin production achieved by HDAC5 shRNA is abrogated by simultaneous knockdown of MEF2C, indicating that MEF2C is a major target of HDAC5 in osteocytes. PMID:25271055

  10. Preparation of the flexible ZrO2/C composite nanofibrous film via electrospinning

    NASA Astrophysics Data System (ADS)

    Yin, Xin; Song, Lixin; Xie, Xueyao; Zhou, Yangyang; Guan, Yingli; Xiong, Jie

    2016-07-01

    The flexible ZrO2/C composite nanofibrous film was fabricated by electrospinning and thermal treatment. Field-emission scanning electron microscopy, transmission electron microscopy, X-ray diffractometer, and Fourier transform infrared spectra were used to characterize the morphology and microstructure of the ZrO2/C composite nanofibrous film. The ZrO2/C nanofibers exhibited rough surface and had the average diameter of about 230 ± 35 nm. And the ZrO2 nanoparticles were incorporated in carbon matrix and in tetragonal and monoclinic. The flexural property of the ZrO2/C composite nanofibrous film was investigated in detail. The results showed that the flexural property of the nanofibrous film was greatly improved with addition of the ZrO2 nanoparticles. Besides, with the increase of the contents of ZrO2 nanoparticles, the flexural modulus of the nanofibrous film decreased, reached a lowest value, and then increased. The lowest flexural modulus of the ZrO2/C composite nanofibrous film in precursor concentration of 7.0 wt% was 8.55 ± 0.06 MPa.

  11. Electron affinity of trans-2-C4F8 from electron attachment-detachment kinetics.

    PubMed

    Van Doren, Jane M; Condon, Laura R; DeSouza-Goding, Antonet; Miller, Thomas M; Bopp, Joseph C; Viggiano, A A

    2010-01-28

    Electron attachment and detachment kinetics of 2-C(4)F(8) were studied over the temperature range 298-487 K with a flowing-afterglow Langmuir-probe apparatus. Only parent anions were formed in the attachment process throughout this temperature range. At the highest temperatures, thermal electron detachment of the parent anions is important. Analysis of the 2-C(4)F(8) gas showed an 82/18 mixture of trans/cis isomers. The kinetic data at the higher temperatures were used to determine the electron affinity EA(trans-2-C(4)F(8)) = 0.79 +/- 0.06 eV after making some reasonable assumptions. The same quantity was calculated using the G3(MP2) compound method, yielding 0.74 eV. The kinetic data were not sufficient to establish a reliable value for EA(cis-2-C(4)F(8)), but G3(MP2) calculations give a value 0.017 eV greater than that for trans-2-C(4)F(8). MP2 and density functional theory were used to study the structural properties of the neutral and anion isomers.

  12. Pitx2c ensures habenular asymmetry by restricting parapineal cell number

    PubMed Central

    Garric, Laurence; Ronsin, Brice; Roussigné, Myriam; Booton, Sabrina; Gamse, Joshua T.; Dufourcq, Pascale; Blader, Patrick

    2014-01-01

    Left-right (L/R) asymmetries in the brain are thought to underlie lateralised cognitive functions. Understanding how neuroanatomical asymmetries are established has been achieved through the study of the zebrafish epithalamus. Morphological symmetry in the epithalamus is broken by leftward migration of the parapineal, which is required for the subsequent elaboration of left habenular identity; the habenular nuclei flank the midline and show L/R asymmetries in marker expression and connectivity. The Nodal target pitx2c is expressed in the left epithalamus, but nothing is known about its role during the establishment of asymmetry in the brain. We show that abrogating Pitx2c function leads to the right habenula adopting aspects of left character, and to an increase in parapineal cell numbers. Parapineal ablation in Pitx2c loss of function results in right habenular isomerism, indicating that the parapineal is required for the left character detected in the right habenula in this context. Partial parapineal ablation in the absence of Pitx2c, however, reduces the number of parapineal cells to wild-type levels and restores habenular asymmetry. We provide evidence suggesting that antagonism between Nodal and Pitx2c activities sets an upper limit on parapineal cell numbers. We conclude that restricting parapineal cell number is crucial for the correct elaboration of epithalamic asymmetry. PMID:24598158

  13. Further Advances in Optimizing (2-Phenylcyclopropyl)methylamines as Novel Serotonin 2C Agonists: Effects on Hyperlocomotion, Prepulse Inhibition, and Cognition Models.

    PubMed

    Cheng, Jianjun; Giguere, Patrick M; Schmerberg, Claire M; Pogorelov, Vladimir M; Rodriguiz, Ramona M; Huang, Xi-Ping; Zhu, Hu; McCorvy, John D; Wetsel, William C; Roth, Bryan L; Kozikowski, Alan P

    2016-01-28

    A series of novel compounds with two halogen substituents have been designed and synthesized to further optimize the 2-phenylcyclopropylmethylamine scaffold in the quest for drug-like 5-HT2C agonists. Compound (+)-22a was identified as a potent 5-HT2C receptor agonist, with good selectivity against the 5-HT2B and the 5-HT2A receptors. ADMET assays showed that compound (+)-22a possessed desirable properties in terms of its microsomal stability, and CYP and hERG inhibition, along with an excellent brain penetration profile. Evaluation of (+)-22a in animal models of schizophrenia-related behaviors revealed that it had a desirable activity profile, as it reduced d-amphetamine-stimulated hyperlocomotion in the open field test, it restored d-amphetamine-disrupted prepulse inhibition, it induced cognitive improvements in the novel object recognition memory test in NR1-KD animals, and it produced very little catalepsy relative to haloperidol. These data support the further development of (+)-22a as a drug candidate for the treatment of schizophrenia. PMID:26704965

  14. Orbiting GPS Receiver Modified to Track New L2C Signal

    NASA Technical Reports Server (NTRS)

    Meehan, Tom K.; Robison, David; Munson, Tim N.; Young, Larry E.; Stoyanov, Stephen

    2006-01-01

    The L2C signal is a great step forward for civil applications of GPS, enabling high-accuracy dual-frequency measurements. Engineers from the Jet Propulsion Laboratory and ITT teamed to reprogram FPGA firmware and add tracking software on an orbiting receiver to track the new GPS L2C signal from SAC-C. SAC-C is an Argentinean science satellite and was launched in November 2000 with a BlackJack GPS receiver. This is a dual-frequency digital receiver with 48 tracking channels and four antennas. On SAC-C, it provides precise orbits, atmospheric occultation data, tests of GPS surface reflections, and serves as an orbiting test bed for new GPS development such as the L2C tracking reported here.

  15. First principle investigation of the electronic and thermoelectric properties of Mg2C

    NASA Astrophysics Data System (ADS)

    Kulwinder, Kaur; Ranjan, Kumar

    2016-02-01

    In this paper, electronic and thermoelectric properties of Mg2C are investigated by using first principle pseudo potential method based on density functional theory and Boltzmann transport equations. We calculate the lattice parameters, bulk modulus, band gap and thermoelectric properties (Seebeck coefficient, electrical conductivity, and thermal conductivity) of this material at different temperatures and compare them with available experimental and other theoretical data. The calculations show that Mg2C is indirect band semiconductor with a band gap of 0.75 eV. The negative value of Seebeck coefficient shows that the conduction is due to electrons. The electrical conductivity decreases with temperature and Power factor (PF) increases with temperature. The thermoelectric properties of Mg2C have been calculated in a temperature range of 100 K-1200 K. Kulwinder Kaur thanks Council of Scientific & Industrial Research (CSIR), India for providing fellowship.

  16. Selective deoxygenation of aldehydes and alcohols on molybdenum carbide (Mo2C) surfaces

    NASA Astrophysics Data System (ADS)

    Xiong, Ke; Yu, Weiting; Chen, Jingguang G.

    2014-12-01

    The selective deoxygenation of aldehydes and alcohols without cleaving the Csbnd C bond is crucial for upgrading bio-oil and other biomass-derived molecules to useful fuels and chemicals. In this work, propanal, 1-propanol, furfural and furfuryl alcohol were selected as probe molecules to study the deoxygenation of aldehydes and alcohols on molybdenum carbide (Mo2C) prepared over a Mo(1 1 0) surface. The reaction pathways were investigated using temperature programmed desorption (TPD) and high resolution electron energy loss spectroscopy (HREELS). The deoxygenation of propanal and 1-propanol went through a similar intermediate (propoxide or η2(C,O)-propanal) to produce propene. The deoxygenation of furfural and furfuryl alcohol produced a surface intermediate similar to adsorbed 2-methylfuran. The comparison of these results revealed the promising deoxygenation performance of Mo2C, as well as the effect of the furan ring on the selective deoxygenation of the Cdbnd O and Csbnd OH bonds.

  17. Modeling Myotonic Dystrophy 1 in C2C12 Myoblast Cells.

    PubMed

    Liang, Rui; Dong, Wei; Shen, Xiaopeng; Peng, Xiaoping; Aceves, Angie G; Liu, Yu

    2016-01-01

    Myotonic dystrophy 1 (DM1) is a common form of muscular dystrophy. Although several animal models have been established for DM1, myoblast cell models are still important because they offer an efficient cellular alternative for studying cellular and molecular events. Though C2C12 myoblast cells have been widely used to study myogenesis, resistance to gene transfection, or viral transduction, hinders research in C2C12 cells. Here, we describe an optimized protocol that includes daily maintenance, transfection and transduction procedures to introduce genes into C2C12 myoblasts and the induction of myocyte differentiation. Collectively, these procedures enable best transfection/transduction efficiencies, as well as consistent differentiation outcomes. The protocol described in establishing DM1 myoblast cell models would benefit the study of myotonic dystrophy, as well as other muscular diseases. PMID:27501221

  18. Activation of Methane Promoted by Adsorption of CO on Mo2 C2 (-) Cluster Anions.

    PubMed

    Liu, Qing-Yu; Ma, Jia-Bi; Li, Zi-Yu; Zhao, Chongyang; Ning, Chuan-Gang; Chen, Hui; He, Sheng-Gui

    2016-05-01

    Atomic clusters are being actively studied for activation of methane, the most stable alkane molecule. While many cluster cations are very reactive with methane, the cluster anions are usually not very reactive, particularly for noble metal free anions. This study reports that the reactivity of molybdenum carbide cluster anions with methane can be much enhanced by adsorption of CO. The Mo2 C2 (-) is inert with CH4 while the CO addition product Mo2 C3 O(-) brings about dehydrogenation of CH4 under thermal collision conditions. The cluster structures and reactions are characterized by mass spectrometry, photoelectron spectroscopy, and quantum chemistry calculations, which demonstrate that the Mo2 C3 O(-) isomer with dissociated CO is reactive but the one with non-dissociated CO is unreactive. The enhancement of cluster reactivity promoted by CO adsorption in this study is compared with those of reported systems of a few carbonyl complexes. PMID:27060286

  19. MM1+2C sporadic Creutzfeldt-Jakob disease presenting as rapidly progressive nonfluent aphasia.

    PubMed

    Allegri, Ricardo F; Bartoloni, Leonardo; Iturry, Mónica; Romero, Carlos; Begué, Christián; Sevlever, Gustavo; Taratuto, Ana Lía

    2014-01-01

    We report a 77-year-old man, presenting with progressive aphasia as an initial symptom, who developed severe dementia over the course of 20 months. Frontal cortex PrPSc western blot was type 2 and codon 129 was MM; brain neuropathology showed cortical vacuoles with perivacuolar PrP immunostaining characteristic of MM2C. Cerebellum showed focal coarse, patchy staining in different sections of the molecular layer, diffuse fine punctuate and coarse PrP immunopositive deposits in the granule cell layer, and focal synaptic immunostaining in the molecular layer, suggestive of MM1+2C by histotyping. This clinical presentation has not yet been described in an MM1+2C subtype by histotyping.

  20. CYP2C subfamily, primarily CYP2C9, catalyses the enantioselective demethylation of the endocrine disruptor pesticide methoxychlor in human liver microsomes: use of inhibitory monoclonal antibodies in P450 identification.

    PubMed

    Hu, Y; Krausz, K; Gelboin, H V; Kupfer, D

    2004-02-01

    1. The endocrine disruptor pesticide methoxychlor undergoes O-demethylation by mammalian liver microsomes forming chiral mono-phenolic (1,1,1-trichloro-2-(4-hydroxyphenyl)-2-(4-methoxyphenyl)ethane, i.e. mono-OH-M) and achiral bis-phenolic oestrogenic metabolites. Human liver microsomes (HLM) generated primarily the S-mono-OH-M. 2. Inhibitory monoclonal antibodies (MAb) identified those P450s catalysing the enantioselective O-demethylation of methoxychlor. In HLM, O-demethylation was inhibited by MAb anti-2C9 (30-40%), diminishing the per cent of S-mono-OH-M from about 80 to 55-60%. MAb anti-CYP1A2, 2A6, 2B6, 2C8, 2C19, 2D6 and 3A4 did not affect the demethylation rate in HLM. Nevertheless, MAb anti-CYP1A2 decreased the formation of R-mono-OH-M from 21-23 to 10-17%, indicating that CYP1A2 exhibits a role in generating the R-enantiomer. 3. Among cDNA-expressed human P450s (supersomes), CYP2C19 was the most active in demethylation, but in HLM, CYP2C19 appeared inactive (no inhibition by MAb anti-CYP2C19). There was a substantial difference in the per cent inhibition of demethylation by MAb anti-CYP2C9 and anti-rat CYP2C (MAb inhibiting all human CYP2C forms) and in altering the enantioselectivity, suggesting that demethylation by combined CYP2C8, 2C18 and 2C19 was significant (20-30%). 4. Polymorphism of methoxychlor demethylation was examined with supersomes and HLM-expressing CYP2C9 allelic variants. CYP2C9*1 and 2C9*2 were highly active; however, CYP2C9*3 appeared inactive.

