Science.gov

Sample records for cell nicotinic cholinergic

  1. Mixed nicotinic and muscarinic features of cholinergic receptor coupled to secretion in bovine chromaffin cells.

    PubMed Central

    Shirvan, M H; Pollard, H B; Heldman, E

    1991-01-01

    Acetylcholine evokes release from cultured bovine chromaffin cells by a mechanism that is believed to be classically nicotinic. However, we found that the full muscarinic agonist oxotremorine-M (Oxo-M) induced a robust catecholamine (CA) secretion. By contrast, muscarine, pilocarpine, bethanechol, and McN-A-343 did not elicit any secretory response. Desensitization of the response to nicotine by Oxo-M and desensitization of the response to Oxo-M by nicotine suggest that both nicotine and Oxo-M were acting at the same receptor. Additional experiments supporting this conclusion show that nicotine-induced secretion and Oxo-M-induced secretion were similarly blocked by various muscarinic and nicotinic antagonists. Moreover, secretion induced by nicotine and Oxo-M were Ca2+ dependent, and both agonists induced 45Ca2+ uptake. Equilibrium binding studies showed that [3H]Oxo-M bound to chromaffin cell membranes with a Kd value of 3.08 x 10(-8) M and a Hill coefficient of 1.00, suggesting one binding site for this ligand. Nicotine inhibited Oxo-M binding in a noncompetitive manner, suggesting that both ligands bind at two different sites on the same receptor. We propose that the receptor on bovine chromaffin cells that is coupled to secretion represents an unusual cholinergic receptor that has both nicotinic and muscarinic features. Images PMID:2052567

  2. Mixed nicotinic and muscarinic features of cholinergic receptor coupled to secretion in bovine chromaffin cells

    SciTech Connect

    Shirvan, M.H.; Pollard, H.B.; Heldman, E. )

    1991-06-01

    Acetylcholine evokes release from cultured bovine chromaffin cells by a mechanism that is believed to be classically nicotinic. However, the authors found that the full muscarinic agonist oxotremorine-M (Oxo-M) induced a robust catecholamine (CA) secretion. By contrast, muscarine, pilocarpine, bethanechol, and McN-A-343 did not elicit any secretory response. Desensitization of the response to nicotine by Oxo-M and desensitization of the response to Oxo-M by nicotine suggest that both nicotine and Oxo-M were acting at the same receptor. Additional experiments supporting this conclusion show that nicotine-induced secretion and Oxo-M-induced secretion were similarly blocked by various muscarinic and nicotinic antagonists. Moreover, secretion induced by nicotine and Oxo-M were Ca{sup 2+} dependent, and both agonists induced {sup 45}Ca{sup 2+} uptake. Equilibrium binding studies showed that ({sup 3}H)Oxo-M bound to chromaffin cell membranes with a K{sub d} value of 3.08 {times} 10{sup {minus}8}M and a Hill coefficient of 1.00, suggesting one binding site for this ligand. Nicotine inhibited Oxo-M binding in a noncompetitive manner, suggesting that both ligands bind at two different sites on the same receptor. They propose that the receptor on bovine chromaffin cells that is coupled to secretion represents an unusual cholinergic receptor that has both nicotinic and muscarinic features.

  3. Cholinergic modulation of dopamine pathways through nicotinic acetylcholine receptors.

    PubMed

    de Kloet, Sybren F; Mansvelder, Huibert D; De Vries, Taco J

    2015-10-15

    Nicotine addiction is highly prevalent in current society and is often comorbid with other diseases. In the central nervous system, nicotine acts as an agonist for nicotinic acetylcholine receptors (nAChRs) and its effects depend on location and receptor composition. Although nicotinic receptors are found in most brain regions, many studies on addiction have focused on the mesolimbic system and its reported behavioral correlates such as reward processing and reinforcement learning. Profound modulatory cholinergic input from the pedunculopontine and laterodorsal tegmentum to dopaminergic midbrain nuclei as well as local cholinergic interneuron projections to dopamine neuron axons in the striatum may play a major role in the effects of nicotine. Moreover, an indirect mesocorticolimbic feedback loop involving the medial prefrontal cortex may be involved in behavioral characteristics of nicotine addiction. Therefore, this review will highlight current understanding of the effects of nicotine on the function of mesolimbic and mesocortical dopamine projections in the mesocorticolimbic circuit. PMID:26208783

  4. Dopaminergic and cholinergic learning mechanisms in nicotine addiction.

    PubMed

    Subramaniyan, Manivannan; Dani, John A

    2015-09-01

    Nicotine addiction drives tobacco use by one billion people worldwide, causing nearly six million deaths a year. Nicotine binds to nicotinic acetylcholine receptors that are normally activated by the endogenous neurotransmitter acetylcholine. The widespread expression of nicotinic receptors throughout the nervous system accounts for the diverse physiological effects triggered by nicotine. A crucial influence of nicotine is on the synaptic mechanisms underlying learning that contribute to the addiction process. Here, we focus on the acquisition phase of smoking addiction and review animal model studies on how nicotine modifies dopaminergic and cholinergic signaling in key nodes of the reinforcement circuitry: ventral tegmental area, nucleus accumbens (NAc), amygdala, and hippocampus. Capitalizing on mechanisms that subserve natural rewards, nicotine activates midbrain dopamine neurons directly and indirectly, and nicotine causes dopamine release in very broad target areas throughout the brain, including the NAc, amygdala, and hippocampus. In addition, nicotine orchestrates local changes within those target structures, alters the release of virtually all major neurotransmitters, and primes the nervous system to the influence of other addictive drugs. Hence, understanding how nicotine affects the circuitry for synaptic plasticity and learning may aid in developing reasoned therapies to treat nicotine addiction. PMID:26301866

  5. Habenula cholinergic neurons regulate anxiety during nicotine withdrawal via nicotinic acetylcholine receptors.

    PubMed

    Pang, Xueyan; Liu, Liwang; Ngolab, Jennifer; Zhao-Shea, Rubing; McIntosh, J Michael; Gardner, Paul D; Tapper, Andrew R

    2016-08-01

    Cholinergic neurons in the medial habenula (MHb) modulate anxiety during nicotine withdrawal although the molecular neuroadaptation(s) within the MHb that induce affective behaviors during nicotine cessation is largely unknown. MHb cholinergic neurons are unique in that they robustly express neuronal nicotinic acetylcholine receptors (nAChRs), although their behavioral role as autoreceptors in these neurons has not been described. To test the hypothesis that nAChR signaling in MHb cholinergic neurons could modulate anxiety, we expressed novel "gain of function" nAChR subunits selectively in MHb cholinergic neurons of adult mice. Mice expressing these mutant nAChRs exhibited increased anxiety-like behavior that was alleviated by blockade with a nAChR antagonist. To test the hypothesis that anxiety induced by nicotine withdrawal may be mediated by increased MHb nicotinic receptor signaling, we infused nAChR subtype selective antagonists into the MHb of nicotine naïve and withdrawn mice. While antagonists had little effect on nicotine naïve mice, blocking α4β2 or α6β2, but not α3β4 nAChRs in the MHb alleviated anxiety in mice undergoing nicotine withdrawal. Consistent with behavioral results, there was increased functional expression of nAChRs containing the α6 subunit in MHb neurons that also expressed the α4 subunit. Together, these data indicate that MHb cholinergic neurons regulate nicotine withdrawal-induced anxiety via increased signaling through nicotinic receptors containing the α6 subunit and point toward nAChRs in MHb cholinergic neurons as molecular targets for smoking cessation therapeutics. PMID:27020042

  6. Neurocircuitry of the nicotinic cholinergic system

    PubMed Central

    Bertrand, Daniel

    2010-01-01

    Continuing to discover how the brain works is one of the great challenges ahead of us. Although understanding the brain anatomy and its functional organization provided a first and indispensable foundation, it became clear that a static view was insufficient. To understand the complexity of neuronal communication, it is necessary to examine the chemical nature of the neurotransmission and, using the example of the acetylcholine receptors, follow the different layers of networks that can be distinguished. The natural alkaloid nicotine contained in tobacco leaves acts as an agonist with a subclass of acetylcholine receptors, and provides an interesting tool to approach brain functions. Analysis of the nicotinic acetylcholine receptors, which are ligand gated channels, revealed that these receptors are expressed at different critical locations on the neurons including the synaptic boutons, neurites, cell bodies, and even on the axons. These receptors can modulate the activity at the microcircuit synaptic level, in the cell processing of information, and, by acting on the velocity of action potential, the synchrony of communication between brain areas. These actions at multiple levels of brain organization provide an example of the complexity of brain neurocircuitry and an illustration of the relevance of this knowledge for psychiatry. PMID:21319492

  7. Physical Chemistry to the Rescue: Differentiating Nicotinic and Cholinergic Agonists

    ERIC Educational Resources Information Center

    King, Angela G.

    2005-01-01

    Researches suggest that two agonists can bind to the same binding site of an important transmembrane protein and elicit a biological response through strikingly different binding interactions. Evidence is provided which suggests two possible types of nicotinic acetylcholine receptor agonist binding like acetlycholine (cholinergic) or like nicotine…

  8. The α7-nicotinic receptor is upregulated in immune cells from HIV-seropositive women: consequences to the cholinergic anti-inflammatory response

    PubMed Central

    Delgado-Vélez, Manuel; Báez-Pagán, Carlos A; Gerena, Yamil; Quesada, Orestes; Santiago-Pérez, Laura I; Capó-Vélez, Coral M; Wojna, Valerie; Meléndez, Loyda; León-Rivera, Rosiris; Silva, Walter; Lasalde-Dominicci, José A

    2015-01-01

    Antiretroviral therapy partially restores the immune system and markedly increases life expectancy of HIV-infected patients. However, antiretroviral therapy does not restore full health. These patients suffer from poorly understood chronic inflammation that causes a number of AIDS and non-AIDS complications. Here we show that chronic inflammation in HIV+ patients may be due to the disruption of the cholinergic anti-inflammatory pathway by HIV envelope protein gp120IIIB. Our results demonstrate that HIV gp120IIIB induces α7 nicotinic acetylcholine receptor (α7) upregulation and a paradoxical proinflammatory phenotype in macrophages, as activation of the upregulated α7 is no longer capable of inhibiting the release of proinflammatory cytokines. Our results demonstrate that disruption of the cholinergic-mediated anti-inflammatory response can result from an HIV protein. Collectively, these findings suggest that HIV tampering with a natural strategy to control inflammation could contribute to a crucial, unresolved problem of HIV infection: chronic inflammation. PMID:26719799

  9. The α7-nicotinic receptor is upregulated in immune cells from HIV-seropositive women: consequences to the cholinergic anti-inflammatory response.

