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Sample records for cholinergic receptor pathways

  1. Involvement of M3 Cholinergic Receptor Signal Transduction Pathway in Regulation of the Expression of Chemokine MOB-1, MCP-1 Genes in Pancreatic Acinar Cells

    Institute of Scientific and Technical Information of China (English)

    郑海; 陈道达; 张景輝; 田原

    2004-01-01

    Whether M3 cholinergic receptor signal transduction pathway is involved in regulation of the activation of NF-κB and the expression of chemokine MOB-1, MCP-1genes in pancreatic acinar cells was investigated. Rat pancreatic acinar cells were isolated, cultured and treated with carbachol, atropine and PDTC in vitro. The MOB-1 and MCP-1 mRNA expression was detected by using RT-PCR. The activation of NF-κB was monitored by using electrophoretic mobility shift assay.The results showed that as compared with control group, M3 cholinergic receptor agonist (103mol/L, 104-4ol/L carbachol) could induce a concentration-dependent and time-dependent increase in the expression of MOB-1, MCP-1 mRNA in pancreatic acinar cells. After treatment with 10 -3mol/L carbachol for 2 h, the expression of MOB-1, MCP-1 mRNA was strongest. The activity of NF-κB in pancreatic acinar cells was significantly increased (P<0.01) after treated with M3 cholinergic receptor agonist (10-3 mol/L carbachol) in vitro for 30 min. Either M3 cholinergic receptor antagonist (10-5 mol/L atropine) or NF-κB inhibitor (10-2 mol/L PDTC) could obviously inhibit the activation of NF-κB and the chemokine MOB-1, MCP-1 mRNA expression induced by carbachol (P <0.05). This inhibitory effect was significantly increased by atropine plus PDTC (P<0.01). The results of these studies indicated that M3 cholinergic receptor signal transduction pathway was likely involved in regulation of the expression of chemokine MOB-1 and MCP-1genes in pancreatic acinar cells in vitro through the activation of NF-κB.

  2. Melanocortin 4 receptor activation protects against testicular ischemia-reperfusion injury by triggering the cholinergic antiinflammatory pathway.

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    Minutoli, Letteria; Bitto, Alessandra; Squadrito, Francesco; Irrera, Natasha; Rinaldi, Mariagrazia; Nicotina, Piero Antonio; Arena, Salvatore; Magno, Carlo; Marini, Herbert; Spaccapelo, Luca; Ottani, Alessandra; Giuliani, Daniela; Romeo, Carmelo; Guarini, Salvatore; Antonuccio, Pietro; Altavilla, Domenica

    2011-10-01

    Melanocortins (MC) trigger a vagus nerve-mediated cholinergic-antiinflammatory pathway projecting to the testis. We tested whether pharmacological activation of brain MC receptors might protect the testis from the damage induced by ischemia-reperfusion. Adult male rats were subjected to 1-h testicular ischemia, followed by 24-h reperfusion [testicular ischemia-reperfusion (TI/R)]. Before TI/R, groups of animals were subjected to bilateral cervical vagotomy, or pretreated with the nicotinic acetylcholine receptor antagonist chlorisondamine or the selective MC(4) receptor antagonist HS024. Immediately after reperfusion, rats were ip treated with saline or the MC analog [Nle(4),D-Phe(7)]α-melanocyte-stimulating hormone (NDP-α-MSH) (340 μg/kg). We evaluated testicular IL-6 and TNF-α by Western blot analysis and organ damage by light microscopy. Some experimental groups were prepared for neural efferent activity recording along the vagus nerve starting 30 min after treatment with NDP-α-MSH or saline, and for a 30-min period. Additional groups of TI/R rats were treated for 30 d with saline, NDP-α-MSH, chlorisondamine plus NDP-α-MSH, or HS024 plus NDP-α-MSH to evaluate spermatogenesis, organ damage, and the apoptosis machinery. After a 24-h reperfusion, in TI/R saline-treated rats, there was an increase in IL-6 and TNF-α expression and a marked damage in both testes. NDP-α-MSH inhibited IL-6 and TNF-α expression, decreased histological damage, and increased neural efferent activity. Furthermore, NDP-α-MSH administration for 30 d greatly improved spermatogenesis, reduced organ damage, and inhibited apoptosis. All positive NDP-α-MSH effects were abrogated by vagotomy, chlorisondamine, or HS024. Our data suggest that selective MC(4) receptor agonists might be therapeutic candidates for the management of testicular torsion.

  3. Libidibia ferrea Mature Seeds Promote Antinociceptive Effect by Peripheral and Central Pathway: Possible Involvement of Opioid and Cholinergic Receptors

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    Luis Armando Sawada

    2014-01-01

    Full Text Available Libidibia ferrea (LF is a medicinal plant that holds many pharmacological properties. We evaluated the antinociceptive effect in the LF aqueous seed extract and Lipidic Portion of Libidibia ferrea (LPLF, partially elucidating their mechanisms. Histochemical tests and Gas chromatography of the LPLF were performed to characterize its fatty acids. Acetic acid-induced abdominal constriction, formalin-induced pain, and hot-plate test in mice were employed in the study. In all experiments, aqueous extract or LPLF was administered systemically at the doses of 1, 5, and 10 mg/kg. LF aqueous seed extract and LPLF demonstrated a dose-dependent antinociceptive effect in all tests indicating both peripheral anti-inflammatory and central analgesia properties. Also, the use of atropine (5 mg/kg, naloxone (5 mg/kg in the abdominal writhing test was able to reverse the antinociceptive effect of the LPLF, indicating that at least one of LF lipids components is responsible for the dose related antinociceptive action in chemical and thermal models of nociception in mice. Together, the present results suggested that Libidibia ferrea induced antinociceptive activity is possibly related to its ability to inhibit opioid, cholinergic receptors, and cyclooxygenase-2 pathway, since its main component, linoleic acid, has been demonstrated to produce such effect in previous studies.

  4. Anti-allergic role of cholinergic neuronal pathway via α7 nicotinic ACh receptors on mucosal mast cells in a murine food allergy model.

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    Takeshi Yamamoto

    Full Text Available The prevalence of food allergy (FA has increased in developed countries over the past few decades. However, no effective drug therapies are currently available. Therefore, we investigated cholinergic anti-inflammatory pathway as a regulatory system to ameliorate disrupted mucosal immune homeostasis in the gut based on the pathophysiological elucidation of mucosal mast cells (MMCs in a murine FA model. BALB/c mice sensitized with ovalbumin received repeated oral ovalbumin for the development of FA. FA mice developed severe allergic diarrhea and exhibited enhanced type 2 helper T (Th2 cell immune responses in both systemic immunity and mucosal immunity, along with MMCs hyperplasia in the colon. MMCs were localized primarily in the strategic position of the mucosal epithelium. Furthermore, the allergic symptoms did not develop in p85α disrupted phosphoinositide-3 kinase-deficient mice that lacked mast cells in the gut. Vagal stimulation by 2-deoxy-D-glucose and drug treatment with nicotinic ACh receptor (nAChR agonists (nicotine and α7 nAChR agonist GTS-21 alleviated the allergic symptoms in the FA mice. Nicotine treatment suppressed MMCs hyperplasia, enhanced MPO and upregulated mRNA expression of Th1 and Th2 cytokines in the FA mice colon. MMCs, which are negatively regulated by α7 nAChRs, were often located in close proximity to cholinergic CGRP-immunoreactive nerve fibers in the FA mice colon. The present results reveal that the cholinergic neuroimmune interaction via α7 nAChRs on MMCs is largely involved in maintaining intestinal immune homeostasis and can be a target for a new therapy against mucosal immune diseases with homeostatic disturbances such as FA.

  5. Central cholinergic regulation of respiration: nicotinic receptors

    Institute of Scientific and Technical Information of China (English)

    Xuesi M SHAO; Jack L FELDMAN

    2009-01-01

    Nicotinic acetylcholine receptors (nAChRs) are expressed in brainstem and spinal cord regions involved in the control of breathing. These receptors mediate central cholinergic regulation of respiration and effects of the exogenous ligand nicotine on respiratory pattern. Activation of a4* nAChRs in the preBotzinger Complex (preBotC), an essential site for normal respiratory rhythm generation in mammals, modulates excitatory glutamatergic neurotransmission and depolarizes preBotC inspiratory neurons, leading to increases in respiratory frequency. nAChRs are also present in motor nuclei innervating respiratory muscles. Activation of post- and/or extra-synaptic a4* nAChRs on hypoglossal (XII) motoneurons depolarizes these neurons, potentiating tonic and respiratory-related rhythmic activity. As perinatal nicotine exposure may contribute to the pathogenesis of sudden infant death syndrome (SIDS), we discuss the effects of perinatal nicotine exposure on development of the cholinergic and other neurotransmitter systems involved in control of breathing. Advances in understanding of the mechanisms underlying central cholinergic/nicotinic modulation of respiration provide a pharmacological basis for exploiting nAChRs as therapeutic targets for neurological disorders related to neural control of breathing such as sleep apnea and SIDS.

  6. The cholinergic anti-inflammatory pathway delays TLR-induced skin allograft rejection in mice: cholinergic pathway modulates alloreactivity.

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    Claude Sadis

    Full Text Available Activation of innate immunity through Toll-like receptors (TLR can abrogate transplantation tolerance by revealing hidden T cell alloreactivity. Separately, the cholinergic anti-inflammatory pathway has the capacity to dampen macrophage activation and cytokine release during endotoxemia and ischemia reperfusion injury. However, the relevance of the α7 nicotinic acetylcholine receptor (α7nAChR-dependent anti-inflammatory pathway in the process of allograft rejection or maintenance of tolerance remains unknown. The aim of our study is to investigate whether the cholinergic pathway could impact T cell alloreactivity and transplant outcome in mice. For this purpose, we performed minor-mismatched skin allografts using donor/recipient combinations genetically deficient for the α7nAChR. Minor-mismatched skin grafts were not rejected unless the mice were housed in an environment with endogenous pathogen exposure or the graft was treated with direct application of imiquimod (a TLR7 ligand. The α7nAChR-deficient recipient mice showed accelerated rejection compared to wild type recipient mice under these conditions of TLR activation. The accelerated rejection was associated with enhanced IL-17 and IFN-γ production by alloreactive T cells. An α7nAChR-deficiency in the donor tissue facilitated allograft rejection but not in recipient mice. In addition, adoptive T cell transfer experiments in skin-grafted lymphopenic animals revealed a direct regulatory role for the α7nAChR on T cells. Taken together, our data demonstrate that the cholinergic pathway regulates alloreactivity and transplantation tolerance at multiple levels. One implication suggested by our work is that, in an organ transplant setting, deliberate α7nAChR stimulation of brain dead donors might be a valuable approach for preventing donor tissue inflammation prior to transplant.

  7. The cholinergic anti-inflammatory pathway delays TLR-induced skin allograft rejection in mice: cholinergic pathway modulates alloreactivity.

    Science.gov (United States)

    Sadis, Claude; Detienne, Sophie; Vokaer, Benoît; Charbonnier, Louis-Marie; Lemaître, Philippe; Spilleboudt, Chloé; Delbauve, Sandrine; Kubjak, Carole; Flamand, Véronique; Field, Kenneth A; Goldman, Michel; Benghiat, Fleur S; Le Moine, Alain

    2013-01-01

    Activation of innate immunity through Toll-like receptors (TLR) can abrogate transplantation tolerance by revealing hidden T cell alloreactivity. Separately, the cholinergic anti-inflammatory pathway has the capacity to dampen macrophage activation and cytokine release during endotoxemia and ischemia reperfusion injury. However, the relevance of the α7 nicotinic acetylcholine receptor (α7nAChR)-dependent anti-inflammatory pathway in the process of allograft rejection or maintenance of tolerance remains unknown. The aim of our study is to investigate whether the cholinergic pathway could impact T cell alloreactivity and transplant outcome in mice. For this purpose, we performed minor-mismatched skin allografts using donor/recipient combinations genetically deficient for the α7nAChR. Minor-mismatched skin grafts were not rejected unless the mice were housed in an environment with endogenous pathogen exposure or the graft was treated with direct application of imiquimod (a TLR7 ligand). The α7nAChR-deficient recipient mice showed accelerated rejection compared to wild type recipient mice under these conditions of TLR activation. The accelerated rejection was associated with enhanced IL-17 and IFN-γ production by alloreactive T cells. An α7nAChR-deficiency in the donor tissue facilitated allograft rejection but not in recipient mice. In addition, adoptive T cell transfer experiments in skin-grafted lymphopenic animals revealed a direct regulatory role for the α7nAChR on T cells. Taken together, our data demonstrate that the cholinergic pathway regulates alloreactivity and transplantation tolerance at multiple levels. One implication suggested by our work is that, in an organ transplant setting, deliberate α7nAChR stimulation of brain dead donors might be a valuable approach for preventing donor tissue inflammation prior to transplant.

  8. The cholinergic system, sigma-1 receptors and cognition

    NARCIS (Netherlands)

    van Waarde, Aren; Ramakrishnan, Nisha K.; Rybczynska, Anna A.; Elsinga, Philip H.; Ishiwata, Kiichi; Nijholt, Ingrid M.; Luiten, Paul G. M.; Dierckx, Rudi A.

    2011-01-01

    This article provides an overview of present knowledge regarding the relationship between the cholinergic system and sigma-1 receptors, and discusses potential applications of sigma-1 receptor agonists in the treatment of memory deficits and cognitive disorders. Sigma-1 receptors, initially consider

  9. Differential effects of selective lesions of cholinergic and dopaminergic neurons on serotonin-type 1 receptors in rat brain

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    Quirion, R.; Richard, J.

    1987-01-01

    Serotonin (5-HT)-type1 receptor binding sites are discretely distributed in rat brain. High densities of (3H)5-HT1 binding sites are especially located in areas enriched with cholinergic and dopaminergic innervation, such as the substantia innominata/ventral pallidum, striatum, septal nuclei, hippocampus and substantia nigra. The possible association of (3H)5-HT1 binding sites with cholinergic or dopaminergic cell bodies and/or nerve fiber terminals was investigated by selective lesions of the substantia innominata/ventral pallidum-cortical and septohippocampal cholinergic pathways and the nigrostriatal dopaminergic projection. (3H)5-HT1 receptor binding sites are possibly located on cholinergic cell bodies in the ventral pallidum-cortical pathway since (3H)5-HT1 binding in the substantia innominata/ventral pallidal area was markedly decreased following kainic acid lesions. Fimbriaectomies markedly decreased (3H)5-HT1 binding in the hippocampus, suggesting the presence of 5-HT1 binding sites on cholinergic nerve fiber terminals in the septohippocampal pathway. Lesions of the nigrostriatal dopaminergic projection did not modify (3H)5-HT1 binding in the substantia nigra and the striatum, suggesting that 5-HT1 receptors are not closely associated with dopaminergic cell bodies and nerve terminals in this pathway. These results demonstrate differential association between 5-HT1 receptors and cholinergic and dopaminergic innervation in rat brain.

  10. Muscarinic and dopaminergic receptor subtypes on striatal cholinergic interneurons

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    Dawson, V.L.; Dawson, T.M.; Wamsley, J.K. (Neuropsychiatric Research Institute, Fargo, ND (USA))

    1990-12-01

    Unilateral stereotaxic injection of small amounts of the cholinotoxin, AF64A, caused minimal nonselective tissue damage and resulted in a significant loss of the presynaptic cholinergic markers (3H)hemicholinium-3 (45% reduction) and choline acetyltransferase (27% reduction). No significant change from control was observed in tyrosine hydroxylase or tryptophan hydroxylase activity; presynaptic neuronal markers for dopamine- and serotonin-containing neurons, respectively. The AF64A lesion resulted in a significant reduction of dopamine D2 receptors as evidenced by a decrease in (3H)sulpiride binding (42% reduction) and decrease of muscarinic non-M1 receptors as shown by a reduction in (3H)QNB binding in the presence of 100 nM pirenzepine (36% reduction). Saturation studies revealed that the change in (3H)sulpiride and (3H)QNB binding was due to a change in Bmax not Kd. Intrastriatal injection of AF64A failed to alter dopamine D1 or muscarinic M1 receptors labeled with (3H)SCH23390 and (3H)pirenzepine, respectively. In addition, no change in (3H)forskolin-labeled adenylate cyclase was observed. These results demonstrate that a subpopulation of muscarinic receptors (non-M1) are presynaptic on cholinergic interneurons (hence, autoreceptors), and a subpopulation of dopamine D2 receptors are postsynaptic on cholinergic interneurons. Furthermore, dopamine D1, muscarinic M1 and (3H)forskolin-labeled adenylate cyclase are not localized to striatal cholinergic interneurons.

  11. Pathway analysis of smoking quantity in multiple GWAS identifies cholinergic and sensory pathways.

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    Oscar Harari

    Full Text Available Cigarette smoking is a common addiction that increases the risk for many diseases, including lung cancer and chronic obstructive pulmonary disease. Genome-wide association studies (GWAS have successfully identified and validated several susceptibility loci for nicotine consumption and dependence. However, the trait variance explained by these genes is only a small fraction of the estimated genetic risk. Pathway analysis complements single marker methods by including biological knowledge into the evaluation of GWAS, under the assumption that causal variants lie in functionally related genes, enabling the evaluation of a broad range of signals. Our approach to the identification of pathways enriched for multiple genes associated with smoking quantity includes the analysis of two studies and the replication of common findings in a third dataset. This study identified pathways for the cholinergic receptors, which included SNPs known to be genome-wide significant; as well as novel pathways, such as genes involved in the sensory perception of smell, that do not contain any single SNP that achieves that stringent threshold.

  12. Postlesion estradiol treatment increases cortical cholinergic innervations via estrogen receptor-α dependent nonclassical estrogen signaling in vivo.

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    Koszegi, Zsombor; Szego, Éva M; Cheong, Rachel Y; Tolod-Kemp, Emeline; Ábrahám, István M

    2011-09-01

    17β-Estradiol (E2) treatment exerts rapid, nonclassical actions via intracellular signal transduction system in basal forebrain cholinergic (BFC) neurons in vivo. Here we examined the effect of E2 treatment on lesioned BFC neurons in ovariectomized mice and the role of E2-induced nonclassical action in this treatment. Mice given an N-methyl-d-aspartic acid (NMDA) injection into the substantia innominata-nucleus basalis magnocellularis complex (SI-NBM) exhibited cholinergic cell loss in the SI-NBM and ipsilateral cholinergic fiber loss in the cortex. A single injection of E2 after NMDA lesion did not have an effect on cholinergic cell loss in the SI-NBM, but it restored the ipsilateral cholinergic fiber density in the cortex in a time- and dose-dependent manner. The most effective cholinergic fiber restoration was observed with 33 ng/g E2 treatment at 1 h after NMDA lesion. The E2-induced cholinergic fiber restoration was absent in neuron-specific estrogen receptor-α knockout mice in vivo. Selective activation of nonclassical estrogen signaling in vivo by estren induced E2-like restorative actions. Selective blockade of the MAPK or protein kinase A pathway in vivo prevented E2's ability to restore cholinergic fiber loss. Finally, studies in intact female mice revealed an E2-induced restorative effect that was similar to that of E2-treated ovariectomized mice. These observations demonstrate that a single E2 treatment restores the BFC fiber loss in the cortex, regardless of endogenous E2 levels. They also reveal the critical role of nonclassical estrogen signaling via estrogen receptor-α and protein kinase A-MAPK pathways in E2-induced restorative action in the cholinergic system in vivo.

  13. Neurostimulation of the cholinergic anti-inflammatory pathway ameliorates disease in rat collagen-induced arthritis.

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    Yaakov A Levine

    Full Text Available INTRODUCTION: The inflammatory reflex is a physiological mechanism through which the nervous system maintains immunologic homeostasis by modulating innate and adaptive immunity. We postulated that the reflex might be harnessed therapeutically to reduce pathological levels of inflammation in rheumatoid arthritis by activating its prototypical efferent arm, termed the cholinergic anti-inflammatory pathway. To explore this, we determined whether electrical neurostimulation of the cholinergic anti-inflammatory pathway reduced disease severity in the collagen-induced arthritis model. METHODS: Rats implanted with vagus nerve cuff electrodes had collagen-induced arthritis induced and were followed for 15 days. Animals underwent active or sham electrical stimulation once daily from day 9 through the conclusion of the study. Joint swelling, histology, and levels of cytokines and bone metabolism mediators were assessed. RESULTS: Compared with sham treatment, active neurostimulation of the cholinergic anti-inflammatory pathway resulted in a 52% reduction in ankle diameter (p = 0.02, a 57% reduction in ankle diameter (area under curve; p = 0.02 and 46% reduction overall histological arthritis score (p = 0.01 with significant improvements in inflammation, pannus formation, cartilage destruction, and bone erosion (p = 0.02, accompanied by numerical reductions in systemic cytokine levels, not reaching statistical significance. Bone erosion improvement was associated with a decrease in serum levels of receptor activator of NF-κB ligand (RANKL from 132±13 to 6±2 pg/mL (mean±SEM, p = 0.01. CONCLUSIONS: The severity of collagen-induced arthritis is reduced by neurostimulation of the cholinergic anti-inflammatory pathway delivered using an implanted electrical vagus nerve stimulation cuff electrode, and supports the rationale for testing this approach in human inflammatory disorders.

  14. Right Cervical Vagotomy Aggravates Viral Myocarditis in Mice Via the Cholinergic Anti-inflammatory Pathway

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    Li-Sha, Ge; Xing-Xing, Chen; Lian-Pin, Wu; De-Pu, Zhou; Xiao-Wei, Li; Jia-Feng, Lin; Yue-Chun, Li

    2017-01-01

    The autonomic nervous system dysfunction with increased sympathetic activity and withdrawal of vagal activity may play an important role in the pathogenesis of viral myocarditis. The vagus nerve can modulate the immune response and control inflammation through a ‘cholinergic anti-inflammatory pathway’ dependent on the α7-nicotinic acetylcholine receptor (α7nAChR). Although the role of β-adrenergic stimulation on viral myocarditis has been investigated in our pervious studies, the direct effect of vagal tone in this setting has not been yet studied. Therefore, in the present study, we investigated the effects of cervical vagotomy in a murine model of viral myocarditis. In a coxsackievirus B3 murine myocarditis model (Balb/c), effects of right cervical vagotomy and nAChR agonist nicotine on echocardiography, myocardial histopathology, viral RNA, and proinflammatory cytokine levels were studied. We found that right cervical vagotomy inhibited the cholinergic anti-inflammatory pathway, aggravated myocardial lesions, up-regulated the expression of TNF-α, IL-1β, and IL-6, and worsened the impaired left ventricular function in murine viral myocarditis, and these changes were reversed by co-treatment with nicotine by activating the cholinergic anti-inflammatory pathway. These results indicate that vagal nerve plays an important role in mediating the anti-inflammatory effect in viral myocarditis, and that cholinergic stimulation with nicotine also plays its peripheral anti-inflammatory role relying on α7nAChR, without requirement for the integrity of vagal nerve in the model. The findings suggest that vagus nerve stimulation mediated inhibition of the inflammatory processes likely provide important benefits in myocarditis treatment. PMID:28197102

  15. A cholinergic receptor gene (CHRM2) affects event-related oscillations.

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    Jones, Kevin A; Porjesz, Bernice; Almasy, Laura; Bierut, Laura; Dick, Danielle; Goate, Alison; Hinrichs, Anthony; Rice, John P; Wang, Jen C; Bauer, Lance O; Crowe, Raymond; Foroud, Tatiana; Hesselbrock, Victor; Kuperman, Samuel; Nurnberger, John; O'Connor, Sean J; Rohrbaugh, John; Schuckit, Marc A; Tischfield, Jay; Edenberg, Howard J; Begleiter, Henri

    2006-09-01

    We report genetic linkage and association findings which implicate the gene encoding the muscarinic acetylcholine receptor M2 (CHRM2) in the modulation of a scalp-recorded electrophysiological phenotype. The P3 (P300) response was evoked using a three-stimulus visual oddball paradigm and a phenotype that relates to the energy in the theta band (4-5 Hz) was analyzed. Studies have shown that similar electrophysiological measures represent cognitive correlates of attention, working memory, and response selection; a role has been suggested for the ascending cholinergic pathway in the same functions. The results of our genetic association tests, combined with knowledge regarding the presence of presynaptic cholinergic M2 autoreceptors in the basal forebrain, indicate that the cognitive processes required by the experiment may in part be mediated by inhibitory neural networks. These findings underscore the utility of electrophysiology and neurogenetics in the understanding of cognitive function and the study of brain-related disorders.

  16. Involvement of cholinergic nicotinic receptors in the menthol-induced gastric relaxation.

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    Amato, Antonella; Serio, Rosa; Mulè, Flavia

    2014-12-15

    We have previously demonstrated that menthol reduces murine gastric tone in part through a neural mechanism, involving adrenergic pathways and reduction of ongoing release of acetylcholine from enteric nerves. In the present study we aimed to verify whether the gastric relaxation to menthol may be triggered by interaction with neural receptors or ionic channels proteins, such as transient receptor potential (TRP)-melastatin8 (TRPM8), TRP-ankyrin 1 (TRPA1), 5-hydroxytriptamine 3 (5-HT3) receptor or cholinergic nicotinic receptors. Spontaneous mechanical activity was detected in vitro as changes in intraluminal pressure from isolated mouse stomach. Menthol (0.3-30 mM) induced gastric relaxation which was not affected by 5-benzyloxytryptamine, a TRPM8 receptor antagonist, HC030031, a TRPA1 channel blocker. In addition, allylisothiocyanate, a TRPA1 agonist, but not (2S,5R)-2-Isopropyl-N-(4-methoxyphenyl)-5-methylcyclohexanecarboximide, a selective TRPM8 agonist, induced gastric relaxation. Genic expression of TRPA1, but not of TRPM8, was revealed in mouse stomach. Indeed, menthol-induced gastric relaxation was significantly reduced by hexamethonium, cholinergic nicotinic receptor antagonist. Menthol, at concentrations that failed to affect gastric tone, reduced the contraction induced by dimethylphenylpiperazinium, nicotinic receptor agonist. The joint application of hexamethonium and atropine, muscarinc receptor antagonist, or hexamethonium and phentholamine, α-adrenergic receptor antagonist, did not produce any additive reduction of the relaxant response to menthol. Lastly, ondansetron, a 5-HT3 receptor antagonist, was ineffective. In conclusion, our study suggests that nicotinic receptors, but not TRP and 5-HT3 receptors, are molecular targets for menthol inducing murine gastric relaxation, ultimately due to the reduction of acetylcholine release from enteric nerves.

  17. Nicotine protects kidney from renal ischemia/reperfusion injury through the cholinergic anti-inflammatory pathway.

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    Claude Sadis

    Full Text Available Kidney ischemia/reperfusion injury (I/R is characterized by renal dysfunction and tubular damages resulting from an early activation of innate immunity. Recently, nicotine administration has been shown to be a powerful inhibitor of a variety of innate immune responses, including LPS-induced toxaemia. This cholinergic anti-inflammatory pathway acts via the alpha7 nicotinic acetylcholine receptor (alpha7nAChR. Herein, we tested the potential protective effect of nicotine administration in a mouse model of renal I/R injury induced by bilateral clamping of kidney arteries. Renal function, tubular damages and inflammatory response were compared between control animals and mice receiving nicotine at the time of ischemia. Nicotine pretreatment protected mice from renal dysfunction in a dose-dependent manner and through the alpha7nAChR, as attested by the absence of protection in alpha7nAChR-deficient mice. Additionally, nicotine significantly reduced tubular damages, prevented neutrophil infiltration and decreased productions of the CXC-chemokine KC, TNF-alpha and the proinflammatory high-mobility group box 1 protein. Reduced tubular damage in nicotine pre-treated mice was associated with a decrease in tubular cell apoptosis and proliferative response as attested by the reduction of caspase-3 and Ki67 positive cells, respectively. All together, these data highlight that nicotine exerts a protective anti-inflammatory effect during kidney I/R through the cholinergic alpha7nAChR pathway. In addition, this could provide an opportunity to overcome the effect of surgical cholinergic denervation during kidney transplantation.

  18. Local cholinergic and non-cholinergic neural pathways to the rat supraoptic nucleus

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    Meeker, M.L.

    1986-01-01

    An estimated two thirds of the input to the supraoptic nucleus of the rat hypothalamus (SON) including a functionally significant cholinergic innervation, arise from local sources of unknown origin. The sources of these inputs were identified utilizing Golgi-Cox, retrograde tracing, choline acetyltransferase immunocytochemistry and anterograde tracing methodologies. Multipolar Golgi impregnated neurons located dorsal and lateral to the SON extend spiney processes into the nucleus. Injections of the retrograde tracers, wheat germ agglutinin or wheat germ agglutinin-horseradish peroxidase, into the SON labeled cells bilaterally in the arcuate nucleus, and ipsilaterally in the lateral hypothalamus, anterior hypothalamus, nucleus of the diagonal band, subfornical organ, medial preoptic area, lateral preoptic area and in the region dorsolateral to the nucleus. Immunocytochemistry for choline acetyltransferase revealed cells within the ventro-caudal portion of cholinergic cell group, Ch4, which cluster dorsolateral to the SON, and extend axon- and dendrite-like processes into the SON. Cells double-labeled by choline acetyltransferase immunocytochemistry and retrograde tracer injections into the SON are localized within the same cholinergic cell group dorsolateral to the SON. Injections of the anterograde tracer, Phaseolus vulgaris-leucoagglutinin, deposited dorsolateral to the SON results in labeled pre-and post-synaptic processes within the SON. The identification and characterization of endogenous immunoglobulin within the SON and other neurons innervating areas lacking a blood-brain barrier established a novel and potentially important system for direct communication of the supraoptic cells with blood-borne constitutents.

  19. Replicated Risk Nicotinic Cholinergic Receptor Genes for Nicotine Dependence

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    Lingjun Zuo

    2016-11-01

    Full Text Available 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.

  20. Replicated Risk Nicotinic Cholinergic Receptor Genes for Nicotine Dependence

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    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

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

    Science.gov (United States)

    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.

  2. Vagus nerve stimulation attenuates cerebral ischemia and reperfusion injury via endogenous cholinergic pathway in rat.

    Directory of Open Access Journals (Sweden)

    Ying Jiang

    Full Text Available Inflammation and apoptosis play critical roles in the acute progression of ischemic injury pathology. Emerging evidence indicates that vagus nerve stimulation (VNS following focal cerebral ischemia and reperfusion (I/R may be neuroprotective by limiting infarct size. However, the underlying molecular mechanisms remain unclear. In this study, we investigated whether the protective effects of VNS in acute cerebral I/R injury were associated with anti-inflammatory and anti-apoptotic processes. Male Sprague-Dawley (SD rats underwent VNS at 30 min after focal cerebral I/R surgery. Twenty-four h after reperfusion, neurological deficit scores, infarct volume, and neuronal apoptosis were evaluated. In addition, the levels of pro-inflammatory cytokines were detected using enzyme-linked immune sorbent assay (ELISA, and immunofluorescence staining for the endogenous "cholinergic anti-inflammatory pathway" was also performed. The protein expression of a7 nicotinic acetylcholine receptor (a7nAchR, phosphorylated Akt (p-Akt, and cleaved caspase 3 in ischemic penumbra were determined with Western blot analysis. I/R rats treated with VNS (I/R+VNS had significantly better neurological deficit scores, reduced cerebral infarct volume, and decreased number of TdT mediated dUTP nick end labeling (TUNEL positive cells. Furthermore, in the ischemic penumbra of the I/R+VNS group, the levels of pro-inflammatory cytokines and cleaved caspase 3 protein were significantly decreased, and the levels of a7nAchR and phosphorylated Akt were significantly increased relative to the I/R alone group. These results indicate that VNS is neuroprotective in acute cerebral I/R injury by suppressing inflammation and apoptosis via activation of cholinergic and a7nAchR/Akt pathways.

  3. New Therapeutic Approaches for the Treatment of Rheumatoid Arthritis may Rise from the Cholinergic Anti-Inflammatory Pathway and Antinociceptive Pathway

    Directory of Open Access Journals (Sweden)

    Xiao Hua Pan

    2010-01-01

    Full Text Available Due to the complex etiology of rheumatoid arthritis (RA, it is difficult to be completely cured at the current stage although many approaches have been applied in clinics, especially the wide application of nonsteroidal anti-inflammatory drugs (NSAIDs and disease-modifying antirheumatic drugs (DMARDs. New drug discovery and development via the recently discovered cholinergic anti-inflammatory and antinociceptive pathways should be promising. Based on the above, the nicotinic acetylcholine receptor agonists maintain the potential for the treatment of RA. Therefore, new therapeutic approaches may rise from these two newly discovered pathways. More preclinical experiments and clinical trials are required to confirm our viewpoint.

  4. Therapeutic potential and limitations of cholinergic anti-inflammatory pathway in sepsis.

    Science.gov (United States)

    Kanashiro, Alexandre; Sônego, Fabiane; Ferreira, Raphael G; Castanheira, Fernanda V S; Leite, Caio A; Borges, Vanessa F; Nascimento, Daniele C; Cólon, David F; Alves-Filho, José Carlos; Ulloa, Luis; Cunha, Fernando Q

    2017-03-01

    Sepsis is one of the main causes of mortality in hospitalized patients. Despite the recent technical advances and the development of novel generation of antibiotics, severe sepsis remains a major clinical and scientific challenge in modern medicine. Unsuccessful efforts have been dedicated to the search of therapeutic options to treat the deleterious inflammatory components of sepsis. Recent findings on neuronal networks controlling immunity raised expectations for novel therapeutic strategies to promote the regulation of sterile inflammation, such as autoimmune diseases. Interesting studies have dissected the anatomical constituents of the so-called "cholinergic anti-inflammatory pathway", suggesting that electrical vagus nerve stimulation and pharmacological activation of beta-2 adrenergic and alpha-7 nicotinic receptors could be alternative strategies for improving inflammatory conditions. However, the literature on infectious diseases, such as sepsis, is still controversial and, therefore, the real therapeutic potential of this neuroimmune pathway is not well defined. In this review, we will discuss the beneficial and detrimental effects of neural manipulation in sepsis, which depend on the multiple variables of the immune system and the nature of the infection. These observations suggest future critical studies to validate the clinical implications of vagal parasympathetic signaling in sepsis treatment.

  5. Cholinergic anti-inflammatory pathway: a possible approach to protect against myocardial ischemia reperfusion injury

    Institute of Scientific and Technical Information of China (English)

    XIONG Jun; XUE Fu-shan; YUAN Yu-jing; WANG Qiang; LIAO Xu; WANG Wei-li

    2010-01-01

    Objective A general review was made of studies involving: (1) the concept and mechanism of the cholinergic anti-inflammatory pathway (CAP), (2) the important role of inflammatory response in myocardial ischemia reperfusion (I/R)injury and (3) the evidence and mechanisms by which CAP may provide protection against myocardial I/R injury.Data sources The data used in this review were mainly from manuscripts listed in PubMed that were published in English from 1987 to 2009. The search terms were "vagal nerve stimulation", "myocardial ischemia reperfusion injury","nicotine acetylcholine receptor" and "inflammation".Study selection (1) Clinical and experimental evidence that the inflammatory response induced by reperfusion enhances myocardial I/R injury. (2) Clinical and laboratory evidence that the CAP inhibits the inflammation and provides protection against myocardial I/R injury.Results The myocardial I/R injury is really an inflammatory process characterized by recruitment of neutrophils into the ischemic myocardium and excessive production of pro-inflammatory cytokines. Because the CAP can modulate the inflammatory response by decreasing the production and release of pro-inflammatory cytokines, it can provide protection against myocardial I/R injury.Conclusions The CAP can inhibit the inflammatory response induced by reperfusion and protect against myocardial I/R injury. It represents an exciting opportunity to develop new and novel therapeutics to attenuate the myocardial I/R injury.

  6. Puerarin partly counteracts the inflammatory response after cerebral ischemia/reperfusion via activating the cholinergic anti-inflammatory pathway

    Institute of Scientific and Technical Information of China (English)

    Xiaojie Liu; Zhigang Mei; Jingping Qian; Yongbao Zeng; Mingzhi Wang

    2013-01-01

    Puerarin, a major isoflavonoid derived from the Chinese medical herb radix puerariae (Gegen), has been reported to inhibit neuronal apoptosis and play an anti-inflammatory role in focal cerebral ischemia model rats. Recent findings regarding stroke pathophysiology have recognized that an-ti-inflammation is an important target for the treatment of ischemic stroke. The cholinergic an-ti-inflammatory pathway is a highly robust neural-immune mechanism for inflammation control. This study was to investigate whether activating the cholinergic anti-inflammatory pathway can be in-volved in the mechanism of inhibiting the inflammatory response during puerarin-induced cerebral ischemia/reperfusion in rats. Results showed that puerarin pretreatment (intravenous injection) re-duced the ischemic infarct volume, improved neurological deficit after cerebral ischemia/reperfusion and decreased the levels of interleukin-1β, interleukin-6 and tumor necrosis factor-αin brain tissue. Pretreatment with puerarin (intravenous injection) attenuated the inflammatory response in rats, which was accompanied by janus-activated kinase 2 (JAK2) and signal transducers and activators of transcription 3 (STAT3) activation and nuclear factor kappa B (NF-κB) inhibition. These observa-tions were inhibited by the alpha7 nicotinic acetylcholine receptor (α7nAchR) antagonistα-bungarotoxin (α-BGT). In addition, puerarin pretreatment increased the expression of α7nAchR mRNA in ischemic cerebral tissue. These data demonstrate that puerarin pretreatment strongly protects the brain against cerebral ischemia/reperfusion injury and inhibits the inflammatory re-sponse. Our results also indicated that the anti-inflammatory effect of puerarin may partly be me-diated through the activation of the cholinergic anti-inflammatory pathway.

  7. Modulation of Cholinergic Pathways and Inflammatory Mediators in Blast-Induced Traumatic Brain Injury

    Science.gov (United States)

    2013-01-01

    Neuroinflammation including cross-talk between central and peripheral immune systems is considered to be a primary event after blast exposure...cholinergic anti-inflammatory pathway has been proposed as a link in neuroimmunomodulation, especially during stress con- ditions [8–11]. Neuroinflammation is...BINT) elicits early complement activation and tumor necrosis factor alpha (TNFalpha) release in a rat brain, J. Neurol. Sci. 318 (2012) 146–154. [8

  8. The effects of the alpha2-adrenergic receptor agonists clonidine and rilmenidine, and antagonists yohimbine and efaroxan, on the spinal cholinergic receptor system in the rat

    DEFF Research Database (Denmark)

    Abelson, Klas S P; Höglund, A Urban

    2004-01-01

    Cholinergic agonists produce spinal antinociception via mechanisms involving an increased release of intraspinal acetylcholine. The cholinergic receptor system interacts with several other receptor types, such as alpha2-adrenergic receptors. To fully understand these interactions, the effects...... of various receptor ligands on the cholinergic system must be investigated in detail. This study was initiated to investigate the effects of the alpha2-adrenergic receptor agonists clonidine and rilmenidine and the alpha2-adrenergic receptor antagonists yohimbine and efaroxan on spinal cholinergic receptors...... in the rat. Spinal microdialysis was used to measure in vivo changes of acetylcholine after administration of the ligands, with or without nicotinic receptor blockade. In addition, in vitro binding properties of the ligands on muscarinic and nicotinic receptors were investigated. It was found that clonidine...

  9. Evidence for dopamine D-2 receptors on cholinergic interneurons in the rat caudate-putamen

    Energy Technology Data Exchange (ETDEWEB)

    Dawson, V.L.; Dawson, T.M.; Filloux, F.M.; Wamsley, J.K.

    1988-01-01

    The aziridinium ion of ethylcholine (AF64A) is a neurotoxin that has demonstrated selectivity for cholinergic neurons. Unilateral stereotaxic injection of AF64A into the caudate-putamen of rats, resulted in a decrease in dopamine D-2 receptors as evidenced by a decrease in (/sup 3/H)-sulpiride binding. Dopamine D-1 receptors, labeled with (/sup 3/H)-SCH 23390, were unchanged. The efficacy of the lesion was demonstrated by the reduction of Na/sup +/-dependent high affinity choline uptake sites labeled with (/sup 3/H)-hemicholinium-3. These data indicate that a population of D-2 receptors are postsynaptic on cholinergic interneurons within the striatum of rat brain.

  10. Cross-talk between oxidative stress and modifications of cholinergic and glutaminergic receptors in the pathogenesis of Alzheimer's disease

    Institute of Scientific and Technical Information of China (English)

    Zhi-zhong GUAN

    2008-01-01

    Alzheimer's disease (AD) is the most common neurodegenerative disorder, and its pathogenesis is likely to be associated with multiple etiologies and mechanisms in which oxidative stress and deficits of neurotransmitter receptors may play impor-tant roles. It has been indicated that a high level of free radicals can influence the expressions of nicotinic receptors (nAChRs), muscarinic receptors (mAChRs), and N-methyl-D-aspartate (NMDA) receptors, exhibiting disturbances of cellular mem-brane by lipid peroxidation, damages of the protein receptors by protein oxidation, and possible modified gene expressions of these receptors by DNA oxidation. nAChRs have shown an antioxidative effect by a direct or an indirect pathway; mAChR stimulation may generate reactive oxygen species, which might be a physi-ological compensative reaction, or improve oxidative stress; and high stimulation to NMDA receptors can increase the sensitivity of oxidative stress of neurons. This review may provide complemental information" for understanding the correla-tion between oxidative stress and changed cholinergic and glutaminergic recep-tors in AD processing, and for revealing the underlying molecular mechanisms of these factors in the multiple etiologies and pathophysiology of the disorder.

  11. Pharmacological identification of cholinergic receptor subtypes on Drosophila melanogaster larval heart.

    Science.gov (United States)

    Malloy, Cole A; Ritter, Kyle; Robinson, Jonathan; English, Connor; Cooper, Robin L

    2016-01-01

    The Drosophila melanogaster heart is a popular model in which to study cardiac physiology and development. Progress has been made in understanding the role of endogenous compounds in regulating cardiac function in this model. It is well characterized that common neurotransmitters act on many peripheral and non-neuronal tissues as they flow through the hemolymph of insects. Many of these neuromodulators, including acetylcholine (ACh), have been shown to act directly on the D. melanogaster larval heart. ACh is a primary neurotransmitter in the central nervous system (CNS) of vertebrates and at the neuromuscular junctions on skeletal and cardiac tissue. In insects, ACh is the primary excitatory neurotransmitter of sensory neurons and is also prominent in the CNS. A full understanding regarding the regulation of the Drosophila cardiac physiology by the cholinergic system remains poorly understood. Here we use semi-intact D. melanogaster larvae to study the pharmacological profile of cholinergic receptor subtypes, nicotinic acetylcholine receptors (nAChRs) and muscarinic acetylcholine receptors (mAChRs), in modulating heart rate (HR). Cholinergic receptor agonists, nicotine and muscarine both increase HR, while nAChR agonist clothianidin exhibits no significant effect when exposed to an open preparation at concentrations as low as 100 nM. In addition, both nAChR and mAChR antagonists increase HR as well but also display capabilities of blocking agonist actions. These results provide evidence that both of these receptor subtypes display functional significance in regulating the larval heart's pacemaker activity.

  12. Cholinergic excitation in mouse primary vs. associative cortex: region-specific magnitude and receptor balance.

    Science.gov (United States)

    Tian, Michael K; Bailey, Craig D C; Lambe, Evelyn K

    2014-08-01

    Cholinergic stimulation of the cerebral cortex is essential for tasks requiring attention; however, there is still some debate over which cortical regions are required for such tasks. There is extensive cholinergic innervation of both primary and associative cortices, and transient release of acetylcholine (ACh) is detected in deep layers of the relevant primary and/or associative cortex, depending on the nature of the attention task. Here, we investigated the electrophysiological effects of ACh in layer VI, the deepest layer, of the primary somatosensory cortex, the primary motor cortex, and the associative medial prefrontal cortex. Layer VI pyramidal neurons are a major source of top-down modulation of attention, and we found that the strength and homogeneity of their direct cholinergic excitation was region-specific. On average, neurons in the primary cortical regions showed weaker responses to ACh, mediated by a balance of contributions from both nicotinic and muscarinic ACh receptors. Conversely, neurons in the associative medial prefrontal cortex showed significantly stronger excitation by ACh, mediated predominantly by nicotinic receptors. The greatest diversity of responses to ACh was found in the primary somatosensory cortex, with only a subset of neurons showing nicotinic excitation. In a mouse model with attention deficits only under demanding conditions, cholinergic excitation was preserved in primary cortical regions but not in the associative medial prefrontal cortex. These findings demonstrate that the effect of ACh is not uniform throughout the cortex, and suggest that its ability to enhance attention performance may involve different cellular mechanisms across cortical regions.

  13. CHARACTERIZATION OF MUSCARINIC CHOLINERGIC RECEPTOR SUBTYPES IN RAT PROSTATE

    OpenAIRE

    Pontari, M.A.; LUTHIN, G. R.; Braverman, A. S.; Ruggieri, M. R.

    1998-01-01

    The purpose of this study was to characterize the muscarinic receptor subtypes in the individual lobes of the rat prostate. Immunoprecipitation was performed on homogenates of these 3 lobes using antibodies to the m1-m4 muscarinic receptor subtypes. Reverse transcriptase polymerase chain reaction assays (RT-PCR) were also performed using primers specific for each of the five muscarinic receptor subtypes (m1-m5). The susceptibility of the receptors to degradation by endogenous prostate proteas...

  14. Dexmedetomidine controls systemic cytokine levels through the cholinergic anti-inflammatory pathway.

    Science.gov (United States)

    Xiang, Hui; Hu, Bo; Li, Zhifeng; Li, Jianguo

    2014-10-01

    Previous studies have shown that dexmedetomidine exerted anti-inflammatory effect on several animal models with inflammation, but the mechanism is not clear. This study intends to elucidate the anti-inflammatory mechanism of dexmedetomidine through the cholinergic anti-inflammatory pathway. To investigate this therapeutic potential of dexmedetomidine, a murine model of endotoxemia was established induced by lipopolysaccharide (LPS). Animals were assigned to one of four protocols. Protocol one: animals were randomly assigned to control group, dexmedetomidine group, and sterile saline group (n=20 each), and these animals were used for survival analysis. The survival rate was assessed up to 120 h after endotoxin injection. Protocol two: animals were randomly assigned to one of four groups (n=16 each): group 1 (group Saline), treated with sterile saline 15 min prior to endotoxin treatment (10 mg kg(-1) over 2 min); group 2 (group Dex), treated with dexmedetomidine 15 min prior to endotoxin treatment; group 3 (group αBGT+Dex), treated with alpha-7 nicotinic acetylcholine receptors (α7nAChR) antagonist alpha-bungarotoxin (αBGT, 1 μg/kg) 15 min prior to dexmedetomidine treatment; group 4 (group saline+Dex), treated with equivalent sterile saline 15 min prior to dexmedetomidine treatment. Protocol three: animals were randomly assigned to one of two groups (n=16 each): vagotomy group (group VNX+Dex), right cervical vagus nerve was exposed and transected; sham-operated group (group SHAM+Dex), the cervical vagus nerve was visualized, but was neither isolated from the surrounding tissues nor transected. Protocol four: animals were treated with dexmedetomidine (40 μg/kg) and sterile saline to observe the discharge activity of cervical vagus nerves by using BL-420F data acquisition and analysis system (n=16 each). In the survival analysis groups, the survival rate of dexmedetomidine group was significantly higher than that of the endotoxemia group (65 versus 25

  15. Involvement of dopaminergic and cholinergic pathways in the induction of yawning and genital grooming by the aqueous extract of Saccharum officinarum L. (sugarcane) in rats.

    Science.gov (United States)

    Gamberini, Maria T; Gamberini, Maria C; Nasello, Antonia G

    2015-01-01

    Yawning, associated with genital grooming, is a physiological response that may be used for elucidating the mechanism of action of drugs. Preliminary analysis showed that aqueous extract (AE) of Saccharum induced yawns in rats. So, we aimed to quantify these behavioral responses and investigate the pharmacological mechanisms involved in these actions. During 120 min, after AE administration, the yawns and the genital grooming were quantified at 10 min intervals. Since dopaminergic and cholinergic pathways are implied in these responses, AE were evaluated in the presence of haloperidol 0.5 mg/kg and atropine 2 mg/kg. AE 0.5 g/kg increased the yawns, effect that was blocked both by haloperidol and atropine. Genital grooming could only be stimulated by AE 0.5 g/kg when dopaminergic receptors were blocked by haloperidol. However, it was inhibited when atropine was previously administered. So, we demonstrated a central action of Saccharum and it was postulated that neural circuits with the participation of dopaminergic and cholinergic pathways are involved. The fact that AE is comprised of innumerous compounds could justify the extract's distinct responses. Also, we cannot disregard the presence of different neural circuits that count on the participation of dopaminergic and cholinergic pathways and could be activated by the same induction agent.

  16. Liang-Ge-San, a classic traditional Chinese medicine formula, protects against lipopolysaccharide-induced inflammation through cholinergic anti-inflammatory pathway.

    Science.gov (United States)

    Liu, Jun-Shan; Wei, Xi-Duan; Lu, Zi-Bin; Xie, Pei; Zhou, Hong-Ling; Chen, Yu-Yao; Ma, Jia-Mei; Yu, Lin-Zhong

    2016-04-19

    Liang-Ge-San (LGS) is a classic formula in traditional Chinese medicine, which is widely used to treat acute lung injury (ALI), pharyngitis and amygdalitis in clinic. However, the underlying mechanisms remain poorly defined. In this study, we discovered that LGS exerted potent anti-inflammatory effects in lipopolysaccharide (LPS)-induced inflammation. We found that LGS significantly depressed the production of IL-6 and TNF-α in LPS-stimulated RAW 264.7 macrophage cells. The degradation and phosphorylation of IκBα and the nuclear translocation of NF-κB p65 were also inhibited. Moreover, LGS activated α7 nicotinic cholinergic receptor (α7nAchR). The blockage of α7nAchR by selective inhibitor methyllycaconitine (MLA) or α7nAchR siRNA attenuated the inhibitory effects of LGS on IκBα, NF-κB p65, IL-6 and TNF-α. Critically, LGS significantly inhibited inflammation in LPS-induced ALI rats through the activation of NF-κB signaling pathway. However, these protective effects could be counteracted by the treatment of MLA. Taken together, we first demonstrated anti-inflammatory effects of LGS both in vitro and in vivo through cholinergic anti-inflammatory pathway. The study provides a rationale for the clinical application of LGS as an anti-inflammatory agent and supports the critical role of cholinergic anti-inflammatory pathway in inflammation.

  17. The Protective Effect of Electroacupuncturing Zusanli Points on Hemorrhagic Shock Rats through Cholinergic Anti-inflammatory Pathway

    Institute of Scientific and Technical Information of China (English)

    Zhao-Hui DU; Jian-Guo LI; Yan-Lin WANG; Zhou-Quan PENG; Xiao-Feng YE

    2005-01-01

    @@ 1 Introduction In conditions of circulatory shock, systemic inflammatory response (SIRS) plays a funda mental pathogenetic role, with activation of transcription nuclear factors(mainly NF- kB) and markedly increased production of cytokines (mainly TNF-a), which trigger the inflammatory cascade active ation. Recent research have identified a basic neural pathway that reflexively monitors and adjusts such response. It is through the rapid activation (in "real-time") of efferent vagus nerve fibres(the recentlyrecognized "brain cholinergic antiinflammatory pathway" ) [1].There are show that the rapid activation cholinergic antiinflammatory pathway can protect against the hemorrhagic shock[2,3].

  18. Measurement of functional cholinergic innervation in rat heart with a novel vesamicol receptor ligand

    Energy Technology Data Exchange (ETDEWEB)

    Coffeen, Paul R.; Efange, S.M.N.; Haidet, George C.; McKnite, Scott; Langason, Rosemary B.; Khare, A.B.; Pennington, Jennifer; Lurie, Keith G

    1996-10-01

    Regional differences in cholinergic activity in the cardiac conduction system have been difficult to study. We tested the utility of (+)-m-[{sup 125}I]iodobenzyl)trozamicol(+)-[{sup 125}I]MIBT), a novel radioligand that binds to the vesamicol receptor located on the synaptic vesicle in presynaptic cholinergic neurons, as a functional marker of cholinergic activity in the conduction system. The (+)-[{sup 125}I]MIBT was injected intravenously into four rats. Three hours later, the rats were killed and their hearts were frozen. Quantitative autoradiography was performed on 20-micron-thick sections that were subsequently stained for acetylcholinesterase to identify specific conduction-system elements. Marked similarities existed between (+)-[{sup 125}I]MIBT uptake and acetylcholinesterase-positive regions. Optical densitometric analysis of regional (+)-[{sup 125}I]MIBT uptake revealed significantly greater (+)-[{sup 125}I]MIBT binding (nCi/mg) in the atrioventricular node (AVN) and His bundle regions compared with other conduction and contractile elements (AVN: 3.43 {+-} 0.37; His bundle: 2.16 {+-} 0.30; right bundle branch: 0.95 {+-} 0.13; right atrium: 0.68 {+-} 0.05; right ventricle: 0.57 {+-} 0.03; and left ventricle: 0.57 {+-} 0.03; p < 0.05 comparing conduction elements with ventricular muscle). This study demonstrates that (+)-[{sup 125}I]MIBT binds avidly to cholinergic nerve tissue innervating specific conduction-system elements. Thus, (+)-[{sup 125}I]MIBT may be a useful functional marker in studies on cholinergic innervation in the cardiac conduction system.

  19. GABAA receptors are located in cholinergic terminals in the nucleus pontis oralis of the rat: implications for REM sleep control.

    Science.gov (United States)

    Liang, Chang-Lin; Marks, Gerald A

    2014-01-16

    The oral pontine reticular formation (PnO) of rat is one region identified in the brainstem as a rapid eye movement (REM) sleep induction zone. Microinjection of GABA(A) receptor antagonists into PnO induces a long lasting increase in REM sleep, which is similar to that produced by cholinergic agonists. We previously showed that this REM sleep-induction can be completely blocked by a muscarinic antagonist, indicating that the REM sleep-inducing effect of GABA(A) receptor antagonism is dependent upon the local cholinergic system. Consistent with these findings, it has been reported that GABA(A) receptor antagonists microdialyzed into PnO resulted in increased levels of acetylcholine. We hypothesize that GABA(A) receptors located on cholinergic boutons in the PnO are responsible for the REM sleep induction by GABA(A) receptor antagonists through blocking GABA inhibition of acetylcholine release. Cholinergic, varicose axon fibers were studied in the PnO by immunofluorescence and confocal, laser scanning microscopy. Immunoreactive cholinergic boutons were found to be colocalized with GABA(A) receptor subunit protein γ2. This finding implicates a specific subtype and location of GABA(A) receptors in PnO of rat in the control of REM sleep.

  20. ( sup 3 H)cytisine binding to nicotinic cholinergic receptors in brain

    Energy Technology Data Exchange (ETDEWEB)

    Pabreza, L.A.; Dhawan, S.; Kellar, K.J. (Georgetown Univ. School of Medicine, Washington, DC (USA))

    1991-01-01

    Cytisine, a ganglionic agonist, competes with high affinity for brain nicotinic cholinergic receptors labeled by any of several nicotinic {sup 3}H-agonist ligands. Here we have examined the binding of ({sup 3}H)cytisine in rat brain homogenates. ({sup 3}H)Cytisine binds with high affinity (Kd less than 1 nM), and specific binding represented 60-90% of total binding at all concentrations examined up to 15 nM. The nicotinic cholinergic agonists nicotine, acetylcholine, and carbachol compete with high affinity for ({sup 3}H)cytisine binding sites, whereas among nicotinic receptor antagonists only dihydro-beta-erythroidine competes with high affinity (in the nanomolar range). Comparison of binding in several brain regions showed that ({sup 3}H)cytisine binding is higher in the thalamus, striatum, and cortex than in the hippocampus, cerebellum, or hypothalamus. The pharmacology and brain regional distribution of ({sup 3}H)cytisine binding sites are those predicted for neuronal nicotinic receptor agonist recognition sites. The high affinity and low nonspecific binding of ({sup 3}H)cytisine should make it a very useful ligand for studying neuronal nicotinic receptors.

  1. In vivo PET imaging of brain nicotinic cholinergic receptors

    Energy Technology Data Exchange (ETDEWEB)

    Bottlaender, M.; Valette, H.; Saba, W.; Schollhorn-Peyronneau, M.A.; Dolle, F.; Syrota, A. [Service Hospitalier Frederic Joliot (CEA/DSV/DRM), 91 - Orsay (France)

    2006-07-01

    Neuronal acetylcholine receptors (nAChRs) are widely distributed throughout the central nervous system where they modulate a number of CNS functions including neurotransmitter release, cognitive function, anxiety, analgesia and control of cerebral blood flow. In the brain, a major subtype is composed of the {alpha}4{beta}2 subunit combination. Density of this subtype has been shown to be decreased in patients with neuro-degenerative disease such as Alzheimer and Parkinson's disease (AD and PD), and mutated receptors has been described in some familial epilepsy. Thus, in vivo mapping of the nicotinic nAChRs by Positron Emission Tomography (PET) are of great interest to monitor the evolution of these pathologies and changes in the neuronal biochemistry induced by therapeutic agents. Recently, a new compound, 3-[2(S)-2-azetidinyl-methoxy]pyridine (A-85380) has been synthesised and labelled with fluorine-18, [{sup 18}F]fluoro-A-85380 (Dolle et al., 1999). The [{sup 18}F]fluoro-A-85380 has been shown to bind with high affinity t o nAChRs in vitro (Saba et al., 2004), and its toxicity was low and compatible with it s use at tracer dose in human PET studies (Valette, 2002). PET studies in baboons showed that, after in vivo administration of [ {sup 18}F]fluoro-A-85380 at a tracer dose, the distribution of the radioactivity in the brain reflect the distribution of the < 4R2 nAChRs. Competition and pre-blocking studies, using nicotinic agonists, confirm that the radiotracer binds specifically to the heteromeric nAChRs in the brain (Valette et al., 1999). The in vivo, characteristics of the [{sup 18}F]fluoro-A-8538 0 combined with its low toxicity make possible the imaging of the nicotinic receptor s in human by PET (Bottlaender 2003). Studies were performed in healthy non-smoker volunteers to evaluate the brain kinetics of [{sup 18}F]fluoro-A-85380 and to assess the quantification of its nAChRs binding in the human brain with PET (Gallezot et a., 2005). The [{sup 18}F

  2. Role of cholinergic anti-inflammatory pathway in regulating host response and its interventional strategy for inflammatory diseases

    Institute of Scientific and Technical Information of China (English)

    WANG Da-wei; ZHOU Rong-bin; YAO Yong-ming

    2009-01-01

    @@ The cholinergic anti-inflammatory pathway (CAP) is a neurophysiological mechanism that regulates the immune system. The CAP inhibits inflammation by suppressing cytokine synthesis via release of acetylcholine in organs of the reticuloendothelial system, including the lungs, spleen, liver, kidneys and gastrointestinal tract.

  3. [Cholinergic system of the heart].

    Science.gov (United States)

    Kučera, Matej; Hrabovská, Anna

    2015-12-01

    The cholinergic system of the heart can be either of neuronal or non-neuronal origin. The neuronal cholinergic system in the heart is represented by preganglionic parasympathetic pathways, intracardiac parasympathetic ganglia and postganglionic parasympathetic neurons projecting to the atria, SA node and AV node. The non-neuronal cholinergic system consists of cardiomyocytes that have complete equipment for synthesis and secretion of acetylcholine. Current knowledge suggests that the non-neuronal cholinergic system in the heart affects the regulation of the heart during sympathetic activation. The non-neuronal cholinergic system of the heart plays also a role in the energy metabolism of cardimyocites. Acetylcholine of both neuronal and non-neuronal origin acts in the heart through muscarinic and nicotinic receptors. The effect of acetylcholine in the heart is terminated by cholinesterases acetylcholinesterase and butyrylcholinesterase. Recently, papers suggest that the increased cholinergic tone in the heart by cholinesterase inhibitors has a positive effect on some cardiovascular disorders such as heart failure. For this reason, the cholinesterase inhibitors might be used in the treatment of certain cardiovascular disorders in the future.

  4. Rabbit forebrain cholinergic system: morphological characterization of nuclei and distribution of cholinergic terminals in the cerebral cortex and hippocampus.

    Science.gov (United States)

    Varga, Csaba; Härtig, Wolfgang; Grosche, Jens; Keijser, Jan; Luiten, Paul G M; Seeger, Johannes; Brauer, Kurt; Harkany, Tibor

    2003-06-09

    Although the rabbit brain, in particular the basal forebrain cholinergic system, has become a common model for neuropathological changes associated with Alzheimer's disease, detailed neuroanatomical studies on the morphological organization of basal forebrain cholinergic nuclei and on their output pathways are still awaited. Therefore, we performed quantitative choline acetyltransferase (ChAT) immunocytochemistry to localize major cholinergic nuclei and to determine the number of respective cholinergic neurons in the rabbit forebrain. The density of ChAT-immunoreactive terminals in layer V of distinct neocortical territories and in hippocampal subfields was also measured. Another cholinergic marker, the low-affinity neurotrophin receptor (p75(NTR)), was also employed to identify subsets of cholinergic neurons. Double-immunofluorescence labeling of ChAT and p75(NTR), calbindin D-28k (CB), parvalbumin, calretinin, neuronal nitric oxide synthase (nNOS), tyrosine hydroxylase, or substance P was used to elucidate the neuroanatomical borders of cholinergic nuclei and to analyze the neurochemical complexity of cholinergic cell populations. Cholinergic projection neurons with heterogeneous densities were found in the medial septum, vertical and horizontal diagonal bands of Broca, ventral pallidum, and magnocellular nucleus basalis (MBN)/substantia innominata (SI) complex; cholinergic interneurons were observed in the caudate nucleus, putamen, accumbens nucleus, and olfactory tubercule, whereas the globus pallidus was devoid of cholinergic nerve cells. Cholinergic interneurons were frequently present in the hippocampus and to a lesser extent in cerebral cortex. Cholinergic projection neurons, except those localized in SI, abundantly expressed p75(NTR), and a subset of cholinergic neurons in posterior MBN was immunoreactive for CB and nNOS. A strict laminar distribution pattern of cholinergic terminals was recorded both in the cerebral cortex and in CA1-CA3 and dentate gyrus

  5. Potentiation of NMDA receptor-mediated transmission in striatal cholinergic interneurons

    Directory of Open Access Journals (Sweden)

    Manfred eOswald

    2015-04-01

    Full Text Available Pauses in the tonic firing of striatal cholinergic interneurons (CINs emerge during reward-related learning in response to conditioning of a neutral cue. We have previously reported that augmenting the postsynaptic response to cortical afferents in CINs is coupled to the emergence of a cell-intrinsic afterhyperpolarisation (AHP underlying pauses in tonic activity. Here we investigated in a bihemispheric rat-brain slice preparation the mechanisms of synaptic plasticity of excitatory afferents to CINs and the association with changes in the AHP. We found that high frequency stimulation (HFS of commissural corticostriatal afferents from the contralateral hemisphere induced a robust long-term depression (LTD of postsynaptic potentials (PSP in CINs. Depression of the PSP of smaller magnitude and duration was observed in response to HFS of the ipsilateral white matter or cerebral cortex. In Mg2+-free solution HFS induced NMDA receptor-dependent potentiation of the PSP, evident in both the maximal slope and amplitude of the PSP. The increase in maximal slope corroborates previous findings, and was blocked by antagonism of either D1-like dopamine receptors with SCH23390 or D2-like dopamine receptors with sulpiride during HFS in Mg2+-free solution. Potentiation of the slower PSP amplitude component was due to augmentation of the NMDA receptor-mediated potential as this was completely reversed on subsequent application of the NMDA receptor antagonist AP5. HFS similarly potentiated NMDA receptor currents isolated by blockade of AMPA/kainate receptors with CNQX. The plasticity-induced increase in the slow PSP component was directly associated with an increase in the subsequent AHP. Thus plasticity of cortical afferent synapses is ideally suited to influence the cue-induced firing dynamics of CINs, particularly through potentiation of NMDA receptor-mediated synaptic transmission.

  6. Ligands for SPECT and PET imaging of muscarinic-cholinergic receptors of the heart and brain

    Energy Technology Data Exchange (ETDEWEB)

    Knapp, F.F. Jr.; McPherson, D.W.; Luo, H. [and others

    1995-06-01

    Interest in the potential use of cerebral SPECT and PET imaging for determination of the density and activity of muscarinic-cholinergic receptors (mAChR) has been stimulated by the changes in these receptors which occur in many neurological diseases. In addition, the important involvement of mAChR in modulating negative inotropic cardiac activity suggests that such receptor ligands may have important applications in evaluation of changes which may occur in cardiac disease. In this paper, the properties of several key muscarinic receptor ligands being developed or which have been used for clinical SPECT and PET are discussed. In addition, the ORNL development of the new iodinated IQNP ligand based on QNB and the results of in vivo biodistribution studies in rats, in vitro competitive binding studies and ex vivo autoradiographic experiments are described. The use of radioiodinated IQNP may offer several advantages in comparison to IQNB because of its easy and high yield preparation and high brain uptake and the potential usefulness of the {open_quotes}partial{close_quotes} subtype selective IONP isomers. We also describe the development of new IQNP-type analogues which offer the opportunity for radiolabeling with positron-emitting radioisotopes (carbon-11, fluorine-18 and bromine-76) for potential use with PET.

  7. Subcellular redistribution of m2 muscarinic acetylcholine receptors in striatal interneurons in vivo after acute cholinergic stimulation.

    Science.gov (United States)

    Bernard, V; Laribi, O; Levey, A I; Bloch, B

    1998-12-01

    The purpose of our work was to investigate how the cholinergic environment influences the targeting and the intracellular trafficking of the muscarinic receptor m2 (m2R) in vivo. To address this question, we have used immunohistochemical approaches at light and electron microscopic levels to detect the m2R in control rats and rats treated with muscarinic receptor agonists. In control animals, m2Rs were located mostly at postsynaptic sites at the plasma membrane of perikarya and dendrites of cholinergic and NPY-somatostatin interneurons as autoreceptors and heteroreceptors, respectively. Presynaptic receptors were also detected in boutons. The m2Rs were usually detected at extrasynaptic sites, but they could be found rarely in association with symmetrical synapses, suggesting that the cholinergic transmission mediated by m2R occurs via synaptic and nonsynaptic mechanisms. The stimulation of muscarinic receptors with oxotremorine provoked a dramatic alteration of m2R compartmentalization, including endocytosis with a decrease of the density of m2R at the membrane (-63%) and an increase of those associated with endosomes (+86%) in perikarya. The very strong increase of m2R associated with multivesicular bodies (+732%) suggests that oxotremorine activated degradation. The slight increase in the Golgi apparatus (+26%) suggests that the m2R stimulation had an effect on the maturation of m2R. The substance P receptor located at the membrane of the same neurons was unaffected by oxotremorine. Our data demonstrate that cholinergic stimulation dramatically influences the subcellular distribution of m2R in striatal interneurons in vivo. These events may have key roles in controlling abundance and availability of muscarinic receptors via regulation of receptor endocytosis, degradation, and/or neosynthesis. Further, the control of muscarinic receptor trafficking may influence the activity of striatal interneurons, including neurotransmitter release and/or electric activity.

  8. Involvement of CB1 and CB2 receptors in the modulation of cholinergic neurotransmission in mouse gastric preparations.

    Science.gov (United States)

    Mulè, Flavia; Amato, Antonella; Baldassano, Sara; Serio, Rosa

    2007-09-01

    While most of the studies concerning the role of cannabinoids on gastric motility have focused the attention on the gastric emptying in in vivo animal models, there is little information about the cannabinoid peripheral influence in the stomach. In addition, the functional features of CB2 receptors in the gastrointestinal tract have been poorly characterized. The purpose of the present study was to investigate the effects of cannabinoid drugs on the excitatory cholinergic and inhibitory non-adrenergic non-cholinergic (NANC) neurotransmission in mouse isolated gastric preparations. Intraluminal pressure from isolated whole stomach was recorded and mechanical responses induced by electrical field stimulation (EFS) were analyzed in different experimental conditions. EFS (0.5ms duration, supramaximal voltage, in trains of 5s, 2-16Hz) caused a cholinergic contraction, which was abolished by atropine or tetrodotoxin (TTX). The cannabinoid receptor agonist, WIN 55,212-2, the endogenous ligand, anandamide, the selective CB1 receptor agonist ACEA, and the selective CB2 receptor agonists, JWH015 and JWH133, produced a concentration-dependent reduction of the EFS-evoked cholinergic contractions. SR141716A, CB1 receptor antagonist, significantly attenuated the inhibitory effects induced by WIN 55,212-2, anandamide or ACEA, without affecting those caused by JWH133. AM630, CB2 receptor antagonist, reduced the inhibitory effects induced by WIN 55,212-2, anandamide, JWH015 or JWH133, without affecting those caused by ACEA. The joint application of SR141716A and AM630 was able of fully preventing the WIN 55,212-2 and anandamide actions. The cannabinoid antagonists failed per se to affect the neurally evoked responses. Cannabinoids did not modify the contractions produced by exogenous carbachol. In the presence of atropine and guanethidine (NANC conditions) EFS-induced TTX-sensitive relaxation consisting in an early and rapid component followed by a second slow phase, which were

  9. Muscarinic cholinergic receptor (M2 plays a crucial role in the development of myopia in mice

    Directory of Open Access Journals (Sweden)

    Veluchamy A. Barathi

    2013-09-01

    Myopia is a huge public health problem worldwide, reaching the highest incidence in Asia. Identification of susceptible genes is crucial for understanding the biological basis of myopia. In this paper, we have identified and characterized a functional myopia-associated gene using a specific mouse-knockout model. Mice lacking the muscarinic cholinergic receptor gene (M2; also known as Chrm2 were less susceptible to lens-induced myopia compared with wild-type mice, which showed significantly increased axial length and vitreous chamber depth when undergoing experimental induction of myopia. The key findings of this present study are that the sclera of M2 mutant mice has higher expression of collagen type I and lower expression of collagen type V than do wild-type mice and mice that are mutant for other muscarinic subtypes, and, therefore, M2 mutant mice were resistant to the development of experimental myopia. Pharmacological blockade of M2 muscarinic receptor proteins retarded myopia progression in the mouse. These results suggest for the first time a role of M2 in growth-related changes in extracellular matrix genes during myopia development in a mammalian model. M2 receptor antagonists might thus provide a targeted therapeutic approach to the management of this refractive error.

  10. Cholinergic neurons of the pelvic autonomic ganglia and uterus of the female rat: distribution of axons and presence of muscarinic receptors.

    Science.gov (United States)

    Papka, R E; Traurig, H H; Schemann, M; Collins, J; Copelin, T; Wilson, K

    1999-05-01

    Acetylcholine (ACh) stimulates contraction of the uterus and dilates the uterine arterial supply. Uterine cholinergic nerves arise from the paracervical ganglia and were, in the past, characterized based on acetylcholinesterase (AChE) histochemistry. However, the histochemical reaction for acetylcholinesterase provides only indirect evidence of acetylcholine location and is a nonspecific marker for cholinergic nerves. The present study: (1) reevaluated cholinergic neurons of the paracervical ganglia, (2) examined the cholinergic innervation of the uterus by using retrograde axonal tracing and antibodies against molecules specific to cholinergic neurons, choline acetyltransferase and the vesicular acetylcholine transporter, and (3) examined muscarinic receptors in the paracervical ganglia using autoradiography and a radiolabeled agonist. Most ganglionic neurons were choline acetyltransferase- and vesicular acetylcholine transporter-immunoreactive and were apposed by choline acetyltransferase/vesicular acetylcholine transporter-immunoreactive terminals. Retrograde tracing showed that some cholinergic neurons projected axons to the uterus. These nerves formed moderately dense plexuses in the myometrium, cervical smooth muscle and microarterial system of the uterine horns and cervix. Finally, the paracervical ganglia contain muscarinic receptors. These results clearly reveal the cholinergic innervation of the uterus and cervix, a source of these nerves, and demonstrate the muscarinic receptor content of the paracervical ganglia. Cholinergic nerves could play significant roles in the control of uterine myometrium and vasculature.

  11. Dorsal raphe nucleus acetylcholine-mediated neurotransmission modulates post-ictal antinociception: The role of muscarinic and nicotinic cholinergic receptors.

    Science.gov (United States)

    de Oliveira, Rithiele Cristina; de Oliveira, Ricardo; Biagioni, Audrey Francisco; Falconi-Sobrinho, Luiz Luciano; Coimbra, Norberto Cysne

    2016-01-15

    The dorsal raphe nucleus (DRN) is a key structure of the endogenous pain inhibitory system. Although the DRN is rich in serotoninergic neurons, cholinergic neurons are also found in that nucleus. Both ictal and inter-ictal states are followed by post-ictal analgesia. The present study investigated the role of cholinergic mechanisms in postictal antinociceptive processes using microinjections of atropine and mecamylamine, muscarinic and nicotinic cholinergic receptor antagonists, respectively, in the DRN of rats. Intraperitoneal injection of pentylenetetrazole (PTZ) (at 64mg/kg) caused tonic and tonic-clonic seizures. The convulsive motor reactions were followed by an increase in pain thresholds, a phenomenon known as post-ictal analgesia. Pre-treatment of the DRN with atropine or mecamylamine at 1µg, 3µg and 5µg/0.2µL decreased the post-ictal antinociceptive phenomenon. The present results showed that the post-ictal analgesia was mediated by muscarinic and nicotinic cholinergic receptors in the DRN, a structure crucially involved in the neural network that organises post-ictal hypoalgesia.

  12. Cholinergic Mechanisms in Spinal Locomotion - Potential Target for Rehabilitation Approaches

    Directory of Open Access Journals (Sweden)

    L M Jordan

    2014-11-01

    Full Text Available Previous experiments implicate cholinergic brainstem and spinal systems in the control of locomotion. Our results demonstrate that the endogenous cholinergic propriospinal system, acting via M2 and M3 muscarinic receptors, is capable of consistently producing well-coordinated locomotor activity in the in vitro neonatal preparation, placing it in a position to contribute to normal locomotion and to provide a basis for recovery of locomotor capability in the absence of descending pathways. Tests of these suggestions, however, reveal that the spinal cholinergic system plays little if any role in the induction of locomotion, because MLR-evoked locomotion in decerebrate cats is not prevented by cholinergic antagonists. Furthermore, it is not required for the development of stepping movements after spinal cord injury, because cholinergic agonists do not facilitate the appearance of locomotion after spinal cord injury, unlike the dramatic locomotion-promoting effects of clonidine, a noradrenergic α-2 agonist. Furthermore, cholinergic antagonists actually improve locomotor activity after spinal cord injury, suggesting that plastic changes in the spinal cholinergic system interfere with locomotion rather than facilitating it. Changes that have been observed in the cholinergic innervation of motoneurons after spinal cord injury do not decrease motoneuron excitability, as expected. Instead, the development of a hyper-cholinergic state after spinal cord injury appears to enhance motoneuron output and suppress locomotion. A cholinergic suppression of afferent input from the limb after spinal cord injury is also evident from our data, and this may contribute to the ability of cholinergic antagonists to improve locomotion. Not only is a role for the spinal cholinergic system in supressing locomotion after SCI suggested by our results, but an obligatory contribution of a brainstem cholinergic relay to reticulospinal locomotor command systems is not confirmed

  13. Fetal cholinergic anti-inflammatory pathway and necrotizing enterocolitis: the brain-gut connection begins in utero

    Directory of Open Access Journals (Sweden)

    Luca eGarzoni

    2013-08-01

    Full Text Available Necrotizing enterocolitis (NEC is an acute neonatal inflammatory disease that affects the intestine and may result in necrosis, systemic sepsis and multisystem organ failure. NEC affects 5-10% of all infants with birth weight ≤ 1500 g or gestational age less than 30 weeks. Chorioamnionitis (CA is the main manifestation of pathological inflammation in the fetus and is strongly associated with NEC. CA affects 20% of full-term pregnancies and up to 60% of preterm pregnancies and, notably, is often an occult finding. Intrauterine exposure to inflammatory stimuli may switch innate immunity cells such as macrophages to a reactive phenotype (‘priming’. Confronted with renewed inflammatory stimuli during labour or postnatally, such sensitized cells can sustain a chronic or exaggerated production of proinflammatory cytokines associated with NEC (two-hit hypothesis. Via the cholinergic anti-inflammatory pathway, a neurally mediated innate anti-inflammatory mechanism, higher levels of vagal activity are associated with lower systemic levels of proinflammatory cytokines. This effect is mediated by the α7 subunit nicotinic acetylcholine receptor (α7nAChR on macrophages. The gut is the most extensive organ innervated by the vagus nerve; it is also the primary site of innate immunity in the newborn. Here we review the mechanisms of possible neuroimmunological brain-gut interactions involved in the induction and control of antenatal intestinal inflammatory response and priming. We propose a neuroimmunological framework to 1 study the long-term effects of perinatal intestinal response to infection and 2 to uncover new targets for preventive and therapeutic intervention.

  14. [Properties of cholinergic receptor-mediated ion channels on type I vestibular hair cells of guinea pigs].

    Science.gov (United States)

    Zhu, Yun; Kong, Wei-Jia; Xia, Jiao; Zhang, Yu; Cheng, Hua-Mao; Guo, Chang-Kai

    2008-06-25

    To confirm the existence of cholinergic receptors on type I vestibular hair cells (VHCs I) of guinea pigs and to study the properties of the cholinergic receptor-mediated ion channels on VHCs I, electrophysiological responses of isolated VHCs I to external ACh were examined by means of whole-cell patch-clamp recordings. The results showed that 7.5% (21/279) VHCs I were found to be sensitive to ACh (10-1000 μmol/L). ACh generated an outward current in a steady, slow, dose-dependent [EC(50) was (63.78±2.31) μmol/L] and voltage-independent manner. In standard extracellular solution, ACh at the concentration of 100 μmol/L triggered a calcium-dependent current of (170±15) pA at holding potential of -50 mV, and the current amplitude could be depressed by extracellularly added calcium-dependent potassium channel antagonist TEA. The time interval for the next complete activation of ACh-sensitive current was no less than 1 min. The ion channels did not shut off even when they were exposed to ACh for an extended period of time (8 min). The results suggest that dose-dependent, calcium-dependent and voltage-independent cholinergic receptors were located on a few of the VHCs I investibular epithelium of guinea pigs. The cholinergic receptors did not show desensitization to ACh. This work reveals the existence of efferent neurotransmitter receptors on VHCs I and helps in understanding the function of vestibular efferent nervous system, and may provide some useful information on guiding the clinical rehabilitative treatment of vertigo.

  15. An increase in intracelluar free calcium ions modulated by cholinergic receptors in rat facial nucleus

    Institute of Scientific and Technical Information of China (English)

    SUN Da-wei; ZHOU Rui; LI Na; ZHANG Qiu-gui; ZHU Fu-gao

    2009-01-01

    Background Ca2+in the central nervous system plays important roles in brain physiology, including neuronal survival and regeneration in rats with injured facial motoneurons. The present research was to study the modulations of intracellular free Ca2+ concentrations by cholinergic receptors in rat facial nucleus, and the mechanisms of the modulations. Methods The fluorescence intensity of facial nucleus in Fluo-3 AM loaded acute brainstem slices was detected by applying intracellular free Ca2+ measurement technique via confocal laser scanning microscope. The changes of fluorescence intensity of facial nucleus indicate the average changes of intracellular free Ca2+ levels of the neurons. Results Acetylcholine was effective at increasing the fluorescence intensity of facial nucleus. Muscarine chlorlde induced a marked increase of fluorescence intensity in a concentration dependent fashion. The enhancement of fluorescence intensity by muscarine chloride was significantly reduced by thapsigargin (depletor of intracellular Ca2+ store; P0.05). And the increase of fluorescence intensity was also significantly inhibited by pirenzepine (M1 subtype selective antagonist; P0.05).Conclusions The data provide the evidence that muscarinic receptors may induce the increase of intracellular free Ca2+ levels through the Ca2+ release of intracellular Ca2+ stores, in a manner related to M1 and M3 subtypes of muscarinic receptors in rat facial nucleus. Nicotine may increase intracellular free Ca2+ concentrations via the influx of extracellular Ca2+ mainly across L-type voltage-gated Ca2+ channels, in a manner related to the α4β2 subtype of nicotinic receptors.

  16. Ultrastructural localization of cholinergic muscarinic receptors in rat brain cortical capillaries

    NARCIS (Netherlands)

    Luiten, PGM; deJong, GI; VanderZee, EA; vanDijken, H; Dijken, H. van

    1996-01-01

    Cholinergic innervation of the cerebrovasculature is known to regulate vascular tone, perfusion rate and permeability of the microvascular wall. Notably the cholinergic innervation of cerebral capillaries is of interest since these capillaries form the blood-brain barrier. Although there is a genera

  17. Cholinergic cells in the nucleus basalis of mice express the N-methyl-D-aspartate-receptor subunit NR2C and its replacement by the NR2B subunit enhances frontal and amygdaloid acetylcholine levels

    NARCIS (Netherlands)

    De Souza Silva, M. A.; Dolga, Amalia; Pieri, I.; Marchetti, L.; Eisel, U. L. M.; Huston, J. P.; Dere, E.

    2006-01-01

    It is known that glutamatergic and cholinergic systems interact functionally at the level of the cholinergic basal forebrain. The N-methyl-D-aspartate receptor (NMDA-R) is a multiprotein complex composed of NR1, NR2 and/or NR3 subunits. The subunit composition of NMDA-R of cholinergic cells in the n

  18. Association of m1 and m2 muscarinic receptor proteins with asymmetric synapses in the primate cerebral cortex: morphological evidence for cholinergic modulation of excitatory neurotransmission.

    OpenAIRE

    Mrzljak, L; Levey, A I; Goldman-Rakic, P S

    1993-01-01

    Muscarinic m1 receptors traditionally are considered to be postsynaptic to cholinergic fibers, while m2 receptors are largely presynaptic receptors associated with axons. We have examined the distribution of these receptor proteins in the monkey cerebral cortex and obtained results that are at odds with this expectation. Using immunohistochemistry with specific antibodies to recombinant m1 and m2 muscarinic receptor proteins, we have demonstrated that both m1 and m2 receptors are prominently ...

  19. Macromolecular Instabilities and Dynamical Coding in Brain Enzymes, Polypeptide Ligands, Polypeptide and Cholinergic Receptors, and Sodium and Cholinergic Channel Proteins

    Science.gov (United States)

    1988-03-01

    potency of the analog. That is our theorl as to why the salmon is a stronger calcitonin than man in man. Current Work Involving Cholirnergic Receptor...turned to the problem of designing a calcitonin molecule. The large naturally occuring calcitonin family is examined Yith perhaps the nicest

  20. Immunohistochemical localisation of cholinergic muscarinic receptor subtype 1 (M1r) in the guinea pig and human enteric nervous system.

    Science.gov (United States)

    Harrington, A M; Hutson, J M; Southwell, B R

    2007-07-01

    Little is known regarding the location of cholinergic muscarinic receptor 1 (M1r) in the ENS, even though physiological data suggest that M1rs are central to cholinergic neurotransmission. This study localised M1rs in the ENS of the guinea pig ileum and human colon using fluorescence immunohistochemistry and RT-PCR in human colon. Double labelling using antibodies against neurochemical markers was used to identify neuron subytpes bearing M1r. M1r immunoreactivity (IR) was present on neurons in the myenteric and submucosal ganglia. The two antibodies gave similar M1r-IR patterns and M1r-IR was abolished upon antibody preabsorption. M1r-IR was present on cholinergic and nNOS-IR nerve cell bodies in both guinea pig and human myenteric neurons. Presynaptic M1r-IR was present on NOS-IR and VAChT-IR nerve fibres in the circular muscle in the human colon. In the submucosal ganglia, M1r-IR was present on a population of neurons that contained cChAT-IR, but did not contain NPY-IR or calretinin-IR. M1r-IR was present on endothelial cells of blood vessels in the submucosal plexus. The localisation of M1r-IR in the guinea pig and human ENS shown in this study agrees with physiological studies. M1r-IR in cholinergic and nitrergic neurons and nerve fibres indicate that M1rs have a role in both cholinergic and nitrergic transmission. M1r-IR present in submucosal neurons suggests a role in mediating acetylcholine's effect on submucosal sensory and secretomotor/vasodilator neurons. M1r-IR present on blood vessel endothelial cells suggests that M1rs may also mediate acetylcholine's direct effect on vasoactivation.

  1. Research on Autoantibodies Against Myocardial β1-adrenergic and M2 Cholinergic Receptors in Patients With Chronic Keshan Disease

    Institute of Scientific and Technical Information of China (English)

    Han Zhenhua; Niu Xiaolin; Ren Fuxian

    2006-01-01

    Objectives To explore the relationship between serum autoantibodies against myocardial β1-adrenergic, M2-cholinergic receptors and chronic Keshan disease (CKD). Methods The second extracellular loops of β1 and M2 receptors on human cardiomyocytes were used as the antigens.Enzyme linked immunosorbent assay (ELISA) was applied to determine serum autoantibodies against myocardial β1 and M2 receptors in 32 CKD patients. 31 healthy subjects from endemic area were selected as the control. Results Positive rate of autoantibodies against myocardial β1 adrenergic (51.3%, 17/32) and M2cholinergic (56.3% , 18/32) receptors weresignificantly higher than those in the control (9.7%, 3/31; 12.9%, 4/31) (both P < 0.01). Both positive rate and titers of above autoantibodies in NYHA Ⅱ~Ⅲ CKD patients were significantly higher than those in NYHA Ⅳ , demonstrating an apparently positive correlation between serum antibodies against myocardial β1 and M2 receptors (r=0.95). Conclusions Autoantibodies against myocardial β1 and M2 receptors were found in sera of CKD patients; distribution of positive rate and titers of the autoantibodies in CKD patients in various NYHA classes of cardiac function are significantly different.

  2. Nicotinic cholinergic receptors in esophagus: Early alteration during carcinogenesis and prognostic value

    Science.gov (United States)

    Chianello Nicolau, Marina; Pinto, Luis Felipe Ribeiro; Nicolau-Neto, Pedro; de Pinho, Paulo Roberto Alves; Rossini, Ana; de Almeida Simão, Tatiana; Soares Lima, Sheila Coelho

    2016-01-01

    AIM To compare expression of nicotinic cholinergic receptors (CHRNs) in healthy and squamous cell carcinoma-affected esophagus and determine the prognostic value. METHODS We performed RT-qPCR to measure the expression of CHRNs in 44 esophageal samples from healthy individuals and in matched normal surrounding mucosa, and in tumors from 28 patients diagnosed with esophageal squamous cell carcinoma (ESCC). Next, we performed correlation analysis for the detected expression of these receptors with the habits and clinico-pathological characteristics of all study participants. In order to investigate the possible correlations between the expression of the different CHRN subunits in both healthy esophagus and tissues from ESCC patients, correlation matrices were generated. Subsequently, we evaluated whether the detected alterations in expression of the various CHRNs could precede histopathological modifications during the esophageal carcinogenic processes by using receiver operating characteristic curve analysis. Finally, we evaluated the impact of CHRNA5 and CHRNA7 expression on overall survival by using multivariate analysis. RESULTS CHRNA3, CHRNA5, CHRNA7 and CHRNB4, but not CHRNA1, CHRNA4, CHRNA9 or CHRNA10, were found to be expressed in normal (healthy) esophageal mucosa. In ESCC, CHRNA5 and CHRNA7 were overexpressed as compared with patient-matched surrounding non-tumor mucosa (ESCC-adjacent mucosa; P < 0.0001 and P = 0.0091, respectively). Positive correlations were observed between CHRNA3 and CHRNB4 expression in all samples analyzed. Additionally, CHRNB4 was found to be differentially expressed in the healthy esophagus and the normal-appearing ESCC-adjacent mucosa, allowing for distinguishment between these tissues with a sensitivity of 75.86% and a specificity of 78.95% (P = 0.0002). Finally, CHRNA5 expression was identified as an independent prognostic factor in ESCC; patients with high CHRNA5 expression showed an increased overall survival, in comparison with

  3. Effect of cholinergic ligands on the lipids of acetylcholine receptor-rich membrane preparations from Torpedo californica

    Energy Technology Data Exchange (ETDEWEB)

    Martinez-Carrion, M.; Raftery, M.A.; Thomas, J.K.; Sator, V.

    1976-01-01

    Ion permeation, triggered by ligand-receptor interaction, is associated with the primary events of membrane depolarization at the neuromuscular junction and synaptic connections. To explore the possible sites of ion permeation, the long-lived fluorescent probe pyrene (fluorescence lifetime approximately 400 nsec) has been inserted into the lipid phase of acetylcholine receptor-rich membrane (AcChR-M) preparations from Torpedo californica. The pyrene probe is susceptible to both fluidity and permeability changes in the lipid bilayer. These changes are detected by variations in the rate of decay of the excited singlet state of pyrene after pulsation with a 10-nsec ruby laser flash. Variations of these lifetimes in the membrane preparations alone or in the presence of quenchers show that binding of cholinergic agonists and antagonists, neurotoxins, and local anesthetics to AcChR-M produces varying effects on the properties of the pyrene probe in the lipid phase. It is concluded that binding of cholinergic ligands to the receptor does not significantly alter the fluidity or permeability of the lipids in the bilayer in contact with pyrene. On the other hand, local anesthetics do affect these properties.

  4. Cognitive disorder and changes in cholinergic receptors, N-methyl-D aspartate receptors, neural cell adhesion molecule, and brain-derived neurotrophic factor following brain injury

    Institute of Scientific and Technical Information of China (English)

    Weiliang Zhao; Dezhi Kang; Yuanxiang Lin

    2008-01-01

    BACKGROUND: Learning and memory damage is one of the most permanent and the severest symptoms of traumatic brain injury; it can seriously influence the normal life and work of patients. Some research has demonstrated that cognitive disorder is closely related to nicotine cholinergic receptors, N-methyl-D aspartate receptors, neural cell adhesion molecule, and brain-derived neurotrophic factor. OBJECTIVE: To summarize the cognitive disorder and changes in nicotine cholinergic receptors, N-methyl-D aspartate receptors, neural cell adhesion molecule, and brain-derived neurotrophic factor following brain injury. RETRIEVAL STRATEGY: A computer-based online search was conducted in PUBMED for English language publications containing the key words "brain injured, cognitive handicap, acetylcholine, N-methyl-D aspartate receptors, neural cell adhesion molecule, brain-derived neurotrophic factor" from January 2000 to December 2007. There were 44 papers in total. Inclusion criteria: ① articles about changes in nicotine cholinergic receptors, N-methyl-D aspartate receptors, neural cell adhesion molecule, and brain-derived neurotrophic factor following brain injury; ② articles in the same researching circle published in authoritative journals or recently published. Exclusion criteria: duplicated articles.LITERATURE EVALUATION: References were mainly derived from research on changes in these four factors following brain injury. The 20 included papers were clinical or basic experimental studies. DATA SYNTHESIS: After craniocerebral injury, changes in these four factors in brain were similar to those during recovery from cognitive disorder, to a certain degree. Some data have indicated that activation of nicotine cholinergic receptors, N-methyl-D aspartate receptors, neural cell adhesion molecule, and brain-derived neurotrophic factor could greatly improve cognitive disorder following brain injury. However, there are still a lot of questions remaining; for example, how do these

  5. Interaction between muscarinic receptor subtype signal transduction pathways mediating bladder contraction.

    Science.gov (United States)

    Braverman, Alan S; Tallarida, Ronald J; Ruggieri, Michael R

    2002-09-01

    M(3) muscarinic receptors mediate cholinergic-induced contraction in most smooth muscles. However, in the denervated rat bladder, M(2) receptors participate in contraction because M(3)-selective antagonists [para-fluoro-hexahydro-sila-diphenidol (p-F-HHSiD) and 4-DAMP] have low affinities. However, the affinity of the M(2)-selective antagonist methoctramine in the denervated bladder is consistent with M(3) receptor mediating contraction. It is possible that two pathways interact to mediate contraction: one mediated by the M(2) receptor and one by the M(3) receptor. To determine whether an interaction exists, the inhibitory potencies of combinations of methoctramine and p-F-HHSiD for reversing cholinergic contractions were measured. In normal bladders, all combinations gave additive effects. In denervated bladders, synergistic effects were seen with the 10:1 and 1:1 (methoctramine:p-F-HHSiD wt/wt) combinations. After application of the sarcoplasmic reticulum ATPase inhibitor thapsigargin to normal tissue, the 10:1 and 1:1 ratios became synergistic, mimicking denervated tissue. Thus in normal bladders both M(2) and M(3) receptors can induce contraction. In the denervated bladder, the M(2) and the M(3) receptors interact in a facilitatory manner to mediate contraction.

  6. Interaction between muscarinic receptor subtype signal transduction pathways mediating bladder contraction

    Science.gov (United States)

    BRAVERMAN, ALAN S.; TALLARIDA, RONALD J.; RUGGIERI, MICHAEL R.

    2012-01-01

    M3 muscarinic receptors mediate cholinergic-induced contraction in most smooth muscles. However, in the denervated rat bladder, M2 receptors participate in contraction because M3-selective antagonists [para-fluoro-hexahydro-sila-diphenidol (p-F-HHSiD) and 4-DAMP] have low affinities. However, the affinity of the M2-selective antagonist methoctramine in the denervated bladder is consistent with M3 receptor mediating contraction. It is possible that two pathways interact to mediate contraction: one mediated by the M2 receptor and one by the M3 receptor. To determine whether an interaction exists, the inhibitory potencies of combinations of methoctramine and p-F-HHSiD for reversing cholinergic contractions were measured. In normal bladders, all combinations gave additive effects. In denervated bladders, synergistic effects were seen with the 10:1 and 1:1 (methoctramine:p-F-HHSiD wt/wt) combinations. After application of the sarcoplasmic reticulum ATPase inhibitor thapsigargin to normal tissue, the 10:1 and 1:1 ratios became synergistic, mimicking denervated tissue. Thus in normal bladders both M2 and M3 receptors can induce contraction. In the denervated bladder, the M2 and the M3 receptors interact in a facilitatory manner to mediate contraction. PMID:12185001

  7. Nicotinic and muscarinic cholinergic receptors are recruited by acetylcholine-mediated neurotransmission within the locus coeruleus during the organisation of post-ictal antinociception.

    Science.gov (United States)

    de Oliveira, Rithiele Cristina; de Oliveira, Ricardo; Biagioni, Audrey Franceschi; Falconi-Sobrinho, Luiz Luciano; Dos Anjos-Garcia, Tayllon; Coimbra, Norberto Cysne

    2016-10-01

    Post-ictal antinociception is characterised by an increase in the nociceptive threshold that accompanies tonic and tonic-clonic seizures (TCS). The locus coeruleus (LC) receives profuse cholinergic inputs from the pedunculopontine tegmental nucleus. Different concentrations (1μg, 3μg and 5μg/0.2μL) of the muscarinic cholinergic receptor antagonist atropine and the nicotinic cholinergic receptor antagonist mecamylamine were microinjected into the LC of Wistar rats to investigate the role of cholinergic mechanisms in the severity of TCS and the post-ictal antinociceptive response. Five minutes later, TCS were induced by systemic administration of pentylenetetrazole (PTZ) (64mg/kg). Seizures were recorded inside the open field apparatus for an average of 10min. Immediately after seizures, the nociceptive threshold was recorded for 130min using the tail-flick test. Pre-treatment of the LC with 1μg, 3μg and 5μg/0.2μL concentrations of both atropine and mecamylamine did not cause a significant effect on seizure severity. However, the same treatments decreased the post-ictal antinociceptive phenomenon. In addition, mecamylamine caused an earlier decrease in the post-ictal antinociception compared to atropine. These results suggest that muscarinic and mainly nicotinic cholinergic receptors of the LC are recruited to organise tonic-clonic seizure-induced antinociception.

  8. The Regulatory Action of Radix Astragali on M-Cholinergic Receptor of the Brain of Senile Rats

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    @@The changes in density of M-cholinergic receptors in different areas of senile rats and the regulatory action of Huang Qi (黄芪Radix Astragali, a drug for warming yang and replenishing qi) were observed by autoradiography. The results showed that the gray scale displayed in brain sections was clear and mainly distributed in the cortex, hippocampus and striate body, while that due to nonspecific combination was negligible. The gray scale in the cortex, hippocampus and striate body of the experimental group was markedly lower than that in the young control rats, decreased respectively by 24.87%, 14.12% and 12.76% (all P<0.05); but it was obviously higher than those in the senile control rats, increased respectively by 24.15%, 14.38% and 13.47% (P<0.05). The data indicate that Huang Qi (黄芪Radix Astragali) may up-regulate the decreased density of M-cholinergic receptors in the brain of senile rats.

  9. C. elegans dopaminergic D2-like receptors delimit recurrent cholinergic-mediated motor programs during a goal-oriented behavior.

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    Paola Correa

    Full Text Available Caenorhabditis elegans male copulation requires coordinated temporal-spatial execution of different motor outputs. During mating, a cloacal circuit consisting of cholinergic sensory-motor neurons and sex muscles maintains the male's position and executes copulatory spicule thrusts at his mate's vulva. However, distinct signaling mechanisms that delimit these behaviors to their proper context are unclear. We found that dopamine (DA signaling directs copulatory spicule insertion attempts to the hermaphrodite vulva by dampening spurious stimulus-independent sex muscle contractions. From pharmacology and genetic analyses, DA antagonizes stimulatory ACh signaling via the D2-like receptors, DOP-2 and DOP-3, and Gα(o/i proteins, GOA-1 and GPA-7. Calcium imaging and optogenetics suggest that heightened DA-expressing ray neuron activities coincide with the cholinergic cloacal ganglia function during spicule insertion attempts. D2-like receptor signaling also attenuates the excitability of additional mating circuits to reduce the duration of mating attempts with unproductive and/or inappropriate partners. This suggests that, during wild-type mating, simultaneous DA-ACh signaling modulates the activity threshold of repetitive motor programs, thus confining the behavior to the proper situational context.

  10. Orexin receptor activation generates gamma band input to cholinergic and serotonergic arousal system neurons and drives an intrinsic Ca2+-dependent resonance in LDT and PPT cholinergic neurons.

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    Masaru eIshibashi

    2015-06-01

    Full Text Available A hallmark of the waking state is a shift in EEG power to higher frequencies with epochs of synchronized intracortical gamma activity (30-60 Hz - a process associated with high-level cognitive functions. The ascending arousal system, including cholinergic laterodorsal (LDT and pedunculopontine (PPT tegmental neurons and serotonergic dorsal raphe (DR neurons, promotes this state. Recently, this system has been proposed as a gamma wave generator, in part, because some neurons produce high-threshold, Ca2+-dependent oscillations at gamma frequencies. However, it is not known whether arousal-related inputs to these neurons generate such oscillations, or whether such oscillations are ever transmitted to neuronal targets. Since key arousal input arises from hypothalamic orexin (hypocretin neurons, we investigated whether the unusually noisy, depolarizing orexin current could provide significant gamma input to cholinergic and serotonergic neurons, and whether such input could drive Ca2+-dependent oscillations. Whole-cell recordings in brain slices were obtained from mice expressing Cre-induced fluorescence in cholinergic LDT and PPT, and serotonergic DR neurons. After first quantifying reporter expression accuracy in cholinergic and serotonergic neurons, we found that the orexin current produced significant high frequency, including gamma, input to both cholinergic and serotonergic neurons. Then, by using a dynamic clamp, we found that adding a noisy orexin conductance to cholinergic neurons induced a Ca2+-dependent resonance that peaked in the theta and alpha frequency range (4 - 14 Hz and extended up to 100 Hz. We propose that this orexin current noise and the Ca2+ dependent resonance work synergistically to boost the encoding of high-frequency synaptic inputs into action potentials and to help ensure cholinergic neurons fire during EEG activation. This activity could reinforce thalamocortical states supporting arousal, REM sleep and intracortical

  11. Differential actions of orexin receptors in brainstem cholinergic and monoaminergic neurons revealed by receptor knockouts: implications for orexinergic signaling in arousal and narcolepsy

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    Kristi A Kohlmeier

    2013-12-01

    Full Text Available Orexin neuropeptides influence multiple homeostatic functions and play an essential role in the expression of normal sleep-wake behavior. While their two known receptors (OX1 and OX2 are targets for novel pharmacotherapeutics, the actions mediated by each receptor remain largely unexplored. Using brain slices from mice constitutively lacking either receptor, we used whole-cell and Ca2+ imaging methods to delineate the cellular actions of each receptor within cholinergic (laterodorsal tegmental nucleus; LDT and monoaminergic (dorsal raphe; DR and locus coeruleus; LC brainstem nuclei – where orexins promote arousal and suppress REM sleep. In slices from OX2-/- mice, orexin-A (300 nM elicited wild-type responses in LDT, DR and LC neurons consisting of a depolarizing current and augmented voltage-dependent Ca2+ transients. In slices from OX1-/- mice, the depolarizing current was absent in LDT and LC neurons and was attenuated in DR neurons, although Ca2+-transients were still augmented. Since orexin-A produced neither of these actions in slices lacking both receptors, our findings suggest that orexin-mediated depolarization is mediated by both receptors in DR, but is exclusively mediated by OX1 in LDT and LC neurons, even though OX2 is present and OX2 mRNA appears elevated in brainstems from OX1-/- mice. Considering published behavioral data, these findings support a model in which orexin-mediated excitation of mesopontine cholinergic and monoaminergic neurons contributes little to stabilizing spontaneous waking and sleep bouts, but functions in context-dependent arousal and helps restrict muscle atonia to REM sleep. The augmented Ca2± transients mediated by both receptors appeared mediated by influx via L-type Ca2+ channels, which is often linked to transcriptional signaling. This could provide an adaptive signal to compensate for receptor loss or prolonged antagonism and may contribute to the reduced severity of narcolepsy in single receptor

  12. Medial-to-lateral gradient of neostriatal NGF receptors: relationship to cholinergic neurons and NGF-like immunoreactivity.

    Science.gov (United States)

    Altar, C A; Dugich-Djordjevic, M; Armanini, M; Bakhit, C

    1991-03-01

    High-affinity binding sites for recombinant human NGF (rhNGF) were studied in the caudate-putamen of the adult rat and rabbit. Displaceable 125I-rhNGF binding sites were densely distributed throughout the caudate-putamen and were 2-3-fold more prevalant in the ventrolateral and lateral than in the medial caudate-putamen. The amount of nondisplaceable binding did not vary throughout the caudate-putamen. The medial-to-lateral receptor gradient was correlated (r = +0.99) with a 2-3-fold medial-to-lateral increase in ChAT activity. In contrast, NGF-like immunoreactivity (NGF-LI) was prevalent but uniformly distributed in the caudate-putamen. Lesions of intrinsic cholinergic neurons by quinolinic acid produced extensive gliosis in the medial, central, and lateral caudate-putamen, yet 125I-rhNGF binding was decreased in each of these regions. The activity of ChAT and 125I-rhNGF binding throughout the caudate-putamen were each decreased by 40% following quinolinic acid. Binding was not changed after 70-77% dopamine nerve terminal depletions induced by 6-hydroxydopamine, demonstrating a nonglial, nondopaminergic locus for striatal NGF binding sites. The cholinergiclike topography of NGF binding sites throughout the intact caudate-putamen, the parallel decreases of cholinergic neurons and NGF binding sites following intrinsic neuronal loss, and the uniform neostriatal gradient of NGF-LI are consistent with the trophic role of endogenous NGF for cholinergic interneurons of the caudate-putamen.

  13. Mediators, Receptors, and Signalling Pathways in the Anti-Inflammatory and Antihyperalgesic Effects of Acupuncture

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    John L. McDonald

    2015-01-01

    Full Text Available Acupuncture has been used for millennia to treat allergic diseases including both intermittent rhinitis and persistent rhinitis. Besides the research on the efficacy and safety of acupuncture treatment for allergic rhinitis, research has also investigated how acupuncture might modulate immune function to exert anti-inflammatory effects. A proposed model has previously hypothesized that acupuncture might downregulate proinflammatory neuropeptides, proinflammatory cytokines, and neurotrophins, modulating transient receptor potential vallinoid (TRPV1, a G-protein coupled receptor which plays a central role in allergic rhinitis. Recent research has been largely supportive of this model. New advances in research include the discovery of a novel cholinergic anti-inflammatory pathway activated by acupuncture. A chemokine-mediated proliferation of opioid-containing macrophages in inflamed tissues, in response to acupuncture, has also been demonstrated for the first time. Further research on the complex cross talk between receptors during inflammation is also helping to elucidate the mediators and signalling pathways activated by acupuncture.

  14. Evidence for activation of both adrenergic and cholinergic nervous pathways by yohimbine, an alpha 2-adrenoceptor antagonist.

    Science.gov (United States)

    Bagheri, H; Chale, J J; Guyen, L N; Tran, M A; Berlan, M; Montastruc, J L

    1995-01-01

    Adrenoceptors are involved in the control of the activity of the autonomic nervous system and especially the sympathetic nervous system. Activation of alpha 2-adrenoceptors decreases sympathetic tone whereas their blockade has an opposite effect. However, previous investigations have shown that yohimbine (a potent alpha 2-adrenoceptor antagonist) increases salivary secretion through activation of cholinergic pathways. The aim of the present experiment was to investigate the involvement of both the sympathetic and the parasympathetic system in several pharmacological effects of yohimbine. For this purpose, salivary secretion and various endocrino-metabolic parameters (noradrenaline and insulin secretions, lipomobilization) were evaluated in conscious fasting dogs before and after blockade of either the sympathetic (with the beta-adrenoceptor antagonist agent nadolol) or the parasympathetic (with the anticholinergic agent atropine) systems. Yohimbine alone (0.4 mg.kg-1, i.v.) increased within 5-15 minutes, plasma noradrenaline (600%), insulin levels (300%), free-fatty acids (79%) and salivary secretion (143%). Atropine (0.2 mg.kg-1, i.v.) suppressed yohimbine-induced salivary secretion (90%) but did not significantly modify the yohimbine induced changes in noradrenaline (312%), insulin (277%) and free-fatty acids (102%) plasma levels. Administration of nadolol (1 mg.kg-1, i.v.) did not change the magnitude of the increase in both noradrenaline plasma levels (550%) and salivary secretion (300%) induced by yohimbine. However, nadolol totally blunted the increase in insulin (15%) and free-fatty acids (4%) plasma levels. These results show that yohimbine-induced increase in salivary secretion is a cholinergic effect whereas the increase in insulin and free fatty acids can be explained by an increase in sympathetic tone.(ABSTRACT TRUNCATED AT 250 WORDS)

  15. Cholinesterases: structure of the active site and mechanism of the effect of cholinergic receptor blockers on the rate of interaction with ligands

    Energy Technology Data Exchange (ETDEWEB)

    Antokhin, A M; Gainullina, E T; Taranchenko, V F [Federal State Agency ' 27 Scientific Centre of Ministry of Defence of the Russian Federation' (Russian Federation); Ryzhikov, S B; Yavaeva, D K [Department of Physics, M.V.Lomonosov Moscow State University (Russian Federation)

    2010-10-19

    Modern views on the structure of cholinesterase active sites and the mechanism of their interaction with organophosphorus inhibitors are considered. The attention is focused on the mechanism of the effect of cholinergic receptor blockers, acetylcholine antagonists, on the rate of interaction of acetylcholine esterase with organophosphorus inhibitors.

  16. Developmental profile of the aberrant dopamine D2 receptor response in striatal cholinergic interneurons in DYT1 dystonia.

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    Giuseppe Sciamanna

    Full Text Available BACKGROUND: DYT1 dystonia, a severe form of genetically determined human dystonia, exhibits reduced penetrance among carriers and begins usually during adolescence. The reasons for such age dependence and variability remain unclear. METHODS AND RESULTS: We characterized the alterations in D2 dopamine receptor (D2R signalling in striatal cholinergic interneurons at different ages in mice overexpressing human mutant torsinA (hMT. An abnormal excitatory response to the D2R agonist quinpirole was recorded at postnatal day 14, consisting of a membrane depolarization coupled to an increase in spiking frequency, and persisted unchanged at 3 and 9 months in hMT mice, compared to mice expressing wild-type human torsinA and non-transgenic mice. This response was blocked by the D2R antagonist sulpiride and depended upon G-proteins, as it was prevented by intrapipette GDP-β-S. Patch-clamp recordings from dissociated interneurons revealed a significant increase in the Cav2.2-mediated current fraction at all ages examined. Consistently, chelation of intracellular calcium abolished the paradoxical response to quinpirole. Finally, no gross morphological changes were observed during development. CONCLUSIONS: These results suggest that an imbalanced striatal dopaminergic/cholinergic signaling occurs early in DYT1 dystonia and persists along development, representing a susceptibility factor for symptom generation.

  17. Protection against ventricular fibrillation via cholinergic receptor stimulation and the generation of nitric oxide

    Science.gov (United States)

    Kalla, Manish; Chotalia, Minesh; Coughlan, Charles; Hao, Guoliang; Crabtree, Mark J.; Tomek, Jakub; Bub, Gil; Paterson, David J.

    2016-01-01

    Key points Animal studies suggest an anti‐fibrillatory action of the vagus nerve on the ventricle, although the exact mechanism is controversial.Using a Langendorff perfused rat heart, we show that the acetylcholine analogue carbamylcholine raises ventricular fibrillation threshold (VFT) and flattens the electrical restitution curve.The anti‐fibrillatory action of carbamylcholine was prevented by the nicotinic receptor antagonist mecamylamine, inhibitors of neuronal nitric oxide synthase (nNOS) and soluble guanylyl cyclase (sGC), and can be mimicked by the nitric oxide (NO) donor sodium nitroprusside.Carbamylcholine increased NO metabolite content in the coronary effluent and this was prevented by mecamylamine.The anti‐fibrillatory action of both carbamylcholine and sodium nitroprusside was ultimately dependent on muscarinic receptor stimulation as all effects were blocked by atropine.These data demonstrate a protective effect of carbamylcholine on VFT that depends upon both muscarinic and nicotinic receptor stimulation, where the generation of NO is likely to be via a neuronal nNOS–sGC dependent pathway. Abstract Implantable cardiac vagal nerve stimulators are a promising treatment for ventricular arrhythmia in patients with heart failure. Animal studies suggest the anti‐fibrillatory effect may be nitric oxide (NO) dependent, although the exact site of action is controversial. We investigated whether a stable analogue of acetylcholine could raise ventricular fibrillation threshold (VFT), and whether this was dependent on NO generation and/or muscarinic/nicotinic receptor stimulation. VFT was determined in Langendorff perfused rat hearts by burst pacing until sustained VF was induced. Carbamylcholine (CCh, 200 nmol l–1, n = 9) significantly (P < 0.05) reduced heart rate from 292 ± 8 to 224 ± 6 b.p.m. Independent of this heart rate change, CCh caused a significant increase in VFT (control 1.5 ± 0.3 mA, CCh 2.4 ± 0.4 mA, wash 1.1

  18. Pathway for interferon-gamma to promote the differentiation of cholinergic neurons in rat embryonic basal forebrain/septal nuclei

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    BACKGROUND: The supernatant of interferon-gamma (IFN γ ) co-cultured with neonatal rat cortical glia can promote the cells in embryonic basal forebrain/septal nuclei to differentiate into cholinergic neurons, but the mechanism is still unclear.OBJECTIVE: To analyze the pathways for IFN γ to promote the differentiation of primarily cultured cholinergic neurons in rat embryonic basal forebrain/septal nuclei through culture in different conditioned medium.DESIGN: A controlled experiment taking cells as the observational target.SETTINGS: Department of Biochemistry and Molecular Biology, Youjiang Medical College for Nationalities; Department of Cell Biology, Beijing University Health Science Center.MATERIALS: Sixty-four pregnant Wistar rats for 16 days (250 - 350 g) and 84 Wistar rats (either male or female, 5 - 7 g) of 0 - 1 day after birth were provided by the experimental animal department of Beijing University Health Science Center. Rat IFN γ were provided by Gibco Company; Glial fibrillary acidic protein by Huamei Company.METHODS: The experiments were carried out in the Department of Cell Biology, Beijing University Health Science Center and Daheng Image Company of Chinese Academy of Science from July 1995 to December 2002. ① Interventions: The nerve cells in the basal forebrain/septal nuclei of the pregnant Wistar rats for 16 days were primarily cultured, and then divided into four groups: Blank control group (not any supernatant and medium was added); Control group (added by mixed glial cell or astrocyte conditioned medium); IFN γ group (added by mixed glial cell or astrocyte conditioned medium+IFN γ ). Antibody group (added by mixed glial cell or astrocyte conditioned medium+IFN γ +Ab-IFN γ ). Mixed glial cell or astrocyte conditioned medium was prepared using cerebral cortex of Wistar rats of 0 - 1 day after birth. ② Evaluation: The immunohistochemical method was used to perform the choline acetyltransferase (ChAT) staining of cholinergic neurons

  19. Cholinergic dermographism.

    Science.gov (United States)

    Mayou, S C; Kobza Black, A; Eady, R A; Greaves, M W

    1986-09-01

    We report a patient with cholinergic urticaria in whom stroking the skin produced a band of erythema studded with the small weals characteristics of cholinergic urticaria. This response was suppressed by pre-treatment with topical scopolamine. Light and electron microscopy of the weal showed mast cell degranulation and a moderate mononuclear cell infiltrate.

  20. Cholinergic nicotinic receptor genes implicated in a nicotine dependence association study targeting 348 candidate genes with 3713 SNPs.

    Science.gov (United States)

    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 beta3 nicotinic receptor subunit gene (P = 9.4 x 10(-5)). Biologically, the most compelling evidence for a risk variant came from a non-synonymous SNP in the alpha5 nicotinic receptor subunit gene CHRNA5 (P = 6.4 x 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.

  1. Electroacupuncture at Zusanli Prevents Severe Scalds-Induced Gut Ischemia and Paralysis by Activating the Cholinergic Pathway

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    Huan Wang

    2015-01-01

    Full Text Available Severe burn injuries may result in gastrointestinal paralysis, and barrier dysfunction due to gut ischemia and lowered vagus excitability. In this study we investigate whether electroacupuncture (EA at Zusanli (ST36 could prevent severe scalds-induced gut ischemia, paralysis, and barrier dysfunction and whether the protective role of EA at ST36 is related to the vagus nerve. 35% burn area rats were divided into six groups: (a EAN: EA nonchannel acupoints followed by scald injury; (b EA: EA at ST36 after scald injury; (c VGX/EA: vagotomy (VGX before EA at ST36 and scald injury; (d VGX/EAN: VGX before EAN and scald injury; (e atropine/EA: applying atropine before scald injury and then EA at ST36; (f atropine/EAN: applying atropine before scald injury and then EA at nonchannel acupoints. EA at the Zusanli point significantly promoted the intestinal impelling ratio and increased the amount of mucosal blood flow after scald injury. The plasma diamine oxidase (DAO and intestinal permeability decreased significantly after scald injury in the EA group compared with others. However, EA after atropine injection or cervical vagotomy failed to improve intestinal motility and mucosa blood flow suggesting that the mechanism of EA may be related to the activation of the cholinergic nerve pathway.

  2. Fundamental study on nuclear medicine imaging of cholinergic innervation in the brain; Changes of neurotransmitter and receptor in animal model of Alzheimer's disease

    Energy Technology Data Exchange (ETDEWEB)

    Matsuda, Hiroshi; Kinuya, Keiko; Sumiya, Hisashi; Hisada, Kinichi (Kanazawa Univ. (Japan). School of Medicine); Tsuji, Shiro; Terada, Hitoshi; Shiba, Kazuhiro; Mori, Hirofumi

    1990-10-01

    A fundamental study was performed on the nuclear medicine imaging of cholinergic innervation in the brain. In a cholinergic denervation model prepared by producing an unilateral basal forebrain lesion in the rat, which is reported to be one of animal models of Alzheimer' disease, quantitative determination of acetylcholine in parietal cortices revealed statistically significant 31% decrease on an average in the ipsilateral side relative to the contralateral side to the lesion. In vitro receptor autoradiography showed no significant differences in total, M{sub 1}, and M{sub 2} muscarinic acetylcholine receptors between the ipsilateral and contralateral cortices to the lesion. Simultaneous mapping of presynaptic cholinergic innervation using {sup 3}H-2-(4-phenylpiperidino) cyclohexanol (AH5183) demonstrated significant 14% decrease of AH5183 binding on an average in the ipsilateral relative to the contralateral fronto-parieto-temporal cortices to the lesion. These results suggest that AH5183 is a promising ligand for mapping cholinergic innervation in nuclear medicine imaging. (author).

  3. Dose-dependent effect of donepezil administration on long-term enhancement of visually evoked potentials and cholinergic receptor overexpression in rat visual cortex.

    Science.gov (United States)

    Chamoun, Mira; Groleau, Marianne; Bhat, Menakshi; Vaucher, Elvire

    2016-09-01

    Stimulation of the cholinergic system tightly coupled with periods of visual stimulation boosts the processing of specific visual stimuli via muscarinic and nicotinic receptors in terms of intensity, priority and long-term effect. However, it is not known whether more diffuse pharmacological stimulation with donepezil, a cholinesterase inhibitor, is an efficient tool for enhancing visual processing and perception. The goal of the present study was to potentiate cholinergic transmission with donepezil treatment (0.5 and 1mg/kg) during a 2-week visual training to examine the effect on visually evoked potentials and to profile the expression of cholinergic receptor subtypes. The visual training was performed daily, 10min a day, for 2weeks. One week after the last training session, visual evoked potentials were recorded, or the mRNA expression level of muscarinic (M1-5) and nicotinic (α/β) receptors subunits was determined by quantitative RT-PCR. The visual stimulation coupled with any of the two doses of donepezil produced significant amplitude enhancement of cortical evoked potentials compared to pre-training values. The enhancement induced by the 1mg/kg dose of donepezil was spread to neighboring spatial frequencies, suggesting a better sensitivity near the visual detection threshold. The M3, M4, M5 and α7 receptors mRNA were upregulated in the visual cortex for the higher dose of donepezil but not the lower one, and the receptors expression was stable in the somatosensory (non-visual control) cortex. Therefore, higher levels of acetylcholine within the cortex sustain the increased intensity of the cortical response and trigger the upregulation of cholinergic receptors.

  4. Axonal transport of muscarinic cholinergic receptors in rat vagus nerve: high and low affinity agonist receptors move in opposite directions and differ in nucleotide sensitivity

    Energy Technology Data Exchange (ETDEWEB)

    Zarbin, M.A.; Wamsley, J.K.; Kuhar, M.J.

    1982-07-01

    The presence and transport of muscarinic cholinergic binding sites have been detected in the rat vagus nerve. These binding sites accumulate both proximal and distal to ligatures in a time-dependent manner. The results of double ligature and colchicine experiments are compatible with the notion that the anterogradely transported binding sites move by fast transport. Most of the sites accumulating proximal to ligatures bind the agonist carbachol with high affinity, while most of the sites accumulating distally bind carbachol with a low affinity. Also, the receptors transported in the anterograde direction are affected by a guanine nucleotide analogue (GppNHp), while those transported in the retrograde direction are less, or not, affected. The bulk of the sites along the unligated nerve trunk bind carbachol with a low affinity and are less sensitive to GppNHp modulation than the anterogradely transported sites. These results suggest that some receptors in the vagus may undergo axonal transport in association with regulatory proteins and that receptor molecules undergo changes in their binding and regulatory properties during their life cycle. These data also support the notion that the high and low affinity agonist form of the muscarinic receptor represent different modulated forms of a single receptor molecule.

  5. Astrocytes mediate in vivo cholinergic-induced synaptic plasticity.

    Directory of Open Access Journals (Sweden)

    Marta Navarrete

    2012-02-01

    Full Text Available Long-term potentiation (LTP of synaptic transmission represents the cellular basis of learning and memory. Astrocytes have been shown to regulate synaptic transmission and plasticity. However, their involvement in specific physiological processes that induce LTP in vivo remains unknown. Here we show that in vivo cholinergic activity evoked by sensory stimulation or electrical stimulation of the septal nucleus increases Ca²⁺ in hippocampal astrocytes and induces LTP of CA3-CA1 synapses, which requires cholinergic muscarinic (mAChR and metabotropic glutamate receptor (mGluR activation. Stimulation of cholinergic pathways in hippocampal slices evokes astrocyte Ca²⁺ elevations, postsynaptic depolarizations of CA1 pyramidal neurons, and LTP of transmitter release at single CA3-CA1 synapses. Like in vivo, these effects are mediated by mAChRs, and this cholinergic-induced LTP (c-LTP also involves mGluR activation. Astrocyte Ca²⁺ elevations and LTP are absent in IP₃R2 knock-out mice. Downregulating astrocyte Ca²⁺ signal by loading astrocytes with BAPTA or GDPβS also prevents LTP, which is restored by simultaneous astrocyte Ca²⁺ uncaging and postsynaptic depolarization. Therefore, cholinergic-induced LTP requires astrocyte Ca²⁺ elevations, which stimulate astrocyte glutamate release that activates mGluRs. The cholinergic-induced LTP results from the temporal coincidence of the postsynaptic activity and the astrocyte Ca²⁺ signal simultaneously evoked by cholinergic activity. Therefore, the astrocyte Ca²⁺ signal is necessary for cholinergic-induced synaptic plasticity, indicating that astrocytes are directly involved in brain storage information.

  6. A comparison of β-adrenoceptors and muscarinic cholinergic receptors in tissues of brown bullhead catfish (Ameiurus nebulosus) from the black river and old woman creek, Ohio

    Science.gov (United States)

    Steevens, Jeffery A.; Baumann, Paul C.; Jones, Susan B.

    1996-01-01

    β-Adrenoceptors (βARs) and muscarinic cholinergic receptors were measured in brain, gill, and heart tissues of brown bullhead catfish exposed to polycyclic aromatic hydrocarbons in the Black River, Ohio, USA, and were compared to values from Old Woman Creek, Ohio, a reference site. A decreased number of βARs were found in the gill from Black River fish, possibly indicating a compensatory response subsequent to chemical stress.

  7. Nematode cholinergic pharmacology

    Energy Technology Data Exchange (ETDEWEB)

    Segerberg, M.A.

    1989-01-01

    Nematode acetylcholine (ACh) receptors were characterized using both biochemical and electrophysiological techniques, including: (1) receptor binding studies in crude homogenates of the free-living nematode Caenorhabditis elegans and the parasitic nematode Ascaris lumbricoides with the high-affinity probe ({sup 3}H)N-methylscopolamine (({sup 3}H)NMS) which binds to muscarinic receptors in many vertebrate and invertebrate tissues (2) measurement of depolarization and contraction induced by a variety of cholinergic agents, including N-methylscopolamine (NMS), in an innervated dorsal muscle strip preparation of Ascaris; (3) examination of the antagonistic actions of d-tubocurarine (dTC) and NMS at dorsal neuromuscular junction; (4) measurement of input resistance changes in Ascaris commissural motorneurons induced by ACh, dTC, NMS, pilocarpine and other cholinergic drugs.

  8. TITERS OF ANTIBODIES TO Β1-ADRENOCEPTOR AND M2 CHOLINERGIC RECEPTORS IN PATIENTS WITH VENTRICULAR ARRHYTHMIAS WITHOUT AN ORGANIC CARDIOVASCULAR DISEASE AND THEIR POSSIBLE CLINICAL SIGNIFICANCE

    Directory of Open Access Journals (Sweden)

    M. M. Rogova

    2012-01-01

    Full Text Available Aim. To identify the most promising epitopes that simulate various sites β1-adrenergic and M2-cholinergic receptors, and to evaluate their possible contribution to the development and maintenance of cardiac arrhythmias, particularly idiopathic ventricular arrhythmia. Material and methods. Patients with ventricular arrhythmias without organic cardiovascular disease (the study group; n=70 were included in the study. The control group consisted of 20 healthy volunteers. Evaluation of levels of antibodies to antigenic determinants, modeling various sites β1-adrenergic and M2-cholinergic performed in all patients. Causal treatment with clarithromycin and valacyclovir performed in part of patients. Results. Antibodies to different peptide sequences of β1-adrenergic and M2-cholinergic receptors have been identified in 25% of main group patients. A direct correlation between the frequency of episodes of ventricular tachycardia and IgG levels to MRI-MRIV (p=0.02 revealed. Increase in titre of antibodies to β1-adrenoceptors, to a peptide sequence β8 (p=0.02, and lower titers of antibodies to the M2 acetylcholine receptor — chimera MRI-MRIV IgM (p=0.06 and ARI-MRIV IgM (p=0.07 were observed when assessing the efficacy of the therapy in the causal dynamics in the group of "untreated" patients. IgG titer reduction of ARI-MRIV (p=0.02, which is 4 times out of 10 with reduction of ventricular ectopic activity , recorded after valacyclovir therapy. Clarithromycin therapy on the level of antibodies exerted no significant effect. Conclusion. Possible involvement of antibodies to β1-adrenoceptor and M2-cholinergic receptors in the development of idiopathic ventricular arrhythmias demonstrated. The relationship between the frequency of episodes of ventricular tachycardia and levels of antibody titers to M2-cholinergic receptors found. Attempt of causal treatment, depending on the possible mechanisms of the autoimmune process is executed. Further studies to

  9. Involvement of Cholinergic and Adrenergic Receptors in Pathogenesis and Inflammatory Response Induced by Alpha-Neurotoxin Bot III of Scorpion Venom.

    Science.gov (United States)

    Nakib, Imene; Martin-Eauclaire, Marie-France; Laraba-Djebari, Fatima

    2016-10-01

    Bot III neurotoxin is the most lethal α neurotoxin purified from Buthus occitanus tunetanus scorpion venom. This toxin binds to the voltage-gated sodium channel of excitable cells and blocks its inactivation, inducing an increased release of neurotransmitters (acetylcholine and catecholamines). This study aims to elucidate the involvement of cholinergic and adrenergic receptors in pathogenesis and inflammatory response triggered by this toxin. Injection of Bot III to animals induces an increase of peroxidase activities, an imbalance of oxidative status, tissue damages in lung parenchyma, and myocardium correlated with metabolic disorders. The pretreatment with nicotine (nicotinic receptor agonist) or atropine (muscarinic receptor antagonist) protected the animals from almost all disorders caused by Bot III toxin, especially the immunological alterations. Bisoprolol administration (selective β1 adrenergic receptor antagonist) was also efficient in the protection of animals, mainly on tissue damage. Propranolol (non-selective adrenergic receptor antagonist) showed less effect. These results suggest that both cholinergic and adrenergic receptors are activated in the cardiopulmonary manifestations induced by Bot III. Indeed, the muscarinic receptor appears to be more involved than the nicotinic one, and the β1 adrenergic receptor seems to dominate the β2 receptor. These results showed also that the activation of nicotinic receptor leads to a significant protection of animals against Bot III toxin effect. These findings supply a supplementary data leading to better understanding of the mechanism triggered by scorpionic neurotoxins and suggest the use of drugs targeting these receptors, especially the nicotinic one in order to counteract the inflammatory response observed in scorpion envenomation.

  10. Learning to Ignore: A Modeling Study of a Decremental Cholinergic Pathway and Its Influence on Attention and Learning

    Science.gov (United States)

    Oros, Nicolas; Chiba, Andrea A.; Nitz, Douglas A.; Krichmar, Jeffrey L.

    2014-01-01

    Learning to ignore irrelevant stimuli is essential to achieving efficient and fluid attention, and serves as the complement to increasing attention to relevant stimuli. The different cholinergic (ACh) subsystems within the basal forebrain regulate attention in distinct but complementary ways. ACh projections from the substantia innominata/nucleus…

  11. Distinct synaptic properties of perisomatic inhibitory cell types and their different modulation by cholinergic receptor activation in the CA3 region of the mouse hippocampus.

    Science.gov (United States)

    Szabó, Gergely G; Holderith, Noémi; Gulyás, Attila I; Freund, Tamás F; Hájos, Norbert

    2010-06-01

    Perisomatic inhibition originates from three types of GABAergic interneurons in cortical structures, including parvalbumin-containing fast-spiking basket cells (FSBCs) and axo-axonic cells (AACs), as well as cholecystokinin-expressing regular-spiking basket cells (RSBCs). These interneurons may have significant impact in various cognitive processes, and are subjects of cholinergic modulation. However, it is largely unknown how cholinergic receptor activation modulates the function of perisomatic inhibitory cells. Therefore, we performed paired recordings from anatomically identified perisomatic interneurons and pyramidal cells in the CA3 region of the mouse hippocampus. We determined the basic properties of unitary inhibitory postsynaptic currents (uIPSCs) and found that they differed among cell types, e.g. GABA released from axon endings of AACs evoked uIPSCs with the largest amplitude and with the longest decay measured at room temperature. RSBCs could also release GABA asynchronously, the magnitude of the release increasing with the discharge frequency of the presynaptic interneuron. Cholinergic receptor activation by carbachol significantly decreased the uIPSC amplitude in all three types of cell pairs, but to different extents. M2-type muscarinic receptors were responsible for the reduction in uIPSC amplitudes in FSBC- and AAC-pyramidal cell pairs, while an antagonist of CB(1) cannabinoid receptors recovered the suppression in RSBC-pyramidal cell pairs. In addition, carbachol suppressed or even eliminated the short-term depression of uIPSCs in FSBC- and AAC-pyramidal cell pairs in a frequency-dependent manner. These findings suggest that not only are the basic synaptic properties of perisomatic inhibitory cells distinct, but acetylcholine can differentially control the impact of perisomatic inhibition from different sources.

  12. Hook-up of GluA2, GRIP and liprin-α for cholinergic muscarinic receptor-dependent LTD in the hippocampus

    Directory of Open Access Journals (Sweden)

    Wu Long-Jun

    2009-06-01

    Full Text Available Abstract The molecular mechanism underlying muscarinic acetylcholine receptor-dependent LTD (mAChR-LTD in the hippocampus is less studied. In a recent study, a novel mechanism is described. The induction of mAChR-LTD required the activation of protein tyrosine phosphatase (PTP, and the expression was mediated by AMPA receptor endocytosis via interactions between GluA2, GRIP and liprin-α. The hook-up of these proteins may result in the recruitment of leukocyte common antigen-related receptor (LAR, a PTP that is known to be involved in AMPA receptor trafficking. Interestingly, the similar molecular interaction cannot be applied to mGluR-LTD, despite the fact that the same G-protein involved in LTD is activated by both mAChR and mGluR. This discovery provides key molecular insights for cholinergic dependent cognitive function, and mAChR-LTD can serve as a useful cellular model for studying the roles of cholinergic mechanism in learning and memory.

  13. Impairment of the nerve growth factor pathway driving amyloid accumulation in cholinergic neurons:the incipit of the Alzheimer’s disease story?

    Institute of Scientific and Technical Information of China (English)

    Viviana Triaca; Pietro Calissano

    2016-01-01

    The current idea behind brain pathology is that disease is initiated by mild disturbances of common physiological processes. Overtime, the disruption of the neuronal homeostasis will determine irreversible degeneration and neuronal apoptosis. hTis could be also true in the case of nerve growth factor (NGF) al-terations in sporadic Alzheimer’s disease (AD), an age-related pathology characterized by cholinergic loss, amyloid plaques and neurofibrillary tangles. In fact, the pathway activated by NGF, a key neurotrophin for the metabolism of basal forebrain cholinergic neurons (BFCN), is one of the ifrst homeostatic systems affected in prodromal AD. NGF signaling dysfunctions have been thought for decades to occur in AD late stages, as a mere consequence of amyloid-driven disruption of the retrograde axonal transport of neuro-trophins to BFCN. Nowadays, a wealth of knowledge is potentially opening a new scenario: NGF signaling impairment occurs at the onset of AD and correlates better than amyloid load with cognitive decline. hTe recent acceleration in the characterization of anatomical, functional and molecular proifles of early AD is aimed at maximizing the efficacy of existing treatments and setting novel therapies. Accordingly, the elucidation of the molecular events underlying APP metabolism regulation by the NGF pathway in the sep-to-hippocampal system is crucial for the identiifcation of new target molecules to slow and eventually halt mild cognitive impairment (MCI) and its progression toward AD.

  14. Impairment of the nerve growth factor pathway driving amyloid accumulation in cholinergic neurons: the incipit of the Alzheimer′s disease story?

    Directory of Open Access Journals (Sweden)

    Viviana Triaca

    2016-01-01

    Full Text Available The current idea behind brain pathology is that disease is initiated by mild disturbances of common physiological processes. Overtime, the disruption of the neuronal homeostasis will determine irreversible degeneration and neuronal apoptosis. This could be also true in the case of nerve growth factor (NGF alterations in sporadic Alzheimer′s disease (AD, an age-related pathology characterized by cholinergic loss, amyloid plaques and neurofibrillary tangles. In fact, the pathway activated by NGF, a key neurotrophin for the metabolism of basal forebrain cholinergic neurons (BFCN, is one of the first homeostatic systems affected in prodromal AD. NGF signaling dysfunctions have been thought for decades to occur in AD late stages, as a mere consequence of amyloid-driven disruption of the retrograde axonal transport of neurotrophins to BFCN. Nowadays, a wealth of knowledge is potentially opening a new scenario: NGF signaling impairment occurs at the onset of AD and correlates better than amyloid load with cognitive decline. The recent acceleration in the characterization of anatomical, functional and molecular profiles of early AD is aimed at maximizing the efficacy of existing treatments and setting novel therapies. Accordingly, the elucidation of the molecular events underlying APP metabolism regulation by the NGF pathway in the septo-hippocampal system is crucial for the identification of new target molecules to slow and eventually halt mild cognitive impairment (MCI and its progression toward AD.

  15. Cerebellar Nicotinic Cholinergic Receptors are Intrinsic to the Cerebellum: Implications for Diverse Functional Roles

    Science.gov (United States)

    Turner, Jill R.; Ortinski, Pavel I.; Sherrard, Rachel M.

    2016-01-01

    Although recent studies have delineated the specific nicotinic subtypes present in the mammalian cerebellum, very little is known about their location or function within the cerebellum. This is of increased interest since nicotinic receptors (nAChRs) in the cerebellum have recently been implicated in the pathology of autism spectrum disorders. To begin to better understand the roles of these heteromeric nAChRs in the cerebellar circuitry and their therapeutic potential as targets for drug development, we used various chemical and stereotaxic lesion models in conjunction with slice electrophysiology to examine how specific heteromeric nAChR subtypes may influence the surrounding cerebellar circuitry. Using subunit-specific immunoprecipitation of radiolabeled nAChRs in the cerebella following N-(2-chloroethyl)-N-ethyl-2-bromobenzylamine hydrochloride, p-chloroamphetamine, and pendunculotomy lesions, we show that most, if not all, cerebellar nicotinic receptors are present in cells within the cerebellum itself and not in extracerebellar afferents. Furthermore, we demonstrate that the β4-containing, but not the β2-containing, nAChRs intrinsic to the cerebellum can regulate inhibitory synaptic efficacy at two major classes of cerebellar neurons. These tandem findings suggest that nAChRs may present a potential drug target for disorders involving the cerebellum. PMID:21562921

  16. Low-Affinity Neurotrophin Receptor p75 Promotes the Transduction of Targeted Lentiviral Vectors to Cholinergic Neurons of Rat Basal Forebrain.

    Science.gov (United States)

    Antyborzec, Inga; O'Leary, Valerie B; Dolly, James O; Ovsepian, Saak V

    2016-10-01

    Basal forebrain cholinergic neurons (BFCNs) are one of the most affected neuronal types in Alzheimer's disease (AD), with their extensive loss documented at late stages of the pathology. While discriminatory provision of neuroprotective agents and trophic factors to these cells is thought to be of substantial therapeutic potential, the intricate topography and structure of the forebrain cholinergic system imposes a major challenge. To overcome this, we took advantage of the physiological enrichment of BFCNs with a low-affinity p75 neurotrophin receptor (p75(NTR)) for their targeting by lentiviral vectors within the intact brain of adult rat. Herein, a method is described that affords selective and effective transduction of BFCNs with a green fluorescence protein (GFP) reporter, which combines streptavidin-biotin technology with anti-p75(NTR) antibody-coated lentiviral vectors. Specific GFP expression in cholinergic neurons was attained in the medial septum and nuclei of the diagonal band Broca after a single intraventricular administration of such targeted vectors. Bioelectrical activity of GFP-labeled neurons was proven to be unchanged. Thus, proof of principle is obtained for the utility of the low-affinity p75(NTR) for targeted transduction of vectors to BFCNs in vivo.

  17. Muscarinic cholinergic receptors modulate inhibitory synaptic rhythms in hippocampus and neocortex

    Directory of Open Access Journals (Sweden)

    Bradley E Alger

    2014-09-01

    Full Text Available Activation of muscarinic acetylcholine (ACh receptors (mAChRs powerfully affects many neuronal properties as well as numerous cognitive behaviors. Small neuronal circuits constitute an intermediate level of organization between neurons and behaviors, and mAChRs affect interactions among cells that compose these circuits. Circuit activity is often assessed by extracellular recordings of the local field potentials (LFPs, which are analogous to in vivo EEGs, generated by coordinated neuronal interactions. Coherent forms of physiologically relevant circuit activity manifest themselves as rhythmic oscillations in the LFPs. Frequencies of rhythmic oscillations that are most closely associated with animal behavior are in the range of 4-80 Hz, which is subdivided into theta (4-14 Hz, beta (15-29 Hz and gamma (30-80 Hz bands. Activation of mAChRs triggers rhythmic oscillations in these bands in the hippocampus and neocortex. Inhibitory responses mediated by GABAergic interneurons constitute a prominent feature of these oscillations, and indeed, appear to be their major underlying factor in many cases. An important issue is which interneurons are involved in rhythm generation. Besides affecting cellular and network properties directly, mAChRs can cause the mobilization of endogenous cannabinoids (endocannabinoids, eCBs that, by acting on the principal cannabinoid receptor of the brain, CB1R, regulate the release of certain neurotransmitters, including GABA. CB1Rs are heavily expressed on only a subset of interneurons and, at lower density, on glutamatergic neurons. Exogenous cannabinoids typically disrupt oscillations in the θ and Υ ranges, which probably contributes to the behavioral effects of these drugs. It is important to understand how neuronal circuit activity is affected by mAChR-driven eCBs, as this information will provide deeper insight into circuit behavior as the effects both eCBs and exogenous cannabinoids in intacts behavior. After

  18. Luteolin enhances cholinergic activities in PC12 cells through ERK1/2 and PI3K/Akt pathways.

    Science.gov (United States)

    El Omri, Abdelfatteh; Han, Junkyu; Kawada, Kiyokazu; Ben Abdrabbah, Manef; Isoda, Hiroko

    2012-02-09

    Luteolin, a 3', 4', 5, 7-tetrahydroxyflavone, is an active compound in Rosmarinus officinalis (Lamiacea), and has been reported to exert several benefits in neuronal cells. However cholinergic-induced activities of luteolin still remain unknown. Neuronal differentiation encompasses an elaborate developmental program which plays a key role in the development of the nervous system. The advent of several cell lines, like PC12 cells, able to differentiate in culture proved to be the turning point for gaining and understanding of molecular neuroscience. In this work, we investigated the ability of luteolin to induce PC12 cell differentiation and its effect on cholinergic activities. Our findings showed that luteolin treatment significantly induced neurite outgrowth extension, enhanced acetylcholinesterase (AChE) activity, known as neuronal differentiation marker, and increased the level of total choline and acetylcholine in PC12 cells. In addition, luteolin persistently, activated extracellular signal-regulated kinase 1/2 (ERK1/2) and Akt; while the addition of pharmacological MEK/ERK1/2 inhibitor (U0126) and PI3k/Akt inhibitor (LY294002) attenuated luteolin-induced AChE activity and neurite outgrowth in PC12 cells. The above findings suggest that luteolin induces neurite outgrowth and enhanced cholinergic activities, at least in part, through the activation of ERK1/2 and Akt signaling.

  19. Activation of nicotinic cholinergic receptors prevents ventilator-induced lung injury in rats.

    Directory of Open Access Journals (Sweden)

    Fabienne Brégeon

    Full Text Available Respiratory distress syndrome is responsible for 40 to 60 percent mortality. An over mortality of about 10 percent could result from additional lung injury and inflammation due to the life-support mechanical ventilation, which stretches the lung. It has been recently demonstrated, in vitro, that pharmacological activation of the alpha 7 nicotinic receptors (α7-nAChR could down regulate intracellular mediators involved in lung cell inflammatory response to stretch. Our aim was to test in vivo the protective effect of the pharmacological activation of the α7-nAChR against ventilator-induced lung injury (VILI. Anesthetized rats were ventilated for two hours with a high stretch ventilation mode delivering a stroke volume large enough to generate 25-cmH(2O airway pressure, and randomly assigned to four groups: pretreated with parenteral injection of saline or specific agonist of the α7-nAChR (PNU-282987, or submitted to bilateral vagus nerve electrostimulation while pre-treated or not with the α7-nAChR antagonist methyllycaconitine (MLA. Controls ventilated with a conventional stroke volume of 10 mL/kg gave reference data. Physiological indices (compliance of the respiratory system, lung weight, blood oxygenation, arterial blood pressure and lung contents of inflammatory mediators (IL-6 measured by ELISA, substance P assessed using HPLC were severely impaired after two hours of high stretch ventilation (sham group. Vagal stimulation was able to maintain the respiratory parameters close to those obtained in Controls and reduced lung inflammation except when associated to nicotinic receptor blockade (MLA, suggesting the involvement of α7-nAChR in vagally-mediated protection against VILI. Pharmacological pre-treatment with PNU-282987 strongly decreased lung injury and lung IL-6 and substance P contents, and nearly abolished the increase in plasmatic IL-6 levels. Pathological examination of the lungs confirmed the physiological differences observed

  20. Hippocampal α7-nicotinic cholinergic receptors modulate memory reconsolidation: a potential strategy for recovery from amnesia.

    Science.gov (United States)

    Blake, M G; Boccia, M M; Krawczyk, M C; Baratti, C M

    2013-11-01

    When subjects are exposed to new learning experiences, the novel information could be acquired and eventually stored through memory consolidation process. The exposure of mice to a novel experience (a hole-board) after being trained in an inhibitory avoidance apparatus is followed by impaired performance of the avoidance memory in subsequent tests. The same impairing effect is produced when mice are exposed to the novel environment after the reactivation of the avoidance memory. This interfering effect is due to impaired consolidation or reconsolidation of the avoidance memory. The administration of the α7-nicotinic receptor agonist choline (Ch) in the dorsal hippocampus (0.8 μg/hippocampus) immediately after the inhibitory avoidance memory reactivation, allowed memory recovery. This effect of Ch was time-dependent, and retention performance was not affected in drug-treated mice that were not subjected to memory reactivation, suggesting that the effects on performance are not due to non-specific effects of the drug. The effects of Ch also depended on the age of the reactivated memory. Altogether, our results suggest that Ch exerts its effects by modulating memory reconsolidation, and that the memory impairment induced by new learning is a memory expression failure and not a storage deficit. Therefore, reconsolidation, among other functions, might serve to change whether a memory will be expressed in later tests. Summarizing, our results open new avenues about the behavioral significance and the physiological functions of memory reconsolidation, providing new strategies for recovering memories from some types of amnesia.

  1. Blockade of GABA, type A, receptors in the rat pontine reticular formation induces rapid eye movement sleep that is dependent upon the cholinergic system.

    Science.gov (United States)

    Marks, G A; Sachs, O W; Birabil, C G

    2008-09-22

    The brainstem reticular formation is an area important to the control of rapid eye movement (REM) sleep. The antagonist of GABA-type A (GABA(A)) receptors, bicuculline methiodide (BMI), injected into the rat nucleus pontis oralis (PnO) of the reticular formation resulted in a long-lasting increase in REM sleep. Thus, one factor controlling REM sleep appears to be the number of functional GABA(A) receptors in the PnO. The long-lasting effect produced by BMI may result from secondary influences on other neurotransmitter systems known to have long-lasting effects. To study this question, rats were surgically prepared for chronic sleep recording and additionally implanted with guide cannulas aimed at sites in the PnO. Multiple, 60 nl, unilateral injections were made either singly or in combination. GABA(A) receptor antagonists, BMI and gabazine (GBZ), produced dose-dependent increases in REM sleep with GBZ being approximately 35 times more potent than BMI. GBZ and the cholinergic agonist, carbachol, produced very similar results, both increasing REM sleep for about 8 h, mainly through increased period frequency, with little reduction in REM latency. Pre-injection of the muscarinic antagonist, atropine, completely blocked the REM sleep-increase by GBZ. GABAergic control of REM sleep in the PnO requires the cholinergic system and may be acting through presynaptic modulation of acetylcholine release.

  2. Cholinergic receptor blockade by scopolamine and mecamylamine exacerbates global cerebral ischemia induced memory dysfunction in C57BL/6J mice.

    Science.gov (United States)

    Ray, R S; Rai, S; Katyal, A

    2014-12-01

    Global cerebral ischemia/reperfusion (GCI/R) injury encompasses complex pathophysiological sequalae, inducing loss of hippocampal neurons and behavioural deficits. Progressive neuronal death and memory dysfunctions culminate from several different mechanisms like oxidative stress, excitotoxicity, neuroinflammation and cholinergic hypofunction. Experimental evidences point to the beneficial effects of cholinomimetic agents such as rivastigmine and galantamine in improving memory outcomes following GCI/R injury. However, the direct implications of muscarinic and nicotinic receptor blockade during global cerebral ischemia/reperfusion injury have not been investigated. Therefore, we evaluated the relative involvement of muscarinic and nicotinic receptors in spatial/associative memory functions and neuronal damage during global cerebral ischemia reperfusion injury. The outcomes of present study support the idea that preservation of both muscarinic and nicotinic receptor functions is essential to alleviate hippocampal neuronal death in CA1 region following global cerebral ischemia/reperfusion injury.

  3. Research progress of muscarinic cholinergic receptors in tumors%毒蕈碱胆碱受体与肿瘤关系的研究进展

    Institute of Scientific and Technical Information of China (English)

    何花; 张淑香

    2015-01-01

    非神经元性胆碱能信号通路与肿瘤关系密切,许多肿瘤细胞表达胆碱能自分泌环。肿瘤细胞自分泌及旁分泌乙酰胆碱,作用于自身或邻近细胞的烟碱胆碱受体及毒蕈碱胆碱受体,调节肿瘤细胞的增殖、血管发生及凋亡。毒蕈碱胆碱受体是 G 蛋白耦联受体,主要有 M1R-M5R 共5个亚型。研究发现毒蕈碱胆碱受体在肺癌、结肠癌、黑色素瘤、乳腺癌、卵巢癌、前列腺癌、胃癌和脑星形细胞瘤等多种恶性肿瘤中均有表达,与肿瘤细胞的增殖、迁移、血管发生、凋亡有密切关系,其中尤以毒蕈碱胆碱受体3最为重要,这为肿瘤的治疗提供了一个新的研究方向。%Non-neuronal cholinergic system is closely related with tumor.Many tumor cells express a cholinergic autocrine loop.Acetylcholine secreted by the tumor or neighboring cells interacts with nicotinic cholinergic receptors and muscarinic cholinergic receptors (MRs)expressed on the tumor cells to stimulate tumor cells proliferation,angiogenesis,and apoptosis.MRs are G-protein-coupled receptors and five subtypes have been identified.Researches have found that MRs are expressed in a variety of tumors, such as lung cancer,colon cancer,melanoma,breast cancer,ovarian cancer,prostate cancer,gastric cancer, and brain cancer.M3R is the most important one.This may provide a new direction for the treatment of cancer.

  4. The cholinergic system, circadian rhythmicity, and time memory

    NARCIS (Netherlands)

    Hut, R. A.; Van der Zee, E. A.

    2011-01-01

    This review provides an overview of the interaction between the mammalian cholinergic system and circadian system, and its possible role in time memory. Several studies made clear that circadian (daily) fluctuations in acetylcholine (ACh) release, cholinergic enzyme activity and cholinergic receptor

  5. The selective 5-HT6 receptor antagonist Ro4368554 restores memory performance in cholinergic and serotonergic models of memory deficiency in the rat.

    Science.gov (United States)

    Lieben, Cindy K J; Blokland, Arjan; Sik, Ayhan; Sung, Eric; van Nieuwenhuizen, Petra; Schreiber, Rudy

    2005-12-01

    Antagonists at serotonin type 6 (5-HT(6)) receptors show activity in models of learning and memory. Although the underlying mechanism(s) are not well understood, these effects may involve an increase in acetylcholine (ACh) levels. The present study sought to characterize the cognitive-enhancing effects of the 5-HT(6) antagonist Ro4368554 (3-benzenesulfonyl-7-(4-methyl-piperazin-1-yl)1H-indole) in a rat object recognition task employing a cholinergic (scopolamine pretreatment) and a serotonergic- (tryptophan (TRP) depletion) deficient model, and compared its pattern of action with that of the acetylcholinesterase inhibitor metrifonate. Initial testing in a time-dependent forgetting task employing a 24-h delay between training and testing showed that metrifonate improved object recognition (at 10 and 30 mg/kg, p.o.), whereas Ro4368554 was inactive. Both, Ro4368554 (3 and 10 mg/kg, intraperitoneally (i.p.)) and metrifonate (10 mg/kg, p.o., respectively) reversed memory deficits induced by scopolamine and TRP depletion (10 mg/kg, i.p., and 3 mg/kg, p.o., respectively). In conclusion, although Ro4368554 did not improve a time-related retention deficit, it reversed a cholinergic and a serotonergic memory deficit, suggesting that both mechanisms may be involved in the facilitation of object memory by Ro4368554 and, possibly, other 5-HT(6) receptor antagonists.

  6. The long-term effects of neonatal morphine administration on the pentylenetetrazol seizure model in rats: the role of hippocampal cholinergic receptors in adulthood.

    Science.gov (United States)

    Saboory, Ehsan; Gholami, Morteza; Zare, Samad; Roshan-Milani, Shiva

    2014-04-01

    Early life exposure to opiates may affect neuropathological conditions, such as epilepsy, during adulthood. We investigated whether neonatal morphine exposure affects pentylenetetrazol (PTZ)-induced seizures in adulthood. Male rats were subcutaneously injected with morphine or saline on postnatal days 8-14. During adulthood, each rat was assigned to 1 of the following 10 sub-groups: saline, nicotine (0.1, 0.5, or 1 μg), atropine (0.25 or 1 μg), oxotremorine M (0.1 or 1 μg), or mecamylamine (2 or 8 μg). An intrahippocampal infusion of the indicated compound was administered 30 min before seizure induction (80 mg/kg PTZ). Compared with the saline/oxotremorine (1 μg), saline/saline, and morphine/saline groups, the morphine/oxotremorine (1 μg) group showed a significantly increased latency to the first epileptic behavior. The duration of tonic-clonic seizures was significantly lower in the morphine/oxotremorine (1 μg) group compared to the saline/saline and morphine/saline groups. The severity of seizure was significantly decreased in the morphine/atropine (1 μg) group than in the saline/atropine (1 μg). Seizure severity was also decreased in the morphine/mecamylamine (2 μg) group than in the saline/mecamylamine (2 μg) group. Latency for death was significantly lower in the morphine/mecamylamine (2 μg) group compared with the saline/mecamylamine (2 μg) group. Mortality rates in the morphine/atropine (1 μg) and morphine/mecamylamine (2 μg) groups were significantly lower than those in the saline/atropine (1 μg) and saline/mecamylamine (2 μg) groups, respectively. Chronic neonatal morphine administration attenuated PTZ-induced seizures, reduced the mortality rate, and decreased the impact of the hippocampal cholinergic system on seizures and mortality rate in adult rats. Neonatal morphine exposure induces changes to μ-receptors that may lead to activation of GABAergic neurons in the hippocampus. This pathway may explain the anti-convulsant effects of

  7. The involvement of ventral tegmental area cholinergic muscarinic receptors in classically conditioned fear expression as measured with fear-potentiated startle.

    Science.gov (United States)

    Greba, Q; Munro, L J; Kokkinidis, L

    2000-07-01

    Accumulating evidence suggests that dopamine (DA) neurons in the ventral tegmental area (VTA) contribute to the complex amygdala-based neurocircuitry that mediates fear-motivated behaviors. Because of acetylcholine's (ACh) role in DA neuronal activation, the involvement of VTA cholinergic muscarinic receptors in Pavlovian conditioned fear responding was evaluated in the present study. Fear-potentiated startle was used to assess the effects of intraVTA infused methylscopolamine on conditioned fear performance in laboratory rats. Application of this nonspecific muscarinic receptor antagonist to VTA neurons was observed to inhibit the ability of a conditioned stimulus (CS) previously paired with footshock to enhance the amplitude of the acoustic startle reflex. Doses of methylscopolamine that blocked conditioned fear expression did not alter baseline sensorimotor responding. These results identify ACh neurotransmission in the VTA as a potential excitatory mechanism underlying the fear-arousing properties of threatening environmental stimuli.

  8. Modulatory compartments in cortex and local regulation of cholinergic tone.

    Science.gov (United States)

    Coppola, Jennifer J; Ward, Nicholas J; Jadi, Monika P; Disney, Anita A

    2016-09-01

    Neuromodulatory signaling is generally considered broad in its impact across cortex. However, variations in the characteristics of cortical circuits may introduce regionally-specific responses to diffuse modulatory signals. Features such as patterns of axonal innervation, tissue tortuosity and molecular diffusion, effectiveness of degradation pathways, subcellular receptor localization, and patterns of receptor expression can lead to local modification of modulatory inputs. We propose that modulatory compartments exist in cortex and can be defined by variation in structural features of local circuits. Further, we argue that these compartments are responsible for local regulation of neuromodulatory tone. For the cholinergic system, these modulatory compartments are regions of cortical tissue within which signaling conditions for acetylcholine are relatively uniform, but between which signaling can vary profoundly. In the visual system, evidence for the existence of compartments indicates that cholinergic modulation likely differs across the visual pathway. We argue that the existence of these compartments calls for thinking about cholinergic modulation in terms of finer-grained control of local cortical circuits than is implied by the traditional view of this system as a diffuse modulator. Further, an understanding of modulatory compartments provides an opportunity to better understand and perhaps correct signal modifications that lead to pathological states.

  9. Muscarinic and nicotinic cholinergic receptor antagonists differentially mediate acquisition of fructose-conditioned flavor preference and quinine-conditioned flavor avoidance in rats.

    Science.gov (United States)

    Rotella, Francis M; Olsson, Kerstin; Vig, Vishal; Yenko, Ira; Pagirsky, Jeremy; Kohen, Ilanna; Aminov, Alon; Dindyal, Trisha; Bodnar, Richard J

    2015-09-01

    Rats display both conditioned flavor preference (CFP) for fructose, and conditioned flavor avoidance (CFA) following sweet adulteration with quinine. Previous pharmacological analyses revealed that fructose-CFP expression was significantly reduced by dopamine (DA) D1 or D2 antagonists, but not NMDA or opioid antagonists. Fructose-CFP acquisition was significantly reduced by DA D1, DA D2 or NMDA antagonists, but not opioid antagonists. Quinine-CFA acquisition was significantly enhanced and prolonged by DA D1, NMDA or opioid, but not DA D2 antagonists. Cholinergic interneurons and projections interact with DA systems in the nucleus accumbens and ventral tegmental area. Further, both muscarinic and nicotinic cholinergic receptor signaling have been implicated in sweet intake and development of food-related preferences. Therefore, the present study examined whether systemic administration of muscarinic (scopolamine: SCOP) or nicotinic (mecamylamine: MEC) cholinergic receptor antagonists mediated fructose-CFP expression, fructose-CFP acquisition and quinine-CFA acquisition. For fructose-CFP expression, rats were trained over 10 sessions with a CS+ flavor in 8% fructose and 0.2% saccharin and a CS- flavor in 0.2% saccharin. Two-bottle choice tests with CS+ and CS- flavors mixed in 0.2% saccharin occurred following vehicle, SCOP (0.1-10mg/kg) and MEC (1-8mg/kg). For fructose-CFP acquisition, six groups of rats received vehicle, SCOP (1 or 2.5mg/kg), MEC (4 or 6mg/kg) or a limited intake vehicle control 0.5h prior to 10 CS+ and CS- training sessions followed by six 2-bottle CS+ and CS- choice tests in 0.2% saccharin. For quinine-CFA acquisition, five groups of rats received vehicle, SCOP (1 or 2.5mg/kg) or MEC (4 or 6mg/kg) 0.5h prior to 8 one-bottle CS- (8% fructose+0.2% saccharin: FS) and CS+ (fructose+saccharin+quinine (0.030%: FSQ) training sessions followed by six 2-bottle CS- and CS+ choice tests in fructose-saccharin solutions. Fructose-CFP expression was

  10. Mechanisms mediating cholinergic antral circular smooth muscle contraction in rats

    Institute of Scientific and Technical Information of China (English)

    Helena F Wrzos; Tarun Tandon; Ann Ouyang

    2004-01-01

    AIM: To investigate the pathway (s) mediating rat antral circular smooth muscle contractile responses to the cholinomimetic agent, bethanechol and the subtypes of muscarinic receptors mediating the cholinergic contraction.METHODS: Circular smooth muscle strips from the antrum of Sprague-Dawley rats were mounted in muscle baths in Krebs buffer. Isometric tension was recorded. Cumulative concentration-response curves were obtained for (+)-cisdioxolane (cD), a nonspecific muscarinic agonist, at 10-8-10-4 mol/L, in the presence of tetrodotoxin (TTX, 10-7 mol/L).Results were normalized to cross sectional area. A repeat concentration-response curve was obtained after incubation of the muscle for 90 min with antagonists for M1 (pirenzepine),M2 (methoctramine) and M3 (darifenacin) muscarinic receptor subtypes. The sensitivity to PTX was tested by the ip injection of 100 mg/kg of PTX 5 d before the experiment. The antral circular smooth muscles were removed from PTX-treated and non-treated rats as strips and dispersed smooth muscle cells to identify whether PTX-linked pathway mediated the contractility to bethanechol.RESULTS: A dose-dependent contractile response observed with bethanechol, was not affected by TTX. The pretreatment of rats with pertussis toxin decreased the contraction induced by bethanechol. Lack of calcium as Well as the presence of the L-type calcium channel blocker, nifedipine, also inhibited the cholinergic contraction, with a reduction in response from 2.5±0.4 g/mm2 to 1.2±0.4 g/mm2 (P<0.05). The doseresponse curves were shifted to the right by muscarinic antagonists in the following order of affinity: darifenacin(M3)>methocramine (M2)>pirenzepine (M1).CONCLUSION: The muscarinic receptors-dependent contraction of rat antral circular smooth muscles was linked to the signal transduction pathway(s) involving pertussis-toxin sensitive GTP-binding proteins and to extracellular calcium via L-type voltage gated calcium channels. The presence of the

  11. Histaminergic modulation of cholinergic release from the nucleus basalis magnocellularis into insular cortex during taste aversive memory formation.

    Directory of Open Access Journals (Sweden)

    Liliana Purón-Sierra

    Full Text Available The ability of acetylcholine (ACh to alter specific functional properties of the cortex endows the cholinergic system with an important modulatory role in memory formation. For example, an increase in ACh release occurs during novel stimulus processing, indicating that ACh activity is critical during early stages of memory processing. During novel taste presentation, there is an increase in ACh release in the insular cortex (IC, a major structure for taste memory recognition. There is extensive evidence implicating the cholinergic efferents of the nucleus basalis magnocellularis (NBM in cortical activity changes during learning processes, and new evidence suggests that the histaminergic system may interact with the cholinergic system in important ways. However, there is little information as to whether changes in cholinergic activity in the IC are modulated during taste memory formation. Therefore, in the present study, we evaluated the influence of two histamine receptor subtypes, H1 in the NBM and H3 in the IC, on ACh release in the IC during conditioned taste aversion (CTA. Injection of the H3 receptor agonist R-α-methylhistamine (RAMH into the IC or of the H1 receptor antagonist pyrilamine into the NBM during CTA training impaired subsequent CTA memory, and simultaneously resulted in a reduction of ACh release in the IC. This study demonstrated that basal and cortical cholinergic pathways are finely tuned by histaminergic activity during CTA, since dual actions of histamine receptor subtypes on ACh modulation release each have a significant impact during taste memory formation.

  12. Neuropeptide receptor transcriptome reveals unidentified neuroendocrine pathways.

    Directory of Open Access Journals (Sweden)

    Naoki Yamanaka

    Full Text Available Neuropeptides are an important class of molecules involved in diverse aspects of metazoan development and homeostasis. Insects are ideal model systems to investigate neuropeptide functions, and the major focus of insect neuropeptide research in the last decade has been on the identification of their receptors. Despite these vigorous efforts, receptors for some key neuropeptides in insect development such as prothoracicotropic hormone, eclosion hormone and allatotropin (AT, remain undefined. In this paper, we report the comprehensive cloning of neuropeptide G protein-coupled receptors from the silkworm, Bombyx mori, and systematic analyses of their expression. Based on the expression patterns of orphan receptors, we identified the long-sought receptor for AT, which is thought to stimulate juvenile hormone biosynthesis in the corpora allata (CA. Surprisingly, however, the AT receptor was not highly expressed in the CA, but instead was predominantly transcribed in the corpora cardiaca (CC, an organ adjacent to the CA. Indeed, by using a reverse-physiological approach, we purified and characterized novel allatoregulatory peptides produced in AT receptor-expressing CC cells, which may indirectly mediate AT activity on the CA. All of the above findings confirm the effectiveness of a systematic analysis of the receptor transcriptome, not only in characterizing orphan receptors, but also in identifying novel players and hidden mechanisms in important biological processes. This work illustrates how using a combinatorial approach employing bioinformatic, molecular, biochemical and physiological methods can help solve recalcitrant problems in neuropeptide research.

  13. Activation of Muscarinic Acetylcholine Receptor Subtype 4 is Essential for Cholinergic Stimulation of Gastric Acid Secretion - Relation To D Cell/Somatostatin -

    Directory of Open Access Journals (Sweden)

    Koji Takeuchi

    2016-08-01

    Full Text Available AbstractBackground/Aim: Muscarinic acetylcholine receptors exist in five subtypes (M1~M5, and they are widely expressed in various tissues to mediate diverse autonomic functions, including gastric secretion. In the present study, we demonstrated, using M1~M5 KO mice, the importance of M4 receptors in carbachol (CCh stimulation of acid secretion and investigated how the secretion is modulated by the activation of M4 receptors. Methods: C57BL/6J mice of wild-type (WT and M1-M5 KO were used. Under urethane anesthesia, acid secretion was measured in the stomach equipped with an acute fistula. CCh (30 µg/kg was given s.c. to stimulate acid secretion. Atropine or octreotide (a somatostatin analogue was given s.c. 20 min before the administration of CCh. CYN154806 (a somatostatin SST2 receptor antagonist was given i.p. 20 min before the administration of octreotide or CCh. Results: CCh caused an increase of acid secretion in WT mice, and the effect was totally inhibited by prior administration of atropine. The effect of CCh was similarly observed in the animals lacking M1, M2 or M5 receptors but significantly decreased in M3 or M4 KO mice. CYN154806, the SST2 receptor antagonist, dose-dependently and significantly reversed the decreased acid response to CCh in M4 but not M3 KO mice. Octreotide, the somatostatin analogue, inhibited the secretion of acid under CCh-stimulated conditions in WT mice. The immunohistochemical study showed the localization of M4 receptors on D cells in the stomach. Serum somatostatin levels in M4 KO mice were higher than WT mice under basal conditions, while those in WT mice were significantly decreased in response to CCh. Conclusions: These results suggest that under cholinergic stimulation the acid secretion is directly mediated by M3 receptors and indirectly modified by M4 receptors. It is assumed that the activation of M4 receptors inhibits the release of somatostatin from D cells and minimizes the acid inhibitory effect

  14. Antidepressant-like effects of the cannabinoid receptor ligands in the forced swimming test in mice: mechanism of action and possible interactions with cholinergic system.

    Science.gov (United States)

    Kruk-Slomka, Marta; Michalak, Agnieszka; Biala, Grazyna

    2015-05-01

    The purpose of the experiments was to explore the role of the endocannabinoid system, through cannabinoid (CB) receptor ligands, nicotine and scopolamine, in the depression-related responses using the forced swimming test (FST) in mice. Our results revealed that acute injection of oleamide (10 and 20 mg/kg), a CB1 receptor agonist, caused antidepressant-like effect in the FST, while AM 251 (0.25-3 mg/kg), a CB1 receptor antagonist, did not provoke any effect in this test. Moreover, acute administration of both CB2 receptor agonist, JWH 133 (0.5 and 1 mg/kg) and CB2 receptor antagonist, AM 630 (0.5 mg/kg), exhibited antidepressant action. Antidepressant effects of oleamide and JWH 133 were attenuated by acute injection of both non-effective dose of AM 251, as well as AM 630. Among the all CB compounds used, only the combination of non-effective dose of oleamide (2.5 mg/kg) with non-effective dose of nicotine (0.5 mg/kg) caused an antidepressant effect. However, none of the CB receptor ligands, had influence on the antidepressant effects provoked by nicotine (0.2 mg/kg) injection. In turn, the combination of non-effective dose of oleamide (2.5 mg/kg); JWH (2 mg/kg) or AM 630 (2 mg/kg), but not of AM 251 (0.25 mg/kg), with non-effective dose of scopolamine (0.1 mg/kg), exhibited antidepressant properties. Indeed, all of the CB compounds used, intensified the antidepressant-like effects induced by an acute injection of scopolamine (0.3 mg/kg). Our results provide clear evidence that the endocannabinoid system participates in the depression-related behavior and through interactions with cholinergic system modulate these kind of responses.

  15. The epidermal growth factor receptor pathway in chronic kidney diseases

    NARCIS (Netherlands)

    Harskamp, Laura R.; Gansevoort, Ron T.; Goor, van Harry; Meijer, Esther

    2016-01-01

    The epidermal growth factor receptor (EGFR) pathway has a critical role in renal development, tissue repair and electrolyte handling. Numerous studies have reported an association between dysregulation of this pathway and the initiation and progression of various chronic kidney diseases such as diab

  16. Involvement of mu(1)-opioid receptors and cholinergic neurotransmission in the endomorphins-induced impairment of passive avoidance learning in mice.

    Science.gov (United States)

    Ukai, Makoto; Lin, Hui Ping

    2002-02-01

    The effects of naloxonazine, a mu(1)-opioid receptor antagonist, and physostigmine, a cholinesterase inhibitor, on the endomorphins-induced impairment of passive avoidance learning were investigated in mice. Endomorphin-1 (10 microg) and endomorphin-2 (10 microg) significantly impaired passive avoidance learning, while naloxonazine (35 mg/kg, s.c.), a mu(1)-opioid receptor antagonist, which alone failed to influence passive avoidance learning significantly inhibited the endomorphin-1 (10 microg)- but not endomorphin-2 (10 microg)-induced disturbance of such learning. A rather nonselective higher dose (50 mg/kg, s.c.) of naloxonazine almost completely antagonized the endomorphin-1 (10 microg)- and endomorphin-2 (10 microg)-induced impairment of passive avoidance learning. In contrast, physostigmine (0.025 and 0.05 mg/kg, i.p.) significantly reversed the endomorphin-1 (10 microg)- and endomorphin-2 (10 microg)-induced disturbance of passive avoidance learning, whereas physostigmine (0.025 and 0.05 mg/kg, i.p.) alone did not influence such learning. These results suggest that endomorphin-1 but not endomorphin-2 impairs learning and memory resulting from cholinergic dysfunction, and from activation of mu(1)-opioid receptors.

  17. Physical activity, by enhancing parasympathetic tone and activating the cholinergic anti-inflammatory pathway, is a therapeutic strategy to restrain chronic inflammation and prevent many chronic diseases.

    Science.gov (United States)

    Lujan, Heidi L; DiCarlo, Stephen E

    2013-05-01

    Chronic diseases are the leading cause of death in the world and chronic inflammation is a key contributor to many chronic diseases. Accordingly, interventions that reduce inflammation may be effective in treating multiple adverse chronic conditions. In this context, physical activity is documented to reduce systemic low-grade inflammation and is acknowledged as an anti-inflammatory intervention. Furthermore, physically active individuals are at a lower risk of developing chronic diseases. However the mechanisms mediating this anti-inflammatory phenotype and range of health benefits are unknown. We hypothesize that the "cholinergic anti-inflammatory pathway" (CAP) mediates the anti-inflammatory phenotype and range of health benefits associated with physical activity. The CAP is an endogenous, physiological mechanism by which acetylcholine from the vagus nerve, interacts with the innate immune system to modulate and restrain the inflammatory cascade. Importantly, higher levels of physical activity are associated with enhanced parasympathetic (vagal) tone and lower levels of C-reactive protein, a marker of low-grade inflammation. Accordingly, physical activity, by enhancing parasympathetic tone and activating the CAP, may be a therapeutic strategy to restrain chronic inflammation and prevent many chronic diseases.

  18. Central cholinergic activation of a vagus nerve-to-spleen circuit alleviates experimental colitis.

    Science.gov (United States)

    Ji, H; Rabbi, M F; Labis, B; Pavlov, V A; Tracey, K J; Ghia, J E

    2014-03-01

    The cholinergic anti-inflammatory pathway is an efferent vagus nerve-based mechanism that regulates immune responses and cytokine production through α7 nicotinic acetylcholine receptor (α7nAChR) signaling. Decreased efferent vagus nerve activity is observed in inflammatory bowel disease. We determined whether central activation of this pathway alters inflammation in mice with colitis and the mediating role of a vagus nerve-to-spleen circuit and α7nAChR signaling. Two experimental models of colitis were used in C57BL/6 mice. Central cholinergic activation induced by the acetylcholinesterase inhibitor galantamine or a muscarinic acetylcholine receptor agonist treatments resulted in reduced mucosal inflammation associated with decreased major histocompatibility complex II level and pro-inflammatory cytokine secretion by splenic CD11c⁺ cells mediated by α7nAChR signaling. The cholinergic anti-inflammatory efficacy was abolished in mice with vagotomy, splenic neurectomy, or splenectomy. In conclusion, central cholinergic activation of a vagus nerve-to-spleen circuit controls intestinal inflammation and this regulation can be explored to develop novel therapeutic strategies.

  19. DMPD: The negative regulation of Toll-like receptor and associated pathways. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 17621314 The negative regulation of Toll-like receptor and associated pathways. Lan...) Show The negative regulation of Toll-like receptor and associated pathways. PubmedID 17621314 Title The ne...gative regulation of Toll-like receptor and associated pathways. Authors Lang T,

  20. Cholinergic regulation of the vasopressin neuroendocrine system

    Energy Technology Data Exchange (ETDEWEB)

    Michels, K.M.

    1987-01-01

    To clarify the physical and functional relationship between the cholinergic system, and the neurodocrine cells of the supraoptic nucleus, a combination of experiments on receptor binding, localization and function were carried out. The putative nicotinic receptor probe (/sup 125/I)alpha bungarotoxin ((/sup 125/I)alpha BTX) bound with high affinity and specificity to the vasopressin and oxytocin magnocellular neurons of the supraoptic nucleus, nucleus circularis, and paraventricular nucleus. Binding of (/sup 125/I)alpha BTX within the neural lobe was very low. In contrast, the muscarinic cholinergic receptor probe (/sup 3/H)quinuclidinylbenzilate ((/sup 3/H)QNB) did not bind to magnocellular vasopressin and oxytocin cell groups. The median eminence, which contains the neurosecretory axons, and the neural lobe of the pituitary contain low levels of (/sup 3/H)QNB binding. The physiological significance of these cholinergic receptors in regulation of vasopressin release was tested using an in vitro preparation of the supraoptic - neural lobe system.

  1. The Protective Effect of Electroacupuncturing Zusanli Points on Hemorrhagic Shock Rats through Cholinergic Anti-inflammatory Pathway

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    1 IntroductionIn conditions of circulatory shock, systemic inflammatory response (SIRS) plays a funda mental pathogenetic role, with activation of transcription nuclear factors (mainly NF- kB) and markedly increased production of cytokines (mainly TNF-a), which trigger the inflammatory cascade active ation. Recent research have identified a basic neural pathway that reflexively monitors and adjusts such response. It is through the rapid activation (in “real-time”) of efferent vagus nerve fibres(the recently...

  2. Rabbit Forebrain cholinergic system: Morphological characterization of nuclei and distribution of cholinergic terminals in the cerebral cortex and hippocampus

    OpenAIRE

    C. Varga; Hartig, W.; Grosche, J.; Luiten, PGM; Seeger, J.; K. Brauer; Harkany, T.; Härtig, Wolfgang; Keijser, Jan N.

    2003-01-01

    Although the rabbit brain, in particular the basal forebrain cholinergic system, has become a common model for neuropathological changes associated with Alzheimer's disease, detailed neuroanatomical studies on the morphological organization of basal forebrain cholinergic nuclei and on their output pathways are still awaited. Therefore, we performed quantitative choline acetyltransferase (ChAT) immunocytochemistry to localize major cholinergic nuclei and to determine the number of respective c...

  3. Interleukin-6 receptor pathways in coronary heart disease

    DEFF Research Database (Denmark)

    Sarwar, Nadeem; Butterworth, Adam S; Freitag, Daniel F

    2012-01-01

    Persistent inflammation has been proposed to contribute to various stages in the pathogenesis of cardiovascular disease. Interleukin-6 receptor (IL6R) signalling propagates downstream inflammation cascades. To assess whether this pathway is causally relevant to coronary heart disease, we studied...

  4. Tryptophan and cystein residues of the acetylcholine receptors of Torpedo species. Relationship to binding of cholinergic ligands.

    Science.gov (United States)

    Eldefrawi, M E; Eldefrawi, A T; Wilson, D B

    1975-09-23

    Several methods were used to analyze for tryptophan in the acetylcholine (ACh) receptors purified from the electric organs of the electric rays, Torpedo californica and Torpedo marmorata. The best value of tryptophan was 2.4 mol %. When excited at 290 nm, both receptors fluoresced with a maximum at 336, but there was no change in the fluorescence emission spectra upon binding of carbamylcholine, d-tubocurarine, ACh, or decamethonium. The free SH content of the Torpedo receptors varied in different preparations, and was highest in that purified from fresh T. californica using deaerated solutions and dialysis under nitrogen, and lowest in that prepared from the aged lyophilized membranes of T. marmorata. The maximum free SH content was 20 nmol/mg of protein or 0.22 mol %, equal to at most 18% of the total cysteic acid residues. Reaction of either 33% or of all the SH residues with p-chloromercuribenzoate reduced maximum ACh binding to the pure receptor prepared from fresh T. californica by only 23%.

  5. Signaling flux redistribution at toll-like receptor pathway junctions.

    Directory of Open Access Journals (Sweden)

    Kumar Selvarajoo

    Full Text Available Various receptors on cell surface recognize specific extracellular molecules and trigger signal transduction altering gene expression in the nucleus. Gain or loss-of-function mutations of one molecule have shown to affect alternative signaling pathways with a poorly understood mechanism. In Toll-like receptor (TLR 4 signaling, which branches into MyD88- and TRAM-dependent pathways upon lipopolysaccharide (LPS stimulation, we investigated the gain or loss-of-function mutations of MyD88. We predict, using a computational model built on the perturbation-response approach and the law of mass conservation, that removal and addition of MyD88 in TLR4 activation, enhances and impairs, respectively, the alternative TRAM-dependent pathway through signaling flux redistribution (SFR at pathway branches. To verify SFR, we treated MyD88-deficient macrophages with LPS and observed enhancement of TRAM-dependent pathway based on increased IRF3 phosphorylation and induction of Cxcl10 and Ifit2. Furthermore, increasing the amount of MyD88 in cultured cells showed decreased TRAM binding to TLR4. Investigating another TLR4 pathway junction, from TRIF to TRAF6, RIP1 and TBK1, the removal of MyD88-dependent TRAF6 increased expression of TRAM-dependent Cxcl10 and Ifit2. Thus, we demonstrate that SFR is a novel mechanism for enhanced activation of alternative pathways when molecules at pathway junctions are removed. Our data suggest that SFR may enlighten hitherto unexplainable intracellular signaling alterations in genetic diseases where gain or loss-of-function mutations are observed.

  6. Involvement of MAPK/NF-κB signaling in the activation of the cholinergic anti-inflammatory pathway in experimental colitis by chronic vagus nerve stimulation.

    Directory of Open Access Journals (Sweden)

    Peng Sun

    Full Text Available BACKGROUND: Autonomic nervous system dysfunction is implicated in the etiopathogenesis of inflammatory bowel diseases (IBD. Therapies that increase cardiovagal activity, such as Mind-Body interventions, are currently confirmed to be effective in clinical trials in IBD. However, a poor understanding of pathophysiological mechanisms limits the popularization of therapies in clinical practice. The aim of the present study was to explore the mechanisms of these therapies against 2,4,6-trinitrobenzenesulfonic acid (TNBS-induced colitis in rats using a chronic vagus nerve stimulation model in vivo, as well as the lipopolysaccharide (LPS-induced inflammatory response in human epithelial colorectal adenocarcinoma cells (Caco-2 by acetylcholine in vitro. METHODS AND RESULTS: Colitis was induced in rats with rectal instillation of TNBS, and the effect of chronic VNS (0.25 mA, 20 Hz, 500 ms on colonic inflammation was evaluated. Inflammatory responses were assessed by disease activity index (DAI, histological scores, myeloperoxidase (MPO activity, inducible nitric oxide synthase (iNOS, TNF-α and IL-6 production. The expression of Mitogen-activated protein kinases (MAPK family members, IκB-α, and nuclear NF-κB p65 were studied by immunoblotting. Heart rate variability (HRV analysis was also applied to assess the sympathetic-vagal balance. DAI, histological scores, MPO activity, iNOS, TNF-α and IL-6 levels were significantly decreased by chronic VNS. Moreover, both VNS and acetylcholine reduced the phosphorylation of MAPKs and prevented the nuclear translocation of NF-κB p65. Methyllycaconitine (MLA only reversed the inhibitory effect on p-ERK and intranuclear NF-κB p65 expression by ACh in vitro, no significant change was observed in the expression of p-p38 MAPK or p-JNK by MLA. CONCLUSION: Vagal activity modification contributes to the beneficial effects of the cholinergic anti-inflammatory pathway in IBD-related inflamed colonic mucosa based on the

  7. Cholinergic interneurons control local circuit activity and cocaine conditioning.

    Science.gov (United States)

    Witten, Ilana B; Lin, Shih-Chun; Brodsky, Matthew; Prakash, Rohit; Diester, Ilka; Anikeeva, Polina; Gradinaru, Viviana; Ramakrishnan, Charu; Deisseroth, Karl

    2010-12-17

    Cholinergic neurons are widespread, and pharmacological modulation of acetylcholine receptors affects numerous brain processes, but such modulation entails side effects due to limitations in specificity for receptor type and target cell. As a result, causal roles of cholinergic neurons in circuits have been unclear. We integrated optogenetics, freely moving mammalian behavior, in vivo electrophysiology, and slice physiology to probe the cholinergic interneurons of the nucleus accumbens by direct excitation or inhibition. Despite representing less than 1% of local neurons, these cholinergic cells have dominant control roles, exerting powerful modulation of circuit activity. Furthermore, these neurons could be activated by cocaine, and silencing this drug-induced activity during cocaine exposure (despite the fact that the manipulation of the cholinergic interneurons was not aversive by itself) blocked cocaine conditioning in freely moving mammals.

  8. Intracerebroventricular injection of mu- and delta-opiate receptor antagonists block 60 Hz magnetic field-induced decreases in cholinergic activity in the frontal cortex and hippocampus of the rat.

    Science.gov (United States)

    Lai, H; Carino, M

    1998-01-01

    In previous research, we have found that acute exposure to a 60 Hz magnetic field decreased cholinergic activity in the frontal cortex and hippocampus of the rat as measured by sodium-dependent high-affinity choline uptake activity. We concluded that the effect was mediated by endogenous opioids inside the brain because it could be blocked by pretreatment of rats before magnetic field exposure with the opiate antagonist naltrexone, but not by the peripheral antagonist naloxone methiodide. In the present study, the involvement of opiate receptor subtypes was investigated. Rats were pretreated by intracerebroventricular injection of the mu-opiate receptor antagonist, beta-funaltrexamine, or the delta-opiate receptor antagonist, naltrindole, before exposure to a 60 Hz magnetic field (2 mT, 1 hour). It was found that the effects of magnetic field on high-affinity choline uptake in the frontal cortex and hippocampus were blocked by the drug treatments. These data indicate that both mu- and delta-opiate receptors in the brain are involved in the magnetic field-induced decreases in cholinergic activity in the frontal cortex and hippocampus of the rat.

  9. Effects of beta-amyloid protein on M1 and M2 subtypes of muscarinic acetylcholine receptors in the medial septum-diagonal band complex of the rat: relationship with cholinergic, GABAergic, and calcium-binding protein perikarya.

    Science.gov (United States)

    González, Iván; Arévalo-Serrano, Juan; Sanz-Anquela, José Miguel; Gonzalo-Ruiz, Alicia

    2007-06-01

    Cortical cholinergic dysfunction has been correlated with the expression and processing of beta-amyloid precursor protein. However, it remains unclear as to how cholinergic dysfunction and beta-amyloid (Abeta) formation and deposition might be related to one another. Since the M1- and M2 subtypes of muscarinic acetylcholine receptors (mAChRs) are considered key molecules that transduce the cholinergic message, the purpose of the present study was to assess the effects of the injected Abeta peptide on the number of M1mAchR- and M2mAChR-immunoreactive cells in the medial septum-diagonal band (MS-nDBB) complex of the rat. Injections of Abeta protein into the retrosplenial cortex resulted in a decrease in M1mAChR and M2mAChR immunoreactivity in the MS-nDBB complex. Quantitative analysis revealed a significant reduction in the number of M1mAChR- and M2mAChR-immunoreactive cells in the medial septum nucleus (MS) and in the horizontal nucleus of the diagonal band of Broca (HDB) as compared to the corresponding hemisphere in control animals and with that seen in the contralateral hemisphere, which corresponds to the PBS-injected side. Co-localization studies showed that the M1mAChR protein is localized in GABA-immunoreactive cells of the MS-nDBB complex, in particular those of the MS nucleus, while M2mAChR protein is localized in both the cholinergic and GABAergic cells. Moreover, GABAergic cells containing M2mAChR are mainly localized in the MS nucleus, while cholinergic cells containing M2mAChR are localized in the MS and the HDB nuclei. Our findings suggest that Abeta induces a reduction in M1mAChR- and M2mAChR-containing cells, which may contribute to impairments of cholinergic and GABAergic transmission in the MS-nDBB complex.

  10. Peroxisome Proliferator-Activated Receptor and Vitamin D Receptor Signaling Pathways in Cancer Cells

    Energy Technology Data Exchange (ETDEWEB)

    Matsuda, Satoru, E-mail: smatsuda@cc.nara-wu.ac.jp; Kitagishi, Yasuko [Department of Food Science and Nutrition, Nara Women’s University, Kita-Uoya Nishimachi, Nara 630-8506 (Japan)

    2013-10-21

    Peroxisome proliferator-activated receptors (PPARs) are members of the superfamily of nuclear hormone receptors, which respond to specific ligands such as polyunsaturated fatty acids by altering gene expression. Three subtypes of this receptor have been discovered, each evolving to achieve different biological functions. Like other nuclear receptors, the transcriptional activity of PPARs is affected not only by ligand-stimulation, but also by cross-talk with other molecules. For example, both PPARs and the RXRs are ligand-activated transcription factors that coordinately regulate gene expression. In addition, PPARs and vitamin D receptor (VDR) signaling pathways regulate a multitude of genes that are of importance for cellular functions including cell proliferation and cell differentiation. Interaction of the PPARs and VDR signaling pathways has been shown at the level of molecular cross-regulation of their transcription factor. A variety of ligands influencing the PPARs and VDR signaling pathways have been shown to reveal chemopreventive potential by mediating tumor suppressive activities in human cancers. Use of these compounds may represent a potential novel strategy to prevent cancers. This review summarizes the roles of the PPARs and the VDR in pathogenesis and progression of cancer.

  11. Toll-Like Receptor Pathways in Autoimmune Diseases.

    Science.gov (United States)

    Chen, Ji-Qing; Szodoray, Peter; Zeher, Margit

    2016-02-01

    Autoimmune diseases are a family of chronic systemic inflammatory disorders, characterized by the dysregulation of the immune system which finally results in the break of tolerance to self-antigen. Several studies suggest that Toll-like receptors (TLRs) play an essential role in the pathogenesis of autoimmune diseases. TLRs belong to the family of pattern recognition receptors (PRRs) that recognize a wide range of pathogen-associated molecular patterns (PAMPs). TLRs are type I transmembrane proteins and located on various cellular membranes. Two main groups have been classified based on their location; the extracelluar group referred to the ones located on the plasma membrane while the intracellular group all located in endosomal compartments responsible for the recognition of nucleic acids. They are released by the host cells and trigger various intracellular pathways which results in the production of proinflammatory cytokines, chemokines, as well as the expression of co-stimulatory molecules to protect against invading microorganisms. In particular, TLR pathway-associated proteins, such as IRAK, TRAF, and SOCS, are often dysregulated in this group of diseases. TLR-associated gene expression profile analysis together with single nucleotide polymorphism (SNP) assessment could be important to explain the pathomechanism driving autoimmune diseases. In this review, we summarize recent findings on TLR pathway regulation in various autoimmune diseases, including Sjögren's syndrome (SS), systemic lupus erythematosus (SLE), multiple sclerosis (MS), rheumatoid arthritis (RA), systemic sclerosis (SSc), and psoriasis.

  12. ATP, P2X receptors and pain pathways.

    Science.gov (United States)

    Ding, Y; Cesare, P; Drew, L; Nikitaki, D; Wood, J N

    2000-07-01

    A role for ATP in nociception and pain induction was proposed on the basis of human psychophysical experiments shortly after the formulation of the purinergic hypothesis. Following the pharmacological definition of distinct P2X and P2Y purinergic receptor subtypes by Burnstock and his collaborators, molecular cloning studies have identified the gene products that underlie the effects of ATP on peripheral sensory neurons. One particular receptor, P2X(3), is of particular interest in the context of pain pathways, because it is relatively selectively expressed at high levels by nociceptive sensory neurons. Evidence that this receptor may play a role in the excitation of sensory neurons has recently been complemented by studies that suggest an additional presynaptic role in the regulation of glutamate release from primary afferent neurons in the dorsal horn of the spinal cord. In this brief review, we discuss the present state of knowledge of the role of ATP in pain induction through its action on peripheral P2X receptors.

  13. Treatment of beta amyloid 1–42 (Aβ1–42)-induced basal forebrain cholinergic damage by a non-classical estrogen signaling activator in vivo

    Science.gov (United States)

    Kwakowsky, Andrea; Potapov, Kyoko; Kim, SooHyun; Peppercorn, Katie; Tate, Warren P.; Ábrahám, István M.

    2016-01-01

    In Alzheimer’s disease (AD), there is a loss in cholinergic innervation targets of basal forebrain which has been implicated in substantial cognitive decline. Amyloid beta peptide (Aβ1–42) accumulates in AD that is highly toxic for basal forebrain cholinergic (BFC) neurons. Although the gonadal steroid estradiol is neuroprotective, the administration is associated with risk of off-target effects. Previous findings suggested that non-classical estradiol action on intracellular signaling pathways has ameliorative potential without estrogenic side effects. After Aβ1–42 injection into mouse basal forebrain, a single dose of 4-estren-3α, 17β-diol (estren), the non-classical estradiol pathway activator, restored loss of cholinergic cortical projections and also attenuated the Aβ1–42-induced learning deficits. Estren rapidly and directly phosphorylates c-AMP-response–element-binding-protein and extracellular-signal-regulated-kinase-1/2 in BFC neurons and restores the cholinergic fibers via estrogen receptor-α. These findings indicated that selective activation of non-classical intracellular estrogen signaling has a potential to treat the damage of cholinergic neurons in AD. PMID:26879842

  14. Estrogen receptors regulate innate immune cells and signaling pathways.

    Science.gov (United States)

    Kovats, Susan

    2015-04-01

    Humans show strong sex differences in immunity to infection and autoimmunity, suggesting sex hormones modulate immune responses. Indeed, receptors for estrogens (ERs) regulate cells and pathways in the innate and adaptive immune system, as well as immune cell development. ERs are ligand-dependent transcription factors that mediate long-range chromatin interactions and form complexes at gene regulatory elements, thus promoting epigenetic changes and transcription. ERs also participate in membrane-initiated steroid signaling to generate rapid responses. Estradiol and ER activity show profound dose- and context-dependent effects on innate immune signaling pathways and myeloid cell development. While estradiol most often promotes the production of type I interferon, innate pathways leading to pro-inflammatory cytokine production may be enhanced or dampened by ER activity. Regulation of innate immune cells and signaling by ERs may contribute to the reported sex differences in innate immune pathways. Here we review the recent literature and highlight several molecular mechanisms by which ERs regulate the development or functional responses of innate immune cells.

  15. Striatal cholinergic interneuron regulation and circuit effects

    Directory of Open Access Journals (Sweden)

    Sean Austin Lim

    2014-10-01

    Full Text Available The striatum plays a central role in motor control and motor learning. Appropriate responses to environmental stimuli, including pursuit of reward or avoidance of aversive experience all require functional striatal circuits. These pathways integrate synaptic inputs from limbic and cortical regions including sensory, motor and motivational information to ultimately connect intention to action. Although many neurotransmitters participate in striatal circuitry, one critically important player is acetylcholine (ACh. Relative to other brain areas, the striatum contains exceptionally high levels of ACh, the enzymes that catalyze its synthesis and breakdown, as well as both nicotinic and muscarinic receptor types that mediate its postsynaptic effects. The principal source of striatal ACh is the cholinergic interneuron (ChI, which comprises only about 1-2% of all striatal cells yet sends dense arbors of projections throughout the striatum. This review summarizes recent advances in our understanding of the factors affecting the excitability of these neurons through acute effects and long term changes in their synaptic inputs. In addition, we discuss the physiological effects of ACh in the striatum, and how changes in ACh levels may contribute to disease states during striatal dysfunction.

  16. Neurotransmitter receptor-mediated signaling pathways as modulators of carcinogenesis.

    Science.gov (United States)

    Schuller, Hildegard M

    2007-01-01

    The autonomic nervous system with its two antagonistic branches, the sympathicus and the parasympathicus, regulates the activities of all body functions that are not under voluntary control. While the autonomic regulation of organ functions has been extensively studied, little attention has been given to the potential role of neurohumoral transmission at the cellular level in the development of cancer. Studies conducted by our laboratory first showed that binding of the parasympathetic neurotransmitter, acetylcholine, as well as nicotine or its nitrosated cancer-causing derivative, NNK, to nicotinic acetylcholine receptors comprised of alpha7 subunits activated a mitogenic signal transduction pathway in normal and neoplastic pulmonary neuroendocrine cells. On the other hand, beta-adrenergic receptors (Beta-ARs), which transmit signals initiated by binding of the catecholamine neurotransmitters of the sympathicus, were identified by our laboratory as important regulators of cell proliferation in cell lines derived from human adenocarcinomas of the lungs, pancreas, and breast. The tobacco-specific carcinogen NNK bound with high affinity to Beta1- and Beta2-ARs, thus activating cAMP, protein kinase A, and the transcription factor CREB. Collectively, neurotransmitter receptors of the nicotinic and Beta-adrenergic families appear to regulate cellular functions essential for the development and survival of the most common human cancers.

  17. Cholinergic systems mediate action from movement to higher consciousness.

    Science.gov (United States)

    Woolf, Nancy J; Butcher, Larry L

    2011-08-10

    There is a fundamental link between cholinergic neurotransmitter function and overt and covert actions. Major cholinergic systems include peripheral motor neurons organizing skeletal muscle movements into overt behaviors and cholinergic neurons in the basal forebrain and mesopontine regions that mediate covert actions realized as states of consciousness, arousal, selective attention, perception, and memory. Cholinergic interneurons in the striatum appear to integrate conscious and unconscious actions. Neural network models involving cholinergic neurons, as well as neurons using other neurotransmitters, emphasize connective circuitry as being responsible for both motor programs and neural correlates of higher consciousness. This, however, is only a partial description. At a more fundamental level lie intracellular mechanisms involving the cytoskeleton, which are common to both muscle contraction and neuroplastic responses in targets of central cholinergic cells attendant with higher cognition. Acetylcholine, acting through nicotinic receptors, triggers interactions between cytoskeletal proteins in skeletal muscle cells, as has been long known. There is also evidence that acetylcholine released at central sites acts through muscarinic and nicotinic receptors to initiate responses in actin and microtubule proteins. These effects and their implications for cholinergic involvement in higher cognition are explored in this review.

  18. Cholinergic Abnormalities, Endosomal Alterations and Up-Regulation of Nerve Growth Factor Signaling in Niemann-Pick Type C Disease

    Directory of Open Access Journals (Sweden)

    Cabeza Carolina

    2012-03-01

    Full Text Available Abstract Background Neurotrophins and their receptors regulate several aspects of the developing and mature nervous system, including neuronal morphology and survival. Neurotrophin receptors are active in signaling endosomes, which are organelles that propagate neurotrophin signaling along neuronal processes. Defects in the Npc1 gene are associated with the accumulation of cholesterol and lipids in late endosomes and lysosomes, leading to neurodegeneration and Niemann-Pick type C (NPC disease. The aim of this work was to assess whether the endosomal and lysosomal alterations observed in NPC disease disrupt neurotrophin signaling. As models, we used i NPC1-deficient mice to evaluate the central cholinergic septo-hippocampal pathway and its response to nerve growth factor (NGF after axotomy and ii PC12 cells treated with U18666A, a pharmacological cellular model of NPC, stimulated with NGF. Results NPC1-deficient cholinergic cells respond to NGF after axotomy and exhibit increased levels of choline acetyl transferase (ChAT, whose gene is under the control of NGF signaling, compared to wild type cholinergic neurons. This finding was correlated with increased ChAT and phosphorylated Akt in basal forebrain homogenates. In addition, we found that cholinergic neurons from NPC1-deficient mice had disrupted neuronal morphology, suggesting early signs of neurodegeneration. Consistently, PC12 cells treated with U18666A presented a clear NPC cellular phenotype with a prominent endocytic dysfunction that includes an increased size of TrkA-containing endosomes and reduced recycling of the receptor. This result correlates with increased sensitivity to NGF, and, in particular, with up-regulation of the Akt and PLC-γ signaling pathways, increased neurite extension, increased phosphorylation of tau protein and cell death when PC12 cells are differentiated and treated with U18666A. Conclusions Our results suggest that the NPC cellular phenotype causes neuronal

  19. Regulated Extracellular Choline Acetyltransferase Activity- The Plausible Missing Link of the Distant Action of Acetylcholine in the Cholinergic Anti-Inflammatory Pathway.

    Directory of Open Access Journals (Sweden)

    Swetha Vijayaraghavan

    Full Text Available Acetylcholine (ACh, the classical neurotransmitter, also affects a variety of nonexcitable cells, such as endothelia, microglia, astrocytes and lymphocytes in both the nervous system and secondary lymphoid organs. Most of these cells are very distant from cholinergic synapses. The action of ACh on these distant cells is unlikely to occur through diffusion, given that ACh is very short-lived in the presence of acetylcholinesterase (AChE and butyrylcholinesterase (BuChE, two extremely efficient ACh-degrading enzymes abundantly present in extracellular fluids. In this study, we show compelling evidence for presence of a high concentration and activity of the ACh-synthesizing enzyme, choline-acetyltransferase (ChAT in human cerebrospinal fluid (CSF and plasma. We show that ChAT levels are physiologically balanced to the levels of its counteracting enzymes, AChE and BuChE in the human plasma and CSF. Equilibrium analyses show that soluble ChAT maintains a steady-state ACh level in the presence of physiological levels of fully active ACh-degrading enzymes. We show that ChAT is secreted by cultured human-brain astrocytes, and that activated spleen lymphocytes release ChAT itself rather than ACh. We further report differential CSF levels of ChAT in relation to Alzheimer's disease risk genotypes, as well as in patients with multiple sclerosis, a chronic neuroinflammatory disease, compared to controls. Interestingly, soluble CSF ChAT levels show strong correlation with soluble complement factor levels, supporting a role in inflammatory regulation. This study provides a plausible explanation for the long-distance action of ACh through continuous renewal of ACh in extracellular fluids by the soluble ChAT and thereby maintenance of steady-state equilibrium between hydrolysis and synthesis of this ubiquitous cholinergic signal substance in the brain and peripheral compartments. These findings may have important implications for the role of cholinergic

  20. Current Views of Toll-Like Receptor Signaling Pathways

    Directory of Open Access Journals (Sweden)

    Masahiro Yamamoto

    2010-01-01

    Full Text Available On microbial invasion, the host immediately evokes innate immune responses. Recent studies have demonstrated that Toll-like receptors (TLRs play crucial roles in innate responses that lead not only to the clearance of pathogens but also to the efficient establishment of acquired immunity by directly detecting molecules from microbes. In terms of intracellular TLR-mediated signaling pathways, cytoplasmic adaptor molecules containing Toll/IL-1R (TIR domains play important roles in inflammatory immune responses through the production of proinflammatory cytokines, nitric oxide, and type I interferon, and upregulation of costimulatory molecules. In this paper, we will describe our current understanding of the relationship between TLRs and their ligands derived from pathogens such as viruses, bacteria, fungi, and parasites. Moreover, we will review the historical and current literature to describe the mechanisms behind TLR-mediated activation of innate immune responses.

  1. The Toll-like receptor pathway establishes commensal gut colonization

    Science.gov (United States)

    Round, June L.; Lee, S. Melanie; Li, Jennifer; Tran, Gloria; Jabri, Bana; Chatila, Talal A.; Mazmanian, Sarkis K.

    2011-01-01

    Mucosal surfaces are in continuous contact with microbes. Toll-like receptors (TLRs) mediate recognition of microbial molecules to eliminate pathogens. In contrast, we demonstrate here that the prominent gut commensal, Bacteroides fragilis, activates the TLR pathway on T lymphocytes to establish host-microbial symbiosis. TLR2 deletion on CD4+ T cells results in anti-microbial immune responses that reduce B. fragilis colonization of a unique mucosal niche during homeostasis. A symbiosis factor (PSA) of B. fragilis activates TLR2 directly on Foxp3+ regulatory T cells through a novel process to engender mucosal tolerance. Remarkably, B. fragilis lacking PSA is unable to restrain host immune responses and is defective in niche-specific mucosal colonization. Therefore, unlike pathogens whose TLR ligands trigger inflammation, some commensal bacteria exploit the TLR pathway to actively suppress immune reactions. We propose that the immunologic distinction between pathogens and the microbiota is mediated not solely by host mechanisms, but also through specialized molecules evolved by symbiotic bacteria that enable commensal colonization. PMID:21512004

  2. Cross-regulation of signaling pathways: An example of nuclear hormone receptors and the canonical Wnt pathway

    Energy Technology Data Exchange (ETDEWEB)

    Beildeck, Marcy E. [Lombardi Comprehensive Cancer Center, Georgetown University, 3970 Reservoir Road, NW, Washington, DC 20057 (United States); Gelmann, Edward P. [Columbia University, Department of Medicine, New York, NY (United States); Byers, Stephen W., E-mail: byerss@georgetown.edu [Lombardi Comprehensive Cancer Center, Georgetown University, 3970 Reservoir Road, NW, Washington, DC 20057 (United States)

    2010-07-01

    Predicting the potential physiological outcome(s) of any given molecular pathway is complex because of cross-talk with other pathways. This is particularly evident in the case of the nuclear hormone receptor and canonical Wnt pathways, which regulate cell growth and proliferation, differentiation, apoptosis, and metastatic potential in numerous tissues. These pathways are known to intersect at many levels: in the intracellular space, at the membrane, in the cytoplasm, and within the nucleus. The outcomes of these interactions are important in the control of stem cell differentiation and maintenance, feedback loops, and regulating oncogenic potential. The aim of this review is to demonstrate the importance of considering pathway cross-talk when predicting functional outcomes of signaling, using nuclear hormone receptor/canonical Wnt pathway cross-talk as an example.

  3. GABAergic actions on cholinergic laterodorsal tegmental neurons

    DEFF Research Database (Denmark)

    Kohlmeier, K A; Kristiansen, Uffe

    2010-01-01

    (IRK) mediated this effect. Further, outward currents were never additive with those induced by application of carbachol, suggesting that they were mediated by activation of GABA(B) receptors linked to the same G(IRK) activated in these cells by muscarinic receptor stimulation. Activation of GABA(B) receptors....... Therefore, we studied the actions of GABA agonists and antagonists on cholinergic LDT cells by performing patch clamp recordings in mouse brain slices. Under conditions where detection of Cl(-) -mediated events was optimized, GABA induced gabazine (GZ)-sensitive inward currents in the majority of LDT...... neurons. Post-synaptic location of GABA(A) receptors was demonstrated by persistence of muscimol-induced inward currents in TTX and low Ca(2+) solutions. THIP, a selective GABA(A) receptor agonist with a preference for d-subunit containing GABA(A) receptors, induced inward currents, suggesting...

  4. Dopamine D1-D2 receptor heteromer signaling pathway in the brain: emerging physiological relevance

    Directory of Open Access Journals (Sweden)

    Hasbi Ahmed

    2011-06-01

    Full Text Available Abstract Dopamine is an important catecholamine neurotransmitter modulating many physiological functions, and is linked to psychopathology of many diseases such as schizophrenia and drug addiction. Dopamine D1 and D2 receptors are the most abundant dopaminergic receptors in the striatum, and although a clear segregation between the pathways expressing these two receptors has been reported in certain subregions, the presence of D1-D2 receptor heteromers within a unique subset of neurons, forming a novel signaling transducing functional entity has been shown. Recently, significant progress has been made in elucidating the signaling pathways activated by the D1-D2 receptor heteromer and their potential physiological relevance.

  5. Striatal cholinergic interneurons Drive GABA release from dopamine terminals.

    Science.gov (United States)

    Nelson, Alexandra B; Hammack, Nora; Yang, Cindy F; Shah, Nirao M; Seal, Rebecca P; Kreitzer, Anatol C

    2014-04-01

    Striatal cholinergic interneurons are implicated in motor control, associative plasticity, and reward-dependent learning. Synchronous activation of cholinergic interneurons triggers large inhibitory synaptic currents in dorsal striatal projection neurons, providing one potential substrate for control of striatal output, but the mechanism for these GABAergic currents is not fully understood. Using optogenetics and whole-cell recordings in brain slices, we find that a large component of these inhibitory responses derive from action-potential-independent disynaptic neurotransmission mediated by nicotinic receptors. Cholinergically driven IPSCs were not affected by ablation of striatal fast-spiking interneurons but were greatly reduced after acute treatment with vesicular monoamine transport inhibitors or selective destruction of dopamine terminals with 6-hydroxydopamine, indicating that GABA release originated from dopamine terminals. These results delineate a mechanism in which striatal cholinergic interneurons can co-opt dopamine terminals to drive GABA release and rapidly inhibit striatal output neurons.

  6. Nicotinic and muscarinic agonists and acetylcholinesterase inhibitors stimulate a common pathway to enhance GluN2B-NMDAR responses

    OpenAIRE

    Ishibashi, Masaru; Yamazaki, Yoshihiko; Miledi, Ricardo; Sumikawa, Katumi

    2014-01-01

    The cellular mechanisms by which nicotinic and muscarinic cholinergic systems facilitate learning and memory largely remain to be elucidated. This study identified a common signaling pathway stimulated by cognitive-enhancing drugs targeted to nicotinic and m1 muscarinic receptors and acetylcholinesterase. Stimulation of this signaling pathway induces significant increases in glutamate receptor, ionotropic, N-methyl D-aspartate 2B (GluN2B)-containing NMDA receptor (NMDAR)-mediated responses at...

  7. Cholinergic imaging in dementia spectrum disorders

    Energy Technology Data Exchange (ETDEWEB)

    Roy, Roman; Niccolini, Flavia; Pagano, Gennaro; Politis, Marios [Institute of Psychiatry, Psychology and Neuroscience, King' s College London, Neurodegeneration Imaging Group, Department of Basic and Clinical Neuroscience, London (United Kingdom)

    2016-07-15

    The multifaceted nature of the pathology of dementia spectrum disorders has complicated their management and the development of effective treatments. This is despite the fact that they are far from uncommon, with Alzheimer's disease (AD) alone affecting 35 million people worldwide. The cholinergic system has been found to be crucially involved in cognitive function, with cholinergic dysfunction playing a pivotal role in the pathophysiology of dementia. The use of molecular imaging such as SPECT and PET for tagging targets within the cholinergic system has shown promise for elucidating key aspects of underlying pathology in dementia spectrum disorders, including AD or parkinsonian dementias. SPECT and PET studies using selective radioligands for cholinergic markers, such as [{sup 11}C]MP4A and [{sup 11}C]PMP PET for acetylcholinesterase (AChE), [{sup 123}I]5IA SPECT for the α{sub 4}β{sub 2} nicotinic acetylcholine receptor and [{sup 123}I]IBVM SPECT for the vesicular acetylcholine transporter, have been developed in an attempt to clarify those aspects of the diseases that remain unclear. This has led to a variety of findings, such as cortical AChE being significantly reduced in Parkinson's disease (PD), PD with dementia (PDD) and AD, as well as correlating with certain aspects of cognitive function such as attention and working memory. Thalamic AChE is significantly reduced in progressive supranuclear palsy (PSP) and multiple system atrophy, whilst it is not affected in PD. Some of these findings have brought about suggestions for the improvement of clinical practice, such as the use of a thalamic/cortical AChE ratio to differentiate between PD and PSP, two diseases that could overlap in terms of initial clinical presentation. Here, we review the findings from molecular imaging studies that have investigated the role of the cholinergic system in dementia spectrum disorders. (orig.)

  8. Interaction of nerve agent antidotes with cholinergic systems.

    Science.gov (United States)

    Soukup, O; Tobin, G; Kumar, U K; Binder, J; Proska, J; Jun, D; Fusek, J; Kuca, K

    2010-01-01

    The poisoning with organophosphorus compounds represents a life threatening danger especially in the time of terroristic menace. No universal antidote has been developed yet and other therapeutic approaches not related to reactivation of acetylcholinesterase are being investigated. This review describes the main features of the cholinergic system, cholinergic receptors, cholinesterases and their inhibitors. It also focuses on the organophosphorus nerve agents, their properties, effects and a large part describes various possibilities in treatments, mainly traditional oxime therapies based on reactivation of AChE. Furthermore, non-cholinesterase coupled antidotal effects of the oximes are thoroughly discussed. These antidotal effects principally include oxime interactions with muscarinic and nicotinic receptors.

  9. The role of cholinergic pathway lesions in vascular cognitive impairment%胆碱能通路损伤在血管性认知功能障碍中的作用

    Institute of Scientific and Technical Information of China (English)

    黄纯臣; 李林昕; 韩翔; 王亮; 董强

    2010-01-01

    目的 通过比较胆碱能通路高信号评分(CHIPS)与缺血性脑卒中患者认知功能之间的关系,探索胆碱能通路损伤在血管性认知功能障碍中的作用.方法 采用MRI对住院缺血性脑卒中患者进行CHIPS评分、总体白质高信号Schelten评分,同时使用北京版蒙特利尔认知量表(MoCA)进行认知功能评估,分析影像学评分与认知评估间的相关性.结果 共纳入34例研究对象[45~82岁,平均(62.2±8.8)岁],该群体CHIPS评分与MoCA得分间标准化回归系数β=-0.382,P=0.026,而Schelten评分与MoCA得分间β=-0.357,P=0.042;在视空间与执行功能、命名、注意与抽象分项评分中,CHIPS与分项评分存在相关性;Schelten评分与命名、注意和抽象评分亦存在相关性.结论 胆碱能通路损伤在白质病变所致血管性认知功能障碍中起作用,其主要作用可能是影响视空间与执行功能.%Objective To investigate the relationship between white matter lesions (WML) within the cholinergic pathway and vascular cognitive impairment.Method Middle-aged and elderly stroke patients underwent brain MRI examination and Montreal Cognitive Assessment (MoCA).Cholinergic Pathways Hyperintensities Scale (CHIPS) scores and the overall WML burden by Schelten on fluidattenuated inversion recovery MRI images were determined and compared with MoCA scores.Spearman partial rank correlation coefficients and standardized regression coefficients were calculated.Results Thirty four patients were included ( mean age ( 62.2 ± 8.8 ) years, 45-82 years).MoCA scores negatively correlated with WML burdens by Schelten scores ( β = - 0.357, P = 0.042) and CHIPS scores ( β =-0.382,P=0.026).CHIPS scores were negatively associated with visuospatial and executive function (r = - 0.290, P = 0.048 ), naming function ( r = - 0.486, P = 0.002 ), attention ( r = - 0.311, P =0.037) and abstraction ( r = - 0.344, P = 0.023).Schelten scores were negatively associated with naming

  10. Signaling of human frizzled receptors to the mating pathway in yeast.

    Directory of Open Access Journals (Sweden)

    Dietmar Dirnberger

    Full Text Available Frizzled receptors have seven membrane-spanning helices and are considered as atypical G protein-coupled receptors (GPCRs. The mating response of the yeast Saccharomyces cerevisiae is mediated by a GPCR signaling system and this model organism has been used extensively in the past to study mammalian GPCR function. We show here that human Frizzled receptors (Fz1 and Fz2 can be properly targeted to the yeast plasma membrane, and that they stimulate the yeast mating pathway in the absence of added Wnt ligands, as evidenced by cell cycle arrest in G1 and reporter gene expression dependent on the mating pathway-activated FUS1 gene. Introducing intracellular portions of Frizzled receptors into the Ste2p backbone resulted in the generation of constitutively active receptor chimeras that retained mating factor responsiveness. Introducing intracellular portions of Ste2p into the Frizzled receptor backbone was found to strongly enhance mating pathway activation as compared to the native Frizzleds, likely by facilitating interaction with the yeast Galpha protein Gpa1p. Furthermore, we show reversibility of the highly penetrant G1-phase arrests exerted by the receptor chimeras by deletion of the mating pathway effector FAR1. Our data demonstrate that Frizzled receptors can functionally replace mating factor receptors in yeast and offer an experimental system to study modulators of Frizzled receptors.

  11. Signaling of human frizzled receptors to the mating pathway in yeast.

    Science.gov (United States)

    Dirnberger, Dietmar; Seuwen, Klaus

    2007-09-26

    Frizzled receptors have seven membrane-spanning helices and are considered as atypical G protein-coupled receptors (GPCRs). The mating response of the yeast Saccharomyces cerevisiae is mediated by a GPCR signaling system and this model organism has been used extensively in the past to study mammalian GPCR function. We show here that human Frizzled receptors (Fz1 and Fz2) can be properly targeted to the yeast plasma membrane, and that they stimulate the yeast mating pathway in the absence of added Wnt ligands, as evidenced by cell cycle arrest in G1 and reporter gene expression dependent on the mating pathway-activated FUS1 gene. Introducing intracellular portions of Frizzled receptors into the Ste2p backbone resulted in the generation of constitutively active receptor chimeras that retained mating factor responsiveness. Introducing intracellular portions of Ste2p into the Frizzled receptor backbone was found to strongly enhance mating pathway activation as compared to the native Frizzleds, likely by facilitating interaction with the yeast Galpha protein Gpa1p. Furthermore, we show reversibility of the highly penetrant G1-phase arrests exerted by the receptor chimeras by deletion of the mating pathway effector FAR1. Our data demonstrate that Frizzled receptors can functionally replace mating factor receptors in yeast and offer an experimental system to study modulators of Frizzled receptors.

  12. Cholinergic neurons in the dorsomedial hypothalamus regulate mouse brown adipose tissue metabolism

    Directory of Open Access Journals (Sweden)

    Jae Hoon Jeong

    2015-06-01

    Conclusion: DMH cholinergic neurons directly send efferent signals to sympathetic premotor neurons in the Rpa. Elevated cholinergic input to this area reduces BAT activity through activation of M2 mAChRs on serotonergic neurons. Therefore, the direct DMHACh–Rpa5-HT pathway may mediate physiological heat-defense responses to elevated environmental temperature.

  13. Amyloid-β depresses excitatory cholinergic synaptic transmission in Drosophila

    Institute of Scientific and Technical Information of China (English)

    Liqun Fang; Jingjing Duan; Dongzhi Ran; Zihao Fan; Ying Yan; Naya Huang; Huaiyu Gu; Yulan Zhu

    2012-01-01

    Objective Decline,disruption,or alterations of nicotinic cholinergic mechanisms contribute to cognitive dysfunctions like Alzheimer's disease (AD).Although amyloid-β (Aβ) aggregation is a pathological hallmark of AD,the mechanisms by which Aβ peptides modulate cholinergic synaptic transmission and memory loss remain obscure.This study was aimed to investigate the potential synaptic modulation by Aβ of the cholinergic synapses between olfactory receptor neurons and projection neurons (PNs) in the olfactory lobe of the fruit fly.Methods Cholinergic spontaneous and miniature excitatory postsynaptic current (mEPSC) were recorded with whole-cell patch clamp from PNs in Drosophila AD models expressing Aβ40,Aβ42,or Aβ42Arc peptides in neural tissue.Results In fly pupae (2 days before eclosion),overexpression of Aβ42 or Aβ42Arc,but not Aβ40,led to a significant decrease of mEPSC frequency,while overexpression of Aβ40,Aβ42,or Aβ42Arc had no significant effect on mEPSC amplitude.In contrast,Pavlovian olfactory associative learning and lifespan assays showed that both short-term memory and lifespan were decreased in the Drosophila models expressing Aβ40,Aβ42,or Aβ42Arc.Conclusion Both electrophysiological and behavioral results showed an effect of Aβ peptide on cholinergic synaptic transmission and suggest a possible mechanism by which Aβ peptides cause cholinergic neuron degeneration and the consequent memory loss.

  14. DMPD: The Toll-like receptors: analysis by forward genetic methods. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available ods. Authors Beutler B. Publication Immunogenetics. 2005 Jul;57(6):385-92. Pathwa...y forward genetic methods. PubmedID 16001129 Title The Toll-like receptors: analysis by forward genetic meth

  15. Monitoring cholinergic activity during attentional performance in mice heterozygous for the choline transporter: a model of cholinergic capacity limits.

    Science.gov (United States)

    Paolone, Giovanna; Mallory, Caitlin S; Koshy Cherian, Ajeesh; Miller, Thomas R; Blakely, Randy D; Sarter, Martin

    2013-12-01

    Reductions in the capacity of the human choline transporter (SLC5A7, CHT) have been hypothesized to diminish cortical cholinergic neurotransmission, leading to risk for cognitive and mood disorders. To determine the acetylcholine (ACh) release capacity of cortical cholinergic projections in a mouse model of cholinergic hypofunction, the CHT+/- mouse, we assessed extracellular ACh levels while mice performed an operant sustained attention task (SAT). We found that whereas SAT-performance-associated increases in extracellular ACh levels of CHT+/- mice were significantly attenuated relative to wildtype littermates, performance on the SAT was normal. Tetrodotoxin-induced blockade of neuronal excitability reduced both dialysate ACh levels and SAT performance similarly in both genotypes. Likewise, lesions of cholinergic neurons abolished SAT performance in both genotypes. However, cholinergic activation remained more vulnerable to the reverse-dialyzed muscarinic antagonist atropine in CHT+/- mice. Additionally, CHT+/- mice displayed greater SAT-disrupting effects of reverse dialysis of the nAChR antagonist mecamylamine. Receptor binding assays revealed a higher density of α4β2* nAChRs in the cortex of CHT+/- mice compared to controls. These findings reveal compensatory mechanisms that, in the context of moderate cognitive challenges, can overcome the performance deficits expected from the significantly reduced ACh capacity of CHT+/- cholinergic terminals. Further analyses of molecular and functional compensations in the CHT+/- model may provide insights into both risk and resiliency factors involved in cognitive and mood disorders.

  16. Personalized genetics of the cholinergic blockade of neuroinflammation.

    Science.gov (United States)

    Simchovitz, Alon; Heneka, Michael T; Soreq, Hermona

    2017-03-21

    Acetylcholine signaling is essential for cognitive functioning and blocks inflammation. To maintain homeostasis, cholinergic signaling is subjected to multi-leveled and bidirectional regulation by both proteins and non-coding microRNAs ('CholinomiRs'). CholinomiRs coordinate the cognitive and inflammatory aspects of cholinergic signaling by targeting major cholinergic transcripts including the acetylcholine hydrolyzing enzyme acetylcholinesterase (AChE). Notably, AChE inhibitors are the only currently approved line of treatment for Alzheimer's disease patients. Since cholinergic signaling blocks neuroinflammation which is inherent to Alzheimer's disease, genomic changes modifying AChE's properties and its susceptibility to inhibitors and/or to CholinomiRs regulation may affect the levels and properties of inflammasome components such as NLRP3. This calls for genomic-based medicine approaches based on genotyping of both coding and non-coding single nucleotide polymorphisms (SNPs) in the genes involved in cholinergic signaling. An example is a SNP in a recognition element for the primate-specific microRNA-608 within the 3' untranslated region of the AChE transcript. Carriers of the minor allele of that SNP present massively elevated brain AChE levels, increased trait anxiety and inflammation, accompanied by perturbed CholinomiR-608 regulatory networks and elevated prefrontal activity under exposure to stressful insults. Several additional SNPs in the AChE and other cholinergic genes await further studies, and might likewise involve different CholinomiRs and pathways including those modulating the initiation and progression of neurodegenerative diseases. CholinomiRs regulation of the cholinergic system thus merits in-depth interrogation and is likely to lead to personalized medicine approaches for achieving better homeostasis in health and disease. This is an article for the special issue XVth International Symposium on Cholinergic Mechanisms.

  17. Taurolithocholic acid promotes intrahepatic cholangiocarcinoma cell growth via muscarinic acetylcholine receptor and EGFR/ERK1/2 signaling pathway.

    Science.gov (United States)

    Amonyingcharoen, Sumet; Suriyo, Tawit; Thiantanawat, Apinya; Watcharasit, Piyajit; Satayavivad, Jutamaad

    2015-01-01

    Cholangiocarcinoma (CCA) is a malignant cancer of the biliary tract and its occurrence is associated with chronic cholestasis which causes an elevation of bile acids in the liver and bile duct. The present study aimed to investigate the role and mechanistic effect of bile acids on the CCA cell growth. Intrahepatic CCA cell lines, RMCCA-1 and HuCCA-1, were treated with bile acids and their metabolites to determine the growth promoting effect. Cell viability, cell cycle analysis, EdU incorporation assays were conducted. Intracellular signaling proteins were detected by western immunoblotting. Among eleven forms of bile acids and their metabolites, only taurolithocholic acid (TLCA) concentration dependently (1-40 µM) increased the cell viability of RMCCA-1, but not HuCCA-1 cells. The cell cycle analysis showed induction of cells in the S phase and the EdU incorporation assay revealed induction of DNA synthesis in the TLCA-treated RMCCA-1 cells. Moreover, TLCA increased the phosphorylation of EGFR, ERK 1/2 and also increased the expression of cyclin D1 in RMCCA-1 cells. Furthermore, TLCA-induced RMCCA-1 cell growth could be inhibited by atropine, a non-selective muscarinic acetylcholine receptor (mAChR) antagonist, AG 1478, a specific EGFR inhibitor, or U 0126, a specific MEK 1/2 inhibitor. These results suggest that TLCA induces CCA cell growth via mAChR and EGFR/EKR1/2 signaling pathway. Moreover, the functional presence of cholinergic system plays a certain role in TLCA-induced CCA cell growth.

  18. DMPD: Crosstalk among Jak-STAT, Toll-like receptor, and ITAM-dependent pathways inmacrophage activation. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 17502339 Crosstalk among Jak-STAT, Toll-like receptor, and ITAM-dependent pathways inmacrophage activation...T, Toll-like receptor, and ITAM-dependent pathways inmacrophage activation. Authors Hu X, Chen J, Wang L, Iv...ivation. PubmedID 17502339 Title Crosstalk among Jak-STA...May 14. (.png) (.svg) (.html) (.csml) Show Crosstalk among Jak-STAT, Toll-like receptor, and ITAM-dependent pathways inmacrophage act

  19. Cholinergic urethral brush cells are widespread throughout placental mammals.

    Science.gov (United States)

    Deckmann, Klaus; Krasteva-Christ, Gabriela; Rafiq, Amir; Herden, Christine; Wichmann, Judy; Knauf, Sascha; Nassenstein, Christina; Grevelding, Christoph G; Dorresteijn, Adriaan; Chubanov, Vladimir; Gudermann, Thomas; Bschleipfer, Thomas; Kummer, Wolfgang

    2015-11-01

    We previously identified a population of cholinergic epithelial cells in murine, human and rat urethrae that exhibits a structural marker of brush cells (villin) and expresses components of the canonical taste transduction signaling cascade (α-gustducin, phospholipase Cβ2 (PLCβ2), transient receptor potential cation channel melanostatin 5 (TRPM5)). These cells serve as sentinels, monitoring the chemical composition of the luminal content for potentially hazardous compounds such as bacteria, and initiate protective reflexes counteracting further ingression. In order to elucidate cross-species conservation of the urethral chemosensory pathway we investigated the occurrence and molecular make-up of urethral brush cells in placental mammals. We screened 11 additional species, at least one in each of the five mammalian taxonomic units primates, carnivora, perissodactyla, artiodactyla and rodentia, for immunohistochemical labeling of the acetylcholine synthesizing enzyme, choline acetyltransferase (ChAT), villin, and taste cascade components (α-gustducin, PLCβ2, TRPM5). Corresponding to findings in previously investigated species, urethral epithelial cells with brush cell shape were immunolabeled in all 11 mammals. In 8 species, immunoreactivities against all marker proteins and ChAT were observed, and double-labeling immunofluorescence confirmed the cholinergic nature of villin-positive and chemosensory (TRPM5-positive) cells. In cat and horse, these cells were not labeled by the ChAT antiserum used in this study, and unspecific reactions of the secondary antiserum precluded conclusions about ChAT-expression in the bovine epithelium. These data indicate that urethral brush cells are widespread throughout the mammalian kingdom and evolved not later than about 64.5millionyears ago.

  20. REDUCTION OF ADENOSINE-A1-RECEPTORS IN THE PERFORANT PATHWAY TERMINAL ZONE IN ALZHEIMER HIPPOCAMPUS

    NARCIS (Netherlands)

    JAARSMA, D; SEBENS, JB; KORF, J

    1991-01-01

    The cells of origin of the perforant pathway are destroyed in Alzheimer's disease (AD). In rat the adenosine A1-receptors are specifically localized on the perforant path terminals in the molecular layer of the dentate gyrus. In the present study the density of A1-receptors in the hippocampus of Alz

  1. Evolutionary patterns of Toll-like receptor signaling pathway genes in the Suidae

    NARCIS (Netherlands)

    Darfour-Oduro, K.A.; Megens, Hendrik Jan; Roca, A.L.; Groenen, M.A.M.; Schook, L.B.

    2016-01-01

    Background: The Toll-like receptor (TLR) signaling pathway constitutes an essential component of the innate immune system. Highly conserved proteins, indicative of their critical roles in host survival, characterize this pathway. Selective constraints could vary depending on the gene's position w

  2. Neurobeachin Regulates Glutamate- and GABA-Receptor Targeting to Synapses via Distinct Pathways.

    Science.gov (United States)

    Farzana, F; Zalm, R; Chen, N; Li, K W; Grant, Seth G N; Smit, A B; Toonen, R F; Verhage, M

    2016-05-01

    Neurotransmission and synaptic strength depend on expression of post-synaptic receptors on the cell surface. Post-translational modification of receptors, trafficking to the synapse through the secretory pathway, and subsequent insertion into the synapse involves interaction of the receptor with A-kinase anchor proteins (AKAPs) and scaffolding proteins. Neurobeachin (Nbea), a brain specific AKAP, is required for synaptic surface expression of both glutamate and GABA receptors. Here, we investigated the role of Nbea-dependent targeting of postsynaptic receptors by studying Nbea interaction with synapse-associated protein 102 (SAP102/Dlg3) and protein kinase A subunit II (PKA II). A Nbea mutant lacking the PKA binding domain showed a similar distribution as wild-type Nbea in Nbea null neurons and partially restored GABA receptor surface expression. To understand the relevance of Nbea interaction with SAP102, we analysed SAP102 null mutant mice. Nbea levels were reduced by ~80% in SAP102 null mice, but glutamatergic receptor expression was normal. A single-point mutation in the pleckstrin homology domain of Nbea (E2218R) resulted in loss of binding with SAP102. When expressed in Nbea null neurons, this mutant fully restored GABA receptor surface expression, but not glutamate receptor expression. Our results suggest that the PKA-binding domain is not essential for Nbea's role in receptor targeting and that Nbea targets glutamate and GABA receptors to the synapse via distinct molecular pathways by interacting with specific effector proteins.

  3. Structural Characterization of the Putative Cholinergic Binding Region alpha(179-201) of the Nicotinic Acetylcholine Receptor. Part 1. Review and Experimental Design.

    Science.gov (United States)

    1993-04-01

    ct-bungarotoxin. Most studies indicate there are two binding sites per AchR rnonomer(Maelicke 1984; Popot and Changeux 1984), this is consistent with...Acetylcholine Receptor a-subunit by epitope mapping," J. Biol. Chem, vol. 265(0), pp. 569-581, 1990. Popot , J.L and Changeux, J-P, Nicotinic receptor of

  4. Heart failure causes cholinergic transdifferentiation of cardiac sympathetic nerves via gp130-signaling cytokines in rodents.

    Science.gov (United States)

    Kanazawa, Hideaki; Ieda, Masaki; Kimura, Kensuke; Arai, Takahide; Kawaguchi-Manabe, Haruko; Matsuhashi, Tomohiro; Endo, Jin; Sano, Motoaki; Kawakami, Takashi; Kimura, Tokuhiro; Monkawa, Toshiaki; Hayashi, Matsuhiko; Iwanami, Akio; Okano, Hideyuki; Okada, Yasunori; Ishibashi-Ueda, Hatsue; Ogawa, Satoshi; Fukuda, Keiichi

    2010-02-01

    Although several cytokines and neurotrophic factors induce sympathetic neurons to transdifferentiate into cholinergic neurons in vitro, the physiological and pathophysiological roles of this remain unknown. During congestive heart failure (CHF), sympathetic neural tone is upregulated, but there is a paradoxical reduction in norepinephrine synthesis and reuptake in the cardiac sympathetic nervous system (SNS). Here we examined whether cholinergic transdifferentiation can occur in the cardiac SNS in rodent models of CHF and investigated the underlying molecular mechanism(s) using genetically modified mice. We used Dahl salt-sensitive rats to model CHF and found that, upon CHF induction, the cardiac SNS clearly acquired cholinergic characteristics. Of the various cholinergic differentiation factors, leukemia inhibitory factor (LIF) and cardiotrophin-1 were strongly upregulated in the ventricles of rats with CHF. Further, LIF and cardiotrophin-1 secreted from cultured failing rat cardiomyocytes induced cholinergic transdifferentiation in cultured sympathetic neurons, and this process was reversed by siRNAs targeting Lif and cardiotrophin-1. Consistent with the data in rats, heart-specific overexpression of LIF in mice caused cholinergic transdifferentiation in the cardiac SNS. Further, SNS-specific targeting of the gene encoding the gp130 subunit of the receptor for LIF and cardiotrophin-1 in mice prevented CHF-induced cholinergic transdifferentiation. Cholinergic transdifferentiation was also observed in the cardiac SNS of autopsied patients with CHF. Thus, CHF causes target-dependent cholinergic transdifferentiation of the cardiac SNS via gp130-signaling cytokines secreted from the failing myocardium.

  5. Regulation of cellular metabolism by the Notch receptor signalling pathway

    OpenAIRE

    2012-01-01

    Seven genes involved in metabolism were tested as direct targets of the Notch signalling pathway. For each gene the occupancy of its enhancers by Su(H), its transcriptional response to Notch pathway and its biological functionality was verified in vitro and in vivo.

  6. Integrated Regulation of Toll-like Receptor Responses by Notch and Interferon-γ Pathways

    OpenAIRE

    2008-01-01

    Toll-like receptor (TLR) responses are regulated to avoid toxicity and achieve coordinated responses appropriate for the cell environment. We found that Notch and TLR pathways cooperated to activate canonical Notch target genes, including transcriptional repressors Hes1 and Hey1, and to increase production of canonical TLR-induced cytokines TNF, IL-6 and IL-12. Cooperation by these pathways to increase target gene expression was mediated the Notch pathway component and transcription factor RB...

  7. Morphine dependence and withdrawal induced changes in cholinergic signaling

    Science.gov (United States)

    Neugebauer, Nichole M.; Einstein, Emily B.; Lopez, Maria B.; McClure-Begley, Tristan D.; Mineur, Yann S.; Picciotto, Marina R.

    2013-01-01

    Cholinergic signaling is thought to be involved in morphine dependence and withdrawal, but the specific mechanisms involved remain unclear. The current study aimed to identify alterations in the cholinergic system that may contribute to the development of morphine dependence and withdrawal. Acetylcholinesterase (AChE) activity and [3H]-epibatidine binding were evaluated in order to determine if morphine dependence and withdrawal induces alterations in cholinergic signaling or expression of high affinity nicotinic acetylcholine receptors (nAChRs) in the midbrain (MB), medial habenula (MHb) and interpeduncular nucleus (IPN). The effect of cholinergic signaling through nAChRs on morphine-withdrawal induced jumping behavior was then determined. Lastly, the contribution of β4-containing nAChRs receptors in the MHb to morphine-withdrawal induced jumping behavior and neuronal activity as indicated by c-fos expression was assessed. Chronic morphine administration decreased AChE activity in MB and MHb, an effect that was no longer present following precipitated withdrawal. Morphine dependent mice showed increased nicotinic acetylcholine receptor (nAChR) levels in MB. Further, nicotine (0.4 mg/kg) and lobeline (3 mg/kg) decreased jumping behavior while mecamylamine (1 mg/kg) had no effect. Knock-down of β4 subunit-containing nAChRs in the MHb attenuated c-fos activation, but did not decrease morphine withdrawal-induced jumping. Thus, morphine withdrawal induces cholinergic signaling in the MHb, but this does not appear to be responsible for the effects of cholinergic drugs on somatic signs of opiate withdrawal, as measured by jumping behavior. PMID:23651795

  8. The involvement of cholinergic neurons in the spreading of tau pathology

    Directory of Open Access Journals (Sweden)

    Diana eSimon

    2013-06-01

    Full Text Available Long time ago, it was described the selective loss of cholinergic neurons during the development of Alzheimer disease. Recently, it has been suggested that tau protein may play a role in that loss of cholinergic neurons through a mechanism involving the interaction of extracellular tau with M1/M3 muscarinic receptors present in the cholinergic neurons. This interaction between tau and muscarinic receptors may be a way, although not the only one, to explain the spreading of tau pathology occurring in Alzheimer disease.

  9. The peroxisomal receptor dislocation pathway: to the exportomer and beyond.

    Science.gov (United States)

    Platta, Harald W; Hagen, Stefanie; Reidick, Christina; Erdmann, Ralf

    2014-03-01

    The biogenesis of peroxisomes is an ubiquitin-dependent process. In particular, the import of matrix proteins into the peroxisomal lumen requires the modification of import receptors with ubiquitin. The matrix proteins are synthesized on free polyribosomes in the cytosol and are recognized by import receptors via a peroxisomal targeting sequence (PTS). Subsequent to the transport of the receptor/cargo-complex to the peroxisomal membrane and the release of the cargo into the peroxisomal lumen, the PTS-receptors are exported back to the cytosol for further rounds of matrix protein import. The exportomer represents the molecular machinery required for the retrotranslocation of the PTS-receptors. It comprises enzymes for the ubiquitination as well as for the ATP-dependent extraction of the PTS-receptors from the peroxisomal membrane. Furthermore, recent evidence indicates a mechanistic interconnection of the ATP-dependent removal of the PTS-receptors with the translocation of the matrix protein into the organellar lumen. Interestingly, the components of the peroxisomal exportomer seem also to be involved in cellular tasks that are distinct from the ubiquitination and dislocation of the peroxisomal PTS-receptors. This includes work that indicates a central function of this machinery in the export of peroxisomal matrix proteins in plants, while a subset of exportomer components is involved in the meiocyte formation in some fungi, the peroxisome-chloroplast contact during photorespiration in plants and possibly even the selective degradation of peroxisomes via pexophagy. In this review, we want to discuss the central role of the exportomer during matrix protein import, but also highlight distinct roles of exportomer constituents in additional cellular processes. This article is part of a Special Issue entitled: Peroxisomes: biogenesis, functions and diseases.

  10. Cholinergic Signaling Exerts Protective Effects in Models of Sympathetic Hyperactivity-Induced Cardiac Dysfunction

    Science.gov (United States)

    Gavioli, Mariana; Lara, Aline; Almeida, Pedro W. M.; Lima, Augusto Martins; Damasceno, Denis D.; Rocha-Resende, Cibele; Ladeira, Marina; Resende, Rodrigo R.; Martinelli, Patricia M.; Melo, Marcos Barrouin; Brum, Patricia C.; Fontes, Marco Antonio Peliky; Souza Santos, Robson A.; Prado, Marco A. M.; Guatimosim, Silvia

    2014-01-01

    Cholinergic control of the heart is exerted by two distinct branches; the autonomic component represented by the parasympathetic nervous system, and the recently described non-neuronal cardiomyocyte cholinergic machinery. Previous evidence has shown that reduced cholinergic function leads to deleterious effects on the myocardium. Yet, whether conditions of increased cholinergic signaling can offset the pathological remodeling induced by sympathetic hyperactivity, and its consequences for these two cholinergic axes are unknown. Here, we investigated two models of sympathetic hyperactivity: i) the chronic beta-adrenergic receptor stimulation evoked by isoproterenol (ISO), and ii) the α2A/α2C-adrenergic receptor knockout (KO) mice that lack pre-synaptic adrenergic receptors. In both models, cholinergic signaling was increased by administration of the cholinesterase inhibitor, pyridostigmine. First, we observed that isoproterenol produces an autonomic imbalance characterized by increased sympathetic and reduced parasympathetic tone. Under this condition transcripts for cholinergic proteins were upregulated in ventricular myocytes, indicating that non-neuronal cholinergic machinery is activated during adrenergic overdrive. Pyridostigmine treatment prevented the effects of ISO on autonomic function and on the ventricular cholinergic machinery, and inhibited cardiac remodeling. α2A/α2C-KO mice presented reduced ventricular contraction when compared to wild-type mice, and this dysfunction was also reversed by cholinesterase inhibition. Thus, the cardiac parasympathetic system and non-neuronal cardiomyocyte cholinergic machinery are modulated in opposite directions under conditions of increased sympathetic drive or ACh availability. Moreover, our data support the idea that pyridostigmine by restoring ACh availability is beneficial in heart disease. PMID:24992197

  11. Cholinergic signaling exerts protective effects in models of sympathetic hyperactivity-induced cardiac dysfunction.

    Directory of Open Access Journals (Sweden)

    Mariana Gavioli

    Full Text Available Cholinergic control of the heart is exerted by two distinct branches; the autonomic component represented by the parasympathetic nervous system, and the recently described non-neuronal cardiomyocyte cholinergic machinery. Previous evidence has shown that reduced cholinergic function leads to deleterious effects on the myocardium. Yet, whether conditions of increased cholinergic signaling can offset the pathological remodeling induced by sympathetic hyperactivity, and its consequences for these two cholinergic axes are unknown. Here, we investigated two models of sympathetic hyperactivity: i the chronic beta-adrenergic receptor stimulation evoked by isoproterenol (ISO, and ii the α2A/α2C-adrenergic receptor knockout (KO mice that lack pre-synaptic adrenergic receptors. In both models, cholinergic signaling was increased by administration of the cholinesterase inhibitor, pyridostigmine. First, we observed that isoproterenol produces an autonomic imbalance characterized by increased sympathetic and reduced parasympathetic tone. Under this condition transcripts for cholinergic proteins were upregulated in ventricular myocytes, indicating that non-neuronal cholinergic machinery is activated during adrenergic overdrive. Pyridostigmine treatment prevented the effects of ISO on autonomic function and on the ventricular cholinergic machinery, and inhibited cardiac remodeling. α2A/α2C-KO mice presented reduced ventricular contraction when compared to wild-type mice, and this dysfunction was also reversed by cholinesterase inhibition. Thus, the cardiac parasympathetic system and non-neuronal cardiomyocyte cholinergic machinery are modulated in opposite directions under conditions of increased sympathetic drive or ACh availability. Moreover, our data support the idea that pyridostigmine by restoring ACh availability is beneficial in heart disease.

  12. Quantitative impedimetric NPY-receptor activation monitoring and signal pathway profiling in living cells.

    Science.gov (United States)

    te Kamp, Verena; Lindner, Ricco; Jahnke, Heinz-Georg; Krinke, Dana; Kostelnik, Katja B; Beck-Sickinger, Annette G; Robitzki, Andrea A

    2015-05-15

    Label-free and non-invasive monitoring of receptor activation and identification of the involved signal pathways in living cells is an ongoing analytic challenge and a great opportunity for biosensoric systems. In this context, we developed an impedance spectroscopy-based system for the activation monitoring of NPY-receptors in living cells. Using an optimized interdigital electrode array for sensitive detection of cellular alterations, we were able for the first time to quantitatively detect the NPY-receptor activation directly without a secondary or enhancer reaction like cAMP-stimulation by forskolin. More strikingly, we could show that the impedimetric based NPY-receptor activation monitoring is not restricted to the Y1-receptor but also possible for the Y2- and Y5-receptor. Furthermore, we could monitor the NPY-receptor activation in different cell lines that natively express NPY-receptors and proof the specificity of the observed impedimetric effect by agonist/antagonist studies in recombinant NPY-receptor expressing cell lines. To clarify the nature of the observed impedimetric effect we performed an equivalent circuit analysis as well as analyzed the role of cell morphology and receptor internalization. Finally, an antagonist based extensive molecular signal pathway analysis revealed small alterations of the actin cytoskeleton as well as the inhibition of at least L-type calcium channels as major reasons for the observed NPY-induced impedance increase. Taken together, our novel impedance spectroscopy based NPY-receptor activation monitoring system offers the opportunity to identify signal pathways as well as for novel versatile agonist/antagonist screening systems for identification of novel therapeutics in the field of obesity and cancer.

  13. Molecular pathways: the role of NR4A orphan nuclear receptors in cancer.

    LENUS (Irish Health Repository)

    Mohan, Helen M

    2012-06-15

    Nuclear receptors are of integral importance in carcinogenesis. Manipulation of classic ligand-activated nuclear receptors, such as estrogen receptor blockade in breast cancer, is an important established cancer therapy. Orphan nuclear receptors, such as nuclear family 4 subgroup A (NR4A) receptors, have no known natural ligand(s). These elusive receptors are increasingly recognized as molecular switches in cell survival and a molecular link between inflammation and cancer. NR4A receptors act as transcription factors, altering expression of downstream genes in apoptosis (Fas-ligand, TRAIL), proliferation, DNA repair, metabolism, cell migration, inflammation (interleukin-8), and angiogenesis (VEGF). NR4A receptors are modulated by multiple cell-signaling pathways, including protein kinase A\\/CREB, NF-κB, phosphoinositide 3-kinase\\/AKT, c-jun-NH(2)-kinase, Wnt, and mitogen-activated protein kinase pathways. NR4A receptor effects are context and tissue specific, influenced by their levels of expression, posttranslational modification, and interaction with other transcription factors (RXR, PPAR-Υ). The subcellular location of NR4A "nuclear receptors" is also important functionally; novel roles have been described in the cytoplasm where NR4A proteins act both indirectly and directly on the mitochondria to promote apoptosis via Bcl-2. NR4A receptors are implicated in a wide variety of malignancies, including breast, lung, colon, bladder, and prostate cancer; glioblastoma multiforme; sarcoma; and acute and\\/or chronic myeloid leukemia. NR4A receptors modulate response to conventional chemotherapy and represent an exciting frontier for chemotherapeutic intervention, as novel agents targeting NR4A receptors have now been developed. This review provides a concise clinical overview of current knowledge of NR4A signaling in cancer and the potential for therapeutic manipulation.

  14. Endogenous cholinergic neurotransmission contributes to behavioral sensitization to morphine.

    Directory of Open Access Journals (Sweden)

    Dusica Bajic

    Full Text Available Neuroplasticity in the mesolimbic dopaminergic system is critical for behavioral adaptations associated with opioid reward and addiction. These processes may be influenced by cholinergic transmission arising from the laterodorsal tegmental nucleus (LDTg, a main source of acetylcholine to mesolimbic dopaminergic neurons. To examine this possibility we asked if chronic systemic morphine administration affects expression of genes in ventral and ventrolateral periaqueductal gray at the level of the LDTg using rtPCR. Specifically, we examined gene expression changes in the area of interest using Neurotransmitters and Receptors PCR array between chronic morphine and saline control groups. Analysis suggested that chronic morphine administration led to changes in expression of genes associated, in part, with cholinergic neurotransmission. Furthermore, using a quantitative immunofluorescent technique, we found that chronic morphine treatment produced a significant increase in immunolabeling of the cholinergic marker (vesicular acetylcholine transporter in neurons of the LDTg. Finally, systemic administration of the nonselective and noncompetitive neuronal nicotinic antagonist mecamylamine (0.5 or 2 mg/kg dose-dependently blocked the expression, and to a lesser extent the development, of locomotor sensitization. The same treatment had no effect on acute morphine antinociception, antinociceptive tolerance or dependence to chronic morphine. Taken together, the results suggest that endogenous nicotinic cholinergic neurotransmission selectively contributes to behavioral sensitization to morphine and this process may, in part, involve cholinergic neurons within the LDTg.

  15. Kainate receptors mediate signaling in both transient and sustained OFF bipolar cell pathways in mouse retina.

    Science.gov (United States)

    Borghuis, Bart G; Looger, Loren L; Tomita, Susumu; Demb, Jonathan B

    2014-04-30

    A fundamental question in sensory neuroscience is how parallel processing is implemented at the level of molecular and circuit mechanisms. In the retina, it has been proposed that distinct OFF cone bipolar cell types generate fast/transient and slow/sustained pathways by the differential expression of AMPA- and kainate-type glutamate receptors, respectively. However, the functional significance of these receptors in the intact circuit during light stimulation remains unclear. Here, we measured glutamate release from mouse bipolar cells by two-photon imaging of a glutamate sensor (iGluSnFR) expressed on postsynaptic amacrine and ganglion cell dendrites. In both transient and sustained OFF layers, cone-driven glutamate release from bipolar cells was blocked by antagonists to kainate receptors but not AMPA receptors. Electrophysiological recordings from bipolar and ganglion cells confirmed the essential role of kainate receptors for signaling in both transient and sustained OFF pathways. Kainate receptors mediated responses to contrast modulation up to 20 Hz. Light-evoked responses in all mouse OFF bipolar pathways depend on kainate, not AMPA, receptors.

  16. N-Methyl-D-Aspartate Receptor Antagonist MK-801 and Radical Scavengers Protect Cholinergic Nucleus Basalis Neurons against β-Amyloid Neurotoxicity

    NARCIS (Netherlands)

    Harkany, T.; Mulder, J.; Sasvári, M.; Ábrahám, I.; Kónya, C.; Zarándi, M.; Penke, B.; Luiten, P.G.M.; Nyakas, C.

    1999-01-01

    Previous experimental data indicate the involvement of Ca2+-related excitotoxic processes, possibly mediated by N-Methyl-D-Aspartate (NMDA) receptors, in β-amyloid (βA) neurotoxicity. On the other hand, other lines of evidence support the view that free radical generation is a critical step in the β

  17. N-methyl-D-aspartate receptor antagonist MK-801 and radical scavengers protect cholinergic nucleus basalis neurons against beta-amyloid neurotoxicity

    NARCIS (Netherlands)

    Harkany, T; Mulder, J; Sasvari, M; Abraham, [No Value; Konya, C; Zarandi, M; Penke, B; Luiten, PGM; Nyakas, C

    1999-01-01

    Previous experimental data indicate the involvement of Ca2+-related excitotoxic processes, possibly mediated by N-Methyl-D-Aspartate (NMDA) receptors, in beta-amyloid (beta A) neurotoxicity. On the other hand, other lines of evidence support the view that free radical generation is a critical step i

  18. Cholinergic deficiency involved in vascular dementia:possible mechanism and strategy of treatment

    Institute of Scientific and Technical Information of China (English)

    Juan WANG; Hai-yan ZHANG; Xi-can TANG

    2009-01-01

    Vascular dementia (VaD) is a progressive neurodegenerative disease with a high prevalence.Several studies have recently reported that VaD patients present cholinergic deficits in the brain and cerebrospinal fluid (CSF) that may be closely related to the pathophysiology of cognitive impairment.Moreover,cholinergic therapies have shown promising effects on cognitive improvement in VaD patients.The precise mechanisms of these cholinergic agents are currently not fully understood;however,accumulating evidence indicates that these drugs may act through the cholinergic anti-inflammatory pathway,in which the efferent vagus nerve signals suppress pro-inflammatory cytokine release and inhibit inflammation,although regulation of oxidative stress and energy metabolism,alleviation of apoptosis may also be involved.In this paper,we provide a brief overview of the cholinergic treatment strategy for VaD and its relevant mechanisms of anti-inflammation.

  19. DMPD: Signal transduction pathways mediated by the interaction of CpG DNA withToll-like receptor 9. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 14751759 Signal transduction pathways mediated by the interaction of CpG DNA withTo...;16(1):17-22. (.png) (.svg) (.html) (.csml) Show Signal transduction pathways mediated by the interaction of... CpG DNA withToll-like receptor 9. PubmedID 14751759 Title Signal transduction pathways media

  20. Nicotinic and muscarinic agonists and acetylcholinesterase inhibitors stimulate a common pathway to enhance GluN2B-NMDAR responses

    Science.gov (United States)

    Ishibashi, Masaru; Yamazaki, Yoshihiko; Miledi, Ricardo; Sumikawa, Katumi

    2014-01-01

    Nicotinic and muscarinic ACh receptor agonists and acetylcholinesterase inhibitors (AChEIs) can enhance cognitive function. However, it is unknown whether a common signaling pathway is involved in the effect. Here, we show that in vivo administration of nicotine, AChEIs, and an m1 muscarinic (m1) agonist increase glutamate receptor, ionotropic, N-methyl D-aspartate 2B (GluN2B)-containing NMDA receptor (NR2B-NMDAR) responses, a necessary component in memory formation, in hippocampal CA1 pyramidal cells, and that coadministration of the m1 antagonist pirenzepine prevents the effect of cholinergic drugs. These observations suggest that the effect of nicotine is secondary to increased release of ACh via the activation of nicotinic ACh receptors (nAChRs) and involves m1 receptor activation through ACh. In vitro activation of m1 receptors causes the selective enhancement of NR2B-NMDAR responses in CA1 pyramidal cells, and in vivo exposure to cholinergic drugs occludes the in vitro effect. Furthermore, in vivo exposure to cholinergic drugs suppresses the potentiating effect of Src on NMDAR responses in vitro. These results suggest that exposure to cholinergic drugs maximally stimulates the m1/guanine nucleotide-binding protein subunit alpha q/PKC/proline-rich tyrosine kinase 2/Src signaling pathway for the potentiation of NMDAR responses in vivo, occluding the in vitro effects of m1 activation and Src. Thus, our results indicate not only that nAChRs, ACh, and m1 receptors are on the same pathway involving Src signaling but also that NR2B-NMDARs are a point of convergence of cholinergic and glutamatergic pathways involved in learning and memory. PMID:25114227

  1. G-Protein–Coupled Receptors Signaling Pathways in New Antiplatelet Drug Development

    OpenAIRE

    Gurbel, Paul A.; Kuliopulos, Athan; Tantry, Udaya S.

    2015-01-01

    Platelet G-protein–coupled receptors influence platelet function by mediating the response to various agonists, including ADP, thromboxane A2, and thrombin. Blockade of the ADP receptor, P2Y12, in combination with cyclooxygenase-1 inhibition by aspirin has been among the most widely used pharmacological strategies to reduce cardiovascular event occurrence in high-risk patients. The latter dual pathway blockade strategy is one of the greatest advances in the field of cardiovascular medicine. I...

  2. Probing Wnt Receptor Turnover: A Critical Regulatory Point of Wnt Pathway.

    Science.gov (United States)

    Jiang, Xiaomo; Cong, Feng

    2016-01-01

    Wnt pathways are critical for embryonic development and adult tissue homeostasis in all multicellular animals. Many regulatory mechanisms exist to control proper signaling output. Recent studies suggest that cell surface Wnt receptor level is controlled by ubiquitination, and serve as a critical regulatory point of Wnt pathway activity as it determines the responsiveness of cells to Wnt signal. Here, we describe flow cytometry, cell surface protein biotinylation, and immunofluorescence pulse-chase methods to probe the surface expression, ubiquitination, and internalization of the Wnt receptors FZD and LRP6.

  3. Delineation of the GPRC6A Receptor Signaling Pathways Using a Mammalian Cell Line Stably Expressing the Receptor

    DEFF Research Database (Denmark)

    Jacobsen, Stine Engesgaard; Nørskov-Lauritsen, Lenea; Thomsen, Alex Rojas Bie;

    2013-01-01

    receptor has been suggested to couple to multiple G protein classes albeit via indirect methods. Thus, the exact ligand preferences and signaling pathways are yet to be elucidated. In the present study, we generated a Chinese hamster ovary (CHO) cell line that stably expresses mouse GPRC6A. In an effort...... of the stable CHO cell line with robust receptor responsiveness and optimization of the highly sensitive homogeneous time resolved fluorescence technology allow fast assessment of Gq activation without previous manipulations like cotransfection of mutated G proteins. This cell-based assay system for GPRC6A...

  4. The catecholaminergic-cholinergic balance hypothesis of bipolar disorder revisited.

    Science.gov (United States)

    van Enkhuizen, Jordy; Janowsky, David S; Olivier, Berend; Minassian, Arpi; Perry, William; Young, Jared W; Geyer, Mark A

    2015-04-15

    Bipolar disorder is a unique illness characterized by fluctuations between mood states of depression and mania. Originally, an adrenergic-cholinergic balance hypothesis was postulated to underlie these different affective states. In this review, we update this hypothesis with recent findings from human and animal studies, suggesting that a catecholaminergic-cholinergic hypothesis may be more relevant. Evidence from neuroimaging studies, neuropharmacological interventions, and genetic associations support the notion that increased cholinergic functioning underlies depression, whereas increased activations of the catecholamines (dopamine and norepinephrine) underlie mania. Elevated functional acetylcholine during depression may affect both muscarinic and nicotinic acetylcholine receptors in a compensatory fashion. Increased functional dopamine and norepinephrine during mania on the other hand may affect receptor expression and functioning of dopamine reuptake transporters. Despite increasing evidence supporting this hypothesis, a relationship between these two neurotransmitter systems that could explain cycling between states of depression and mania is missing. Future studies should focus on the influence of environmental stimuli and genetic susceptibilities that may affect the catecholaminergic-cholinergic balance underlying cycling between the affective states. Overall, observations from recent studies add important data to this revised balance theory of bipolar disorder, renewing interest in this field of research.

  5. Preferential entry of botulinum neurotoxin A Hc domain through intestinal crypt cells and targeting to cholinergic neurons of the mouse intestine.

    Directory of Open Access Journals (Sweden)

    Aurélie Couesnon

    Full Text Available Botulism, characterized by flaccid paralysis, commonly results from botulinum neurotoxin (BoNT absorption across the epithelial barrier from the digestive tract and then dissemination through the blood circulation to target autonomic and motor nerve terminals. The trafficking pathway of BoNT/A passage through the intestinal barrier is not yet fully understood. We report that intralumenal administration of purified BoNT/A into mouse ileum segment impaired spontaneous muscle contractions and abolished the smooth muscle contractions evoked by electric field stimulation. Entry of BoNT/A into the mouse upper small intestine was monitored with fluorescent HcA (half C-terminal domain of heavy chain which interacts with cell surface receptor(s. We show that HcA preferentially recognizes a subset of neuroendocrine intestinal crypt cells, which probably represent the entry site of the toxin through the intestinal barrier, then targets specific neurons in the submucosa and later (90-120 min in the musculosa. HcA mainly binds to certain cholinergic neurons of both submucosal and myenteric plexuses, but also recognizes, although to a lower extent, other neuronal cells including glutamatergic and serotoninergic neurons in the submucosa. Intestinal cholinergic neuron targeting by HcA could account for the inhibition of intestinal peristaltism and secretion observed in botulism, but the consequences of the targeting to non-cholinergic neurons remains to be determined.

  6. From behavioral context to receptors: serotonergic modulatory pathways in the IC.

    Science.gov (United States)

    Hurley, Laura M; Sullivan, Megan R

    2012-01-01

    In addition to ascending, descending, and lateral auditory projections, inputs extrinsic to the auditory system also influence neural processing in the inferior colliculus (IC). These types of inputs often have an important role in signaling salient factors such as behavioral context or internal state. One route for such extrinsic information is through centralized neuromodulatory networks like the serotonergic system. Serotonergic inputs to the IC originate from centralized raphe nuclei, release serotonin in the IC, and activate serotonin receptors expressed by auditory neurons. Different types of serotonin receptors act as parallel pathways regulating specific features of circuitry within the IC. This results from variation in subcellular localizations and effector pathways of different receptors, which consequently influence auditory responses in distinct ways. Serotonin receptors may regulate GABAergic inhibition, influence response gain, alter spike timing, or have effects that are dependent on the level of activity. Serotonin receptor types additionally interact in nonadditive ways to produce distinct combinatorial effects. This array of effects of serotonin is likely to depend on behavioral context, since the levels of serotonin in the IC transiently increase during behavioral events including stressful situations and social interaction. These studies support a broad model of serotonin receptors as a link between behavioral context and reconfiguration of circuitry in the IC, and the resulting possibility that plasticity at the level of specific receptor types could alter the relationship between context and circuit function.

  7. Characterizing and Targeting Androgen Receptor Pathway-Independent Prostate Cancer

    Science.gov (United States)

    2013-11-01

    Histone demethylation mediated by the nuclear amine oxidase homolog LSD1. Cell 119, 941–953. Shi, Y.J., Matson, C., Lan, F., Iwase, S., Baba, T., and...dione) pathway to DHT by protein resistance to ubiquitination and degradation rather than increased catalytic activity. Selection for 3bHSD1(367T) is... Bio -Rad) in an ABI-7500 Real-Time PCR machine (Applied Biosystems). Protein half- life was determined after transient transfection with pCMX-HSD3B1-HA

  8. Muscarinic receptor-mediated bronchoconstriction is coupled to caveolae in murine airways

    OpenAIRE

    Schlenz, Heike; Kummer, Wolfgang; Jositsch, Gitte; Wess, Jürgen; Krasteva, Gabriela

    2009-01-01

    Cholinergic bronchoconstriction is mediated by M2 and M3 muscarinic receptors (MR). In heart and urinary bladder, MR are linked to caveolin-1 or -3, the structural proteins of caveolae. Caveolae are cholesterol-rich, omega-shaped invaginations of the plasma membrane. They provide a scaffold for multiple G protein receptors and membrane-bound enzymes, thereby orchestrating signaling into the cell interior. Hence, we hypothesized that airway MR signaling pathways are coupled to caveolae as well...

  9. Membrane glycoprotein M6A promotes μ-opioid receptor endocytosis and facilitates receptor sorting into the recycling pathway

    Institute of Scientific and Technical Information of China (English)

    Ying-Jian Liang; Dai-Fei Wu; Ralf Stumm; Volker H(o)llt; Thomas Koch

    2008-01-01

    The interaction of μ-opioid receptor (MOPr) with the neuronal membrane glycoprotein M6a is known to facilitate MOPr endocytosis in human embryonic kidney 293 (HEK293) cells. To further study the role of M6a in the post-endocytotic sorting of MOPr, we investigated the agonist-induced co-internalization of MOPr and M6a and protein targeting after internalization in HEK293 cells that co-expressed HA-tagged MOPr and Myc-tagged M6a. We found that M6a, MOPr, and Rab 11, a marker for recycling endosomes, co-localized in endocytotic vesicles, indicating that MOPr and M6a are primarily targeted to recycling endosomes after endocytosis. Furthermore, co-expression of M6a augmented the post-endocytotic sorting of δ-opioid receptors into the recycling pathway, indicating that M6a might have a more general role in opioid receptor post-ndocytotic sorting. The enhanced post-endocytotic sorting of MOPr into the recycling pathway was accompanied by a decrease in agonist-induced receptor down-regulation of M6a in co-expressing cells. We tested the physiological relevance of these findings in primary cultures of cortical neurons and found that co-expression of M6a markedly increased the translocation of MOPrs from the plasma membrane to intracellular vesicles at steady state and significantly enhanced both constitutive and agonist-induced receptor endocytosis. In conclusion, our results strongly indicate that M6a modulates MOPr endocytosis and post-endocytotic sorting and has an important role in receptor regulation.

  10. Novel aspects of cholinergic regulation of colonic ion transport

    Science.gov (United States)

    Bader, Sandra; Diener, Martin

    2015-01-01

    Nicotinic receptors are not only expressed by excitable tissues, but have been identified in various epithelia. One aim of this study was to investigate the expression of nicotinic receptors and their involvement in the regulation of ion transport across colonic epithelium. Ussing chamber experiments with putative nicotinic agonists and antagonists were performed at rat colon combined with reverse transcription polymerase chain reaction (RT-PCR) detection of nicotinic receptor subunits within the epithelium. Dimethylphenylpiperazinium (DMPP) and nicotine induced a tetrodotoxin-resistant anion secretion leading to an increase in short-circuit current (Isc) across colonic mucosa. The response was suppressed by the nicotinic receptor antagonist hexamethonium. RT-PCR experiments revealed the expression of α2, α4, α5, α6, α7, α10, and β4 nicotinic receptor subunits in colonic epithelium. Choline, the product of acetylcholine hydrolysis, is known for its affinity to several nicotinic receptor subtypes. As a strong acetylcholinesterase activity was found in colonic epithelium, the effect of choline on Isc was examined. Choline induced a concentration-dependent, tetrodotoxin-resistant chloride secretion which was, however, resistant against hexamethonium, but was inhibited by atropine. Experiments with inhibitors of muscarinic M1 and M3 receptors revealed that choline-evoked secretion was mainly due to a stimulation of epithelial M3 receptors. Although choline proved to be only a partial agonist, it concentration-dependently desensitized the response to acetylcholine, suggesting that it might act as a modulator of cholinergically induced anion secretion. Thus the cholinergic regulation of colonic ion transport – up to now solely explained by cholinergic submucosal neurons stimulating epithelial muscarinic receptors – is more complex than previously assumed. PMID:26236483

  11. Long-term relationships between cholinergic tone, synchronous bursting and synaptic remodeling.

    Directory of Open Access Journals (Sweden)

    Maya Kaufman

    Full Text Available Cholinergic neuromodulation plays key roles in the regulation of neuronal excitability, network activity, arousal, and behavior. On longer time scales, cholinergic systems play essential roles in cortical development, maturation, and plasticity. Presumably, these processes are associated with substantial synaptic remodeling, yet to date, long-term relationships between cholinergic tone and synaptic remodeling remain largely unknown. Here we used automated microscopy combined with multielectrode array recordings to study long-term relationships between cholinergic tone, excitatory synapse remodeling, and network activity characteristics in networks of cortical neurons grown on multielectrode array substrates. Experimental elevations of cholinergic tone led to the abrupt suppression of episodic synchronous bursting activity (but not of general activity, followed by a gradual growth of excitatory synapses over hours. Subsequent blockage of cholinergic receptors led to an immediate restoration of synchronous bursting and the gradual reversal of synaptic growth. Neither synaptic growth nor downsizing was governed by multiplicative scaling rules. Instead, these occurred in a subset of synapses, irrespective of initial synaptic size. Synaptic growth seemed to depend on intrinsic network activity, but not on the degree to which bursting was suppressed. Intriguingly, sustained elevations of cholinergic tone were associated with a gradual recovery of synchronous bursting but not with a reversal of synaptic growth. These findings show that cholinergic tone can strongly affect synaptic remodeling and synchronous bursting activity, but do not support a strict coupling between the two. Finally, the reemergence of synchronous bursting in the presence of elevated cholinergic tone indicates that the capacity of cholinergic neuromodulation to indefinitely suppress synchronous bursting might be inherently limited.

  12. [Modulation of the cholinergic system during inflammation].

    Science.gov (United States)

    Nezhinskaia, G I; Vladykin, A L; Sapronov, N S

    2008-01-01

    This review describes the effects of realization of the central and peripheral "cholinergic antiinflammatory pathway" in a model of endotoxic and anaphylactic shock. Under endotoxic shock conditions, a pharmacological correction by means of the central m-cholinomimetic action (electrical stimulation of the distal ends of nervus vagus after bilateral cervical vagotomy, surgical implantation of the stimulant devise, activation of efferent vagal neurons by means of muscarinic agonist) is directed toward the elimination of LPS-induced hypotension. During the anaphylaxis, peripheral effects of the cholinergic system induced by blocking m-AChR on the target cells (neuronal and non-neuronal lung cells) and acetylcholinesterase inhibition are related to suppression of the bronchoconstrictor response. The role of immune system in the pathogenesis of endotoxic shock is associated with the production of proinflammatory cytokines by macrophages, increase in IgM concentration, and complement activation, while the role in the pathogenesis of anaphylactic shock is associated with IgE, IgG1 augmentation. Effects of B cell stimulation may be important in hypoxia and in the prophylaxis of stress ulcers and other diseases. Plasma proteins can influence the effects of the muscarinic antagonist methacine: IgG enhance its action while albumin and CRP abolish it.

  13. Physical urticarias and cholinergic urticaria.

    Science.gov (United States)

    Abajian, Marina; Schoepke, Nicole; Altrichter, Sabine; Zuberbier, Torsten; Zuberbier, H C Torsten; Maurer, Marcus

    2014-02-01

    Physical urticarias are a unique subgroup of chronic urticaria in which urticarial responses can be reproducibly induced by different specific physical stimuli acting on the skin. These conditions include urticaria factitia/symptomatic dermographism, delayed pressure urticaria, cold contact urticaria, heat contact urticaria, solar urticaria, and vibratory urticaria/angioedema. Physical urticarias and cholinergic urticarias are diagnosed based on the patients' history and provocation tests including trigger threshold testing where possible. Treatment is mainly symptomatic. Many patients benefit from avoiding eliciting triggers, and desensitization to these triggers can be helpful in some physical urticarias and in cholinergic urticaria.

  14. Transcriptional Crosstalk between Nuclear Receptors and Cytokine Signal Transduction Pathways in Immunity

    Institute of Scientific and Technical Information of China (English)

    Lihua Wang; Xiaohu Zhang; William L. Farrar; Xiaoyi Yang

    2004-01-01

    The nuclear receptor superfamily and the transcriptional factors associated with cytokines are inherently different families of signaling molecules and activate gene transcription by binding to their respective responsive element. However, it has become increasingly clear from our works and others that nuclear receptors are important regulators of cytokine production and function through complex and varied interactions between these distinct transcriptional factors. This review provides a general overview of the mechanism of action of nuclear receptors and their transcriptional crosstalk with transcriptional factors associated with cytokine transduction pathways. One of the most important mechanistic aspects is protein to protein interaction through a direct or co-regulator-mediated indirect manner. Such crosstalk is crucially involved in physiological and therapeutic roles of nuclear receptors and their ligands in immunity,inflammation and cytokine-related tumors. Cellular & Molecular Immunology. 2004;1(6):416-424.

  15. Olfactory receptor and neural pathway responsible for highly selective sensing of musk odors.

    Science.gov (United States)

    Shirasu, Mika; Yoshikawa, Keiichi; Takai, Yoshiki; Nakashima, Ai; Takeuchi, Haruki; Sakano, Hitoshi; Touhara, Kazushige

    2014-01-01

    Musk odorants are used widely in cosmetic industries because of their fascinating animalic scent. However, how this aroma is perceived in the mammalian olfactory system remains a great mystery. Here, we show that muscone, one musk odor secreted by various animals from stink glands, activates a few glomeruli clustered in a neuroanatomically unique anteromedial olfactory bulb. The muscone-responsive glomeruli are highly specific to macrocyclic ketones; interestingly, other synthetic musk odorants with nitro or polycyclic moieties or ester bonds activate distinct but nearby glomeruli. Anterodorsal bulbar lesions cause muscone anosmia, suggesting that this region is involved in muscone perception. Finally, we identified the mouse olfactory receptor, MOR215-1, that was a specific muscone receptor expressed by neurons innervating the muscone-responsive anteromedial glomeruli and also the human muscone receptor, OR5AN1. The current study documents the olfactory neural pathway in mice that senses and transmits musk signals from receptor to brain.

  16. M2-like macrophages are responsible for collagen degradation through a mannose receptor-mediated pathway

    DEFF Research Database (Denmark)

    Madsen, Daniel H; Leonard, Daniel; Masedunskas, Andrius

    2013-01-01

    of the collagen receptors mannose receptor (Mrc1) and urokinase plasminogen activator receptor-associated protein (Endo180 and Mrc2) impaired this intracellular collagen degradation pathway. This study demonstrates the importance of receptor-mediated cellular uptake to collagen turnover in vivo and identifies......Tissue remodeling processes critically depend on the timely removal and remodeling of preexisting collagen scaffolds. Nevertheless, many aspects related to the turnover of this abundant extracellular matrix component in vivo are still incompletely understood. We therefore took advantage of recent...... advances in optical imaging to develop an assay to visualize collagen turnover in situ and identify cell types and molecules involved in this process. Collagen introduced into the dermis of mice underwent cellular endocytosis in a partially matrix metalloproteinase-dependent manner and was subsequently...

  17. Endogenous cholinergic input to the pontine REM sleep generator is not required for REM sleep to occur.

    Science.gov (United States)

    Grace, Kevin P; Vanstone, Lindsay E; Horner, Richard L

    2014-10-22

    Initial theories of rapid eye movement (REM) sleep generation posited that induction of the state required activation of the pontine subceruleus (SubC) by cholinergic inputs. Although the capacity of cholinergic neurotransmission to contribute to REM sleep generation has been established, the role of cholinergic inputs in the generation of REM sleep is ultimately undetermined as the critical test of this hypothesis (local blockade of SubC acetylcholine receptors) has not been rigorously performed. We used bilateral microdialysis in freely behaving rats (n = 32), instrumented for electroencephalographic and electromyographic recording, to locally manipulate neurotransmission in the SubC with select drugs. As predicted, combined microperfusion of D-AP5 (glutamate receptor antagonist) and muscimol (GABAA receptor agonist) in the SubC virtually eliminated REM sleep. However, REM sleep was not reduced by scopolamine microperfusion in this same region, at a concentration capable of blocking the effects of cholinergic receptor stimulation. This result suggests that transmission of REM sleep drive to the SubC is acetylcholine-independent. Although SubC cholinergic inputs are not majorly involved in REM sleep generation, they may perform a minor function in the reinforcement of transitions into REM sleep, as evidenced by increases in non-REM-to-REM sleep transition duration and failure rate during cholinergic receptor blockade. Cholinergic receptor antagonism also attenuated the normal increase in hippocampal θ oscillations that characterize REM sleep. Using computational modeling, we show that our in vivo results are consistent with a mutually excitatory interaction between the SubC and cholinergic neurons where, importantly, cholinergic neuron activation is gated by SubC activity.

  18. Experiment K-7-18: Effects of Spaceflight in the Muscle Adductor Longus of Rats Flown in the Soviet Biosatellite Cosmos 2044. Part 2; Quantitative Autoradiographic Analysis of Gaba (Benzodiazepine) and Muscarinic (Cholinergic) Receptors in the Forebrain of Rats Flown on Cosmos 2044

    Science.gov (United States)

    Wu, L.; Daunton, N. G.; Krasnov, I. B.; DAmelio, F.; Hyde, T. M.; Sigworth, S. K.

    1994-01-01

    Quantitative autoradiographic analysis of receptors for GABA and acetylcholine in the forebrain of rats flown on COSMOS 2044 was undertaken as part of a joint US-Soviet study to determine the effects of microgravity on the central nervous system, and in particular on the sensory and motor portions of the forebrain. Changes in binding of these receptors in tissue from animals exposed to microgravity would provide evidence for possible changes in neural processing as a result of exposure to microgravity. Tritium-labelled diazepam and Quinuclidinyl-benzilate (QNB) were used to visualize GABA (benzodiazepine) and muscarinic (cholinergic) receptors, respectively. The density of tritium-labelled radioligands bound to various regions in the forebrain of both flight and control animals were measured from autoradiograms. Data from rats flown in space and from ground-based control animals that were not exposed to microgravity were compared.

  19. Identification of neurons that express ghrelin receptors in autonomic pathways originating from the spinal cord.

    Science.gov (United States)

    Furness, John B; Cho, Hyun-Jung; Hunne, Billie; Hirayama, Haruko; Callaghan, Brid P; Lomax, Alan E; Brock, James A

    2012-06-01

    positive terminals around them. Ghrelin receptors are therefore expressed by subgroups of preganglionic neurons, including those of vasoconstrictor pathways and of pathways controlling gut function, but are absent from some other neurons, including those innervating sweat glands and the secretomotor neurons that supply the submaxillary salivary glands.

  20. Effects of histamine H1 receptor signaling on glucocorticoid receptor activity. Role of canonical and non-canonical pathways.

    Science.gov (United States)

    Zappia, Carlos Daniel; Granja-Galeano, Gina; Fernández, Natalia; Shayo, Carina; Davio, Carlos; Fitzsimons, Carlos P; Monczor, Federico

    2015-12-04

    Histamine H1 receptor (H1R) antagonists and glucocorticoid receptor (GR) agonists are used to treat inflammatory conditions such as allergic rhinitis, atopic dermatitis and asthma. Consistent with the high morbidity levels of such inflammatory conditions, these receptors are the targets of a vast number of approved drugs, and in many situations their ligands are co-administered. However, this drug association has no clear rationale and has arisen from clinical practice. We hypothesized that H1R signaling could affect GR-mediated activity, impacting on its transcriptional outcome. Indeed, our results show a dual regulation of GR activity by the H1R: a potentiation mediated by G-protein βγ subunits and a parallel inhibitory effect mediated by Gαq-PLC pathway. Activation of the H1R by its full agonists resulted in a composite potentiating effect. Intriguingly, inactivation of the Gαq-PLC pathway by H1R inverse agonists resulted also in a potentiation of GR activity. Moreover, histamine and clinically relevant antihistamines synergized with the GR agonist dexamethasone to induce gene transactivation and transrepression in a gene-specific manner. Our work provides a delineation of molecular mechanisms underlying the widespread clinical association of antihistamines and GR agonists, which may contribute to future dosage optimization and reduction of well-described side effects associated with glucocorticoid administration.

  1. Mapping physiological G protein-coupled receptor signaling pathways reveals a role for receptor phosphorylation in airway contraction.

    Science.gov (United States)

    Bradley, Sophie J; Wiegman, Coen H; Iglesias, Max Maza; Kong, Kok Choi; Butcher, Adrian J; Plouffe, Bianca; Goupil, Eugénie; Bourgognon, Julie-Myrtille; Macedo-Hatch, Timothy; LeGouill, Christian; Russell, Kirsty; Laporte, Stéphane A; König, Gabriele M; Kostenis, Evi; Bouvier, Michel; Chung, Kian Fan; Amrani, Yassine; Tobin, Andrew B

    2016-04-19

    G protein-coupled receptors (GPCRs) are known to initiate a plethora of signaling pathways in vitro. However, it is unclear which of these pathways are engaged to mediate physiological responses. Here, we examine the distinct roles of Gq/11-dependent signaling and receptor phosphorylation-dependent signaling in bronchial airway contraction and lung function regulated through the M3-muscarinic acetylcholine receptor (M3-mAChR). By using a genetically engineered mouse expressing a G protein-biased M3-mAChR mutant, we reveal the first evidence, to our knowledge, of a role for M3-mAChR phosphorylation in bronchial smooth muscle contraction in health and in a disease state with relevance to human asthma. Furthermore, this mouse model can be used to distinguish the physiological responses that are regulated by M3-mAChR phosphorylation (which include control of lung function) from those responses that are downstream of G protein signaling. In this way, we present an approach by which to predict the physiological/therapeutic outcome of M3-mAChR-biased ligands with important implications for drug discovery.

  2. Effects of histamine H1 receptor signaling on glucocorticoid receptor activity. Role of canonical and non-canonical pathways

    Science.gov (United States)

    Zappia, Carlos Daniel; Granja-Galeano, Gina; Fernández, Natalia; Shayo, Carina; Davio, Carlos; Fitzsimons, Carlos P.; Monczor, Federico

    2015-01-01

    Histamine H1 receptor (H1R) antagonists and glucocorticoid receptor (GR) agonists are used to treat inflammatory conditions such as allergic rhinitis, atopic dermatitis and asthma. Consistent with the high morbidity levels of such inflammatory conditions, these receptors are the targets of a vast number of approved drugs, and in many situations their ligands are co-administered. However, this drug association has no clear rationale and has arisen from clinical practice. We hypothesized that H1R signaling could affect GR-mediated activity, impacting on its transcriptional outcome. Indeed, our results show a dual regulation of GR activity by the H1R: a potentiation mediated by G-protein βγ subunits and a parallel inhibitory effect mediated by Gαq-PLC pathway. Activation of the H1R by its full agonists resulted in a composite potentiating effect. Intriguingly, inactivation of the Gαq-PLC pathway by H1R inverse agonists resulted also in a potentiation of GR activity. Moreover, histamine and clinically relevant antihistamines synergized with the GR agonist dexamethasone to induce gene transactivation and transrepression in a gene-specific manner. Our work provides a delineation of molecular mechanisms underlying the widespread clinical association of antihistamines and GR agonists, which may contribute to future dosage optimization and reduction of well-described side effects associated with glucocorticoid administration. PMID:26635083

  3. 胆碱能受体激动剂逆转天疱疮棘层松解的机制研究%Mechanisms underlying the reversal of acantholysis in pemphigus by a cholinergic receptor agonist

    Institute of Scientific and Technical Information of China (English)

    李志量; 张洁尘; 徐浩翔; 杨永红; 冯素英; 王宝玺

    2015-01-01

    目的 研究胆碱能受体激动剂对天疱疮棘层松解的逆转作用及其机制.方法 将HaCaT细胞与寻常型天疱疮IgG(PV-IgG)共培养建成天疱疮细胞模型后,再加入胆碱能受体激动剂卡巴胆碱共培养,以PV-IgG诱导的天疱疮细胞模型作为对照,通过细胞解离实验定量分析卡巴胆碱对棘层松解的逆转情况,用免疫荧光方法定性观察桥粒蛋白变化;分别用RIPA和Triton X-100裂解细胞,得到总蛋白和胞质蛋白,用蛋白免疫印迹灰度值定性分析HaCaT细胞表面与黏附相关的桥粒芯蛋白3(Dsg3)、桥斑珠蛋白(PG)的变化,不同时间点p38丝裂原活化蛋白激酶(p38 MAPK)、表皮生长因子受体(EGFR)的磷酸化水平;用定量聚合酶链反应(qPCR)检测上述细胞表面蛋白在mRNA水平的变化;通过免疫共沉淀方法定性分析Dsg3与PG相互作用的变化情况.结果 PV-IgG组细胞碎片数为46.67±2.03,卡巴胆碱组为18.67±2.52,两组比较,t=11.22,P< 0.01;免疫荧光实验发现,卡巴胆碱可以逆转PV-IgG所致的桥粒分子内化.在天疱疮细胞模型中,细胞总的Dsg3和PG含量下降,非桥粒部分的Dsg3下降,非桥粒PG含量增加,且Dsg3与PG的相互作用减弱,加入卡巴胆碱后可逆转上述变化.卡巴胆碱也可使Dsg3 mRNA的相对表达量(2-△△Ct)由1.428±0.215增加至4.974±0.948(t=3.65,P=0.01),PG mRNA的相对表达量由1.563±0.247增加至13.420±1.715(t=6.85,P<0.01).磷酸化实验中,卡巴胆碱可以抑制EGFR磷酸化,而对p38 MAPK磷酸化无明显影响.结论 胆碱能受体激动剂卡巴胆碱具有逆转棘层松解的作用,这种逆转作用的机制可能包括:抑制Dsg3和PG内化并增加其表达,增强Dsg3与PG的相互作用,抑制棘层松解关键信号EGFR的磷酸化.%Objective To evaluate the reversal effect of a cholinergic receptor agonist on acantholysis in pemphigus,and to investigate its mechanism.Methods Human HaCaT keratinocytes were co-cultured with

  4. Modulation of the Cholinergic Mechanisms in the Bronchial Smooth Muscle.

    Science.gov (United States)

    1984-06-01

    Ginsborg and Hirst, 1q72; Sawynok and Jhamandas, 1976), although theopylline has not shown to be a specific adenosine receptor antagonist in all the tissues... theopylline and other cyclic nucletide phosphodiesterase inhibitors. Acta Pharmacol. Toxicol. 45, 336-344. Fredholm, B.B. and P. Hedqvist, 1980...51 mM) evoked release of [3H]-Ach from cholinergic nerves in the bronchial smooth muscle. The effect of theopylline (I mM) on the response to

  5. Dopamine receptors modulate cytotoxicity of natural killer cells via cAMP-PKA-CREB signaling pathway.

    Directory of Open Access Journals (Sweden)

    Wei Zhao

    Full Text Available Dopamine (DA, a neurotransmitter in the nervous system, has been shown to modulate immune function. We have previously reported that five subtypes of DA receptors, including D1R, D2R, D3R, D4R and D5R, are expressed in T lymphocytes and they are involved in regulation of T cells. However, roles of these DA receptor subtypes and their coupled signal-transduction pathway in modulation of natural killer (NK cells still remain to be clarified. The spleen of mice was harvested and NK cells were isolated and purified by negative selection using magnetic activated cell sorting. After NK cells were incubated with various drugs for 4 h, flow cytometry measured cytotoxicity of NK cells against YAC-1 lymphoma cells. NK cells expressed the five subtypes of DA receptors at mRNA and protein levels. Activation of D1-like receptors (including D1R and D5R with agonist SKF38393 enhanced NK cell cytotoxicity, but activation of D2-like receptors (including D2R, D3R and D4R with agonist quinpirole attenuated NK cells. Simultaneously, SKF38393 elevated D1R and D5R expression, cAMP content, and phosphorylated cAMP-response element-binding (CREB level in NK cells, while quinpirole reduced D3R and D4R expression, cAMP content, and phosphorylated CREB level in NK cells. These effects of SKF38393 were blocked by SCH23390, an antagonist of D1-like receptors, and quinpirole effects were abolished by haloperidol, an antagonist of D2-like receptors. In support these results, H89, an inhibitor of phosphokinase A (PKA, prevented the SKF38393-dependent enhancement of NK cells and forskolin, an activator of adenylyl cyclase (AC, counteracted the quinpirole-dependent suppression of NK cells. These findings show that DA receptor subtypes are involved in modulation of NK cells and suggest that D1-like receptors facilitate NK cells by stimulating D1R/D5R-cAMP-PKA-CREB signaling pathway and D2-like receptors suppress NK cells by inhibiting D3R/D4R-cAMP-PKA-CREB signaling pathway. The

  6. Epidermal growth factor receptors destined for the nucleus are internalized via a clathrin-dependent pathway

    Energy Technology Data Exchange (ETDEWEB)

    De Angelis Campos, Ana Carolina; Rodrigues, Michele Angela; Andrade, Carolina de; Miranda de Goes, Alfredo [Department of Biochemistry and Immunology, Federal University of Minas Gerais, Belo Horizonte, MG (Brazil); Nathanson, Michael H. [Department of Internal Medicine, Yale University School of Medicine, New Haven, CT (United States); Gomes, Dawidson A., E-mail: dawidson@icb.ufmg.br [Department of Biochemistry and Immunology, Federal University of Minas Gerais, Belo Horizonte, MG (Brazil)

    2011-08-26

    Highlights: {yields} EGF and its receptor translocates to the nucleus in liver cells. {yields} Real time imaging shows that EGF moves to the nucleus. {yields} EGF moves with its receptor to the nucleus. {yields} Dynamin and clathrin are necessary for EGFR nuclear translocation. -- Abstract: The epidermal growth factor (EGF) transduces its actions via the EGF receptor (EGFR), which can traffic from the plasma membrane to either the cytoplasm or the nucleus. However, the mechanism by which EGFR reaches the nucleus is unclear. To investigate these questions, liver cells were analyzed by immunoblot of cell fractions, confocal immunofluorescence and real time confocal imaging. Cell fractionation studies showed that EGFR was detectable in the nucleus after EGF stimulation with a peak in nuclear receptor after 10 min. Movement of EGFR to the nucleus was confirmed by confocal immunofluorescence and labeled EGF moved with the receptor to the nucleus. Small interference RNA (siRNA) was used to knockdown clathrin in order to assess the first endocytic steps of EGFR nuclear translocation in liver cells. A mutant dynamin (dynamin K44A) was also used to determine the pathways for this traffic. Movement of labeled EGF or EGFR to the nucleus depended upon dynamin and clathrin. This identifies the pathway that mediates the first steps for EGFR nuclear translocation in liver cells.

  7. Huperzine A protects sepsis associated encephalopathy by promoting the deficient cholinergic nervous function.

    Science.gov (United States)

    Zhu, Sen-Zhi; Huang, Wei-Ping; Huang, Lin-Qiang; Han, Yong-Li; Han, Qian-Peng; Zhu, Gao-Feng; Wen, Miao-Yun; Deng, Yi-Yu; Zeng, Hong-Ke

    2016-09-19

    Neuroinflammatory deregulation in the brain plays a crucial role in the pathogenesis of sepsis associated encephalopathy (SAE). Given the mounting evidence of anti-inflammatory and neuroprotective effects of the cholinergic nervous system, it is surprising that there is little information about its changes in the brain during sepsis. To elucidate the role of the cholinergic nervous system in SAE, hippocampal choline acetyltransferase, muscarinic acetylcholine receptor-1, acetylcholinesterase and acetylcholine were evaluated in LPS-induced sepsis rats. Expression of pro-inflammatory cytokines, neuronal apoptosis, and animal cognitive performance were also assessed. Furthermore, therapeutic effects of the acetylcholinesterase inhibitor Huperzine A (HupA) on the hippocampal cholinergic nervous function and neuroinflammation were evaluated. A deficiency of the cholinergic nervous function was revealed in SAE, accompanied with over-expressed pro-inflammatory cytokines, increase in neuronal apoptosis and brain cognitive impairment. HupA remarkably promoted the deficient cholinergic nervous function and attenuated the abnormal neuroinflammation in SAE, paralleled with the recovery of brain function. We suggest that the deficiency of the cholinergic nervous function and the abnormal neuroinflammation are synergistically implicated in the pathogenesis of SAE. Thus, HupA is a potential therapeutic candidate for SAE, as it improves the deficient cholinergic nervous function and exerts anti-inflammatory action.

  8. A cholinergic hypothesis of the unconscious in affective disorders.

    Directory of Open Access Journals (Sweden)

    Costa eVakalopoulos

    2013-11-01

    Full Text Available The interactions between distinct pharmacological systems are proposed as a key dynamic in the formation of unconscious memories underlying rumination and mood disorder, but also reflect the plastic capacity of neural networks that can aid recovery. An inverse and reciprocal relationship is postulated between cholinergic and monoaminergic receptor subtypes. M1-type muscarinic receptor transduction facilitates encoding of unconscious, prepotent behavioural repertoires at the core of affective disorders and ADHD. Behavioural adaptation to new contingencies is mediated by the classic prototype receptor: 5-HT1A (Gi/o and its modulation of m1-plasticity. Reversal of learning is dependent on increased phasic activation of midbrain monoaminergic nuclei and is a function of hippocampal theta. Acquired hippocampal dysfunction due to abnormal activation of the hypothalamic-pituitary-adrenal (HPA axis predicts deficits in hippocampal-dependent memory and executive function and further impairments to cognitive inhibition. Encoding of explicit memories is mediated by Gq/11 and Gs signalling of monoamines only. A role is proposed for the phasic activation of the basal forebrain cholinergic nucleus by cortical projections from the complex consisting of the insula and claustrum. Although controversial. recent studies suggest a common ontogenetic origin of the two structures and a functional coupling. Lesions of the region result in loss of motivational behaviour and familiarity based judgements. A major hypothesis of the paper is that these lost faculties result indirectly, from reduced cholinergic tone.

  9. The Architecture of the TIR Domain Signalosome in the Toll-like Receptor-4 Signaling Pathway

    OpenAIRE

    Emine Guven-Maiorov; Ozlem Keskin; Attila Gursoy; Carter VanWaes; Zhong Chen; Chung-Jung Tsai; Ruth Nussinov

    2015-01-01

    Scientific Reports | 5:13128 | DOI: 10.1038/srep13128 1 www.nature.com/scientificreports The Architecture of the TIR Domain Signalosome in the Toll-like Receptor-4 Signaling Pathway Emine Guven-Maiorov1,2, Ozlem Keskin1,2, Attila Gursoy2,3, Carter VanWaes4, Zhong Chen4, Chung-Jung Tsai5 & Ruth Nussinov5,6 Activated Toll-like receptors (TLRs) cluster in lipid rafts and induce pro- and anti-tumor responses. The organization of the assembly is critical to the understandin...

  10. Cholinergic enhancement of visual attention and neural oscillations in the human brain.

    Science.gov (United States)

    Bauer, Markus; Kluge, Christian; Bach, Dominik; Bradbury, David; Heinze, Hans Jochen; Dolan, Raymond J; Driver, Jon

    2012-03-06

    Cognitive processes such as visual perception and selective attention induce specific patterns of brain oscillations. The neurochemical bases of these spectral changes in neural activity are largely unknown, but neuromodulators are thought to regulate processing. The cholinergic system is linked to attentional function in vivo, whereas separate in vitro studies show that cholinergic agonists induce high-frequency oscillations in slice preparations. This has led to theoretical proposals that cholinergic enhancement of visual attention might operate via gamma oscillations in visual cortex, although low-frequency alpha/beta modulation may also play a key role. Here we used MEG to record cortical oscillations in the context of administration of a cholinergic agonist (physostigmine) during a spatial visual attention task in humans. This cholinergic agonist enhanced spatial attention effects on low-frequency alpha/beta oscillations in visual cortex, an effect correlating with a drug-induced speeding of performance. By contrast, the cholinergic agonist did not alter high-frequency gamma oscillations in visual cortex. Thus, our findings show that cholinergic neuromodulation enhances attentional selection via an impact on oscillatory synchrony in visual cortex, for low rather than high frequencies. We discuss this dissociation between high- and low-frequency oscillations in relation to proposals that lower-frequency oscillations are generated by feedback pathways within visual cortex.

  11. GABAERGIC MODULATION OF STRIATAL CHOLINERGIC INTERNEURONS - AN IN-VIVO MICRODIALYSIS STUDY

    NARCIS (Netherlands)

    DEBOER, P; WESTERINK, BHC

    1994-01-01

    Striatal cholinergic interneurons have been shown to receive input from striatal gamma-aminobutyric acid (GABA)-containing cell elements. GABA is known to act on two different types of receptors, the GABA(A) and the GABA(B) receptor. Using in vivo microdialysis, we have studied the effect of intrast

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

    Science.gov (United States)

    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.

  13. Subcellular localization of frizzled receptors, mediated by their cytoplasmic tails, regulates signaling pathway specificity.

    Directory of Open Access Journals (Sweden)

    Jun Wu

    2004-07-01

    Full Text Available The Frizzled (Fz; called here Fz1 and Fz2 receptors have distinct signaling specificities activating either the canonical Wnt/beta-catenin pathway or Fz/planar cell polarity (PCP signaling in Drosophila. The regulation of signaling specificity remains largely obscure. We show that Fz1 and Fz2 have different subcellular localizations in imaginal disc epithelia, with Fz1 localizing preferentially to apical junctional complexes, and Fz2 being evenly distributed basolaterally. The subcellular localization difference directly contributes to the signaling specificity outcome. Whereas apical localization favors Fz/PCP signaling, it interferes with canonical Wnt/beta-catenin signaling. Receptor localization is mediated by sequences in the cytoplasmic tail of Fz2 that appear to block apical accumulation. Based on these data, we propose that subcellular Fz localization, through the association with other membrane proteins, is a critical aspect in regulating the signaling specificity within the Wnt/Fz signaling pathways.

  14. Elabela-apelin receptor signaling pathway is functional in mammalian systems.

    Science.gov (United States)

    Wang, Zhi; Yu, Daozhan; Wang, Mengqiao; Wang, Qilong; Kouznetsova, Jennifer; Yang, Rongze; Qian, Kun; Wu, Wenjun; Shuldiner, Alan; Sztalryd, Carole; Zou, Minghui; Zheng, Wei; Gong, Da-Wei

    2015-02-02

    Elabela (ELA) or Toddler is a recently discovered hormone which is required for normal development of heart and vasculature through activation of apelin receptor (APJ), a G protein-coupled receptor (GPCR), in zebrafish. The present study explores whether the ELA-APJ signaling pathway is functional in the mammalian system. Using reverse-transcription PCR, we found that ELA is restrictedly expressed in human pluripotent stem cells and adult kidney whereas APJ is more widely expressed. We next studied ELA-APJ signaling pathway in reconstituted mammalian cell systems. Addition of ELA to HEK293 cells over-expressing GFP-AJP fusion protein resulted in rapid internalization of the fusion receptor. In Chinese hamster ovarian (CHO) cells over-expressing human APJ, ELA suppresses cAMP production with EC50 of 11.1 nM, stimulates ERK1/2 phosphorylation with EC50 of 14.3 nM and weakly induces intracellular calcium mobilization. Finally, we tested ELA biological function in human umbilical vascular endothelial cells and showed that ELA induces angiogenesis and relaxes mouse aortic blood vessel in a dose-dependent manner through a mechanism different from apelin. Collectively, we demonstrate that the ELA-AJP signaling pathways are functional in mammalian systems, indicating that ELA likely serves as a hormone regulating the circulation system in adulthood as well as in embryonic development.

  15. Bacterial and Fungal Pattern Recognition Receptors in Homologous Innate Signaling Pathways of Insects and Mammals

    Directory of Open Access Journals (Sweden)

    Bethany A Stokes

    2015-01-01

    Full Text Available In response to bacterial and fungal infections in insects and mammals, distinct families of innate immune pattern recognition receptors initiate highly complex intracellular signaling cascades. Those cascades induce a variety of immune functions that restrain the spread of microbes in the host. Insect and mammalian innate immune receptors include molecules that recognize conserved microbial molecular patterns. Innate immune recognition leads to the recruitment of adaptor molecules forming multi-protein complexes that include kinases, transcription factors and other regulatory molecules. Innate immune signaling cascades induce the expression of genes encoding antimicrobial peptides and other key factors that mount and regulate the immune response against microbial challenge. In this review, we summarize our current understanding of the bacterial and fungal pattern recognition receptors for homologous innate signaling pathways of insects and mammals in an effort to provide a framework for future studies.

  16. Reducing cholinergic constriction: the major reversible mechanism in COPD

    Directory of Open Access Journals (Sweden)

    V. Brusasco

    2006-12-01

    Full Text Available The airway narrowing in chronic obstructive pulmonary disease (COPD has often been misunderstood as being irreversible. However, a large proportion of patients with COPD do respond to bronchodilator agents with significant changes in lung function. Unlike in asthma, abnormalities in airway smooth muscle structure or function are not believed to play a key role in COPD airway narrowing. Although there are only limited data suggesting that cholinergic tone may be increased in COPD, the well-documented efficacy of antimuscarinic agents in increasing airway calibre suggests that cholinergic tone represents the major reversible component of airflow obstruction in these patients. Airway wall thickening and loss of airway-to-parenchyma interdependence are nonreversible components of airflow obstruction in COPD that may amplify the effect of changes in airway smooth muscle tone. Thus, keeping airway smooth muscle tone to a minimum might offer patients long-lasting airway patency and protection against breathlessness, which is the major complaint of patients with COPD. Receptor antagonism by anticholinergic agents can achieve effective relaxation of airway smooth muscle in COPD. According to a classical view of cholinergic receptor function and distribution, the ideal anticholinergic bronchodilator would be one that blocks both M1 and M3 receptors, which mediate airway smooth muscle contraction, but not the M2 receptor, stimulation of which reduces acetylcholine release from vagus nerve endings and prevents the airway smooth muscle from contracting by excessive increments. Agents with such pharmacodynamic selectivity are not available, but effective and prolonged inhibition of airway smooth muscle tone has been obtained with tiotropium, which binds to all three major muscarinic receptor subtypes, but for much longer to M3 than to M2 receptors. Recent data show that long-term treatment with tiotropium for 1 yr helps sustain 24-h airway patency. This

  17. The GPRC6A Receptor displays Constitutive Internalization and Sorting to the Slow Recycling Pathway.

    Science.gov (United States)

    Jacobsen, Stine Engesgaard; Ammendrup-Johnsen, Ina; Jansen, Anna Mai; Gether, Ulrik; Madsen, Kenneth Lindegaard; Bräuner-Osborne, Hans

    2017-03-09

    The class C G protein-coupled receptor GPRC6A is a putative nutrient sensing receptor and represents a possible new drug target in metabolic disorders. However, the specific physiological role of this receptor has yet to be identified, and the mechanisms regulating its activity and cell surface availability also remain enigmatic. In the present study, we investigated the trafficking properties of GPRC6A by use of both a classical antibody feeding internalization assay in which cells were visualized using confocal microscopy and a novel internalization assay that is based on real-time measurements of fluorescence resonance energy transfer. Both assays revealed that GPRC6A predominantly undergoes constitutive internalization while the agonist-induced effects were imperceptible. Moreover, post-endocytic sorting was investigated by assessing the co-localization of internalized GPRC6A with selected Rab protein markers. Internalized GPRC6A was mainly co-localized with the early endosome marker Rab5 and the long loop recycling endosome marker Rab11 and to a much lesser extent with the late endosome marker Rab7. This suggests that upon agonist-independent internalization, GPRC6A is recycled via the Rab11-positive slow recycling pathway, which may be responsible for ensuring a persistent pool of GPRC6A receptors at the cell surface despite chronic agonist exposure. Distinct trafficking pathways have been reported for several of the class C receptors, and our results thus substantiate that non-canonical trafficking mechanisms are a common feature for the nutrient sensing class C family that ensure functional receptors in the cell membrane despite prolonged agonist exposure.

  18. Alleviating effects of Bushen-Yizhi formula on ibotenic acid-induced cholinergic impairments in rat.

    Science.gov (United States)

    Hou, Xue-Qin; Zhang, Lei; Yang, Cong; Rong, Cui-Ping; He, Wen-Qing; Zhang, Chun-Xia; Li, Shi; Su, Ru-Yu; Chang, Xiang; Qin, Ji-Huan; Chen, Yun-Bo; Xian, Shao-Xiang; Wang, Qi

    2015-04-01

    This study explored the curative effect and underlying mechanisms of a traditional Chinese medicine compound prescription, Bushen-Yizhi formula (BSYZ), in ibotenic acid (IBO)-induced rats. Morris water maze and novel object recognition tests showed that BSYZ significantly improved spatial and object memory. Brain immunohistochemistry staining showed that BSYZ significantly up-regulated expression of choline acetyltransferase (ChAT) and nerve growth factor (NGF) in the hippocampus and cortex. The protein tyrosine kinase high-affinity receptor TrkA was slightly increased in the hippocampus and cortex, and significantly enhanced in the nucleus basalis of Meynert (NBM) after BSYZ intervention. The immunoreactivity of the p75 low-affinity receptor in BSYZ-treated rats was significantly strengthened in the cortex. Similar expression trends of nerve growth factor (NGF), TrkA, and p75 mRNA were observed in the hippocampus and cortex. Additionally, BSYZ reversed IBO-induced disorders of acetylcholine (ACh) levels, ChAT, and cholinesterase (ChE) in the cortex, which was consistent with the changes in mRNA levels of ChAT and acetylcholinesterase (AChE). Expression of ChAT and AChE proteins and mRNA in the hippocampus was up-regulated, whereas the apoptosis-relative protein cleaved caspase-3 was decreased after administration of BSYZ. Moreover, changes in cell death were confirmed by histological morphology. Thus, the results indicated that the BSYZ formula could ameliorate memory impairments in IBO-induced rats, and it exerted its therapeutic action probably by modulating cholinergic pathways, NGF signaling, and anti-apoptosis. Overall, it is suggested that the BSYZ formula might be a potential therapeutic approach for the treatment of Alzheimer's disease (AD) and other cholinergic impairment-related diseases.

  19. Ubiquitin/proteasome pathway regulates levels of retinoic acid receptor gamma and retinoid X receptor alpha in human keratinocytes.

    Science.gov (United States)

    Boudjelal, M; Wang, Z; Voorhees, J J; Fisher, G J

    2000-04-15

    Repeated exposure of human skin to solar UV radiation leads to premature aging (photoaging) and skin cancer. UV-induced skin damage can be ameliorated by all-trans retinoic acid treatment. The actions of retinoic acid in skin keratinocytes are mediated primarily by nuclear retinoic acid receptor gamma (RARgamma) and retinoid X receptor alpha (RXRalpha). We found that exposure of cultured primary human keratinocytes to UV irradiation (30 mJ/cm2) substantially reduced (50-90%) RARgamma and RXRalpha mRNA and protein within 8 h. The rates of disappearance of RARgamma and RXRalpha proteins after UV exposure or treatment with the protein synthesis inhibitor cycloheximide were similar. UV irradiation did not increase the rate of breakdown of RARgamma or RXRalpha but rather reduced their rate of synthesis. The addition of proteasome inhibitors MG132 and LLvL, but not the lysosomal inhibitor E64, prevented loss of RARgamma and RXRalpha proteins after exposure of keratinocytes to either UV radiation or cycloheximide. Soluble extracts from nonirradiated or UV-irradiated keratinocytes possessed similar levels of proteasome activity that degraded RARgamma and RXRalpha proteins in vitro. Furthermore, RARgamma and RXRalpha were polyubiquitinated in intact cells. RXRalpha was found to contain two proline, glutamate/aspartate, serine, and threonine (PEST) motifs, which confer rapid turnover of many short-lived regulatory proteins that are degraded by the ubiquitin/proteasome pathway. However, the PEST motifs in RXRalpha did not function to regulate its stability, because deletion of the PEST motifs individually or together did not alter ubiquitination or proteasome-mediated degradation of RXRalpha. These results demonstrate that loss of RARgamma and RXRalpha proteins after UV irradiation results from degradation via the ubiquitin/proteasome pathway. Taken together, the data here indicate that ubiquitin/proteasome-mediated breakdown is an important mechanism regulating the levels of

  20. Central cholinergic control of vasopressin release in conscious rats

    Energy Technology Data Exchange (ETDEWEB)

    Iitake, K.; Share, L.; Ouchi, Y.; Crofton, J.T.; Brooks, D.P.

    1986-08-01

    Intracerebroventricular (icv) administration of carbachol into conscious rats evoked a substantial increase in vasopressin secretion and blood pressure in a dose-dependent manner. These effects were blocked by pretreatment with the muscarinic blocker, atropine (10 g icv), but not by the nicotinic blocker, hexamethonium (10 g icv). Hexamethonium did, however, block the increase in blood pressure, the decrease in heart rate, and they very small elevation in the plasma vasopressin concentration induced by nicotine (10 g icv). These results indicate that stimulation of either central nicotinic or muscarinic receptors can affect the cardiovascular system and suggest that the cholinergic stimulation of vasopressin secretion may involve primarily muscarinic receptors in the conscious rat.

  1. The modulatory role of M2 muscarinic receptor on apomorphine-induced yawning and genital grooming.

    Science.gov (United States)

    Gamberini, Maria Thereza; Bolognesi, Maria Laura; Nasello, Antonia Gladys

    2012-12-01

    The interaction between dopaminergic and cholinergic pathways in the induction of behavioral responses has been previously established. In the brain, M2 receptors are found predominantly in presynaptic cholinergic neurons as autoreceptors, and in dopaminergic neurons as heteroceptors, suggesting a control role of acetylcholine and dopamine release, respectively. Our aim was to investigate the role of M2 receptors on the yawning and genital grooming of rats induced by apomorphine, a dopaminergic receptor agonist, focusing on the interaction between cholinergic and dopaminergic pathways. Initially, the effect of atropine, a non-selective muscarinic antagonist, on yawning and genital grooming induced by apomorphine (100 μg/kg s.c.) was analyzed. Atropine doses of 0.5, 1 and 2 mg/kg i.p. were administered to Wistar rats 30 min before induction of the behavioral responses by apomorphine. Number of yawns and time spent genital grooming were quantified over a 60 min period. Apomorphine-induced yawning was increased by low dose (0.5 mg/kg i.p.) but not by high doses (1 and 2 mg/kg, i.p.) of atropine. Genital grooming was antagonized by 2 mg/kg i.p. of atropine and showed no changes at the other doses tested. Tripitramine, a selective M2 cholinergic antagonist, was used as a tool for distinguishing between M2 and all other muscarinic receptor subtypes in yawning and genital grooming. Tripitramine doses of 0.01, 0.02 and 0.04 μmol/kg i.p. were administered to Wistar rats 30 min before apomorphine (100 μg/kg s.c.). Number of yawns and time spent genital grooming were also quantified over a 60 min period. Tripitramine 0.01 μmol/kg increased all parameters. Higher doses, which possibly block all subtypes of muscarinic receptor, did not modify the response of apomorphine, suggesting a non-selective effect of tripitramine at these doses. Given that low doses of tripitramine increased the behavioral responses induced by apomorphine and that the main distribution of the M2

  2. Lactobacillus bulgaricus OLL1181 activates the aryl hydrocarbon receptor pathway and inhibits colitis.

    Science.gov (United States)

    Takamura, Takeyuki; Harama, Daisuke; Fukumoto, Suguru; Nakamura, Yuki; Shimokawa, Naomi; Ishimaru, Kayoko; Ikegami, Shuji; Makino, Seiya; Kitamura, Masanori; Nakao, Atsuhito

    2011-10-01

    Increasing evidence suggests that the aryl hydrocarbon receptor (AhR) pathway has an important role in the regulation of inflammatory responses. Most recently, we have shown that the activation of the AhR pathway by a potent AhR agonist inhibits the development of dextran sodium sulfate (DSS)-induced colitis, a model of human ulcerative colitis, by the induction of prostaglandin E2 (PGE2) in the large intestine. Because several strains of probiotic lactic acid bacteria have been reported to inhibit DSS-induced colitis by unidentified mechanisms, we hypothesized that particular strains of lactic acid bacterium might have the potential to activate the AhR pathway, thereby inhibiting DSS-induced colitis. This study investigated whether there are specific lactic acid bacterial strains that can activate the AhR pathway, and if so, whether this AhR-activating potential is associated with suppression of DSS-induced colitis. By using AhR signaling reporter cells, we found that Lactobacillus bulgaricus OLL1181 had the potential to activate the AhR pathway. OLL1181 also induced the mRNA expression of cytochrome P450 family 1A1 (CYP1A1), a target gene of the AhR pathway, in human colon cells, which was inhibited by the addition of an AhR antagonist, α-naphthoflavon (αNF). In addition, mice treated orally with OLL1181 showed an increase in CYP1A1 mRNA expression in the large intestine and amelioration of DSS-induced colitis. Thus, OLL1181 can induce activation of the intestinal AhR pathway and inhibit DSS-induced colitis in mice. This strain of lactic acid bacterium has therefore the potential to activate the AhR pathway, which may be able to suppress colitis.

  3. Endocytosis of adiponectin receptor 1 through a clathrin-and Rab5-dependent pathway

    Institute of Scientific and Technical Information of China (English)

    Qiurong Ding; Zhenzhen Wang; Yan Chen

    2009-01-01

    In eukaryotic cells, receptor endocytosis is a key event regulating signaling transduction. Adiponectin receptors belong to a new receptor family that is distinct from G-protein-coupled receptors and has critical roles in the pathogen-esis of diabetes and metabolic syndrome. Here, we analyzed the endocytosis of adiponectin and adiponectin receptor 1 (AdipoR1) and found that they are both internalized into transferrin-positive compartments that follow similar traffic routes. Blocking clathrin-mediated endocytosis by expressing Epsl5 mutants or depleting K+ trapped AdipoRl at the plasma membrane, and K+ depletion abolished adiponectin internalization, indicating that the endocytosis of AdipoRl and adiponectin is clathrin-dependent. Depletion of K+ and overexpression of Eps15 mutants enhance adiponectin-stimulated AMP-activated protein kinase phosphorylation, suggesting that the endocytosis of AdipoR1 might down-regulate adiponectin signaling. In addition, AdipoR1 colocalizes with the small GTPase Rab5, and a dominant negative Rab5 abrogates AdipoR1 endocytosis. These data indicate that AdipoRl is internalized through a clathrin- and Rab5-dependent pathway and that endocytosis may play a role in the regulation of adiponectin signaling.

  4. Growth factor receptors and related signalling pathways as targets for novel treatment strategies of hepatocellular cancer

    Institute of Scientific and Technical Information of China (English)

    Michael Hopfner; Detlef Schuppan; Hans Scherübl

    2008-01-01

    Growth factors and their corresponding receptors are commonly overexpressed and/or dysregulated in many cancers including hepatocellular cancer (HCC). Clinical trials indicate that growth factor receptors and their related signalling pathways play important roles in HCC cancer etiology and progression, thus providing rational targets for innovative cancer therapies. A number of strategies including monoclonal antibodies, tyrosine kinase inhibitors ("small molecule inhibitors") and antisense oligonucleotides have already been evaluated for their potency to inhibit the activity and downstream signalling cascades of these receptors in HCC. First clinical trials have also shown that multi-kinase inhibition is an effective novel treatment strategy in HCC. In this respect sorafenib, an inhibitor of Raf-, VEGF- and PDGF-signalling, is the first multi-kinase inhibitor that has been approved by the FDA for the treatment of advanced HCC. Moreover, the serine-threonine kinase of mammalian target of rapamycin (mTOR) upon which the signalling of several growth factor receptors converge plays a central role in cancer cell proliferation, mTOR inhibition of HCC is currently also being studied in preclinical trials. As HCCs represent hypervascularized neoplasms, inhibition of tumour vessel formation via interfering with the VEGF/VEGFR system is another promising approach in HCC treatment. This review will summarize the current status of the various growth factor receptor-based treatment strategies and in view of the multitude of novel targeted approaches, the rationale for combination therapies for advanced HCC treatment will also be taken into account.

  5. Neurokinin receptor 3 peptide exacerbates 6-hydroxydopamine-induced dopaminergic degeneration in rats through JNK pathway.

    Science.gov (United States)

    Chu, John Man Tak; Chan, Ying Shing; Chen, Liang Wei; Yung, Ken Kin Lam

    2012-11-01

    Neurokinin 3 (NK3) receptor is predominantly expressed in striatum and substantia nigra (SN). Evidences have indicated the roles of NK3 receptor in the pathogenesis of Parkinson's disease. By administrating NK3 receptor agonist senktide into 6-hydroxydopamine (6-OHDA)-lesioned rats, exacerbation of dopaminergic degeneration was found in striatum and substantia nigra pars compacta. From apomorphine rotation test, significant increase of contralateral rotation number was detected in 6-OHDA-lesioned rats with senktide injection. Furthermore, tyrosine hydroxylase expression in striatum and substantia nigra pars compacta were examined by immunohistochemistry and Western blotting. Further reduction of tyrosine hydroxylase immunoreactivities was found in 6-OHDA-lesioned rats that received senktide treatment. Also, phosphorylation of N-methyl-D-aspartate receptor 1 subunit was investigated in SN region and significant up-regulation was revealed in senktide-treated 6-OHDA-lesioned rats. Finally, phosphorylation of mitogen-activated protein kinase c-Jun N-terminal kinase (JNK) and c-Jun were examined in nigral region. Up-regulation of phosphorylated JNK molecules was shown in SN region after senktide injection. In line with this evidence, phosphorylation of c-Jun at Ser 63 and Ser 73 was also up-regulated by senktide treatment, thus presenting new aspects that NK3 peptide could exacerbate 6-OHDA toxicity in in vivo models and the possible mechanism may be contributed by the modulation of N-methyl-D-aspartate receptor 1 subunit and JNK pathway activities.

  6. Acetylcholine produces contraction mediated by cyclooxigenase pathway in arterial vessels in the marine fish (Isacia conceptionis

    Directory of Open Access Journals (Sweden)

    FA. Moraga

    Full Text Available Preliminary studies showed that dorsal artery contraction mediated by acetylcholine (ACh is blocked with indomethacin in intertidal fish (G. laevifrons. Our objective was to characterize the cholinergic pathway in several artery vessels of the I. conceptionis. Afferent and efferent branchial, dorsal and mesenteric arteries were dissected of 6 juvenile specimens, isometric tension studies were done using doses response curves (DRC for Ach (10–13 to 10–3 M, and cholinergic pathways were obtained by blocking with atropine or indomethacin. CRC to ACh showed a pattern of high sensitivity only in efferente branchial artery and low sensibility in all vessels. Furthermore, these contractions were blocked in the presence of atropine and indomethacin in all vessels. Our results corroborate previous results observed in intertidal species that contraction induced by acetylcholine is mediated by receptors that activate a cyclooxygenase contraction pathway.

  7. TRH/TRH-R1 receptor signaling in the brain medulla as a pathway of vagally mediated gut responses during the cephalic phase.

    Science.gov (United States)

    Taché, Yvette; Adelson, David; Yang, Hong

    2014-01-01

    Pavlov's seminal findings in the early twentieth century showed that the sight, smell or taste of food in dogs with chronic esophagostomy induces a vagal-dependent gastric acid secretion. These observations established the concept of the cephalic phase of digestion. Compelling experimental evidence in rats indicates that the three amino acid peptide thyrotropin-releasing hormone (TRH) expressed in the brainstem plays a key role in the vagal stimulation of gastric function. Neurons in the dorsal motor nucleus of the vagus (DMN) expressed TRH receptor subtype (TRH-R1) and received efferent input from TRH containing fibers arising from TRH synthesizing neurons in the raphe pallidus, raphe obscurus, and the parapyramidal regions. TRH microinjected into the DMN or intracisternally excites the firing of DMN neurons and stimulates efferent activity in the gastric branch of the vagus nerve and gastric myenteric cholinergic neurons. At the functional level, this results in a vagally-mediated and atropine-sensitive stimulation of gastric epithelial and endocrine cells secreting acid, pepsin, serotonin, histamine and ghrelin, and enteric neurons leading to increased gastric motility and emptying. Importantly, the blockade of TRH or TRH-R1 in the brainstem by pretreatment into the cisterna magna or the DMN with TRH antibody or TRH-R1 oligodeoxynucleotide antisense respectively abolishes the stimulation of gastric acid induced by sham-feeding. The gastric response to TRH injected into the DMN is potentiated by serotonin and the proTRH flanking peptide, Ps4 and suppressed by a number of brainstem peptides and cytokines activated during stress or immune response and inhibiting food intake and gastric acid secretion. These convergent data strongly support a physiological involvement of TRH signaling pathway in the brainstem to stimulate vagal activity and identified TRH-TRH-R1 system as a major effector in the dorsal vagal complex to drive the vagally mediated gut response

  8. DMPD: Signal transduction by the lipopolysaccharide receptor, Toll-like receptor-4. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 15379975 Signal transduction by the lipopolysaccharide receptor, Toll-like receptor... Signal transduction by the lipopolysaccharide receptor, Toll-like receptor-4. PubmedID 15379975 Title Signal transduction by the lip

  9. White Matter Damage in the Cholinergic System Contributes to Cognitive Impairment in Subcortical Vascular Cognitive Impairment, No Dementia

    Science.gov (United States)

    Liu, Qing; Zhu, Zude; Teipel, Stefan J.; Yang, Jianwei; Xing, Yi; Tang, Yi; Jia, Jianping

    2017-01-01

    Cholinergic deficiency has been implicated in the pathogenesis of vascular cognitive impairment (VCI), but the extent of involvement and underlying mechanism remain unclear. In this study, targeting the early stage of VCI, we determined regional atrophy within the basal forebrain and deficiency in cholinergic pathways in 25 patients with vascular cognitive impairment no dementia (VCIND) compared to 24 healthy elderly subjects. By applying stereotaxic cytoarchitectonic maps of the nucleus basalis of Meynert (NbM), no significant atrophy was identified in VCIND. Using probabilistic tractography analysis, our study tracked the two major white matter tracks which map to cholinergic pathways. We identified significantly lower fractional anisotropy (FA) in VCIND. Mediation analysis demonstrated that FA in the tracked pathways could fully account for the executive dysfunction, and partly mediate the memory and global cognition impairment. Our study suggests that the fibers mapped to the cholinergic pathways, but not the NbM, are significantly impaired in VCIND. MRI-based in vivo tracking of cholinergic pathways together with NbM measurement may become a valuable in vivo marker for evaluating the cholinergic system in cognitive disorders. PMID:28289381

  10. The Fas/Fas ligand death receptor pathway contributes to phenylalanine-induced apoptosis in cortical neurons.

    Directory of Open Access Journals (Sweden)

    Xiaodong Huang

    Full Text Available Phenylketonuria (PKU, an autosomal recessive disorder of amino acid metabolism caused by mutations in the phenylalanine hydroxylase (PAH gene, leads to childhood mental retardation by exposing neurons to cytotoxic levels of phenylalanine (Phe. A recent study showed that the mitochondria-mediated (intrinsic apoptotic pathway is involved in Phe-induced apoptosis in cultured cortical neurons, but it is not known if the death receptor (extrinsic apoptotic pathway and endoplasmic reticulum (ER stress-associated apoptosis also contribute to neurodegeneration in PKU. To answer this question, we used specific inhibitors to block each apoptotic pathway in cortical neurons under neurotoxic levels of Phe. The caspase-8 inhibitor Z-IETD-FMK strongly attenuated apoptosis in Phe-treated neurons (0.9 mM, 18 h, suggesting involvement of the Fas receptor (FasR-mediated cell death receptor pathway in Phe toxicity. In addition, Phe significantly increased cell surface Fas expression and formation of the Fas/FasL complex. Blocking Fas/FasL signaling using an anti-Fas antibody markedly inhibited apoptosis caused by Phe. In contrast, blocking the ER stress-induced cell death pathway with salubrinal had no effect on apoptosis in Phe-treated cortical neurons. These experiments demonstrate that the Fas death receptor pathway contributes to Phe-induced apoptosis and suggest that inhibition of the death receptor pathway may be a novel target for neuroprotection in PKU patients.

  11. Lesions of cholinergic pedunculopontine tegmental nucleus neurons fail to affect cocaine or heroin self-administration or conditioned place preference in rats.

    Directory of Open Access Journals (Sweden)

    Stephan Steidl

    Full Text Available Cholinergic input to the ventral tegmental area (VTA is known to contribute to reward. Although it is known that the pedunculopontine tegmental nucleus (PPTg provides an important source of excitatory input to the dopamine system, the specific role of PPTg cholinergic input to the VTA in cocaine reward has not been previously determined. We used a diphtheria toxin conjugated to urotensin-II (Dtx::UII, the endogenous ligand for urotensin-II receptors expressed by PPTg cholinergic but not glutamatergic or GABAergic cells, to lesion cholinergic PPTg neurons. Dtx::UII toxin infusion resulted in the loss of 95.78 (±0.65% of PPTg cholinergic cells but did not significantly alter either cocaine or heroin self-administration or the development of cocaine or heroin conditioned place preferences. Thus, cholinergic cells originating in PPTg do not appear to be critical for the rewarding effects of cocaine or of heroin.

  12. Poliovirus trafficking toward central nervous system via human poliovirus receptor-dependent and -independent pathway.

    Directory of Open Access Journals (Sweden)

    Seii eOHKA

    2012-04-01

    Full Text Available In humans, paralytic poliomyelitis results from the invasion of the central nervous system by circulating poliovirus (PV via the blood-brain barrier (BBB. After the virus enters the central nervous system (CNS, it replicates in neurons, especially in motor neurons (MNs, inducing the cell death that causes paralytic poliomyelitis. Along with this route of dissemination, neural pathway has been reported in humans, monkeys, and PV-sensitive human PV receptor (hPVR/CD155-transgenic (Tg mice. We demonstrated that a fast retrograde axonal transport process is required for PV dissemination through the sciatic nerve of hPVR-Tg mice and that intramuscularly inoculated PV causes paralysis in a hPVR-dependent manner. We also showed that hPVR-independent axonal transport of PV exists in hPVR-Tg and non-Tg mice, indicating that several different pathways for PV axonal transport exist in these mice. Circulating PV after intravenous inoculation in mice cross the BBB at a high rate in a hPVR-independent manner. Recently, we identified transferrin receptor 1 (TfR1 of mouse brain capillary endothelial cells as a binding protein to PV, implicating that TfR1 is a possible receptor for PV to permeate the BBB.

  13. Osteogenesis on nanoparticulate mineralized collagen scaffolds via autogenous activation of the canonical BMP receptor signaling pathway.

    Science.gov (United States)

    Ren, Xiaoyan; Bischoff, David; Weisgerber, Daniel W; Lewis, Michael S; Tu, Victor; Yamaguchi, Dean T; Miller, Timothy A; Harley, Brendan A C; Lee, Justine C

    2015-05-01

    Skeletal regenerative medicine frequently incorporates deliverable growth factors to stimulate osteogenesis. However, the cost and side effects secondary to supraphysiologic dosages of growth factors warrant investigation of alternative methods of stimulating osteogenesis for clinical utilization. In this work, we describe growth factor independent osteogenic induction of human mesenchymal stem cells (hMSCs) on a novel nanoparticulate mineralized collagen glycosaminoglycan scaffold (MC-GAG). hMSCs demonstrated elevated osteogenic gene expression and mineralization on MC-GAG with minimal to no effect upon addition of BMP-2 when compared to non-mineralized scaffolds (Col-GAG). To investigate the intracellular pathways responsible for the increase in osteogenesis, we examined the canonical and non-canonical pathways downstream from BMP receptor activation. Constitutive Smad1/5 phosphorylation with nuclear translocation occurred on MC-GAG independent of BMP-2, whereas Smad1/5 phosphorylation depended on BMP-2 stimulation on Col-GAG. When non-canonical BMPR signaling molecules were examined, ERK1/2 phosphorylation was found to be decreased in MC-GAG but elevated in Col-GAG. No differences in Smad2/3 or p38 activation were detected. Collectively, these results demonstrated that MC-GAG scaffolds induce osteogenesis without exogenous BMP-2 addition via endogenous activation of the canonical BMP receptor signaling pathway.

  14. Effect of docosahexaenoic acid on interleukin-2 receptor signaling pathway in lipid rafts

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Recent studies have shown that polyunsaturated fatty acids (PUFA) regulated the functions of membrane receptors in T cells and suppressed T cell -mediated immune responses. But the molecular mechanisms of immune regulation are not yet elucidated. Lipid rafts are plasma membrane microdomains, in which many receptors localized. The purpose of this study was to investigate the effect of DHA on IL-2R signaling pathway in lipid rafts. We isolated lipid rafts by discontinuous sucrose density gradient ultracentrifugation, and found that DHA could change the composition of lipid rafts and alter the distribution of key molecules of IL-2R signaling pathway, which transferred from lipid rafts to detergent-soluble membrane fractions. These results revealed that DHA treatment increased the proportion of polyunsaturated fatty acids especially n(3 polyunsaturated fatty acids in lipid rafts and changed the lipid environment of membrane microdomains in T cells. Compared with controls, DHA changed the localization of IL-2R, STAT5a and STAT5b in lipid rafts and suppressed the expression of JAK1, JAK3 and tyrosine phosphotyrosine in soluble membrane fractions. Summarily, this study concluded the effects of DHA on IL-2R signaling pathway in lipid rafts and explained the regulation of PUFAs in T cell-mediated immune responses.

  15. INTRAHIPPOCAMPAL ADMINISTRATION OF IBOTENIC ACID INDUCED CHOLINERGIC DYSFUNCTION via NR2A/NR2B EXPRESSION: IMPLICATIONS OF RESVERATROL AGAINST ALZHEIMER DISEASE PATHOPHYSIOLOGY

    Directory of Open Access Journals (Sweden)

    Chennakesavan eKarthick

    2016-04-01

    Full Text Available Although several drugs revealed moderate amelioration of symptoms, none of them have sufficient potency to prevent or reverse the progression towards Alzheimer’s disease (AD pathology. Resveratrol (RSV, a polyphenolic compound has shown an outstanding therapeutic effect on a broad spectrum of diseases like age-associated neurodegeneration, inflammation etc. The present study was thus conducted to assess the therapeutic efficacy of RSV in ameliorating the deleterious effects of Ibotenic acid (IBO in male Wistar rats. Stereotactic intrahippocampal administration of IBO (5µg/µl lesioned rats impairs cholinergic transmission, learning and memory performance that is rather related to AD and thus chosen as a suitable model to understand the drug efficacy in preventing AD pathophysiology. Since IBO is an agonist of glutamate, it is expected to exhibit an excitotoxic effect by altering glutamatergic receptors like NMDA receptor. The current study displayed significant alterations in the mRNA expression of NR2A and NR2B subunits of NMDA receptors, and further it is surprising to note that cholinergic receptors decreased in expression particularly α7-nAChR with increased m1AChR. RSV administration (20mg/kg body weight, i.p significantly reduced these changes in IBO induced rats. Glutamatergic and cholinergic receptor alterations were associated with significant changes in the behavioral parameters of rats induced by IBO. While RSV improved spatial learning performance, attenuated immobility and improvised open field activity in IBO induced rats. NR2B activation in the present study might mediate cell death through oxidative stress that form the basis of abnormal behavioral pattern in IBO induced rats. Interestingly, RSV that could efficiently encounter oxidative stress have significantly decreased stress markers viz., nitrite, PCO, and MDA levels by enhancing antioxidant status. Histopathological analysis displayed significant reduction in the

  16. Intrahippocampal Administration of Ibotenic Acid Induced Cholinergic Dysfunction via NR2A/NR2B Expression: Implications of Resveratrol against Alzheimer Disease Pathophysiology.

    Science.gov (United States)

    Karthick, Chennakesavan; Periyasamy, Sabapathy; Jayachandran, Kesavan S; Anusuyadevi, Muthuswamy

    2016-01-01

    Although several drugs revealed moderate amelioration of symptoms, none of them have sufficient potency to prevent or reverse the progression toward Alzheimer's disease (AD) pathology. Resveratrol (RSV), a polyphenolic compound has shown an outstanding therapeutic effect on a broad spectrum of diseases like age-associated neurodegeneration, inflammation etc. The present study was thus conducted to assess the therapeutic efficacy of RSV in ameliorating the deleterious effects of Ibotenic acid (IBO) in male Wistar rats. Stereotactic intrahippocampal administration of IBO (5 μg/μl) lesioned rats impairs cholinergic transmission, learning and memory performance that is rather related to AD and thus chosen as a suitable model to understand the drug efficacy in preventing AD pathophysiology. Since IBO is an agonist of glutamate, it is expected to exhibit an excitotoxic effect by altering glutamatergic receptors like NMDA receptor. The current study displayed significant alterations in the mRNA expression of NR2A and NR2B subunits of NMDA receptors, and further it is surprising to note that cholinergic receptors decreased in expression particularly α7-nAChR with increased m1AChR. RSV administration (20 mg/kg body weight, i.p.) significantly reduced these changes in IBO induced rats. Glutamatergic and cholinergic receptor alterations were associated with significant changes in the behavioral parameters of rats induced by IBO. While RSV improved spatial learning performance, attenuated immobility, and improvised open field activity in IBO induced rats. NR2B activation in the present study might mediate cell death through oxidative stress that form the basis of abnormal behavioral pattern in IBO induced rats. Interestingly, RSV that could efficiently encounter oxidative stress have significantly decreased stress markers viz., nitrite, PCO, and MDA levels by enhancing antioxidant status. Histopathological analysis displayed significant reduction in the hippocampal

  17. Functional and laminar dissociations between muscarinic and nicotinic cholinergic neuromodulation in the tree shrew primary visual cortex.

    Science.gov (United States)

    Bhattacharyya, Anwesha; Bießmann, Felix; Veit, Julia; Kretz, Robert; Rainer, Gregor

    2012-04-01

    Acetylcholine is an important neuromodulator involved in cognitive function. The impact of cholinergic neuromodulation on computations within the cortical microcircuit is not well understood. Here we investigate the effects of layer-specific cholinergic drug application in the tree shrew primary visual cortex during visual stimulation with drifting grating stimuli of varying contrast and orientation. We describe differences between muscarinic and nicotinic cholinergic effects in terms of both the layer of cortex and the attribute of visual representation. Nicotinic receptor activation enhanced the contrast response in the granular input layer of the cortex, while tending to reduce neural selectivity for orientation across all cortical layers. Muscarinic activation modestly enhanced the contrast response across cortical layers, and tended to improve orientation tuning. This resulted in highest orientation selectivity in the supra- and infragranular layers, where orientation selectivity was already greatest in the absence of pharmacological stimulation. Our results indicate that laminar position plays a crucial part in functional consequences of cholinergic stimulation, consistent with the differential distribution of cholinergic receptors. Nicotinic receptors function to enhance sensory representations arriving in the cortex, whereas muscarinic receptors act to boost the cortical computation of orientation tuning. Our findings suggest close homology between cholinergic mechanisms in tree shrew and primate visual cortices.

  18. Effect of receptor-selective retinoids on growth and differentiation pathways in mouse melanoma cells.

    Science.gov (United States)

    Desai, S H; Boskovic, G; Eastham, L; Dawson, M; Niles, R M

    2000-05-15

    Treatment of B16 mouse melanoma cells with all-trans-retinoic acid (ATRA) results in inhibition of cell proliferation and induction of differentiation. Accompanying these events is an induction of retinoic acid receptor beta (RARbeta) expression, an increase in protein kinase Calpha (PKCalpha) expression, and enhanced activator protein-1 (AP-1) transcriptional activity. These cells express nuclear RARalpha and RARgamma and nuclear retinoid X receptors (RXR) alpha and beta constitutively. We tested the ability of receptor-selective retinoids to induce the biochemical changes found in ATRA-treated melanoma cells and also tested their effectiveness in decreasing anchorage-dependent and -independent growth. The RXR-selective ligand (2E,4E)-6-(5,6,7,8-tetrahydro-3,5,5,8, 8-pentamethyl-2-naphthalenyl)-3,7-dimethyl-2,4,6-octatrienoic acid (SR11246) was most effective at inhibiting anchorage-dependent growth, whereas the RARgamma-selective ligand 6-[(5,6,7, 8-tetrahydro-5,5,8, 8-tetramethyl-2-naphthalenyl)(hydroxyimino)methyl]-2-naphthalen ecarbo xylic acid (SR11254) was most potent at inhibiting anchorage-independent growth. In contrast, 4-(5,6,7,8-tetrahydro-5,5, 8,8-tetramethyl-2-naphthalenecarboxamido)-benzoic acid (Am580), an RARalpha-selective ligand, was the most effective receptor-selective agonist for inducing RARbeta mRNA and increasing the amount of PKCalpha protein. All of the retinoids induced a concentration-dependent increase in AP-1 transcriptional activity, with little difference in effectiveness among the receptor-selective retinoids. A synergistic increase in the amount of PKCalpha was found when an RAR-selective agonist was combined with an RXR-selective agonist. One possible explanation for this result is that an RXR-RAR heterodimer in which both receptors are liganded is required for maximum expression of this critical component of the ATRA-induced differentiation pathway. Our data suggest that synthetic retinoids can activate different growth and

  19. A novel taspine derivative, HMQ1611, inhibits breast cancer cell growth via estrogen receptor α and EGF receptor signaling pathways.

    Science.gov (United States)

    Zhan, Yingzhuan; Zhang, Yanmin; Liu, Cuicui; Zhang, Jie; Smith, Wanli W; Wang, Nan; Chen, Yinnan; Zheng, Lei; He, Langchong

    2012-06-01

    Breast cancer is a common cancer with a leading cause of cancer mortality in women. Currently, the chemotherapy for breast cancer is underdeveloped. Here, we report a novel taspine derivative, HMQ1611, which has anticancer effects using in vitro and in vivo breast cancer models. HMQ1611 reduced cancer cell proliferation in four human breast cancer cell lines including MDA-MB-231, SK-BR-3, ZR-75-30, and MCF-7. HMQ1611 more potently reduced growth of estrogen receptor α (ERα)-positive breast cancer cells (ZR-75-30 and MCF-7) than ERα-negative cells (MDA-MB-231 and SK-BR-3). Moreover, HMQ1611 arrested breast cancer cell cycle at S-phase. In vivo tumor xenograft model, treatment of HMQ1611 significantly reduced tumor size and weight compared with vehicles. We also found that HMQ1611 reduced ERα expression and inhibited membrane ERα-mediated mitogen-activated protein kinase (MAPK) signaling following the stimulation of cells with estrogen. Knockdown of ERα by siRNA transfection in ZR-75-30 cells attenuated HMQ1611 effects. In contrast, overexpression of ERα in MDA-MB-231 cells enhanced HMQ1611 effects, suggesting that ERα pathway mediated HMQ1611's inhibition of breast cancer cell growth in ERα-positive breast cancer. HMQ1611 also reduced phosphorylation of EGF receptor (EGFR) and its downstream signaling players extracellular signal-regulated kinase (ERK)1/2 and AKT activation both in ZR-75-30 and MDA-MB-231 cells. These results showed that the novel compound HMQ1611 had anticancer effects, and partially via ERα and/or EGFR signaling pathways, suggesting that HMQ1611 may be a potential novel candidate for human breast cancer intervention.

  20. Lesions of the basal forebrain cholinergic system in mice disrupt idiothetic navigation.

    Directory of Open Access Journals (Sweden)

    Adam S Hamlin

    Full Text Available Loss of integrity of the basal forebrain cholinergic neurons is a consistent feature of Alzheimer's disease, and measurement of basal forebrain degeneration by magnetic resonance imaging is emerging as a sensitive diagnostic marker for prodromal disease. It is also known that Alzheimer's disease patients perform poorly on both real space and computerized cued (allothetic or uncued (idiothetic recall navigation tasks. Although the hippocampus is required for allothetic navigation, lesions of this region only mildly affect idiothetic navigation. Here we tested the hypothesis that the cholinergic medial septo-hippocampal circuit is important for idiothetic navigation. Basal forebrain cholinergic neurons were selectively lesioned in mice using the toxin saporin conjugated to a basal forebrain cholinergic neuronal marker, the p75 neurotrophin receptor. Control animals were able to learn and remember spatial information when tested on a modified version of the passive place avoidance test where all extramaze cues were removed, and animals had to rely on idiothetic signals. However, the exploratory behaviour of mice with cholinergic basal forebrain lesions was highly disorganized during this test. By contrast, the lesioned animals performed no differently from controls in tasks involving contextual fear conditioning and spatial working memory (Y maze, and displayed no deficits in potentially confounding behaviours such as motor performance, anxiety, or disturbed sleep/wake cycles. These data suggest that the basal forebrain cholinergic system plays a specific role in idiothetic navigation, a modality that is impaired early in Alzheimer's disease.

  1. Alpha2-Adrenergic Receptors and Breast Tumor Stroma: A Novel Pathway Driving Breast Cancer Growth and Metastasis

    Science.gov (United States)

    2015-10-01

    1 AWARD NUMBER: W81XWH-13-1-0439 TITLE: Alpha2-Adrenergic Receptors and Breast Tumor Stroma: A Novel Pathway Driving Breast Cancer Growth and...treatment of breast cancer often experience severe and chronic psychological stress. The sympathetic nervous system (SNS) is an important pathway by which...Sephton SE, McDonald PG, et al. The influence of bio-behavioural factors on tumour biology: pathways and mechanisms. Nat Rev Cancer . 2006;6:240-8. 3

  2. Mechanistic pathways and biological roles for receptor-independent activators of G-protein signaling.

    Science.gov (United States)

    Blumer, Joe B; Smrcka, Alan V; Lanier, Stephen M

    2007-03-01

    Signal processing via heterotrimeric G-proteins in response to cell surface receptors is a central and much investigated aspect of how cells integrate cellular stimuli to produce coordinated biological responses. The system is a target of numerous therapeutic agents and plays an important role in adaptive processes of organs; aberrant processing of signals through these transducing systems is a component of various disease states. In addition to G-protein coupled receptor (GPCR)-mediated activation of G-protein signaling, nature has evolved creative ways to manipulate and utilize the Galphabetagamma heterotrimer or Galpha and Gbetagamma subunits independent of the cell surface receptor stimuli. In such situations, the G-protein subunits (Galpha and Gbetagamma) may actually be complexed with alternative binding partners independent of the typical heterotrimeric Galphabetagamma. Such regulatory accessory proteins include the family of regulator of G-protein signaling (RGS) proteins that accelerate the GTPase activity of Galpha and various entities that influence nucleotide binding properties and/or subunit interaction. The latter group of proteins includes receptor-independent activators of G-protein signaling (AGS) proteins that play surprising roles in signal processing. This review provides an overview of our current knowledge regarding AGS proteins. AGS proteins are indicative of a growing number of accessory proteins that influence signal propagation, facilitate cross talk between various types of signaling pathways, and provide a platform for diverse functions of both the heterotrimeric Galphabetagamma and the individual Galpha and Gbetagamma subunits.

  3. Adenovirus core protein pVII is translocated into the nucleus by multiple import receptor pathways.

    Science.gov (United States)

    Wodrich, Harald; Cassany, Aurelia; D'Angelo, Maximiliano A; Guan, Tinglu; Nemerow, Glen; Gerace, Larry

    2006-10-01

    Adenoviruses are nonenveloped viruses with an approximately 36-kb double-stranded DNA genome that replicate in the nucleus. Protein VII, an abundant structural component of the adenovirus core that is strongly associated with adenovirus DNA, is imported into the nucleus contemporaneously with the adenovirus genome shortly after virus infection and may promote DNA import. In this study, we evaluated whether protein VII uses specific receptor-mediated mechanisms for import into the nucleus. We found that it contains potent nuclear localization signal (NLS) activity by transfection of cultured cells with protein VII fusion constructs and by microinjection of cells with recombinant protein VII fusions. We identified three NLS-containing regions in protein VII by deletion mapping and determined important NLS residues by site-specific mutagenesis. We found that recombinant protein VII and its NLS-containing domains strongly and specifically bind to importin alpha, importin beta, importin 7, and transportin, which are among the most abundant cellular nuclear import receptors. Moreover, these receptors can mediate the nuclear import of protein VII fusions in vitro in permeabilized cells. Considered together, these data support the hypothesis that protein VII is a major NLS-containing adaptor for receptor-mediated import of adenovirus DNA and that multiple import pathways are utilized to promote efficient nuclear entry of the viral genome.

  4. Somatostatin receptor biology in neuroendocrine and pituitary tumours: part 1--molecular pathways.

    Science.gov (United States)

    Cakir, Mehtap; Dworakowska, Dorota; Grossman, Ashley

    2010-11-01

    Neuroendocrine tumours (NETs) may occur at many sites in the body although the majority occur within the gastroenteropancreatic axis. Non-gastroenteropancreatic NETs encompass phaeochromocytomas and paragangliomas, medullary thyroid carcinoma, anterior pituitary tumour, broncho-pulmonary NETs and parathyroid tumours. Like most endocrine tumours, NETs also express somatostatin (SST) receptors (subtypes 1-5) whose ligand SST is known to inhibit endocrine and exocrine secretions and have anti-tumour effects. In the light of this knowledge, the idea of using SST analogues in the treatment of NETs has become increasingly popular and new studies have centred upon the development of new SST analogues. We attempt to review SST receptor (SSTR) biology primarily in neuroendocrine tissues, focusing on pituitary tumours. A full data search was performed through PubMed over the years 2000-2009 with keywords 'somatostatin, molecular biology, somatostatin receptors, somatostatin signalling, NET, pituitary' and all relevant publications have been included, together with selected publications prior to that date. SSTR signalling in non-neuroendocrine solid tumours is beyond the scope of this review. SST is a potent anti-proliferative and anti-secretory agent for some NETs. The successful therapeutic use of SST analogues in the treatment of these tumours depends on a thorough understanding of the diverse effects of SSTR subtypes in different tissues and cell types. Further studies will focus on critical points of SSTR biology such as homo- and heterodimerization of SSTRs and the differences between post-receptor signalling pathways of SSTR subtypes.

  5. The subcellular distribution of [3H]-CGS 21680 binding sites in the rat striatum: copurification with cholinergic nerve terminals.

    Science.gov (United States)

    James, S; Richardson, P J

    1993-08-01

    The subcellular distribution of the adenosine A2a receptor in rat striatum has been investigated using specific binding of the A2a-selective ligand [3H]-CGS 21680. After subcellular fractionation, the distribution of [3H]-CGS 21680 binding was similar to that of the cholinergic nerve terminal marker acetylcholinesterase rather than the more general membrane marker 5'-nucleotidase, with 42% of binding associated with the synaptosomal sub-fraction and 19% with a light membrane fraction. Binding of [3H]-CGS 21680 was also found to co-purify with the cholinergic nerve terminal marker choline acetyltransferase during immunoaffinity purification of striatal cholinergic nerve terminals. These results demonstrate that some adenosine A2a receptors are present on cholinergic nerve terminals in rat striatum.

  6. DMPD: Toll-like receptors and Type I interferons. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available . Pathway - PNG File (.png) SVG File (.svg) HTML File (.html) CSML File (.csml) Open .csml file with CIOPlayer Open .csm...m. 2007 May 25;282(21):15319-23. Epub 2007 Mar 29. (.png) (.svg) (.html) (.csml) Show Toll-like receptors an...l file with CIOPlayer - ※CIO Playerのご利用上の注意 Open .csml file with CIO Open .csml file with CIO - ※CIOのご利用上の注意 ...

  7. DMPD: A Toll-like receptor in horseshoe crabs. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available mmunol Rev. 2004 Apr;198:106-15. (.png) (.svg) (.html) (.csml) Show A Toll-like receptor in horseshoe crabs....blication Immunol Rev. 2004 Apr;198:106-15. Pathway - PNG File (.png) SVG File (....svg) HTML File (.html) CSML File (.csml) Open .csml file with CIOPlayer Open .csml file with CIOPlayer - ※CI...O Playerのご利用上の注意 Open .csml file with CIO Open .csml file with CIO - ※CIOのご利用上の注意 ...

  8. DMPD: Viral recognition by Toll-like receptors. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available .svg) HTML File (.html) CSML File (.csml) Open .csml file with CIOPlayer Open .csml file with CIOPlayer - ※C...eb;19(1):33-40. Epub 2007 Mar 2. (.png) (.svg) (.html) (.csml) Show Viral recognition by Toll-like receptors...IO Playerのご利用上の注意 Open .csml file with CIO Open .csml file with CIO - ※CIOのご利用上の注意 ... ...unol. 2007 Feb;19(1):33-40. Epub 2007 Mar 2. Pathway - PNG File (.png) SVG File (

  9. Involvement of Steroid Receptor Coactivators/Ubiquitin Pathway Enzymes in Mammary Gland Tumorigenesis

    Science.gov (United States)

    2005-06-01

    PRINCIPAL INVESTIGATOR: Xiuhua Gao, M.D., Ph.D. CONTRACTING ORGANIZATION: Baylor College of Medicine Houston, TX 77030 REPORT DATE: June 2005 TYPE OF REPORT...Summary 13 May 2002 - 12 May 2005 4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER Involvement of Steroid Receptor Coactivators/Ubiquitin Pathway 5b...Usell tc localization of MUcle ~s. Eý a, Eý Ca exaressiorn Crofile; E-p groffle; W1~’, API staining for nUcleUs. E6-AP DAMP -HI +E Figure 2: Effect of

  10. Toll-like receptor 3 regulates neural stem cell proliferation by modulating the Sonic Hedgehog pathway.

    Directory of Open Access Journals (Sweden)

    Kavitha Yaddanapudi

    Full Text Available Toll-like receptor 3 (TLR3 signaling has been implicated in neural stem/precursor cell (NPC proliferation. However, the molecular mechanisms involved, and their relationship to classical TLR-mediated innate immune pathways, remain unknown. Here, we report investigation of the mechanics of TLR3 signaling in neurospheres comprised of epidermal growth factor (EGF-responsive NPC isolated from murine embryonic cerebral cortex of C57BL/6 (WT or TLR3 deficient (TLR3(-/- mice. Our data indicate that the TLR3 ligand polyinosinic-polycytidylic acid (PIC negatively regulates NPC proliferation by inhibiting Sonic Hedgehog (Shh signaling, that PIC induces apoptosis in association with inhibition of Ras-ERK signaling and elevated expression of Fas, and that these effects are TLR3-dependent, suggesting convergent signaling between the Shh and TLR3 pathways.

  11. The C. elegans ROR receptor tyrosine kinase, CAM-1, non-autonomously inhibits the Wnt pathway.

    Science.gov (United States)

    Green, Jennifer L; Inoue, Takao; Sternberg, Paul W

    2007-11-01

    Inhibitors of Wnt signaling promote normal development and prevent cancer by restraining when and where the Wnt pathway is activated. ROR proteins, a class of Wnt-binding receptor tyrosine kinases, inhibit Wnt signaling by an unknown mechanism. To clarify how RORs inhibit the Wnt pathway, we examined the relationship between Wnts and the sole C. elegans ROR homolog, cam-1, during C. elegans vulval development, a Wnt-regulated process. We found that loss and overexpression of cam-1 causes reciprocal defects in Wnt-mediated cell-fate specification. Our molecular and genetic analyses revealed that the CAM-1 extracellular domain (ECD) is sufficient to non-autonomously antagonize multiple Wnts, suggesting that the CAM-1/ROR ECD sequesters Wnts. A sequestration model is supported by our findings that the CAM-1 ECD binds to several Wnts in vitro. These results demonstrate how ROR proteins help to refine the spatial pattern of Wnt activity in a complex multicellular environment.

  12. Cholinergic Depletion in Alzheimer’s Disease Shown by [18F]FEOBV Autoradiography

    Directory of Open Access Journals (Sweden)

    Maxime J. Parent

    2013-01-01

    Full Text Available Rationale. Alzheimer’s Disease (AD is a neurodegenerative condition characterized in part by deficits in cholinergic basalocortical and septohippocampal pathways. [18F]Fluoroethoxybenzovesamicol ([18F]FEOBV, a Positron Emission Tomography ligand for the vesicular acetylcholine transporter (VAChT, is a potential molecular agent to investigate brain diseases associated with presynaptic cholinergic losses. Purpose. To demonstrate this potential, we carried out an [18F]FEOBV autoradiography study to compare postmortem brain tissues from AD patients to those of age-matched controls. Methods. [18F]FEOBV autoradiography binding, defined as the ratio between regional grey and white matter, was estimated in the hippocampus (13 controls, 8 AD and prefrontal cortex (13 controls, 11 AD. Results. [18F]FEOBV binding was decreased by 33% in prefrontal cortex, 25% in CA3, and 20% in CA1. No changes were detected in the dentate gyrus of the hippocampus, possibly because of sprouting or upregulation toward the resilient glutamatergic neurons of the dentate gyrus. Conclusion. This is the first demonstration of [18F]FEOBV focal binding changes in cholinergic projections to the cortex and hippocampus in AD. Such cholinergic synaptic (and more specifically VAChT alterations, in line with the selective basalocortical and septohippocampal cholinergic losses documented in AD, indicate that [18F]FEOBV is indeed a promising ligand to explore cholinergic abnormalities in vivo.

  13. Oncogenic fingerprint of epidermal growth factor receptor pathway and emerging epidermal growth factor receptor blockade resistance in colorectal cancer

    Science.gov (United States)

    Sobani, Zain A; Sawant, Ashwin; Jafri, Mikram; Correa, Amit Keith; Sahin, Ibrahim Halil

    2016-01-01

    Epidermal growth factor receptor (EGFR) has been an attractive target for treatment of epithelial cancers, including colorectal cancer (CRC). Evidence from clinical trials indicates that cetuximab and panitumumab (anti-EGFR monoclonal antibodies) have clinical activity in patients with metastatic CRC. The discovery of intrinsic EGFR blockade resistance in Kirsten RAS (KRAS)-mutant patients led to the restriction of anti-EGFR antibodies to KRAS wild-type patients by Food and Drug Administration and European Medicine Agency. Studies have since focused on the evaluation of biomarkers to identify appropriate patient populations that may benefit from EGFR blockade. Accumulating evidence suggests that patients with mutations in EGFR downstream signaling pathways including KRAS, BRAF, PIK3CA and PTEN could be intrinsically resistant to EGFR blockade. Recent whole genome studies also suggest that dynamic alterations in signaling pathways downstream of EGFR leads to distinct oncogenic signatures and subclones which might have some impact on emerging resistance in KRAS wild-type patients. While anti-EGFR monoclonal antibodies have a clear potential in the management of a subset of patients with metastatic CRC, further studies are warranted to uncover exact mechanisms related to acquired resistance to EGFR blockade. PMID:27777877

  14. Cholinergic Neurons - Keeping Check on Amyloid beta in the Cerebral Cortex

    Directory of Open Access Journals (Sweden)

    Saak V. Ovsepian

    2013-12-01

    Full Text Available The physiological relevance of the uptake of ligands with no apparent trophic functions via the p75 neurotrophin receptor (p75NTR remains unclear. Herein, we propose a homeostatic role for this in clearance of amyloid β (Aβ in the brain. We hypothesize that uptake of Aβ in conjunction with p75NTR followed by its degradation in lysosomes endows cholinergic basalo-cortical projections enriched in this receptor a facility for maintaining physiological levels of Aβ in target areas. Thus, in addition to the diffuse modulator influence and channeling of extra-thalamic signals, cholinergic innervations could supply the cerebral cortex with an elaborate system for Aβ drainage. Interpreting the emerging relationship of new molecular data with established role of cholinergic modulator system in regulating cortical network dynamics should provide new insights into the brain physiology and mechanisms of neuro-degenerative diseases.

  15. The emerging role of toll-like receptor pathways in surgical diseases.

    LENUS (Irish Health Repository)

    Romics, Laszlo Jr

    2012-02-03

    OBJECTIVE: To outline the emerging significance of Toll-like receptor (TLR) signaling pathways in surgical diseases. DATA SOURCES: A systematic review of the literature was undertaken by searching the MEDLINE database for the period 1966 to 2005 without language restriction. STUDY SELECTION: Original or review articles that described experimental data on the activation of TLR signaling pathways in surgically relevant diseases were selected for inclusion in this review. DATA EXTRACTION: Data were obtained from peer-reviewed articles and references. DATA SYNTHESIS: The role of TLRs in the recognition of pathogens renders them a key figure in the activation of both innate and adaptive immune responses during sepsis. However, emerging evidence points to fundamentally important roles in ulcerative colitis, Crohn disease, and Helicobacter pylori infection in the gastrointestinal tract and in the development of atherosclerotic plaques in the cardiovascular system. Furthermore, recent studies suggest that the regulation of the TLR pathway fulfills a central role in anticancer immunotherapy and in organ rejection after transplantation. CONCLUSION: Given the clinical significance of TLR pathways, the targeting of individual molecular components is likely to offer a broad range of future therapeutic modalities.

  16. Imipramine protects retinal ganglion cells from oxidative stress through the tyrosine kinase receptor B signaling pathway

    Institute of Scientific and Technical Information of China (English)

    Ming-lei Han; Guo-hua Liu; Jin Guo; Shu-juan Yu; Jing Huang

    2016-01-01

    Retinal ganglion cell (RGC) degeneration is irreversible in glaucoma and tyrosine kinase receptor B (TrkB)-associated signaling pathways have been implicated in the process. In this study, we attempted to examine whether imipramine, a tricyclic antidepressant, may protect hydrogen peroxide (H2O2)-induced RGC degeneration through the activation of the TrkB pathway in RGC-5 cell lines. RGC-5 cell lines were pre-treated with imipramine 30 minutes before exposure to H2O2. Western blot assay showed that in H2O2-damaged RGC-5 cells, imipramine activated TrkB pathways through extracellular signal-regulated protein kinase/TrkB phosphorylation. TUNEL staining assay also demonstrated that imipramine ameliorated H2O2-induced apoptosis in RGC-5 cells. Finally, TrkB-IgG intervention was able to reverse the protective effect of imipramine on H2O2-induced RGC-5 apoptosis. Imipramine therefore protects RGCs from oxidative stress-induced apoptosis through the TrkB signaling pathway.

  17. Imipramine protects retinal ganglion cells from oxidative stress through the tyrosine kinase receptor B signaling pathway

    Directory of Open Access Journals (Sweden)

    Ming-lei Han

    2016-01-01

    Full Text Available Retinal ganglion cell (RGC degeneration is irreversible in glaucoma and tyrosine kinase receptor B (TrkB-associated signaling pathways have been implicated in the process. In this study, we attempted to examine whether imipramine, a tricyclic antidepressant, may protect hydrogen peroxide (H 2 O 2 -induced RGC degeneration through the activation of the TrkB pathway in RGC-5 cell lines. RGC-5 cell lines were pre-treated with imipramine 30 minutes before exposure to H 2 O 2 . Western blot assay showed that in H 2 O 2 -damaged RGC-5 cells, imipramine activated TrkB pathways through extracellular signal-regulated protein kinase/TrkB phosphorylation. TUNEL staining assay also demonstrated that imipramine ameliorated H 2 O 2 -induced apoptosis in RGC-5 cells. Finally, TrkB-IgG intervention was able to reverse the protective effect of imipramine on H 2 O 2 -induced RGC-5 apoptosis. Imipramine therefore protects RGCs from oxidative stress-induced apoptosis through the TrkB signaling pathway.

  18. Hypertensive stretch regulates endothelial exocytosis of Weibel-Palade bodies through VEGF receptor 2 signaling pathways.

    Science.gov (United States)

    Xiong, Yan; Hu, Zhenqian; Han, Xiaofan; Jiang, Beibei; Zhang, Rongli; Zhang, Xiaoyu; Lu, Yao; Geng, Chenyang; Li, Wei; He, Yulong; Huo, Yingqing; Shibuya, Masabumi; Luo, Jincai

    2013-06-01

    Regulated endothelial exocytosis of Weibel-Palade bodies (WPBs), the first stage in leukocyte trafficking, plays a pivotal role in inflammation and injury. Acute mechanical stretch has been closely associated with vascular inflammation, although the precise mechanism is unknown. Here, we show that hypertensive stretch regulates the exocytosis of WPBs of endothelial cells (ECs) through VEGF receptor 2 (VEGFR2) signaling pathways. Stretch triggers a rapid release (within minutes) of von Willebrand factor and interleukin-8 from WPBs in cultured human ECs, promoting the interaction between leukocytes and ECs through the translocation of P-selectin to the cell membrane. We further show that hypertensive stretch significantly induces P-selectin translocation of intact ECs and enhances leukocyte adhesion both ex vivo and in vivo. Stretch-induced endothelial exocytosis is mediated via a VEGFR2/PLCγ1/calcium pathway. Interestingly, stretch also induces a negative feedback via a VEGFR2/Akt/nitric oxide pathway. Such dual effects are confirmed using pharmacological and genetic approaches in carotid artery segments, as well as in acute hypertensive mouse models. These studies reveal mechanical stretch as a potent agonist for endothelial exocytosis, which is modulated by VEGFR2 signaling. Thus, VEGFR2 signaling pathways may represent novel therapeutic targets in limiting hypertensive stretch-related inflammation.

  19. The Aryl Hydrocarbon Receptor Pathway: A Key Component of the microRNA-Mediated AML Signalisome

    Directory of Open Access Journals (Sweden)

    Julia E. Rager

    2012-05-01

    Full Text Available Recent research has spotlighted the role of microRNAs (miRNAs as critical epigenetic regulators of hematopoietic stem cell differentiation and leukemia development. Despite the recent advances in knowledge surrounding epigenetics and leukemia, the mechanisms underlying miRNAs’ influence on leukemia development have yet to be clearly elucidated. Our aim was to identify high ranking biological pathways altered at the gene expression level and under epigenetic control. Specifically, we set out to test the hypothesis that miRNAs dysregulated in acute myeloid leukemia (AML converge on a common pathway that can influence signaling related to hematopoiesis and leukemia development. We identified genes altered in AML patients that are under common regulation of seven key miRNAs. By mapping these genes to a global interaction network, we identified the “AML Signalisome”. The AML Signalisome comprises 53 AML-associated molecules, and is enriched for proteins that play a role in the aryl hydrocarbon receptor (AhR pathway, a major regulator of hematopoiesis. Furthermore, we show biological enrichment for hematopoiesis-related proteins within the AML Signalisome. These findings provide important insight into miRNA-regulated pathways in leukemia, and may help to prioritize targets for disease prevention and treatment.

  20. Hypertensive stretch regulates endothelial exocytosis of Weibel-Palade bodies through VEGF receptor 2 signaling pathways

    Institute of Scientific and Technical Information of China (English)

    Yan Xiong; Zhenqian Hu; Xiaofan Han; Beibei Jiang; Rongli Zhang; Xiaoyu Zhang; Yao Lu

    2013-01-01

    Regulated endothelial exocytosis of Weibel-Palade bodies (WPBs),the first stage in leukocyte trafficking,plays a pivotal role in inflammation and injury.Acute mechanical stretch has been closely associated with vascular inflammation,although the precise mechanism is unknown.Here,we show that hypertensive stretch regulates the exocytosis of WPBs of endothelial ceils (ECs) through VEGF receptor 2 (VEGFR2) signaling pathways.Stretch triggers a rapid release (within minutes) of von Willebrand factor and interleukin-8 from WPBs in cultured human ECs,promoting the interaction between leukocytes and ECs through the translocation of P-selectin to the cell membrane.We further show that hypertensive stretch significantly induces P-selectin translocation of intact ECs and enhances leukocyte adhesion both ex vivo and in vivo.Stretch-induced endothelial exocytosis is mediated via a VEGFR2/PLCy1/calcium pathway.Interestingly,stretch also induces a negative feedback via a VEGFR2/Akt/nitric oxide pathway.Such dual effects are confirmed using pharmacological and genetic approaches in carotid artery segments,as well as in acute hypertensive mouse models.These studies reveal mechanical stretch as a potent agonist for endothelial exocytosis,which is modulated by VEGFR2 signaling.Thus,VEGFR2 signaling pathways may represent novel therapeutic targets in limiting hypertensive stretch-related inflammation.

  1. B-cell receptor signalling and its crosstalk with other pathways in normal and malignant cells.

    Science.gov (United States)

    Seda, Vaclav; Mraz, Marek

    2015-03-01

    The physiology of B cells is intimately connected with the function of their B-cell receptor (BCR). B-cell lymphomas frequently (dys)regulate BCR signalling and thus take advantage of this pre-existing pathway for B-cell proliferation and survival. This has recently been underscored by clinical trials demonstrating that small molecules (fosfamatinib, ibrutinib, idelalisib) inhibiting BCR-associated kinases (SYK, BTK, PI3K) have an encouraging clinical effect. Here we describe the current knowledge of the specific aspects of BCR signalling in diffuse large B-cell lymphoma (DLBCL), follicular lymphoma, chronic lymphocytic leukaemia (CLL) and normal B cells. Multiple factors can contribute to BCR pathway (dys)regulation in these malignancies and the activation of 'chronic' or 'tonic' BCR signalling. In lymphoma B cells, the balance of initiation, amplitude and duration of BCR activation can be influenced by a specific immunoglobulin structure, the expression and mutations of adaptor molecules (like GAB1, BLNK, GRB2, CARD11), the activity of kinases (like LYN, SYK, PI3K) or phosphatases (like SHIP-1, SHP-1 and PTEN) and levels of microRNAs. We also discuss the crosstalk of BCR with other signalling pathways (NF-κB, adhesion through integrins, migration and chemokine signalling) to emphasise that the 'BCR inhibitors' target multiple pathways interconnected with BCR, which might explain some of their clinical activity.

  2. Potentiation of nerve growth factor-induced neurite outgrowth by fluvoxamine: role of sigma-1 receptors, IP3 receptors and cellular signaling pathways.

    Directory of Open Access Journals (Sweden)

    Tomoko Nishimura

    Full Text Available BACKGROUND: Selective serotonin reuptake inhibitors (SSRIs have been widely used and are a major therapeutic advance in psychopharmacology. However, their pharmacology is quite heterogeneous. The SSRI fluvoxamine, with sigma-1 receptor agonism, is shown to potentiate nerve-growth factor (NGF-induced neurite outgrowth in PC 12 cells. However, the precise cellular and molecular mechanisms underlying potentiation by fluvoxamine are not fully understood. In this study, we examined the roles of cellular signaling pathways in the potentiation of NGF-induced neurite outgrowth by fluvoxamine and sigma-1 receptor agonists. METHODS AND FINDINGS: The effects of three SSRIs (fluvoxamine, sertraline, paroxetine and three sigma-1 receptor agonists (SA4503, 4-phenyl-1-(4-phenylbutyl piperidine (PPBP, and dehydroepiandrosterone (DHEA-sulfate on NGF-induced neurite outgrowth in PC12 cells were examined. Also examined were the effects of the sigma-1 receptor antagonist NE-100, inositol 1,4,5-triphosphate (IP(3 receptor antagonist, and specific inhibitors of signaling pathways in the potentiation of NGF-induced neurite outgrowth by selective sigma-1 receptor agonist SA4503. Fluvoxamine (but not sertraline or paroxetine and the sigma-1 receptor agonists SA4503, PPBP, and DHEA-sulfate significantly potentiated NGF-induced neurite outgrowth in PC12 cells in a concentration-dependent manner. The potentiation by fluvoxamine and the three sigma-1 receptor agonists was blocked by co-administration of the selective sigma-1 receptor antagonist NE-100, suggesting that sigma-1 receptors play a role in blocking the enhancement of NGF-induced neurite outgrowth. Moreover, the potentiation by SA4503 was blocked by co-administration of the IP(3 receptor antagonist xestospongin C. In addition, the specific inhibitors of phospholipase C (PLC-gamma, phosphatidylinositol 3-kinase (PI3K, p38MAPK, c-Jun N-terminal kinase (JNK, and the Ras/Raf/mitogen-activated protein kinase (MAPK

  3. Adenosine Inhibits the Excitatory Synaptic Inputs to Basal Forebrain Cholinergic, GABAergic and Parvalbumin Neurons in mice

    Directory of Open Access Journals (Sweden)

    Chun eYang

    2013-06-01

    Full Text Available Coffee and tea contain the stimulants caffeine and theophylline. These compounds act as antagonists of adenosine receptors. Adenosine promotes sleep and its extracellular concentration rises in association with prolonged wakefulness, particularly in the basal forebrain (BF region involved in activating the cerebral cortex. However, the effect of adenosine on identified BF neurons, especially non-cholinergic neurons, is incompletely understood. Here we used whole-cell patch-clamp recordings in mouse brain slices prepared from two validated transgenic mouse lines with fluorescent proteins expressed in GABAergic or parvalbumin (PV neurons to determine the effect of adenosine. Whole-cell recordings were made BF cholinergic neurons and from BF GABAergic & PV neurons with the size (>20 µm and intrinsic membrane properties (prominent H-currents corresponding to cortically projecting neurons. A brief (2 min bath application of adenosine (100 μM decreased the frequency but not the amplitude of spontaneous excitatory postsynaptic currents in all groups of BF cholinergic, GABAergic and PV neurons we recorded. In addition, adenosine decreased the frequency of miniature EPSCs in BF cholinergic neurons. Adenosine had no effect on the frequency of spontaneous inhibitory postsynaptic currents in cholinergic neurons or GABAergic neurons with large H-currents but reduced them in a group of GABAergic neurons with smaller H-currents. All effects of adenosine were blocked by a selective, adenosine A1 receptor antagonist, cyclopentyltheophylline (CPT, 1 μM. Adenosine had no postsynaptic effects. Taken together, our work suggests that adenosine promotes sleep by an A1-receptor mediated inhibition of glutamatergic inputs to cortically-projecting cholinergic and GABA/PV neurons. Conversely, caffeine and theophylline promote attentive wakefulness by inhibiting these A1 receptors in BF thereby promoting the high-frequency oscillations in the cortex required for

  4. Whole-brain mapping of inputs to projection neurons and cholinergic interneurons in the dorsal striatum.

    Science.gov (United States)

    Guo, Qingchun; Wang, Daqing; He, Xiaobin; Feng, Qiru; Lin, Rui; Xu, Fuqiang; Fu, Ling; Luo, Minmin

    2015-01-01

    The dorsal striatum integrates inputs from multiple brain areas to coordinate voluntary movements, associative plasticity, and reinforcement learning. Its projection neurons consist of the GABAergic medium spiny neurons (MSNs) that express dopamine receptor type 1 (D1) or dopamine receptor type 2 (D2). Cholinergic interneurons account for a small portion of striatal neuron populations, but they play important roles in striatal functions by synapsing onto the MSNs and other local interneurons. By combining the modified rabies virus with specific Cre- mouse lines, a recent study mapped the monosynaptic input patterns to MSNs. Because only a small number of extrastriatal neurons were labeled in the prior study, it is important to reexamine the input patterns of MSNs with higher labeling efficiency. Additionally, the whole-brain innervation pattern of cholinergic interneurons remains unknown. Using the rabies virus-based transsynaptic tracing method in this study, we comprehensively charted the brain areas that provide direct inputs to D1-MSNs, D2-MSNs, and cholinergic interneurons in the dorsal striatum. We found that both types of projection neurons and the cholinergic interneurons receive extensive inputs from discrete brain areas in the cortex, thalamus, amygdala, and other subcortical areas, several of which were not reported in the previous study. The MSNs and cholinergic interneurons share largely common inputs from areas outside the striatum. However, innervations within the dorsal striatum represent a significantly larger proportion of total inputs for cholinergic interneurons than for the MSNs. The comprehensive maps of direct inputs to striatal MSNs and cholinergic interneurons shall assist future functional dissection of the striatal circuits.

  5. In silico analysis of the histaprodifen induced activation pathway of the guinea-pig histamine H1-receptor

    Science.gov (United States)

    Straßer, Andrea; Wittmann, Hans-Joachim

    2010-09-01

    The binding of (partial) agonists in the binding pocket of biogenic amine receptors induces a conformational change from the inactive to the active state of the receptors. There is only little knowledge about the binding pathways of ligands into binding pocket on molecular level. So far, it was not possible with molecular dynamic simulations to observe the ligand binding and receptor activation. Furthermore, there is nearly nothing known, in which state of ligand binding, the receptor gets activated. The aim of this study was to get more detailed insight into the process of ligand binding and receptor activation. With the recently developed LigPath algorithm, we scanned the potential energy surface of the binding process of dimeric histaprodifen, a partial agonist at the histamine H1-receptor, into the guinea pig histamine H1-receptor, taking also into account the receptor activation. The calculations exhibited large conformational changes of Trp6.48 and Phe6.55 during ligand binding and receptor activation. Additionally, conformational changes were also observed for Phe6.52, Tyr6.51 and Phe6.44. Conformational changes of Trp6.48 and Phe6.52 are discussed in literature as rotamer toggle switch in context with receptor activation. Additionally, the calculations indicate that the binding of dimeric histaprodifen, accompanied by receptor activation is energetically preferred. In general, this study gives new, theoretical insights onto ligand binding and receptor activation on molecular level.

  6. A nuclear receptor-like pathway regulating multidrug resistance in fungi.

    Science.gov (United States)

    Thakur, Jitendra K; Arthanari, Haribabu; Yang, Fajun; Pan, Shih-Jung; Fan, Xiaochun; Breger, Julia; Frueh, Dominique P; Gulshan, Kailash; Li, Darrick K; Mylonakis, Eleftherios; Struhl, Kevin; Moye-Rowley, W Scott; Cormack, Brendan P; Wagner, Gerhard; Näär, Anders M

    2008-04-03

    Multidrug resistance (MDR) is a serious complication during treatment of opportunistic fungal infections that frequently afflict immunocompromised individuals, such as transplant recipients and cancer patients undergoing cytotoxic chemotherapy. Improved knowledge of the molecular pathways controlling MDR in pathogenic fungi should facilitate the development of novel therapies to combat these intransigent infections. MDR is often caused by upregulation of drug efflux pumps by members of the fungal zinc-cluster transcription-factor family (for example Pdr1p orthologues). However, the molecular mechanisms are poorly understood. Here we show that Pdr1p family members in Saccharomyces cerevisiae and the human pathogen Candida glabrata directly bind to structurally diverse drugs and xenobiotics, resulting in stimulated expression of drug efflux pumps and induction of MDR. Notably, this is mechanistically similar to regulation of MDR in vertebrates by the PXR nuclear receptor, revealing an unexpected functional analogy of fungal and metazoan regulators of MDR. We have also uncovered a critical and specific role of the Gal11p/MED15 subunit of the Mediator co-activator and its activator-targeted KIX domain in antifungal/xenobiotic-dependent regulation of MDR. This detailed mechanistic understanding of a fungal nuclear receptor-like gene regulatory pathway provides novel therapeutic targets for the treatment of multidrug-resistant fungal infections.

  7. Thyroid Hormone Receptor α1 Follows a Cooperative CRM1/Calreticulin-mediated Nuclear Export Pathway*

    Science.gov (United States)

    Grespin, Matthew E.; Bonamy, Ghislain M. C.; Roggero, Vincent R.; Cameron, Nicole G.; Adam, Lindsay E.; Atchison, Andrew P.; Fratto, Victoria M.; Allison, Lizabeth A.

    2008-01-01

    The thyroid hormone receptor α1 (TRα) exhibits a dual role as an activator or repressor of its target genes in response to thyroid hormone (T3). Previously, we have shown that TRα, formerly thought to reside solely in the nucleus bound to DNA, actually shuttles rapidly between the nucleus and cytoplasm. An important aspect of the shuttling activity of TRα is its ability to exit the nucleus through the nuclear pore complex. TRα export is not sensitive to treatment with the CRM1-specific inhibitor leptomycin B (LMB) in heterokaryon assays, suggesting a role for an export receptor other than CRM1. Here, we have used a combined approach of in vivo fluorescence recovery after photobleaching experiments, in vitro permeabilized cell nuclear export assays, and glutathione S-transferase pull-down assays to investigate the export pathway used by TRα. We show that, in addition to shuttling in heterokaryons, TRα shuttles rapidly in an unfused monokaryon system as well. Furthermore, our data show that TRα directly interacts with calreticulin, and point to the intriguing possibility that TRα follows a cooperative export pathway in which both calreticulin and CRM1 play a role in facilitating efficient translocation of TRα from the nucleus to cytoplasm. PMID:18641393

  8. Thyroid hormone receptor alpha1 follows a cooperative CRM1/calreticulin-mediated nuclear export pathway.

    Science.gov (United States)

    Grespin, Matthew E; Bonamy, Ghislain M C; Roggero, Vincent R; Cameron, Nicole G; Adam, Lindsay E; Atchison, Andrew P; Fratto, Victoria M; Allison, Lizabeth A

    2008-09-12

    The thyroid hormone receptor alpha1 (TRalpha) exhibits a dual role as an activator or repressor of its target genes in response to thyroid hormone (T(3)). Previously, we have shown that TRalpha, formerly thought to reside solely in the nucleus bound to DNA, actually shuttles rapidly between the nucleus and cytoplasm. An important aspect of the shuttling activity of TRalpha is its ability to exit the nucleus through the nuclear pore complex. TRalpha export is not sensitive to treatment with the CRM1-specific inhibitor leptomycin B (LMB) in heterokaryon assays, suggesting a role for an export receptor other than CRM1. Here, we have used a combined approach of in vivo fluorescence recovery after photobleaching experiments, in vitro permeabilized cell nuclear export assays, and glutathione S-transferase pull-down assays to investigate the export pathway used by TRalpha. We show that, in addition to shuttling in heterokaryons, TRalpha shuttles rapidly in an unfused monokaryon system as well. Furthermore, our data show that TRalpha directly interacts with calreticulin, and point to the intriguing possibility that TRalpha follows a cooperative export pathway in which both calreticulin and CRM1 play a role in facilitating efficient translocation of TRalpha from the nucleus to cytoplasm.

  9. Downstream reporter gene imaging for signal transduction pathway of dopamine type 2 receptor

    Energy Technology Data Exchange (ETDEWEB)

    Le, Uyenchi N.; Min, Jung Joon; Moon, Sung Min; Bom, Hee Seung [School of Midicine, Chonnam National University, Gwangju (Korea, Republic of)

    2004-07-01

    The Dopamine 2 receptor (D2R) signal pathway regulates gene expression by phosphorylation of proteins including cAMP reponse element-binding protein (CREB), a transcription factor. In this study, we developed a reporter strategy using the GAL4 fusion CREB to assess the phosphorylation of CREB, one of the targets of the D2R signal transduction pathway. We used three plasmids: GAL4 fusion transactivator (pCMV-CREB), firefly luciferase reporter with GAL4 binding sites (pG5-FLUC), and D2R plasmid (pCMV-D2R). Group 1 293T cells were transiently transfected with pCMV-CREB and pG5-FLUC, and group 2 cells were transfected with all three plasmids. Transfected cells were stimulated with different concentrations of dopamine (0-200 M). For animal studies, group 1 and 2 cells (1x10{sup 6}) were subcutaneously injected on the left and right thigh of six nude mice, respectively. Dopamine stimiulation was performed with intraperitoneal injection of L-DOPA incombination with carbidopa, a peripheral DOPA decarboxylase inhibitor. Bioluminescence optical imaging studies were performed before and after L-DOPA injection. In cell culture studies, group 1 cells showed strong luciferase activity which implies direct activation of the signaling pathway due to growth factors contained in culture medium. Group 2 cells showed strong luciferase activity and a further increase after administration of dopamine. In animal studies, group 1 and 2 cells showed bioluminescence signal before L-DOPA injection, but signal from group 2 cells significantly increased 12 h after L-DOPA injection. The signal from group 1 cells disappeared thereafter, but group 2 cells continued to show signal until 36 h of L-DOPA injection. This study demonstrates imaging of the D2R signal transduction pathway and should be useful for noninvasive imaging of downstream effects of G-coupled protein pathways.

  10. Dysregulation of Uterine Signaling Pathways in Progesterone Receptor-Cre Knockout of Dicer

    Science.gov (United States)

    Andreu-Vieyra, Claudia V.; Kim, Tae Hoon; Jeong, Jae-Wook; Hodgson, Myles C.; Chen, Ruihong; Creighton, Chad J.; Lydon, John P.; Gunaratne, Preethi H.; DeMayo, Francesco J.; Matzuk, Martin M.

    2012-01-01

    Epithelial-stromal interactions in the uterus are required for normal uterine functions such as pregnancy, and multiple signaling pathways are essential for this process. Although Dicer and microRNA (miRNA) have been implicated in several reproductive processes, the specific roles of Dicer and miRNA in uterine development are not known. To address the roles of miRNA in the regulation of key uterine pathways, we generated a conditional knockout of Dicer in the postnatal uterine epithelium and stroma using progesterone receptor-Cre. These Dicer conditional knockout females are sterile with small uteri, which demonstrate significant defects, including absence of glandular epithelium and enhanced stromal apoptosis, beginning at approximately postnatal d 15, with coincident expression of Cre and deletion of Dicer. Specific miRNA (miR-181c, −200b, −101, let-7d) were down-regulated and corresponding predicted proapoptotic target genes (Bcl2l11, Aldh1a3) were up-regulated, reflecting the apoptotic phenomenon. Although these mice had normal serum hormone levels, critical uterine signaling pathways, including progesterone-responsive genes, Indian hedgehog signaling, and the Wnt/β-catenin canonical pathway, were dysregulated at the mRNA level. Importantly, uterine stromal cell proliferation in response to progesterone was absent, whereas uterine epithelial cell proliferation in response to estradiol was maintained in adult uteri. These data implicate Dicer and appropriate miRNA expression as essential players in the regulation of multiple uterine signaling pathways required for uterine development and appropriate function. PMID:22798293

  11. Signaling pathways involved in the inhibition of epidermal growth factor receptor by erlotinib in hepatocellular cancer

    Institute of Scientific and Technical Information of China (English)

    Alexander Huether; Michael H(o)pfner; Andreas P Sutter; Viola Baradari; Detlef Schuppan; Hans Scherübl

    2006-01-01

    AIM: To examine the underlying mechanisms of erlotinib-induced growth inhibition in hepatocellular carcinoma (HCC).METHODS: Erlotinib-induced alterations in gene expression were evaluated using cDNA array technology;changes in protein expression and/or protein activation due to erlotinib treatment as well as IGF-1-induced EGFR transactivation were investigated using Western blotting. RESULTS: Erlotinib treatment inhibited the mitogen activated protein (MAP)-kinase pathway and signal transducer of activation and transcription (STAT)mediated signaling which led to an altered expression of apoptosis and cell cycle regulating genes as demonstrated by cDNA array technology. Overexpression of proapoptotic factors like caspases and gadds associated with a down-regulation of antiapoptoticfactors like Bcl-2, Bcl-XL or jun D accounted for erlotinib's potency to induce apoptosis. Downregulation of cell cycle regulators promoting the G1/S-transition and overexpression of cyclin-dependent kinase inhibitors and gadds contributed to the induction of a G1/Go-arrest in response to erlotinib. Furthermore, we displayed the transactivation of EGFR-mediated signaling by the IGF-1-receptor and showed erlotinib's inhibitory effects on the receptor-receptor cross talk. CONCLUSION: Our study sheds light on the understanding of the mechanisms of action of EGFR-TKinhibition in HCC-cells and thus might facilitate the design of combination therapies that act additively or synergistically. Moreover, our data on the pathways responding to erlotinib treatment could be helpful in predicting the responsiveness of tumors to EGFR-TKIs in the future.

  12. TLR4 and CD14 receptors expressed in rat pineal gland trigger NFKB pathway.

    Science.gov (United States)

    da Silveira Cruz-Machado, Sanseray; Carvalho-Sousa, Claudia Emanuele; Tamura, Eduardo Koji; Pinato, Luciana; Cecon, Erika; Fernandes, Pedro Augusto Carlos Magno; de Avellar, Maria Christina Werneck; Ferreira, Zulma Silva; Markus, Regina Pekelmann

    2010-09-01

    Nuclear factor-kappa B (NFKB), a pivotal player in inflammatory responses, is constitutively expressed in the pineal gland. Corticosterone inhibits pineal NFKB leading to an enhancement of melatonin production, while tumor necrosis factor (TNF) leads to inhibition of Aa-nat transcription and the production of N-acetylserotonin in cultured glands. The reduction in nocturnal melatonin surge favors the mounting of the inflammatory response. Despite these data, there is no clear evidence of the ability of the pineal gland to recognize molecules that signal infection. This study investigated whether the rat pineal gland expresses receptors for lipopolysaccharide (LPS), the endotoxin from the membranes of Gram-negative bacteria, and to establish the mechanism of action of LPS. Here, we show that pineal glands possess both CD14 and toll-like receptor 4 (TLR4), membrane proteins that bind LPS and trigger the NFKB pathway. LPS induced the nuclear translocation of p50/p50 and p50/RELA dimers and the synthesis of TNF. The maximal expression of TNF in cultured glands coincides with an increase in the expression of TNF receptor 1 (TNFR1) in isolated pinealocytes. In addition, LPS inhibited the synthesis of N-acetylserotonin and melatonin. Therefore, the pineal gland transduces Gram-negative endotoxin stimulation by producing TNF and inhibiting melatonin synthesis. Here, we provide evidence to reinforce the idea of an immune-pineal axis, showing that the pineal gland is a constitutive player in the innate immune response.

  13. Macrophage Receptor with Collagenous Structure (MARCO Is Processed by either Macropinocytosis or Endocytosis-Autophagy Pathway.

    Directory of Open Access Journals (Sweden)

    Seishiro Hirano

    Full Text Available The Macrophage Receptor with COllagenous structure (MARCO protein is a plasma membrane receptor for un-opsonized or environmental particles on phagocytic cells. Here, we show that MARCO was internalized either by ruffling of plasma membrane followed by macropinocytosis or by endocytosis followed by fusion with autophagosome in CHO-K1 cells stably transfected with GFP-MARCO. The macropinocytic process generated large vesicles when the plasma membrane subsided. The endocytosis/autophagosome (amphisome generated small fluorescent puncta which were visible in the presence of glutamine, chloroquine, bafilomycin, ammonia, and other amines. The small puncta, but not the large vesicles, co-localized with LC3B and lysosomes. The LC3-II/LC3-I ratio increased in the presence of glutamine, ammonia, and chloroquine in various cells. The small puncta trafficked between the peri-nuclear region and the distal ends of cells back and forth at rates of up to 2-3 μm/sec; tubulin, but not actin, regulated the trafficking of the small puncta. Besides phagocytosis MARCO, an adhesive plasma membrane receptor, may play a role in incorporation of various extracellular materials into the cell via both macropinocytic and endocytic pathways.

  14. Distinct signaling mechanisms in multiple developmental pathways by the SCRAMBLED receptor of Arabidopsis.

    Science.gov (United States)

    Kwak, Su-Hwan; Woo, Sooah; Lee, Myeong Min; Schiefelbein, John

    2014-10-01

    SCRAMBLED (SCM), a leucine-rich repeat receptor-like kinase in Arabidopsis (Arabidopsis thaliana), is required for positional signaling in the root epidermis and for tissue/organ development in the shoot. To further understand SCM action, we generated a series of kinase domain variants and analyzed their ability to complement scm mutant defects. We found that the SCM kinase domain, but not kinase activity, is required for its role in root epidermal patterning, supporting the view that SCM is an atypical receptor kinase. We also describe a previously uncharacterized role for SCM in fruit dehiscence, because mature siliques from scm mutants fail to open properly. Interestingly, the kinase domain of SCM appears to be dispensable for this developmental process. Furthermore, we found that most of the SCM kinase domain mutations dramatically inhibit inflorescence development. Because this process is not affected in scm null mutants, it is likely that SCM acts redundantly to regulate inflorescence size. The importance of distinct kinase residues for these three developmental processes provides an explanation for the maintenance of the conserved kinase domain in the SCM protein, and it may generally explain its conservation in other atypical kinases. Furthermore, these results indicate that individual leucine-rich repeat receptor-like kinases may participate in multiple pathways using distinct signaling mechanisms to mediate diverse cellular communication events.

  15. Early postnatal nicotine exposure causes hippocampus-dependent memory impairments in adolescent mice: Association with altered nicotinic cholinergic modulation of LTP, but not impaired LTP.

    Science.gov (United States)

    Nakauchi, Sakura; Malvaez, Melissa; Su, Hailing; Kleeman, Elise; Dang, Richard; Wood, Marcelo A; Sumikawa, Katumi

    2015-02-01

    Fetal nicotine exposure from smoking during pregnancy causes long-lasting cognitive impairments in offspring, yet little is known about the mechanisms that underlie this effect. Here we demonstrate that early postnatal exposure of mouse pups to nicotine via maternal milk impairs long-term, but not short-term, hippocampus-dependent memory during adolescence. At the Schaffer collateral (SC) pathway, the most widely studied synapses for a cellular correlate of hippocampus-dependent memory, the induction of N-methyl-D-aspartate receptor-dependent transient long-term potentiation (LTP) and protein synthesis-dependent long-lasting LTP are not diminished by nicotine exposure, but rather unexpectedly the threshold for LTP induction becomes lower after nicotine treatment. Using voltage sensitive dye to visualize hippocampal activity, we found that early postnatal nicotine exposure also results in enhanced CA1 depolarization and hyperpolarization after SC stimulation. Furthermore, we show that postnatal nicotine exposure induces pervasive changes to the nicotinic modulation of CA1 activity: activation of nicotinic receptors no longer increases CA1 network depolarization, acute nicotine inhibits rather than facilitates the induction of LTP at the SC pathway by recruiting an additional nicotinic receptor subtype, and acute nicotine no longer blocks LTP induction at the temporoammonic pathway. These findings reflect the pervasive impact of nicotine exposure during hippocampal development, and demonstrate an association of hippocampal memory impairments with altered nicotinic cholinergic modulation of LTP, but not impaired LTP. The implication of our results is that nicotinic cholinergic-dependent plasticity is required for long-term memory formation and that postnatal nicotine exposure disrupts this form of plasticity.

  16. H1 antihistamines in allergic rhinitis: The molecular pathways of interleukin and toll - like receptor systems

    Directory of Open Access Journals (Sweden)

    Jonny Karunia Fajar

    2016-03-01

    Full Text Available The complex interaction between inflammatory mediators in allergic rhinitis (AR is determined by the role of genetic polymorphisms, including interleukin (IL and toll-like receptor (TLR genes. This study aimed to discuss the effects of H1-antihistamines on IL and TLR systems. Several ILs involved in AR pathogenesis are: IL-4 (rs2243250, rs1800925, rs1801275, rs2227284, rs2070874, IL-6 (rs1800795, rs1800797, IL-10 (rs1800871, rs1800872, IL-12R (rs438421, IL-13 (rs1800925, rs20541, IL-17 (rs3819024, IL-18 (rs360721, rs360718, rs360717, rs187238, IL-23R (rs7517847, and IL-27 (rs153109, rs17855750. In the IL system, histamines stimulate the IL production in Type 2 helper T (Th2 cells through protein kinase A (PKA, janus kinase-signal transducer and activator of transcription (JAK-STAT pathway, and the activation of H1-histamine receptor and histidine decarboxylase (HDC genes. On contrary, antihistamines down-regulate the H1-histamine receptor gene expression through the transcription suppression of HDC and IL genes and suppress histamine basal signaling through the inverse agonistic activity. TLRs involved in AR pathogenesis are TLR2 (rs4696480, rs3804099, rs5743708, TLR4 (rs4986790, TLR6 (rs2381289, TLR7 (rs179008, rs5935438, TRL8 (rs2407992, rs5741883, rs17256081, rs4830805, rs3788935, rs178998, and TLR10 (rs11466651. In the TLR system, histamines trigger the TLR expression by stimulating interferon-γ (IFN-γ to up-regulate mast cells and by stimulating receptor-interacting protein (RIP to activate IκB kinase-β. Contrastingly, antihistamines suppress TIR-domain-containing adaptor protein inducing IFN-β (TRIF and RIP protein and thus inhibit the expression of TLR. In addition, several studies indicated that H1-antihistamines inhibit the IL and TLR systems indirectly.

  17. Berberine induces GLP-1 secretion through activation of bitter taste receptor pathways.

    Science.gov (United States)

    Yu, Yunli; Hao, Gang; Zhang, Quanying; Hua, Wenyan; Wang, Meng; Zhou, Wenjia; Zong, Shunlin; Huang, Ming; Wen, Xiaozhou

    2015-09-15

    Our previous studies revealed that berberine-mediated GLP-1 secretion was a possible mechanism for berberine exerting good effects on hyperglycemia. This study was designed to ascertain whether berberine-induced secretion of GLP-1 was related with activation of bitter taste receptors expressed in gastrointestinal tract. Western blotting results showed that TAS2R38, a subtype of bitter taste receptor, was expressed on human enteroendocrine NCI-H716 cells. GLP-1 secretion induced by berberine from NCI-H716 cells was inhibited by incubation with anti-TAS2R38 antibody. We further performed gene silencing using siRNA to knockdown TAS2R38 from NCI-H716 cells, which showed that siRNA knockdown of the TAS2R38 reduced berberine-mediated GLP-1 secretion. We adopted inhibitors of PLC and TRPM5 known to be involved in bitter taste transduction to investigate the underlying pathways mediated in berberine-induced GLP-1 secretion. It was found that PLC inhibitor U73122 inhibited berberine-induced GLP-1 release in NCI-H716 cells, while TRPM5 blocker quinine failed to attenuate berberine-induced secretion of GLP-1. The present results demonstrated that berberine stimulated GLP-1 secretion via activation of gut-expressed bitter taste receptors in a PLC-dependent manner. Because berberine was found to be a ligand of bitter taste receptor, the results of present study may provide an explanation for some bitter taste substance obtain hypoglycemic effect.

  18. Somatostatin receptor biology in neuroendocrine and pituitary tumours: part 1 – molecular pathways

    Science.gov (United States)

    Cakir, Mehtap; Dworakowska, Dorota; Grossman, Ashley

    2010-01-01

    Abstract Neuroendocrine tumours (NETs) may occur at many sites in the body although the majority occur within the gastroenteropancreatic axis. Non-gastroenteropancreatic NETs encompass phaeochromocytomas and paragangliomas, medullary thyroid carcinoma, anterior pituitary tumour, broncho-pulmonary NETs and parathyroid tumours. Like most endocrine tumours, NETs also express somatostatin (SST) receptors (subtypes 1–5) whose ligand SST is known to inhibit endocrine and exocrine secretions and have anti-tumour effects. In the light of this knowledge, the idea of using SST analogues in the treatment of NETs has become increasingly popular and new studies have centred upon the development of new SST analogues. We attempt to review SST receptor (SSTR) biology primarily in neuroendocrine tissues, focusing on pituitary tumours. A full data search was performed through PubMed over the years 2000–2009 with keywords ‘somatostatin, molecular biology, somatostatin receptors, somatostatin signalling, NET, pituitary’ and all relevant publications have been included, together with selected publications prior to that date. SSTR signalling in non-neuroendocrine solid tumours is beyond the scope of this review. SST is a potent anti-proliferative and anti-secretory agent for some NETs. The successful therapeutic use of SST analogues in the treatment of these tumours depends on a thorough understanding of the diverse effects of SSTR subtypes in different tissues and cell types. Further studies will focus on critical points of SSTR biology such as homo- and heterodimerization of SSTRs and the differences between post-receptor signalling pathways of SSTR subtypes. PMID:20629989

  19. Cross talk of signaling pathways in the regulation of the glucocorticoid receptor function.

    Science.gov (United States)

    Davies, Laura; Karthikeyan, Nirupama; Lynch, James T; Sial, Elin-Alia; Gkourtsa, Areti; Demonacos, Constantinos; Krstic-Demonacos, Marija

    2008-06-01

    Several posttranslational modifications including phosphorylation have been detected on the glucocorticoid receptor (GR). However, the interdependence and combinatorial regulation of these modifications and their role in GR functions are poorly understood. We studied the effects of c-Jun N-terminal kinase (JNK)-dependent phosphorylation of GR on its sumoylation status and the impact that these modifications have on GR transcriptional activity. GR is targeted for phosphorylation at serine 246 (S246) by the JNK protein family in a rapid and transient manner. The levels of S246 phosphorylation of endogenous GR increased significantly in cells treated with UV radiation that activates JNK. S246 GR phosphorylation by JNK facilitated subsequent GR sumoylation at lysines 297 and 313. GR sumoylation increased with JNK activation and was inhibited in cells treated with JNK inhibitor. GR sumoylation in cells with activated JNK was mediated preferentially by small ubiquitin-like modifier (SUMO)2 rather than SUMO1. An increase in GR transcriptional activity was observed after inhibition of JNK or SUMO pathways and suppression of GR transcriptional activity after activation of both pathways in cells transfected with GR-responsive reporter genes. Endogenous GR transcriptional activity was inhibited on endogenous target genes IGF binding protein (IGFBP) and glucocorticoid-induced leucine zipper (GILZ) when JNK and SUMO pathways were induced individually or simultaneously. Activation of both of these signals inhibited GR-mediated regulation of human inhibitor of apoptosis gene (hIAP), whereas simultaneous activation had no effect. We conclude that phosphorylation aids GR sumoylation and that cross talk of JNK and SUMO pathways fine tune GR transcriptional activity in a target gene-specific manner, thereby modulating the hormonal response of cells exposed to stress.

  20. Repositioning of Memantine as a Potential Novel Therapeutic Agent against Meningitic E. coli-Induced Pathogenicities through Disease-Associated Alpha7 Cholinergic Pathway and RNA Sequencing-Based Transcriptome Analysis of Host Inflammatory Responses.

    Directory of Open Access Journals (Sweden)

    Jing-Yi Yu

    Full Text Available Neonatal sepsis and meningitis (NSM remains a leading cause worldwide of mortality and morbidity in newborn infants despite the availability of antibiotics over the last several decades. E. coli is the most common gram-negative pathogen causing NSM. Our previous studies show that α7 nicotinic receptor (α7 nAChR, an essential regulator of inflammation, plays a detrimental role in the host defense against NSM. Despite notable successes, there still exists an unmet need for new effective therapeutic approaches to treat this disease. Using the in vitro/in vivo models of the blood-brain barrier (BBB and RNA-seq, we undertook a drug repositioning study to identify unknown antimicrobial activities for known drugs. We have demonstrated for the first time that memantine (MEM, a FDA-approved drug for treatment of Alzheimer's disease, could very efficiently block E. coli-caused bacteremia and meningitis in a mouse model of NSM in a manner dependent on α7 nAChR. MEM was able to synergistically enhance the antibacterial activity of ampicillin in HBMEC infected with E. coli K1 (E44 and in neonatal mice with E44-caused bacteremia and meningitis. Differential gene expression analysis of RNA-Seq data from mouse BMEC infected with E. coli K1 showed that several E44-increased inflammatory factors, including IL33, IL18rap, MMP10 and Irs1, were significantly reduced by MEM compared to the infected cells without drug treatment. MEM could also significantly up-regulate anti-inflammatory factors, including Tnfaip3, CISH, Ptgds and Zfp36. Most interestingly, these factors may positively and negatively contribute to regulation of NF-κB, which is a hallmark feature of bacterial meningitis. Furthermore, we have demonstrated that circulating BMEC (cBMEC are the potential novel biomarkers for NSM. MEM could significantly reduce E44-increased blood level of cBMEC in mice. Taken together, our data suggest that memantine can efficiently block host inflammatory responses to

  1. Effects of (-)-Epigallocatechin gallate on some protein factors involved in the epidermal growth factor receptor signaling pathway

    Institute of Scientific and Technical Information of China (English)

    Yinjiu Huang; Ruiqing Xu; Baoan Song; Song Yang; Li Zhao; Shouwei Wua

    2009-01-01

    (-)-Epigallocatechin gallate (EGCG), a major polyphenolic constituent of green tea, can inhibit activity of specific receptor tyrosine kinases (RTKs) and related downstream signal transduction pathways, resulting in the control of unwanted cell proliferation. The epidermal growth factor receptor (EGFR) signaling pathway is one of the most important pathways that regulates growth, survival, proliferation and differentiation in mammalian cells. This review addresses the effects of EGCG on some protein factors involved in the EGFR signaling pathway in a direct or indirect manner. Based on our understanding of the interaction between EGCG and these factors, and based on their structures, EGCG could be used as a lead compound for designing and synthesizing novel drugs with significant biological activity.

  2. Illuminating the role of cholinergic signaling in circuits of attention and emotionally salient behaviors

    Directory of Open Access Journals (Sweden)

    Antonio eLuchicchi

    2014-10-01

    Full Text Available Acetylcholine (ACh signaling underlies specific aspects of cognitive functions and behaviors, including attention, learning, memory and motivation. Alterations in ACh signaling are involved in the pathophysiology of multiple neuropsychiatric disorders. In the central nervous system, ACh transmission is mainly guaranteed by dense innervation of select cortical and subcortical regions from disperse groups of cholinergic neurons within the basal forebrain (e.g. diagonal band, medial septal, nucleus basalis and the pontine-mesencephalic nuclei, respectively. Despite the fundamental role of cholinergic signaling in the CNS and the long standing knowledge of the organization of cholinergic circuitry, remarkably little is known about precisely how ACh release modulates cortical and subcortical neural activity and the behaviors these circuits subserve. Growing interest in cholinergic signaling in the CNS focuses on the mechanism(s of action by which endogenously released ACh regulates cognitive functions, acting as a neuromodulator and /or as a direct transmitter via nicotinic and muscarinic receptors. The development of optogenetic techniques has provided a valuable toolbox with which we can address these questions, as it allows the selective manipulation of the excitability of cholinergic inputs to the diverse array of cholinergic target fields within cortical and subcortical domains. Here, we review recent papers that use the light-sensitive opsins in the cholinergic system to elucidate the role of ACh in circuits related to attention and emotionally salient behaviors. In particular, we highlight recent optogenetic studies which have tried to disentangle the precise role of ACh in the modulation of cortical-, hippocampal- and striatal-dependent functions.

  3. Evaluation of cholinergic markers in Alzheimer's disease and in a model of cholinergic deficit

    OpenAIRE

    2005-01-01

    Cognitive deficits in neuropsychiatric disorders, such as Alzheimer's disease (AD), have been closely related to cholinergic deficits. We have compared different markers of cholinergic function to assess the best biomarker of cognitive deficits associated to cholinergic hypoactivity. In post-mortem frontal cortex from AD patients, acetylcholine (ACh) levels, cholinacetyltransferase (ChAT) and acetylcholinesterase (AChE) activity were all reduced compared to controls. Both ChAT and AChE activi...

  4. Control of hepatitis B virus replication by interferons and Toll-like receptor signaling pathways.

    Science.gov (United States)

    Pei, Rong-Juan; Chen, Xin-Wen; Lu, Meng-Ji

    2014-09-07

    Hepatitis B virus (HBV) infection is one of the major causes of liver diseases, affecting more than 350 million people worldwide. The interferon (IFN)-mediated innate immune responses could restrict HBV replication at the different steps of viral life cycle. Indeed, IFN-α has been successfully used for treatment of patients with chronic hepatitis B. However, the role of the innate immune response in HBV replication and the mechanism of the anti-HBV effect of IFN-α are not completely explored. In this review, we summarized the currently available knowledge about the IFN-mediated anti-HBV effect in the HBV life cycle and the possible effectors downstream the IFN signaling pathway. The antiviral effect of Toll-like receptors (TLRs) in HBV replication is briefly discussed. The strategies exploited by HBV to evade the IFN- and TLR-mediated antiviral actions are summarized.

  5. Skeletal muscle lipid accumulation in type 2 diabetes may involve the liver X receptor pathway

    DEFF Research Database (Denmark)

    Kase, Eili T; Wensaas, Andreas J; Aas, Vigdis;

    2005-01-01

    . Interestingly, in response to activation of LXRs, myotubes from patients with type 2 diabetes showed an elevated uptake and incorporation of palmitate into complex lipids but an absence of palmitate oxidation to CO(2). These results provide evidence for a functional role of LXRs in both lipid and glucose...... metabolism and energy uncoupling in human myotubes. Furthermore, these data suggest that increased intramyocellular lipid content in type 2 diabetic patients may involve an altered response to activation of components in the LXR pathway........ Consistently, activation of LXRs induced the expression of relevant genes: fatty acid translocase (CD36/FAT), glucose transporters (GLUT1 and -4), sterol regulatory element-binding protein-1c, peroxisome proliferator-activated receptor-gamma, carnitine palmitoyltransferase-1, and uncoupling protein 2 and 3...

  6. Increased leptin/leptin receptor pathway affects systemic and airway inflammation in COPD former smokers

    Directory of Open Access Journals (Sweden)

    Bruno A

    2011-05-01

    /leptin receptor pathway in the regulation of host defense after smoking cessation.Keywords: COPD, smokers, inflammation, leptin, neutrophils

  7. Selective Activation of Cholinergic Interneurons Enhances Accumbal Phasic Dopamine Release: Setting the Tone for Reward Processing

    Directory of Open Access Journals (Sweden)

    Roger Cachope

    2012-07-01

    Full Text Available Dopamine plays a critical role in motor control, addiction, and reward-seeking behaviors, and its release dynamics have traditionally been linked to changes in midbrain dopamine neuron activity. Here, we report that selective endogenous cholinergic activation achieved via in vitro optogenetic stimulation of nucleus accumbens, a terminal field of dopaminergic neurons, elicits real-time dopamine release. This mechanism occurs via direct actions on dopamine terminals, does not require changes in neuron firing within the midbrain, and is dependent on glutamatergic receptor activity. More importantly, we demonstrate that in vivo selective activation of cholinergic interneurons is sufficient to elicit dopamine release in the nucleus accumbens. Therefore, the control of accumbal extracellular dopamine levels by endogenous cholinergic activity results from a complex convergence of neurotransmitter/neuromodulator systems that may ultimately synergize to drive motivated behavior.

  8. SUMOylation modulates the transcriptional activity of androgen receptor in a target gene and pathway selective manner.

    Science.gov (United States)

    Sutinen, Päivi; Malinen, Marjo; Heikkinen, Sami; Palvimo, Jorma J

    2014-07-01

    Androgen receptor (AR) plays an important regulatory role in prostate cancer. AR's transcriptional activity is regulated by androgenic ligands, but also by post-translational modifications, such as SUMOylation. To study the role of AR SUMOylation in genuine chromatin environment, we compared androgen-regulated gene expression and AR chromatin occupancy in PC-3 prostate cancer cell lines stably expressing wild-type (wt) or doubly SUMOylation site-mutated AR (AR-K386R,K520R). Our genome-wide gene expression analyses reveal that the SUMOylation modulates the AR function in a target gene and pathway selective manner. The transcripts that are differentially regulated by androgen and SUMOylation are linked to cellular movement, cell death, cellular proliferation, cellular development and cell cycle. Fittingly, SUMOylation mutant AR cells proliferate faster and are more sensitive to apoptosis. Moreover, ChIP-seq analyses show that the SUMOylation can modulate the chromatin occupancy of AR on many loci in a fashion that parallels their differential androgen-regulated expression. De novo motif analyses reveal that FOXA1, C/EBP and AP-1 motifs are differentially enriched at the wtAR- and the AR-K386R,K520R-preferred genomic binding positions. Taken together, our data indicate that SUMOylation does not simply repress the AR activity, but it regulates AR's interaction with the chromatin and the receptor's target gene selection.

  9. Molecular and cellular dynamics of the Toll-like receptor 4 pathway.

    Directory of Open Access Journals (Sweden)

    Nick eGay

    2014-10-01

    Full Text Available As well as being the primary signaling receptor for bacterial endotoxin or lipopolysaccharide Toll-like receptor 4 function is modulated by numerous factors not only in the context of microbial pathogenesis but also autoimmune and allergic diseases. TLR4 is subject to multiple levels of endogenous control and regulation from biosynthesis and trafficking to signal transduction and degradation. On the other hand regulation of TLR4 activity breaks down during Gram –ve sepsis leading to systemic damage, multi organ failure and death. In this article we review how TLR4 traffics from the early secretory pathway, the cis/trans Golgi to the cell surface and endolysosomal compartments. We will present evidence about how these processes influence signaling and can potentially lead to ligand independent constitutive activation that may contribute to pathogenesis in sepsis. We will also discuss how sustained signaling may be coupled to endocytosis and consider the potential molecular mechanisms of immuno-modulators that modify TLR4 signalling function including the cat allergen FelD1 and endogenous protein ligands such as the extracellular matrix protein tenascin C and calprotectin (MRP8/14.

  10. Estrogen receptor-mediated transcription involves the activation of multiple kinase pathways in neuroblastoma cells.

    Science.gov (United States)

    Clark, Sara; Rainville, Jennifer; Zhao, Xing; Katzenellenbogen, Benita S; Pfaff, Donald; Vasudevan, Nandini

    2014-01-01

    While many physiological effects of estrogens (E) are due to regulation of gene transcription by liganded estrogen receptors (ERs), several effects are also mediated, at least in part, by rapid non-genomic actions of E. Though the relative importance of rapid versus genomic effects in the central nervous system is controversial, we showed previously that membrane-limited effects of E, initiated by an estradiol bovine serum albumin conjugate (E2-BSA), could potentiate transcriptional effects of 17β-estradiol from an estrogen response element (ERE)-reporter in neuroblastoma cells. Here, using specific inhibitors and activators in a pharmacological approach, we show that activation of phosphatidylinositol-3-phosphate kinase (PI3K) and mitogen activated protein kinase (MAPK) pathways, dependent on a Gαq coupled receptor signaling are important in this transcriptional potentiation. We further demonstrate, using ERα phospho-deficient mutants, that E2-BSA mediated phosphorylation of ERα is one mechanism to potentiate transcription from an ERE reporter construct. This study provides a possible mechanism by which signaling from the membrane is coupled to transcription in the nucleus, providing an integrated view of hormone signaling in the brain.

  11. Toll-like receptors (TLRs) in aquatic animals: signaling pathways, expressions and immune responses.

    Science.gov (United States)

    Rauta, Pradipta R; Samanta, Mrinal; Dash, Hirak R; Nayak, Bismita; Das, Surajit

    2014-01-01

    The innate system's recognition of non-self and danger signals is mediated by a limited number of germ-line encoded pattern recognition receptors (PRRs) that recognize pathogen associated molecular patterns (PAMPs). Toll-like receptors (TLRs) are single, non-catalytic, membrane-spanning PRRs present in invertebrates and vertebrates. They act by specifically recognizing PAMPs of a variety of microbes and activate signaling cascades to induce innate immunity. A large number of TLRs have been identified in various aquatic animals of phyla Cnidaria, Annelida, Mollusca, Arthropoda, Echinodermata and Chordata. TLRs of aquatic and warm-blooded higher animals exhibit some distinctive features due to their diverse evolutionary lineages. However, majority of them share conserve signaling pathways in pathogen recognition and innate immunity. Functional analysis of novel TLRs in aquatic animals is very important in understanding the comparative immunology between warm-blooded and aquatic animals. In additions to innate immunity, recent reports have highlighted the additional roles of TLRs in adaptive immunity. Therefore, vaccines against many critical diseases of aquatic animals may be made more effective by supplementing TLR activators which will stimulate dendritic cells. This article describes updated information of TLRs in aquatic animals and their structural and functional relationship with warm-blooded animals.

  12. Transcriptomic Evaluation of the Nicotinic Acetylcholine Receptor Pathway in Levamisole-resistant and -sensitive Oesophagostomum dentatum

    Science.gov (United States)

    Romine, Nathan M.; Martin, Richard J.; Beetham, Jeffrey K.

    2014-01-01

    Nematode anthelminthic resistance is widespread for the 3 major drug classes commonly used in agriculture: benzamidazoles, macrocyclic lactones, and nicotinic agonists e.g. levamisole. In parasitic nematodes the genetics of resistance are unknown other than to the benzimidazoles which primarily involve a single gene. In previous work with a levamisole resistant Oesophagostomum dentatum isolate, the nicotinic acetylcholine receptor (nAChR) exhibited decreased levamisole sensitivity. Here, using a transcriptomic approach on the same isolate, we investigate whether that decreased nAChR sensitivity is achieved via a 1-gene mechanism involving 1 of 27 nAChR pathway genes. 3 nAChR receptor subunit genes exhibited ≥ 2-fold change in transcript abundance: acr-21 and acr-25 increased, and unc-63 decreased. 4 SNPs having a ≥ 2-fold change in frequency were also identified. These data suggest that resistance is likely polygenic, involving modulated abundance of multiple subunits comprising the heteropentameric nAChR, and is not due to a simple 1-gene mechanism. PMID:24530453

  13. The M-type receptor PLA2R regulates senescence through the p53 pathway.

    Science.gov (United States)

    Augert, Arnaud; Payré, Christine; de Launoit, Yvan; Gil, Jesus; Lambeau, Gérard; Bernard, David

    2009-03-01

    Senescence is a stable proliferative arrest induced by various stresses such as telomere erosion, oncogenic or oxidative stress. Compelling evidence suggests that it acts as a barrier against tumour development. Describing new mechanisms that favour an escape from senescence can thus reveal new insights into tumorigenesis. To identify new genes controlling the senescence programme, we performed a loss-of-function genetic screen in primary human fibroblasts. We report that knockdown of the M-type receptor PLA2R (phospholipase A2 receptor) prevents the onset of replicative senescence and diminishes stress-induced senescence. Interestingly, expression of PLA2R increases during replicative senescence, and its ectopic expression results in premature senescence. We show that PLA2R regulates senescence in a reactive oxygen species-DNA damage-p53-dependent manner. Taken together, our study identifies PLA2R as a potential new tumour suppressor gene crucial in the induction of cellular senescence through the activation of the p53 pathway.

  14. Identification of pathway-biased and deleterious melatonin receptor mutants in autism spectrum disorders and in the general population.

    Directory of Open Access Journals (Sweden)

    Pauline Chaste

    Full Text Available Melatonin is a powerful antioxidant and a synchronizer of many physiological processes. Alteration of the melatonin pathway has been reported in circadian disorders, diabetes and autism spectrum disorders (ASD. However, very little is known about the genetic variability of melatonin receptors in humans. Here, we sequenced the melatonin receptor MTNR1A and MTNR1B, genes coding for MT1 and MT2 receptors, respectively, in a large panel of 941 individuals including 295 patients with ASD, 362 controls and 284 individuals from different ethnic backgrounds. We also sequenced GPR50, coding for the orphan melatonin-related receptor GPR50 in patients and controls. We identified six non-synonymous mutations for MTNR1A and ten for MTNR1B. The majority of these variations altered receptor function. Particularly interesting mutants are MT1-I49N, which is devoid of any melatonin binding and cell surface expression, and MT1-G166E and MT1-I212T, which showed severely impaired cell surface expression. Of note, several mutants possessed pathway-selective signaling properties, some preferentially inhibiting the adenylyl cyclase pathway, others preferentially activating the MAPK pathway. The prevalence of these deleterious mutations in cases and controls indicates that they do not represent major risk factor for ASD (MTNR1A case 3.6% vs controls 4.4%; MTNR1B case 4.7% vs 3% controls. Concerning GPR50, we detected a significant association between ASD and two variations, Delta502-505 and T532A, in affected males, but it did not hold up after Bonferonni correction for multiple testing. Our results represent the first functional ascertainment of melatonin receptors in humans and constitute a basis for future structure-function studies and for interpreting genetic data on the melatonin pathway in patients.

  15. Upregulating Nonneuronal Cholinergic Activity Decreases TNF Release from Lipopolysaccharide-Stimulated RAW264.7 Cells

    Directory of Open Access Journals (Sweden)

    Yi Lv

    2014-01-01

    Full Text Available Nonneuronal cholinergic system plays a primary role in maintaining homeostasis. It has been proved that endogenous neuronal acetylcholine (ACh could play an anti-inflammatory role, and exogenous cholinergic agonists could weaken macrophages inflammatory response to lipopolysaccharide (LPS stimulation through activation of α7 subunit-containing nicotinic acetylcholine receptor (α7nAChR. We assumed that nonneuronal cholinergic system existing in macrophages could modulate inflammation through autocrine ACh and expressed α7nAChR on the cells. Therefore, we explored whether LPS continuous stimulation could upregulate the nonneuronal cholinergic activity in macrophages and whether increasing autocrine ACh could decrease TNF release from the macrophages. The results showed that, in RAW264.7 cells incubated with LPS for 20 hours, the secretion of ACh was significantly decreased at 4 h and then gradually increased, accompanied with the enhancement of α7nAChR expression level. The release of TNF was greatly increased from RAW264.7 cells at 4 h and 8 h exposure to LPS; however, it was suppressed at 20 h. Upregulating choline acetyltransferase (ChAT expression through ChAT gene transfection could enhance ACh secretion and reduce TNF release from the infected RAW264. 7cells. The results indicated that LPS stimulation could modulate the activity of nonneuronal cholinergic system of RAW264.7 cells. Enhancing autocrine ACh production could attenuate TNF release from RAW264.7 cells.

  16. The cholinergic REM induction test with RS 86 after scopolamine pretreatment in healthy subjects.

    Science.gov (United States)

    Riemann, D; Hohagen, F; Fleckenstein, P; Schredl, M; Berger, M

    1991-09-01

    A shortened latency of rapid eye movement (REM) sleep is one of the most stable biological abnormalities described in depressive patients. According to the reciprocal interaction model of non-REM and REM sleep regulation, REM sleep disinhibition at the beginning of the night in depression is a consequence of heightened central nervous system cholinergic transmitter activity in relation to aminergic transmitter activity. A recent study has indicated that muscarinic supersensitivity, rather than quantitatively enhanced cholinergic activity, may be the primary cause of REM sleep abnormalities in depression. The present study tested this hypothesis by treating healthy volunteers for 3 days with a cholinergic antagonist (scopolamine) in the morning, in an effort to induce muscarinic receptor supersensitivity. On the last day of scopolamine administration, RS 86, an orally active cholinergic agonist, was administered before bedtime to test whether this procedure would induce sleep onset REM periods. Whereas scopolamine treatment tended to advance REM sleep and to heighten REM density in healthy controls in comparison to NaCl administration, the additional cholinergic stimulation did not provoke further REM sleep disinhibition. This result underlines the need to take a hypofunction of aminergic transmitter systems into account in attempts to explain the pronounced advance of REM sleep typically seen in depressives.

  17. The DAF-7/TGF-β signaling pathway regulates abundance of the Caenorhabditis elegans glutamate receptor GLR-1.

    Science.gov (United States)

    McGehee, Annette M; Moss, Benjamin J; Juo, Peter

    2015-07-01

    Transforming growth factor-β (TGF-β) family signaling pathways have roles in both neuronal development and the regulation of synaptic function. Here we identify a novel role for the Caenorhabditis elegans DAF-7/TGF-β signaling pathway in the regulation of the AMPA-type glutamate receptor GLR-1. We found that the abundance of GLR-1 increases at synapses in the ventral nerve cord (VNC) of animals with loss-of-function mutations in multiple DAF-7/TGF-β pathway components including the TGF-β ligand DAF-7, the type I receptor DAF-1, and the Smads DAF-8 and DAF-14. The GLR-1 defect can be rescued by expression of daf-8 specifically in glr-1-expressing interneurons. The effect on GLR-1 was specific for the DAF-7 pathway because mutations in the DBL-1/TGF-β family pathway did not increase GLR-1 levels in the VNC. Immunoblot analysis indicates that total levels of GLR-1 protein are increased in neurons of DAF-7/TGF-β pathway mutants. The increased abundance of GLR-1 in the VNC of daf-7 pathway mutants is dependent on the transcriptional regulator DAF-3/Smad suggesting that DAF-3-dependent transcription controls GLR-1 levels. Furthermore, we found that glr-1 transcription is increased in daf-7 mutants based on a glr-1 transcriptional reporter. Together these results suggest that the DAF-7/TGF-β signaling pathway functions in neurons and negatively regulates the abundance of GLR-1, in part, by controlling transcription of the receptor itself. Finally, DAF-7/TGF-β pathway mutants exhibit changes in spontaneous locomotion that are dependent on endogenous GLR-1 and consistent with increased glutamatergic signaling. These results reveal a novel mechanism by which TGF-β signaling functions in the nervous system to regulate behavior.

  18. Distinct Structural Pathways Coordinate the Activation of AMPA Receptor-Auxiliary Subunit Complexes.

    Science.gov (United States)

    Dawe, G Brent; Musgaard, Maria; Aurousseau, Mark R P; Nayeem, Naushaba; Green, Tim; Biggin, Philip C; Bowie, Derek

    2016-03-16

    Neurotransmitter-gated ion channels adopt different gating modes to fine-tune signaling at central synapses. At glutamatergic synapses, high and low activity of AMPA receptors (AMPARs) is observed when pore-forming subunits coassemble with or without auxiliary subunits, respectively. Whether a common structural pathway accounts for these different gating modes is unclear. Here, we identify two structural motifs that determine the time course of AMPAR channel activation. A network of electrostatic interactions at the apex of the AMPAR ligand-binding domain (LBD) is essential for gating by pore-forming subunits, whereas a conserved motif on the lower, D2 lobe of the LBD prolongs channel activity when auxiliary subunits are present. Accordingly, channel activity is almost entirely abolished by elimination of the electrostatic network but restored via auxiliary protein interactions at the D2 lobe. In summary, we propose that activation of native AMPAR complexes is coordinated by distinct structural pathways, favored by the association/dissociation of auxiliary subunits.

  19. NOD-like receptor signaling and inflammasome-related pathways are highlighted in psoriatic epidermis.

    Science.gov (United States)

    Tervaniemi, Mari H; Katayama, Shintaro; Skoog, Tiina; Siitonen, H Annika; Vuola, Jyrki; Nuutila, Kristo; Sormunen, Raija; Johnsson, Anna; Linnarsson, Sten; Suomela, Sari; Kankuri, Esko; Kere, Juha; Elomaa, Outi

    2016-03-15

    Psoriatic skin differs distinctly from normal skin by its thickened epidermis. Most gene expression comparisons utilize full-thickness biopsies, with substantial amount of dermis. We assayed the transcriptomes of normal, lesional, and non-lesional psoriatic epidermis, sampled as split-thickness skin grafts, with 5'-end RNA sequencing. We found that psoriatic epidermis contains more mRNA per total RNA than controls, and took this into account in the bioinformatic analysis. The approach highlighted innate immunity-related pathways in psoriasis, including NOD-like receptor (NLR) signaling and inflammasome activation. We demonstrated that the NLR signaling genes NOD2, PYCARD, CARD6, and IFI16 are upregulated in psoriatic epidermis, and strengthened these findings by protein expression. Interestingly, PYCARD, the key component of the inflammasome, showed an altered expression pattern in the lesional epidermis. The profiling of non-lesional skin highlighted PSORS4 and mitochondrially encoded transcripts, suggesting that their gene expression is altered already before the development of lesions. Our data suggest that all components needed for the active inflammasome are present in the keratinocytes of psoriatic skin. The characterization of inflammasome pathways provides further opportunities for therapy. Complementing previous transcriptome studies, our approach gives deeper insight into the gene regulation in psoriatic epidermis.

  20. Physiological Testosterone Retards Cardiomyocyte Aging in Tfm Mice via Androgen Receptor-independent Pathway

    Institute of Scientific and Technical Information of China (English)

    Li Zhang; Da Lei; Gui-ping Zhu; Lei Hong; Sai-zhu Wu

    2013-01-01

    Objective To determine whether testosterone modulates markers of cardiomyocytes aging via itsclassic androgen receptor (AR)-dependent pathway or conversion to estradiol.Methods Male littermates and testicular feminized (Tfm) mice were randomly separated into 4experimental groups: littermate controls (n=8), Tfm mice (n=7), testosterone-treated Tfm mice (n=8), and Tfm mice treated with testosterone in combination with the aromatase inhibitor anastrazole (n=7).Cardiomyocytes were isolated from mouse left ventricles, the activity of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px), and the amount of malondialdehyde (MDA) were measuredus-ing colorimetry method, and expression ofp16INK4α and retinoblastoma (Rb) proteins were detected by Western blotting.Results The SOD and GSH-Px enzyme activities of cardiomyocytes were decreased, andthe MDA levels and the expression of p16INK4α and Rbproteinswereincreased in Tfm micecomparedwith control mice.Anincrease was observed in theactivities of SOD andGSH-Px enzymeaswellasa decrease in MDA levels and the expressionofp16INK4α and Rb proteins inthe testosterone-treated Tfm mice. After co-treatment with anastrazole inTfm mice, these improvement were partly inhib-ited.Conclusion Physiological testosterone replacement can delay cardiomyocyte aging in Tfm mice, an effect that is independent of theAR pathway and in part conversion to estradiol.

  1. Conservation of toll-like receptor signaling pathways in teleost fish

    Science.gov (United States)

    Purcell, M.K.; Smith, K.D.; Aderem, A.; Hood, L.; Winton, J.R.; Roach, J.C.

    2006-01-01

    In mammals, toll-like receptors (TLR) recognize ligands, including pathogen-associated molecular patterns (PAMPs), and respond with ligand-specific induction of genes. In this study, we establish evolutionary conservation in teleost fish of key components of the TLR-signaling pathway that act as switches for differential gene induction, including MYD88, TIRAP, TRIF, TRAF6, IRF3, and IRF7. We further explore this conservation with a molecular phylogenetic analysis of MYD88. To the extent that current genomic analysis can establish, each vertebrate has one ortholog to each of these genes. For molecular tree construction and phylogeny inference, we demonstrate a methodology for including genes with only partial primary sequences without disrupting the topology provided by the high-confidence full-length sequences. Conservation of the TLR-signaling molecules suggests that the basic program of gene regulation by the TLR-signaling pathway is conserved across vertebrates. To test this hypothesis, leukocytes from a model fish, rainbow trout (Oncorhynchus mykiss), were stimulated with known mammalian TLR agonists including: Diacylated and triacylated forms of lipoprotein, flagellin, two forms of LPS, synthetic double-stranded RNA, and two imidazoquinoline compounds (loxoribine and R848). Trout leukocytes responded in vitro to a number of these agonists with distinct patterns of cytokine expression that correspond to mammalian responses. Our results support the key prediction from our phylogenetic analyses that strong selective pressure of pathogenic microbes has preserved both TLR recognition and signaling functions during vertebrate evolution. ?? 2005 Elsevier Inc. All rights reserved.

  2. Synthesis of inositol phosphate ligands of plant hormone-receptor complexes: pathways of inositol hexakisphosphate turnover.

    Science.gov (United States)

    Hanke, David E; Parmar, Paroo N; Caddick, Samuel E K; Green, Porntip; Brearley, Charles A

    2012-06-15

    Reduction of phytate is a major goal of plant breeding programs to improve the nutritional quality of crops. Remarkably, except for the storage organs of crops such as barley, maize and soybean, we know little of the stereoisomeric composition of inositol phosphates in plant tissues. To investigate the metabolic origins of higher inositol phosphates in photosynthetic tissues, we have radiolabelled leaf tissue of Solanum tuberosum with myo-[2-3H]inositol, undertaken a detailed analysis of inositol phosphate stereoisomerism and permeabilized mesophyll protoplasts in media containing inositol phosphates. We describe the inositol phosphate composition of leaf tissue and identify pathways of inositol phosphate metabolism that we reveal to be common to other kingdoms. Our results identify the metabolic origins of a number of higher inositol phosphates including ones that are precursors of cofactors, or cofactors of plant hormone-receptor complexes. The present study affords alternative explanations of the effects of disruption of inositol phosphate metabolism reported in other species, and identifies different inositol phosphates from that described in photosynthetic tissue of the monocot Spirodela polyrhiza. We define the pathways of inositol hexakisphosphate turnover and shed light on the occurrence of a number of inositol phosphates identified in animals, for which metabolic origins have not been defined.

  3. High glucose induces podocyte injury via enhanced (prorenin receptor-Wnt-β-catenin-snail signaling pathway.

    Directory of Open Access Journals (Sweden)

    Caixia Li

    Full Text Available (Prorenin receptor (PRR expression is upregulated in diabetes. We hypothesized that PRR contributes to podocyte injury via activation of Wnt-β-catenin-snail signaling pathway. Mouse podocytes were cultured in normal (5 mM or high (25 mM D-glucose for 3 days. Compared to normal glucose, high glucose significantly decreased mRNA and protein expressions of podocin and nephrin, and increased mRNA and protein expressions of PRR, Wnt3a, β-catenin, and snail, respectively. Confocal microscopy studies showed significant reduction in expression and reorganization of podocyte cytoskeleton protein, F-actin, in response to high glucose. Transwell functional permeability studies demonstrated significant increase in albumin flux through podocytes monolayer with high glucose. Cells treated with high glucose and PRR siRNA demonstrated significantly attenuated mRNA and protein expressions of PRR, Wnt3a, β-catenin, and snail; enhanced expressions of podocin mRNA and protein, improved expression and reorganization of F-actin, and reduced transwell albumin flux. We conclude that high glucose induces podocyte injury via PRR-Wnt-β-catenin-snail signaling pathway.

  4. Effects of histamine H1 receptor signaling on glucocorticoid receptor activity. Role of canonical and non-canonical pathways

    NARCIS (Netherlands)

    Zappia, C.D.; Granja-Galeano, G.; Fernández, N.; Shayo, C.; Davio, C.; Fitzsimons, C.P.; Monczor, F.

    2015-01-01

    Histamine H1 receptor (H1R) antagonists and glucocorticoid receptor (GR) agonists are used to treat inflammatory conditions such as allergic rhinitis, atopic dermatitis and asthma. Consistent with the high morbidity levels of such inflammatory conditions, these receptors are the targets of a vast nu

  5. Identification of Distinct Conformations of the Angiotensin-II Type 1 Receptor Associated with the Gq/11 Protein Pathway and the β-Arrestin Pathway Using Molecular Dynamics Simulations*

    Science.gov (United States)

    Cabana, Jérôme; Holleran, Brian; Leduc, Richard; Escher, Emanuel; Guillemette, Gaétan; Lavigne, Pierre

    2015-01-01

    Biased signaling represents the ability of G protein-coupled receptors to engage distinct pathways with various efficacies depending on the ligand used or on mutations in the receptor. The angiotensin-II type 1 (AT1) receptor, a prototypical class A G protein-coupled receptor, can activate various effectors upon stimulation with the endogenous ligand angiotensin-II (AngII), including the Gq/11 protein and β-arrestins. It is believed that the activation of those two pathways can be associated with distinct conformations of the AT1 receptor. To verify this hypothesis, microseconds of molecular dynamics simulations were computed to explore the conformational landscape sampled by the WT-AT1 receptor, the N111G-AT1 receptor (constitutively active and biased for the Gq/11 pathway), and the D74N-AT1 receptor (biased for the β-arrestin1 and -2 pathways) in their apo-forms and in complex with AngII. The molecular dynamics simulations of the AngII-WT-AT1, N111G-AT1, and AngII-N111G-AT1 receptors revealed specific structural rearrangements compared with the initial and ground state of the receptor. Simulations of the D74N-AT1 receptor revealed that the mutation stabilizes the receptor in the initial ground state. The presence of AngII further stabilized the ground state of the D74N-AT1 receptor. The biased agonist [Sar1,Ile8]AngII also showed a preference for the ground state of the WT-AT1 receptor compared with AngII. These results suggest that activation of the Gq/11 pathway is associated with a specific conformational transition stabilized by the agonist, whereas the activation of the β-arrestin pathway is linked to the stabilization of the ground state of the receptor. PMID:25934394

  6. Brain-derived neurotrophic factor activation of extracellular signal-regulated kinase is autonomous from the dominant extrasynaptic NMDA receptor extracellular signal-regulated kinase shutoff pathway.

    Science.gov (United States)

    Mulholland, P J; Luong, N T; Woodward, J J; Chandler, L J

    2008-01-24

    NMDA receptors bidirectionally modulate extracellular signal-regulated kinase (ERK) through the coupling of synaptic NMDA receptors to an ERK activation pathway that is opposed by a dominant ERK shutoff pathway thought to be coupled to extrasynaptic NMDA receptors. In the present study, synaptic NMDA receptor activation of ERK in rat cortical cultures was partially inhibited by the highly selective NR2B antagonist Ro25-6981 (Ro) and the less selective NR2A antagonist NVP-AAM077 (NVP). When Ro and NVP were added together, inhibition appeared additive and equal to that observed with the NMDA open-channel blocker MK-801. Consistent with a selective coupling of extrasynaptic NMDA receptors to the dominant ERK shutoff pathway, pre-block of synaptic NMDA receptors with MK-801 did not alter the inhibitory effect of bath-applied NMDA on ERK activity. Lastly, in contrast to a complete block of synaptic NMDA receptor activation of ERK by extrasynaptic NMDA receptors, activation of extrasynaptic NMDA receptors had no effect upon ERK activation by brain-derived neurotrophic factor. These results suggest that the synaptic NMDA receptor ERK activation pathway is coupled to both NR2A and NR2B containing receptors, and that the extrasynaptic NMDA receptor ERK inhibitory pathway is not a non-selective global ERK shutoff.

  7. Acute ethanol administration inhibits Toll-like receptor 4 signaling pathway in rat intestinal epithelia.

    Science.gov (United States)

    Zhou, Chao; Zhao, Ji; Li, Jing; Wang, Haiying; Tang, Chengwei

    2013-05-01

    Excess alcohol intake, as in binge drinking, increases susceptibility to microbial pathogens. Alcohol impairs macrophage function by suppression of the Toll-like receptor 4 (TLR4) pathway. This study investigated the effects of acute ethanol intake on the TLR4 pathway in rat intestinal epithelia, which usually encounters luminal antigens at first and participates in the development of intestinal immunity. Twenty Wistar rats were randomly assigned to an ethanol group given ethanol as a 25% (v/v) solution in water at 7.5 g/kg, or a control group given saline, by oral gavage daily for 3 days. The epithelial histology and ultrastructure, the intestinal microflora, peripheral and portal venous plasma lipopolysaccharide (LPS) levels, and somatostatin (SST) levels in the peripheral plasma and small intestine were evaluated. Somatostatin receptor 2 (SSTR2), TLR4, TANK binding kinase-1 (TBK1), activated nuclear factor-κB (NF-κB), interferon-γ (IFN-γ) and tumor necrosis factor-α (TNF-α) in the intestinal mucosa were assayed. LPS responsiveness with or without SST pretreatment was assayed in vitro by quantification of TLR4, TBK1, activated NF-κB, IFN-γ and TNF-α in isolated intestinal epithelia. Mucosal damage was observed in the ethanol group by light and electron microscopy. Escherichia coli cultures were unchanged in rat intestine of the ethanol group compared with controls, but lactobacilli cultures were reduced (p TNF-α were unchanged in the ethanol group. LPS treatment in vitro up-regulated the level of TLR4, TBK1 and nuclear NF-κB as well as the production of IFN-γ and TNF-α in isolated intestinal epithelia in the control (p inhibited by SST pretreatment (p < 0.05). The peripheral plasma and intestinal levels of SST and the mucosal expression of SSTR2 in the ethanol group were significantly higher than in the control group (p < 0.05). These findings suggest the hyposensitivity of intestinal epithelial TLR4 to LPS induced by acute alcohol abuse

  8. Association of Interacting Genes in the Toll-Like Receptor Signaling Pathway and the Antibody Response to Pertussis Vaccination

    NARCIS (Netherlands)

    Kimman, Tjeerd G.; Banus, Sander; Reijmerink, Naomi; Reimerink, Johan; Stelma, Foekje F.; Koppelman, Gerard H.; Thijs, Carel; Postma, Dirkje S.; Kerkhof, Marjan

    2008-01-01

    Background: Activation of the Toll-like receptor (TLR) signaling pathway through TLR4 may be important in the induction of protective immunity against Bordetella pertussis with TLR4-mediated activation of dendritic and B cells, induction of cytokine expression, and reversal of tolerance as crucial s

  9. Differential pathway coupling efficiency of the activated insulin receptor drives signaling selectivity by xmeta, an allosteric partial agonist antibody

    Science.gov (United States)

    XMetA, an anti-insulin receptor (IR) monoclonal antibody, is an allosteric partial agonist of the IR. We have previously reported that XMetA activates the “metabolic-biased” Akt kinase signaling pathway while having little or no effect on the “mitogenic” MAPK signaling pathwayof ERK 1/2. To inves...

  10. Changed gene expression in subjects with schizophrenia and low cortical muscarinic M1 receptors predicts disrupted upstream pathways interacting with that receptor.

    Science.gov (United States)

    Scarr, E; Udawela, M; Thomas, E A; Dean, B

    2016-11-01

    We tested the hypothesis that, compared with subjects with no history of psychiatric illness (controls), changes in gene expression in the dorsolateral prefrontal cortex from two subgroups of subjects with schizophrenia, one with a marked deficit in muscarinic M1 receptors (muscarinic receptor-deficit schizophrenia (MRDS)), would identify different biochemical pathways that would be affected by their aetiologies. Hence, we measured levels of cortical (Brodmann area 9) mRNA in 15 MRDS subjects, 15 subjects with schizophrenia but without a deficit in muscarinic M1 receptors (non-MRDS) and 15 controls using Affymetrix Exon 1.0 ST arrays. Levels of mRNA for 65 genes were significantly different in the cortex of subjects with MRDS and predicted changes in pathways involved in cellular movement and cell-to-cell signalling. Levels of mRNA for 45 genes were significantly different in non-MRDS and predicted changes in pathways involved in cellular growth and proliferation as well as cellular function and maintenance. Changes in gene expression also predicted effects on pathways involved in amino acid metabolism, molecular transport and small-molecule biochemistry in both MRDS and non-MRDS. Overall, our data argue a prominent role for glial function in MRDS and neurodevelopment in non-MRDS. Finally, the interactions of gene with altered levels of mRNA in the cortex of subjects with MRDS suggest many of their affects will be upstream of the muscarinic M1 receptor. Our study gives new insight into the molecular pathways affected in the cortex of subjects with MRDS and supports the notion that studying subgroups within the syndrome of schizophrenia is worthwhile.Molecular Psychiatry advance online publication, 1 November 2016; doi:10.1038/mp.2016.195.

  11. Agonist-induced internalisation of the glucagon-like peptide-1 receptor is mediated by the Gαq pathway.

    Science.gov (United States)

    Thompson, Aiysha; Kanamarlapudi, Venkateswarlu

    2015-01-01

    The glucagon-like peptide-1 receptor (GLP-1R) is a G-protein-coupled receptor (GPCR) and an important target in the treatment of type 2 diabetes mellitus (T2DM). Upon stimulation with agonist, the GLP-1R signals through both Gαs and Gαq coupled pathways to stimulate insulin secretion. The agonist-induced GLP-1R internalisation has recently been shown to be important for insulin secretion. However, the molecular mechanisms underlying GLP-1R internalisation remain unknown. The aim of this study was to determine the role of GLP-1R downstream signalling pathways in its internalisation. Agonist-induced human GLP-1R (hGLP-1R) internalisation and activity were examined using a number of techniques including immunoblotting, ELISA, immunofluorescence and luciferase assays to determine cAMP production, intracellular Ca(2+) accumulation and ERK phosphorylation. Agonist-induced hGLP-1R internalisation is dependent on caveolin-1 and dynamin. Inhibition of the Gαq pathway but not the Gαs pathway affected hGLP-1R internalisation. Consistent with this, hGLP-1R mutant T149M and small-molecule agonists (compound 2 and compound B), which activate only the Gαs pathway, failed to induce internalisation of the receptor. Chemical inhibitors of the Gαq pathway, PKC and ERK phosphorylation significantly reduced agonist-induced hGLP-1R internalisation. These inhibitors also suppressed agonist-induced ERK1/2 phosphorylation demonstrating that the phosphorylated ERK acts downstream of the Gαq pathway in the hGLP-1R internalisation. In summary, agonist-induced hGLP-1R internalisation is mediated by the Gαq pathway. The internalised hGLP-1R stimulates insulin secretion from pancreatic β-cells, indicating the importance of GLP-1 internalisation for insulin secretion.

  12. Vesicular Trafficking to the Immune Synapse: How to Assemble Receptor-Tailored Pathways from a Basic Building Set.

    Science.gov (United States)

    Onnis, Anna; Finetti, Francesca; Baldari, Cosima T

    2016-01-01

    The signals that orchestrate T-cell activation are coordinated within a highly organized interface with the antigen-presenting cell (APC), known as the immune synapse (IS). IS assembly depends on T-cell antigen receptor engagement by a specific peptide antigen-major histocompatibility complex ligand. This primary event leads to polarized trafficking of receptors and signaling mediators associated with recycling endosomes to the cellular interface, which contributes to IS assembly as well as signal termination and favors information transfer from T cells to APCs. Here, we will review recent advances on the vesicular pathways implicated in IS assembly and maintenance, focusing on the spatiotemporal regulation of the traffic of specific receptors by Rab GTPases. Based on accumulating evidence that the IS is a functional homolog of the primary cilium, which coordinates several central signaling pathways in ciliated cells, we will also discuss the similarities in the mechanisms regulating vesicular trafficking to these specialized membrane domains.

  13. DMPD: Intracellular NOD-like receptors in host defense and disease. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 17967410 Intracellular NOD-like receptors in host defense and disease. Kanneganti T...D-like receptors in host defense and disease. PubmedID 17967410 Title Intracellular NOD-like receptors in host defense and dise

  14. CC趋化因子偶联受体信号途径%CC Chemokine Receptor-coupled Signalling Pathways

    Institute of Scientific and Technical Information of China (English)

    NEW David C.; WONG Yung H.

    2003-01-01

    The isolation and characterization of multiple CC chemokine receptors (CCRs) in a wide range of tissues and cells signifies the functional diversity of CC chemokines. The realization that multiple chemokines activate individual receptors and that some chemokines are functional at several different CCRs, indicates that interplay between a complex network of intracellular pathways is required for the full expression of the physiological function of each ligand. In different cellular environments, chemokines can regulate distinct second messengers or even positively or negatively regulate the same signal transduction pathway. The specific interactions between many signalling molecules have been discerned in an increasing number of cellular systems and this information is being used to explain the physiological actions of chemokines. This review will attempt to summarize recent research by many groups that has revealed numerous subtleties of the CC chemokine-coupled signalling pathways.

  15. Exposure pathways and biological receptors: baseline data for the canyon uranium mine, Coconino County, Arizona

    Science.gov (United States)

    Hinck, Jo E.; Linder, Greg L.; Darrah, Abigail J.; Drost, Charles A.; Duniway, Michael C.; Johnson, Matthew J.; Méndez-Harclerode, Francisca M.; Nowak, Erika M.; Valdez, Ernest W.; Van Riper, Charles; Wolff, S.W.

    2014-01-01

    Recent restrictions on uranium mining within the Grand Canyon watershed have drawn attention to scientific data gaps in evaluating the possible effects of ore extraction to human populations as well as wildlife communities in the area. Tissue contaminant concentrations, one of the most basic data requirements to determine exposure, are not available for biota from any historical or active uranium mines in the region. The Canyon Uranium Mine is under development, providing a unique opportunity to characterize concentrations of uranium and other trace elements, as well as radiation levels in biota, found in the vicinity of the mine before ore extraction begins. Our study objectives were to identify contaminants of potential concern and critical contaminant exposure pathways for ecological receptors; conduct biological surveys to understand the local food web and refine the list of target species (ecological receptors) for contaminant analysis; and collect target species for contaminant analysis prior to the initiation of active mining. Contaminants of potential concern were identified as arsenic, cadmium, chromium, copper, lead, mercury, nickel, selenium, thallium, uranium, and zinc for chemical toxicity and uranium and associated radionuclides for radiation. The conceptual exposure model identified ingestion, inhalation, absorption, and dietary transfer (bioaccumulation or bioconcentration) as critical contaminant exposure pathways. The biological survey of plants, invertebrates, amphibians, reptiles, birds, and small mammals is the first to document and provide ecological information on .200 species in and around the mine site; this study also provides critical baseline information about the local food web. Most of the species documented at the mine are common to ponderosa pine Pinus ponderosa and pinyon–juniper Pinus–Juniperus spp. forests in northern Arizona and are not considered to have special conservation status by state or federal agencies; exceptions

  16. Cholinergic interneurons in the dorsal and ventral striatum: anatomical and functional considerations in normal and diseased conditions.

    Science.gov (United States)

    Gonzales, Kalynda K; Smith, Yoland

    2015-09-01

    Striatal cholinergic interneurons (ChIs) are central for the processing and reinforcement of reward-related behaviors that are negatively affected in states of altered dopamine transmission, such as in Parkinson's disease or drug addiction. Nevertheless, the development of therapeutic interventions directed at ChIs has been hampered by our limited knowledge of the diverse anatomical and functional characteristics of these neurons in the dorsal and ventral striatum, combined with the lack of pharmacological tools to modulate specific cholinergic receptor subtypes. This review highlights some of the key morphological, synaptic, and functional differences between ChIs of different striatal regions and across species. It also provides an overview of our current knowledge of the cellular localization and function of cholinergic receptor subtypes. The future use of high-resolution anatomical and functional tools to study the synaptic microcircuitry of brain networks, along with the development of specific cholinergic receptor drugs, should help further elucidate the role of striatal ChIs and permit efficient targeting of cholinergic systems in various brain disorders, including Parkinson's disease and addiction.

  17. G Protein-coupled Receptor Gpr4 Senses Amino Acids and Activates the cAMP-PKA Pathway in Cryptococcus neoformansD⃞

    OpenAIRE

    Xue, Chaoyang; Bahn, Yong-Sun; Cox, Gary M.; Heitman, Joseph

    2006-01-01

    The Gα protein Gpa1 governs the cAMP-PKA signaling pathway and plays a central role in virulence and differentiation in the human fungal pathogen Cryptococcus neoformans, but the signals and receptors that trigger this pathway were unknown. We identified seven putative proteins that share identity with known G protein-coupled receptors (GPCRs). One protein, Gpr4, shares limited sequence identity with the Dictyostelium discoideum cAMP receptor cAR1 and the Aspergillus nidulans GPCR protein Gpr...

  18. Presenilin 1 regulates epidermal growth factor receptor turnover and signaling in the endosomal-lysosomal pathway.

    Science.gov (United States)

    Repetto, Emanuela; Yoon, Il-Sang; Zheng, Hui; Kang, David E

    2007-10-26

    Mutations in the gene encoding presenilin 1 (PS1) cause the most aggressive form of early-onset familial Alzheimer disease. In addition to its well established role in Abeta production and Notch proteolysis, PS1 has been shown to mediate other physiological activities, such as regulation of the Wnt/beta-catenin signaling pathway, modulation of phosphatidylinositol 3-kinase/Akt and MEK/ERK signaling, and trafficking of select membrane proteins and/or intracellular vesicles. In this study, we present evidence that PS1 is a critical regulator of a key signaling receptor tyrosine kinase, epidermal growth factor receptor (EGFR). Specifically, EGFR levels were robustly increased in fibroblasts deficient in both PS1 and PS2 (PS(-/-)) due to delayed turnover of EGFR protein. Stable transfection of wild-type PS1 but not PS2 corrected EGFR to levels comparable to PS(+/+) cells, while FAD PS1 mutations showed partial loss of activity. The C-terminal fragment of PS1 was sufficient to fully reduce EGFR levels. In addition, the rapid ligand-induced degradation of EGFR was markedly delayed in PS(-/-) cells, resulting in prolonged signal activation. Despite the defective turnover of EGFR, ligand-induced autophosphorylation, ubiquitination, and endocytosis of EGFR were not affected by the lack of PS1. Instead, the trafficking of EGFR from early endosomes to lysosomes was severely delayed by PS1 deficiency. Elevation of EGFR was also seen in brains of adult mice conditionally ablated in PS1 and in skin tumors associated with the loss of PS1. These findings demonstrate a critical role of PS1 in the trafficking and turnover of EGFR and suggest potential pathogenic effects of elevated EGFR as well as perturbed endosomal-lysosomal trafficking in cell cycle control and Alzheimer disease.

  19. Reexposure to nicotine during withdrawal increases the pacemaking activity of cholinergic habenular neurons

    Science.gov (United States)

    Görlich, Andreas; Antolin-Fontes, Beatriz; Ables, Jessica L.; Frahm, Silke; Ślimak, Marta A.; Dougherty, Joseph D.; Ibañez-Tallon, Inés

    2013-01-01

    The discovery of genetic variants in the cholinergic receptor nicotinic CHRNA5-CHRNA3-CHRNB4 gene cluster associated with heavy smoking and higher relapse risk has led to the identification of the midbrain habenula–interpeduncular axis as a critical relay circuit in the control of nicotine dependence. Although clear roles for α3, β4, and α5 receptors in nicotine aversion and withdrawal have been established, the cellular and molecular mechanisms that participate in signaling nicotine use and contribute to relapse have not been identified. Here, using translating ribosome affinity purification (TRAP) profiling, electrophysiology, and behavior, we demonstrate that cholinergic neurons, but not peptidergic neurons, of the medial habenula (MHb) display spontaneous tonic firing of 2–10 Hz generated by hyperpolarization-activated cyclic nucleotide-gated (HCN) pacemaker channels and that infusion of the HCN pacemaker antagonist ZD7288 in the habenula precipitates somatic and affective signs of withdrawal. Further, we show that a strong, α3β4-dependent increase in firing frequency is observed in these pacemaker neurons upon acute exposure to nicotine. No change in the basal or nicotine-induced firing was observed in cholinergic MHb neurons from mice chronically treated with nicotine. We observe, however, that, during withdrawal, reexposure to nicotine doubles the frequency of pacemaking activity in these neurons. These findings demonstrate that the pacemaking mechanism of cholinergic MHb neurons controls withdrawal, suggesting that the heightened nicotine sensitivity of these neurons during withdrawal may contribute to smoking relapse. PMID:24082085

  20. Nonalcoholic steatohepatitis-related hepatocellular carcinoma: is there a role for the androgen receptor pathway?

    Directory of Open Access Journals (Sweden)

    Ali MA

    2017-03-01

    Full Text Available Mahmoud A Ali,1 Sahin Lacin,1 Reham Abdel-Wahab,1,2 Mark Uemura,1 Manal Hassan,1 Asif Rashid,3 Dan G Duda,4 Ahmed O Kaseb1 1Department of Gastrointestinal Medical Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA; 2Department of Clinical Oncology, Assiut University, Assiut, Egypt; 3Department of Pathology, The University of Texas MD Anderson Cancer Center, Houston, TX, 4Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA Abstract: The epidemic of insulin resistance, obesity, and metabolic syndrome has led to the emergence of nonalcoholic steatohepatitis (NASH as the most common cause of liver disease in the US. Patients with NASH are at an increased risk for hepatic disease-related morbidity and death, and chronic inflammation in NASH patients can lead to hepatocellular carcinoma (HCC. The prevalence of HCC is higher in males than in females, and genetic studies have identified androgen and androgen receptors (ARs as partially responsible for the gender disparity in the development of liver disease and HCC. Although many factors are known to play important roles in the progression of inflammation in NASH patients, the role of androgen and AR in the progression of NASH to HCC has been understudied. This review summarizes the evidence for a potential role of androgen and the AR pathway in the development of NASH-related HCC and in the treatment of HCC. It has been proposed that AR plays a role in the progression of HCC: inhibitory roles in early stages of hepatocarcinogenesis and tumor-promoting roles in advanced stages. AR can be activated by several pathways, even in the absence of androgen. While AR has been explored as a potential therapeutic target in HCC, several clinical trials have failed to demonstrate a clinical benefit of antiandrogen drugs in HCC. This review discusses the potential reason for these observations and discuss the potential future trials

  1. Exogenous Estradiol Benzoate Induces Spermatogenesis Disorder through Influencing Apoptosis and Oestrogen Receptor Signalling Pathway.

    Science.gov (United States)

    Lei, X; Cui, K; Liu, Q; Zhang, H; Li, Z; Huang, B; Shi, D

    2016-02-01

    As the exact role for exogenous oestrogen in spermatogenesis is not fully understood, the aim of this study was to investigate the effect of estradiol benzoate (EB) exposure to male mice on their spermatogenesis and fertility. Sixty male mice aged 4 weeks were randomly divided into three groups, including a control group and two treatment groups. The mice of the control group were injected with 250 μl paraffin oil only by every other day subcutaneous injection for 4 weeks. Meantime, the mice of the treatment groups were injected with EB at the concentration of 5 or 10 mg/kg, respectively. Results showed that EB slowed down the body weight gains and generated testicular atrophy with spermatogenesis disorder compared with that of the control mice, and consequently induced their infertility. Moreover, the number of TUNEL-positive cells in the testis of EB-treated mice was significantly increased with the EB concentration rise. In comparison with controls, the mRNA expression level of pro-apoptosis factors (Fas, TNF, Cytochrome C, Apaf1, Chop, Caspase-3, Caspase-8, Caspase-9 and Caspase-12) and key genes in oestrogen receptor (ER) signalling pathway (ER α, ER β, Erk1/2, Hsp90 and DAX-1) were upregulated in the testes of the treatment groups. Furthermore, Western blotting results proved the protein expression level of Fas, TNF, Cytochrome C, Chop, Caspase-3, cleaved Caspase-3, Caspase-9, Erk1/2 and Hsp90 were upregulated, and the phosphorylation level of Erk1/2 was also increased. These results indicate that EB may impair spermatogenesis through influencing the apoptosis and ER signalling pathway.

  2. Brain region-specific alterations in the gene expression of cytokines, immune cell markers and cholinergic system components during peripheral endotoxin-induced inflammation.

    Science.gov (United States)

    Silverman, Harold A; Dancho, Meghan; Regnier-Golanov, Angelique; Nasim, Mansoor; Ochani, Mahendar; Olofsson, Peder S; Ahmed, Mohamed; Miller, Edmund J; Chavan, Sangeeta S; Golanov, Eugene; Metz, Christine N; Tracey, Kevin J; Pavlov, Valentin A

    2015-03-11

    Inflammatory conditions characterized by excessive peripheral immune responses are associated with diverse alterations in brain function, and brain-derived neural pathways regulate peripheral inflammation. Important aspects of this bidirectional peripheral immune-brain communication, including the impact of peripheral inflammation on brain region-specific cytokine responses, and brain cholinergic signaling (which plays a role in controlling peripheral cytokine levels), remain unclear. To provide insight, we studied gene expression of cytokines, immune cell markers and brain cholinergic system components in the cortex, cerebellum, brainstem, hippocampus, hypothalamus, striatum and thalamus in mice after an intraperitoneal lipopolysaccharide injection. Endotoxemia was accompanied by elevated serum levels of interleukin (IL)-1β, IL-6 and other cytokines and brain region-specific increases in Il1b (the highest increase, relative to basal level, was in cortex; the lowest increase was in cerebellum) and Il6 (highest increase in cerebellum; lowest increase in striatum) mRNA expression. Gene expression of brain Gfap (astrocyte marker) was also differentially increased. However, Iba1 (microglia marker) mRNA expression was decreased in the cortex, hippocampus and other brain regions in parallel with morphological changes, indicating microglia activation. Brain choline acetyltransferase (Chat ) mRNA expression was decreased in the striatum, acetylcholinesterase (Ache) mRNA expression was decreased in the cortex and increased in the hippocampus, and M1 muscarinic acetylcholine receptor (Chrm1) mRNA expression was decreased in the cortex and the brainstem. These results reveal a previously unrecognized regional specificity in brain immunoregulatory and cholinergic system gene expression in the context of peripheral inflammation and are of interest for designing future antiinflammatory approaches.

  3. Both pre- and post-synaptic alterations contribute to aberrant cholinergic transmission in superior cervical ganglia of APP(-/-) mice.

    Science.gov (United States)

    Cai, Zhao-Lin; Zhang, Jia-Jia; Chen, Ming; Wang, Jin-Zhao; Xiao, Peng; Yang, Li; Long, Cheng

    2016-11-01

    Though amyloid precursor protein (APP) can potentially be cleaved to generate the pathological amyloid β peptide (Aβ), APP itself plays an important role in regulating neuronal activity. APP deficiency causes functional impairment in cholinergic synaptic transmission and cognitive performance. However, the mechanisms underlying altered cholinergic synaptic transmission in APP knock-out mice (APP(-/-)) are poorly understood. In this study, we conducted in vivo extracellular recording to investigate cholinergic compound action potentials (CAPs) of the superior cervical ganglion (SCG) in APP(-/-) and littermate wild-type (WT) mice. Our results demonstrate that APP not only regulates presynaptic activity, but also affects postsynaptic function at cholinergic synapses in SCG. APP deficiency reduces the number of vesicles in presynaptic terminalsand attenuatesthe amplitude of CAPs, likely due to dysfunction of high-affinity choline transporters. Pharmacological and biochemical examination showed that postsynaptic responsesmediated by α4β2 and α7 nicotinic acetylcholine receptors are reduced in the absence of APP. Our research provides evidences on how APP regulates cholinergic function and therefore may help to identify potential therapeutic targets to treat cholinergic dysfunction associated with Alzheimer's disease pathogenesis.

  4. Dopamine D1-histamine H3 receptor heteromers provide a selective link to MAPK signaling in GABAergic neurons of the direct striatal pathway.

    Science.gov (United States)

    Moreno, Estefanía; Hoffmann, Hanne; Gonzalez-Sepúlveda, Marta; Navarro, Gemma; Casadó, Vicent; Cortés, Antoni; Mallol, Josefa; Vignes, Michel; McCormick, Peter J; Canela, Enric I; Lluís, Carme; Moratalla, Rosario; Ferré, Sergi; Ortiz, Jordi; Franco, Rafael

    2011-02-18

    Previously, using artificial cell systems, we identified receptor heteromers between the dopamine D(1) or D(2) receptors and the histamine H(3) receptor. In addition, we demonstrated two biochemical characteristics of the dopamine D(1) receptor-histamine H(3) receptor heteromer. We have now extended this work to show the dopamine D(1) receptor-histamine H(3) receptor heteromer exists in the brain and serves to provide a novel link between the MAPK pathway and the GABAergic neurons in the direct striatal efferent pathway. Using the biochemical characteristics identified previously, we found that the ability of H(3) receptor activation to stimulate p44 and p42 extracellular signal-regulated MAPK (ERK 1/2) phosphorylation was only observed in striatal slices of mice expressing D(1) receptors but not in D(1) receptor-deficient mice. On the other hand, the ability of both D(1) and H(3) receptor antagonists to block MAPK activation induced by either D(1) or H(3) receptor agonists was also found in striatal slices. Taken together, these data indicate the occurrence of D(1)-H(3) receptor complexes in the striatum and, more importantly, that H(3) receptor agonist-induced ERK 1/2 phosphorylation in striatal slices is mediated by D(1)-H(3) receptor heteromers. Moreover, H(3) receptor-mediated phospho-ERK 1/2 labeling co-distributed with D(1) receptor-containing but not with D(2) receptor-containing striatal neurons. These results indicate that D(1)-H(3) receptor heteromers work as processors integrating dopamine- and histamine-related signals involved in controlling the function of striatal neurons of the direct striatal pathway.

  5. Eps15 is recruited to the plasma membrane upon epidermal growth factor receptor activation and localizes to components of the endocytic pathway during receptor internalization

    DEFF Research Database (Denmark)

    Torrisi, M R; Lotti, L V; Belleudi, F;

    1999-01-01

    Eps15 is a substrate for the tyrosine kinase of the epidermal growth factor receptor (EGFR) and is characterized by the presence of a novel protein:protein interaction domain, the EH domain. Eps15 also stably binds the clathrin adaptor protein complex AP-2. Previous work demonstrated an essential...... role for eps15 in receptor-mediated endocytosis. In this study we show that, upon activation of the EGFR kinase, eps15 undergoes dramatic relocalization consisting of 1) initial relocalization to the plasma membrane and 2) subsequent colocalization with the EGFR in various intracellular compartments...... of the endocytic pathway, with the notable exclusion of coated vesicles. Relocalization of eps15 is independent of its binding to the EGFR or of binding of the receptor to AP-2. Furthermore, eps15 appears to undergo tyrosine phosphorylation both at the plasma membrane and in a nocodazole-sensitive compartment...

  6. mGluR5 positive modulators both potentiate activation and restore inhibition in NMDA receptors by PKC dependent pathway

    Directory of Open Access Journals (Sweden)

    Liao Pei-Fei

    2011-02-01

    Full Text Available Abstract Background In order to understand the interaction between the metabotropic glutamate subtype 5 (mGluR5 and N-methyl-D-aspartate (NMDA receptors, the influence of mGluR5 positive modulators in the inhibition of NMDA receptors by the noncompetitive antagonist ketamine, the competitive antagonist D-APV and the selective NR2B inhibitor ifenprodil was investigated. Methods This study used the multi-electrode dish (MED system to observe field potentials in hippocampal slices of mice. Results Data showed that the mGluR5 agonist (RS-2-chloro-5-hydroxyphenylglycine (CHPG, as well as the positive allosteric modulators 3-cyano-N-(1,3-diphenyl-1H-pyrazol-5-yl benzamide (CDPPB and 3,3'-difluorobenzaldazine (DFB alone did not alter the basal field potentials, but enhanced the amplitude of field potentials induced by NMDA. The inhibitory action of ketamine on NMDA-induced response was reversed by CHPG, DFB, and CDPPB, whereas the blockade of NMDA receptor by D-APV was restored by CHPG and CDPPB, but not by DFB. Alternatively, activation of NMDA receptors prior to the application of mGluR5 modulators, CHPG was able to enhance NMDA-induced field potentials and reverse the suppressive effect of ketamine and D-APV, but not ifenprodil. In addition, chelerythrine chloride (CTC, a protein kinase C (PKC inhibitor, blocked the regulation of mGluR5 positive modulators in enhancing NMDA receptor activation and recovering NMDA receptor inhibition. The PKC activator (PMA mimicked the effects of mGluR5 positive modulators on enhancing NMDA receptor activation and reversing NMDA antagonist-evoked NMDA receptor suppression. Conclusion Our results demonstrate that the PKC-dependent pathway may be involved in the positive modulation of mGluR5 resulting in potentiating NMDA receptor activation and reversing NMDA receptor suppression induced by NMDA antagonists.

  7. How a Cytokine Is Chaperoned through the Secretory Pathway by Complexing with Its Own Receptor: Lessons from Interleukin-15 (IL-15)/IL-15 Receptor α▿

    Science.gov (United States)

    Duitman, Erwin H.; Orinska, Zane; Bulanova, Elena; Paus, Ralf; Bulfone-Paus, Silvia

    2008-01-01

    While it is well appreciated that receptors for secreted cytokines transmit ligand-induced signals, little is known about additional roles for cytokine receptor components in the control of ligand transport and secretion. Here, we show that interleukin-15 (IL-15) translocation into the endoplasmic reticulum occurs independently of the presence of IL-15 receptor α (IL-15Rα). Subsequently, however, IL-15 is transported through the Golgi apparatus only in association with IL-15Rα and then is secreted. This intracellular IL-15/IL-15Rα complex already is formed in the endoplasmic reticulum and, thus, enables the further trafficking of complexed IL-15 through the secretory pathway. Just transfecting IL-15Rα in cells, which transcribe but normally do not secrete IL-15, suffices to induce IL-15 secretion. Thus, we provide the first evidence of how a cytokine is chaperoned through the secretory pathway by complexing with its own high-affinity receptor and show that IL-15/IL-15Rα offers an excellent model system for the further exploration of this novel mechanism for the control of cytokine secretion. PMID:18505820

  8. How a cytokine is chaperoned through the secretory pathway by complexing with its own receptor: lessons from interleukin-15 (IL-15)/IL-15 receptor alpha.

    Science.gov (United States)

    Duitman, Erwin H; Orinska, Zane; Bulanova, Elena; Paus, Ralf; Bulfone-Paus, Silvia

    2008-08-01

    While it is well appreciated that receptors for secreted cytokines transmit ligand-induced signals, little is known about additional roles for cytokine receptor components in the control of ligand transport and secretion. Here, we show that interleukin-15 (IL-15) translocation into the endoplasmic reticulum occurs independently of the presence of IL-15 receptor alpha (IL-15R alpha). Subsequently, however, IL-15 is transported through the Golgi apparatus only in association with IL-15R alpha and then is secreted. This intracellular IL-15/IL-15R alpha complex already is formed in the endoplasmic reticulum and, thus, enables the further trafficking of complexed IL-15 through the secretory pathway. Just transfecting IL-15R alpha in cells, which transcribe but normally do not secrete IL-15, suffices to induce IL-15 secretion. Thus, we provide the first evidence of how a cytokine is chaperoned through the secretory pathway by complexing with its own high-affinity receptor and show that IL-15/IL-15R alpha offers an excellent model system for the further exploration of this novel mechanism for the control of cytokine secretion.

  9. [Involvement of cross interaction between central cholinergic and histaminergic systems in the nucleus tractus solitarius in regulating carotid sinus baroreceptor reflex].

    Science.gov (United States)

    Hu, Li-Xun; Zhang, Guo-Xing; Zhang, Yu-Ying; Zhao, Hong-Fen; Yu, Kang-Ying; Wang, Guo-Qing

    2013-12-25

    possible modulatory mechanism of preceding microinjection with different histaminergic receptor antagonists, the selective histaminergic H1 receptor antagonist, i.e., chlorpheniramine (CHL) or the H2 receptor antagonist, i.e., cimetidine (CIM) into the NTS on the changes in function of CSR resulted from the i.c.v. cholinesterase inhibitor, physostigmine (PHY) were also examined in order to confirm and to analyze effects of cross interaction between central histaminergic and cholinergic systems on CSR. The main results obtained are as follows. (1) Standalone microinjection of different selective cholinergic receptor antagonists (PRZ, MTR or HEX) or different selective histaminergic receptor antagonists (CHL or CIM) into the NTS with each given dose had no effects on the CSR function and on the basic levels of the artery blood pressure, respectively (P > 0.05). (2) The pretreatment of PRZ or MTR into the NTS with each corresponding dose could attenuate CSR resetting resulted from i.c.v. HA in some degrees, which remarkably moved the posterior half range of ISP-MAP relationship curve downwards (P 0.05). (3) The effects of pretreatment of CHL or CIM into the NTS with each corresponding dose on CSR resetting made by i.c.v. PHY were similar to those of pretreatment of PRZ or MTR into the NTS on CSR resetting resulted from i.c.v. HA, and the decreasing effects of pretreatment with CHL into the NTS on CSR resetting induced by i.c.v. PHY were more remarkable than those with CIM (P < 0.05). These findings suggest that CSR resetting resulted from either HA or PHY into the lateral ventricle may partly involve the descending histaminergic or cholinergic pathway from the hypothalamus to NTS, which might evoke a cross activation of the cholinergic system in the NTS, via cholinergic M1 and M2 receptors mediation, especially the M2 receptors showing actions, or trigger another cross activation of the histaminergic system in the NTS, by histaminergic H1 and H2 receptors mediation

  10. Ventral tegmental area cholinergic mechanisms mediate behavioral responses in the forced swim test.

    Science.gov (United States)

    Addy, N A; Nunes, E J; Wickham, R J

    2015-07-15

    Recent studies revealed a causal link between ventral tegmental area (VTA) phasic dopamine (DA) activity and pro-depressive and antidepressant-like behavioral responses in rodent models of depression. Cholinergic activity in the VTA has been demonstrated to regulate phasic DA activity, but the role of VTA cholinergic mechanisms in depression-related behavior is unclear. The goal of this study was to determine whether pharmacological manipulation of VTA cholinergic activity altered behavioral responding in the forced swim test (FST) in rats. Here, male Sprague-Dawley rats received systemic or VTA-specific administration of the acetylcholinesterase inhibitor, physostigmine (systemic; 0.06 or 0.125mg/kg, intra-cranial; 1 or 2μg/side), the muscarinic acetylcholine receptor (AChR) antagonist scopolamine (2.4 or 24μg/side), or the nicotinic AChR antagonist mecamylamine (3 or 30μg/side), prior to the FST test session. In control experiments, locomotor activity was also examined following systemic and intra-cranial administration of cholinergic drugs. Physostigmine administration, either systemically or directly into the VTA, significantly increased immobility time in FST, whereas physostigmine infusion into a dorsal control site did not alter immobility time. In contrast, VTA infusion of either scopolamine or mecamylamine decreased immobility time, consistent with an antidepressant-like effect. Finally, the VTA physostigmine-induced increase in immobility was blocked by co-administration with scopolamine, but unaltered by co-administration with mecamylamine. These data show that enhancing VTA cholinergic tone and blocking VTA AChRs has opposing effects in FST. Together, the findings provide evidence for a role of VTA cholinergic mechanisms in behavioral responses in FST.

  11. Muscarinic signaling influences the patterning and phenotype of cholinergic amacrine cells in the developing chick retina

    Directory of Open Access Journals (Sweden)

    Fischer Andy J

    2008-02-01

    Full Text Available Abstract Background Many studies in the vertebrate retina have characterized the differentiation of amacrine cells as a homogenous class of neurons, but little is known about the genes and factors that regulate the development of distinct types of amacrine cells. Accordingly, the purpose of this study was to characterize the development of the cholinergic amacrine cells and identify factors that influence their development. Cholinergic amacrine cells in the embryonic chick retina were identified by using antibodies to choline acetyltransferase (ChAT. Results We found that as ChAT-immunoreactive cells differentiate they expressed the homeodomain transcription factors Pax6 and Islet1, and the cell-cycle inhibitor p27kip1. As differentiation proceeds, type-II cholinergic cells, displaced to the ganglion cell layer, transiently expressed high levels of cellular retinoic acid binding protein (CRABP and neurofilament, while type-I cells in the inner nuclear layer did not. Although there is a 1:1 ratio of type-I to type-II cells in vivo, in dissociated cell cultures the type-I cells (ChAT-positive and CRABP-negative out-numbered the type-II cells (ChAT and CRABP-positive cells by 2:1. The relative abundance of type-I to type-II cells was not influenced by Sonic Hedgehog (Shh, but was affected by compounds that act at muscarinic acetylcholine receptors. In addition, the abundance and mosaic patterning of type-II cholinergic amacrine cells is disrupted by interfering with muscarinic signaling. Conclusion We conclude that: (1 during development type-I and type-II cholinergic amacrine cells are not homotypic, (2 the phenotypic differences between these subtypes of cells is controlled by the local microenvironment, and (3 appropriate levels of muscarinic signaling between the cholinergic amacrine cells are required for proper mosaic patterning.

  12. Genomics in cardiovascular diseases: analysis of the importance of the toll-like receptor signaling pathway

    Directory of Open Access Journals (Sweden)

    Bustamante J

    2012-10-01

    Full Text Available J Bustamante,1 E Tamayo,2 J Herreros3,41Department of Cardiovascular Surgery, Hospital Universitario La Princesa, Madrid, 2Department of Anesthesiology and Intensive Care, Hospital Clinico Universitario de Valladolid, Valladolid, 3Department of Cardiovascular Surgery, Hospital Universitario Valdecilla, Santander, 4Biomedical Engineering Institute of Santander, Santander, SpainAbstract: The development of techniques for genomics study makes it possible for us to further our knowledge about the physiopathology of various immunological or infectious diseases. These techniques improve our understanding of the development and evolution of such diseases, including those of cardiovascular origin, whilst they help to bring about the design of new therapeutic strategies. We are reviewing the genetic alterations of immunity in said field, and focusing on the signaling pathway of toll-like receptors because not only does this play a decisive role in response to microorganisms, it is also heavily involved in modulating the inflammatory response to tissue damage, a side effect of numerous cardiovascular diseases. These alterations in tissue homeostasis are present under a wide range of circumstances, such as reperfusion ischemia (myocardial infarction phenomena, arteriosclerosis, or valvulopathy.Keywords: genome-wide association study, single-nucleotide polymorphism, innate immune system, ischemic/reperfusion, myocardial infarction

  13. IL-12 Family Cytokines: General Characteristics, Pathogenic Microorganisms, Receptors, and Signalling Pathways.

    Science.gov (United States)

    Behzadi, Payam; Behzadi, Elham; Ranjbar, Reza

    2016-03-01

    Among a wide range of cytokines, the Interleukin 12 (IL-12) family has its unique structural, functional, and immunological characteristics that have made this family as important immunological playmakers. Because of the importance of IL-12 heterodimeric cytokines in microbial infections, autoimmune diseases, and cancers, the authors of this literature discuss about the general characteristics of IL-12 family members, the interactions between IL-12 cytokines and pathogenic microorganisms, the interleukins receptors and their strategies for selecting different signalling pathways. IL-12 and IL-23 are similar in p40 subunits and both are involved in proinflammatory responses while, IL-27 and IL-35 contribute to anti-inflammatory activities; however, IL-27 is also involved in pro-inflammatory responses. There are some similarities and dissimilarities among IL-12 family members which make them a unique bridge between innate and adaptive immune systems. The bioactivities of IL-12 family indicate a brilliant promise for their applications in different fields of medicine. The members of IL-12 family are candidate for several therapeutics including gene therapy, cancer therapy, tumour therapy, and vaccination. To have an accurate diagnostic technique and definite treatment regarding to infectious diseases, the playmakers of IL-12 family as effective criteria together with microarray technology are the best choices for current and future applications.

  14. Vitamin D receptor pathway is required for probiotic protection in colitis.

    Science.gov (United States)

    Wu, Shaoping; Yoon, Sonia; Zhang, Yong-Guo; Lu, Rong; Xia, Yinglin; Wan, Jiandi; Petrof, Elaine O; Claud, Erika C; Chen, Di; Sun, Jun

    2015-09-01

    Low expression of vitamin D receptor (VDR) and dysfunction of vitamin D/VDR signaling are reported in patients with inflammatory bowel disease (IBD); therefore, restoration of VDR function to control inflammation in IBD is desirable. Probiotics have been used in the treatment of IBD. However, the role of probiotics in the modulation of VDR signaling to effectively reduce inflammation is unknown. We identified a novel role of probiotics in activating VDR activity, thus inhibiting inflammation, using cell models and VDR knockout mice. We found that the probiotics Lactobacillus rhamnosus strain GG (LGG) and Lactobacillus plantarum (LP) increased VDR protein expression in both mouse and human intestinal epithelial cells. Using the VDR luciferase reporter vector, we detected increased transcriptional activity of VDR after probiotic treatment. Probiotics increased the expression of the VDR target genes, such as antimicrobial peptide cathelicidin, at the transcriptional level. Furthermore, the role of probiotics in regulating VDR signaling was tested in vivo using a Salmonella-colitis model in VDR knockout mice. Probiotic treatment conferred physiological and histologic protection from Salmonella-induced colitis in VDR(+/+) mice, whereas probiotics had no effects in the VDR(-/-) mice. Probiotic treatment also enhanced numbers of Paneth cells, which secrete AMPs for host defense. These data indicate that the VDR pathway is required for probiotic protection in colitis. Understanding how probiotics enhance VDR signaling and inhibit inflammation will allow probiotics to be used effectively, resulting in innovative approaches to the prevention and treatment of chronic inflammation.

  15. Penduliflaworosin, a Diterpenoid from Croton crassifolius, Exerts Anti-Angiogenic Effect via VEGF Receptor-2 Signaling Pathway

    Directory of Open Access Journals (Sweden)

    Yeyin Liang

    2017-01-01

    Full Text Available Anti-angiogenesis targeting vascular endothelial growth factor receptor-2 (VEGFR-2 has been considered as an important strategy for cancer therapy. Penduliflaworosin is a diterpenoid isolated from the plant Croton crassifolius. Our previous study showed that this diterpenoid possesses strong anti-angiogenic activity by inhibiting vessel formation in zebrafish. This study was conducted to further investigate the anti-angiogenic activity and mechanism of penduliflaworosin. Results revealed that penduliflaworosin significantly inhibited VEGF-induced angiogenesis processes including proliferation, invasion, migration, and tube formation of human umbilical vein endothelial cells (HUVECs. Moreover, it notably inhibited VEGF-induced sprout formation of aortic rings and blocked VEGF-induced vessel formation in mice. Western blotting studies showed that penduliflaworosin inhibited phosphorylation of the VEGF receptor-2 and its downstream signaling mediators in HUVECs, suggesting that the anti-angiogenic activity was due to an interference with the VEGF/VEGF receptor-2 pathway. In addition, molecular docking simulation indicated that penduliflaworosin could form hydrogen bonds within the ATP-binding region of the VEGF receptor-2 kinase unit. Finally, cytotoxicity assay showed that penduliflaworosin possessed little toxicity toward both cancer and normal cells. Taken together, our findings demonstrate that penduliflaworosin exerts its anti-angiogenic effect via the VEGF receptor-2 signaling pathway. The anti-angiogenic property and low cytotoxicity of penduliflaworosin suggest that it may be useful in cancer treatments.

  16. Cholinergic dysfunction and amnesia in patients with Wernicke-Korsakoff syndrome: a transcranial magnetic stimulation study.

    Science.gov (United States)

    Nardone, Raffaele; Bergmann, Jürgen; De Blasi, Pierpaolo; Kronbichler, Martin; Kraus, Jörg; Caleri, Francesca; Tezzon, Frediano; Ladurner, Gunther; Golaszewski, Stefan

    2010-03-01

    The specific neurochemical substrate underlying the amnesia in patients with Wernicke-Korsakoff syndrome (WKS) is still poorly defined. Memory impairment has been linked to dysfunction of neurons in the cholinergic system. A transcranial magnetic stimulation (TMS) protocol, the short latency afferent inhibition (SAI), may give direct information about the function of some cholinergic pathways in the human motor cortex. In the present study, we measured SAI in eight alcoholics with WKS and compared the data with those from a group of age-matched healthy individuals; furthermore, we correlated the individual SAI values of the WKS patients with memory and other cognitive functions. Mean SAI was significantly reduced in WKS patients when compared with the controls. SAI was increased after administration of a single dose of donezepil in a subgroup of four patients. The low score obtained in the Rey Complex Figure delayed recall test, the Digit Span subtest of the Wechsler Adult Intelligence Scale-Revised (WAIS-R) and the Corsi's Block Span subtest of the WAIS-R documented a severe impairment in the anterograde memory and short-term memory. None of the correlations between SAI values and these neuropsychological tests reached significance. We provide physiological evidence of cholinergic involvement in WKS. However, this putative marker of central cholinergic activity did not significantly correlate with the memory deficit in our patients. These findings suggest that the cholinergic dysfunction does not account for the memory disorder and that damage to the cholinergic system is not sufficient to cause a persisting amnesic syndrome in WKS.

  17. Effects of histamine and cholinergic systems on memory retention of passive avoidance learning in rats.

    Science.gov (United States)

    Eidi, Maryam; Zarrindast, Mohammad-Reza; Eidi, Akram; Oryan, Shahrbanoo; Parivar, Kazem

    2003-03-28

    In the present study, the effects of the histamine and cholinergic systems on memory retention in adult male rats were investigated. Post-training intracerebroventricular injections were carried out in all the experiments. Cholinoceptor agonist, acetylcholine (1-10 microg/rat) or nicotine (1-10 microg/rat), increased, while a cholinoceptor antagonist, scopolamine (5-20 microg/rat), decreased memory retention. The response to acetylcholine was attenuated by scopolamine. Administration of histamine (5-20 microg/rat) reduced, but the histamine H(1) receptor antagonist, pyrilamine (10-50 microg/rat), and the histamine H(2) receptor antagonist, cimetidine (1-50 microg/rat), increased memory retention in rats. The histamine receptor antagonists attenuated the response to histamine. Histamine reduced the acetylcholine- or nicotine-induced enhancement. The histamine receptor antagonists enhanced the nicotine- or acetylcholine-induced response. Histamine potentiated the inhibitory effect induced by scopolamine. It is concluded that histaminergic and cholinergic systems have opposing effects on memory retention. Also, the histaminergic system elicits an interaction with the cholinergic system in memory retention.

  18. Differential CB1 and CB2 cannabinoid receptor-inotropic response of rat isolated atria: endogenous signal transduction pathways.

    Science.gov (United States)

    Sterin-Borda, Leonor; Del Zar, Claudia F; Borda, Enri

    2005-06-15

    In this study, we have determined the contractile effects of CB1 and CB2 cannabinoid receptor activation on rat isolated atria and the different signaling pathways involved. Anandamide did not has significantly effect on atria contractility, however, the treatment with both CB1 (AM251) or CB2 (AM630) receptor antagonists, the endocannabinoids triggered stimulation or inhibition on contractility respectively. The ACEA stimulation of CB1 receptor exerted decrease on contractility, that significantly correlated with the decrement of cAMP and the stimulation of nitric oxide synthase (NOS) and the accumulation of cyclic GMP (cGMP). On the contrary, JWH 015 stimulation of CB2 receptor triggered positive contractile response that significantly correlated with the increase cAMP production. The inhibiton of adenylate cyclase activity impaired the JWH 015 activation of CB1 receptor induced positive contractile effect, while inhibitors of phospholipase C (PLC), NOS and soluble nitric oxide (NO)-sensitive guanylate cyclase blocked the dose-response curves of ACEA on contractility. Those inhibitors also attenuated the CB1 receptor-dependent increase in activation of NOS and cGMP accumulation. These results suggest that CB2 receptor agonist mediated positive contractile effect associated with increased production on cAMP while CB1 receptor agonist mediated decrease on contractility associated with decreased cAMP accumulation and increase production of NO and cGMP; that occur secondarily to stimulation of PLC, NOS and soluble guanylate cyclase. Data give pharmacological evidence for the existence of functional CB1 and CB2 cannabinoid receptors in rat isolated atria and may contribute to a better understanding the effects of cannabinoids in the cardiovascular system.

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

    Science.gov (United States)

    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.

  20. Rabbit Forebrain cholinergic system : Morphological characterization of nuclei and distribution of cholinergic terminals in the cerebral cortex and hippocampus

    NARCIS (Netherlands)

    Varga, C; Hartig, W; Grosche, J; Luiten, PGM; Seeger, J; Brauer, K; Harkany, T; Härtig, Wolfgang; Keijser, Jan N.

    2003-01-01

    Although the rabbit brain, in particular the basal forebrain cholinergic system, has become a common model for neuropathological changes associated with Alzheimer's disease, detailed neuroanatomical studies on the morphological organization of basal forebrain cholinergic nuclei and on their output p

  1. A novel signaling pathway of tissue kallikrein in promoting keratinocyte migration: Activation of proteinase-activated receptor 1 and epidermal growth factor receptor

    Energy Technology Data Exchange (ETDEWEB)

    Gao, Lin; Chao, Lee [Department of Biochemistry and Molecular Biology, Medical University of South Carolina, 173 Ashley Avenue, Charleston, SC 29425-2211 (United States); Chao, Julie, E-mail: chaoj@musc.edu [Department of Biochemistry and Molecular Biology, Medical University of South Carolina, 173 Ashley Avenue, Charleston, SC 29425-2211 (United States)

    2010-02-01

    Biological functions of tissue kallikrein (TK, KLK1) are mainly mediated by kinin generation and subsequent kinin B2 receptor activation. In this study, we investigated the potential role of TK and its signaling pathways in cultured human keratinocyte migration and in a rat skin wound healing model. Herein, we show that TK promoted cell migration and proliferation in a concentration- and time-dependent manner. Inactive TK or kinin had no significant effect on cell migration. Interestingly, cell migration induced by active TK was not blocked by icatibant or L-NAME, indicating an event independent of kinin B2 receptor and nitric oxide formation. TK's stimulatory effect on cell migration was inhibited by small interfering RNA for proteinase-activated receptor 1 (PAR{sub 1}), and by PAR{sub 1} inhibitor. TK-induced migration was associated with increased phosphorylation of epidermal growth factor receptor (EGFR) and extracellular signal-regulated kinase (ERK), which was blocked by inhibition of protein kinase C (PKC), Src, EGFR and ERK. TK-induced cell migration and EGFR phosphorylation were blocked by metalloproteinase (MMP) inhibitor, heparin, and antibodies against EGFR external domain, heparin-binding EGF-like growth factor (HB-EGF) and amphiregulin (AR). Local application of TK promoted skin wound healing in rats, whereas icatibant and EGFR inhibitor blocked TK's effect. Skin wound healing was further delayed by aprotinin and neutralizing TK antibody. This study demonstrates a novel role of TK in skin wound healing and uncovers new signaling pathways mediated by TK in promoting keratinocyte migration through activation of the PAR{sub 1}-PKC-Src-MMP pathway and HB-EGF/AR shedding-dependent EGFR transactivation.

  2. Kynurenine pathway and cognitive impairments in schizophrenia: Pharmacogenetics of galantamine and memantine

    Directory of Open Access Journals (Sweden)

    Maju Mathew Koola

    2016-06-01

    Full Text Available The Measurement and Treatment Research to Improve Cognition in Schizophrenia (MATRICS project designed to facilitate the development of new drugs for the treatment of cognitive impairments in people with schizophrenia, identified three drug mechanisms of particular interest: dopaminergic, cholinergic, and glutamatergic. Galantamine is an acetylcholinesterase inhibitor and a positive allosteric modulator of the α7 nicotinic receptors. Memantine is an N-methyl-D-aspartate (NMDA receptor antagonist. There is evidence to suggest that the combination of galantamine and memantine may be effective in the treatment of cognitive impairments in schizophrenia. There is a growing body of evidence that excess kynurenic acid (KYNA is associated with cognitive impairments in schizophrenia. The α-7 nicotinic and the NMDA receptors may counteract the effects of kynurenic acid (KYNA resulting in cognitive enhancement. Galantamine and memantine through its α-7 nicotinic and NMDA receptors respectively may counteract the effects of KYNA thereby improving cognitive impairments. The Single Nucleotide Polymorphisms in the Cholinergic Receptor, Nicotinic, Alpha 7 gene (CHRNA7, Glutamate (NMDA Receptor, Metabotropic 1 (GRM1 gene, Dystrobrevin Binding Protein 1 (DTNBP1 and kynurenine 3-monooxygenase (KMO gene may predict treatment response to galantamine and memantine combination for cognitive impairments in schizophrenia in the kynurenine pathway.

  3. Disruption of low-density lipoprotein receptor pathway induced by inflammation contributes to podocyte injury in diabetic nephropathy

    Institute of Scientific and Technical Information of China (English)

    张洋

    2014-01-01

    Objective To investigate the effects of low density lipoprotein receptor(LDLr)pathway on podocyte injury in diabetic nephropathy(DN)under inflammatory stress.Methods Male db/db mice and db/m mice were randomly divided into four groups(8 mice in each group):db/m group(control),casein injected db/m group(db/m+casein),db/db group(db/db),and casein injected

  4. Coding the direct/indirect pathways by D1 and D2 receptors is not valid for accumbens projections.

    Science.gov (United States)

    Kupchik, Yonatan M; Brown, Robyn M; Heinsbroek, Jasper A; Lobo, Mary Kay; Schwartz, Danielle J; Kalivas, Peter W

    2015-09-01

    It is widely accepted that D1 dopamine receptor-expressing striatal neurons convey their information directly to the output nuclei of the basal ganglia, whereas D2-expressing neurons do so indirectly via pallidal neurons. Combining optogenetics and electrophysiology, we found that this architecture does not apply to mouse nucleus accumbens projections to the ventral pallidum. Thus, current thinking attributing D1 and D2 selectivity to accumbens projections akin to dorsal striatal pathways needs to be reconsidered.

  5. DMPD: Toll-like receptors regulation of viral infection and disease. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 18280610 Toll-like receptors regulation of viral infection and disease. Thompson JM...how Toll-like receptors regulation of viral infection and disease. PubmedID 18280610 Title Toll-like recepto...rs regulation of viral infection and disease. Authors Thompson JM, Iwasaki A. Pub

  6. DMPD: Is HIV infection a TNF receptor signalling-driven disease? [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 18178131 Is HIV infection a TNF receptor signalling-driven disease? Herbein G, Khan... KA. Trends Immunol. 2008 Feb;29(2):61-7. (.png) (.svg) (.html) (.csml) Show Is HIV infection a TNF receptor signalling-driven dise...ase? PubmedID 18178131 Title Is HIV infection a TNF receptor signalling-driven diseas

  7. DMPD: C-type lectin receptors in antifungal immunity. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 18160296 C-type lectin receptors in antifungal immunity. Willment JA, Brown GD. Tre...nds Microbiol. 2008 Jan;16(1):27-32. Epub 2007 Dec 21. (.png) (.svg) (.html) (.csml) Show C-type lectin receptors in anti...fungal immunity. PubmedID 18160296 Title C-type lectin receptors in antifungal immunity. Author

  8. DMPD: Signals and receptors involved in recruitment of inflammatory cells. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 7744810 Signals and receptors involved in recruitment of inflammatory cells. Ben-Ba...ow Signals and receptors involved in recruitment of inflammatory cells. PubmedID 7744810 Title Signals and r...eceptors involved in recruitment of inflammatory cells. Authors Ben-Baruch A, Mic

  9. DMPD: Shaping of monocyte and macrophage function by adenosine receptors. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 17056121 Shaping of monocyte and macrophage function by adenosine receptors. Hasko ...tml) (.csml) Show Shaping of monocyte and macrophage function by adenosine receptors. PubmedID 17056121 Titl...e Shaping of monocyte and macrophage function by adenosine receptors. Authors Has

  10. DMPD: Toll like receptors and autoimmunity: a critical appraisal. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 17959357 Toll like receptors and autoimmunity: a critical appraisal. Papadimitraki ...ml) Show Toll like receptors and autoimmunity: a critical appraisal. PubmedID 17959357 Title Toll like recep...tors and autoimmunity: a critical appraisal. Authors Papadimitraki ED, Bertsias G

  11. DMPD: Lysophospholipid receptors: signaling and biology. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 15189145 Lysophospholipid receptors: signaling and biology. Ishii I, Fukushima N, Y...e X, Chun J. Annu Rev Biochem. 2004;73:321-54. (.png) (.svg) (.html) (.csml) Show Lysophospholipid receptors: signaling and biology.... PubmedID 15189145 Title Lysophospholipid receptors: signaling and biology. Authors

  12. DMPD: Nuclear receptor signaling in macrophages. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 14698033 Nuclear receptor signaling in macrophages. Valledor AF, Ricote M. Biochem ...Pharmacol. 2004 Jan 15;67(2):201-12. (.png) (.svg) (.html) (.csml) Show Nuclear receptor signaling in macrop...hages. PubmedID 14698033 Title Nuclear receptor signaling in macrophages. Authors Valledor AF, Ricote M. Pub

  13. DMPD: Type I interferon receptors: biochemistry and biological functions. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 17502368 Type I interferon receptors: biochemistry and biological functions. de Wee...(.html) (.csml) Show Type I interferon receptors: biochemistry and biological functions. PubmedID 17502368 T...itle Type I interferon receptors: biochemistry and biological functions. Authors

  14. DMPD: NOD-like receptors (NLRs): bona fide intracellular microbial sensors. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 18585455 NOD-like receptors (NLRs): bona fide intracellular microbial sensors. Shaw...tml) (.csml) Show NOD-like receptors (NLRs): bona fide intracellular microbial sensors. PubmedID 18585455 Ti...tle NOD-like receptors (NLRs): bona fide intracellular microbial sensors. Authors

  15. DMPD: Endogenous ligands of Toll-like receptors. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 15178705 Endogenous ligands of Toll-like receptors. Tsan MF, Gao B. J Leukoc Biol. ...2004 Sep;76(3):514-9. Epub 2004 Jun 3. (.png) (.svg) (.html) (.csml) Show Endogenous ligands of Toll-like re...ceptors. PubmedID 15178705 Title Endogenous ligands of Toll-like receptors. Authors Tsan MF, Gao B. Publicat

  16. DMPD: Toll-like receptors in atherosclerosis. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 18031244 Toll-like receptors in atherosclerosis. Tobias PS, Curtiss LK. Biochem Soc... Trans. 2007 Dec;35(Pt 6):1453-5. (.png) (.svg) (.html) (.csml) Show Toll-like receptors in atherosclerosis.... PubmedID 18031244 Title Toll-like receptors in atherosclerosis. Authors Tobias PS, Curtiss LK. Publication

  17. DMPD: Receptor tyrosine kinases and the regulation of macrophage activation. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 14726496 Receptor tyrosine kinases and the regulation of macrophage activation. Cor...(.csml) Show Receptor tyrosine kinases and the regulation of macrophage activation. PubmedID 14726496 Title ...Receptor tyrosine kinases and the regulation of macrophage activation. Authors Co

  18. Postnatal lead exposure and the cholinergic system: effects on cholinergically mediated behaviors and cholinergic development and plasticity in the hippocampus

    Energy Technology Data Exchange (ETDEWEB)

    Alfano, D.P.

    1982-01-01

    A review of previous evidence suggested the possibility of a functional association between the behavioral effect of early lead (Pb) exposure, hippocampal damage and cholinergic deficiency. To further assess this possibility, Long-Evans hooded rat pups were exposed to Pb for the first 25 postnatal days via the maternal milk. Beginning at 65 days of age, animals were tested on behavioral tasks sensitive to both Pb exposure and cholinergic deficiency. Exposure to both levels of Pb impaired passive avoidance acquisition and produced lower rates of spontaneous alternation. The anticholinergic scopolamine (0.4 mg/kg) impaired passive avoidance acquisition, lowered the rate of spontaneous alternation and decreased open field activity scores in control animals. At 30 days of age, the brains of High Pb and control animals were processed for acetylcholinesterase (AChE) histochemistry. Morphometric evaluation of the molecular layer of the hippocampal dentate gyrus indicated no effects of Pb on the development of the cholinergic innervation of this brain region. The results provide strong evidence for the involvement of deficient cholinergic functioning in the behavioral changes observed following postnatal Pb exposure. Further, these findings indicate that a decrease in neuroanatomical plasticity may be a critical brain mechanism underlying the learning deficits observed following exposure to Pb.

  19. Endomorphins 1 and 2 reduce relaxant non-adrenergic, non-cholinergic neurotransmission in rat gastric fundus.

    Science.gov (United States)

    Storr, M; Gaffal, E; Schusdziarra, V; Allescher, H-D

    2002-06-14

    It is now well established that opioids modulate cholinergic excitatory neurotransmission in the gastrointestinal tract. The aim of the present study was to characterize a possible effect of endomorphins on nonadrenergic, noncholinergic (NANC) relaxant neurotransmission in the rat gastric fundus in vitro. The drugs used in the experiments were the endogenous mu-opioid receptors (MORs) endomorphin 1 and 2 and the mu-opioid receptor antagonist CTAP (D-Phe-Cys-Tyr-D-Trp-Arg-Thr-Pen-Thr-NH2). CTAP left the basal tonus and the spontaneous activity of the preparation unchanged. Electrical field stimulation (EFS) under NANC conditions at frequencies ranging from 0.5 to 16 Hz caused a frequency-dependent relaxant response on the 5-hydoxytryptamine (5-HT) (10(-7) M) precontracted smooth-muscle strip. Both endomorphin 1 and endomorphin 2 significantly reduced this relaxation in a concentration-dependent manner. Endomorphin 1 proved to be more potent in reducing the relaxant responses. The endomorphin effects were significantly reversed by the MOR antagonist CTAP. CTAP itself did not influence the EFS-induced relaxation. In summary, these data provide evidence that the endogenous MOR agonists endomorphin 1 and 2 can reduce nonadrenergic, noncholinergic neurotransmission in the rat gastric fundus smooth muscle via a pathway involving MORs. The physiological relevance of these findings remains to be established, since the data presented suggest that the endomorphins act as neuromodulators within NANC relaxant neurotransmission.

  20. Presynaptic Adenosine Receptor-Mediated Regulation of Diverse Thalamocortical Short-Term Plasticity in the Mouse Whisker Pathway.

    Science.gov (United States)

    Ferrati, Giovanni; Martini, Francisco J; Maravall, Miguel

    2016-01-01

    Short-term synaptic plasticity (STP) sets the sensitivity of a synapse to incoming activity and determines the temporal patterns that it best transmits. In "driver" thalamocortical (TC) synaptic populations, STP is dominated by depression during stimulation from rest. However, during ongoing stimulation, lemniscal TC connections onto layer 4 neurons in mouse barrel cortex express variable STP. Each synapse responds to input trains with a distinct pattern of depression or facilitation around its mean steady-state response. As a result, in common with other synaptic populations, lemniscal TC synapses express diverse rather than uniform dynamics, allowing for a rich representation of temporally varying stimuli. Here, we show that this STP diversity is regulated presynaptically. Presynaptic adenosine receptors of the A1R type, but not kainate receptors (KARs), modulate STP behavior. Blocking the receptors does not eliminate diversity, indicating that diversity is related to heterogeneous expression of multiple mechanisms in the pathway from presynaptic calcium influx to neurotransmitter release.

  1. Presynaptic adenosine receptor-mediated regulation of diverse thalamocortical short-term plasticity in the mouse whisker pathway

    Directory of Open Access Journals (Sweden)

    Giovanni eFerrati

    2016-02-01

    Full Text Available Short-term synaptic plasticity (STP sets the sensitivity of a synapse to incoming activity and determines the temporal patterns that it best transmits. In driver thalamocortical (TC synaptic populations, STP is dominated by depression during stimulation from rest. However, during ongoing stimulation, lemniscal TC connections onto layer 4 neurons in mouse barrel cortex express variable STP. Each synapse responds to input trains with a distinct pattern of depression or facilitation around its mean steady-state response. As a result, in common with other synaptic populations, lemniscal TC synapses express diverse rather than uniform dynamics, allowing for a rich representation of temporally varying stimuli. Here we show that this STP diversity is regulated presynaptically. Presynaptic adenosine receptors of the A1R type, but not kainate receptors, modulate STP behavior. Blocking the receptors does not eliminate diversity, indicating that diversity is related to heterogeneous expression of multiple mechanisms in the pathway from presynaptic calcium influx to neurotransmitter release.

  2. Epidermal growth factor receptor (EGFR-RAS signaling pathway in penile squamous cell carcinoma.

    Directory of Open Access Journals (Sweden)

    Hong-Feng Gou

    Full Text Available Penile Squamous Cell Carcinoma (SCC is a rare cancer with poor prognosis and limited response to conventional chemotherapy. The genetic and epigenetic alterations of Epidermal Growth Factor Receptor (EGFR-RAS-RAF signaling in penile SCC are unclear. This study aims to investigate four key members of this pathway in penile SCC. We examined the expression of EGFR and RAS-association domain family 1 A (RASSF1A as well as the mutation status of K-RAS and BRAF in 150 cases of penile SCC. EGFR and RASSF1A expression was evaluated by immunohistochemistry. KRAS mutations at codons 12 and 13, and the BRAF mutation at codon 600 were analyzed on DNA isolated from formalin fixed paraffin embedded tissues by direct genomic sequencing. EGFR expression was positive in all specimens, and its over-expression rate was 92%. RASSF1A expression rate was only 3.42%. Significant correlation was not found between the expression of EGFR or RASSF1A and tumor grade, pT stage or lymph node metastases. The detection of KRAS and BRAF mutations analysis was performed in 94 and 83 tumor tissues, respectively. We found KRAS mutation in only one sample and found no BRAF V600E point mutation. In summary, we found over-expression of EGFR in the majority cases of penile SCC, but only rare expression of RASSF1A, rare KRAS mutation, and no BRAF mutation in penile SCC. These data suggest that anti-EGFR agents may be potentially considered as therapeutic options in penile SCC.

  3. Comprehensive logic based analyses of Toll-like receptor 4 signal transduction pathway.

    Directory of Open Access Journals (Sweden)

    Mahesh Kumar Padwal

    Full Text Available Among the 13 TLRs in the vertebrate systems, only TLR4 utilizes both Myeloid differentiation factor 88 (MyD88 and Toll/Interleukin-1 receptor (TIR-domain-containing adapter interferon-β-inducing Factor (TRIF adaptors to transduce signals triggering host-protective immune responses. Earlier studies on the pathway combined various experimental data in the form of one comprehensive map of TLR signaling. But in the absence of adequate kinetic parameters quantitative mathematical models that reveal emerging systems level properties and dynamic inter-regulation among the kinases/phosphatases of the TLR4 network are not yet available. So, here we used reaction stoichiometry-based and parameter independent logical modeling formalism to build the TLR4 signaling network model that captured the feedback regulations, interdependencies between signaling kinases and phosphatases and the outcome of simulated infections. The analyses of the TLR4 signaling network revealed 360 feedback loops, 157 negative and 203 positive; of which, 334 loops had the phosphatase PP1 as an essential component. The network elements' interdependency (positive or negative dependencies in perturbation conditions such as the phosphatase knockout conditions revealed interdependencies between the dual-specific phosphatases MKP-1 and MKP-3 and the kinases in MAPK modules and the role of PP2A in the auto-regulation of Calmodulin kinase-II. Our simulations under the specific kinase or phosphatase gene-deficiency or inhibition conditions corroborated with several previously reported experimental data. The simulations to mimic Yersinia pestis and E. coli infections identified the key perturbation in the network and potential drug targets. Thus, our analyses of TLR4 signaling highlights the role of phosphatases as key regulatory factors in determining the global interdependencies among the network elements; uncovers novel signaling connections; identifies potential drug targets for

  4. Bile acids regulate hepatic gluconeogenic genes and farnesoid X receptor via G(alpha)i-protein-coupled receptors and the AKT pathway.

    Science.gov (United States)

    Cao, Risheng; Cronk, Zhumei Xu; Zha, Weibin; Sun, Lixin; Wang, Xuan; Fang, Youwen; Studer, Elaine; Zhou, Huiping; Pandak, William M; Dent, Paul; Gil, Gregorio; Hylemon, Phillip B

    2010-08-01

    Bile acids are important regulatory molecules that can activate specific nuclear receptors and cell signaling pathways in the liver and gastrointestinal tract. In the current study, the chronic bile fistula (CBF) rat model and primary rat hepatocytes (PRH) were used to study the regulation of gluconeogenic genes phosphoenolpyruvate carboxykinase (PEPCK) and glucose-6-phosphatase (G-6-Pase) and the gene encoding short heterodimeric partner (SHP) by taurocholate (TCA). The intestinal infusion of TCA into the CBF rat rapidly (1h) activated the AKT (approximately 9-fold) and ERK1/2 (3- to 5-fold) signaling pathways, downregulated (approximately 50%, 30 min) the mRNA levels of PEPCK and G-6-Pase, and induced (14-fold in 3 h) SHP mRNA. TCA rapidly ( approximately 50%, 1-2 h) downregulated PEPCK and G-6-Pase mRNA levels in PRH. The downregulation of these genes by TCA was blocked by pretreatment of PRH with pertussis toxin (PTX). In PRH, TCA plus insulin showed a significantly stronger inhibition of glucose secretion/synthesis from lactate and pyruvate than either alone. The induction of SHP mRNA in PRH was strongly blocked by inhibition of PI3 kinase or PKCzeta by specific chemical inhibitors or knockdown of PKCzeta by siRNA encoded by a recombinant lentivirus. Activation of the insulin signaling pathway appears to be linked to the upregulation of farnesoid X receptor functional activity and SHP induction.

  5. Identification of aryl hydrocarbon receptor signaling pathways altered in TCDD-treated red seabream embryos by transcriptome analysis.

    Science.gov (United States)

    Iida, Midori; Fujii, Satoshi; Uchida, Masaya; Nakamura, Hiroshi; Kagami, Yoshihiro; Agusa, Tetsuro; Hirano, Masashi; Bak, Su-Min; Kim, Eun-Young; Iwata, Hisato

    2016-08-01

    2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) induces a broad spectrum of toxic effects including craniofacial malformation and neural damage in fish embryos. These effects are mainly mediated by the aryl hydrocarbon receptor (AHR). However, the mode of action between TCDD-induced AHR activation and adverse outcomes is not yet understood. To provide a comprehensive picture of the AHR signaling pathway in fish embryos exposed to TCDD, red seabream (Pagrus major) embryos were treated with graded concentrations of TCDD (0.3-37nM) in seawater, or with a mixture of TCDD and 500nM CH223191, an AHR-specific antagonist. The transcriptome of red seabream embryos was analyzed using a custom-made microarray with 6000 probes specifically prepared for this species. A Jonckheere-Terpstra test was performed to screen for genes that demonstrated altered mRNA expression levels following TCDD exposure. The signals of 1217 genes (as human homologs) were significantly altered in a TCDD concentration-dependent manner (q-valueTCDD-induced alteration in mRNA expression was alleviated by co-exposure to CH223191, suggesting that the mRNA expression level of these genes was regulated by AHR. To identify TCDD-activated pathways, the microarray data were further subjected to gene set enrichment analysis (GSEA) and functional protein-protein interaction (PPI) network analysis. GSEA demonstrated that the effects of TCDD on sets of genes involved calcium, mitogen-activated protein kinase (MAPK), actin cytoskeleton, chemokine, T cell receptor, melanoma, vascular endothelial growth factor (VEGF), axon guidance, and renal cell carcinoma signaling pathways. These results suggest the hypotheses that TCDD induces immunosuppression via the calcium, MAPK, chemokine, and T cell receptor signaling pathways, neurotoxicity via VEGF signaling, and axon guidance alterations and teratogenicity via the dysregulation of the actin cytoskeleton and melanoma and renal cell carcinoma signaling pathways. Furthermore

  6. Cholinergic profiles in the Goettingen miniature pig (Sus scrofa domesticus) brain.

    Science.gov (United States)

    Mahady, Laura J; Perez, Sylvia E; Emerich, Dwaine F; Wahlberg, Lars U; Mufson, Elliott J

    2017-02-15

    Central cholinergic structures within the brain of the even-toed hoofed Goettingen miniature domestic pig (Sus scrofa domesticus) were evaluated by immunohistochemical visualization of choline acetyltransferase (ChAT) and the low-affinity neurotrophin receptor, p75(NTR) . ChAT-immunoreactive (-ir) perikarya were seen in the olfactory tubercle, striatum, medial septal nucleus, vertical and horizontal limbs of the diagonal band of Broca, and the nucleus basalis of Meynert, medial habenular nucleus, zona incerta, neurosecretory arcuate nucleus, cranial motor nuclei III and IV, Edinger-Westphal nucleus, parabigeminal nucleus, pedunculopontine nucleus, and laterodorsal tegmental nucleus. Cholinergic ChAT-ir neurons were also found within transitional cortical areas (insular, cingulate, and piriform cortices) and hippocampus proper. ChAT-ir fibers were seen throughout the dentate gyrus and hippocampus, in the mediodorsal, laterodorsal, anteroventral, and parateanial thalamic nuclei, the fasciculus retroflexus of Meynert, basolateral and basomedial amygdaloid nuclei, anterior pretectal and interpeduncular nuclei, as well as select laminae of the superior colliculus. Double immunofluorescence demonstrated that virtually all ChAT-ir basal forebrain neurons were also p75(NTR) -positive. The present findings indicate that the central cholinergic system in the miniature pig is similar to other mammalian species. Therefore, the miniature pig may be an appropriate animal model for preclinical studies of neurodegenerative diseases where the cholinergic system is compromised. J. Comp. Neurol. 525:553-573, 2017. © 2016 Wiley Periodicals, Inc.

  7. DMPD: Toll-like receptors. II. Distribution and pathways involved in TLR signalling. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available uc M. Publication Folia Biol (Praha). 2005;51(6):188-97. Pathway - PNG File (.png) SVG File (.svg) HTML File (.html) CSML File (.csm...ing. Sandor F, Buc M. Folia Biol (Praha). 2005;51(6):188-97. (.png) (.svg) (.html) (.csml) Show Toll-like re...l) Open .csml file with CIOPlayer Open .csml file with CIOPlayer - ※CIO Playerのご利用上の注意 Open .csml file with CIO Open .csml file with CIO - ※CIOのご利用上の注意 ...

  8. Developmental Neurotoxicity of Tobacco Smoke Directed Toward Cholinergic and Serotonergic Systems: More Than Just Nicotine.

    Science.gov (United States)

    Slotkin, Theodore A; Skavicus, Samantha; Card, Jennifer; Stadler, Ashley; Levin, Edward D; Seidler, Frederic J

    2015-09-01

    Tobacco smoke contains thousands of compounds in addition to nicotine, a known neuroteratogen. We evaluated the developmental neurotoxicity of tobacco smoke extract (TSE) administered to pregnant rats starting preconception and continued through the second postnatal week. We simulated nicotine concentrations encountered with second-hand smoke, an order of magnitude below those seen in active smokers, and compared TSE with an equivalent dose of nicotine alone, and to a 10-fold higher nicotine dose. We conducted longitudinal evaluations in multiple brain regions, starting in adolescence (postnatal day 30) and continued to full adulthood (day 150). TSE exposure impaired presynaptic cholinergic activity, exacerbated by a decrement in nicotinic cholinergic receptor concentrations. Although both nicotine doses produced presynaptic cholinergic deficits, these were partially compensated by hyperinnervation and receptor upregulation, effects that were absent with TSE. TSE also produced deficits in serotonin receptors in females that were not seen with nicotine. Regression analysis showed a profound sex difference in the degree to which nicotine could account for overall TSE effects: whereas the 2 nicotine doses accounted for 36%-46% of TSE effects in males, it accounted for only 7%-13% in females. Our results show that the adverse effects of TSE on neurodevelopment exceed those that can be attributed to just the nicotine present in the mixture, and further, that the sensitivity extends down to levels commensurate with second-hand smoke exposure. Because nicotine itself evoked deficits at low exposures, "harm reduction" nicotine products do not eliminate the potential for neurodevelopmental damage.

  9. Assessment of variation in immunosuppressive pathway genes reveals TGFBR2 to be associated with prognosis of estrogen receptor-negative breast cancer after chemotherapy

    NARCIS (Netherlands)

    J. Lei (Jieping); A. Rudolph (Anja); K.B. Moysich (Kirsten); M. Rafiq (Meena); T.W. Behrens (Timothy); E.L. Goode (Ellen); P.D.P. Pharoah (Paul); P. Seibold (Petra); P.A. Fasching (Peter); I.L. Andrulis (Irene); V. Kristensen (Vessela); F.J. Couch (Fergus); U. Hamann (Ute); M.J. Hooning (Maartje); H. Nevanlinna (Heli); U. Eilber (Ursula); M.K. Bolla (Manjeet); J. Dennis (Joe); Q. Wang (Qing); A. Lindblom (Annika); A. Mannermaa (Arto); D. Lambrechts (Diether); M. García-Closas (Montserrat); P. Hall (Per); G. Chenevix-Trench (Georgia); M. Shah (Mitul); R.N. Luben (Robert); L. Haeberle (Lothar); A.B. Ekici (Arif); M.W. Beckmann (Matthias); J.A. Knight (Julia); G. Glendon (Gord); S. Tchatchou (Sandrine); G.G. Alnæs (Grethe Grenaker); A.-L. Borresen-Dale (Anne-Lise); S. Nord (Silje); J.E. Olson (Janet); B. Hallberg (Boubou); C. Vachon (Celine); D. Torres (Diana); H.U. Ulmer (Hans); T. Rud̈iger (Thomas); A. Jager (Agnes); C.H.M. van Deurzen (Carolien); M.M.A. Tilanus-Linthorst (Madeleine); T.A. Muranen (Taru); K. Aittomäki (Kristiina); C. Blomqvist (Carl); S. Margolin (Sara); V-M. Kosma (Veli-Matti); J.M. Hartikainen (J.); V. Kataja (Vesa); S. Hatse (Sigrid); H. Wildiers (Hans); A. Smeets (Ann); J.D. Figueroa (Jonine); S.J. Chanock (Stephen); J. Lissowska (Jolanta); J. Li (Jingmei); M.K. Humphreys (Manjeet); K.-A. Phillips (Kelly-Anne); S.C. Linn (Sabine); S. Cornelissen (Sten); S.A.J. van den Broek (Sandra Alexandra); D. Kang (Daehee); J.-Y. Choi (J.); S.K. Park (Sue); K.Y. Yoo; C.-N. Hsiung (Chia-Ni); P.-E. Wu (Pei-Ei); M.-F. Hou (Ming-Feng); C-Y. Shen (Chen-Yang); S.-H. Teo; N.A.M. Taib (Nur Aishah Mohd); C.-H. Yip (Cheng-Har); G.F. Ho (Gwo Fuang); K. Matsuo (Keitaro); H. Ito (Hidemi); H. Iwata (Hisato); K. Tajima (Kazuo); A.M. Dunning (Alison); J. Benítez (Javier); K. Czene (Kamila); L. Sucheston (Lara); T. Maishman (Tom); W. Tapper (William); D. Eccles (Diana); D.F. Easton (Douglas); M.K. Schmidt (Marjanka); J. Chang-Claude (Jenny)

    2015-01-01

    textabstractIntroduction: Tumor lymphocyte infiltration is associated with clinical response to chemotherapy in estrogen receptor (ER) negative breast cancer. To identify variants in immunosuppressive pathway genes associated with prognosis after adjuvant chemotherapy for ER-negative patients, we st

  10. Integration of G-Protein Coupled Receptor Signaling Pathways for Activation of a Transcription Factor (EGR-3)

    Institute of Scientific and Technical Information of China (English)

    Xuehai Tan; Pam Sanders; Jack Bolado Jr.; Mike Whitney

    2003-01-01

    We recently reported the use of a gene-trapping approach to isolate cell clones in which a reporter gene had integrated into genes modulated by T-cell activation. We have now tested a panel of clones from that report and identified the one that responds to a variety of G-protein coupled receptors (GPCR). The βlactamase tagged EGR-3 Jurkat cell was used to dissect specific GPCR signaling in vivo. Three GPCRs were studied, including the chemokine receptor CXCR4 (Gicoupled) that was endogenously expressed, the platelet activation factor (PAF) receptor (Gq-coupled), andβ2 adrenergic receptor (Gs-coupled) that was both stably transfected. Agonists for each receptor activated transcription of theβ-lactamase tagged EGR-3 gene. Induction of EGR-3 through CXCR4 was blocked by pertussis toxin and PD58059, a specific inhibitor of MEK (MAPK/ERK kinase). Neither of these inhibitors blocked isoproterenol or PAF-mediated activation of EGR-3. Conversely, β2- and PAF-mediated EGR-3 activation was blocked by the p38, specific inhibitor SB580. In addition, bothβ2- and PAF-mediated EGR-3 activation could be synergistically activated by CXCR4 activation. This combined result indicates that EGR-3 can be activated through distinct signal transduction pathways by different GPCRs and that signals can be integrated and amplified to efficiently tune the level of activation.

  11. Driving Cellular Plasticity and Survival Through the Signal Transduction Pathways of Metabotropic Glutamate Receptors

    OpenAIRE

    2005-01-01

    Metabotropic glutamate receptors (mGluRs) share a common molecular morphology with other G protein–linked receptors, but there expression throughout the mammalian nervous system places these receptors as essential mediators not only for the initial development of an organism, but also for the vital determination of a cell’s fate during many disorders in the nervous system that include amyotrophic lateral sclerosis, Parkinson’s disease, Alzheimer’s disease, Huntington’s disease, Multiple Scler...

  12. The cannabinoid CB1 receptor and mTORC1 signalling pathways interact to modulate glucose homeostasis in mice.

    Science.gov (United States)

    Bermudez-Silva, Francisco J; Romero-Zerbo, Silvana Y; Haissaguerre, Magalie; Ruz-Maldonado, Inmaculada; Lhamyani, Said; El Bekay, Rajaa; Tabarin, Antoine; Marsicano, Giovanni; Cota, Daniela

    2016-01-01

    The endocannabinoid system (ECS) is an intercellular signalling mechanism that is present in the islets of Langerhans and plays a role in the modulation of insulin secretion and expansion of the β-cell mass. The downstream signalling pathways mediating these effects are poorly understood. Mammalian target of rapamycin complex 1 (mTORC1) signalling is a key intracellular pathway involved in energy homeostasis and is known to importantly affect the physiology of pancreatic islets. We investigated the possible relationship between cannabinoid type 1 (CB1) receptor signalling and the mTORC1 pathway in the endocrine pancreas of mice by using pharmacological analysis as well as mice genetically lacking the CB1 receptor or the downstream target of mTORC1, the kinase p70S6K1. In vitro static secretion experiments on islets, western blotting, and in vivo glucose and insulin tolerance tests were performed. The CB1 receptor antagonist rimonabant decreased glucose-stimulated insulin secretion (GSIS) at 0.1 µM while increasing phosphorylation of p70S6K1 and ribosomal protein S6 (rpS6) within the islets. Specific pharmacological blockade of mTORC1 by 3 nM rapamycin, as well as genetic deletion of p70S6K1, impaired the CB1-antagonist-mediated decrease in GSIS. In vivo experiments showed that 3 mg/kg body weight rimonabant decreased insulin levels and induced glucose intolerance in lean mice without altering peripheral insulin sensitivity; this effect was prevented by peripheral administration of low doses of rapamycin (0.1 mg/kg body weight), which increased insulin sensitivity. These findings suggest a functional interaction between the ECS and the mTORC1 pathway within the endocrine pancreas and at the whole-organism level, which could have implications for the development of new therapeutic approaches for pancreatic β-cell diseases.

  13. Rod and cone pathway signalling is altered in the P2X7 receptor knock out mouse.

    Directory of Open Access Journals (Sweden)

    Kirstan A Vessey

    Full Text Available The P2X7 receptor (P2X7-R is expressed in the retina and brain and has been implicated in neurodegenerative diseases. However, whether it is expressed by neurons and plays a role as a neurotransmitter receptor has been the subject of controversy. In this study, we first show that the novel vesicular transporter for ATP, VNUT, is expressed in the retina, verifying the presence of the molecular machinery for ATP to act as neurotransmitter at P2X7-Rs. Secondly we show the presence of P2X7-R mRNA and protein in the retina and cortex and absence of the full length variant 1 of the receptor in the P2X7-R knock out (P2X7-KO mouse. The role of the P2X7-R in neuronal function of the retina was assessed by comparing the electroretinogram response of P2X7-KO with WT mice. The rod photoreceptor response was found to be similar, while both rod and cone pathway post-photoreceptor responses were significantly larger in P2X7-KO mice. This suggests that activation of P2X7-Rs modulates output of second order retinal neurons. In line with this finding, P2X7-Rs were found in the outer plexiform layer and on inner retinal cell classes, including horizontal, amacrine and ganglion cells. The receptor co-localized with conventional synapses in the IPL and was expressed on amacrine cells post-synaptic to rod bipolar ribbon synapses. In view of the changes in visual function in the P2X7-KO mouse and the immunocytochemical location of the receptor in the normal retina, it is likely the P2X7-R provides excitatory input to photoreceptor terminals or to inhibitory cells that shape both the rod and cone pathway response.

  14. Attenuation of cocaine's reinforcing and discriminative stimulus effects via muscarinic M1 acetylcholine receptor stimulation

    DEFF Research Database (Denmark)

    Thomsen, Morgane; Conn, P Jeffrey; Lindsley, Craig

    2010-01-01

    Muscarinic cholinergic receptors modulate dopaminergic function in brain pathways thought to mediate cocaine's abuse-related effects. Here, we sought to confirm and extend in the mouse species findings that nonselective muscarinic receptor antagonists can enhance cocaine's discriminative stimulus....... More importantly, we tested the hypothesis that muscarinic receptor agonists with varied receptor subtype selectivity can blunt cocaine's discriminative stimulus and reinforcing effects; we hypothesized a critical role for the M(1) and/or M(4) receptor subtypes in this modulation. Mice were trained...... to discriminate cocaine from saline, or to self-administer intravenous cocaine chronically. The nonselective muscarinic antagonists scopolamine and methylscopolamine, the nonselective muscarinic agonists oxotremorine and pilocarpine, the M(1)/M(4)-preferring agonist xanomeline, the putative M(1)-selective agonist...

  15. Obesity Suppresses Estrogen Receptor Beta Expression in Breast Cancer Cells via a HER2-Mediated Pathway.

    Directory of Open Access Journals (Sweden)

    Laura W Bowers

    Full Text Available Obesity is associated with a worse breast cancer prognosis, while greater breast tumor estrogen receptor beta (ERβ expression is correlated with improved therapy response and survival. The objective of this study was to determine the impact of obesity on breast cancer cell ERβ expression, which is currently unknown. We utilized an in vitro model of obesity in which breast cancer cells were exposed to patient serum pooled by body mass index category (obese (OB: ≥30 kg/m2; normal weight (N: 18.5-24.9 kg/m2. Four human mammary tumor cell lines representing the major breast cancer subtypes (SKBR3, MCF-7, ZR75, MDA-MB-231 and mammary tumor cells from MMTV-neu mice were used. ERβ expression, assessed by qPCR and western blotting, was suppressed in the two HER2-overexpressing cell lines (SKBR3, MMTV-neu following OB versus N sera exposure, but did not vary in the other cell lines. Expression of Bcl-2 and cyclin D1, two genes negatively regulated by ERβ, was elevated in SKBR3 cells following exposure to OB versus N sera, but this difference was eliminated when the ERβ gene was silenced with siRNA. Herceptin, a HER2 antagonist, and siRNA to HER2 were used to evaluate the role of HER2 in sera-induced ERβ modulation. SKBR3 cell treatment with OB sera plus Herceptin increased ERβ expression three-fold. Similar results were obtained when HER2 expression was silenced with siRNA. OB sera also promoted greater SKBR3 cell viability and growth, but this variance was not present when ERβ was silenced or the cells were modified to overexpress ERβ. Based on this data, we conclude that obesity-associated systemic factors suppress ERβ expression in breast cancer cells via a HER2-mediated pathway, leading to greater cell viability and growth. Elucidation of the mechanism(s mediating this effect could provide important insights into how ERβ expression is regulated as well as how obesity promotes a more aggressive disease.

  16. Tyrosine-based signal mediates LRP6 receptor endocytosis and desensitization of Wnt/β-catenin pathway signaling.

    Science.gov (United States)

    Liu, Chia-Chen; Kanekiyo, Takahisa; Roth, Barbara; Bu, Guojun

    2014-10-03

    Wnt/β-catenin signaling orchestrates a number of critical events including cell growth, differentiation, and cell survival during development. Misregulation of this pathway leads to various human diseases, specifically cancers. Endocytosis and phosphorylation of the LDL receptor-related protein 6 (LRP6), an essential co-receptor for Wnt/β-catenin signaling, play a vital role in mediating Wnt/β-catenin signal transduction. However, its regulatory mechanism is not fully understood. In this study, we define the mechanisms by which LRP6 endocytic trafficking regulates Wnt/β-catenin signaling activation. We show that LRP6 mutant with defective tyrosine-based signal in its cytoplasmic tail has an increased cell surface distribution and decreased endocytosis rate. These changes in LRP6 endocytosis coincide with an increased distribution to caveolae, increased phosphorylation, and enhanced Wnt/β-catenin signaling. We further demonstrate that treatment of Wnt3a ligands or blocking the clathrin-mediated endocytosis of LRP6 leads to a redistribution of wild-type receptor to lipid rafts. The LRP6 tyrosine mutant also exhibited an increase in signaling activation in response to Wnt3a stimulation when compared with wild-type LRP6, and this activation is suppressed when caveolae-mediated endocytosis is blocked. Our results reveal molecular mechanisms by which LRP6 endocytosis routes regulate its phosphorylation and the strength of Wnt/β-catenin signaling, and have implications on how this pathway can be modulated in human diseases.

  17. Pathogen sensing pathways in human embryonic stem cell derived-endothelial cells: role of NOD1 receptors.

    Directory of Open Access Journals (Sweden)

    Daniel M Reed

    Full Text Available Human embryonic stem cell-derived endothelial cells (hESC-EC, as well as other stem cell derived endothelial cells, have a range of applications in cardiovascular research and disease treatment. Endothelial cells sense Gram-negative bacteria via the pattern recognition receptors (PRR Toll-like receptor (TLR-4 and nucleotide-binding oligomerisation domain-containing protein (NOD-1. These pathways are important in terms of sensing infection, but TLR4 is also associated with vascular inflammation and atherosclerosis. Here, we have compared TLR4 and NOD1 responses in hESC-EC with those of endothelial cells derived from other stem cells and with human umbilical vein endothelial cells (HUVEC. HUVEC, endothelial cells derived from blood progenitors (blood outgrowth endothelial cells; BOEC, and from induced pluripotent stem cells all displayed both a TLR4 and NOD1 response. However, hESC-EC had no TLR4 function, but did have functional NOD1 receptors. In vivo conditioning in nude rats did not confer TLR4 expression in hESC-EC. Despite having no TLR4 function, hESC-EC sensed Gram-negative bacteria, a response that was found to be mediated by NOD1 and the associated RIP2 signalling pathways. Thus, hESC-EC are TLR4 deficient but respond to bacteria via NOD1. This data suggests that hESC-EC may be protected from unwanted TLR4-mediated vascular inflammation, thus offering a potential therapeutic advantage.

  18. Brain Natriuretic Peptide Stimulates Lipid Metabolism through Its Receptor NPR1 and the Glycerolipid Metabolism Pathway in Chicken Adipocytes.

    Science.gov (United States)

    Huang, H Y; Zhao, G P; Liu, R R; Li, Q H; Zheng, M Q; Li, S F; Liang, Z; Zhao, Z H; Wen, J

    2015-11-03

    Brain natriuretic peptide (BNP) is related to lipid metabolism in mammals, but its effect and the molecular mechanisms underlying it in chickens are incompletely understood. We found that the level of natriuretic peptide precursor B (NPPB, which encodes BNP) mRNA expression in high-abdominal-fat chicken groups was significantly higher than that of low-abdominal-fat groups. Partial correlations indicated that changes in the weight of abdominal fat were positively correlated with NPPB mRNA expression level. In vitro, compared with the control group, preadipocytes with NPPB interference showed reduced levels of proliferation, differentiation, and glycerin in media. Treatments of cells with BNP led to enhanced proliferation and differentiation of cells and glycerin concentration, and mRNA expression of its receptor natriuretic peptide receptor 1 (NPR1) was upregulated significantly. In cells exposed to BNP, 482 differentially expressed genes were identified compared with controls without BNP. Four genes known to be related to lipid metabolism (diacylglycerol kinase; lipase, endothelial; 1-acylglycerol-3-phosphate O-acyltransferase 1; and 1-acylglycerol-3-phosphate O-acyltransferase 2) were enriched in the glycerolipid metabolism pathway and expressed differentially. In conclusion, BNP stimulates the proliferation, differentiation, and lipolysis of preadipocytes through upregulation of the levels of expression of its receptor NPR1 and key genes enriched in the glycerolipid metabolic pathway.

  19. Gene-environment interactions in male reproductive health: special reference to the aryl hydrocarbon receptor signaling pathway

    Directory of Open Access Journals (Sweden)

    Leon J S Brokken

    2014-02-01

    Full Text Available Over the last few decades, there have been numerous reports of adverse effects on the reproductive health of wildlife and laboratory animals caused by exposure to endocrine disrupting chemicals (EDCs. The increasing trends in human male reproductive disorders and the mounting evidence for causative environmental factors have therefore sparked growing interest in the health threat posed to humans by EDCs, which are substances in our food, environment and consumer items that interfere with hormone action, biosynthesis or metabolism, resulting in disrupted tissue homeostasis or reproductive function. The mechanisms of EDCs involve a wide array of actions and pathways. Examples include the estrogenic, androgenic, thyroid and retinoid pathways, in which the EDCs may act directly as agonists or antagonists, or indirectly via other nuclear receptors. Dioxins and dioxin-like EDCs exert their biological and toxicological actions through activation of the aryl hydrocarbon-receptor, which besides inducing transcription of detoxifying enzymes also regulates transcriptional activity of other nuclear receptors. There is increasing evidence that genetic predispositions may modify the susceptibility to adverse effects of toxic chemicals. In this review, potential consequences of hereditary predisposition and EDCs are discussed, with a special focus on the currently available publications on interactions between dioxin and androgen signaling.

  20. Characterization of murine melanocortin receptors mediating adipocyte lipolysis and examination of signalling pathways involved

    DEFF Research Database (Denmark)

    Møller, Cathrine Laustrup; Raun, Kirsten; Jacobsen, Marianne Lambert

    2011-01-01

    The melanocortin receptors (MCRs) belong to the G-protein coupled receptors (family A). So far, 5 different subtypes have been described (MC1R-MC5R) and of these MC2R and MC5R have been proposed to act directly in adipocytes and regulate lipolysis in rodents. Using ACTH and a-melanocyte stimulating...

  1. DMPD: Nuclear receptors in macrophages: a link between metabolism and inflammation. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 18022390 Nuclear receptors in macrophages: a link between metabolism and inflammati...on. Szanto A, Roszer T. FEBS Lett. 2008 Jan 9;582(1):106-16. Epub 2007 Nov 20. (.png) (.svg) (.html) (.csml) Show Nuclear... receptors in macrophages: a link between metabolism and inflammation. PubmedID 18022390 Title Nuclear

  2. Growth Hormone Receptor Signaling Pathways and its Negative Regulation by SOCS2

    DEFF Research Database (Denmark)

    Fernández Pérez, Leandro; Flores-Morales, Amilcar; Guerra, Borja;

    2016-01-01

    development, adulthood, and aging. GHR belongs to a family of receptors without intrinsic kinase activity. However, GH binding to homodimers of GHR results in a conformational change in the receptors and the associated tyrosine kinase Janus kinase 2 (JAK2) molecules. Activated JAK2 phosphorylates the GHR...

  3. TGFβ activated kinase 1 (TAK1 at the crossroad of B cell receptor and Toll-like receptor 9 signaling pathways in human B cells.

    Directory of Open Access Journals (Sweden)

    Dániel Szili

    Full Text Available B cell development and activation are regulated by combined signals mediated by the B cell receptor (BCR, receptors for the B-cell activating factor of the tumor necrosis factor family (BAFF-R and the innate receptor, Toll-like receptor 9 (TLR9. However, the underlying mechanisms by which these signals cooperate in human B cells remain unclear. Our aim was to elucidate the key signaling molecules at the crossroads of BCR, BAFF-R and TLR9 mediated pathways and to follow the functional consequences of costimulation.Therefore we stimulated purified human B cells by combinations of anti-Ig, B-cell activating factor of the tumor necrosis factor family (BAFF and the TLR9 agonist, CpG oligodeoxynucleotide. Phosphorylation status of various signaling molecules, B cell proliferation, cytokine secretion, plasma blast generation and the frequency of IgG producing cells were investigated. We have found that BCR induced signals cooperate with BAFF-R- and TLR9-mediated signals at different levels of cell activation. BCR and BAFF- as well as TLR9 and BAFF-mediated signals cooperate at NFκB activation, while BCR and TLR9 synergistically costimulate mitogen activated protein kinases (MAPKs, ERK, JNK and p38. We show here for the first time that the MAP3K7 (TGF beta activated kinase, TAK1 is responsible for the synergistic costimulation of B cells by BCR and TLR9, resulting in an enhanced cell proliferation, plasma blast generation, cytokine and antibody production. Specific inhibitor of TAK1 as well as knocking down TAK1 by siRNA abrogates the synergistic signals. We conclude that TAK1 is a key regulator of receptor crosstalk between BCR and TLR9, thus plays a critical role in B cell development and activation.

  4. Muscarinic ACh Receptors Contribute to Aversive Olfactory Learning in Drosophila

    Science.gov (United States)

    Silva, Bryon; Molina-Fernández, Claudia; Ugalde, María Beatriz; Tognarelli, Eduardo I.; Angel, Cristian; Campusano, Jorge M.

    2015-01-01

    The most studied form of associative learning in Drosophila consists in pairing an odorant, the conditioned stimulus (CS), with an unconditioned stimulus (US). The timely arrival of the CS and US information to a specific Drosophila brain association region, the mushroom bodies (MB), can induce new olfactory memories. Thus, the MB is considered a coincidence detector. It has been shown that olfactory information is conveyed to the MB through cholinergic inputs that activate acetylcholine (ACh) receptors, while the US is encoded by biogenic amine (BA) systems. In recent years, we have advanced our understanding on the specific neural BA pathways and receptors involved in olfactory learning and memory. However, little information exists on the contribution of cholinergic receptors to this process. Here we evaluate for the first time the proposition that, as in mammals, muscarinic ACh receptors (mAChRs) contribute to memory formation in Drosophila. Our results show that pharmacological and genetic blockade of mAChRs in MB disrupts olfactory aversive memory in larvae. This effect is not explained by an alteration in the ability of animals to respond to odorants or to execute motor programs. These results show that mAChRs in MB contribute to generating olfactory memories in Drosophila. PMID:26380118

  5. Muscarinic ACh Receptors Contribute to Aversive Olfactory Learning in Drosophila

    Directory of Open Access Journals (Sweden)

    Bryon Silva

    2015-01-01

    Full Text Available The most studied form of associative learning in Drosophila consists in pairing an odorant, the conditioned stimulus (CS, with an unconditioned stimulus (US. The timely arrival of the CS and US information to a specific Drosophila brain association region, the mushroom bodies (MB, can induce new olfactory memories. Thus, the MB is considered a coincidence detector. It has been shown that olfactory information is conveyed to the MB through cholinergic inputs that activate acetylcholine (ACh receptors, while the US is encoded by biogenic amine (BA systems. In recent years, we have advanced our understanding on the specific neural BA pathways and receptors involved in olfactory learning and memory. However, little information exists on the contribution of cholinergic receptors to this process. Here we evaluate for the first time the proposition that, as in mammals, muscarinic ACh receptors (mAChRs contribute to memory formation in Drosophila. Our results show that pharmacological and genetic blockade of mAChRs in MB disrupts olfactory aversive memory in larvae. This effect is not explained by an alteration in the ability of animals to respond to odorants or to execute motor programs. These results show that mAChRs in MB contribute to generating olfactory memories in Drosophila.

  6. The role of MAPK and FAS death receptor pathways in testicular germ cell apoptosis induced by lead

    Institute of Scientific and Technical Information of China (English)

    Shuying Dong; Duoping Liang; Na An; Li Jia; Yujuan Shan; Chao Chen; Kuo Sun; Fei Niu; Huiyan Li; Songbin Fu

    2009-01-01

    The aim of the present study is to investigate gene expression involved in the signal pathway of MAPK and death signal receptor pathway of FAS in lead-induced apoptosis of testicular germ cells. First, cell viabilities were determined by MTT assay. Second, using single cell gel-electrophoresis test (comet assay) and TUNEL staining technique, apoptotie rate and cell apoptosis localization of testicular germ cells were measured in mice treated with 0.15%, 0.3%, and 0.6% lead, respectively. Third, the immunolocalization of K-ras, c-fos, Fas, and active caspase-3 proteins was determined by immunohistochemistry. Finally, changes in the translational levels of K-ras, c-fos, Fas, and active caspase-3 were further detected by western blot analysis. Our results showed that lead could significantly induce testicular germ cell apoptosis in a dose-dependent manner (P < 0.01). The mechanisms were closely related to the increased expressions of K-ras, c-fos, Fas, and active caspase-3 in apoptotic germ cells. In conclusion, K-ras/c-fos and Fas/caspase-3 death signaling receptor pathways were involved in the lead-induced apoptosis of the testicular germ cells in mice.

  7. Maternal exposure to hexachlorophene targets intermediate-stage progenitor cells in the hippocampal neurogenesis involving myelin vacuolation of cholinergic and glutamatergic inputs in mice.

    Science.gov (United States)

    Kato, Mizuho; Abe, Hajime; Itahashi, Megu; Kikuchihara, Yoh; Kimura, Masayuki; Mizukami, Sayaka; Yoshida, Toshinori; Shibutani, Makoto

    2016-02-01

    Hexachlorophene (HCP) has been shown to induce myelin vacuolation due to intramyelinic edema of the nerve fibers in animal neural tissue. We investigated the maternal exposure effect of HCP on hippocampal neurogenesis in the offspring of pregnant mice supplemented with 0 (control), 33 or 100 ppm HCP in diet from gestational day 6 to day 21 after delivery. On postnatal day (PND) 21, offspring as examined in males exhibited decreased granule cell lineage populations expressing paired box 6, sex-determining region Y-box 2 and eomesodermin in the hippocampal subgranular zone (SGZ) accompanied by myelin vacuolation involving white matter tracts of the hippocampal fimbria at ≥ 33 ppm. However, SGZ cellular populations expressing brain lipid binding protein and doublecortin were unchanged at any dose. Transcript expression of cholinergic receptor genes, Chrna4 and Chrnb2, and glutamate receptor genes, Grm1 and Grin2d, examined at 100 ppm, decreased in the dentate gyrus. HCP exposure did not alter the number of proliferating or apoptotic cells in the SGZ, or reelin- or calcium-binding protein-expressing γ-aminobutyric acid (GABA)ergic interneurons in the dentate hilus, on PND 21 and PND 77. All neurogenesis-related changes observed in HCP-exposed offspring on PND 21 disappeared on PND 77, suggesting that maternal HCP exposure at ≥ 33 ppm reversibly decreased type 2 intermediate-stage progenitor cells in the hippocampal neurogenesis. Myelin vacuolation might be responsible for changes in neurogenesis possibly by reducing nerve conduction velocity of cholinergic inputs from the septal-hippocampal pathway to granule cell lineages and/or GABAergic interneurons, and of glutamatergic inputs to granule cell lineages.

  8. A Functionally Significant Cross-talk between Androgen Receptor and ErbB2 Pathways in Estrogen Receptor Negative Breast Cancer

    Directory of Open Access Journals (Sweden)

    Ali Naderi

    2008-06-01

    Full Text Available Recent studies have identified novel subgroups in ER-negative breast cancer based on the expression pattern of androgen receptor (AR. One subtype (molecular apocrine has an over-expression of steroid-response genes and ErbB2. Using breast cancer cell lines with molecular apocrine features, we demonstrate a functional cross-talk between AR and ErbB2 pathways. We show that stimulation of AR and ErbB2 pathways leads to the cross-regulation of gene expression for AR, ErbB2, FOXA1, XBP1, TFF3, and KLK3. As opposed to the physiologic transient phosphorylation of extracellular signal–regulated kinase (ERK1/2 observed with the testosterone treatment, we demonstrate that the addition of ErbB2 inhibition leads to a persistent phosphorylation of ERK1/2, which negatively regulates the downstream signaling and cell growth. This suggests a mechanism for the cross-talk involving the ERK pathway. Moreover, testosterone stimulates the proliferation of molecular apocrine breast cell lines, and this effect can be reversed using antiandrogen flutamide and anti-ErbB2 AG825. Conversely, the growth stimulatory effect of heregulin can also be inhibited with flutamide, suggesting a cross-talk between the AR and ErbB2 pathways affecting cell proliferation. Importantly, there is a synergy with the combined use of flutamide and AG825 on cell proliferation and apoptosis, which indicates a therapeutic advantage in the combined blockage of AR and ErbB2 pathways.

  9. A functionally significant cross-talk between androgen receptor and ErbB2 pathways in estrogen receptor negative breast cancer.

    Science.gov (United States)

    Naderi, Ali; Hughes-Davies, Luke

    2008-06-01

    Recent studies have identified novel subgroups in ER-negative breast cancer based on the expression pattern of androgen receptor (AR). One subtype (molecular apocrine) has an over-expression of steroid-response genes and ErbB2. Using breast cancer cell lines with molecular apocrine features, we demonstrate a functional cross-talk between AR and ErbB2 pathways. We show that stimulation of AR and ErbB2 pathways leads to the cross-regulation of gene expression for AR, ErbB2, FOXA1, XBP1, TFF3, and KLK3. As opposed to the physiologic transient phosphorylation of extracellular signal-regulated kinase (ERK1/2) observed with the testosterone treatment, we demonstrate that the addition of ErbB2 inhibition leads to a persistent phosphorylation of ERK1/2, which negatively regulates the downstream signaling and cell growth. This suggests a mechanism for the cross-talk involving the ERK pathway. Moreover, testosterone stimulates the proliferation of molecular apocrine breast cell lines, and this effect can be reversed using antiandrogen flutamide and anti-ErbB2 AG825. Conversely, the growth stimulatory effect of heregulin can also be inhibited with flutamide, suggesting a cross-talk between the AR and ErbB2 pathways affecting cell proliferation. Importantly, there is a synergy with the combined use of flutamide and AG825 on cell proliferation and apoptosis, which indicates a therapeutic advantage in the combined blockage of AR and ErbB2 pathways.

  10. Effects of Liver × receptor agonist treatment on signal transduction pathways in acute lung inflammation

    Directory of Open Access Journals (Sweden)

    Bramanti Placido

    2010-02-01

    Full Text Available Abstract Background Liver × receptor α (LXRα and β (LXRβ are members of the nuclear receptor super family of ligand-activated transcription factors, a super family which includes the perhaps better known glucocorticoid receptor, estrogen receptor, thyroid receptor, and peroxisome proliferator-activated receptors. There is limited evidence that LXL activation may reduces acute lung inflammation. The aim of this study was to investigate the effects of T0901317, a potent LXR receptor ligand, in a mouse model of carrageenan-induced pleurisy. Methods Injection of carrageenan into the pleural cavity of mice elicited an acute inflammatory response characterized by: accumulation of fluid containing a large number of neutrophils (PMNs in the pleural cavity, infiltration of PMNs in lung tissues and subsequent lipid peroxidation, and increased production of nitrite/nitrate (NOx, tumor necrosis factor-α, (TNF-α and interleukin-1β (IL-1β. Furthermore, carrageenan induced the expression of iNOS, nitrotyrosine and PARP, as well as induced apoptosis (TUNEL staining and Bax and Bcl-2 expression in the lung tissues. Results Administration of T0901317, 30 min after the challenge with carrageenan, caused a significant reduction in a dose dependent manner of all the parameters of inflammation measured. Conclusions Thus, based on these findings we propose that LXR ligand such as T0901317, may be useful in the treatment of various inflammatory diseases.

  11. A protein phosphatase is involved in the cholinergic suppression of the Ca(2+)-activated K(+) current sI(AHP) in hippocampal pyramidal neurons.

    Science.gov (United States)

    Krause, M; Pedarzani, P

    2000-04-27

    The slow calcium-activated potassium current sI(AHP) underlies spike-frequency adaptation and has a substantial impact on the excitability of hippocampal CA1 pyramidal neurons. Among other neuromodulatory substances, sI(AHP) is modulated by acetylcholine acting via muscarinic receptors. The second-messenger systems mediating the suppression of sI(AHP) by muscarinic agonists are largely unknown. Both protein kinase C and A do not seem to be involved, whereas calcium calmodulin kinase II has been shown to take part in the muscarinic action on sI(AHP). We re-examined the mechanism of action of muscarinic agonists on sI(AHP) combining whole-cell recordings with the use of specific inhibitors or activators of putative constituents of the muscarinic pathway. Our results suggest that activation of muscarinic receptors reduces sI(AHP) in a G-protein-mediated and phospholipase C-independent manner. Furthermore, we obtained evidence for the involvement of the cGMP-cGK pathway and of a protein phosphatase in the cholinergic suppression of sI(AHP), whereas release of Ca(2+) from IP(3)-sensitive stores seems to be relevant neither for maintenance nor for modulation of sI(AHP).

  12. Convergent Signaling Pathways Controlled by LRP1 (Receptor-related Protein 1) Cytoplasmic and Extracellular Domains Limit Cellular Cholesterol Accumulation.

    Science.gov (United States)

    El Asmar, Zeina; Terrand, Jérome; Jenty, Marion; Host, Lionel; Mlih, Mohamed; Zerr, Aurélie; Justiniano, Hélène; Matz, Rachel L; Boudier, Christian; Scholler, Estelle; Garnier, Jean-Marie; Bertaccini, Diego; Thiersé, Danièle; Schaeffer, Christine; Van Dorsselaer, Alain; Herz, Joachim; Bruban, Véronique; Boucher, Philippe

    2016-03-04

    The low density lipoprotein receptor-related protein 1 (LRP1) is a ubiquitously expressed cell surface receptor that protects from intracellular cholesterol accumulation. However, the underlying mechanisms are unknown. Here we show that the extracellular (α) chain of LRP1 mediates TGFβ-induced enhancement of Wnt5a, which limits intracellular cholesterol accumulation by inhibiting cholesterol biosynthesis and by promoting cholesterol export. Moreover, we demonstrate that the cytoplasmic (β) chain of LRP1 suffices to limit cholesterol accumulation in LRP1(-/-) cells. Through binding of Erk2 to the second of its carboxyl-terminal NPXY motifs, LRP1 β-chain positively regulates the expression of ATP binding cassette transporter A1 (ABCA1) and of neutral cholesterol ester hydrolase (NCEH1). These results highlight the unexpected functions of LRP1 and the canonical Wnt5a pathway and new therapeutic potential in cholesterol-associated disorders including cardiovascular diseases.

  13. Multiple motifs regulate the trafficking of GABA(B) receptors at distinct checkpoints within the secretory pathway.

    Science.gov (United States)

    Restituito, Sophie; Couve, Andrés; Bawagan, Hinayana; Jourdain, Sabine; Pangalos, Menelas N; Calver, Andrew R; Freeman, Katie B; Moss, Stephen J

    2005-04-01

    gamma-Aminobutyric acid type B receptors (GABA(B)) are G-protein-coupled receptors that mediate GABAergic inhibition in the brain. Their functional expression is dependent upon the formation of heterodimers between GABA(B)R1 and GABA(B)R2 subunits, a process that occurs within the endoplasmic reticulum (ER). However, the mechanisms that regulate receptor surface expression remain largely unknown. Here, we demonstrate that access to the cell surface for GABA(B)R1 is sequentially controlled by an RSR(R) motif and a LL motif within its cytoplasmic domain. In addition, we reveal that msec7-1, a guanine-nucleotide-exchange factor (GEF) for the ADP-ribosylation factor (ARF) family of GTPases, critical regulators of vesicular membrane trafficking, interacts with GABA(B)R1 via the LL motif in this subunit. Finally, we establish that msec7-1 modulates the cell surface expression of GABA(B) receptors, a process that is dependent upon the integrity of the LL motif in GABA(B)R1. Together, our results demonstrate that the cell surface expression of the GABA(B)R1 subunit is regulated by multiple motifs, which act at distinct checkpoints in the secretory pathway, and also suggest a novel role for msec7-1 in regulating the membrane trafficking of GABA(B)R1 subunits.

  14. Multiple signaling pathways involved in stimulation of osteoblast differentiation by N-methyl-D-aspartate receptors activation in vitro

    Institute of Scientific and Technical Information of China (English)

    Jie-li LI; Lin ZHAO; Bin CUI; Lian-fu DENG; Guang NING; Jian-min LIU

    2011-01-01

    Aim: Glutamate receptors are expressed in osteoblastic cells. The present study was undertaken to investigate the mechanisms underlying the stimulation of osteoblast differentiation by N-methyl-D-aspartate (NMDA) receptor activation in vitro.Methods: Primary culture of osteoblasts was prepared from SD rats. Microarray was used to detect the changes of gene expression.The effect of NMDA receptor agonist or antagonist on individual gene was examined using RT-PCR. The activity of alkaloid phosphotase (ALP) was assessed using a commercial ALP staining kit.Results: Microarray analyses revealed that 10 genes were up-regulated by NMDA (0.5 mmol/L) and down-regulated by MK801 (100μmol/L), while 13 genes down-regulated by NMDA (0.5 mmol/L) and up-regulated by MK801 (100 μmol/L). Pretreatment of osteoblasts with the specific PKC inhibitor Calphostin C (0.05 μmol/L), the PKA inhibitor H-89 (20 nmol/L), or the PI3K inhibitor wortmannin (100 nmol/L) blocked the ALP activity increase caused by NMDA (0.5 mmol/L). Furthermore, NMDA (0.5 mmol/L) rapidly increased PI3K phosphorylation, which could be blocked by pretreatment of wortmannin (100 nmol/L).Conclusion: The results suggest that activation of NMDA receptors stimulates osteoblasts differentiation through PKA, PKC, and PI3K signaling pathways, which is a new role for glutamate in regulating bone remodeling.

  15. Negative regulation of opioid receptor-G protein-Ca2+ channel pathway by the nootropic nefiracetam.

    Science.gov (United States)

    Yoshii, Mitsunobu; Furukawa, Taiji; Ogihara, Yoshiyasu; Watabe, Shigeo; Shiotani, Tadashi; Ishikawa, Yasuro; Nishimura, Masao; Nukada, Toshihide

    2004-10-01

    It has recently been reported that nefiracetam, a nootropic agent, is capable of attenuating the development of morphine dependence and tolerance in mice. The mechanism of this antimorphine action is not clear. The present study was designed to address this issue using Xenopus oocytes expressing delta-opioid receptors, G proteins (G(i3alpha) or G(o1alpha)), and N-type (alpha1B) Ca2+ channels. Membrane currents through Ca2+ channels were recorded from the oocytes under voltage-clamp conditions. The Ca2+ channel currents were reduced reversibly by 40-60% in the presence of 1 microM leucine-enkephalin (Leu-Enk). The Leu-Enk-induced current inhibition was recovered promptly by nefiracetam (1 microM), while control currents in the absence of Leu-Enk were not influenced by nefiracetam. A binding assay revealed that 3H-nefiracetam preferentially bound to the membrane fraction of oocytes expressing G(i3alpha). When delta-opioid receptors were coexpressed, the binding was significantly increased. However, an additional expression of alpha1B Ca2+ channels decreased the binding. The results suggest that nefiracetam preferentially binds to G(i3alpha) associated with delta-opioid receptors, thereby inhibiting the association of G proteins with Ca2+ channels. In conclusion, nefiracetam negatively regulates the inhibitory pathway of opioid receptor-G protein-Ca2+ channel.

  16. The gastric CB1 receptor modulates ghrelin production through the mTOR pathway to regulate food intake.

    Directory of Open Access Journals (Sweden)

    Lucia L Senin

    Full Text Available Over the years, the knowledge regarding the relevance of the cannabinoid system to the regulation of metabolism has grown steadily. A central interaction between the cannabinoid system and ghrelin has been suggested to regulate food intake. Although the stomach is the main source of ghrelin and CB1 receptor expression in the stomach has been described, little information is available regarding the possible interaction between the gastric cannabinoid and ghrelin systems in the integrated control of energy homeostasis. The main objective of the present work was to assess the functional interaction between these two systems in terms of food intake using a combination of in vivo and in vitro approaches. The present work demonstrates that the peripheral blockade of the CB1 receptor by rimonabant treatment decreased food intake but only in food-deprived animals. This anorexigenic effect is likely a consequence of decreases in gastric ghrelin secretion induced by the activation of the mTOR/S6K1 intracellular pathway in the stomach following treatment with rimonabant. In support of this supposition, animals in which the mTOR/S6K1 intracellular pathway was blocked by chronic rapamycin treatment, rimonabant had no effect on ghrelin secretion. Vagal communication may also be involved because rimonabant treatment was no longer effective when administered to animals that had undergone surgical vagotomy. In conclusion, to the best of our knowledge, the present work is the first to describe a CB1 receptor-mediated mechanism that influences gastric ghrelin secretion and food intake through the mTOR pathway.

  17. Inflammatory receptors and pathways in human NT2-N neurons during hypoxia and reoxygenation. Impact of acidosis.

    Science.gov (United States)

    Frøyland, Elisabeth; Skjaeret, Camilla; Wright, Marianne S; Dalen, Marit Lunde; Cvancarova, Milada; Kasi, Cecilie; Rootwelt, Terje

    2008-06-27

    Cytokines are released in response to brain injury and inflammation. By binding to receptors, they can cause, exacerbate or inhibit cellular injury and repair. We studied RNA expression of cytokine receptors and members of inflammatory pathways in human NT2-N neurons during 3 h of hypoxia and glucose deprivation followed by 21 h of reoxygenation, and the impact of acidosis. Right after acidotic hypoxia, RNA of IL-10RA and CXCR4 were significantly increased relative to acidotic control, while Bcl-2 and Bcl-xL were significantly decreased. After 21 h of neutral reoxygenation after neutral hypoxia, there was a significant increase in RNA of CXCR1 (relative quantification (RQ)=4.1, p<0.05), CXCR2 (3.6, p<0.05), CCR2 (3.8, p<0.05), Hsp70 (2.4, p<0.05), HIF-1alpha (1.5, p<0.001), TRAF6 (1.3, p<0.05) and TNFR1 (1.6, p<0.05). After 21 h of acidotic reoxygenation after acidotic hypoxia, we found a significant increase in RNA of IL-1R1, IL-10RA, CXCR4 and Hsp70 compared to control, and a significant decrease in FAS and TRAF6. There was a significant increase in Bax expression and a significant decrease in Bcl-2 and Bcl-xL expression in three out of four pH groups after 21 h of reoxygenation. Acidotic, relative to neutral, hypoxia and reoxygenation also influenced the expression of various genes. We conclude that inflammatory receptors and pathways are activated during hypoxia and reoxygenation in NT2-N neurons, and that this activation is pH dependent. This supports the concept that inflammatory pathways play a role in cerebral hypoxic-ischemic damage, and that they may represent important pharmacological targets.

  18. Uterine and placental expression of TRPV6 gene is regulated via progesterone receptor- or estrogen receptor-mediated pathways during pregnancy in rodents

    Directory of Open Access Journals (Sweden)

    Choi Kyung-Chul

    2009-05-01

    Full Text Available Abstract Transient receptor potential cation channel, subfamily V, member 6 (TRPV6 is an epithelial Ca2+ channel protein expressed in calcium absorbing organs. In the present study, we investigated the expression and regulation of uterine and placental TRPV6 during gestation in rodents. Uterine TRPV6 peaked at pregnancy day (P 0.5, P5.5 and, P13.5 and was detected in uterine epithelium and glands of rats, while placental TRPV6 mRNA levels increased in mid-gestation. Uterine and placental TRPV6 mRNA levels in rats appear to cyclically change during pregnancy, suggesting that TRPV6 may participate in the implantation process. In addition, uterine TRPV6 mRNA is only expressed in placenta-unattached areas of the uterus, and uterine TRPV6 immunoreactivity was observed in luminal and glandular epithelial cells. In the placenta, TRPV6 was detected in the labyrinth and spongy zone. These results may indicate that TRPV6 has at least two functions: implantation of the embryo and maintenance of pregnancy. To investigate the pathway(s mediating TRPV6 expression in rodents, anti-steroid hormone antagonists were injected prior to maximal TRPV6 expression. In rats, TRPV6 expression was reduced by RU486 (an anti-progesterone through progesterone receptors, and ICI 182,780 (an anti-estrogen blocked TRPV6 expression via estrogen receptors in mice. The juxtaposition of uterine and placental TRPV6 expressed in these tissues supports the notion that TRPV6 participates in transferring calcium ions between the maternal and fetal compartments. Taken together, TRPV6 gene may function as a key element in controlling calcium transport in the uterus between the embryo and the placenta during pregnancy.

  19. Decrease of a Current Mediated by Kv1.3 Channels Causes Striatal Cholinergic Interneuron Hyperexcitability in Experimental Parkinsonism

    Directory of Open Access Journals (Sweden)

    Cecilia Tubert

    2016-09-01

    Full Text Available The mechanism underlying a hypercholinergic state in Parkinson’s disease (PD remains uncertain. Here, we show that disruption of the Kv1 channel-mediated function causes hyperexcitability of striatal cholinergic interneurons in a mouse model of PD. Specifically, our data reveal that Kv1 channels containing Kv1.3 subunits contribute significantly to the orphan potassium current known as IsAHP in striatal cholinergic interneurons. Typically, this Kv1 current provides negative feedback to depolarization that limits burst firing and slows the tonic activity of cholinergic interneurons. However, such inhibitory control of cholinergic interneuron excitability by Kv1.3-mediated current is markedly diminished in the parkinsonian striatum, suggesting that targeting Kv1.3 subunits and their regulatory pathways may have therapeutic potential in PD therapy. These studies reveal unexpected roles of Kv1.3 subunit-containing channels in the regulation of firing patterns of striatal cholinergic interneurons, which were thought to be largely dependent on KCa channels.

  20. 毒蕈碱乙酰胆碱M2/M4受体亚型在调节脊髓背角神经元谷氨酸能递质释放中的作用%Role of muscarinic cholinergic receptor subtypes in regulating glutamatergic synaptic transmission in rat spinal dorsal horn

    Institute of Scientific and Technical Information of China (English)

    杜威; 郭英; 袁维秀

    2013-01-01

    Objective To investigate the role of muscarinic cholinergic receptor (mAChR) subtypes in the regulation of glutamatergic input to the spinal dorsal horn neurons and the possible mechanism.Methods Whole-cell voltage-clamp recordings on acute spinal slice was utilized to investigate the effect of activation of mAChRs and blockade of M2/M4 subtypes on glutamatergic synaptic transmission in rat spinal dorsal horn neurons.Results The nonselective mAChRs agonist oxotremorine-M concentration-dependently decreased the amplitude of monosynaptic and polysynaptic evoked glutamate-mediated excitatory postsynaptic currents (eEPSCs) in most of the neurons.The M2/M4 antagonist himbacine completely blocked the inhibitory effect of oxotremorine-M in 92.3% of monosynaptic and 75% of polysynaptic neurons in the spinal cord slices.In the remaining 16% neurons,himbacine partially blocked the inhibitory effect of oxotremorine-M.Conclusions Activation of mAChRs in the spinal cord attenuates synaptic glutamate release to the dorsal horn neurons mainly through M2 and M4 receptor subtypes,indicating that a presynaptic inhibition in the spinal cord may be involved in the regulation of nociception by the cholinergic system and mAChRs.%目的 研究毒蕈碱胆碱能受体(mAChRs)亚型对脊髓背角感觉神经元谷氨酸能突触传递的调节机制.方法 在急性切取的腰段脊髓切片上,利用全细胞膜片钳法记录mAChRs非特异性激动剂氢化震颤素M(Oxo-M)对脊髓背角浅层神经元谷氨酸能兴奋性突触后电流(eEPSCs)的影响,给予M2/M4受体特异性拮抗剂喜巴辛,观察mAChRs在脊髓背角浅层神经元谷氨酸能递质释放调节过程中的作用.结果 不同浓度Oxo-M使脊髓背角神经元单突触和多突触eEPSCs的幅度显著降低,其抑制强度呈浓度依赖性,喜巴辛可以拮抗Oxo-M对刺激诱发eEPSCs幅度的抑制作用,在记录的25个细胞中,92.3%的单突触细胞和75%的多突触细胞表现为Oxo-M

  1. DMPD: A novel negative regulator for IL-1 receptor and Toll-like receptor 4. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available ion Immunol Lett. 2005 Jan 15;96(1):27-31. Pathway - PNG File (.png) SVG File (.svg) HTML File (.html) CSML File (.csml) Open .csm...w FY, Liu H, Xu D. Immunol Lett. 2005 Jan 15;96(1):27-31. (.png) (.svg) (.html) (.csml) Show A novel negativ...l file with CIOPlayer Open .csml file with CIOPlayer - ※CIO Playerのご利用上の注意 Open .csml file with CIO Open .csml file with CIO - ※CIOのご利用上の注意 ...

  2. Regulated release of BDNF by cortical oligodendrocytes is mediated through metabotropic glutamate receptors and the PLC pathway

    Directory of Open Access Journals (Sweden)

    Issa P Bagayogo

    2009-04-01

    Full Text Available A number of studies suggest that OLGs (oligodendrocytes), the myelinating cells of the central nervous system, are also a source of trophic molecules, such as neurotrophins that may influence survival of proximate neurons. What is less clear is how the release of these molecules may be regulated. The present study investigated the effects of BDNF (brain-derived neurotrophic factor) derived from cortical OLGs on proximate neurons, as well as regulatory mechanisms mediating BDNF release. Initial work determined that BDNF derived from cortical OLGs increased the numbers of VGLUT1 (vesicular glutamate transporter 1)-positive glutamatergic cortical neurons. Furthermore, glutamate acting through metabotropic, and not AMPA/kainate or NMDA (N-methyl-d-aspartate), receptors increased BDNF release. The PLC (phospholipase C) pathway is a key mediator of metabotropic actions to release BDNF in astrocytes and neurons. Treatment of OLGs with the PLC activator m-3M3FBS [N-(3-trifluoromethylphenyl)-2,4,6-trimethylbenzenesulfonamide] induced robust release of BDNF. Moreover, release elicited by the metabotropic receptor agonist ACPD [trans-(1S,3R)-1-aminocyclopentane-1,3-dicarboxylic acid] was inhibited by the PLC antagonist U73122, the IP3 (inositol triphosphate 3) receptor inhibitor 2-APB (2-aminoethoxydiphenylborane) and the intracellular calcium chelator BAPTA/AM [1,2-bis-(o-aminophenoxy)ethane-N,N,N′,N′-tetra-acetic acid tetrakis(acetoxymethyl ester)]. Taken together, these results suggest that OLG lineage cells release BDNF, a molecule trophic for proximate neurons. BDNF release is regulated by glutamate acting through mGluRs (metabotropic glutamate receptors) and the PLC pathway. Thus glutamate and BDNF may be molecules that support neuron–OLG interactions in the cortex.

  3. Expression of the spinal 5-HT7 receptor and p-ERK pathway in the carrageenan inflammatory pain of rats

    OpenAIRE

    Cho, Soo Young; Ki, Hyoung Gon; Kim, Joung Min; Oh, Jin Myung; Yang, Ji Hoon; Kim, Woong Mo; Lee, Hyung Gon; Yoon, Myung Ha; Choi, Jeong Il

    2015-01-01

    Background Although the inhibitory role of the 5-hydroxytrypatmine receptor 7(5-HT7R) on nociceptive processing is generally recognized, an excitatory effect associated with a reduced 5-HT7R expression has also been observed in the nerve injury model. In the carrageenan model, no significant effect is produced by the 5-HT7R activation, but the change in 5-HT7R expression has not been examined. Lesioning of the spinal serotonergic pathway enhances allodynia in the carrageenan model, but it als...

  4. The Degradation Pathway of the Mitophagy Receptor Atg32 Is Re-Routed by a Posttranslational Modification.

    Science.gov (United States)

    Levchenko, Mariia; Lorenzi, Isotta; Dudek, Jan

    2016-01-01

    The outer mitochondrial membrane protein Atg32 is the central receptor for mitophagy, the mitochondria-specific form of autophagy. Atg32 is an unstable protein, and is rapidly degraded under conditions in which mitophagy is not induced. Here we show that Atg32 undergoes a posttranslational modification upon induction of mitophagy. The modification is dependent on the core autophagic machinery, including Atg8, and on the mitophagy-specific adaptor protein Atg11. The modified Atg32 is targeted to the vacuole where it becomes stabilized when vacuolar proteases are deficient. Interestingly, we find that this degradation pathway differs from the degradation pathway of non-modified Atg32, which neither involves vacuolar proteases, nor the proteasome. These analyses reveal that a posttranslational modification discriminates a form of Atg32 targeting mitochondria for mitophagy from that, which escapes mitophagy by rapid degradation.

  5. Endosomal sorting of Notch receptors through COMMD9-dependent pathways modulates Notch signaling

    NARCIS (Netherlands)

    Li, H.; Koo, Y.; Mao, X.; Sifuentes-Dominguez, L.; Morris, L.L.; Jia, D.; Miyata, N; Faulkner, R.A.; Deursen, J.M.A. van; Vooijs, M.; Billadeau, D.D.; Sluis, B. van de; Cleaver, O.; Burstein, E.

    2015-01-01

    Notch family members are transmembrane receptors that mediate essential developmental programs. Upon ligand binding, a proteolytic event releases the intracellular domain of Notch, which translocates to the nucleus to regulate gene transcription. In addition, Notch trafficking across the endolysosom

  6. Neuropeptide Y inhibits the trigeminovascular pathway through NPY Y1 receptor: implications for migraine.

    Science.gov (United States)

    Oliveira, Margarida-Martins; Akerman, Simon; Tavares, Isaura; Goadsby, Peter J

    2016-08-01

    Migraine is a painful neurologic disorder with premonitory symptomatology that can include disturbed appetite. Migraine pathophysiology involves abnormal activation of trigeminocervical complex (TCC) neurons. Neuropeptide Y (NPY) is synthesized in the brain and is involved in pain modulation. NPY receptors are present in trigeminal ganglia and trigeminal nucleus caudalis suggesting a role in migraine pathophysiology. The present study aimed to determine the effect of systemic administration of NPY on TCC neuronal activity in response to dural nociceptive trigeminovascular activation. We performed in vivo electrophysiology in anesthetized rats, administered NPY (10, 30, and 100 µg·kg), and investigated the receptors involved by studying NPY Y1 (30 µg·kg), Y2 (30 µg·kg), and Y5 receptor agonists (100·µg·kg), and NPY Y1 receptor antagonist (30 µg·kg). NPY (30 and 100 µg·kg) significantly reduced TCC neuronal firing in response to dural-evoked trigeminovascular activation, but only NPY (30 µg·kg) significantly reduced spontaneous trigeminal firing. NPY Y1 receptor agonist also significantly reduced dural-evoked and spontaneous TCC neuronal firing. NPY (10 µg·kg), NPY Y2, and Y5 receptor agonists, and the NPY Y1 receptor antagonist had no significant effects on nociceptive dural-evoked neuronal firing in the TCC or spontaneous trigeminal firing. This study demonstrates that NPY dose dependently inhibits dural-evoked trigeminal activity, through NPY Y1 receptor activation, indicating antinociceptive actions of NPY in a migraine animal model. Based on the role of NPY in appetite regulation, it is possible that disruption of the NPY system might explain changes of appetite in migraineurs.

  7. Effects of eccentric exercise on toll-like receptor 4 signaling pathway in peripheral blood mononuclear cells.

    Science.gov (United States)

    Fernandez-Gonzalo, Rodrigo; De Paz, José A; Rodriguez-Miguelez, Paula; Cuevas, María J; González-Gallego, Javier

    2012-06-01

    This study aimed to investigate the response of the toll-like receptor 4 (TLR4) signaling pathway to an acute bout of eccentric exercise, and to assess whether eccentric training attenuated the effects induced by acute eccentric exercise. Twenty men (22.4 ± 0.5 yr) were divided into a control group (CG, n = 8) and a training group (TG, n = 12). Both groups performed two acute eccentric bouts on a squat machine in a 9-wk interval. During this time, TG followed a 6-wk eccentric training program (3 session/wk; 3-5 sets of 10 repetitions with loads ranging between the 40 and 50% of maximal isometric voluntary contraction). CD14, TLR4, and TNF-α mRNA levels, and CD14, TLR4, myeloid differentiation factor 88, tumor necrosis factor receptor-associated factor 6, TIR-domain-containing adapter-inducing interferon-β, phospho-IκB kinases, phospho-IκB, phospho-ERK-1/2, and TNF-α protein concentration were measured in peripheral blood mononuclear cells, before, immediately, and 2 h after each eccentric bout. The first acute eccentric bout triggered a proinflammatory response mediated by an upregulation of all of the factors measured within the TLR4 signaling pathway. Following the training period and after the second acute bout, CG showed a similar proinflammatory response than that seen after the first bout. However, the eccentric training intervention decreased significantly the protein concentration of all factors analyzed in TG compared with results obtained after the first bout. These results suggest that the TLR4-signaling pathway plays a critical role in the proinflammatory response seen after acute eccentric exercise. This response was attenuated after an eccentric training program through myeloid differentiation factor 88-dependent and -independent pathways.

  8. Chlamydial Lipoproteins Stimulate Toll-Like Receptors 1/2 Mediated Inflammatory Responses through MyD88-Dependent Pathway

    Science.gov (United States)

    Wang, Yong; Liu, Qiong; Chen, Ding; Guan, Jie; Ma, Linghui; Zhong, Guangming; Shu, Hengping; Wu, Xiang

    2017-01-01

    Chlamydiae are very important pathogens which could cause several types of diseases in human, but little is known about its pathogenic mechanism. In order to elucidate host inflammatory response and the signal pathway induced by Chlamydial lipoproteins, the predicted lipoproteins of Chlamydia trachomatis were tested for their ability to induce the release of proinflammatory cytokines by mouse macrophages or human TLR (Toll-Like Receptor) expressing cell lines. The results showed that recombinant proteins of C. trachomatis D381, D541, D067, and D775 displayed a strong ability to induce the release of IL-8 in TLR expressing cell line. The signal pathways involved TLR1/2 and TLR2/CD14 but not TLR4. Moreover, except D067, the proinflammatory cytokine induction by D381, D541, and D775 required the thioacylation site (cysteine) for lipid modification and the induction was through MyD88-mediated pathway. Our data supported that lipoproteins played a vital role in pathogenesis of C. trachomatis-induced inflammatory responses via TLR pathway. It was the first study to characterize other chlamydial lipoproteins after identifying the role of MIP (D541) on pathogenesis of Chlamydial diseases. PMID:28184217

  9. Involvement of Toll-Like Receptor 2 and Pro-Apoptotic Signaling Pathways in Bone Remodeling in Osteomyelitis

    Directory of Open Access Journals (Sweden)

    Qianbo Chen

    2014-11-01

    Full Text Available Background and Aims: Osteomyelitis is a common manifestation of invasive Staphylococcus aureus infection characterized by bone loss and destruction. We investigated the role of toll-like receptor 2 (TLR2 in bacterial recognition and clearance in response to infection with an osteomyelitis isolate of S. aureus. Methods: Apoptosis was assessed in the osteoblastic cell line MC3T3-E1 by Annexin V-FITC/PI staining and flow cytometry. The expression of TLR2 and apoptosis-related and mitogen-activated protein kinase pathway proteins was assessed by qRT-PCR and western blotting. Alkaline phosphatase (ALP activity and calcium deposition were assessed by ALP activity assay and Alizarin red staining. Results: S. aureus induced apoptosis, upregulated TLR2 expression, and activated mitogen-activated protein kinase pathways in a time dependent manner. Inhibition of the c-Jun N-terminal kinase (JNK pathway downregulated TLR2 and suppressed the S. aureus induced activation of pro-apoptotic pathways. Short-hairpin RNA mediated silencing of TLR2 reversed S. aureus induced apoptosis and decrease in ALP activity and calcium deposition, and inhibition of JNK had a similar effect. Conclusion: We showed that osteoblast apoptosis and osteogenic differentiation in response to bacterial invasion are dependent on TLR2 expression and JNK activation, suggesting novel potential therapeutic targets for the treatment of osteomyelitis.

  10. Signal transduction mediated by Bid, a pro-death Bcl-2 family proteins, connects the death receptor and mitochondria apoptosis pathways

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Two major apoptosis pathways have been defined in mammalian cells, the Fas/TNF-R1 death receptor pathway and the mitochondria pathway. The Bcl-2 family proteins consist of both anti-apoptosis and pro- apoptosis members that regulate apoptosis, mainly by controlling the release of cytochrome c and other mitochondrial apoptotic events. However, death signals mediated by Fas/TNF-R1 receptors can usually activate caspases directly, bypassing the need for mitochondria and escaping the regulation by Bcl-2 family proteins. Bid is a novel pro-apoptosis Bcl-2 family protein that is activated by caspase 8 in response to Fas/TNF-R1 death receptor signals. Activated Bid is translocated to mitochondria and induces cytochrome c release, which in turn activates downstream caspases. Such a connection between the two apoptosis pathways could be important for induction of apoptosis in certain types of cells and responsible for the pathogenesis of a number of human diseases.

  11. Impact of basal forebrain cholinergic inputs on basolateral amygdala neurons.

    Science.gov (United States)

    Unal, Cagri T; Pare, Denis; Zaborszky, Laszlo

    2015-01-14

    In addition to innervating the cerebral cortex, basal forebrain cholinergic (BFc) neurons send a dense projection to the basolateral nucleus of the amygdala (BLA). In this study, we investigated the effect of near physiological acetylcholine release on BLA neurons using optogenetic tools and in vitro patch-clamp recordings. Adult transgenic mice expressing cre-recombinase under the choline acetyltransferase promoter were used to selectively transduce BFc neurons with channelrhodopsin-2 and a reporter through the injection of an adeno-associated virus. Light-induced stimulation of BFc axons produced different effects depending on the BLA cell type. In late-firing interneurons, BFc inputs elicited fast nicotinic EPSPs. In contrast, no response could be detected in fast-spiking interneurons. In principal BLA neurons, two different effects were elicited depending on their activity level. When principal BLA neurons were quiescent or made to fire at low rates by depolarizing current injection, light-induced activation of BFc axons elicited muscarinic IPSPs. In contrast, with stronger depolarizing currents, eliciting firing above ∼ 6-8 Hz, these muscarinic IPSPs lost their efficacy because stimulation of BFc inputs prolonged current-evoked afterdepolarizations. All the effects observed in principal neurons were dependent on muscarinic receptors type 1, engaging different intracellular mechanisms in a state-dependent manner. Overall, our results suggest that acetylcholine enhances the signal-to-noise ratio in principal BLA neurons. Moreover, the cholinergic engagement of afterdepolarizations may contribute to the formation of stimulus associations during fear-conditioning tasks where the timing of conditioned and unconditioned stimuli is not optimal for the induction of synaptic plasticity.

  12. Mechanisms of activation of nucleus accumbens neurons by cocaine via sigma-1 receptor-inositol 1,4,5-trisphosphate-transient receptor potential canonical channel pathways.

    Science.gov (United States)

    Barr, Jeffrey L; Deliu, Elena; Brailoiu, G Cristina; Zhao, Pingwei; Yan, Guang; Abood, Mary E; Unterwald, Ellen M; Brailoiu, Eugen

    2015-08-01

    Cocaine promotes addictive behavior primarily by blocking the dopamine transporter, thus increasing dopamine transmission in the nucleus accumbens (nAcc); however, additional mechanisms are continually emerging. Sigma-1 receptors (σ1Rs) are known targets for cocaine, yet the mechanisms underlying σ1R-mediated effects of cocaine are incompletely understood. The present study examined direct effects of cocaine on dissociated nAcc neurons expressing phosphatidylinositol-linked D1 receptors. Endoplasmic reticulum-located σ1Rs and inositol 1,4,5-trisphosphate (IP3) receptors (IP3Rs) were targeted using intracellular microinjection. IP3 microinjection robustly elevated intracellular Ca(2+) concentration, [Ca(2+)]i. While cocaine alone was devoid of an effect, the IP3-induced response was σ1R-dependently enhanced by cocaine co-injection. Likewise, cocaine augmented the [Ca(2+)]i increase elicited by extracellularly applying an IP3-generating molecule (ATP), via σ1Rs. The cocaine-induced enhancement of the IP3/ATP-mediated Ca(2+) elevation occurred at pharmacologically relevant concentrations and was mediated by transient receptor potential canonical channels (TRPC). IP3 microinjection elicited a slight, transient depolarization, further converted to a greatly enhanced, prolonged response, by cocaine co-injection. The cocaine-triggered augmentation was σ1R-dependent, TRPC-mediated and contingent on [Ca(2+)]i elevation. ATP-induced depolarization was similarly enhanced by cocaine. Thus, we identify a novel mechanism by which cocaine promotes activation of D1-expressing nAcc neurons: enhancement of IP3R-mediated responses via σ1R activation at the endoplasmic reticulum, resulting in augmented Ca(2+) release and amplified depolarization due to subsequent stimulation of TRPC. In vivo, intra-accumbal blockade of σ1R or TRPC significantly diminished cocaine-induced hyperlocomotion and locomotor sensitization, endorsing a physio-pathological significance of the pathway

  13. THE ROLE OF VENTRAL MIDLINE THALAMUS IN CHOLINERGIC-BASED RECOVERY IN THE AMNESTIC RAT

    Science.gov (United States)

    Bobal, Michael G.; Savage, Lisa M.

    2014-01-01

    The thalamus is a critical node for several pathways involved in learning and memory. Damage to the thalamus by trauma, disease or malnourishment can impact the effectiveness of the prefrontal cortex (PFC) and hippocampus (HPC) and lead to a profound amnesia state. Using the pyrithiamine-induced thiamine deficiency (PTD) rat model of human Wernicke-Korsakoff syndrome, we tested the hypothesis that co-infusion of the acetylcholinesterase inhibitor physostigmine across the PFC and HPC would recover spatial alternation performance in PTD rats. When cholinergic tone was increased by dual injections across the PFC-HPC, spontaneous alternation performance in PTD rats was recovered. In addition, we tested a second hypothesis that two ventral midline thalamic nuclei, the rhomboid nucleus and nucleus reuniens (Rh-Re), form a critical node needed for the recovery of function observed when cholinergic tone was increased across the PFC and HPC. By using the GABAA agonist muscimol to temporarily deactivate the Rh-Re the recovery of alternation behavior obtained in the PTD model by cholinergic stimulation across the PFC-HPC was blocked. In control pair-fed (PF) rats, inactivation of the Rh-Re impaired spontaneous alternation. However, when inactivation of the Rh-Re co-occurred with physostigmine infusions across the PFC-HPC, PF rats had normal performance. These results further demonstrate that the Rh-Re is critical in facilitating interactions between the HPC and PFC, but other redundant pathways also exist. PMID:25446352

  14. Acetylcholinesterase loosens the brain's cholinergic anti-inflammatory response and promotes epileptogenesis

    Directory of Open Access Journals (Sweden)

    Yehudit eGnatek

    2012-05-01

    Full Text Available Recent studies show a key role of brain inflammation in epilepsy. However, the mechanisms controlling brain immune response are only partly understood. In the periphery, acetylcholine (ACh release by the vagus nerve restrains inflammation by inhibiting the activation of leukocytes. Recent reports suggested a similar anti-inflammatory effect for ACh in the brain. Since brain cholinergic dysfunction are documented in epileptic animals, we explored changes in brain cholinergic gene expression and associated immune response during pilocarpine-induced epileptogenesis. Levels of acetylcholinesterase (AChE and inflammatory markers were measured using real-time RT-PCR, in-situ hybridization and immunostaining in wild type (WT and transgenic mice over-expressing the "synaptic" splice variant AChE-S (TgS. One month following pilocarpine, mice were video-monitored for spontaneous seizures. To test directly the effect of ACh on the brain's innate immune response, cytokines expression levels were measured in acute brain slices treated with cholinergic agents. We report a robust upregulation of AChE as early as 48 hrs following pilocarpine-induced status epilepticus (SE. AChE was expressed in hippocampal neurons, microglia and endothelial cells but rarely in astrocytes. TgS mice overexpressing AChE showed constitutive increased microglial activation, elevated levels of pro-inflammatory cytokines 48 hrs after SE and accelerated epileptogenesis compared to their WT counterparts. Finally we show a direct, muscarine-receptor dependant, nicotine-receptor independent anti-inflammatory effect of ACh in brain slices maintained ex vivo. Our work demonstrates for the first time, that ACh directly suppresses brain innate immune response and that AChE up-regulation after SE is associated with enhanced immune response, facilitating the epileptogenic process. Our results highlight the cholinergic system as a potential new target for the prevention of seizures and epilepsy.

  15. Role of the Toll/interleukin-1 receptor signaling pathway in host resistance and pathogenesis during infection with protozoan parasites.

    Science.gov (United States)

    Gazzinelli, Ricardo T; Ropert, Catherine; Campos, Marco A

    2004-10-01

    Different studies have illustrated the activation of the innate immune system during infection with protozoan parasites. Experiments performed in vivo also support the notion that innate immunity has a crucial role in resistance as well as pathogenesis observed during protozoan infections such as malaria, leishmaniasis, toxoplasmosis, and trypanosomiasis. While major advances have been made in the assignment of bacterial molecules as Toll-like receptors (TLRs) agonists as well as defining the role of the Toll/interleukin-1 receptor (TIR) signaling pathway in host resistance to bacterial infection, this research area is now emerging in the field of protozoan parasites. In this review, we discuss the recent studies describing parasite molecules as TLR agonists and those studies indicating the essential role of the TIR-domain bearing molecule named myeloid differentiation factor 88 in host resistance to infection with protozoan parasites. Together, these studies support the hypothesis that the TIR signaling pathway is involved in the initial recognition of protozoan parasites by the immune system of the vertebrate host, early resistance to infection, development of acquired immunity, as well as pathology observed during acute infection with this class of pathogens.

  16. DMPD: Toll-like receptor 3: a link between toll-like receptor, interferon and viruses. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 15031527 Toll-like receptor 3: a link between toll-like receptor, interferon and virus... (.csml) Show Toll-like receptor 3: a link between toll-like receptor, interferon and viruses. PubmedID 1503...1527 Title Toll-like receptor 3: a link between toll-like receptor, interferon and virus

  17. Nicotinic receptor abnormalities in Alzheimer's and Parkinson's diseases.

    OpenAIRE

    1987-01-01

    The status of cholinergic receptors in dementia is related to the question of potential cholinergic therapy. Whilst muscarinic receptor binding is generally reported to be normal or near normal, findings are reported which indicate substantial reductions of hippocampal nicotinic (high affinity nicotine) binding (occurring in conjunction with decreased choline acetyltransferase) in both Alzheimer's and Parkinson's but not Huntington's disease. A further indication that nicotinic receptor funct...

  18. Agonist-biased signaling via proteinase activated receptor-2: differential activation of calcium and mitogen-activated protein kinase pathways.

    Science.gov (United States)

    Ramachandran, Rithwik; Mihara, Koichiro; Mathur, Maneesh; Rochdi, Moulay Driss; Bouvier, Michel; Defea, Kathryn; Hollenberg, Morley D

    2009-10-01

    proteolytically revealed TL sequence(s) and the mode of its presentation to the receptor (tethered versus soluble) can confer biased signaling by PAR(2), its arrestin recruitment, and its internalization. Thus, PAR(2) can signal to multiple pathways that are differentially triggered by distinct proteinase-revealed TLs or by synthetic signal-selective activating peptides.

  19. α1A-adrenergic receptor induces activation of extracellular signal-regulated kinase 1/2 through endocytic pathway.

    Directory of Open Access Journals (Sweden)

    Fei Liu

    Full Text Available G protein-coupled receptors (GPCRs activate mitogen-activated protein kinases through a number of distinct pathways in cells. Increasing evidence has suggested that endosomal signaling has an important role in receptor signal transduction. Here we investigated the involvement of endocytosis in α(1A-adrenergic receptor (α(1A-AR-induced activation of extracellular signal-regulated kinase 1/2 (ERK1/2. Agonist-mediated endocytic traffic of α(1A-AR was assessed by real-time imaging of living, stably transfected human embryonic kidney 293A cells (HEK-293A. α(1A-AR was internalized dynamically in cells with agonist stimulation, and actin filaments regulated the initial trafficking of α(1A-AR. α(1A-AR-induced activation of ERK1/2 but not p38 MAPK was sensitive to disruption of endocytosis, as demonstrated by 4°C chilling, dynamin mutation and treatment with cytochalasin D (actin depolymerizing agent. Activation of protein kinase C (PKC and C-Raf by α(1A-AR was not affected by 4°C chilling or cytochalasin D treatment. U73122 (a phospholipase C [PLC] inhibitor and Ro 31-8220 (a PKC inhibitor inhibited α(1B-AR- but not α(1A-AR-induced ERK1/2 activation. These data suggest that the endocytic pathway is involved in α(1A-AR-induced ERK1/2 activation, which is independent of G(q/PLC/PKC signaling.

  20. Analysis of Activated Platelet-Derived Growth Factor β Receptor and Ras-MAP Kinase Pathway in Equine Sarcoid Fibroblasts

    Directory of Open Access Journals (Sweden)

    Gennaro Altamura

    2013-01-01

    Full Text Available Equine sarcoids are skin tumours of fibroblastic origin affecting equids worldwide. Bovine papillomavirus type-1 (BPV-1 and, less commonly, type-2 are recognized as etiological factors of sarcoids. The transforming activity of BPV is related to the functions of its major oncoprotein E5 which binds to the platelet-derived growth factor β receptor (PDGFβR causing its phosphorylation and activation. In this study, we demonstrate, by coimmunoprecipitation and immunoblotting, that in equine sarcoid derived cell lines PDGFβR is phosphorylated and binds downstream molecules related to Ras-mitogen-activated protein kinase-ERK pathway thus resulting in Ras activation. Imatinib mesylate is a tyrosine kinase receptors inhibitor which selectively inhibits the activation of PDGFβR in the treatment of several human and animal cancers. Here we show that imatinib inhibits receptor phosphorylation, and cell viability assays demonstrate that this drug decreases sarcoid fibroblasts viability in a dose-dependent manner. This study contributes to a better understanding of the molecular mechanisms involved in the pathology of sarcoids and paves the way to a new therapeutic approach for the treatment of this common equine skin neoplasm.

  1. Presynaptic Adenosine Receptor-Mediated Regulation of Diverse Thalamocortical Short-Term Plasticity in the Mouse Whisker Pathway

    Science.gov (United States)

    Ferrati, Giovanni; Martini, Francisco J.; Maravall, Miguel

    2016-01-01

    Short-term synaptic plasticity (STP) sets the sensitivity of a synapse to incoming activity and determines the temporal patterns that it best transmits. In “driver” thalamocortical (TC) synaptic populations, STP is dominated by depression during stimulation from rest. However, during ongoing stimulation, lemniscal TC connections onto layer 4 neurons in mouse barrel cortex express variable STP. Each synapse responds to input trains with a distinct pattern of depression or facilitation around its mean steady-state response. As a result, in common with other synaptic populations, lemniscal TC synapses express diverse rather than uniform dynamics, allowing for a rich representation of temporally varying stimuli. Here, we show that this STP diversity is regulated presynaptically. Presynaptic adenosine receptors of the A1R type, but not kainate receptors (KARs), modulate STP behavior. Blocking the receptors does not eliminate diversity, indicating that diversity is related to heterogeneous expression of multiple mechanisms in the pathway from presynaptic calcium influx to neurotransmitter release. PMID:26941610

  2. α-Taxilin interacts with sorting nexin 4 and participates in the recycling pathway of transferrin receptor.

    Directory of Open Access Journals (Sweden)

    Hiroshi Sakane

    Full Text Available Membrane traffic plays a crucial role in delivering proteins and lipids to their intracellular destinations. We previously identified α-taxilin as a binding partner of the syntaxin family, which is involved in intracellular vesicle traffic. α-Taxilin is overexpressed in tumor tissues and interacts with polymerized tubulin, but the precise function of α-taxilin remains unclear. Receptor proteins on the plasma membrane are internalized, delivered to early endosomes and then either sorted to the lysosome for degradation or recycled back to the plasma membrane. In this study, we found that knockdown of α-taxilin induced the lysosomal degradation of transferrin receptor (TfnR, a well-known receptor which is generally recycled back to the plasma membrane after internalization, and impeded the recycling of transferrin. α-Taxilin was immunoprecipitated with sorting nexin 4 (SNX4, which is involved in the recycling of TfnR. Furthermore, knockdown of α-taxilin decreased the number and length of SNX4-positive tubular structures. We report for the first time that α-taxilin interacts with SNX4 and plays a role in the recycling pathway of TfnR.

  3. The PTK7 and ROR2 Protein Receptors Interact in the Vertebrate WNT/Planar Cell Polarity (PCP) Pathway.

    Science.gov (United States)

    Martinez, Sébastien; Scerbo, Pierluigi; Giordano, Marilyn; Daulat, Avais M; Lhoumeau, Anne-Catherine; Thomé, Virginie; Kodjabachian, Laurent; Borg, Jean-Paul

    2015-12-18

    The non-canonical WNT/planar cell polarity (WNT/PCP) pathway plays important roles in morphogenetic processes in vertebrates. Among WNT/PCP components, protein tyrosine kinase 7 (PTK7) is a tyrosine kinase receptor with poorly defined functions lacking catalytic activity. Here we show that PTK7 associates with receptor tyrosine kinase-like orphan receptor 2 (ROR2) to form a heterodimeric complex in mammalian cells. We demonstrate that PTK7 and ROR2 physically and functionally interact with the non-canonical WNT5A ligand, leading to JNK activation and cell movements. In the Xenopus embryo, Ptk7 functionally interacts with Ror2 to regulate protocadherin papc expression and morphogenesis. Furthermore, we show that Ptk7 is required for papc activation induced by Wnt5a. Interestingly, we find that Wnt5a stimulates the release of the tagged Ptk7 intracellular domain, which can translocate into the nucleus and activate papc expression. This study reveals novel molecular mechanisms of action of PTK7 in non-canonical WNT/PCP signaling that may promote cell and tissue movements.

  4. Neonatal Fc receptors discriminates and monitors the pathway of native and modified immunoglobulin G in placental endothelial cells.

    Science.gov (United States)

    Radulescu, Luminita; Antohe, Felicia; Jinga, Victor; Ghetie, Victor; Simionescu, Maya

    2004-06-01

    In the placenta, immunoglobulin G (IgG) is selectively transported from mother to fetus by a highly regulated transcellular mechanism aimed to achieve fetal humoral immunity. We questioned the role of neonatal Fc receptors (FcRn) in the traffic of IgG in human placental endothelial cells (HPEC). Cells were cultured in a double-chamber system and further exposed to IgG or Fc or to diethylpyrocarbonate-modified IgG or Fc in which the receptor recognition domain of the molecule (CH2-CH3) was altered. We provide evidence that the native IgG/Fc probes are transcytosed or recycled by HPEC, whereas the probes with the altered receptor recognition domain (which do not bind to FcRn) massively accumulate into the endocytic/lysosomal compartments. The results indicate that FcRn distinguishes between the intact and modified IgG and control their cellular traffic: native IgG is salvaged and released out of the cells, whereas modified IgG is retained and sorted to a degradative pathway. The data advance the understanding of the basic mechanism for IgG traffic in human endothelial cells, which may be exploited for the specific transport of antibodies in various immune disorders.

  5. (Pro)renin receptor is crucial for glioma development via the Wnt/β-catenin signaling pathway.

    Science.gov (United States)

    Kouchi, Masaaki; Shibayama, Yuki; Ogawa, Daisuke; Miyake, Keisuke; Nishiyama, Akira; Tamiya, Takashi

    2017-01-06

    OBJECTIVE The (pro)renin receptor (PRR) plays an essential role in the early development of the central nervous system by activating the Wnt/β-catenin signaling pathway. The authors investigated the potential role of the PRR in the pathogenesis of glioma. METHODS The authors performed immunohistochemical analysis to detect both the PRR and isocitrate dehydrogenase 1 with mutations involving arginine 132 ( IDH1(R132H)) in paraffin sections of 31 gliomas. Expression of the PRR and Wnt pathway components in cultured human glioma cell lines (U251MG, U87MG, and T98G) was measured using Western blotting. The effects of PRR short interfering RNA (siRNA) on glioma cell proliferation (WST-1 assay and direct cell counting) and apoptosis (flow cytometry and the caspase-3 assay) were also examined. RESULTS PRR expression was significantly higher in glioblastoma than in normal tissue or in lower grade glioma, regardless of IDH1(R132H) mutation. PRR expression was also higher in human glioblastoma cell lines than in human astrocytes. PRR expression showed a significant positive correlation with the Ki-67 labeling index, while it had a significant negative correlation with the survival time of glioma patients. Treatment with PRR siRNA significantly reduced expression of Wnt2, activated β-catenin, and cyclin D1 by human glioblastoma cell lines, and it reduced the proliferative capacity of these cell lines and induced apoptosis. CONCLUSIONS This is the first evidence that the PRR has an important role in development of glioma by aberrant activation of the Wnt/β-catenin signaling pathway. This receptor may be both a prognostic marker and a therapeutic target for glioma.

  6. Distinct neural pathways mediate alpha7 nicotinic acetylcholine receptor-dependent activation of the forebrain

    DEFF Research Database (Denmark)

    Thomsen, Morten S; Hay-Schmidt, Anders; Hansen, Henrik H;

    2010-01-01

    alpha(7) nicotinic acetylcholine receptor (nAChR) agonists are candidates for the treatment of cognitive deficits in schizophrenia. Selective alpha(7) nAChR agonists, such as SSR180711, activate neurons in the medial prefrontal cortex (mPFC) and nucleus accumbens shell (ACCshell) in rats, regions...

  7. Molecular scaffolds regulate bidirectional crosstalk between Wnt and classical seven-transmembrane-domain receptor signaling pathways.

    Science.gov (United States)

    Force, Thomas; Woulfe, Kathleen; Koch, Walter J; Kerkelä, Risto

    2007-07-31

    Signaling downstream of classical seven-transmembrane domain receptors (7TMRs) had generally been thought to recruit factors that are in large part separate from those recruited by atypical 7TMRs, such as Frizzleds (Fzs), receptors for the Wnt family of glycoproteins. Classical 7TMRs are also known as G protein-coupled receptors (GPCRs) and are mediated by signaling factors such as heterotrimeric guanine nucleotide-binding proteins (G proteins), GPCR kinases (GRKs), and beta-arrestins. Over the past few years, it has become increasingly apparent that classical and atypical 7TMRs share these factors, which are often associated with mediating classical 7TMR signaling, as well as the scaffolding proteins that were initially thought to be involved in transmitting atypical 7TMR signals. This sharing of signaling components by agonists that bind classical 7TMRs and those binding to atypical 7TMRs establishes the possibility of extensive crosstalk between these receptor classes. We discuss the evidence for, and against, crosstalk, and examine mechanisms by which this can occur.

  8. Lactate modulates the activity of primary cortical neurons through a receptor-mediated pathway.

    Directory of Open Access Journals (Sweden)

    Luigi Bozzo

    Full Text Available Lactate is increasingly described as an energy substrate of the brain. Beside this still debated metabolic role, lactate may have other effects on brain cells. Here, we describe lactate as a neuromodulator, able to influence the activity of cortical neurons. Neuronal excitability of mouse primary neurons was monitored by calcium imaging. When applied in conjunction with glucose, lactate induced a decrease in the spontaneous calcium spiking frequency of neurons. The effect was reversible and concentration dependent (IC50 ∼4.2 mM. To test whether lactate effects are dependent on energy metabolism, we applied the closely related substrate pyruvate (5 mM or switched to different glucose concentrations (0.5 or 10 mM. None of these conditions reproduced the effect of lactate. Recently, a Gi protein-coupled receptor for lactate called HCA1 has been introduced. To test if this receptor is implicated in the observed lactate sensitivity, we incubated cells with pertussis toxin (PTX an inhibitor of Gi-protein. PTX prevented the decrease of neuronal activity by L-lactate. Moreover 3,5-dyhydroxybenzoic acid, a specific agonist of the HCA1 receptor, mimicked the action of lactate. This study indicates that lactate operates a negative feedback on neuronal activity by a receptor-mediated mechanism, independent from its intracellular metabolism.

  9. Lactate modulates the activity of primary cortical neurons through a receptor-mediated pathway.

    Science.gov (United States)

    Bozzo, Luigi; Puyal, Julien; Chatton, Jean-Yves

    2013-01-01

    Lactate is increasingly described as an energy substrate of the brain. Beside this still debated metabolic role, lactate may have other effects on brain cells. Here, we describe lactate as a neuromodulator, able to influence the activity of cortical neurons. Neuronal excitability of mouse primary neurons was monitored by calcium imaging. When applied in conjunction with glucose, lactate induced a decrease in the spontaneous calcium spiking frequency of neurons. The effect was reversible and concentration dependent (IC50 ∼4.2 mM). To test whether lactate effects are dependent on energy metabolism, we applied the closely related substrate pyruvate (5 mM) or switched to different glucose concentrations (0.5 or 10 mM). None of these conditions reproduced the effect of lactate. Recently, a Gi protein-coupled receptor for lactate called HCA1 has been introduced. To test if this receptor is implicated in the observed lactate sensitivity, we incubated cells with pertussis toxin (PTX) an inhibitor of Gi-protein. PTX prevented the decrease of neuronal activity by L-lactate. Moreover 3,5-dyhydroxybenzoic acid, a specific agonist of the HCA1 receptor, mimicked the action of lactate. This study indicates that lactate operates a negative feedback on neuronal activity by a receptor-mediated mechanism, independent from its intracellular metabolism.

  10. Neural Stem Cell Transplant-Induced Effect on Neurogenesis and Cognition in Alzheimer Tg2576 Mice Is Inhibited by Concomitant Treatment with Amyloid-Lowering or Cholinergic α7 Nicotinic Receptor Drugs.

    Science.gov (United States)

    Lilja, Anna M; Malmsten, Linn; Röjdner, Jennie; Voytenko, Larysa; Verkhratsky, Alexei; Ögren, Sven Ove; Nordberg, Agneta; Marutle, Amelia

    2015-01-01

    Stimulating regeneration in the brain has the potential to rescue neuronal networks and counteract progressive pathological changes in Alzheimer's disease (AD). This study investigated whether drugs with different mechanisms of action could enhance neurogenesis and improve cognition in mice receiving human neural stem cell (hNSC) transplants. Six- to nine-month-old AD Tg2576 mice were treated for five weeks with the amyloid-modulatory and neurotrophic drug (+)-phenserine or with the partial α7 nicotinic receptor (nAChR) agonist JN403, combined with bilateral intrahippocampal hNSC transplantation. We observed improved spatial memory in hNSC-transplanted non-drug-treated Tg2576 mice but not in those receiving drugs, and this was accompanied by an increased number of Doublecortin- (DCX-) positive cells in the dentate gyrus, a surrogate marker for newly generated neurons. Treatment with (+)-phenserine did however improve graft survival in the hippocampus. An accumulation of α7 nAChR-expressing astrocytes was observed around the injection site, suggesting their involvement in repair and scarring processes. Interestingly, JN403 treatment decreased the number of α7 nAChR-expressing astrocytes, correlating with a reduction in the number of DCX-positive cells in the dentate gyrus. We conclude that transplanting hNSCs enhances endogenous neurogenesis and prevents further cognitive deterioration in Tg2576 mice, while simultaneous treatments with (+)-phenserine or JN403 result in countertherapeutic effects.

  11. Neural Stem Cell Transplant-Induced Effect on Neurogenesis and Cognition in Alzheimer Tg2576 Mice Is Inhibited by Concomitant Treatment with Amyloid-Lowering or Cholinergic α7 Nicotinic Receptor Drugs

    Directory of Open Access Journals (Sweden)

    Anna M. Lilja

    2015-01-01

    Full Text Available Stimulating regeneration in the brain has the potential to rescue neuronal networks and counteract progressive pathological changes in Alzheimer’s disease (AD. This study investigated whether drugs with different mechanisms of action could enhance neurogenesis and improve cognition in mice receiving human neural stem cell (hNSC transplants. Six- to nine-month-old AD Tg2576 mice were treated for five weeks with the amyloid-modulatory and neurotrophic drug (+-phenserine or with the partial α7 nicotinic receptor (nAChR agonist JN403, combined with bilateral intrahippocampal hNSC transplantation. We observed improved spatial memory in hNSC-transplanted non-drug-treated Tg2576 mice but not in those receiving drugs, and this was accompanied by an increased number of Doublecortin- (DCX- positive cells in the dentate gyrus, a surrogate marker for newly generated neurons. Treatment with (+-phenserine did however improve graft survival in the hippocampus. An accumulation of α7 nAChR-expressing astrocytes was observed around the injection site, suggesting their involvement in repair and scarring processes. Interestingly, JN403 treatment decreased the number of α7 nAChR-expressing astrocytes, correlating with a reduction in the number of DCX-positive cells in the dentate gyrus. We conclude that transplanting hNSCs enhances endogenous neurogenesis and prevents further cognitive deterioration in Tg2576 mice, while simultaneous treatments with (+-phenserine or JN403 result in countertherapeutic effects.

  12. Metabotropic glutamate receptor 5 shows different patterns of localization within the parallel visual pathways in macaque and squirrel monkeys

    Directory of Open Access Journals (Sweden)

    Shostak Y

    2014-09-01

    Full Text Available Yuri Shostak,1,5 Ashley Wenger,4 Julia Mavity-Hudson,1 Vivien A Casagrande1–3 1Department of Cell and Developmental Biology, 2Department of Psychology, 3Department of Ophthalmology and Visual Sciences, 4Undergraduate Neuroscience Program, Vanderbilt University, Nashville, TN, USA; 5Foreign Trade Unitary Enterprise, Minsk, Belarus Abstract: Glutamate is used as an excitatory neurotransmitter by the koniocellular (K, magnocellular (M, and parvocellular (P pathways to transfer signals from the primate lateral geniculate nucleus (LGN to primary visual cortex (V1. Glutamate acts through both fast ionotropic receptors, which appear to carry the main sensory message, and slower, modulatory metabotropic receptors (mGluRs. In this study, we asked whether mGluR5 relates in distinct ways to the K, M, and P LGN axons in V1. To answer this question, we used light microscopic immunocytochemistry and preembedding electron microscopic immunogold labeling to determine the localization of mGluR5 within the layers of V1 in relation to the K, M, and P pathways in macaque and squirrel monkeys. These pathways were labeled separately via wheat germ agglutinin–horseradish peroxidase (WGA–HRP injections targeting the LGN layers. mGluR5 is of interest because it: 1 has been shown to be expressed in the thalamic input layers; 2 appears to be responsible for some types of oscillatory firing, which could be important in the binding of visual features; and 3 has been associated with a number of sensory-motor gating-related pathologies, including schizophrenia and autism. Our results demonstrated the presence of mGluR5 in the neuropil of all V1 layers. This protein was lowest in IVCa (M input and the infragranular layers. In layer IVC, mGluR5 also was found postsynaptic to about 30% of labeled axons, but the distribution was uneven, such that postsynaptic mGluR5 label tended to occur opposite smaller (presumed P, and not larger (presumed M axon terminals. Only in the K

  13. Peroxisome Proliferator-Activated Receptor γ Induces the Expression of Tissue Factor Pathway Inhibitor-1 (TFPI-1) in Human Macrophages

    Science.gov (United States)

    Copin, C.; Derudas, B.; Marx, N.

    2016-01-01

    Tissue factor (TF) is the initiator of the blood coagulation cascade after interaction with the activated factor VII (FVIIa). Moreover, the TF/FVIIa complex also activates intracellular signalling pathways leading to the production of inflammatory cytokines. The TF/FVIIa complex is inhibited by the tissue factor pathway inhibitor-1 (TFPI-1). Peroxisome proliferator-activated receptor gamma (PPARγ) is a transcription factor that, together with PPARα and PPARβ/δ, controls macrophage functions. However, whether PPARγ activation modulates the expression of TFP1-1 in human macrophages is not known. Here we report that PPARγ activation increases the expression of TFPI-1 in human macrophages in vitro as well as in vivo in circulating peripheral blood mononuclear cells. The induction of TFPI-1 expression by PPARγ ligands, an effect shared by the activation of PPARα and PPARβ/δ, occurs also in proinflammatory M1 and in anti-inflammatory M2 polarized macrophages. As a functional consequence, treatment with PPARγ ligands significantly reduces the inflammatory response induced by FVIIa, as measured by variations in the IL-8, MMP-2, and MCP-1 expression. These data identify a novel role for PPARγ in the control of TF the pathway. PMID:28115923

  14. FGF-receptor substrate 2 functions as a molecular sensor integrating external regulatory signals into the FGF pathway

    Institute of Scientific and Technical Information of China (English)

    Wenchao Zhou; Xiujing Feng; Yingjie Wu; Johannes Benge; Zhe Zhang; Zhengjun Chen

    2009-01-01

    Fibroblast growth factor (FGF) receptor substrate 2α (FRS2α) is the main mediator of signaling in the FGF path-way. Recent studies have shown that n/itogen-activated protein kinase (MAPK) phosphorylates serine and threonine residues in FRS2, negatively affecting FGF-induced tyrosine phosphorylation (PY) of FRS2. Several kinds of stimuli can induce serine/threonine phosphorylation (PS/T) of FRS2, indicating that FRS2 may be useful for studying cross-talk between growth factor signaling pathways. Here, we report that FGF-induced PY of FRS2 can be attenuated by EGF co-stimulation in PC12cells; this inhibitory effect could be completely reversed by U0126, an inhibitor of MEK. We further identified the ERK1/2-binding motif in FRS2 and generated FRS2-3KL, a mutant lacking MAPK binding and PT upon FGF and/or EGF stimulation. Unlike wild-type (WT) FRS2, FGF-induced PY of FRS2-3KL could not be inhibited by EGF co-stimulation, and FRS2-3KL-expressing PC12 cells exhibited more differentiating potential than FRS2-WT-expressing cells in response to FGF treatment. These results suggest that PSfr of FRS2 mediated by the FRS2-MAPK negative regulatory loop may function as a molecular switch integrating negative regulatory signals from other pathways into FGFR-generated signal transduction.

  15. Growth Factor Receptors and Apoptosis Regulators: Signaling Pathways, Prognosis, Chemosensitivity and Treatment Outcomes of Breast Cancer

    Directory of Open Access Journals (Sweden)

    Siddik Sarkar

    2009-01-01

    Full Text Available Biomarkers of breast cancer are necessary for prognosis and prediction to chemotherapy. Prognostic biomarkers provide information regarding outcome irrespective of therapy, while predictive biomarkers provide information regarding response to therapy. Candidate prognostic biomarkers for breast cancers are growth factor receptors, steroid receptors, Ki-67, cyclins, urokinase plasminogen activator, p53, p21, pro- and anti-apoptotic factors, BRCA1 and BRCA2. But currently, the predictive markers are Estrogen and Progesterone receptors responding to endocrine therapy, and HER-2 responding to herceptin. But there are numerous breast cancer cases, where tamoxifen is ineffective even after estrogen receptor positivity. This lead to search of new prognostic and predictive markers and the number of potential markers is constantly increasing due to proteomics and genomics studies. However, most biomarkers individually have poor sensitivity or specificity, or other clinical value. It can be resolved by studying various biomarkers simultaneously, which will help in better prognosis and increasing sensitivity for chemotherapeutic agents. This review is focusing on growth factor receptors, apoptosis markers, signaling cascades, and their correlation with other associated biomarkers in breast cancers. As our knowledge regarding molecular biomarkers for breast cancer increases, prognostic indices will be developed that combine the predictive power of individual molecular biomarkers with specific clinical and pathologic factors. Rigorous comparison of these existing as well as emerging markers with current treatment selection is likely to see an escalation in an era of personalized medicines to ensure the breast cancer patients receive optimal treatment. This will also solve the treatment modalities and complications related to chemotherapeutic regimens.

  16. Activated niacin receptor HCA2 inhibits chemoattractant-mediated macrophage migration via Gβγ/PKC/ERK1/2 pathway and heterologous receptor desensitization

    Science.gov (United States)

    Shi, Ying; Lai, Xiangru; Ye, Lingyan; Chen, Keqiang; Cao, Zheng; Gong, Wanghua; Jin, Lili; Wang, Chunyan; Liu, Mingyong; Liao, Yuan; Wang, Ji Ming; Zhou, Naiming

    2017-01-01

    The niacin receptor HCA2 is implicated in controlling inflammatory host responses with yet poorly understood mechanistic basis. We previously reported that HCA2 in A431 epithelial cells transduced Gβγ-protein kinase C- and Gβγ-metalloproteinase/EGFR-dependent MAPK/ERK signaling cascades. Here, we investigated the role of HCA2 in macrophage-mediated inflammation and the underlying mechanisms. We found that proinflammatory stimulants LPS, IL-6 and IL-1β up-regulated the expression of HCA2 on macrophages. Niacin significantly inhibited macrophage chemotaxis in response to chemoattractants fMLF and CCL2 by disrupting polarized distribution of F-actin and Gβ protein. Niacin showed a selected additive effect on chemoattractant-induced activation of ERK1/2, JNK and PI3K pathways, but only the MEK inhibitor UO126 reduced niacin-mediated inhibition of macrophage chemotaxis, while activation of ERK1/2 by EGF alone did not inhibit fMLF-mediated migration of HEK293T cells co-expressing HCA2 and fMLF receptor FPR1. In addition, niacin induced heterologous desensitization and internalization of FPR1. Furthermore, niacin rescued mice from septic shock by diminishing inflammatory symptoms and the effect was abrogated in HCA2−/− mice. These results suggest that Gβγ/PKC-dependent ERK1/2 activation and heterologous desensitization of chemoattractant receptors are involved in the inhibition of chemoattractant-induced migration of macrophages by niacin. Thus, HCA2 plays a critical role in host protection against pro-inflammatory insults. PMID:28186140

  17. Distinct signalling pathways of murine histamine H1- and H4-receptors expressed at comparable levels in HEK293 cells.

    Directory of Open Access Journals (Sweden)

    Silke Beermann

    Full Text Available Histamine (HA is recognized by its target cells via four G-protein-coupled receptors, referred to as histamine H1-receptor (H1R, H2R, H3R, and H4R. Both H1R and H4R exert pro-inflammatory functions. However, their signal transduction pathways have never been analyzed in a directly comparable manner side by side. Moreover, the analysis of pharmacological properties of the murine orthologs, representing the main targets of pre-clinical research, is very important. Therefore, we engineered recombinant HEK293 cells expressing either mouse (mH1R or mH4R at similar levels and analyzed HA-induced signalling in these cells. HA induced intracellular calcium mobilization via both mH1R and mH4R, with the mH1R being much more effective. Whereas cAMP accumulation was potentiated via the mH1R, it was reduced via the mH4R. The regulation of both second messengers via the H4R, but not the H1R, was sensitive to pertussis toxin (PTX. The mitogen-activated protein kinases (MAPKs ERK 1/2 were massively activated downstream of both receptors and demonstrated a functional involvement in HA-induced EGR-1 gene expression. The p38 MAPK was moderately activated via both receptors as well, but was functionally involved in HA-induced EGR-1 gene expression only in H4R-expressing cells. Surprisingly, in this system p38 MAPK activity reduced the HA-induced gene expression. In summary, using this system which allows a direct comparison of mH1R- and mH4R-induced signalling, qualitative and quantitative differences on the levels of second messenger generation and also in terms of p38 MAPK function became evident.

  18. LARG links histamine-H1-receptor-activated Gq to Rho-GTPase-dependent signaling pathways.

    Science.gov (United States)

    Pfreimer, Mariana; Vatter, Petra; Langer, Torben; Wieland, Thomas; Gierschik, Peter; Moepps, Barbara

    2012-03-01

    Activation of heterotrimeric G proteins, such as G(12/13) and G(q), by cell surface receptors is coupled to the regulation of numerous cellular functions controlled by activated Rho GTPases. Previous studies have implicated the Rho guanine nucleotide exchange factor (RhoGEF) leukemia-associated RhoGEF (LARG) as a regulatory protein receiving stimulatory inputs from activated Gα(12/13) and Gα(q). However, the molecular mechanisms of the Gα(q)-mediated LARG activation are not fully understood and the structural elements of LARG involved in this process have remained unclear. In the present work, the specific coupling of the histamine H1 receptor (HRH1) exogenously expressed in COS-7 cells to G(q), but not to G(12/13), was used to conduct a detailed analysis of receptor- and Gα(q)-mediated LARG activation and to define its structural requirements. The results show that HRH1-mediated activation of the strictly Rho-dependent transcriptional activity of serum response factor requires the PDZ domain of LARG and can be mimicked by activated Gα(q)(Q209L). The functional interaction between activated Gα(q) and LARG requires no more than the catalytic DH-PH tandem of LARG, and is independent of PLCβ activation and distinct from the mechanisms of Gα(q)-mediated p63RhoGEF and PLCβ(3) activation. Activated Gα(q) physically interacts with the relevant portions of LARG in COS-7 cells and histamine causes activation of LARG in native HeLa cells endogenously expressing HRH1, G(q), and LARG. This work is the first positive demonstration of a stimulatory effect of LARG on the ability of a strictly G(q)-coupled receptor to cause activation of a Rho-GTPase-dependent signaling pathway.

  19. Noninvasive imaging of receptor function: signal transduction pathways and physiological readouts.

    Science.gov (United States)

    Rudin, Markus

    2008-09-01

    Intracellular signaling describes the process of information propagation from the cell surface to the location within the cell where a biological response is executed. Signaling pathways involve a complex network of interacting molecular species. It is obvious that information on the activation of individual pathways is highly relevant in biomedical research, both from a diagnostic point of view and for evaluating therapeutic interventions. Modern molecular imaging approaches are capable of providing such information in a temporo-spatially resolved manner. Two strategies can be pursued: imaging individual pathway molecules or targeting protein-protein interactions, which are key elements of the signaling networks. Assays such as fluorescence resonance energy transfer, two-hybrid, protein fragment complementation or protein splicing have been adapted to allow studies in live mice. The major issues in imaging signal transduction are sensitivity, as critical species occur at low concentration, and the fact that the processes targeted are intracellular, that is, exogenous probes have to cross the cell membrane. Currently, the majority of these imaging methods are based on genetic engineering approaches and are therefore confined to experimental studies in animals. Exogenous probes for targeting intracellular pathway molecules are being developed and may allow translation into the clinic.

  20. Activation of α7-containing nicotinic receptors on astrocytes triggers AMPA receptor recruitment to glutamatergic synapses.

    Science.gov (United States)

    Wang, Xulong; Lippi, Giordano; Carlson, David M; Berg, Darwin K

    2013-12-01

    Astrocytes, an abundant form of glia, are known to promote and modulate synaptic signaling between neurons. They also express α7-containing nicotinic acetylcholine receptors (α7-nAChRs), but the functional relevance of these receptors is unknown. We show here that stimulation of α7-nAChRs on astrocytes releases components that induce hippocampal neurons to acquire more α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors post-synaptically at glutamatergic synapses. The increase is specific in that no change is seen in synaptic NMDA receptor clusters or other markers for glutamatergic synapses, or in markers for GABAergic synapses. Moreover, the increases in AMPA receptors on the neuron surface are accompanied by increases in the frequency of spontaneous miniature synaptic currents mediated by the receptors and increases in the ratio of evoked synaptic currents mediated by AMPA versus NMDA receptors. This suggests that stimulating α7-nAChRs on astrocytes can convert 'silent' glutamatergic synapses to functional status. Astrocyte-derived thrombospondin is necessary but not sufficient for the effect, while tumor necrosis factor-α is sufficient but not necessary. The results identify astrocyte α7-nAChRs as a novel pathway through which nicotinic cholinergic signaling can promote the development of glutamatergic networks, recruiting AMPA receptors to post-synaptic sites and rendering the synapses more functional. We find that activation of nicotinic receptors on astrocytes releases a component that specifically recruits AMPA receptors to glutamatergic synapses. The recruitment appears to occur preferentially at what may be 'silent synapses', that is, synapses that have all the components required for glutamatergic transmission (including NMDA receptors) but lack sufficient AMPA receptors to generate a response. The results are unexpected and open up new possibilities for mechanisms underlying network formation and synaptic plasticity.

  1. Reflex pathways connect receptors in the human lower leg to the erector spinae muscles of the lower back.

    Science.gov (United States)

    Clair, J M; Okuma, Y; Misiaszek, J E; Collins, D F

    2009-06-01

    Reflex pathways connect all four limbs in humans. Presently, we tested the hypothesis that reflexes also link sensory receptors in the lower leg with muscles of the lower back (erector spinae; ES). Taps were applied to the right Achilles' tendon and electromyographic activity was recorded from the right soleus and bilaterally from ES. Reflexes were compared between sitting and standing and between standing with the eyes open versus closed. Reflexes were evoked bilaterally in ES and consisted of an early latency excitation, a medium latency inhibition, and a longer latency excitation. During sitting but not standing, the early excitation was larger in the ES muscle ipsilateral to the stimulation (iES) than in the contralateral ES (cES). During standing but not sitting, the longer latency excitation in cES was larger than in iES. This response in cES was also larger during standing compared to sitting. Responses were not significantly different between the eyes open and eyes closed conditions. Taps applied to the lateral calcaneus (heel taps) evoked responses in ES that were not significantly different in amplitude or latency than those evoked by tendon taps, despite a 75-94% reduction in the amplitude of the soleus stretch reflex evoked by the heel taps. Electrical stimulation of the sural nerve, a purely cutaneous nerve at the ankle, evoked ES reflexes that were not significantly different in amplitude but had significantly longer latencies than those evoked by the tendon and heel taps. These results support the hypothesis that reflex pathways connect receptors in the lower leg with muscles of the lower back and show that that the amplitude of these reflexes is modulated by task. Responses evoked by stimulation of the sural nerve establish that reflex pathways connect the ES muscles with cutaneous receptors of the foot. In contrast, the large volley in muscle spindle afferents induced by the tendon taps compared to the heel taps did not alter the ES responses

  2. Somatostatin receptor biology in neuroendocrine and pituitary tumours: part 1 – molecular pathways

    OpenAIRE

    Cakir, Mehtap; Dworakowska, Dorota; Grossman, Ashley

    2010-01-01

    Abstract Neuroendocrine tumours (NETs) may occur at many sites in the body although the majority occur within the gastroenteropancreatic axis. Non-gastroenteropancreatic NETs encompass phaeochromocytomas and paragangliomas, medullary thyroid carcinoma, anterior pituitary tumour, broncho-pulmonary NETs and parathyroid tumours. Like most endocrine tumours, NETs also express somatostatin (SST) receptors (subtypes 1–5) whose ligand SST is known to inhibit endocrine and exocrine secretions and hav...

  3. Differential regulation of atrial natriuretic peptide- and adrenergic receptor-dependent lipolytic pathways in human adipose tissue.

    Science.gov (United States)

    Moro, Cédric; Polak, Jan; Richterova, Blanka; Sengenès, Coralie; Pelikanova, Terezie; Galitzky, Jean; Stich, Vladimir; Lafontan, Max; Berlan, Michel

    2005-01-01

    The aim of the study was to investigate the regulation affecting the recently described atrial natriuretic peptide (ANP)-dependent lipolytic pathway in comparison with the adrenergic lipolytic cascade. We studied in vivo the effect of a euglycemic-hyperinsulinemic clamp on the changes occurring in the extracellular glycerol concentration (EGC) of subcutaneous adipose tissue (SCAT) during ANP or epinephrine perfusion in a microdialysis probe. Homologous desensitization and the incidence of hyperinsulinemia on the ANP- and catecholaminergic-dependent control of lipolysis were also investigated in vitro on fat cells from SCAT. When perfused in SCAT, epinephrine and ANP promoted an increase in EGC; the EGC increase was significantly lower during the clamp. The reduction of epinephrine-induced lipolysis was limited (18%) when phentolamine (an alpha(2)-adrenergic receptor [AR] antagonist) was perfused together with epinephrine. Unlike the effect of epinephrine, the response to ANP observed during the second perfusion was reduced by 32%. The increase in extracellular guanosine 3',5' -cyclic monophosphate concentration, which reflects ANP activity, was also reduced during the second perfusion. Desensitization of the lipolytic effects of ANP was observed in vitro after a 2-hour period of recovery, while the effects of alpha(2)-AR agonist or of epinephrine were unchanged. Insulin was without any effect on ANP-induced lipolysis and alpha(2)-AR-mediated antilipolysis, while it reduced beta-AR-induced lipolysis. The ANP-dependent lipolytic pathway undergoes desensitization in vitro and in situ. Insulin had no inhibitory effect on either ANP- or alpha(2)-AR-dependent pathways, while it counteracted the beta-AR pathway.

  4. The Association of CXC Receptor 4 Mediated Signaling Pathway with Oxaliplatin-Resistant Human Colorectal Cancer Cells

    Science.gov (United States)

    Huang, Cheng-Yi; Kuo, Yi-Hung; Tung, Shui-Yi; Shen, Chien-Heng; Hsieh, Yung-Yu; Teng, Chih-Chuan; Lee, Kam-Fai; Chen, Te-Chuan; Lee, Ko-Chao; Kuo, Hsing-Chun

    2016-01-01

    The stromal cell–derived factor-1 (SDF-1)/CXC receptor 4 (CXCR4) axis plays an important role in tumor angiogenesis and invasiveness in colorectal cancer (CRC) progression. In addition, metastatic CRC remains one of the most difficult human malignancies to treat because of its chemoresistant behavior. However, the mechanism by which correlation occurs between CXCR4 and the clinical response of CRC to chemotherapy remains unknown. We generated chemoresistant cells with increasing doses of oxaliplatin (OXA) and 5-Fluorouracil (5FU) to develop resistance at a clinical dose. We found that the putative markers did not change in the parental cells, but HCT-116/OxR and HCT-116/5-FUR were more aggressive and had higher tumor growth (demonstrated by wound healing, chemotaxis assay, and a nude mice xenograft model) with the use of oxaliplatin. Apoptosis induced by oxaliplatin treatment was significantly decreased in HCT-116/OxR compared to the parental cells. Moreover, HCT-116/OxR cells displayed increased levels of p-gp, p-Akt p-ERK, p-IKBβ, CXCR4, and Bcl-2, but they also significantly inhibited the apoptotic pathways when compared to the parental strain. We evaluated the molecular mechanism governing the signaling pathway associated with anti-apoptosis activity and the aggressive status of chemoresistant cells. Experiments involving specific inhibitors demonstrated that the activation of the pathways associated with CXCR4, ERK1/2 mitogen-activated protein kinase (MAPK), and phosphatidylinositol 3-kinase (PI3K)/Akt is critical to the functioning of the HCT-116/OxR and HCT-116/5-FUR characteristics of chemosensitivity. These findings elucidate the mechanism of CXCR4/PI3K/Akt downstream signaling and provide strategies to inhibit CXCR4 mediated signaling pathway in order to overcome CRC’s resistance to chemotherapy. PMID:27668882

  5. The involvement of the central cholinergic system in the pressor and bradycardic effects of centrally administrated melittin in normotensive conscious rats.

    Science.gov (United States)

    Yalcin, Murat; Erturk, Melih

    2007-04-01

    Recently we demonstrated that centrally administrated melittin, a phospholipase A(2) (PLA(2)) activator, caused pressor and bradycardic effect in the normotensive conscious rats. In the current study we aimed to determine the mediation of central cholinergic system in the pressor and bradycardic effect of centrally administrated melittin. Studies were performed in normotensive male Sprague-Dawley rats. 1.5, 3.0 or 6.0microg/5.0microl doses of melittin were injected intracerebroventricularly (i.c.v.). Melittin caused dose- and time-dependent increases in mean arterial pressure (MAP) and decrease in heart rate (HR). In order to test the mediation of central cholinergic system on the pressor and bradycardic effect of melittin, the rats were pretreated with mecamylamine (50microg; i.c.v.), cholinergic nonselective nicotinic receptor antagonist, atropine sulfate (10microg; i.c.v.), a cholinergic nonselective muscarinic receptor antagonist, hemicholinium-3 (20microg; i.c.v.), a high affinity neuronal choline uptake inhibitor, methyllycaconitine (10 and 25microg; i.c.v.) or alpha-bungarotoxin (10 and 25microg; i.c.v.), selective antagonists of alpha-7 subtype nicotinic acetylcholine receptors (alpha7nAChRs), 15min prior to melittin (3.0microg) injection. Pretreatment with mecamylamine, hemicholinium-3, methyllycaconitine or alpha-bungarotoxin partially attenuated the pressor and bradicardia effect of elicited by melittin in the normotensive conscious rats whereas pretreatment with atropine had no effect. In conclusion, i.c.v. administration of melittin increases MAP and decreases HR in conscious rats. The activation of central nicotinic cholinergic receptors, predominantly alpha7nAChRs, partially acts as a mediator in the pressor responses to i.c.v. injection of melittin in the normotensive conscious rats. Moreover, decreased uptake of choline to the cholinergic terminals may consider that melittin activates central choline and acetylcholine release, as well.

  6. Effects of diazinon on the lymphocytic cholinergic system of Nile tilapia fish (Oreochromis niloticus).

    Science.gov (United States)

    Toledo-Ibarra, G A; Díaz-Resendiz, K J G; Pavón-Romero, L; Rojas-García, A E; Medina-Díaz, I M; Girón-Pérez, M I

    2016-08-01

    Fish rearing under intensive farming conditions can be easily disturbed by pesticides, substances that have immunotoxic properties and may predispose to infections. Organophosphorus pesticides (OPs) are widely used in agricultural activities; however, the mechanism of immunotoxicity of these substances is unclear. The aim of this study was to evaluate the effect of diazinon pesticides (OPs) on the cholinergic system of immune cells as a possible target of OP immunotoxicity. We evaluated ACh levels and cholinergic (nicotinic and muscarinic) receptor concentration. Additionally, AChE activity was evaluated in mononuclear cells of Nile tilapia (Oreochromis niloticus), a freshwater fish mostly cultivated in tropical regions around the world. The obtained results indicate that acute exposure to diazinon induces an increase in ACh concentration and a decrease in nAChR and mAChR concentrations and AChE activity in fish immune cells, This suggests that the non-neuronal lymphocytic cholinergic system may be the main target in the mechanism of OP immunotoxicity. This study contributes to the understanding of the mechanisms of immunotoxicity of pollutants and may help to take actions for animal health improvement.

  7. D2-like receptors in the descending dopaminergic pathway are not involved in the decreased postoperative nociceptive threshold induced by plantar incision in adult rats

    Directory of Open Access Journals (Sweden)

    Ohtani N

    2016-10-01

    Full Text Available Norimasa Ohtani, Eiji Masaki Division of Dento-oral Anesthesiology, Tohoku University Graduate School of Dentistry, Sendai, Miyagi, Japan Background: Approximately half of all patients who undergo surgery develop postoperative pain, the mechanisms of which are not well understood by anesthesiologists. D2-like receptors in the descending dopaminergic pathway play an important role in regulation of pain transmission in the spinal cord. Impairment of inhibitory neurons in the spinal cord is suggested as part of the mechanism for neuropathic pain, which is one component of postoperative pain. The purpose of this study was to investigate whether impairment of D2-like receptors in the descending dopaminergic pathway in the spinal cord is involved in the decreased postoperative nociceptive threshold in rats.Methods: Male Sprague-Dawley rats (250–300 g were anesthetized with sevoflurane and an intrathecal (IT catheter was implanted. Six days later, a plantar incision was made. On the following day, saline, a D2-like receptor agonist (quinpirole, or a D2-like receptor antagonist (sulpiride was administered intrathecally. Thermal and mechanical nociceptive responses were assessed by exposure to infrared radiant heat and the von Frey filament test before and after plantar incision.Results: Plantar incision decreased both thermal latency and the mechanical nociceptive threshold. IT administration of quinpirole inhibited the nociceptive responses induced by plantar incision, but sulpiride had no effect.Conclusion: A D2-like receptor agonist had antinociceptive effects on the hypersensitivity response triggered by a surgical incision, but a D2-like receptor antagonist had no effect on this response. These results suggest that impairment and/or modification of D2-like receptors in the descending dopaminergic pathway in the spinal cord is not involved in the postoperative decrease in nociceptive threshold. Keywords: postoperative pain, descending pathway

  8. Unraveling the mechanism of neuroprotection of curcumin in arsenic induced cholinergic dysfunctions in rats

    Energy Technology Data Exchange (ETDEWEB)

    Srivastava, Pranay [CSIR-Indian Institute of Toxicology Research, Post Box 80, MG Marg, Lucknow 226 001 (India); Yadav, Rajesh S. [CSIR-Indian Institute of Toxicology Research, Post Box 80, MG Marg, Lucknow 226 001 (India); Department of Crimnology and Forensic Science, Harisingh Gour University, Sagar 470 003 (India); Chandravanshi, Lalit P.; Shukla, Rajendra K.; Dhuriya, Yogesh K.; Chauhan, Lalit K.S. [CSIR-Indian Institute of Toxicology Research, Post Box 80, MG Marg, Lucknow 226 001 (India); Dwivedi, Hari N. [Babu Banarasi Das University, BBD City, Faizabad Road, Lucknow 227 015 (India); Pant, Aditiya B. [CSIR-Indian Institute of Toxicology Research, Post Box 80, MG Marg, Lucknow 226 001 (India); Khanna, Vinay K., E-mail: vkkhanna1@gmail.com [CSIR-Indian Institute of Toxicology Research, Post Box 80, MG Marg, Lucknow 226 001 (India)

    2014-09-15

    Earlier, we found that arsenic induced cholinergic deficits in rat brain could be protected by curcumin. In continuation to this, the present study is focused to unravel the molecular mechanisms associated with the protective efficacy of curcumin in arsenic induced cholinergic deficits. Exposure to arsenic (20 mg/kg body weight, p.o) for 28 days in rats resulted to decrease the expression of CHRM2 receptor gene associated with mitochondrial dysfunctions as evident by decrease in the mitochondrial membrane potential, activity of mitochondrial complexes and enhanced apoptosis both in the frontal cortex and hippocampus in comparison to controls. The ultrastructural images of arsenic exposed rats, assessed by transmission electron microscope, exhibited loss of myelin sheath and distorted cristae in the mitochondria both in the frontal cortex and hippocampus as compared to controls. Simultaneous treatment with arsenic (20 mg/kg body weight, p.o) and curcumin (100 mg/kg body weight, p.o) for 28 days in rats was found to protect arsenic induced changes in the mitochondrial membrane potential and activity of mitochondrial complexes both in frontal cortex and hippocampus. Alterations in the expression of pro- and anti-apoptotic proteins and ultrastructural damage in the frontal cortex and hippocampus following arsenic exposure were also protected in rats simultaneously treated with arsenic and curcumin. The data of the present study reveal that curcumin could protect arsenic induced cholinergic deficits by modulating the expression of pro- and anti-apoptotic proteins in the brain. More interestingly, arsenic induced functional and ultrastructural changes in the brain mitochondria were also protected by curcumin. - Highlights: • Neuroprotective mechanism of curcumin in arsenic induced cholinergic deficits studied • Curcumin protected arsenic induced enhanced expression of stress markers in rat brain • Arsenic compromised mitochondrial electron transport chain protected

  9. Regional and muscle layer variations in cholinergic nerve control of the rat myometrium during the oestrous cycle.

    Science.gov (United States)

    Houdeau, Eric; Rossano, Bernadette; Prud'homme, Marie-Jeanne

    2003-02-28

    To determine regional and muscle layer differences in the cholinergic nerve control of uterine activity, functional and immunohistochemical experiments were carried out on the cervix, and circular and longitudinal muscle from the caudal and rostral uterine horn in cyclic rats. During oestrus, in vitro electrical field stimulation evoked contractions in the cervix and myometrium of the caudal horn, predominantly in circular muscle layer. All evoked responses were tetrodotoxin-sensitive and completely abolished by atropine, thus were cholinergic nerve-mediated. In contrast, no electrical field stimulation-induced contraction occurred in either the circular or longitudinal muscle from the rostral uterus. Concentration-response curves for carbachol showed that muscarinic receptor-mediated contractions occurred in all uterine regions and muscle layers during oestrus. Immunohistochemistry for the cholinergic nerve marker, vesicular acetylcholine transporter showed that the predominance of the acetylcholine-dependent contractions in circular muscle preparations were related to a layer-specific distribution of cholinergic nerve fibres, abundant in the circular muscle but scarce in the longitudinal muscle layer. In addition, the absence of electrical field stimulation-evoked acetylcholine-dependent contractions in the rostral uterus was correlated to a marked decrease in the density of cholinergic fibres along the caudo-rostral axis of the organ. In the uterus from diestrus rats, contractions were not elicited in response to electrical field stimulation in the cervix and circular or longitudinal muscle from the caudal as well as rostral uterine horn. Addition of cumulative doses of carbachol failed to increase in a concentration-dependent manner the frequency and amplitude of contractions in the cervix and myometrial layers from either the caudal and rostral uterine horn. The distribution and density of cholinergic nerve fibres along the uterus and between the muscle layers

  10. The basal forebrain cholinergic system in aging and dementia : Rescuing cholinergic neurons from neurotoxic amyloid-beta 42 with memantine

    NARCIS (Netherlands)

    Nyakas, Csaba; Granic, Ivica; Halmy, Laszlo G.; Banerjee, Pradeep; Luiten, Paul G. M.

    2011-01-01

    The dysfunction and loss of basal forebrain cholinergic neurons and their cortical projections are among the earliest pathological events in the pathogenesis of Alzheimer's disease (AD). The evidence pointing to cholinergic impairments come from studies that report a decline in the activity of choli

  11. Hypoxia and prostaglandin E receptor 4 signalling pathways synergise to promote endometrial adenocarcinoma cell proliferation and tumour growth.

    Directory of Open Access Journals (Sweden)

    Rob D Catalano

    Full Text Available The prostaglandin endoperoxide synthase (PTGS pathway is a potent driver of tumour development in humans by enhancing the biosynthesis and signalling of prostaglandin (PG E(2. PTGS2 expression and PGE(2 biosynthesis is elevated in endometrial adenocarcinoma, however the mechanism whereby PTGS and PGE(2 regulate endometrial tumour growth is unknown. Here we investigated (a the expression profile of the PGE synthase enzymes (PTGES, PTGES-2, PTGES-3 and PGE receptors (PTGER1-4 in endometrial adenocarcinomas compared with normal endometrium and (b the role of PTGER4 in endometrial tumorigenesis in vivo. We found elevated expression of PTGES2 and PTGER4 and suppression of PTGER1 and PTGER3 in endometrial adenocarcinomas compared with normal endometrium. Using WT Ishikawa endometrial adenocarcinoma cells and Ishikawa cells stably transfected with the full length PTGER4 cDNA (PTGER4 cells xenografted in the dorsal flanks of nude mice, we show that PTGER4 rapidly and significantly enhances tumour growth rate. Coincident with enhanced PTGER4-mediated tumour growth we found elevated expression of PTGS2 in PTGER4 xenografts compared with WT xenografts. Furthermore we found that the augmented growth rate of the PTGER4 xenografts was not due to enhanced angiogenesis, but regulated by an increased proliferation index and hypoxia. In vitro, we found that PGE(2 and hypoxia independently induce expression of PTGER4 indicating two independent pathways regulating prostanoid receptor expression. Finally we have shown that PGE(2 and hypoxia synergise to promote cellular proliferation of endometrial adenocarcinoma cells.

  12. Sodium depletion enhances renal expression of (pro)renin receptor via cyclic GMP-protein kinase G signaling pathway.

    Science.gov (United States)

    Huang, Jiqian; Siragy, Helmy M

    2012-02-01

    (Pro)renin receptor (PRR) is expressed in renal vasculature, glomeruli, and tubules. The physiological regulation of this receptor is not well established. We hypothesized that sodium depletion increases PRR expression through cGMP- protein kinase G (PKG) signaling pathway. Renal PRR expressions were evaluated in Sprague-Dawley rats on normal sodium or low-sodium diet (LS) and in cultured rat proximal tubular cells and mouse renal inner medullary collecting duct cells exposed to LS concentration. LS augmented PRR expression in renal glomeruli, proximal tubules, distal tubules, and collecting ducts. LS also increased cGMP production and PKG activity. In cells exposed to normal sodium, cGMP analog increased PKG activity and upregulated PRR expression. In cells exposed to LS, blockade of guanylyl cyclase with 1H-(1,2,4)oxadiazolo(4,3-a)quinoxalin-1-one decreased PKG activity and downregulated PRR expression. PKG inhibition decreased phosphatase protein phosphatase 2A activity; suppressed LS-mediated phosphorylation of extracellular signal-regulated kinase, c-Jun N-terminal kinase, c-Jun, and nuclear factor-κB p65; and attenuated LS-mediated PRR upregulation. LS also enhanced DNA binding of cAMP response element binding protein 1 to cAMP response elements, nuclear factor-κB p65 to nuclear factor-κB elements, and c-Jun to activator protein 1 elements in PRR promoter in proximal tubular cells. We conclude that sodium depletion upregulates renal PRR expression via the cGMP-PKG signaling pathway by enhancing binding of cAMP response element binding protein 1, nuclear factor-κB p65, and c-Jun to PRR promotor.

  13. Class A Scavenger Receptor Exacerbates Osteoclastogenesis by an Interleukin-6-Mediated Mechanism through ERK and JNK Signaling Pathways

    Science.gov (United States)

    Guo, Shuyu; Ni, Yuanyuan; Ben, Jingjing; Xia, Yang; Zhou, Tingting; Wang, Dongyue; Ni, Jieli; Bai, Hui; Wang, Lin; Ma, Junqing; Chen, Qi

    2016-01-01

    Osteoclasts originate from bone marrow monocyte/macrophage lineage cells, which are important for bone health. Class A scavenger receptor (SR-A) is a multifunctional molecule that functions during differentiation of monocyte into macrophages and osteoclasts. To further characterize the role of SR-A in osteoclasts, we used the murine tooth movement model (TM) and the murine anterior cruciate ligament transection model of osteoarthritis (ACLT OA). In these two models the bones involved are of different origin and have different properties. Bone resorption was decreased in SR-A-/- mice compared to SR-A+/+ mice. Further evaluation showed that the number of multinucleated osteoclasts in SR-A-/- mice, compared to SR-A+/+ mice, was significantly decreased both in vivo and in vitro. The levels of interleukin-6 (IL-6) produced by osteoclasts were reduced in SR-A-/- mice compared to SR-A+/+ mice. In the in vitro marrow-derived osteoclast formation assay and in both mouse models, osteoclastogenesis was restored to normal in SR-A-/- mice by administration of recombinant murine IL-6. Moreover, neutralization of IL-6 reduced the number of osteoclasts formed in SR-A+/+ mice of TM model. Both extracellular signal-regulated kinase (ERK) and c-Jun N-terminal protein kinase (JNK), but not p38, signaling pathways were downregulated in receptor activator of nuclear factor-κB ligand (RANKL)-stimulated SR-A-/- osteoclasts. Importantly, when treated with either ERK or JNK inhibitor, the numbers of osteoclasts generated from RANKL-induced bone marrow derived-macrophages of SR-A+/+ mice, and their IL-6 production, were significantly decreased. This suggests that SR-A activates the ERK and JNK signaling pathways, and promotes production of IL-6 by osteoclasts to further stimulate osteoclast formation. PMID:27766031

  14. Origin and consequences of brain Toll-like receptor 4 pathway stimulation in an experimental model of depression

    Directory of Open Access Journals (Sweden)

    Madrigal José LM

    2011-11-01

    Full Text Available Abstract Background There is a pressing need to identify novel pathophysiological pathways relevant to depression that can help to reveal targets for the development of new medications. Toll-like receptor 4 (TLR-4 has a regulatory role in the brain's response to stress. Psychological stress may compromise the intestinal barrier, and increased gastrointestinal permeability with translocation of lipopolysaccharide (LPS from Gram-negative bacteria may play a role in the pathophysiology of major depression. Methods Adult male Sprague-Dawley rats were subjected to chronic mild stress (CMS or CMS+intestinal antibiotic decontamination (CMS+ATB protocols. Levels of components of the TLR-4 signaling pathway, of LPS and of different inflammatory, oxidative/nitrosative and anti-inflammatory mediators were measured by RT-PCR, western blot and/or ELISA in brain prefrontal cortex. Behavioral despair was studied using Porsolt's test. Results CMS increased levels of TLR-4 and its co-receptor MD-2 in brain as well as LPS and LPS-binding protein in plasma. In addition, CMS also increased interleukin (IL-1β, COX-2, PGE2 and lipid peroxidation levels and reduced levels of the anti-inflammatory prostaglandin 15d-PGJ2 in brain tissue. Intestinal decontamination reduced brain levels of the pro-inflammatory parameters and increased 15d-PGJ2, however this did not affect depressive-like behavior induced by CMS. Conclusions Our results suggest that LPS from bacterial translocation is responsible, at least in part, for the TLR-4 activation found in brain after CMS, which leads to release of inflammatory mediators in the CNS. The use of Gram-negative antibiotics offers a potential therapeutic approach for the adjuvant treatment of depression.

  15. Differential expression of glutamate receptors in avian neural pathways for learned vocalization.

    Science.gov (United States)

    Wada, Kazuhiro; Sakaguchi, Hironobu; Jarvis, Erich D; Hagiwara, Masatoshi

    2004-08-01

    Learned vocalization, the substrate for human language, is a rare trait. It is found in three distantly related groups of birds-parrots, hummingbirds, and songbirds. These three groups contain cerebral vocal nuclei for learned vocalization not found in their more closely related vocal nonlearning relatives. Here, we cloned 21 receptor subunits/subtypes of all four glutamate receptor families (AMPA, kainate, NMDA, and metabotropic) and examined their expression in vocal nuclei of songbirds. We also examined expression of a subset of these receptors in vocal nuclei of hummingbirds and parrots, as well as in the brains of dove species as examples of close vocal nonlearning relatives. Among the 21 subunits/subtypes, 19 showed higher and/or lower prominent differential expression in songbird vocal nuclei relative to the surrounding brain subdivisions in which the vocal nuclei are located. This included relatively lower levels of all four AMPA subunits in lMAN, strikingly higher levels of the kainite subunit GluR5 in the robust nucleus of the arcopallium (RA), higher and lower levels respectively of the NMDA subunits NR2A and NR2B in most vocal nuclei and lower levels of the metabotropic group I subtypes (mGluR1 and -5) in most vocal nuclei and the group II subtype (mGluR2), showing a unique expression pattern of very low levels in RA and very high levels in HVC. The splice variants of AMPA subunits showed further differential expression in vocal nuclei. Some of the receptor subunits/subtypes also showed differential expression in hummingbird and parrot vocal nuclei. The magnitude of differential expression in vocal nuclei of all three vocal learners was unique compared with the smaller magnitude of differences found for nonvocal areas of vocal learners and vocal nonlearners. Our results suggest that evolution of vocal learning was accompanied by differential expression of a conserved gene family for synaptic transmission and plasticity in vocal nuclei. They also suggest

  16. Enhancing the GLP-1 receptor signaling pathway leads to proliferation and neuroprotection in human neuroblastoma cells

    OpenAIRE

    Li, Yazhou; Tweedie, David; Mattson, Mark P.; Holloway, Harold W.; Greig, Nigel H.

    2010-01-01

    Increasing evidence suggests that glucagon-like peptide-1 (GLP-1), an incretin hormone of current interest in type 2 diabetes, is neuroprotective in both cell culture and animal models. To characterize the neuroprotective properties of GLP-1 and associated underlying mechanisms, we over-expressed the GLP-1 receptor (R) on human neuroblastoma SH-SY5Y cells to generate a neuronal culture system featuring enhanced GLP-1R signaling. In GLP-1R over-expressing SH-SY5Y (SH-hGLP-1R#9) cells, GLP-1 an...

  17. Calycosin promotes angiogenesis involving estrogen receptor and mitogen-activated protein kinase (MAPK signaling pathway in zebrafish and HUVEC.

    Directory of Open Access Journals (Sweden)

    Jing Yan Tang

    as raloxifene and tamoxifen, by displaying selective potency and affinity to estrogen receptors ERalpha and ERbeta. Our results further indicated that calycosin promotes angiogenesis via activation of MAPK with the involvement of ERK1/2 and ER. Together, this study revealed, for the first time, that calycosin acts as a selective estrogen receptor modulator (SERM to promote angiogenesis, at least in part through VEGF-VEGFR2 and MAPK signaling pathways.

  18. SmShb, the SH2-Containing Adaptor Protein B of Schistosoma mansoni Regulates Venus Kinase Receptor Signaling Pathways

    Science.gov (United States)

    Morel, Marion; Vanderstraete, Mathieu; Cailliau, Katia; Hahnel, Steffen; Grevelding, Christoph G.; Dissous, Colette

    2016-01-01

    Venus kinase receptors (VKRs) are invertebrate receptor tyrosine kinases (RTKs) formed by an extracellular Venus Fly Trap (VFT) ligand binding domain associated via a transmembrane domain with an intracellular tyrosine kinase (TK) domain. Schistosoma mansoni VKRs, SmVKR1 and SmVKR2, are both implicated in reproductive activities of the parasite. In this work, we show that the SH2 domain-containing protein SmShb is a partner of the phosphorylated form of SmVKR1. Expression of these proteins in Xenopus oocytes allowed us to demonstrate that the SH2 domain of SmShb interacts with the phosphotyrosine residue (pY979) located in the juxtamembrane region of SmVKR1. This interaction leads to phosphorylation of SmShb on tyrosines and promotes SmVKR1 signaling towards the JNK pathway. SmShb transcripts are expressed in all parasite stages and they were found in ovary and testes of adult worms, suggesting a possible colocalization of SmShb and SmVKR1 proteins. Silencing of SmShb in adult S. mansoni resulted in an accumulation of mature sperm in testes, indicating a possible role of SmShb in gametogenesis. PMID:27636711