  1. MicroRNA-21 dysregulates the expression of MEF2C in neurons in monkey and human SIV/HIV neurological disease.

    PubMed

    Yelamanchili, S V; Chaudhuri, A Datta; Chen, L-N; Xiong, Huangui; Fox, H S

    2010-01-01

    MicroRNAs (miRNAs) play important roles in regulating a plethora of physiological and pathophysiogical processes including neurodegeneration. In both HIV associated dementia in humans and its monkey model SIV encephalitis we find miR-21, a miRNA largely known for its link to oncogenesis, to be significantly upregulated in the brain. In situ hybridization of the diseased brain sections revealed induction of miR-21 in neurons. MiR-21 can be induced in neurons by prolonged N-methyl-D-aspartic acid receptor stimulation, an excitotoxic process active in HIV and other neurodegenerative diseases. Introduction of miR-21 into human neurons leads to pathological functional defects. Furthermore, we show that miR-21 specifically targets the mRNA of myocyte enhancer factor 2C (MEF2C), a transcription factor crucial for neuronal function, and reduces its expression. MEF2C is dramatically downregulated in neurons of HIV-associated dementia patients as well as monkeys with SIVE. Together, this study elucidates a novel role for miR-21 in the brain, not only as a potential signature of neurological disease but also as a crucial effector of HIV induced neuronal dysfunction and neurodegeneration.

  2. Tricyclic Pyrazoles. Part 5. Novel 1,4-Dihydroindeno[1,2-c]pyrazole CB2 Ligands Using Molecular Hybridization Based on Scaffold Hopping

    PubMed Central

    Murineddu, Gabriele; Asproni, Battistina; Ruiu, Stefania; Deligia, Francesco; Falzoi, Matteo; Pau, Amedeo; Thomas, Brian F; Zhang, Yanan; Pinna, Gérard A; Pani, Luca; Lazzari, Paolo

    2012-01-01

    In search of new selective CB2 ligands, the synthesis and preliminary biological evaluation of novel 1,4-dihydroindeno[1,2-c]pyrazole hybrids of the highly potent prototypicals 5-(4-chloro-3-methylphenyl)-1-(4-methylbenzyl)-N-fenchyl-1H-pyrazole-3-carboxamide 1 and 1-(2,4-dichlorophenyl)-6-methyl-N-(piperidin-1-yl)-1,4-dihydroindeno[1,2-c]pyrazole-3-carboxamide 2 are detailed. We postulated that the introduction of those pharmacophoric elements essential for activity of 1 in the tricyclic core of 2 might provide CB2 ligands with further improved receptor selectivity and biological activity. Among the compounds, 6-chloro-7-methyl-1-(2,4-dichlorophenyl)-N-fenchyl-1,4-dihydroindeno[1,2-c]pyrazole-3-carboxamide (22) exhibited low two digit nanomolar affinity for the cannabinoid CB2R and maintained a high level of CB2-selectivity. PMID:22876271

  3. The Viral E8^E2C Repressor Limits Productive Replication of Human Papillomavirus 16

    PubMed Central

    Straub, Elke; Dreer, Marcel; Fertey, Jasmin; Iftner, Thomas

    2014-01-01

    Productive replication of human papillomavirus type 16 (HPV16) occurs only in differentiated keratinocyte cells. In addition to the viral E2 activator protein, HPV16 and related HPV types express transcripts coding for an E8^E2C fusion protein, which limits genome replication in undifferentiated keratinocytes. To address E8^E2C's role in productive replication of HPV16, stable keratinocyte cell lines containing wild-type (wt), E8^E2C knockout (E8−), or E8 KWK mutant (mt) genomes, in which conserved E8 residues were inactivated, were established. Copy numbers of E8− and E8 KWK mt genomes and amounts of early and late viral transcripts were greatly increased compared to those for the wt in undifferentiated keratinocytes, suggesting that HPV16 E8^E2C activities are highly dependent upon the E8 part. Upon differentiation in organotypic cultures, E8 mt genomes displayed higher early viral transcript levels, but no changes in cellular differentiation or virus-induced cellular DNA replication in suprabasal cells were observed. E8 mt genomes were amplified to higher copy numbers and showed increased L1 transcripts compared to wt genomes. Furthermore, the number of cells expressing the viral late protein E4 or L1 or amplifying viral genomes was greatly increased in E8 mt cell lines. In wild-type cells, E8^E2C transcript levels did not decrease by differentiation. Our data indicate that the E8^E2C repressor limits viral transcription and replication throughout the complete life cycle of HPV16. PMID:24198405

  4. Enzyme source effects on CYP2C9 kinetics and inhibition.

    PubMed

    Kumar, Vikas; Rock, Dan A; Warren, Chad J; Tracy, Timothy S; Wahlstrom, Jan L

    2006-11-01

    When choosing a recombinant cytochrome P450 (P450) enzyme system for in vitro studies, it is critical to understand the strengths, limitations, and applicability of the enzyme system to the study design. Although literature kinetic data may be available to assist in enzyme system selection, comparison of data from separate laboratories is often confounded by differences in experimental conditions and bioanalytical techniques. We measured the Michaelis-Menten kinetic parameters for four CYP2C9 substrates (diclofenac, (S)-warfarin, tolbutamide, and (S)-flurbiprofen) using four recombinant CYP2C9 enzyme systems (Supersomes, Baculosomes, RECO system, and in-house purified, reconstituted enzyme) to determine whether the enzyme systems exhibited kinetic differences in metabolic product formation rates under uniform experimental conditions. The purified, reconstituted enzyme systems exhibited higher K(m) values, reduced substrate affinity, and lower calculated intrinsic clearance values compared with baculovirus microsomal preparations. Six- to 25-fold differences in predicted intrinsic clearance values were calculated for each substrate depending on the enzyme system-substrate combination. Results suggest that P450 reductase interactions with the CYP2C9 protein and varying ratios of CYP2C9/P450 reductase in the enzyme preparations may play a role in these observed differences. In addition, when (S)-flurbiprofen was used as a substrate probe to determine CYP2C9 inhibition with a set of 12 inhibitors, decreased inhibition potency was observed across 11 of those inhibitors in the RECO purified, reconstituted enzyme compared with the Supersomes baculovirus microsomal preparation and pooled human liver microsomes. Considering these differences, consistent use of an enzyme source is an important component in producing comparable and reproducible kinetics and inhibition data with CYP2C9. PMID:16928789

  5. Effect of mitochondrial fission inhibition on C2C12 differentiation.

    PubMed

    Bloemberg, Darin; Quadrilatero, Joe

    2016-06-01

    The differentiation of skeletal muscle is commonly examined in cell culture using the C2C12 line of mouse skeletal myoblasts. This process shares many similarities with that which occurs during embryonic development, such as the transient activation of caspases. Here, we examined the effect of inhibiting mitochondrial fission, using mdivi-1, on the ability of C2C12 cells to terminally differentiate. This was performed using immunofluorescent identification of cell morphology and myosin expression, as well as immunoblotting for markers of muscle differentiation. Furthermore, the effect of mdivi-1 administration on activation of caspase-2 and -3 was assessed using spectrofluorometric measurement of specific enzyme activity. PMID:27054170

  6. Sc3N and Sc2C2 encapsulated B40: Smarter than its carbon analogue

    NASA Astrophysics Data System (ADS)

    Shah, Esha V.; Roy, Debesh R.

    2016-10-01

    A detailed comparative investigation on the recently synthesised B40 and C40 along with their metal nitride (Sc3N)and carbide (Sc2C2) encapsulated endohedral fullerenes, is performed under density functional theory for the first time. The structures, electronic, thermodynamic and magnetic properties of all the considered compounds are explored in detail. The present study identifies borospherene (B40) and its encapsulated nitride (Sc3N@B40) and carbide (Sc2C2@B40) endohedral borofullerenes as the better candidates for future novel nano-applications compared to their carbon bucky ball analogues.

  7. A study about credible cloud classification model based on FY-2/C data

    NASA Astrophysics Data System (ADS)

    Liu, Liangming; Dong, Xinyi; Zhou, Zheng

    2008-12-01

    Basic clustering algorithms including K-means, fusion c-means and C4.5 decision tree have been applied in cloud detection with FY-2C data. With the limitation that no reliable template is available, supervised classification algorithm is utilized to test the credibility of non-supervised classification algorithms, which contribute to generate a cloud classification model with high credibility. It is proved that cloud classification product distributed by National Satellite Meteorological Center enjoys a high credibility and stability. It is also demonstrated that FY-2C data is eligible to classify cloud into 4 types as cumulonimbus, cirrostratus, dense-cirrus and low and middle cloud.

  8. Modelling the B2C Marketplace: Evaluation of a Reputation Metric for e-Commerce

    NASA Astrophysics Data System (ADS)

    Gutowska, Anna; Sloane, Andrew

    This paper evaluates recently developed novel and comprehensive reputation metric designed for the distributed multi-agent reputation system for the Business-to-Consumer (B2C) E-commerce applications. To do that an agent-based simulation framework was implemented which models different types of behaviours in the marketplace. The trustworthiness of different types of providers is investigated to establish whether the simulation models behaviour of B2C e-Commerce systems as they are expected to behave in real life.

  9. Transport Anisotropy in ErNi2B2C Along c-AXIS

    NASA Astrophysics Data System (ADS)

    Lee, W. C.

    The resistivities along c-axis ρc(H, T) of ErNi2 B2C have been measured with H⊥ and H‖ c-axis for 2 < T < 300 K and the superconducting upper critical field Hc2(T) curves of ErNi2B2C were constructed for each magnetic fields. Our Hc2(T) curves have been compared and discussed with those from ρab(H, T) measurements which explain the anisotropy and its temperature dependence of Hc2(T) are thought to arise from magnetic pair breaking and the anisotropic field dependence of Néel temperature TN originated from Er+3 sublattice.

  10. E2C(R2) Periodic Benefit-Risk Evaluation Report and E2C(R2) Periodic Benefit-Risk Evaluation Report--Questions and Answers; International Council for Harmonisation; Guidances for Industry; Availability. Notice.

    PubMed

    2016-07-19

    The Food and Drug Administration (FDA or Agency) is announcing the availability of guidances for industry entitled ``E2C(R2) Periodic Benefit-Risk Evaluation'' (E2C(R2) guidance) and ``E2C(R2) Periodic Benefit-Risk Evaluation Report--Questions and Answers'' (E2C(R2) Q&A guidance). These guidances were prepared under the auspices of the International Council for Harmonisation (ICH), formerly the International Conference on Harmonisation. The E2C(R2) draft guidance, issued April 11, 2012, updated and combined two ICH guidances, ``E2C Clinical Safety Data Management: Periodic Safety Update Reports for Marketed Drugs'' (E2C guidance) and ``Addendum to E2C Clinical Safety Data Management: Periodic Safety Update Reports for Marketed Drugs'' (addendum to the E2C guidance). The E2C(R2) guidance is intended to describe the format, content, and timing of a Periodic Benefit-Risk Evaluation Report (PBRER) for an approved drug or biologic, and it finalizes the draft guidance. The E2C(R2) Q&A guidance is a supplementary guidance that is intended to clarify key issues in the E2C(R2) guidance.

  11. E2C(R2) Periodic Benefit-Risk Evaluation Report and E2C(R2) Periodic Benefit-Risk Evaluation Report--Questions and Answers; International Council for Harmonisation; Guidances for Industry; Availability. Notice.

    PubMed

    2016-07-19

    The Food and Drug Administration (FDA or Agency) is announcing the availability of guidances for industry entitled ``E2C(R2) Periodic Benefit-Risk Evaluation'' (E2C(R2) guidance) and ``E2C(R2) Periodic Benefit-Risk Evaluation Report--Questions and Answers'' (E2C(R2) Q&A guidance). These guidances were prepared under the auspices of the International Council for Harmonisation (ICH), formerly the International Conference on Harmonisation. The E2C(R2) draft guidance, issued April 11, 2012, updated and combined two ICH guidances, ``E2C Clinical Safety Data Management: Periodic Safety Update Reports for Marketed Drugs'' (E2C guidance) and ``Addendum to E2C Clinical Safety Data Management: Periodic Safety Update Reports for Marketed Drugs'' (addendum to the E2C guidance). The E2C(R2) guidance is intended to describe the format, content, and timing of a Periodic Benefit-Risk Evaluation Report (PBRER) for an approved drug or biologic, and it finalizes the draft guidance. The E2C(R2) Q&A guidance is a supplementary guidance that is intended to clarify key issues in the E2C(R2) guidance. PMID:27459749

  12. Comprehensive Evaluation for Substrate Selectivity of Cynomolgus Monkey Cytochrome P450 2C9, a New Efavirenz Oxidase.

    PubMed

    Hosaka, Shinya; Murayama, Norie; Satsukawa, Masahiro; Uehara, Shotaro; Shimizu, Makiko; Iwasaki, Kazuhide; Iwano, Shunsuke; Uno, Yasuhiro; Yamazaki, Hiroshi

    2015-07-01

    Cynomolgus monkeys are widely used as primate models in preclinical studies, because of their evolutionary closeness to humans. In humans, the cytochrome P450 (P450) 2C enzymes are important drug-metabolizing enzymes and highly expressed in livers. The CYP2C enzymes, including CYP2C9, are also expressed abundantly in cynomolgus monkey liver and metabolize some endogenous and exogenous substances like testosterone, S-mephenytoin, and diclofenac. However, comprehensive evaluation regarding substrate specificity of monkey CYP2C9 has not been conducted. In the present study, 89 commercially available drugs were examined to find potential monkey CYP2C9 substrates. Among the compounds screened, 20 drugs were metabolized by monkey CYP2C9 at a relatively high rates. Seventeen of these compounds were substrates or inhibitors of human CYP2C9 or CYP2C19, whereas three drugs were not, indicating that substrate specificity of monkey CYP2C9 resembled those of human CYP2C9 or CYP2C19, with some differences in substrate specificities. Although efavirenz is known as a marker substrate for human CYP2B6, efavirenz was not oxidized by CYP2B6 but by CYP2C9 in monkeys. Liquid chromatography-mass spectrometry analysis revealed that monkey CYP2C9 and human CYP2B6 formed the same mono- and di-oxidized metabolites of efavirenz at 8 and 14 positions. These results suggest that the efavirenz 8-oxidation could be one of the selective markers for cynomolgus monkey CYP2C9 among the major three CYP2C enzymes tested. Therefore, monkey CYP2C9 has the possibility of contributing to limited specific differences in drug oxidative metabolism between cynomolgus monkeys and humans. PMID:25948712

  13. Comprehensive Evaluation for Substrate Selectivity of Cynomolgus Monkey Cytochrome P450 2C9, a New Efavirenz Oxidase.

    PubMed

    Hosaka, Shinya; Murayama, Norie; Satsukawa, Masahiro; Uehara, Shotaro; Shimizu, Makiko; Iwasaki, Kazuhide; Iwano, Shunsuke; Uno, Yasuhiro; Yamazaki, Hiroshi

    2015-07-01

    Cynomolgus monkeys are widely used as primate models in preclinical studies, because of their evolutionary closeness to humans. In humans, the cytochrome P450 (P450) 2C enzymes are important drug-metabolizing enzymes and highly expressed in livers. The CYP2C enzymes, including CYP2C9, are also expressed abundantly in cynomolgus monkey liver and metabolize some endogenous and exogenous substances like testosterone, S-mephenytoin, and diclofenac. However, comprehensive evaluation regarding substrate specificity of monkey CYP2C9 has not been conducted. In the present study, 89 commercially available drugs were examined to find potential monkey CYP2C9 substrates. Among the compounds screened, 20 drugs were metabolized by monkey CYP2C9 at a relatively high rates. Seventeen of these compounds were substrates or inhibitors of human CYP2C9 or CYP2C19, whereas three drugs were not, indicating that substrate specificity of monkey CYP2C9 resembled those of human CYP2C9 or CYP2C19, with some differences in substrate specificities. Although efavirenz is known as a marker substrate for human CYP2B6, efavirenz was not oxidized by CYP2B6 but by CYP2C9 in monkeys. Liquid chromatography-mass spectrometry analysis revealed that monkey CYP2C9 and human CYP2B6 formed the same mono- and di-oxidized metabolites of efavirenz at 8 and 14 positions. These results suggest that the efavirenz 8-oxidation could be one of the selective markers for cynomolgus monkey CYP2C9 among the major three CYP2C enzymes tested. Therefore, monkey CYP2C9 has the possibility of contributing to limited specific differences in drug oxidative metabolism between cynomolgus monkeys and humans.

  14. User-Interface Design Characteristics of Fortune 500 B2C E-Commerce Sites and Industry Differences

    ERIC Educational Resources Information Center

    Zhao, Jensen J.; Truell, Allen D.; Alexander, Melody W.

    2006-01-01

    This study examined the user-interface design characteristics of 107 Fortune 500 B2C e-commerce Web sites and industry differences. Data were collected from corporate homepages, B2C product/service pages, B2C interactive shopping pages, as well as customer satisfaction of 321 online shoppers. The findings indicate that (a) to attract online…

  15. 77 FR 21782 - International Conference on Harmonisation; Draft Guidance for Industry on E2C(R2) Periodic...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-11

    ... individual case safety reports to regulatory authorities, automated data mining techniques, more attention to... and combines two ICH guidances, ``E2C Clinical Safety Data Management: Periodic Safety Update Reports for Marketed Drugs'' (E2C guidance) and ``Addendum to E2C Clinical Safety Data Management:...

  16. G9a inhibits MEF2C activity to control sarcomere assembly

    PubMed Central

    Ow, Jin Rong; Palanichamy Kala, Monica; Rao, Vinay Kumar; Choi, Min Hee; Bharathy, Narendra; Taneja, Reshma

    2016-01-01

    In this study, we demonstrate that the lysine methyltransferase G9a inhibits sarcomere organization through regulation of the MEF2C-HDAC5 regulatory axis. Sarcomeres are essential for muscle contractile function. Presently, skeletal muscle disease and dysfunction at the sarcomere level has been associated with mutations of sarcomere proteins. This study provides evidence that G9a represses expression of several sarcomere genes and its over-expression disrupts sarcomere integrity of skeletal muscle cells. G9a inhibits MEF2C transcriptional activity that is essential for expression of sarcomere genes. Through protein interaction assays, we demonstrate that G9a interacts with MEF2C and its co-repressor HDAC5. In the presence of G9a, calcium signaling-dependent phosphorylation and export of HDAC5 to the cytoplasm is blocked which likely results in enhanced MEF2C-HDAC5 association. Activation of calcium signaling or expression of constitutively active CaMK rescues G9a-mediated repression of HDAC5 shuttling as well as sarcomere gene expression. Our results demonstrate a novel epigenetic control of sarcomere assembly and identifies new therapeutic avenues to treat skeletal and cardiac myopathies arising from compromised muscle function. PMID:27667720

  17. Surface morphology of orthorhombic Mo2C catalyst and high coverage hydrogen adsorption

    NASA Astrophysics Data System (ADS)

    Wang, Tao; Tian, Xinxin; Yang, Yong; Li, Yong-Wang; Wang, Jianguo; Beller, Matthias; Jiao, Haijun

    2016-09-01

    High coverage hydrogen adsorption on twenty two terminations of orthorhombic Mo2C has been systematically studied by using density functional theory and ab initio thermodynamics. Hydrogen stable coverage on the surfaces highly depends on temperatures and H2 partial pressure. The estimated hydrogen desorption temperatures under ultra-high vacuum condition on Mo2C are in reasonable agreement with the available temperature-programmed desorption data. Obviously, hydrogen adsorption can affect the surface stability and therefore modify the surface morphology of Mo2C. Upon increasing the chemical potential of hydrogen which can be achieved by increasing the H2 partial pressure and/or decreasing the temperature, the proportions of the (001), (010), (011) and (100) surfaces increase, while those of the (101), (110) and (111) surfaces decrease. Among these surfaces, the (100) surface is most sensitive upon hydrogen adsorption and the (111) surface is most exposed under a wide range of conditions. Our study clearly reveals the role of hydrogen on the morphology of orthorhombic Mo2C catalyst in conjugation with hydro-treating activity.

  18. A functional genomic analysis of Arabidopsis thaliana PP2C clade D

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In the reference dicot plant Arabidopsis thaliana, the PP2C family of P-protein phosphatases includes the products of 80 genes that have been separated into 10 multi-protein clades plus six singletons. Clade D includes the products of nine genes distributed among 3 chromosomes (PPD1, At3g12620; PPD2...

  19. Deoxygenation of glycolaldehyde and furfural on Mo2C/Mo(100)

    NASA Astrophysics Data System (ADS)

    McManus, Jesse R.; Vohs, John M.

    2014-12-01

    The desire to produce fuels and chemicals in an energy conscious, environmentally sympathetic approach has motivated considerable research on the use of cellulosic biomass feedstocks. One of the major challenges facing the utilization of biomass is finding effective catalysts for the efficient and selective removal of oxygen from the highly-oxygenated, biomass-derived platform molecules. Herein, a study of the reaction pathways for the biomass-derived platform molecule furfural and biomass-derived sugar model compound glycolaldehyde provides insight into the mechanisms of hydrodeoxygenation (HDO) on a model molybdenum carbide catalyst, Mo2C/Mo(100). Using temperature programmed desorption (TPD) and high resolution electron energy loss spectroscopy (HREELS), it was found that the Mo2C/Mo(100) catalyst was active for selective deoxygenation of the aldehyde carbonyl by facilitating adsorption of the aldehyde in an η2(C,O) bonding configuration. Furthermore, the catalyst showed no appreciable activity for furanic ring hydrogenation, highlighting the promise of relatively inexpensive Mo2C catalysts for selective HDO chemistry.

  20. Thermal ramp tritium release in COBRA-1A2 C03 beryllium pebbles

    SciTech Connect

    Baldwin, D.L.

    1998-03-01

    Tritium release kinetics, using the method of thermal ramp heating at three linear ramp rates, were measured on the COBRA-1A2 C03 1-mm beryllium pebbles. This report includes a brief discussion of the test, and the test data in graph format.

  1. High-throughput radiometric CYP2C19 inhibition assay using tritiated (S)-mephenytoin.

    PubMed

    Di Marco, Annalise; Cellucci, Antonella; Chaudhary, Ashok; Fonsi, Massimiliano; Laufer, Ralph

    2007-10-01

    A rapid and sensitive radiometric assay for assessing the potential of drugs to inhibit cytochrome P450 (P450) 2C19 in human liver microsomes is described. The new assay, which does not require high-performance liquid chromatography (HPLC) separation or mass spectrometric detection, is based on the release of tritium as tritiated water that occurs upon CYP2C19-mediated 4'-hydroxylation of (S)-mephenytoin labeled with tritium in the 4' position. Because this reaction is subject to an NIH shift, tritium was also introduced into the 3'- and 5'-positions of the tracer to enhance formation of a tritiated water product. Tritiated water was separated from the substrate using 96-well solid-phase extraction plates. The reaction is NADPH-dependent and sensitive to CYP2C19 inhibitors. IC(50) values for 15 diverse drugs differed less than 2.5-fold from those determined by quantification of the unlabeled 4'-hydroxy-(S)-mephenytoin product, using HPLC coupled to mass spectrometric detection. All of the steps of the new assay, namely incubation, product separation, and radioactivity counting, are performed in a 96-well format and can be automated. This assay represents a non-HPLC, high-throughput version of the classic (S)-mephenytoin 4'-hydroxylation assay, which is the most widely used method to assess the potential for CYP2C19 inhibition of new chemical entities.

  2. Anomalous behavior of PrNi{sub 2}B{sub 2}C borocarbide

    SciTech Connect

    Narozhnyi, V.N.; Freudenberger, J.; Fuchs, G.; Nenkov, K.A.; Eckert, D.; Czopnik, A.; Mueller, K.H.

    1999-12-01

    Electrical resistivity {rho}(T), specific heat C{sub p}(T), magnetic susceptibility {chi}(T), and magnetization M(H) have been measured for polycrystalline PrNi{sub 2}B{sub 2}C. Maxima in C{sub p}(T) and {vert{underscore}bar}d{chi}(T)/dT{vert{underscore}bar} dependencies were found at T{sub N} {approx} 4.3 K connected with AFM ordering observed earlier by neutron diffraction. The Sommerfeld coefficient is at least 250 mJ/mol K{sup 2}. The values of T{sub N} for PrNi{sub 2}B{sub 2}C and {vert{underscore}bar}d{Tc}/dx{vert{underscore}bar} for Y{sub 1{minus}x}Pr{sub x}Ni{sub 2}B{sub 2}C were found to be much larger than estimated by the de Gennes scaling from the Gd-based borocarbides. These facts as well as anomalous decrease of {rho}(T) found below 20K are connected with moderate heavy fermion behavior of antiferromagnetic PrNi{sub 2}B{sub 2}C.

  3. BAMBI Promotes C2C12 Myogenic Differentiation by Enhancing Wnt/β-Catenin Signaling

    PubMed Central

    Zhang, Qiangling; Shi, Xin-E; Song, Chengchuang; Sun, Shiduo; Yang, Gongshe; Li, Xiao

    2015-01-01

    Bone morphogenic protein and activin membrane-bound inhibitor (BAMBI) is regarded as an essential regulator of cell proliferation and differentiation that represses transforming growth factor-β and enhances Wnt/β-catenin signaling in various cell types. However, its role in skeletal muscle remains largely unknown. In the current study, we found that the expression level of BAMBI peaked in the early differentiation phase of the C2C12 rodent myoblast cell line. Knockdown of BAMBI via siRNA inhibited C2C12 differentiation, indicated by repressed MyoD, MyoG, and MyHC expression as well as reductions in the differentiation and fusion indices. BAMBI knockdown reduced the activity of Wnt/β-catenin signaling, as characterized by the decreased nuclear translocation of β-catenin and the lowered transcription of Axin2, which is a well-documented target gene of the Wnt/β-catenin signaling pathway. Furthermore, treatment with LiCl, an activator of Wnt/β-catenin signaling, rescued the reduction in C2C12 differentiation caused by BAMBI siRNA. Taken together, our data suggest that BAMBI is required for normal C2C12 differentiation, and that its role in myogenesis is mediated by the Wnt/β-catenin pathway. PMID:26247931

  4. 76 FR 77833 - Scientific Information Request on CYP2C19 Variants and Platelet Reactivity Tests

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-14

    ... Variants and Platelet Reactivity Tests AGENCY: Agency for Healthcare Research and Quality (AHRQ), HHS... platelet reactivity tests. Scientific information is being solicited to inform our Comparative... for studies that report on CYP2C19 variants and platelet reactivity tests, including those...

  5. Cytochrome P450 2C9 gene polymorphism in phenytoin induced gingival enlargement: A case report.

    PubMed

    Babu, S P K Kennedy; Ramesh, V; Samidorai, Agila; Charles, N S C

    2013-07-01

    Gingival enlargement comprises any clinical condition in which an increase in the size of the gingiva is observed. Among the drugs that induce gingival enlargement, the antiepileptic agent phenytoin has been widely related to this condition. The Cytochrome P450(CYP) superfamily is the most commonly involved enzymes in metabolism of drugs. Common coding region CYP variants that affects drug elimination and response has been studied in great detail. Pharmacogenetic influences on drug metabolism have been widely reviewed and gene polymorphism of cytochrome P450 2C9 appeared to be responsible for much of the interindividual variability on drug elimination. Genetic variation in the CYP2C9 gene can affect metabolism, leading to altered phenotypes. Individuals with poor metaboliser alleles of CYP2C9 gene were shown to have a reduced metabolism of phenytoin compared with wild-type alleles. Thus identification of patients genotype prior to anti-epileptic drug administration could potentially prevent higher serum drug concentrations leading to adverse side effects such as gingival enlargement. This case report addresses the influence of CYP2C9 genetic polymorphism on Phenytoin drug metabolism thereby causing gingival enlargement. PMID:24082701

  6. The MEF2C-Related and 5q14.3q15 Microdeletion Syndrome

    PubMed Central

    Zweier, M.; Rauch, A.

    2012-01-01

    Disorders related to the autosomal transcription factor MEF2C located in 5q14.3 were first described in 2009 and have since evolved to one of the more common microdeletion syndromes. Mutational screening in a larger cohort revealed heterozygous de novo mutations of MEF2C in about 1% of patients with moderate to severe intellectual disability, and the phenotype is similar in patients with intragenic deletions and multigenic microdeletions. Clinically, MEF2C-related disorders are characterized by severe intellectual disability with absent speech and limited walking abilities, hypotonia, seizures, and a variety of minor brain anomalies. The majority of patients show a similar facial gestalt with broad forehead, flat nasal bridge, hypotonic mouth, and small chin, as well as strabismus, but this phenotype is clinically not well recognized. The course of the disease is generally quite uniform, but patients with point mutations and smaller deletions seem to have a higher chance of walking skills and a lower risk of refractory seizures. Patients in whom the microdeletion also includes the RASA1 gene show features of the respective capillary and arterio-venous malformations and fistula syndrome. The phenotypic overlap with Rett syndrome is explained by a shared pathway and, accordingly, diminished MECP2 and CDKL5 expression is measureable in patients with MEF2C defects. Further research of this pathway may therefore eventually lead to a common therapeutic target. PMID:22670137

  7. The Development of B2C E-Commerce in Greece: Current Situation and Future Potential.

    ERIC Educational Resources Information Center

    Kardaras, Dimitris; Papathanassiou, Eleutherios

    2000-01-01

    Reports on the results of a survey of 120 companies in Greece that evaluated the potential of business to customer (B2C) Internet applications and investigated how the Internet and e-commerce can offer new opportunities for businesses to improve their customers' satisfaction. Discusses electronic commerce problems and future technology. (Contains…

  8. Structure and Dynamics of the Membrane-Bound Cytochrome P450 2C9

    PubMed Central

    Cojocaru, Vlad; Balali-Mood, Kia; Sansom, Mark S. P.; Wade, Rebecca C.

    2011-01-01

    The microsomal, membrane-bound, human cytochrome P450 (CYP) 2C9 is a liver-specific monooxygenase essential for drug metabolism. CYPs require electron transfer from the membrane-bound CYP reductase (CPR) for catalysis. The structural details and functional relevance of the CYP-membrane interaction are not understood. From multiple coarse grained molecular simulations started with arbitrary configurations of protein-membrane complexes, we found two predominant orientations of CYP2C9 in the membrane, both consistent with experiments and conserved in atomic-resolution simulations. The dynamics of membrane-bound and soluble CYP2C9 revealed correlations between opening and closing of different tunnels from the enzyme's buried active site. The membrane facilitated the opening of a tunnel leading into it by stabilizing the open state of an internal aromatic gate. Other tunnels opened selectively in the simulations of product-bound CYP2C9. We propose that the membrane promotes binding of liposoluble substrates by stabilizing protein conformations with an open access tunnel and provide evidence for selective substrate access and product release routes in mammalian CYPs. The models derived here are suitable for extension to incorporate other CYPs for oligomerization studies or the CYP reductase for studies of the electron transfer mechanism, whereas the modeling procedure is generally applicable to study proteins anchored in the bilayer by a single transmembrane helix. PMID:21852944

  9. "Expectations to Change" ((E2C): A Participatory Method for Facilitating Stakeholder Engagement with Evaluation Findings

    ERIC Educational Resources Information Center

    Adams, Adrienne E.; Nnawulezi, Nkiru A.; Vandenberg, Lela

    2015-01-01

    From a utilization-focused evaluation perspective, the success of an evaluation is rooted in the extent to which the evaluation was used by stakeholders. This paper details the "Expectations to Change" (E2C) process, an interactive, workshop-based method designed to engage primary users with their evaluation findings as a means of…

  10. Phagocytosis and solubilization of fixed cells by metastatic hamster embryo fibroblasts, Nil2C2

    SciTech Connect

    Sakiyama, H.; Nishino, Y.; Nishimura, K.; Noda, Y.; Otsu, H.

    1984-05-01

    When Nil2C2, a metastatic clone derived from hamster embryo fibroblasts (Nil), was inoculated over (/sup 3/H)leucine-labeled fixed cells, Nil2C2 cells solubilized and phagocytosed fixed cells, and the radioactivity was released into the culture medium as trichloroacetic acid-soluble fragments. The solubilization of fixed cells was dependent on both the time of incubation of living cells with fixed cells and the number of living cells inoculated. Nil2C2 cells were shown by autoradiographic and electron microscopic studies to peel off fixed cells and ingest them as large fragments. The solubilization of fixed cells was significantly decreased when plasminogen was depleted from the culture medium. Protease inhibitors such as leupeptin, epsilon-aminocaproic acid, and soybean trypsin inhibitor partially inhibited the proteolysis and phagocytosis of Nil2C2 cells. Mouse peritoneal macrophages activated by Salmonella typhimurium solubilized fixed cells after the addition of 12-O-tetradecanoylphorbol-13-acetate. However, they did not phagocytose fixed cells as large fragments.

  11. Overexpression of alpha2C-adrenoceptors impairs water maze navigation.

    PubMed

    Björklund, M; Sirviö, J; Riekkinen, M; Sallinen, J; Scheinin, M; Riekkinen, P

    2000-01-01

    We investigated the role of overexpression of alpha2C-adrenoceptors in water maze navigation in mice transgenically manipulated to have a threefold overexpression of the alpha2C-adrenoreceptors. Alpha2C-adrenoreceptors overexpressing mice swam more in the peripheral annulus of the pool and did not find the hidden escape platform as well as the wild type control mice. A subtype-nonselective alpha2-adrenoreceptor antagonist, atipamezole (ATI, 1000 microg/kg, s.c.), fully reversed the deficit in platform finding and search strategy in overexpressing mice. Noradrenaline depletion (-95%) induced by N-(2-chloroethyl)-N-ethyl-2-bromobenzylamine (DSP-4) did not impair platform finding of wild type or overexpressing mice. The DSP-4 lesion slightly increased swimming in the peripheral annulus in wild type mice, but not in overexpressing mice. The DSP-4 lesion produced a dissociable effect on the action of atipamezole to improve platform finding and search strategy in overexpressing mice: atipamezole did not alleviate the platform finding deficit in DSP-4 lesioned overexpressing mice, but normalized their abnormal search strategy. These results suggest that the abnormal search pattern and deficit in the accuracy of platform finding are mediated by constitutive activity of overexpressed alpha2C-adrenoreceptors.

  12. Trends and Variations of Ocean Surface Latent Heat Flux: Results from GSSTF2c Data Set

    NASA Technical Reports Server (NTRS)

    Gao, Si; Chiu, Long S.; Shie, Chung-Lin

    2013-01-01

    Trends and variations of Goddard Satellite-based Surface Turbulent Fluxes (GSSTF) version 2c (GSSTF2c) latent heat flux (LHF) are examined. This version of LHF takes account of the correction in Earth incidence angle. The trend of global mean LHF for GSSTF2c is much reduced relative to GSSTF version 2b Set 1 and Set 2 for the same period 1988-2008. Temporal increase of GSSTF2c LHF in the two decades is 11.0%, in which 3.1%, 5.8%, and 2.1% are attributed to the increase in wind, the increase in sea surface saturated air humidity, and the decrease in near-surface air humidity, respectively. The first empirical orthogonal function of LHF is a conventional El Nino Southern Oscillation (ENSO) mode. However, the trends in LHF are independent of conventional ENSO phenomena. After removing ENSO signal, the pattern of LHF trends is primarily determined by the pattern of air-sea humidity difference trends.

  13. Nanoparticle-mediated intracellular lipid accumulation during C2C12 cell differentiation

    SciTech Connect

    Tsukahara, Tamotsu; Haniu, Hisao

    2011-03-25

    Research highlights: {yields} HTT2800 has a significant effect on intracellular lipid accumulation. {yields} HTT2800 reduced muscle-specific genes and led to the emergence of adipocyte-related genes. {yields} HT2800 converts the differentiation pathway of C2C12 myoblasts to that of adipoblast-like cells. -- Abstract: In this report, we sought to elucidate whether multiwall carbon nanotubes are involved in the modulation of the proliferation and differentiation of the skeletal muscle cell line C2C12. Skeletal muscle is a major mass peripheral tissue that accounts for 40% of total body weight and 50% of energy consumption. We focused on the differentiation pathway of myoblasts after exposure to a vapor-grown carbon fiber, HTT2800, which is one of the most highly purified carbon nanotubes. This treatment leads in parallel to the expression of a typical adipose differentiation program. We found that HTT2800 stimulated intracellular lipid accumulation in C2C12 cells. We have also shown by quantified PCR analysis that the expression of adipose-related genes was markedly upregulated during HTT2800 exposure. Taken together, these results suggest that HTT2800 specifically converts the differentiation pathway of C2C12 myoblasts to that of adipoblast-like cells.

  14. Structure and Dynamics of the Membrane-Bound Cytochrome P450 2C9

    SciTech Connect

    Cojocaru, Vlad; Balali-Mood, Kia; Sansom, Mark S.; Wade, Rebecca C.

    2011-08-11

    The microsomal, membrane-bound, human cytochrome P450 (CYP) 2C9 is a liver-specific monooxygenase essential for drug metabolism. CYPs require electron transfer from the membrane-bound CYP reductase (CPR) for catalysis. The structural details and functional relevance of the CYP-membrane interaction are not understood. From multiple coarse grained molecular simulations started with arbitrary configurations of protein-membrane complexes, we found two predominant orientations of CYP2C9 in the membrane, both consistent with experiments and conserved in atomic-resolution simulations. The dynamics of membrane-bound and soluble CYP2C9 revealed correlations between opening and closing of different tunnels from the enzyme’s buried active site. The membrane facilitated the opening of a tunnel leading into it by stabilizing the open state of an internal aromatic gate. Other tunnels opened selectively in the simulations of product-bound CYP2C9. We propose that the membrane promotes binding of liposoluble substrates by stabilizing protein conformations with an open access tunnel and provide evidence for selective substrate access and product release routes in mammalian CYPs. The models derived here are suitable for extension to incorporate other CYPs for oligomerization studies or the CYP reductase for studies of the electron transfer mechanism, whereas the modeling procedure is generally applicable to study proteins anchored in the bilayer by a single transmembrane helix.

  15. High reflectance and low stress Mo2C/Be multilayers

    DOEpatents

    Bajt, Sasa; Barbee, Jr., Troy W.

    2001-01-01

    A material for extreme ultraviolet (EUV) multilayers that will reflect at about 11.3 nm, have a high reflectance, low stress, and high thermal and radiation stability. The material consists of alternating layers of Mo.sub.2 C and Be deposited by DC magnetron sputtering on a substrate, such as silicon. In one example a Mo.sub.2 C/Be multilayer gave 65.2% reflectance at 11.25 nm measured at 5 degrees off normal incidence angle, and consisted of 70 bilayers with a deposition period of 5.78 nm, and was deposited at 0.83 mTorr argon (Ar) sputtering pressure, with the first and last layers being Be. The stress of the multilayer is tensile and only +88 MPa, compared to +330 MPa of a Mo/Be multilayers of the same thickness. The Mo.sub.2 C/Be multilayer was capped with carbon which produced an increase in reflectivity of about 7% over a similar multilayer with no carbon capping material, thus raising the reflectivity from 58.3% to over 65%. The multilayers were formed using either Mo.sub.2 C or Be as the first and last layers, and initial testing has shown the formation of beryllium carbide at the interfaces between the layers which both stabilizes and has a smoothing effect, and appear to be smoother than the interfaces in Mo/Be multilayers.

  16. Magnetic structures in RNi{sub 2}B{sub 2}C (R = Ho, Er) superconductors

    SciTech Connect

    Stassis, C.; Goldman, A.I.; Dervenagas, P.; Zarestky, J.; Canfield, P.C.; Cho, B.K.; Johnston, D.C.; Sternlieb, B.; Sternlieb, B.

    1994-12-31

    Single crystal neutron diffraction techniques have been employed to study the evolution of magnetic structures in RNi{sub 2}B{sub 2}C compounds in an attempt to understand the relationship between magnetic ordering and superconductivity in several members of this series. For HoNi{sub 2}B{sub 2}C, below the superconducting transition (T{sub c} = 8 K), an incommensurate magnetic structure characterized by two wave vectors (0.585 a* and 0.915 c*) is found in a narrow temperature range between 4.7 K and 6 K. This is the same temperature range where bulk measurements find a deep minimum in the upper critical field, H{sub c2}. Below 4.7 K, HoNi{sub 2}B{sub 2}C is a simple collinear antiferromagnet. ErNi{sub 2}B{sub 2}C ({Tc} = 11 K) orders in an incommensurate modulated antiferromagnetic state characterized by an ordering wave vector 0.553 a* below 7 K, which coexists with superconductivity.

  17. Accelerating MP2C dispersion corrections for dimers and molecular crystals

    NASA Astrophysics Data System (ADS)

    Huang, Yuanhang; Shao, Yihan; Beran, Gregory J. O.

    2013-06-01

    The MP2C dispersion correction of Pitonak and Hesselmann [J. Chem. Theory Comput. 6, 168 (2010)], 10.1021/ct9005882 substantially improves the performance of second-order Møller-Plesset perturbation theory for non-covalent interactions, albeit with non-trivial computational cost. Here, the MP2C correction is computed in a monomer-centered basis instead of a dimer-centered one. When applied to a single dimer MP2 calculation, this change accelerates the MP2C dispersion correction several-fold while introducing only trivial new errors. More significantly, in the context of fragment-based molecular crystal studies, combination of the new monomer basis algorithm and the periodic symmetry of the crystal reduces the cost of computing the dispersion correction by two orders of magnitude. This speed-up reduces the MP2C dispersion correction calculation from a significant computational expense to a negligible one in crystals like aspirin or oxalyl dihydrazide, without compromising accuracy.

  18. Magnetotransport Properties in High-Quality Ultrathin Two-Dimensional Superconducting Mo2C Crystals.

    PubMed

    Wang, Libin; Xu, Chuan; Liu, Zhibo; Chen, Long; Ma, Xiuliang; Cheng, Hui-Ming; Ren, Wencai; Kang, Ning

    2016-04-26

    Ultrathin transition metal carbides are a class of developing two-dimensional (2D) materials with superconductivity and show great potentials for electrical energy storage and other applications. Here, we report low-temperature magnetotransport measurements on high-quality ultrathin 2D superconducting α-Mo2C crystals synthesized by a chemical vapor deposition method. The magnetoresistance curves exhibit reproducible oscillations at low magnetic fields for temperature far below the superconducting transition temperature of the crystals. We interpret the oscillatory magnetoresistance as a consequence of screening currents circling around the boundary of triangle-shaped terraces found on the surface of ultrathin Mo2C crystals. As the sample thickness decreases, the Mo2C crystals exhibit negative magnetoresistance deep in the superconducting transition regime, which reveals strong phase fluctuations of the superconducting order parameters associated with the superconductor-insulator transition. Our results demonstrate that the ultrathin superconducting Mo2C crystals provide an interesting system for studying rich transport phenomena in a 2D crystalline superconductor with enhanced quantum fluctuations.

  19. Orbit Determination Using SLR Data for STSAT-2C: Short-arc Analysis

    NASA Astrophysics Data System (ADS)

    Kim, Young-Rok; Park, Eunseo; Kucharski, Daniel; Lim, Hyung-Chul

    2015-09-01

    In this study, we present the results of orbit determination (OD) using satellite laser ranging (SLR) data for the Science and Technology Satellite (STSAT)-2C by a short-arc analysis. For SLR data processing, the NASA/GSFC GEODYN II software with one year (2013/04 - 2014/04) of normal point observations is used. As there is only an extremely small quantity of SLR observations of STSAT-2C and they are sparsely distribution, the selection of the arc length and the estimation intervals for the atmospheric drag coefficients and the empirical acceleration parameters was made on an arc-to-arc basis. For orbit quality assessment, the post-fit residuals of each short-arc and orbit overlaps of arcs are investigated. The OD results show that the weighted root mean square post-fit residuals of short-arcs are less than 1 cm, and the average 1-day orbit overlaps are superior to 50/600/900 m for the radial/cross-track/along-track components. These results demonstrate that OD for STSAT-2C was successfully achieved with cm-level range precision. However its orbit quality did not reach the same level due to the availability of few and sparse measurement conditions. From a mission analysis viewpoint, obtaining the results of OD for STSAT-2C is significant for generating enhanced orbit predictions for more frequent tracking.

  20. The tyrosine kinase inhibitor nilotinib selectively inhibits CYP2C8 activities in human liver microsomes.

    PubMed

    Kim, Min-Jung; Lee, Jae-Won; Oh, Kyung-Suk; Choi, Chang-Soo; Kim, Kwang Hee; Han, Won Seok; Yoon, Chang-No; Chung, Eun Sook; Kim, Dong-Hyun; Shin, Jae-Gook

    2013-01-01

    The tyrosine kinase inhibitor nilotinib was examined for its inhibition of cytochrome P450s (CYPs) in human liver microsomes and in human CYPs expressed in a baculovirus-insect cell system. Nilotinib demonstrated preferential inhibition of CYP2C8-mediated paclitaxel 6α-hydroxylation, rosiglitazone hydroxylation and amodiaquine N-deethylation in human liver microsomes, with IC₅₀ values of 0.4, 7.5 and 0.7 µM, respectively. The IC₅₀ value of nilotinib for paclitaxel 6α-hydroxylation was 20-fold lower than that of the other five tyrosine-kinase inhibitors tested. Nilotinib appears to display competitive inhibition against paclitaxel 6α-hydroxylation and amodiaquine N-deethylation, with estimated mean Ki values of 0.90 and 0.15 µM in human liver microsomes and 0.10 and 0.61 µM in recombinant human CYP2C8, respectively. These results are consistent with those of molecular docking simulations, where paclitaxel could not access the CYP2C8 catalytic site in the presence of nilotinib, but the binding of midazolam, a substrate of CYP3A4, to the catalytic site of CYP3A4 was not affected by nilotinib. The demonstrated inhibitory activity of nilotinib against CYP2C8 at concentrations less than those observed in patients who received nilotinib therapy is of potential clinical relevance and further in vivo exploration is warranted.

  1. Anaerobic Oxidation of [1,2-C]Dichloroethene under Mn(IV)-Reducing Conditions.

    PubMed

    Bradley, P M; Landmeyer, J E; Dinicola, R S

    1998-04-01

    Anaerobic oxidation of [1,2-C]dichloroethene to CO(2) under Mn(IV)-reducing conditions was demonstrated. The results indicate that oxidative degradation of partially chlorinated solvents like dichloroethene can be significant even under anoxic conditions and demonstrate the potential importance of Mn(IV) reduction for remediation of chlorinated groundwater contaminants.

  2. The impact of CYP2C8 polymorphism and grapefruit juice on the pharmacokinetics of repaglinide

    PubMed Central

    Bidstrup, Tanja Busk; Damkier, Per; Olsen, Anette Kristensen; Ekblom, Marianne; Karlsson, Anders; Brøsen, Kim

    2006-01-01

    Aims The primary aim of the study was to investigate the possible effect of the CYP2C8 3 allele and of grapefruit juice on the pharmacokinetics of repaglinide. Furthermore, the impact of a single dose of grapefruit juice on the pharmacokinetics of repaglinide in relation to dose. Methods Thirty-six healthy male subjects, genotyped for CYP2C8 3 (11 genotyped as CYP2C8 1/ 3, one as CYP2C8 3/ 3 and 24 as CYP2C8 1/ 1), participated in a randomized, cross-over trial. In the two phases, the subjects drank 300 mL water or 300 mL grapefruit juice, in randomized order, 2 h before administration of a single dose of either 0.25 mg or 2 mg repaglinide. Results Neither the mean AUC0−∞ (geometric mean ratio: 1.01; 95% CI: 0.93–1.1, P = 0.88) nor the mean Cmax (geometric mean ratio: 1.05; 95% CI: 0.94–1.2, P = 0.35) of repaglinide were statistically significantly different in the group carrying the CYP2C8 3 mutant allele compared with wild-types. Grapefruit juice caused a 19% decrease in the geometric mean ratio of the 3-hydroxyquinidine to quinidine ratio (difference: 0.81; 95% CI: 0.75–0.87, P < 0.0001), which was used as an index of CYP3A4 activity, and an increase in the mean AUC0−∞ of repaglinide (geometric mean ratio: 1.13; 95% CI: 1.04–1.2, P = 0.0048), but had no statistically significant effect on the t1/2. There was no statistically significant difference in blood glucose concentration in subjects who had or had not ingested grapefruit juice. The effect was more pronounced at the low dose of repaglinide (0.25 mg) than at the therapeutic dose of 2 mg. Conclusions The pharmacokinetics of repaglinide in subjects carrying the CYP2C8*3 mutant allele did not differ significantly from those in the wild-types. Grapefruit juice increased the bioavailability of repaglinide, suggesting significant intestinal elimination of the drug which was assumed to be primarily mediated by CYP3A4 in the gut. PMID:16390351

  3. Quadrupolar interaction of ^57Fe in compounds RENi_2B_2C: Experimental and Theoretical Studies

    NASA Astrophysics Data System (ADS)

    Zeng, Zhi; Guenzburger, Diana; Sanchez, D. R. S.; Bud'Ko, S. L.; Fontes, Magda B.; Baggia-Saitovitch, E. M.; Ellis, D. E.

    1996-03-01

    ^57Fe Mössbauer spectra were taken with the RE(Ni_0.99^57Fe_0.01)_2B_2C (RE=Tb, Dy, Ho, Er) samples in a variable temperature helium crysostat to study the interplay between superconductivity and magnetism in the RENi_2B_2C (RE=Dy, Ho, Er, Tm) compounds. The rare earth dependent quadrupole splitting (QS) from ^57Fe Mössbauer spectra decreases with the lanthanide contraction^footnotetext^The lanthanide contraction causes an increase in the ratio c/a along the RE series. from QS=0.27mm/s for TbNi_2B_2C to QS=0.14mm/s for ErNi_2B_2C. Self-consistent frist-principles electronic structure calculation[1] were performed for clusters with 71 atoms (Fe-12RE-14Ni-32B-12C), which were embedded in the charge denisity of several shells of neighbours in the crystal, representing the doped compounds RE(Ni_0.93Fe_0.07)_2B_2C (RE=Gd, Tb, Dy, Ho, and Er). The quadrupole splitting was obtained with the nuclear quadrupole moment Q=0.16b of ^57Fe[2]. The calculated results are in good agreement with experiment. The theoretical results give negative signs for all the QS values; which have not been determined by experiment, except for the compounds with Tb and Ho, for which they are negative. REFERENCES D.E. Ellis, Int. J. Quant. Chem. Suppl. 2, 35(1968); D.E. Ellis and G.S. Painter, Phys. Rev. B, 2, 2887(1970). Ohilipp Dufek, Peter Blaha and K. Schwarz, Phys. Rev. Lett. 75, 3545(1995).

  4. Apoptosis in differentiating C2C12 muscle cells selectively targets Bcl-2-deficient myotubes

    PubMed Central

    Schoneich, Christian; Dremina, Elena; Galeva, Nadezhda; Sharov, Victor

    2014-01-01

    Muscle cell apoptosis accompanies normal muscle development and regeneration, as well as degenerative diseases and aging. C2C12 murine myoblast cells represent a common model to study muscle differentiation. Though it was already shown that myogenic differentiation of C2C12 cells is accompanied by enhanced apoptosis in a fraction of cells, either the cell population sensitive to apoptosis or regulatory mechanisms for the apoptotic response are unclear so far. In the current study we characterize apoptotic phenotypes of different types of C2C12 cells at all stages of differentiation, and report here that myotubes of differentiated C2C12 cells with low levels of anti-apoptotic Bcl-2 expression are particularly vulnerable to apoptosis even though they are displaying low levels of pro-apoptotic proteins Bax, Bak and Bad. In contrast, reserve cells exhibit higher levels of Bcl-2 and high resistance to apoptosis. The transfection of proliferating myoblasts with Bcl-2 prior to differentiation did not protect against spontaneous apoptosis accompanying differentiation of C2C12 cell but led to Bcl-2 overexpression in myotubes and to significant protection from apoptotic cell loss caused by exposure to hydrogen peroxide. Overall, our data advocate for a Bcl-2-dependent mechanism of apoptosis in differentiated muscle cells. However, downstream processes for spontaneous and hydrogen peroxide induced apoptosis are not completely similar. Apoptosis in differentiating myoblasts and myotubes is regulated not through interaction of Bcl-2 with pro-apoptotic Bcl-2 family proteins such as Bax, Bak, and Bad. PMID:24129924

  5. The challenge of precise orbit determination for STSAT-2C using extremely sparse SLR data

    NASA Astrophysics Data System (ADS)

    Kim, Young-Rok; Park, Eunseo; Kucharski, Daniel; Lim, Hyung-Chul; Kim, Byoungsoo

    2016-03-01

    The Science and Technology Satellite (STSAT)-2C is the first Korean satellite equipped with a laser retro-reflector array for satellite laser ranging (SLR). SLR is the only on-board tracking source for precise orbit determination (POD) of STSAT-2C. However, POD for the STSAT-2C is a challenging issue, as the laser measurements of the satellite are extremely sparse, largely due to the inaccurate two-line element (TLE)-based orbit predictions used by the SLR tracking stations. In this study, POD for the STSAT-2C using extremely sparse SLR data is successfully implemented, and new laser-based orbit predictions are obtained. The NASA/GSFC GEODYN II software and seven-day arcs are used for the SLR data processing of two years of normal points from March 2013 to May 2015. To compensate for the extremely sparse laser tracking, the number of estimation parameters are minimized, and only the atmospheric drag coefficients are estimated with various intervals. The POD results show that the weighted root mean square (RMS) post-fit residuals are less than 10 m, and the 3D day boundaries vary from 30 m to 3 km. The average four-day orbit overlaps are less than 20/330/20 m for the radial/along-track/cross-track components. The quality of the new laser-based prediction is verified by SLR observations, and the SLR residuals show better results than those of previous TLE-based predictions. This study demonstrates that POD for the STSAT-2C can be successfully achieved against extreme sparseness of SLR data, and the results can deliver more accurate predictions.

  6. Structural and energetic analysis to provide insight residues of CYP2C9, 2C11 and 2E1 involved in valproic acid dehydrogenation selectivity.

    PubMed

    Bello, Martiniano; Mendieta-Wejebe, Jessica E; Correa-Basurto, José

    2014-07-15

    Docking and molecular dynamics (MD) simulation have been two computational techniques used to gain insight about the substrate orientation within protein active sites, allowing to identify potential residues involved in the binding and catalytic mechanisms. In this study, both methods were combined to predict the regioselectivity in the binding mode of valproic acid (VPA) on three cytochrome P-450 (CYP) isoforms CYP2C9, CYP2C11, and CYP2E1, which are involved in the biotransformation of VPA yielding reactive hepatotoxic intermediate 2-n-propyl-4-pentenoic acid (4nVPA). There are experimental data about hydrogen atom abstraction of the C4-position of VPA to yield 4nVPA, however, there are not structural evidence about the binding mode of VPA and 4nVPA on CYPs. Therefore, the complexes between these CYP isoforms and VPA or 4nVPA were studied to explore their differences in binding and energetic stabilization. Docking results showed that VPA and 4nVPA are coupled into CYPs binding site in a similar conformation, but it does not explain the VPA hydrogen atom abstraction. On the other hand, MD simulations showed a set of energetic states that reorient VPA at the first ns, then making it susceptible to a dehydrogenation reaction. For 4nVPA, multiple binding modes were observed in which the different states could favor either undergo other reaction mechanism or ligand expulsion from the binding site. Otherwise, the energetic and entropic contribution point out a similar behavior for the three CYP complexes, showing as expected a more energetically favorable binding free energy for the complexes between CYPs and VPA than with 4nVPA.

  7. Toward reduction in animal sacrifice for drugs: molecular modeling of Macaca fascicularis P450 2C20 for virtual screening of Homo sapiens P450 2C8 substrates.

    PubMed

    Rua, Francesco; Di Nardo, Giovanna; Sadeghi, Sheila J; Gilardi, Gianfranco

    2012-01-01

    Macaca fascicularis P450 2C20 shares 92% identity with human cytochrome P450 2C8, which is involved in the metabolism of more than 8% of all prescribed drugs. To date, only paclitaxel and amodiaquine, two substrate markers of the human P450 2C8, have been experimentally confirmed as M. fascicularis P450 2C20 drugs. To bridge the lack of information on the ligands recognized by M. fascicularis P450 2C20, in this study, a three-dimensional homology model of this enzyme was generated on the basis of the available crystal structure of the human homologue P450 2C8 using YASARA. The results indicated that 90.0%, 9.0%, 0.5%, and 0.5% of the residues of the P450 2C20 model were located in the most favorable, allowed, generously allowed, and disallowed regions, respectively. The root-mean-square deviation of the C-alpha superposition of the M. fascicularis P450 2C20 model with the Homo sapiens P450 2C8 was 0.074 Å, indicating a very high similarity of the two structures. Subsequently, the 2C20 model was used for in silico screening of 58 known P450 2C8 substrates and 62 inhibitors. These were also docked in the active site of the crystal structure of the human P450 2C8. The affinity of each compound for the active site of both cytochromes proved to be very similar, meaning that the few key residues that are mutated in the active site of the M. fascicularis P450 do not prevent the P450 2C20 from recognizing the same substrates as the human P450 2C8.

  8. Sedative-Hypnotic and Receptor Binding Studies of Fermented Marine Organisms

    PubMed Central

    Joung, Hye-Young; Kang, Young Mi; Lee, Bae-Jin; Chung, Sun Yong; Kim, Kyung-Soo; Shim, Insop

    2015-01-01

    This study was performed to investigate the sedative-hypnotic activity of γ-aminobutyric acid (GABA)-enriched fermented marine organisms (FMO), including sea tangle (FST) and oyster (FO) by Lactobacillus brevis BJ20 (L. brevis BJ20). FST and FO were tested for their binding activity of the GABAA-benzodiazepine and 5-HT2C receptors, which are well-known molecular targets for sleep aids. We also measured the sleep latency and sleep duration during pentobarbital-induced sleep in mice after oral administration of FST and FO. In GABAA and 5-HT2C receptor binding assays, FST displayed an effective concentration-dependent binding affinity to GABAA receptor, similar to the binding affinity to 5-HT2C receptor. FO exhibited higher affinity to 5-HT2C receptor, compared with the GABAA receptor. The oral administration of FST and FO produced a dose-dependent decrease in sleep latency and increase in sleep duration in pentobarbital-induced hypnosis. The data demonstrate that FST and FO possess sedative-hypnotic activity possibly by modulating GABAA and 5-HT2C receptors. We propose that FST and FO might be effective agents for treatment of insomnia. PMID:26336589

  9. The effect of intrahippocampal injections of ritanserin (5HT2A/2C antagonist) and granisetron (5HT3 antagonist) on learning as assessed in the spatial version of the water maze.

    PubMed

    Naghdi, Nasser; Harooni, Hooman E

    2005-02-28

    5HT(2A/2C) and 5HT(3) receptors have an important role in cognitive behavior specially in spatial learning and memory but the literature concerning the role of these receptors in hippocampus in cognition remains controversial. In the present study a 5HT(2A/2C) antagonist ritanserin (0, 2, 4, 8 microg/0.5 microl) and a 5HT(3) antagonist granisetron (0.0, 0.05, 0.25, 0.5 microg/0.5 microl) were injected bilaterally into the CA1 region of rat hippocampus, 20 min before each training session in Morris Water Maze (MWM) task. Compare with control group, ritanserin (4 microg/0.5 microl) significantly reduced the escape latency and traveled distance of swimming to platform, but granisetron (0.25 microg/0.5 microl) significantly increased those parameters. Both drugs had no effect on escape latency and traveled distance of a non-spatial visual discrimination task. These results suggest a differential role of 5HT(2A/2C) and 5HT(3) receptors during spatial learning that ritanserin improves rat performance in spatial discrimination task whereas granisetron impairs it.

  10. Effect of GABAergic ligands on the anxiolytic-like activity of DOI (a 5-HT(2A/2C) agonist) in the four-plate test in mice.

    PubMed

    Massé, Fabienne; Hascoët, Martine; Bourin, Michel

    2007-01-01

    5-HTergic and GABAergic systems are involved in neurobiology of anxiety. Precedent studies have demonstrated that SSRIs possessed an anxiolytic-like effect in the four-plate test (FPT) at doses that did not modify spontaneous locomotor activity. This effect seems to be mediated through the activation of 5-HT(2A) postsynaptic receptors. The purpose of the present study was to examine the implication of GABA system in the anxiolytic-like activity of DOI in the FPT. To achieve this, the co-administration of DOI (5-HT(2A/2C) receptor agonists) with GABA(A) and GABA(B) receptor ligands was evaluated in the FPT. Alprazolam, diazepam and muscimol (for higher dose) potentiated the anxiolytic-like effect of DOI. Bicuculline, picrotoxin and baclofen inhibited the anxiolytic-like effect of DOI. Flumazenil and CGP 35348 had no effect on the anxiolytic-like activity of DOI. These results suggest that the GABA system seems to be strongly implicated in the anxiolytic-like activity of DOI in the FPT.

  11. First-principles study of electronic states in Mg2C

    NASA Astrophysics Data System (ADS)

    Trivedi, D. K.; Galav, K. L.; Paliwal, U.; Joshi, K. B.

    2016-05-01

    The electronic properties of magnesium methanide Mg2C are reported. Investigations are carried out applying the linear combination of atomic orbitals method. After settling ground state of the antifluorite structure the electronic band structure calculations are undertaken using PBE-GGA exchange and correlation functional and PBE0 hybrid functional. All calculations show that Mg2C has indirect band gap with conduction band minimum at Γ and valence band maximum at the X point. The values of band gap from PBE and the PBE0 are 2.05 and 3.46 eV respectively. In comparison to beryllium methanide the electronic bands are flat suggesting ionic nature of bonding.

  12. Degradation of triclocarban by a triclosan-degrading Sphingomonas sp. strain YL-JM2C.

    PubMed

    Mulla, Sikandar I; Hu, Anyi; Wang, Yuwen; Sun, Qian; Huang, Shir-Ly; Wang, Han; Yu, Chang-Ping

    2016-02-01

    Bacterial degradation plays a vital role in determining the environmental fate of micropollutants like triclocarban. The mechanism of triclocarban degradation by pure bacterium is not yet explored. The purpose of this study was to identify metabolic pathway that might be involved in bacterial degradation of triclocarban. Triclosan-degrading Sphingomonas sp. strain YL-JM2C was first found to degrade up to 35% of triclocarban (4 mg L(-1)) within 5 d. Gas chromatography-mass spectrometry detected 3,4-dichloroaniline, 4-chloroaniline and 4-chlorocatechol as the major metabolites of the triclocarban degradation. Furthermore, total organic carbon results confirmed that the intermediates, 3,4-dichloroaniline (4 mg L(-1)) and 4-chloroaniline (4 mg L(-1)) could be degraded up to 77% and 80% by strain YL-JM2C within 5 d. PMID:26364219

  13. Novel Polycarbo-Substituted Imidazo[1,2-c]quinazolines: Synthesis and Cytotoxicity Study.

    PubMed

    Khoza, Tebogo Ankie; Makhafola, Tshepiso Jan; Mphahlele, Malose Jack

    2015-01-01

    Amination of the 2-aryl-6-bromo-4-chloro-8-iodoquinazolines with 2-aminoethanol followed by acid-promoted cyclodehydration of the incipient 2-((6,8-dihalo-2-phenylquinazolin-4-yl)amino)ethanols afforded the corresponding novel 5-aryl-9-bromo-7-iodo-2,3-dihydro-2H-imidazo[1,2-c]quinazolines. The latter were, in turn, subjected to sequential (Sonogashira and Suzuki-Miyaura) and one-pot two-step (Sonogashira/Stille) cross-coupling reactions to afford diversely functionalized polycarbo-substituted 2H-imidazo[1,2-c]quinazolines. The imidazoquinazolines were screened for in vitro cytotoxicity against human breast adenocarcinoma (MCF-7) cells and human cervical cancer (HeLa) cells. PMID:26694336

  14. Degradation of triclocarban by a triclosan-degrading Sphingomonas sp. strain YL-JM2C.

    PubMed

    Mulla, Sikandar I; Hu, Anyi; Wang, Yuwen; Sun, Qian; Huang, Shir-Ly; Wang, Han; Yu, Chang-Ping

    2016-02-01

    Bacterial degradation plays a vital role in determining the environmental fate of micropollutants like triclocarban. The mechanism of triclocarban degradation by pure bacterium is not yet explored. The purpose of this study was to identify metabolic pathway that might be involved in bacterial degradation of triclocarban. Triclosan-degrading Sphingomonas sp. strain YL-JM2C was first found to degrade up to 35% of triclocarban (4 mg L(-1)) within 5 d. Gas chromatography-mass spectrometry detected 3,4-dichloroaniline, 4-chloroaniline and 4-chlorocatechol as the major metabolites of the triclocarban degradation. Furthermore, total organic carbon results confirmed that the intermediates, 3,4-dichloroaniline (4 mg L(-1)) and 4-chloroaniline (4 mg L(-1)) could be degraded up to 77% and 80% by strain YL-JM2C within 5 d.

  15. The transport properties of the molecular-scale B2C and BC3 electronic devices

    NASA Astrophysics Data System (ADS)

    Li, Guiqin; Li, Runqin

    2012-09-01

    The transport properties of the molecular-scale B2C and BC3 electronic devices are investigated with an ab initio method combined with a nonequilibrium Green function technique. The effects of different BC graphenes and ribbon lengths on the transport properties of the devices are significant. The results show that the devices with different BC graphenes and sizes have unusual transmission coefficients, which leads to special current transport mechanisms for the devices. Notably, the current strength of the device with the shortest ribbon length is the largest in three B2C devices, but the current strength of the device with the shortest ribbon length is the smallest for BC3 device.

  16. Capacitance behavior of nanostructured ɛ-MnO2/C composite electrode using different carbons matrix

    NASA Astrophysics Data System (ADS)

    Tran, Van Man; Ha, An The; Loan Phung Le, My

    2014-06-01

    In this work nanostructured ɛ-MnO2/C composite electrode was synthesized via the reduction reaction of potassium permanganate. A wide range of carbons such as mesoporous carbon (MC), graphite (GC), super P carbon (super P) and Vulcan carbon (VC) were used in order to enhance the interfacial electrical conductivity and the electrochemical capacitance of the composite electrodes. Physical properties, structure and specific surface area of electrode materials were investigated by scanning electron microscopy (SEM), x-ray diffraction and nitrogen adsorption measurements. The capacitance behavior of MnO2/C materials was studied in aqueous and non-aqueous solution using cyclic voltammetry, galvanostatic charge/discharge and impedance spectroscopy measurements. The composite electrode exhibits the highest capacitance at 30 wt% activated carbon. Among different carbons used, the maximum capacitance of MnO2/super P electrode is as high as 205 F g-1 at 50 mV s-1 and retains 98% after 300 cycles.

  17. Electronic shell structures of Russian-doll-style Sc 4C 2@C 80

    NASA Astrophysics Data System (ADS)

    Chen, Zhifan; Kah, Cherno B.; Wang, Xiao-Qian

    2011-04-01

    We have studied the electronic properties of a 'Russian-doll'-style endohedral fullerene Sc 4C 2@C 80 based on first-principles density-functional calculations coupled with many-body GW correction. Our calculation results yield a GW rectified gap of 1.8 eV for the 'Russian doll' structured Sc 4C 2@C 80, in very good conformity with experimental observed value of 1.6 eV. The calculated electronic characteristics of the Russian-doll fullerene reveal distinct shell structures, which are embellished in the GW approach. The analysis of vibrational frequency demonstrates profound hybridizations associated with the interactions between the Sc 4C 2 core and C 80 shell.

  18. 12. 'Portal Strut for 1 208'101/2' C. to C. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    12. 'Portal Strut for 1 - 208'-10-1/2' C. to C. End Pins S. Tr. Thro. Skew Span, 6th Crossing of Sacramento River, So. Pac. Co., The Phoenix Bridge Co., C.O. 836D, Drawing No. 12, Scale - 1' = 1', Engineer - B.M. Krohn, May 22nd `01, J.C.S.' - Southern Pacific Railroad Shasta Route, Bridge No. 301.85, Milepost 301.85, Pollard Flat, Shasta County, CA

  19. 11. 'Erection Plan, 1 208'101/2' C. to C. End ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    11. 'Erection Plan, 1 - 208'-10-1/2' C. to C. End Pins S. Tr. Thro. Skew Span, 6th Crossing Sacramento River, Pacific System, Southern Pacific Company, The Phoenix Bridge Co., C.O. 836D, Drawing No. 13, Scale 1/8' = 1'0', Engineer, B.M. Krohn, Draftsman, W.L. Clegg, Date, May 25th 1901' - Southern Pacific Railroad Shasta Route, Bridge No. 301.85, Milepost 301.85, Pollard Flat, Shasta County, CA

  20. 13. 'Transverse Bracing for 1 208'101/2' C. to C. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    13. 'Transverse Bracing for 1 - 208'-10-1/2' C. to C. End Pins S. Tr. Thro. Skew Span, 6th Crossing of Sacramento River, So. Pac. Co., The Phoenix Bridge Co., C.O. 836D, Drawing No. 7, Scale - 1' = 1', Engineer - B.M. Krohn, May 11th `01, Slaughter' - Southern Pacific Railroad Shasta Route, Bridge No. 301.85, Milepost 301.85, Pollard Flat, Shasta County, CA

  1. Intercomparison of an improved 20th Century reanalysis version 2c dataset spanning 1850 to 2012

    NASA Astrophysics Data System (ADS)

    Compo, G. P.; Whitaker, J. S.; Sardeshmukh, P. D.; Giese, B. S.; Brohan, P.

    2014-12-01

    The historical reanalysis dataset generated by NOAA ESRL and the University of Colorado CIRES, the Twentieth Century Reanalysis version 2 (20CRv2), is a comprehensive global atmospheric circulation dataset spanning 1871-2012, assimilating only surface pressure and using monthly Hadley Centre SST and sea ice distributions (HadISST1.1) as boundary conditions. It has been made possible through collaboration with GCOS, WCRP, and the ACRE initiative. It is chiefly motivated by a need to provide an observational validation dataset, with quantified uncertainties, for assessments of climate model simulations of the 20th century, with emphasis on the statistics of daily weather. It uses, together with an NCEP global numerical weather prediction (NWP) land/atmosphere model to provide background "first guess" fields, an Ensemble Kalman Filter (EnKF) data assimilation method. This yields a global analysis every 6 hours as the most likely state of the atmosphere, and also yields the uncertainty of that analysis. Improvements in the new version ("2c") include an extension back to 1850 and the specification of new boundary conditions. These come from new fields of monthly COBE-SST2 sea ice concentrations and an ensemble of daily Simple Ocean Data Assimilation with Sparse Input (SODAsi.2c) sea surface temperatures. SODAsi.2c itself was forced with 20CR, allowing these boundary conditions to be more consistent with the atmospheric reanalysis. Millions of additional pressure observations contained in the new International Surface Pressure Databank version 3 are also included. These improvements result in 20CR version "2c" having comparable or better analyses, as suggested by improved 24 hour forecast skill, more realistic uncertainty in near-surface air temperature, and a reduction in spurious centennial trends in the tropical and polar regions. An intercomparison with ERA-Interim, MERRA, and JRA-55 reanalyses that assimilate all available upper-air and satellite observations will

  2. Floating zone growth and magnetic properties of Y2C two-dimensional electride

    NASA Astrophysics Data System (ADS)

    Otani, Shigeki; Hirata, Kazuto; Adachi, Yutaka; Ohashi, Naoki

    2016-11-01

    The floating zone method was used to obtain single crystals several mm in size of the low-temperature rhombohedral form of Y2C rather than its typical rocksalt-type cubic form. This was achieved through optimization of the chemical compositions of the starting materials with the aim of producing a two-dimensional electride material. The crystals obtained exhibited a paramagnetic temperature-dependence at 1.8-300 K, with no trace of any obvious magnetic ordering.

  3. Experimental Investigation of the Cr3C2 C Peritectic Fixed Point

    NASA Astrophysics Data System (ADS)

    Zheng, W.; Yamada, Y.; Wang, Y.

    2008-06-01

    The Cr3C2 C (1,826°C) peritectic point was investigated for its performance as a high-temperature fixed point. Dependence on the impurity content was observed, although it was less severe for the higher of the two equilibrium temperatures obtained with the same cell, the Cr3C2 C peritectic point, than for the lower, the Cr7C3 Cr3C2 eutectic point. Thermal history had an effect on the melting plateau duration, but not on the point-of-inflection temperature nor on the melting range. The melting rate had no apparent effect. The repeatability evaluated as the standard deviation of the repeated melting plateaux within a day was 20 mK for the Cr3C2 C peritectic point, while for the Cr7C3 Cr3C2 eutectic point, this was 210 mK. For both the Cr3C2 C peritectic and the Cr7C3 Cr3C2 eutectic, the freezing plateaux often showed deep supercools, which made them unsuitable for use. The observed good repeatability shows the peritectic-point performance to be comparable to the best MC-eutectic high-temperature fixed points investigated so far. The insensitivity to thermal history constitutes an important and practical advantage. The low price of chromium is a clear benefit as compared to Pt C (1,738°C) or Ru C (1,953°C) eutectic points, the M C eutectic points in this temperature range.

  4. I2C: a system for the indexing, storage, and retrieval of medical images by content.

    PubMed

    Orphanoudakis, S C; Chronaki, C; Kostomanolakis, S

    1994-01-01

    Image indexing, storage, and retrieval based on pictorial content is a feature of image database systems which is becoming of increasing importance in many application domains. Medical image database systems, which support the retrieval of images generated by different modalities based on their pictorial content, will provide added value to future generation picture archiving and communication systems (PACS), and can be used as a diagnostic decision support tools and as a tool for medical research and training. We present the architecture and features of I2C, a system for the indexing, storage, and retrieval of medical images by content. A unique design feature of this architecture is that it also serves as a platform for the implementation and performance evaluation of image description methods and retrieval strategies. I2C is a modular and extensible system, which has been developed based on object-oriented principles. It consists of a set of cooperating modules which facilitate the addition of new graphical tools, image description and matching algorithms. These can be incorporated into the system at the application level. The core concept of I2C is an image class hierarchy. Image classes encapsulate different segmentation and image content description algorithms. Medical images are assigned to image classes based on a set of user-defined attributes such as imaging modality, type of study, anatomical characteristics, etc. This class-based treatment of images in the I2C system achieves increased accuracy and efficiency of content-based retrievals, by limiting the search space and allowing specific algorithms to be fine-tuned for images acquired by different modalities or representing different parts of the anatomy.

  5. Direct evidence for the electronic phase inhomogeneity in HoNi 2B 2C

    NASA Astrophysics Data System (ADS)

    Chechersky, Vladimir; Nath, Amar; Cava, R. J.

    1998-07-01

    We substitute a few parts per million of 57Co for Ni. The Mössbauer spectra of HoNi2( 57Co) B2C reveal the presence of two components, one of which is truly metallic as indicated by delocalization of 3d electrons. In the other component, the electrons are delocalized to a lesser extent. The relative ratio of the components can vary from sample to sample.

  6. CMIP and ATP2C2 Modulate Phonological Short-Term Memory in Language Impairment

    PubMed Central

    Newbury, Dianne F.; Winchester, Laura; Addis, Laura; Paracchini, Silvia; Buckingham, Lyn-Louise; Clark, Ann; Cohen, Wendy; Cowie, Hilary; Dworzynski, Katharina; Everitt, Andrea; Goodyer, Ian M.; Hennessy, Elizabeth; Kindley, A. David; Miller, Laura L.; Nasir, Jamal; O'Hare, Anne; Shaw, Duncan; Simkin, Zoe; Simonoff, Emily; Slonims, Vicky; Watson, Jocelynne; Ragoussis, Jiannis; Fisher, Simon E.; Seckl, Jonathon R.; Helms, Peter J.; Bolton, Patrick F.; Pickles, Andrew; Conti-Ramsden, Gina; Baird, Gillian; Bishop, Dorothy V.M.; Monaco, Anthony P.

    2009-01-01

    Specific language impairment (SLI) is a common developmental disorder characterized by difficulties in language acquisition despite otherwise normal development and in the absence of any obvious explanatory factors. We performed a high-density screen of SLI1, a region of chromosome 16q that shows highly significant and consistent linkage to nonword repetition, a measure of phonological short-term memory that is commonly impaired in SLI. Using two independent language-impaired samples, one family-based (211 families) and another selected from a population cohort on the basis of extreme language measures (490 cases), we detected association to two genes in the SLI1 region: that encoding c-maf-inducing protein (CMIP, minP = 5.5 × 10−7 at rs6564903) and that encoding calcium-transporting ATPase, type2C, member2 (ATP2C2, minP = 2.0 × 10−5 at rs11860694). Regression modeling indicated that each of these loci exerts an independent effect upon nonword repetition ability. Despite the consistent findings in language-impaired samples, investigation in a large unselected cohort (n = 3612) did not detect association. We therefore propose that variants in CMIP and ATP2C2 act to modulate phonological short-term memory primarily in the context of language impairment. As such, this investigation supports the hypothesis that some causes of language impairment are distinct from factors that influence normal language variation. This work therefore implicates CMIP and ATP2C2 in the etiology of SLI and provides molecular evidence for the importance of phonological short-term memory in language acquisition. PMID:19646677

  7. Characterization of triclosan metabolism in Sphingomonas sp. strain YL-JM2C

    PubMed Central

    Mulla, Sikandar I.; Wang, Han; Sun, Qian; Hu, Anyi; Yu, Chang-Ping

    2016-01-01

    Triclosan (TCS) is one of the most widespread emerging contaminants and has adverse impact on aquatic ecosystem, yet little is known about its complete biodegradation mechanism in bacteria. Sphingomonas sp, strain YL-JM2C, isolated from activated sludge of a wastewater treatment plant, was very effective on degrading TCS. Response surface methodology (RSM) was applied to optimize the conditions like temperature and pH. From RSM, the optimal TCS degradation conditions were found to be 30 °C and pH 7.0. Under optimal conditions, strain YL-JM2C completely mineralized TCS (5 mg L−1) within 72 h. Gas chromatography-mass spectrometry analysis revealed that 2,4-dichlorophenol, 2-chlorohydroquinone and hydroquinone are three main by-products of TCS. Furthermore, stable isotope experimental results revealed that the 13C12-TCS was completely mineralized into CO2 and part of heavier carbon (13C) of labeled TCS was utilized by strain YL-JM2C to synthesize fatty acids (PLFAs). Cell surface hydrophobicity (CSH) and degradation test results suggested that the strain could enhance degradation capacity of TCS through increasing CSH. In addition, the bacterium also completely degraded spiked TCS (5 mg L−1) in wastewater collected from the wastewater treatment plant. Hence, these results suggest that the strain has potential to remediate TCS in the environment. PMID:26912101

  8. Cyclotron Production of (99m)Tc using (100)Mo2C targets.

    PubMed

    Richards, Vernal N; Mebrahtu, Efrem; Lapi, Suzanne E

    2013-10-01

    An investigative study of the (100)Mo (p,2n)(99m)Tc reaction on a medical cyclotron using (100)Mo2C is reported. This is the first report of this compound being used as a target for this reaction. (100)Mo2C, a refractory carbide with high thermal conductivity, properties which underscore its use on a cyclotron, was synthesized using (100)MoO3. Its ease of oxidation back to (100)MoO3 under air at elevated temperatures facilitates the use of thermo-chromatography, a high temperature gas phase separation technique for the separation and isolation of (99m)Tc. Activity yields for (99m)Tc averaged 84% of the calculated theoretical yields. Additionally, the percent recovery of MoO3, the precursor for Mo2C, was consistently high at 85% ensuring a good life cycle for this target material. The produced (99m)Tc was radio-chemically pure and easily labeled MDP for imaging purposes.

  9. Li2C2, a High-Capacity Cathode Material for Lithium Ion Batteries.

    PubMed

    Tian, Na; Gao, Yurui; Li, Yurong; Wang, Zhaoxiang; Song, Xiaoyan; Chen, Liquan

    2016-01-11

    As a typical alkaline earth metal carbide, lithium carbide (Li2C2) has the highest theoretical specific capacity (1400 mA h g(-1)) among all the reported lithium-containing cathode materials for lithium ion batteries. Herein, the feasibility of using Li2C2 as a cathode material was studied. The results show that at least half of the lithium can be extracted from Li2C2 and the reversible specific capacity reaches 700 mA h g(-1). The C≡C bond tends to rotate to form C4 (C≡C⋅⋅⋅C≡C) chains during lithium extraction, as indicated with the first-principles molecular dynamics (FPMD) simulation. The low electronic and ionic conductivity are believed to be responsible for the potential gap between charge and discharge, as is supported with density functional theory (DFT) calculations and Arrhenius fitting results. These findings illustrate the feasibility to use the alkali and alkaline earth metal carbides as high-capacity electrode materials for secondary batteries.

  10. Elementary Steps of Syngas Reactions on Mo2C(001): Adsorption Thermochemistry and Bond Dissociation

    SciTech Connect

    Medford, Andrew

    2012-02-16

    Density functional theory (DFT) and ab initio thermodynamics are applied in order to investigate the most stable surface and subsurface terminations of Mo{sub 2}C(001) as a function of chemical potential and in the presence of syngas. The Mo-terminated (001) surface is then used as a model surface to evaluate the thermochemistry and energetic barriers for key elementary steps in syngas reactions. Adsorption energy scaling relations and Broensted-Evans-Polanyi relationships are established and used to place Mo{sub 2}C into the context of transition metal surfaces. The results indicate that the surface termination is a complex function of reaction conditions and kinetics. It is predicted that the surface will be covered by either C{sub 2}H{sub 2} or O depending on conditions. Comparisons to transition metals indicate that the Mo-terminated Mo{sub 2}C(001) surface exhibits carbon reactivity similar to transition metals such as Ru and Ir, but is significantly more reactive towards oxygen.

  11. Composite Interlaminar Shear Fracture Toughness, G(sub 2c): Shear Measurement of Sheer Myth?

    NASA Technical Reports Server (NTRS)

    OBrien, T. Kevin

    1997-01-01

    The concept of G2c as a measure of the interlaminar shear fracture toughness of a composite material is critically examined. In particular, it is argued that the apparent G2c as typically measured is inconsistent with the original definition of shear fracture. It is shown that interlaminar shear failure actually consists of tension failures in the resin rich layers between plies followed by the coalescence of ligaments created by these failures and not the sliding of two planes relative to one another that is assumed in fracture mechanics theory. Several strain energy release rate solutions are reviewed for delamination in composite laminates and structural components where failures have been experimentally documented. Failures typically occur at a location where the mode 1 component accounts for at least one half of the total G at failure. Hence, it is the mode I and mixed-mode interlaminar fracture toughness data that will be most useful in predicting delamination failure in composite components in service. Although apparent G2c measurements may prove useful for completeness of generating mixed-mode criteria, the accuracy of these measurements may have very little influence on the prediction of mixed-mode failures in most structural components.

  12. Cited3 activates Mef2c to control muscle cell differentiation and survival.

    PubMed

    Devakanmalai, Gnanapackiam Sheela; Zumrut, Hasan E; Ozbudak, Ertuğrul M

    2013-05-15

    Vertebrate muscle development occurs through sequential differentiation of cells residing in somitic mesoderm - a process that is largely governed by transcriptional regulators. Our recent spatiotemporal microarray study in zebrafish has identified functionally uncharacterized transcriptional regulators that are expressed at the initial stages of myogenesis. cited3 is one such novel gene encoding a transcriptional coactivator, which is expressed in the precursors of oxidative slow-twitch myofibers. Our experiments placed cited3 into a gene regulatory network, where it acts downstream of Hedgehog signaling and myoD/myf5 but upstream of mef2c. Knockdown of expression of cited3 by antisense morpholino oligonucleotides impaired muscle cell differentiation and growth, caused muscle cell death and eventually led to total immotility. Transplantation experiments demonstrated that Cited3 cell-autonomously activates the expression of mef2c in slow myofibers, while it non-cell-autonomously regulates expression of structural genes in fast myofibers. Restoring expression of cited3 or mef2c rescued all the cited3 loss-of-function phenotypes. Protein truncation experiments revealed the functional necessity of C-terminally conserved domain of Cited3, which is known to mediate interactions of Cited-family proteins with histone acetylases. Our findings demonstrate that Cited3 is a critical transcriptional coactivator functioning during muscle differentiation and its absence leads to defects in terminal differentiation and survival of muscle cells.

  13. Gene Expression and Methylation Signatures of MAN2C1 are Associated with PTSD

    PubMed Central

    Uddin, Monica; Galea, Sandro; Chang, Shun-Chiao; Aiello, Allison E.; Wildman, Derek E.; de los Santos, Regina; Koenen, Karestan C.

    2011-01-01

    As potential regulators of DNA accessibility and activity, epigenetic modifications offer a mechanism by which the environment can moderate the effects of genes. To date, however, there have been relatively few studies assessing epigenetic modifications associated with post-traumatic stress disorder (PTSD). Here we investigate PTSD-associated methylation differences in 33 genes previously shown to differ in whole blood-derived gene expression levels between those with vs. without the disorder. Drawing on DNA samples similarly obtained from whole blood in 100 individuals, 23 with and 77 without lifetime PTSD, we used methylation microarray data to assess whether these 33 candidate genes showed epigenetic signatures indicative of increased risk for, or resilience to, PTSD. Logistic regression analyses were performed to assess the main and interacting effects of candidate genes’ methylation values and number of potentially traumatic events (PTEs), adjusting for age and other covariates. Results revealed that only one candidate gene–MAN2C1–showed a significant methylation x PTE interaction, such that those with both higher MAN2C1 methylation and greater exposure to PTEs showed a marked increase in risk of lifetime PTSD (OR 4.35, 95% CI: 1.07, 17.77, p = 0.04). These results indicate that MAN2C1 methylation levels modify cumulative traumatic burden on risk of PTSD, and suggest that both gene expression and epigenetic changes at specific loci are associated with this disorder. PMID:21508515

  14. Enhancement of anti-OVA IgG2c production in vivo by enalapril

    PubMed Central

    Almeida, L.C.; Muraro, L.S.; Albuquerque, D.A.

    2016-01-01

    Angiotensin-converting enzyme (ACE) inhibitors have non-hemodynamic, pleiotropic effects on the immune response. The effects of ACE inhibitors on the production of cytokines and T-cell functions are well established. However, little is known on the effects of these medicines on humoral response to foreign antigens. In this study, we investigated the effect of enalapril treatment on ovalbumin (OVA)-specific IgG1 and IgG2c production in mice determined by ELISA. Two groups of 8-week-old C57BL/6 females mice (3–4/group) were subcutaneously immunized with OVA (10 μg/animal) in presence of Alhydrogel (1 mg/mouse) and boosted at day 21. The mice were treated with enalapril (5 mg/kg daily, po) or were left without treatment for one month. The animals were bled from the orbital plexus on days 0, 7, 14, 21, and 28 after the first immunization and the sera were stored at –20°C until usage. OVA-specific serum IgG1 and IgG2c were determined by ELISA using serum from each individual animal. The results showed that enalapril significantly increased anti-OVA serum IgG2c in the secondary response without affecting IgG1 synthesis. These data expand our understanding on the properties of enalapril on the immune response, including antibody production. PMID:27409332

  15. Preparation of mesoporous MnO2/C catalyst for n-hexyl acetate synthesis

    NASA Astrophysics Data System (ADS)

    Yang, Zeheng; Pan, Yanmei; Mei, Zhousheng; Zhang, Weixin

    2012-03-01

    A mesoporous MnO2/C composite was prepared by impregnating self-made porous carbon spheres with manganese nitrate aqueous solution and subsequently reacting with KMnO4 aqueous solution. It was characterized with X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), field emission scanning electron microscopy (FESEM), the Brunauer-Emmett-Teller (BET) surface area and the Barrett-Joyner-Halenda (BJH) pore size distribution. The as-prepared mesoporous MnO2/C composite was used as catalyst for the synthesis of n-hexyl acetate, and the effects of MnO2 loading and esterification reaction parameters on the esterification rate were investigated. The results prove that MnO2 loading has a significant effect on the catalytic activity and that the mesoporous MnO2/C composite exhibits high catalytic activity with an esterification rate of 96.42% under the conditions below: MnO2 loading (73.09 wt%), catalyst dosage (0.1% in total weight), acetic acid/n-hexanol molar ratio (2:1), reaction temperature (130 °C) and reaction time (5 h).

  16. Lysophosphatidic Acid Stimulates MCP-1 Secretion from C2C12 Myoblast.

    PubMed

    Tsukahara, Tamotsu; Haniu, Hisao

    2012-01-01

    Chemokines are regulatory proteins that play an important role in muscle cell migration and proliferation. In this study, C2C12 cells treated with lysophosphatidic acid (LPA) showed an increase in endogenous monocyte chemotactic protein-1 (MCP-1) expression and secretion. LPA is a naturally occurring bioactive lysophospholipid with hormone- and growth-factor-like activities. LPA is produced by activated platelets, cytokine-stimulated leukocytes, and possibly by other cell types. However, the LPA analog cyclic phosphatidic acid (cPA) had no effect on the expression and secretion of MCP-1. LPA, although similar in structure to cPA, had potent inducing effects on MCP-1 expression in C2C12 cells. In this study, we showed that LPA enhanced MCP-1 mRNA expression and protein secretion in a dose-dependent manner. Taken together, these results suggest that LPA enhances MCP-1 secretion in C2C12 cells and thus may play an important role in cell proliferation. PMID:24049655

  17. Li2C2, a High-Capacity Cathode Material for Lithium Ion Batteries.

    PubMed

    Tian, Na; Gao, Yurui; Li, Yurong; Wang, Zhaoxiang; Song, Xiaoyan; Chen, Liquan

    2016-01-11

    As a typical alkaline earth metal carbide, lithium carbide (Li2C2) has the highest theoretical specific capacity (1400 mA h g(-1)) among all the reported lithium-containing cathode materials for lithium ion batteries. Herein, the feasibility of using Li2C2 as a cathode material was studied. The results show that at least half of the lithium can be extracted from Li2C2 and the reversible specific capacity reaches 700 mA h g(-1). The C≡C bond tends to rotate to form C4 (C≡C⋅⋅⋅C≡C) chains during lithium extraction, as indicated with the first-principles molecular dynamics (FPMD) simulation. The low electronic and ionic conductivity are believed to be responsible for the potential gap between charge and discharge, as is supported with density functional theory (DFT) calculations and Arrhenius fitting results. These findings illustrate the feasibility to use the alkali and alkaline earth metal carbides as high-capacity electrode materials for secondary batteries. PMID:26609636