    PubMed

    Delgado-Vélez, Manuel; Báez-Pagán, Carlos A; Gerena, Yamil; Quesada, Orestes; Santiago-Pérez, Laura I; Capó-Vélez, Coral M; Wojna, Valerie; Meléndez, Loyda; León-Rivera, Rosiris; Silva, Walter; Lasalde-Dominicci, José A

    2015-12-01

    Antiretroviral therapy partially restores the immune system and markedly increases life expectancy of HIV-infected patients. However, antiretroviral therapy does not restore full health. These patients suffer from poorly understood chronic inflammation that causes a number of AIDS and non-AIDS complications. Here we show that chronic inflammation in HIV+ patients may be due to the disruption of the cholinergic anti-inflammatory pathway by HIV envelope protein gp120IIIB. Our results demonstrate that HIV gp120IIIB induces α7 nicotinic acetylcholine receptor (α7) upregulation and a paradoxical proinflammatory phenotype in macrophages, as activation of the upregulated α7 is no longer capable of inhibiting the release of proinflammatory cytokines. Our results demonstrate that disruption of the cholinergic-mediated anti-inflammatory response can result from an HIV protein. Collectively, these findings suggest that HIV tampering with a natural strategy to control inflammation could contribute to a crucial, unresolved problem of HIV infection: chronic inflammation. PMID:26719799

  10. An autoradiographic analysis of cholinergic receptors in mouse brain after chronic nicotine treatment

    SciTech Connect

    Pauly, J.R.; Marks, M.J.; Gross, S.D.; Collins, A.C. )

    1991-09-01

    Quantitative autoradiographic procedures were used to examine the effects of chronic nicotine infusion on the number of central nervous system nicotinic cholinergic receptors. Female DBA mice were implanted with jugular cannulas and infused with saline or various doses of nicotine (0.25, 0.5, 1.0 or 2.0 mg/kg/hr) for 10 days. The animals were then sacrificed and the brains were removed and frozen in isopentane. Cryostat sections were collected and prepared for autoradiographic procedures as previously described. Nicotinic cholinergic receptors were labeled with L-(3H)nicotine or alpha-(125I)bungarotoxin; (3H)quinuclidinyl benzilate was used to measure muscarinic cholinergic receptor binding. Chronic nicotine infusion increased the number of sites labeled by (3H)nicotine in most brain areas. However, the extent of the increase in binding as well as the dose-response curves for the increase were widely different among brain regions. After the highest treatment dose, binding was increased in 67 of 86 regions measured. Septal and thalamic regions were most resistant to change. Nicotinic binding measured by alpha-(125I)bungarotoxin also increased after chronic treatment, but in a less robust fashion. At the highest treatment dose, only 26 of 80 regions were significantly changes. Muscarinic binding was not altered after chronic nicotine treatment. These data suggest that brain regions are not equivalent in the mechanisms that regulate alterations in nicotinic cholinergic receptor binding after chronic nicotine treatment.

  11. Developmental Neurotoxicity of Tobacco Smoke Directed Toward Cholinergic and Serotonergic Systems: More Than Just Nicotine.

    PubMed

    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. PMID:26085346

  12. Multiple cholinergic nicotinic receptor genes affect nicotine dependence risk in African and European Americans

    PubMed Central

    Saccone, Nancy L.; Schwantes-An, Tae-Hwi; Wang, Jen C.; Grucza, Richard A.; Breslau, Naomi; Hatsukami, Dorothy; Johnson, Eric O.; Rice, John P.; Goate, Alison M.; Bierut, Laura J.

    2010-01-01

    Several independent studies show that the chromosome 15q25.1 region, which contains the CHRNA5-CHRNA3-CHRNB4 gene cluster, harbors variants strongly associated with nicotine dependence, other smoking behaviors, lung cancer, and chronic obstructive pulmonary disease. We investigated whether variants in other cholinergic nicotinic receptor subunit (CHRN) genes affect risk for nicotine dependence in a new sample of African-Americans (N = 710). We also analyzed this African-American sample together with a European-American sample (N=2062, 1608 of which have been previously studied), allowing for differing effects in the two populations. Cases are current nicotine-dependent smokers and controls are non-dependent smokers. Variants in or near CHRND-CHRNG, CHRNA7, and CHRNA10 show modest association with nicotine dependence risk in the African-American sample. In addition, CHRNA4, CHRNB3-CHRNA6, and CHRNB1 show association in at least one population. CHRNG and CHRNA4 harbor SNPs that have opposite directions of effect in the two populations. In each of the population samples, these loci substantially increase the trait variation explained, although no loci meet Bonferroni-corrected significance in the African-American sample alone. The trait variation explained by three key associated SNPs in CHRNA5-CHRNA3-CHRNB4 is 1.9% in European-Americans and also 1.9% in African-Americans; this increases to 4.5% in EAs and 7.3% in AAs when we add six variants representing associations at other CHRN genes. Multiple nicotinic receptor subunit genes outside of chromosome 15q25 are likely to be important in the biological processes and development of nicotine dependence, and some of these risks may be shared across diverse populations. PMID:20584212

  13. The α2-subunit of the nicotinic cholinergic receptor is specifically expressed in medial subpallium-derived cells of mammalian amygdala.

    PubMed

    Pombero, Ana; Martinez, Salvador

    2015-08-01

    Nicotinic acetylcholine receptor (nAChR) subtypes are expressed in specific neuronal populations, which are involved in numerous neural functions such as sleep, fatigue, anxiety, and cognition, as well as the central processing of pain and food intake. Moreover, mutations in nAChRs subunits have been related to frontal lobe epilepsy, neurodegenerative diseases, and other neurological disorders, including schizophrenia and attention deficit and hyperactivity disorder (ADHD). Previous studies have shown that the α2-subunit of the AChR (Chrna2) is expressed in the basal forebrain, in the septum, and in some amygdalar nuclei in the adult rodent brain. However, although the importance of this amygdalar expression in emotion-related behavior and the physiopathology of neuropsychiatric disorders has been accepted, a detailed study of the Chrna2 expression pattern during development has been lacking. In this study we found that Chrna2 is specifically expressed in medial subpallium-derived amygdalar nuclei from early developmental stages to adult. This finding could help us to better understand the role of Chrna2 in the differentiation and functional maturation of amygdalar neurons involved in cholinergic-regulated emotional behavior. PMID:25641263

  14. Nicotine-Induced Modulation of the Cholinergic Twitch Response in the Ileum of Guinea Pig.

    PubMed

    Donnerer, Josef; Liebmann, Ingrid

    2015-01-01

    In the present study, the direct drug effects of nicotine and its effects on the cholinergic twitch responses of the electrically stimulated longitudinal muscle-myenteric plexus strip from the ileum of guinea pig were investigated. Nicotine dose-dependently (0.3-10 µmol/l) evoked the well-known contractile responses on its own. Whereas the interposed twitch responses remained present without a change in height at 1 µmol/l nicotine, a nicotine concentration of 3 µmol/l slightly and a concentration of 10 µmol/l markedly diminished the twitch during their presence. After the washout of 1-10 µmol/l nicotine, the height of the twitch response was also temporarily and significantly reduced by 30-77%. The P2X purinoceptor agonist αβ-methylene ATP (1-10 µmol/l) dose-dependently induced contractions on its own and reduced the twitch response during its presence in the organ bath; however, it did not diminish the twitch responses after washout of the drug as nicotine did. The P2X antagonist pyridoxalphosphate-6-azophenyl-2'-4'-disulphonic acid, the NMDA channel blocker MK-801 and the inhibitor of small conductance Ca(2+)-activated K(+) (SK) channels apamin reduced the contractile effect of 1 µmol/l nicotine. Apamin also significantly prevented the 'post-nicotine inhibition of the twitch' following the washout of 1-3 µmol/l nicotine. As a conclusion, we provide evidence for a functional interaction between nicotinic receptors and the P2X receptors in the ileum of the guinea pig. The 'post-nicotine inhibition of the twitch' is not due to nicotinic acetylcholine receptor desensitization or transmitter depletion, but most probably the secondary effects of nicotine on SK channels determine the reduced cholinergic motor neuron excitability. PMID:26088942

  15. In vivo labeling of nicotinic cholinergic receptors in brain with [3H]cytisine.

    PubMed

    Flesher, J E; Scheffel, U; London, E D; Frost, J J

    1994-01-01

    [3H]Cytisine was evaluated as an in vivo ligand for the nicotinic cholinergic receptor (nAchR) in mouse brain. The tracer was injected intravenously, and radioactivity in brain regions was analyzed. Radioactivity peaked in the brain at 30 minutes. It was highest in the thalamus, intermediate in the superior colliculi, prefrontal cortex and hippocampus, and low in the cerebellum. Pretreatment with unlabeled cytisine inhibited binding in the thalamus, but not in the cerebellum. Binding was displaced by l-nicotine, but not by d-nicotine or dexetimide. The results suggest that cytisine, appropriately labeled with a positron emitting radionuclide, may be useful for study of nicotinic cholinergic receptors in humans by emission computed tomography. PMID:8196506

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

    SciTech Connect

    Pabreza, L.A.; Dhawan, S.; Kellar, K.J. )

    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.

  17. Optogenetic studies of nicotinic contributions to cholinergic signaling in the central nervous system

    PubMed Central

    Jiang, Li; López-Hernández, Gretchen Y.; Lederman, James; Talmage, David A.; Role, Lorna W.

    2015-01-01

    Molecular manipulations and targeted pharmacological studies provide a compelling picture of which nicotinic receptor subtypes are where in the central nervous system (CNS) and what happens if one activates or deletes them. However, understanding the physiological contribution of nicotinic receptors to endogenous acetylcholine (ACh) signaling in the CNS has proven a more difficult problem to solve. In this review, we provide a synopsis of the literature on the use of optogenetic approaches to control the excitability of cholinergic neurons and to examine the role of CNS nicotinic ACh receptors (nAChRs). As is often the case, this relatively new technology has answered some questions and raised others. Overall, we believe that optogenetic manipulation of cholinergic excitability in combination with some rigorous pharmacology will ultimately advance our understanding of the many functions of nAChRs in the brain. PMID:25051276

  18. Nicotinic cholinergic receptors in rat brain. Annual report No. 2

    SciTech Connect

    Kellar, K.J.

    1985-05-13

    We have conducted experiments to determine if 3H acetylcholine (3Hach) nicotinic recognition sites are located presynaptically on catecholamine and/or serotonin axons. Lesions of these axons by intraventricular injections of neurotoxins resulted in marked decreases in 3Hach binding sites in the striatum and hypothalamus, but not in the cortex or thalamus. These results indicate that 3Hach nicotinic binding sites are located on catecholamine and serotonin axons in specific areas of the brain. In other experiments, we determined that repeated administration of nicotine results in enhanced behavioral responses to a subsequent injection of nicotine, and that there appears to be a correlation between the enhanced response to nicotine and increased 3Hach binding sites in cerebral cortex.

  19. Preclinical Evidence for a Role of the Nicotinic Cholinergic System in Parkinson's Disease.

    PubMed

    Perez, Xiomara A

    2015-12-01

    One of the primary deficits in Parkinson's disease (PD) is the loss of dopaminergic neurons in the substantia nigra pars compacta which leads to striatal dopaminergic deficits that underlie the motor symptoms associated with the disease. A plethora of animal models have been developed over the years to uncover the molecular alterations that lead to PD development. These models have provided valuable information on neurotransmitter pathways and mechanisms involved. One such a system is the nicotinic cholinergic system. Numerous studies show that nigrostriatal damage affects nicotinic receptor-mediated dopaminergic signaling; therefore therapeutic modulation of the nicotinic cholinergic system may offer a novel approach to manage PD. In fact, there is evidence showing that nicotinic receptor drugs may be useful as neuroprotective agents to prevent Parkinson's disease progression. Additional preclinical studies also show that nicotinic receptor drugs may be beneficial for the treatment of L-dopa induced dyskinesias. Here, we review preclinical findings supporting the idea that nicotinic receptors are valuable therapeutic targets for PD. PMID:26553323

  20. The effect of the augmentation of cholinergic neurotransmission by nicotine on EEG indices of visuospatial attention.

    PubMed

    Logemann, H N A; Böcker, K B E; Deschamps, P K H; Kemner, C; Kenemans, J L

    2014-03-01

    The cholinergic system has been implicated in visuospatial attention but the exact role remains unclear. In visuospatial attention, bias refers to neuronal signals that modulate the sensitivity of sensory cortex, while disengagement refers to the decoupling of attention making reorienting possible. In the current study we investigated the effect of facilitating cholinergic neurotransmission by nicotine (Nicorette Freshmint 2mg, polacrilex chewing gum) on behavioral and electrophysiological indices of bias and disengagement. Sixteen non-smoking participants performed in a Visual Spatial Cueing (VSC) task while EEG was recorded. A randomized, single-blind, crossover design was implemented. Based on the scarce literature, it was expected that nicotine would specifically augment disengagement related processing, especially manifest as an increase of the modulation of the Late Positive Deflection (LPD) by validity of cueing. No effect was expected on bias related components (cue-locked: EDAN, LDAP; target-locked: P1 and N1 modulations). Results show weak indications for a reduction of the reaction time validity effect by nicotine, but only for half of the sample in which the validity effect on the pretest was largest. Nicotine reduced the result of bias as indexed by a reduced P1 modulation by validity, especially in subjects with strong peripheral responses to nicotine. Nicotine did not affect ERP manifestations of the directing of bias (EDAN, LDAP) or disengagement (LPD). PMID:24316088

  1. Activated cholinergic signaling provides a target in squamous cell lung carcinoma.

    PubMed

    Song, Pingfang; Sekhon, Harmanjatinder S; Fu, Xiao Wen; Maier, Michelle; Jia, Yibing; Duan, Jie; Proskosil, Becky J; Gravett, Courtney; Lindstrom, Jon; Mark, Gregory P; Saha, Saurabh; Spindel, Eliot R

    2008-06-15

    The binding of exogenous nicotine to nicotinic acetylcholine (ACh) receptors (nAChR) and the binding of endogenous ACh to both nAChR and muscarinic ACh receptors (mAChR) stimulate growth of both small cell and non-small cell lung carcinomas. Understanding how cholinergic signaling is up-regulated in lung cancer may suggest new therapeutic approaches. Analysis of 28 squamous cell lung carcinomas (SCC) showed increased levels of alpha5 and beta3 nAChR mRNA and increased levels of ACh associated with increased levels of choline acetyltransferase mRNA and decreased cholinesterase mRNAs. Lynx1, an allosteric inhibitor of nAChR activity, was also decreased in SCC. Thus, cholinergic signaling is broadly increased in SCC caused by increased levels of receptors, increased levels of ligands, and decreased levels of receptor inhibitors. Partially explaining the cholinergic up-regulation seen in SCC, incubation of the H520 SCC cell line with nicotine increased levels of ACh secretion, increased expression of nAChR, and, as measured by electrophysiologic recording, increased activity of the expressed nAChR. Consistent with these effects, nicotine stimulated proliferation of H520 cells. One approach to blocking proliferative effects of nicotine and ACh on growth of lung cancers may be through M3 mAChR antagonists, which can limit the activation of mitogen-activated protein kinase that is caused by both nicotinic and muscarinic signaling. This was tested with the M3-selective muscarinic antagonist darifenacin. Darifenacin blocked nicotine-stimulated H520 growth in vitro and also blocked H520 growth in nude mice in vivo. Thus, cholinergic signaling is broadly up-regulated in SCC and blocking cholinergic signaling can limit basal and nicotine-stimulated growth of SCC. PMID:18559515

  2. Nicotinic Cholinergic Synaptic Mechanisms in the Ventral Tegmental Area Contribute to Nicotine Addiction

    ERIC Educational Resources Information Center

    Pidoplichko, Volodymyr I.; Noguchi, Jun; Areola, Oluwasanmi O.; Liang, Yong; Peterson, Jayms; Zhang, Tianxiang; Dani, John A.

    2004-01-01

    Tobacco use is a major health problem that is estimated to cause 4 million deaths a year worldwide. Nicotine is the main addictive component of tobacco. It acts as an agonist to activate and desensitize nicotinic acetylcholine receptors (nAChRs). A component of nicotine's addictive power is attributable to actions on the mesolimbic dopaminergic…

  3. Selective lesions of the cholinergic neurons within the posterior pedunculopontine do not alter operant learning or nicotine sensitization.

    PubMed

    MacLaren, Duncan A A; Wilson, David I G; Winn, Philip

    2016-04-01

    Cholinergic neurons within the pedunculopontine tegmental nucleus have been implicated in a range of functions, including behavioral state control, attention, and modulation of midbrain and basal ganglia systems. Previous experiments with excitotoxic lesions have found persistent learning impairment and altered response to nicotine following lesion of the posterior component of the PPTg (pPPTg). These effects have been attributed to disrupted input to midbrain dopamine systems, particularly the ventral tegmental area. The pPPTg contains a dense collection of cholinergic neurons and also large numbers of glutamatergic and GABAergic neurons. Because these interdigitated populations of neurons are all susceptible to excitotoxins, the effects of such lesions cannot be attributed to one neuronal population. We wished to assess whether the learning impairments and altered responses to nicotine in excitotoxic PPTg-lesioned rats were due to loss of cholinergic neurons within the pPPTg. Selective depletion of cholinergic pPPTg neurons is achievable with the fusion toxin Dtx-UII, which targets UII receptors expressed only by cholinergic neurons in this region. Rats bearing bilateral lesions of cholinergic pPPTg neurons (>90 % ChAT+ neuronal loss) displayed no deficits in the learning or performance of fixed and variable ratio schedules of reinforcement for pellet reward. Separate rats with the same lesions had a normal locomotor response to nicotine and furthermore sensitized to repeated administration of nicotine at the same rate as sham controls. Previously seen changes in these behaviors following excitotoxic pPPTg lesions cannot be attributed solely to loss of cholinergic neurons. These findings indicate that non-cholinergic neurons within the pPPTg are responsible for the learning deficits and altered responses to nicotine seen after excitotoxic lesions. The functions of cholinergic neurons may be related to behavioral state control and attention rather than learning

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

    PubMed Central

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

    2014-01-01

    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. PMID:25545599

  5. Electrophysiological and pharmacological evaluation of the nicotinic cholinergic system in chagasic rats

    PubMed Central

    2013-01-01

    Background Two theories attempt to explain the changes observed in the nicotinic acetylcholine receptors (nAChRs) in chagasic cardiomyopathy. The neurogenic theory proposes that receptor changes are due to loss of intracardiac ganglia parasympathetic neurons. The immunogenic theory proposes that the nAChRs changes are the result of autoantibodies against these receptors. Both theories agreed that nAChRs functional expression could be impaired in Chagas disease. Methods We evaluated nAChRs functional integrity in 54 Sprague Dawley rats, divided in two groups: healthy and chronic chagasic rats. Rats were subjected to electrocardiographic studies in the whole animal under pentobarbital anesthesia, by isolation and stimulation of vagus nerves and in isolated beating hearts (Langendorff’s preparation). Results Nicotine, 10 μM, induced a significant bradycardia in both groups. However, rats that had previously received reserpine did not respond to nicotine stimulation. β-adrenergic stimulation, followed by nicotine treatment, induced tachycardia in chagasic rats; while inducing bradycardia in healthy rats. Bilateral vagus nerve stimulation induced a significantly higher level of bradycardia in healthy rats, compared to chagasic rats; physostigmine potentiated the bradycardic response to vagal stimulation in both experimental groups. Electric stimulation (e.g., ≥ 2 Hz), in the presence of physostigmine, produced a comparable vagal response in both groups. In isolated beating-heart preparations 1 μM nicotine induced sustained bradycardia in healthy hearts while inducing tachycardia in chagasic hearts. Higher nicotine doses (e.g.,10 – 100 uM) promoted the characteristic biphasic response (i.e., bradycardia followed by tachycardia) in both groups. 10 nM DHβE antagonized the effect of 10 μM nicotine, unmasking the cholinergic bradycardic effect in healthy rats only. 1 nM α-BGT alone induced bradycardia in healthy hearts but antagonized the 10 μM nicotine

  6. A ten fold reduction of nicotine yield in tobacco smoke does not spare the central cholinergic system in adolescent mice.

    PubMed

    Abreu-Villaça, Yael; Correa-Santos, Monique; Dutra-Tavares, Ana C; Paes-Branco, Danielle; Nunes-Freitas, Andre; Manhães, Alex C; Filgueiras, Cláudio C; Ribeiro-Carvalho, Anderson

    2016-08-01

    The tobacco industry has gradually decreased nicotine content in cigarette smoke but the impact of this reduction on health is still controversial. Since the central cholinergic system is the primary site of action of nicotine, here, we investigated the effects of exposure of adolescent mice to tobacco smoke containing either high or low levels of nicotine on the central cholinergic system and the effects associated with cessation of exposure. From postnatal day (PN) 30 to 45, male and female Swiss mice were exposed to tobacco smoke (whole body exposure, 8h/day, 7 days/week) generated from 2R1F (HighNic group: 1.74mg nicotine/cigarette) or 4A1 (LowNic group: 0.14mg nicotine/cigarette) research cigarettes, whereas control mice were exposed to ambient air. Cholinergic biomarkers were assessed in the cerebral cortex and midbrain by the end of exposure (PN45), at short- (PN50) and long-term (PN75) deprivation. In the cortex, nicotinic cholinergic receptor upregulation was observed with either type of cigarette. In the midbrain, upregulation was detected only in HighNic mice and remained significant in females at short-term deprivation. The high-affinity choline transporter was reduced in the cortex: of HighNic mice by the end of exposure; of both HighNic and LowNic females at short-term deprivation; of LowNic mice at long-term deprivation. These decrements were separable from effects on choline acetyltransferase and acetylcholinesterase activities, suggesting cholinergic synaptic impairment. Here, we demonstrated central cholinergic alterations in an animal model of tobacco smoke exposure during adolescence. This system was sensitive even to tobacco smoke with very low nicotine content. PMID:27287270

  7. Nicotine inhibits potassium currents in Aplysia bag cell neurons.

    PubMed

    White, Sean H; Sturgeon, Raymond M; Magoski, Neil S

    2016-06-01

    Acetylcholine and the archetypal cholinergic agonist, nicotine, are typically associated with the opening of ionotropic receptors. In the bag cell neurons, which govern the reproductive behavior of the marine snail, Aplysia californica, there are two cholinergic responses: a relatively large acetylcholine-induced current and a relatively small nicotine-induced current. Both currents are readily apparent at resting membrane potential and result from the opening of distinct ionotropic receptors. We now report a separate current response elicited by applying nicotine to cultured bag cell neurons under whole cell voltage-clamp. This current was ostensibly inward, best resolved at depolarized voltages, presented a noncooperative dose-response with a half-maximal concentration near 1.5 mM, and associated with a decrease in membrane conductance. The unique nicotine-evoked response was not altered by intracellular perfusion with the G protein blocker GDPβS or exposure to classical nicotinic antagonists but was occluded by replacing intracellular K(+) with Cs(+) Consistent with an underlying mechanism of direct inhibition of one or more K(+) channels, nicotine was found to rapidly reduce the fast-inactivating A-type K(+) current as well as both components of the delayed-rectifier K(+) current. Finally, nicotine increased bag cell neuron excitability, which manifested as reduction in spike threshold, greater action potential height and width, and markedly more spiking to continuous depolarizing current injection. In contrast to conventional transient activation of nicotinic ionotropic receptors, block of K(+) channels could represent a nonstandard means for nicotine to profoundly alter the electrical properties of neurons over prolonged periods of time. PMID:26864763

  8. Nicotinic Antagonists Enhance Process Outgrowth by Rat Retinal Ganglion Cells in Culture

    NASA Astrophysics Data System (ADS)

    Lipton, Stuart A.; Frosch, Matthew P.; Phillips, Micheal D.; Tauck, David L.; Aizenman, Elias

    1988-03-01

    Functional nicotinic cholinergic receptors are found on mammalian retinal ganglion cell neurons in culture. The neurotransmitter acetylcholine (ACh) can be detected in the medium of many of these retinal cultures, after release presumably from the choline acetyltransferase-positive amacrine cells. The postsynaptic effect of endogenous or applied ACh on the ganglion cells can be blocked with specific nicotinic antagonists. Here it is shown that within 24 hours of producing such a pharmacologic blockade, the retinal ganglion cells begin to sprout or regenerate neuronal processes. Thus, the growth-enhancing effect of nicotinic antagonists may be due to the removal of inhibition to growth by tonic levels of ACh present in the culture medium. Since there is a spontaneous leak of ACh in the intact retina, the effects of nicotinic cholinergic drugs on process outgrowth in culture may reflect a normal control mechanism for growth or regeneration of retinal ganglion cell processes that is exerted by ACh in vivo.

  9. A novel cholinergic receptor mediates inhibition of chick cochlear hair cells.

    PubMed

    Fuchs, P A; Murrow, B W

    1992-04-22

    The central nervous system provides feedback regulation at several points within the peripheral auditory apparatus. One component of that feedback is inhibition of cochlear hair cells by release of acetylcholine (ACh) from efferent brainstem neurons. The mechanism of hair cell inhibition, and the character of the presumed cholinergic receptor, however, have eluded understanding. Both nicotinic and muscarinic, as well as some non-cholinergic ligands can affect the efferent action. We have made whole-cell, tight-seal recordings from short (outer) hair cells isolated from the chick's cochlea. These are the principal targets of cochlear efferents in birds. ACh hyperpolarizes short hair cells by opening a cation channel through which Ca2+ enters the cell and subsequently activates Ca(2+)-dependent K+ current (Fuchs & Murrow 1991, 1992). Both curare and atropine are effective-antagonists of cholinergic inhibition at 3 microM, whereas trimethaphan camsylate and strychnine block at 1 microM. The normally irreversible nicotinic antagonist, alpha-bungarotoxin, reversibly blocked the hair cell response, as did kappa-bungarotoxin. The half-blocking concentration for alpha-bungarotoxin was 26 nM. It is proposed that the hair cell AChR is a ligand-gated cation channel related to the nicotinic receptor of nerve and muscle. PMID:1355909

  10. Nicotinic acetylcholine receptor-mediated GABAergic inputs to cholinergic interneurons in the striosomes and the matrix compartments of the mouse striatum.

    PubMed

    Inoue, Ritsuko; Suzuki, Takeo; Nishimura, Kinya; Miura, Masami

    2016-06-01

    The striatum consists of two neurochemically distinct compartments: the striosomes (or patches) and the extrastriosomal matrix. Although striatal neurons are strongly innervated by intrinsic cholinergic interneurons, acetylcholinesterase is expressed more abundantly in the matrix than in the striosomes. At present, little is known about the different cholinergic functions of the striatal compartments. In this study, we examined gamma-aminobutyric acidergic (GABAergic) inputs to cholinergic interneurons in both compartments. We found that nicotinic receptor-mediated GABAergic responses were evoked more frequently in the matrix than in the striosomes. Furthermore, a single action potential of cholinergic neurons induced nicotinic receptor-mediated GABAergic inputs to the cholinergic neurons themselves, suggesting mutual connections that shape the temporal firing pattern of cholinergic neurons. The nicotinic receptor-mediated GABAergic responses were attenuated by continuous application of acetylcholine or the acetylcholinesterase inhibitor eserine and were enhanced by desformylflustrabromine, a positive allosteric modulator of the α4β2 subunit containing a nicotinic receptor. These results suggest that the nicotinic impact on the GABAergic responses are not uniform despite the massive and continuous cholinergic innervation. It has been reported that differential activation of neurons in the striosomes and the matrix produce a repetitive behavior called stereotypy. Drugs acting on α4β2 nicotinic receptors might provide potential tools for moderating the imbalanced activities between the compartments. PMID:26808315

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

    PubMed Central

    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

  12. Impairment of reward-related learning by cholinergic cell ablation in the striatum.

    PubMed

    Kitabatake, Yasuji; Hikida, Takatoshi; Watanabe, Dai; Pastan, Ira; Nakanishi, Shigetada

    2003-06-24

    The striatum in the basal ganglia-thalamocortical circuitry is a key neural substrate that is implicated in motor balance and procedural learning. The projection neurons in the striatum are dynamically modulated by nigrostriatal dopaminergic input and intrastriatal cholinergic input. The role of intrastriatal acetylcholine (ACh) in learning behaviors, however, remains to be fully clarified. In this investigation, we examine the involvement of intrastriatal ACh in different categories of learning by selectively ablating the striatal cholinergic neurons with use of immunotoxin-mediated cell targeting. We show that selective ablation of cholinergic neurons in the striatum impairs procedural learning in the tone-cued T-maze memory task. Spatial delayed alternation in the T-maze learning test is also impaired by cholinergic cell elimination. In contrast, the deficit in striatal ACh transmission has no effect on motor learning in the rota-rod test or spatial learning in the Morris water-maze test or on contextual- and tone-cued conditioning fear responses. We also report that cholinergic cell elimination adaptively up-regulates nicotinic ACh receptors not only within the striatum but also in the cerebral cortex and substantia nigra. The present investigation indicates that cholinergic modulation in the local striatal circuit plays a pivotal role in regulation of neural circuitry involving reward-related procedural learning and working memory. PMID:12802017

  13. Nicotinic cholinergic receptors in rat brain. Annual report No. 3, 1 May 85-30 Apr 86

    SciTech Connect

    Kellar, K.J.

    1986-05-01

    We have compared the characteristics of the recognition sites for 3(H)acetylcholine and 3H(-)nicotine in rat brain and found that the pharmacology, distribution, disulfide bond requirement, and regulation by chronic administration of nicotine and soman are identical. From these studies we conclude that 3Hacetylcholine and 3H(-)nicotine recognize the same recognition site which has the characteristics expected of a nicotinic cholinergic receptor. We have also determined that 3Hacetylcholine of high specific radioactivity (80 Ci/mmol) is an excellent ligand with which to study muscarinic receptors that have high affinity for agonists. These receptors may represent a subtype of muscarinic receptors found in brain, heart, glands, an some smooth muscle. (JS)

  14. The effect of enhancing cholinergic neurotransmission by nicotine on EEG indices of inhibition in the human brain.

    PubMed

    Logemann, H N A; Böcker, K B E; Deschamps, P K H; Kemner, C; Kenemans, J L

    2014-07-01

    The role of the cholinergic system in inhibition remains to be elucidated. Nicotine is a potent tool to augment this system, but most studies investigated its effects solely on behavior. Reference to brain activity is important to specifically identify inhibition-related mechanisms. In the current study the objective was to elucidate the role of the cholinergic system in inhibition. 16 healthy non-smokers performed in a stop task while EEG was recorded. A pre- versus post-treatment, within subjects, placebo controlled, single-blind design was used. It was hypothesized that nicotine would decrease stop-signal reaction time (SSRT) and increase the amplitude of inhibition-related event related potentials, the stop N2 and stop P3. Behavioral measures show nicotine shortened SSRT, but only when pretreatment values were not taken into account. On EEG measures, an enhanced stop P3 under nicotine was found, but only in a subsample sensitive to nicotine based on diastolic blood pressure. The results are indicative of enhanced inhibitory activity possibly reflecting enhanced activation in the superior frontal gyrus. PMID:24690513

  15. Structural characteristics of the recognition site for cholinergic ligands in the nicotinic acetylcholine receptor from squid optical ganglia

    SciTech Connect

    Plyashkevich, Yu.G.; Demushkin, V.P.

    1986-01-20

    The influence of chemical modification on the parameters of the binding of cholinergic ligands by the nicotinic acetylcholine receptor of squid optical ganglia was investigated. The presence of two subpopulations of recognition sites, differing in the composition of the groups contained in them, was detected. It was established with high probability that subpopulation I contains arginine and tyrosine residues and a carboxyl group while subpopulation II contains an amino group, a thyrosine residue, and a carboxyl group. Moreover, in both subpopulations there is an amino group important only for the binding of tubocurarin. On the basis of the results obtained, a model of the recognition sites for cholinergic ligands of the nicotinic acetylcholine receptor of squid optical ganglia is proposed.

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

    PubMed

    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. PMID:26620541

  17. Involvement of nicotinic and muscarinic receptors in the endogenous cholinergic modulation of the balance between excitation and inhibition in the young rat visual cortex.

    PubMed

    Lucas-Meunier, Estelle; Monier, Cyril; Amar, Muriel; Baux, Gérard; Frégnac, Yves; Fossier, Philippe

    2009-10-01

    This study aims to clarify how endogenous release of cortical acetylcholine (ACh) modulates the balance between excitation and inhibition evoked in visual cortex. We show that electrical stimulation in layer 1 produced a significant release of ACh measured intracortically by chemoluminescence and evoked a composite synaptic response recorded intracellularly in layer 5 pyramidal neurons of rat visual cortex. The pharmacological specificity of the ACh neuromodulation was determined from the continuous whole-cell voltage clamp measurement of stimulation-locked changes of the input conductance during the application of cholinergic agonists and antagonists. Blockade of glutamatergic and gamma-aminobutyric acid (GABAergic) receptors suppressed the evoked response, indicating that stimulation-induced release of ACh does not directly activate a cholinergic synaptic conductance in recorded neurons. Comparison of cytisine and mecamylamine effects on nicotinic receptors showed that excitation is enhanced by endogenous evoked release of ACh through the presynaptic activation of alpha(*)beta4 receptors located on glutamatergic fibers. DHbetaE, the selective alpha4beta2 nicotinic receptor antagonist, induced a depression of inhibition. Endogenous ACh could also enhance inhibition by acting directly on GABAergic interneurons, presynaptic to the recorded cell. We conclude that endogenous-released ACh amplifies the dominance of the inhibitory drive and thus decreases the excitability and sensory responsiveness of layer 5 pyramidal neurons. PMID:19176636

  18. Activation of Alpha 7 Cholinergic Nicotinic Receptors Reduce Blood–Brain Barrier Permeability following Experimental Traumatic Brain Injury

    PubMed Central

    Zhao, Jing; Kobori, Nobuhide; Redell, John B.; Hylin, Michael J.; Hood, Kimberly N.; Moore, Anthony N.

    2016-01-01

    Traumatic brain injury (TBI) is a major human health concern that has the greatest impact on young men and women. The breakdown of the blood–brain barrier (BBB) is an important pathological consequence of TBI that initiates secondary processes, including infiltration of inflammatory cells, which can exacerbate brain inflammation and contribute to poor outcome. While the role of inflammation within the injured brain has been examined in some detail, the contribution of peripheral/systemic inflammation to TBI pathophysiology is largely unknown. Recent studies have implicated vagus nerve regulation of splenic cholinergic nicotinic acetylcholine receptor α7 (nAChRa7) signaling in the regulation of systemic inflammation. However, it is not known whether this mechanism plays a role in TBI-triggered inflammation and BBB breakdown. Following TBI, we observed that plasma TNF-α and IL-1β levels, as well as BBB permeability, were significantly increased in nAChRa7 null mice (Chrna7−/−) relative to wild-type mice. The administration of exogenous IL-1β and TNF-α to brain-injured animals worsened Evans Blue dye extravasation, suggesting that systemic inflammation contributes to TBI-triggered BBB permeability. Systemic administration of the nAChRa7 agonist PNU-282987 or the positive allosteric modulator PNU-120596 significantly attenuated TBI-triggered BBB compromise. Supporting a role for splenic nAChRa7 receptors, we demonstrate that splenic injection of the nicotinic receptor blocker α-bungarotoxin increased BBB permeability in brain-injured rats, while PNU-282987 injection decreased such permeability. These effects were not seen when α-bungarotoxin or PNU-282987 were administered to splenectomized, brain-injured rats. Together, these findings support the short-term use of nAChRa7-activating agents as a strategy to reduce TBI-triggered BBB permeability. SIGNIFICANCE STATEMENT Breakdown of the blood–brain barrier (BBB) in response to traumatic brain injury (TBI

  19. Cholinergic neurotransmission links solitary chemosensory cells to nasal inflammation

    PubMed Central

    Saunders, Cecil J.; Christensen, Michael; Finger, Thomas E.; Tizzano, Marco

    2014-01-01

    Solitary chemosensory cells (SCCs) of the nasal cavity are specialized epithelial chemosensors that respond to irritants through the canonical taste transduction cascade involving Gα-gustducin and transient receptor potential melastatin 5. When stimulated, SCCs trigger peptidergic nociceptive (or pain) nerve fibers, causing an alteration of the respiratory rate indicative of trigeminal activation. Direct chemical excitation of trigeminal pain fibers by capsaicin evokes neurogenic inflammation in the surrounding epithelium. In the current study, we test whether activation of nasal SCCs can trigger similar local inflammatory responses, specifically mast cell degranulation and plasma leakage. The prototypical bitter compound, denatonium, a well-established activator of SCCs, caused significant inflammatory responses in WT mice but not mice with a genetic deletion of elements of the canonical taste transduction cascade, showing that activation of taste signaling components is sufficient to trigger local inflammation. Chemical ablation of peptidergic trigeminal fibers prevented the SCC-induced nasal inflammation, indicating that SCCs evoke inflammation only by neural activity and not by release of local inflammatory mediators. Additionally, blocking nicotinic, but not muscarinic, acetylcholine receptors prevents SCC-mediated neurogenic inflammation for both denatonium and the bacterial signaling molecule 3-oxo-C12-homoserine lactone, showing the necessity for cholinergic transmission. Finally, we show that the neurokinin 1 receptor for substance P is required for SCC-mediated inflammation, suggesting that release of substance P from nerve fibers triggers the inflammatory events. Taken together, these results show that SCCs use cholinergic neurotransmission to trigger peptidergic trigeminal nociceptors, which link SCCs to the neurogenic inflammatory pathway. PMID:24711432

  20. Targeting the Nicotinic Cholinergic System to Treat Attention-Deficit/Hyperactivity Disorder: Rationale and Progress to Date

    PubMed Central

    Potter, Alexandra S.; Schaubhut, Geoffrey; Shipman, Megan

    2014-01-01

    Attention-Deficit/Hyperactivity Disorder (ADHD) is a common, chronic neurobehavioral disorder related to clinically significant levels of inattention, hyperactivity and/or impulsivity. ADHD begins in childhood and symptoms persist into adulthood for the majority of those with the disorder. Associated features of ADHD include emotion dysregulation and cognitive impairments which contribute to the considerable functional impairments in this disorder. Current approved treatments are reasonably effective however a significant need remains for new pharmacotherapies, both for individuals who do not achieve a full therapeutic response and for symptoms that are under-treated including cognition and emotion regulation. The striking relationship between ADHD and cigarette smoking and the known effects of nicotine on cognition has spurred research into the therapeutic potential of nicotinic agents for ADHD. Although there are no approved medications for ADHD that target nicotinic acetylcholine receptor (nAChR) function, results from many trials of nicotinic drugs are available and reviewed in this article. ADHD symptoms were reduced in the majority of published studies of nicotine and novel α4β2 nicotinic agonists in adult ADHD. The drugs were generally well tolerated, with mild to moderate side effects reported, which were largely consistent with cholinergic stimulation and included nausea, dizziness, and gastrointestinal distress. Within-subject crossover study designs were used in the majority of positive studies. This design may be particularly useful in ADHD trials because it minimizes variability in this notoriously heterogeneous diagnostic group. In addition, many studies found evidence for a beneficial effect of nicotinic stimulation on cognitive and emotional domains. Thus, targeting nAChRs in ADHD appears to have modest clinical benefit in adult ADHD. Continued refinement of nAChR agonists with greater specificity and fewer side effects may lead to even more

  1. 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

    PubMed Central

    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. PMID:26257960

  2. Analysis of cyclic and acyclic nicotinic cholinergic agonists using radioligand binding, single channel recording, and nuclear magnetic resonance spectroscopy.

    PubMed Central

    McGroddy, K A; Carter, A A; Tubbert, M M; Oswald, R E

    1993-01-01

    The relationship between the structure and function of a series of nicotinic cholinergic agonists has been studied using radioligand binding, single channel recording, and nuclear magnetic resonance spectroscopy. The cyclic compound 1,1-dimethyl-4-acetylpiperazinium iodide and its trifluoromethyl analogue (F3-PIP) interact with nicotinic acetylcholine receptors (nAChRs) from both Torpedo electroplaque and BC3H-1 cells at lower concentrations than the acyclic derivatives, N,N,N,N'-tetramethyl-N'-acetylethylenediamine iodide and its fluorinated analogue (F3-TED). The magnitude of the difference in potencies depends on the type of measurement. In binding experiments, the differences between the two classes of compounds depends mainly on the conditions of the experiment. In measurements of the initial interaction with the nAChR, the PIP compounds have an affinity approximately one order of magnitude higher than that of the TED compounds. Longer incubations indicated that the PIP compounds were able to induce a time-dependent shift in receptor affinity consistent with desensitization, whereas the TED compounds were unable to induce such a shift. The activation of single channel currents by the cyclic compounds occurs at concentrations approximately two orders of magnitude lower than for the acyclic compounds, but the TED compounds exhibit a larger degree of channel blockade than the PIP compounds. Previous work (McGroddy, K.A., and R.E. Oswald. 1992. Biophys. J. 64:314-324) has shown that the TED compounds can exist in two energetically distinct conformational states related by an isomerization of the amide bond. 19F nuclear magnetic resonance experiments suggest that the higher energy population of the TED compounds may interact preferentially with the ACh binding sites on the nAChRs and that a significant fraction of the difference between the initial affinity of the PIP and TED compounds may be accounted for by the predominance in solution of a conformational state

  3. Blockade of cholinergic transmission elicits somatic signs in nicotine-naïve adolescent rats

    PubMed Central

    Schmidt, Clare E.; Manbeck, Katherine E.; Shelley, David; Harris, Andrew C.

    2015-01-01

    High doses of the nicotinic acetylcholine receptor (nAChR) antagonist mecamylamine can elicit somatic signs resembling those associated with nicotine withdrawal in nicotine-naïve adult rats. Understanding this phenomenon, and its possible modulation by acute nicotine and age, could inform the use of mecamylamine as both an experimental tool and potential pharmacotherapy for tobacco dependence and other disorders. This study evaluated the ability of high-dose mecamylamine to elicit somatic signs in adolescent rats, and the potential for acute nicotine pretreatment to potentiate this effect as previously reported in adults. Single or repeated injections of mecamylamine (1.5 or 3.0 mg/kg, s.c.) elicited somatic signs in nicotine-naïve adolescents, but this effect was not influenced by 2 h pretreatment with acute nicotine (0.5 mg/kg, s.c.). In an initial evaluation of the effects of age in this model, mecamylamine (2.25 mg/kg, s.c.) elicited somatic signs in nicotine-naïve adolescents and adults. This effect was modestly enhanced following acute nicotine injections in adults but not in adolescents, even when a higher nicotine dose (1.0 rather than 0.5 mg/kg, s.c.) was used in adolescents to account for age differences in nicotine pharmacokinetics. These studies are the first to show that mecamylamine elicits somatic signs in nicotine-naïve adolescent rats, an effect that should be considered when designing and interpreting studies examining effects of high doses of mecamylamine in adolescents. Our findings also provide preliminary evidence that these signs may be differentially modulated by acute nicotine pretreatment in adolescents versus adults. PMID:26539119

  4. Cholinergic activation enhances retinoic acid-induced differentiation in the human NB-4 acute promyelocytic leukemia cell line.

    PubMed

    Chotirat, Sadudee; Suriyo, Tawit; Hokland, Marianne; Hokland, Peter; Satayavivad, Jutamaad; Auewarakul, Chirayu U

    2016-07-01

    The non-neuronal cholinergic system (NNCS) has been shown to play a role in regulating hematopoietic differentiation. We determined the expression of cholinergic components in leukemic cell lines by Western blotting and in normal leukocyte subsets by flow cytometry and found a heterogeneous expression of choline acetyltransferase (ChAT), acetylcholinesterase (AChE), choline transporter (CHT), M3 muscarinic acetylcholine receptor (M3-mAChR) and α7 nicotinic acetylcholine receptor (α7-nAChR). We then evaluated NNCS role in differentiation of human NB-4 acute promyelocytic leukemia cell line and discovered a dramatic induction of M3-mAChR after all-trans retinoic acid (ATRA) treatment (p<0.0001). Adding carbachol which is a cholinergic agonist to the ATRA treatment resulted in an increase of a granulocytic differentiation marker (CD11b) as compared with ATRA treatment alone (p<0.05), indicating that cholinergic activation enhanced ATRA in inducing NB-4 maturation. The combination of carbachol and ATRA treatment for 72h also resulted in decreased viability and increased cleaved caspase-3 expression when compared with ATRA treatment alone (p<0.05). However, this combination did not cause poly (ADP-ribose) polymerase (PARP) cleavage. Overall, we have shown that NB-4 cells expressed M3-mAChR in a differentiation-dependent manner and cholinergic stimulation induced maturation and death of ATRA-induced differentiated NB-4 cells. PMID:27282572

  5. Cholinergic modulation of the medial prefrontal cortex: the role of nicotinic receptors in attention and regulation of neuronal activity

    PubMed Central

    Bloem, Bernard; Poorthuis, Rogier B.; Mansvelder, Huibert D.

    2014-01-01

    Acetylcholine (ACh) release in the medial prefrontal cortex (mPFC) is crucial for normal cognitive performance. Despite the fact that many have studied how ACh affects neuronal processing in the mPFC and thereby influences attention behavior, there is still a lot unknown about how this occurs. Here we will review the evidence that cholinergic modulation of the mPFC plays a role in attention and we will summarize the current knowledge about the role between ACh receptors (AChRs) and behavior and how ACh receptor activation changes processing in the cortical microcircuitry. Recent evidence implicates fast phasic release of ACh in cue detection and attention. This review will focus mainly on the fast ionotropic nicotinic receptors and less on the metabotropic muscarinic receptors. Finally, we will review limitations of the existing studies and address how innovative technologies might push the field forward in order to gain understanding into the relation between ACh, neuronal activity and behavior. PMID:24653678

  6. Neuroanatomical and neuropharmacological approaches to postictal antinociception-related prosencephalic neurons: the role of muscarinic and nicotinic cholinergic receptors.

    PubMed

    de Freitas, Renato Leonardo; Bolognesi, Luana Iacovelo; Twardowschy, André; Corrêa, Fernando Morgan Aguiar; Sibson, Nicola R; Coimbra, Norberto Cysne

    2013-05-01

    Several studies have suggested the involvement of the hippocampus in the elaboration of epilepsy. There is evidence that suggests the hippocampus plays an important role in the affective and motivational components of nociceptive perception. However, the exact nature of this involvement remains unclear. Therefore, the aim of this study was to determine the role of muscarinic and nicotinic cholinergic receptors in the dorsal hippocampus (dH) in the organization of postictal analgesia. In a neuroanatomical study, afferent connections were found from the somatosensory cortex, the medial septal area, the lateral septal area, the diagonal band of Broca, and the dentate gyrus to the dH; all these areas have been suggested to modulate convulsive activity. Outputs to the dH were also identified from the linear raphe nucleus, the median raphe nucleus (MdRN), the dorsal raphe nucleus, and the locus coeruleus. All these structures comprise the endogenous pain modulatory system and may be involved either in postictal pronociception or antinociception that is commonly reported by epileptic patients. dH-pretreatment with cobalt chloride (1.0 mmol/L CoCl2/0.2 μL) to transiently inhibit local synapses decreased postictal analgesia 10 min after the end of seizures. Pretreatment of the dH with either atropine or mecamylamine (1.0 μg/0.2 μL) attenuated the postictal antinociception 30 min after seizures, while the higher dose (5.0 μg/0.2 μL) decreased postictal analgesia immediately after the end of seizures. These findings suggest that the dH exerts a critical role in the organization of postictal analgesia and that muscarinic and nicotinic cholinergic receptor-mediated mechanisms in the dH are involved in the elaboration of antinociceptive processes induced by generalized tonic-clonic seizures. PMID:23785660

  7. Neuroanatomical and neuropharmacological approaches to postictal antinociception-related prosencephalic neurons: the role of muscarinic and nicotinic cholinergic receptors

    PubMed Central

    de Freitas, Renato Leonardo; Bolognesi, Luana Iacovelo; Twardowschy, André; Corrêa, Fernando Morgan Aguiar; Sibson, Nicola R; Coimbra, Norberto Cysne

    2013-01-01

    Several studies have suggested the involvement of the hippocampus in the elaboration of epilepsy. There is evidence that suggests the hippocampus plays an important role in the affective and motivational components of nociceptive perception. However, the exact nature of this involvement remains unclear. Therefore, the aim of this study was to determine the role of muscarinic and nicotinic cholinergic receptors in the dorsal hippocampus (dH) in the organization of postictal analgesia. In a neuroanatomical study, afferent connections were found from the somatosensory cortex, the medial septal area, the lateral septal area, the diagonal band of Broca, and the dentate gyrus to the dH; all these areas have been suggested to modulate convulsive activity. Outputs to the dH were also identified from the linear raphe nucleus, the median raphe nucleus (MdRN), the dorsal raphe nucleus, and the locus coeruleus. All these structures comprise the endogenous pain modulatory system and may be involved either in postictal pronociception or antinociception that is commonly reported by epileptic patients. dH-pretreatment with cobalt chloride (1.0 mmol/L CoCl2/0.2 μL) to transiently inhibit local synapses decreased postictal analgesia 10 min after the end of seizures. Pretreatment of the dH with either atropine or mecamylamine (1.0 μg/0.2 μL) attenuated the postictal antinociception 30 min after seizures, while the higher dose (5.0 μg/0.2 μL) decreased postictal analgesia immediately after the end of seizures. These findings suggest that the dH exerts a critical role in the organization of postictal analgesia and that muscarinic and nicotinic cholinergic receptor-mediated mechanisms in the dH are involved in the elaboration of antinociceptive processes induced by generalized tonic-clonic seizures. PMID:23785660

  8. Nicotine increases impulsivity and decreases willingness to exert cognitive effort despite improving attention in "slacker" rats: insights into cholinergic regulation of cost/benefit decision making.

    PubMed

    Hosking, Jay G; Lam, Fred C W; Winstanley, Catharine A

    2014-01-01

    Successful decision making in our daily lives requires weighing an option's costs against its associated benefits. The neuromodulator acetylcholine underlies both the etiology and treatment of a number of illnesses in which decision making is perturbed, including Alzheimer's disease, attention-deficit/hyperactivity disorder, and schizophrenia. Nicotine acts on the cholinergic system and has been touted as a cognitive enhancer by both smokers and some researchers for its attention-boosting effects; however, it is unclear whether treatments that have a beneficial effect on attention would also have a beneficial effect on decision making. Here we utilize the rodent Cognitive Effort Task (rCET), wherein animals can choose to allocate greater visuospatial attention for a greater reward, to examine cholinergic contributions to both attentional performance and choice based on attentional demand. Following the establishment of baseline behavior, four drug challenges were administered: nicotine, mecamylamine, scopolamine, and oxotremorine (saline plus three doses for each). As per previous rCET studies, animals were divided by their baseline preferences, with "worker" rats choosing high-effort/high-reward options more than their "slacker" counterparts. Nicotine caused slackers to choose even fewer high-effort trials than at baseline, but had no effect on workers' choice. Despite slackers' decreased willingness to expend effort, nicotine improved their attentional performance on the task. Nicotine also increased measures of motor impulsivity in all animals. In contrast, scopolamine decreased animals' choice of high-effort trials, especially for workers, while oxotremorine decreased motor impulsivity for all animals. In sum, the cholinergic system appears to contribute to decision making, and in part these contributions can be understood as a function of individual differences. While nicotine has been considered as a cognitive enhancer, these data suggest that its modest

  9. IL-4 Induces Cholinergic Differentiation of Retinal Cells In Vitro.

    PubMed

    Granja, Marcelo Gomes; Braga, Luis Eduardo Gomes; Carpi-Santos, Raul; de Araujo-Martins, Leandro; Nunes-Tavares, Nilson; Calaza, Karin C; Dos Santos, Aline Araujo; Giestal-de-Araujo, Elizabeth

    2015-07-01

    Interleukin-4 (IL-4) is a pleiotropic cytokine that regulates several phenomena, among them survival and differentiation of neuronal and glial cells. The aim of this work was to investigate the effect of IL-4 on the cholinergic differentiation of neonatal rat retinal cells in vitro, evaluating its effect on the levels of cholinergic markers (CHT1-high-affinity choline transporter; VAChT-vesicular acetylcholine transporter, ChAT-choline acetyltransferase, AChE-acetylcholinesterase), muscarinic receptors, and on the signaling pathways involved. Lister Hooded rat pups were used in postnatal days 0-2 (P0-P2). Our results show that IL-4 treatment (50 U/mL) for 48 h increases the levels of the cholinergic transporters VAChT and CHT1, the acetylcholinesterase activity, and the number of ChAT-positive cells. It also induces changes in muscarinic receptor levels, leading to a small decrease in M1 levels and a significant increase in M3 and M5 levels after 48 h of treatment. We also showed that IL-4 effect on M3 receptors is dependent on type I IL-4 receptor and on an increase in NFκB phosphorylation. These results indicate that IL-4 stimulates cholinergic differentiation of retinal cells. PMID:25682112

  10. Genetic Risk For Nicotine Dependence in the Cholinergic System and Activation of the Brain Reward System in Healthy Adolescents

    PubMed Central

    Nees, F; Witt, S H; Lourdusamy, A; Vollstädt-Klein, S; Steiner, S; Poustka, L; Banaschewski, T; Barker, G J; Büchel, C; Conrod, P J; Frank, J; Gallinat, J; Garavan, H; Heinz, A; Ittermann, B; Loth, E; Mann, K; Artiges, E; Paus, T; Pausova, Z; Smolka, M N; Struve, M; Schumann, G; Rietschel, M; Flor, H

    2013-01-01

    Genetic variation in a genomic region on chromosome 15q25.1, which encodes the alpha5, alpha3, and beta4 subunits of the cholinergic nicotinic receptor genes, confers risk to smoking and nicotine dependence (ND). Neural reward-related responses have previously been identified as important factors in the development of drug dependence involving ND. Applying an imaging genetics approach in two cohorts (N=487; N=478) of healthy non-smoking adolescents, we aimed to elucidate the impact of genome-wide significant smoking-associated variants in the CHRNA5–CHRNA3–CHRNB4 gene cluster on reward-related neural responses in central regions such as the striatum, orbitofrontal and anterior cingulate cortex (ACC), and personality traits related to addiction. In both samples, carriers of the rs578776 GG compared with AG/AA genotype showed a significantly lower neural response to reward outcomes in the right ventral and dorsal ACC but not the striatum or the orbitofrontal cortex. Rs578776 was unrelated to neural reward anticipation or reward magnitude. Significantly higher scores of anxiety sensitivity in GG compared with AG/AA carriers were found only in sample 1. Associations with other personality traits were not observed. Our findings suggest that the rs578776 risk variant influences susceptibility to ND by dampening the response of the ACC to reward feedback, without recruiting the striatum or orbitofrontal cortex during feedback or anticipation. Thus, it seems to have a major role in the processing of and behavioral adaptation to changing reward outcomes. PMID:23689675

  11. Genetic risk for nicotine dependence in the cholinergic system and activation of the brain reward system in healthy adolescents.

    PubMed

    Nees, F; Witt, S H; Lourdusamy, A; Vollstädt-Klein, S; Steiner, S; Poustka, L; Banaschewski, T; Barker, G J; Büchel, C; Conrod, P J; Frank, J; Gallinat, J; Garavan, H; Heinz, A; Ittermann, B; Loth, E; Mann, K; Artiges, E; Paus, T; Pausova, Z; Smolka, M N; Struve, M; Schumann, G; Rietschel, M; Flor, H

    2013-10-01

    Genetic variation in a genomic region on chromosome 15q25.1, which encodes the alpha5, alpha3, and beta4 subunits of the cholinergic nicotinic receptor genes, confers risk to smoking and nicotine dependence (ND). Neural reward-related responses have previously been identified as important factors in the development of drug dependence involving ND. Applying an imaging genetics approach in two cohorts (N=487; N=478) of healthy non-smoking adolescents, we aimed to elucidate the impact of genome-wide significant smoking-associated variants in the CHRNA5-CHRNA3-CHRNB4 gene cluster on reward-related neural responses in central regions such as the striatum, orbitofrontal and anterior cingulate cortex (ACC), and personality traits related to addiction. In both samples, carriers of the rs578776 GG compared with AG/AA genotype showed a significantly lower neural response to reward outcomes in the right ventral and dorsal ACC but not the striatum or the orbitofrontal cortex. Rs578776 was unrelated to neural reward anticipation or reward magnitude. Significantly higher scores of anxiety sensitivity in GG compared with AG/AA carriers were found only in sample 1. Associations with other personality traits were not observed. Our findings suggest that the rs578776 risk variant influences susceptibility to ND by dampening the response of the ACC to reward feedback, without recruiting the striatum or orbitofrontal cortex during feedback or anticipation. Thus, it seems to have a major role in the processing of and behavioral adaptation to changing reward outcomes. PMID:23689675

  12. Distribution of cholinergic cells in guinea pig brainstem

    PubMed Central

    Motts, S.D.; Slusarczyk, A.S.; Sowick, C.S.; Schofield, B.R.

    2008-01-01

    We used an antibody to choline acetyltransferase (ChAT) to label cholinergic cells in guinea pig brainstem. ChAT-immunoreactive (ChAT-IR) cells comprise several prominent groups, including the pedunculopontine tegmental nucleus, laterodorsal tegmental nucleus, and parabigeminal nucleus, as well as the cranial nerve somatic motor and parasympathetic nuclei. Additional concentrations are present in the parabrachial nuclei and superior colliculus. Among auditory nuclei, the majority of ChAT-IR cells are in the superior olive, particularly in and around the lateral superior olive, the ventral nucleus of the trapezoid body and the superior paraolivary nucleus. A discrete group of ChAT-IR cells is located in the sagulum, and additional cells are scattered in the nucleus of the brachium of the inferior colliculus. A group of ChAT-IR cells lies dorsal to the dorsal nucleus of the lateral lemniscus. A few ChAT-IR cells are found in the cochlear nucleus and the ventral nucleus of the lateral lemniscus. The distribution of cholinergic cells in guinea pigs is largely similar to that of other species; differences occur mainly in cell groups that have few ChAT-IR cells. The results provide a basis for further studies to characterize the connections of these cholinergic groups. PMID:18222049

  13. Onset of cholinergic efferent synaptic function in sensory hair cells of the rat cochlea.

    PubMed

    Roux, Isabelle; Wersinger, Eric; McIntosh, J Michael; Fuchs, Paul A; Glowatzki, Elisabeth

    2011-10-19

    In the developing mammalian cochlea, the sensory hair cells receive efferent innervation originating in the superior olivary complex. This input is mediated by α9/α10 nicotinic acetylcholine receptors (nAChRs) and is inhibitory due to the subsequent activation of calcium-dependent SK2 potassium channels. We examined the acquisition of this cholinergic efferent input using whole-cell voltage-clamp recordings from inner hair cells (IHCs) in acutely excised apical turns of the rat cochlea from embryonic day 21 to postnatal day 8 (P8). Responses to 1 mm acetylcholine (ACh) were detected from P0 on in almost every IHC. The ACh-activated current amplitude increased with age and demonstrated the same pharmacology as α9-containing nAChRs. Interestingly, at P0, the ACh response was not coupled to SK2 channels, so that the initial cholinergic response was excitatory and could trigger action potentials in IHCs. Coupling to SK current was detected earliest at P1 in a subset of IHCs and by P3 in every IHC studied. Clustered nAChRs and SK2 channels were found on IHCs from P1 on using Alexa Fluor 488 conjugated α-bungarotoxin and SK2 immunohistochemistry. The number of nAChRs clusters increased with age to 16 per IHC at P8. Cholinergic efferent synaptic currents first appeared in a subset of IHCs at P1 and by P3 in every IHC studied, contemporaneously with ACh-evoked SK currents, suggesting that SK2 channels may be necessary at onset of synaptic function. An analogous pattern of development was observed for the efferent synapses that form later (P6-P8) on outer hair cells in the basal cochlea. PMID:22016543

  14. Requisite Role of the Cholinergic α7 Nicotinic Acetylcholine Receptor Pathway in Suppressing Gram-Negative Sepsis-Induced Acute Lung Inflammatory Injury

    PubMed Central

    Su, Xiao; Matthay, Michael A.; Malik, Asrar B.

    2010-01-01

    Although activation of the α7 nicotinic acetylcholine receptor (α7 nAChR) modulates the response to sepsis, the role of this pathway in the development of sepsis-induced acute lung injury (ALI) is not known. In this study, we addressed the contribution of α7 nAChR in mediating endotoxin- and live Escherichia coli–induced ALI in mice. Because we found that α7 nAChR+ alveolar macrophages and neutrophils were present in bronchoalveolar lavage and injured lungs of mice, we tested whether acetylcholine released by lung vagal innervation stimulated these effector cells and thereby down-regulated proinflammatory chemokine/cytokine generation. Administration of α7 nAChR agonists reduced bronchoalveolar lavage MIP-2 production and transalveolar neutrophil migration and reduced mortality in E. coli pneumonia mice, whereas vagal denervation increased MIP-2 production and airway neutrophil accumulation and increased mortality. In addition, α7 nAChR−/− mice developed severe lung injury and had higher mortality compared with α7 nAChR+/+ mice. The immunomodulatory cholinergic α7 nAChR pathway of alveolar macrophages and neutrophils blocked LPS- and E. coli–induced ALI by reducing chemokine production and transalveolar neutrophil migration, suggesting that activation of α7 nAChR may be a promising strategy for treatment of sepsis-induced ALI. PMID:19949071

  15. Central Muscarinic Cholinergic Activation Alters Interaction between Splenic Dendritic Cell and CD4+CD25- T Cells in Experimental Colitis

    PubMed Central

    Pavlov, Valentin A.; Tracey, Kevin J.; Khafipour, Ehsan; Ghia, Jean-Eric

    2014-01-01

    Background The cholinergic anti-inflammatory pathway (CAP) is based on vagus nerve (VN) activity that regulates macrophage and dendritic cell responses in the spleen through alpha-7 nicotinic acetylcholine receptor (a7nAChR) signaling. Inflammatory bowel disease (IBD) patients present dysautonomia with decreased vagus nerve activity, dendritic cell and T cell over-activation. The aim of this study was to investigate whether central activation of the CAP alters the function of dendritic cells (DCs) and sequential CD4+/CD25−T cell activation in the context of experimental colitis. Methods The dinitrobenzene sulfonic acid model of experimental colitis in C57BL/6 mice was used. Central, intracerebroventricular infusion of the M1 muscarinic acetylcholine receptor agonist McN-A-343 was used to activate CAP and vagus nerve and/or splenic nerve transection were performed. In addition, the role of α7nAChR signaling and the NF-kB pathway was studied. Serum amyloid protein (SAP)-A, colonic tissue cytokines, IL-12p70 and IL-23 in isolated splenic DCs, and cytokines levels in DC-CD4+CD25−T cell co-culture were determined. Results McN-A-343 treatment reduced colonic inflammation associated with decreased pro-inflammatory Th1/Th17 colonic and splenic cytokine secretion. Splenic DCs cytokine release was modulated through α7nAChR and the NF-kB signaling pathways. Cholinergic activation resulted in decreased CD4+CD25−T cell priming. The anti-inflammatory efficacy of central cholinergic activation was abolished in mice with vagotomy or splenic neurectomy. Conclusions Suppression of splenic immune cell activation and altered interaction between DCs and T cells are important aspects of the beneficial effect of brain activation of the CAP in experimental colitis. These findings may lead to improved therapeutic strategies in the treatment of IBD. PMID:25295619

  16. Nicotinic α4 Receptor-Mediated Cholinergic Influences on Food Intake and Activity Patterns in Hypothalamic Circuits

    PubMed Central

    Schaaf, Laura; Heeley, Nicholas; Heuschmid, Lena; Bai, Yunjing; Barrantes, Francisco J.; Apergis-Schoute, John

    2015-01-01

    Nicotinic acetylcholine receptors (nAChRs) play an important role in regulating appetite and have been shown to do so by influencing neural activity in the hypothalamus. To shed light on the hypothalamic circuits governing acetylcholine’s (ACh) regulation of appetite this study investigated the influence of hypothalamic nAChRs expressing the α4 subunit. We found that antagonizing the α4β2 nAChR locally in the lateral hypothalamus with di-hydro-ß-erythroidine (DHβE), an α4 nAChR antagonist with moderate affinity, caused an increase in food intake following free access to food after a 12 hour fast, compared to saline-infused animals. Immunocytochemical analysis revealed that orexin/hypocretin (HO), oxytocin, and tyrosine hydroxylase (TH)-containing neurons in the A13 and A12 of the hypothalamus expressed the nAChR α4 subunit in varying amounts (34%, 42%, 50%, and 51%, respectively) whereas melanin concentrating hormone (MCH) neurons did not, suggesting that DHβE-mediated increases in food intake may be due to a direct activation of specific hypothalamic circuits. Systemic DHβE (2 mg/kg) administration similarly increased food intake following a 12 hour fast. In these animals a subpopulation of orexin/hypocretin neurons showed elevated activity compared to control animals and MCH neuronal activity was overall lower as measured by expression of the immediate early gene marker for neuronal activity cFos. However, oxytocin neurons in the paraventricular hypothalamus and TH-containing neurons in the A13 and A12 did not show differential activity patterns. These results indicate that various neurochemically distinct hypothalamic populations are under the influence of α4β2 nAChRs and that cholinergic inputs to the lateral hypothalamus can affect satiety signals through activation of local α4β2 nAChR-mediated transmission. PMID:26247203

  17. Nicotine induces fibrogenic changes in human liver via nicotinic acetylcholine receptors expressed on hepatic stellate cells

    SciTech Connect

    Soeda, Junpei; Morgan, Maelle; McKee, Chad; Mouralidarane, Angelina; Lin, ChingI; Roskams, Tania; Oben, Jude A.

    2012-01-06

    Highlights: Black-Right-Pointing-Pointer Cigarette smoke may induce liver fibrosis via nicotine receptors. Black-Right-Pointing-Pointer Nicotine induces proliferation of hepatic stellate cells (HSCs). Black-Right-Pointing-Pointer Nicotine activates hepatic fibrogenic pathways. Black-Right-Pointing-Pointer Nicotine receptor antagonists attenuate HSC proliferation. Black-Right-Pointing-Pointer Nicotinic receptor antagonists may have utility as novel anti-fibrotic agents. -- Abstract: Background and aims: Cigarette smoke (CS) may cause liver fibrosis but possible involved mechanisms are unclear. Among the many chemicals in CS is nicotine - which affects cells through nicotinic acetylcholine receptors (nAChR). We studied the effects of nicotine, and involved pathways, on human primary hepatic stellate cells (hHSCs), the principal fibrogenic cells in the liver. We then determined possible disease relevance by assaying nAChR in liver samples from human non-alcoholic steatohepatitis (NASH). Methods: hHSC were isolated from healthy human livers and nAChR expression analyzed - RT-PCR and Western blotting. Nicotine induction of hHSC proliferation, upregulation of collagen1-{alpha}2 and the pro-fibrogenic cytokine transforming growth factor beta 1 (TGF-{beta}1) was determined along with involved intracellular signaling pathways. nAChR mRNA expression was finally analyzed in whole liver biopsies obtained from patients diagnosed with non-alcoholic steatohepatitis (NASH). Results: hHSCs express muscle type ({alpha}1, {beta}1, delta and epsilon) and neuronal type ({alpha}3, {alpha}6, {alpha}7, {beta}2 and {beta}4) nAChR subunits at the mRNA level. Among these subunits, {alpha}3, {alpha}7, {beta}1 and {epsilon} were predominantly expressed as confirmed by Western blotting. Nicotine induced hHSC proliferation was attenuated by mecamylamine (p < 0.05). Additionally, collagen1-{alpha}2 and TGF-{beta}1 mRNA expression were significantly upregulated by nicotine and inhibited by

  18. Identification, characterization, and regulation of a nicotinic acetylcholine receptor on bovine adrenal chromaffin cells in culture

    SciTech Connect

    Higgins, L.S.

    1988-01-01

    Synaptic input to bovine adrenal chromaffin cells is mediated by nicotinic acetylcholine receptors (AChRs) and results in secretion of catecholamines. Three probes previously shown to recognize AChRs on neurons were used to identify the AChR on bovine adrenal chromaffin cells in culture: monoclonal antibody mAb 35, a toxin that blocks receptor function, and the agonist nicotine. Competition for {sup 3}H-nicotine binding was used to measure the affinity of cholinergic ligands, and revealed the pharmacological profile expected for a neuronal-type AChR. At steady state the rate both of receptor insertion into and loss from the plasma membrane is about 3%/hour, resulting in a half-life in the surface of about 24 hours. Exposure to the anti-AChR antibody results in a loss of AChRs from the surface of the cells through a process that has the characteristics of antigenic modulation. The number of AChRs on the surface of the chromaffin cells can also be modulated by agonists and hormones, including glucocotricoids. Catecholamines, three peptides that may be secreted by chromaffin cells, and K{sup +}-induced secretion reduce agonist-induced catecholamine release by decreasing the number of AChRs, providing a mechanism for autoregulation.

  19. Modulation of muscarinic and micotinic cholinergic receptor mediated catecholamine secretion in guinea pig chromaffin cells by phorbol esters

    SciTech Connect

    Figueiredo, J.C.; Fisher, S.K.; Horowitz, M.I.

    1986-05-01

    Isolated guinea pig chromaffin cells possess both nicotinic (nAChR) and muscarinic (mAChR) cholinergic receptors that are positively coupled to catecholamine (CA) release. Sixty to 70% of CA release is mediated by nAChRs and 30-40% by mAChRs. In the absence of added calcium, nAChR mediated CA release was reduced by 65% whereas the muscarinic response was unaffected. The addition of 100nM 12-0-tetradecanoylphorbol-13-acetate (TPA), an activator of protein kinase C (PKC), also resulted in an increased CA release. Temporally and quantitatively, this response resembled that of mAChR activation. Addition of optimal concentrations of nicotine (50..mu..M) and TPA (100nM) induced a synergistic increase in CA release. Addition of muscarine (1mM) and TPA resulted in an additive response despite a 40-60% inhibition of mAChR mediated inositol phosphate release by TPA. Thus, in guinea pig chromaffin cells, it appears that PKC activation alone is a sufficient stimulus for CA release and that activation of both nicotinic and muscarinic receptors may further increase this enzyme's activity.

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

    PubMed

    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. PMID:26044348

  1. Cholinergic Enhancement of Cell Proliferation in the Postnatal Neurogenic Niche of the Mammalian Spinal Cord

    PubMed Central

    Corns, Laura F.; Atkinson, Lucy; Daniel, Jill; Edwards, Ian J.; New, Lauryn

    2015-01-01

    Abstract The region surrounding the central canal (CC) of the spinal cord is a highly plastic area, defined as a postnatal neurogenic niche. Within this region are ependymal cells that can proliferate and differentiate to form new astrocytes and oligodendrocytes following injury and cerebrospinal fluid contacting cells (CSFcCs). The specific environmental conditions, including the modulation by neurotransmitters that influence these cells and their ability to proliferate, are unknown. Here, we show that acetylcholine promotes the proliferation of ependymal cells in mice under both in vitro and in vivo conditions. Using whole cell patch clamp in acute spinal cord slices, acetylcholine directly depolarized ependymal cells and CSFcCs. Antagonism by specific nicotinic acetylcholine receptor (nAChR) antagonists or potentiation by the α7 containing nAChR (α7*nAChR) modulator PNU 120596 revealed that both α7*nAChRs and non‐α7*nAChRs mediated the cholinergic responses. Using the nucleoside analogue EdU (5‐ethynyl‐2'‐deoxyuridine) as a marker of cell proliferation, application of α7*nAChR modulators in spinal cord cultures or in vivo induced proliferation in the CC region, producing Sox‐2 expressing ependymal cells. Proliferation also increased in the white and grey matter. PNU 120596 administration also increased the proportion of cells coexpressing oligodendrocyte markers. Thus, variation in the availability of acetylcholine can modulate the rate of proliferation of cells in the ependymal cell layer and white and grey matter through α7*nAChRs. This study highlights the need for further investigation into how neurotransmitters regulate the response of the spinal cord to injury or during aging. Stem Cells 2015;33:2864–2876 PMID:26038197

  2. Effect of Oxidative Phytochemicals on Nicotine-stressed UMNSAH/DF-1 Cell Line.

    PubMed

    Chakraborty, Amlan; Gupta, Apoorv; Singh, Abhinay Kr; Patni, Pranav

    2014-04-01

    Nicotine is a parasympathomimetic alkaloid found in the nightshade family of plants (Solanaceae) and is a cholinergic drug. It acts directly by stimulating the nicotinic or muscarinic receptors or indirectly by inhibiting cholinesterase, promoting acetylcholine release, or by other mechanisms. 3% of tobacco or one cigarette yields 1 mg of nicotine. As nicotine enters the body, it disturbs the healthy functioning of the body. In this study, we isolated UMNSAH/DF-1 cell line from Gallus gallus. For this, 9 ± 2 day old chicken embryo was taken. This was followed by the extraction of nicotine (1 mg/ml) from cigarette. The cells were then given nicotine stress and were observed for blackening after 24 h of incubation under 40× resolution of microscope. It was found that this blackening of the cells was permanent even after a wash with 1× phosphate-buffered saline (PBS) followed by replenishing the medium. The phytochemicals extracted were from the dried powder, which included Curcuma longa ( Jiāng Huáng; Turmeric) 40 mg/ml, Azadirachta indica (neem) 50 mg/ml, Cinnamomum tamala (bay leaf) 30 mg/ml, Camellia sinensis ( Lǜ Chá; Green Tea) 100 mg/ml, and Ocimum sanctum (tulsi) 30 mg/ml. When applied to nicotine-stressed cells, it was observed that ursolic acid in neem recovered 70%, followed by 65% recovery by tulsi (having triterpenoid), 50% recovery by the catechins in Ca. sinensis, and very little recovery shown by Ci. tamala. Due to the yellow coloration of the cells by Cu. longa, much could not be inferred, although it was inferable that it had resulted in little effects. Mixtures of these phytochemicals were used, and it was found that neem: tulsi diluted in 3:1 ratio was highly effective and cell recovery was almost 80%. 68% was recovered by tulsi: green tea in a ratio 1:3 and 42% by turmeric:green tea in a ratio of 1:5. PMID:24860736

  3. Effect of Oxidative Phytochemicals on Nicotine-stressed UMNSAH/DF-1 Cell Line

    PubMed Central

    Chakraborty, Amlan; Gupta, Apoorv; Singh, Abhinay Kr.; Patni, Pranav

    2014-01-01

    Nicotine is a parasympathomimetic alkaloid found in the nightshade family of plants (Solanaceae) and is a cholinergic drug. It acts directly by stimulating the nicotinic or muscarinic receptors or indirectly by inhibiting cholinesterase, promoting acetylcholine release, or by other mechanisms. 3% of tobacco or one cigarette yields 1 mg of nicotine. As nicotine enters the body, it disturbs the healthy functioning of the body. In this study, we isolated UMNSAH/DF-1 cell line from Gallus gallus. For this, 9 ± 2 day old chicken embryo was taken. This was followed by the extraction of nicotine (1 mg/ml) from cigarette. The cells were then given nicotine stress and were observed for blackening after 24 h of incubation under 40× resolution of microscope. It was found that this blackening of the cells was permanent even after a wash with 1× phosphate-buffered saline (PBS) followed by replenishing the medium. The phytochemicals extracted were from the dried powder, which included Curcuma longa (薑黃 Jiāng Huáng; Turmeric) 40 mg/ml, Azadirachta indica (neem) 50 mg/ml, Cinnamomum tamala (bay leaf) 30 mg/ml, Camellia sinensis (綠茶 Lǜ Chá; Green Tea) 100 mg/ml, and Ocimum sanctum (tulsi) 30 mg/ml. When applied to nicotine-stressed cells, it was observed that ursolic acid in neem recovered 70%, followed by 65% recovery by tulsi (having triterpenoid), 50% recovery by the catechins in Ca. sinensis, and very little recovery shown by Ci. tamala. Due to the yellow coloration of the cells by Cu. longa, much could not be inferred, although it was inferable that it had resulted in little effects. Mixtures of these phytochemicals were used, and it was found that neem: tulsi diluted in 3:1 ratio was highly effective and cell recovery was almost 80%. 68% was recovered by tulsi: green tea in a ratio 1:3 and 42% by turmeric:green tea in a ratio of 1:5. PMID:24860736

  4. Single-Cell Gene Expression Analysis of Cholinergic Neurons in the Arcuate Nucleus of the Hypothalamus.

    PubMed

    Jeong, Jae Hoon; Woo, Young Jae; Chua, Streamson; Jo, Young-Hwan

    2016-01-01

    The cholinoceptive system in the hypothalamus, in particular in the arcuate nucleus (ARC), plays a role in regulating food intake. Neurons in the ARC contain multiple neuropeptides, amines, and neurotransmitters. To study molecular and neurochemical heterogeneity of ARC neurons, we combine single-cell qRT-PCR and single-cell whole transcriptome amplification methods to analyze expression patterns of our hand-picked 60 genes in individual neurons in the ARC. Immunohistochemical and single-cell qRT-PCR analyses show choline acetyltransferase (ChAT)-expressing neurons in the ARC. Gene expression patterns are remarkably distinct in each individual cholinergic neuron. Two-thirds of cholinergic neurons express tyrosine hydroxylase (Th) mRNA. A large subset of these Th-positive cholinergic neurons is GABAergic as they express the GABA synthesizing enzyme glutamate decarboxylase and vesicular GABA transporter transcripts. Some cholinergic neurons also express the vesicular glutamate transporter transcript gene. POMC and POMC-processing enzyme transcripts are found in a subpopulation of cholinergic neurons. Despite this heterogeneity, gene expression patterns in individual cholinergic cells appear to be highly regulated in a cell-specific manner. In fact, membrane receptor transcripts are clustered with their respective intracellular signaling and downstream targets. This novel population of cholinergic neurons may be part of the neural circuitries that detect homeostatic need for food and control the drive to eat. PMID:27611685

  5. Nicotine and angiogenesis: a new paradigm for tobacco-related diseases.

    PubMed

    Cooke, John P; Bitterman, Haim

    2004-01-01

    The pathophysiology of tobacco-related diseases is complex and multifactorial. Among the approximately 4,000 compounds in tobacco smoke are carcinogens such as nitrosamines, irritants such as a variety of phenolic compounds, volatiles such as carbon monoxide, and of course nicotine. Nicotine itself has quite complex actions, mediated in part by nicotinic cholinergic receptors that may have extraneuronal, as well as neuronal distribution. This review discusses the mechanisms by which nicotine contributes to tobacco-related disease, with a focus on the surprising new finding that nicotine is a potent angiogenic agent. Nicotine hijacks an endogenous nicotinic cholinergic pathway present in endothelial cells that is involved in physiological, as well as pathological angiogenesis. PMID:15000345

  6. Nicotine improves the functional activity of late endothelial progenitor cells via nicotinic acetylcholine receptors.

    PubMed

    Yu, Min; Liu, Qian; Sun, Jing; Yi, Kaihong; Wu, Libiao; Tan, Xuerui

    2011-08-01

    The aim of this study is to investigate whether nicotinic acetylcholine receptors (nAChRs) are involved in the modulation of functional activity of late endothelial progenitor cells (EPCs) induced by nicotine. Total mononuclear cells (MNCs) were isolated from human umbilical cord blood by Ficoll density gradient centrifugation, and then the cells were plated on fibronectin-coated culture plates. Late EPCs were positive for 1,1-dioctadecyl-3,3,3,3-tetramethylindocarbocyanine-labeled acetylated low-density lipoprotein (DiI-acLDL) uptake and fluorescein-isothiocyanate-conjugated Ulex europaeus agglutinin lectin (UEA-1) binding. Expression of von Willbrand factor (vWF), kinase insert domain receptor (KDR), and α7 nAChR was detected by indirect immunofluorescence staining. Late EPCs of 3-5 passages were treated for 32 h with either vehicle or nicotine with or without pre-incubation of nAChR antagonism, mecamylamine, or α-bungarotoxin. The viability, migration, and in vitro vasculogenesis activity of late EPCs were assayed with 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, modified Boyden chamber assay, and in vitro angiogenesis assay, respectively. Late EPCs adhesion assay was performed by replating cells on fibronectin-coated plates, and then adherent cells were counted. Incubation with 10 nmol/L nicotine enhanced viable, migratory, adhesive, and in vitro vasculogenesis capacity of late EPCs. The effect of nicotine on late EPCs can be attenuated by mecamylamine or α-bungarotoxin. In conclusion, nicotine improves the functional activity of late EPCs via nAChRs. PMID:21774635

  7. Mast cell-cholinergic nerve interaction in mouse airways.

    PubMed

    Weigand, Letitia A; Myers, Allen C; Meeker, Sonya; Undem, Bradley J

    2009-07-01

    We addressed the mechanism by which antigen contracts trachea isolated from actively sensitized mice. Trachea were isolated from mice (C57BL/6J) that had been actively sensitized to ovalbumin (OVA). OVA (10 microg ml(-1)) caused histamine release (approximately total tissue content), and smooth muscle contraction that was rapid in onset and short-lived (t(1/2) < 1 min), reaching approximately 25% of the maximum tissue response. OVA contraction was mimicked by 5-HT, and responses to both OVA and 5-HT were sensitive to 10 microm-ketanserin (5-HT(2) receptor antagonist) and strongly inhibited by atropine (1microm). Epithelial denudation had no effect on the OVA-induced contraction. Histological assessment revealed about five mast cells/tracheal section the vast majority of which contained 5-HT. There were virtually no mast cells in the mast cell-deficient (sash -/-) mouse trachea. OVA failed to elicit histamine release or contractile responses in trachea isolated from sensitized mast cell-deficient (sash -/-) mice. Intracellular recordings of the membrane potential of parasympathetic neurons in mouse tracheal ganglia revealed a ketanserin-sensitive 5-HT-induced depolarization and similar depolarization in response to OVA challenge. These data support the hypothesis that antigen-induced contraction of mouse trachea is epithelium-independent, and requires mast cell-derived 5-HT to activate 5-HT(2) receptors on parasympathetic cholinergic neurons. This leads to acetylcholine release from nerve terminals, and airway smooth muscle contraction. PMID:19403609

  8. The Role of Muscarinic and Nicotinic Cholinergic Neurotransmission in Aversive Conditioning: Comparing Pavlovian Fear Conditioning and Inhibitory Avoidance

    ERIC Educational Resources Information Center

    Tinsley, Matthew R.; Quinn, Jennifer J.; Fanselow, Michael S.

    2004-01-01

    Aversive conditioning is an ideal model for studying cholinergic effects on the processes of learning and memory for several reasons. First, deficits produced by selective lesions of the anatomical structures shown to be critical for Pavlovian fear conditioning and inhibitory avoidance (such as the amygdala and hippocampus) resemble those deficits…

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

    PubMed

    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. Cholinergic regulation of protein phosphorylation in bovine adrenal chromaffin cells

    SciTech Connect

    Haycock, J.W.; Browning, M.D.; