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Sample records for a2a receptor gene

  1. Adenosine A(2A) receptor gene (ADORA2A) variants may increase autistic symptoms and anxiety in autism spectrum disorder.

    PubMed

    Freitag, Christine M; Agelopoulos, Konstantin; Huy, Ellen; Rothermundt, Matthias; Krakowitzky, Petra; Meyer, Jobst; Deckert, Jürgen; von Gontard, Alexander; Hohoff, Christa

    2010-01-01

    Autism spectrum disorders (ASDs) are heterogeneous disorders presenting with increased rates of anxiety. The adenosine A(2A) receptor gene (ADORA2A) is associated with panic disorder and is located on chromosome 22q11.23. Its gene product, the adenosine A(2A) receptor, is strongly expressed in the caudate nucleus, which also is involved in ASD. As autistic symptoms are increased in individuals with 22q11.2 deletion syndrome, and large 22q11.2 deletions and duplications have been observed in ASD individuals, in this study, 98 individuals with ASD and 234 control individuals were genotyped for eight single-nucleotide polymorphisms in ADORA2A. Nominal association with the disorder was observed for rs2236624-CC, and phenotypic variability in ASD symptoms was influenced by rs3761422, rs5751876 and rs35320474. In addition, association of ADORA2A variants with anxiety was replicated for individuals with ASD. Findings point toward a possible mediating role of ADORA2A variants on phenotypic expression in ASD that need to be replicated in a larger sample.

  2. Adenosine A2A Receptors and A2A Receptor Heteromers as Key Players in Striatal Function

    PubMed Central

    Ferré, Sergi; Quiroz, César; Orru, Marco; Guitart, Xavier; Navarro, Gemma; Cortés, Antonio; Casadó, Vicent; Canela, Enric I.; Lluis, Carme; Franco, Rafael

    2011-01-01

    A very significant density of adenosine A2A receptors (A2ARs) is present in the striatum, where they are preferentially localized postsynaptically in striatopallidal medium spiny neurons (MSNs). In this localization A2ARs establish reciprocal antagonistic interactions with dopamine D2 receptors (D2Rs). In one type of interaction, A2AR and D2R are forming heteromers and, by means of an allosteric interaction, A2AR counteracts D2R-mediated inhibitory modulation of the effects of NMDA receptor stimulation in the striatopallidal neuron. This interaction is probably mostly responsible for the locomotor depressant and activating effects of A2AR agonist and antagonists, respectively. The second type of interaction involves A2AR and D2R that do not form heteromers and takes place at the level of adenylyl cyclase (AC). Due to a strong tonic effect of endogenous dopamine on striatal D2R, this interaction keeps A2AR from signaling through AC. However, under conditions of dopamine depletion or with blockade of D2R, A2AR-mediated AC activation is unleashed with an increased gene expression and activity of the striatopallidal neuron and with a consequent motor depression. This interaction is probably the main mechanism responsible for the locomotor depression induced by D2R antagonists. Finally, striatal A2ARs are also localized presynaptically, in cortico-striatal glutamatergic terminals that contact the striato-nigral MSN. These presynaptic A2ARs heteromerize with A1 receptors (A1Rs) and their activation facilitates glutamate release. These three different types of A2ARs can be pharmacologically dissected by their ability to bind ligands with different affinity and can therefore provide selective targets for drug development in different basal ganglia disorders. PMID:21731559

  3. Agonist Derived Molecular Probes for A2A Adenosine Receptors

    PubMed Central

    Jacobson, Kenneth A.; Pannell, Lewis K.; Ji, Xiao-duo; Jarvis, Michael F.; Williams, Michael; Hutchison, Alan J.; Barrington, William W.; Stiles, Gary L.

    2011-01-01

    The adenosine agonist 2-(4-(2-carboxyethyl)phenylethylamino)-5′-N-ethylcarboxamidoadenosine (CGS21680) was recently reported to be selective for the A2A adenosine receptor subtype, which mediates its hypotensive action. To investigate structurelactivity relationships at a distal site, CGS21680 was derivatized using a functionalized congener approach. The carboxylic group of CGS21680 has been esterified to form a methyl ester, which was then treated with ethylenediamine to produce an amine congener. The amine congener was an intermediate for acylation reactions, in which the reactive acyl species contained a reported group, or the precursor for such. For radioiodination, derivatives of p-hydroxyphenylpropionic, 2-thiophenylacetic, and p-aminophenylacetic acids were prepared. The latter derivative (PAPA-APEC) was iodinated electrophilically using [125I]iodide resulting in a radioligand which was used for studies of competition of binding to striatal A, adenosine receptors in bovine brain. A biotin conjugate and an aryl sulfonate were at least 350-fold selective for A, receptors. For spectroscopic detection, a derivative of the stable free radical tetramethyl-1-piperidinyloxy (TEMPO) was prepared. For irreversible inhibition of receptors, meta- and para-phenylenediisothiocyanate groups were incorporated in the analogs. We have demonstrated that binding at A2A receptors is relatively insensitive to distal structural changes at the 2-position, and we report high affinity molecular probes for receptor characterization by radioactive, spectroscopic and affinity labelling methodology. PMID:2561548

  4. Astrocytic adenosine receptor A2A and Gs-coupled signaling regulate memory

    PubMed Central

    Orr, Anna G.; Hsiao, Edward C.; Wang, Max M.; Ho, Kaitlyn; Kim, Daniel H.; Wang, Xin; Guo, Weikun; Kang, Jing; Yu, Gui-Qiu; Adame, Anthony; Devidze, Nino; Dubal, Dena B.; Masliah, Eliezer; Conklin, Bruce R.; Mucke, Lennart

    2014-01-01

    Astrocytes express a variety of G protein-coupled receptors and might influence cognitive functions, such as learning and memory. However, the roles of astrocytic Gs-coupled receptors in cognitive function are not known. We found that humans with Alzheimer’s disease (AD) had increased levels of the Gs-coupled adenosine receptor A2A in astrocytes. Conditional genetic removal of these receptors enhanced long-term memory in young and aging mice, and increased the levels of Arc/Arg3.1, an immediate-early gene required for long-term memory. Chemogenetic activation of astrocytic Gs-coupled signaling reduced long-term memory in mice without affecting learning. Similar to humans with AD, aging mice expressing human amyloid precursor protein (hAPP) showed increased levels of astrocytic A2A receptors. Conditional genetic removal of these receptors enhanced memory in aging hAPP mice. Together, these findings establish a regulatory role for astrocytic Gs-coupled receptors in memory and suggest that AD-linked increases in astrocytic A2A receptor levels contribute to memory loss. PMID:25622143

  5. Adenosine A2A Receptor Gene Knockout Prevents l-3,4-Dihydroxyphenylalanine-Induced Dyskinesia by Downregulation of Striatal GAD67 in 6-OHDA-Lesioned Parkinson’s Mice

    PubMed Central

    Yin, Su-bing; Zhang, Xiao-guang; Chen, Shuang; Yang, Wen-ting; Zheng, Xia-wei; Zheng, Guo-qing

    2017-01-01

    l-3,4-Dihydroxyphenylalanine (l-DOPA) remains the primary pharmacological agent for the symptomatic treatment of Parkinson’s disease (PD). However, the development of l-DOPA-induced dyskinesia (LID) limits the long-term use of l-DOPA for PD patients. Some data have reported that adenosine A2A receptor (A2AR) antagonists prevented LID in animal model of PD. However, the mechanism in which adenosine A2AR blockade alleviates the symptoms of LID has not been fully clarified. Here, we determined to knock out (KO) the gene of A2AR and explored the possible underlying mechanisms implicated in development of LID in a mouse model of PD. A2AR gene KO mice were unilaterally injected into the striatum with 6-hydroxydopamine (6-OHDA) in order to damage dopamine neurons on one side of the brain. 6-OHDA-lesioned mice were then injected once daily for 21 days with l-DOPA. Abnormal involuntary movements (AIMs) were evaluated on days 3, 8, 13, and 18 after l-DOPA administration, and real-time polymerase chain reaction and immunohistochemistry for glutamic acid decarboxylase (GAD) 65 and GAD67 were performed. We found that A2AR gene KO was effective in reducing AIM scores and accompanied with decrease of striatal GAD67, rather than GAD65. These results demonstrated that the possible mechanism involved in alleviation of AIM symptoms by A2AR gene KO might be through reducing the expression of striatal GAD67. PMID:28377741

  6. Striatal adenosine-cannabinoid receptor interactions in rats over-expressing adenosine A2A receptors.

    PubMed

    Chiodi, Valentina; Ferrante, Antonella; Ferraro, Luca; Potenza, Rosa Luisa; Armida, Monica; Beggiato, Sarah; Pèzzola, Antonella; Bader, Michael; Fuxe, Kjell; Popoli, Patrizia; Domenici, Maria Rosaria

    2016-03-01

    Adenosine A2A receptors (A2 A Rs) and cannabinoid CB1 receptors (CB1 Rs) are highly expressed in the striatum, where they functionally interact and form A2A /CB1 heteroreceptor complexes. We investigated the effects of CB1 R stimulation in a transgenic rat strain over-expressing A2 A Rs under the control of the neural-specific enolase promoter (NSEA2A rats) and in age-matched wild-type (WT) animals. The effects of the CB1 R agonist WIN 55,212-2 (WIN) were significantly lower in NSEA2A rats than in WT animals, as demonstrated by i) electrophysiological recordings of synaptic transmission in corticostriatal slices; ii) the measurement of glutamate outflow from striatal synaptosomes and iii) in vivo experiments on locomotor activity. Moreover, while the effects of WIN were modulated by both A2 A R agonist (CGS 21680) and antagonists (ZM 241385, KW-6002 and SCH-442416) in WT animals, the A2 A R antagonists failed to influence WIN-mediated effects in NSEA2A rats. The present results demonstrate that in rats with genetic neuronal over-expression of A2 A Rs, the effects mediated by CB1 R activation in the striatum are significantly reduced, suggesting a change in the stoichiometry of A2A and CB1 receptors and providing a strategy to dissect the involvement of A2 A R forming or not forming heteromers in the modulation of striatal functions. These findings add additional evidence for the existence of an interaction between striatal A2 A Rs and CB1 Rs, playing a fundamental role in the regulation of striatal functions. We studied A2A -CB1 receptor interaction in transgenic rats over-expressing adenosine A2A receptors under the control of the neuron-specific enolase promoter (NSEA2A ). In these rats, we demonstrated a reduced effect of the CB1 receptor agonist WIN 55,212-2 in the modulation of corticostriatal synaptic transmission and locomotor activity, while CB1 receptor expression level did not change with respect to WT rats. A reduction in the expression of A2A -CB1

  7. Remodeling of striatal NMDA receptors by chronic A(2A) receptor blockade in Huntington's disease mice.

    PubMed

    Martire, Alberto; Ferrante, Antonella; Potenza, Rosa Luisa; Armida, Monica; Ferretti, Roberta; Pézzola, Antonella; Domenici, Maria Rosaria; Popoli, Patrizia

    2010-01-01

    Excitotoxicity plays a major role in the pathogenesis of Huntington disease (HD), a fatal neurodegenerative disorder. Adenosine A(2A) receptors (A(2A)Rs) modulate excitotoxicity and have been suggested to play a pathogenetic role in HD. The main aim of this study was to evaluate the effect of A(2A)R blockade on the expression and functions of NMDA receptors in the striatum of HD mice (R6/2). We found that 3 weeks' treatment with SCH 58261 (0.01 mg/kg/day i.p. from the 8th week of age) modified NR1 and NR2A/NR2B expression in the striatum of R6/2 (Western blotting) while had no effect on NMDA-induced toxicity in corticostriatal slices (electrophysiological experiments). In conclusion, in vivo A(2A)R blockade induced a remodeling of NMDA receptors in the striatum of HD mice. Even though the functional relevance of the above effect remains to be fully elucidated, these results add further evidence to the modulatory role of A(2A)Rs in HD.

  8. Potential therapeutic interest of adenosine A2A receptors in psychiatric disorders.

    PubMed

    Cunha, Rodrigo A; Ferré, Sergi; Vaugeois, Jean-Marie; Chen, Jiang-Fan

    2008-01-01

    The interest on targeting adenosine A(2A) receptors in the realm of psychiatric diseases first arose based on their tight physical and functional interaction with dopamine D(2) receptors. However, the role of central A(2A) receptors is now viewed as much broader than just controlling D(2) receptor function. Thus, there is currently a major interest in the ability of A(2A) receptors to control synaptic plasticity at glutamatergic synapses. This is due to a combined ability of A(2A) receptors to facilitate the release of glutamate and the activation of NMDA receptors. Therefore, A(2A) receptors are now conceived as a normalizing device promoting adequate adaptive responses in neuronal circuits, a role similar to that fulfilled, in essence, by dopamine. This makes A(2A) receptors particularly attractive targets to manage psychiatric disorders since adenosine may act as go-between glutamate and dopamine, two of the key players in mood processing. Furthermore, A(2A) receptors also control glia function and brain metabolic adaptation, two other emerging mechanisms to understand abnormal processing of mood, and A(2A) receptors are important players in controlling the demise of neurodegeneration, considered an amplificatory loop in psychiatric disorders. Current data only provide an indirect confirmation of this putative role of A(2A) receptors, based on the effects of caffeine (an antagonist of both A(1) and A(2A) receptors) in psychiatric disorders. However, the introduction of A(2A) receptors antagonists in clinics as anti-parkinsonian agents is hoped to bolster our knowledge on the role of A(2A) receptors in mood disorders in the near future.

  9. Functional efficacy of adenosine A2A receptor agonists is positively correlated to their receptor residence time

    PubMed Central

    Guo, Dong; Mulder-Krieger, Thea; IJzerman, Adriaan P; Heitman, Laura H

    2012-01-01

    BACKGROUND AND PURPOSE The adenosine A2A receptor belongs to the superfamily of GPCRs and is a promising therapeutic target. Traditionally, the discovery of novel agents for the A2A receptor has been guided by their affinity for the receptor. This parameter is determined under equilibrium conditions, largely ignoring the kinetic aspects of the ligand-receptor interaction. The aim of this study was to assess the binding kinetics of A2A receptor agonists and explore a possible relationship with their functional efficacy. EXPERIMENTAL APPROACH We set up, validated and optimized a kinetic radioligand binding assay (a so-called competition association assay) at the A2A receptor from which the binding kinetics of unlabelled ligands were determined. Subsequently, functional efficacies of A2A receptor agonists were determined in two different assays: a novel label-free impedance-based assay and a more traditional cAMP determination. KEY RESULTS A simplified competition association assay yielded an accurate determination of the association and dissociation rates of unlabelled A2A receptor ligands at their receptor. A correlation was observed between the receptor residence time of A2A receptor agonists and their intrinsic efficacies in both functional assays. The affinity of A2A receptor agonists was not correlated to their functional efficacy. CONCLUSIONS AND IMPLICATIONS This study indicates that the molecular basis of different agonist efficacies at the A2A receptor lies within their different residence times at this receptor. PMID:22324512

  10. Adenosine A2A receptor antagonism and neuroprotection: mechanisms, lights, and shadows.

    PubMed

    Popoli, Patrizia; Minghetti, Luisa; Tebano, Maria Teresa; Pintor, Annita; Domenici, Maria Rosaria; Massotti, Marino

    2004-01-01

    Adenosine A2A receptor antagonists are regarded as potential neuroprotective drugs, although the mechanisms underlying their effects remain to be elucidated. In this review, quinolinic acid (QA)-induced striatal toxicity was used as a tool to investigate the mechanisms of the neuroprotective effects of A2A receptor antagonists. After having examined the effects of selective A2A receptor antagonists toward different mechanisms of QA toxicity, we conclude that (1) the effect elicited by A2A receptor blockade on QA-induced glutamate outflow may be one of the mechanisms of the neuroprotective activity of A2A receptor antagonists; (2) A2A receptor antagonists have a potentially worsening influence on QA-dependent NMDA receptor activation; and (3) the ability of A2A receptor antagonists to prevent QA-induced lipid peroxidation does not correlate with the neuroprotective effects. These results suggest that A2A receptor antagonists may have either potentially beneficial or detrimental influence in models of neurodegeneration that are mainly due to increased glutamate levels or enhanced sensitivity of NMDA receptors, respectively.

  11. A2A-D2 receptor-receptor interaction modulates gliotransmitter release from striatal astrocyte processes.

    PubMed

    Cervetto, Chiara; Venturini, Arianna; Passalacqua, Mario; Guidolin, Diego; Genedani, Susanna; Fuxe, Kjell; Borroto-Esquela, Dasiel O; Cortelli, Pietro; Woods, Amina; Maura, Guido; Marcoli, Manuela; Agnati, Luigi F

    2017-01-01

    Evidence for striatal A2A-D2 heterodimers has led to a new perspective on molecular mechanisms involved in schizophrenia and Parkinson's disease. Despite the increasing recognition of astrocytes' participation in neuropsychiatric disease vulnerability, involvement of striatal astrocytes in A2A and D2 receptor signal transmission has never been explored. Here, we investigated the presence of D2 and A2A receptors in isolated astrocyte processes prepared from adult rat striatum by confocal imaging; the effects of receptor activation were measured on the 4-aminopyridine-evoked release of glutamate from the processes. Confocal analysis showed that A2A and D2 receptors were co-expressed on the same astrocyte processes. Evidence for A2A-D2 receptor-receptor interactions was obtained by measuring the release of the gliotransmitter glutamate: D2 receptors inhibited the glutamate release, while activation of A2A receptors, per se ineffective, abolished the effect of D2 receptor activation. The synthetic D2 peptide VLRRRRKRVN corresponding to the receptor region involved in electrostatic interaction underlying A2A-D2 heteromerization abolished the ability of the A2A receptor to antagonize the D2 receptor-mediated effect. Together, the findings are consistent with heteromerization of native striatal astrocytic A2A-D2 receptors that via allosteric receptor-receptor interactions could play a role in the control of striatal glutamatergic transmission. These new findings suggest possible new pathogenic mechanisms and/or therapeutic approaches to neuropsychiatric disorders.

  12. A tail of two signals: the C terminus of the A(2A)-adenosine receptor recruits alternative signaling pathways.

    PubMed

    Gsandtner, Ingrid; Freissmuth, Michael

    2006-08-01

    G protein-coupled receptors are endowed with carboxyl termini that vary greatly in length and sequence. In most instances, the distal portion of the C terminus is dispensable for G protein coupling. This is also true for the A(2A)-adenosine receptor, where the last 100 amino acids are of very modest relevance to G(s) coupling. The C terminus was originally viewed mainly as the docking site for regulatory proteins of the beta-arrestin family. These beta-arrestins bind to residues that have been phosphorylated by specialized kinases (G protein-coupled receptor kinases) and thereby initiate receptor desensitization and endocytosis. More recently, it has become clear that many additional "accessory" proteins bind to C termini of G protein-coupled receptors. The article by Sun et al. in the current issue of Molecular Pharmacology identifies translin-associated protein-X as yet another interaction partner of the A(2A) receptor; translin-associated protein allows the A(2A) receptor to impinge on the signaling mechanisms by which p53 regulates neuronal differentiation, but the underlying signaling pathways are uncharted territory. With a list of five known interaction partners, the C terminus of the A(2A) receptor becomes a crowded place. Hence, there must be rules that regulate the interaction. This allows the C terminus to act as coincidence detector and as signal integrator. Despite our ignorance about the precise mechanisms, the article has exciting implications: the gene encoding for translin-associated protein-X maps to a locus implicated in some forms of schizophrenia; A(2A) receptor agonists are candidate drugs for the treatment of schizophrenic symptoms. It is of obvious interest to explore a possible link.

  13. A critical evaluation of adenosine A2A receptors as potentially "druggable" targets in Huntington's disease.

    PubMed

    Popoli, Patrizia; Blum, David; Domenici, Maria Rosaria; Burnouf, Sylvie; Chern, Yijuang

    2008-01-01

    Huntington's disease (HD) is a dominantly inherited neurodegenerative disorder caused by the expansion of a polymorphic CAG trinucleotide repeat encoding a poly-glutamine tract within the Huntingtin protein. GABAergic enkephalin neurons of the basal ganglia, which show the highest levels of expression of adenosine A(2A) receptors, are the most vulnerable in HD. Such a selective neuronal vulnerability, which occurs despite ubiquitous expression of mutant and normal Huntingtin, has suggested that adenosine A(2A) receptors might play a pathogenetic role in HD. In agreement, changes in A(2A) receptor expression and signaling have been reported in various experimental models of HD. The interpretation of the functional significance of the aberrant A(2A) receptor phenotype in HD mice is however complicated by the conflicting data so far reported on the potential neuroprotective and neurodegenerative effects of these receptors in the brain, with some data suggesting a potential pathogenetic role and some other data suggesting activation of trophic or protective pathways in neurons. The same complex profile has emerged in experimental models of HD, in which both A(2A) receptor agonists and antagonists have shown beneficial effects. The main aim of this review is to critically evaluate whether adenosine A(2A) receptors may represent a suitable target to develop drugs against HD.

  14. GABAergic involvement in motor effects of an adenosine A(2A) receptor agonist in mice.

    PubMed

    Khisti, R T; Chopde, C T; Abraham, E

    2000-04-03

    Adenosine A(2A) agonists are known to induce catalepsy and inhibit dopamine mediated motor hyperactivity. An antagonistic interaction between adenosine A(2A) and dopamine D(2) receptors is known to regulate GABA-mediated neurotransmission in striatopallidal neurons. Stimulation of adenosine A(2A) and dopamine D(2) receptors has been shown to increase and inhibit GABA release respectively in pallidal GABAergic neurons. However, the role of GABAergic neurotransmission in the motor effects of adenosine A(2A) receptors is not yet known. Therefore in the present study the effect of GABAergic agents on adenosine A(2A) receptor agonist (NECA- or CGS 21680) induced catalepsy and inhibition of amphetamine elicited motor hyperactivity was examined. Pretreatment with GABA, the GABA(A) agonist muscimol or the GABA(B) agonist baclofen potentiated whereas the GABA(A) antagonist bicuculline attenuated NECA- or CGS 21680-induced catalepsy. However, the GABA(B) antagonists phaclophen and delta-aminovaleric acid had no effect. Administration of NECA or CGS 21680 not only reduced spontaneous locomotor activity but also antagonized amphetamine elicited motor hyperactivity. These effects of NECA and CGS 21680 were potentiated by GABA or muscimol and antagonized by bicuculline. These findings provide behavioral evidence for the role of GABA in the motor effects of adenosine A(2A) receptor agonists. Activation of adenosine A(2A) receptors increases GABA release which could reduce dopaminergic tone and induce catalepsy or inhibit amphetamine mediated motor hyperactivity.

  15. The importance of the adenosine A(2A) receptor-dopamine D(2) receptor interaction in drug addiction.

    PubMed

    Filip, M; Zaniewska, M; Frankowska, M; Wydra, K; Fuxe, K

    2012-01-01

    Drug addiction is a serious brain disorder with somatic, psychological, psychiatric, socio-economic and legal implications in the developed world. Illegal (e.g., psychostimulants, opioids, cannabinoids) and legal (alcohol, nicotine) drugs of abuse create a complex behavioral pattern composed of drug intake, withdrawal, seeking and relapse. One of the hallmarks of drugs that are abused by humans is that they have different mechanisms of action to increase dopamine (DA) neurotransmission within the mesolimbic circuitry of the brain and indirectly activate DA receptors. Among the DA receptors, D(2) receptors are linked to drug abuse and addiction because their function has been proven to be correlated with drug reinforcement and relapses. The recognition that D(2) receptors exist not only as homomers but also can form heteromers, such as with the adenosine (A)(2A) receptor, that are pharmacologically and functionally distinct from their constituent receptors, has significantly expanded the range of potential drug targets and provided new avenues for drug design in the search for novel drug addiction therapies. The aim of this review is to bring current focus on A(2A) receptors, their physiology and pharmacology in the central nervous system, and to discuss the therapeutic relevance of these receptors to drug addiction. We concentrate on the contribution of A(2A) receptors to the effects of different classes of drugs of abuse examined in preclinical behavioral experiments carried out with pharmacological and genetic tools. The consequences of chronic drug treatment on A(2A) receptor-assigned functions in preclinical studies are also presented. Finally, the neurochemical mechanism of the interaction between A(2A) receptors and drugs of abuse in the context of the heteromeric A(2A)-D(2) receptor complex is discussed. Taken together, a significant amount of experimental analyses provide evidence that targeting A(2A) receptors may offer innovative translational strategies

  16. Adenosine A2A Receptors Modulate Acute Injury and Neuroinflammation in Brain Ischemia

    PubMed Central

    Pedata, Felicita; Pugliese, Anna Maria; Coppi, Elisabetta; Dettori, Ilaria; Maraula, Giovanna; Cellai, Lucrezia; Melani, Alessia

    2014-01-01

    The extracellular concentration of adenosine in the brain increases dramatically during ischemia. Adenosine A2A receptor is expressed in neurons and glial cells and in inflammatory cells (lymphocytes and granulocytes). Recently, adenosine A2A receptor emerged as a potential therapeutic attractive target in ischemia. Ischemia is a multifactorial pathology characterized by different events evolving in the time. After ischemia the early massive increase of extracellular glutamate is followed by activation of resident immune cells, that is, microglia, and production or activation of inflammation mediators. Proinflammatory cytokines, which upregulate cell adhesion molecules, exert an important role in promoting recruitment of leukocytes that in turn promote expansion of the inflammatory response in ischemic tissue. Protracted neuroinflammation is now recognized as the predominant mechanism of secondary brain injury progression. A2A receptors present on central cells and on blood cells account for important effects depending on the time-related evolution of the pathological condition. Evidence suggests that A2A receptor antagonists provide early protection via centrally mediated control of excessive excitotoxicity, while A2A receptor agonists provide protracted protection by controlling massive blood cell infiltration in the hours and days after ischemia. Focus on inflammatory responses provides for adenosine A2A receptor agonists a wide therapeutic time-window of hours and even days after stroke. PMID:25165414

  17. Triggering neurotrophic factor actions through adenosine A2A receptor activation: implications for neuroprotection

    PubMed Central

    Sebastião, Ana M; Ribeiro, Joaquim A

    2009-01-01

    G protein coupled receptors and tropomyosin-related kinase (Trk) receptors have distinct structure and transducing mechanisms; therefore, cross-talk among them was unexpected. Evidence has, however, accumulated showing that tonic adenosine A2A receptor activity is a required step to allow synaptic actions of neurotrophic factors, namely upon synaptic transmission at both pre- and post-synaptic level as well as upon synaptic plasticity. An enhancement of A2A receptor tonus upon ageing may partially compensate the loss of TrkB receptors, rescuing to certain degree the facilitatory action of brain derived neurotrophic factor in aged animals, which might prove particularly relevant in the prevention of neurodegeneration upon ageing. A2A receptors also trigger synaptic actions of other neurotrophic factors, such as glial derived neurotrophic factor at dopaminergic striatal nerve endings. The growing evidence that tonic adenosine A2A receptor activity is a crucial step to allow actions of neurotrophic factors in neurones will be reviewed and discussed in the light of therapeutic strategies for neurodegenerative diseases. PMID:19508402

  18. A new ethyladenine antagonist of adenosine A(2A) receptors: behavioral and biochemical characterization as an antiparkinsonian drug.

    PubMed

    Pinna, Annalisa; Tronci, Elisabetta; Schintu, Nicoletta; Simola, Nicola; Volpini, Rosaria; Pontis, Silvia; Cristalli, Gloria; Morelli, Micaela

    2010-03-01

    Adenosine A(2A) receptor antagonists have emerged as an attractive non-dopaminergic target in clinical trials aimed at evaluating improvement in motor deficits in Parkinson's disease (PD). Moreover, preclinical studies suggest that A(2A) receptor antagonists may slow the course of the underlying neurodegeneration of dopaminergic neurons. In this study, we evaluated the efficacy of the new adenosine A(2A) receptor antagonist 8-ethoxy-9-ethyladenine (ANR 94) in parkinsonian models of akinesia and tremor. In addition, induction of the immediate early gene zif-268, and neuroprotective and anti-inflammatory effects of ANR 94 were evaluated. ANR 94 was effective in reversing parkinsonian tremor induced by the administration of tacrine. ANR 94 also counteracted akinesia (stepping test) and sensorimotor deficits (vibrissae-elicited forelimb-placing test), as well as potentiating l-dopa-induced contralateral turning behavior in 6-hydroxydopamine (6-OHDA) lesion model of PD. Potentiation of motor behavior in 6-OHDA-lesioned rats was not associated with increased induction of the immediate early gene zif-268 in the striatum, suggesting that ANR 94 does not induce long-term plastic changes in this structure. Finally, in a subchronic 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) mouse model of PD, ANR 94 protected nigrostriatal dopaminergic neurons from degeneration and counteracted neuroinflammatory processes by contrasting astroglial (glial fibrillary acidic protein, GFAP) and microglial (CD11b) activation. A(2A) receptor antagonism represents a uniquely realistic opportunity for improving PD treatment, since A(2A) receptor antagonists offer substantial symptomatic benefits and possibly disease-modifying activity. The characterization of ANR 94 may represent a further therapeutic opportunity for the treatment of PD with this new class of drugs.

  19. The A2a adenosine receptor modulates the reinforcement efficacy and neurotoxicity of MDMA.

    PubMed

    Ruiz-Medina, Jessica; Ledent, Catherine; Carretón, Olga; Valverde, Olga

    2011-04-01

    Adenosine is an endogenous purine nucleoside that plays a neuromodulatory role in the central nervous system. A2a adenosine receptors have been involved in reward-related processes, inflammatory phenomena and neurotoxicity reactions. In the present study, we investigated the role of A2a adenosine receptors on the acute pharmacological effects, reinforcement and neuroinflammation induced by MDMA administration. First, the acute effects of MDMA on body temperature, locomotor activity and anxiety-like responses were measured in A2a knockout mice and wild-type littermates. Second, MDMA reinforcing properties were evaluated using the intravenous self-administration paradigm. Finally, we assessed striatal astrogliosis and microgliosis as markers of MDMA neurotoxicity. Our results showed that acute MDMA produced a biphasic effect on body temperature and increased locomotor activity and anxiogenic-like responses in both genotypes. However, MDMA reinforcing properties were dramatically affected by the lack of A2a adenosine receptors. Thus, wild-type mice maintained MDMA self-administration under a fixed ratio 1 reinforcement schedule, whereas the operant response appeared completely abolished in A2a knockout mice. In addition, the MDMA neurotoxic regime produced an enhanced inflammatory response in striatum of wild-type mice, revealed by a significant increase in glial expression, whereas such activation was attenuated in mutant mice. This is the first report indicating that A2a adenosine receptors play a key role in reinforcement and neuroinflammation induced by the widely used psychostimulant.

  20. Adenosine A2A receptors are necessary and sufficient to trigger memory impairment in adult mice

    PubMed Central

    Pagnussat, N; Almeida, A S; Marques, D M; Nunes, F; Chenet, G C; Botton, P H S; Mioranzza, S; Loss, C M; Cunha, R A; Porciúncula, L O

    2015-01-01

    Background and Purpose Caffeine (a non-selective adenosine receptor antagonist) prevents memory deficits in aging and Alzheimer’s disease, an effect mimicked by adenosine A2A receptor, but not A1 receptor, antagonists. Hence, we investigated the effects of adenosine receptor agonists and antagonists on memory performance and scopolamine-induced memory impairment in mice. Experimental Approach We determined whether A2A receptors are necessary for the emergence of memory impairments induced by scopolamine and whether A2A receptor activation triggers memory deficits in naïve mice, using three tests to assess short-term memory, namely the object recognition task, inhibitory avoidance and modified Y-maze. Key Results Scopolamine (1.0 mg·kg−1, i.p.) impaired short-term memory performance in all three tests and this scopolamine-induced amnesia was prevented by the A2A receptor antagonist (SCH 58261, 0.1–1.0 mg·kg−1, i.p.) and by the A1 receptor antagonist (DPCPX, 0.2–5.0 mg·kg−1, i.p.), except in the modified Y-maze where only SCH58261 was effective. Both antagonists were devoid of effects on memory or locomotion in naïve rats. Notably, the activation of A2A receptors with CGS 21680 (0.1–0.5 mg·kg−1, i.p.) before the training session was sufficient to trigger memory impairment in the three tests in naïve mice, and this effect was prevented by SCH 58261 (1.0 mg·kg−1, i.p.). Furthermore, i.c.v. administration of CGS 21680 (50 nmol) also impaired recognition memory in the object recognition task. Conclusions and Implications These results show that A2A receptors are necessary and sufficient to trigger memory impairment and further suggest that A1 receptors might also be selectively engaged to control the cholinergic-driven memory impairment. PMID:25939452

  1. Mechanisms of the adenosine A2A receptor-induced sensitization of esophageal C fibers.

    PubMed

    Brozmanova, M; Mazurova, L; Ru, F; Tatar, M; Hu, Y; Yu, S; Kollarik, M

    2016-02-01

    Clinical studies indicate that adenosine contributes to esophageal mechanical hypersensitivity in some patients with pain originating in the esophagus. We have previously reported that the esophageal vagal nodose C fibers express the adenosine A2A receptor. Here we addressed the hypothesis that stimulation of the adenosine A2A receptor induces mechanical sensitization of esophageal C fibers by a mechanism involving transient receptor potential A1 (TRPA1). Extracellular single fiber recordings of activity originating in C-fiber terminals were made in the ex vivo vagally innervated guinea pig esophagus. The adenosine A2A receptor-selective agonist CGS21680 induced robust, reversible sensitization of the response to esophageal distention (10-60 mmHg) in a concentration-dependent fashion (1-100 nM). At the half-maximally effective concentration (EC50: ≈3 nM), CGS21680 induced an approximately twofold increase in the mechanical response without causing an overt activation. This sensitization was abolished by the selective A2A antagonist SCH58261. The adenylyl cyclase activator forskolin mimicked while the nonselective protein kinase inhibitor H89 inhibited mechanical sensitization by CGS21680. CGS21680 did not enhance the response to the purinergic P2X receptor agonist α,β-methylene-ATP, indicating that CGS21680 does not nonspecifically sensitize to all stimuli. Mechanical sensitization by CGS21680 was abolished by pretreatment with two structurally different TRPA1 antagonists AP18 and HC030031. Single cell RT-PCR and whole cell patch-clamp studies in isolated esophagus-specific nodose neurons revealed the expression of TRPA1 in A2A-positive C-fiber neurons and demonstrated that CGS21682 potentiated TRPA1 currents evoked by allylisothiocyanate. We conclude that stimulation of the adenosine A2A receptor induces mechanical sensitization of nodose C fibers by a mechanism sensitive to TRPA1 antagonists indicating the involvement of TRPA1.

  2. Functions, dysfunctions and possible therapeutic relevance of adenosine A2A receptors in Huntington's disease.

    PubMed

    Popoli, Patrizia; Blum, David; Martire, Alberto; Ledent, Catherine; Ceruti, Stefania; Abbracchio, Maria P

    2007-04-01

    The aim of this review is to summarize and critically discuss the complex role played by adenosine A(2A) receptors (A(2A)Rs) in Huntington's disease (HD). Since A(2A)Rs are mainly localized on the neurons, which degenerate early in HD, and given their ability to stimulate glutamate outflow and inflammatory gliosis, it was hypothesized that they could be involved in the pathogenesis of HD, and that A(2A)R antagonists could be neuroprotective. This was further sustained by the demonstration that A(2A)Rs and underlying signaling systems undergo profound changes in cellular and animal models of HD. More recently, however, the equation A(2A) receptor blockade=neuroprotection has appeared too simplistic. First, it is now definitely clear that, besides mediating 'bad' responses (for example, stimulation of glutamate outflow and excessive glial activation), A(2A)Rs also promote 'good' responses (such as trophic and antinflammatory effects). This implies that A(2A)R blockade results either in pro-toxic or neuroprotective effects according to the mechanisms involved in a given experimental model. Second, since HD is a chronically progressive disease, the multiple mechanisms involving A(2A)Rs may play different relative roles along the degenerative process. Such different mechanisms can be influenced by A(2A)R activation or blockade in different ways, even leading to opposite outcomes depending on the time of agonist/antagonist administration. The number, and the complexity, of the possible scenarios is further increased by the influence of mutant Huntingtin on both the expression and functions of A(2A)Rs, and by the strikingly different effects mediated by A(2A)Rs expressed by different cell populations within the brain.

  3. Targeting Adenosine A2A Receptors in Parkinson’s Disease

    DTIC Science & Technology

    2006-11-01

    dysfunction in the rat hippocampus (collaboration with MA Lynch). Conclusion: These results prompt the hypothesis that the neuroprotection associated...stimuli and show reduced responses to morphine . The role of the A2A receptor in pain is less clear and we, and others, have shown the receptor is absent...cerebral cortex, striatum, hippocampus , olfactory bulb, and hypothalamus) but not in the cerebellum. (2), immunohistochemical analysis showed that

  4. Multiple sclerosis lymphocytes upregulate A2A adenosine receptors that are antiinflammatory when stimulated.

    PubMed

    Vincenzi, Fabrizio; Corciulo, Carmen; Targa, Martina; Merighi, Stefania; Gessi, Stefania; Casetta, Ilaria; Gentile, Mauro; Granieri, Enrico; Borea, Pier Andrea; Varani, Katia

    2013-08-01

    Multiple sclerosis (MS) is an autoimmune-mediated inflammatory disease characterized by multifocal areas of demyelination. Experimental evidence indicates that A2A adenosine receptors (ARs) play a pivotal role in the inhibition of inflammatory processes. The aim of this study was to investigate the contribution of A2A ARs in the inhibition of key pro-inflammatory mediators for the pathogenesis of MS. In lymphocytes from MS patients, A1, A2A, A2B, and A3 ARs were analyzed by using RT-PCR, Western blotting, immunofluorescence, and binding assays. Moreover the effect of A2A AR stimulation on proinflammatory cytokine release such as TNF-α, IFN-γ, IL-6, IL-1β, IL-17, and on lymphocyte proliferation was evaluated. The capability of an A2A AR agonist on the modulation of very late antigen (VLA)-4 expression and NF-κB was also explored. A2A AR upregulation was observed in lymphocytes from MS patients in comparison with healthy subjects. The stimulation of these receptors mediated a significant inhibition of TNF-α, IFN-γ, IL-6, IL-1β, IL-17, and cell proliferation as well as VLA-4 expression and NF-κB activation. This new evidence highlights that A2A AR agonists could represent a novel therapeutic tool for MS treatment as suggested by the antiinflammatory role of A2A ARs in lymphocytes from MS patients.

  5. Pre-synaptic adenosine A2A receptors control cannabinoid CB1 receptor-mediated inhibition of striatal glutamatergic neurotransmission.

    PubMed

    Martire, Alberto; Tebano, Maria Teresa; Chiodi, Valentina; Ferreira, Samira G; Cunha, Rodrigo A; Köfalvi, Attila; Popoli, Patrizia

    2011-01-01

    An interaction between adenosine A(2A) receptors (A(2A) Rs) and cannabinoid CB(1) receptors (CB(1) Rs) has been consistently reported to occur in the striatum, although the precise mechanisms are not completely understood. As both receptors control striatal glutamatergic transmission, we now probed the putative interaction between pre-synaptic CB(1) R and A(2A) R in the striatum. In extracellular field potentials recordings in corticostriatal slices from Wistar rats, A(2A) R activation by CGS21680 inhibited CB(1) R-mediated effects (depression of synaptic response and increase in paired-pulse facilitation). Moreover, in superfused rat striatal nerve terminals, A(2A) R activation prevented, while A(2A) R inhibition facilitated, the CB(1) R-mediated inhibition of 4-aminopyridine-evoked glutamate release. In summary, the present study provides converging neurochemical and electrophysiological support for the occurrence of a tight control of CB(1) R function by A(2A) Rs in glutamatergic terminals of the striatum. In view of the key role of glutamate to trigger the recruitment of striatal circuits, this pre-synaptic interaction between CB(1) R and A(2A) R may be of relevance for the pathogenesis and the treatment of neuropsychiatric disorders affecting the basal ganglia.

  6. A2a and a2b adenosine receptors affect HIF-1α signaling in activated primary microglial cells.

    PubMed

    Merighi, Stefania; Borea, Pier Andrea; Stefanelli, Angela; Bencivenni, Serena; Castillo, Carlos Alberto; Varani, Katia; Gessi, Stefania

    2015-05-15

    Microglia are central nervous system (CNS)-resident immune cells, that play a crucial role in neuroinflammation. Hypoxia-inducible factor-1 (HIF-1), the main transcription factor of hypoxia-inducible genes, is also involved in the immune response, being regulated in normoxia by inflammatory mediators. Adenosine is an ubiquitous nucleoside that has an influence on many immune properties of microglia through interaction with four receptor subtypes. The aim of this study was to investigate whether adenosine may affect microglia functions by acting on HIF-1α modulation. Primary murine microglia were activated with lipopolysaccharide (LPS) with or without adenosine, adenosine receptor agonists and antagonists and HIF-1α accumulation and downstream genes regulation were determined. Adenosine increased LPS-induced HIF-1α accumulation leading to an increase in HIF-1α target genes involved in cell metabolism [glucose transporter-1 (GLUT-1)] and pathogens killing [inducible nitric-oxide synthase (iNOS)] but did not induce HIF-1α dependent genes related to angiogenesis [vascular endothelial growth factor (VEGF)] and inflammation [tumor necrosis factor-α (TNF-α)]. The stimulatory effect of adenosine on HIF-1α and its target genes was essentially exerted by activation of A2A through p44/42 and A2B subtypes via p38 mitogen-activated protein kinases (MAPKs) and Akt phosphorylation. Furthermore the nucleoside raised VEGF and decreased TNF-α levels, by activating A2B subtypes. In conclusion adenosine increases GLUT-1 and iNOS gene expression in a HIF-1α-dependent way, through A2A and A2B receptors, suggesting their role in the regulation of microglial cells function following injury. However, inhibition of TNF-α adds an important anti-inflammatory effect only for the A2B subtype. GLIA 2015.

  7. A covalent antagonist for the human adenosine A2A receptor.

    PubMed

    Yang, Xue; Dong, Guo; Michiels, Thomas J M; Lenselink, Eelke B; Heitman, Laura; Louvel, Julien; IJzerman, Ad P

    2016-12-03

    The structure of the human A2A adenosine receptor has been elucidated by X-ray crystallography with a high affinity non-xanthine antagonist, ZM241385, bound to it. This template molecule served as a starting point for the incorporation of reactive moieties that cause the ligand to covalently bind to the receptor. In particular, we incorporated a fluorosulfonyl moiety onto ZM241385, which yielded LUF7445 (4-((3-((7-amino-2-(furan-2-yl)-[1, 2, 4]triazolo[1,5-a][1, 3, 5]triazin-5-yl)amino)propyl)carbamoyl)benzene sulfonyl fluoride). In a radioligand binding assay, LUF7445 acted as a potent antagonist, with an apparent affinity for the hA2A receptor in the nanomolar range. Its apparent affinity increased with longer incubation time, suggesting an increasing level of covalent binding over time. An in silico A2A-structure-based docking model was used to study the binding mode of LUF7445. This led us to perform site-directed mutagenesis of the A2A receptor to probe and validate the target lysine amino acid K153 for covalent binding. Meanwhile, a functional assay combined with wash-out experiments was set up to investigate the efficacy of covalent binding of LUF7445. All these experiments led us to conclude LUF7445 is a valuable molecular tool for further investigating covalent interactions at this receptor. It may also serve as a prototype for a therapeutic approach in which a covalent antagonist may be needed to counteract prolonged and persistent presence of the endogenous ligand adenosine.

  8. A2A Adenosine Receptor Antagonism Enhances Synaptic and Motor Effects of Cocaine via CB1 Cannabinoid Receptor Activation

    PubMed Central

    Tozzi, Alessandro; de Iure, Antonio; Marsili, Valentina; Romano, Rosaria; Tantucci, Michela; Di Filippo, Massimiliano; Costa, Cinzia; Napolitano, Francesco; Mercuri, Nicola Biagio; Borsini, Franco; Giampà, Carmen; Fusco, Francesca Romana; Picconi, Barbara; Usiello, Alessandro; Calabresi, Paolo

    2012-01-01

    Background Cocaine increases the level of endogenous dopamine (DA) in the striatum by blocking the DA transporter. Endogenous DA modulates glutamatergic inputs to striatal neurons and this modulation influences motor activity. Since D2 DA and A2A-adenosine receptors (A2A-Rs) have antagonistic effects on striatal neurons, drugs targeting adenosine receptors such as caffeine-like compounds, could enhance psychomotor stimulant effects of cocaine. In this study, we analyzed the electrophysiological effects of cocaine and A2A-Rs antagonists in striatal slices and the motor effects produced by this pharmacological modulation in rodents. Principal Findings Concomitant administration of cocaine and A2A-Rs antagonists reduced glutamatergic synaptic transmission in striatal spiny neurons while these drugs failed to produce this effect when given in isolation. This inhibitory effect was dependent on the activation of D2-like receptors and the release of endocannabinoids since it was prevented by L-sulpiride and reduced by a CB1 receptor antagonist. Combined application of cocaine and A2A-R antagonists also reduced the firing frequency of striatal cholinergic interneurons suggesting that changes in cholinergic tone might contribute to this synaptic modulation. Finally, A2A-Rs antagonists, in the presence of a sub-threshold dose of cocaine, enhanced locomotion and, in line with the electrophysiological experiments, this enhanced activity required activation of D2-like and CB1 receptors. Conclusions The present study provides a possible synaptic mechanism explaining how caffeine-like compounds could enhance psychomotor stimulant effects of cocaine. PMID:22715379

  9. Role of Adenosine Receptor A2A in Traumatic Optic Neuropathies

    DTIC Science & Technology

    2012-12-01

    in Traumatic Optic Neuropathies ” PRINCIPAL INVESTIGATOR: Gregory I. Liou, PhD CONTRACTING ORGANIZATION: Georgia Health Sciences...Adenosine Receptor A2A in Traumatic Optic Neuropathies 5b. GRANT NUMBER W81XWH-11-2-0046 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT...ABSTRACT Our goal is to develop an early therapeutic intervention before the progression of traumatic optic neuropathy (TON), a vision-threatening

  10. Therapeutic Opportunities for Caffeine and A2A Receptor Antagonists in Retinal Diseases.

    PubMed

    Boia, Raquel; Ambrósio, António Francisco; Santiago, Ana Raquel

    2016-01-01

    Caffeine, the major component of coffee, is the most consumed psychostimulant in the world. Caffeine is an adenosine analog and acts as a nonselective adenosine receptor antagonist. The majority of the effects of caffeine are mainly mediated by the blockade of adenosine receptors, and the proved neuroprotective effects of caffeine in brain disorders have been mimicked by the blockade of adenosine A2A receptor (A2AR). A growing body of evidence demonstrates that microglia-mediated neuroinflammation plays a key role in the pathophysiology of brain and retinal diseases. Moreover, the control of microglia reactivity by blocking A2AR has been proposed to be the mechanism underlying the observed protective effects of caffeine. Hence, it is conceivable that caffeine and A2AR antagonists offer therapeutic value for the treatment of retinal diseases, mainly those involving microglia-mediated neuroinflammation.

  11. Adenosine A2A receptors enable the synaptic effects of cannabinoid CB1 receptors in the rodent striatum.

    PubMed

    Tebano, Maria Teresa; Martire, Alberto; Chiodi, Valentina; Pepponi, Rita; Ferrante, Antonella; Domenici, Maria Rosaria; Frank, Claudio; Chen, Jiang-Fan; Ledent, Catherine; Popoli, Patrizia

    2009-09-01

    Adenosine A(2A), cannabinoid CB(1) and metabotropic glutamate 5 (mGlu(5)) receptors are all highly expressed in the striatum. The aim of the present work was to investigate whether, and by which mechanisms, the above receptors interact in the regulation of striatal synaptic transmission. By extracellular field potentials (FPs) recordings in corticostriatal slices, we demonstrated that the ability of the selective type 1 cannabinoid receptor (CB(1)R) agonist WIN55,212-2 to depress synaptic transmission was prevented by the pharmacological blockade or the genetic inactivation of A(2A)Rs. Such a permissive effect of A(2A)Rs towards CB(1)Rs does not seem to occur pre-synaptically as the ability of WIN55,212-2 to increase the R2/R1 ratio under a protocol of paired-pulse stimulation was not modified by ZM241385. Furthermore, the effects of WIN55,212-2 were reduced in slices from mice lacking post-synaptic striatal A(2A)Rs. The selective mGlu(5)R agonist (RS)-2-chloro-5-hydroxyphenylglycine (CHPG) potentiated the synaptic effects of WIN55,212-2, and such a potentiation was abolished by A(2A)R blockade. Unlike the synaptic effects, the ability of WIN55,212-2 to prevent NMDA-induced toxicity was not influenced by ZM241385. Altogether, these results show that the state of activation of A(2A)Rs regulates the synaptic effects of CB(1)Rs and that A(2A)Rs may control CB(1) effects also indirectly, namely through mGlu(5)Rs.

  12. Clinical/pharmacological aspect of adenosine A2A receptor antagonist for dyskinesia.

    PubMed

    Kanda, Tomoyuki; Uchida, Shin-ichi

    2014-01-01

    Dopamine replacement therapy using the dopamine precursor, l-3,4-dihydroxyphenylalanine (l-DOPA), with a peripheral dopa decarboxylase inhibitor is the most effective treatment currently available for the symptoms of Parkinson's disease (PD). However, the long-term use of dopaminergic therapies for PD is often limited by the development of motor response complications, such as dyskinesia. Adenosine A2A receptors are a promising nondopaminergic target for the treatment of PD. The treatment of motor response complications involves combinations of regular and controlled release L-DOPA, perhaps with the addition of a COMT inhibitor or the use of a longer-acting dopamine agonist. However, when dyskinesia is already established, the increase in dopaminergic load produced by the addition of a dopamine agonist can result in an increase in the severity and duration of dyskinesia. Currently, there are no well-tolerated antidyskinesia agents available. Amantadine, which may exert its effects through the inhibition of N-methyl-D-aspartate (NMDA) receptors, shows some effects on established dyskinesia. Dyskinesia has a negative impact on the quality of life of patients, sometimes being more disabling than PD itself. Although some patients prefer experiencing dyskinesia than being in the OFF state and unable to move, alternative, more effective therapies are still required for severe disabling dyskinesia to afford patients an improved quality of life while in the ON state. The mechanisms causing and maintaining the dyskinesia have not been clarified. The application of a nondopaminergic approach to modify the basal ganglial activity would be helpful to better understand and treat dyskinesia. The use of an adenosine A2A receptor may provide one such approach. In this literature review, we will summarize the current knowledge from both clinical and nonclinical studies on the effects of adenosine A2A receptor blockade on dyskinesia.

  13. Effect of low frequency electromagnetic fields on A2A adenosine receptors in human neutrophils

    PubMed Central

    Varani, Katia; Gessi, Stefania; Merighi, Stefania; Iannotta, Valeria; Cattabriga, Elena; Spisani, Susanna; Cadossi, Ruggero; Borea, Pier Andrea

    2002-01-01

    The present study describes the effect of low frequency, low energy, pulsing electromagnetic fields (PEMFs) on A2A adenosine receptors in human neutrophils.Saturation experiments performed using a high affinity adenosine antagonist [3H]-ZM 241385 revealed a single class of binding sites in control and in PEMF-treated human neutrophils with similar affinity (KD=1.05±0.10 and 1.08±0.12 nM, respectively). Furthermore, after 1 h of exposure to PEMFs the receptor density was statistically increased (P<0.01) (Bmax =126±10 and 215±15 fmol mg−1 protein, respectively).The effect of PEMFs was specific to the A2A adenosine receptors. This effect was also intensity, time and temperature dependent.In the adenylyl cyclase assays the A2A receptor agonists, HE-NECA and NECA, increased cyclic AMP accumulation in untreated human neutrophils with an EC50 value of 43 (40 – 47) and 255 (228 – 284) nM, respectively. The capability of HE-NECA and NECA to stimulate cyclic AMP levels in human neutrophils was increased (P<0.01) after exposure to PEMFs with an EC50 value of 10(8 – 13) and 61(52 – 71) nM, respectively.In the superoxide anion (O2−) production assays HE-NECA and NECA inhibited the generation of O2− in untreated human neutrophils, with an EC50 value of 3.6(3.1 – 4.2) and of 23(20 – 27) nM, respectively. Moreover, in PEMF-treated human neutrophils, the same compounds show an EC50 value of 1.6(1.2 – 2.1) and of 6.0(4.7 – 7.5) nM respectively.These results indicate the presence of significant alterations in the expression and in the functionality of adenosine A2A receptors in human neutrophils treated with PEMFs. PMID:11976268

  14. Molecular Determinants of CGS21680 Binding to the Human Adenosine A2A Receptor.

    PubMed

    Lebon, Guillaume; Edwards, Patricia C; Leslie, Andrew G W; Tate, Christopher G

    2015-06-01

    The adenosine A2A receptor (A(2A)R) plays a key role in transmembrane signaling mediated by the endogenous agonist adenosine. Here, we describe the crystal structure of human A2AR thermostabilized in an active-like conformation bound to the selective agonist 2-[p-(2-carboxyethyl)phenylethyl-amino]-5'-N-ethylcarboxamido adenosine (CGS21680) at a resolution of 2.6 Å. Comparison of A(2A)R structures bound to either CGS21680, 5'-N-ethylcarboxamido adenosine (NECA), UK432097 [6-(2,2-diphenylethylamino)-9-[(2R,3R,4S,5S)-5-(ethylcarbamoyl)-3,4-dihydroxy-tetrahydrofuran-2-yl]-N-[2-[[1-(2-pyridyl)-4-piperidyl]carbamoylamino]ethyl]purine-2-carboxamide], or adenosine shows that the adenosine moiety of the ligands binds to the receptor in an identical fashion. However, an extension in CGS21680 compared with adenosine, the (2-carboxyethyl)phenylethylamino group, binds in an extended vestibule formed from transmembrane regions 2 and 7 (TM2 and TM7) and extracellular loops 2 and 3 (EL2 and EL3). The (2-carboxyethyl)phenylethylamino group makes van der Waals contacts with side chains of amino acid residues Glu169(EL2), His264(EL3), Leu267(7.32), and Ile274(7.39), and the amine group forms a hydrogen bond with the side chain of Ser67(2.65). Of these residues, only Ile274(7.39) is absolutely conserved across the human adenosine receptor subfamily. The major difference between the structures of A(2A)R bound to either adenosine or CGS21680 is that the binding pocket narrows at the extracellular surface when CGS21680 is bound, due to an inward tilt of TM2 in that region. This conformation is stabilized by hydrogen bonds formed by the side chain of Ser67(2.65) to CGS21680, either directly or via an ordered water molecule. Mutation of amino acid residues Ser67(2.65), Glu169(EL2), and His264(EL3), and analysis of receptor activation either in the presence or absence of ligands implicates this region in modulating the level of basal activity of A(2A)R.

  15. Behavioural and neurochemical characterization of the adenosine A2A receptor antagonist ST1535.

    PubMed

    Galluzzo, Mariangela; Pintor, Anita; Pèzzola, Antonella; Grieco, Rosa; Borsini, Franco; Popoli, Patrizia

    2008-01-28

    ST1535 (2-butyl-9-methyl-8-(2H-1,2,3-triazol 2-yl)-9 H-purin-6-ylamine) is a novel compound showing a preferential adenosine A(2A) receptor antagonist profile. To explore the potential neuroprotective profile of this compound, we evaluated whether ST1535 prevented quinolinic acid (QA)-induced glutamate outflow in the rat striatum (a reliable index of neuroprotective activity in vivo). Microdialysis experiments were performed in naive Wistar rats. In these experiments, a behaviourally active and inactive doses of ST1535 were used. Both doses significantly prevented QA-induced glutamate outflow in the striatum. These results show that ST1535 protects towards striatal excitotoxicity, even though its reduced A(2A)/A(1) selectivity might limit its actual neuroprotective potential.

  16. Dissecting striatal adenosine-cannabinoid receptor interactions. New clues from rats over-expressing adenosine A2A receptors.

    PubMed

    Ferré, Sergi; Sebastião, Ana Maria

    2016-03-01

    This Editorial highlights a study by Chiodi et al. () showing that the effects mediated by cannabinoid CB1 receptor (CB1R) activation in the striatum are significantly reduced in rats with neuronal over-expression of adenosine A2A receptors (A2AR). Two hypotheses are derived from that study. Hypothesis A: two subpopulations of pre-synaptic CB1R in corticostriatal glutamatergic terminals exist, one forming and another not forming heteromers with A2AR. Hypothesis B: CB1R are predominantly forming heteromers with A2AR. In the case of hypothesis A, the A2AR might be required for CB1R-A2AR heteromeric signaling, whereas non-heteromeric CB1R activity is inhibited by A2ARs. In the case of hypothesis B, up-regulation of A2ARs may perturb heteromeric stoichiometry, thus reducing CB1R functioning. In any case, pre-synaptic striatal A2AR-CB1R heteromers emerge as important targets of the effects of cannabinoids demonstrated at the neuronal and behavioral level. Read the highlighted article 'Striatal adenosine-cannabinoid receptor interactions in rats over-expressing adenosine A2A receptors' on page 907.

  17. Physical origins of remarkable thermostabilization by an octuple mutation for the adenosine A2a receptor

    NASA Astrophysics Data System (ADS)

    Kajiwara, Yuta; Ogino, Takahiro; Yasuda, Satoshi; Takamuku, Yuuki; Murata, Takeshi; Kinoshita, Masahiro

    2016-07-01

    It was experimentally showed that the thermal stability of a membrane protein, the adenosine A2a receptor, was remarkably enhanced by an octuple mutation. Here we theoretically prove that the energy decrease arising from the formation of protein intramolecular hydrogen bonds and the solvent-entropy gain upon protein folding are made substantially larger by the mutation, leading to the remarkable enhancement. The solvent is formed by hydrocarbon groups constituting nonpolar chains of the lipid bilayer within a membrane. The mutation modifies geometric characteristics of the structure so that the solvent crowding can be reduced to a larger extent when the protein folds.

  18. Role of Adenosine Receptor A2A in Traumatic Optic Neuropathies (Addendum)

    DTIC Science & Technology

    2016-03-01

    diabetic retinopathy. Life Sci. 2013 Jul 30;93(2-3):78-88. doi: 10.1016/j.lfs.2013.05.024. Epub 2013 Jun 12.PMID:23770229 7 AIMS: This study was...undertaken to determine the effect of an adenosine kinase inhibitor (AKI) in diabetic retinopathy (DR). We have shown previously that adenosine signaling...via A2A receptors (A2AAR) is involved in retinal protection from diabetes -induced inflammation. Here we demonstrate that AKI-enhanced adenosine

  19. Key modulatory role of presynaptic adenosine A2A receptors in cortical neurotransmission to the striatal direct pathway.

    PubMed

    Quiroz, César; Luján, Rafael; Uchigashima, Motokazu; Simoes, Ana Patrícia; Lerner, Talia N; Borycz, Janusz; Kachroo, Anil; Canas, Paula M; Orru, Marco; Schwarzschild, Michael A; Rosin, Diane L; Kreitzer, Anatol C; Cunha, Rodrigo A; Watanabe, Masahiko; Ferré, Sergi

    2009-11-18

    Basal ganglia processing results from a balanced activation of direct and indirect striatal efferent pathways, which are controlled by dopamine D1 and D2 receptors, respectively. Adenosine A2A receptors are considered novel antiparkinsonian targets, based on their selective postsynaptic localization in the indirect pathway, where they modulate D2 receptor function. The present study provides evidence for the existence of an additional, functionally significant, segregation of A2A receptors at the presynaptic level. Using integrated anatomical, electrophysiological, and biochemical approaches, we demonstrate that presynaptic A2A receptors are preferentially localized in cortical glutamatergic terminals that contact striatal neurons of the direct pathway, where they exert a selective modulation of corticostriatal neurotransmission. Presynaptic striatal A2A receptors could provide a new target for the treatment of neuropsychiatric disorders.

  20. In vitro metabolism studies of new adenosine A 2A receptor antagonists.

    PubMed

    Marucci, Gabriella; Finaurini, Sara; Buccioni, Michela; Lammi, Carmen; Kandhavelu, Meenakshisundaram; Volpini, Rosaria; Ricciutelli, Massimo; Angeli, Piero; Commandeur, Jan N M; Cristalli, Gloria

    2008-12-01

    Evidence, obtained in rodent and primate models of Parkinson's disease (PD) and in preliminary clinical trials, indicates that adenosine A(2A) receptor antagonists might represent a promising non-dopaminergic therapeutic tool for the treatment of PD. Recently, we have reported the biological evaluation of 8-substituted 9-ethyladenines (ANR) as new A(2A) receptor antagonists, three of which (ANR 82, ANR 94, and ANR 152) showed high efficacy in in vivo models for Parkinson's. Understanding the metabolic pathways of new drug candidates is an important aspect of drug discovery. The ANR compounds have been investigated in order to clarify their activity on rat liver microsomes, and more specifically on recombinant human cytochrome P450 2D6 (CYP2D6). The metabolites of all three compounds were detected by liquid chromatography/tandem mass spectrometry (LC-MS/MS). The results indicate that this class of 9-ethyladenines is metabolized only to a fraction of 1.5-5%. These compounds also act as potent mechanism-based inhibitors of CYP450 and in particular of human isoform CYP2D6. Kinetic-analysis of enzyme inactivation was used to describe the effect of these time-dependent inhibitors and to derive the inhibition parameters K(inact) and K(i) defined with respect to the O-demethylation of dextromethorphan.

  1. Neuroprotection by caffeine in the MPTP model of parkinson's disease and its dependence on adenosine A2A receptors.

    PubMed

    Xu, K; Di Luca, D G; Orrú, M; Xu, Y; Chen, J-F; Schwarzschild, M A

    2016-05-13

    Considerable epidemiological and laboratory data have suggested that caffeine, a nonselective adenosine receptor antagonist, may protect against the underlying neurodegeneration of parkinson's disease (PD). Although both caffeine and more specific antagonists of the A2A subtype of adenosine receptor (A2AR) have been found to confer protection in animal models of PD, the dependence of caffeine's neuroprotective effects on the A2AR is not known. To definitively determine its A2AR dependence, the effect of caffeine on 1-methyl-4-phenyl-1,2,3,6 tetra-hydropyridine (MPTP) neurotoxicity was compared in wild-type (WT) and A2AR gene global knockout (A2A KO) mice, as well as in central nervous system (CNS) cell type-specific (conditional) A2AR knockout (cKO) mice that lack the receptor either in postnatal forebrain neurons or in astrocytes. In WT and in heterozygous A2AR KO mice caffeine pretreatment (25mg/kgip) significantly attenuated MPTP-induced depletion of striatal dopamine. By contrast in homozygous A2AR global KO mice caffeine had no effect on MPTP toxicity. In forebrain neuron A2AR cKO mice, caffeine lost its locomotor stimulant effect, whereas its neuroprotective effect was mostly preserved. In astrocytic A2AR cKO mice, both caffeine's locomotor stimulant and protective properties were undiminished. Taken together, these results indicate that neuroprotection by caffeine in the MPTP model of PD relies on the A2AR, although the specific cellular localization of these receptors remains to be determined.

  2. Potential therapeutic relevance of adenosine A2B and A2A receptors in the central nervous system.

    PubMed

    Popoli, Patrizia; Pepponi, Rita

    2012-09-01

    Adenosine A2B and, much more importantly, adenosine A2A receptors modulate many physiological and pathological processes in the brain. In this review, the most recent evidence concerning the role of such receptors and their potential therapeutic relevance is discussed. The low affinity of A2B receptors for adenosine implies that they might represent a good therapeutic target, since they are activated only under pathological conditions (when adenosine levels raise up to micromolar concentrations). The availability of selective ligands for A2B receptors would allow exploration of such an hypothesis. Since adenosine A2A receptors mediate both potentially neuroprotective and potentially neurotoxic effects, their role in neurodegenerative diseases is highly controversial. Nevertheless, A2A receptor antagonists have shown clear antiparkinsonian effects, and a great interest exists on the role of A2A receptors in Alzheimer's disease, brain ischaemia, spinal cord injury, drug addiction and other conditions. In order to establish whether such receptors represent a target for CNS diseases, at least two conditions are needed: the full comprehension of A2A-dependent mechanisms and the availability of ligands capable of discriminating among the different receptor populations.

  3. Postsynaptic Adenosine A2A Receptors Modulate Intrinsic Excitability of Pyramidal Cells in the Rat Basolateral Amygdala

    PubMed Central

    Rau, Andrew R.; Ariwodola, Olusegun J.

    2015-01-01

    Background: The basolateral amygdala plays a critical role in the etiology of anxiety disorders and addiction. Pyramidal neurons, the primary output cells of this region, display increased firing following exposure to stressors, and it is thought that this increase in excitability contributes to stress responsivity and the expression of anxiety-like behaviors. However, much remains unknown about the underlying mechanisms that regulate the intrinsic excitability of basolateral amygdala pyramidal neurons. Methods: Ex vivo gramicidin perforated patch recordings were conducted in current clamp mode where hyper- and depolarizing current steps were applied to basolateral amygdala pyramidal neurons to assess the effects of adenosine A2A receptor modulation on intrinsic excitability. Results: Activation of adenosine A2A receptors with the selective A2A receptor agonist CGS-21680 significantly increased the firing rate of basolateral amygdala pyramidal neurons in rat amygdala brain slices, likely via inhibition of the slow afterhyperpolarization potential. Both of these A2A receptor-mediated effects were blocked by preapplication of a selective A2A receptor antagonist (ZM-241385) or by intra-pipette infusion of a protein kinase A inhibitor, suggesting a postsynaptic locus of A2A receptors on basolateral amygdala pyramidal neurons. Interestingly, bath application of the A2A receptor antagonist alone significantly attenuated basolateral amygdala pyramidal cell firing, consistent with a role for tonic adenosine in the regulation of the intrinsic excitability of these neurons. Conclusions: Collectively, these data suggest that adenosine, via activation of A2A receptors, may directly facilitate basolateral amygdala pyramidal cell output, providing a possible balance for the recently described inhibitory effects of adenosine A1 receptor activation on glutamatergic excitation of basolateral amygdala pyramidal cells. PMID:25716780

  4. Past, present and future of A(2A) adenosine receptor antagonists in the therapy of Parkinson's disease.

    PubMed

    Armentero, Marie Therese; Pinna, Annalisa; Ferré, Sergi; Lanciego, José Luis; Müller, Christa E; Franco, Rafael

    2011-12-01

    Several selective antagonists for adenosine A(2A) receptors (A(2A)R) are currently under evaluation in clinical trials (phases I to III) to treat Parkinson's disease, and they will probably soon reach the market. The usefulness of these antagonists has been deduced from studies demonstrating functional interactions between dopamine D₂ and adenosine A(2A) receptors in the basal ganglia. At present it is believed that A(2A)R antagonists can be used in combination with the dopamine precursor L-DOPA to minimize the motor symptoms of Parkinson's patients. However, a considerable body of data indicates that in addition to ameliorating motor symptoms, adenosine A(2A)R antagonists may also prevent neurodegeneration. Despite these promising indications, one further issue must be considered in order to develop fully optimized antiparkinsonian drug therapy, namely the existence of (hetero)dimers/oligomers of G protein-coupled receptors, a topic that is currently the focus of intense debate within the scientific community. Dopamine D₂ receptors (D₂Rs) expressed in the striatum are known to form heteromers with A(2A) adenosine receptors. Thus, the development of heteromer-specific A(2A) receptor antagonists represents a promising strategy for the identification of more selective and safer drugs.

  5. New adenosine A2A receptor antagonists: actions on Parkinson's disease models.

    PubMed

    Pinna, Annalisa; Volpini, Rosaria; Cristalli, Gloria; Morelli, Micaela

    2005-04-11

    The 8-substituted 9-ethyladenine derivatives: 8-bromo-9-ethyladenine (ANR 82), 8-ethoxy- 9-ethyladenine (ANR 94), and 8-furyl-9-ethyladenine (ANR 152) have been characterized in vitro as adenosine receptor antagonists. Adenosine is deeply involved in the control of motor behaviour and substantial evidences indicate that adenosine A(2A) receptor antagonists improve motor deficits in animal models of Parkinson's disease. On this basis, the efficacy of ANR 82, ANR 94, and ANR 152 in rat models of Parkinson's disease was evaluated. All compounds tested reversed the catalepsy induced by haloperidol. However, in unilaterally 6-hydroxydopamine-lesioned rats, only ANR 94 and ANR 152 potentiated l-dihydroxy-phenylalanine (l-DOPA) effect on turning behaviour and induced contralateral turning behaviour in rats sensitised to l-DOPA. Taken together the results of this study indicate that some 8-substituted 9-ethyladenine derivatives ameliorate motor deficits in rat models of Parkinson's disease, suggesting a potential therapeutic role of these compounds.

  6. A2A adenosine receptors are up-regulated in lymphocytes from amyotrophic lateral sclerosis patients.

    PubMed

    Vincenzi, Fabrizio; Corciulo, Carmen; Targa, Martina; Casetta, Ilaria; Gentile, Mauro; Granieri, Enrico; Borea, Pier Andrea; Popoli, Patrizia; Varani, Katia

    2013-09-01

    Adenosine, a purine nucleoside interacting with A1, A2A, A2B and A3 adenosine receptors (ARs), is a potent endogenous modulator of inflammatory and neuronal processes involved in the pathophysiology of several neurodegenerative diseases. In the present study, ARs were investigated in lymphocytes from patients with amyotrophic lateral sclerosis (ALS) and compared with age-matched healthy subjects. In ALS patients A2AARs were analysed by using RT-PCR, Western blotting and saturation binding experiments. The effect of A2AAR stimulation on cyclic AMP levels was evaluated in lymphocytes from ALS patients and healthy subjects. An up-regulation of A2AARs was observed in ALS patients with respect to healthy subjects while A1, A2B and A3AR affinity and density did not change. In ALS patients, the A2AAR density values correlated with the Amyotrophic Lateral Sclerosis Functional Rating Scale-Revised (ALSFRS-R) scores. Furthermore, the stimulation of A2AARs mediated a significant increase in cyclic AMP levels in lymphocytes from ALS patients, with a higher potency than in lymphocytes from healthy subjects. In conclusion, the positive correlation between A2AAR density and ALSFRS-R scores could indicate a possible protective effect of this receptor subtype, representing an interesting starting point for the study of alternative therapeutic approaches for ALS based on A2AAR modulation.

  7. A2A adenosine receptor regulates the human blood brain barrier permeability

    PubMed Central

    Kim, Do-Geun; Bynoe, Margaret S.

    2015-01-01

    The blood brain barrier (BBB) symbolically represents the gateway to the central nervous system. It is a single layer of specialized endothelial cells that coats the central nervous system (CNS) vasculature and physically separates the brain environment from the blood constituents, to maintain the homeostasis of the CNS. However, this protective measure is a hindrance to the delivery of therapeutics to treat neurological diseases. Here, we show that activation of A2A adenosine receptor (AR) with an FDA-approved agonist potently permeabilizes an in vitro primary human brain endothelial barrier (hBBB) to the passage of chemotherapeutic drugs and T cells. T cell migration under AR signaling occurs primarily by paracellular transendothelial route. Permeabilization of the hBBB is rapid, time-dependent and reversible and is mediated by morphological changes in actin-cytoskeletal reorganization induced by RhoA signaling and a potent down-regulation of Claudin-5 and VE-Cadherin. Moreover, the kinetics of BBB permeability in mice closely overlaps with the permeability kinetics of the hBBB. These data suggest that activation of A2A AR is an endogenous mechanism that may be used for CNS drug delivery in human. PMID:25262373

  8. Reduced striatal adenosine A2A receptor levels define a molecular subgroup in schizophrenia.

    PubMed

    Villar-Menéndez, Izaskun; Díaz-Sánchez, Sara; Blanch, Marta; Albasanz, José Luis; Pereira-Veiga, Thais; Monje, Alfonso; Planchat, Luis Maria; Ferrer, Isidre; Martín, Mairena; Barrachina, Marta

    2014-04-01

    Schizophrenia (SZ) is a mental disorder of unknown origin. Some scientific evidence seems to indicate that SZ is not a single disease entity, since there are patient groups with clear symptomatic, course and biomarker differences. SZ is characterized by a hyperdopaminergic state related to high dopamine D2 receptor activity. It has also been proposed that there is a hypoadenosynergic state. Adenosine is a nucleoside widely distributed in the organism with neuromodulative and neuroprotective activity in the central nervous system. In the brain, the most abundant adenosine receptors are A1R and A2AR. In the present report, we characterize the presence of both receptors in human postmortem putamens of patients suffering SZ with real time TaqMan PCR, western blotting and radioligand binding assay. We show that A1R levels remain unchanged with respect to age-matched controls, whereas nearly fifty percent of patients have reduced A2AR, at the transcriptional and translational levels. Moreover, we describe how DNA methylation plays a role in the pathological A2AR levels with the bisulfite-sequencing technique. In fact, an increase in 5-methylcytosine percentage in the 5' UTR region of ADORA2A was found in those SZ patients with reduced A2AR levels. Interestingly, there was a relationship between the A2A/β-actin ratio and motor disturbances as assessed with some items of the PANSS, AIMS and SAS scales. Therefore, there may be a subgroup of SZ patients with reduced striatal A2AR levels accompanied by an altered motor phenotype.

  9. Selective adenosine A2A receptor agonists and antagonists protect against spinal cord injury through peripheral and central effects

    PubMed Central

    2011-01-01

    Background Permanent functional deficits following spinal cord injury (SCI) arise both from mechanical injury and from secondary tissue reactions involving inflammation. Enhanced release of adenosine and glutamate soon after SCI represents a component in the sequelae that may be responsible for resulting functional deficits. The role of adenosine A2A receptor in central ischemia/trauma is still to be elucidated. In our previous studies we have demonstrated that the adenosine A2A receptor-selective agonist CGS21680, systemically administered after SCI, protects from tissue damage, locomotor dysfunction and different inflammatory readouts. In this work we studied the effect of the adenosine A2A receptor antagonist SCH58261, systemically administered after SCI, on the same parameters. We investigated the hypothesis that the main action mechanism of agonists and antagonists is at peripheral or central sites. Methods Spinal trauma was induced by extradural compression of SC exposed via a four-level T5-T8 laminectomy in mouse. Three drug-dosing protocols were utilized: a short-term systemic administration by intraperitoneal injection, a chronic administration via osmotic minipump, and direct injection into the spinal cord. Results SCH58261, systemically administered (0.01 mg/kg intraperitoneal. 1, 6 and 10 hours after SCI), reduced demyelination and levels of TNF-α, Fas-L, PAR, Bax expression and activation of JNK mitogen-activated protein kinase (MAPK) 24 hours after SCI. Chronic SCH58261 administration, by mini-osmotic pump delivery for 10 days, improved the neurological deficit up to 10 days after SCI. Adenosine A2A receptors are physiologically expressed in the spinal cord by astrocytes, microglia and oligodendrocytes. Soon after SCI (24 hours), these receptors showed enhanced expression in neurons. Both the A2A agonist and antagonist, administered intraperitoneally, reduced expression of the A2A receptor, ruling out the possibility that the neuroprotective effects

  10. Potentiation by tonic A2a-adenosine receptor activation of CGRP-facilitated [3H]-ACh release from rat motor nerve endings.

    PubMed Central

    Correia-de-Sá, P.; Ribeiro, J. A.

    1994-01-01

    1. The effect of calcitonin gene-related peptide (CGRP) on [3H]-acetylcholine ([3H]-ACh) release from motor nerve endings and its interaction with presynaptic facilitatory A2a-adenosine and nicotinic acetylcholine receptors was studied on rat phrenic nerve-hemidiaphragm preparations loaded with [3H]-choline. 2. CGRP (100-400 nM) increased electrically evoked [3H]-ACh release from phrenic nerve endings in a concentration-dependent manner. 3. The magnitude of CGRP excitation increased with the increase of the stimulation pulse duration from 40 microseconds to 1 ms, keeping the frequency, the amplitude and the train length constants. With 1 ms pulses, the evoked [3H]-ACh release was more intense than with 40 microseconds pulse duration. 4. Both the nicotinic acetylcholine receptor agonist, 1,1-dimethyl-4-phenylpiperazinium, and the A2a adenosine receptor agonist, CGS 21680C, increased evoked [3H]-ACh release, but only CGS 21680C potentiated the facilitatory effect of CGRP. This potentiation was prevented by the A2a adenosine receptor antagonist, PD 115,199. 5. Adenosine deaminase prevented the excitatory effect of CGRP (400 nM) on [3H]-ACh release. This effect was reversed by the non-hydrolysable A2a-adenosine receptor agonist, CGS 21680C. 6. The nicotinic antagonist, tubocurarine, did not significantly change, whereas the A2-adenosine receptor antagonist, PD 115,199, blocked the CGRP facilitation. The A1-adenosine receptor antagonist, 1,3-dipropyl-8-cyclopentylxanthine, potentiated the CGRP excitatory effect. 7. The results suggest that the facilitatory effect of CGRP on evoked [3H]-ACh release from rat phrenic motor nerve endings depends on the presence of endogenous adenosine which tonically activates A2a-adenosine receptors.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8004402

  11. Adenosine A(2A)-cannabinoid CB(1) receptor interaction: an integrative mechanism in striatal glutamatergic neurotransmission.

    PubMed

    Tebano, Maria Teresa; Martire, Alberto; Popoli, Patrizia

    2012-10-02

    The striatum is a subcortical area involved in sensorimotor, cognitive and emotional processes. Adenosine A(2A) receptors (A(2A)Rs) are highly expressed in the striatum, and their ability to establish functional and molecular interactions with many other receptors attributes to a pivotal role in the modulation and integration of striatal neurotransmission. This review will focus on the interaction between A(2A)Rs and cannabinoid CB(1) receptors (CB(1)Rs), taking it as a paradigmatic example of synaptic integration. Indeed, A(2A)Rs can exert an opposite (permissive vs. inhibitory) influence on CB1-dependent synaptic effect. These apparently irreconcilable functions could depend on a different role of pre- vs. postsynaptic A(2A)Rs, on their interaction with other receptors (namely adenosine A(1), metabotropic glutamate 5 and dopamine D2 receptors), and on whether A(2A)Rs form or not heteromers with CB(1)Rs. Besides providing a good example of the intricate pattern of events taking place in striatal synapses, the A(2A)/CB(1)R interaction proves very informative to understand the physiology of the basal ganglia and the mechanisms of related diseases. This article is part of a Special Issue entitled: Brain Integration.

  12. FGF acts as a co-transmitter through Adenosine A2A receptor to regulate morphological and physiological synaptic plasticity

    PubMed Central

    Flajolet, Marc; Wang, Zhongfeng; Futter, Marie; Shen, Weixing; Nuangchamnong, Nina; Bendor, Jacob; Palaszewski, Iwona; Nairn, Angus C.; Surmeier, D. James; Greengard, Paul

    2009-01-01

    Summary Abnormalities of striatal function have been implicated in several major neurological and psychiatric disorders, including Parkinson's disease, schizophrenia, and depression. Adenosine, by activation of A2A receptors, antagonizes dopamine signaling at D2 receptors and A2A receptor antagonists have been tested as therapeutic agents for Parkinson's disease. We report here a direct physical interaction between the G protein-coupled A2A receptor and the receptor tyrosine kinase FGF receptor. Concomitant activation of these two classes of receptors, but not individual activation of either one alone, causes a robust activation of the MAPK/ERK pathway, differentiation and neurite extension of PC12 cells, spine morphogenesis in primary neuronal cultures, and cortico-striatal plasticity induced by a novel A2AR/FGFR-dependent mechanism. The discovery of a direct physical interaction between the A2A and FGF receptors and the robust physiological consequences of this association shed light on the mechanism underlying FGF functions as a co-transmitter and open new avenues for therapeutic interventions. PMID:18953346

  13. Characterization of [125I]ZM 241385 binding to adenosine A2A receptors in the pineal of sheep brain.

    PubMed

    Yan, X; Koos, B J; Kruger, L; Linden, J; Murray, T F

    2006-06-22

    Adenosine is a ubiquitous neuromodulator and homeostatic regulator that exerts its physiologic actions through activation of A(1), A(2A), A(2B) and A(3) adenosine receptor subtypes. In the central nervous system, adenosine's action in neurons is manifested in its modulation of tonic inhibitory control. Adenosine released in the brain during hypoxia has critical depressant effects on breathing in fetal and newborn mammals, an action suggested to be mediated by A(2A) receptors in the posteromedial thalamus. In an effort to more accurately define the spatial distribution of adenosine A(2A) receptors in fetal sheep diencephalon, we have used a receptor autoradiographic technique utilizing an iodinated radioligand [(125)I]ZM 241385, which has greater sensitivity and resolution than the tritiated compound. The distribution of ligand binding sites in the fetal sheep diencephalon indicated that the highest levels of binding were in select thalamic nuclei, including those implicated in hypoxic depression of fetal breathing, and the pineal. Given the high density of labeled A(2A) receptors in the pineal, these sites were characterized more fully in homogenate radioligand binding assays. These data indicate that [(125)I]ZM 241385 binding sites display a pharmacological signature consistent with that of adenosine A(2A) receptors and are expressed at similar levels in fetal, lamb and adult ovine brain. The adenosine A(2A) receptor pharmacologic signature of the [(125)I]ZM 241385 binding site in pineal cell membranes generalized to the site characterized in membranes derived from other portions of the lamb thalamus, including the sector involved in hypoxic inhibition of fetal breathing. These results have important implications for the functional roles of adenosine A(2A) receptors in the thalamus and pineal of sheep brain.

  14. A1 and A2a receptors mediate inhibitory effects of adenosine on the motor activity of human colon.

    PubMed

    Fornai, M; Antonioli, L; Colucci, R; Ghisu, N; Buccianti, P; Marioni, A; Chiarugi, M; Tuccori, M; Blandizzi, C; Del Tacca, M

    2009-04-01

    Experimental evidence in animal models suggests that adenosine is involved in the regulation of digestive functions. This study examines the influence of adenosine on the contractile activity of human colon. Reverse transcription-polymerase chain reaction revealed A(1) and A(2a) receptor expression in colonic neuromuscular layers. Circular muscle preparations were connected to isotonic transducers to determine the effects of 8-cyclopentyl-1,3-dipropylxanthine (DPCPX; A(1) receptor antagonist), ZM 241385 (A(2a) receptor antagonist), CCPA (A(1) receptor agonist) and 2-[(p-2-carboxyethyl)-phenethylamino]-5'-N-ethyl-carboxamide-adenosine (CGS 21680; A(2a) receptor agonist) on motor responses evoked by electrical stimulation or carbachol. Electrically evoked contractions were enhanced by DPCPX and ZM 241385, and reduced by CCPA and CGS 21680. Similar effects were observed when colonic preparations were incubated with guanethidine (noradrenergic blocker), L-732,138, GR-159897 and SB-218795 (NK receptor antagonists). However, in the presence of guanethidine, NK receptor antagonists and N(omega)-propyl-L-arginine (NPA; neuronal nitric oxide synthase inhibitor), the effects of DPCPX and CCPA were still evident, while those of ZM 241385 and CGS 21680 no longer occurred. Carbachol-induced contractions were unaffected by A(2a) receptor ligands, but they were enhanced or reduced by DPCPX and CCPA, respectively. When colonic preparations were incubated with guanethidine, NK antagonists and atropine, electrically induced relaxations were partly reduced by ZM 241385 or NPA, but unaffected by DPCPX. Dipyridamole or application of exogenous adenosine reduced electrically and carbachol-evoked contractions, whereas adenosine deaminase enhanced such motor responses. In conclusion, adenosine exerts an inhibitory control on human colonic motility. A(1) receptors mediate direct modulating actions on smooth muscle, whereas A(2a) receptors operate through inhibitory nitrergic nerve pathways.

  15. Ex vivo Perfusion with Adenosine A2A Receptor Agonist Enhances Rehabilitation of Murine Donor Lungs after Circulatory Death

    PubMed Central

    Stone, Mathew L.; Sharma, Ashish K.; Mas, Valeria. R.; Gehrau, Ricardo C.; Mulloy, Daniel P.; Zhao, Yunge; Lau, Christine L.; Kron, Irving L.; Laubach, Victor E.

    2015-01-01

    Background Ex vivo lung perfusion (EVLP) enables assessment and rehabilitation of marginal donor lungs prior to transplantation. We previously demonstrated that adenosine A2A receptor (A2AR) agonism attenuates lung ischemia-reperfusion injury. The current study utilizes a novel murine EVLP model to test the hypothesis that A2AR agonist enhances EVLP-mediated rehabilitation of donation after circulatory death (DCD) lungs. Methods Mice underwent euthanasia and 60 min warm ischemia, and lungs were flushed with Perfadex and underwent cold static preservation (CSP, 60 min). Three groups were studied: no EVLP (CSP), EVLP with Steen solution for 60 min (EVLP), and EVLP with Steen solution supplemented with ATL1223, a selective A2AR agonist (EVLP+ATL1223). Lung function, wet/dry weight, cytokines and neutrophil numbers were measured. Microarrays were performed using the Affymetrix GeneChip Mouse Genome 430A 2.0 Array. Results EVLP significantly improved lung function versus CSP, which was further, significantly improved by EVLP+ATL1223. Lung edema, cytokines and neutrophil counts were reduced after EVLP and further, significantly reduced after EVLP+ATL1223. Gene array analysis revealed differential expression of 1,594 genes after EVLP, which comprise canonical pathways involved in inflammation and innate immunity including IL-1, IL-8, IL-6 and IL-17 signaling. Several pathways were uniquely regulated by EVLP+ATL1223 including the downregulation of genes involved in IL-1 signaling such as ADCY9, ECSIT, IRAK1, MAPK12 and TOLLIP. Conclusion EVLP modulates pro-inflammatory genes and reduces pulmonary dysfunction, edema and inflammation in DCD lungs, which are further reduced by A2AR agonism. This murine EVLP model provides a novel platform to study rehabilitative mechanisms of DCD lungs. PMID:26262504

  16. Adenosine A2A receptor blockade differentially influences excitotoxic mechanisms at pre- and postsynaptic sites in the rat striatum.

    PubMed

    Tebano, Maria Teresa; Pintor, Annita; Frank, Claudio; Domenici, Maria Rosaria; Martire, Alberto; Pepponi, Rita; Potenza, Rosa Luisa; Grieco, Rosa; Popoli, Patrizia

    2004-07-01

    Adenosine A(2A) receptor antagonists are being regarded as potential neuroprotective drugs, although the mechanisms underlying their effects need to be better studied. The aim of this work was to investigate further the mechanism of the neuroprotective action of A(2A) receptor antagonists in models of pre- and postsynaptic excitotoxicity. In microdialysis studies, the intrastriatal perfusion of the A(2A) receptor antagonist ZM 241385 (5 and 50 nM) significantly reduced, in an inversely dose-dependent way, the raise in glutamate outflow induced by 5 mM quinolinic acid (QA). In rat corticostriatal slices, ZM 241385 (30-100 nM) significantly reduced 4-aminopyridine (4-AP)-induced paired-pulse inhibition (PPI; an index of neurotransmitter release), whereas it worsened the depression of field potential amplitude elicited by N-methyl-D-aspartate (NMDA; 12.5 and 50 microM). The A(2A) antagonist SCH 58261 (30 nM) mimicked the effects of ZM 241385, whereas the A(2A) agonist CGS 21680 (100 nM) showed a protective influence toward 50 microM NMDA. In rat striatal neurons, 50 nM ZM 241385 did not affect the increase in [Ca(2+)](i) or the release of lactate dehydrogenase (LDH) induced by 100 and 300 microM NMDA, respectively. The ability of ZM 241385 to prevent QA-induced glutamate outflow and 4-AP-induced effects confirms that A(2A) receptor antagonists have inhibitory effects on neurotransmitter release, whereas the results obtained toward NMDA-induced effects suggest that A(2A) receptor blockade does not reduce, or even amplifies, excitotoxic mechanisms due to direct NMDA receptor stimulation. This indicates that the neuroprotective potential of A(2A) antagonists may be evident mainly in models of neurodegeneration in which presynaptic mechanisms play a major role.

  17. Enhancement of AMPA currents and GluR1 membrane expression through PKA-coupled adenosine A(2A) receptors.

    PubMed

    Dias, Raquel B; Ribeiro, Joaquim A; Sebastião, Ana M

    2012-02-01

    Phosphorylation of glutamate α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors by Protein Kinase A (PKA) is known to regulate AMPA receptor (AMPAR) trafficking and stabilization at the postsynaptic membrane, which in turn is one of the key mechanisms by which synaptic transmission and plasticity are tuned. However, not much is known as to how Gs-coupled receptors contribute to endogenous PKA-mediated regulation of AMPA receptor function. Here we report that activation of the excitatory A(2A) adenosine receptor by 2-[4-(2-p-carboxyethyl)phenylamino]-5'-N-ethylcarboxamidoadenosine (CGS 21680, 1-30 nM) facilitates AMPA-evoked currents in CA1 pyramidal neurons, by a mechanism dependent on PKA activation, but not on protein synthesis. This modulation of AMPA currents was mimicked by forskolin (1 μM) and did not occur in stratum radiatum interneurons. Superfusion of the A(2A) receptor agonist also caused an increase in the amplitude of miniature excitatory postsynaptic currents (mEPSCs), as well as in the membrane levels of GluR1 subunits phosphorylated at the PKA site (Ser845). The impact of this increase on GluR1-containing AMPA receptor expression was evidenced by the potentiation of LTP at the CA3-CA1 synapse that followed brief activation of A(2A) receptors. We thus propose that in conditions of increased adenosine availability, A(2A) receptor activation is responsible for setting part of the endogenous GluR1 Ser-845 phosphorylation tonus and hence, the availability of the GluR1-containing AMPA receptor extrasynaptic pool for synaptic insertion and reinforcement of synaptic strength.

  18. A differential role for the adenosine A2A receptor in opiate reinforcement vs opiate-seeking behavior.

    PubMed

    Brown, Robyn Mary; Short, Jennifer Lynn; Cowen, Michael Scott; Ledent, Catherine; Lawrence, Andrew John

    2009-03-01

    The adenosine A(2A) receptor is specifically enriched in the medium spiny neurons that make up the 'indirect' output pathway from the ventral striatum, a structure known to have a crucial, integrative role in processes such as reward, motivation, and drug-seeking behavior. In the present study we investigated the impact of adenosine A(2A) receptor deletion on behavioral responses to morphine in a number of reward-related paradigms. The acute, rewarding effects of morphine were evaluated using the conditioned place preference paradigm. Operant self-administration of morphine on both fixed and progressive ratio schedules as well as cue-induced drug-seeking was assessed. In addition, the acute locomotor response to morphine as well as sensitization to morphine was evaluated. Decreased morphine self-administration and breakpoint in A(2A) knockout mice was observed. These data support a decrease in motivation to consume the drug, perhaps reflecting diminished rewarding effects of morphine in A(2A) knockout mice. In support of this finding, a place preference to morphine was not observed in A(2A) knockout mice but was present in wild-type mice. In contrast, robust cue-induced morphine-seeking behavior was exhibited by both A(2A) knockout and wild-type mice after a period of withdrawal. The acute locomotor response to morphine in the A(2A) knockout was similar to wild-type mice, yet A(2A) knockout mice did not display tolerance to chronic morphine under the present paradigm. Both genotypes display locomotor sensitization to morphine, implying a lack of a role for the A(2A) receptor in the drug-induced plasticity necessary for the development or expression of sensitization. Collectively, these data suggest a differential role for adenosine A(2A) receptors in opiate reinforcement compared to opiate-seeking.

  19. A2A receptor antagonists do not induce dyskinesias in drug-naive or L-dopa sensitized rats.

    PubMed

    Jones, N; Bleickardt, C; Mullins, D; Parker, E; Hodgson, R

    2013-09-01

    L-dopa, the precursor to dopamine, is currently the gold standard treatment for Parkinson's disease (PD). However, chronic exposure is associated with L-dopa-induced dyskinesias (LIDs), a serious side effect characterized by involuntary movements. Adenosine A2A receptor antagonists have been studied as a novel non-dopaminergic PD treatment. Because A2A receptor antagonists do not act on dopamine receptors, it has been hypothesized that they will not induce dyskinesias characteristic of L-dopa. To test this hypothesis in a rodent model, the A2A receptor antagonists SCH 412348 (3 mg/kg), vipadenant (10 mg/kg), caffeine (30 mg/kg), or istradefylline (3 mg/kg) were chronically (19-22 days) administered to Sprague Dawley rats, and dyskinetic behaviors were scored across this chronic dosing paradigm. Unlike L-dopa, there was no evidence of dyskinetic activity resulting from any of the four A2A receptor antagonists tested. When delivered to animals previously sensitized with L-dopa (6 mg/kg), SCH 412348, vipadenant, caffeine or istradefylline treatment produced no dyskinesias. When administered in combination with L-dopa (6 mg/kg), SCH 412348 (3 mg/kg) neither exacerbated nor prevented the induction of LIDs over the course of 19 days of treatment. Collectively, our data indicate that A2A receptor antagonists are likely to have a reduced dyskinetic liability relative to L-dopa but do not block dyskinesias when coadministered with L-dopa. Clinical studies are required to fully understand the dyskinesia profiles of A2A receptor antagonists.

  20. High salt diet exacerbates vascular contraction in the absence of adenosine A2A receptor

    PubMed Central

    Pradhan, Isha; Zeldin, Darryl C.; Ledent, Catherine; Mustafa, S. Jamal; Falck, John R.; Nayeem, Mohammed A

    2014-01-01

    High salt (4%NaCl, HS) diet modulates adenosine-induced vascular response through adenosine A2A-receptor (A2AAR). Evidence suggests A2AAR stimulates cyp450-epoxygenases, leading to epoxyeicosatrienoic acids (EETs) generation. The aim of this study was to understand the vascular reactivity to HS and underlying signaling mechanism in the presence or absence of A2AAR. Therefore, we hypothesized that HS enhances adenosine-induced relaxation through EETs in A2AAR+/+, but exaggerates contraction in A2AAR−/−. Organ-bath and Western-blot experiments were conducted in HS and normal salt (NS, 0.18% NaCl)-fed A2AAR+/+ and A2AAR−/− mice aortae. HS produced concentration-dependent relaxation to non-selective adenosine analog, NECA in A2AAR+/+, whereas contraction was observed in A2AAR−/− mice and this was attenuated by A1AR antagonist (DPCPX). CGS-21680 (selective A2AAR-agonist) enhanced relaxation in HS-A2AAR+/+ vs. NS-A2AAR+/+, that was blocked by EETs antagonist (14,15-EEZE). Compared to NS, HS significantly upregulated expression of vasodilators A2AAR and cyp2c29, while vasoconstrictors A1AR and cyp4a in A2AAR+/+ were downregulated. In A2AAR−/− mice, however, HS significantly downregulated the expression of cyp2c29, while A1AR and cyp4a were upregulated compared to A2AAR+/+ mice. Hence, our data suggest that in A2AAR+/+, HS enhances A2AAR-induced relaxation through increased cyp-expoxygenases-derived EETs and decreased A1AR levels, whereas in A2AAR−/−, HS exaggerates contraction through decreased cyp-epoxygenases and increased A1AR levels. PMID:24390173

  1. A2A Adenosine Receptor (A2AAR) as a Therapeutic Target in Diabetic Retinopathy

    PubMed Central

    Ibrahim, Ahmed S.; El-shishtawy, Mamdouh M.; Zhang, Wenbo; Caldwell, Ruth B.; Liou, Gregory I.

    2011-01-01

    In diabetic retinopathy (DR), abnormalities in vascular and neuronal function are closely related to the local production of inflammatory mediators whose potential source is microglia. A2A adenosine receptor (A2AAR) has been shown to possess anti-inflammatory properties that have not been studied in DR. Here, we evaluate the role of A2AAR and its underlying signaling in retinal complications associated with diabetes. Initial studies in wild-type mice revealed that the treatment with the A2AAR agonist resulted in marked decreases in hyperglycemia-induced retinal cell death and tumor necrosis factor (TNF)-α release. To further assess the role of A2AAR in DR, we studied the effects of A2AAR ablation on diabetes-induced retinal abnormalities. Diabetic A2AAR−/− mice had significantly more terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling-positive cells, TNF-α release, and intercellular adhesion molecule-1 expression compared with diabetic wild-type mice. To explore a potential mechanism by which A2AAR signaling regulates inflammation in DR, we performed additional studies using microglial cells treated with Amadori-glycated albumin, a risk factor in diabetic disorders. The results showed that activation of A2AAR attenuated Amadori-glycated albumin-induced TNF-α release in a cAMP/exchange protein directly activated by cAMP-dependent mechanism and significantly repressed the inflammatory cascade, C-Raf/extracellular signal-regulated kinase (ERK), in activated microglia. Collectively, this work provides pharmacological and genetic evidence for A2AAR signaling as a control point of cell death in DR and suggests that the retinal protective effect of A2AAR is mediated by abrogating the inflammatory response that occurs in microglia via interaction with C-Raf/ERK pathway. PMID:21514428

  2. Structure of the adenosine A(2A) receptor in complex with ZM241385 and the xanthines XAC and caffeine.

    PubMed

    Doré, Andrew S; Robertson, Nathan; Errey, James C; Ng, Irene; Hollenstein, Kaspar; Tehan, Ben; Hurrell, Edward; Bennett, Kirstie; Congreve, Miles; Magnani, Francesca; Tate, Christopher G; Weir, Malcolm; Marshall, Fiona H

    2011-09-07

    Methylxanthines, including caffeine and theophylline, are among the most widely consumed stimulant drugs in the world. These effects are mediated primarily via blockade of adenosine receptors. Xanthine analogs with improved properties have been developed as potential treatments for diseases such as Parkinson's disease. Here we report the structures of a thermostabilized adenosine A(2A) receptor in complex with the xanthines xanthine amine congener and caffeine, as well as the A(2A) selective inverse agonist ZM241385. The receptor is crystallized in the inactive state conformation as defined by the presence of a salt bridge known as the ionic lock. The complete third intracellular loop, responsible for G protein coupling, is visible consisting of extended helices 5 and 6. The structures provide new insight into the features that define the ligand binding pocket of the adenosine receptor for ligands of diverse chemotypes as well as the cytoplasmic regions that interact with signal transduction proteins.

  3. Integrating Pharmacophore into Membrane Molecular Dynamics Simulations to Improve Homology Modeling of G Protein-coupled Receptors with Ligand Selectivity: A2A Adenosine Receptor as an Example.

    PubMed

    Zeng, Lingxiao; Guan, Mengxin; Jin, Hongwei; Liu, Zhenming; Zhang, Liangren

    2015-12-01

    Homology modeling has been applied to fill in the gap in experimental G protein-coupled receptors structure determination. However, achievement of G protein-coupled receptors homology models with ligand selectivity remains challenging due to structural diversity of G protein-coupled receptors. In this work, we propose a novel strategy by integrating pharmacophore and membrane molecular dynamics (MD) simulations to improve homology modeling of G protein-coupled receptors with ligand selectivity. To validate this integrated strategy, the A2A adenosine receptor (A2A AR), whose structures in both active and inactive states have been established, has been chosen as an example. We performed blind predictions of the active-state A2A AR structure based on the inactive-state structure and compared the performance of different refinement strategies. The blind prediction model combined with the integrated strategy identified ligand-receptor interactions and conformational changes of key structural elements related to the activation of A2 A AR, including (i) the movements of intracellular ends of TM3 and TM5/TM6; (ii) the opening of ionic lock; (iii) the movements of binding site residues. The integrated strategy of pharmacophore with molecular dynamics simulations can aid in the optimization in the identification of side chain conformations in receptor models. This strategy can be further investigated in homology modeling and expand its applicability to other G protein-coupled receptor modeling, which should aid in the discovery of more effective and selective G protein-coupled receptor ligands.

  4. Deletion of striatal adenosine A(2A) receptor spares latent inhibition and prepulse inhibition but impairs active avoidance learning.

    PubMed

    Singer, Philipp; Wei, Catherine J; Chen, Jiang-Fan; Boison, Detlev; Yee, Benjamin K

    2013-04-01

    Following early clinical leads, the adenosine A(2A)R receptor (A(2A)R) has continued to attract attention as a potential novel target for treating schizophrenia, especially against the negative and cognitive symptoms of the disease because of A(2A)R's unique modulatory action over glutamatergic in addition to dopaminergic signaling. Through (i) the antagonistic interaction with the dopamine D(2) receptor, and (ii) the regulation of glutamate release and N-methyl-d-aspartate receptor function, striatal A(2A)R is ideally positioned to fine-tune the dopamine-glutamate balance, the disturbance of which is implicated in the pathophysiology of schizophrenia. However, the precise function of striatal A(2A)Rs in the regulation of schizophrenia-relevant behavior is poorly understood. Here, we tested the impact of conditional striatum-specific A(2A)R knockout (st-A(2A)R-KO) on latent inhibition (LI) and prepulse inhibition (PPI) - behavior that is tightly regulated by striatal dopamine and glutamate. These are two common cross-species translational tests for the assessment of selective attention and sensorimotor gating deficits reported in schizophrenia patients; and enhanced performance in these tests is associated with antipsychotic drug action. We found that neither LI nor PPI was significantly affected in st-A(2A)R-KO mice, although a deficit in active avoidance learning was identified in these animals. The latter phenotype, however, was not replicated in another form of aversive conditioning - namely, conditioned taste aversion. Hence, the present study shows that neither learned inattention (as measured by LI) nor sensory gating (as indexed by PPI) requires the integrity of striatal A(2A)Rs - a finding that may undermine the hypothesized importance of A(2A)R in the genesis and/or treatment of schizophrenia.

  5. Caffeine and adenosine A(2a) receptor antagonists prevent beta-amyloid (25-35)-induced cognitive deficits in mice.

    PubMed

    Dall'Igna, Oscar P; Fett, Paulo; Gomes, Marcio W; Souza, Diogo O; Cunha, Rodrigo A; Lara, Diogo R

    2007-01-01

    Consumption of caffeine, an adenosine receptor antagonist, was found to be inversely associated with the incidence of Alzheimer's disease. Moreover, caffeine protects cultured neurons against beta-amyloid-induced toxicity, an effect mimicked by adenosine A(2A) but not A(1) receptor antagonists. We now tested if caffeine administration would prevent beta-amyloid-induced cognitive impairment in mice and if this was mimicked by A(2A) receptor blockade. One week after icv administration of the 25-35 fragment of beta-amyloid (Abeta, 3 nmol), mice displayed impaired performance in both inhibitory avoidance and spontaneous alternation tests. Prolonged treatment with caffeine (1 mg/ml) had no effect alone but prevented the Abeta-induced cognitive impairment in both tasks when associated with acute caffeine (30 mg/kg) 30 min treatment before Abeta administration. The same protective effect was observed after subchronic (4 days) treatment with daily injections of either caffeine (30 mg/kg) or the selective adenosine A(2A) receptor antagonist SCH58261 (0.5 mg/kg). This provides the first direct in vivo evidence that caffeine and A(2A) receptor antagonists afford a protection against Abeta-induced amnesia, which prompts their interest for managing Alzheimer's disease.

  6. Membrane omega-3 fatty acids modulate the oligomerisation kinetics of adenosine A2A and dopamine D2 receptors

    PubMed Central

    Guixà-González, Ramon; Javanainen, Matti; Gómez-Soler, Maricel; Cordobilla, Begoña; Domingo, Joan Carles; Sanz, Ferran; Pastor, Manuel; Ciruela, Francisco; Martinez-Seara, Hector; Selent, Jana

    2016-01-01

    Membrane levels of docosahexaenoic acid (DHA), an essential omega-3 polyunsaturated fatty acid (ω-3 PUFA), are decreased in common neuropsychiatric disorders. DHA modulates key cell membrane properties like fluidity, thereby affecting the behaviour of transmembrane proteins like G protein-coupled receptors (GPCRs). These receptors, which have special relevance for major neuropsychiatric disorders have recently been shown to form dimers or higher order oligomers, and evidence suggests that DHA levels affect GPCR function by modulating oligomerisation. In this study, we assessed the effect of membrane DHA content on the formation of a class of protein complexes with particular relevance for brain disease: adenosine A2A and dopamine D2 receptor oligomers. Using extensive multiscale computer modelling, we find a marked propensity of DHA for interaction with both A2A and D2 receptors, which leads to an increased rate of receptor oligomerisation. Bioluminescence resonance energy transfer (BRET) experiments performed on living cells suggest that this DHA effect on the oligomerisation of A2A and D2 receptors is purely kinetic. This work reveals for the first time that membrane ω-3 PUFAs play a key role in GPCR oligomerisation kinetics, which may have important implications for neuropsychiatric conditions like schizophrenia or Parkinson’s disease. PMID:26796668

  7. Membrane omega-3 fatty acids modulate the oligomerisation kinetics of adenosine A2A and dopamine D2 receptors

    NASA Astrophysics Data System (ADS)

    Guixà-González, Ramon; Javanainen, Matti; Gómez-Soler, Maricel; Cordobilla, Begoña; Domingo, Joan Carles; Sanz, Ferran; Pastor, Manuel; Ciruela, Francisco; Martinez-Seara, Hector; Selent, Jana

    2016-01-01

    Membrane levels of docosahexaenoic acid (DHA), an essential omega-3 polyunsaturated fatty acid (ω-3 PUFA), are decreased in common neuropsychiatric disorders. DHA modulates key cell membrane properties like fluidity, thereby affecting the behaviour of transmembrane proteins like G protein-coupled receptors (GPCRs). These receptors, which have special relevance for major neuropsychiatric disorders have recently been shown to form dimers or higher order oligomers, and evidence suggests that DHA levels affect GPCR function by modulating oligomerisation. In this study, we assessed the effect of membrane DHA content on the formation of a class of protein complexes with particular relevance for brain disease: adenosine A2A and dopamine D2 receptor oligomers. Using extensive multiscale computer modelling, we find a marked propensity of DHA for interaction with both A2A and D2 receptors, which leads to an increased rate of receptor oligomerisation. Bioluminescence resonance energy transfer (BRET) experiments performed on living cells suggest that this DHA effect on the oligomerisation of A2A and D2 receptors is purely kinetic. This work reveals for the first time that membrane ω-3 PUFAs play a key role in GPCR oligomerisation kinetics, which may have important implications for neuropsychiatric conditions like schizophrenia or Parkinson’s disease.

  8. Blunted dynamics of adenosine A2A receptors is associated with increased susceptibility to Candida albicans infection in the elderly

    PubMed Central

    Rodrigues, Lisa; Miranda, Isabel M.; Andrade, Geanne M.; Mota, Marta; Cortes, Luísa; Rodrigues, Acácio G.; Cunha, Rodrigo A.; Gonçalves, Teresa

    2016-01-01

    Opportunistic gut infections and chronic inflammation, in particular due to overgrowth of Candida albicans present in the gut microbiota, are increasingly reported in the elder population. In aged, adult and young mice, we now compared the relative intestinal over-colonization by ingested C. albicans and their translocation to other organs, focusing on the role of adenosine A2A receptors that are a main stop signal of inflammation. We report that elderly mice are more prone to over-colonization by C. albicans than adult and young mice. This fungal over-growth seems to be related with higher growth rate in intestinal lumen, independent of gut tissues invasion, but resulting in higher GI tract inflammation. We observed a particularly high colonization of the stomach, with increased rate of yeast-to-hypha transition in aged mice. We found a correlation between A2A receptor density and tissue damage due to yeast infection: comparing with young and adults, aged mice have a lower gut A2A receptor density and C. albicans infection failed to increase it. In conclusion, this study shows that aged mice have a lower ability to cope with inflammation due to C. albicans over-colonization, associated with an inability to adaptively adjust adenosine A2A receptors density. PMID:27590517

  9. Activation of A1, A2A, or A3 adenosine receptors attenuates lung ischemia-reperfusion injury

    PubMed Central

    Gazoni, Leo M.; Walters, Dustin M.; Unger, Eric B.; Linden, Joel; Kron, Irving L.; Laubach, Victor E.

    2010-01-01

    Objective Adenosine and the activation of specific adenosine receptors are implicated in the attenuation of inflammation and organ ischemia-reperfusion (IR) injury. We hypothesized that activation of A1, A2A, or A3 adenosine receptors would provide protection against lung IR injury. Methods Using an isolated, ventilated, blood-perfused rabbit lung model, lungs underwent 18 hours cold ischemia followed by 2 hours reperfusion. Lungs were administered either vehicle, adenosine, or selective A1, A2A, or A3 receptor agonists (CCPA, ATL-313, or IB-MECA, respectively) alone or with their respective antagonists (DPCPX, ZM241385, or MRS1191) during reperfusion. Results Compared to the vehicle-treated control group, treatment with A1, A2A, or A3 agonists significantly improved function (increased lung compliance and oxygenation and decreased pulmonary artery pressure), decreased neutrophil infiltration by myeloperoxidase activity, decreased edema, and reduced TNF-α production. Adenosine treatment was also protective but not to the level of the agonists. When each agonist was paired with its respective antagonist, all protective effects were blocked. The A2A agonist reduced pulmonary artery pressure and myeloperoxidase activity and increased oxygenation to a greater degree than the A1 or A3 agonists. Conclusions Selective activation of A1, A2A, or A3 adenosine receptors provides significant protection against lung IR injury. The decreased elaboration of the potent proinflammatory cytokine, TNF-α, and decreased neutrophil sequestration likely contribute to the overall improvement in pulmonary function. These results provide evidence for the therapeutic potential of specific adenosine receptor agonists in lung transplant recipients. PMID:20398911

  10. A2A Adenosine Receptor Antagonism Reverts the Blood-Brain Barrier Dysfunction Induced by Sleep Restriction

    PubMed Central

    Hurtado-Alvarado, Gabriela; Domínguez-Salazar, Emilio; Velázquez-Moctezuma, Javier

    2016-01-01

    Chronic sleep restriction induces blood-brain barrier disruption and increases pro-inflammatory mediators in rodents. Those inflammatory mediators may modulate the blood-brain barrier and constitute a link between sleep loss and blood-brain barrier physiology. We propose that adenosine action on its A2A receptor may be modulating the blood-brain barrier dynamics in sleep-restricted rats. We administrated a selective A2A adenosine receptor antagonist (SCH58261) in sleep-restricted rats at the 10th day of sleep restriction and evaluated the blood-brain barrier permeability to dextrans coupled to fluorescein (FITC-dextrans) and Evans blue. In addition, we evaluated by western blot the expression of tight junction proteins (claudin-5, occludin, ZO-1), adherens junction protein (E-cadherin), A2A adenosine receptor, adenosine-synthesizing enzyme (CD73), and neuroinflammatory markers (Iba-1 and GFAP) in the cerebral cortex, hippocampus, basal nuclei and cerebellar vermis. Sleep restriction increased blood-brain barrier permeability to FITC-dextrans and Evans blue, and the effect was reverted by the administration of SCH58261 in almost all brain regions, excluding the cerebellum. Sleep restriction increased the expression of A2A adenosine receptor only in the hippocampus and basal nuclei without changing the expression of CD73 in all brain regions. Sleep restriction reduced the expression of tight junction proteins in all brain regions, except in the cerebellum; and SCH58261 restored the levels of tight junction proteins in the cortex, hippocampus and basal nuclei. Finally, sleep restriction induced GFAP and Iba-1 overexpression that was attenuated with the administration of SCH58261. These data suggest that the action of adenosine on its A2A receptor may have a crucial role in blood-brain barrier dysfunction during sleep loss probably by direct modulation of brain endothelial cell permeability or through a mechanism that involves gliosis with subsequent inflammation and

  11. Controlling the Dissociation of Ligands from the Adenosine A2A Receptor through Modulation of Salt Bridge Strength.

    PubMed

    Segala, Elena; Guo, Dong; Cheng, Robert K Y; Bortolato, Andrea; Deflorian, Francesca; Doré, Andrew S; Errey, James C; Heitman, Laura H; IJzerman, Adriaan P; Marshall, Fiona H; Cooke, Robert M

    2016-07-14

    The association and dissociation kinetics of ligands binding to proteins vary considerably, but the mechanisms behind this variability are poorly understood, limiting their utilization for drug discovery. This is particularly so for G protein-coupled receptors (GPCRs) where high resolution structural information is only beginning to emerge. Engineering the human A2A adenosine receptor has allowed structures to be solved in complex with the reference compound ZM241385 and four related ligands at high resolution. Differences between the structures are limited, with the most pronounced being the interaction of each ligand with a salt bridge on the extracellular side of the receptor. Mutagenesis experiments confirm the role of this salt bridge in controlling the dissociation kinetics of the ligands from the receptor, while molecular dynamics simulations demonstrate the ability of ligands to modulate salt bridge stability. These results shed light on a structural determinant of ligand dissociation kinetics and identify a means by which this property may be optimized.

  12. The GS Protein-coupled A2a Adenosine Receptor Controls T Cell Help in the Germinal Center.

    PubMed

    Abbott, Robert K; Silva, Murillo; Labuda, Jasmine; Thayer, Molly; Cain, Derek W; Philbrook, Phaethon; Sethumadhavan, Shalini; Hatfield, Stephen; Ohta, Akio; Sitkovsky, Michail

    2017-01-27

    T follicular helper (TFH) cells have been shown to be critically required for the germinal center (GC) reaction where B cells undergo class switch recombination and clonal selection to generate high affinity neutralizing antibodies. However, detailed knowledge of the physiological cues within the GC microenvironment that regulate T cell help is limited. The cAMP-elevating, Gs protein-coupled A2a adenosine receptor (A2aR) is an evolutionarily conserved receptor that limits and redirects cellular immunity. However, the role of A2aR in humoral immunity and B cell differentiation is unknown. We hypothesized that the hypoxic microenvironment within the GC facilitates an extracellular adenosine-rich milieu, which serves to limit TFH frequency and function, and also promotes immunosuppressive T follicular regulatory cells (TFR). In support of this hypothesis, we found that following immunization, mice lacking A2aR (A2aRKO) exhibited a significant expansion of T follicular cells, as well as increases in TFH to TFR ratio, GC T cell frequency, GC B cell frequency, and class switching of GC B cells to IgG1. Transfer of CD4 T cells from A2aRKO or wild type donors into T cell-deficient hosts revealed that these increases were largely T cell-intrinsic. Finally, injection of A2aR agonist, CGS21680, following immunization suppressed T follicular differentiation, GC B cell frequency, and class switching of GC B cells to IgG1. Taken together, these observations point to a previously unappreciated role of GS protein-coupled A2aR in regulating humoral immunity, which may be pharmacologically targeted during vaccination or pathological states in which GC-derived autoantibodies contribute to the pathology.

  13. Ultraslow Water-Mediated Transmembrane Interactions Regulate the Activation of A2A Adenosine Receptor

    NASA Astrophysics Data System (ADS)

    Lee, Yoonji; Kim, Songmi; Choi, Sun; Hyeon, Changbong

    2016-09-01

    Water molecules inside G-protein coupled receptor have recently been spotlighted in a series of crystal structures. To decipher the dynamics and functional roles of internal waters in GPCR activity, we studied A$_{\\text{2A}}$ adenosine receptor using $\\mu$sec-molecular dynamics simulations. Our study finds that the amount of water flux across the transmembrane (TM) domain varies depending on the receptor state, and that the water molecules of the TM channel in the active state flow three times slower than those in the inactive state. Depending on the location in solvent-protein interface as well as the receptor state, the average residence time of water in each residue varies from $\\sim\\mathcal{O}(10^2)$ psec to $\\sim\\mathcal{O}(10^2)$ nsec. Especially, water molecules, exhibiting ultraslow relaxation ($\\sim\\mathcal{O}(10^2)$ nsec) in the active state, are found around the microswitch residues that are considered activity hotspots for GPCR function. A continuous allosteric network spanning the TM domain, arising from water-mediated contacts, is unique in the active state, underscoring the importance of slow waters in the GPCR activation.

  14. Increased non-rapid eye movement sleep by cocaine withdrawal: possible involvement of A2A receptors.

    PubMed

    Yang, Shu-Long; Han, Jin-Yi; Kim, Yun-Bae; Nam, Sang-Yoon; Song, Sukgil; Hong, Jin Tae; Oh, Ki-Wan

    2011-02-01

    This study attempted to clarify whether cocaine withdrawal altered sleep architecture and the role of adenosine receptors in this process. Cocaine (20 mg/kg) was administered subcutaneously once per day for 7 days to rat implanted with sleep/wake recording electrode. Polygraphic signs of undisturbed sleep/wake activities were recorded for 24 h before cocaine administration (basal recording as control); withdrawal-day 1 (after 1 day of repeated cocaine administration), withdrawal-day 8 (after 8 days of repeated cocaine administration), and withdrawal-day 14 (after 14 days of repeated cocaine administration), respectively. On cocaine withdrawal-day 1, wakefulness was significantly increased, total sleep was decreased, non-rapid eye movement sleep was markedly reduced, and rapid eye movement sleep was enhanced. Sleep/wake cycles were also increased on cocaine withdrawal day 1. However, non-rapid eye movement sleep was increased on withdrawal-day 8 and 14, whereas rapid eye movement sleep was decreased and no significant changes were observed in the total sleep and sleep/wake cycles during these periods. Adenosine A(2A) receptors expression was increased on withdrawal-day 8 and 14, whereas A(1) receptors levels were reduced after 14 days of withdrawal and the A(2B) receptors remained unchanged. Our findings suggest that alterations of sleep and sleep architecture during cocaine subacute and subchronic withdrawals after repeated cocaine administration may be partially involved in A(2A) receptors over-expression in the rat hypothalamus.

  15. Chronic methamphetamine treatment induces oxytocin receptor up-regulation in the amygdala and hypothalamus via an adenosine A2A receptor-independent mechanism.

    PubMed

    Zanos, Panos; Wright, Sherie R; Georgiou, Polymnia; Yoo, Ji Hoon; Ledent, Catherine; Hourani, Susanna M; Kitchen, Ian; Winsky-Sommerer, Raphaelle; Bailey, Alexis

    2014-04-01

    There is mounting evidence that the neuropeptide oxytocin is a possible candidate for the treatment of drug addiction. Oxytocin was shown to reduce methamphetamine self-administration, conditioned place-preference, hyperactivity and reinstatement in rodents, highlighting its potential for the management of methamphetamine addiction. Thus, we hypothesised that the central endogenous oxytocinergic system is dysregulated following chronic methamphetamine administration. We tested this hypothesis by examining the effect of chronic methamphetamine administration on oxytocin receptor density in mice brains with the use of quantitative receptor autoradiographic binding. Saline (4ml/kg/day, i.p.) or methamphetamine (1mg/kg/day, i.p.) was administered daily for 10 days to male, CD1 mice. Quantitative autoradiographic mapping of oxytocin receptors was carried out with the use of [(125)I]-vasotocin in brain sections of these animals. Chronic methamphetamine administration induced a region specific upregulation of oxytocin receptor density in the amygdala and hypothalamus, but not in the nucleus accumbens and caudate putamen. As there is evidence suggesting an involvement of central adenosine A2A receptors on central endogenous oxytocinergic function, we investigated whether these methamphetamine-induced oxytocinergic neuroadaptations are mediated via an A2A receptor-dependent mechanism. To test this hypothesis, autoradiographic oxytocin receptor binding was carried out in brain sections of male CD1 mice lacking A2A receptors which were chronically treated with methamphetamine (1mg/kg/day, i.p. for 10 days) or saline. Similar to wild-type animals, chronic methamphetamine administration induced a region-specific upregulation of oxytocin receptor binding in the amygdala and hypothalamus of A2A receptor knockout mice and no genotype effect was observed. These results indicate that chronic methamphetamine use can induce profound neuroadaptations of the oxytocinergic receptor

  16. Promotion of Wound Healing by an Agonist of Adenosine A2A Receptor Is Dependent on Tissue Plasminogen Activator.

    PubMed

    Montesinos, M Carmen; Desai-Merchant, Avani; Cronstein, Bruce N

    2015-12-01

    Impaired wound healing, as it occurs in diabetes mellitus or long-term corticoid treatment, is commonly associated with disability, diminished quality of life, and high economic costs. Selective agonists of the A2A receptor subtype of adenosine, an endogenous regulator of inflammation, promote tissue repair in animal models, both healthy and with impaired healing. Plasmin-mediated proteolysis of fibrin and other matrix proteins is essential for cell migration at sites of injury. Since adenosine A2A receptor activation increases plasminogen activator release from macrophages and mast cells, we studied the effect of a selective agonist, CGS-21680, on full-thickness excisional wound closure in wild-type, urokinase plasminogen activator (uPA)-deficient, and tissue plasminogen activator (tPA)-deficient mice. Wound closure was impaired in tPA- and uPA-deficient mice as compared with wild-type mice, and topical application of CGS-21680 significantly increased the rate at which wounds closed in wild-type mice and uPA-deficient mice, but not in tPA-deficient mice. Immunostaining of tissue sections showed that tPA was present in endothelial cells and histiocytes by day 3 post-wound and also by day 6. In contrast, uPA was more prominent in these cell types only by day 6 post-wound. Our results confirm that plasminogen activation contributes to wound repair and are consistent with the hypothesis that adenosine A2A receptor activation promotes wound closure by a mechanism that depends upon tPA, but not uPA. Moreover, our results suggest that topical adenosine A2A receptor agonists may be useful in promotion of wound closure in patients with impaired wound healing.

  17. Crystal structure of the adenosine A2A receptor bound to an antagonist reveals a potential allosteric pocket

    PubMed Central

    Sun, Bingfa; Bachhawat, Priti; Chu, Matthew Ling-Hon; Wood, Martyn; Ceska, Tom; Sands, Zara A.; Mercier, Joel; Lebon, Florence; Kobilka, Tong Sun; Kobilka, Brian K.

    2017-01-01

    The adenosine A2A receptor (A2AR) has long been implicated in cardiovascular disorders. As more selective A2AR ligands are being identified, its roles in other disorders, such as Parkinson’s disease, are starting to emerge, and A2AR antagonists are important drug candidates for nondopaminergic anti-Parkinson treatment. Here we report the crystal structure of A2A receptor bound to compound 1 (Cmpd-1), a novel A2AR/N-methyl d-aspartate receptor subtype 2B (NR2B) dual antagonist and potential anti-Parkinson candidate compound, at 3.5 Å resolution. The A2A receptor with a cytochrome b562-RIL (BRIL) fusion (A2AR–BRIL) in the intracellular loop 3 (ICL3) was crystallized in detergent micelles using vapor-phase diffusion. Whereas A2AR–BRIL bound to the antagonist ZM241385 has previously been crystallized in lipidic cubic phase (LCP), structural differences in the Cmpd-1–bound A2AR–BRIL prevented formation of the lattice observed with the ZM241385–bound receptor. The crystals grew with a type II crystal lattice in contrast to the typical type I packing seen from membrane protein structures crystallized in LCP. Cmpd-1 binds in a position that overlaps with the native ligand adenosine, but its methoxyphenyl group extends to an exosite not previously observed in other A2AR structures. Structural analysis revealed that Cmpd-1 binding results in the unique conformations of two tyrosine residues, Tyr91.35 and Tyr2717.36, which are critical for the formation of the exosite. The structure reveals insights into antagonist binding that are not observed in other A2AR structures, highlighting flexibility in the binding pocket that may facilitate the development of A2AR-selective compounds for the treatment of Parkinson’s disease. PMID:28167788

  18. Sinomenine protects against lipopolysaccharide-induced acute lung injury in mice via adenosine A(2A) receptor signaling.

    PubMed

    Li, Jun; Zhao, Li; He, Xie; Zeng, Yi-Jun; Dai, Shuang-Shuang

    2013-01-01

    Sinomenine (SIN) is a bioactive alkaloid extracted from the Chinese medicinal plant Sinomenium acutum, which is widely used in the clinical treatment of rheumatoid arthritis (RA). However, its role in acute lung injury (ALI) is unclear. In this study, we investigate the role of SIN in lipopolysaccharide (LPS)-induced ALI in mice. After ALI, lung water content and histological signs of pulmonary injury were attenuated, whereas the PaO2/FIO2 (P/F) ratios were elevated significantly in the mice pretreated with SIN. Additionally, SIN markedly inhibited inflammatory cytokine TNF-α and IL-1β expression levels as well as neutrophil infiltration in the lung tissues of the mice. Microarray analysis and real-time PCR showed that SIN treatment upregulated adenosine A(2A) receptor (A(2A)R) expression, and the protective effect of SIN was abolished in A(2A)R knockout mice. Further investigation in isolated mouse neutrophils confirmed the upregulation of A(2A)R by SIN and showed that A(2A)R-cAMP-PKA signaling was involved in the anti-inflammatory effect of SIN. Taken together, these findings demonstrate an A(2A)R-associated anti-inflammatory effect and the protective role of SIN in ALI, which suggests a potential novel approach to treat ALI.

  19. Binding mode similarity measures for ranking of docking poses: a case study on the adenosine A2A receptor

    NASA Astrophysics Data System (ADS)

    Anighoro, Andrew; Bajorath, Jürgen

    2016-06-01

    We report an investigation designed to explore alternative approaches for ranking of docking poses in the search for antagonists of the adenosine A2A receptor, an attractive target for structure-based virtual screening. Calculation of 3D similarity of docking poses to crystallographic ligand(s) as well as similarity of receptor-ligand interaction patterns was consistently superior to conventional scoring functions for prioritizing antagonists over decoys. Moreover, the use of crystallographic antagonists and agonists, a core fragment of an antagonist, and a model of an agonist placed into the binding site of an antagonist-bound form of the receptor resulted in a significant early enrichment of antagonists in compound rankings. Taken together, these findings showed that the use of binding modes of agonists and/or antagonists, even if they were only approximate, for similarity assessment of docking poses or comparison of interaction patterns increased the odds of identifying new active compounds over conventional scoring.

  20. Structure-Activity Relationships of the Sustained Effects of Adenosine A2A Receptor Agonists Driven by Slow Dissociation Kinetics

    PubMed Central

    Hothersall, J. Daniel; Guo, Dong; Sarda, Sunil; Sheppard, Robert J.; Chen, Hongming; Keur, Wesley; Waring, Michael J.; IJzerman, Adriaan P.; Hill, Stephen J.; Dale, Ian L.

    2017-01-01

    The duration of action of adenosine A2A receptor (A2A) agonists is critical for their clinical efficacy, and we sought to better understand how this can be optimized. The in vitro temporal response profiles of a panel of A2A agonists were studied using cAMP assays in recombinantly (CHO) and endogenously (SH-SY5Y) expressing cells. Some agonists (e.g., 3cd; UK-432,097) but not others (e.g., 3ac; CGS-21680) demonstrated sustained wash-resistant agonism, where residual receptor activation continued after washout. The ability of an antagonist to reverse pre-established agonist responses was used as a surrogate read-out for agonist dissociation kinetics, and together with radioligand binding studies suggested a role for slow off-rate in driving sustained effects. One compound, 3ch, showed particularly marked sustained effects, with a reversal t1/2 > 6 hours and close to maximal effects that remained for at least 5 hours after washing. Based on the structure-activity relationship of these compounds, we suggest that lipophilic N6 and bulky C2 substituents can promote stable and long-lived binding events leading to sustained agonist responses, although a high compound logD is not necessary. This provides new insight into the binding interactions of these ligands and we anticipate that this information could facilitate the rational design of novel long-acting A2A agonists with improved clinical efficacy. PMID:27803241

  1. Adenosine A2A Receptor Blockade Prevents Rotenone-Induced Motor Impairment in a Rat Model of Parkinsonism

    PubMed Central

    Fathalla, Ahmed M.; Soliman, Amira M.; Ali, Mohamed H.; Moustafa, Ahmed A.

    2016-01-01

    Pharmacological studies implicate the blockade of adenosine receptorsas an effective strategy for reducing Parkinson’s disease (PD) symptoms. The objective of this study is to elucidate the possible protective effects of ZM241385 and 8-cyclopentyl-1, 3-dipropylxanthine, two selective A2A and A1 receptor antagonists, on a rotenone rat model of PD. Rats were split into four groups: vehicle control (1 ml/kg/48 h), rotenone (1.5 mg/kg/48 h, s.c.), ZM241385 (3.3 mg/kg/day, i.p) and 8-cyclopentyl-1, 3-dipropylxanthine (5 mg/kg/day, i.p). After that, animals were subjected to behavioral (stride length and grid walking) and biochemical (measuring concentration of dopamine levels using high performance liquid chromatography, HPLC). In the rotenone group, rats displayed a reduced motor activity and disturbed movement coordination in the behavioral tests and a decreased dopamine concentration as foundby HPLC. The effect of rotenone was partially prevented in the ZM241385 group, but not with 8-cyclopentyl-1,3-dipropylxanthine administration. The administration of ZM241385 improved motor function and movement coordination (partial increase of stride length and partial decrease in the number of foot slips) and an increase in dopamine concentration in the rotenone-injected rats. However, the 8-cyclopentyl-1,3-dipropylxanthine and rotenone groups were not significantly different. These results indicate that selective A2A receptor blockade by ZM241385, but not A1 receptor blockadeby 8-cyclopentyl-1,3-dipropylxanthine, may treat PD motor symptoms. This reinforces the potential use of A2A receptor antagonists as a treatment strategy for PD patients. PMID:26973484

  2. Adenosine A2A receptor deletion affects social behaviors and anxiety in mice: Involvement of anterior cingulate cortex and amygdala.

    PubMed

    López-Cruz, Laura; Carbó-Gas, Maria; Pardo, Marta; Bayarri, Pilar; Valverde, Olga; Ledent, Catherine; Salamone, John D; Correa, Mercè

    2017-03-15

    Blockade of adenosine A2A receptors can potentiate motivation to work for natural reinforcers such as food. Conspecific interaction is a potent natural reinforcer in social animals that can be manifested as preference for social exploration versus other sources of novel stimulation. Deficiencies in this type of motivated behavior (social withdrawal) have been seen in several pathologies such as autism and depression. However, the role of A2A receptors in motivation for social interaction has not been widely explored. Social interaction paradigms evaluate the natural preference of animals for exploring other conspecifics, and the ability to differentiate between familiar versus novel ones. Anxiety is one of the factors that can induce avoidance of social interaction. In the present study, adenosine A2A knockout (A2AKO) and wild-type (WT) mice were assessed for social and anxiety-related behaviors. c-Fos immunoreactivity was evaluated as a measure of neuronal activation in brain areas involved in different aspects of motivation and emotional processes. Although A2AKO mice showed an anxious profile, they displayed higher levels of sociability and were less sensitive to social novelty. WT mice displayed a typical pattern of social recognition 24h later, but not A2AKO mice, which explored equally both conspecifics. There were no differences between strains in aggressiveness, perseverance or social odor preferences. c-Fos immunoreactivity in A2AKO mice was higher in anterior cingulate and amygdala compared to WT mice. Thus, A2A receptors appear to be potential targets for the improvement of pathologies related to social function.

  3. mGlu5, Dopamine D2 and Adenosine A2A Receptors in L-DOPA-induced Dyskinesias

    PubMed Central

    Morin, Nicolas; Morissette, Marc; Grégoire, Laurent; Di Paolo, Thérèse

    2016-01-01

    Patients with Parkinson’s disease (PD) receiving L-3,4-dihydroxyphenylalanine (L-DOPA, the gold-standard treatment for this disease) frequently develop abnormal involuntary movements, termed L-DOPA-induced dyskinesias (LID). Glutamate overactivity is well documented in PD and LID. An approach to manage LID is to add to L-DOPA specific agents to reduce dyskinesias such as metabotropic glutamate receptor (mGlu receptor) drugs. This article reviews the contribution of mGlu type 5 (mGlu5) receptors in animal models of PD. Several mGlu5 negative allosteric modulators acutely attenuate LID in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) monkeys and 6-hydroxydopamine(6-OHDA)-lesioned rats. Chronic administration of mGlu5 negative allosteric modulators to MPTP monkeys and 6-OHDA rats also attenuates LID while maintaining the anti-parkinsonian effect of L-DOPA. Radioligand autoradiography shows an elevation of striatal mGlu5 receptors of dyskinetic L-DOPA-treated MPTP monkeys but not in those without LID. The brain molecular correlates of the long-term effect of mGlu5 negative allosteric modulators treatments with L-DOPA attenuating development of LID was shown to extend beyond mGlu5 receptors with normalization of glutamate activity in the basal ganglia of L-DOPA-induced changes of NMDA, AMPA, mGlu2/3 receptors and VGlut2 transporter. In the basal ganglia, mGlu5 receptor negative allosteric modulators also normalize the L-DOPA-induced changes of dopamine D2 receptors, their associated signaling proteins (ERK1/2 and Akt/GSK3β) and neuropeptides (preproenkephalin, preprodynorphin) as well as the adenosine A2A receptors expression. These results show in animal models of PD reduction of LID with mGlu5 negative allosteric modulation associated with normalization of glutamate, dopamine and adenosine receptors suggesting a functional link of these receptors in chronic treatment with L-DOPA. PMID:26639458

  4. mGlu5, Dopamine D2 and Adenosine A2A Receptors in L-DOPA-induced Dyskinesias.

    PubMed

    Morin, Nicolas; Morissette, Marc; Grégoire, Laurent; Di Paolo, Thérèse

    2016-01-01

    Patients with Parkinson's disease (PD) receiving L-3,4-dihydroxyphenylalanine (L-DOPA, the gold-standard treatment for this disease) frequently develop abnormal involuntary movements, termed L-DOPA-induced dyskinesias (LID). Glutamate overactivity is well documented in PD and LID. An approach to manage LID is to add to L-DOPA specific agents to reduce dyskinesias such as metabotropic glutamate receptor (mGlu receptor) drugs. This article reviews the contribution of mGlu type 5 (mGlu5) receptors in animal models of PD. Several mGlu5 negative allosteric modulators acutely attenuate LID in 1-methyl-4-phenyl-1,2,3,6- tetrahydropyridine (MPTP) monkeys and 6-hydroxydopamine(6-OHDA)-lesioned rats. Chronic administration of mGlu5 negative allosteric modulators to MPTP monkeys and 6-OHDA rats also attenuates LID while maintaining the antiparkinsonian effect of L-DOPA. Radioligand autoradiography shows an elevation of striatal mGlu5 receptors of dyskinetic L-DOPA-treated MPTP monkeys but not in those without LID. The brain molecular correlates of the long-term effect of mGlu5 negative allosteric modulators treatments with L-DOPA attenuating development of LID was shown to extend beyond mGlu5 receptors with normalization of glutamate activity in the basal ganglia of L-DOPA-induced changes of NMDA, AMPA, mGlu2/3 receptors and VGlut2 transporter. In the basal ganglia, mGlu5 receptor negative allosteric modulators also normalize the L-DOPA-induced changes of dopamine D2receptors, their associated signaling proteins (ERK1/2 and Akt/GSK3β) and neuropeptides (preproenkephalin, preprodynorphin) as well as the adenosine A2A receptors expression. These results show in animal models of PD reduction of LID with mGlu5 negative allosteric modulation associated with normalization of glutamate, dopamine and adenosine receptors suggesting a functional link of these receptors in chronic treatment with L-DOPA.

  5. Allelic association of the D2 dopamine receptor gene with receptor-binding characteristics in alcoholism

    SciTech Connect

    Noble, E.P.; Blum, K.; Ritchie, T.; Montgomery, A.; Sheridan, P.J. )

    1991-07-01

    The allelic association of the human D2 dopamine receptor gene with the binding characteristics of the D2 dopamine receptor was determined in 66 brains of alcoholic and non-alcoholic subjects. In a blinded experiment, DNA from the cerebral cortex was treated with the restriction endonuclease Taql and probed with a 1.5-kilobase (kb) digest of a clone (lambda hD2G1) of the human D2 dopamine receptor gene. The binding characteristics (Kd (binding affinity) and Bmax (number of binding sites)) of the D2 dopamine receptor were determined in the caudate nuclei of these brains using tritiated spiperone as the ligand. The adjusted Kd was significantly lower in alcoholic than in nonalcoholic subjects. In subjects with the A1 allele, in whom a high association with alcoholism was found, the Bmax was significantly reduced compared with the Bmax of subjects with the A2 allele. Moreover, a progressively reduced Bmax was found in subjects with A2/A2, A1/A2, and A1/A1 alleles, with subjects with A2/A2 having the highest mean values, and subjects with A1/A1, the lowest. The polymorphic pattern of the D2 dopamine receptor gene and its differential expression of receptors suggests the involvement of the dopaminergic system in conferring susceptibility to at least one subtype of severe alcoholism.

  6. Striatal adenosine A2A and cannabinoid CB1 receptors form functional heteromeric complexes that mediate the motor effects of cannabinoids.

    PubMed

    Carriba, Paulina; Ortiz, Oskar; Patkar, Kshitij; Justinova, Zuzana; Stroik, Jessica; Themann, Andrea; Müller, Christa; Woods, Anima S; Hope, Bruce T; Ciruela, Francisco; Casadó, Vicent; Canela, Enric I; Lluis, Carme; Goldberg, Steven R; Moratalla, Rosario; Franco, Rafael; Ferré, Sergi

    2007-11-01

    The mechanism of action responsible for the motor depressant effects of cannabinoids, which operate through centrally expressed cannabinoid CB1 receptors, is still a matter of debate. In the present study, we report that CB1 and adenosine A2A receptors form heteromeric complexes in co-transfected HEK-293T cells and rat striatum, where they colocalize in fibrilar structures. In a human neuroblastoma cell line, CB1 receptor signaling was found to be completely dependent on A2A receptor activation. Accordingly, blockade of A2A receptors counteracted the motor depressant effects produced by the intrastriatal administration of a cannabinoid CB1 receptor agonist. These biochemical and behavioral findings demonstrate that the profound motor effects of cannabinoids depend on physical and functional interactions between striatal A2A and CB1 receptors.

  7. Adenosine through the A2A adenosine receptor increases IL-1β in the brain contributing to anxiety

    PubMed Central

    Chiu, Gabriel S.; Darmody, Patrick T.; Walsh, John P.; Moon, Morgan L.; Kwakwa, Kristin A.; Bray, Julie K.; McCusker, Robert H.; Freund, Gregory G.

    2014-01-01

    Anxiety is one of the most commonly reported psychiatric conditions, but its pathogenesis is poorly understood. Ailments associated with activation of the innate immune system, however, are increasingly linked to anxiety disorders. In adult male mice, we found that adenosine doubled caspase-1 activity in brain by a pathway reliant on ATP-sensitive potassium (KATP) channels, protein kinase A (PKA) and the A2A adenosine receptor (AR). In addition, adenosine-dependent activation of caspase-1 increased interleukin (IL)-1β in the brain by two-fold. Peripheral administration of adenosine in wild-type (WT) mice led to a 2.3-fold increase in caspase-1 activity in the amygdala and to a 33% and 42% reduction in spontaneous locomotor activity and food intake, respectively, that were not observed in caspase-1 knockout (KO), IL-1 receptor type 1 (IL-1R1) KO and A2A AR KO mice or in mice administered a caspase-1 inhibitor centrally. Finally, adenosine administration increased anxiety-like behaviors in WT mice by 28% in the open field test and by 55% in the elevated zero-maze. Caspase-1 KO mice, IL-1R1 KO mice, A2A AR KO mice and WT mice treated with the KATP channel blocker, glyburide, were resistant to adenosine-induced anxiety-like behaviors. Thus, our results indicate that adenosine can act as an anxiogenic by activating caspase-1 and increasing IL-1β in the brain. PMID:24907587

  8. Selecting an optimal number of binding site waters to improve virtual screening enrichments against the adenosine A2A receptor.

    PubMed

    Lenselink, Eelke B; Beuming, Thijs; Sherman, Woody; van Vlijmen, Herman W T; IJzerman, Adriaan P

    2014-06-23

    A major challenge in structure-based virtual screening (VS) involves the treatment of explicit water molecules during docking in order to improve the enrichment of active compounds over decoys. Here we have investigated this in the context of the adenosine A2A receptor, where water molecules have previously been shown to be important for achieving high enrichment rates with docking, and where the positions of some binding site waters are known from a high-resolution crystal structure. The effect of these waters (both their presence and orientations) on VS enrichment was assessed using a carefully curated set of 299 high affinity A2A antagonists and 17,337 decoys. We show that including certain crystal waters greatly improves VS enrichment and that optimization of water hydrogen positions is needed in order to achieve the best results. We also show that waters derived from a molecular dynamics simulation - without any knowledge of crystallographic waters - can improve enrichments to a similar degree as the crystallographic waters, which makes this strategy applicable to structures without experimental knowledge of water positions. Finally, we used decision trees to select an ensemble of structures with different water molecule positions and orientations that outperforms any single structure with water molecules. The approach presented here is validated against independent test sets of A2A receptor antagonists and decoys from the literature. In general, this water optimization strategy could be applied to any target with waters-mediated protein-ligand interactions.

  9. Influence of CGS 21680, a selective adenosine A(2A) receptor agonist, on NMDA receptor function and expression in the brain of Huntington's disease mice.

    PubMed

    Ferrante, Antonella; Martire, Alberto; Armida, Monica; Chiodi, Valentina; Pézzola, Antonella; Potenza, Rosa Luisa; Domenici, Maria Rosaria; Popoli, Patrizia

    2010-04-06

    The effect of chronic treatment with the selective adenosine A(2A) receptor agonist CGS 21680 on N-Methyl-d-Aspartate (NMDA) receptor function and expression has been studied in the striatum and cortex of R6/2 mice, a genetic mouse model of Huntington's disease (HD). Starting from 8weeks of age, R6/2 and wild type (WT) mice were treated daily with CGS 21680 (0.5mg/kg i.p.) for 3weeks and the expression levels of NMDA receptor subunits were then evaluated. In addition, to study CGS 21680-induced changes in NMDA receptor function, NMDA-induced toxicity in corticostriatal slices from both R6/2 and WT mice was investigated. We found that CGS 21680 increased NR2A subunit expression and the NR2A/NR2B ratio in the cortex of R6/2 mice, having no effect in WT mice. In the striatum, CGS 21680 reduced NR1 expression in both R6/2 and WT mice while the effect on NR2A and NR2/NR2B expression was genotype-dependent, reducing and increasing their expression in WT and R6/2 mice, respectively. On the contrary, NMDA-induced toxicity in corticostriatal slices was not modified by the treatment in WT or HD mice. These results demonstrate that in vivo activation of A(2A) receptors modulates the subunit composition of NMDA receptors in the brain of HD mice.

  10. Effect of Caffeine Chronically Consumed During Pregnancy on Adenosine A1 and A2A Receptors Signaling in Both Maternal and Fetal Heart from Wistar Rats.

    PubMed

    Iglesias, Inmaculada; Albasanz, Jose Luis; Martín, Mairena

    2014-12-01

    Background: Caffeine is the most widely consumed psychoactive substance in the world, even during pregnancy. Its stimulatory effects are mainly due to antagonism of adenosine actions by blocking adenosine A1 and A2A receptors. Previous studies have shown that caffeine can cross the placenta and therefore modulate these receptors not only in the fetal brain but also in the heart. Methods: In the present work, the effect of caffeine chronically consumed during pregnancy on A1 and A2A receptors in Wistar rat heart, from both mothers and their fetuses, were studied using radioligand binding, Western-blotting, and adenylyl cyclase activity assays, as well as reverse transcription polymerase chain reaction. Results: Caffeine did not significantly alter A1R neither at protein nor at gene expression level in both the maternal and fetal heart. On the contrary, A2AR significantly decreased in the maternal heart, although mRNA was not affected. Gi and Gs proteins were also preserved. Finally, A1R-mediated inhibition of adenylyl cyclase activity did not change in the maternal heart, but A2AR mediated stimulation of this enzymatic activity significantly decreased according to the detected loss of this receptor. Conclusions: Opposite to the downregulation and desensitization of the A1R/AC pathway previously reported in the brain, these results show that this pathway is not affected in rat heart after caffeine exposure during pregnancy. In addition, A2AR is downregulated and desensitized in the maternal heart, suggesting a differential modulation of these receptor-mediated pathways by caffeine.

  11. Effect of Caffeine Chronically Consumed During Pregnancy on Adenosine A1 and A2A Receptors Signaling in Both Maternal and Fetal Heart from Wistar Rats

    PubMed Central

    Iglesias, Inmaculada; Albasanz, Jose Luis

    2014-01-01

    Background: Caffeine is the most widely consumed psychoactive substance in the world, even during pregnancy. Its stimulatory effects are mainly due to antagonism of adenosine actions by blocking adenosine A1 and A2A receptors. Previous studies have shown that caffeine can cross the placenta and therefore modulate these receptors not only in the fetal brain but also in the heart. Methods: In the present work, the effect of caffeine chronically consumed during pregnancy on A1 and A2A receptors in Wistar rat heart, from both mothers and their fetuses, were studied using radioligand binding, Western-blotting, and adenylyl cyclase activity assays, as well as reverse transcription polymerase chain reaction. Results: Caffeine did not significantly alter A1R neither at protein nor at gene expression level in both the maternal and fetal heart. On the contrary, A2AR significantly decreased in the maternal heart, although mRNA was not affected. Gi and Gs proteins were also preserved. Finally, A1R-mediated inhibition of adenylyl cyclase activity did not change in the maternal heart, but A2AR mediated stimulation of this enzymatic activity significantly decreased according to the detected loss of this receptor. Conclusions: Opposite to the downregulation and desensitization of the A1R/AC pathway previously reported in the brain, these results show that this pathway is not affected in rat heart after caffeine exposure during pregnancy. In addition, A2AR is downregulated and desensitized in the maternal heart, suggesting a differential modulation of these receptor-mediated pathways by caffeine. PMID:25538864

  12. Adenosine A2A receptors and uric acid mediate protective effects of inosine against TNBS-induced colitis in rats.

    PubMed

    Rahimian, Reza; Fakhfouri, Gohar; Daneshmand, Ali; Mohammadi, Hamed; Bahremand, Arash; Rasouli, Mohammad Reza; Mousavizadeh, Kazem; Dehpour, Ahmad Reza

    2010-12-15

    Inflammatory bowel disease comprises chronic recurrent inflammation of gastrointestinal tract. This study was conducted to investigate inosine, a potent immunomodulator, in 2,4,6-trinitrobenzene sulphonic acid (TNBS)-induced chronic model of experimental colitis, and contribution of adenosine A(2A) receptors and the metabolite uric acid as possible underlying mechanisms. Experimental colitis was rendered in rats by a single colonic administration of 10 mg of TNBS. Inosine, potassium oxonate (a hepatic uricase inhibitor), SCH-442416 (a selective adenosine A(2A) receptor antagonist), inosine+potassium oxonate, or inosine+SCH-442416 were given twice daily for 7 successive days. At the end of experiment, macroscopic and histopathologic scores, colonic malondialdehyde (MDA), Tumor Necrosis Factor-alpha (TNF-α) and Interleukin-1beta (IL-1β) levels, and myeloperoxidase (MPO) activity were assessed. Plasma uric acid level was measured throughout the experiment. Both macroscopic and histological features of colonic injury were markedly ameliorated by either inosine, oxonate or inosine+oxonate. Likewise, the elevated amounts of MPO and MDA abated as well as those of TNF-α and IL-1β (P<0.05). SCH-442416 partially reversed the effect of inosine on theses markers, while inosine+oxonate showed a higher degree of protection than each treatment alone (P<.0.05). No significant difference was observed between TNBS and SCH-442416 groups. Uric acid levels were significantly higher in inosine or oxonate groups compared to control. Inosine+oxonate resulted in an even more elvelated uric acid level than each treatment alone (P<0.05). Inosine elicits notable anti-inflammatory effects on TNBS-induced colitis in rats. Uric acid and adenosine A(2A) receptors contribute to these salutary properties.

  13. Dipyridamole attenuates ischemia reperfusion induced acute kidney injury through adenosinergic A1 and A2A receptor agonism in rats.

    PubMed

    Puri, Nikkita; Mohey, Vinita; Singh, Manjinder; Kaur, Tajpreet; Pathak, Devendra; Buttar, Harpal Singh; Singh, Amrit Pal

    2016-04-01

    Dipyridamole (DYP) is an anti-platelet agent with marked vasodilator, anti-oxidant, and anti-inflammatory activity. The present study investigated the role of adenosine receptors in DYP-mediated protection against ischemia reperfusion-induced acute kidney injury (AKI) in rats. The rats were subjected to bilateral renal ischemia for 40 min followed by reperfusion for 24 h. The renal damage induced by ischemia reperfusion injury (IRI) was assessed by measuring creatinine clearance, blood urea nitrogen, uric acid, plasma potassium, fractional excretion of sodium, and microproteinuria in rats. The oxidative stress in renal tissues was assessed by quantification of thiobarbituric acid-reactive substances, superoxide anion generation, and reduced glutathione level. The hematoxylin-eosin staining was carried out to observe histopathological changes in renal tissues. DYP (10 and 30 mg/kg, intraperitoneal, i.p.) was administered 30 min before subjecting the rats to renal IRI. In separate groups, caffeine (50 mg/kg, i.p.), an adenosinergic A1 and A2A receptor antagonist was administered with and without DYP treatment before subjecting the rats to renal IRI. The ischemia reperfusion-induced AKI was demonstrated by significant changes in serum as well as urinary parameters, enhanced oxidative stress, and histopathological changes in renal tissues. The administration of DYP demonstrated protection against AKI. The prior treatment with caffeine abolished DYP-mediated reno-protection suggesting role of A1 and A2A adenosine receptors in DYP-mediated reno-protection in rats. It is concluded that adenosine receptors find their definite involvement in DYP-mediated anti-oxidative and reno-protective effect against ischemia reperfusion-induced AKI.

  14. Genetic deletion of the adenosine A(2A) receptor prevents nicotine-induced upregulation of α7, but not α4β2* nicotinic acetylcholine receptor binding in the brain.

    PubMed

    Metaxas, Athanasios; Al-Hasani, Ream; Farshim, Pamela; Tubby, Kristina; Berwick, Amy; Ledent, Catherine; Hourani, Susanna; Kitchen, Ian; Bailey, Alexis

    2013-08-01

    Considerable evidence indicates that adenosine A(2A) receptors (A(2A)Rs) modulate cholinergic neurotransmission, nicotinic acetylcholine receptor (nAChR) function, and nicotine-induced behavioural effects. To explore the interaction between A(2A) and nAChRs, we examined if the complete genetic deletion of adenosine A(2A)Rs in mice induces compensatory alterations in the binding of different nAChR subtypes, and whether the long-term effects of nicotine on nAChR regulation are altered in the absence of the A(2A)R gene. Quantitative autoradiography was used to measure cytisine-sensitive [¹²⁵I]epibatidine and [¹²⁵I]α-bungarotoxin binding to α4β2* and α7 nAChRs, respectively, in brain sections of drug-naïve (n = 6) or nicotine treated (n = 5-7), wild-type and adenosine A(2A)R knockout mice. Saline or nicotine (7.8 mg/kg/day; free-base weight) were administered to male CD1 mice via subcutaneous osmotic minipumps for a period of 14 days. Blood plasma levels of nicotine and cotinine were measured at the end of treatment. There were no compensatory developmental alterations in nAChR subtype distribution or density in drug-naïve A(2A)R knockout mice. In nicotine treated wild-type mice, both α4β2* and α7 nAChR binding sites were increased compared with saline treated controls. The genetic ablation of adenosine A(2A)Rs prevented nicotine-induced upregulation of α7 nAChRs, without affecting α4β2* receptor upregulation. This selective effect was observed at plasma levels of nicotine that were within the range reported for smokers (10-50 ng ml⁻¹). Our data highlight the involvement of adenosine A(2A)Rs in the mechanisms of nicotine-induced α7 nAChR upregulation, and identify A(2A)Rs as novel pharmacological targets for modulating the long-term effects of nicotine on α7 receptors.

  15. Impact of purification conditions and history on A2A adenosine receptor activity: The role of CHAPS and lipids

    DOE PAGES

    Naranjo, Andrea N.; McNeely, Patrick M.; Katsaras, John; ...

    2016-05-27

    The adenosine A2A receptor (A2AR) is a much-studied class A G protein-coupled receptor (GPCR). For biophysical studies, A2AR is commonly purified in a detergent mixture of dodecylmaltoside (DDM), 3-(3-cholamidopropyl) dimethylammoniopropane sulfonate (CHAPS), and cholesteryl hemisuccinate (CHS). Here we studied the effects of CHAPS on the ligand binding activity and stability of wild type, full-length human A2AR. We also tested the cholesterol requirement for maintaining the active conformation of the receptor when solubilized in detergent micelles. To this end, the receptor was purified using DDM, DDM/CHAPS, or the short hydrocarbon chain lipid 1,2-dihexanoyl-sn-glycero-3-phosphocholine (DHPC, di-6:0PC). After solubilization in DDM, DDM/CHAPS, ormore » DHPC micelles, although A2AR was found to retain its native-like fold, its binding ability was significantly compromised compared to DDM or DDM/CHAPS with CHS. It therefore appears that although cholesterol is not needed for A2AR to retain a native-like, α-helical conformation, it may be a critical component for high affinity ligand binding. Further, this result suggests that the conformational differences between the active and inactive protein may be so subtle that commonly used spectroscopic methods are unable to differentiate between the two forms, highlighting the need for activity measurements. Furthermore, the studies presented in this paper also underline the importance of the protein’s purification history; i.e., detergents that interact with the protein during purification affect the ligand binding properties of the receptor in an irreversible manner.« less

  16. Role of adenosine A2A receptor signaling in the nicotine-evoked attenuation of reflex cardiac sympathetic control.

    PubMed

    El-Mas, Mahmoud M; El-Gowilly, Sahar M; Fouda, Mohamed A; Saad, Evan I

    2011-08-01

    Baroreflex dysfunction contributes to increased cardiovascular risk in cigarette smokers. Given the importance of adenosinergic pathways in baroreflex control, the hypothesis was tested that defective central adenosinergic modulation of cardiac autonomic activity mediates the nicotine-baroreflex interaction. Baroreflex curves relating changes in heart rate (HR) to increases or decreases in blood pressure (BP) evoked by i.v. doses (1-16μg/kg) of phenylephrine (PE) and sodium nitroprusside (SNP), respectively, were constructed in conscious rats; slopes of the curves were taken as measures of baroreflex sensitivity (BRS). Nicotine (25 and 100μg/kg i.v.) dose-dependently reduced BRS(SNP) in contrast to no effect on BRS(PE). BRS(SNP) was also attenuated after intracisternal (i.c.) administration of nicotine. Similar reductions in BRS(SNP) were observed in rats pretreated with atropine or propranolol. The combined treatment with nicotine and atropine produced additive inhibitory effects on BRS, an effect that was not demonstrated upon concurrent exposure to nicotine and propranolol. BRS(SNP) was reduced in preparations treated with i.c. 8-phenyltheophylline (8-PT, nonselective adenosine receptor antagonist), 8-(3-Chlorostyryl) caffeine (CSC, A(2A) antagonist), or VUF5574 (A(3) antagonist). In contrast, BRS(SNP) was preserved after blockade of A(1) (DPCPX) or A(2B) (alloxazine) receptors or inhibition of adenosine uptake by dipyridamole. CSC or 8-PT abrogated the BRS(SNP) depressant effect of nicotine whereas other adenosinergic antagonists were without effect. Together, nicotine preferentially impairs reflex tachycardia via disruption of adenosine A(2A) receptor-mediated facilitation of reflex cardiac sympathoexcitation. Clinically, the attenuation by nicotine of compensatory sympathoexcitation may be detrimental in conditions such as hypothalamic defense response, posture changes, and ventricular rhythms.

  17. Up-regulation of striatal adenosine A(2A) receptors with iron deficiency in rats: effects on locomotion and cortico-striatal neurotransmission.

    PubMed

    Quiroz, César; Pearson, Virginia; Gulyani, Seema; Allen, Richard; Earley, Christopher; Ferré, Sergi

    2010-07-01

    Brain iron deficiency leads to altered dopaminergic function in experimental animals, which can provide a mechanistic explanation for iron deficiency-related human sensory-motor disorders, such as Restless Legs Syndrome (RLS). However, mechanisms linking both conditions have not been determined. Considering the strong modulation exerted by adenosine on dopamine signaling, one connection could involve changes in adenosine receptor expression or function. In the striatum, presynaptic A(2A) receptors are localized in glutamatergic terminals contacting GABAergic dynorphinergic neurons and their function can be analyzed by the ability of A(2A) receptor antagonists to block the motor output induced by cortical electrical stimulation. Postsynaptic A(2A) receptors are localized in the dendritic field of GABAergic enkephalinergic neurons and their function can be analyzed by studying the ability of A(2A) receptor antagonists to produce locomotor activity and to counteract striatal ERK1/2 phosphorylation induced by cortical electrical stimulation. Increased density of striatal A(2A) receptors was found in rats fed during 3 weeks with an iron-deficient diet during the post-weaning period. In iron-deficient rats, the selective A(2A) receptor antagonist MSX-3, at doses of 1 and 3 mg/kg, was more effective at blocking motor output induced by cortical electrical stimulation (presynaptic A(2A) receptor-mediated effect) and at enhancing locomotor activation and blocking striatal ERK phosphorylation induced by cortical electrical stimulation (postsynaptic A(2A) receptor-mediated effects). These results indicate that brain iron deficiency induces a functional up-regulation of both striatal pre- and postsynaptic A(2A) receptor, which could be involved in sensory-motor disorders associated with iron deficiency such as RLS.

  18. Salidroside attenuates chronic hypoxia-induced pulmonary hypertension via adenosine A2a receptor related mitochondria-dependent apoptosis pathway.

    PubMed

    Huang, Xiaoying; Zou, Lizhen; Yu, Xiaoming; Chen, Mayun; Guo, Rui; Cai, Hui; Yao, Dan; Xu, Xiaomei; Chen, Yanfan; Ding, Cheng; Cai, Xueding; Wang, Liangxing

    2015-05-01

    Pulmonary arterial hypertension (PAH) is characterized by pulmonary arterial remodeling mainly due to excess cellular proliferation and apoptosis resistance of pulmonary arterial smooth muscle cells (PASMCs). Salidroside, an active ingredient isolated from Rhodiola rosea is proposed to exert protective effects against PAH. However, the function of salidroside in PAH has not been investigated systematically and the underlying mechanisms are not clear. To investigate the effects of salidroside on PAH, the mice in chronic hypoxia model of PAH were given by an increasing concentration of salidroside (0, 16 mg/kg, 32 mg/kg, and 64 mg/kg). After salidroside treatment, the chronic hypoxia-induced right ventricular hypertrophy and pulmonary arterial remodeling were attenuated, suggesting a protective role played by salidroside in PAH. To explore the potential mechanisms, the apoptosis of PASMCs after salidroside treatment under hypoxia conditions were determined in vivo and in vitro, and also the mitochondria-dependent apoptosis factors, Bax, Bcl-2, cytochrome C, and caspase 9 were examined. The results revealed that salidroside reversed hypoxia-induced cell apoptosis resistance at least partially via a mitochondria-dependent pathway. In addition, salidroside upregulated the expression of adenosine A2a receptor (A2aR) in lung tissues of mice and in PASMCs in vitro after hypoxia exposure. Combined the evidence above, we conclude that salidroside can attenuate chronic hypoxia-induced PAH by promoting PASMCs apoptosis via an A2aR related mitochondria dependent pathway.

  19. A2A adenosine receptor modulates drug efflux transporter P-glycoprotein at the blood-brain barrier

    PubMed Central

    Kim, Do-Geun; Bynoe, Margaret S.

    2016-01-01

    The blood-brain barrier (BBB) protects the brain from toxic substances within the peripheral circulation. It maintains brain homeostasis and is a hurdle for drug delivery to the CNS to treat neurodegenerative diseases, including Alzheimer’s disease and brain tumors. The drug efflux transporter P-glycoprotein (P-gp) is highly expressed on brain endothelial cells and blocks the entry of most drugs delivered to the brain. Here, we show that activation of the A2A adenosine receptor (AR) with an FDA-approved A2A AR agonist (Lexiscan) rapidly and potently decreased P-gp expression and function in a time-dependent and reversible manner. We demonstrate that downmodulation of P-gp expression and function coincided with chemotherapeutic drug accumulation in brains of WT mice and in primary mouse and human brain endothelial cells, which serve as in vitro BBB models. Lexiscan also potently downregulated the expression of BCRP1, an efflux transporter that is highly expressed in the CNS vasculature and other tissues. Finally, we determined that multiple pathways, including MMP9 cleavage and ubiquitinylation, mediated P-gp downmodulation. Based on these data, we propose that A2A AR activation on BBB endothelial cells offers a therapeutic window that can be fine-tuned for drug delivery to the brain and has potential as a CNS drug-delivery technology. PMID:27043281

  20. Adenosine A2A receptor and ecto-5'-nucleotidase/CD73 are upregulated in hippocampal astrocytes of human patients with mesial temporal lobe epilepsy (MTLE).

    PubMed

    Barros-Barbosa, Aurora R; Ferreirinha, Fátima; Oliveira, Ângela; Mendes, Marina; Lobo, M Graça; Santos, Agostinho; Rangel, Rui; Pelletier, Julie; Sévigny, Jean; Cordeiro, J Miguel; Correia-de-Sá, Paulo

    2016-12-01

    Refractoriness to existing medications of up to 80 % of the patients with mesial temporal lobe epilepsy (MTLE) prompts for finding new antiepileptic drug targets. The adenosine A2A receptor emerges as an interesting pharmacological target since its excitatory nature partially counteracts the dominant antiepileptic role of endogenous adenosine acting via inhibitory A1 receptors. Gain of function of the excitatory A2A receptor has been implicated in a significant number of brain pathologies commonly characterized by neuronal excitotoxicity. Here, we investigated changes in the expression and cellular localization of the A2A receptor and of the adenosine-generating enzyme, ecto-5'-nucleotidase/CD73, in the hippocampus of control individuals and MTLE human patients. Western blot analysis indicates that the A2A receptor is more abundant in the hippocampus of MTLE patients compared to control individuals. Immunoreactivity against the A2A receptor predominates in astrocytes staining positively for the glial fibrillary acidic protein (GFAP). No co-localization was observed between the A2A receptor and neuronal cell markers, like synaptotagmin 1/2 (nerve terminals) and neurofilament 200 (axon fibers). Hippocampal astrogliosis observed in MTLE patients was accompanied by a proportionate increase in A2A receptor and ecto-5'-nucleotidase/CD73 immunoreactivities. Given our data, we hypothesize that selective blockade of excessive activation of astrocytic A2A receptors and/or inhibition of surplus adenosine formation by membrane-bound ecto-5'-nucleotidase/CD73 may reduce neuronal excitability, thus providing a novel therapeutic target for drug-refractory seizures in MTLE patients.

  1. Novel Alexa Fluor-488 labeled antagonist of the A(2A) adenosine receptor: Application to a fluorescence polarization-based receptor binding assay.

    PubMed

    Kecskés, Miklós; Kumar, T Santhosh; Yoo, Lena; Gao, Zhan-Guo; Jacobson, Kenneth A

    2010-08-15

    Fluorescence polarization (FP) assay has many advantages over the traditional radioreceptor binding studies. We developed an A(2A) adenosine receptor (AR) FP assay using a newly synthesized fluorescent antagonist of the A(2A)AR (MRS5346), a pyrazolo[4,3-e][1,2,4]triazolo[1,5-c]pyrimidin-5-amine derivative conjugated to the fluorescent dye Alexa Fluor-488. MRS5346 displayed a K(i) value of 111+/-16nM in radioligand binding using [(3)H]CGS21680 and membranes prepared from HEK293 cells stably expressing the human A(2A)AR. In a cyclic AMP functional assay, MRS5346 was shown to be an A(2A)AR antagonist. MRS5346 did not show any effect on A(1) and A(3) ARs in binding or the A(2B)AR in a cyclic AMP assay at 10microM. Its suitability as a fluorescent tracer was indicated in an initial observation of an FP signal following A(2A)AR binding. The FP signal was optimal with 20nM MRS5346 and 150microg protein/mL HEK293 membranes. The association and dissociation kinetic parameters were readily determined using this FP assay. The K(d) value of MRS5346 calculated from kinetic parameters was 16.5+/-4.7nM. In FP competition binding experiments using MRS5346 as a tracer, K(i) values of known AR agonists and antagonists consistently agreed with K(i) values from radioligand binding. Thus, this FP assay, which eliminates using radioisotopes, appears to be appropriate for both routine receptor binding and high-throughput screening with respect to speed of analysis, displaceable signal and precision. The approach used in the present study could be generally applicable to other GPCRs.

  2. Effect of adenosine A(2A) receptor antagonists on L-DOPA-induced hydroxyl radical formation in rat striatum.

    PubMed

    Gołembiowska, Krystyna; Dziubina, Anna; Kowalska, Magdalena; Kamińska, Katarzyna

    2009-02-01

    A(2A) adenosine receptor antagonists have been proposed as a new therapy for Parkinson's disease (PD). Since oxidative stress plays an important role in the pathogenesis of PD, we studied the effect of the selective A(2A) adenosine receptor antagonists 8-(3-chlorostyryl)caffeine (CSC) and 4-(2-[7-amino-2-(2-furyl)[1,2,4]triazolo[2,3-a][1,3,5]triazin-5-ylamino]ethyl)phenol (ZM 241385) on L: -3,4-dihydroxyphenylalanine (L: -DOPA)-induced hydroxyl radical generation using in vivo microdialysis in the striatum of freely moving rats. L: -DOPA (100 mg/kg; in the presence of benserazide, 50 mg/kg) given acutely or repeatedly for 14 days generated a high level of hydroxyl radicals, measured by HPLC with electrochemical detection, as the product of their reaction with p-hydroxybenzoic acid (PBA). CSC (1 mg/kg) and ZM 241385 (3 mg/kg) decreased haloperidol (0.5 mg/kg)-induced catalepsy, while at low doses of 0.1 and 0.3 mg/kg, respectively, they did not display an effect. CSC (1 and 5 mg/kg) and ZM 241385 (3 and 9 mg/kg) given acutely, or CSC (1 mg/kg) and ZM 241385 (3 mg/kg) given repeatedly, increased the production of hydroxyl radicals in dialysates from rat striatum. Both acute and repeated administration of CSC (0.1 and 1 mg/kg) and ZM 241385 (3 mg/kg) decreased L: -DOPA-induced generation of hydroxyl radicals. However, a high single dose of either CSC (5 mg/kg) and ZM 241385 (9 mg/kg) markedly potentiated the effect of L: -DOPA on hydroxyl radical production. The increase in hydroxyl radical production by acute and chronic injection of CSC and ZM 241385 may be related to the increased release of dopamine (DA) and its metabolism in striatal dialysates. Similarly, increased DA release following a single high dose of CSC or ZM 241385 appears to be responsible for augmentation of L: -DOPA-induced hydroxyl radical formation. Conversely, the inhibition of L: -DOPA-induced production of hydroxyl radical by single and repeated low doses of CSC or repeated low doses of ZM

  3. Dual blockade of the A1 and A2A adenosine receptor prevents amyloid beta toxicity in neuroblastoma cells exposed to aluminum chloride.

    PubMed

    Giunta, Salvatore; Andriolo, Violetta; Castorina, Alessandro

    2014-09-01

    In a previous work we have shown that exposure to aluminum (Al) chloride (AlCl3) enhanced the neurotoxicity of the amyloid beta(25-35) fragment (Abeta(25-35)) in neuroblastoma cells and affected the expression of Alzheimer's disease (AD)-related genes. Caffein, a compound endowed with beneficial effects against AD, exerts neuroprotection primarily through its antagonist activity on A2A adenosine receptors (A2AR), although it also inhibits A1Rs with similar potency. Still, studies on the specific involvement of these receptors in neuroprotection in a model of combined neurotoxicity (Abeta(25-35)+AlCl3) are missing. To address this issue, cultured SH-SY5Y cells exposed to Abeta(25-35)+AlCl3 were assessed for cell viability, morphology, intracellular ROS activity and expression of apoptosis-, stress- and AD-related proteins. To define the role of A1R and A2ARs, pretreatment with caffein, specific receptor antagonists (DPCPX or SCH58261) or siRNA-mediated gene knockdown were delivered. Results indicate that AlCl3 treatment exacerbated Abeta(25-35) toxicity, increased ROS production, lipid peroxidation, β-secretase-1 (BACE1) and amyloid precursor protein (APP). Interestingly, SCH58261 successfully prevented toxicity associated to Abeta(25-35) only, whereas pretreatment with both DPCPX and SCH58261 was required to fully avert Abeta(25-35)+AlCl3-induced damage, suggesting that A1Rs might also be critically involved in protection during combined toxicity. The effects of caffein were mimicked by both N-acetyl cysteine, an antioxidant, and desferrioxamine, likely acting through distinct mechanisms. Altogether, our data establish a novel protective function associated with A1R inhibition in the setting of combined Abeta(25-35)+AlCl3 neurotoxicity, and expand our current knowledge on the potential beneficial role of caffein to prevent AD progression in subjects environmentally exposed to aluminum.

  4. Habit Formation after Random Interval Training Is Associated with Increased Adenosine A2A Receptor and Dopamine D2 Receptor Heterodimers in the Striatum

    PubMed Central

    He, Yan; Li, Yan; Chen, Mozi; Pu, Zhilan; Zhang, Feiyang; Chen, Long; Ruan, Yang; Pan, Xinran; He, Chaoxiang; Chen, Xingjun; Li, Zhihui; Chen, Jiang-Fan

    2016-01-01

    Striatal adenosine A2A receptors (A2ARs) modulate striatal synaptic plasticity and instrumental learning, possibly by functional interaction with the dopamine D2 receptors (D2Rs) and metabotropic glutamate receptors 5 (mGluR5) through receptor-receptor heterodimers, but in vivo evidence for these interactions is lacking. Using in situ proximity ligation assay (PLA), we studied the subregional distribution of the A2AR-D2R and A2AR-mGluR5 heterodimer complexes in the striatum and their adaptive changes over the random interval and random ratio training of instrumental learning. After confirming the specificity of the PLA detection of the A2AR-D2R heterodimers with the A2AR knockout and D2R knockout mice, we detected a heterogeneous distribution of the A2AR-D2R heterodimer complexes in the striatum, being more abundant in the dorsolateral than the dorsomedial striatum. Importantly, habit formation after the random interval training was associated with the increased formation of the A2AR-D2R heterodimer complexes, with prominant increase in the dorsomedial striatum. Conversely, goal-directed behavior after the random ratio schedule was not associated with the adaptive change in the A2AR-D2R heterodimer complexes. In contrast to the A2AR-D2R heterodimers, the A2AR-mGluR5 heterodimers showed neither subregional variation in the striatum nor adaptive changes over either the random ratio (RR) or random interval (RI) training of instrumental learning. These findings suggest that development of habit formation is associated with increased formation of the A2AR-D2R heterodimer protein complexes which may lead to reduced dependence on D2R signaling in the striatum. PMID:28082865

  5. Modulation of Ca2+-currents by sequential and simultaneous activation of adenosine A1 and A 2A receptors in striatal projection neurons.

    PubMed

    Hernández-González, O; Hernández-Flores, T; Prieto, G A; Pérez-Burgos, A; Arias-García, M A; Galarraga, E; Bargas, J

    2014-01-01

    D(1)- and D(2)-types of dopamine receptors are located separately in direct and indirect pathway striatal projection neurons (dSPNs and iSPNs). In comparison, adenosine A(1)-type receptors are located in both neuron classes, and adenosine A(2A)-type receptors show a preferential expression in iSPNs. Due to their importance for neuronal excitability, Ca(2+)-currents have been used as final effectors to see the function of signaling cascades associated with different G protein-coupled receptors. For example, among many other actions, D(1)-type receptors increase, while D(2)-type receptors decrease neuronal excitability by either enhancing or reducing, respectively, CaV1 Ca(2+)-currents. These actions occur separately in dSPNs and iSPNs. In the case of purinergic signaling, the actions of A(1)- and A(2A)-receptors have not been compared observing their actions on Ca(2+)-channels of SPNs as final effectors. Our hypotheses are that modulation of Ca(2+)-currents by A(1)-receptors occurs in both dSPNs and iSPNs. In contrast, iSPNs would exhibit modulation by both A(1)- and A2A-receptors. We demonstrate that A(1)-type receptors reduced Ca(2+)-currents in all SPNs tested. However, A(2A)-type receptors enhanced Ca(2+)-currents only in half tested neurons. Intriguingly, to observe the actions of A(2A)-type receptors, occupation of A(1)-type receptors had to occur first. However, A(1)-receptors decreased Ca(V)2 Ca(2+)-currents, while A(2A)-type receptors enhanced current through Ca(V)1 channels. Because these channels have opposing actions on cell discharge, these differences explain in part why iSPNs may be more excitable than dSPNs. It is demonstrated that intrinsic voltage-gated currents expressed in SPNs are effectors of purinergic signaling that therefore play a role in excitability.

  6. Guanosine may increase absence epileptic activity by means of A2A adenosine receptors in Wistar Albino Glaxo Rijswijk rats.

    PubMed

    Lakatos, Renáta Krisztina; Dobolyi, Árpád; Todorov, Mihail Ivilinov; Kékesi, Katalin A; Juhász, Gábor; Aleksza, Magdolna; Kovács, Zsolt

    2016-06-01

    The non-adenosine nucleoside guanosine (Guo) was demonstrated to decrease quinolinic acid(QA)-induced seizures, spontaneously emerged absence epileptic seizures and lipopolysaccharide(LPS)-evoked induction of absence epileptic seizures suggesting its antiepileptic potential. It was also described previously that intraperitoneal (i.p.) injection of 20 and 50mg/kg Guo decreased the number of spike-wave discharges (SWDs) in a well investigated model of human absence epilepsy, the Wistar Albino Glaxo Rijswijk (WAG/Rij) rats during 4th (20mg/kg Guo) and 3rd as well as 4th (50mg/kg Guo) measuring hours. Guanosine can potentially decrease SWD number by means of its putative receptors but absence epileptic activity changing effects of Guo by means of increased extracellular adenosine (Ado) cannot be excluded. An increase in the dose of i.p. injected Guo is limited by its low solubility in saline, therefore, we addressed in the present study whether higher doses of Guo, diluted in sodium hydroxide (NaOH) solution, have more potent antiepileptic effect in WAG/Rij rats. We confirmed that i.p. 50mg/kg Guo decreased but, surprisingly, i.p. 100mg/kg Guo enhanced the number of SWDs in WAG/Rij rats. Combined i.p. injection of a non-selective Ado receptor antagonist theophylline (5mg/kg) or a selective Ado A2A receptor (A2AR) antagonist SCH 58261 (7-(2-phenylethyl)-5-amino-2-(2-furyl)-pyrazolo-[4,3-e]-1,2,4-triazolo[1,5-c]pyrimidine) (1mg/kg) and a cyclooxygenase 1 and 2/COX-1 and COX-2 inhibitor indomethacin (10mg/kg) with 100mg/kg Guo decreased the SWD number compared to i.p. 100mg/kg Guo alone. The results suggest that i.p. 100mg/kg Guo can increase SWD number by means of the adenosinergic system.

  7. Neuroprotective potential of adenosine A2A and cannabinoid CB1 receptor antagonists in an animal model of Parkinson disease.

    PubMed

    Cerri, Silvia; Levandis, Giovanna; Ambrosi, Giulia; Montepeloso, Elena; Antoninetti, Gian Filippo; Franco, Rafael; Lanciego, José Luis; Baqi, Younis; Müller, Christa E; Pinna, Annalisa; Blandini, Fabio; Armentero, Marie Therese

    2014-05-01

    The development of nondopaminergic therapeutic strategies that may improve motor and nonmotor deficits, while possibly slowing down the neurodegenerative process and associated neuroinflammation,is a primary goal of Parkinson disease (PD) research. We investigated the neuroprotective and anti-inflammatory potential of combined and single treatment with adenosine A2A and cannabinoid CB1 receptor antagonists MSX-3 and rimonabant, respectively, in a rodent model of PD. Rats bearing a unilateral intrastriatal 6-hydroxydopamine lesion were treated chronically with MSX-3 (0.5or 1 mg/kg/d) and rimonabant (0.1 mg/kg/d) given as monotherapy or combined. The effects of the treatments to counteract dopaminergic cell death and neuroinflammation were assessed by immunohistochemistry for tyrosine hydroxylase and glial cell markers, respectively. Both rimonabant and MSX-3 (1 mg/kg/d) promoted dopaminergic neuron survival in the substantia nigra pars compacta (SNc) when given alone; this effect was weakened when the compounds were combined. Glial activation was not significantly affected by MSX-3 (1 mg/kg/d), whereas rimonabant seemed to increase astrocyte cell density in the SNc. Our findings demonstrate the neuroprotective potential of single treatments and suggest that glial cells might be involved in this protective effect. The results also indicate that the neuroprotective potential of combined therapy may not necessarily reflect or promote single-drug effects and point out that special care should be taken when considering multidrug therapies in PD.

  8. Sinomenine Protects against Lipopolysaccharide-Induced Acute Lung Injury in Mice via Adenosine A2A Receptor Signaling

    PubMed Central

    Li, Jun; Zhao, Li; He, Xie; Zeng, Yi-Jun; Dai, Shuang-Shuang

    2013-01-01

    Sinomenine (SIN) is a bioactive alkaloid extracted from the Chinese medicinal plant Sinomenium acutum, which is widely used in the clinical treatment of rheumatoid arthritis (RA). However, its role in acute lung injury (ALI) is unclear. In this study, we investigate the role of SIN in lipopolysaccharide (LPS)-induced ALI in mice. After ALI, lung water content and histological signs of pulmonary injury were attenuated, whereas the PaO2/FIO2 (P/F) ratios were elevated significantly in the mice pretreated with SIN. Additionally, SIN markedly inhibited inflammatory cytokine TNF-α and IL-1β expression levels as well as neutrophil infiltration in the lung tissues of the mice. Microarray analysis and real-time PCR showed that SIN treatment upregulated adenosine A2A receptor (A2AR) expression, and the protective effect of SIN was abolished in A2AR knockout mice. Further investigation in isolated mouse neutrophils confirmed the upregulation of A2AR by SIN and showed that A2AR-cAMP-PKA signaling was involved in the anti-inflammatory effect of SIN. Taken together, these findings demonstrate an A2AR-associated anti-inflammatory effect and the protective role of SIN in ALI, which suggests a potential novel approach to treat ALI. PMID:23555007

  9. Selected C8 two-chain linkers enhance the adenosine A1/A2A receptor affinity and selectivity of caffeine.

    PubMed

    van der Walt, M M; Terre'Blanche, G

    2017-01-05

    Recent research exploring C8 substitution on the caffeine core identified 8-(2-phenylethyl)-1,3,7-trimethylxanthine as a non-selective adenosine receptor antagonist. To elaborate further, we included various C8 two-chain-length linkers to enhance adenosine receptor affinity. The results indicated that the unsubstituted benzyloxy linker (1e A1Ki = 1.52 μM) displayed the highest affinity for the A1 adenosine receptor and the para-chloro-substituted phenoxymethyl (1d A2AKi = 1.33 μM) linker the best A2A adenosine receptor affinity. The position of the oxygen revealed that the phenoxymethyl linker favoured A1 adenosine receptor selectivity over the benzyloxy linker and, by introducing a para-chloro substituent, A2A adenosine receptor selectivity was obtained. Selected compounds (1c, 1e) behaved as A1 adenosine receptor antagonists in GTP shift assays and therefore represent selective and non-selective A1 and A2A adenosine receptor antagonists that may have potential for treating neurological disorders.

  10. Chronic and acute adenosine A2A receptor blockade prevents long-term episodic memory disruption caused by acute cannabinoid CB1 receptor activation.

    PubMed

    Mouro, Francisco M; Batalha, Vânia L; Ferreira, Diana G; Coelho, Joana E; Baqi, Younis; Müller, Christa E; Lopes, Luísa V; Ribeiro, Joaquim A; Sebastião, Ana M

    2017-05-01

    Cannabinoid-mediated memory impairment is a concern in cannabinoid-based therapies. Caffeine exacerbates cannabinoid CB1 receptor (CB1R)-induced memory deficits through an adenosine A1 receptor-mediated mechanism. We now evaluated how chronic or acute blockade of adenosine A2A receptors (A2ARs) affects long-term episodic memory deficits induced by a single injection of a selective CB1R agonist. Long-term episodic memory was assessed by the novel object recognition (NOR) test. Mice received an intraperitoneal (i.p.) injection of the CB1/CB2 receptor agonist WIN 55,212-2 (1 mg/kg) immediately after the NOR training, being tested for novelty recognition 24 h later. Anxiety levels were assessed by the Elevated Plus Maze test, immediately after the NOR. Mice were also tested for exploratory behaviour at the Open Field. For chronic A2AR blockade, KW-6002 (istradefylline) (3 mg/kg/day) was administered orally for 30 days; acute blockade of A2ARs was assessed by i.p. injection of SCH 58261 (1 mg/kg) administered either together with WIN 55,212-2 or only 30 min before the NOR test phase. The involvement of CB1Rs was assessed by using the CB1R antagonist, AM251 (3 mg/kg, i.p.). WIN 55,212-2 caused a disruption in NOR, an action absent in mice also receiving AM251, KW-6002 or SCH 58261 during the encoding/consolidation phase; SCH 58251 was ineffective if present during retrieval only. No effects were detected in the Elevated Plus maze or Open Field Test. The finding that CB1R-mediated memory disruption is prevented by antagonism of adenosine A2ARs, highlights a possibility to prevent cognitive side effects when therapeutic application of CB1R drugs is desired.

  11. Persistent reduction of cocaine seeking by pharmacological manipulation of adenosine A1 and A2A receptors during extinction training in rats

    PubMed Central

    O’Neill, Casey E.; Hobson, Benjamin D.; Levis, Sophia C.; Bachtell, Ryan K.

    2014-01-01

    Rationale Adenosine receptor stimulation and blockade has been shown to modulate a variety of cocaine related behaviors. Objectives These studies identify the direct effects of adenosine receptor stimulation on cocaine seeking during extinction training and the persistent effects on subsequent reinstatement to cocaine seeking. Methods Rats self-administered cocaine on a fixed-ratio 1 schedule in daily sessions over 3 weeks. Following 1 week withdrawal, the direct effects of adenosine receptor modulation were tested by administering the adenosine A1 receptor agonist, CPA (0.03 mg/kg and 0.1 mg/kg), the adenosine A2A agonist, CGS 21680 (0.03 mg/kg and 0.1 mg/kg), the presynaptic adenosine A2A receptor antagonist, SCH 442416 (0.3 mg/kg, 1 mg/kg, and 3 mg/kg), or vehicle prior to each of 6 daily extinction sessions. The persistent effects of adenosine receptor modulation during extinction training were subsequently tested on reinstatement to cocaine seeking induced by cues, cocaine, and the dopamine D2 receptor agonist, quinpirole. Results All doses of CPA and CGS 21680 impaired initial extinction responding, however only CPA treatment during extinction produced persistent impairment in subsequent cocaine- and quinpirole-induced seeking. Dissociating CPA treatment from extinction did not alter extinction responding or subsequent reinstatement. Administration of SCH 442416 had no direct effects on extinction responding, but produced dose-dependent persistent impairment of cocaine- and quinpirole-induced seeking. Conclusions These findings demonstrate that adenosine A1 or A2A receptor stimulation directly impair extinction responding. Interestingly, adenosine A1 receptor stimulation or presynaptic adenosine A2A receptor blockade during extinction produces lasting changes in relapse susceptibility. PMID:24562064

  12. Beneficial effects of a novel agonist of the adenosine A2A receptor on monocrotaline-induced pulmonary hypertension in rats

    PubMed Central

    Alencar, Allan K N; Pereira, Sharlene L; Montagnoli, Tadeu L; Maia, Rodolfo C; Kümmerle, Arthur E; Landgraf, Sharon S; Caruso-Neves, Celso; Ferraz, Emanuelle B; Tesch, Roberta; Nascimento, José H M; de Sant'Anna, Carlos M R; Fraga, Carlos A M; Barreiro, Eliezer J; Sudo, Roberto T; Zapata-Sudo, Gisele

    2013-01-01

    Background and Purpose Pulmonary arterial hypertension (PAH) is characterized by enhanced pulmonary vascular resistance, right ventricular hypertrophy and increased right ventricular systolic pressure. Here, we investigated the effects of a N-acylhydrazone derivative, 3,4-dimethoxyphenyl-N-methyl-benzoylhydrazide (LASSBio-1359), on monocrotaline (MCT)-induced pulmonary hypertension in rats. Experimental Approach PAH was induced in male Wistar rats by a single i.p. injection of MCT (60 mg·kg−1) and 2 weeks later, oral LASSBio-1359 (50 mg·kg−1) or vehicle was given once daily for 14 days. Echocardiography was used to measure cardiac function and pulmonary artery dimensions, with histological assay of vascular collagen. Studies of binding to human recombinant adenosine receptors (A1, A2A, A3) and of docking with A2A receptors were also performed. Key Results MCT administration induced changes in vascular and ventricular structure and function, characteristic of PAH. These changes were reversed by treatment with LASSBio-1359. MCT also induced endothelial dysfunction in pulmonary artery, as measured by diminished relaxation of pre-contracted arterial rings, and this dysfunction was reversed by LASSBio-1359. In pulmonary artery rings from normal Wistar rats, LASSBio-1359 induced relaxation, which was decreased by the adenosine A2A receptor antagonist, ZM 241385. In adenosine receptor binding studies, LASSBio-1359 showed most affinity for the A2A receptor and in the docking analyses, binding modes of LASSBio-1359 and the A2A receptor agonist, CGS21680, were very similar. Conclusion and Implications In rats with MCT-induced PAH, structural and functional changes in heart and pulmonary artery were reversed by treatment with oral LASSBio-1359, most probably through the activation of adenosine A2A receptors. PMID:23530610

  13. Wound healing effects of noni (Morinda citrifolia L.) leaves: a mechanism involving its PDGF/A2A receptor ligand binding and promotion of wound closure.

    PubMed

    Palu, Afa; Su, Chen; Zhou, Bing-Nan; West, Brett; Jensen, Jarakae

    2010-10-01

    Morinda citrifolia L. (Rubiaceae) commonly known as noni, has been used in Polynesia by traditional healers for the treatment of cuts, bruises and wounds. Our objective was to investigate the wound-healing mechanisms of the noni leaf. The investigations of its wound-healing mechanisms were carried out using fresh noni leaf juice (NLJ), noni leaf ethanol extract (NLEE) and its methanol (MFEE) and hexane (HFEE) fractions on the PDGF and A(2A) receptors in vitro and topically in mice. Fresh noni leaf juice showed significant affinity to PDGF receptors, and displayed 166% binding inhibition of the ligand binding to its receptors, while at the same concentration, it only had 7% inhibition of the ligand binding to the A(2A) receptors. NLEE, HFEE and MFEE showed significant affinity to A(2A) receptors, concentration dependently, with IC(50) values of 34.1, 42.9 and 86.7 μg/mL, respectively. However, MFEE significantly increased wound closure and reduced the half closure time in mice with a CT(50) of 5.4 ± 0.2 days compared with control (p < 0.05). These results suggest that noni leaf significantly accelerated wound healing in mice via its ligand binding to the PDGF and A(2A) receptors as its probable mechanisms of wound-healing and also support its traditional usage for wound-healing in Polynesia.

  14. Nicotine and ethanol activate protein kinase A synergistically via G(i) betagamma subunits in nucleus accumbens/ventral tegmental cocultures: the role of dopamine D(1)/D(2) and adenosine A(2A) receptors.

    PubMed

    Inoue, Yuichiro; Yao, Lina; Hopf, F Woodward; Fan, Peidong; Jiang, Zhan; Bonci, Antonello; Diamond, Ivan

    2007-07-01

    Tobacco and alcohol are the most commonly used drugs of abuse and show the most serious comorbidity. The mesolimbic dopamine system contributes significantly to nicotine and ethanol reinforcement, but the underlying cellular signaling mechanisms are poorly understood. Nicotinic acetylcholine (nACh) receptors are highly expressed on ventral tegmental area (VTA) dopamine neurons, with relatively low expression in nucleus accumbens (NAcb) neurons. Because dopamine receptors D(1) and D(2) are highly expressed on NAcb neurons, nicotine could influence NAcb neurons indirectly by activating VTA neurons to release dopamine in the NAcb. To investigate this possibility in vitro, we established primary cultures containing neurons from VTA or NAcb separately or in cocultures. Nicotine increased cAMP response element-mediated gene expression only in cocultures; this increase was blocked by nACh or dopamine D(1) or D(2) receptor antagonists. Furthermore, subthreshold concentrations of nicotine with ethanol increased gene expression in cocultures, and this increase was blocked by nACh, D(2) or adenosine A(2A) receptor antagonists, Gbetagamma or protein kinase A (PKA) inhibitors, and adenosine deaminase. These results suggest that nicotine activated VTA neurons, causing the release of dopamine, which in turn stimulated both D(1) and D(2) receptors on NAcb neurons. In addition, subthreshold concentrations of nicotine and ethanol in combination also activated NAcb neurons through synergy between D(2) and A(2A) receptors. These data provide a novel cellular mechanism, involving Gbetagamma subunits, A(2A) receptors, and PKA, whereby combined use of tobacco and alcohol could enhance the reinforcing effect in humans as well as facilitate long-term neuroadaptations, increasing the risk for developing coaddiction.

  15. Btn2a2, a T cell immunomodulatory molecule coregulated with MHC class II genes

    PubMed Central

    Sarter, Kerstin; Leimgruber, Elisa; Gobet, Florian; Agrawal, Vishal; Dunand-Sauthier, Isabelle; Barras, Emmanuèle; Mastelic-Gavillet, Béatris; Kamath, Arun; Fontannaz, Paola; Guéry, Leslie; Duraes, Fernanda do Valle; Lippens, Carla; Ravn, Ulla; Santiago-Raber, Marie-Laure; Magistrelli, Giovanni; Fischer, Nicolas; Siegrist, Claire-Anne; Hugues, Stéphanie

    2016-01-01

    Evidence has recently emerged that butyrophilins, which are members of the extended B7 family of co-stimulatory molecules, have diverse functions in the immune system. We found that the human and mouse genes encoding butyrophilin-2A2 (BTN2A2) are regulated by the class II trans-activator and regulatory factor X, two transcription factors dedicated to major histocompatibility complex class II expression, suggesting a role in T cell immunity. To address this, we generated Btn2a2-deficient mice. Btn2a2−/− mice exhibited enhanced effector CD4+ and CD8+ T cell responses, impaired CD4+ regulatory T cell induction, potentiated antitumor responses, and exacerbated experimental autoimmune encephalomyelitis. Altered immune responses were attributed to Btn2a2 deficiency in antigen-presenting cells rather than T cells or nonhematopoietic cells. These results provide the first genetic evidence that BTN2A2 is a co-inhibitory molecule that modulates T cell–mediated immunity. PMID:26809444

  16. Adenosine A2A receptor agonist prevents cardiac remodeling and dysfunction in spontaneously hypertensive male rats after myocardial infarction

    PubMed Central

    da Silva, Jaqueline S; Gabriel-Costa, Daniele; Sudo, Roberto T; Wang, Hao; Groban, Leanne; Ferraz, Emanuele B; Nascimento, José Hamilton M; Fraga, Carlos Alberto M; Barreiro, Eliezer J; Zapata-Sudo, Gisele

    2017-01-01

    Background This work evaluated the hypothesis that 3,4-methylenedioxybenzoyl-2-thienylhydrazone (LASSBio-294), an agonist of adenosine A2A receptor, could be beneficial for preventing cardiac dysfunction due to hypertension associated with myocardial infarction (MI). Methods Male spontaneously hypertensive rats (SHR) were randomly divided into four groups (six animals per group): sham-operation (SHR-Sham), and myocardial infarction rats (SHR-MI) were treated orally either with vehicle or LASSBio-294 (10 and 20 mg.kg−1.d−1) for 4 weeks. Echocardiography and in vivo hemodynamic parameters measured left ventricle (LV) structure and function. Exercise tolerance was evaluated using a treadmill test. Cardiac remodeling was accessed by LV collagen deposition and tumor necrosis factor α expression. Results Early mitral inflow velocity was significantly reduced in the SHR-MI group, and there was significant recovery in a dose-dependent manner after treatment with LASSBio-294. Exercise intolerance observed in the SHR-MI group was prevented by 10 mg.kg−1.d−1 of LASS-Bio-294, and exercise tolerance exceeded that of the SHR-Sham group at 20 mg.kg−1.d−1. LV end-diastolic pressure increased after MI, and this was prevented by 10 and 20 mg.kg−1.d−1 of LASSBio-294. Sarcoplasmic reticulum Ca2+ ATPase levels were restored in a dose-dependent manner after treatment with LASSBio-294. Fibrosis and inflammatory processes were also counteracted by LASSBio-294, with reductions in LV collagen deposition and tumor necrosis factor α expression. Conclusion In summary, oral administration of LASSBio-294 after MI in a dose-dependent manner prevented the development of cardiac dysfunction, demonstrating this compound’s potential as an alternative treatment for heart failure in the setting of ischemic heart disease with superimposed chronic hypertension. PMID:28293100

  17. Genetic blockade of adenosine A2A receptors induces cognitive impairments and anatomical changes related to psychotic symptoms in mice.

    PubMed

    Moscoso-Castro, Maria; Gracia-Rubio, Irene; Ciruela, Francisco; Valverde, Olga

    2016-07-01

    Schizophrenia is a chronic severe mental disorder with a presumed neurodevelopmental origin, and no effective treatment. Schizophrenia is a multifactorial disease with genetic, environmental and neurochemical etiology. The main theories on the pathophysiology of this disorder include alterations in dopaminergic and glutamatergic neurotransmission in limbic and cortical areas of the brain. Early hypotheses also suggested that nucleoside adenosine is a putative affected neurotransmitter system, and clinical evidence suggests that adenosine adjuvants improve treatment outcomes, especially in poorly responsive patients. Hence, it is important to elucidate the role of the neuromodulator adenosine in the pathophysiology of schizophrenia. A2A adenosine receptor (A2AR) subtypes are expressed in brain areas controlling motivational responses and cognition, including striatum, and in lower levels in hippocampus and cerebral cortex. The aim of this study was to characterize A2AR knockout (KO) mice with complete and specific inactivation of A2AR, as an animal model for schizophrenia. We performed behavioral, anatomical and neurochemical studies to assess psychotic-like symptoms in adult male and female KO and wild-type (WT) littermates. Our results show impairments in inhibitory responses and sensory gating in A2AR KO animals. Hyperlocomotion induced by d-amphetamine and MK-801 was reduced in KO animals when compared to WT littermates. Moreover, A2AR KO animals show motor disturbances, social and cognitive alterations. Finally, behavioral impairments were associated with enlargement of brain lateral ventricles and decreased BDNF levels in the hippocampus. These data highlight the role of adenosine in the pathophysiology of schizophrenia and provide new possibilities for the therapeutic management of schizophrenia.

  18. A novel conjugated agent between dopamine and an A2A adenosine receptor antagonist as a potential anti-Parkinson multitarget approach.

    PubMed

    Dalpiaz, Alessandro; Cacciari, Barbara; Vicentini, Chiara Beatrice; Bortolotti, Fabrizio; Spalluto, Giampiero; Federico, Stephanie; Pavan, Barbara; Vincenzi, Fabrizio; Borea, Pier Andrea; Varani, Katia

    2012-03-05

    We propose a potential antiparkinsonian prodrug DP-L-A(2A)ANT (2) obtained by amidic conjugation of dopamine (1) via a succinic spacer to a new triazolo-triazine A(2A) adenosine receptor (AR) antagonist A(2A)ANT (3). The affinity of 2 and its hydrolysis products-1, 3, dopamine-linker DP-L (4) and A(2A)ANT-linker L-A(2A)ANT (5)-was evaluated for hA(1), hA(2A), hA(2B) and hA(3) ARs and rat striatum A(2A)ARs or D(2) receptors. The hydrolysis patterns of 2, 4 and 5 and the stabilities of 1 and 3 were evaluated by HPLC analysis in human whole blood and rat brain homogenates. High hA(2A) affinity was shown by compounds 2 (K(i) = 7.32 ± 0.65 nM), 3 (K(i) = 35 ± 3 nM) and 5 (K(i) = 72 ± 5 nM), whose affinity values were similar in rat striatum. These compounds were not able to change dopamine affinity for D(2) receptors but counteracted the CGS 21680-induced reduction of dopamine affinity. DP-L (4) was inactive on adenosine and dopaminergic receptors. As for stability studies, compounds 4 and 5 were not degraded in incubation media. In human blood, the prodrug 2 was hydrolyzed (half-life = 2.73 ± 0.23 h) mainly on the amidic bound coupling the A(2A)ANT (3), whereas in rat brain homogenates the prodrug 2 was hydrolyzed (half-life > eight hours) exclusively on the amidic bound coupling dopamine, allowing its controlled release and increasing its poor stability as characterized by half-life = 22.5 ± 1.5 min.

  19. Hyperthermia-induced seizures alter adenosine A1 and A2A receptors and 5'-nucleotidase activity in rat cerebral cortex.

    PubMed

    León-Navarro, David Agustín; Albasanz, José L; Martín, Mairena

    2015-08-01

    Febrile seizure is one of the most common convulsive disorders in children. The neuromodulator adenosine exerts anticonvulsant actions through binding adenosine receptors. Here, the impact of hyperthermia-induced seizures on adenosine A1 and A2A receptors and 5'-nucleotidase activity has been studied at different periods in the cerebral cortical area by using radioligand binding, real-time PCR, and 5'-nucleotidase activity assays. Hyperthermic seizures were induced in 13-day-old rats using a warmed air stream from a hair dryer. Neonates exhibited rearing and falling over associated with hindlimb clonus seizures (stage 5 on Racine scale criteria) after hyperthermic induction. A significant increase in A1 receptor density was observed using [(3) H]DPCPX as radioligand, and mRNA coding A1 was observed 48 h after hyperthermia-induced seizures. In contrast, a significant decrease in A2A receptor density was detected, using [(3) H]ZM241385 as radioligand, 48 h after hyperthermia-evoked convulsions. These short-term changes in A1 and A2A receptors were also accompanied by a loss of 5'-nucleotidase activity. No significant variations either in A1 or A2A receptor density or 5'-nucleotidase were observed 5 and 20 days after hyperthermic seizures. Taken together, both regulation of A1 and A2A receptors and loss of 5'-nucleotidase in the cerebral cortex suggest the existence of a neuroprotective mechanism against seizures. Febrile seizure is one of the most common convulsive disorders in children. The consequences of hyperthermia-induced seizures (animal model of febrile seizures) on adenosine A1 and A2A receptors and 5'-nucleotidase activity have been studied at different periods in cerebral cortical area. A significant increase in A1 receptor density and mRNA coding A1 was observed 48 h after hyperthermia-induced seizures. In contrast, a significant decrease in A2A receptor density and 5'-nucleotidase activity was detected 48 h after convulsions evoked by hyperthermia

  20. 2-Amino-N-pyrimidin-4-ylacetamides as A2A receptor antagonists: 2. Reduction of hERG activity, observed species selectivity, and structure-activity relationships.

    PubMed

    Slee, Deborah H; Moorjani, Manisha; Zhang, Xiaohu; Lin, Emily; Lanier, Marion C; Chen, Yongsheng; Rueter, Jaimie K; Lechner, Sandra M; Markison, Stacy; Malany, Siobhan; Joswig, Tanya; Santos, Mark; Gross, Raymond S; Williams, John P; Castro-Palomino, Julio C; Crespo, María I; Prat, Maria; Gual, Silvia; Díaz, José-Luis; Jalali, Kayvon; Sai, Yang; Zuo, Zhiyang; Yang, Chun; Wen, Jenny; O'Brien, Zhihong; Petroski, Robert; Saunders, John

    2008-03-27

    Previously we have described a series of novel A 2A receptor antagonists with excellent water solubility. As described in the accompanying paper, the antagonists were first optimized to remove an unsubstituted furyl moiety, with the aim of avoiding the potential metabolic liabilities that can arise from the presence of an unsubstituted furan. This effort identified a series of potent and selective methylfuryl derivatives. Herein, we describe the further optimization of this series to increase potency, maintain selectivity for the human A 2A vs the human A 1 receptor, and minimize activity against the hERG channel. In addition, the observed structure-activity relationships against both the human and the rat A 2A receptor are reported.

  1. Role of adenosine A(2A) receptors in modulating synaptic functions and brain levels of BDNF: a possible key mechanism in the pathophysiology of Huntington's disease.

    PubMed

    Tebano, Maria Teresa; Martire, Alberto; Chiodi, Valentina; Ferrante, Antonella; Popoli, Patrizia

    2010-09-01

    In the last few years, accumulating evidence has shown the existence of an important cross-talk between adenosine A(2A) receptors (A(2A)Rs) and brain-derived neurotrophic factor (BDNF). Not only are A(2A)Rs involved in the mechanism of transactivation of BDNF receptor TrkB, they also modulate the effect of BDNF on synaptic transmission, playing a facilitatory and permissive role. The cAMP-PKA pathway, the main transduction system operated by A(2A)Rs, is involved in such effects. Furthermore, a basal tonus of A(2A)Rs is required to allow the regulation of BDNF physiological levels in the brain, as demonstrated by the reduced protein levels measured in A(2A)Rs KO mice. The crucial role of adenosine A(2A)Rs in the maintenance of synaptic functions and BDNF levels will be reviewed here and discussed in the light of possible implications for Huntington's disease therapy, in which a joint impairment of BDNF and A(2A)Rs seems to play a pathogenetic role.

  2. Cocaine self-administration differentially affects allosteric A2A-D2 receptor-receptor interactions in the striatum. Relevance for cocaine use disorder.

    PubMed

    Pintsuk, Julia; Borroto-Escuela, Dasiel O; Pomierny, Bartosz; Wydra, Karolina; Zaniewska, Magdalena; Filip, Malgorzata; Fuxe, Kjell

    2016-05-01

    In the current study behavioral and biochemical experiments were performed to study changes in the allosteric A2AR-D2R interactions in the ventral and dorsal striatum after cocaine self-administration versus corresponding yoked saline control. By using ex vivo [(3)H]-raclopride/quinpirole competition experiments, the effects of the A2AR agonist CGS 21680 (100 nM) on the KiH and KiL values of the D2-like receptor (D2-likeR) were determined. One major result was a significant reduction in the D2-likeR agonist high affinity state observed with CGS 21680 after cocaine self-administration in the ventral striatum compared with the yoked saline group. The results therefore support the hypothesis that A2AR agonists can at least in part counteract the motivational actions of cocaine. This action is mediated via the D2-likeR by targeting the A2AR protomer of A2AR-D2-like R heteroreceptor complexes in the ventral striatum, which leads to the reduction of D2-likeR protomer recognition through the allosteric receptor-receptor interaction. In contrast, in the dorsal striatum the CGS 21680-induced antagonistic modulation in the D2-likeR agonist high affinity state was abolished after cocaine self-administration versus the yoked saline group probably due to a local dysfunction/disruption of the A2AR-D2-like R heteroreceptor complexes. Such a change in the dorsal striatum in cocaine self-administration can contribute to the development of either locomotor sensitization, habit-forming learning and/or the compulsive drug seeking by enhanced D2-likeR protomer signaling. Potential differences in the composition and stoichiometry of the A2AR-D2R heteroreceptor complexes, including differential recruitment of sigma 1 receptor, in the ventral and dorsal striatum may explain the differential regional changes observed in the A2A-D2-likeR interactions after cocaine self-administration.

  3. Differential Expression of Adenosine A1 and A2A Receptors After Upper Cervical (C2) Spinal Cord Hemisection in Adult Rats

    PubMed Central

    Petrov, Theodor; Kreipke, Christian; Alilain, Warren; Nantwi, Kwaku D

    2007-01-01

    Background: In an animal model of spinal cord injury, a latent respiratory motor pathway can be pharmacologically activated via adenosine receptors to restore respiratory function after cervical (C2) spinal cord hemisection that paralyzes the hemidiaphragm ipsilateral to injury. Although spinal phrenic motoneurons immunopositive for adenosine receptors have been demonstrated (C3–C5), it is unclear if adenosine receptor protein levels are altered after C2 hemisection and theophylline administration. Objective: To assess the effects of C2 spinal cord hemisection and theophylline administration on the expression of adenosine receptor proteins. Methods: Adenosine A1 and A2A receptor protein levels were assessed in adult rats classified as (a) noninjured and theophylline treated, (b) C2 hemisected, (c) C2 hemisected and administered theophylline orally (3× daily) for 3 days only, and (d) C2 hemisected and administered theophylline (3× daily for 3 days) and assessed 12 days after drug administration. Assessment of A1 protein levels was carried out via immunohistochemistry and A2A protein levels by densitometry. Results: Adenosine A1 protein levels decreased significantly (both ipsilateral and contralateral to injury) after C2 hemisection; however, the decrease was attenuated in hemisected and theophylline-treated animals. Attenuation in adenosine A1 receptor protein levels persisted when theophylline administration was stopped for 12 days prior to assessment. Adenosine A2A protein levels were unchanged by C2 hemisection; however, theophylline reduced the levels within the phrenic motoneurons. Furthermore, the decrease in A2A levels persisted 12 days after theophylline was withdrawn. Conclusion: Our findings suggest that theophylline mitigates the effects of C2 hemisection by attenuating the C2 hemisection–induced decrease in A1 protein levels. Furthermore, A2A protein levels are unaltered by C2 hemisection but decrease after continuous or interrupted theophylline

  4. Involvement of adenosine A1 and A2A receptors in the adenosinergic modulation of the discriminative-stimulus effects of cocaine and methamphetamine in rats.

    PubMed

    Justinova, Zuzana; Ferre, Sergi; Segal, Pavan N; Antoniou, Katerina; Solinas, Marcello; Pappas, Lara A; Highkin, Jena L; Hockemeyer, Jorg; Munzar, Patrik; Goldberg, Steven R

    2003-12-01

    Adenosine, by acting on adenosine A1 and A2A receptors, is known to antagonistically modulate dopaminergic neurotransmission. We have recently reported that nonselective adenosine receptor antagonists (caffeine and 3,7-dimethyl-1-propargylxanthine) can partially substitute for the discriminative-stimulus effects of methamphetamine. In the present study, by using more selective compounds, we investigated the involvement of A1 and A2A receptors in the adenosinergic modulation of the discriminative-stimulus effects of both cocaine and methamphetamine. The effects of the A1 receptor agonist N6-cyclopentyladenosine (CPA; 0.01-0.1 mg/kg) and antagonist 8-cyclopentyl-1,3-dimethylxanthine (CPT; 1.3-23.7 mg/kg) and the A2A receptor agonist 2-p-(2-carboxyethyl)phenethylamino-5'-N-ethylcarboxamidoadenosine hydrochloride (CGS 21680; 0.03-0.18 mg/kg) and antagonist 3-(3-hydroxypropyl)-8-(3-methoxystyryl)-7-methyl-1-propargylxanthin phosphate disodium salt (MSX-3; 1-56 mg/kg) were evaluated in rats trained to discriminate either 1 mg/kg methamphetamine or 10 mg/kg cocaine from saline under a fixed-ratio 10 schedule of food presentation. The A1 and A2A receptor antagonists (CPT and MSX-3) both produced high levels of drug-lever selection when substituted for either methamphetamine or cocaine and significantly shifted dose-response curves of both psychostimulants to the left. Unexpectedly, the A2A receptor agonist CGS 21680 also produced drug-appropriate responding (although at lower levels) when substituted for the cocaine-training stimulus, and both CGS 21680 and the A1 receptor agonist CPA significantly shifted the cocaine dose-response curve to the left. In contrast, both agonists did not produce significant levels of drug-lever selection when substituted for the methamphetamine-training stimulus and failed to shift the methamphetamine dose-response curve. Therefore, adenosine A1 and A2A receptors appear to play important but differential roles in the modulation of the

  5. Histamine H3 Receptor Activation Counteracts Adenosine A2A Receptor-Mediated Enhancement of Depolarization-Evoked [3H]-GABA Release from Rat Globus Pallidus Synaptosomes

    PubMed Central

    2014-01-01

    High levels of histamine H3 receptors (H3Rs) are found in the globus pallidus (GP), a neuronal nucleus in the basal ganglia involved in the control of motor behavior. By using rat GP isolated nerve terminals (synaptosomes), we studied whether H3R activation modified the previously reported enhancing action of adenosine A2A receptor (A2AR) stimulation on depolarization-evoked [3H]-GABA release. At 3 and 10 nM, the A2AR agonist CGS-21680 enhanced [3H]-GABA release induced by high K+ (20 mM) and the effect of 3 nM CGS-21680 was prevented by the A2AR antagonist ZM-241385 (100 nM). The presence of presynaptic H3Rs was confirmed by the specific binding of N-α-[methyl-3H]-histamine to membranes from GP synaptosomes (maximum binding, Bmax, 1327 ± 79 fmol/mg protein; dissociation constant, Kd, 0.74 nM), which was inhibited by the H3R ligands immepip, clobenpropit, and A-331440 (inhibition constants, Ki, 0.28, 8.53, and 316 nM, respectively). Perfusion of synaptosomes with the H3R agonist immepip (100 nM) had no effect on K+-evoked [3H]-GABA release, but inhibited the stimulatory action of A2AR activation. In turn, the effect of immepip was blocked by the H3R antagonist clobenpropit, which had no significant effect of its own on K+-induced [3H]-GABA release. These data indicate that H3R activation selectively counteracts the facilitatory action of A2AR stimulation on GABA release from striato-pallidal projections. PMID:24884070

  6. The androgen receptor gene mutations database.

    PubMed

    Patterson, M N; Hughes, I A; Gottlieb, B; Pinsky, L

    1994-09-01

    The androgen receptor gene mutations database is a comprehensive listing of mutations published in journals and meetings proceedings. The majority of mutations are point mutations identified in patients with androgen insensitivity syndrome. Information is included regarding the phenotype, the nature and location of the mutations, as well as the effects of the mutations on the androgen binding activity of the receptor. The current version of the database contains 149 entries, of which 114 are unique mutations. The database is available from EMBL (NetServ@EMBL-Heidelberg.DE) or as a Macintosh Filemaker file (mc33001@musica.mcgill.ca).

  7. Synthesis and pharmacological evaluation of dual acting ligands targeting the adenosine A2A and dopamine D2 receptors for the potential treatment of Parkinson's disease.

    PubMed

    Jörg, Manuela; May, Lauren T; Mak, Frankie S; Lee, Kiew Ching K; Miller, Neil D; Scammells, Peter J; Capuano, Ben

    2015-01-22

    A relatively new strategy in drug discovery is the development of dual acting ligands. These molecules are potentially able to interact at two orthosteric binding sites of a heterodimer simultaneously, possibly resulting in enhanced subtype selectivity, higher affinity, enhanced or modified physiological response, and reduced reliance on multiple drug administration regimens. In this study, we have successfully synthesized a series of classical heterobivalent ligands as well as a series of more integrated and "drug-like" dual acting molecules, incorporating ropinirole as a dopamine D2 receptor agonist and ZM 241385 as an adenosine A2A receptor antagonist. The best compounds of our series maintained the potency of the original pharmacophores at both receptors (adenosine A2A and dopamine D2). In addition, the integrated dual acting ligands also showed promising results in preliminary blood-brain barrier permeability tests, whereas the classical heterobivalent ligands are potentially more suited as pharmacological tools.

  8. The caffeine-binding adenosine A2A receptor induces age-like HPA-axis dysfunction by targeting glucocorticoid receptor function.

    PubMed

    Batalha, Vânia L; Ferreira, Diana G; Coelho, Joana E; Valadas, Jorge S; Gomes, Rui; Temido-Ferreira, Mariana; Shmidt, Tatiana; Baqi, Younis; Buée, Luc; Müller, Christa E; Hamdane, Malika; Outeiro, Tiago F; Bader, Michael; Meijsing, Sebastiaan H; Sadri-Vakili, Ghazaleh; Blum, David; Lopes, Luísa V

    2016-08-11

    Caffeine is associated with procognitive effects in humans by counteracting overactivation of the adenosine A2A receptor (A2AR), which is upregulated in the human forebrain of aged and Alzheimer's disease (AD) patients. We have previously shown that an anti-A2AR therapy reverts age-like memory deficits, by reestablishment of the hypothalamic-pituitary-adrenal (HPA) axis feedback and corticosterone circadian levels. These observations suggest that A2AR over-activation and glucocorticoid dysfunction are key events in age-related hippocampal deficits; but their direct connection has never been explored. We now show that inducing A2AR overexpression in an aging-like profile is sufficient to trigger HPA-axis dysfunction, namely loss of plasmatic corticosterone circadian oscillation, and promotes reduction of GR hippocampal levels. The synaptic plasticity and memory deficits triggered by GR in the hippocampus are amplified by A2AR over-activation and were rescued by anti-A2AR therapy; finally, we demonstrate that A2AR act on GR nuclear translocation and GR-dependent transcriptional regulation. We provide the first demonstration that A2AR is a major regulator of GR function and that this functional interconnection may be a trigger to age-related memory deficits. This supports the idea that the procognitive effects of A2AR antagonists, namely caffeine, on Alzheimer's and age-related cognitive impairments may rely on its ability to modulate GR actions.

  9. The caffeine-binding adenosine A2A receptor induces age-like HPA-axis dysfunction by targeting glucocorticoid receptor function

    PubMed Central

    Batalha, Vânia L.; Ferreira, Diana G.; Coelho, Joana E.; Valadas, Jorge S.; Gomes, Rui; Temido-Ferreira, Mariana; Shmidt, Tatiana; Baqi, Younis; Buée, Luc; Müller, Christa E.; Hamdane, Malika; Outeiro, Tiago F.; Bader, Michael; Meijsing, Sebastiaan H.; Sadri-Vakili, Ghazaleh; Blum, David; Lopes, Luísa V.

    2016-01-01

    Caffeine is associated with procognitive effects in humans by counteracting overactivation of the adenosine A2A receptor (A2AR), which is upregulated in the human forebrain of aged and Alzheimer’s disease (AD) patients. We have previously shown that an anti-A2AR therapy reverts age-like memory deficits, by reestablishment of the hypothalamic-pituitary-adrenal (HPA) axis feedback and corticosterone circadian levels. These observations suggest that A2AR over-activation and glucocorticoid dysfunction are key events in age-related hippocampal deficits; but their direct connection has never been explored. We now show that inducing A2AR overexpression in an aging-like profile is sufficient to trigger HPA-axis dysfunction, namely loss of plasmatic corticosterone circadian oscillation, and promotes reduction of GR hippocampal levels. The synaptic plasticity and memory deficits triggered by GR in the hippocampus are amplified by A2AR over-activation and were rescued by anti-A2AR therapy; finally, we demonstrate that A2AR act on GR nuclear translocation and GR-dependent transcriptional regulation. We provide the first demonstration that A2AR is a major regulator of GR function and that this functional interconnection may be a trigger to age-related memory deficits. This supports the idea that the procognitive effects of A2AR antagonists, namely caffeine, on Alzheimer’s and age-related cognitive impairments may rely on its ability to modulate GR actions. PMID:27510168

  10. Adenosine A2A receptor antagonists improve deficits in initiation of movement and sensory motor integration in the unilateral 6-hydroxydopamine rat model of Parkinson's disease.

    PubMed

    Pinna, Annalisa; Pontis, Silvia; Borsini, Franco; Morelli, Micaela

    2007-08-01

    Evidence obtained in rodent and primate models of Parkinson's disease (PD) and preliminary clinical trials, indicates that adenosine A(2A) receptor antagonists might represent a promising nondopaminergic therapeutic tool for the treatment of PD. Those studies demonstrated the ability of adenosine A(2A) receptor antagonists to potentiate l-dopa-mediated motor improvement, whereas very little is known about counteraction of specific motor deficits and on the effects of these compounds when administered alone. To this aim we evaluated the effects of different adenosine A(2A) receptor antagonists on initiation of movement deficits, gait impairment and sensory-motor deficits, induced in rats by a unilateral 6-hydroxydopamine lesion of dopaminergic nigrostriatal neurons. The following tests were used: (1) initiation time of stepping; (2) adjusting step (stepping with forelimb was measured as the forelimb was dragged laterally); (3) vibrissae-elicited forelimb placing (as index of sensory-motor integration deficits). Acute administration of the A(2A) receptor antagonists SCH 58261 (5 mg/kg i.p.) and ST 1535 (20 mg/kg i.p.) similarly to l-dopa (6 mg/kg i.p.) counteracted the impairments in the initiation time of stepping test, in the adjusting step and in the vibrissae-elicited forelimb placing induced by the lesion. The intensity of the effect was l-dopa > SCH 58261 > ST 1535. The results provide the first evidence that blockade of A(2A) receptors is effective in antagonizing specific motor deficit induced by DA neuron degeneration, such as initiation of movement and sensory-motor integration deficits, even without l-dopa combined administration.

  11. Differential effects of presynaptic versus postsynaptic adenosine A2A receptor blockade on Δ9-tetrahydrocannabinol (THC) self-administration in squirrel monkeys.

    PubMed

    Justinová, Zuzana; Redhi, Godfrey H; Goldberg, Steven R; Ferré, Sergi

    2014-05-07

    Different doses of an adenosine A2A receptor antagonist MSX-3 [3,7-dihydro-8-[(1E)-2-(3-ethoxyphenyl)ethenyl]-7 methyl-3-[3-(phosphooxy)propyl-1-(2 propynil)-1H-purine-2,6-dione] were found previously to either decrease or increase self-administration of cannabinoids delta-9-tetrahydrocannabinol (THC) or anandamide in squirrel monkeys. It was hypothesized that the decrease observed with a relatively low dose of MSX-3 was related to blockade of striatal presynaptic A2A receptors that modulate glutamatergic neurotransmission, whereas the increase observed with a higher dose was related to blockade of postsynaptic A2A receptors localized in striatopallidal neurons. This hypothesis was confirmed in the present study by testing the effects of the preferential presynaptic and postsynaptic A2A receptor antagonists SCH-442416 [2-(2-furanyl)-7-[3-(4-methoxyphenyl)propyl]-7H-pyrazolo[4,3-e][1,2,4]triazolo[1,5-c]pyrimidin-5-amine] and KW-6002 [(E)-1, 3-diethyl-8-(3,4-dimethoxystyryl)-7-methyl-3,7-dihydro-1H-purine-2,6-dione], respectively, in squirrel monkeys trained to intravenously self-administer THC. SCH-442416 produced a significant shift to the right of the THC self-administration dose-response curves, consistent with antagonism of the reinforcing effects of THC. Conversely, KW-6002 produced a significant shift to the left, consistent with potentiation of the reinforcing effects of THC. These results show that selectively blocking presynaptic A2A receptors could provide a new pharmacological approach to the treatment of marijuana dependence and underscore corticostriatal glutamatergic neurotransmission as a possible main mechanism involved in the rewarding effects of THC.

  12. Initial Evaluation of a Novel Adenosine A2A Receptor Ligand, (11)C-Preladenant, in Healthy Human Subjects.

    PubMed

    Sakata, Muneyuki; Ishibashi, Kenji; Imai, Masamichi; Wagatsuma, Kei; Ishii, Kenji; Zhou, Xiaoyun; de Vries, Erik F; Elsinga, Philip H; Ishiwata, Kiichi; Toyohara, Jun

    2017-03-09

    (11)C-Preladenant is a novel selective antagonist for mapping of cerebral adenosine A2A receptors (A2ARs) by positron emission tomography (PET). This is a first-in-human study to examine the safety, radiation dosimetry, and brain imaging of (11)C-preladenant in healthy human subjects. Methods: Dynamic (11)C-preladenant PET scans (90 min) were performed in 5 healthy male subjects. During the scan, arterial blood was sampled at various time intervals, and the fraction of the parent compound in plasma was determined. For anatomic coregistration, T1-weighted magnetic resonance imaging was performed. The total distribution volume (VT) was estimated using one- and two-tissue compartment models (1T and 2T, respectively). Distribution volume ratio (DVR) was calculated from VT of target and reference region, and obtained with a non-invasive Logan graphical reference tissue method (LGRM) (t* = 30 min). The applicability of a shortened protocol as an alternative to the 90 min PET scan was investigated. Tracer biodistribution and dosimetry were determined in 3 healthy male subjects, using serial whole-body PET scan acquired over 2 h post (11)C-preladenant injection. Results: There were no serious adverse events in any of the subjects throughout the study period. (11)C-Preladenat readily entered the brain, with a peak uptake in the putamen and head of the caudate nucleus 30-40 min after tracer injection. Other brain regions showed rapid clearance of radioactivity. The regional distribution of (11)C-preladenant was consistent with known A2AR densities in the brain. At pseudoequilibrium (reached at 40 min after injection), stable target-to-cerebellar cortex ratios of around 3.8-10.0 were obtained. The 2T fit better than the 1T in the low-density A2AR regions. In contrast, there were no significant differences between 1T and 2T in the high A2AR density regions. DVRs in putamen and head of the caudate nucleus were around 3.8-10.3 when estimated using a LGRM with cerebellum as the

  13. Adenosine A2A receptor antagonism and genetic deletion attenuate the effects of dopamine D2 antagonism on effort-based decision making in mice.

    PubMed

    Pardo, M; Lopez-Cruz, L; Valverde, O; Ledent, C; Baqi, Y; Müller, C E; Salamone, J D; Correa, M

    2012-04-01

    Brain dopamine (DA) and adenosine interact in the regulation of behavioral activation and effort-related processes. In the present studies, a T-maze task was developed in mice for the assessment of effort-related decision making. With this task, the two arms of the maze have different reinforcement densities, and a vertical barrier is positioned in the arm with the higher density (HD), presenting the animal with an effort-related challenge. Under control conditions mice prefer the HD arm, and climb the barrier to obtain the larger amount of food. The DA D(2) receptor antagonist haloperidol decreased selection of the HD arm and increased selection of the arm with the low density of reinforcement. However, the HD arm was still the preferred choice in haloperidol-treated mice trained with barriers in both arms. Pre-feeding the mice to reduce food motivation dramatically increased omissions, an effect that was distinct from the actions of haloperidol. Co-administration of theophylline, a nonselective adenosine receptor antagonist, partially reversed the effects of haloperidol. This effect seems to be mediated by the A(2A) receptor but not the A(1) receptor, since the A(2A) antagonist MSX-3, but not the A(1) antagonist CPT, dose dependently reversed the effects of haloperidol on effort-related choice and on c-Fos expression in the dorsal striatum and nucleus accumbens. In addition, adenosine A(2A) receptor knockout mice were resistant to the effects of haloperidol on effort-related choice in the maze. These results indicate that DA D(2) and adenosine A(2A) receptors interact to regulate effort-related decision making and effort expenditure in mice.

  14. Social regulation of cortisol receptor gene expression

    PubMed Central

    Korzan, Wayne J.; Grone, Brian P.; Fernald, Russell D.

    2014-01-01

    In many social species, individuals influence the reproductive capacity of conspecifics. In a well-studied African cichlid fish species, Astatotilapia burtoni, males are either dominant (D) and reproductively competent or non-dominant (ND) and reproductively suppressed as evidenced by reduced gonadotropin releasing hormone (GnRH1) release, regressed gonads, lower levels of androgens and elevated levels of cortisol. Here, we asked whether androgen and cortisol levels might regulate this reproductive suppression. Astatotilapia burtoni has four glucocorticoid receptors (GR1a, GR1b, GR2 and MR), encoded by three genes, and two androgen receptors (ARα and ARβ), encoded by two genes. We previously showed that ARα and ARβ are expressed in GnRH1 neurons in the preoptic area (POA), which regulates reproduction, and that the mRNA levels of these receptors are regulated by social status. Here, we show that GR1, GR2 and MR mRNAs are also expressed in GnRH1 neurons in the POA, revealing potential mechanisms for both androgens and cortisol to influence reproductive capacity. We measured AR, MR and GR mRNA expression levels in a microdissected region of the POA containing GnRH1 neurons, comparing D and ND males. Using quantitative PCR (qPCR), we found D males had higher mRNA levels of ARα, MR, total GR1a and GR2 in the POA compared with ND males. In contrast, ND males had significantly higher levels of GR1b mRNA, a receptor subtype with a reduced transcriptional response to cortisol. Through this novel regulation of receptor type, neurons in the POA of an ND male will be less affected by the higher levels of cortisol typical of low status, suggesting GR receptor type change as a potential adaptive mechanism to mediate high cortisol levels during social suppression. PMID:25013108

  15. A(2A) adenosine receptors are differentially modulated by pharmacological treatments in rheumatoid arthritis patients and their stimulation ameliorates adjuvant-induced arthritis in rats.

    PubMed

    Vincenzi, Fabrizio; Padovan, Melissa; Targa, Martina; Corciulo, Carmen; Giacuzzo, Sarah; Merighi, Stefania; Gessi, Stefania; Govoni, Marcello; Borea, Pier Andrea; Varani, Katia

    2013-01-01

    A(2A) adenosine receptors (ARs) play a key role in the inhibition of the inflammatory process. The purpose of this study was to evaluate the modulation of A(2A)ARs in rheumatoid arthritis (RA) patients after different pharmacological treatments and to investigate the effect of A(2A)AR stimulation in a rat model of arthritis. We investigated A(2A)AR density and functionality in RA progression by using a longitudinal study in RA patients before and after methotrexate (MTX), anti-TNFα agents or rituximab treatments. A(2A)ARs were analyzed by saturation binding assays in lymphocytes from RA patients throughout the 24-month study timeframe. In an adjuvant-induced arthritis model in rats we showed the efficacy of the A(2A)AR agonist, CGS 21680 in comparison with standard therapies by means of paw volume assessment, radiographic and ultrasonographic imaging. Arthritic-associated pain was investigated in mechanical allodynia and thermal hyperalgesia tests. IL-10 release following A(2A)AR stimulation in lymphocytes from RA patients and in serum from arthritic rats was measured. In lymphocytes obtained from RA patients, the A(2A)AR up-regulation was gradually reduced in function of the treatment time and the stimulation of these receptors mediated a significant increase of IL-10 production. In the same cells, CGS 21680 did not affected cell viability and did not produced cytotoxic effects. The A(2A)AR agonist CGS 21680 was highly effective, as suggested by the marked reduction of clinical signs, in rat adjuvant-induced arthritis and associated pain. This study highlighted that A(2A)AR agonists represent a physiological-like therapeutic alternative for RA treatment as suggested by the anti-inflammatory role of A(2A)ARs in lymphocytes from RA patients. The effectiveness of A(2A)AR stimulation in a rat model of arthritis supported the role of A(2A)AR agonists as potential pharmacological treatment for RA.

  16. Protein kinase A mediates adenosine A2a receptor modulation of neurotransmitter release via synapsin I phosphorylation in cultured cells from medulla oblongata.

    PubMed

    Matsumoto, Joao Paulo Pontes; Almeida, Marina Gomes; Castilho-Martins, Emerson Augusto; Costa, Maisa Aparecida; Fior-Chadi, Debora Rejane

    2014-08-01

    Synaptic transmission is an essential process for neuron physiology. Such process is enabled in part due to modulation of neurotransmitter release. Adenosine is a synaptic modulator of neurotransmitter release in the Central Nervous System, including neurons of medulla oblongata, where several nuclei are involved with neurovegetative reflexes. Adenosine modulates different neurotransmitter systems in medulla oblongata, specially glutamate and noradrenaline in the nucleus tractussolitarii, which are involved in hypotensive responses. However, the intracellular mechanisms involved in this modulation remain unknown. The adenosine A2a receptor modulates neurotransmitter release by activating two cAMP protein effectors, the protein kinase A and the exchange protein activated by cAMP. Therefore, an in vitro approach (cultured cells) was carried out to evaluate modulation of neurotransmission by adenosine A2a receptor and the signaling intracellular pathway involved. Results show that the adenosine A2a receptor agonist, CGS 21680, increases neurotransmitter release, in particular, glutamate and noradrenaline and such response is mediated by protein kinase A activation, which in turn increased synapsin I phosphorylation. This suggests a mechanism of A2aR modulation of neurotransmitter release in cultured cells from medulla oblongata of Wistar rats and suggest that protein kinase A mediates this modulation of neurotransmitter release via synapsin I phosphorylation.

  17. Role and Function of A2A and A₃ Adenosine Receptors in Patients with Ankylosing Spondylitis, Psoriatic Arthritis and Rheumatoid Arthritis.

    PubMed

    Ravani, Annalisa; Vincenzi, Fabrizio; Bortoluzzi, Alessandra; Padovan, Melissa; Pasquini, Silvia; Gessi, Stefania; Merighi, Stefania; Borea, Pier Andrea; Govoni, Marcello; Varani, Katia

    2017-03-24

    Rheumatoid arthritis (RA), ankylosing spondylitis (AS) and psoriatic arthritis (PsA) are chronic inflammatory rheumatic diseases that affect joints, causing debilitating pain and disability. Adenosine receptors (ARs) play a key role in the mechanism of inflammation, and the activation of A2A and A₃AR subtypes is often associated with a reduction of the inflammatory status. The aim of this study was to investigate the involvement of ARs in patients suffering from early-RA (ERA), RA, AS and PsA. Messenger RNA (mRNA) analysis and saturation binding experiments indicated an upregulation of A2A and A₃ARs in lymphocytes obtained from patients when compared with healthy subjects. A2A and A₃AR agonists inhibited nuclear factor κ-light-chain-enhancer of activated B cells (NF-κB) activation and reduced inflammatory cytokines release, such as tumor necrosis factor-α (TNF-α), interleukin (IL)-1β and IL-6. Moreover, A2A and A₃AR activation mediated a reduction of metalloproteinases (MMP)-1 and MMP-3. The effect of the agonists was abrogated by selective antagonists demonstrating the direct involvement of these receptor subtypes. Taken together, these data confirmed the involvement of ARs in chronic autoimmune rheumatic diseases highlighting the possibility to exploit A2A and A₃ARs as therapeutic targets, with the aim to limit the inflammatory responses usually associated with RA, AS and PsA.

  18. Suppression of adenosine 2a receptor (A2aR)-mediated adenosine signaling improves disease phenotypes in a mouse model of amyotrophic lateral sclerosis.

    PubMed

    Ng, Seng Kah; Higashimori, Haruki; Tolman, Michaela; Yang, Yongjie

    2015-05-01

    Amyotrophic lateral sclerosis (ALS) is a rapidly progressing neurodegenerative disease in which the majority of upper and lower motor neurons are degenerated. Despite intensive efforts to identify drug targets and develop neuroprotective strategies, effective therapeutics for ALS remains unavailable. The identification and characterization of novel targets and pathways remain crucial in the development of ALS therapeutics. Adenosine is a major neuromodulator that actively regulates synaptic transmission. Interestingly, adenosine levels are significantly elevated in the cerebrospinal fluid (CSF) of progressing human ALS patients. In the current study, we showed that adenosine 2a receptor (A2aR), but not adenosine 1 receptor (A1R), is highly enriched in spinal (motor) neurons. A2aR expression is also selectively increased at the symptomatic onset in the spinal cords of SOD1G93A mice and end-stage human ALS spinal cords. Interestingly, we found that direct adenosine treatment is sufficient to induce embryonic stem cell-derived motor neuron (ESMN) cell death in cultures. Subsequent pharmacological inhibition and partial genetic ablation of A2aR (A2aR(+/-)) significantly protect ESMN from SOD1G93A(+) astrocyte-induced cell death and delay disease progression of SOD1G93A mice. Taken together, our results provide compelling novel evidence that A2aR-mediated adenosine signaling contributes to the selective spinal motor neuron degeneration observed in the SOD1G93A mouse model of ALS.

  19. Suppression of adenosine 2a receptor (A2aR)-mediated adenosine signaling improves disease phenotypes in a mouse model of amyotrophic lateral sclerosis

    PubMed Central

    Ng, Seng kah; Higashimori, Haruki; Tolman, Michaela; Yang, Yongjie

    2017-01-01

    Amyotrophic lateral sclerosis (ALS) is a rapidly progressing neurodegenerative disease in which the majority of upper and lower motor neurons are degenerated. Despite intensive efforts to identify drug targets and develop neuroprotective strategies, effective therapeutics for ALS remains unavailable. The identification and characterization of novel targets and pathways remain crucial in the development of ALS therapeutics. Adenosine is a major neuromodulator that actively regulates synaptic transmission. Interestingly, adenosine levels are significantly elevated in the cerebrospinal fluid (CSF) of progressing human ALS patients. In the current study, we showed that adenosine 2a receptor (A2aR), but not adenosine 1 receptor (A1R), is highly enriched in spinal (motor) neurons. A2aR expression is also selectively increased at the symptomatic onset in the spinal cords of SOD1G93A mice and end-stage human ALS spinal cords. Interestingly, we found that direct adenosine treatment is sufficient to induce embryonic stem cell-derived motor neuron (ESMN) cell death in cultures. Subsequent pharmacological inhibition and partial genetic ablation of A2aR (A2aR+/−) significantly protect ESMN from SOD1G93A+ astrocyte-induced cell death and delay disease progression of SOD1G93A mice. Taken together, our results provide compelling novel evidence that A2aR-mediated adenosine signaling contributes to the selective spinal motor neuron degeneration observed in the SOD1G93A mouse model of ALS. PMID:25779930

  20. Creatine, similarly to ketamine, affords antidepressant-like effects in the tail suspension test via adenosine A₁ and A2A receptor activation.

    PubMed

    Cunha, Mauricio P; Pazini, Francis L; Rosa, Julia M; Ramos-Hryb, Ana B; Oliveira, Ágatha; Kaster, Manuella P; Rodrigues, Ana Lúcia S

    2015-06-01

    The benefits of creatine supplementation have been reported in a broad range of central nervous systems diseases, including depression. A previous study from our group demonstrated that creatine produces an antidepressant-like effect in the tail suspension test (TST), a predictive model of antidepressant activity. Since depression is associated with a dysfunction of the adenosinergic system, we investigated the involvement of adenosine A1 and A2A receptors in the antidepressant-like effect of creatine in the TST. The anti-immobility effect of creatine (1 mg/kg, po) or ketamine (a fast-acting antidepressant, 1 mg/kg, ip) in the TST was prevented by pretreatment of mice with caffeine (3 mg/kg, ip, nonselective adenosine receptor antagonist), 8-cyclopentyl-1,3-dipropylxanthine (DPCPX) (2 mg/kg, ip, selective adenosine A1 receptor antagonist), and 4-(2-[7-amino-2-{2-furyl}{1,2,4}triazolo-{2,3-a}{1,3,5}triazin-5-yl-amino]ethyl)-phenol (ZM241385) (1 mg/kg, ip, selective adenosine A2A receptor antagonist). In addition, the combined administration of subeffective doses of creatine and adenosine (0.1 mg/kg, ip, nonselective adenosine receptor agonist) or inosine (0.1 mg/kg, ip, nucleoside formed by the breakdown of adenosine) reduced immobility time in the TST. Moreover, the administration of subeffective doses of creatine or ketamine combined with N-6-cyclohexyladenosine (CHA) (0.05 mg/kg, ip, selective adenosine A1 receptor agonist), N-6-[2-(3,5-dimethoxyphenyl)-2-(methylphenyl)ethyl]adenosine (DPMA) (0.1 mg/kg, ip, selective adenosine A2A receptor agonist), or dipyridamole (0.1 μg/mouse, icv, adenosine transporter inhibitor) produced a synergistic antidepressant-like effect in the TST. These results indicate that creatine, similarly to ketamine, exhibits antidepressant-like effect in the TST probably mediated by the activation of both adenosine A1 and A2A receptors, further reinforcing the potential of targeting the purinergic system to the management of mood disorders.

  1. The Evolution of Mammalian Olfactory Receptor Genes

    PubMed Central

    Issel-Tarver, L.; Rine, J.

    1997-01-01

    We performed a comparative study of four subfamilies of olfactory receptor genes first identified in the dog to assess changes in the gene family during mammalian evolution, and to begin linking the dog genetic map to that of humans. The human subfamilies were localized to chromosomes 7, 11, and 19. The two subfamilies that were tightly linked in the dog genome were also tightly linked in the human genome. The four subfamilies were compared in human (primate), horse (perissodactyl), and a variety of artiodactyls and carnivores. Some changes in gene number were detected, but overall subfamily size appeared to have been established before the divergence of these mammals 60-100 million years ago. PMID:9017400

  2. Physiological roles of A1 and A2A adenosine receptors in regulating heart rate, body temperature, and locomotion as revealed using knockout mice and caffeine.

    PubMed

    Yang, Jiang-Ning; Chen, Jiang-Fan; Fredholm, Bertil B

    2009-04-01

    Heart rate (HR), body temperature (Temp), locomotor activity (LA), and oxygen consumption (O(2)C) were studied in awake mice lacking one or both of the adenosine A(1) or A(2A) receptors (A(1)R or A(2A)R, respectively) using telemetry and respirometry, before and after caffeine administration. All parameters were lower during day than night and higher in females than males. When compared with wild-type (WT) littermates, HR was higher in male A(1)R knockout (A(1)RKO) mice but lower in A(2A)RKO mice and intermediate in A(1)-A(2A)R double KO mice. A single dose of an unselective beta-blocker (timolol; 1 mg/kg) abolished the HR differences between these genotypes. Deletion of A(1)Rs had little effect on Temp, whereas deletion of A(2A)Rs increased it in females and decreased it in males. A(1)-A(2A)RKO mice had lower Temp than WT mice. LA was unaltered in A(1)RKO mice and lower in A(2A)RKO and A(1)-A(2A)RKO mice than in WT mice. Caffeine injection increased LA but only in mice expressing A(2A)R. Caffeine ingestion also increased LA in an A(2A)R-dependent manner in male mice. Caffeine ingestion significantly increased O(2)C in WT mice, but less in the different KO mice. Injection of 30 mg/kg caffeine decreased Temp, especially in KO mice, and hence in a manner unrelated to A(1)R or A(2A)R blockade. Selective A(2B) antagonism had little or no effect. Thus A(1)R and A(2A)R influence HR, Temp, LA, and O(2)C in mice in a sex-dependent manner, indicating effects of endogenous adenosine. The A(2A)R plays an important role in the modulation of O(2)C and LA by acute and chronic caffeine administration. There is also evidence for effects of higher doses of caffeine being independent of both A(1)R and A(2A)R.

  3. The adenosine A2A receptor antagonist ZM241385 enhances neuronal survival after oxygen-glucose deprivation in rat CA1 hippocampal slices

    PubMed Central

    Pugliese, AM; Traini, C; Cipriani, S; Gianfriddo, M; Mello, T; Giovannini, MG; Galli, A; Pedata, F

    2009-01-01

    Background and purpose: Activation of adenosine A2A receptors in the CA1 region of rat hippocampal slices during oxygen-glucose deprivation (OGD), a model of cerebral ischaemia, was investigated. Experimental approach: We made extracellular recordings of CA1 field excitatory postsynaptic potentials (fepsps) followed by histochemical and immunohistochemical techniques coupled to Western blots. Key results: OGD (7 or 30 min duration) elicited an irreversible loss of fepsps invariably followed by the appearance of anoxic depolarization (AD), an unambiguous sign of neuronal damage. The application of the selective adenosine A2A receptor antagonist, ZM241385 (4-(2-[7-amino-2-{2-furyl}{1,2,4}triazolo{2,3-a}{1,3,5}triazin-5-ylamino]ethyl)phenol; 100–500 nmol·L−1) prevented or delayed AD appearance induced by 7 or 30 min OGD and protected from the irreversible fepsp depression elicited by 7 min OGD. Two different selective adenosine A2A receptor antagonists, SCH58261 and SCH442416, were less effective than ZM241385 during 7 min OGD. The extent of CA1 cell injury was assessed 3 h after the end of 7 min OGD by propidium iodide. Substantial CA1 pyramidal neuronal damage occurred in untreated slices, exposed to OGD, whereas injury was significantly prevented by 100 nmol·L−1 ZM241385. Glial fibrillary acid protein (GFAP) immunostaining showed that 3 h after 7 min OGD, astrogliosis was appreciable. Western blot analysis indicated an increase in GFAP 30 kDa fragment which was significantly reduced by treatment with 100 nmol·L−1 ZM241385. Conclusions and implications: In the CA1 hippocampus, antagonism of A2A adenosine receptors by ZM241385 was protective during OGD (a model of cerebral ischaemia) by delaying AD appearance, decreasing astrocyte activation and improving neuronal survival. PMID:19422385

  4. Caffeine consumption prevents memory impairment, neuronal damage, and adenosine A2A receptors upregulation in the hippocampus of a rat model of sporadic dementia.

    PubMed

    Espinosa, Janaína; Rocha, Andreia; Nunes, Fernanda; Costa, Marcelo S; Schein, Vanessa; Kazlauckas, Vanessa; Kalinine, Eduardo; Souza, Diogo O; Cunha, Rodrigo A; Porciúncula, Lisiane O

    2013-01-01

    Intracerebroventricular (icv) streptozotocin (STZ) administration induces pathological and behavioral alterations similar to those observed in Alzheimer's disease (AD) and is thus considered an experimental model of sporadic AD. Since caffeine (an adenosine receptor antagonist) and selective antagonists of adenosine A2A receptors modify the course of memory impairment in different amyloid-β-based experimental models of AD, we now tested the impact of caffeine on STZ-induced dementia and associated neurodegeneration in the hippocampus as well as on the expression and density of adenosine receptors. Adult male rats received a bilateral infusion of saline or STZ (3 mg/kg, icv), which triggered memory deficits after four weeks, as gauged by impaired object recognition memory. This was accompanied by a reduced NeuN immunoreactivity in the hippocampal CA1 region and an increased expression and density of adenosine A2A receptors (A2AR), but not A1R, in the hippocampus. Caffeine consumption (1 g/L in the drinking water starting 2 weeks before the STZ challenge) prevented the STZ-induced memory impairment and neurodegeneration as well as the upregulation of A2AR. These findings provide the first demonstration that caffeine prevents sporadic dementia and implicate the control of central A2AR as its likely mechanism of action.

  5. Engineering AAV receptor footprints for gene therapy.

    PubMed

    Madigan, Victoria J; Asokan, Aravind

    2016-06-01

    Adeno-associated viruses (AAV) are currently at the forefront of human gene therapy clinical trials as recombinant vectors. Significant progress has been made in elucidating the structure, biology and tropisms of different naturally occurring AAV isolates in the past decade. In particular, a spectrum of AAV capsid interactions with host receptors have been identified and characterized. These studies have enabled a better understanding of key determinants of AAV cell recognition and entry in different hosts. This knowledge is now being applied toward engineering new, lab-derived AAV capsids with favorable transduction profiles. The current review conveys a structural perspective of capsid-glycan interactions and provides a roadmap for generating synthetic strains by engineering AAV receptor footprints.

  6. Opposite effects of the A2A receptor agonist CGS21680 in the striatum of Huntington's disease versus wild-type mice.

    PubMed

    Martire, Alberto; Calamandrei, Gemma; Felici, Fabio; Scattoni, Maria Luisa; Lastoria, Giusi; Domenici, Maria Rosaria; Tebano, Maria Teresa; Popoli, Patrizia

    2007-04-24

    Huntington's disease (HD) is an inherited neurodegenerative disorder. Adenosine A(2A) receptors (A(2A)Rs) are involved in excitotoxic/neurodegenerative processes, and A(2A)R ligands may be neuroprotective in models of HD. However, changes in the transcription, expression and function of A(2A)Rs have been reported to occur in HD models. The aim of the present work was to verify whether A(2A)R-mediated effects are altered in the striatum of transgenic HD (R6/2) versus wild-type (WT) mice. Extracellular field potentials (FPs) were recorded in corticostriatal slices from R6/2 mice in early (7-8 weeks) or frankly (12-13 weeks) symptomatic phases, and age-matched WT. In 12-13 weeks aged WT animals, the application of 75 microM NMDA induced a transient disappearance of the FP followed by an almost complete recovery at washout. In slices from HD mice, the mean FP recovery was significantly reduced (P<0.01 versus WT). A(2A)R activation oppositely modulated NMDA-induced toxicity in the striatum of HD versus WT mice. Indeed, the A(2A)R agonist CGS21680 reduced the FP recovery in slices from WT mice, while it significantly increased it in slices from R6/2 mice. In early symptomatic (7-8 weeks) mice, no differences were observed between WT and HD animals in terms of basal synaptic transmission and response to NMDA. At the same age, the behavioural effects elicited by CGS21680 were qualitatively identical in WT and HD mice. These findings may have very important implications for the neuroprotective potential of A(2A)R ligands in HD.

  7. Caffeine promotes anti-tumor immune response during tumor initiation: Involvement of the adenosine A2A receptor.

    PubMed

    Eini, Hadar; Frishman, Valeria; Yulzari, Robert; Kachko, Leonid; Lewis, Eli C; Chaimovitz, Cidio; Douvdevani, Amos

    2015-11-01

    Epidemiologic studies depict a negative correlation between caffeine consumption and incidence of tumors in humans. The main pharmacological effects of caffeine are mediated by antagonism of the adenosine receptor, A2AR. Here, we examine whether the targeting of A2AR by caffeine plays a role in anti-tumor immunity. In particular, the effects of caffeine are studied in wild-type and A2AR knockout (A2AR(-/-)) mice. Tumor induction was achieved using the carcinogen 3-methylcholanthrene (3-MCA). Alternatively, tumor cells, comprised of 3-MCA-induced transformed cells or B16 melanoma cells, were inoculated into animal footpads. Cytokine release was determined in a mixed lymphocyte tumor reaction (MLTR). According to our findings, caffeine-consuming mice (0.1% in water) developed tumors at a lower rate compared to water-consuming mice (14% vs. 53%, respectively, p=0.0286, n=15/group). Within the caffeine-consuming mice, tumor-free mice displayed signs of autoimmune alopecia and pronounced leukocyte recruitment intocarcinogen injection sites. Similarly, A2AR(-/-) mice exhibited reduced rates of 3-MCA-induced tumors. In tumor inoculation studies, caffeine treatment resulted in inhibition of tumor growth and elevation in proinflammatory cytokine release over water-consuming mice, as depicted by MLTR. Addition of the adenosine receptor agonist, NECA, to MLTR resulted in a sharp decrease in IFNγ levels; this was reversed by the highly selective A2AR antagonist, ZM241385. Thus, immune response modulation through either caffeine or genetic deletion of A2AR leads to a Th1 immune profile and suppression of carcinogen-induced tumorigenesis. Taken together, our data suggest that the use of pharmacologic A2AR antagonists may hold therapeutic potential in diminishing the rate of cancer development.

  8. The role of adenosine A1 and A2A receptors in the caffeine effect on MDMA-induced DA and 5-HT release in the mouse striatum.

    PubMed

    Górska, A M; Gołembiowska, K

    2015-04-01

    3,4-Methylenedioxymethamphetamine (MDMA, "ecstasy") popular as a designer drug is often used with caffeine to gain a stronger stimulant effect. MDMA induces 5-HT and DA release by interaction with monoamine transporters. Co-administration of caffeine and MDMA may aggravate MDMA-induced toxic effects on DA and 5-HT terminals. In the present study, we determined whether caffeine influences DA and 5-HT release induced by MDMA. We also tried to find out if adenosine A1 and A2A receptors play a role in the effect of caffeine by investigating the effect of the selective adenosine A1 and A2A receptor antagonists, DPCPX and KW 6002 on DA and 5-HT release induced by MDMA. Mice were treated with caffeine (10 mg/kg) and MDMA (20 or 40 mg/kg) alone or in combination. DA and 5-HT release in the mouse striatum was measured using in vivo microdialysis. Caffeine exacerbated the effect of MDMA on DA and 5-HT release. DPCPX or KW 6002 co-administered with MDMA had similar influence as caffeine, but KW 6002 was more potent than caffeine or DPCPX. To exclude the contribution of MAO inhibition by caffeine in the caffeine effect on MDMA-induced increase in DA and 5-HT, we also tested the effect of the nonxanthine adenosine receptor antagonist CGS 15943A lacking properties of MAO activity modification. Our findings indicate that adenosine A1 and A2A receptor blockade may account for the caffeine-induced exacerbation of the MDMA effect on DA and 5-HT release and may aggravate MDMA toxicity.

  9. The Androgen Receptor Gene Mutations Database.

    PubMed

    Gottlieb, B; Lehvaslaiho, H; Beitel, L K; Lumbroso, R; Pinsky, L; Trifiro, M

    1998-01-01

    The current version of the androgen receptor (AR) gene mutations database is described. The total number of reported mutations has risen from 272 to 309 in the past year. We have expanded the database: (i) by giving each entry an accession number; (ii) by adding information on the length of polymorphic polyglutamine (polyGln) and polyglycine (polyGly) tracts in exon 1; (iii) by adding information on large gene deletions; (iv) by providing a direct link with a completely searchable database (courtesy EMBL-European Bioinformatics Institute). The addition of the exon 1 polymorphisms is discussed in light of their possible relevance as markers for predisposition to prostate or breast cancer. The database is also available on the internet (http://www.mcgill. ca/androgendb/ ), from EMBL-European Bioinformatics Institute (ftp. ebi.ac.uk/pub/databases/androgen ), or as a Macintosh FilemakerPro or Word file (MC33@musica.mcgill.ca).

  10. Activation of Th1 and Tc1 cell adenosine A2A receptors directly inhibits IL-2 secretion in vitro and IL-2-driven expansion in vivo.

    PubMed

    Erdmann, Andreas A; Gao, Zhan-Guo; Jung, Unsu; Foley, Jason; Borenstein, Todd; Jacobson, Kenneth A; Fowler, Daniel H

    2005-06-15

    To evaluate the direct effect of adenosine on cytokine-polarized effector T cells, murine type 1 helper T cells (Th1) and type 1 cytotoxic T lymphocytes (Tc1) and Th2/Tc2 cells were generated using an antigen-presenting cell (APC)-free method. Tc1 and Tc2 cells had similar adenosine signaling, as measured by intracellular cyclic AMP (cAMP) increase upon adenosine A(2A) receptor agonism by CGS21680 (CGS). CGS greatly reduced Tc1 and Tc2 cell interleukin 2 (IL-2) and tumor necrosis factor alpha (TNF-alpha) secretion, with nominal effect on interferon gamma (IFN-gamma) secretion. Tc2 cell IL-4 and IL-5 secretion was not reduced by CGS, and IL-10 secretion was moderately reduced. Agonist-mediated inhibition of IL-2 and TNF-alpha secretion occurred via A(2A) receptors, with no involvement of A(1), A(2B), or A(3) receptors. Adenosine agonist concentrations that abrogated cytokine secretion did not inhibit Tc1 or Tc2 cell cytolytic function. Adenosine modulated effector T cells in vivo, as CGS administration reduced CD4(+)Th1 and CD8(+)Tc1 cell expansion to alloantigen and, in a separate model, reduced antigen-specific CD4(+) Th1 cell numbers. Remarkably, agonist-mediated T-cell inhibition was abrogated by in vivo IL-2 therapy. Adenosine receptor activation therefore preferentially inhibits type I cytokine secretion, most notably IL-2. Modulation of adenosine receptors may thus represent a suitable target primarily for inflammatory conditions mediated by Th1 and Tc1 cells.

  11. Identification of a family of muscarinic acetylcholine receptor genes

    SciTech Connect

    Bonner, T.I.; Buckley, N.J.; Young, A.C.; Brann, M.R.

    1987-07-31

    Complementary DNAs for three different muscarinic acetylcholine receptors were isolated from a rat cerebral cortex library, and the cloned receptors were expressed in mammalian cells. Analysis of human and rat genomic clones indicates that there are at least four functional muscarinic receptor genes and that these genes lack introns in the coding sequence. This gene family provides a new basis for evaluating the diversity of muscarinic mechanisms in the nervous system.

  12. Ethanol and Caffeine Effects on Social Interaction and Recognition in Mice: Involvement of Adenosine A2A and A1 Receptors.

    PubMed

    López-Cruz, Laura; San-Miguel, Noemí; Bayarri, Pilar; Baqi, Younis; Müller, Christa E; Salamone, John D; Correa, Mercé

    2016-01-01

    Ethanol and caffeine are frequently consumed in combination and have opposite effects on the adenosine system: ethanol metabolism leads to an increase in adenosine levels, while caffeine is a non-selective adenosine A1/A2A receptor antagonist. These receptors are highly expressed in striatum and olfactory tubercle, brain areas involved in exploration and social interaction in rodents. Ethanol modulates social interaction processes, but the role of adenosine in social behavior is still poorly understood. The present work was undertaken to study the impact of ethanol, caffeine and their combination on social behavior, and to explore the involvement of A1 and A2A receptors on those actions. Male CD1 mice were evaluated in a social interaction three-chamber paradigm, for preference of conspecific vs. object, and also for long-term recognition memory of familiar vs. novel conspecific. Ethanol showed a biphasic effect, with low doses (0.25 g/kg) increasing social contact and higher doses (1.0-1.5 g/kg) reducing social interaction. However, no dose changed social preference; mice always spent more time sniffing the conspecific than the object, independently of the ethanol dose. Ethanol, even at doses that did not change social exploration, produced amnestic effects on social recognition the following day. Caffeine reduced social contact (15.0-60.0 mg/kg), and even blocked social preference at higher doses (30.0-60.0 mg/kg). The A1 antagonist Cyclopentyltheophylline (CPT; 3-9 mg/kg) did not modify social contact or preference on its own, and the A2A antagonist MSX-3 (1.5-6 mg/kg) increased social interaction at all doses. Ethanol at intermediate doses (0.5-1.0 g/kg) was able to reverse the reduction in social exploration induced by caffeine (15.0-30.0 mg/kg). Although there was no interaction between ethanol and CPT or MSX-3 on social exploration in the first day, MSX-3 blocked the amnestic effects of ethanol observed on the following day. Thus, ethanol impairs the

  13. Ethanol and Caffeine Effects on Social Interaction and Recognition in Mice: Involvement of Adenosine A2A and A1 Receptors

    PubMed Central

    López-Cruz, Laura; San-Miguel, Noemí; Bayarri, Pilar; Baqi, Younis; Müller, Christa E.; Salamone, John D.; Correa, Mercé

    2016-01-01

    Ethanol and caffeine are frequently consumed in combination and have opposite effects on the adenosine system: ethanol metabolism leads to an increase in adenosine levels, while caffeine is a non-selective adenosine A1/A2A receptor antagonist. These receptors are highly expressed in striatum and olfactory tubercle, brain areas involved in exploration and social interaction in rodents. Ethanol modulates social interaction processes, but the role of adenosine in social behavior is still poorly understood. The present work was undertaken to study the impact of ethanol, caffeine and their combination on social behavior, and to explore the involvement of A1 and A2A receptors on those actions. Male CD1 mice were evaluated in a social interaction three-chamber paradigm, for preference of conspecific vs. object, and also for long-term recognition memory of familiar vs. novel conspecific. Ethanol showed a biphasic effect, with low doses (0.25 g/kg) increasing social contact and higher doses (1.0–1.5 g/kg) reducing social interaction. However, no dose changed social preference; mice always spent more time sniffing the conspecific than the object, independently of the ethanol dose. Ethanol, even at doses that did not change social exploration, produced amnestic effects on social recognition the following day. Caffeine reduced social contact (15.0–60.0 mg/kg), and even blocked social preference at higher doses (30.0–60.0 mg/kg). The A1 antagonist Cyclopentyltheophylline (CPT; 3–9 mg/kg) did not modify social contact or preference on its own, and the A2A antagonist MSX-3 (1.5–6 mg/kg) increased social interaction at all doses. Ethanol at intermediate doses (0.5–1.0 g/kg) was able to reverse the reduction in social exploration induced by caffeine (15.0–30.0 mg/kg). Although there was no interaction between ethanol and CPT or MSX-3 on social exploration in the first day, MSX-3 blocked the amnestic effects of ethanol observed on the following day. Thus, ethanol

  14. Spatiotemporal brain dynamics of emotional face processing modulations induced by the serotonin 1A/2A receptor agonist psilocybin.

    PubMed

    Bernasconi, Fosco; Schmidt, André; Pokorny, Thomas; Kometer, Michael; Seifritz, Erich; Vollenweider, Franz X

    2014-12-01

    Emotional face processing is critically modulated by the serotonergic system. For instance, emotional face processing is impaired by acute psilocybin administration, a serotonin (5-HT) 1A and 2A receptor agonist. However, the spatiotemporal brain mechanisms underlying these modulations are poorly understood. Here, we investigated the spatiotemporal brain dynamics underlying psilocybin-induced modulations during emotional face processing. Electrical neuroimaging analyses were applied to visual evoked potentials in response to emotional faces, following psilocybin and placebo administration. Our results indicate a first time period of strength (i.e., Global Field Power) modulation over the 168-189 ms poststimulus interval, induced by psilocybin. A second time period of strength modulation was identified over the 211-242 ms poststimulus interval. Source estimations over these 2 time periods further revealed decreased activity in response to both neutral and fearful faces within limbic areas, including amygdala and parahippocampal gyrus, and the right temporal cortex over the 168-189 ms interval, and reduced activity in response to happy faces within limbic and right temporo-occipital brain areas over the 211-242 ms interval. Our results indicate a selective and temporally dissociable effect of psilocybin on the neuronal correlates of emotional face processing, consistent with a modulation of the top-down control.

  15. In search of novel ligands using a structure-based approach: a case study on the adenosine A2A receptor

    NASA Astrophysics Data System (ADS)

    Lenselink, Eelke B.; Beuming, Thijs; van Veen, Corine; Massink, Arnault; Sherman, Woody; van Vlijmen, Herman W. T.; IJzerman, Adriaan P.

    2016-10-01

    In this work, we present a case study to explore the challenges associated with finding novel molecules for a receptor that has been studied in depth and has a wealth of chemical information available. Specifically, we apply a previously described protocol that incorporates explicit water molecules in the ligand binding site to prospectively screen over 2.5 million drug-like and lead-like compounds from the commercially available eMolecules database in search of novel binders to the adenosine A2A receptor (A2AAR). A total of seventy-one compounds were selected for purchase and biochemical assaying based on high ligand efficiency and high novelty (Tanimoto coefficient ≤0.25 to any A2AAR tested compound). These molecules were then tested for their affinity to the adenosine A2A receptor in a radioligand binding assay. We identified two hits that fulfilled the criterion of 50 % radioligand displacement at a concentration of 10 μM. Next we selected an additional eight novel molecules that were predicted to make a bidentate interaction with Asn2536.55, a key interacting residue in the binding pocket of the A2AAR. None of these eight molecules were found to be active. Based on these results we discuss the advantages of structure-based methods and the challenges associated with finding chemically novel molecules for well-explored targets.

  16. Interleukin-1beta but not tumor necrosis factor-alpha potentiates neuronal damage by quinolinic acid: protection by an adenosine A2A receptor antagonist.

    PubMed

    Stone, Trevor W; Behan, Wilhelmina M H

    2007-04-01

    Quinolinic acid is an agonist at glutamate receptors sensitive to N-methyl-D-aspartate (NMDA). It has been implicated in neural dysfunction associated with infections, trauma, and ischemia, although its neurotoxic potency is relatively low. This study was designed to examine the effects of a combination of quinolinic acid and the proinflammatory cytokines interleukin-1beta (IL-1beta) and tumor necrosis factor-alpha (TNF-alpha). Compounds were administered to the hippocampus of anesthetized male rats, animals being allowed to recover for 7 days before histological analysis of the hippocampus for neuronal damage estimated by counting of intact, healthy neurons. A low dose of quinolinic acid or IL-1beta produced no damage by itself, but the two together induced a significant loss of pyramidal neurons in the hippocampus. Higher doses produced almost total loss of pyramidal cells. Intrahippocampal TNF-alpha produced no effect alone but significantly reduced the neuronal loss produced by quinolinic acid. The adenosine A(2A) receptor antagonist ZM241385 reduced neuronal loss produced by the combinations of quinolinic acid and IL-1beta. The results suggest that simultaneous quinolinic acid and IL-1beta, both being induced by cerebral infection or injury, are synergistic in the production of neuronal damage and could together contribute substantially to traumatic, infective, or ischemic cerebral damage. Antagonism of adenosine A(2A) receptors protects neurons against the combination of quinolinic acid and IL-1beta.

  17. The effect of caffeine to increase reaction time in the rat during a test of attention is mediated through antagonism of adenosine A2A receptors.

    PubMed

    Higgins, Guy A; Grzelak, Michael E; Pond, Annamarie J; Cohen-Williams, Mary E; Hodgson, Robert A; Varty, Geoffrey B

    2007-12-11

    Caffeine produces effects on cognitive function particularly relating to aspects of attention such as reaction time. Considering the plasma exposure levels following regular caffeine intake, and the affinity of caffeine for known protein targets, these effects are likely mediated by either the adenosine A(1) or A(2A) receptor. In the present studies, two rat strains [Long-Evans (LE) and CD] were trained to asymptote performance in a test of selective attention, the 5-choice serial reaction time task (5-CSRTT). Next, the effects of caffeine were compared to the selective A(2A) antagonists, SCH 412348 and KW-6002 (Istradefylline), and the A(1) antagonist, DPCPX. Further studies compared the psychostimulant effects of each drug. Finally, we tested the A(2A) agonist, CGS-21680, on 5-CSRTT performance and given the antipsychotic potential of this drug class, studied the interaction between CGS-21680 and amphetamine in this task. Caffeine (3-10mg/kg IP) increased reaction time in both LE and CD rats, with no effect on accuracy, an effect replicated by SCH 412348 (0.1-1mg/kg PO) and KW-6002 (1-3mg/kg PO), but not DPCPX (3-30 mg/kg PO). At least with SCH 412348, these effects were at doses that were not overtly psychostimulant. In contrast, CGS-21680 (0.03-0. 3mg/kg IP) slowed reaction speed and increased omissions. Interestingly, at a comparatively low dose of 0.03 mg/kg, CGS-21680 attenuated the increased premature responding produced by amphetamine (1mg/kg IP). The present results suggest that the attention-enhancing effects of caffeine are mediated through A(2A) receptor blockade, and selective A(2A) receptor antagonists may have potential as therapies for attention-related disorders. Furthermore, the improvement in response control in amphetamine-treated rats following CGS-21680 pretreatment supports the view that A(2A) agonists have potential as novel antipsychotics.

  18. Polydeoxyribonucleotide, an Adenosine-A2A Receptor Agonist, Preserves Blood Testis Barrier from Cadmium-Induced Injury

    PubMed Central

    Squadrito, Francesco; Micali, Antonio; Rinaldi, Mariagrazia; Irrera, Natasha; Marini, Herbert; Puzzolo, Domenico; Pisani, Antonina; Lorenzini, Cesare; Valenti, Andrea; Laurà, Rosaria; Germanà, Antonino; Bitto, Alessandra; Pizzino, Gabriele; Pallio, Giovanni; Altavilla, Domenica; Minutoli, Letteria

    2017-01-01

    Cadmium (Cd) impairs blood-testis barrier (BTB). Polydeoxyribonucleotide (PDRN), an adenosine A2A agonist, has positive effects on male reproductive system. We investigated the effects of PDRN on the morphological and functional changes induced by Cd in mice testes. Adult Swiss mice were divided into four groups: controls administered with 0.9% NaCl (1 ml/kg, i.p., daily) or with PDRN (8 mg/kg, i.p. daily), animals challenged with Cd chloride (CdCl2; 2 mg/kg, i.p, daily) and animals challenged with CdCl2 (2 mg/kg, i.p., daily) and treated with PDRN (8 mg/kg, i.p., daily). Experiments lasted 14 days. Testes were processed for biochemical, structural, and ultrastructural evaluation and hormones were assayed in serum. CdCl2 increased pERK 1/2 expression and Follicle Stimulating Hormone (FSH) and Luteinizing Hormone (LH) levels; it decreased testosterone (TE) and inhibin-B levels and induced structural damages in extratubular compartment and in seminiferous epithelium, with ultrastructural features of BTB disruption. Many TUNEL-positive germ cells were present. CdCl2 increased tubular TGF-β3 immunoreactivity and reduced claudin-11, occludin, and N-cadherin immunoreactivity. PDRN administration reduced pERK 1/2 expression, FSH, and LH levels; it increased TE and inhibin-B levels, ameliorated germinal epithelium changes and protected BTB ultrastructure. Few TUNEL-positive germ cells were present and the extratubular compartment was preserved. Furthermore, PDRN decreased TGF-β3 immunoreactivity and enhanced claudin-11, occludin, and N-cadherin immunoreactivity. We demonstrate a protective effect of PDRN on Cd-induced damages of BTB and suggest that PDRN may play an important role against Cd, particularly against its harmful effects on gametogenesis. PMID:28119612

  19. Calcium modulates calmodulin/α-actinin 1 interaction with and agonist-dependent internalization of the adenosine A2A receptor.

    PubMed

    Piirainen, Henni; Taura, Jaume; Kursula, Petri; Ciruela, Francisco; Jaakola, Veli-Pekka

    2017-04-01

    Adenosine receptors are G protein-coupled receptors that sense extracellular adenosine to transmit intracellular signals. One of the four adenosine receptor subtypes, the adenosine A2A receptor (A2AR), has an exceptionally long intracellular C terminus (A2AR-ct) that mediates interactions with a large array of proteins, including calmodulin and α-actinin. Here, we aimed to ascertain the α-actinin 1/calmodulin interplay whilst binding to A2AR and the role of Ca(2+) in this process. First, we studied the A2AR-α-actinin 1 interaction by means of native polyacrylamide gel electrophoresis, isothermal titration calorimetry, and surface plasmon resonance, using purified recombinant proteins. α-Actinin 1 binds the A2AR-ct through its distal calmodulin-like domain in a Ca(2+)-independent manner with a dissociation constant of 5-12μM, thus showing an ~100 times lower affinity compared to the A2AR-calmodulin/Ca(2+) complex. Importantly, calmodulin displaced α-actinin 1 from the A2AR-ct in a Ca(2+)-dependent fashion, disrupting the A2AR-α-actinin 1 complex. Finally, we assessed the impact of Ca(2+) on A2AR internalization in living cells, a function operated by the A2AR-α-actinin 1 complex. Interestingly, while Ca(2+) influx did not affect constitutive A2AR endocytosis, it abolished agonist-dependent internalization. In addition, we demonstrated that the A2AR/α-actinin interaction plays a pivotal role in receptor internalization and function. Overall, our results suggest that the interplay of A2AR with calmodulin and α-actinin 1 is fine-tuned by Ca(2+), a fact that might power agonist-mediated receptor internalization and function.

  20. Pharmacokinetic modelling of the haemodynamic effects of the A2a adenosine receptor agonist CGS 21680C in conscious normotensive rats.

    PubMed Central

    Mathôt, R A; Cleton, A; Soudijn, W; IJzerman, A P; Danhof, M

    1995-01-01

    1. The aim of the present investigation was to determine the relationship between the blood concentration and haemodynamic effects of the adenosine A2a receptor agonist, CGS 21680C (the sodium salt of 2-p-(2-carboxyethyl)phenylethylamino-5'-N-ethylcarboxamidoadeno sin e) in conscious normotensive rats. 2. Chronically cannulated rats were randomly assigned to three groups which received 300, 1000 or 3000 micrograms kg-1 (0.56, 1.9 or 5.6 mumol kg-1) of CGS 21680C intravenously over 15 min. The mean arterial blood pressure (MAP) and heart rate (HR) were monitored continuously during the experiment and serial arterial blood samples were taken for analysis of drug concentration. The ratio MAP/HR was also calculated, which may reflect changes in total peripheral resistance on the assumption that no changes in stroke volume occur. 3. For each individual rat the reduction in mean arterial pressure was related to the blood concentration according to the sigmoidal Emax model. The concentration-effect relationships were consistent for the different treatment groups. The potency based on free drug concentrations (EC50,u) was 5.8 ng ml-1 (11 nM) (mean +/- s.e.; n = 19) and correlated well with the reported adenosine A2a receptor affinity (Ki 19 nM). In comparison with the reduction in blood pressure, CGS 21680C exhibited a greater potency for the reduction of the ratio MAP/HR. 4. It is concluded that estimates can be obtained for the potency and intrinsic activity of adenosine A2a receptor agonists in vivo by pharmacokinetic-pharmacodynamic analysis of mean arterial pressure data in a rat model.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7773536

  1. Cannabidiol, a non-psychotropic plant-derived cannabinoid, decreases inflammation in a murine model of acute lung injury: role for the adenosine A(2A) receptor.

    PubMed

    Ribeiro, Alison; Ferraz-de-Paula, Viviane; Pinheiro, Milena L; Vitoretti, Luana B; Mariano-Souza, Domenica P; Quinteiro-Filho, Wanderley M; Akamine, Adriana T; Almeida, Vinícius I; Quevedo, João; Dal-Pizzol, Felipe; Hallak, Jaime E; Zuardi, Antônio W; Crippa, José A; Palermo-Neto, João

    2012-03-05

    Acute lung injury is an inflammatory condition for which treatment is mainly supportive because effective therapies have not been developed. Cannabidiol, a non-psychotropic cannabinoid component of marijuana (Cannabis sativa), has potent immunosuppressive and anti-inflammatory properties. Therefore, we investigated the possible anti-inflammatory effect of cannabidiol in a murine model of acute lung injury. Analysis of total inflammatory cells and differential in bronchoalveolar lavage fluid was used to characterize leukocyte migration into the lungs; myeloperoxidase activity of lung tissue and albumin concentration in the bronchoalveolar lavage fluid were analyzed by colorimetric assays; cytokine/chemokine production in the bronchoalveolar lavage fluid was also analyzed by Cytometric Bead Arrays and Enzyme-Linked Immunosorbent Assay (ELISA). A single dose of cannabidiol (20mg/kg) administered prior to the induction of LPS (lipopolysaccharide)-induced acute lung injury decreases leukocyte (specifically neutrophil) migration into the lungs, albumin concentration in the bronchoalveolar lavage fluid, myeloperoxidase activity in the lung tissue, and production of pro-inflammatory cytokines (TNF and IL-6) and chemokines (MCP-1 and MIP-2) 1, 2, and 4days after the induction of LPS-induced acute lung injury. Additionally, adenosine A(2A) receptor is involved in the anti-inflammatory effects of cannabidiol on LPS-induced acute lung injury because ZM241385 (4-(2-[7-Amino-2-(2-furyl)[1,2,4]triazolo[2,3-a][1,3,5]triazin-5-ylamino]ethyl)phenol) (a highly selective antagonist of adenosine A(2A) receptor) abrogated all of the anti-inflammatory effects of cannabidiol previously described. Thus, we show that cannabidiol has anti-inflammatory effects in a murine model of acute lung injury and that this effect is most likely associated with an increase in the extracellular adenosine offer and signaling through adenosine A(2A) receptor.

  2. 2-Amino-N-pyrimidin-4-ylacetamides as A2A receptor antagonists: 1. Structure-activity relationships and optimization of heterocyclic substituents.

    PubMed

    Slee, Deborah H; Chen, Yongsheng; Zhang, Xiaohu; Moorjani, Manisha; Lanier, Marion C; Lin, Emily; Rueter, Jaimie K; Williams, John P; Lechner, Sandra M; Markison, Stacy; Malany, Siobhan; Santos, Mark; Gross, Raymond S; Jalali, Kayvon; Sai, Yang; Zuo, Zhiyang; Yang, Chun; Castro-Palomino, Julio C; Crespo, María I; Prat, Maria; Gual, Silvia; Díaz, José-Luis; Saunders, John

    2008-03-27

    Previously we have described a novel series of potent and selective A 2A receptor antagonists (e.g., 1) with excellent aqueous solubility. While these compounds are efficacious A 2A antagonists in vivo, the presence of an unsubstituted furyl moiety was a cause of some concern. In order to avoid the potential metabolic liabilities that could arise from an unsubstituted furyl moiety, an optimization effort was undertaken with the aim of replacing the unsubstituted furan with a more metabolically stable group while maintaining potency and selectivity. Herein, we describe the synthesis and SAR of a range of novel heterocyclic systems and the successful identification of a replacement for the unsubstituted furan moiety with a methylfuran or thiazole moiety while maintaining potency and selectivity.

  3. Regulatory Features for Odorant Receptor Genes in the Mouse Genome

    PubMed Central

    Degl’Innocenti, Andrea; D’Errico, Anna

    2017-01-01

    The odorant receptor genes, seven transmembrane receptor genes constituting the vastest mammalian gene multifamily, are expressed monogenically and monoallelicaly in each sensory neuron in the olfactory epithelium. This characteristic, often referred to as the one neuron–one receptor rule, is driven by mostly uncharacterized molecular dynamics, generally named odorant receptor gene choice. Much attention has been paid by the scientific community to the identification of sequences regulating the expression of odorant receptor genes within their loci, where related genes are usually arranged in genomic clusters. A number of studies identified transcription factor binding sites on odorant receptor promoter sequences. Similar binding sites were also found on a number of enhancers that regulate in cis their transcription, but have been proposed to form interchromosomal networks. Odorant receptor gene choice seems to occur via the local removal of strongly repressive epigenetic markings, put in place during the maturation of the sensory neuron on each odorant receptor locus. Here we review the fast-changing state of art for the study of regulatory features for odorant receptor genes. PMID:28270833

  4. Regulatory Features for Odorant Receptor Genes in the Mouse Genome.

    PubMed

    Degl'Innocenti, Andrea; D'Errico, Anna

    2017-01-01

    The odorant receptor genes, seven transmembrane receptor genes constituting the vastest mammalian gene multifamily, are expressed monogenically and monoallelicaly in each sensory neuron in the olfactory epithelium. This characteristic, often referred to as the one neuron-one receptor rule, is driven by mostly uncharacterized molecular dynamics, generally named odorant receptor gene choice. Much attention has been paid by the scientific community to the identification of sequences regulating the expression of odorant receptor genes within their loci, where related genes are usually arranged in genomic clusters. A number of studies identified transcription factor binding sites on odorant receptor promoter sequences. Similar binding sites were also found on a number of enhancers that regulate in cis their transcription, but have been proposed to form interchromosomal networks. Odorant receptor gene choice seems to occur via the local removal of strongly repressive epigenetic markings, put in place during the maturation of the sensory neuron on each odorant receptor locus. Here we review the fast-changing state of art for the study of regulatory features for odorant receptor genes.

  5. Analysis of antigen receptor genes in Hodgkin's disease.

    PubMed Central

    Angel, C A; Pringle, J H; Naylor, J; West, K P; Lauder, I

    1993-01-01

    AIM--To analyse the configuration of the antigen receptor genes in Hodgkin's disease. METHODS--DNA extracted from 45 samples of Hodgkin's disease was analysed using Southern blotting and DNA hybridisation, using probes to the joining region of the immunoglobulin heavy chain gene, the constant region of kappa immunoglobulin light chain gene, and the constant region of the beta chain of the T cell receptor gene. RESULTS--A single case of nodular sclerosing disease showed clonal rearrangement of the immunoglobulin heavy and light chain genes, all other samples having germline immunoglobulin genes. The nature of the clonal population in the diseased tissue is uncertain, because the intensity of the rearranged bands did not correlate with the percentage of Reed-Sternberg cells present. The T cell receptor genes were in germline configuration in all the samples. CONCLUSIONS--Antigen receptor gene rearrangement is a rare finding in unselected cases of Hodgkin's disease. Images PMID:8388407

  6. Potent, Metabolically Stable 2-Alkyl-8-(2H-1,2,3-triazol-2-yl)-9H-adenines as Adenosine A2A Receptor Ligands.

    PubMed

    Pace, Silvia; Brogin, Giandomenico; Stasi, Maria Antonietta; Riccioni, Teresa; Borsini, Franco; Capocasa, Francesca; Manera, Francesco; Tallarico, Carlo; Grossi, Pietro; Vacondio, Federica; Bassi, Michele; Bartoccini, Francesca; Lucarini, Simone; Piersanti, Giovanni; Tarzia, Giorgio; Cabri, Walter; Minetti, Patrizia

    2015-07-01

    Inhibition of adenosine A2A receptors has been shown to elicit a therapeutic response in preclinical animal models of Parkinson's disease (PD). We previously identified the triazolo-9H-purine, ST1535, as a potent A(2A)R antagonist. Studies revealed that ST1535 is extensively hydroxylated at the ω-1 position of the butyl side chain. Here, we describe the synthesis and evaluation of derivatives in which the ω-1 position has been substituted (F, Me, OH) in order to block metabolism. The stability of the compounds was evaluated in human liver microsomes (HLM), and the affinity for A(2A)R was determined. Two compounds, (2-(3,3-dimethylbutyl)-9-methyl-8-(2H-1,2,3-triazol-2-yl)-9H-purin-6-amine (3 b) and 4-(6-amino-9-methyl-8-(2H-1,2,3-triazol-2-yl)-9H-purin-2-yl)-2-methylbutan-2-ol (3 c), exhibited good affinity against A(2A)R (Ki =0.4 nM and 2 nM, respectively) and high in vitro metabolic stability (89.5% and 95.3% recovery, respectively, after incubation with HLM for two hours).

  7. The androgen receptor gene mutations database.

    PubMed

    Gottlieb, B; Trifiro, M; Lumbroso, R; Vasiliou, D M; Pinsky, L

    1996-01-01

    The current version of the androgen receptor (AR) gene mutations database is described. We have added (if available) data on the androgen binding phenotype of the mutant AR, the clinical phenotype of the affected persons, the family history and whether the pathogenicity of a mutation has been proven. Exonic mutations are now listed in 5'-->3' sequence regardless of type and single base pair changes are presented in codon context. Splice site and intronic mutations are listed separately. The database has allowed us to substantiate and amplify the observation of mutational hot spots within exons encoding the AR androgen binding domain. The database is available from EML (ftp://www.ebi.ac.uk/pub/databases/androgen) or as a Macintosh Filemaker file (MC33@musica.mcgill.ca).

  8. The androgen receptor gene mutations database.

    PubMed

    Gottlieb, B; Trifiro, M; Lumbroso, R; Pinsky, L

    1997-01-01

    The current version of the androgen receptor (AR) gene mutations database is described. The total number of reported mutations has risen from 212 to 272. We have expanded the database: (i) by adding a large amount of new data on somatic mutations in prostatic cancer tissue; (ii) by defining a new constitutional phenotype, mild androgen insensitivity (MAI); (iii) by placing additional relevant information on an internet site (http://www.mcgill.ca/androgendb/ ). The database has allowed us to examine the contribution of CpG sites to the multiplicity of reports of the same mutation in different families. The database is also available from EMBL (ftp.ebi.ac.uk/pub/databases/androgen) or as a Macintosh Filemaker Pro or Word file (MC33@musica,mcgill.ca)

  9. The antidepressant-like effect of inosine in the FST is associated with both adenosine A1 and A 2A receptors.

    PubMed

    Kaster, Manuella P; Budni, Josiane; Gazal, Marta; Cunha, Mauricio P; Santos, Adair R S; Rodrigues, Ana Lúcia S

    2013-09-01

    Inosine is an endogenous purine nucleoside, which is formed during the breakdown of adenosine. The adenosinergic system was already described as capable of modulating mood in preclinical models; we now explored the effects of inosine in two predictive models of depression: the forced swim test (FST) and tail suspension test (TST). Mice treated with inosine displayed higher anti-immobility in the FST (5 and 50 mg/kg, intraperitoneal route (i.p.)) and in the TST (1 and 10 mg/kg, i.p.) when compared to vehicle-treated groups. These antidepressant-like effects started 30 min and lasted for 2 h after intraperitoneal administration of inosine and were not accompanied by any changes in the ambulatory activity in the open-field test. Both adenosine A1 and A2A receptor antagonists prevented the antidepressant-like effect of inosine in the FST. In addition, the administration of an adenosine deaminase inhibitor (1 and 10 mg/kg, i.p.) also caused an antidepressant-like effect in the FST. These results indicate that inosine possesses an antidepressant-like effect in the FST and TST probably through the activation of adenosine A1 and A2A receptors, further reinforcing the potential of targeting the purinergic system to the management of mood disorders.

  10. Adenosine A2a receptor stimulation blocks development of nonalcoholic steatohepatitis in mice by multilevel inhibition of signals that cause immunolipotoxicity.

    PubMed

    Alchera, Elisa; Rolla, Simona; Imarisio, Chiara; Bardina, Valentina; Valente, Guido; Novelli, Francesco; Carini, Rita

    2016-12-06

    Lipotoxicity and immunoinflammation are associated with the evolution of steatosis toward nonalcoholic steatohepatitis (NASH). This study reports the ability of adenosine A2a receptor (A2aR) activation to inhibit NASH development by modulating the responses of CD4(+) T-helper (Th) cells to avoid an immuno-mediated potentiation of lipotoxicity. The effect of the A2aR agonist CGS21680 on immunoinflammatory signals, CD4(+)Th cell infiltration and immunolipotoxicity was analyzed in steatotic C57BL/6 mice fed with a methionine-choline-deficient (MCD) diet and in mouse hepatocytes exposed to palmitic acid (PA). CGS21680 inhibited NASH development in steatotic mice and decreased cytokines and chemokines involved in Th cell recruitment or polarization (namely CXCL10, CCL2, tumor necrosis factor alfa [TNFα], tumor growth factor [TGFβ], and IL-12). CGS21680 also reduced the expansion of Th17, Th22, and Th1 cells and increased the immunosuppressive activity of T regulatory cells. In PA-treated mice hepatocytes, CGS21680 inhibited the production of CXCL10, TNFα, TGFβ, IL-12, and CCL2; CGS21680 also prevented JNK-dependent lipotoxicity and its intensification by IL-17 or IL-17 plus IL-22 through Akt/PI3-kinase stimulation and inhibition of the negative regulator of PI3-kinase, (phosphatase and tensin homologue deleted from chromosome 10 (PTEN), which is upregulated by IL-17. In MCD livers, CGS21680 reduced JNK activation and PTEN expression and increased Akt phosphorylation. In conclusion, A2aR stimulation inhibited NASH development by reducing Th17 cell expansion and inhibiting the exacerbation of the IL-17-induced JNK-dependent lipotoxicity. These data promote the implementation of further studies to evaluate the potential clinical application of A2aR agonists that, by being able to function as both cytoprotective and immunomodulatory agents, could efficiently antagonize the multi-faced pathogenesis of NASH.

  11. Tetanic depression is overcome by tonic adenosine A2A receptor facilitation of L-type Ca2+ influx into rat motor nerve terminals

    PubMed Central

    Oliveira, Laura; Timóteo, M Alexandrina; Correia-de-Sá, Paulo

    2004-01-01

    Motor nerve terminals possess multiple voltage-sensitive calcium channels operating acetylcholine (ACh) release. In this study, we investigated whether facilitation of neuromuscular transmission by adenosine generated during neuronal firing was operated by Ca2+ influx via ‘prevalent’ P-type or via the recruitment of ‘silent’ L-type channels. The release of [3H]ACh from rat phrenic nerve endings decreased upon increasing the stimulation frequency of the trains (750 pulses) from 5 Hz (83 ± 4 × 103 disintegrations per minute per gram (d.p.m. g−1); n = 11) to 50 Hz (30 ± 3 × 103 d.p.m. g−1; n = 5). The P-type Ca2+ channel blocker, ω-agatoxin IVA (100 nm) reduced (by 40 ± 10%; n = 6) the release of [3H]ACh evoked by 50-Hz trains, while nifedipine (1 μm, an L-type blocker) was inactive. Tetanic depression was overcome (88 ± 6 × 103 d.p.m. g−1; n = 12) by stimulating the phrenic nerve with 50-Hz bursts (five bursts of 150 pulses, 20 s interburst interval). In these conditions, ω-agatoxin IVA (100 nm) failed to affect transmitter release, but nifedipine (1 μm) decreased [3H]ACh release by 21 ± 7% (n = 4). Inactivation of endogenous adenosine with adenosine deaminase (ADA, 0.5 U ml−1) reduced (by 54 ± 8%, n = 5) the release of [3H]ACh evoked with 50-Hz bursts. This effect was opposite to the excitatory actions of adenosine (0.5 mm), S-(p-nitrobenzyl)-6-thioinosine (5 μm, an adenosine uptake blocker) and CGS 21680C (3 nm, a selective A2A receptor agonist); as the A1 receptor agonist R-N6-phenylisopropyl adenosine (R-PIA, 300 nm) failed to affect the release of [3H]ACh, the results indicate that adenosine generated during 50-Hz bursts exerts an A2A-receptor-mediated tonus. The effects of ADA (0.5 U ml−1) and CGS 21680C (3 nm) were prevented by nifedipine (1 μm). Blocking tonic A2A receptor activation, with ADA (0.5 U ml−1) or 3,7-dimethyl-1-propargyl xanthine (10 μm, an A2A antagonist), recovered ω-agatoxin IVA (100 nm) inhibition and

  12. Oral administration of Japanese sake yeast (Saccharomyces cerevisiae sake) promotes non-rapid eye movement sleep in mice via adenosine A2A receptors.

    PubMed

    Nakamura, Yoshitaka; Midorikawa, Tatsuyuki; Monoi, Noriyuki; Kimura, Eriko; Murata-Matsuno, Ayumi; Sano, Tomomi; Oka, Kengo; Sugafuji, Toshihiro; Uchiyama, Akira; Murakoshi, Michiaki; Sugiyama, Keikichi; Nishino, Hoyoku; Urade, Yoshihiro

    2016-12-01

    We have demonstrated previously that Japanese sake yeast improves sleep quality in humans. In the present study, we examined the molecular mechanisms of sake yeast to induce sleep by monitoring locomotor activity, electromyogram and electroencephalogram in mice. Oral administration of Japanese sake yeast (100, 200, and 300 mg kg(-1) ) decreased the locomotor activity by 18, 46 and 59% and increased the amount of non-rapid eye movement (NREM) sleep by 1.5-, 2.3- and 2.4-fold (to 37 ± 6, 57 ± 8, and 60 ± 4 min from 25 ± 6 min in the vehicle-administered group, respectively) in a dose-dependent manner for 4 h after oral administration. However, Japanese sake yeast did not change the amount of rapid eye movement (REM) sleep, the electroencephalogram power density during NREM sleep or show any adverse effects, such as rebound of insomnia, during 24 h postadministration and on the next day. An intraperitoneal pretreatment with an adenosine A2A receptor-selective antagonist, ZM241385 (15 mg kg(-1) ), reduced the amount of NREM sleep of sake yeast-administered mice to the basal level, without changing basal amount of sleep. Conversely, an A1 receptor-selective antagonist, 8-cyclopentyltheophylline (10 mg kg(-1) ), did not affect the sleep-promoting effect of Japanese sake yeast. Thus, Japanese sake yeast promotes NREM sleep via activation of adenosine A2A but not A1 receptors.

  13. The effect of adenosine A(2A) receptor antagonists on hydroxyl radical, dopamine, and glutamate in the striatum of rats with altered function of VMAT2.

    PubMed

    Gołembiowska, Krystyna; Dziubina, Anna

    2012-08-01

    It has been shown that a decreased vesicular monoamine transporter (VMAT2) function and the disruption of dopamine (DA) storage is an early contributor to oxidative damage of dopamine neurons in Parkinson's disease (PD). In our previous study, we demonstrated that adenosine A(2A) receptor antagonists suppressed oxidative stress in 6-hydroxydopamine-treated rats suggesting that this effect may account for neuroprotective properties of drugs. In the present study, rats were injected with reserpine (10 mg/kg sc) and 18 h later the effect of the adenosine A(2A) receptor antagonists 8-(3-chlorostyryl)caffeine (CSC) and 4-(2-[7-amino-2-(2-furyl)[1,2,4]triazolo[2,3-a][1,3,5]triazin-5-ylamino]ethyl)phenol (ZM 241385) on extracellular DA, glutamate and hydroxyl radical formation was studied in the rat striatum using in vivo microdialysis. By disrupting VMAT2 function, reserpine depleted DA stores, and increased glutamate and hydroxyl radical levels in the rat striatum. CSC (1 mg/kg) but not ZM 241385 (3 mg/kg) increased extracellular DA level and production of hydroxyl radical in reserpinised rats. Both antagonists decreased the reserpine-induced increase in extracellular glutamate. L-3,4-Dihydroxyphenylalanine (L-DOPA) (25 mg/kg) significantly enhanced extracellular DA, had no effect on reserpine-induced hydroxyl radical production and decreased extracellular glutamate concentration. CSC but not ZM 241385 given jointly with L-DOPA increased the effect of L-DOPA on extracellular DA and augmented the reserpine-induced hydroxyl radical production. CSC and ZM 241385 did not influence extracellular glutamate level, which was decreased by L-DOPA. It seems that by decreasing the MAO-dependent DA metabolism rate, CSC raised cytosolic DA and by DA autoxidation, it induced hydroxyl radical overproduction. Thus, the methylxanthine A(2A) receptor antagonists bearing properties of MAO-B inhibitor, like CSC, may cause a risk of oxidative stress resulting from dysfunctional DA storage

  14. Gene Transfer and Molecular Cloning of the Human NGF Receptor

    NASA Astrophysics Data System (ADS)

    Chao, Moses V.; Bothwell, Mark A.; Ross, Alonzo H.; Koprowski, Hilary; Lanahan, Anthony A.; Buck, C. Randall; Sehgal, Amita

    1986-04-01

    Nerve growth factor (NGF) and its receptor are important in the development of cells derived from the neural crest. Mouse L cell transformants have been generated that stably express the human NGF receptor gene transfer with total human DNA. Affinity cross-linking, metabolic labeling and immunoprecipitation, and equilibrium binding with 125I-labeled NGF revealed that this NGF receptor had the same size and binding characteristics as the receptor from human melanoma cells and rat PC12 cells. The sequences encoding the NGF receptor were molecularly cloned using the human Alu repetitive sequence as a probe. A cosmid clone that contained the human NGF receptor gene allowed efficient transfection and expression of the receptor.

  15. Regulation of cytochrome P450 (CYP) genes by nuclear receptors.

    PubMed Central

    Honkakoski, P; Negishi, M

    2000-01-01

    Members of the nuclear-receptor superfamily mediate crucial physiological functions by regulating the synthesis of their target genes. Nuclear receptors are usually activated by ligand binding. Cytochrome P450 (CYP) isoforms often catalyse both formation and degradation of these ligands. CYPs also metabolize many exogenous compounds, some of which may act as activators of nuclear receptors and disruptors of endocrine and cellular homoeostasis. This review summarizes recent findings that indicate that major classes of CYP genes are selectively regulated by certain ligand-activated nuclear receptors, thus creating tightly controlled networks. PMID:10749660

  16. Early synaptic deficits in the APP/PS1 mouse model of Alzheimer's disease involve neuronal adenosine A2A receptors

    PubMed Central

    Viana da Silva, Silvia; Haberl, Matthias Georg; Zhang, Pei; Bethge, Philipp; Lemos, Cristina; Gonçalves, Nélio; Gorlewicz, Adam; Malezieux, Meryl; Gonçalves, Francisco Q.; Grosjean, Noëlle; Blanchet, Christophe; Frick, Andreas; Nägerl, U Valentin; Cunha, Rodrigo A.; Mulle, Christophe

    2016-01-01

    Synaptic plasticity in the autoassociative network of recurrent connections among hippocampal CA3 pyramidal cells is thought to enable the storage of episodic memory. Impaired episodic memory is an early manifestation of cognitive deficits in Alzheimer's disease (AD). In the APP/PS1 mouse model of AD amyloidosis, we show that associative long-term synaptic potentiation (LTP) is abolished in CA3 pyramidal cells at an early stage. This is caused by activation of upregulated neuronal adenosine A2A receptors (A2AR) rather than by dysregulation of NMDAR signalling or altered dendritic spine morphology. Neutralization of A2AR by acute pharmacological inhibition, or downregulation driven by shRNA interference in a single postsynaptic neuron restore associative CA3 LTP. Accordingly, treatment with A2AR antagonists reverts one-trial memory deficits. These results provide mechanistic support to encourage testing the therapeutic efficacy of A2AR antagonists in early AD patients. PMID:27312972

  17. Effect of adenosine A(2A) receptor antagonists and L-DOPA on hydroxyl radical, glutamate and dopamine in the striatum of 6-OHDA-treated rats.

    PubMed

    Gołembiowska, Krystyna; Dziubina, Anna

    2012-02-01

    A(2A) adenosine receptor antagonists have been proposed as a new therapy of PD. Since oxidative stress plays an important role in the pathogenesis of PD, we studied the effect of the selective A(2A) adenosine receptor antagonists 8-(-3-chlorostyryl)caffeine (CSC) and 4-(2-[7-amino-2-(2-furyl)[1,2,4]triazolo[2,3-a][1,3,5]triazin-5-ylamino]ethyl)phenol (ZM 241385) on hydroxyl radical generation, and glutamate (GLU) and dopamine (DA) extracellular level using a microdialysis in the striatum of 6-OHDA-treated rats. CSC (1 mg/kg) and ZM 241385 (3 mg/kg) given repeatedly for 14 days decreased the production of hydroxyl radical and extracellular GLU level, both enhanced by prior 6-OHDA treatment in dialysates from the rat striatum. CSC and ZM 241385 did not affect DA and its metabolites, 3,4-dihydroxyphenylacetic acid (DOPAC) and homovanilic acid (HVA) extracellular levels in the striatum of 6-OHDA-treated rats. L-DOPA (6 mg/kg) given twice daily for two weeks in the presence of benserazide (3 mg/kg) decreased striatal hydroxyl radical and glutamate extracellular level in 6-OHDA-treated rats. At the same time, L-DOPA slightly but significantly increased the extracellular levels of DOPAC and HVA. A combined repeated administration of L-DOPA and CSC or ZM 241385 did not change the effect of L-DOPA on hydroxyl radical production and glutamate extracellular level in spite of an enhancement of extracellular DA level by CSC and elevation of extracellular level of DOPAC and HVA by ZM 241385. The data suggest that the 6-OHDA-induced damage of nigrostriatal DA-terminals is related to oxidative stress and excessive release of glutamate. Administration of L-DOPA in combination with CSC or ZM 241385, by restoring striatal DA-glutamate balance, suppressed 6-OHDA-induced overproduction of hydroxyl radical.

  18. Inhibition of small HA fragment activity and stimulation of A2A adenosine receptor pathway limit apoptosis and reduce cartilage damage in experimental arthritis.

    PubMed

    Campo, Giuseppe M; Micali, Antonio; Avenoso, Angela; D'Ascola, Angela; Scuruchi, Michele; Pisani, Antonina; Bruschetta, Antongiulio; Calatroni, Alberto; Puzzolo, Domenico; Campo, Salvatore

    2015-05-01

    Recent studies have found that the inactivation of small hyaluronan (HA) fragments originating from native HA during inflammation reduced the inflammatory response in models of experimental arthritis. The stimulation of adenosine receptors A2A reduced inflammation by inhibiting NF-kB activation. The combination of both treatments was significantly more effective than either of the individual treatments. The aim of this study was to further investigate the effects of a combined treatment using the HA inhibitor Pep-1 and a selective A2AR agonist (CV-1808) on the structure and ultrastructure of the articular cartilage and on apoptosis in a model of collagen-induced arthritis (CIA) in mice. Arthritic mice were treated with Pep-1 and/or CV-1808 intraperitoneally daily for 20 days. At day 35, the hind limbs were processed for light microscopy (hematoxylin/eosin and Safranin-O-Fast Green) and for transmission and scanning electron microscopy. CIA increased IL-6, caspase-3 and caspase-7 mRNA expression and the related protein levels in arthritic articular cartilage, and significantly increased concentrations of Bcl-2-associated X protein (Bax), while B cell-lymphoma-2 protein (Bcl-2) was markedly reduced. The combined Pep-1/CV-1808 treatment significantly reduced CIA injury, particularly at the highest doses, demonstrated by the presence of Safranin-O-positive cartilage, with a smooth surface and normal chondrocytes in the superficial, intermediate and deep zones. Morphological data and histological scoring were strongly supported by the reduction in inflammation and apoptotic markers. The results further support the role of HA degradation and A2A receptors in arthritis.

  19. Dopamine receptor genes: new tools for molecular psychiatry.

    PubMed Central

    Niznik, H B; Van Tol, H H

    1992-01-01

    For over a decade it has been generally assumed that all the pharmacological and biochemical actions of dopamine within the central nervous system and periphery were mediated by two distinct dopamine receptors. These receptors, termed D1 and D2, were defined as those coupled to the stimulation or inhibition of adenylate cyclase, respectively, and by their selectivity and avidity for various drugs and compounds. The concept that two dopamine receptors were sufficient to account for all the effects mediated by dopamine was an oversimplification. Recent molecular biological studies have identified five distinct genes which encode at least eight functional dopamine receptors. The members of the expanded dopamine receptor family, however, can still be codifed by way of the original D1 and D2 receptor dichotomy. These include two genes encoding dopamine D1-like receptors (D1 [D1A]/D5 [D1B]) and three genes encoding D2-like receptors (D2/D3/D4). We review here our recent work on the cloning and characterization of some of the members of the dopamine receptor gene family (D1, D2, D4, D5), their relationship to neuropsychiatric disorders and their potential role in antipsychotic drug action. Images Fig. 1 PMID:1450188

  20. Cannabidiol provides long-lasting protection against the deleterious effects of inflammation in a viral model of multiple sclerosis: a role for A2A receptors.

    PubMed

    Mecha, M; Feliú, A; Iñigo, P M; Mestre, L; Carrillo-Salinas, F J; Guaza, C

    2013-11-01

    Inflammation in the central nervous system (CNS) is a complex process that involves a multitude of molecules and effectors, and it requires the transmigration of blood leukocytes across the blood-brain barrier (BBB) and the activation of resident immune cells. Cannabidiol (CBD), a non-psychotropic cannabinoid constituent of Cannabis sativa, has potent anti-inflammatory and immunosuppressive properties. Yet, how this compound modifies the deleterious effects of inflammation in TMEV-induced demyelinating disease (TMEV-IDD) remains unknown. Using this viral model of multiple sclerosis (MS), we demonstrate that CBD decreases the transmigration of blood leukocytes by downregulating the expression of vascular cell adhesion molecule-1 (VCAM-1), chemokines (CCL2 and CCL5) and the proinflammatory cytokine IL-1β, as well as by attenuating the activation of microglia. Moreover, CBD administration at the time of viral infection exerts long-lasting effects, ameliorating motor deficits in the chronic phase of the disease in conjunction with reduced microglial activation and pro-inflammatory cytokine production. Adenosine A2A receptors participate in some of the anti-inflammatory effects of CBD, as the A2A antagonist ZM241385 partially blocks the protective effects of CBD in the initial stages of inflammation. Together, our findings highlight the anti-inflammatory effects of CBD in this viral model of MS and demonstrate the significant therapeutic potential of this compound for the treatment of pathologies with an inflammatory component.

  1. Chronic oral administration of MPEP, an antagonist of mGlu5 receptor, during gestation and lactation alters mGlu5 and A2A receptors in maternal and neonatal brain.

    PubMed

    López-Zapata, Antonio; León-Navarro, David Agustín; Crespo, María; Albasanz, José Luis; Martín, Mairena

    2017-03-06

    Antidepressant and anxiolytic drugs are widely consumed even by pregnant and lactating women. The metabotropic glutamate receptor 5 (mGlu5) antagonist 2-methyl-6-(phenylethynyl)-pyridine (MPEP) exerts antidepressant- and anxiolytic-like actions. Given that treatment for anxiety and depression use to be prolonged in time, it is conceivable a possible modulation of metabotropic glutamate receptors (mGlu receptors) after prolonged MPEP exposure, which could also modify adenosine A2A receptors (A2AR) since functional cross-talk between them has been reported. Here we report that MPEP crosses placental barrier and reaches neonatal brain through maternal milk using LC-MS/MS methods. Therefore, we analyzed mGlu receptors, mainly mGlu5, and A2AR in both maternal and fetal brain after chronic maternal consumption of MPEP during gestation and/or lactation using radioligand binding, Western-blotting, real-time PCR and phospholipase C (PLC) activity assays. In maternal brain, chronic MPEP consumption caused a significant loss of mGlu, including mGlu5, and A2AR receptors level in plasma membrane. PLC activity assays showed that mGlu5 signaling pathway was desensitized. No variations on mRNA level coding A2AR, A1R and mGlu5 were found after MPEP treatments. In female neonatal brain, maternal consumption of MPEP caused a significant increase in mGlu, including mGlu5, and A2AR receptors level. Neither mGlu receptors nor A2AR were modified in male neonatal brain after maternal MPEP intake. Finally, neither molecular nor behavioral changes (anxiety- and depression-like behavior) were observed in 3-month-old female offspring. In summary, mGlu5 and A2AR are altered in both maternal and female neonatal brain after chronic maternal consumption of MPEP during gestation and/or lactation.

  2. Adenovirus receptors and their implications in gene delivery

    PubMed Central

    Sharma, Anurag; Li, Xiaoxin; Bangari, Dinesh S.; Mittal, Suresh K.

    2010-01-01

    Adenoviruses (Ads) have gained popularity as gene delivery vectors for therapeutic and prophylactic applications. Ad entry into host cells involves specific interactions between cell surface receptors and viral capsid proteins. Several cell surface molecules have been identified as receptors for Ad attachment and entry. Tissue tropism of Ad vectors is greatly influenced by their receptor usage. A variety of strategies have been investigated to modify Ad vector tropism by manipulating the receptor-interacting moieties. Many such strategies are aimed at targeting and/or detargeting of Ad vectors. In this review, we discuss the various cell surface molecules that are implicated as receptors for virus attachment and internalization. Special emphasis is given to Ad types that are utilized as gene delivery vectors. Various strategies to modify Ad tropism using the knowledge of Ad receptors are also discussed. PMID:19647886

  3. L-DOPA disrupts adenosine A(2A)-cannabinoid CB(1)-dopamine D(2) receptor heteromer cross-talk in the striatum of hemiparkinsonian rats: biochemical and behavioral studies.

    PubMed

    Pinna, Annalisa; Bonaventura, Jordi; Farré, Daniel; Sánchez, Marta; Simola, Nicola; Mallol, Josefa; Lluís, Carme; Costa, Giulia; Baqi, Younis; Müller, Christa E; Cortés, Antoni; McCormick, Peter; Canela, Enric I; Martínez-Pinilla, Eva; Lanciego, José L; Casadó, Vicent; Armentero, Marie-Therese; Franco, Rafael

    2014-03-01

    Long-term therapy with L-3,4-dihydroxyphenylalanine (L-DOPA), still the most effective treatment in Parkinson's disease (PD), is associated with severe motor complications such as dyskinesia. Experimental and clinical data have indicated that adenosine A2A receptor antagonists can provide symptomatic improvement by potentiating L-DOPA efficacy and minimizing its side effects. It is known that the G-protein-coupled adenosine A2A, cannabinoid CB1 and dopamine D2 receptors may interact and form functional A2A-CB1-D2 receptor heteromers in co-transfected cells as well as in rat striatum. These data suggest that treatment with a combination of drugs or a single compound selectively acting on A2A-CB1-D2 heteromers may represent an alternative therapeutic treatment of PD. We investigated the expression of A2A-CB1-D2 receptor heteromers in the striatum of both naïve and hemiparkinsonian rats (HPD-rats) bearing a unilateral 6-hydroxydopamine (6-OHDA) lesion, and assessed how receptor heteromer expression and biochemical properties were affected by L-DOPA treatment. Radioligand binding data showed that A2A-CB1-D2 receptor heteromers are present in the striatum of both naïve and HPD-rats. However, behavioral results indicated that the combined administration of A2A (MSX-3 or SCH58261) and CB1 (rimonabant) receptor antagonists, in the presence of L-DOPA does not produce a response different from administration of the A2A receptor antagonist alone. These behavioral results prompted identification of heteromers in L-DOPA-treated animals. Interestingly, the radioligand binding results in samples from lesioned animals suggest that the heteromer is lost following acute or chronic treatment with L-DOPA.

  4. Effect of subtype-selective adenosine receptor antagonists on basal or haloperidol-regulated striatal function: studies of exploratory locomotion and c-Fos immunoreactivity in outbred and A(2A)R KO mice.

    PubMed

    Pardo, M; López-Cruz, L; Valverde, O; Ledent, C; Baqi, Y; Müller, C E; Salamone, J D; Correa, M

    2013-06-15

    Behavioral activation is regulated by dopamine (DA) in striatal areas. At low doses, while typical antipsychotic drugs produce psychomotor slowing, psychostimulants promote exploration. Minor stimulants such as caffeine, which act as adenosine receptor antagonists, can also potentiate behavioral activation. Striatal areas are rich in adenosine and DA receptors, and adenosine A2A receptors are mainly expressed in the striatum where they are co-localized with DA D2 receptors. Adenosine antagonists with different receptor-selectivity profiles were used to study spontaneous or haloperidol-impaired exploration and c-Fos expression in different striatal areas. Because A2A antagonists were expected to be more selective for reversing the effects of the D2 antagonist haloperidol, A2A receptor knockout (A2ARKO) mice were also assessed. CD1 and A2ARKO male mice were tested in an open field and in a running wheel. Only the A1/A2A receptor antagonist theophylline (5.0-15.0 mg/kg) and the A2A antagonist MSX-3 (2.0 mg/kg) increased spontaneous locomotion and rearing. Co-administration of theophylline (10.0-15.0 mg/kg), and MSX-3 (1.0-3.0 mg/kg) reversed haloperidol-induced suppression of locomotion. The A1 antagonist CPT was only marginally effective in reversing the effects of haloperidol. Although adenosine antagonists did not affect c-Fos expression on their own, theophylline and MSX-3, but not CPT, attenuated haloperidol induction of c-Fos expression. A2ARKO mice were resistant to the behavioral effects of haloperidol at intermediate doses (0.1 mg/kg) in the open field and in the running wheel. A2A receptors are important for regulating behavioral activation, and interact with D2 receptors in striatal areas to regulate neural processes involved in exploratory activity.

  5. A2A Adenosine Receptors Are Differentially Modulated by Pharmacological Treatments in Rheumatoid Arthritis Patients and Their Stimulation Ameliorates Adjuvant-Induced Arthritis in Rats

    PubMed Central

    Vincenzi, Fabrizio; Padovan, Melissa; Targa, Martina; Corciulo, Carmen; Giacuzzo, Sarah; Merighi, Stefania; Gessi, Stefania; Govoni, Marcello; Borea, Pier Andrea; Varani, Katia

    2013-01-01

    A2A adenosine receptors (ARs) play a key role in the inhibition of the inflammatory process. The purpose of this study was to evaluate the modulation of A2AARs in rheumatoid arthritis (RA) patients after different pharmacological treatments and to investigate the effect of A2AAR stimulation in a rat model of arthritis. We investigated A2AAR density and functionality in RA progression by using a longitudinal study in RA patients before and after methotrexate (MTX), anti-TNFα agents or rituximab treatments. A2AARs were analyzed by saturation binding assays in lymphocytes from RA patients throughout the 24-month study timeframe. In an adjuvant-induced arthritis model in rats we showed the efficacy of the A2AAR agonist, CGS 21680 in comparison with standard therapies by means of paw volume assessment, radiographic and ultrasonographic imaging. Arthritic-associated pain was investigated in mechanical allodynia and thermal hyperalgesia tests. IL-10 release following A2AAR stimulation in lymphocytes from RA patients and in serum from arthritic rats was measured. In lymphocytes obtained from RA patients, the A2AAR up-regulation was gradually reduced in function of the treatment time and the stimulation of these receptors mediated a significant increase of IL-10 production. In the same cells, CGS 21680 did not affected cell viability and did not produced cytotoxic effects. The A2AAR agonist CGS 21680 was highly effective, as suggested by the marked reduction of clinical signs, in rat adjuvant-induced arthritis and associated pain. This study highlighted that A2AAR agonists represent a physiological-like therapeutic alternative for RA treatment as suggested by the anti-inflammatory role of A2AARs in lymphocytes from RA patients. The effectiveness of A2AAR stimulation in a rat model of arthritis supported the role of A2AAR agonists as potential pharmacological treatment for RA. PMID:23326596

  6. The stimulation of adenosine A2A receptors ameliorates the pathological phenotype of fibroblasts from Niemann-Pick type C patients.

    PubMed

    Visentin, Sergio; De Nuccio, Chiara; Bernardo, Antonietta; Pepponi, Rita; Ferrante, Antonella; Minghetti, Luisa; Popoli, Patrizia

    2013-09-25

    Niemann-Pick type C1 (NPC1) disease is a rare neurovisceral disorder characterized by intracellular accumulation of unesterified cholesterol, sphingolipids, and other lipids in the lysosomal compartment. A deregulation of lysosomal calcium has been identified as one of the earliest steps of the degenerative process. Since adenosine A2A receptors (A2ARs) control lysosome trafficking and pH, which closely regulates lysosomal calcium, we hypothesized a role for these receptors in NPC1. The aim of this study was to evaluate the effects of the A2AR agonist CGS21680 on human control and NPC1 fibroblasts. We show that CGS21680 raises lysosomal calcium levels and rescues mitochondrial functionality (mitochondrial inner membrane potential and expression of the complex IV of the mitochondrial respiratory chain), which is compromised in NPC1 cells. These effects are prevented by the selective blockade of A2ARs by the antagonist ZM241385. The effects of A2AR activation on lysosomal calcium are not mediated by the cAMP/PKA pathway but they appear to involve the phosphorylation of ERK1/2. Finally, CGS21680 reduces cholesterol accumulation (Filipin III staining), which is the main criterion currently used for identification of a compound or pathway that would be beneficial for NPC disease, and such an effect is prevented by the Ca(2+) chelator BAPTA-AM. Our findings strongly support the hypothesis that A2AR agonists may represent a therapeutic option for NPC1 and provide insights on their mechanisms of action.

  7. Adenosine A2A receptors induced on iNKT and NK cells reduce pulmonary inflammation and injury in mice with sickle cell disease

    PubMed Central

    Wallace, Kori L.

    2010-01-01

    We showed previously that pulmonary function and arterial oxygen saturation in NY1DD mice with sickle cell disease (SCD) are improved by depletion of invariant natural killer T (iNKT) cells or blockade of their activation. Here we demonstrate that SCD causes a 9- and 6-fold induction of adenosine A2A receptor (A2AR) mRNA in mouse pulmonary iNKT and natural killer (NK) cells, respectively. Treating SCD mice with the A2AR agonist ATL146e produced a dose-dependent reversal of pulmonary dysfunction with maximal efficacy at 10 ng/kg/minute that peaked within 3 days and persisted throughout 7 days of continuous infusion. Crossing NY1DD mice with Rag1−/− mice reduced pulmonary injury that was restored by adoptive transfer of 106 purified iNKT cells. Reconstituted injury was reversed by ATL146e unless the adoptively transferred iNKT cells were pretreated with the A2AR alkylating antagonist, FSPTP (5-amino-7-[2-(4-fluorosulfonyl)phenylethyl]-2-(2-furyl)-pryazolo[4,3-ϵ]-1,2,4-triazolo[1,5-c]pyrimidine), which completely prevented pro-tection. In NY1DD mice exposed to hypoxia-reoxygenation, treatment with ATL146e at the start of reoxygenation prevented further lung injury. Together, these data indicate that activation of induced A2ARs on iNKT and NK cells in SCD mice is sufficient to improve baseline pulmonary function and prevent hypoxia-reoxygenation–induced exacerbation of pulmonary injury. A2A agonists have promise for treating diseases associated with iNKT or NK cell activation. PMID:20798237

  8. Stimulation of adenosine A2A receptors reduces intracellular cholesterol accumulation and rescues mitochondrial abnormalities in human neural cell models of Niemann-Pick C1.

    PubMed

    Ferrante, A; De Nuccio, C; Pepponi, R; Visentin, S; Martire, A; Bernardo, A; Minghetti, L; Popoli, P

    2016-04-01

    Niemann Pick C 1 (NPC1) disease is an incurable, devastating lysosomal-lipid storage disorder characterized by hepatosplenomegaly, progressive neurological impairment and early death. Current treatments are very limited and the research of new therapeutic targets is thus mandatory. We recently showed that the stimulation of adenosine A2A receptors (A2ARs) rescues the abnormal phenotype of fibroblasts from NPC1 patients suggesting that A2AR agonists could represent a therapeutic option for this disease. However, since all NPC1 patients develop severe neurological symptoms which can be ascribed to the complex pathology occurring in both neurons and oligodendrocytes, in the present paper we tested the effects of the A2AR agonist CGS21680 in human neuronal and oligodendroglial NPC1 cell lines (i.e. neuroblastoma SH-SY5Y and oligodendroglial MO3.13 transiently transfected with NPC1 small interfering RNA). The down-regulation of the NPC1 protein effectively resulted in intracellular cholesterol accumulation and altered mitochondrial membrane potential. Both effects were significantly attenuated by CGS21680 (500 nM). The protective effects of CGS were prevented by the selective A2AR antagonist ZM241385 (500 nM). The involvement of calcium modulation was demonstrated by the ability of Bapta-AM (5-7 μM) in reverting the effect of CGS. The A2A-dependent activity was prevented by the PKA-inhibitor KT5720, thus showing the involvement of the cAMP/PKA signaling. These findings provide a clear in vitro proof of concept that A2AR agonists are promising potential drugs for NPC disease.

  9. Impact of estrogen receptor α gene and oxytocin receptor gene polymorphisms on female sexuality.

    PubMed

    Armeni, Anastasia K; Assimakopoulos, Konstantinos; Marioli, Dimitra; Koika, Vassiliki; Michaelidou, Euthychia; Mourtzi, Niki; Iconomou, Gregoris; Georgopoulos, Neoklis A

    2017-01-01

    Over the past decades, research attention has increasingly been paid to the neurobiological component of sexual behavior. The aim of the present study was to investigate the correlation of estrogen receptor α (ERA) gene polymorphism (rs2234693-PvuII) (T→C substitution) and oxytocin receptor gene polymorphism (rs53576) (G→A substitution) with sexuality parameters of young, healthy women. One hundred thirty-three Greek heterosexual women, students in higher education institutions, 20-25 years of age, sexually active, with normal menstrual cycles (28-35 days), were recruited in the study. Exclusion criteria were chronic and/or major psychiatric diseases, use of oral contraceptive pills (OCs), polycystic ovary syndrome (PCOS), thyroid diseases as well as drugs that are implicated in hypothalamus-pituitary-gonadal axis. T allele (wildtype) of rs2234693 (PvuII) polymorphism of ERA gene was correlated with increased levels of arousal and lubrication, whereas A allele (polymorphic) of rs53576 (OXTR) polymorphism was correlated with increased arousal levels. The simultaneous presence of both T allele of rs2234693 (PvuII) and A allele of rs53576 (OXTR) polymorphisms (T + A group) was correlated with increased arousal, orgasm levels as well as female sexual function index full score. To our knowledge, this is the first study to investigate the interaction between ERA and OXTR with regard to sexual function in women. Female sexuality is a complex behavioral trait that encompasses both biological and psychological components. It seems that variability in female sexual response stems from genetic variability that characterizes endocrine, neurotransmitter and central nervous system influences.

  10. Impact of estrogen receptor α gene and oxytocin receptor gene polymorphisms on female sexuality

    PubMed Central

    Armeni, Anastasia K; Assimakopoulos, Konstantinos; Marioli, Dimitra; Koika, Vassiliki; Michaelidou, Euthychia; Mourtzi, Niki; Iconomou, Gregoris

    2017-01-01

    Over the past decades, research attention has increasingly been paid to the neurobiological component of sexual behavior. The aim of the present study was to investigate the correlation of estrogen receptor α (ERA) gene polymorphism (rs2234693-PvuII) (T→C substitution) and oxytocin receptor gene polymorphism (rs53576) (G→A substitution) with sexuality parameters of young, healthy women. One hundred thirty-three Greek heterosexual women, students in higher education institutions, 20–25 years of age, sexually active, with normal menstrual cycles (28–35 days), were recruited in the study. Exclusion criteria were chronic and/or major psychiatric diseases, use of oral contraceptive pills (OCs), polycystic ovary syndrome (PCOS), thyroid diseases as well as drugs that are implicated in hypothalamus–pituitary–gonadal axis. T allele (wildtype) of rs2234693 (PvuII) polymorphism of ERA gene was correlated with increased levels of arousal and lubrication, whereas A allele (polymorphic) of rs53576 (OXTR) polymorphism was correlated with increased arousal levels. The simultaneous presence of both T allele of rs2234693 (PvuII) and A allele of rs53576 (OXTR) polymorphisms (T + A group) was correlated with increased arousal, orgasm levels as well as female sexual function index full score. To our knowledge, this is the first study to investigate the interaction between ERA and OXTR with regard to sexual function in women. Female sexuality is a complex behavioral trait that encompasses both biological and psychological components. It seems that variability in female sexual response stems from genetic variability that characterizes endocrine, neurotransmitter and central nervous system influences. PMID:28069897

  11. Estrogen increases renal oxytocin receptor gene expression.

    PubMed

    Ostrowski, N L; Young, W S; Lolait, S J

    1995-04-01

    Estrogens have been implicated in the sodium and fluid imbalances associated with the menstrual cycle and late pregnancy. An estrogen-dependent role for renal oxytocin receptors in fluid homeostasis is suggested by the present findings which demonstrate that estradiol benzoate treatment increases the expression of the oxytocin receptor messenger ribonucleic acid and 125I-OTA binding to oxytocin receptors in the renal cortex and medullary collecting ducts of ovariectomized female rats. Moreover, estradiol induced high levels of oxytocin receptor expression in outer stripe proximal tubules of ovariectomized female and adrenalectomized male rats. Proximal tubule induction was inhibited in a dose-dependent manner by the antiestrogen tamoxifen, but cortical expression of oxytocin receptors in macula densa cells was unaffected by tamoxifen. These data demonstrate cell-specific regulation of oxytocin receptor expression in macula densa and proximal tubule cells, and suggest a important role for these receptors in mediating estrogen-induced alterations in renal fluid dynamics by possibly affecting glomerular filtration and water and solute reabsorption during high estrogen states.

  12. Characteristics of the mouse genomic histamine H1 receptor gene

    SciTech Connect

    Inoue, Isao; Taniuchi, Ichiro; Kitamura, Daisuke

    1996-08-15

    We report here the molecular cloning of a mouse histamine H1 receptor gene. The protein deduced from the nucleotide sequence is composed of 488 amino acid residues with characteristic properties of GTP binding protein-coupled receptors. Our results suggest that the mouse histamine H1 receptor gene is a single locus, and no related sequences were detected. Interspecific backcross analysis indicated that the mouse histamine H1 receptor gene (Hrh1) is located in the central region of mouse Chromosome 6 linked to microphthalmia (Mitfmi), ras-related fibrosarcoma oncogene 1 (Raf1), and ret proto-oncogene (Ret) in a region of homology with human chromosome 3p. 12 refs., 3 figs.

  13. Molecular docking studies of 1-(substituted phenyl)-3-(naphtha [1, 2-d] thiazol-2-yl) urea/thiourea derivatives with human adenosine A(2A) receptor.

    PubMed

    Azam, Faizul; Prasad, Medapati Vijaya Vara; Thangavel, Neelaveni; Ali, Hamed Ismail

    2011-01-01

    Computational assessment of the binding interactions of drugs is an important component of computer-aided drug design paradigms. In this perspective, a set of 30 1-(substituted phenyl)-3-(naphtha[1, 2-d] thiazol-2-yl) urea/thiourea derivatives showing antiparkinsonian activity were docked into inhibitor binding cavity of human adenosine A(2A) receptor (AA2AR) to understand their mode of binding interactions in silico. Lamarckian genetic algorithm methodology was employed for docking simulations using AutoDock 4.2 program. The results signify that the molecular docking approach is reliable and produces a good correlation coefficient (r(2) = 0.483) between docking score and antiparkinsonian activity (in terms of % reduction in catalepsy score). Potent antiparkinsonian agents carried methoxy group in the phenyl ring, exhibited both hydrophilic and lipophilic interactions with lower energy of binding at the AA(2A)R. These molecular docking analyses should, in our view, contribute for further development of selective AA(2A)R antagonists for the treatment of Parkinson's disease.

  14. Molecular Docking and Prediction of Pharmacokinetic Properties of Dual Mechanism Drugs that Block MAO-B and Adenosine A(2A) Receptors for the Treatment of Parkinson's Disease.

    PubMed

    Azam, Faizul; Madi, Arwa M; Ali, Hamed I

    2012-07-01

    Monoamine oxidase B (MAO-B) inhibitory potential of adenosine A(2A) receptor (AA(2A)R) antagonists has raised the possibility of designing dual-target-directed drugs that may provide enhanced symptomatic relief and that may also slow the progression of Parkinson's disease (PD) by protecting against further neurodegeneration. To explain the dual inhibition of MAO-B and AA(2A)R at the molecular level, molecular docking technique was employed. Lamarckian genetic algorithm methodology was used for flexible ligand docking studies. A good correlation (R(2)= 0.524 and 0.627 for MAO-B and AA(2A)R, respectively) was established between docking predicted and experimental K(i) values, which confirms that the molecular docking approach is reliable to study the mechanism of dual interaction of caffeinyl analogs with MAO-B and AA(2A)R. Parameters for Lipinski's "Rule-of-Five" were also calculated to estimate the pharmacokinetic properties of dual-target-directed drugs where both MAO-B inhibition and AA(2A)R antagonism exhibited a positive correlation with calculated LogP having a correlation coefficient R(2) of 0.535 and 0.607, respectively. These results provide some beneficial clues in structural modification for designing new inhibitors as dual-target-directed drugs with desired pharmacokinetic properties for the treatment of PD.

  15. The adenosine A2A receptor agonist CGS 21680 decreases ethanol self-administration in both non-dependent and dependent animals.

    PubMed

    Houchi, Hakim; Persyn, Wolfgang; Legastelois, Rémi; Naassila, Mickaël

    2013-09-01

    There is emerging evidence that the adenosinergic system might be involved in drug addiction and alcohol dependence. We have already demonstrated the involvement of A2A receptors (A2AR) in ethanol-related behaviours in mice. Here, we investigated whether the A2AR agonist CGS 21680 can reduce ethanol operant self-administration in both non-dependent and ethanol-dependent Wistar rats. To rule out a potential involvement of the A1R in the effects of CGS 21680, we also tested its effectiveness to reduce ethanol operant self-administration in both heterozygous and homozygous A1R knockout mice. Our results demonstrated that CGS 21680 (0.065, 0.095 and 0.125 mg/kg, i.p.) had a bimodal effect on 10% ethanol operant self-administration in non-dependent rats. The intermediate dose was also effective in reducing 2% sucrose self-administration. Interestingly, the intermediate dose reduced 10% ethanol self-administration in dependent animals more effectively (75% decrease) when compared with non-dependent animals (57% decrease). These results suggest that the A2AR are involved in CGS 21680 effects since the reduction of ethanol self-administration was not dependent upon the presence of A1R in mice. In conclusion, our findings demonstrated the effectiveness of the A2AR agonist CGS 21680 in a preclinical model of alcohol addiction and suggested that the adenosinergic pathway is a promising target to treat alcohol addiction.

  16. Adenosine Type A2A Receptor in Peripheral Cell from Patients with Alzheimer's Disease, Vascular Dementia, and Idiopathic Normal Pressure Hydrocephalus: A New/Old Potential Target.

    PubMed

    Arosio, Beatrice; Casati, Martina; Gussago, Cristina; Ferri, Evelyn; Abbate, Carlo; Scortichini, Valeria; Colombo, Elena; Rossi, Paolo Dionigi; Mari, Daniela

    2016-09-06

    As the European population gets older, the incidence of neurological disorders increases with significant impact on social costs. Despite differences in disease etiology, several brain disorders in the elderly (e.g., Alzheimer's disease, vascular dementia, normal pressure hydrocephalus) share dementia as a common clinical feature. The current treatment for the majority of these diseases is merely symptomatic and does not modify the course of the illness. Symptoms of normal pressure hydrocephalus are the only ones that can be modified if they are recognized in time and treated appropriately. Therefore, an important clinical strategy may be disclosed by pathogenic pathways that can be modified and to find drugs that can slow down or even arrest disease progression. Possibly a way to answer this question could be by re-examining all the molecules which have so far succeeded in improving many aspects of cognitive deterioration in some neurodegenerative conditions, that were not considered because of controversial opinions. The main purpose of this summary is to further substantiate the hypothesis that the pathway of adenosine type A2A receptor could be used as a potential target to develop new/old therapeutic strategies.

  17. Prolactin receptor and signal transduction to milk protein genes

    SciTech Connect

    Djiane, J.; Daniel, N.; Bignon, C.

    1994-06-01

    After cloning of the mammary gland prolactin (PRL) receptor cDNA, a functional assay was established using co-transfection of PRL receptor cDNA together with a milk protein promoter/chloramphenicol acetyl transferase (CAT) construct in Chinese hamster ovary (CHO) cells. Different mutants of the PRL receptor were tested in this CAT assay to delimit the domains in the receptor necessary for signal transduction to milk protein genes. In CHO cells stably transfected with PRL receptor cDNA, high numbers of PRL receptor are expressed. By metabolic labeling and immunoprecipitation, expressed PRL receptor was identified as a single species of 100 kDa. Using these cells, we analyzed the effects of PRL on intracellular free Ca{sup ++} concentration. PRL stimulates Ca{sup ++} entry and induces secondary Ca{sup ++} mobilization. The entry of Ca{sup ++} is a result of an increase in K{sup +} conductance that hyperpolarizes the membranes. We have also analyzed tyrosine phosphorylation induced by PRL. In CHO cells stably transfected with PRL receptor cDNA, PRL induced a very rapid and transient tyrosine phosphorylation of a 100-kDa protein which is most probably the PRL receptor. The same finding was obtained in mammary membranes after PRL injection to lactating rabbits. Whereas tyrosine kinase inhibitors genistein and lavendustin were without effect, PRL stimulation of milk protein gene promoters was partially inhibited by 2 {mu}M herbimycin in CHO cells co-transfected with PRL receptor cDNA and the {Beta} lactoglobulin CAT construct. Taken together these observations indicate that the cytoplasmic domain of the PRL receptor interacts with one or several tyrosine kinases, which may represent early postreceptor events necessary for PRL signal transduction to milk protein genes. 14 refs., 4 figs.

  18. Structure of the human histamine H1 receptor gene.

    PubMed Central

    De Backer, M D; Loonen, I; Verhasselt, P; Neefs, J M; Luyten, W H

    1998-01-01

    Histamine H1 receptor expression has been reported to change in disorders such as allergic rhinitis, autoimmune myocarditis, rheumatoid arthritis and atherosclerosis. Here we report the isolation and characterization of genomic clones containing the 5' flanking (regulatory) region of the human histamine H1 receptor gene. An intron of approx. 5.8 kb was identified in the 5' untranslated region, which suggests that an entire subfamily of G-protein-coupled receptors may contain an intron immediately upstream of the start codon. The transcription initiation site was mapped by 5' rapid amplification of cDNA ends to a region 6.2 kb upstream of the start codon. Immediately upstream of the transcription start site a fragment of 1.85 kb was identified that showed promoter activity when placed upstream of a luciferase reporter gene and transiently transfected into cells expressing the histamine H1 receptor. The promoter sequence shares a number of characteristics with the promoter sequences of other G-protein-coupled receptor encoding genes, including binding sites for several transcription factors, and the absence of TATA and CAAT sequences at the appropriate locations. The promoter sequence described here differs from that reported previously [Fukui, Fujimoto, Mizuguchi, Sakamoto, Horio, Takai, Yamada and Ito (1994) Biochem. Biophys. Res. Commun. 201, 894-901] because the reported genomic clone was chimaeric. Furthermore our study provides evidence that the 3' untranslated region of the H1 receptor mRNA is much longer than previously accepted. Together, these findings provide a complete view of the structure of the human histamine H1 receptor gene. Both the coding region of the H1 receptor gene and its promoter region were independently mapped to chromosome 3p25. PMID:9794809

  19. A2A adenosine-receptor-mediated facilitation of noradrenaline release in rat tail artery involves protein kinase C activation and betagamma subunits formed after alpha2-adrenoceptor activation.

    PubMed

    Fresco, Paula; Oliveira, Jorge M A; Kunc, Filip; Soares, Ana Sofia; Rocha-Pereira, Carolina; Gonçalves, Jorge; Diniz, Carmen

    2007-07-01

    This work aimed to investigate the molecular mechanisms involved in the interaction of alpha2-adrenoceptors and adenosine A2A-receptor-mediated facilitation of noradrenaline release in rat tail artery, namely the type of G-protein involved in this effect and the step or steps where the signalling cascades triggered by alpha2-adrenoceptors and A2A-receptors interact. The selective adenosine A2A-receptor agonist 2-p-(2-carboxy ethyl) phenethylamino-5'-N-ethylcarboxamidoadenosine (CGS 21680; 100 nM) enhanced tritium overflow evoked by trains of 100 pulses at 5 Hz. This effect was abolished by the selective adenosine A2A-receptor antagonist 5-amino-7-(2-phenyl ethyl)-2-(2-furyl)-pyrazolo-[4,3-e]-1,2,4-triazolo [1,5-c]pyrimidine (SCH 58261; 20 nM) and by yohimbine (1 microM). CGS 21680-mediated effects were also abolished by drugs that disrupted G(i/o)-protein coupling with receptors, PTX (2 microg/ml) or NEM (40 microM), by the anti-G(salpha) peptide (2 microg/ml) anti-G(betagamma) peptide (10 microg/ml) indicating coupling of A2A-receptors to G(salpha) and suggesting a crucial role for G(betagamma) subunits in the A(2A)-receptor-mediated enhancement of tritium overflow. Furthermore, phorbol 12-myristate 13-acetate (PMA; 1 microM) or forskolin (1 microM), direct activators of protein kinase C and of adenylyl cyclase, respectively, also enhanced tritium overflow. In addition, PMA-mediated effects were not observed in the presence of either yohimbine or PTX. Results indicate that facilitatory adenosine A2A-receptors couple to G(salpha) subunits which is essential, but not sufficient, for the release facilitation to occur, requiring the involvement of G(i/o)-protein coupling (it disappears after disruption of G(i/o)-protein coupling, PTX or NEM) and/or G(betagamma) subunits (anti-G(betagamma)). We propose a mechanism for the interaction in study suggesting group 2 AC isoforms as a plausible candidate for the interaction site, as these isoforms can integrate inputs from G

  20. Inosine, an Endogenous Purine Nucleoside, Suppresses Immune Responses and Protects Mice from Experimental Autoimmune Encephalomyelitis: a Role for A2A Adenosine Receptor.

    PubMed

    Junqueira, Stella Célio; Dos Santos Coelho, Igor; Lieberknecht, Vicente; Cunha, Mauricio Peña; Calixto, João B; Rodrigues, Ana Lúcia S; Santos, Adair Roberto Soares; Dutra, Rafael Cypriano

    2016-04-30

    were blocked by inosine treatment. Additionally, inosine consistently inhibited IL-17 levels in peripheral lymphoid tissue, as well as IL-4 levels and A2AR up-regulation in the spinal cord, likely, through an ERK1-independent pathway. EAE: experimental autoimmune encephalomyelitis; MS: multiple sclerosis; A2AR: adenosine A2A receptor; IL-17: interleukin-17; IL-4: interleukin-4.

  1. N9-benzyl-substituted 1,3-dimethyl- and 1,3-dipropyl-pyrimido[2,1-f]purinediones: synthesis and structure-activity relationships at adenosine A1 and A2A receptors.

    PubMed

    Drabczyńska, Anna; Müller, Christa E; Karolak-Wojciechowska, Janina; Schumacher, Britta; Schiedel, Anke; Yuzlenko, Olga; Kieć-Kononowicz, Katarzyna

    2007-07-15

    Synthesis and physicochemical properties of N-benzyl pyrimido[2,1-f]purinediones are described. These derivatives were synthesized by the cyclization of 7-chloropropylo-8-bromo-1,3-dimethyl- or 1,3-dipropyl xanthine derivatives with corresponding (un)substituted benzylamines. Dipropyl derivatives were obtained under microwave irradiation conditions either. The obtained compounds (1-20) were evaluated for their affinity to adenosine A1 and A2A receptors, selected compounds were additionally investigated for affinity to the A3 receptor subtype. The results of the radioligand binding assays to A1 and A2A adenosine receptors showed that most of the 1,3-dimethyl-9-benzylpyrimidopurinediones exhibited selective affinity to A2A receptors at micromolar or submicromolar concentrations (for example, derivative 9 with o-methoxy substituent displayed a Ki value of 0.699 microM at rat A2A receptor with more than 36-fold selectivity). Contrary to previously described arylpyrimido[2,1-f]purinediones dipropyl derivatives (compounds 15-20) showed affinity to both kinds of receptors increased, however A1 affinity increased to a larger extent, with the result that A2A selectivity was abolished. The best adenosine A1 receptor ligand was m-chlorobenzyl derivative 18 (Ki=0.089 microM and 5-fold A1 selectivity). Structure-activity relationships were discussed with the analysis of lipophilic and spatial properties of the investigated compounds. Pharmacophore model of adenosine A1 receptor antagonist was adopted for this purpose.

  2. Down-regulation of adenosine A1 and A2A receptors in peripheral cells from idiopathic normal-pressure hydrocephalus patients.

    PubMed

    Casati, Martina; Arosio, Beatrice; Gussago, Cristina; Ferri, Evelyn; Magni, Lorenzo; Assolari, Lara; Scortichini, Valeria; Nani, Carolina; Rossi, Paolo Dionigi; Mari, Daniela

    2016-02-15

    Idiopathic normal-pressure hydrocephalus (iNPH) is a neurological disease that usually develops in the elderly. Natural history of iNPH is still unknown. It has been hypothesized that cerebrovascular diseases could have a role in etiology of chronic hydrocephalus and studies show an increased prevalence of cardiovascular diseases in iNPH patients. Moreover, evidences show a possible alteration of immune system in iNPH patients. Adenosine (Ado) is a metabolite produced in response to metabolic stress and injury. Adenosine and its receptors play an important role in vascular protection and in the modulation of inflammatory reactions and neuroinflammation. Our aim is to evaluate gene and protein expression of A1R and A2AR in the peripheral blood mononuclear cells (PBMCs) from iNPH patients compared to control subjects. We investigate if Ado system, that plays an important role in central nervous system, in vascular system, and also in inflammation, is involved in pathophysiology of iNPH disease. Our analysis showed that A1R mRNA levels and A1R density in PBMCs from iNPH patients were significantly lower than CT subjects (0.84 ± 0.12 and 2.42 ± 0.42, p<0.001 and 0.31 ± 0.02 and 0.42 ± 0.04, p=0.043; respectively). About A2AR, the gene expression in PBMCs was significantly lower in iNPH than CT (0.65 ± 0.09 and 1.5 ± 0.14, p<0.001) as well as there was a trend in protein expression: iNPH and CT (0.51 ± 0.05 and 0.62 ± 0.03; p=0.172). This preliminary study underlines the involvement of Ado system in iNPH disease whose pathophysiology is still unclear.

  3. Caffeine Reverts Memory But Not Mood Impairment in a Depression-Prone Mouse Strain with Up-Regulated Adenosine A2A Receptor in Hippocampal Glutamate Synapses.

    PubMed

    Machado, Nuno J; Simões, Ana Patrícia; Silva, Henrique B; Ardais, Ana Paula; Kaster, Manuella P; Garção, Pedro; Rodrigues, Diana I; Pochmann, Daniela; Santos, Ana Isabel; Araújo, Inês M; Porciúncula, Lisiane O; Tomé, Ângelo R; Köfalvi, Attila; Vaugeois, Jean-Marie; Agostinho, Paula; El Yacoubi, Malika; Cunha, Rodrigo A; Gomes, Catarina A

    2017-03-01

    Caffeine prophylactically prevents mood and memory impairments through adenosine A2A receptor (A2AR) antagonism. A2AR antagonists also therapeutically revert mood and memory impairments, but it is not known if caffeine is also therapeutically or only prophylactically effective. Since depression is accompanied by mood and memory alterations, we now explored if chronic (4 weeks) caffeine consumption (0.3 g/L) reverts mood and memory impairment in helpless mice (HM, 12 weeks old), a bred-based model of depression. HM displayed higher immobility in the tail suspension and forced swimming tests, greater anxiety in the elevated plus maze, and poorer memory performance (modified Y-maze and object recognition). HM also had reduced density of synaptic (synaptophysin, SNAP-25), namely, glutamatergic (vGluT1; -22 ± 7 %) and GABAergic (vGAT; -23 ± 8 %) markers in the hippocampus. HM displayed higher A2AR density (72 ± 6 %) in hippocampal synapses, an enhanced facilitation of hippocampal glutamate release by the A2AR agonist, CGS21680 (30 nM), and a larger LTP amplitude (54 ± 8 % vs. 21 ± 5 % in controls) that was restored to control levels (30 ± 10 %) by the A2AR antagonist, SCH58261 (50 nM). Notably, caffeine intake reverted memory deficits and reverted the loss of hippocampal synaptic markers but did not affect helpless or anxiety behavior. These results reinforce the validity of HM as an animal model of depression by showing that they also display reference memory deficits. Furthermore, caffeine intake selectively reverted memory but not mood deficits displayed by HM, which are associated with an increased density and functional impact of hippocampal A2AR controlling synaptic glutamatergic function.

  4. Cocaine-Induced Changes of Synaptic Transmission in the Striatum are Modulated by Adenosine A2A Receptors and Involve the Tyrosine Phosphatase STEP

    PubMed Central

    Chiodi, Valentina; Mallozzi, Cinzia; Ferrante, Antonella; Chen, Jiang F; Lombroso, Paul J; Di Stasi, Anna Maria Michela; Popoli, Patrizia; Domenici, Maria Rosaria

    2014-01-01

    The striatum is a brain area implicated in the pharmacological action of drugs of abuse. Adenosine A2A receptors (A2ARs) are highly expressed in the striatum and mediate, at least in part, cocaine-induced psychomotor effects in vivo. Here we studied the synaptic mechanisms implicated in the pharmacological action of cocaine in the striatum and investigated the influence of A2ARs. We found that synaptic transmission was depressed in corticostriatal slices after perfusion with cocaine (10 μM). This effect was reduced by the A2AR antagonist ZM241385 and almost abolished in striatal A2AR-knockout mice (mice lacking A2ARs in striatal neurons, stA2ARKO). The effect of cocaine on synaptic transmission was also prevented by the protein tyrosine phosphatases (PTPs) inhibitor sodium orthovanadate (Na3VO4). In synaptosomes prepared from striatal slices, we found that the activity of striatal-enriched protein tyrosine phosphatase (STEP) was upregulated by cocaine, prevented by ZM241385, and absent in synaptosomes from stA2ARKO. The role played by STEP in cocaine modulation of synaptic transmission was investigated in whole-cell voltage clamp recordings from medium spiny neurons of the striatum. We found that TAT-STEP, a peptide that renders STEP enzymatically inactive, prevented cocaine-induced reduction in AMPA- and NMDA-mediated excitatory post-synaptic currents, whereas the control peptide, TAT-myc, had no effect. These results demonstrate that striatal A2ARs modulate cocaine-induced synaptic depression in the striatum and highlight the potential role of PTPs and specifically STEP in the effects of cocaine. PMID:23989619

  5. Cocaine-induced changes of synaptic transmission in the striatum are modulated by adenosine A2A receptors and involve the tyrosine phosphatase STEP.

    PubMed

    Chiodi, Valentina; Mallozzi, Cinzia; Ferrante, Antonella; Chen, Jiang F; Lombroso, Paul J; Di Stasi, Anna Maria Michela; Popoli, Patrizia; Domenici, Maria Rosaria

    2014-02-01

    The striatum is a brain area implicated in the pharmacological action of drugs of abuse. Adenosine A2A receptors (A2ARs) are highly expressed in the striatum and mediate, at least in part, cocaine-induced psychomotor effects in vivo. Here we studied the synaptic mechanisms implicated in the pharmacological action of cocaine in the striatum and investigated the influence of A2ARs. We found that synaptic transmission was depressed in corticostriatal slices after perfusion with cocaine (10 μM). This effect was reduced by the A2AR antagonist ZM241385 and almost abolished in striatal A2AR-knockout mice (mice lacking A2ARs in striatal neurons, stA2ARKO). The effect of cocaine on synaptic transmission was also prevented by the protein tyrosine phosphatases (PTPs) inhibitor sodium orthovanadate (Na3VO4). In synaptosomes prepared from striatal slices, we found that the activity of striatal-enriched protein tyrosine phosphatase (STEP) was upregulated by cocaine, prevented by ZM241385, and absent in synaptosomes from stA2ARKO. The role played by STEP in cocaine modulation of synaptic transmission was investigated in whole-cell voltage clamp recordings from medium spiny neurons of the striatum. We found that TAT-STEP, a peptide that renders STEP enzymatically inactive, prevented cocaine-induced reduction in AMPA- and NMDA-mediated excitatory post-synaptic currents, whereas the control peptide, TAT-myc, had no effect. These results demonstrate that striatal A2ARs modulate cocaine-induced synaptic depression in the striatum and highlight the potential role of PTPs and specifically STEP in the effects of cocaine.

  6. Pharmacokinetics and metabolism of [(14)C]-tozadenant (SYN-115), a novel A2a receptor antagonist ligand, in healthy volunteers.

    PubMed

    Mancel, Valérie; Mathy, François-Xavier; Boulanger, Pierre; English, Stephen; Croft, Marie; Kenney, Christopher; Knott, Tarra; Stockis, Armel; Bani, Massimo

    2016-09-02

    1. This phase-I study (NCT02240290) was designed to investigate the human absorption, disposition and mass balance of (14)C-tozadenant, a novel A2a receptor antagonist in clinical development for Parkinson s disease. 2. Six healthy male subjects received a single oral dose of tozadenant (240 mg containing 81.47 KBq of [(14)C]-tozadenant). Blood, urine and feces were collected over 14 days. Radioactivity was determined by liquid scintillation counting or accelerator mass spectrometry (AMS). Tozadenant and metabolites were characterized using HPLC-MS/MS and HPLC-AMS with fraction collection. 3. At 4 h, the Cmax of tozadenant was 1.74 μg/mL and AUC(0-t) 35.0 h μg/mL, t1/2 15 h, Vz/F 1.82 L/kg and CL/F 1.40 mL/min/kg. For total [(14)C] radioactivity, the Cmax was 2.29 μg eq/mL at 5 h post-dose and AUC(0-t) 43.9 h μg eq/mL. Unchanged tozadenant amounted to 93% of the radiocarbon AUC(0-48h). At 312 h post-dose, cumulative urinary and fecal excretion of radiocarbon reached 30.5% and 55.1% of the dose, respectively. Unchanged tozadenant reached 11% in urine and 12% of the dose in feces. Tozadenant was excreted as metabolites, including di-and mono-hydroxylated metabolites, N/O dealkylated metabolites, hydrated metabolites. 4. The only identified species circulating in plasma was unchanged tozadenant. Tozadenant was primarily excreted in urine and feces in the form of metabolites.

  7. Adenosine A2A receptor signaling attenuates LPS-induced pro-inflammatory cytokine formation of mouse macrophages by inducing the expression of DUSP1.

    PubMed

    Köröskényi, Krisztina; Kiss, Beáta; Szondy, Zsuzsa

    2016-07-01

    Adenosine is known to reduce inflammation by suppressing the activity of most immune cells. Previous studies have shown that lipopolysaccharide (LPS) stimulated mouse macrophages produce adenosine, and the adenosine A2A receptor (A2AR) signaling activated in an autocrine manner attenuates LPS-induced pro-inflammatory cytokine formation. It has been suggested that A2AR signaling inhibits LPS-induced pro-inflammatory cytokine production through a unique cAMP-dependent, but PKA- and Epac-independent signaling pathway. However, the mechanism of inhibition was not identified so far. Here we report that LPS stimulation enhances A2AR expression in mouse bone marrow derived macrophages, and loss of A2ARs results in enhanced LPS-induced pro-inflammatory response. Loss of A2ARs in A2AR null macrophages did not alter the LPS-induced NF-κB activation, but an enhanced basal and LPS-induced phosphorylation of MAP kinases (especially that of JNKs) was detected in A2AR null cells. A2AR signaling did not alter the LPS-induced phosphorylation of their upstream kinases, but by regulating adenylate cyclase activity it enhanced the expression of dual specific phosphatase (DUSP)1, a negative regulator of MAP kinases. As a result, lower basal and LPS-induced DUSP1 mRNA and protein levels can be detected in A2AR null macrophages. Silencing of DUSP1 mRNA expression resulted in higher basal and LPS-induced JNK phosphorylation and LPS-induced pro-inflammatory cytokine formation in wild type macrophages, but had no effect on that in A2AR null cells. Our data indicate that A2AR signaling regulates both basal and LPS-induced DUSP1 levels in macrophages via activating the adenylate cyclase pathway.

  8. Androgen receptor gene mutation, rearrangement, polymorphism

    PubMed Central

    Eisermann, Kurtis; Wang, Dan; Jing, Yifeng; Pascal, Laura E.

    2013-01-01

    Genetic aberrations of the androgen receptor (AR) caused by mutations, rearrangements, and polymorphisms result in a mutant receptor that has varied functions compared to wild type AR. To date, over 1,000 mutations have been reported in the AR with most of these being associated with androgen insensitivity syndrome (AIS). While mutations of AR associated with prostate cancer occur less often in early stage localized disease, mutations in castration-resistant prostate cancer (CRPC) patients treated with anti-androgens occur more frequently with 10-30% of these patients having some form of mutation in the AR. Resistance to anti-androgen therapy usually results from gain-of-function mutations in the LBD such as is seen with bicalutamide and more recently with enzalutamide (MDV3100). Thus, it is crucial to investigate these new AR mutations arising from drug resistance to anti-androgens and other small molecule pharmacological agents. PMID:25045626

  9. Mouse T-cell receptor variable gene segment families

    SciTech Connect

    Arden, B.; Kabelitz, D.; Clark, S.P.; Mak, T.W.

    1995-10-01

    All mouse T-cell receptor {alpha}/{delta}, {beta}, and {gamma} variable (Tcra/d-, b-, and g-V) gene segments were aligned to compare the sequences with one another, to group them into subfamilies, and to derive a name which complies with the standard nomenclature. it was necessary to change the names of some V gene segments because they conflicted with those of other segments. The traditional classification into subfamilies was re-evaluated using a much larger pool of sequences. In the mouse, most V gene segments can be grouped into subfamilies of closely related genes with significantly less similarity between different subfamilies. 118 refs., 11 figs., 4 tabs.

  10. Combining selectivity and affinity predictions using an integrated Support Vector Machine (SVM) approach: An alternative tool to discriminate between the human adenosine A(2A) and A(3) receptor pyrazolo-triazolo-pyrimidine antagonists binding sites.

    PubMed

    Michielan, Lisa; Bolcato, Chiara; Federico, Stephanie; Cacciari, Barbara; Bacilieri, Magdalena; Klotz, Karl-Norbert; Kachler, Sonja; Pastorin, Giorgia; Cardin, Riccardo; Sperduti, Alessandro; Spalluto, Giampiero; Moro, Stefano

    2009-07-15

    G Protein-coupled receptors (GPCRs) selectivity is an important aspect of drug discovery process, and distinguishing between related receptor subtypes is often the key to therapeutic success. Nowadays, very few valuable computational tools are available for the prediction of receptor subtypes selectivity. In the present study, we present an alternative application of the Support Vector Machine (SVM) and Support Vector Regression (SVR) methodologies to simultaneously describe both A(2A)R versus A(3)R subtypes selectivity profile and the corresponding receptor binding affinities. We have implemented an integrated application of SVM-SVR approach, based on the use of our recently reported autocorrelated molecular descriptors encoding for the Molecular Electrostatic Potential (autoMEP), to simultaneously discriminate A(2A)R versus A(3)R antagonists and to predict their binding affinity to the corresponding receptor subtype of a large dataset of known pyrazolo-triazolo-pyrimidine analogs. To validate our approach, we have synthetized 51 new pyrazolo-triazolo-pyrimidine derivatives anticipating both A(2A)R/A(3)R subtypes selectivity and receptor binding affinity profiles.

  11. Peroxisome proliferator-activated receptor alpha target genes.

    PubMed

    Rakhshandehroo, Maryam; Knoch, Bianca; Müller, Michael; Kersten, Sander

    2010-01-01

    The peroxisome proliferator-activated receptor alpha (PPARα) is a ligand-activated transcription factor involved in the regulation of a variety of processes, ranging from inflammation and immunity to nutrient metabolism and energy homeostasis. PPARα serves as a molecular target for hypolipidemic fibrates drugs which bind the receptor with high affinity. Furthermore, PPARα binds and is activated by numerous fatty acids and fatty acid-derived compounds. PPARα governs biological processes by altering the expression of a large number of target genes. Accordingly, the specific role of PPARα is directly related to the biological function of its target genes. Here, we present an overview of the involvement of PPARα in lipid metabolism and other pathways through a detailed analysis of the different known or putative PPARα target genes. The emphasis is on gene regulation by PPARα in liver although many of the results likely apply to other organs and tissues as well.

  12. Peroxisome Proliferator-Activated Receptor Alpha Target Genes

    PubMed Central

    Rakhshandehroo, Maryam; Knoch, Bianca; Müller, Michael; Kersten, Sander

    2010-01-01

    The peroxisome proliferator-activated receptor alpha (PPARα) is a ligand-activated transcription factor involved in the regulation of a variety of processes, ranging from inflammation and immunity to nutrient metabolism and energy homeostasis. PPARα serves as a molecular target for hypolipidemic fibrates drugs which bind the receptor with high affinity. Furthermore, PPARα binds and is activated by numerous fatty acids and fatty acid-derived compounds. PPARα governs biological processes by altering the expression of a large number of target genes. Accordingly, the specific role of PPARα is directly related to the biological function of its target genes. Here, we present an overview of the involvement of PPARα in lipid metabolism and other pathways through a detailed analysis of the different known or putative PPARα target genes. The emphasis is on gene regulation by PPARα in liver although many of the results likely apply to other organs and tissues as well. PMID:20936127

  13. Synthesis and in vivo Evaluation of Fluorine-18 and Iodine-123 Pyrazolo[4,3-e]-1,2,4-triazolo[1,5-c]pyrimidine Derivatives as PET and SPECT Radiotracers for Mapping A2A Receptors.

    PubMed

    Vala, Christine; Morley, Thomas J; Zhang, Xuechun; Papin, Caroline; Tavares, Adriana Alexandre S; Lee, H Sharon; Constantinescu, Cristian; Barret, Olivier; Carroll, Vincent M; Baldwin, Ronald M; Tamagnan, Gilles D; Alagille, David

    2016-09-06

    Imaging agents that target adenosine type 2A (A2A ) receptors play an important role in evaluating new pharmaceuticals targeting these receptors, such as those currently being developed for the treatment of movement disorders like Parkinson's disease. They are also useful for monitoring progression and treatment efficacy by providing a noninvasive tool to map changes in A2A receptor density and function in neurodegenerative diseases. We previously described the successful evaluation of two A2A -specific radiotracers in both nonhuman primates and in subsequent human clinical trials: [(123) I]MNI-420 and [(18) F]MNI-444. Herein we describe the development of both of these radiotracers by selection from a series of A2A ligands, based on the pyrazolo[4,3-e]-1,2,4-triazolo[1,5-c]pyrimidine core of preladenant. Each of this series of 16 ligands was found to bind to recombinant human A2A receptor in the low nanomolar range, and of these 16, six were radiolabeled with either fluorine-18 or iodine-123 and evaluated in nonhuman primates. These initial in vivo results resulted in the identification of 7-(2-(4-(4-(2-[(18) F]fluoroethoxy)phenyl)piperazin-1-yl)ethyl)-2-(furan-2-yl)-7H-pyrazolo[4,3-e][1,2,4]triazolo[1,5-c]pyrimidin-5-amine ([(18) F]MNI-444) and 7-(2-(4-(2-fluoro-4-[(123) I]iodophenyl)piperazin-1-yl)ethyl)-2-(furan-2-yl)-7H-imidazo[1,2-c]pyrazolo[4,3-e]pyrimidin-5-amine ([(123) I]MNI-420) as PET and SPECT radiopharmaceuticals for mapping A2A receptors in brain.

  14. Evolution of an expanded mannose receptor gene family.

    PubMed

    Staines, Karen; Hunt, Lawrence G; Young, John R; Butter, Colin

    2014-01-01

    Sequences of peptides from a protein specifically immunoprecipitated by an antibody, KUL01, that recognises chicken macrophages, identified a homologue of the mammalian mannose receptor, MRC1, which we called MRC1L-B. Inspection of the genomic environment of the chicken gene revealed an array of five paralogous genes, MRC1L-A to MRC1L-E, located between conserved flanking genes found either side of the single MRC1 gene in mammals. Transcripts of all five genes were detected in RNA from a macrophage cell line and other RNAs, whose sequences allowed the precise definition of spliced exons, confirming or correcting existing bioinformatic annotation. The confirmed gene structures were used to locate orthologues of all five genes in the genomes of two other avian species and of the painted turtle, all with intact coding sequences. The lizard genome had only three genes, one orthologue of MRC1L-A and two orthologues of the MRC1L-B antigen gene resulting from a recent duplication. The Xenopus genome, like that of most mammals, had only a single MRC1-like gene at the corresponding locus. MRC1L-A and MRC1L-B genes had similar cytoplasmic regions that may be indicative of similar subcellular migration and functions. Cytoplasmic regions of the other three genes were very divergent, possibly indicating the evolution of a new functional repertoire for this family of molecules, which might include novel interactions with pathogens.

  15. Selection for Genes Encoding Secreted Proteins and Receptors

    NASA Astrophysics Data System (ADS)

    Klein, Robert D.; Gu, Qimin; Goddard, Audrey; Rosenthal, Arnon

    1996-07-01

    Extracellular proteins play an essential role in the formation, differentiation, and maintenance of multicellular organisms. Despite that, the systematic identification of genes encoding these proteins has not been possible. We describe here a highly efficient method to isolate genes encoding secreted and membrane-bound proteins by using a single-step selection in yeast. Application of this method, termed signal peptide selection, to various tissues yielded 559 clones that appear to encode known or novel extracellular proteins. These include members of the transforming growth factor and epidermal growth factor protein families, endocrine hormones, tyrosine kinase receptors, serine/threonine kinase receptors, seven transmembrane receptors, cell adhesion molecules, extracellular matrix proteins, plasma proteins, and ion channels. The eventual identification of most, or all, extracellular signaling molecules will advance our understanding of fundamental biological processes and our ability to intervene in disease states.

  16. Characterization of the "CCR5" Chemokine Receptor Gene

    ERIC Educational Resources Information Center

    Thomas, John C.

    2004-01-01

    The life cycle of retroviruses is an essential topic of modern cell biology instruction. Furthermore, the process of HIV viral entry into the cell is a question of great interest in basic and clinical biology. This paper describes how students can easily recover their own DNA, amplify a portion of the "CCR5" chemokine receptor gene, characterize…

  17. Receptor-like kinases from Arabidopsis form a monophyletic gene family related to animal receptor kinases

    PubMed Central

    Shiu, Shin-Han; Bleecker, Anthony B.

    2001-01-01

    Plant receptor-like kinases (RLKs) are proteins with a predicted signal sequence, single transmembrane region, and cytoplasmic kinase domain. Receptor-like kinases belong to a large gene family with at least 610 members that represent nearly 2.5% of Arabidopsis protein coding genes. We have categorized members of this family into subfamilies based on both the identity of the extracellular domains and the phylogenetic relationships between the kinase domains of subfamily members. Surprisingly, this structurally defined group of genes is monophyletic with respect to kinase domains when compared with the other eukaryotic kinase families. In an extended analysis, animal receptor kinases, Raf kinases, plant RLKs, and animal receptor tyrosine kinases form a well supported group sharing a common origin within the superfamily of serine/threonine/tyrosine kinases. Among animal kinase sequences, Drosophila Pelle and related cytoplasmic kinases fall within the plant RLK clade, which we now define as the RLK/Pelle family. A survey of expressed sequence tag records for land plants reveals that mosses, ferns, conifers, and flowering plants have similar percentages of expressed sequence tags representing RLK/Pelle homologs, suggesting that the size of this gene family may have been close to the present-day level before the diversification of land plant lineages. The distribution pattern of four RLK subfamilies on Arabidopsis chromosomes indicates that the expansion of this gene family is partly a consequence of duplication and reshuffling of the Arabidopsis genome and of the generation of tandem repeats. PMID:11526204

  18. Optimization of 6-Heterocyclic-2-(1H-pyrazol-1-yl)-N-(pyridin-2-yl)pyrimidin-4-amine as Potent Adenosine A2A Receptor Antagonists for the Treatment of Parkinson’s Disease

    PubMed Central

    2014-01-01

    Parkinson’s disease is a neurodegenerative disease characterized by the motor symptoms of bradykinesia, tremor, and rigidity. Current therapies are based mainly on dopaminergic replacement strategies by administration of either dopamine agonists or dopamine precursor levodopa (L-Dopa). These treatments provide symptomatic relief without slowing or stopping the disease progression, and long-term usage of these drugs is associated with diminished efficacy, motor fluctuation, and dyskinisia. Unfortunately, there had been few novel treatments developed in the past decades. Among nondopaminergic strategies for the treatment of Parkinson’s disease, antagonism of the adenosine A2A receptor has emerged to show great potential. Here we report the optimization of a new chemical scaffold, which achieved exceptional receptor binding affinity and ligand efficiency against adenosine A2A receptor. The leading compounds demonstrated excellent efficacy in the haloperidol induced catalepsy model for Parkinson’s disease. PMID:24922583

  19. Interspecies variations in Bordetella catecholamine receptor gene regulation and function.

    PubMed

    Brickman, Timothy J; Suhadolc, Ryan J; Armstrong, Sandra K

    2015-12-01

    Bordetella bronchiseptica can use catecholamines to obtain iron from transferrin and lactoferrin via uptake pathways involving the BfrA, BfrD, and BfrE outer membrane receptor proteins, and although Bordetella pertussis has the bfrD and bfrE genes, the role of these genes in iron uptake has not been demonstrated. In this study, the bfrD and bfrE genes of B. pertussis were shown to be functional in B. bronchiseptica, but neither B. bronchiseptica bfrD nor bfrE imparted catecholamine utilization to B. pertussis. Gene fusion analyses found that expression of B. bronchiseptica bfrA was increased during iron starvation, as is common for iron receptor genes, but that expression of the bfrD and bfrE genes of both species was decreased during iron limitation. As shown previously for B. pertussis, bfrD expression in B. bronchiseptica was also dependent on the BvgAS virulence regulatory system; however, in contrast to the case in B. pertussis, the known modulators nicotinic acid and sulfate, which silence Bvg-activated genes, did not silence expression of bfrD in B. bronchiseptica. Further studies using a B. bronchiseptica bvgAS mutant expressing the B. pertussis bvgAS genes revealed that the interspecies differences in bfrD modulation are partly due to BvgAS differences. Mouse respiratory infection experiments determined that catecholamine utilization contributes to the in vivo fitness of B. bronchiseptica and B. pertussis. Additional evidence of the in vivo importance of the B. pertussis receptors was obtained from serologic studies demonstrating pertussis patient serum reactivity with the B. pertussis BfrD and BfrE proteins.

  20. Interspecies Variations in Bordetella Catecholamine Receptor Gene Regulation and Function

    PubMed Central

    Brickman, Timothy J.; Suhadolc, Ryan J.

    2015-01-01

    Bordetella bronchiseptica can use catecholamines to obtain iron from transferrin and lactoferrin via uptake pathways involving the BfrA, BfrD, and BfrE outer membrane receptor proteins, and although Bordetella pertussis has the bfrD and bfrE genes, the role of these genes in iron uptake has not been demonstrated. In this study, the bfrD and bfrE genes of B. pertussis were shown to be functional in B. bronchiseptica, but neither B. bronchiseptica bfrD nor bfrE imparted catecholamine utilization to B. pertussis. Gene fusion analyses found that expression of B. bronchiseptica bfrA was increased during iron starvation, as is common for iron receptor genes, but that expression of the bfrD and bfrE genes of both species was decreased during iron limitation. As shown previously for B. pertussis, bfrD expression in B. bronchiseptica was also dependent on the BvgAS virulence regulatory system; however, in contrast to the case in B. pertussis, the known modulators nicotinic acid and sulfate, which silence Bvg-activated genes, did not silence expression of bfrD in B. bronchiseptica. Further studies using a B. bronchiseptica bvgAS mutant expressing the B. pertussis bvgAS genes revealed that the interspecies differences in bfrD modulation are partly due to BvgAS differences. Mouse respiratory infection experiments determined that catecholamine utilization contributes to the in vivo fitness of B. bronchiseptica and B. pertussis. Additional evidence of the in vivo importance of the B. pertussis receptors was obtained from serologic studies demonstrating pertussis patient serum reactivity with the B. pertussis BfrD and BfrE proteins. PMID:26371128

  1. Folate receptor gene variants and neural tube defect occurrence

    SciTech Connect

    Finnell, R.; Greer, K.; Lammer, E.

    1994-09-01

    Recent epidemiological evidence shows that periconceptional use of folic acid supplements may prevent 40-50% of neural tube defects (NTDs). The FDA has subsequently recommended folic acid supplementation of all women of childbearing potential, even though the mechanism by which folic acid prevents NTDs is unknown. We investigated genetic variation of a candidate gene, the 5-methyltetrahydrofolate (5-MeTHF) receptor, that may mediate this preventive effect. The receptor concentrates folate within cells and we have localized its mRNA to neuroepithelial cells during neurulation. Our hypothesis is that dysfunctional 5-MeTHF receptors inadequately concentrate folate intracellularly, predisposing infants to NTDs. We have completed SSCP analysis on 3 of the 4 coding exons of the 5-MeTHF receptor gene of 474 infants participating in a large population-based epidemiological case-control study of NTDs in California; genotyping of another 500 infants is ongoing. Genomic DNA was extracted from residual blood spots from newborn screening samples of cases and controls. Genotyping was done blinded to case status. Polymorphisms have been detected for exons 4 and 5; fourteen percent of the infants have exon 5 polymorphisms. Data will be presented on the prevalence of 5-MeTHF receptor polymorphisms among cases and controls. Relationships among the polymorphisms and NTD occurrence may shed light on how folic acid supplementation prevents NTDs.

  2. CRDB: Database of Chemosensory Receptor Gene Families in Vertebrate

    PubMed Central

    Wu, Xiaoli; Zhong, Yang

    2012-01-01

    Chemosensory receptors (CR) are crucial for animals to sense the environmental changes and survive on earth. The emergence of whole-genome sequences provides us an opportunity to identify the entire CR gene repertoires. To completely gain more insight into the evolution of CR genes in vertebrates, we identified the nearly all CR genes in 25 vertebrates using homology-based approaches. Among these CR gene repertoires, nearly half of them were identified for the first time in those previously uncharacterized species, such as the guinea pig, giant panda and elephant, etc. Consistent with previous findings, we found that the numbers of CR genes vary extensively among different species, suggesting an extreme form of ‘birth-and-death’ evolution. For the purpose of facilitating CR gene analysis, we constructed a database with the goals to provide a resource for CR genes annotation and a web tool for exploring their evolutionary patterns. Besides a search engine for the gene extraction from a specific chromosome region, an easy-to-use phylogenetic analysis tool was also provided to facilitate online phylogeny study of CR genes. Our work can provide a rigorous platform for further study on the evolution of CR genes in vertebrates. PMID:22393364

  3. Olfactory receptor gene expression in tiger salamander olfactory epithelium.

    PubMed

    Marchand, James E; Yang, Xinhai; Chikaraishi, Dona; Krieger, Jurgen; Breer, Heinz; Kauer, John S

    2004-06-28

    Physiological studies of odor-elicited responses from the olfactory epithelium and bulb in the tiger salamander, Ambystoma tigrinum, have elucidated a number of features of olfactory coding that appear to be conserved across several vertebrate species. This animal model has provided an accessible in vivo system for observing individual and ensemble olfactory responses to odorant stimulation using biochemical, neurophysiological, and behavioral assays. In this paper we have complemented these studies by characterizing 35 candidate odorant receptor genes. These receptor sequences are similar to those of the large families of olfactory receptors found in mammals and fish. In situ hybridization, using RNA probes to 20 of these sequences, demonstrates differential distributions of labeled cells across the extent and within the depth of the olfactory epithelium. The distributions of cells labeled with probes to different receptors show spatially restricted patterns that are generally localized to different degrees in medial-lateral and anterior-posterior directions. The patterns of receptor expression in the ventral olfactory epithelium (OE) are mirrored in the dorsal OE. We present a hypothesis as to how the sensory neuron populations expressing different receptor types responding to a particular odorant may relate to the distribution patterns of epithelial and bulbar responses previously characterized using single-unit and voltage-sensitive dye recording methods.

  4. Parallel evolution of domesticated Caenorhabditis species targets pheromone receptor genes.

    PubMed

    McGrath, Patrick T; Xu, Yifan; Ailion, Michael; Garrison, Jennifer L; Butcher, Rebecca A; Bargmann, Cornelia I

    2011-08-17

    Evolution can follow predictable genetic trajectories, indicating that discrete environmental shifts can select for reproducible genetic changes. Conspecific individuals are an important feature of an animal's environment, and a potential source of selective pressures. Here we show that adaptation of two Caenorhabditis species to growth at high density, a feature common to domestic environments, occurs by reproducible genetic changes to pheromone receptor genes. Chemical communication through pheromones that accumulate during high-density growth causes young nematode larvae to enter the long-lived but non-reproductive dauer stage. Two strains of Caenorhabditis elegans grown at high density have independently acquired multigenic resistance to pheromone-induced dauer formation. In each strain, resistance to the pheromone ascaroside C3 results from a deletion that disrupts the adjacent chemoreceptor genes serpentine receptor class g (srg)-36 and -37. Through misexpression experiments, we show that these genes encode redundant G-protein-coupled receptors for ascaroside C3. Multigenic resistance to dauer formation has also arisen in high-density cultures of a different nematode species, Caenorhabditis briggsae, resulting in part from deletion of an srg gene paralogous to srg-36 and srg-37. These results demonstrate rapid remodelling of the chemoreceptor repertoire as an adaptation to specific environments, and indicate that parallel changes to a common genetic substrate can affect life-history traits across species.

  5. Identification of novel androgen receptor target genes in prostate cancer

    PubMed Central

    Jariwala, Unnati; Prescott, Jennifer; Jia, Li; Barski, Artem; Pregizer, Steve; Cogan, Jon P; Arasheben, Armin; Tilley, Wayne D; Scher, Howard I; Gerald, William L; Buchanan, Grant; Coetzee, Gerhard A; Frenkel, Baruch

    2007-01-01

    Background The androgen receptor (AR) plays critical roles in both androgen-dependent and castrate-resistant prostate cancer (PCa). However, little is known about AR target genes that mediate the receptor's roles in disease progression. Results Using Chromatin Immunoprecipitation (ChIP) Display, we discovered 19 novel loci occupied by the AR in castrate resistant C4-2B PCa cells. Only four of the 19 AR-occupied regions were within 10-kb 5'-flanking regulatory sequences. Three were located up to 4-kb 3' of the nearest gene, eight were intragenic and four were in gene deserts. Whereas the AR occupied the same loci in C4-2B (castrate resistant) and LNCaP (androgen-dependent) PCa cells, differences between the two cell lines were observed in the response of nearby genes to androgens. Among the genes strongly stimulated by DHT in C4-2B cells – D-dopachrome tautomerase (DDT), Protein kinase C delta (PRKCD), Glutathione S- transferase theta 2 (GSTT2), Transient receptor potential cation channel subfamily V member 3 (TRPV3), and Pyrroline-5-carboxylate reductase 1 (PYCR1) – most were less strongly or hardly stimulated in LNCaP cells. Another AR target gene, ornithine aminotransferase (OAT), was AR-stimulated in a ligand-independent manner, since it was repressed by AR siRNA knockdown, but not stimulated by DHT. We also present evidence for in vivo AR-mediated regulation of several genes identified by ChIP Display. For example, PRKCD and PYCR1, which may contribute to PCa cell growth and survival, are expressed in PCa biopsies from primary tumors before and after ablation and in metastatic lesions in a manner consistent with AR-mediated stimulation. Conclusion AR genomic occupancy is similar between LNCaP and C4-2B cells and is not biased towards 5' gene flanking sequences. The AR transcriptionally regulates less than half the genes nearby AR-occupied regions, usually but not always, in a ligand-dependent manner. Most are stimulated and a few are repressed. In general

  6. The Role of Metabotropic Glutamate Receptor Genes in Schizophrenia

    PubMed Central

    Maj, Carlo; Minelli, Alessandra; Giacopuzzi, Edoardo; Sacchetti, Emilio; Gennarelli, Massimo

    2016-01-01

    Genomic studies revealed two main components in the genetic architecture of schizophrenia, one constituted by common variants determining a distributed polygenic effect and one represented by a large number of heterogeneous rare and highly disruptive mutations. These gene modifications often affect neural transmission and different studies proved an involvement of metabotropic glutamate receptors in schizophrenia phenotype. Through the combination of literature information with genomic data from public repositories, we analyzed the current knowledge on the involvement of genetic variations of the human metabotropic glutamate receptors in schizophrenia and related endophenotypes. Despite the analysis did not reveal a definitive connection, different suggestive associations have been identified and in particular a relevant role has emerged for GRM3 in affecting specific schizophrenia endophenotypes. This supports the hypothesis that these receptors are directly involved in schizophrenia disorder. PMID:27296644

  7. The Role of Metabotropic Glutamate Receptor Genes in Schizophrenia.

    PubMed

    Maj, Carlo; Minelli, Alessandra; Giacopuzzi, Edoardo; Sacchetti, Emilio; Gennarelli, Massimo

    2016-01-01

    Genomic studies revealed two main components in the genetic architecture of schizophrenia, one constituted by common variants determining a distributed polygenic effect and one represented by a large number of heterogeneous rare and highly disruptive mutations. These gene modifications often affect neural transmission and different studies proved an involvement of metabotropic glutamate receptors in schizophrenia phenotype. Through the combination of literature information with genomic data from public repositories, we analyzed the current knowledge on the involvement of genetic variations of the human metabotropic glutamate receptors in schizophrenia and related endophenotypes. Despite the analysis did not reveal a definitive connection, different suggestive associations have been identified and in particular a relevant role has emerged for GRM3 in affecting specific schizophrenia endophenotypes. This supports the hypothesis that these receptors are directly involved in schizophrenia disorder.

  8. Replicated Risk Nicotinic Cholinergic Receptor Genes for Nicotine Dependence

    PubMed Central

    Zuo, Lingjun; Garcia-Milian, Rolando; Guo, Xiaoyun; Zhong, Chunlong; Tan, Yunlong; Wang, Zhiren; Wang, Jijun; Wang, Xiaoping; Kang, Longli; Lu, Lu; Chen, Xiangning; Li, Chiang-Shan R.; Luo, Xingguang

    2016-01-01

    It has been hypothesized that the nicotinic acetylcholine receptors (nAChRs) play important roles in nicotine dependence (ND) and influence the number of cigarettes smoked per day (CPD) in smokers. We compiled the associations between nicotinic cholinergic receptor genes (CHRNs) and ND/CPD that were replicated across different studies, reviewed the expression of these risk genes in human/mouse brains, and verified their expression using independent samples of both human and mouse brains. The potential functions of the replicated risk variants were examined using cis-eQTL analysis or predicted using a series of bioinformatics analyses. We found replicated and significant associations for ND/CPD at 19 SNPs in six genes in three genomic regions (CHRNB3-A6, CHRNA5-A3-B4 and CHRNA4). These six risk genes are expressed in at least 18 distinct areas of the human/mouse brain, with verification in our independent human and mouse brain samples. The risk variants might influence the transcription, expression and splicing of the risk genes, alter RNA secondary or protein structure. We conclude that the replicated associations between CHRNB3-A6, CHRNA5-A3-B4, CHRNA4 and ND/CPD are very robust. More research is needed to examine how these genetic variants contribute to the risk for ND/CPD. PMID:27827986

  9. Replicated Risk Nicotinic Cholinergic Receptor Genes for Nicotine Dependence.

    PubMed

    Zuo, Lingjun; Garcia-Milian, Rolando; Guo, Xiaoyun; Zhong, Chunlong; Tan, Yunlong; Wang, Zhiren; Wang, Jijun; Wang, Xiaoping; Kang, Longli; Lu, Lu; Chen, Xiangning; Li, Chiang-Shan R; Luo, Xingguang

    2016-11-07

    It has been hypothesized that the nicotinic acetylcholine receptors (nAChRs) play important roles in nicotine dependence (ND) and influence the number of cigarettes smoked per day (CPD) in smokers. We compiled the associations between nicotinic cholinergic receptor genes (CHRNs) and ND/CPD that were replicated across different studies, reviewed the expression of these risk genes in human/mouse brains, and verified their expression using independent samples of both human and mouse brains. The potential functions of the replicated risk variants were examined using cis-eQTL analysis or predicted using a series of bioinformatics analyses. We found replicated and significant associations for ND/CPD at 19 SNPs in six genes in three genomic regions (CHRNB3-A6, CHRNA5-A3-B4 and CHRNA4). These six risk genes are expressed in at least 18 distinct areas of the human/mouse brain, with verification in our independent human and mouse brain samples. The risk variants might influence the transcription, expression and splicing of the risk genes, alter RNA secondary or protein structure. We conclude that the replicated associations between CHRNB3-A6, CHRNA5-A3-B4,CHRNA4 and ND/CPD are very robust. More research is needed to examine how these genetic variants contribute to the risk for ND/CPD.

  10. Mechanisms of oestrogen receptor (ER) gene regulation in breast cancer

    PubMed Central

    2016-01-01

    Most breast cancers are driven by a transcription factor called oestrogen receptor (ER). Understanding the mechanisms of ER activity in breast cancer has been a major research interest and recent genomic advances have revealed extraordinary insights into how ER mediates gene transcription and what occurs during endocrine resistance. This review discusses our current understanding on ER activity, with an emphasis on several evolving, but important areas of ER biology. PMID:26884552

  11. Complete structural characterisation of the human aryl hydrocarbon receptor gene

    PubMed Central

    Bennett, P; Ramsden, D B; Williams, A C

    1996-01-01

    Aims—To clone and characterise the complete structural gene for the human aryl hydrocarbon receptor (AhR). This gene, located on chromosome 7, encodes a cytosolic receptor protein which, upon activation by various xenobiotic ligands, translocates to the nucleus, where it acts as a specific transcription factor. Methods—Primers, based on the AhR cDNA sequence, were used in conjunction with recently developed long range PCR techniques to amplify contiguous sections of the cognate gene. The amplicons produced were then cloned and characterised. A cDNA probe was also used to screen a human P1 library. Results—Using the cDNA primers, DNA fragments which mapped the entire coding region of the gene were amplified and cloned. All but one of these fragments were amplified directly from human genomic DNA. The remaining fragment was amplified using DNA prepared from a P1 clone as the PCR template. This P1 clone, obtained by screening a human P1 library, also contained the entire Ah locus. Characterisation of amplified and cloned DNA fragments provided sufficient information for the construction of a complete structural map of the gene. This also included 150 base pairs of nucleotide sequence data at all intronic termini. Conclusions—These data indicate that the human AhR gene is about 50 kilobases long and contains 11 exons. The overall intron/exon structure of the human gene is homologous to that of the previously characterised mouse gene; however, it is probably some 20 kilobases larger. These results demonstrate the need for further characterisation and provide the data to facilitate this. Images PMID:16696038

  12. Constitutive androstane receptor activation evokes the expression of glycolytic genes.

    PubMed

    Yarushkin, Andrei A; Kazantseva, Yuliya A; Prokopyeva, Elena A; Markova, Diana N; Pustylnyak, Yuliya A; Pustylnyak, Vladimir O

    2016-09-23

    It is well-known that constitutive androstane receptor (CAR) activation by 1,4-bis[2-(3,5-dichloropyridyloxy)]benzene (TCPOBOP) increases the liver-to-body weight ratio. CAR-mediated liver growth is correlated with increased expression of the pleiotropic transcription factor cMyc, which stimulates cell cycle regulatory genes and drives proliferating cells into S phase. Because glycolysis supports cell proliferation and cMyc is essential for the activation of glycolytic genes, we hypothesized that CAR-mediated up-regulation of cMyc in mouse livers might play a role in inducing the expression of glycolytic genes. The aim of the present study was to examine the effect of long-term CAR activation on glycolytic genes in a mouse model not subjected to metabolic stress. We demonstrated that long-term CAR activation by TCPOBOP increases expression of cMyc, which was correlated with reduced expression of gluconeogenic genes and up-regulation of glucose transporter, glycolytic and mitochondrial pyruvate metabolising genes. These changes in gene expression after TCPOBOP treatment were strongly correlated with changes in levels of glycolytic intermediates in mouse livers. Moreover, we demonstrated a significant positive regulatory effect of TCPOBOP-activated CAR on both mRNA and protein levels of Pkm2, a master regulator of glucose metabolism and cell proliferation. Thus, our findings provide evidence to support the conclusion that CAR activation initiates a transcriptional program that facilitates the coordinated metabolic activities required for cell proliferation.

  13. Polymorphism of the progesterone receptor gene associated with endometriosis in patients from Goiás, Brazil.

    PubMed

    Costa, I R; Silva, R C P C; Frare, A B; Silva, C T X; Bordin, B M; Souza, S R; Ribeiro Júnior, C L; Moura, K K V O

    2011-07-06

    We investigated a possible link between endometriosis and polymorphism of the progesterone receptor gene (PROGINS). The endometriosis group consisted of 54 patients with a diagnosis of endometriosis by laparoscopy, and the control group comprised 44 women without endometriosis. Genotypes for PROGINS polymorphisms (A1/A1, A1/A2 and A2/A2) were determined by polymerase chain reaction and analyzed on a 2% agarose gel stained with ethidium bromide. The frequency of polymorphic genotypes (A1/A2 and A2/A2) was significantly higher in patients with endometriosis (33%) than in the control group (16%). We conclude that there is a significant correlation between PROGINS polymorphism and endometriosis.

  14. Dopamine Receptor Genes Modulate Associative Memory in Old Age.

    PubMed

    Papenberg, Goran; Becker, Nina; Ferencz, Beata; Naveh-Benjamin, Moshe; Laukka, Erika J; Bäckman, Lars; Brehmer, Yvonne

    2017-02-01

    Previous research shows that associative memory declines more than item memory in aging. Although the underlying mechanisms of this selective impairment remain poorly understood, animal and human data suggest that dopaminergic modulation may be particularly relevant for associative binding. We investigated the influence of dopamine (DA) receptor genes on item and associative memory in a population-based sample of older adults (n = 525, aged 60 years), assessed with a face-scene item associative memory task. The effects of single-nucleotide polymorphisms of DA D1 (DRD1; rs4532), D2 (DRD2/ANKK1/Taq1A; rs1800497), and D3 (DRD3/Ser9Gly; rs6280) receptor genes were examined and combined into a single genetic score. Individuals carrying more beneficial alleles, presumably associated with higher DA receptor efficacy (DRD1 C allele; DRD2 A2 allele; DRD3 T allele), performed better on associative memory than persons with less beneficial genotypes. There were no effects of these genes on item memory or other cognitive measures, such as working memory, executive functioning, fluency, and perceptual speed, indicating a selective association between DA genes and associative memory. By contrast, genetic risk for Alzheimer disease (AD) was associated with worse item and associative memory, indicating adverse effects of APOE ε4 and a genetic risk score for AD (PICALM, BIN1, CLU) on episodic memory in general. Taken together, our results suggest that DA may be particularly important for associative memory, whereas AD-related genetic variations may influence overall episodic memory in older adults without dementia.

  15. Carbon dioxide receptor genes in cotton bollworm Helicoverpa armigera

    NASA Astrophysics Data System (ADS)

    Xu, Wei; Anderson, Alisha

    2015-04-01

    Carbon dioxide (CO2) is important in insect ecology, eliciting a range of behaviours across different species. Interestingly, the numbers of CO2 gustatory receptors (GRs) vary among insect species. In the model organism Drosophila melanogaster, two GRs (DmelGR21a and DmelGR63a) have been shown to detect CO2. In the butterfly, moth, beetle and mosquito species studied so far, three CO2 GR genes have been identified, while in tsetse flies, four CO2 GR genes have been identified. In other species including honeybees, pea aphids, ants, locusts and wasps, no CO2 GR genes have been identified from the genome. These genomic differences may suggest different mechanisms for CO2 detection exist in different insects but, with the exception of Drosophila and mosquitoes, limited attention has been paid to the CO2 GRs in insects. Here, we cloned three putative CO2 GR genes from the cotton bollworm Helicoverpa armigera and performed phylogenetic and expression analysis. All three H. armigera CO2 GRs (HarmGR1, HarmGR2 and HarmGR3) are specifically expressed in labial palps, the CO2-sensing tissue of this moth. HarmGR3 is significantly activated by NaHCO3 when expressed in insect Sf9 cells but HarmGR1 and HarmGR2 are not. This is the first report characterizing the function of lepidopteran CO2 receptors, which contributes to our general understanding of the molecular mechanisms of insect CO2 gustatory receptors.

  16. Carbon dioxide receptor genes in cotton bollworm Helicoverpa armigera.

    PubMed

    Xu, Wei; Anderson, Alisha

    2015-04-01

    Carbon dioxide (CO2) is important in insect ecology, eliciting a range of behaviours across different species. Interestingly, the numbers of CO2 gustatory receptors (GRs) vary among insect species. In the model organism Drosophila melanogaster, two GRs (DmelGR21a and DmelGR63a) have been shown to detect CO2. In the butterfly, moth, beetle and mosquito species studied so far, three CO2 GR genes have been identified, while in tsetse flies, four CO2 GR genes have been identified. In other species including honeybees, pea aphids, ants, locusts and wasps, no CO2 GR genes have been identified from the genome. These genomic differences may suggest different mechanisms for CO2 detection exist in different insects but, with the exception of Drosophila and mosquitoes, limited attention has been paid to the CO2 GRs in insects. Here, we cloned three putative CO2 GR genes from the cotton bollworm Helicoverpa armigera and performed phylogenetic and expression analysis. All three H. armigera CO2 GRs (HarmGR1, HarmGR2 and HarmGR3) are specifically expressed in labial palps, the CO2-sensing tissue of this moth. HarmGR3 is significantly activated by NaHCO3 when expressed in insect Sf9 cells but HarmGR1 and HarmGR2 are not. This is the first report characterizing the function of lepidopteran CO2 receptors, which contributes to our general understanding of the molecular mechanisms of insect CO2 gustatory receptors.

  17. BDNF prevents NMDA-induced toxicity in models of Huntington's disease: the effects are genotype specific and adenosine A2A receptor is involved.

    PubMed

    Martire, Alberto; Pepponi, Rita; Domenici, Maria Rosaria; Ferrante, Antonella; Chiodi, Valentina; Popoli, Patrizia

    2013-04-01

    NMDA receptor-mediated excitotoxicity is thought to play a pivotal role in the pathogenesis of Huntington's disease (HD). The neurotrophin brain-derived neurotrophic factor (BDNF), which is also highly involved in HD and whose effects are modulated by adenosine A2 ARs, influences the activity and expression of striatal NMDA receptors. In electrophysiology experiments, we investigated the role of BDNF toward NMDA-induced effects in HD models, and the possible involvement of A2ARs. In corticostriatal slices from wild-type mice and age-matched symptomatic R6/2 mice (a model of HD), NMDA application (75 μM) induced a transient or a permanent (i.e., toxic) reduction of field potential amplitude, respectively. BDNF (10 ng/mL) potentiated NMDA effects in wild-type, while it protected from NMDA toxicity in R6/2 mice. Both effects of BDNF were prevented by A2 AR blockade. The protective effect of BDNF against NMDA-induced toxicity was reproduced in a cellular model of HD. These findings may have very important implications for the neuroprotective potential of BDNF and A2 AR ligands in HD.

  18. Prospects and limitations of T cell receptor gene therapy.

    PubMed

    Jorritsma, Annelies; Schotte, Remko; Coccoris, Miriam; de Witte, Moniek A; Schumacher, Ton N M

    2011-08-01

    Adoptive transfer of antigen-specific T cells is an attractive means to provide cancer patients with immune cells of a desired specificity and the efficacy of such adoptive transfers has been demonstrated in several clinical trials. Because the T cell receptor is the single specificity-determining molecule in T cell function, adoptive transfer of TCR genes into patient T cells may be used as an alternative approach for the transfer of tumor-specific T cell immunity. On theoretical grounds, TCR gene therapy has two substantial advantages over conventional cellular transfer. First, it circumvents the demanding process of in vitro generation of large numbers of specific immune cells. Second, it allows the use of a set of particularly effective TCR genes in large patient groups. Conversely, TCR gene therapy may be associated with a number of specific problems that are not confronted during classical cellular therapy. Here we review our current understanding of the potential and possible problems of TCR gene therapy, as based on in vitro experiments, mouse model systems and phase I clinical trials. Furthermore, we discuss the prospects of widespread clinical application of this gene therapy approach for the treatment of human cancer.

  19. Perilipin, a critical regulator of fat storage and breakdown, is a target gene of estrogen receptor-related receptor {alpha}

    SciTech Connect

    Akter, Mst. Hasina; Yamaguchi, Tomohiro; Hirose, Fumiko; Osumi, Takashi

    2008-04-11

    Perilipin is a protein localized on lipid droplet surfaces in adipocytes and steroidogenic cells, playing a central role in regulated lipolysis. Expression of the perilipin gene is markedly induced during adipogenesis. We found that transcription from the perilipin gene promoter is activated by an orphan nuclear receptor, estrogen receptor-related receptor (ERR){alpha}. A response element to this receptor was identified in the promoter region by a gene reporter assay, the electrophoretic-gel mobility-shift assay and the chromatin immunoprecipitation assay. Peroxisome proliferator-activated receptor {gamma} coactivator (PGC)-1{alpha} enhanced, whereas small heterodimer partner (SHP) repressed, the transactivating function of ERR{alpha} on the promoter. Thus, the perilipin gene expression is regulated by a transcriptional network controlling energy metabolism, substantiating the functional importance of perilipin in the maintenance of body energy balance.

  20. Dissecting the regulation of yeast genes by the osmotin receptor

    PubMed Central

    Kupchak, Brian R.; Villa, Nancy Y.; Kulemina, Lidia; Lyons, Thomas J.

    2008-01-01

    The Izh2p protein from Saccharomyces cerevisiae is a receptor for the plant antifungal protein, osmotin. Since Izh2p is conserved in fungi, understanding its biochemical function could inspire novel strategies for the prevention of fungal growth. However, it has been difficult to determine the exact role of Izh2p because it has pleiotropic effects on cellular biochemistry. Herein, we demonstrate that Izh2p negatively regulates functionally divergent genes through a CCCTC promoter motif. Moreover, we show that Izh2p-dependent promoters containing this motif are regulated by the Nrg1p/Nrg2p and Msn2p/Msn4p transcription factors. The fact that Izh2p can regulate gene expression through this widely dispersed element presents a reasonable explanation of its pleiotropy. The involvement of Nrg1p/Nrgp2 in Izh2p-dependent gene regulation also suggests a role for this receptor in regulating fungal differentiation in response to stimuli produced by plants. PMID:18625204

  1. Functional characterization of ecdysone receptor gene switches in mammalian cells.

    PubMed

    Panguluri, Siva K; Kumar, Prasanna; Palli, Subba R

    2006-12-01

    Regulated expression of transgene is essential in basic research as well as for many therapeutic applications. The main purpose of the present study is to understand the functioning of the ecdysone receptor (EcR)-based gene switch in mammalian cells and to develop improved versions of EcR gene switches. We utilized EcR mutants to develop new EcR gene switches that showed higher ligand sensitivity and higher magnitude of induction of reporter gene expression in the presence of ligand. We also developed monopartite versions of EcR gene switches with reduced size of the components that are accommodated into viral vectors. Ligand binding assays revealed that EcR alone could not bind to the nonsteroidal ligand, RH-2485. The EcR's heterodimeric partner, ultraspiracle, is required for efficient binding of EcR to the ligand. The essential role of retinoid X receptor (RXR) or its insect homolog, ultraspiracle, in EcR function is shown by RXR knockdown experiments using RNAi. Chromatin immunoprecipitation assays demonstrated that VP16 (activation domain, AD):GAL4(DNA binding domain, DBD):EcR(ligand binding domain, LBD) or GAL4(DBD):EcR(LBD) fusion proteins can bind to GAL4 response elements in the absence of ligand. The VP16(AD) fusion protein of a chimera between human and locust RXR could heterodimerize with GAL4(DBD):EcR(LBD) in the absence of ligand but the VP16(AD) fusion protein of Homo sapiens RXR requires ligand for its heterodimerization with GAL4(DBD):EcR(LBD).

  2. Nuclear Receptor Corepressor Recruitment by Unliganded Thyroid Hormone Receptor in Gene Repression during Xenopus laevis Development

    PubMed Central

    Sachs, Laurent M.; Jones, Peter L.; Havis, Emmanuelle; Rouse, Nicole; Demeneix, Barbara A.; Shi, Yun-Bo

    2002-01-01

    Thyroid hormone receptors (TR) act as activators of transcription in the presence of the thyroid hormone (T3) and as repressors in its absence. While many in vitro approaches have been used to study the molecular mechanisms of TR action, their physiological relevance has not been addressed. Here we investigate how TR regulates gene expression during vertebrate postembryonic development by using T3-dependent amphibian metamorphosis as a model. Earlier studies suggest that TR acts as a repressor during premetamorphosis when T3 is absent. We hypothesize that corepressor complexes containing the nuclear receptor corepressor (N-CoR) are key factors in this TR-dependent gene repression, which is important for premetamorphic tadpole growth. To test this hypothesis, we isolated Xenopus laevis N-CoR (xN-CoR) and showed that it was present in pre- and metamorphic tadpoles. Using a chromatin immunoprecipitation assay, we demonstrated that xN-CoR was recruited to the promoters of T3 response genes during premetamorphosis and released upon T3 treatment, accompanied by a local increase in histone acetylation. Furthermore, overexpression of a dominant-negative N-CoR in tadpole tail muscle led to increased transcription from a T3-dependent promoter. Our data indicate that N-CoR is recruited by unliganded TR to repress target gene expression during premetamorphic animal growth, an important process that prepares the tadpole for metamorphosis. PMID:12446772

  3. Human T-cell receptor variable gene segment families

    SciTech Connect

    Arden, B.; Kabelitz, D.; Clark, S.P.; Mak, T.W.

    1995-10-01

    Multiple DNA and protein sequence alignments have been constructed for the human T-cell receptor {alpha}/{delta}, {beta}, and {gamma} (TCRA/D, B, and G) variable (V) gene segments. The traditional classification into subfamilies was confirmed using a much larger pool of sequences. For each sequence, a name was derived which complies with the standard nomenclature. The traditional numbering of V gene segments in the order of their discovery was continued and changed when in conflict with names of other segments. By discriminating between alleles at the same locus versus genes from different loci, we were able to reduce the number of more than 150 different TCRBV sequences in the database to a repertoire of only 47 functional TCRBV gene segments. An extension of this analysis to the over 100 TCRAV sequences results in a predicted repertoire of 42 functional TCRAV gene segments. Our alignment revealed two residues that distinguish between the highly homologous V{delta} and V{alpha}, one at a site that in V{sub H} contacts the constant region, the other at the interface between immunoglobulin V{sub H} and V{sub L}. This site may be responsible for restricted pairing between certain V{delta} and V{gamma} chains. On the other hand, V{beta} and V{gamma} appear to be related by the fact that their CDR2 length is increased by four residues as compared with that of V{alpha}/{delta} peptides. 150 refs., 12 figs., 5 tabs.

  4. Cardiac gene expression data and in silico analysis provide novel insights into human and mouse taste receptor gene regulation.

    PubMed

    Foster, Simon R; Porrello, Enzo R; Stefani, Maurizio; Smith, Nicola J; Molenaar, Peter; dos Remedios, Cristobal G; Thomas, Walter G; Ramialison, Mirana

    2015-10-01

    G protein-coupled receptors are the principal mediators of the sweet, umami, bitter, and fat taste qualities in mammals. Intriguingly, the taste receptors are also expressed outside of the oral cavity, including in the gut, airways, brain, and heart, where they have additional functions and contribute to disease. However, there is little known about the mechanisms governing the transcriptional regulation of taste receptor genes. Following our recent delineation of taste receptors in the heart, we investigated the genomic loci encoding for taste receptors to gain insight into the regulatory mechanisms that drive their expression in the heart. Gene expression analyses of healthy and diseased human and mouse hearts showed coordinated expression for a subset of chromosomally clustered taste receptors. This chromosomal clustering mirrored the cardiac expression profile, suggesting that a common gene regulatory block may control the taste receptor locus. We identified unique domains with strong regulatory potential in the vicinity of taste receptor genes. We also performed de novo motif enrichment in the proximal promoter regions and found several overrepresented DNA motifs in cardiac taste receptor gene promoters corresponding to ubiquitous and cardiac-specific transcription factor binding sites. Thus, combining cardiac gene expression data with bioinformatic analyses, this study has provided insights into the noncoding regulatory landscape for taste GPCRs. These findings also have broader relevance for the study of taste GPCRs outside of the classical gustatory system, where understanding the mechanisms controlling the expression of these receptors may have implications for future therapeutic development.

  5. The Orphan Nuclear Receptor ERRγ Regulates Hepatic CB1 Receptor-Mediated Fibroblast Growth Factor 21 Gene Expression

    PubMed Central

    Jung, Yoon Seok; Lee, Ji-Min; Kim, Don-Kyu; Lee, Yong-Soo; Kim, Ki-Sun; Kim, Yong-Hoon; Kim, Jina; Lee, Myung-Shik; Lee, In-Kyu; Kim, Seong Heon; Cho, Sung Jin; Jeong, Won-Il; Lee, Chul-Ho; Harris, Robert A.; Choi, Hueng-Sik

    2016-01-01

    Background Fibroblast growth factor 21 (FGF21), a stress inducible hepatokine, is synthesized in the liver and plays important roles in glucose and lipid metabolism. However, the mechanism of hepatic cannabinoid type 1 (CB1) receptor-mediated induction of FGF21 gene expression is largely unknown. Results Activation of the hepatic CB1 receptor by arachidonyl-2’-chloroethylamide (ACEA), a CB1 receptor selective agonist, significantly increased FGF21 gene expression. Overexpression of estrogen-related receptor (ERR) γ increased FGF21 gene expression and secretion both in hepatocytes and mice, whereas knockdown of ERRγ decreased ACEA-mediated FGF21 gene expression and secretion. Moreover, ERRγ, but not ERRα and ERRβ, induced FGF21 gene promoter activity. In addition, deletion and mutation analysis of the FGF21 promoter identified a putative ERRγ-binding motif (AGGTGC, a near-consensus response element). A chromatin immunoprecipitation assay revealed direct binding of ERRγ to the FGF21 gene promoter. Finally, GSK5182, an ERRγ inverse agonist, significantly inhibited hepatic CB1 receptor-mediated FGF21 gene expression and secretion. Conclusion Based on our data, we conclude that ERRγ plays a key role in hepatic CB1 receptor-mediated induction of FGF21 gene expression and secretion. PMID:27455076

  6. A reference gene set for chemosensory receptor genes of Manduca sexta.

    PubMed

    Koenig, Christopher; Hirsh, Ariana; Bucks, Sascha; Klinner, Christian; Vogel, Heiko; Shukla, Aditi; Mansfield, Jennifer H; Morton, Brian; Hansson, Bill S; Grosse-Wilde, Ewald

    2015-11-01

    The order of Lepidoptera has historically been crucial for chemosensory research, with many important advances coming from the analysis of species like Bombyx mori or the tobacco hornworm, Manduca sexta. Specifically M. sexta has long been a major model species in the field, especially regarding the importance of olfaction in an ecological context, mainly the interaction with its host plants. In recent years transcriptomic data has led to the discovery of members of all major chemosensory receptor families in the species, but the data was fragmentary and incomplete. Here we present the analysis of the newly available high-quality genome data for the species, supplemented by additional transcriptome data to generate a high quality reference gene set for the three major chemosensory receptor gene families, the gustatory (GR), olfactory (OR) and antennal ionotropic receptors (IR). Coupled with gene expression analysis our approach allows association of specific receptor types and behaviors, like pheromone and host detection. The dataset will provide valuable support for future analysis of these essential chemosensory modalities in this species and in Lepidoptera in general.

  7. Update of the androgen receptor gene mutations database.

    PubMed

    Gottlieb, B; Beitel, L K; Lumbroso, R; Pinsky, L; Trifiro, M

    1999-01-01

    The current version of the androgen receptor (AR) gene mutations database is described. The total number of reported mutations has risen from 309 to 374 during the past year. We have expanded the database by adding information on AR-interacting proteins; and we have improved the database by identifying those mutation entries that have been updated. Mutations of unknown significance have now been reported in both the 5' and 3' untranslated regions of the AR gene, and in individuals who are somatic mosaics constitutionally. In addition, single nucleotide polymorphisms, including silent mutations, have been discovered in normal individuals and in individuals with male infertility. A mutation hotspot associated with prostatic cancer has been identified in exon 5. The database is available on the internet (http://www.mcgill.ca/androgendb/), from EMBL-European Bioinformatics Institute (ftp.ebi.ac.uk/pub/databases/androgen), or as a Macintosh FilemakerPro or Word file (MC33@musica.mcgill.ca).

  8. Evolution of dopamine receptor genes of the D1 class in vertebrates.

    PubMed

    Yamamoto, Kei; Mirabeau, Olivier; Bureau, Charlotte; Blin, Maryline; Michon-Coudouel, Sophie; Demarque, Michaël; Vernier, Philippe

    2013-04-01

    The receptors of the dopamine neurotransmitter belong to two unrelated classes named D1 and D2. For the D1 receptor class, only two subtypes are found in mammals, the D1A and D1B, receptors, whereas additional subtypes, named D1C, D1D, and D1X, have been found in other vertebrate species. Here, we analyzed molecular phylogeny, gene synteny, and gene expression pattern of the D1 receptor subtypes in a large range of vertebrate species, which leads us to propose a new view of the evolution of D1 dopamine receptor genes. First, we show that D1C and D1D receptor sequences are encoded by orthologous genes. Second, the previously identified Cypriniform D1X sequence is a teleost-specific paralog of the D1B sequences found in all groups of jawed vertebrates. Third, zebrafish and several sauropsid species possess an additional D1-like gene, which is likely to form another orthology group of vertebrate ancestral genes, which we propose to name D1E. Ancestral jawed vertebrates are thus likely to have possessed four classes of D1 receptor genes-D1A, D1B(X), D1C(D), and D1E-which arose from large-scale gene duplications. The D1C receptor gene would have been secondarily lost in the mammalian lineage, whereas the D1E receptor gene would have been lost independently in several lineages of modern vertebrates. The D1A receptors are well conserved throughout jawed vertebrates, whereas sauropsid D1C receptors have rapidly diverged, to the point that they were misidentified as D1D. The functional significance of the D1C receptor loss is not known. It is possible that the function may have been substituted with D1A or D1B receptors in mammals, following the disappearance of D1C receptors in these species.

  9. Thyrotropin receptor gene alterations in thyroid hyperfunctioning adenomas

    SciTech Connect

    Russo, D.; Arturi, F.; Filetti, S.

    1996-04-01

    Forty-four thyroid autonomously hyperfunctioning adenomas were analyzed to assess the frequency of mutations occurring in the TSH receptor (TSHR). PCR-amplified fragments encompassing the entire exon 10 of the TSHR gene were obtained from the genomic DNA extracted from the tumors and their adjacent normal tissues and were examined by direct nucleotide sequencing. Point mutations were found in 9 of 44 adenomas examined (20%). One mutation occurred in codon 619 (Asp to Gly), four in codon 623 (three were Ala to Ser, one Ala to substitution), two in codon 632 (both Thr to Ile), and two in codon 633 (Asp to Tyr or His). All the alterations were located in a part of the gene coding for an area including the third intracellular loop and the sixth transmembrane domain of the TSH receptor. All mutations were somatic and heterozygotic, and none was simultaneous with alterations of ras or gsp oncogenes. Thus, our data show that in our series of 44 hyperfunctioning thyroid adenomas, a somatic mutation of the TSHR, responsible for the constitutive activation of the cAMP pathway, occurs in 20% of the tumors. 28 refs., 2 tabs.

  10. Variability of the Transferrin Receptor 2 Gene in AMD

    PubMed Central

    Blasiak, Janusz; Dorecka, Mariola; Kowalska, Marta; Pawlowska, Elzbieta; Szaflik, Jerzy; Szaflik, Jacek Pawel

    2014-01-01

    Oxidative stress is a major factor in the pathogenesis of age-related macular degeneration (AMD). Iron may catalyze the Fenton reaction resulting in overproduction of reactive oxygen species. Transferrin receptor 2 plays a critical role in iron homeostasis and variability in its gene may influence oxidative stress and AMD occurrence. To verify this hypothesis we assessed the association between polymorphisms of the TFR2 gene and AMD. A total of 493 AMD patients and 171 matched controls were genotyped for the two polymorphisms of the TFR2 gene: c.1892C>T (rs2075674) and c.−258+123T>C (rs4434553). We also assessed the modulation of some AMD risk factors by these polymorphisms. The CC and TT genotypes of the c.1892C>T were associated with AMD occurrence but the latter only in obese patients. The other polymorphism was not associated with AMD occurrence, but the CC genotype was correlated with an increasing AMD frequency in subjects with BMI < 26. The TT genotype and the T allele of this polymorphism decreased AMD occurrence in subjects above 72 years, whereas the TC genotype and the C allele increased occurrence of AMD in this group. The c.1892C>T and c.−258+123T>C polymorphisms of the TRF2 gene may be associated with AMD occurrence, either directly or by modulation of risk factors. PMID:24648608

  11. Variability of the transferrin receptor 2 gene in AMD.

    PubMed

    Wysokinski, Daniel; Blasiak, Janusz; Dorecka, Mariola; Kowalska, Marta; Robaszkiewicz, Jacek; Pawlowska, Elzbieta; Szaflik, Jerzy; Szaflik, Jacek Pawel

    2014-01-01

    Oxidative stress is a major factor in the pathogenesis of age-related macular degeneration (AMD). Iron may catalyze the Fenton reaction resulting in overproduction of reactive oxygen species. Transferrin receptor 2 plays a critical role in iron homeostasis and variability in its gene may influence oxidative stress and AMD occurrence. To verify this hypothesis we assessed the association between polymorphisms of the TFR2 gene and AMD. A total of 493 AMD patients and 171 matched controls were genotyped for the two polymorphisms of the TFR2 gene: c.1892C>T (rs2075674) and c.-258+123T>C (rs4434553). We also assessed the modulation of some AMD risk factors by these polymorphisms. The CC and TT genotypes of the c.1892C>T were associated with AMD occurrence but the latter only in obese patients. The other polymorphism was not associated with AMD occurrence, but the CC genotype was correlated with an increasing AMD frequency in subjects with BMI < 26. The TT genotype and the T allele of this polymorphism decreased AMD occurrence in subjects above 72 years, whereas the TC genotype and the C allele increased occurrence of AMD in this group. The c.1892C>T and c.-258+123T>C polymorphisms of the TRF2 gene may be associated with AMD occurrence, either directly or by modulation of risk factors.

  12. Involvement of cAMP-PKA pathway in adenosine A1 and A2A receptor-mediated regulation of acetaldehyde-induced activation of HSCs.

    PubMed

    Yang, Yaru; Wang, He; Lv, Xiongwen; Wang, Qi; Zhao, Han; Yang, Feng; Yang, Yan; Li, Jun

    2015-08-01

    The present study was undertaken to investigate the mechanism by which adenosine receptors (ARs)-mediated the cAMP/PKA/CREB signal pathway regulates the activation of acetaldehyde-induced hepatic stellate cells (HSCs). Primary HSCs were isolated from SD rats, cultured in vitro, and activated with different concentrations of acetaldehyde at different time points. Quantitative real-time PCR and Western blotting were used to quantify both protein and mRNA levels of the four AR (A1R, A2AR, A2BR, and A3R) in rat HSCs. Selective inhibitors of PDEs and the Gi/o protein pathway, general AR agonists, and AR subtype specific agents were used to study the AR signaling. The level of cAMP was measured by radio-immunoassay, and the expression of α-SMA, collagen type I and III, PKA and p-CREB were also detected by Western blotting. Acetaldehyde could significantly promote HSC proliferation, with a maximum stimulatory effect observed at 48 h after exposure to 200 μM acetaldehyde. All four AR subtypes could be present in rat HSCs, and the mRNA and protein expression levels for A2AR and A1R in much greater abundance than those for A2BR and A3R. The expression of A2AR and A1R was significantly increased in acetaldehyde-induced HSCs as compared with that of control group, whereas the expression of A2BR and A3R remained unaffected by the addition of acetaldehyde. Curiously, there is coupling of A2AR to the Gs-AC signaling, as well as coupling of A1R to the Gi/o-AC signaling pathway in acetaldehyde-induced HSCs. Both the A2AR and A1R antagonists could suppress the activation of HSC, although they have opposing effects on cAMP signal transduction. These results suggested that a combination of cAMP/PKA/CREB signals via A2AR and A1R likely mediate the activation of acetaldehyde-induced HSCs, and A1R coupled to the Gi/o-AC signaling pathway may be masked by the more predominant A2AR that coupled to the Gs-AC signaling pathway.

  13. Evolution of Dopamine Receptor Genes of the D1 Class in Vertebrates

    PubMed Central

    Yamamoto, Kei; Mirabeau, Olivier; Bureau, Charlotte; Blin, Maryline; Michon-Coudouel, Sophie; Demarque, Michaël; Vernier, Philippe

    2013-01-01

    The receptors of the dopamine neurotransmitter belong to two unrelated classes named D1 and D2. For the D1 receptor class, only two subtypes are found in mammals, the D1A and D1B, receptors, whereas additional subtypes, named D1C, D1D, and D1X, have been found in other vertebrate species. Here, we analyzed molecular phylogeny, gene synteny, and gene expression pattern of the D1 receptor subtypes in a large range of vertebrate species, which leads us to propose a new view of the evolution of D1 dopamine receptor genes. First, we show that D1C and D1D receptor sequences are encoded by orthologous genes. Second, the previously identified Cypriniform D1X sequence is a teleost-specific paralog of the D1B sequences found in all groups of jawed vertebrates. Third, zebrafish and several sauropsid species possess an additional D1-like gene, which is likely to form another orthology group of vertebrate ancestral genes, which we propose to name D1E. Ancestral jawed vertebrates are thus likely to have possessed four classes of D1 receptor genes—D1A, D1B(X), D1C(D), and D1E—which arose from large-scale gene duplications. The D1C receptor gene would have been secondarily lost in the mammalian lineage, whereas the D1E receptor gene would have been lost independently in several lineages of modern vertebrates. The D1A receptors are well conserved throughout jawed vertebrates, whereas sauropsid D1C receptors have rapidly diverged, to the point that they were misidentified as D1D. The functional significance of the D1C receptor loss is not known. It is possible that the function may have been substituted with D1A or D1B receptors in mammals, following the disappearance of D1C receptors in these species. PMID:23197594

  14. Anxious behavior induces elevated hippocampal Cb2 receptor gene expression.

    PubMed

    Robertson, James M; Achua, Justin K; Smith, Justin P; Prince, Melissa A; Staton, Clarissa D; Ronan, Patrick J; Summers, Tangi R; Summers, Cliff H

    2017-04-07

    Anxiety is differentially expressed across a continuum of stressful/fearful intensity, influenced endocannabinoid systems and receptors. The hippocampus plays important roles in the regulation of affective behavior, emotion, and anxiety, as well as memory. Location of Cb1/Cb2 receptor action could be important in determining emotional valence, because while the dorsal hippocampus is involved in spatial memory and cognition, the ventral hippocampus has projections to the PFC, BNST, amygdala, and HPA axis, and is important for emotional responses to stress. During repeated social defeat in a Stress-Alternatives Model arena (SAM; an oval open field with escape portals only large enough for smaller mice), smaller C57BL6/N mice are subject to fear conditioning (tone=CS), and attacked by novel larger aggressive CD1 mice (US) over four daily (5min) trials. Each SAM trial presents an opportunity for escape or submission, with stable behavioral responses established by the second day of interaction. Additional groups had access to a running wheel. Social aggression plus fear conditioning stimulates enhanced Cb2 receptor gene expression in the dorsal CA1, dorsal and ventral dentate gyrus subregions in animals displaying a submissive behavioral phenotype. Escape behavior is associated with reduced Cb2 expression in the dorsal CA1 region, with freezing and escape latency correlated with mRNA levels. Escaping and submitting animals with access to running wheels had increased Cb2 mRNA in dorsal DG/CA1. These results suggest that the Cb2 receptor system is rapidly induced during anxiogenic social interactions plus fear conditioning or exercise; with responses potentially adaptive for coping mechanisms.

  15. Blockade of striatal adenosine A2A receptor reduces, through a presynaptic mechanism, quinolinic acid-induced excitotoxicity: possible relevance to neuroprotective interventions in neurodegenerative diseases of the striatum.

    PubMed

    Popoli, Patrizia; Pintor, Annita; Domenici, Maria Rosaria; Frank, Claudio; Tebano, Maria Teresa; Pèzzola, Antonella; Scarchilli, Laura; Quarta, Davide; Reggio, Rosaria; Malchiodi-Albedi, Fiorella; Falchi, Mario; Massotti, Marino

    2002-03-01

    The aim of the present study was to evaluate whether, and by means of which mechanisms, the adenosine A2A receptor antagonist SCH 58261 [5-amino-7-(2-phenylethyl)-2-(2-furyl)-pyrazolo[4,3-e]-1,2,4-triazolo[1,5-c]pyrimidine] exerted neuroprotective effects in a rat model of Huntington's disease. In a first set of experiments, SCH 58261 (0.01 and 1 mg/kg) was administered intraperitoneally to Wistar rats 20 min before the bilateral striatal injection of quinolinic acid (QA) (300 nmol/1 microl). SCH 58261 (0.01 but not 1 mg/kg, i.p.) did reduce significantly the effects of QA on motor activity, electroencephalographic changes, and striatal gliosis. Because QA acts by both increasing glutamate outflow and directly stimulating NMDA receptors, a second set of experiments was performed to evaluate whether SCH 58261 acted by preventing the presynaptic and/or the postsynaptic effects of QA. In microdialysis experiments in naive rats, striatal perfusion with QA (5 mm) enhanced glutamate levels by approximately 500%. Such an effect of QA was completely antagonized by pretreatment with SCH 58261 (0.01 but not 1 mg/kg, i.p.). In primary striatal cultures, bath application of QA (900 microm) significantly increased intracellular calcium levels, an effect prevented by the NMDA receptor antagonist MK-801 [(+)-5-methyl-10,11-dihydro-5H-dibenzo [a,d] cyclohepten-5,10-imine maleate]. In this model, bath application of SCH 58261 (15-200 nm) tended to potentiate QA-induced calcium increase. We conclude the following: (1) the adenosine A2A receptor antagonist SCH 58261 has neuroprotective effects, although only at low doses, in an excitotoxic rat model of HD, and (2) the inhibition of QA-evoked glutamate outflow seems to be the major mechanism underlying the neuroprotective effects of SCH 58261.

  16. Pulsed Electromagnetic Fields Increased the Anti-Inflammatory Effect of A2A and A3 Adenosine Receptors in Human T/C-28a2 Chondrocytes and hFOB 1.19 Osteoblasts

    PubMed Central

    Vincenzi, Fabrizio; Targa, Martina; Corciulo, Carmen; Gessi, Stefania; Merighi, Stefania; Setti, Stefania; Cadossi, Ruggero; Goldring, Mary B.; Borea, Pier Andrea; Varani, Katia

    2013-01-01

    Adenosine receptors (ARs) have an important role in the regulation of inflammation and their activation is involved in the inhibition of pro-inflammatory cytokine release. The effects of pulsed electromagnetic fields (PEMFs) on inflammation have been reported and we have demonstrated that PEMFs increased A2A and A3AR density and functionality in different cell lines. Chondrocytes and osteoblasts are two key cell types in the skeletal system that play important role in cartilage and bone metabolism representing an interesting target to study the effect of PEMFs. The primary aim of the present study was to evaluate if PEMF exposure potentiated the anti-inflammatory effect of A2A and/or A3ARs in T/C-28a2 chondrocytes and hFOB 1.19 osteoblasts. Immunofluorescence, mRNA analysis and saturation binding assays revealed that PEMF exposure up-regulated A2A and A3AR expression. A2A and A3ARs were able to modulate cAMP production and cell proliferation. The activation of A2A and A3ARs resulted in the decrease of some of the most relevant pro-inflammatory cytokine release such as interleukin (IL)-6 and IL-8, following the treatment with IL-1β as an inflammatory stimuli. In human chondrocyte and osteoblast cell lines, the inhibitory effect of A2A and A3AR stimulation on the release of prostaglandin E2 (PGE2), an important lipid inflammatory mediator, was observed. In addition, in T/C-28a2 cells, the activation of A2A or A3ARs elicited an inhibition of vascular endothelial growth factor (VEGF) secretion. In hFOB 1.19 osteoblasts, PEMF exposure determined an increase of osteoprotegerin (OPG) production. The effect of the A2A or A3AR agonists in the examined cells was enhanced in the presence of PEMFs and completely blocked by using well-known selective antagonists. These results demonstrated that PEMF exposure significantly increase the anti-inflammatory effect of A2A or A3ARs suggesting their potential therapeutic use in the therapy of inflammatory bone and joint disorders

  17. Fc-receptor and M-protein genes of group A streptococci are products of gene duplication.

    PubMed Central

    Heath, D G; Cleary, P P

    1989-01-01

    The partial nucleotide sequence for an Fc-receptor gene from an M-type 76 group A streptococcus was determined. DNA sequence analysis revealed considerable sequence similarity between the Fc-receptor and M-protein genes in their proposed promoter regions, signal sequences, and 3' termini. Additional analysis indicated that the deduced Fc-receptor protein contains a proline-rich region and membrane anchor region highly similar to that of M protein. In view of these results, we postulated that Fc-receptor and M-protein genes of group A streptococci are the products of gene duplication from a common ancestral gene. It is proposed that DNA sequence similarity between these two genes may allow for extragenic homologous recombination as a means of generating antigenic diversity in these two surface proteins. PMID:2660147

  18. Decreased glucocorticoid receptor activity following glucocorticoid receptor antisense RNA gene fragment transfection.

    PubMed Central

    Pepin, M C; Barden, N

    1991-01-01

    Depression is often characterized by increased cortisol secretion caused by hyperactivity of the hypothalamic-pituitary-adrenal axis and by nonsuppression of cortisol secretion following dexamethasone administration. This hyperactivity of the hypothalamic-pituitary-adrenal axis could result from a reduced glucocorticoid receptor (GR) activity in neurons involved in its control. To investigate the effect of reduced neuronal GR levels, we have blocked cellular GR mRNA processing and/or translation by introduction of a complementary GR antisense RNA strand. Two cell lines were transfected with a reporter plasmid carrying the chloramphenicol acetyltransferase (CAT) gene under control of the mouse mammary tumor virus long terminal repeat (a glucocorticoid-inducible promoter). This gene construction permitted assay of the sensitivity of the cells to glucocorticoid hormones. Cells were also cotransfected with a plasmid containing 1,815 bp of GR cDNA inserted in the reverse orientation downstream from either a neurofilament gene promoter element or the Rous sarcoma virus promoter element. Northern (RNA) blot analysis demonstrated formation of GR antisense RNA strands. Measurement of the sensitivity of CAT activity to exogeneous dexamethasone showed that although dexamethasone increased CAT activity by as much as 13-fold in control incubations, expression of GR antisense RNA caused a 2- to 4-fold decrease in the CAT response to dexamethasone. Stable transfectants bearing the GR antisense gene fragment construction demonstrated a 50 to 70% decrease of functional GR levels compared with normal cells, as evidenced by a ligand-binding assay with the type II glucocorticoid receptor-specific ligand [3H]RU 28362. These results validate the use of antisense RNA to GR to decrease cellular response to glucocorticoids. Images PMID:1996114

  19. Transcriptional Characterization of Porcine Leptin and Leptin Receptor Genes

    PubMed Central

    Pérez-Montarelo, Dafne; Fernández, Almudena; Barragán, Carmen; Noguera, Jose L.; Folch, Josep M.; Rodríguez, M. Carmen; Óvilo, Cristina; Silió, Luis; Fernández, Ana I.

    2013-01-01

    The leptin (LEP) and its receptor (LEPR) regulate food intake and energy balance through hypothalamic signaling. However, the LEP-LEPR axis seems to be more complex and its expression regulation has not been well described. In pigs, LEP and LEPR genes have been widely studied due to their relevance. Previous studies reported significant effects of SNPs located in both genes on growth and fatness traits. The aim of this study was to determine the expression profiles of LEP and LEPR across hypothalamic, adipose, hepatic and muscle tissues in Iberian x Landrace backcrossed pigs and to analyze the effects of gene variants on transcript abundance. To our knowledge, non porcine LEPR isoforms have been described rather than LEPRb. A short porcine LEPR isoform (LEPRa), that encodes a protein lacking the intracellular residues responsible of signal transduction, has been identified for the first time. The LEPRb isoform was only quantifiable in hypothalamus while LEPRa appeared widely expressed across tissues, but at higher levels in liver, suggesting that both isoforms would develop different roles. The unique LEP transcript showed expression in backfat and muscle. The effects of gene variants on transcript expression revealed interesting results. The LEPRc.1987C>T polymorphism showed opposite effects on LEPRb and LEPRa hypothalamic expression. In addition, one out of the 16 polymorphisms identified in the LEPR promoter region revealed high differential expression in hepatic LEPRa. These results suggest a LEPR isoform-specific regulation at tissue level. Conversely, non-differential expression of LEP conditional on the analyzed polymorphisms could be detected, indicating that its regulation is likely affected by other mechanisms rather than gene sequence variants. The present study has allowed a transcriptional characterization of LEP and LEPR isoforms on a range of tissues. Their expression patterns seem to indicate that both molecules develop peripheral roles apart from

  20. Calcium-Sensing Receptor Gene: Regulation of Expression

    PubMed Central

    Hendy, Geoffrey N.; Canaff, Lucie

    2016-01-01

    The human calcium-sensing receptor gene (CASR) has 8 exons, and localizes to chromosome 3q. Exons 1A and 1B encode alternative 5′-untranslated regions (UTRs) that splice to exon 2 encoding the AUG initiation codon. Exons 2–7 encode the CaSR protein of 1078 amino acids. Promoter P1 has TATA and CCAAT boxes upstream of exon 1A, and promoter P2 has Sp1/3 motifs at the start site of exon 1B. Exon 1A transcripts from the P1 promoter are reduced in parathyroid tumors and colon carcinomas. Studies of colon carcinomas and neuroblastomas have emphasized the importance of epigenetic changes—promoter methylation of the GC-rich P2 promoter, histone acetylation—as well as involvement of microRNAs in bringing about CASR gene silencing and reduced CaSR expression. Functional cis-elements in the CASR promoters responsive to 1,25-dihydroxyvitamin D [1,25(OH)2D], proinflammatory cytokines, and the transcription factor glial cells missing-2 (GCM2) have been characterized. Reduced levels of CaSR and reduced responsiveness to active vitamin D in parathyroid neoplasia and colon carcinoma may blunt the “tumor suppressor” activity of the CaSR. The hypocalcemia of critically ill patients with burn injury or sepsis is associated with CASR gene upregulation by TNF-alpha and IL-1beta via kappaB elements, and by IL-6 via Stat1/3 and Sp1/3 elements in the CASR gene promoters, respectively. The CASR is transactivated by GCM2—the expression of which is essential for parathyroid gland development. Hyperactive forms of GCM2 may contribute to later parathyroid hyperactivity or tumorigenesis. The expression of the CaSR—the calciostat—is regulated physiologically and pathophysiologically at the gene level. PMID:27679579

  1. Receptor protein kinase gene encoded at the self-incompatibility locus

    DOEpatents

    Nasrallah, June B.; Nasrallah, Mikhail E.; Stein, Joshua

    1996-01-01

    Described herein is a S receptor kinase gene (SRK), derived from the S locus in Brassica oleracea, having a extracellular domain highly similar to the secreted product of the S-locus glycoprotein gene.

  2. Toll-like receptors and microbial exposure: gene-gene and gene-environment interaction in the development of atopy.

    PubMed

    Reijmerink, N E; Kerkhof, M; Bottema, R W B; Gerritsen, J; Stelma, F F; Thijs, C; van Schayck, C P; Smit, H A; Brunekreef, B; Postma, D S; Koppelman, G H

    2011-10-01

    Environmental and genetic factors contribute to atopy development. High microbial exposure may confer a protective effect on atopy. Toll-like receptors (TLRs) bind microbial products and are important in activating the immune system. To assess whether interactions between microbial exposures and genes encoding TLRs (and related genes) result in atopy, genes, environmental factors and gene-environment interactions of 66 single-nucleotide polymorphisms (SNPs) of 12 genes (TLR 1-6, 9 and 10, CD14, MD2, lipopolysaccharide-binding protein (LBP) and Dectin-1), and six proxy parameters of microbial exposure (sibship size, pets (three different parameters), day-care and intrauterine and childhood tobacco smoke exposure) were analysed for association with atopic phenotypes in 3,062 Dutch children (the Allergenic study). The presence of two or more older siblings increased the risk of developing high total immunoglobulin (Ig)E levels at different ages. This risk increased further in children aged 1-2 yrs carrying the minor allele of TLR6 SNP rs1039559. Furthermore, novel two- and three-factor gene-gene and gene-environment interactions were found (e.g. between sibship size, day-care and LBP SNP rs2232596). Larger sibship size is associated with increased total IgE levels. Furthermore, complex two- and three-factor interactions exist between genes and the environment. The TLRs and related genes interact with proxy parameters of high microbial exposure in atopy development.

  3. Variants in the vitamin D receptor gene and asthma

    PubMed Central

    Wjst, Matthias

    2005-01-01

    Background Early lifetime exposure to dietary or supplementary vitamin D has been predicted to be a risk factor for later allergy. Twin studies suggest that response to vitamin D exposure might be influenced by genetic factors. As these effects are primarily mediated through the vitamin D receptor (VDR), single base variants in this gene may be risk factors for asthma or allergy. Results 951 individuals from 224 pedigrees with at least 2 asthmatic children were analyzed for 13 SNPs in the VDR. There was no preferential transmission to children with asthma. In their unaffected sibs, however, one allele in the 5' region was 0.5-fold undertransmitted (p = 0.049), while two other alleles in the 3' terminal region were 2-fold over-transmitted (p = 0.013 and 0.018). An association was also seen with bronchial hyperreactivity against methacholine and with specific immunoglobulin E serum levels. Conclusion The transmission disequilibrium in unaffected sibs of otherwise multiple-affected families seem to be a powerful statistical test. A preferential transmission of vitamin D receptor variants to children with asthma could not be confirmed but raises the possibility of a protective effect for unaffected children. PMID:15651992

  4. Transcriptional regulation of the bovine oxytocin receptor gene.

    PubMed

    Telgmann, Ralph; Bathgate, Ross A D; Jaeger, Stefanie; Tillmann, Gina; Ivell, Richard

    2003-03-01

    The oxytocin receptor (OTR) is expressed in the cow uterus at high levels at estrus and at term of pregnancy. This expression appears to be controlled mostly at the transcriptional level and correlates with increasing estrogen concentration and progesterone withdrawal. Approximately 3200 base pairs of the upstream region of the bovine OTR gene were cloned and analyzed using a combination of bioinformatic, electrophoretic mobility shift (EMSA), and transfection analyses. Using nuclear proteins from high- and low-expressing tissues, EMSA indicated no significant quantitative or qualitative changes in specific DNA-protein binding, suggesting that transcription is probably controlled by signalling systems targeting constitutive factors. Using various cell types, including primary and immortalized ruminant endometrial epithelial cells, as hosts for transfection of promoter-reporter constructs showed that endogenous activity resided only in the longest, i.e., 3.2-kb, construct but not in those shorter than 1.0 kb. While estrogen appears to be important in vivo, no effect of estradiol was found on any construct directly; only when the longest 3.2-kb construct was used in combination with some cotransfected steroid receptor cofactors, e.g., SRC1e, was an estradiol-dependent effect observed. A putative interferon-responsive element (IRE) was found at approximately -2,400 from the transcription start site. This element was shown to bind mouse IRF1 and IRF2 as well as similar proteins from bovine endometrial and myometrial nuclear extracts. This element also responded to these factors when cotransfected into various cell types. The bovine equivalents to IRF1 and IRF2 were molecularly cloned from endometrial tissue and shown to be expressed in a temporal fashion, supporting the role of interferon-tau in maternal recognition of pregnancy. Of many factors tested or analyzed, these components of the IFN system are the only ones found to significantly influence the transcription

  5. Optimizing T-cell receptor gene therapy for hematologic malignancies

    PubMed Central

    Morris, Emma C.

    2016-01-01

    Recent advances in genetic engineering have enabled the delivery of clinical trials using patient T cells redirected to recognize tumor-associated antigens. The most dramatic results have been seen with T cells engineered to express a chimeric antigen receptor (CAR) specific for CD19, a differentiation antigen expressed in B cells and B lineage malignancies. We propose that antigen expression in nonmalignant cells may contribute to the efficacy of T-cell therapy by maintaining effector function and promoting memory. Although CAR recognition is limited to cell surface structures, T-cell receptors (TCRs) can recognize intracellular proteins. This not only expands the range of tumor-associated self-antigens that are amenable for T-cell therapy, but also allows TCR targeting of the cancer mutagenome. We will highlight biological bottlenecks that potentially limit mutation-specific T-cell therapy and may require high-avidity TCRs that are capable of activating effector function when the concentrations of mutant peptides are low. Unexpectedly, modified TCRs with artificially high affinities function poorly in response to low concentration of cognate peptide but pose an increased safety risk as they may respond optimally to cross-reactive peptides. Recent gene-editing tools, such as transcription activator–like effector nucleases and clustered regularly interspaced short palindromic repeats, provide a platform to delete endogenous TCR and HLA genes, which removes alloreactivity and decreases immunogenicity of third-party T cells. This represents an important step toward generic off-the-shelf T-cell products that may be used in the future for the treatment of large numbers of patients. PMID:27207802

  6. Liver X Receptor Genes Variants Modulate ALS Phenotype.

    PubMed

    Mouzat, Kevin; Molinari, Nicolas; Kantar, Jovana; Polge, Anne; Corcia, Philippe; Couratier, Philippe; Clavelou, Pierre; Juntas-Morales, Raul; Pageot, Nicolas; Lobaccaro, Jean -Marc A; Raoul, Cedric; Lumbroso, Serge; Camu, William

    2017-02-27

    Amyotrophic lateral sclerosis (ALS) is one of the most severe motor neuron (MN) disorders in adults. Phenotype of ALS patients is highly variable and may be influenced by modulators of energy metabolism. Recent works have implicated the liver X receptors α and β (LXRs), either in the propagation process of ALS or in the maintenance of MN survival. LXRs are nuclear receptors activated by oxysterols, modulating cholesterol levels, a suspected modulator of ALS severity. In a cohort of 438 ALS patients and 330 healthy controls, the influence of LXR genes on ALS risk and phenotype was studied using single nucleotide polymorphisms (SNPs). The two LXRα SNPs rs2279238 and rs7120118 were shown to be associated with age at onset in ALS patients. Consistently, homozygotes were twice more correlated than were heterozygotes to delayed onset. The onset was thus delayed by 3.9 years for rs2279238 C/T carriers and 7.8 years for T/T carriers. Similar results were obtained for rs7120118 (+2.1 years and +6.7 years for T/C and C/C genotypes, respectively). The LXRβ SNP rs2695121 was also shown to be associated with a 30% increase of ALS duration (p = 0.0055, FDR = 0.044). The tested genotypes were not associated with ALS risk. These findings add further evidence to the suspected implication of LXR genes in the disease process of ALS and might open new perspectives in ALS therapeutics.

  7. The role of 5-arylalkylamino- and 5-piperazino- moieties on the 7-aminopyrazolo[4,3-d]pyrimidine core in affecting adenosine A1 and A2A receptor affinity and selectivity profiles.

    PubMed

    Squarcialupi, Lucia; Betti, Marco; Catarzi, Daniela; Varano, Flavia; Falsini, Matteo; Ravani, Annalisa; Pasquini, Silvia; Vincenzi, Fabrizio; Salmaso, Veronica; Sturlese, Mattia; Varani, Katia; Moro, Stefano; Colotta, Vittoria

    2017-12-01

    New 7-amino-2-phenylpyrazolo[4,3-d]pyrimidine derivatives, substituted at the 5-position with aryl(alkyl)amino- and 4-substituted-piperazin-1-yl- moieties, were synthesized with the aim of targeting human (h) adenosine A1 and/or A2A receptor subtypes. On the whole, the novel derivatives 1-24 shared scarce or no affinities for the off-target hA2B and hA3 ARs. The 5-(4-hydroxyphenethylamino)- derivative 12 showed both good affinity (Ki = 150 nM) and the best selectivity for the hA2A AR while the 5-benzylamino-substituted 5 displayed the best combined hA2A (Ki = 123 nM) and A1 AR affinity (Ki = 25 nM). The 5-phenethylamino moiety (compound 6) achieved nanomolar affinity (Ki = 11 nM) and good selectivity for the hA1 AR. The 5-(N(4)-substituted-piperazin-1-yl) derivatives 15-24 bind the hA1 AR subtype with affinities falling in the high nanomolar range. A structure-based molecular modeling study was conducted to rationalize the experimental binding data from a molecular point of view using both molecular docking studies and Interaction Energy Fingerprints (IEFs) analysis.[Formula: see text].

  8. The Dopamine D2 Receptor Gene, Perceived Parental Support, and Adolescent Loneliness: Longitudinal Evidence for Gene-Environment Interactions

    ERIC Educational Resources Information Center

    van Roekel, Eeske; Goossens, Luc; Scholte, Ron H. J.; Engels, Rutger C. M. E.; Verhagen, Maaike

    2011-01-01

    Background: Loneliness is a common problem in adolescence. Earlier research focused on genes within the serotonin and oxytocin systems, but no studies have examined the role of dopamine-related genes in loneliness. In the present study, we focused on the dopamine D2 receptor gene (DRD2). Methods: Associations among the DRD2, sex, parental support,…

  9. [60]Fullerene derivative modulates adenosine and metabotropic glutamate receptors gene expression: a possible protective effect against hypoxia

    PubMed Central

    2014-01-01

    Background Glutamate, the main excitatory neurotransmitter, is involved in learning and memory processes but at higher concentration results excitotoxic causing degeneration and neuronal death. Adenosine is a nucleoside that exhibit neuroprotective effects by modulating of glutamate release. Hypoxic and related oxidative conditions, in which adenosine and metabotropic glutamate receptors are involved, have been demonstrated to contribute to neurodegenerative processes occurring in certain human pathologies. Results Human neuroblastoma cells (SH-SY5Y) were used to evaluate the long time (24, 48 and 72 hours) effects of a [60]fullerene hydrosoluble derivative (t3ss) as potential inhibitor of hypoxic insult. Low oxygen concentration (5% O2) caused cell death, which was avoided by t3ss exposure in a concentration dependent manner. In addition, gene expression analysis by real time PCR of adenosine A1, A2A and A2B and metabotropic glutamate 1 and 5 receptors revealed that t3ss significantly increased A1 and mGlu1 expression in hypoxic conditions. Moreover, t3ss prevented the hypoxia-induced increase in A2A mRNA expression. Conclusions As t3ss causes overexpression of adenosine A1 and metabotropic glutamate receptors which have been shown to be neuroprotective, our results point to a radical scavenger protective effect of t3ss through the enhancement of these neuroprotective receptors expression. Therefore, the utility of these nanoparticles as therapeutic target to avoid degeneration and cell death of neurodegenerative diseases is suggested. PMID:25123848

  10. Expression of androgen receptor target genes in skeletal muscle.

    PubMed

    Rana, Kesha; Lee, Nicole K L; Zajac, Jeffrey D; MacLean, Helen E

    2014-01-01

    We aimed to determine the mechanisms of the anabolic actions of androgens in skeletal muscle by investigating potential androgen receptor (AR)-regulated genes in in vitro and in vivo models. The expression of the myogenic regulatory factor myogenin was significantly decreased in skeletal muscle from testosterone-treated orchidectomized male mice compared to control orchidectomized males, and was increased in muscle from male AR knockout mice that lacked DNA binding activity (AR(ΔZF2)) versus wildtype mice, demonstrating that myogenin is repressed by the androgen/AR pathway. The ubiquitin ligase Fbxo32 was repressed by 12 h dihydrotestosterone treatment in human skeletal muscle cell myoblasts, and c-Myc expression was decreased in testosterone-treated orchidectomized male muscle compared to control orchidectomized male muscle, and increased in AR(∆ZF2) muscle. The expression of a group of genes that regulate the transition from myoblast proliferation to differentiation, Tceal7 , p57(Kip2), Igf2 and calcineurin Aa, was increased in AR(∆ZF2) muscle, and the expression of all but p57(Kip2) was also decreased in testosterone-treated orchidectomized male muscle compared to control orchidectomized male muscle. We conclude that in males, androgens act via the AR in part to promote peak muscle mass by maintaining myoblasts in the proliferative state and delaying the transition to differentiation during muscle growth and development, and by suppressing ubiquitin ligase-mediated atrophy pathways to preserve muscle mass in adult muscle.

  11. Melanocortin-4 receptor gene mutations in obese Slovak children.

    PubMed

    Stanikova, D; Surova, M; Ticha, L; Petrasova, M; Virgova, D; Huckova, M; Skopkova, M; Lobotkova, D; Valentinova, L; Mokan, M; Stanik, J; Klimes, I; Gasperikova, D

    2015-01-01

    The most common etiology of non-syndromic monogenic obesity are mutations in gene for the Melanocortin-4 receptor (MC485) with variable prevalence in different countries (1.2-6.3 % of obese children). The aim of our study was 1) to search for MC4R mutations in obese children in Slovakia and compare their prevalence with other European countries, and 2) to describe the phenotype of the mutation carriers. DNA analysis by direct Sanger sequencing of the coding exons and intron/exon boundaries of the MC4R gene was performed in 268 unrelated Slovak children and adolescents with body mass index above the 97(th) percentile for age and sex and obesity onset up to 11 years (mean 4.3+/-2.8 years). Two different previously described heterozygous loss of function MC4R variants (i.e. p.Ser19Alafs*34, p.Ser127Leu) were identified in two obese probands, and one obese (p.Ser19Alafs*34), and one lean (p.Ser127Leu) adult family relatives. No loss of function variants were found in lean controls. The prevalence of loss-of-function MC4R variants in obese Slovak children was 0.7 %, what is one of the lowest frequencies in Europe.

  12. Anti-Epidermal Growth Factor Receptor Gene Therapy for Glioblastoma

    PubMed Central

    Hicks, Martin J.; Chiuchiolo, Maria J.; Ballon, Douglas; Dyke, Jonathan P.; Aronowitz, Eric; Funato, Kosuke; Tabar, Viviane; Havlicek, David; Fan, Fan; Sondhi, Dolan; Kaminsky, Stephen M.; Crystal, Ronald G.

    2016-01-01

    Glioblastoma multiforme (GBM) is the most common and aggressive primary intracranial brain tumor in adults with a mean survival of 14 to 15 months. Aberrant activation of the epidermal growth factor receptor (EGFR) plays a significant role in GBM progression, with amplification or overexpression of EGFR in 60% of GBM tumors. To target EGFR expressed by GBM, we have developed a strategy to deliver the coding sequence for cetuximab, an anti-EGFR antibody, directly to the CNS using an adeno-associated virus serotype rh.10 gene transfer vector. The data demonstrates that single, local delivery of an anti-EGFR antibody by an AAVrh.10 vector coding for cetuximab (AAVrh.10Cetmab) reduces GBM tumor growth and increases survival in xenograft mouse models of a human GBM EGFR-expressing cell line and patient-derived GBM. AAVrh10.CetMab-treated mice displayed a reduction in cachexia, a significant decrease in tumor volume and a prolonged survival following therapy. Adeno-associated-directed delivery of a gene encoding a therapeutic anti-EGFR monoclonal antibody may be an effective strategy to treat GBM. PMID:27711187

  13. Mannose receptor-mediated gene delivery into antigen presenting dendritic cells.

    PubMed

    Diebold, Sandra S; Plank, Christian; Cotten, Matt; Wagner, Ernst; Zenke, Martin

    2002-11-01

    Dendritic cells are professional antigen presenting cells and are unique in their ability to prime naïve T cells. Gene modification of dendritic cells is of particular interest for immunotherapy of diseases where the immune system has failed or is aberrantly regulated, such as in cancer or autoimmune disease, respectively. Dendritic cells abundantly express mannose receptor and mannose receptor-related receptors, and receptor-mediated gene transfer via mannose receptor offers a versatile tool for targeted gene delivery into these cells. Accordingly, mannose polyethylenimine DNA transfer complexes were generated and used for gene delivery into dendritic cells. Mannose receptor belongs to the group of scavenger receptors that allow dendritic cells to take up pathogenic material, which is directed for degradation and MHC class II presentation. Therefore, a limiting step of transgene expression by mannose receptor-mediated gene delivery is endosomal degradation of DNA. Several strategies have been explored to overcome this limitation including the addition of endosomolytic components to DNA transfer complexes like adenovirus particles and influenza peptides. Here, we review the current understanding of mannose receptor-mediated gene delivery into dendritic cells and discuss strategies to identify appropriate endosomolytic agents to improve DNA transfer efficacy.

  14. Androgen Activation of the Folate Receptor α Gene through Partial Tethering of the Androgen Receptor by C/EBPα○

    PubMed Central

    Sivakumaran, Suneethi; Zhang, Juan; Kelley, Karen M.M.; Gonit, Mesfin; Hao, Hong; Ratnam, Manohar

    2010-01-01

    The folate receptor α (FRα) is critical for normal embryonic and fetal development. The receptor has a relatively narrow tissue specificity which includes the visceral endoderm and the placenta and mediates delivery of folate, inadequacy of which results in termination of pregnancy or developmental defects. We have previously reported that the FRα gene is negatively and directly regulated by estrogen and positively but indirectly by progesterone and glucocorticoid. To further investigate hormonal control of this gene and in view of the growing evidence for the importance of the androgen receptor (AR) in endometrial and placental functions, we examined the response of the FRα gene to androgen. Here we demonstrate that the FRα gene is directly activated by androgen. The P4 promoter of the FRα gene is the target of hormone-dependent activation by the androgen receptor (AR) in a manner that is co-activator-dependent. The site of functional association of AR in the FRα gene maps to a 35bp region occurring ~1500bp upstream of the target promoter. The functional elements within this region are an androgen response element (ARE) half-site and a non-canonical C/EBP element that cooperate to recruit AR in a manner that is dependent on the DNA-bound C/EBPα. Since the placenta is rich in C/EBPα, the findings underscore the multiplicity of mechanisms by which the FRα gene is under the exquisite control of steroid hormones. PMID:20817090

  15. Characterization of the hormone responsive element involved in the regulation of the progesterone receptor gene.

    PubMed Central

    Savouret, J F; Bailly, A; Misrahi, M; Rauch, C; Redeuilh, G; Chauchereau, A; Milgrom, E

    1991-01-01

    The transcription of the progesterone receptor gene is induced by estrogens and decreased by progestins. Studies were performed to define the regions of the gene and the molecular mechanisms involved. No hormonal regulation could be observed using 5' flanking regions of the gene up to -2762 in front of a heterologous gene. Estrogen and progestin regulation could be observed only when using fragments of the gene extending down to +788. Progressive deletions from the 5' and 3' ends, site-directed mutagenesis and DNase protection experiments with purified estrogen receptor suggested that the biologically active estrogen responsive element (ERE) is present at +698/+723, overlapping the initiation of translation. An oligonucleotide was synthesized bearing this ERE and shown to impart estrogen inducibility to a heterologous gene. Its regulation by anti-estrogens corresponded to that of the in situ progesterone receptor gene since tamoxifen was a partial agonist whereas ICI 164384 was a full antagonist. This ERE also mediated down-regulation by progestins in the presence of the progesterone receptor, even though it has no progesterone receptor binding ability. DNase footprinting showed that this effect was not due to a decrease of estrogen receptor affinity for the ERE in the presence of progesterone receptor. Finally, use of deletion mutants of the progesterone receptor showed that the steroid binding and the DNA binding domains were necessary for down-regulation whereas deletions of various parts of the N-terminal domain were without effect. Images PMID:2050123

  16. Olfactory Receptor Gene Polymorphisms and Nonallergic Vasomotor Rhinitis

    PubMed Central

    Bernstein, Jonathan A.; Zhang, Ge; Jin, Li; Abbott, Carol; Nebert, Daniel W.

    2009-01-01

    We sought a genotype-phenotype association: between single-nucleotide polymorphisms (SNPs) in olfactory receptor (OR) genes from the two largest OR gene clusters and odor-triggered nonallergic vasomotor rhinitis (nVMR). In the initial pedigree screen, using transmission disequilibrium test (TDT) analysis, six SNPs showed “significant” p-values between 0.0449 and 0.0043. In a second case-control population, the previously identified six SNPs did not re-emerge, whereas four new SNPs showed p-values between 0.0490 and 0.0001. Combining both studies, none of the SNPs in the TDT analysis survived the Bonferroni correction. In the population study, one SNP showed an empirical p-value of 0.0066 by shuffling cases and controls with 105 replicates; however, the p-value for this SNP was 0.83 in the pedigree study. This study emphasizes that underpowered studies having p-values between <0.05 and 0.0001 should be regarded as inconclusive and require further replication before concluding the study is “informative.” However, we believe that our hypothesis that an association between OR genotypes and the nVMR phenotype remains feasible. Future studies using either a genomewide association study of all OR gene-pseudogene regions throughout the genome—at the current recommended density of 2.5 to 5 kb per tag SNP—or studies incorporating microarray analyses of the entire “OR genome” in well-characterized nVMR patients are required. PMID:18446592

  17. Estrogen receptor genes in gastropods: phylogenetic divergence and gene expression responses to a synthetic estrogen.

    PubMed

    Hultin, Cecilia L; Hallgren, Per; Hansson, Maria C

    2016-11-01

    Endocrine disrupting chemicals (EDCs) have the potential to affect development and reproduction in gastropods. However, one is today lacking basic understanding of the Molluscan endocrine system and one can therefore not fully explain these EDC-induced affects. Furthermore, only a few genes that potentially may be connected to the endocrine system have been sequenced in gastropods. An example is the estrogen receptor gene (er) that have been identified in a restricted number of freshwater and marine gastropods. Here, we have identified a new partial coding sequence of an estrogen receptor gene (er) in the European common heterobranch Radix balthica. The following phylogenetic analysis divided the ers of heterobranchs and ceanogastropods in two branches. Furthermore, exposure to the synthetic estrogen 17α-ethinylestradiol (EE2) showed that exposure could significantly affect er expression level in the heterobranch R. balthica. This paper is the first that phylogenetically compares gastropods' er, basal er expression profiles, and transcriptional estrogenic responses in gastropods from two different evolutionary groups.

  18. Olfactory receptor accessory proteins play crucial roles in receptor function and gene choice

    PubMed Central

    Sharma, Ruchira; Ishimaru, Yoshiro; Davison, Ian; Ikegami, Kentaro; Chien, Ming-Shan; You, Helena; Chi, Quiyi; Kubota, Momoka; Yohda, Masafumi; Ehlers, Michael; Matsunami, Hiroaki

    2017-01-01

    Each of the olfactory sensory neurons (OSNs) chooses to express a single G protein-coupled olfactory receptor (OR) from a pool of hundreds. Here, we show the receptor transporting protein (RTP) family members play a dual role in both normal OR trafficking and determining OR gene choice probabilities. Rtp1 and Rtp2 double knockout mice (RTP1,2DKO) show OR trafficking defects and decreased OSN activation. Surprisingly, we discovered a small subset of the ORs are expressed in larger numbers of OSNs despite the presence of fewer total OSNs in RTP1,2DKO. Unlike typical ORs, some overrepresented ORs show robust cell surface expression in heterologous cells without the co-expression of RTPs. We present a model in which developing OSNs exhibit unstable OR expression until they choose to express an OR that exits the ER or undergo cell death. Our study sheds light on the new link between OR protein trafficking and OR transcriptional regulation. DOI: http://dx.doi.org/10.7554/eLife.21895.001 PMID:28262096

  19. Functional Characterization of Soybean Glyma04g39610 as a Brassinosteroid Receptor Gene and Evolutionary Analysis of Soybean Brassinosteroid Receptors

    PubMed Central

    Peng, Suna; Tao, Ping; Xu, Feng; Wu, Aiping; Huo, Weige; Wang, Jinxiang

    2016-01-01

    Brassinosteroids (BR) play important roles in plant growth and development. Although BR receptors have been intensively studied in Arabidopsis, the BR receptors in soybean remain largely unknown. Here, in addition to the known receptor gene Glyma06g15270 (GmBRI1a), we identified five putative BR receptor genes in the soybean genome: GmBRI1b, GmBRL1a, GmBRL1b, GmBRL2a, and GmBRL2b. Analysis of their expression patterns by quantitative real-time PCR showed that they are ubiquitously expressed in primary roots, lateral roots, stems, leaves, and hypocotyls. We used rapid amplification of cDNA ends (RACE) to clone GmBRI1b (Glyma04g39160), and found that the predicted amino acid sequence of GmBRI1b showed high similarity to those of AtBRI1 and pea PsBRI1. Structural modeling of the ectodomain also demonstrated similarities between the BR receptors of soybean and Arabidopsis. GFP-fusion experiments verified that GmBRI1b localizes to the cell membrane. We also explored GmBRI1b function in Arabidopsis through complementation experiments. Ectopic over-expression of GmBRI1b in Arabidopsis BR receptor loss-of-function mutant (bri1-5 bak1-1D) restored hypocotyl growth in etiolated seedlings; increased the growth of stems, leaves, and siliques in light; and rescued the developmental defects in leaves of the bri1-6 mutant, and complemented the responses of BR biosynthesis-related genes in the bri1-5 bak1-D mutant grown in light. Bioinformatics analysis demonstrated that the six BR receptor genes in soybean resulted from three gene duplication events during evolution. Phylogenetic analysis classified the BR receptors in dicots and monocots into three subclades. Estimation of the synonymous (Ks) and the nonsynonymous substitution rate (Ka) and selection pressure (Ka/Ks) revealed that the Ka/Ks of BR receptor genes from dicots and monocots were less than 1.0, indicating that BR receptor genes in plants experienced purifying selection during evolution. PMID:27338344

  20. Understanding the Functional Plasticity in Neural Networks of the Basal Ganglia in Cocaine Use Disorder: A Role for Allosteric Receptor-Receptor Interactions in A2A-D2 Heteroreceptor Complexes

    PubMed Central

    Borroto-Escuela, Dasiel O.; Wydra, Karolina; Pintsuk, Julia; Narvaez, Manuel; Corrales, Fidel; Zaniewska, Magdalena; Agnati, Luigi F.; Franco, Rafael; Tanganelli, Sergio; Filip, Malgorzata

    2016-01-01

    Our hypothesis is that allosteric receptor-receptor interactions in homo- and heteroreceptor complexes may form the molecular basis of learning and memory. This principle is illustrated by showing how cocaine abuse can alter the adenosine A2AR-dopamine D2R heterocomplexes and their receptor-receptor interactions and hereby induce neural plasticity in the basal ganglia. Studies with A2AR ligands using cocaine self-administration procedures indicate that antagonistic allosteric A2AR-D2R heterocomplexes of the ventral striatopallidal GABA antireward pathway play a significant role in reducing cocaine induced reward, motivation, and cocaine seeking. Anticocaine actions of A2AR agonists can also be produced at A2AR homocomplexes in these antireward neurons, actions in which are independent of D2R signaling. At the A2AR-D2R heterocomplex, they are dependent on the strength of the antagonistic allosteric A2AR-D2R interaction and the number of A2AR-D2R and A2AR-D2R-sigma1R heterocomplexes present in the ventral striatopallidal GABA neurons. It involves a differential cocaine-induced increase in sigma1Rs in the ventral versus the dorsal striatum. In contrast, the allosteric brake on the D2R protomer signaling in the A2AR-D2R heterocomplex of the dorsal striatopallidal GABA neurons is lost upon cocaine self-administration. This is potentially due to differences in composition and allosteric plasticity of these complexes versus those in the ventral striatopallidal neurons. PMID:27872762

  1. Ghrelin axis genes, peptides and receptors: recent findings and future challenges.

    PubMed

    Seim, Inge; Josh, Peter; Cunningham, Peter; Herington, Adrian; Chopin, Lisa

    2011-06-20

    The ghrelin axis consists of the gene products of the ghrelin gene (GHRL), and their receptors, including the classical ghrelin receptor GHSR. While it is well-known that the ghrelin gene encodes the 28 amino acid ghrelin peptide hormone, it is now also clear that the locus encodes a range of other bioactive molecules, including novel peptides and non-coding RNAs. For many of these molecules, the physiological functions and cognate receptor(s) remain to be determined. Emerging research techniques, including proteogenomics, are likely to reveal further ghrelin axis-derived molecules. Studies of the role of ghrelin axis genes, peptides and receptors, therefore, promises to be a fruitful area of basic and clinical research in years to come.

  2. Classification of Dopamine Receptor Genes in Vertebrates: Nine Subtypes in Osteichthyes.

    PubMed

    Yamamoto, Kei; Fontaine, Romain; Pasqualini, Catherine; Vernier, Philippe

    2015-01-01

    Dopamine neurotransmission regulates various brain functions, and its regulatory roles are mediated by two families of G protein-coupled receptors: the D1 and D2 receptor families. In mammals, the D1 family comprises two receptor subtypes (D1 and D5), while the D2 family comprises three receptor subtypes (D2, D3 and D4). Phylogenetic analyses of dopamine receptor genes strongly suggest that the common ancestor of Osteichthyes (bony jawed vertebrates) possessed four subtypes in the D1 family and five subtypes in the D2 family. Mammals have secondarily lost almost half of the ancestral dopamine receptor genes, whereas nonmammalian species kept many of them. Although the mammalian situation is an exception among Osteichthyes, the current classification and characterization of dopamine receptors are based on mammalian features, which have led to confusion in the identification of dopamine receptor subtypes in nonmammalian species. Here we begin by reviewing the history of the discovery of dopamine receptors in vertebrates. The recent genome sequencing of coelacanth, gar and elephant shark led to the proposal of a refined scenario of evolution of dopamine receptor genes. We also discuss a current problem of nomenclature of dopamine receptors. Following the official nomenclature of mammalian dopamine receptors from D1 to D5, we propose to name newly identified receptor subtypes from D6 to D9 in order to facilitate the use of an identical name for orthologous genes among different species. To promote a nomenclature change which allows distinguishing the two dopamine receptor families, a nomenclature consortium is needed. This comparative perspective is crucial to correctly interpret data obtained in animal studies on dopamine-related brain disorders, and more fundamentally, to understand the characteristics of dopamine neurotransmission in vertebrates.

  3. Allelic association of human dopamine D sub 2 receptor gene in alcoholism

    SciTech Connect

    Blum, K.; Sheridan, P.J.; Montgomery, A.; Jagadeeswaran, P.; Nogami, H.; Briggs, A.H. ); Noble, E.P.; Ritchie, T.; Cohn, J.B. )

    1990-04-18

    In a blinded experiment, the authors report the first allelic association of the dopamine D{sub 2} receptor gene in alcoholism. From 70 brain samples of alcoholics and nonalcoholics, DNA was digested with restriction endonucleases and probed with a clone that contained the entire 3{prime} coding exon, the polyadenylation signal, and approximately 16.4 kilobases of noncoding 3{prime} sequence of the human dopamine D{sub 2} receptor gene ({lambda}hD2G1). In the present samples, the presence of A1 allele of the dopamine D{sub 2} receptor gene correctly classified 77% of alcoholics, and its absence classified 72% of nonalcoholics. The polymorphic pattern of this receptor gene suggests that a gene that confers susceptibility to at least one form of alcoholism is located on the q22-q23 region of chromosome 11.

  4. Identification of Modulators of the Nuclear Receptor Peroxisome Proliferator-Activated Receptor α (PPARα) in a Mouse Liver Gene Expression Compendium

    EPA Science Inventory

    The nuclear receptor family member peroxisome proliferator-activated receptor α (PPARα) is activated by therapeutic hypolipidemic drugs and environmentally-relevant chemicals to regulate genes involved in lipid transport and catabolism. Chronic activation of PPARα in rodents inc...

  5. Association study of dopamine D3 receptor gene and schizophrenia

    SciTech Connect

    Kennedy, J.L.; Billett, E.A.; Macciardi, F.M.

    1995-12-18

    Several groups have reported an association between schizophrenia and the MscI polymorphism in the first exon of the dopamine D3 receptor gene (DRD3). We studied this polymorphism using a North American sample (117 patients plus 188 controls) and an Italian sample (97 patients plus 64 controls). In the first part of the study, we compared allele frequencies of schizophrenia patients and unmatched controls and observed a significant difference in the total sample (P = 0.01). The second part of the study involved a case control approach in which each schizophrenia patient was matched to a control of the same sex, and of similar age and ethnic background. The DRD3 allele frequencies of patients and controls revealed no significant difference between the two groups in the Italian (N = 53) or the North American (N = 54) matched populations; however, when these two matched samples were combined, a significant difference was observed (P = 0.026). Our results suggest that the MscI polymorphism may be associated with schizophrenia in the populations studied. 32 refs., 2 tabs.

  6. Penguins reduced olfactory receptor genes common to other waterbirds

    PubMed Central

    Lu, Qin; Wang, Kai; Lei, Fumin; Yu, Dan; Zhao, Huabin

    2016-01-01

    The sense of smell, or olfaction, is fundamental in the life of animals. However, penguins (Aves: Sphenisciformes) possess relatively small olfactory bulbs compared with most other waterbirds such as Procellariiformes and Gaviiformes. To test whether penguins have a reduced reliance on olfaction, we analyzed the draft genome sequences of the two penguins, which diverged at the origin of the order Sphenisciformes; we also examined six closely related species with available genomes, and identified 29 one-to-one orthologous olfactory receptor genes (i.e. ORs) that are putatively functionally conserved and important across the eight birds. To survey the 29 one-to-one orthologous ORs in penguins and their relatives, we newly generated 34 sequences that are missing from the draft genomes. Through the analysis of totaling 378 OR sequences, we found that, of these functionally important ORs common to other waterbirds, penguins have a significantly greater percentage of OR pseudogenes than other waterbirds, suggesting a reduction of olfactory capability. The penguin-specific reduction of olfactory capability arose in the common ancestor of penguins between 23 and 60 Ma, which may have resulted from the aquatic specializations for underwater vision. Our study provides genetic evidence for a possible reduction of reliance on olfaction in penguins. PMID:27527385

  7. Identification of Androgen Receptor and Beta-Catenin Target Genes in Prostate and Prostate Cancer

    DTIC Science & Technology

    2013-10-01

    Transdisciplinary Research in Epigenetics and Cancer Journal Clubs and Transdisciplinary Science Meetings, biweekly and monthly 3. To gain expertise...Target Genes in Prostate and Prostate Cancer PRINCIPAL INVESTIGATOR: Laura Lamb CONTRACTING ORGANIZATION: Washington University...TITLE AND SUBTITLE Identification of Androgen Receptor and Beta-Catenin Target Genes in Prostate and Prostate Cancer 5a. CONTRACT NUMBER Genes in

  8. Positive association between a DNA sequence variant in the serotonin 2A receptor gene and schizophrenia

    SciTech Connect

    Inayama, Y.; Yoneda, H.; Sakai, T.

    1996-02-16

    Sixty-two patients with schizophrenia and 96 normal controls were investigated for genetic association with restriction fragment length polymorphisms (RFLPs) in the serotonin receptor genes. A positive association between the serotonin 2A receptor gene (HTR2A) and schizophrenia was found, but not between schizophrenia and the serotonin 1A receptor gene. The positive association we report here would suggest that the DNA region with susceptibility to schizophrenia lies in the HTR2A on the long arm of chromosome 13. 15 refs., 2 tabs.

  9. From "junk" to gene: curriculum vitae of a primate receptor isoform gene.

    PubMed

    Singer, Silke S; Männel, Daniela N; Hehlgans, Thomas; Brosius, Jürgen; Schmitz, Jürgen

    2004-08-20

    Exonization of Alu retroposons awakens public opinion, particularly when causing genetic diseases. However, often neglected, alternative "Alu-exons" also carry the potential to greatly enhance genetic diversity by increasing the transcriptome of primates chiefly via alternative splicing.Here, we report a 5' exon generated from one of the two alternative transcripts in human tumor necrosis factor receptor gene type 2 (p75TNFR) that contains an ancient Alu-SINE, which provides an alternative N-terminal protein-coding domain. We follow the primate evolution over the past 63 million years to reconstruct the key events that gave rise to a novel receptor isoform. The Alu integration and start codon formation occurred between 58 and 40 million years ago (MYA) in the common ancestor of anthropoid primates. Yet a functional gene product could not be generated until a novel splice site and an open reading frame were introduced between 40 and 25 MYA on the catarrhine lineage (Old World monkeys including apes).

  10. Isolation of Drosophila genes encoding G protein-coupled receptor kinases.

    PubMed Central

    Cassill, J A; Whitney, M; Joazeiro, C A; Becker, A; Zuker, C S

    1991-01-01

    G protein-coupled receptors are regulated via phosphorylation by a variety of protein kinases. Recently, termination of the active state of two such receptors, the beta-adrenergic receptor and rhodopsin, has been shown to be mediated by agonist- or light-dependent phosphorylation of the receptor by members of a family of protein-serine/threonine kinases (here referred to as G protein-coupled receptor kinases). We now report the isolation of a family of genes encoding a set of Drosophila protein kinases that appear to code for G protein-coupled receptor kinases. These proteins share a high degree of sequence homology with the bovine beta-adrenergic receptor kinase. The presence of a conserved family of G protein-coupled receptor kinases in vertebrates and invertebrates points to the central role of these kinases in signal transduction cascades. Images PMID:1662381

  11. Epigenetic regulation of olfactory receptor gene expression by the Myb–MuvB/dREAM complex

    PubMed Central

    Sim, Choon Kiat; Perry, Sarah; Tharadra, Sana Khalid; Lipsick, Joseph S.; Ray, Anandasankar

    2012-01-01

    In both mammals and insects, an olfactory neuron will usually select a single olfactory receptor and repress remaining members of large receptor families. Here we show that a conserved multiprotein complex, Myb–MuvB (MMB)/dREAM, plays an important role in mediating neuron-specific expression of the carbon dioxide (CO2) receptor genes (Gr63a/Gr21a) in Drosophila. Activity of Myb in the complex is required for expression of Gr63a/Gr21a and acts in opposition to the histone methyltransferase Su(var)3-9. Consistent with this, we observed repressive dimethylated H3K9 modifications at the receptor gene loci, suggesting a mechanism for silencing receptor gene expression. Conversely, other complex members, Mip120 (Myb-interacting protein 120) and E2F2, are required for repression of Gr63a in inappropriate neurons. Misexpression in mutants is accompanied by an increase in the H3K4me3 mark of active chromatin at the receptor gene locus. Nuclei of CO2 receptor-expressing neurons contain reduced levels of the repressive subunit Mip120 compared with surrounding neurons and increased levels of Myb, suggesting that activity of the complex can be regulated in a cell-specific manner. Our evidence suggests a model in which olfactory receptors are regulated epigenetically and the MMB/dREAM complex plays a critical role in specifying, maintaining, and modulating the receptor-to-neuron map. PMID:23105004

  12. Profiling of Olfactory Receptor Gene Expression in Whole Human Olfactory Mucosa

    PubMed Central

    Tarabichi, Maxime; Gregoire, Françoise; Dumont, Jacques E.; Chatelain, Pierre

    2014-01-01

    Olfactory perception is mediated by a large array of olfactory receptor genes. The human genome contains 851 olfactory receptor gene loci. More than 50% of the loci are annotated as nonfunctional due to frame-disrupting mutations. Furthermore haplotypic missense alleles can be nonfunctional resulting from substitution of key amino acids governing protein folding or interactions with signal transduction components. Beyond their role in odor recognition, functional olfactory receptors are also required for a proper targeting of olfactory neuron axons to their corresponding glomeruli in the olfactory bulb. Therefore, we anticipate that profiling of olfactory receptor gene expression in whole human olfactory mucosa and analysis in the human population of their expression should provide an opportunity to select the frequently expressed and potentially functional olfactory receptors in view of a systematic deorphanization. To address this issue, we designed a TaqMan Low Density Array (Applied Biosystems), containing probes for 356 predicted human olfactory receptor loci to investigate their expression in whole human olfactory mucosa tissues from 26 individuals (13 women, 13 men; aged from 39 to 81 years, with an average of 67±11 years for women and 63±12 years for men). Total RNA isolation, DNase treatment, RNA integrity evaluation and reverse transcription were performed for these 26 samples. Then 384 targeted genes (including endogenous control genes and reference genes specifically expressed in olfactory epithelium for normalization purpose) were analyzed using the same real-time reverse transcription PCR platform. On average, the expression of 273 human olfactory receptor genes was observed in the 26 selected whole human olfactory mucosa analyzed, of which 90 were expressed in all 26 individuals. Most of the olfactory receptors deorphanized to date on the basis of sensitivity to known odorant molecules, which are described in the literature, were found in the

  13. Family structure and phylogenetic analysis of odorant receptor genes in the large yellow croaker (Larimichthys crocea)

    PubMed Central

    2011-01-01

    Background Chemosensory receptors, which are all G-protein-coupled receptors (GPCRs), come in four types: odorant receptors (ORs), vomeronasal receptors, trace-amine associated receptors and formyl peptide receptor-like proteins. The ORs are the most important receptors for detecting a wide range of environmental chemicals in daily life. Most fish OR genes have been identified from genome databases following the completion of the genome sequencing projects of many fishes. However, it remains unclear whether these OR genes from the genome databases are actually expressed in the fish olfactory epithelium. Thus, it is necessary to clone the OR mRNAs directly from the olfactory epithelium and to examine their expression status. Results Eighty-nine full-length and 22 partial OR cDNA sequences were isolated from the olfactory epithelium of the large yellow croaker, Larimichthys crocea. Bayesian phylogenetic analysis classified the vertebrate OR genes into two types, with several clades within each type, and showed that the L. crocea OR genes of each type are more closely related to those of fugu, pufferfish and stickleback than they are to those of medaka, zebrafish and frog. The reconciled tree showed 178 duplications and 129 losses. The evolutionary relationships among OR genes in these fishes accords with their evolutionary history. The fish OR genes have experienced functional divergence, and the different clades of OR genes have evolved different functions. The result of real-time PCR shows that different clades of ORs have distinct expression levels. Conclusion We have shown about 100 OR genes to be expressed in the olfactory epithelial tissues of L. crocea. The OR genes of modern fishes duplicated from their common ancestor, and were expanded over evolutionary time. The OR genes of L. crocea are closely related to those of fugu, pufferfish and stickleback, which is consistent with its evolutionary position. The different expression levels of OR genes of large

  14. Quinoline derivatives: candidate drugs for a Class B G-protein coupled receptor, the Calcitonin gene-related peptide receptor, a cause of migraines

    PubMed Central

    Iftikhar, Hira; Ahmad, Iqra; Gan, Siew Hua; Shaik, Munvar Miya; Iftikhar, Naveed; Nawaz, Muhammad Sulaman; Greig, Nigel H.; Kamal, Mohammad A

    2016-01-01

    Class B G-protein coupled receptors are involved in a wide variety of diseases and are a major focus in drug design. Migraines are a common problem, and one of their major causative agents is class B G-protein coupled receptor, Calcitonin gene-related peptide (CGRP) receptor, a target for competitive drug discovery. The calcitonin receptor-like receptor generates complexes with a receptor activity-modifying protein, which determines the type of receptor protein formed. The CGRP receptor comprises a complex formed from the calcitonin receptor-like receptor and receptor activity-modifying protein 1. In this study, an in silico docking approach was used to target calcitonin receptor-like receptor in the bound form with receptor activity-modifying protein 1 (CGRP receptor), as well as in the unbound form. In both cases, the resulting inhibitors bound to the same cavity of the calcitonin receptor-like receptor. The twelve evaluated compounds were competitive inhibitors and showed efficient inhibitory activity against the CGRP receptor and Calcitonin receptor-like receptor. The two studied quinoline derivatives demonstrated potentially ideal inhibitory activity in terms of binding interactions and low range nano-molar inhibition constants. These compounds could prove helpful in designing drugs for the effective treatment of migraines. We propose that quinoline derivatives possess inhibitory activity by disturbing CGRP binding in the trigeminovascular system and may be considered for further preclinical appraisal for the treatment of migraines. PMID:25230231

  15. A nonsense mutation in the LDL receptor gene leads to familial hypercholesterolemia in the Druze sect

    SciTech Connect

    Landsberger, D.; Meiner, V.; Reshef, A.; Leitersdorf, E. ); Levy, Yishai ); Westhytzen, D.R. van der; Coetzee, G.A. )

    1992-02-01

    Familial hypercholesterolemia (FH) is an autosomal dominant disease caused by mutations in the LDL receptor gene. Here the authors characterize and LDL receptor mutation that is associated with a distinct haplotype and causes FH in the Druze, a small Middle Eastern Islamic sect with a high degree of inbreeding. The mutation was found in FH families from two distinct Druze villages from the Golan Heights (northern Israel). It was not found either in another Druze FH family residing in a different geographical area nor in eight Arab and four Jewish FH heterozygote index cases whose hypercholesterolemia cosegregates with an identical LDL receptor gene haplotype. The mutation, a single-base substitution, results in a termination codon in exon 4 of the LDL receptor gene that encodes for the fourth repeat of the binding domain of the mature receptor. It can be diagnosed by allele-specific oligonucleotide hybridization of PCR-amplified DNA from FH patients.

  16. Differential regulation of alpha7 nicotinic receptor gene (CHRNA7) expression in schizophrenic smokers.

    PubMed

    Mexal, Sharon; Berger, Ralph; Logel, Judy; Ross, Randal G; Freedman, Robert; Leonard, Sherry

    2010-01-01

    The alpha7 neuronal nicotinic receptor gene (CHRNA7) has been implicated in the pathophysiology of schizophrenia by genetic and pharmacological studies. Expression of the alpha7* receptor, as measured by [(125)I]alpha-bungarotoxin autoradiography, is decreased in postmortem brain of schizophrenic subjects compared to non-mentally ill controls. Most schizophrenic patients are heavy smokers, with high levels of serum cotinine. Smoking changes the expression of multiple genes and differentially regulates gene expression in schizophrenic hippocampus. We examined the effects of smoking on CHRNA7 expression in the same tissue and find that smoking differentially regulates expression of both mRNA and protein for this gene. CHRNA7 mRNA and protein levels are significantly lower in schizophrenic nonsmokers compared to control nonsmokers and are brought to control levels in schizophrenic smokers. Sufficient protein but low surface expression of the alpha7* receptor, seen in the autoradiographic studies, suggests aberrant assembly or trafficking of the receptor.

  17. Histamine H1 Receptor Gene Expression and Drug Action of Antihistamines.

    PubMed

    Fukui, Hiroyuki; Mizuguchi, Hiroyuki; Nemoto, Hisao; Kitamura, Yoshiaki; Kashiwada, Yoshiki; Takeda, Noriaki

    2016-11-25

    The upregulation mechanism of histamine H1 receptor through the activation of protein kinase C-δ (PKCδ) and the receptor gene expression was discovered. Levels of histamine H1 receptor mRNA and IL-4 mRNA in nasal mucosa were elevated by the provocation of nasal hypersensitivity model rats. Pretreatment with antihistamines suppressed the elevation of mRNA levels. Scores of nasal symptoms were correlatively alleviated to the suppression level of mRNAs above. A correlation between scores of nasal symptoms and levels of histamine H1 receptor mRNA in the nasal mucosa was observed in patients with pollinosis. Both scores of nasal symptoms and the level of histamine H1 receptor mRNA were improved by prophylactic treatment of antihistamines. Similar to the antihistamines, pretreatment with antiallergic natural medicines showed alleviation of nasal symptoms with correlative suppression of gene expression in nasal hypersensitivity model rats through the suppression of PKCδ. Similar effects of antihistamines and antiallergic natural medicines support that histamine H1 receptor-mediated activation of histamine H1 receptor gene expression is an important signaling pathway for the symptoms of allergic diseases. Antihistamines with inverse agonist activity showed the suppression of constitutive histamine H1 receptor gene expression, suggesting the advantage of therapeutic effect.

  18. Farnesoid X receptor represses hepatic human APOA gene expression

    PubMed Central

    Chennamsetty, Indumathi; Claudel, Thierry; Kostner, Karam M.; Baghdasaryan, Anna; Kratky, Dagmar; Levak-Frank, Sanja; Frank, Sasa; Gonzalez, Frank J.; Trauner, Michael; Kostner, Gert M.

    2011-01-01

    High plasma concentrations of lipoprotein(a) [Lp(a), which is encoded by the APOA gene] increase an individual’s risk of developing diseases, such as coronary artery diseases, restenosis, and stroke. Unfortunately, increased Lp(a) levels are minimally influenced by dietary changes or drug treatment. Further, the development of Lp(a)-specific medications has been hampered by limited knowledge of Lp(a) metabolism. In this study, we identified patients suffering from biliary obstructions with very low plasma Lp(a) concentrations that rise substantially after surgical intervention. Consistent with this, common bile duct ligation in mice transgenic for human APOA (tg-APOA mice) lowered plasma concentrations and hepatic expression of APOA. To test whether farnesoid X receptor (FXR), which is activated by bile acids, was responsible for the low plasma Lp(a) levels in cholestatic patients and mice, we treated tg-APOA and tg-APOA/Fxr–/– mice with cholic acid. FXR activation markedly reduced plasma concentrations and hepatic expression of human APOA in tg-APOA mice but not in tg-APOA/Fxr–/– mice. Incubation of primary hepatocytes from tg-APOA mice with bile acids dose dependently downregulated APOA expression. Further analysis determined that the direct repeat 1 element between nucleotides –826 and –814 of the APOA promoter functioned as a negative FXR response element. This motif is also bound by hepatocyte nuclear factor 4α (HNF4α), which promotes APOA transcription, and FXR was shown to compete with HNF4α for binding to this motif. These findings may have important implications in the development of Lp(a)-lowering medications. PMID:21804189

  19. Increased striatal adenosine A2A receptor levels is an early event in Parkinson's disease-related pathology and it is potentially regulated by miR-34b.

    PubMed

    Villar-Menéndez, Izaskun; Porta, Sílvia; Buira, Sandra P; Pereira-Veiga, Thais; Díaz-Sánchez, Sara; Albasanz, José Luis; Ferrer, Isidre; Martín, Mairena; Barrachina, Marta

    2014-09-01

    Adenosine A2A receptor (A2AR) is a G-protein coupled receptor that stimulates adenylyl cyclase activity. In the brain, A2ARs are found highly enriched in striatal GABAergic medium spiny neurons, related to the control of voluntary movement. Pharmacological modulation of A2ARs is particularly useful in Parkinson's disease (PD) due to their property of antagonizing dopamine D2 receptor activity. Increases in A2AR levels have been described in PD patients showing an important loss of dopaminergic denervation markers, but no data have been reported about A2AR levels in incidental PD brains. In the present report, we show that increased A2ARs protein levels were also detected in the putamen of incidental PD cases (Braak PD stages 1-2) with respect to age-matched controls. By contrast, A2ARs mRNA levels remained unchanged, suggesting that posttranslational mechanisms could be involved in the regulation of A2ARs. It has been described how miR-34b/c downregulation is an early event in PD cases. We found that miR-34b levels are also significantly reduced in the putamen of incidental PD cases and along disease progression. Given that 3'UTR of A2AR contains a predicted target site for miR-34b, the potential role of this miRNA in protein A2AR levels was assessed. In vitro studies revealed that endogenous A2AR protein levels increased when miR-34b function was blocked using a specific anti-miR-34b. Moreover, using a luciferase reporter assay with point mutations in a miR-34b predicted binding site within the 3'UTR region of A2AR mRNA abolished the effect of the miRNA using a miR-34b mimic. In addition, we showed a reduced percentage of DNA methylation in the 5'UTR region of ADORA2A in advanced PD cases. Overall, these findings reveal that increased A2AR protein levels occur in asymptomatic PD patients and provide new insights into the molecular mechanisms underlying A2AR expression levels along the progression of this neurodegenerative disease.

  20. Molecular Pathways: Breaking the Epithelial Cancer Barrier for Chimeric Antigen Receptor and T-cell Receptor Gene Therapy.

    PubMed

    Hinrichs, Christian S

    2016-04-01

    Adoptive transfer of T cells genetically engineered to express a tumor-targeting chimeric antigen receptor (CAR) or T-cell receptor (TCR) can mediate cancer regression in some patients. CARs are synthetic single-chain proteins that use antibody domains to target cell surface antigens. TCRs are natural heterodimeric proteins that can target intracellular antigens through recognition of peptides bound to human leukocyte antigens. CARs have shown promise in B-cell malignancies and TCRs in melanoma, but neither approach has achieved clear success in an epithelial cancer. Treatment of epithelial cancers may be particularly challenging because of a paucity of target antigens expressed by carcinomas and not by important healthy tissues. In addition, epithelial cancers may be protected by inhibitory ligands and soluble factors in the tumor microenvironment. One strategy to overcome these negative regulators is to modulate expression of T-cell genes to enhance intrinsic T-cell function. Programmable nucleases, which can suppress inhibitory genes, and inducible gene expression systems, which can enhance stimulatory genes, are entering clinical testing. Other work is delineating whether control of genes for immune checkpoint receptors (e.g.,PDCD1, CTLA4) and cytokine and TCR signaling regulators (e.g.,CBLB, CISH, IL12, IL15) can increase the antitumor activity of therapeutic T cells.

  1. Structure and chromosomal localization of the human antidiuretic hormone receptor gene

    SciTech Connect

    Seibold, A.; Brabet, P.; Rosenthal, W.; Birnbaumer, M. )

    1992-11-01

    Applying a genomic DNA-expression approach, the authors cloned the gene and cDNA coding for the human antidiuretic hormone receptor, also called vasopressin V2 receptor' (V2R). The nucleotide sequence of both cloned DNAs provided the information to elucidate the structure of the isolated transcriptional unit. The structure of this gene is unusual in that it is the first G protein-coupled receptor gene that contains two very small intervening sequences, the second of which separates the region encoding the seventh transmembrane region from the rest of the open reading frame. The sequence information was used to synthesize appropriate oligonucleotides to be used as primers in the PCR. The V2R gene was localized by PCR using DNA from hybrid cells as template. The gene was found to reside in the q28-qter portion of the human X chromosome, a region identified as the locus for congential nephrogenic diabetes insipidus. 27 refs., 4 figs.

  2. Effects of the adenosine A2A receptor antagonist SCH 58621 on cyclooxygenase-2 expression, glial activation, and brain-derived neurotrophic factor availability in a rat model of striatal neurodegeneration.

    PubMed

    Minghetti, Luisa; Greco, Anita; Potenza, Rosa Luisa; Pezzola, Antonella; Blum, David; Bantubungi, Kadiombo; Popoli, Patrizia

    2007-05-01

    Inhibition of adenosine A2A receptors (A2ARs) is neuroprotective in several experimental models of striatal diseases. However, the mechanisms elicited by A2AR blockade are only partially known, and critical aspects about the potential beneficial effects of A2AR antagonism in models of neurodegeneration still await elucidation. In the present study, we analyzed the influence of the selective A2AR antagonist SCH 58261 in a rat model of striatal excitotoxicity obtained by unilateral intrastriatal injection of quinolinic acid (QA). We found that SCH 58261 differently affected the expression of cyclooxygenase-2 (COX-2) induced by QA in cortex and striatum. The antagonist enhanced COX-2 expression in cortical neurons and prevented it in striatal microglia-like cells. Similarly, SCH 58261 differently regulated astrogliosis and microglial activation in the 2 brain regions. In addition, the A2AR antagonist prevented the QA-induced increase in striatal brain-derived neurotrophic factor levels. Because COX-2 activity has been linked to excitotoxic processes and because brain-derived neurotrophic factor depletion has been observed in mouse models as well as in patients with Huntington disease, we suggest that the final outcome of A2AR blockade (namely neuroprotection vs neurodegeneration) is likely to depend on the balance among its various and region-specific effects.

  3. Novel androgen receptor gene mutation in patient with complete androgen insensitivity syndrome.

    PubMed

    Ning, Ye; Zhang, Feng; Zhu, Yong; Chen, Huixing; Lu, Jianqi; Li, Zheng

    2012-07-01

    To present a rare case of a patient probably with complete androgen insensitivity syndrome (CAIS) and studied its potential genetic cause. A 24-year-old woman with a normal-appearing vulva and vagina presented to us because of primary amenorrhea. Imaging studies showed no uterus or ovary development but inguinal cryptorchism. Histopathologic examination revealed normal testicular structures. Sequencing the CAIS-associated androgen receptor gene revealed a novel missense mutation of T to G (F698L). A novel androgen receptor gene mutation in the ligand binding domain was detected in the present patient with CAIS, supporting the important role of an androgen receptor defect in the etiology of CAIS.

  4. Orphan nuclear receptor oestrogen-related receptor γ (ERRγ) plays a key role in hepatic cannabinoid receptor type 1-mediated induction of CYP7A1 gene expression

    PubMed Central

    Zhang, Yaochen; Kim, Don-Kyu; Lee, Ji-Min; Park, Seung Bum; Jeong, Won-IL; Kim, Seong Heon; Lee, In-Kyu; Lee, Chul-Ho; Chiang, John Y.L.; Choi, Hueng-Sik

    2017-01-01

    Bile acids are primarily synthesized from cholesterol in the liver and have important roles in dietary lipid absorption and cholesterol homoeostasis. Detailed roles of the orphan nuclear receptors regulating cholesterol 7α-hydroxylase (CYP7A1), the rate-limiting enzyme in bile acid synthesis, have not yet been fully elucidated. In the present study, we report that oestrogen-related receptor γ (ERRγ) is a novel transcriptional regulator of CYP7A1 expression. Activation of cannabinoid receptor type 1 (CB1 receptor) signalling induced ERRγ-mediated transcription of the CYP7A1 gene. Overexpression of ERRγ increased CYP7A1 expression in vitro and in vivo, whereas knockdown of ERRγ attenuated CYP7A1 expression. Deletion analysis of the CYP7A1 gene promoter and a ChIP assay revealed an ERRγ -binding site on the CYP7A1 gene promoter. Small heterodimer partner (SHP) inhibited the transcriptional activity of ERRγ and thus regulated CYP7A1 expression. Overexpression of ERRγ led to increased bile acid levels, whereas an inverse agonist of ERRγ, GSK5182, reduced CYP7A1 expression and bile acid synthesis. Finally, GSK5182 significantly reduced hepatic CB1 receptor-mediated induction of CYP7A1 expression and bile acid synthesis in alcohol-treated mice. These results provide the molecular mechanism linking ERRγ and bile acid metabolism. PMID:26348907

  5. Orphan nuclear receptor oestrogen-related receptor γ (ERRγ) plays a key role in hepatic cannabinoid receptor type 1-mediated induction of CYP7A1 gene expression.

    PubMed

    Zhang, Yaochen; Kim, Don-Kyu; Lee, Ji-Min; Park, Seung Bum; Jeong, Won-Il; Kim, Seong Heon; Lee, In-Kyu; Lee, Chul-Ho; Chiang, John Y L; Choi, Hueng-Sik

    2015-09-01

    Bile acids are primarily synthesized from cholesterol in the liver and have important roles in dietary lipid absorption and cholesterol homoeostasis. Detailed roles of the orphan nuclear receptors regulating cholesterol 7α-hydroxylase (CYP7A1), the rate-limiting enzyme in bile acid synthesis, have not yet been fully elucidated. In the present study, we report that oestrogen-related receptor γ (ERRγ) is a novel transcriptional regulator of CYP7A1 expression. Activation of cannabinoid receptor type 1 (CB1 receptor) signalling induced ERRγ-mediated transcription of the CYP7A1 gene. Overexpression of ERRγ increased CYP7A1 expression in vitro and in vivo, whereas knockdown of ERRγ attenuated CYP7A1 expression. Deletion analysis of the CYP7A1 gene promoter and a ChIP assay revealed an ERRγ-binding site on the CYP7A1 gene promoter. Small heterodimer partner (SHP) inhibited the transcriptional activity of ERRγ and thus regulated CYP7A1 expression. Overexpression of ERRγ led to increased bile acid levels, whereas an inverse agonist of ERRγ, GSK5182, reduced CYP7A1 expression and bile acid synthesis. Finally, GSK5182 significantly reduced hepatic CB1 receptor-mediated induction of CYP7A1 expression and bile acid synthesis in alcohol-treated mice. These results provide the molecular mechanism linking ERRγ and bile acid metabolism.

  6. [Severe type A insulin resistance syndrome due to a mutation in the insulin receptor gene].

    PubMed

    Ros, P; Colino-Alcol, E; Grasso, V; Barbetti, F; Argente, J

    2015-01-01

    Insulin resistance syndromes without lipodystrophy are an infrequent and heterogeneous group of disorders with variable clinical phenotypes, associated with hyperglycemia and hyperinsulinemia. The three conditions related to mutations in the insulin receptor gene are leprechaunism or Donohue syndrome, Rabson-Mendenhall syndrome, and Type A syndrome. A case is presented on a patient diagnosed with type A insulin resistance, defined by the triad of extreme insulin resistance, acanthosis nigricans, and hyperandrogenism, carrying a heterozygous mutation in exon 19 of the insulin receptor gene coding for its tyrosine kinase domain that is crucial for the catalytic activity of the receptor. The molecular basis of the syndrome is reviewed, focusing on the structure-function relationships of the insulin receptor, knowing that the criteria for survival are linked to residual insulin receptor function. It is also pointed out that, although type A insulin resistance appears to represent a somewhat less severe condition, these patients have a high morbidity and their treatment is still unsatisfactory.

  7. Scavenger receptor A gene regulatory elements target gene expression to macrophages and to foam cells of atherosclerotic lesions.

    PubMed Central

    Horvai, A; Palinski, W; Wu, H; Moulton, K S; Kalla, K; Glass, C K

    1995-01-01

    Transcription of the macrophage scavenger receptor A gene is markedly upregulated during monocyte to macrophage differentiation. In these studies, we demonstrate that 291 bp of the proximal scavenger receptor promoter, in concert with a 400-bp upstream enhancer element, is sufficient to direct macrophage-specific expression of a human growth hormone reporter in transgenic mice. These regulatory elements, which contain binding sites for PU.1, AP-1, and cooperating ets-domain transcription factors, are also sufficient to mediate regulation of transgene expression during the in vitro differentiation of bone marrow progenitor cells in response to macrophage colony-stimulating factor. Mutation of the PU.1 binding site within the scavenger receptor promoter severely impairs transgene expression, consistent with a crucial role of PU.1 in regulating the expression of the scavenger receptor gene. The ability of the scavenger receptor promoter and enhancer to target gene expression to macrophages in vivo, including foam cells of atherosclerotic lesions, suggests that these regulatory elements will be of general utility in the study of macrophage differentiation and function by permitting specific modifications of macrophage gene expression. Images Fig. 2 Fig. 3 Fig. 4 Fig. 5 PMID:7777517

  8. Evolution of a symbiotic receptor through gene duplications in the legume-rhizobium mutualism.

    PubMed

    De Mita, Stéphane; Streng, Arend; Bisseling, Ton; Geurts, René

    2014-02-01

    The symbiosis between legumes and nitrogen-fixing rhizobia co-opted pre-existing endomycorrhizal features. In particular, both symbionts release lipo-chitooligosaccharides (LCOs) that are recognized by LysM-type receptor kinases. We investigated the evolutionary history of rhizobial LCO receptor genes MtLYK3-LjNFR1 to gain insight into the evolutionary origin of the rhizobial symbiosis. We performed a phylogenetic analysis integrating gene copies from nonlegumes and legumes, including the non-nodulating, phylogenetically basal legume Cercis chinensis. Signatures of differentiation between copies were investigated through patterns of molecular evolution. We show that two rounds of duplication preceded the evolution of the rhizobial symbiosis in legumes. Molecular evolution patterns indicate that the resulting three paralogous gene copies experienced different selective constraints. In particular, one copy maintained the ancestral function, and another specialized into perception of rhizobial LCOs. It has been suggested that legume LCO receptors evolved from a putative ancestral defense-related chitin receptor through the acquisition of two kinase motifs. However, the phylogenetic analysis shows that these domains are actually ancestral, suggesting that this scenario is unlikely. Our study underlines the evolutionary significance of gene duplication and subsequent neofunctionalization in MtLYK3-LjNFR1 genes. We hypothesize that their ancestor was more likely a mycorrhizal LCO receptor, than a defense-related receptor kinase.

  9. CXC motif chemokine receptor 4 gene polymorphism and cancer risk

    PubMed Central

    Wu, Yang; Zhang, Chun; Xu, Weizhang; Zhang, Jianzhong; Zheng, Yuxiao; Lu, Zipeng; Liu, Dongfang; Jiang, Kuirong

    2016-01-01

    Abstract Background: Previous epidemiological studies have reported the relationship between CXC motif chemokine receptor 4 (CXCR4) synonymous polymorphism (rs2228014), and risk of cancer, but the results remained conflicting and controversial. Therefore, this study was devised to evaluate the genetic effects of the rs2228014 polymorphism on cancer risk in a large meta-analysis. Methods: The computer-based databases (EMBASE, Web of Science, and PubMed) were searched for all relevant studies evaluating rs2228014 and susceptibility to cancer. In the analysis, pooled odds ratios (ORs) with its corresponding 95% confidence intervals (CIs) were calculated in 5 genetic models to assess the genetic risk. Egger regression and Begg funnel plots test were conducted to appraise the publication bias. Results: Data on rs2228014 polymorphism and overall cancer risk were available for 3684 cancer patients and 5114 healthy controls participating in 11 studies. Overall, a significantly increased risk of cancer was associated with rs2228014 polymorphism in homozygote model (OR = 2.01, 95% CI: 1.22–3.33) and in recessive model (OR = 1.97, 95% CI: 1.23–3.16). When stratified by ethnicity, the results were positive only in Asian populations (heterozygote model: OR = 1.36, 95% CI: 1.13–1.65; homozygote model: OR = 2.43, 95% CI: 1.21–4.91; dominant model: OR = 1.47, 95% CI: 1.13–1.90; recessive model: OR = 2.25, 95% CI: 1.13–4.48; and allele model: OR = 1.48, 95% CI: 1.10–1.99). Besides, in the subgroup analysis by source of control, the result was significant only in population-based control (homozygote model: OR = 2.39, 95% CI: 1.06–5.40; recessive model: pooled OR = 2.24, 95% CI: 1.02–4.96). Conclusion: In general, our results first indicated that the rs2228014 polymorphism in CXCR4 gene is correlated with an increased risk of cancer, especially among Asian ethnicity. Large, well-designed epidemiological studies are required to verify the current findings. PMID

  10. A common polymorphism in the LDL receptor gene has multiple effects on LDL receptor function.

    PubMed

    Gao, Feng; Ihn, Hansel E; Medina, Marisa W; Krauss, Ronald M

    2013-04-01

    A common synonymous single nucleotide polymorphism in exon 12 of the low-density lipoprotein receptor (LDLR) gene, rs688, has been associated with increased plasma total and LDL cholesterol in several populations. Using immortalized lymphoblastoid cell lines from a healthy study population, we confirmed an earlier report that the minor allele of rs688 is associated with increased exon 12 alternative splicing (P < 0.05) and showed that this triggered nonsense-mediated decay (NMD) of the alternatively spliced LDLR mRNA. However, since synonymous single nucleotide polymorphisms may influence structure and function of the encoded proteins by co-translational effects, we sought to test whether rs688 was also functional in the full-length mRNA. In HepG2 cells expressing LDLR cDNA constructs engineered to contain the major or minor allele of rs688, the latter was associated with a smaller amount of LDLR protein at the cell surface (-21.8 ± 0.6%, P = 0.012), a higher amount in the lysosome fraction (+25.7 ± 0.3%, P = 0.037) and reduced uptake of fluorescently labeled LDL (-24.3 ± 0.7%, P < 0.01). Moreover, in the presence of exogenous proprotein convertase subtilisin/kexin type 9 (PCSK9), a protein that reduces cellular LDL uptake by promoting lysosomal degradation of LDLR, the minor allele resulted in reduced capacity of a PCSK9 monoclonal antibody to increase LDL uptake. These findings are consistent with the hypothesis that rs688, which is located in the β-propeller region of LDLR, has effects on LDLR activity beyond its role in alternative splicing due to impairment of LDLR endosomal recycling and/or PCSK9 binding, processes in which the β-propeller is critically involved.

  11. Adrenomedullin and calcitonin gene-related peptide receptors in endocrine-related cancers: opportunities and challenges.

    PubMed

    Hay, Debbie L; Walker, Christopher S; Poyner, David R

    2011-02-01

    Adrenomedullin (AM), adrenomedullin 2 (AM2/intermedin) and calcitonin gene-related peptide (CGRP) are members of the calcitonin family of peptides. They can act as growth or survival factors for a number of tumours, including those that are endocrine-related. One mechanism through which this occurs is stimulating angiogenesis and lymphangiogenesis. AM is expressed by numerous tumour types and for some cancers, plasma AM levels can be correlated with the severity of the disease. In cancer models, lowering AM content or blocking AM receptors can reduce tumour mass. AM receptors are complexes formed between a seven transmembrane protein, calcitonin receptor-like receptor and one of the two accessory proteins, receptor activity-modifying proteins (RAMPs) 2 or 3 to give the AM1 and AM2 receptors respectively. AM also has affinity at the CGRP receptor, which uses RAMP1. Unfortunately, due to a lack of selective pharmacological tools or antibodies to distinguish AM and CGRP receptors, the precise receptors and signal transduction pathways used by the peptides are often uncertain. Two other membrane proteins, RDC1 and L1/G10D (the 'ADMR'), are not currently considered to be genuine CGRP or AM receptors. In order to properly evaluate whether AM or CGRP receptor inhibition has a role in cancer therapy, it is important to identify which receptors mediate the effects of these peptides. To effectively distinguish AM1 and AM2 receptors, selective receptor antagonists need to be developed. The development of specific CGRP receptor antagonists suggests that this is now feasible.

  12. Identification of a null mutation in the human dopamine D4 receptor gene

    SciTech Connect

    Noethen, M.M.; Cichon, S.; Hebebrand, J.

    1994-09-01

    Dopamine receptors belong to the family of G protein-coupled receptors. Five different dopamine receptor genes have thus far been identified. These receptors are classified into two main subfamilies: D1, which includes the D1 and D5 receptors, and D2, which includes the D2, D3, and D4 receptors. The dopamine D4 receptor is of great interest for research into neuropsychiatric disorders and psychopharmacology in light of the fact that it binds the antipsychotic medication clozapine with higher affinity than does any other dopamine receptor. In addition, among the dopamine receptors, the D4 receptor shows a uniquely high degree of genetic variation in the human population. We identified a new 13 bp deletion in exon 1 of the D4 gene. This frameshift creates a terminator codon at amino acid position 98. mRNA isolated from brain tissue of two heterozygous persons showed both alleles to be expressed. The deletion occurs with a frequency of 2% in the German population. One person was identified to be homozygous for the deletion. Interestingly, he has a normal intelligence and did not exhibit a major psychiatric disorder as defined by DSM III-R. The 13 bp deletion is the first mutation resulting in premature translation termination reported for a dopamine receptor gene so far. This mutation is a good candidate to test for potential effects on disease and/or individual response to pharmacotherapy. Association studies in patients with various psychiatric illnesses and differences in response to clozapine are underway.

  13. Multimodality Imaging of Gene Transfer with a Receptor-Based Reporter Gene

    PubMed Central

    Chen, Ron; Parry, Jesse J.; Akers, Walter J.; Berezin, Mikhail Y.; El Naqa, Issam M.; Achilefu, Samuel; Edwards, W. Barry; Rogers, Buck E.

    2010-01-01

    Gene therapy trials have traditionally used tumor and tissue biopsies for assessing the efficacy of gene transfer. Non-invasive imaging techniques offer a distinct advantage over tissue biopsies in that the magnitude and duration of gene transfer can be monitored repeatedly. Human somatostatin receptor subtype 2 (SSTR2) has been used for the nuclear imaging of gene transfer. To extend this concept, we have developed a somatostatin receptor–enhanced green fluorescent protein fusion construct (SSTR2-EGFP) for nuclear and fluorescent multimodality imaging. Methods An adenovirus containing SSTR2-EGFP (AdSSTR2-EGFP) was constructed and evaluated in vitro and in vivo. SCC-9 human squamous cell carcinoma cells were infected with AdEGFP, AdSSTR2, or AdSSTR2-EGFP for in vitro evaluation by saturation binding, internalization, and fluorescence spectroscopy assays. In vivo biodistribution and nano-SPECT imaging studies were conducted with mice bearing SCC-9 tumor xenografts directly injected with AdSSTR2-EGFP or AdSSTR2 to determine the tumor localization of 111In-diethylenetriaminepentaacetic acid (DTPA)-Tyr3-octreotate. Fluorescence imaging was conducted in vivo with mice receiving intratumoral injections of AdSSTR2, AdSSTR2-EGFP, or AdEGFP as well as ex vivo with tissues extracted from mice. Results The similarity between AdSSTR2-EGFP and wild-type AdSSTR2 was demonstrated in vitro by the saturation binding and internalization assays, and the fluorescence emission spectra of cells infected with AdSSTR2-EGFP was almost identical to the spectra of cells infected with wild-type AdEGFP. Biodistribution studies demonstrated that the tumor uptake of 111In-DTPA-Tyr3-octreotate was not significantly different (P > 0.05) when tumors (n = 5) were injected with AdSSTR2 or AdSSTR2-EGFP but was significantly greater than the uptake in control tumors. Fluorescence was observed in tumors injected with AdSSTR2-EGFP and AdEGFP in vivo and ex vivo but not in tumors injected with AdSSTR2

  14. The low-density lipoprotein receptor gene family: a cellular Swiss army knife?

    PubMed

    Nykjaer, Anders; Willnow, Thomas E

    2002-06-01

    The low-density lipoprotein receptor gene family is an evolutionarily conserved group of cell-surface receptors produced by mammals and other organisms. Initially thought to be endocytic receptors that mediate the uptake of lipoproteins, recent findings have shown that these receptors have other roles in a range of cellular processes. Among other activities, members of this family act as signal transducers in neuronal migration processes, regulate synaptic plasticity or control vitamin homeostasis. Such multifunctionality is achieved by interaction with diverse cell-surface proteins including glycolipid-anchored receptors, G-protein-coupled receptors and ion channels. Here, we review the molecular interactions of this protein family with other cell-surface proteins that provide specificity and versatility - a versatility that may be reminiscent of a cellular Swiss army knife.

  15. Identification of Gene Markers for Activation of the Nuclear Receptor Pregnane X Receptor

    EPA Science Inventory

    Many environmentally-relevant chemicals and drugs activate the nuclear receptor pregnane X receptor (PXR). Activation of PXR in the mouse liver can lead to increases in liver weight in part through increased hepatocyte replication similar to chemicals that activate other nuclear ...

  16. Gene expression profiles of estrogen receptor positive and estrogen receptor negative breast cancers are detectable in histologically normal breast epithelium

    PubMed Central

    Graham, Kelly; Ge, Xijin; de las Morenas, Antonio; Tripathi, Anusri; Rosenberg, Carol L.

    2010-01-01

    Purpose Previously, we found that gene expression in histologically normal breast epithelium (NlEpi) from women at high breast cancer risk can resemble gene expression in NlEpi from cancer-containing breasts. Therefore, we hypothesized that gene expression characteristic of a cancer subtype might be seen in NlEpi of breasts containing that subtype. Experimental Design We examined gene expression in 46 cases of microdissected NlEpi from untreated women undergoing breast cancer surgery. From 30 age-matched cases (15 estrogen receptor (ER)+, 15 ER-) we used Affymetryix U133A arrays. From 16 independent cases (9 ER+, 7 ER-), we validated selected genes using qPCR. We then compared gene expression between NlEpi and invasive breast cancer using 4 publicly available datasets. Results We identified 198 genes that are differentially expressed between NlEpi from breasts with ER+ (NlEpiER+) compared to ER- cancers (NlEpiER-). These include genes characteristic of ER+ and ER- cancers (e.g., ESR1, GATA3, and CX3CL1, FABP7). QPCR validated the microarray results in both the 30 original cases and the 16 independent cases. Gene expression in NlEpiER+ and NlEpiER- resembled gene expression in ER+ and ER- cancers, respectively: 25-53% of the genes or probes examined in 4 external datasets overlapped between NlEpi and the corresponding cancer subtype. Conclusions Gene expression differs in NlEpi of breasts containing ER+ compared to ER- breast cancers. These differences echo differences in ER+ and ER- invasive cancers. NlEpi gene expression may help elucidate subtype-specific risk signatures, identify early genomic events in cancer development and locate targets for prevention and therapy. PMID:21059815

  17. Evidence for association between polymorphisms in the Cannabinoid Receptor 1 (CNR1) gene and cannabis dependence

    PubMed Central

    Agrawal, Arpana; Wetherill, Leah; Dick, Danielle M.; Xuei, Xiaoling; Hinrichs, Anthony; Hesselbrock, Victor; Kramer, John; Nurnberger, John I.; Schuckit, Marc; Bierut, Laura J.; Edenberg, Howard J.; Foroud, Tatiana

    2009-01-01

    Genomic studies of cannabis use disorders have been limited. The cannabinoid receptor 1 gene (CNR1) on chromosome 6q14–15 is an excellent candidate gene for cannabis dependence due to the important role of the G-protein coupled receptor encoded by this gene in the rewarding effects of Δ9-tetrahydrocannabinol. Previous studies have found equivocal evidence for an association between SNPs in CNR1 and a general vulnerability to substance use disorders. We investigate the association between 9 SNPs spanning CNR1 and cannabis dependence in 1,923 individuals. Two SNPs that were previously associated with cannabis dependence in other studies were also significant with this phenotype in our analyses [rs806368 (p = 0.05) and rs806380 (p = 0.009)]. Haplotype analyses revealed the association to be largely driven by the SNP rs806380. These results suggest a role for the cannabinoid receptor 1 gene in cannabis dependence. PMID:19016476

  18. PET/CT imaging of human somatostatin receptor 2 (hsstr2) as reporter gene for gene therapy

    NASA Astrophysics Data System (ADS)

    Hofmann, M.; Gazdhar, A.; Weitzel, T.; Schmid, R.; Krause, T.

    2006-12-01

    Localized information on region-selective gene expression in small animals is widely obtained by use of reporter genes inducing light emission. Using these reporter genes for imaging deep inside the human body fluorescent probes are hindered by attenuation, scattering and possible fluorescence quenching. This can be overcome by use of radio-peptide receptors as reporter genes. Therefore, the feasibility of the somatostatin receptor 2 expression vector system for expression imaging was checked against a control vector containing luciferase gene. For in vivo transduction of vector DNA into the rat forelimb muscles the in vivo electroporation technique was chosen because of its high regio-selectivity. The gene expression was imaged by high-sensitive CCD camera (luciferase activity) and by PET/CT using a Ga-68-DOTATOC as radio peptide probe. The relative sstr2 expression was enhanced by gene transduction at maximum to a factor of 15. The PET/CT images could be fully quantified. The above demonstrated feasibility of radio-peptide PET/CT reporter gene imaging may serve in the future as a tool for full quantitative understanding of regional gene expression, especially in large animals and humans.

  19. 5-HT2 Receptor Regulation of Mitochondrial Genes: Unexpected Pharmacological Effects of Agonists and Antagonists.

    PubMed

    Harmon, Jennifer L; Wills, Lauren P; McOmish, Caitlin E; Demireva, Elena Y; Gingrich, Jay A; Beeson, Craig C; Schnellmann, Rick G

    2016-04-01

    In acute organ injuries, mitochondria are often dysfunctional, and recent research has revealed that recovery of mitochondrial and renal functions is accelerated by induction of mitochondrial biogenesis (MB). We previously reported that the nonselective 5-HT2 receptor agonist DOI [1-(4-iodo-2,5-dimethoxyphenyl)propan-2-amine] induced MB in renal proximal tubular cells (RPTCs). The goal of this study was to determine the role of 5-HT2 receptors in the regulation of mitochondrial genes and oxidative metabolism in the kidney. The 5-HT2C receptor agonist CP-809,101 [2-[(3-chlorophenyl)methoxy]-6-(1-piperazinyl)pyrazine] and antagonist SB-242,084 [6-chloro-2,3-dihydro-5-methyl-N-[6-[(2-methyl-3-pyridinyl)oxy]-3-pyridinyl]-1H-indole-1-carboxyamide dihydrochloride] were used to examine the induction of renal mitochondrial genes and oxidative metabolism in RPTCs and in mouse kidneys in the presence and absence of the 5-HT2C receptor. Unexpectedly, both CP-809,101 and SB-242,084 increased RPTC respiration and peroxisome proliferator-activated receptor γ coactivator-1α (PGC-1α) mRNA expression in RPTCs at 1-10 nM. In addition, CP-809,101 and SB-242,084 increased mRNA expression of PGC-1α and the mitochondrial proteins NADH dehydrogenase subunit 1 and NADH dehydrogenase (ubiquinone) β subcomplex 8 in mice. These compounds increased mitochondrial genes in RPTCs in which the 5-HT2C receptor was downregulated with small interfering RNA and in the renal cortex of mice lacking the 5-HT2C receptor. By contrast, the ability of these compounds to increase PGC-1α mRNA and respiration was blocked in RPTCs treated with 5-HT2A receptor small interfering RNA or the 5-HT2A receptor antagonist eplivanserin. In addition, the 5-HT2A receptor agonist NBOH-2C-CN [4-[2-[[(2-hydroxyphenyl)methyl]amino]ethyl]-2,5-dimethoxybenzonitrile] increased RPTC respiration at 1-100 nM. These results suggest that agonism of the 5-HT2A receptor induces MB and that the classic 5-HT2C receptor agonist CP

  20. The nuclear receptors pregnane X receptor and constitutive androstane receptor contribute to the impact of fipronil on hepatic gene expression linked to thyroid hormone metabolism.

    PubMed

    Roques, Béatrice B; Leghait, Julien; Lacroix, Marlène Z; Lasserre, Frédéric; Pineau, Thierry; Viguié, Catherine; Martin, Pascal G P

    2013-10-01

    Fipronil is described as a thyroid disruptor in rat. Based on the hypothesis that this results from a perturbation of hepatic thyroid hormone metabolism, our goal was to investigate the pathways involved in fipronil-induced liver gene expression regulations. First, we performed a microarray screening in the liver of rats treated with fipronil or vehicle. Fipronil treatment led to the upregulation of several genes involved in the metabolism of xenobiotics, including the cytochrome P450 Cyp2b1, Cyp2b2 and Cyp3a1, the carboxylesterases Ces2 and Ces6, the phase II enzymes Ugt1a1, Sult1b1 and Gsta2, and the membrane transporters Abcc2, Abcc3, Abcg5, Abcg8, Slco1a1 and Slco1a4. Based on a large overlap with the target genes of constitutive androstane receptor (CAR) and pregnane X receptor (PXR), we postulated that these two nuclear receptors are involved in mediating the effects of fipronil on liver gene expression in rodents. We controlled that liver gene expression changes induced by fipronil were generally reproduced in mice, and then studied the effects of fipronil in wild-type, CAR- and PXR-deficient mice. For most of the genes studied, the gene expression modulations were abolished in the liver of PXR-deficient mice and were reduced in the liver of CAR-deficient mice. However, CAR and PXR activation in mouse liver was not associated with a marked increase of thyroid hormone clearance, as observed in rat. Nevertheless, our data clearly indicate that PXR and CAR are key modulators of the hepatic gene expression profile following fipronil treatment which, in rats, may contribute to increase thyroid hormone clearance.

  1. Molecular characterization of the Aphis gossypii olfactory receptor gene families.

    PubMed

    Cao, Depan; Liu, Yang; Walker, William B; Li, Jianhong; Wang, Guirong

    2014-01-01

    The cotton aphid, Aphis gossypii Glover, is a polyphagous pest that inflicts great damage to cotton yields worldwide. Antennal olfaction, which is extremely important for insect survival, mediates key behaviors such as host preference, mate choice, and oviposition site selection. In insects, odor detection is mediated by odorant receptors (ORs) and ionotropic receptors (IRs), which ensure the specificity of the olfactory sensory neuron responses. In this study, our aim is to identify chemosensory receptors in the cotton aphid genome, as a means to uncover olfactory encoding of the polyphagous feeding habits as well as to aid the discovery of new targets for behavioral interference. We identified a total of 45 candidate ORs and 14 IRs in the cotton aphid genome. Among the candidate AgoORs, 9 are apparent pseudogenes, while 19 can be clustered with ORs from the pea aphid, forming 16 AgoOR/ApOR orthologous subgroups. Among the candidate IRs, we identified homologs of the two highly conserved co-receptors IR8a and IR25a; no AgoIR retain the complete glutamic acid binding domain, suggesting that putative AgoIRs bind different ligands. Our results provide the necessary information for functional characterization of the chemosensory receptors of A. gossypii, with potential for new or refined applications of semiochemicals-based control of this pest insect.

  2. Genomic organization of the mouse T-cell receptor beta-chain gene family.

    PubMed Central

    Lai, E; Barth, R K; Hood, L

    1987-01-01

    We have combined three different methods, deletion mapping of T-cell lines, field-inversion gel electrophoresis, and the restriction mapping of a cosmid clone, to construct a physical map of the murine T-cell receptor beta-chain gene family. We have mapped 19 variable (V beta) gene segments and the two clusters of diversity (D beta) and joining (J beta) gene segments and constant (C beta) genes. These members of the beta-chain gene family span approximately equal to 450 kilobases of DNA, excluding one potential gap in the DNA fragment alignments. Images PMID:3035555

  3. Steroid hormone receptor gene expression in human breast cancer cells: inverse relationship between oestrogen and glucocorticoid receptor messenger RNA levels.

    PubMed

    Hall, R E; Lee, C S; Alexander, I E; Shine, J; Clarke, C L; Sutherland, R L

    1990-12-15

    The relative expression in human breast cancer cells of messenger ribonucleic acids (mRNA) encoding different steroid hormone receptors is unknown. Accordingly, mRNA levels in total RNA extracted from 13 human breast cancer cell lines were measured by Northern analysis employing complementary DNA probes for the human oestrogen (ER), progesterone (PR), androgen (AR), vitamin D3 (VDR) and glucocorticoid receptors (GR). The 7 ER+ lines expressed a single 6.4 kilobases (kb) ER mRNA. Interestingly, low concentrations of ER mRNA were detected in the ER- cell lines, MDA-MB-330 and BT 20. PR mRNA, predominantly a 13.5 kb species, was expressed in the 6 lines known to be ER+, PR+ by radioligand binding; however, one ER+ cell line, MDA-MB-134, failed to express PR mRNA. A 10.5 kb AR mRNA was expressed at significantly higher levels in ER+ than ER- cell lines. All cell lines expressed a single 4.6 kb mRNA for VDR and a single 7.4 kb mRNA for GR. ER and PR mRNA levels were positively correlated (p = 0.011) and each was positively correlated with androgen receptor (AR) mRNA levels (p less than or equal to 0.009). ER, PR and AR mRNAs were negatively associated with GR levels (p less than or equal to 0.012), while ER and AR mRNA levels were negatively correlated with mRNA for the epidermal growth factor receptor. In contrast, levels of VDR mRNA were unrelated to the concentration of any other steroid receptor mRNA. Our data demonstrate the coordinate expression of ER, PR and AR genes, and an inverse relationship between sex steroid hormone receptor and GR gene expression in human breast cancer cell lines.

  4. Endogenous hepatic glucocorticoid receptor signaling coordinates sex-biased inflammatory gene expression.

    PubMed

    Quinn, Matthew A; Cidlowski, John A

    2016-02-01

    An individual's sex affects gene expression and many inflammatory diseases present in a sex-biased manner. Glucocorticoid receptors (GRs) are regulators of inflammatory genes, but their role in sex-specific responses is unclear. Our goal was to evaluate whether GR differentially regulates inflammatory gene expression in male and female mouse liver. Twenty-five percent of the 251 genes assayed by nanostring analysis were influenced by sex. Of these baseline sexually dimorphic inflammatory genes, 82% was expressed higher in female liver. Pathway analyses defined pattern-recognition receptors as the most sexually dimorphic pathway. We next exposed male and female mice to the proinflammatory stimulus LPS. Female mice had 177 genes regulated by treatment with LPS, whereas males had 149, with only 66% of LPS-regulated genes common between the sexes. To determine the contribution of GR to sexually dimorphic inflammatory genes we performed nanostring analysis on liver-specific GR knockout (LGRKO) mice in the presence or absence of LPS. Comparing LGRKO to GR(flox/flox) revealed that 36 genes required GR for sexually dimorphic expression, whereas 24 genes became sexually dimorphic in LGRKO. Fifteen percent of LPS-regulated genes in GR(flox/flox) were not regulated in male and female LGRKO mice treated with LPS. Thus, GR action is influenced by sex to regulate inflammatory gene expression.

  5. Massive Losses of Taste Receptor Genes in Toothed and Baleen Whales

    PubMed Central

    Feng, Ping; Zheng, Jinsong; Rossiter, Stephen J.; Wang, Ding; Zhao, Huabin

    2014-01-01

    Taste receptor genes are functionally important in animals, with a surprising exception in the bottlenose dolphin, which shows extensive losses of sweet, umami, and bitter taste receptor genes. To examine the generality of taste gene loss, we examined seven toothed whales and five baleen whales and sequenced the complete repertoire of three sweet/umami (T1Rs) and ten bitter (T2Rs) taste receptor genes. We found all amplified T1Rs and T2Rs to be pseudogenes in all 12 whales, with a shared premature stop codon in 10 of the 13 genes, which demonstrated massive losses of taste receptor genes in the common ancestor of whales. Furthermore, we analyzed three genome sequences from two toothed whales and one baleen whale and found that the sour taste marker gene Pkd2l1 is a pseudogene, whereas the candidate salty taste receptor genes are intact and putatively functional. Additionally, we examined three genes that are responsible for taste signal transduction and found the relaxation of functional constraints on taste signaling pathways along the ancestral branch leading to whales. Together, our results strongly suggest extensive losses of sweet, umami, bitter, and sour tastes in whales, and the relaxation of taste function most likely arose in the common ancestor of whales between 36 and 53 Ma. Therefore, whales represent the first animal group to lack four of five primary tastes, probably driven by the marine environment with high concentration of sodium, the feeding behavior of swallowing prey whole, and the dietary switch from plants to meat in the whale ancestor. PMID:24803572

  6. Massive losses of taste receptor genes in toothed and baleen whales.

    PubMed

    Feng, Ping; Zheng, Jinsong; Rossiter, Stephen J; Wang, Ding; Zhao, Huabin

    2014-05-06

    Taste receptor genes are functionally important in animals, with a surprising exception in the bottlenose dolphin, which shows extensive losses of sweet, umami, and bitter taste receptor genes. To examine the generality of taste gene loss, we examined seven toothed whales and five baleen whales and sequenced the complete repertoire of three sweet/umami (T1Rs) and ten bitter (T2Rs) taste receptor genes. We found all amplified T1Rs and T2Rs to be pseudogenes in all 12 whales, with a shared premature stop codon in 10 of the 13 genes, which demonstrated massive losses of taste receptor genes in the common ancestor of whales. Furthermore, we analyzed three genome sequences from two toothed whales and one baleen whale and found that the sour taste marker gene Pkd2l1 is a pseudogene, whereas the candidate salty taste receptor genes are intact and putatively functional. Additionally, we examined three genes that are responsible for taste signal transduction and found the relaxation of functional constraints on taste signaling pathways along the ancestral branch leading to whales. Together, our results strongly suggest extensive losses of sweet, umami, bitter, and sour tastes in whales, and the relaxation of taste function most likely arose in the common ancestor of whales between 36 and 53 Ma. Therefore, whales represent the first animal group to lack four of five primary tastes, probably driven by the marine environment with high concentration of sodium, the feeding behavior of swallowing prey whole, and the dietary switch from plants to meat in the whale ancestor.

  7. T cell receptor genes in an alloreactive CTL clone: implications for rearrangement and germline diversity of variable gene segments.

    PubMed Central

    Chou, H S; Behlke, M A; Godambe, S A; Russell, J H; Brooks, C G; Loh, D Y

    1986-01-01

    Both cDNA and genomic clones of the T cell receptor (TCR) alpha- and beta-chain genes of the alloreactive cytotoxic T lymphocyte (CTL) clone F3 were examined. Two distinct rearrangement events, one functional and one non-functional, were found for both the alpha and beta loci. Thus only a single functional TCR alpha beta heterodimer could be defined, consistent with allelic exclusion in the TCR genes. The V alpha gene employed by F3 is part of a six-member V alpha subfamily. Genomic clones containing each member of this subfamily were isolated and the V alpha nucleotide sequences determined. Five of these six genes are functional; these genes differ from each other by 7-14% at the amino acid level. A single dominant hypervariable region was defined within this subfamily, in contrast to the pattern of variability seen between V alpha genes in general. Images Fig. 4. Fig. 5. PMID:3490968

  8. Natural Killer Cell Receptor Genes in the Family Equidae: Not only Ly49

    PubMed Central

    Futas, Jan; Horin, Petr

    2013-01-01

    Natural killer (NK) cells have important functions in immunity. NK recognition in mammals can be mediated through killer cell immunoglobulin-like receptors (KIR) and/or killer cell lectin-like Ly49 receptors. Genes encoding highly variable NK cell receptors (NKR) represent rapidly evolving genomic regions. No single conservative model of NKR genes was observed in mammals. Single-copy low polymorphic NKR genes present in one mammalian species may expand into highly polymorphic multigene families in other species. In contrast to other non-rodent mammals, multiple Ly49-like genes appear to exist in the horse, while no functional KIR genes were observed in this species. In this study, Ly49 and KIR were sought and their evolution was characterized in the entire family Equidae. Genomic sequences retrieved showed the presence of at least five highly conserved polymorphic Ly49 genes in horses, asses and zebras. These findings confirmed that the expansion of Ly49 occurred in the entire family. Several KIR-like sequences were also identified in the genome of Equids. Besides a previously identified non-functional KIR-Immunoglobulin-like transcript fusion gene (KIR-ILTA) and two putative pseudogenes, a KIR3DL-like sequence was analyzed. In contrast to previous observations made in the horse, the KIR3DL sequence, genomic organization and mRNA expression suggest that all Equids might produce a functional KIR receptor protein molecule with a single non-mutated immune tyrosine-based inhibition motif (ITIM) domain. No evidence for positive selection in the KIR3DL gene was found. Phylogenetic analysis including rhinoceros and tapir genomic DNA and deduced amino acid KIR-related sequences showed differences between families and even between species within the order Perissodactyla. The results suggest that the order Perissodactyla and its family Equidae with expanded Ly49 genes and with a potentially functional KIR gene may represent an interesting model for evolutionary biology of

  9. Natural killer cell receptor genes in the family Equidae: not only Ly49.

    PubMed

    Futas, Jan; Horin, Petr

    2013-01-01

    Natural killer (NK) cells have important functions in immunity. NK recognition in mammals can be mediated through killer cell immunoglobulin-like receptors (KIR) and/or killer cell lectin-like Ly49 receptors. Genes encoding highly variable NK cell receptors (NKR) represent rapidly evolving genomic regions. No single conservative model of NKR genes was observed in mammals. Single-copy low polymorphic NKR genes present in one mammalian species may expand into highly polymorphic multigene families in other species. In contrast to other non-rodent mammals, multiple Ly49-like genes appear to exist in the horse, while no functional KIR genes were observed in this species. In this study, Ly49 and KIR were sought and their evolution was characterized in the entire family Equidae. Genomic sequences retrieved showed the presence of at least five highly conserved polymorphic Ly49 genes in horses, asses and zebras. These findings confirmed that the expansion of Ly49 occurred in the entire family. Several KIR-like sequences were also identified in the genome of Equids. Besides a previously identified non-functional KIR-Immunoglobulin-like transcript fusion gene (KIR-ILTA) and two putative pseudogenes, a KIR3DL-like sequence was analyzed. In contrast to previous observations made in the horse, the KIR3DL sequence, genomic organization and mRNA expression suggest that all Equids might produce a functional KIR receptor protein molecule with a single non-mutated immune tyrosine-based inhibition motif (ITIM) domain. No evidence for positive selection in the KIR3DL gene was found. Phylogenetic analysis including rhinoceros and tapir genomic DNA and deduced amino acid KIR-related sequences showed differences between families and even between species within the order Perissodactyla. The results suggest that the order Perissodactyla and its family Equidae with expanded Ly49 genes and with a potentially functional KIR gene may represent an interesting model for evolutionary biology of

  10. Sulfotransferase genes: Regulation by nuclear receptors in response to xeno/endo-biotics

    PubMed Central

    Kodama, Susumu; Negishi, Masahiko

    2014-01-01

    Pregnane X receptor (PXR) and constitutive active/androstane receptor (CAR), members of the nuclear receptor superfamily, are two major xeno-sensing transcription factors. They can be activated by a broad range of lipophilic xenobiotics including therapeutics drugs. In addition to xenobiotics, endogenous compounds such as steroid hormones and bile acids can also activate PXR and/or CAR. These nuclear receptors regulate genes that encode enzymes and transporters that metabolize and excrete both xenobiotics and endobiotics. Sulfotransferases (SULTs) are a group of these enzymes and sulfate xenobiotics for detoxification. In general, inactivation by sulfation constitutes the mechanism to maintain homeostasis of endobiotics. Thus, deciphering the molecular mechanism by which PXR and CAR regulate SULT genes is critical for understanding the roles of SULTs in the alterations of physiological and pathophysiological processes caused by drug treatment or environmental exposures. PMID:24025090

  11. Increase of AMPA receptor glutamate receptor 1 subunit and B-cell receptor-associated protein 31 gene expression in hippocampus of fatigued mice.

    PubMed

    Kamakura, Masaki; Tamaki, Keisuke; Sakaki, Toshiyuki; Yoneda, Yukio

    2005-10-14

    Central fatigue is an indispensable biosignal for maintaining life, but the neuronal and molecular mechanisms involved remain unclear. In this study, we searched for genes differentially expressed in the hippocampus of fatigued mice to elucidate the mechanisms underlying fatigue. Mice were forced to swim in an adjustable-current water pool, and the maximum swimming time (endurance) until fatigue was measured thrice. Fatigued and nonfatigued mice with equal swimming capacity and body weight were compared. We found that the genes of GluR1 and B-cell receptor-associated protein 31 (Bap31), which acts as a transport molecule in the secretory pathway or as a mediator of apoptosis, were upregulated in the hippocampus of fatigued mice, and increases of GluR1 and Bap31 were confirmed by Northern blotting and real-time PCR. No change of gene expression of AMPA receptor subunits other than GluR1 was observed. These results suggest that a compositional change of AMPA receptor (increase of GluR1) and upregulation of the Bap31 gene may be implicated in fatigue in mice.

  12. Selective Gene Regulation by Androgen Receptor in Prostate Cancer

    DTIC Science & Technology

    2013-10-01

    androgen receptor pathway in prostate cancer. Curr Opin Pharmacol, 2008. 8(4): p. 440-8. 6. Claessens, F., P. Alen , A. Devos, B. Peeters, G...Chem, 1996. 271(32): p. 19013-6. 7. Schoenmakers, E., P. Alen , G. Verrijdt, B. Peeters, G. Verhoeven, W. Rombauts, and F. Claessens, Differential DNA

  13. Ecdysone Receptor-Based Gene Switches for Applications in Plants

    Technology Transfer Automated Retrieval System (TEKTRAN)

    There are a number of circumstances in which it is advantageous to use an inducible gene regulation system, the most obvious being when introducing transgenes whose constitutive expression is detrimental or even lethal to the host plants. The selective induction of gene expression is typically accom...

  14. T-cell receptor variable region gene usage in T-cell populations.

    PubMed Central

    Garman, R D; Ko, J L; Vulpe, C D; Raulet, D H

    1986-01-01

    We have examined T-cell receptor alpha- and beta-chain variable (V) region gene usage in T-cell populations predicted to have different major histocompatibility complex-restriction specificities. Using a sensitive ribonuclease protection assay to measure T-cell receptor mRNA levels, we found no striking differences in the usage of three V alpha genes and three V beta genes in T-cell populations from three congeneic H-2-disparate strains of mice and between the mutually exclusive Ly2+ L3T4- and Ly2- L3T4+ T-cell subpopulations. These results suggest that major histocompatibility complex restriction cannot be explained by the differential usage of nonoverlapping V alpha or V beta gene pools. In contrast, striking but unpredictable differences were seen in V gene usage in populations of T cells selected by activation with particular alloantigens. Images PMID:3487085

  15. Functional characterization of insulin receptor gene mutations contributing to Rabson-Mendenhall syndrome - phenotypic heterogeneity of insulin receptor gene mutations.

    PubMed

    Jiang, Shan; Fang, Qichen; Zhang, Feng; Wan, Hui; Zhang, Rong; Wang, Congrong; Bao, Yuqian; Zhang, Lei; Ma, Xiaojing; Lu, Junxi; Gao, Fei; Xiang, Kunsan; Jia, Weiping

    2011-01-01

    Rabson-Mendenhall syndrome (RMS) is a rare disorder that presents as severe insulin resistance as a result of mutations present in the insulin receptor (INSR). A Chinese girl with RMS presented with profound diabetes, hyperinsulinemia, acanthosis nigricans, hirsutism, and abnormalities of teeth and nails. Direct sequencing of the patient's INSR detected heterozygote mutations at Arg83Gln (R83Q) and Ala1028Val (A1028V), with the former representing a novel mutation. Functional studies of Chinese hamster ovary (CHO) cells transfected with wild-type (WT) and mutant forms of INSR were performed to evaluate the effects of these mutations on receptor expression and activation. Receptor expression, insulin binding activity, and phosphorylation of the R83Q variant were comparable to WT. In contrast, expression of the A1028V receptor was much lower than that of WT INSR, and impairment of insulin binding and autophosphorylation were nearly commensurate with the decrease in expression detected. Reductions in the phosphorylation of IRS-1, Akt, and Erk1/2 (60%, 40%, and 50% of WT, respectively) indicate that the A1028V receptor contributes to impaired signal transduction. In conclusion, INSR mutations associated with RMS were identified. Moreover, the A1028V mutation associated with a decrease in expression of INSR potentially accounts for loss of function of the INSR.

  16. The DAF-7 TGF-β signaling pathway regulates chemosensory receptor gene expression in C. elegans

    PubMed Central

    Nolan, Katherine M.; Sarafi-Reinach, Trina R.; Horne, Jennifer G.; Saffer, Adam M.; Sengupta, Piali

    2002-01-01

    Regulation of chemoreceptor gene expression in response to environmental or developmental cues provides a mechanism by which animals can alter their sensory responses. Here we demonstrate a role for the daf-7 TGF-β pathway in the regulation of expression of a subset of chemoreceptor genes in Caenorhabditis elegans. We describe a novel role of this pathway in maintaining receptor gene expression in the adult and show that the DAF-4 type II TGF-β receptor functions cell-autonomously to modulate chemoreceptor expression. We also find that the alteration of receptor gene expression in the ASI chemosensory neurons by environmental signals, such as levels of a constitutively produced pheromone, may be mediated via a DAF-7-independent pathway. Receptor gene expression in the ASI and ASH sensory neurons appears to be regulated via distinct mechanisms. Our results suggest that the expression of individual chemoreceptor genes in C. elegans is subject to multiple modes of regulation, thereby ensuring that animals exhibit the responses most appropriate for their developmental stage and environmental conditions. PMID:12464635

  17. Vitamin D Receptor Gene as a Candidate Gene for Parkinson Disease

    PubMed Central

    BUTLER, MEGAN W.; BURT, AMBER; EDWARDS, TODD L.; ZUCHNER, STEPHAN; SCOTT, WILLIAM K.; MARTIN, EDEN R.; VANCE, JEFFERY M.; WANG, LIYONG

    2010-01-01

    Summary Vitamin D and vitamin D receptor (VDR) have been postulated as environmental and genetic factors in neurodegeneration disorders including multiple sclerosis (MS), Alzheimer disease (AD), and recently Parkinson disease (PD). Given the sparse data on PD and VDR, we conducted a two-stage study to evaluate the genetic effects of VDR in PD. In the discovery stage, 30 tagSNPs in VDR were tested for association with PD risk as a discrete trait and age-at-onset of PD as a quantitative trait in 770 Caucasian PD families. In the validation stage, 18 VDR SNPs were tested in an independent Caucasian cohort (267 cases and 267 controls) constructed from a genome-wide association study (GWAS). In the discovery dataset, SNPs in the 5′ end of VDR were associated with both risk and age-at-onset with more significant evidence of association with age-at-onset (nominal p=0.0008 for the most significant SNPs). These SNPs were also associated with AD in a recent GWAS. In the validation dataset, SNPs in the 3′ end of VDR were associated with age-at-onset (nominal p=0.003 for the most significant SNPs but not risk. The most significant 3′end SNP has been be associated with both MS and AD. Our findings suggest VDR as a potential susceptibility gene and support an essential role of vitamin D in PD. PMID:21309754

  18. Cholinergic nicotinic receptor genes implicated in a nicotine dependence association study targeting 348 candidate genes with 3713 SNPs

    PubMed Central

    Saccone, Scott F.; Hinrichs, Anthony L.; Saccone, Nancy L.; Chase, Gary A.; Konvicka, Karel; Madden, Pamela A.F.; Breslau, Naomi; Johnson, Eric O.; Hatsukami, Dorothy; Pomerleau, Ovide; Swan, Gary E.; Goate, Alison M.; Rutter, Joni; Bertelsen, Sarah; Fox, Louis; Fugman, Douglas; Martin, Nicholas G.; Montgomery, Grant W.; Wang, Jen C.; Ballinger, Dennis G.; Rice, John P.; Bierut, Laura Jean

    2007-01-01

    Nicotine dependence is one of the world’s leading causes of preventable death. To discover genetic variants that influence risk for nicotine dependence, we targeted over 300 candidate genes and analyzed 3713 single nucleotide polymorphisms (SNPs) in 1050 cases and 879 controls. The Fagerström test for nicotine dependence (FTND) was used to assess dependence, in which cases were required to have an FTND of 4 or more. The control criterion was strict: control subjects must have smoked at least 100 cigarettes in their lifetimes and had an FTND of 0 during the heaviest period of smoking. After correcting for multiple testing by controlling the false discovery rate, several cholinergic nicotinic receptor genes dominated the top signals. The strongest association was from an SNP representing CHRNB3, the β3 nicotinic receptor subunit gene (P = 9.4 × 10−5). Biologically, the most compelling evidence for a risk variant came from a non-synonymous SNP in the α5 nicotinic receptor subunit gene CHRNA5 (P = 6.4 × 10−4). This SNP exhibited evidence of a recessive mode of inheritance, resulting in individuals having a 2-fold increase in risk of developing nicotine dependence once exposed to cigarette smoking. Other genes among the top signals were KCNJ6 and GABRA4. This study represents one of the most powerful and extensive studies of nicotine dependence to date and has found novel risk loci that require confirmation by replication studies. PMID:17135278

  19. Hormone Receptor and ERBB2 Status in Gene Expression Profiles of Human Breast Tumor Samples

    PubMed Central

    Dvorkin-Gheva, Anna; Hassell, John A.

    2011-01-01

    The occurrence of large publically available repositories of human breast tumor gene expression profiles provides an important resource to discover new breast cancer biomarkers and therapeutic targets. For example, knowledge of the expression of the estrogen and progesterone hormone receptors (ER and PR), and that of the ERBB2 in breast tumor samples enables choice of therapies for the breast cancer patients that express these proteins. Identifying new biomarkers and therapeutic agents affecting the activity of signaling pathways regulated by the hormone receptors or ERBB2 might be accelerated by knowledge of their expression levels in large gene expression profiling data sets. Unfortunately, the status of these receptors is not invariably reported in public databases of breast tumor gene expression profiles. Attempts have been made to employ a single probe set to identify ER, PR and ERBB2 status, but the specificity or sensitivity of their prediction is low. We enquired whether estimation of ER, PR and ERBB2 status of profiled tumor samples could be improved by using multiple probe sets representing these three genes and others with related expression. We used 8 independent datasets of human breast tumor samples to define gene expression signatures comprising 24, 51 and 14 genes predictive of ER, PR and ERBB2 status respectively. These signatures, as demonstrated by sensitivity and specificity measures, reliably identified hormone receptor and ERBB2 expression in breast tumors that had been previously determined using protein and DNA based assays. Our findings demonstrate that gene signatures can be identified which reliably predict the expression status of the estrogen and progesterone hormone receptors and that of ERBB2 in publically available gene expression profiles of breast tumor samples. Using these signatures to query transcript profiles of breast tumor specimens may enable discovery of new biomarkers and therapeutic targets for particular subtypes of

  20. Oxytocin, vasopressin and estrogen receptor gene expression in relation to social recognition in female mice

    PubMed Central

    Clipperton-Allen, Amy E.; Lee, Anna W.; Reyes, Anny; Devidze, Nino; Phan, Anna; Pfaff, Donald W.; Choleris, Elena

    2012-01-01

    Inter- and intra-species differences in social behavior and recognition-related hormones and receptors suggest that different distribution and/or expression patterns may relate to social recognition. We used qRT-PCR to investigate naturally occurring differences in expression of estrogen receptor-alpha (ERα), ER-beta (ERβ), progesterone receptor (PR), oxytocin (OT) and receptor, and vasopressin (AVP) and receptors in proestrous female mice. Following four 5 min exposures to the same two conspecifics, one was replaced with a novel mouse in the final trial (T5). Gene expression was examined in mice showing high (85–100%) and low (40–60%) social recognition scores (i.e., preferential novel mouse investigation in T5) in eight socially-relevant brain regions. Results supported OT and AVP involvement in social recognition, and suggest that in the medial preoptic area, increased OT and AVP mRNA, together with ERα and ERβ gene activation, relate to improved social recognition. Initial social investigation correlated with ERs, PR and OTR in the dorsolateral septum, suggesting that these receptors may modulate social interest without affecting social recognition. Finally, increased lateral amygdala gene activation in the LR mice may be associated with general learning impairments, while decreased lateral amygdala activity may indicate more efficient cognitive mechanisms in the HR mice. PMID:22079582

  1. Molecular cloning of a gene encoding the histamine H2 receptor

    SciTech Connect

    Gantz, I.; Schaeffer, M.; DelValle, J.; Logsdon, C.; Campbell, V.; Uhler, M.; Yamada, Tadataka )

    1991-01-15

    The H2 subclass of histamine receptors mediates gastric acid secretion, and antagonists for this receptor have proven to be effective therapy for acid peptic disorders of the gastrointestinal tract. The physiological action of histamine has been shown to be mediated via a guanine nucleotide-binding protein linked to adenylate cyclase activation and cellular cAMP generation. The authors capitalized on the technique of polymerase chain reaction, using degenerate oligonucleotide primers based on the known homology between cellular receptors linked to guanine nucleotide-binding proteins to obtain a partial-length clone from canine gastric parietal cell cDNA. This clone was used to obtain a full-length receptor gene from a canine genomic library. Histamine increased in a dose-dependent manner cellular cAMP content in L cells permanently transfected with this gene, and preincubation of the cells with the H2-selective antagonist cimetidine shifted the dose-response curve to the right. Cimetidine inhibited the binding of the radiolabeled H2 receptor-selective ligand (methyl-{sup 3}H)tiotidine to the transfected cells in a dose-dependent fashion, but the H1-selective antagonist diphenhydramine did not. These data indicate that they have cloned a gene that encodes the H2 subclass of histamine receptors.

  2. Domain-dependent effects of insulin and IGF-1 receptors on signalling and gene expression

    PubMed Central

    Cai, Weikang; Sakaguchi, Masaji; Kleinridders, Andre; Gonzalez-Del Pino, Gonzalo; Dreyfuss, Jonathan M.; O'Neill, Brian T.; Ramirez, Alfred K.; Pan, Hui; Winnay, Jonathon N.; Boucher, Jeremie; Eck, Michael J.; Kahn, C. Ronald

    2017-01-01

    Despite a high degree of homology, insulin receptor (IR) and IGF-1 receptor (IGF1R) mediate distinct cellular and physiological functions. Here, we demonstrate how domain differences between IR and IGF1R contribute to the distinct functions of these receptors using chimeric and site-mutated receptors. Receptors with the intracellular domain of IGF1R show increased activation of Shc and Gab-1 and more potent regulation of genes involved in proliferation, corresponding to their higher mitogenic activity. Conversely, receptors with the intracellular domain of IR display higher IRS-1 phosphorylation, stronger regulation of genes in metabolic pathways and more dramatic glycolytic responses to hormonal stimulation. Strikingly, replacement of leucine973 in the juxtamembrane region of IR to phenylalanine, which is present in IGF1R, mimics many of these signalling and gene expression responses. Overall, we show that the distinct activities of the closely related IR and IGF1R are mediated by their intracellular juxtamembrane region and substrate binding to this region. PMID:28345670

  3. 5-HT2A receptor gene polymorphisms in Croatian subjects with autistic disorder.

    PubMed

    Hranilovic, Dubravka; Blazevic, Sofia; Babic, Marina; Smurinic, Maja; Bujas-Petkovic, Zorana; Jernej, Branimir

    2010-08-15

    Disturbances in the expression/function of the 5-HT2A receptor are implicated in autism. The association of the 5-HT2A receptor gene with autism was studied in the Croatian population. Distribution frequencies for alleles, genotypes and haplotypes of -1438 A/G and His452Tyr polymorphisms were compared in samples of 103 autistic and 214 control subjects. Significant overrepresentation of the G allele and the GG genotype of the -1438 A/G polymorphism was observed in group of autistic subjects, supporting the possible involvement of the 5-HT2A receptor in the development of autism.

  4. [Histamine H₁ receptor gene as an allergic diseases-sensitive gene and its impact on therapeutics for allergic diseases].

    PubMed

    Mizuguchi, Hiroyuki; Kitamura, Yoshiaki; Kondo, Yuto; Kuroda, Wakana; Yoshida, Haruka; Miyamoto, Yuko; Hattori, Masashi; Takeda, Noriaki; Fukui, Hiroyuki

    2011-02-01

    Therapeutics targeting disease-sensitive genes are required for the therapy of multifactorial diseases. There is no clinical report on therapeutics for allergic disease-sensitive genes. We are focusing on the histamine H₁ receptor (H1R) as a sensitive gene. H1R mediates allergy histamine signals. H1R is a rate-limiting molecule of the H1R signal because the signal is increased with elevated receptor expression level. We discovered that the stimulation of H1R induced H1R gene expression through PKCδ activation, resulting in receptor upregulation. The mechanism of H1R gene expression was revealed to play a key role in the receptor expression level in studies using cultured HeLa cells and allergic rhinitis model rats. Preseasonal prophylactic treatment with antihistamines is recommended for the therapy of pollinosis. However, the mechanism of the therapy remains to be elucidated. We demonstrated that repeated pretreatment treatment with antihistamines in the allergic rhinitis model rats resulted not only in improvement of symptoms but also in suppressed elevation of H1R mRNA levels in the nasal mucosa. A clinical trial was then initiated. When symptoms and H1R mRNA levels in the nasal mucosa of pollinosis patients with or without preseasonal prophylactic treatment with antihistamines were examined, both symptoms and high levels of H1R mRNA were significantly improved in treated compared with untreated patients. These results strongly suggest that H1R is an allergic disease-sensitive gene.

  5. Estrogen receptor-alpha gene expression in the cortex: sex differences during development and in adulthood.

    PubMed

    Wilson, Melinda E; Westberry, Jenne M; Trout, Amanda L

    2011-03-01

    17β-estradiol is a hormone with far-reaching organizational, activational and protective actions in both male and female brains. The organizational effects of early estrogen exposure are essential for long-lasting behavioral and cognitive functions. Estradiol mediates many of its effects through the intracellular receptors, estrogen receptor-alpha (ERα) and estrogen receptor-beta (ERβ). In the rodent cerebral cortex, estrogen receptor expression is high early in postnatal life and declines dramatically as the animal approaches puberty. This decline is accompanied by decreased expression of ERα mRNA. This change in expression is the same in both males and females in the developing isocortex and hippocampus. An understanding of the molecular mechanisms involved in the regulation of estrogen receptor alpha (ERα) gene expression is critical for understanding the developmental, as well as changes in postpubertal expression of the estrogen receptor. One mechanism of suppressing gene expression is by the epigenetic modification of the promoter regions by DNA methylation that results in gene silencing. The decrease in ERα mRNA expression during development is accompanied by an increase in promoter methylation. Another example of regulation of ERα gene expression in the adult cortex is the changes that occur following neuronal injury. Many animal studies have demonstrated that the endogenous estrogen, 17β-estradiol, is neuroprotective. Specifically, low levels of estradiol protect the cortex from neuronal death following middle cerebral artery occlusion (MCAO). In females, this protection is mediated through an ERα-dependent mechanism. ERα expression is rapidly increased following MCAO in females, but not in males. This increase is accompanied by a decrease in methylation of the promoter suggesting a return to the developmental program of gene expression within neurons. Taken together, during development and in adulthood, regulation of ERα gene expression in the

  6. Reciprocal activation of Xenobiotic response genes by nuclear receptors SXR/PXR and CAR

    PubMed Central

    Xie, Wen; Barwick, Joyce L.; Simon, Cynthia M.; Pierce, Alexis M.; Safe, Stephen; Blumberg, Bruce; Guzelian, Philip S.; Evans, Ronald M.

    2000-01-01

    The cytochrome P450 (CYP) gene products such as CYP3A and CYP2B are essential for the metabolism of steroid hormones and xenochemicals including prescription drugs. Nuclear receptor SXR/PXR (steroid and xenobiotic receptor/pregnenolone X receptor) has been shown both biochemically and genetically to activate CYP3A genes, while similar studies have established constitutive androstane receptor (CAR) as a CYP2B regulator. The response elements in these genes are also distinct, furthering the concept of independent regulation. Unexpectedly, we found that SXR can regulate CYP2B, both in cultured cells and in transgenic mice via adaptive recognition of the phenobarbital response element (PBRE). In a type of functional symmetry, orphan receptor CAR was also found to activate CYP3A through previously defined SXR/PXR response elements. These observations not only provide a rational explanation for the activation of multiple CYP gene classes by certain xenobiotics, but also reveal the existence of a metabolic safety net that confers a second layer of protection to the harmful effects of toxic compounds and at the same time increases the propensity for drug–drug interactions. PMID:11114890

  7. Sequence variation in the androgen receptor gene is not a common determinant of male sexual orientation

    SciTech Connect

    Macke, J.P.; Nathans, J.; King, V.L. ); Hu, N.; Hu, S.; Hamer, D.; Bailey, M. ); Brown, T. )

    1993-10-01

    To test the hypothesis that DNA sequence variation in the androgen receptor gene plays a causal role in the development of male sexual orientation, the authors have (1) measured the degree of concordance of androgen receptor alleles in 36 pairs of homosexual brothers, (2) compared the lengths of polyglutamine and polyglycine tracts in the amino-terminal domain of the androgen receptor in a sample of 197 homosexual males and 213 unselected subjects, and (3) screened the entire androgen receptor coding region for sequence variation by PCR and denaturing gradient-gel electrophoresis (DGGE) and/or single-strand conformation polymorphism analysis in 20 homosexual males with homosexual or bisexual brothers and one homosexual male with no homosexual brothers, and screened the amino-terminal domain of the receptor for sequence variation in an additional 44 homosexual males, 37 of whom had one or more first- or second-degree male relatives who were either homosexual or bisexual. These analyses show that (1) homosexual brothers are as likely to be discordant as concordant for androgen receptor alleles; (2) there are no large-scale differences between the distributions of polyglycine or polyglutamine tract lengths in the homosexual and control groups; and (3) coding region sequence variation is not commonly found within the androgen receptor gene of homosexual men. The DGGE screen identified two rare amino acid substitutions, ser[sup 205] -to-arg and glu[sup 793]-to-asp, the biological significance of which is unknown. 32 refs., 2 figs., 2 tabs.

  8. Enhanced antinociceptive effects of morphine in histamine H2 receptor gene knockout mice.

    PubMed

    Mobarakeh, Jalal Izadi; Takahashi, Kazuhiro; Sakurada, Shinobu; Kuramasu, Atsuo; Yanai, Kazuhiko

    2006-09-01

    We have previously shown that antinociceptive effects of morphine are enhanced in histamine H1 receptor gene knockout mice. In the present study, involvement of supraspinal histamine H2 receptor in antinociception by morphine was examined using histamine H2 receptor gene knockout (H2KO) mice and histamine H2 receptor antagonists. Antinociception was evaluated by assays for thermal (hot-plate, tail-flick and paw-withdrawal tests), mechanical (tail-pressure test) and chemical (formalin and capsaicin tests) stimuli. Thresholds for pain perception in H2KO mice were higher than wild-type mice. Antinociceptive effects of intracerebroventricularly administered morphine were enhanced in the H2KO mice compared to wild-type mice. Intracerebroventricular co-administration of morphine and cimetidine produced significant antinociceptive effects in the wild-type mice when compared to morphine or cimetidine alone. Furthermore, zolantidine, a selective and hydrophobic H2 receptor antagonist, enhanced the effects of morphine in all nociceptive assays examined. These results suggest that histamine exerts inhibitory effects on morphine-induced antinociception through H2 receptors at the supraspinal level. Our present and previous studies suggest that H1 and H2 receptors cooperatively function to modulate pain perception in the central nervous system.

  9. The evolution of drug-activated nuclear receptors: one ancestral gene diverged into two xenosensor genes in mammals

    PubMed Central

    Handschin, Christoph; Blättler, Sharon; Roth, Adrian; Looser, Renate; Oscarson, Mikael; Kaufmann, Michel R; Podvinec, Michael; Gnerre, Carmela; Meyer, Urs A

    2004-01-01

    Background Drugs and other xenobiotics alter gene expression of cytochromes P450 (CYP) by activating the pregnane X receptor (PXR) and constitutive androstane receptor (CAR) in mammals. In non-mammalian species, only one xenosensor gene has been found. Using chicken as a model organism, the aim of our study was to elucidate whether non-mammalian species only have one or two xenosensors like mammals. Results To explore the evolutionary aspect of this divergence, we tried to identify additional xenobiotic sensing nuclear receptors in chicken using various experimental approaches. However, none of those revealed novel candidates. Ablation of chicken xenobiotic receptor (CXR) function by RNAi or dominant-negative alleles drastically reduced drug-induction in a chicken hepatoma cell line. Subsequently, we functionally and structurally characterized CXR and compared our results to PXR and CAR. Despite the high similarity in their amino acid sequence, PXR and CAR have very distinct modes of activation. Some aspects of CXR function, e.g. direct ligand activation and high promiscuity are very reminiscent of PXR. On the other hand, cellular localization studies revealed common characteristics of CXR and CAR in terms of cytoplasmic-nuclear distribution. Finally, CXR has unique properties regarding its regulation in comparison to PXR and CAR. Conclusion Our finding thus strongly suggest that CXR constitutes an ancestral gene which has evolved into PXR and CAR in mammals. Future studies should elucidate the reason for this divergence in mammalian versus non-mammalian species. PMID:15479477

  10. The Aryl Hydrocarbon Receptor Complex and the Control of Gene Expression

    PubMed Central

    Beischlag, Timothy V.; Morales, J. Luis; Hollingshead, Brett D.; Perdew, Gary H.

    2008-01-01

    The aryl hydrocarbon receptor (AhR) is a ligand-activated transcription factor that controls the expression of a diverse set of genes. The toxicity of the potent AhR ligand 2,3,7,8-tetrachlorodibenzo-p-dioxin is almost exclusively mediated through this receptor. However, the key alterations in gene expression that mediate toxicity are poorly understood. It has been established through characterization of AhR-null mice that the AhR has a required physiological function, yet how endogenous mediators regulate this orphan receptor remains to be established. A picture as to how the AhR/ARNT heterodimer actually mediates gene transcription is starting to emerge. The AhR/ARNT complex can alter transcription both by binding to its cognate response element and through tethering to other transcription factors. In addition, many of the coregulatory proteins necessary for AhR-mediated transcription have been identified. Cross talk between the estrogen receptor and the AhR at the promoter of target genes appears to be an important mode of regulation. Inflammatory signaling pathways and the AhR also appear to be another important site of cross talk at the level of transcription. A major focus of this review is to highlight experimental efforts to characterize nonclassical mechanisms of AhR-mediated modulation of gene transcription. PMID:18540824

  11. Control of transcriptional repression of the vitellogenin receptor gene in largemouth bass (Micropterus salmoides) by select estrogen receptors isotypes.

    PubMed

    Dominguez, Gustavo A; Bisesi, Joseph H; Kroll, Kevin J; Denslow, Nancy D; Sabo-Attwood, Tara

    2014-10-01

    The vitellogenin receptor (Vtgr) plays an important role in fish reproduction. This receptor functions to incorporate vitellogenin (Vtg), a macromolecule synthesized and released from the liver in the bloodstream, into oocytes where it is processed into yolk. Although studies have focused on the functional role of Vtgr in fish, the mechanistic control of this gene is still unexplored. Here we report the identification and analysis of the first piscine 5' regulatory region of the vtgr gene which was cloned from largemouth bass (Micropterus salmoides). Using this putative promoter sequence, we investigated a role for hormones, including insulin and 17β-estradiol (E2), in transcriptional regulation through cell-based reporter assays. No effect of insulin was observed, however, E2 was able to repress transcriptional activity of the vtgr promoter through select estrogen receptor subtypes, Esr1 and Esr2a but not Esr2b. Electrophoretic mobility shift assay demonstrated that Esr1 likely interacts with the vtgr promoter region through half ERE and/or SP1 sites, in part. Finally we also show that ethinylestradiol (EE2), but not bisphenol-A (BPA), represses promoter activity similarly to E2. These results reveal for the first time that the Esr1 isoform may play an inhibitory role in the expression of LMB vtgr mRNA under the influence of E2, and potent estrogens such as EE2. In addition, this new evidence suggests that vtgr may be a target of select endocrine disrupting compounds through environmental exposures.

  12. Selective prostacyclin receptor agonism augments glucocorticoid-induced gene expression in human bronchial epithelial cells.

    PubMed

    Wilson, Sylvia M; Shen, Pamela; Rider, Christopher F; Traves, Suzanne L; Proud, David; Newton, Robert; Giembycz, Mark A

    2009-11-15

    Prostacyclin receptor (IP-receptor) agonists display anti-inflammatory and antiviral activity in cell-based assays and in preclinical models of asthma and chronic obstructive pulmonary disease. In this study, we have extended these observations by demonstrating that IP-receptor activation also can enhance the ability of glucocorticoids to induce genes with anti-inflammatory activity. BEAS-2B bronchial epithelial cells stably transfected with a glucocorticoid response element (GRE) luciferase reporter were activated in a concentration-dependent manner by the glucocorticoid dexamethasone. An IP-receptor agonist, taprostene, increased cAMP in these cells and augmented luciferase expression at all concentrations of dexamethasone examined. Analysis of the concentration-response relationship that described this effect showed that taprostene increased the magnitude of transcription without affecting the potency of dexamethasone and was, thus, steroid-sparing in this simple system. RO3244794, an IP-receptor antagonist, and oligonucleotides that selectively silenced the IP-receptor gene, PTGIR, abolished these effects of taprostene. Infection of BEAS-2B GRE reporter cells with an adenovirus vector encoding a highly selective inhibitor of cAMP-dependent protein kinase (PKA) also prevented taprostene from enhancing GRE-dependent transcription. In BEAS-2B cells and primary cultures of human airway epithelial cells, taprostene and dexamethasone interacted either additively or cooperatively in the expression of three glucocorticoid-inducible genes (GILZ, MKP-1, and p57(kip2)) that have anti-inflammatory potential. Collectively, these data show that IP-receptor agonists can augment the ability of glucocorticoids to induce anti-inflammatory genes in human airway epithelial cells by activating a cAMP/PKA-dependent mechanism. This observation may have clinical relevance in the treatment of airway inflammatory diseases that are either refractory or respond suboptimally to

  13. The chromosomal localization of the human follicle-stimulating hormone receptor gene (FSHR) on 2p21-p16 ls similar to that of the luteinizing hormone receptor gene

    SciTech Connect

    Rousseau-Merck, M.F.; Berger, R.; Atger, M.; Loosfelt, H.; Milgrom, E. )

    1993-01-01

    Two cDNA probes (5[prime]and 3[prime]region) corresponding to the human follicle-stimulating hormone receptor gene (FSHR) were used for chromosomal localization by in situ hybridization. The localization obtained on chromosome 2p21-p16 is similar to that of the luteinizing hormone/choriogonadotropin (LH/CG) receptor gene. 24 refs. 1 fig., 1 tab.

  14. The Medicago truncatula lysin [corrected] motif-receptor-like kinase gene family includes NFP and new nodule-expressed genes.

    PubMed

    Arrighi, Jean-François; Barre, Annick; Ben Amor, Besma; Bersoult, Anne; Soriano, Lidia Campos; Mirabella, Rossana; de Carvalho-Niebel, Fernanda; Journet, Etienne-Pascal; Ghérardi, Michèle; Huguet, Thierry; Geurts, René; Dénarié, Jean; Rougé, Pierre; Gough, Clare

    2006-09-01

    Rhizobial Nod factors are key symbiotic signals responsible for starting the nodulation process in host legume plants. Of the six Medicago truncatula genes controlling a Nod factor signaling pathway, Nod Factor Perception (NFP) was reported as a candidate Nod factor receptor gene. Here, we provide further evidence for this by showing that NFP is a lysin [corrected] motif (LysM)-receptor-like kinase (RLK). NFP was shown both to be expressed in association with infection thread development and to be involved in the infection process. Consistent with deviations from conserved kinase domain sequences, NFP did not show autophosphorylation activity, suggesting that NFP needs to associate with an active kinase or has unusual functional characteristics different from classical kinases. Identification of nine new M. truncatula LysM-RLK genes revealed a larger family than in the nonlegumes Arabidopsis (Arabidopsis thaliana) or rice (Oryza sativa) of at least 17 members that can be divided into three subfamilies. Three LysM domains could be structurally predicted for all M. truncatula LysM-RLK proteins, whereas one subfamily, which includes NFP, was characterized by deviations from conserved kinase sequences. Most of the newly identified genes were found to be expressed in roots and nodules, suggesting this class of receptors may be more extensively involved in nodulation than was previously known.

  15. [Roles of histamine receptors in pain perception: a study using receptors gene knockout mice].

    PubMed

    Yanai, Kazuhiko; Mobarakeh, Jalal Izadi; Kuramasu, Atsuo; Sakurada, Shinobu

    2003-11-01

    To study the participation of histamine H1- and H2-receptors in pain perception, H1 and H2 receptor knockout (KO) mice were examined for pain threshold by means of three kinds of nociceptive tasks. These included assays for thermal, mechanical, and chemical nociception. H1KO mice showed significantly fewer nociceptive responses to the hot-plate, tail-flick, tail-pressure, paw-withdrawal, formalin, capsaicin, and abdominal constriction tests. Sensitivity to noxious stimuli in H1KO mice was significantly decreased when compared to wild-type mice. The antinociceptive phenotypes of H2KO were relatively less prominent when compared to H1KO mice. We also examined the antinociceptive effects of intrathecally-, intracerebroventricularly-, and subcutaneously-administered morphine in H1KO and H2KO mice. In these nociceptive assays, the antinociceptive effects produced by morphine were more enhanced in both H1KO and H2KO mice. The effects of histamine H1- and H2-receptor antagonists on morphine-induced antinociception were studied in ICR mice. The intrathecal, intracerebroventricular and subcutaneous co-administrations of d-chlorpheniramine enhanced the effects of morphine in all nociceptive assays examined. In addition, intrathecal co-administrations of cimetidine enhanced the antinociception of morphine in the hot plate tests. These results suggest that existing H1 and H2 receptors play an inhibitory role in morphine-induced antinociception in the spinal and supra-spinal levels.

  16. Linkage analysis of schizophrenia with five dopamine receptor genes in nine pedigrees

    SciTech Connect

    Coon, H.; Byerley, W.; Holik, J.; Hoff, M.; Myles-Worsley, M.; Plaetke, R. ); Lannfelt, L. ); Sokoloff, P.; Schwartz, J.C. ); Waldo, M.; Freedman, R. )

    1993-02-01

    Alterations in dopamine neurotransmission have been strongly implicated in the pathogenesis of schizophrenia for nearly 2 decades. Recently, the genes for five dopamine receptors have been cloned and characterized, and genetic and physical map information has become available. Using these five loci as candidate genes, the authors have tested for genetic linkage to schizophrenia in nine multigenerational families which include multiple affected individuals. In addition to testing conservative disease models, the have used a neurophysiological indicator variable, the P50 auditory evoked response. Deficits in gating of the P50 response have been shown to segregate with schizophrenia in this sample and may identify carriers of gene(s) predisposing for schizophrenia. Linkage results were consistently negative, indicating that a defect at any of the actual receptor sites is unlikely to be a major contributor to schizophrenia in the nine families studied. 47 refs., 1 fig., 4 tabs.

  17. Gene expression profiles linked to AT1 angiotensin receptors in the kidney

    PubMed Central

    Makhanova, Natalia A.; Crowley, Steven D.; Griffiths, Robert C.

    2010-01-01

    To characterize gene expression networks linked to AT1 angiotensin receptors in the kidney, we carried out genome-wide transcriptional analysis of RNA from kidneys of wild-type (WT) and AT1A receptor-deficient mice (KOs) at baseline and after 2 days of angiotensin II infusion (1,000 ng·kg−1·min−1). At baseline, 405 genes were differentially expressed (>1.5×) between WT and KO kidneys. Of these, >80% were upregulated in the KO group including genes involved in inflammation, oxidative stress, and cell proliferation. After 2 days of angiotensin II infusion in WT mice, expression of ≈805 genes was altered (18% upregulated, 82% repressed). Genes in metabolism and ion transport pathways were upregulated while there was attenuated expression of genes protective against oxidative stress including glutathione synthetase and mitochondrial superoxide dismutase 2. Angiotensin II infusion had little effect on blood pressure in KOs. Nonetheless, expression of >250 genes was altered in kidneys from KO mice during angiotensin II infusion; 14% were upregulated, while 86% were repressed including genes involved in immune responses, angiogenesis, and glutathione metabolism. Between WT and KO kidneys during angiotensin II infusion, 728 genes were differentially expressed; 10% were increased and 90% were decreased in the WT group. Differentially regulated pathways included those involved in ion transport, immune responses, metabolism, apoptosis, cell proliferation, and oxidative stress. This genome-wide assessment should facilitate identification of critical distal pathways linked to blood pressure regulation. PMID:20807774

  18. Glucocorticoids regulate arrestin gene expression and redirect the signaling profile of G protein-coupled receptors.

    PubMed

    Oakley, Robert H; Revollo, Javier; Cidlowski, John A

    2012-10-23

    G protein-coupled receptors (GPCRs) compose the largest family of cell surface receptors and are the most common target of therapeutic drugs. The nonvisual arrestins, β-arrestin-1 and β-arrestin-2, are multifunctional scaffolding proteins that play critical roles in GPCR signaling. On binding of activated GPCRs at the plasma membrane, β-arrestins terminate G protein-dependent responses (desensitization) and stimulate β-arrestin-dependent signaling pathways. Alterations in the cellular complement of β-arrestin-1 and β-arrestin-2 occur in many human diseases, and their genetic ablation in mice has severe consequences. Surprisingly, however, the factors that control β-arrestin gene expression are poorly understood. We demonstrate that glucocorticoids differentially regulate β-arrestin-1 and β-arrestin-2 gene expression in multiple cell types. Glucocorticoids act via the glucocorticoid receptor (GR) to induce the synthesis of β-arrestin-1 and repress the expression of β-arrestin-2. Glucocorticoid-dependent regulation involves the recruitment of ligand-activated glucocorticoid receptors to conserved and functional glucocorticoid response elements in intron-1 of the β-arrestin-1 gene and intron-11 of the β-arrestin-2 gene. In human lung adenocarcinoma cells, the increased expression of β-arrestin-1 after glucocorticoid treatment impairs G protein-dependent activation of inositol phosphate signaling while enhancing β-arrestin-1-dependent stimulation of the MAPK pathway by protease activated receptor 1. These studies demonstrate that glucocorticoids redirect the signaling profile of GPCRs via alterations in β-arrestin gene expression, revealing a paradigm for cross-talk between nuclear and cell surface receptors and a mechanism by which glucocorticoids alter the clinical efficacy of GPCR-based drugs.

  19. Oxytocin and Vasopressin Receptor Gene Polymorphisms: Role in Social and Psychiatric Traits

    PubMed Central

    Aspé-Sánchez, Mauricio; Moreno, Macarena; Rivera, Maria Ignacia; Rossi, Alejandra; Ewer, John

    2016-01-01

    Oxytocin (OXT) and arginine-vasopressin (AVP) are two phylogenetically conserved neuropeptides that have been implicated in a wide range of social behaviors. Although a large body of research, ranging from rodents to humans, has reported on the effects of OXT and AVP administration on affiliative and trust behaviors, and has highlighted the genetic contributions of OXT and AVP receptor polymorphisms to both social behaviors and to diseases related to social deficits, the consequences of peptide administration on psychiatric symptoms, and the impact of receptor polymorphisms on receptor function, are still unclear. Despite the exciting advances that these reports have brought to social neuroscience, they remain preliminary and suffer from the problems that are inherent to monogenetic linkage and association studies. As an alternative, some studies are using polygenic approaches, and consider the contributions of other genes and pathways, including those involving DA, 5-HT, and reelin, in addition to OXT and AVP; a handful of report are also using genome-wide association studies. This review summarizes findings on the associations between OXT and AVP receptor polymorphism, social behavior, and psychiatric diseases. In addition, we discuss reports on the interactions of OXT and AVP receptor genes and genes involved in other pathways (such as those of dopamine, serotonin, and reelin), as well as research that has shed some light on the impact of gene polymorphisms on the volume, connectivity, and activation of specific neural structures, differential receptor expression, and plasma levels of the OXT and AVP peptides. We hope that this effort will be helpful for understanding the studies performed so far, and for encouraging the inclusion of other candidate genes not explored to date. PMID:26858594

  20. A comparison of reptilian and avian olfactory receptor gene repertoires: Species-specific expansion of group γ genes in birds

    PubMed Central

    Steiger, Silke S; Kuryshev, Vladimir Y; Stensmyr, Marcus C; Kempenaers, Bart; Mueller, Jakob C

    2009-01-01

    Background The detection of odorants is mediated by olfactory receptors (ORs). ORs are G-protein coupled receptors that form a remarkably large protein superfamily in vertebrate genomes. We used data that became available through recent sequencing efforts of reptilian and avian genomes to identify the complete OR gene repertoires in a lizard, the green anole (Anolis carolinensis), and in two birds, the chicken (Gallus gallus) and the zebra finch (Taeniopygia guttata). Results We identified 156 green anole OR genes, including 42 pseudogenes. The OR gene repertoire of the two bird species was substantially larger with 479 and 553 OR gene homologs in the chicken and zebra finch, respectively (including 111 and 221 pseudogenes, respectively). We show that the green anole has a higher fraction of intact OR genes (~72%) compared with the chicken (~66%) and the zebra finch (~38%). We identified a larger number and a substantially higher proportion of intact OR gene homologs in the chicken genome than previously reported (214 versus 82 genes and 66% versus 15%, respectively). Phylogenetic analysis showed that lizard and bird OR gene repertoires consist of group α, θ and γ genes. Interestingly, the vast majority of the avian OR genes are confined to a large expansion of a single branch (the so called γ-c clade). An analysis of the selective pressure on the paralogous genes of each γ-c clade revealed that they have been subjected to adaptive evolution. This expansion appears to be bird-specific and not sauropsid-specific, as it is lacking from the lizard genome. The γ-c expansions of the two birds do not intermix, i.e., they are lineage-specific. Almost all (group γ-c) OR genes mapped to the unknown chromosome. The remaining OR genes mapped to six homologous chromosomes plus three to four additional chromosomes in the zebra finch and chicken. Conclusion We identified a surprisingly large number of potentially functional avian OR genes. Our data supports recent

  1. Cloning, sequencing, and expression of the gene coding for the human platelet. cap alpha. /sub 2/-adrenergic receptor

    SciTech Connect

    Kobilka, B.K.; Matsui, H.; Kobilka, T.S.; Yang-Feng, T.L.; Francke, U.; Caron, M.G.; Lefkowitz, R.J.; Regan, J.W.

    1987-10-30

    The gene for the human platelet ..cap alpha../sub 2/-adrenergic receptor has been cloned with oligonucleotides corresponding to the partial amino acid sequence of the purified receptor. The identity of this gene has been confirmed by the binding of ..cap alpha../sub 2/-adrenergic ligands to the cloned receptor expressed in Xenopus laevis oocytes. The deduced amino acid sequence is most similar to the recently cloned human ..beta../sub 2/- and ..beta../sub 1/-adrenergic receptors; however, similarities to the muscarinic cholinergic receptors are also evident. Two related genes have been identified by low stringency Southern blot analysis. These genes may represent additional ..cap alpha../sub 2/-adrenergic receptor subtypes.

  2. The ERBB3 receptor in cancer and cancer gene therapy

    PubMed Central

    Sithanandam, G; Anderson, LM

    2009-01-01

    ERBB3, a member of the epidermal growth factor receptor (EGFR) family, is unique in that its tyrosine kinase domain is functionally defective. It is activated by neuregulins, by other ERBB and nonERBB receptors as well as by other kinases, and by novel mechanisms. Downstream it interacts prominently with the phosphoinositol 3-kinase/AKT survival/mitogenic pathway, but also with GRB, SHC, SRC, ABL, rasGAP, SYK and the transcription regulator EBP1. There are likely important but poorly understood roles for nuclear localization and for secreted isoforms. Studies of ERBB3 expression in primary cancers and of its mechanistic contributions in cultured cells have implicated it, with varying degrees of certainty, with causation or sustenance of cancers of the breast, ovary, prostate, certain brain cells, retina, melanocytes, colon, pancreas, stomach, oral cavity and lung. Recent results link high ERBB3 activity with escape from therapy targeting other ERBBs in lung and breast cancers. Thus a wide and centrally important role for ERBB3 in cancer is becoming increasingly apparent. Several approaches for targeting ERBB3 in cancers have been tested or proposed. Small inhibitory RNA (siRNA) to ERBB3 or AKT is showing promise as a therapeutic approach to treatment of lung adenocarcinoma. PMID:18404164

  3. Improvement of a Monopartite Ecdysone Receptor Gene Switch and Demonstration of its Utility in Regulation of Transgene Expression in Plants

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Chemical inducible gene regulation systems provide essential tools for the precise regulation of transgene expression in plants and animals. We have recent developed a two-hybrid ecdysone receptor (EcR) gene regulation system that works in conjunction with the retinoid X receptor of Locusta migrato...

  4. Developmentally Regulated Expression of the Nerve Growth Factor Receptor Gene in the Periphery and Brain

    NASA Astrophysics Data System (ADS)

    Buck, C. R.; Martinez, Humberto J.; Black, Ira B.; Chao, Moses V.

    1987-05-01

    Nerve growth factor (NGF) regulates development and maintenance of function of peripheral sympathetic and sensory neurons. A potential role for the trophic factor in brain has been detected only recently. The ability of a cell to respond to NGF is due, in part, to expression of specific receptors on the cell surface. To study tissue-specific expression of the NGF receptor gene, we have used sensitive cRNA probes for detection of NGF receptor mRNA. Our studies indicate that the receptor gene is selectively and specifically expressed in sympathetic (superior cervical) and sensory (dorsal root) ganglia in the periphery, and by the septum-basal forebrain centrally, in the neonatal rat in vivo. Moreover, examination of tissues from neonatal and adult rats reveals a marked reduction in steady-state NGF receptor mRNA levels in sensory ganglia. In contrast, a 2- to 4-fold increase was observed in the basal forebrain and in the sympathetic ganglia over the same time period. Our observations suggest that NGF receptor mRNA expression is developmentally regulated in specific areas of the nervous system in a differential fashion.

  5. Sequence and diversity of rabbit T-cell receptor gamma chain genes

    SciTech Connect

    Isono, T.; Kim, C.J.; Seto, A.

    1995-03-01

    The nucleotide sequences of one constant (C), six variable (V), and two joining (J) gene segments coding for the rabbit T-cell receptor gamma chain (Tcrg) were determined by directly sequencing fragments amplified by the cassette-ligation mediated polymerase chain reaction. The Tcrg-C gene segment did not encode a cysteine residue for connection to the Tcr delta chain in the connecting region, and two variant forms of the Tcrg-C gene segment were generated by alternative splicing, like the human Tcrg-C2 gene. Five of six rabbit Tcrg-V gene segments belonged to the same family and displayed similarity to five productive human Tcrg-V1 family genes as well as the mouse Tcrg-V5 gene. The remaining rabbit Tcrg-V gene segment displayed similarity to the human Tcrg-V3 gene. Both rabbit Tcrg-J gene segments displayed similarity to the human Tcrg-J2.1 and 2.3, respectively. These findings suggested that the genomic organization of rabbit Tcrg genes is more similar to that of human than of mouse Tcrg genes. 18 refs., 4 figs., 1 tab.

  6. Pseudogenization of a sweet-receptor gene accounts for cats' indifference toward sugar.

    PubMed

    Li, Xia; Li, Weihua; Wang, Hong; Cao, Jie; Maehashi, Kenji; Huang, Liquan; Bachmanov, Alexander A; Reed, Danielle R; Legrand-Defretin, Véronique; Beauchamp, Gary K; Brand, Joseph G

    2005-07-01

    Although domestic cats (Felis silvestris catus) possess an otherwise functional sense of taste, they, unlike most mammals, do not prefer and may be unable to detect the sweetness of sugars. One possible explanation for this behavior is that cats lack the sensory system to taste sugars and therefore are indifferent to them. Drawing on work in mice, demonstrating that alleles of sweet-receptor genes predict low sugar intake, we examined the possibility that genes involved in the initial transduction of sweet perception might account for the indifference to sweet-tasting foods by cats. We characterized the sweet-receptor genes of domestic cats as well as those of other members of the Felidae family of obligate carnivores, tiger and cheetah. Because the mammalian sweet-taste receptor is formed by the dimerization of two proteins (T1R2 and T1R3; gene symbols Tas1r2 and Tas1r3), we identified and sequenced both genes in the cat by screening a feline genomic BAC library and by performing PCR with degenerate primers on cat genomic DNA. Gene expression was assessed by RT-PCR of taste tissue, in situ hybridization, and immunohistochemistry. The cat Tas1r3 gene shows high sequence similarity with functional Tas1r3 genes of other species. Message from Tas1r3 was detected by RT-PCR of taste tissue. In situ hybridization and immunohistochemical studies demonstrate that Tas1r3 is expressed, as expected, in taste buds. However, the cat Tas1r2 gene shows a 247-base pair microdeletion in exon 3 and stop codons in exons 4 and 6. There was no evidence of detectable mRNA from cat Tas1r2 by RT-PCR or in situ hybridization, and no evidence of protein expression by immunohistochemistry. Tas1r2 in tiger and cheetah and in six healthy adult domestic cats all show the similar deletion and stop codons. We conclude that cat Tas1r3 is an apparently functional and expressed receptor but that cat Tas1r2 is an unexpressed pseudogene. A functional sweet-taste receptor heteromer cannot form, and

  7. Novel Mutation of Interferon-γ Receptor 1 Gene Presenting as Early Life Mycobacterial Bronchial Disease

    PubMed Central

    Gutierrez, Maria J.; Kalra, Neelu; Horwitz, Alexandra; Nino, Gustavo

    2016-01-01

    Mendelian susceptibility to mycobacterial diseases (MSMD) are a spectrum of inherited disorders characterized by localized or disseminated infections caused by atypical mycobacteria. Interferon-γ receptor 1 (IFNGR1) deficiency was the first identified genetic disorder recognized as MSMD. Mutations in the genes encoding IFNGR1 can be recessive or dominant and cause complete or partial receptor deficiency. We present the case of a 2½-year-old boy with a history of recurrent wheezing, diagnosed with endobronchial mycobacterial infection. Immunological workup revealed a homozygous nonsense mutation in the IFNGR1 gene, a novel mutation predicted in silico to cause complete IFNGR1 deficiency. This case demonstrates that (a) Interferon-γ receptor deficiency can present resembling common disorders of the lung; (b) mycobacterial infections should be suspected when parenchymal lung disease, hilar lymphadenopathy, and endobronchial disease are present; and (c) high index of suspicion for immunodeficiency should be maintained in patients with disseminated nontubercular mycobacterial infection. PMID:27868075

  8. Novel Mutation of Interferon-γ Receptor 1 Gene Presenting as Early Life Mycobacterial Bronchial Disease.

    PubMed

    Gutierrez, Maria J; Kalra, Neelu; Horwitz, Alexandra; Nino, Gustavo

    2016-01-01

    Mendelian susceptibility to mycobacterial diseases (MSMD) are a spectrum of inherited disorders characterized by localized or disseminated infections caused by atypical mycobacteria. Interferon-γ receptor 1 (IFNGR1) deficiency was the first identified genetic disorder recognized as MSMD. Mutations in the genes encoding IFNGR1 can be recessive or dominant and cause complete or partial receptor deficiency. We present the case of a 2½-year-old boy with a history of recurrent wheezing, diagnosed with endobronchial mycobacterial infection. Immunological workup revealed a homozygous nonsense mutation in the IFNGR1 gene, a novel mutation predicted in silico to cause complete IFNGR1 deficiency. This case demonstrates that (a) Interferon-γ receptor deficiency can present resembling common disorders of the lung; (b) mycobacterial infections should be suspected when parenchymal lung disease, hilar lymphadenopathy, and endobronchial disease are present; and (c) high index of suspicion for immunodeficiency should be maintained in patients with disseminated nontubercular mycobacterial infection.

  9. Sensory experience and sensory activity regulate chemosensory receptor gene expression in Caenorhabditis elegans

    PubMed Central

    Peckol, Erin L.; Troemel, Emily R.; Bargmann, Cornelia I.

    2001-01-01

    Changes in the environment cause both short-term and long-term changes in an animal's behavior. Here we show that specific sensory experiences cause changes in chemosensory receptor gene expression that may alter sensory perception in the nematode Caenorhabditis elegans. Three predicted chemosensory receptor genes expressed in the ASI chemosensory neurons, srd-1, str-2, and str-3, are repressed by exposure to the dauer pheromone, a signal of crowding. Repression occurs at pheromone concentrations below those that induce formation of the alternative dauer larva stage, suggesting that exposure to pheromones can alter the chemosensory behaviors of non-dauer animals. In addition, ASI expression of srd-1, but not str-2 and str-3, is induced by sensory activity of the ASI neurons. Expression of two receptor genes is regulated by developmental entry into the dauer larva stage. srd-1 expression in ASI neurons is repressed in dauer larvae. str-2 expression in dauer animals is induced in the ASI neurons, but repressed in the AWC neurons. The ASI and AWC neurons remodel in the dauer stage, and these results suggest that their sensory specificity changes as well. We suggest that experience-dependent changes in chemosensory receptor gene expression may modify olfactory behaviors. PMID:11572964

  10. Methylation of the Glucocorticoid Receptor Gene Promoter in Preschoolers: Links with Internalizing Behavior Problems

    ERIC Educational Resources Information Center

    Parade, Stephanie H.; Ridout, Kathryn K.; Seifer, Ronald; Armstrong, David A.; Marsit, Carmen J.; McWilliams, Melissa A.; Tyrka, Audrey R.

    2016-01-01

    Accumulating evidence suggests that early adversity is linked to methylation of the glucocorticoid receptor (GR) gene, "NR3C1," which is a key regulator of the hypothalamic-pituitary-adrenal axis. Yet no prior work has considered the contribution of methylation of "NR3C1" to emerging behavior problems and psychopathology in…

  11. Comparative study of leptin and leptin receptor gene expression in different swine breeds.

    PubMed

    Georgescu, S E; Manea, M A; Dinescu, S; Costache, M

    2014-02-14

    Leptin is an important regulator of appetite, energy metabolism, and reproduction and is mainly synthesized in the adipocytes and then secreted into the bloodstream. The leptin receptor was classified as type I cytokine receptor due to its structural homology with IL-6 receptors and the signaling pathways in which they are both involved. The aim of our study is to comparatively assess the gene expression levels of leptin (lep) and leptin receptor (lepr) in different swine breeds specialized either in meat production (Duroc, Belgian Landrace, Large White, Synthetic Lines LS-345, and LSP-2000) or fat production (Mangalitsa) in order to correlate them with morphological and productivity characteristics. Additionally, lepr pattern of expression was evaluated comparatively between different tissue types in the Mangalitsa breed. Our results revealed high expression of the lep gene in Mangalitsa compared to those of all the other breeds, while for the lepr gene, average/medium levels were registered in Mangalitsa and increased pattern of expression was found in the synthetic lines LS-345 and LSP-2000. Regarding the comparative analysis of lepr gene expression in various tissues in the Mangalitsa breed, elevated levels were found in the liver and kidney, while the lowest expression was identified in the brain and muscles. Our results suggest that the Mangalitsa population exhibits leptin resistance, which might be correlated with atypical morpho-productive characteristics for this breed, such as below-average prolificacy and a strong tendency to accumulate fat.

  12. An evolutionarily mobile antigen receptor variable region gene: doubly rearranging NAR-TcR genes in sharks.

    PubMed

    Criscitiello, Michael F; Saltis, Mark; Flajnik, Martin F

    2006-03-28

    Distinctive Ig and T cell receptor (TcR) chains define the two major lineages of vertebrate lymphocyte yet similarly recognize antigen with a single, membrane-distal variable (V) domain. Here we describe the first antigen receptor chain that employs two V domains, which are generated by separate VDJ gene rearrangement events. These molecules have specialized "supportive" TcRdeltaV domains membrane-proximal to domains with most similarity to IgNAR V. The ancestral NAR V gene encoding this domain is hypothesized to have recombined with the TRD locus in a cartilaginous fish ancestor >200 million years ago and encodes the first V domain shown to be used in both Igs and TcRs. Furthermore, these data support the view that gamma/delta TcRs have for long used structural conformations recognizing free antigen.

  13. Mapping toll-like receptor signaling pathway genes of Zhikong scallop ( Chlamys farreri) with FISH

    NASA Astrophysics Data System (ADS)

    Zhao, Bosong; Zhao, Liang; Liao, Huan; Cheng, Jie; Lian, Shanshan; Li, Xuan; Huang, Xiaoting; Bao, Zhenmin

    2015-12-01

    Toll-like receptor (TLR) signaling pathway plays a pivotal role in the innate immune system. Studies on TLR signaling pathway genes in Zhikong scallop ( Chlamys farreri) have mainly focused on sequence analysis and expression profiling, no research has been carried out on their localization. The chromosomal position of TLR signaling pathway genes can be valuable for assemblying scallop genome and analysizing gene regulatory networks. In the present study, five key TLR signaling pathway genes ( CfTLR, CfMyd88, CfTRAF6, CfNFκB, and CfIκB) containing bacterial artificial chromosomes (BACs) were isolated and physically mapped through fluorescence in situ hybridization on five non-homologous chromosome pairs, showing a similar distribution to another five model species. The isolation and mapping of these key immune genes of C. farreri will aid to the research on innate immunity, assignment of interested genes to chromosomes, and integration of physical, linkage and cytogenetic maps of this species.

  14. Lethal graft-versus-host disease in mouse models of T cell receptor gene therapy.

    PubMed

    Bendle, Gavin M; Linnemann, Carsten; Hooijkaas, Anna I; Bies, Laura; de Witte, Moniek A; Jorritsma, Annelies; Kaiser, Andrew D M; Pouw, Nadine; Debets, Reno; Kieback, Elisa; Uckert, Wolfgang; Song, Ji-Ying; Haanen, John B A G; Schumacher, Ton N M

    2010-05-01

    The transfer of T cell receptor (TCR) genes can be used to induce immune reactivity toward defined antigens to which endogenous T cells are insufficiently reactive. This approach, which is called TCR gene therapy, is being developed to target tumors and pathogens, and its clinical testing has commenced in patients with cancer. In this study we show that lethal cytokine-driven autoimmune pathology can occur in mouse models of TCR gene therapy under conditions that closely mimic the clinical setting. We show that the pairing of introduced and endogenous TCR chains in TCR gene-modified T cells leads to the formation of self-reactive TCRs that are responsible for the observed autoimmunity. Furthermore, we demonstrate that adjustments in the design of gene therapy vectors and target T cell populations can be used to reduce the risk of TCR gene therapy-induced autoimmune pathology.

  15. Identification of a Bitter-Taste Receptor Gene Repertoire in Different Lagomorphs Species

    PubMed Central

    Ferreira, Ana M.; Marques, Andreia T.; Fontanesi, Luca; Thulin, Carl-Gustaf; Sales-Baptista, Elvira; Araújo, Susana S.; Almeida, André M.

    2016-01-01

    The repertoires of bitter-taste receptor (T2R) gene have been described for several animal species, but these data are still scarce for Lagomorphs. The aim of the present work is to identify potential repertoires of T2R in several Lagomorph species, covering a wide geographical distribution. We studied these genes in Lepus timidus, L. europaeus, Oryctolagus cuniculus algirus, Romerolagus diazi, and Sylvilagus floridanus, using O. cuniculus cuniculus as control species for PCR and DNA sequencing. We studied the identities of the DNA sequences and built the corresponding phylogenetic tree. Sequencing was successful for both subspecies of O. cuniculus for all T2R genes studied, for five genes in Lepus, and for three genes in R. diazi and S. floridanus. We describe for the first time the partial repertoires of T2R genes for Lagomorphs species, other than the common rabbit. Our phylogenetic analyses indicate that sequence proximity levels follow the established taxonomic classification. PMID:27092177

  16. The human insulin receptor substrate-1 gene (IRS1) is localized on 2q36

    SciTech Connect

    Nishiyama, Masaki; Matsufuji, Senya; Hayashi, Shin-ichi; Furusaka, Akihiro; Tanaka, Teruji ); Inazawa, J.; Nakamura, Yusuke ); Ariyama, Takeshi ); Wands, J.R. )

    1994-03-01

    The chromosomal localization of some of the genes participating in the insulin signaling pathway is known. The insulin and insulin receptor genes have been mapped to chromosomes 11 and 19, respectively. To identify the chromosomal localization of the human IRS1 gene, the fluorescence in situ hybridization technique was employed with Genomic Clone B-10. A total of 50 metaphase cells exhibiting either single or double spots of hybridization signals were examined. Among them, 32 showed the specific signals on 2q36. Therefore, the authors assigned the human IRS1 gene to 2q36. The genes for homeobox sequence (HOX4), fibronectin 1, alkaline phosphatase (intestinal), transition protein 1, villin 1, collagen (type IV), Waardenburg syndrome (type 1), alanine-glyoxylate aminotransferase, and glucagon have been localized in the vicinity of the IRS1 gene.

  17. Gene correction in the evolution of the T cell receptor beta chain

    PubMed Central

    1986-01-01

    Mutational mechanisms operating at the T cell receptor beta chain locus have been examined by comparison of the CT beta 1 and CT beta 2 gene sequences from Mus pahari, believed to be the oldest living species in the genus Mus, with those of inbred mice. Results indicate that a gene correction event independent of that suggested to have occurred in inbred mice has homogenized the M. pahari CT beta exon 1 sequences, minimizing diversity in this region of the molecule. These observations suggest that correction events such as gene conversion may occur frequently, even in pauci-gene families with as few as two members, and therefore play a significant role in gene diversification or homogenization of small as well as large gene families. PMID:3783089

  18. 2-[2-[4-[2-[2-[ 1,3-Dihydro- 1,1-bis (4-hydroxyphenyl)-3-oxo-5-isobenzofuranthioureidyl]ethylaminocarbonyl]ethyl]phenyl] ethylamino]-5′-N-ethylcarboxamidoadenosine (FITC-APEC): A Fluorescent Ligand For A2a-Adenosine Receptors

    PubMed Central

    McCabe, R. Tyler; Skolnick, Phil; Jacobson, Kenneth A.

    2011-01-01

    The fluorescein conjugate, FITC-APEC (2-[2-[4-[2-[2-[1,3-dihydro-l,l-bis(4-hydroxyphenyl)-3-oxo-5-isobenzofuranthioureidyl]ethylaminocarbonyl]ethyl]phenyl]ethylamino]-5′-N-ethylcarboxamidoadenosine), is a novel ligand derived from a series of functionalized congeners that act as selective A2a-adenosine receptor agonists. The binding of FITC-APEC to bovine striatal A2a,-adenosine receptors measured by fluorescence techniques was saturable and of a high affinity, with a Bmax, of 2.3 ± 0.3 pmol/mg protein and KD of 57 ± 2 nM. The KD value estimated by fluorescence was consistent with the Ki (11 ± 0.3 nM) obtained by competition studies with [3H]CGS 21680. Additionally, the Bmax, value found by FITC-APEC measurement was in agreement with Bmax, values obtained using radioligand binding. FITC-APEC exhibited rapid and reversible binding to bovine striatum. The potencies of chemically diverse A2a-adenosine receptor ligands estimated by inhibition of FITC-APEC binding were in good agreement with their potencies determined using radioligand binding techniques (r = 0.97, P = 0.0003). FITC-APEC binding was not altered by purine derivatives that do not recognize A2a-adenosine receptors. These findings demonstrate that the novel fluorescent ligand FITC-APEC can be used in the quantitative characterization of ligand binding to A2a-adenosine receptors. PMID:23772170

  19. Somatic and germline mutations of the TSH receptor gene in thyroid diseases

    SciTech Connect

    Van Sande, J.; Parma, J.; Tonacchera, M.

    1995-09-01

    Under physiological circumstances, thyrotropin (TSH) is the primary hormone that controls thyroid function and growth. TSH acts by binding to its receptor at the basolateral membrane of thyroid follicular cells. The TSH receptor is a member of the large family of G protein-coupled receptors, which share a similar structural pattern: seven transmembrane segments connected by three extra and three intracellular loops. Together with the receptors for other glycoprotein hormones LH/CG and FSH, the TSH receptor has a long aminoterminal domain that has been shown to encode the specificity for hormone recognition and binding. The G protein-coupled receptors share a common mode of intracellular signalling: They control the on/off state of a variety of trimeric G proteins (G{alpha}{beta}{gamma}) by stimulating the exchange of GDP for GTP on the {alpha} subunit (G{alpha}). The result is that G{alpha} or G{beta}{gamma}, after dissociation of the trimer, will interact with downstream effectors of the receptor. In the case of the TSH receptor, the main G protein involved is Gs, which activates adenylyl cyclase via Gs{alpha}. In some species, including man, the TSH receptor is also capable of activating phospholipase C (via Gq), thus stimulating the production of diacylglycerol and inositolphosphate (IP{sub 3}). However, higher concentrations of TSH are required to activate phospholipase C, compared with adenylyl cyclase. As a consequence, the main second messenger of TSH effects on the human thyroid is cyclic AMP. The present review will summarize recent findings identifying mutations of the TSH receptor gene as a cause for thyroid diseases. 59 refs., 4 figs.

  20. The daf-4 gene encodes a bone morphogenetic protein receptor controlling C. elegans dauer larva development.

    PubMed

    Estevez, M; Attisano, L; Wrana, J L; Albert, P S; Massagué, J; Riddle, D L

    1993-10-14

    The bone morphogenetic protein (BMP) family is a conserved group of signalling molecules within the transforming growth factor-beta (TGF-beta) superfamily. This group, including the Drosophila decapentaplegic (dpp) protein and the mammalian BMPs, mediates cellular interactions and tissue differentiation during development. Here we show that a homologue of human BMPs controls a developmental switch in the life cycle of the free-living soil nematode Caenorhabditis elegans. Starvation and overcrowding induce C. elegans to form a developmentally arrested, third-stage dauer larva. The daf-4 gene, which acts to inhibit dauer larva formation and promote growth, encodes a receptor protein kinase similar to the daf-1, activin and TGF-beta receptor serine/threonine kinases. When expressed in monkey COS cells, the daf-4 receptor binds human BMP-2 and BMP-4. The daf-4 receptor is the first to be identified for any growth factor in the BMP family.

  1. Phenotypic characterization of a patient homozygous for the D558N LDL receptor gene mutation.

    PubMed

    Jensen, H K; Jensen, L G; Heath, F; Melsen, F; Hansen, P S; Meinertz, H; Bolund, L; Gregersen, N; Faergeman, O

    1996-11-01

    We describe the clinical, biochemical, and genetic features of a patient with true homozygous familial hypercholesterolemia due to the D558N low-density lipoprotein receptor gene mutation, previously designated FH Cincinnati-4. Functional flow-cytometric analysis of the LDL receptorR protein on upregulated EBV-transformed lymphocytes indicated reduction of the number of receptors on the cell surface by 87% and reduction of receptor activity by 89% compared to control cells. With drugs and a portacaval shunt operation, performed when the patient was 15 years old, serum cholesterol was reduced from about 28 to about 15 mmol/l. He died at the age of 32 of a myocardial infarction. The autopsy showed generalized atherosclerosis, especially in the coronary arteries, which were severely stenosed proximally. A rare finding was a large intracranial xanthoma that apparently had been asymptomatic.

  2. Isolation and characterization of alternatively spliced variants of the mouse sigma1 receptor gene, Sigmar1

    PubMed Central

    Pan, Ling; Pasternak, David A.; Xu, Jin; Xu, Mingming; Lu, Zhigang; Pasternak, Gavril W.

    2017-01-01

    The sigma1 receptor acts as a chaperone at the endoplasmic reticulum, associates with multiple proteins in various cellular systems, and involves in a number of diseases, such as addiction, pain, cancer and psychiatric disorders. The sigma1 receptor is encoded by the single copy SIGMAR1 gene. The current study identifies five alternatively spliced variants of the mouse sigma1 receptor gene using a polymerase chain reaction cloning approach. All the splice variants are generated by exon skipping or alternative 3’ or 5’ splicing, producing the truncated sigma1 receptor. Similar alternative splicing has been observed in the human SIGMAR1 gene based on the molecular cloning or genome sequence prediction, suggesting conservation of alternative splicing of SIGMAR1 gene. Using quantitative polymerase chain reactions, we demonstrate differential expression of several splice variants in mouse tissues and brain regions. When expressed in HEK293 cells, all the splice variants fail to bind sigma ligands, implicating that each truncated region in these splice variants is important for ligand binding. However, co-immunoprecipitation (Co-IP) study in HEK293 cells co-transfected with tagged constructs reveals that all the splice variants maintain their ability to physically associate with a mu opioid receptor (mMOR-1), providing useful information to correlate the motifs/sequences necessary for their physical association. Furthermore, a competition Co-IP study showed that all the variants can disrupt in a dose-dependent manner the dimerization of the original sigma1 receptor with mMOR-1, suggesting a potential dominant negative function and providing significant insights into their function. PMID:28350844

  3. Meiotic recombination generates rich diversity in NK cell receptor genes, alleles, and haplotypes

    PubMed Central

    Norman, Paul J.; Abi-Rached, Laurent; Gendzekhadze, Ketevan; Hammond, John A.; Moesta, Achim K.; Sharma, Deepti; Graef, Thorsten; McQueen, Karina L.; Guethlein, Lisbeth A.; Carrington, Christine V.F.; Chandanayingyong, Dasdayanee; Chang, Yih-Hsin; Crespí, Catalina; Saruhan-Direskeneli, Güher; Hameed, Kamran; Kamkamidze, Giorgi; Koram, Kwadwo A.; Layrisse, Zulay; Matamoros, Nuria; Milà, Joan; Park, Myoung Hee; Pitchappan, Ramasamy M.; Ramdath, D. Dan; Shiau, Ming-Yuh; Stephens, Henry A.F.; Struik, Siske; Tyan, Dolly; Verity, David H.; Vaughan, Robert W.; Davis, Ronald W.; Fraser, Patricia A.; Riley, Eleanor M.; Ronaghi, Mostafa; Parham, Peter

    2009-01-01

    Natural killer (NK) cells contribute to the essential functions of innate immunity and reproduction. Various genes encode NK cell receptors that recognize the major histocompatibility complex (MHC) Class I molecules expressed by other cells. For primate NK cells, the killer-cell immunoglobulin-like receptors (KIR) are a variable and rapidly evolving family of MHC Class I receptors. Studied here is KIR3DL1/S1, which encodes receptors for highly polymorphic human HLA-A and -B and comprises three ancient allelic lineages that have been preserved by balancing selection throughout human evolution. While the 3DS1 lineage of activating receptors has been conserved, the two 3DL1 lineages of inhibitory receptors were diversified through inter-lineage recombination with each other and with 3DS1. Prominent targets for recombination were D0-domain polymorphisms, which modulate enhancer function, and dimorphism at position 283 in the D2 domain, which influences inhibitory function. In African populations, unequal crossing over between the 3DL1 and 3DL2 genes produced a deleted KIR haplotype in which the telomeric “half” was reduced to a single fusion gene with functional properties distinct from its 3DL1 and 3DL2 parents. Conversely, in Eurasian populations, duplication of the KIR3DL1/S1 locus by unequal crossing over has enabled individuals to carry and express alleles of all three KIR3DL1/S1 lineages. These results demonstrate how meiotic recombination combines with an ancient, preserved diversity to create new KIR phenotypes upon which natural selection acts. A consequence of such recombination is to blur the distinction between alleles and loci in the rapidly evolving human KIR gene family. PMID:19411600

  4. Structure and variation of three canine genes involved in serotonin binding and transport: the serotonin receptor 1A gene (htr1A), serotonin receptor 2A gene (htr2A), and serotonin transporter gene (slc6A4).

    PubMed

    van den Berg, L; Kwant, L; Hestand, M S; van Oost, B A; Leegwater, P A J

    2005-01-01

    Aggressive behavior is the most frequently encountered behavioral problem in dogs. Abnormalities in brain serotonin metabolism have been described in aggressive dogs. We studied canine serotonergic genes to investigate genetic factors underlying canine aggression. Here, we describe the characterization of three genes of the canine serotonergic system: the serotonin receptor 1A and 2A gene (htr1A and htr2A) and the serotonin transporter gene (slc6A4). We isolated canine bacterial artificial chromosome clones containing these genes and designed oligonucleotides for genomic sequencing of coding regions and intron-exon boundaries. Golden retrievers were analyzed for DNA sequence variations. We found two nonsynonymous single nucleotide polymorphisms (SNPs) in the coding sequence of htr1A; one SNP close to a splice site in htr2A; and two SNPs in slc6A4, one in the coding sequence and one close to a splice site. In addition, we identified a polymorphic microsatellite marker for each gene. Htr1A is a strong candidate for involvement in the domestication of the dog. We genotyped the htr1A SNPs in 41 dogs of seven breeds with diverse behavioral characteristics. At least three SNP haplotypes were found. Our results do not support involvement of the gene in domestication.

  5. Polo-like kinase 2 gene expression is regulated by the orphan nuclear receptor estrogen receptor-related receptor gamma (ERR{gamma})

    SciTech Connect

    Park, Yun-Yong; Kim, Seok-Ho; Kim, Yong Joo; Kim, Sun Yee; Lee, Tae-Hoon; Lee, In-Kyu; Park, Seung Bum; Choi, Hueng-Sik

    2007-10-12

    Estrogen receptor-related receptor gamma (ERR{gamma}) is a member of the nuclear receptor family of transcriptional activators. To date, the target genes and physiological functions of ERR{gamma} are not well understood. In the current study, we identify that Plk2 is a novel target of ERR{gamma}. Northern blot analysis showed that overexpression of ERR{gamma} induced Plk2 expression in cancer cell lines. ERR{gamma} activated the Plk2 gene promoter, and deletion and mutational analysis of the Plk2 promoter revealed that the ERR{gamma}-response region is located between nucleotides (nt) -2327 and -2229 and -441 and -432 (relative to the transcriptional start site at +1). Electrophoretic mobility shift assay (EMSA) and chromatin immunoprecipitation (ChIP) analysis demonstrated that ERR{gamma} binds directly to the Plk2 promoter. Overexpression of ERR{gamma} in the presence of the mitotic inhibitor nocodazole significantly decreased apoptosis, and induced S-phase cell cycle progression through the induction of Plk2 expression. Taken together, these results demonstrated that Plk2 is a novel target of ERR{gamma}, and suggest that this interaction is crucial for cancer cell proliferation.

  6. Self administration of oxycodone by adolescent and adult mice affects striatal neurotransmitter receptor gene expression.

    PubMed

    Mayer-Blackwell, B; Schlussman, S D; Butelman, E R; Ho, A; Ott, J; Kreek, M J; Zhang, Y

    2014-01-31

    Illicit use of prescription opioid analgesics (e.g., oxycodone) in adolescence is a pressing public health issue. Our goal was to determine whether oxycodone self administration differentially affects striatal neurotransmitter receptor gene expression in the dorsal striatum of adolescent compared to adult C57BL/6J mice. Groups of adolescent mice (4 weeks old, n=12) and of adult mice (11 weeks old, n=11) underwent surgery during which a catheter was implanted into their jugular veins. After recovering from surgery, mice self administered oxycodone (0.25 mg/kg/infusion) 2 h/day for 14 consecutive days or served as yoked saline controls. Mice were sacrificed within 1h after the last self-administration session and the dorsal striatum was isolated for mRNA analysis. Gene expression was analyzed with real time PCR using a commercially available neurotransmitter receptor PCR array containing 84 genes. We found that adolescent mice self administered less oxycodone than adult mice over the 14 days. Monoamine oxidase A (Maoa) and neuropeptide Y receptor 5 mRNA levels were lower in adolescent mice than in adult mice without oxycodone exposure. Oxycodone self administration increased Maoa mRNA levels compared to controls in both age groups. There was a positive correlation of the amount of oxycodone self administered in the last session or across 14 sessions with Maoa mRNA levels. Gastrin-releasing peptide receptor mRNA showed a significant Drug × Age interaction, with point-wise significance. More genes in the dorsal striatum of adolescents (19) changed in response to oxycodone self administration compared to controls than in adult (4) mice. Overall, this study demonstrates that repeated oxycodone self administration alters neurotransmitter receptors gene expression in the dorsal striatum of adolescent and adult mice.

  7. Variation in the oxytocin receptor gene (OXTR) is associated with differences in moral judgment.

    PubMed

    Bernhard, Regan M; Chaponis, Jonathan; Siburian, Richie; Gallagher, Patience; Ransohoff, Katherine; Wikler, Daniel; Perlis, Roy H; Greene, Joshua D

    2016-12-01

    Moral judgments are produced through the coordinated interaction of multiple neural systems, each of which relies on a characteristic set of neurotransmitters. Genes that produce or regulate these neurotransmitters may have distinctive influences on moral judgment. Two studies examined potential genetic influences on moral judgment using dilemmas that reliably elicit competing automatic and controlled responses, generated by dissociable neural systems. Study 1 (N = 228) examined 49 common variants (SNPs) within 10 candidate genes and identified a nominal association between a polymorphism (rs237889) of the oxytocin receptor gene (OXTR) and variation in deontological vs utilitarian moral judgment (that is, judgments favoring individual rights vs the greater good). An association was likewise observed for rs1042615 of the arginine vasopressin receptor gene (AVPR1A). Study 2 (N = 322) aimed to replicate these findings using the aforementioned dilemmas as well as a new set of structurally similar medical dilemmas. Study 2 failed to replicate the association with AVPR1A, but replicated the OXTR finding using both the original and new dilemmas. Together, these findings suggest that moral judgment is influenced by variation in the oxytocin receptor gene and, more generally, that single genetic polymorphisms can have a detectable effect on complex decision processes.

  8. Identification and evolution of two insulin receptor genes involved in Tribolium castaneum development and reproduction.

    PubMed

    Sang, Ming; Li, Chengjun; Wu, Wei; Li, Bin

    2016-07-10

    The insulin and insulin-like signaling (IIS) pathway exists in a wide range of organisms from mammals to invertebrates and regulates several vital physiological functions. A phylogenetic analysis have indicated that insulin receptors have been duplicated at least twice among vertebrates, whereas only one duplication occurred in insects before the differentiation of Coleoptera, Hymenoptera, and Hemiptera. Thus, we cloned two putative insulin receptor genes, T.cas-ir1 and T.cas-ir2, from T. castaneum and determined that T.cas-ir1 is most strongly expressed during the late adult and early pupal stages, whereas T.cas-ir2 is most strongly expressed during the late larval stage. We found that larval RNAi against T.cas-ir1 and T.cas-ir2 causes 100% and 42.0% insect death, respectively, and that parental RNAi against T.cas-ir1 and T.cas-ir2 leads to 100% and 33.3% reductions in beetle fecundity, respectively. The hatching rate of ds-ir2 insects was 66.2%. Moreover, RNAi against these two genes increased the expression of the pkc, foxo, jnk, cdc42, ikk, and mekk genes but decreased erk gene expression. Despite these similarities, these two genes act via distinct regulatory pathways. These results indicate that these two receptors have functionally diverged with respect to the development and reproduction of T. castaneum, even though they retain some common regulatory signaling pathways.

  9. Variation in the oxytocin receptor gene (OXTR) is associated with differences in moral judgment

    PubMed Central

    Chaponis, Jonathan; Siburian, Richie; Gallagher, Patience; Ransohoff, Katherine; Wikler, Daniel; Perlis, Roy H.; Greene, Joshua D.

    2016-01-01

    Moral judgments are produced through the coordinated interaction of multiple neural systems, each of which relies on a characteristic set of neurotransmitters. Genes that produce or regulate these neurotransmitters may have distinctive influences on moral judgment. Two studies examined potential genetic influences on moral judgment using dilemmas that reliably elicit competing automatic and controlled responses, generated by dissociable neural systems. Study 1 (N = 228) examined 49 common variants (SNPs) within 10 candidate genes and identified a nominal association between a polymorphism (rs237889) of the oxytocin receptor gene (OXTR) and variation in deontological vs utilitarian moral judgment (that is, judgments favoring individual rights vs the greater good). An association was likewise observed for rs1042615 of the arginine vasopressin receptor gene (AVPR1A). Study 2 (N = 322) aimed to replicate these findings using the aforementioned dilemmas as well as a new set of structurally similar medical dilemmas. Study 2 failed to replicate the association with AVPR1A, but replicated the OXTR finding using both the original and new dilemmas. Together, these findings suggest that moral judgment is influenced by variation in the oxytocin receptor gene and, more generally, that single genetic polymorphisms can have a detectable effect on complex decision processes. PMID:27497314

  10. Mutation analysis of the transferrin receptor-2 gene in patients with iron overload.

    PubMed

    Lee, P L; Halloran, C; West, C; Beutler, E

    2001-01-01

    Three mutations in the transferrin receptor-2 gene have recently been identified in four Sicilian families with iron overload who had a normal hemochromatosis gene, HFE (C. Camaschella, personal communication). To determine the extent to which mutations in the transferrin receptor-2 gene occur in other populations with iron overload, we have completely sequenced this gene in 17 whites, 10 Asians, and 8 African Americans with iron overload and a C282C/C282C HFE genotype, as well as 4 subjects without iron overload and homozygous for the mutant HFE C282Y genotype, 5 patients with iron overload and homozygous for the mutant HFE C282Y genotype, and 5 normal individuals. None of the individuals exhibited the Sicilian mutations, Y250X in exon 6, M172K in exon 4, and E60X in exon 2. One iron-overloaded individual of Asian descent exhibited a I238M mutation which was subsequently found to be a polymorphism present in the Asian population at a frequency of 0.0192. The presence of the I238M mutation was not associated with an increase in ferritin or transferrin saturation levels. Three silent polymorphisms were also identified, nt 1770 (D590D) and nt 1851 (A617A) and a polymorphism at nt 2255 in the 3' UTR. Thus, mutations in the transferrin receptor-2 gene were not responsible for the iron overload seen in our subjects.

  11. Distinct, genome-wide, gene-specific selectivity patterns of four glucocorticoid receptor coregulators.

    PubMed

    Wu, Dai-Ying; Ou, Chen-Yin; Chodankar, Rajas; Siegmund, Kimberly D; Stallcup, Michael R

    2014-01-01

    Glucocorticoids are a class of steroid hormones that bind to and activate the glucocorticoid receptor (GR), which then positively or negatively regulates transcription of many genes that govern multiple important physiological pathways such as inflammation and metabolism of glucose, fat and bone. The remodeling of chromatin and regulated assembly or disassembly of active transcription complexes by GR and other DNA-binding transcription factors is mediated and modulated by several hundred transcriptional coregulator proteins. Previous studies focusing on single coregulators demonstrated that each coregulator is required for regulation of only a subset of all the genes regulated by a steroid hormone. We hypothesized that the gene-specific patterns of coregulators may correspond to specific physiological pathways such that different coregulators modulate the pathway-specificity of hormone action, thereby providing a mechanism for fine tuning of the hormone response. We tested this by direct comparison of multiple coregulators, using siRNA to deplete the products of four steroid hormone receptor coregulator genes (CCAR1, CCAR2, CALCOCO1 and ZNF282). Global analysis of glucocorticoid-regulated gene expression after siRNA mediated depletion of coregulators confirmed that each coregulator acted in a selective and gene-specific manner and demonstrated both positive and negative effects on glucocorticoid-regulated expression of different genes. We identified several classes of hormone-regulated genes based on the effects of coregulator depletion. Each coregulator supported hormonal regulation of some genes and opposed hormonal regulation of other genes (coregulator-modulated genes), blocked hormonal regulation of a second class of genes (coregulator-blocked genes), and had no effect on hormonal regulation of a third gene class (coregulator-independent genes). In spite of previously demonstrated physical and functional interactions among these four coregulators, the majority

  12. NMDA receptor gene variations as modifiers in Huntington disease: a replication study.

    PubMed

    Saft, Carsten; Epplen, Jörg T; Wieczorek, Stefan; Landwehrmeyer, G Bernhard; Roos, Raymund A C; de Yebenes, Justo Garcia; Dose, Matthias; Tabrizi, Sarah J; Craufurd, David; Arning, Larissa

    2011-10-04

    Several candidate modifier genes which, in addition to the pathogenic CAG repeat expansion, influence the age at onset (AO) in Huntington disease (HD) have already been described. The aim of this study was to replicate association of variations in the N-methyl D-aspartate receptor subtype genes GRIN2A and GRIN2B in the "REGISTRY" cohort from the European Huntington Disease Network (EHDN). The analyses did replicate the association reported between the GRIN2A rs2650427 variation and AO in the entire cohort. Yet, when subjects were stratified by AO subtypes, we found nominally significant evidence for an association of the GRIN2A rs1969060 variation and the GRIN2B rs1806201 variation. These findings further implicate the N-methyl D-aspartate receptor subtype genes as loci containing variation associated with AO in HD.

  13. The role of the nuclear receptor CAR as a coordinate regulator of hepatic gene expression in defense against chemical toxicity.

    PubMed

    Yamamoto, Yukio; Kawamoto, Takeshi; Negishi, Masahiko

    2003-01-01

    The nuclear receptor CAR (constitutive active receptor) mediates the induction of transcription of cytochrome P450 (CYP) genes by phenobarbital (PB) and PB-type inducers. A recent study using CAR-null mice has shown that CAR regulates not only the CYP genes but also other genes encoding various drug/steroid-metabolizing enzymes. In addition to coordinating these enzymes, CAR plays other roles in hepatic gene expression: CAR represses various genes including carnitine palmitoyltransferase 1a and phosphoenolpyruvate carboxykinase 1 in response to PB, and the receptor regulates the constitutive expression of genes such as squalene epoxidase. On the other hand, induction of certain genes such as amino levulinate synthase 1 by PB is not regulated by CAR. Here we describe diverse roles of CAR in hepatic gene expression with a particular focus on endogenous substances such as cholesterol, bilirubin, and steroid hormones.

  14. Smallest bitter taste receptor (T2Rs) gene repertoire in carnivores.

    PubMed

    Hu, Ling-Ling; Shi, Peng

    2013-06-01

    Bitter taste reception is presumably associated with dietary selection, preventing animals from ingesting potentially harmful compounds. Accordingly, carnivores, who encounter these toxic substances less often, should have fewer genes associated with bitter taste reception compared with herbivores and omnivores. To investigate the genetic basis of bitter taste reception, we confirmed bitter taste receptor (T2R) genes previously found in the genome sequences of two herbivores (cow and horse), two omnivores (mouse and rat) and one carnivore (dog). We also identified, for the first time, the T2R repertoire from the genome of other four carnivore species (ferret, giant panda, polar bear and cat) and detected 17-20 bitter receptor genes from the five carnivore genomes, including 12-16 intact genes, 0-1 partial but putatively functional genes, and 3-8 pseudogenes. Both the intact T2R genes and the total T2R gene number among carnivores were the smallest among the tested species, supporting earlier speculations that carnivores have fewer T2R genes, herbivores an intermediate number, and omnivores the largest T2R gene repertoire. To further explain the genetic basis for this disparity, we constructed a phylogenetic tree, which showed most of the T2R genes from the five carnivores were one-to-one orthologs across the tree, suggesting that carnivore T2Rs were conserved among mammals. Similarly, the small carnivore T2R family size was likely due to rare duplication events. Collectively, these results strengthen arguments for the connection between T2R gene family size, diet and habit.

  15. Structural and phylogenetic analysis of the MHC class I-like Fc receptor gene

    SciTech Connect

    Kandil, Eman; Ishibashi, Teruo; Kasahara, Masanori

    1995-06-01

    The intestinal epithelium of neonatal mice and rats expresses an Fc receptor that mediates selective uptake of IgG in mothers`milk. This receptor (FcRn), which helps newborn animals to acquire passive immunity, is an MHC class I-like heterodimer made up of a heavy chain and {beta}{sub 2}-microglobulin. In the present study, we determined the genomic structure of a mouse gene (FcRn) encoding the heavy of FcRn. The overall exon-intron organization of the Fcrn gene was similar to that of the Fcrn gene, thus providing structural evidence that Fcrn os a bona fide class I gene. The 5{prime}-flanking region of the Fcrn gene contained the binding motifs for two cytokine-inducible transcription factors, NF-IL6 and NF1. However, regulatory elements found in MHC class I genes (enhancer A, enhancer B, and the IFN response element) were absent. Phylogenetic tree analysis suggested that, like the MICA, AZGP1, and CD1 genes, the Fcrn gene diverged form MHC class I genes after the emergence of amphibians but before the split of placental and marsupial mammals. Consistent with this result, Southern blot analysis with a mouse Fcrn cDNA probe detected cross-hybridizing bands in various mammalian species and chickens. Sequence analysis of the Fcrn gene isolated from eight mouse strains showed that the membrane-distal domain of FcRn has at least three amino acid variants. The fact that Fcrn is a single copy gene indicates that it is expressed in both the neonatal intestine and the fetal yolk sac. 74 refs., 7 figs., 2 tabs.

  16. Glucocorticoid receptor represses proinflammatory genes at distinct steps of the transcription cycle.

    PubMed

    Gupte, Rebecca; Muse, Ginger W; Chinenov, Yurii; Adelman, Karen; Rogatsky, Inez

    2013-09-03

    Widespread anti-inflammatory actions of glucocorticoid hormones are mediated by the glucocorticoid receptor (GR), a ligand-dependent transcription factor of the nuclear receptor superfamily. In conjunction with its corepressor GR-interacting protein-1 (GRIP1), GR tethers to the DNA-bound activator protein-1 and NF-κB and represses transcription of their target proinflammatory cytokine genes. However, these target genes fall into distinct classes depending on the step of the transcription cycle that is rate-limiting for their activation: Some are controlled through RNA polymerase II (PolII) recruitment and initiation, whereas others undergo signal-induced release of paused elongation complexes into productive RNA synthesis. Whether these genes are differentially regulated by GR is unknown. Here we report that, at the initiation-controlled inflammatory genes in primary macrophages, GR inhibited LPS-induced PolII occupancy. In contrast, at the elongation-controlled genes, GR did not affect PolII recruitment or transcription initiation but promoted, in a GRIP1-dependent manner, the accumulation of the pause-inducing negative elongation factor. Consistently, GR-dependent repression of elongation-controlled genes was abolished specifically in negative elongation factor-deficient macrophages. Thus, GR:GRIP1 use distinct mechanisms to repress inflammatory genes at different stages of the transcription cycle.

  17. The regulation of oxytocin receptor gene expression during adipogenesis.

    PubMed

    Yi, K J; So, K H; Hata, Y; Suzuki, Y; Kato, D; Watanabe, K; Aso, H; Kasahara, Y; Nishimori, K; Chen, C; Katoh, K; Roh, S G

    2015-05-01

    Although it has been reported that oxytocin stimulates lipolysis in adipocytes, changes in the expression of oxytocin receptor (OTR) mRNA in adipogenesis are still unknown. The present study aimed to investigate the expression of OTR mRNA during adipocyte differentiation and fat accumulation in adipocytes. OTR mRNA was highly expressed in adipocytes prepared from mouse adipose tissues compared to stromal-vascular cells. OTR mRNA expression was increased during the adipocyte differentiation of 3T3-L1 cells. OTR expression levels were higher in subcutaneous and epididymal adipose tissues of 14-week-old male mice compared to 7-week-old male mice. Levels of OTR mRNA expression were higher in adipose tissues at four different sites of mice fed a high-fat diet than in those of mice fed a normal diet. The OTR expression level was also increased by refeeding for 4 h after fasting for 16 h. Oxytocin significantly induced lipolysis in 3T3-L1 adipocytes. In conclusion, a new regulatory mechanism is demonstrated for oxytocin to control the differentiation and fat accumulation in adipocytes via activation of OTR as a part of the hypothalamic-pituitary-adipose axis.

  18. High-throughput mapping of the promoters of the mouse olfactory receptor genes reveals a new type of mammalian promoter and provides insight into olfactory receptor gene regulation

    PubMed Central

    Clowney, E. Josephine; Magklara, Angeliki; Colquitt, Bradley M.; Pathak, Nidhi; Lane, Robert P.; Lomvardas, Stavros

    2011-01-01

    The olfactory receptor (OR) genes are the largest mammalian gene family and are expressed in a monogenic and monoallelic fashion in olfactory neurons. Using a high-throughput approach, we mapped the transcription start sites of 1085 of the 1400 murine OR genes and performed computational analysis that revealed potential transcription factor binding sites shared by the majority of these promoters. Our analysis produced a hierarchical model for OR promoter recognition in which unusually high AT content, a unique epigenetic signature, and a stereotypically positioned O/E site distinguish OR promoters from the rest of the murine promoters. Our computations revealed an intriguing correlation between promoter AT content and evolutionary plasticity, as the most AT-rich promoters regulate rapidly evolving gene families. Within the AT-rich promoter category the position of the TATA-box does not correlate with the transcription start site. Instead, a spike in GC composition might define the exact location of the TSS, introducing the concept of “genomic contrast” in transcriptional regulation. Finally, our experiments show that genomic neighborhood rather than promoter sequence correlates with the probability of different OR genes to be expressed in the same olfactory cell. PMID:21705439

  19. Identification and functional analysis of pheromone and receptor genes in the B3 mating locus of Pleurotus eryngii.

    PubMed

    Kim, Kyung-Hee; Kang, Young Min; Im, Chak Han; Ali, Asjad; Kim, Sun Young; Je, Hee-Jeong; Kim, Min-Keun; Rho, Hyun Su; Lee, Hyun Sook; Kong, Won-Sik; Ryu, Jae-San

    2014-01-01

    Pleurotus eryngii has recently become a major cultivated mushroom; it uses tetrapolar heterothallism as a part of its reproductive process. Sexual development progresses only when the A and B mating types are compatible. Such mating incompatibility occasionally limits the efficiency of breeding programs in which crossing within loci-shared strains or backcrossing strategies are employed. Therefore, understanding the mating system in edible mushroom fungi will help provide a short cut in the development of new strains. We isolated and identified pheromone and receptor genes in the B3 locus of P. eryngii and performed a functional analysis of the genes in the mating process by transformation. A genomic DNA library was constructed to map the entire mating-type locus. The B3 locus was found to contain four pheromone precursor genes and four receptor genes. Remarkably, receptor PESTE3.3.1 has just 34 amino acid residues in its C-terminal cytoplasmic region; therefore, it seems likely to be a receptor-like gene. Real-time quantitative RT-PCR (real-time qRT-PCR) revealed that most pheromone and receptor genes showed significantly higher expression in monokaryotic cells than dikaryotic cells. The pheromone genes PEphb3.1 and PEphb3.3 and the receptor gene PESTE3.3.1 were transformed into P5 (A3B4). The transformants were mated with a tester strain (A4B4), and the progeny showed clamp connections and a normal fruiting body, which indicates the proposed role of these genes in mating and fruiting processes. This result also confirms that PESTE3.3.1 is a receptor gene. In this study, we identified pheromone and receptor genes in the B3 locus of P. eryngii and found that some of those genes appear to play a role in the mating and fruiting processes. These results might help elucidate the mechanism of fruiting differentiation and improve breeding efficiency.

  20. Ecdysone Receptor Gene Switch Technology for Inducible Gene Expression in Plants

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Inducible gene regulation systems based on specific chemicals have many potential applications in agriculture and in the basic understanding of gene function. As a result several gene switches have been developed. However, the properties of the chemicals used in most of these switches make their use...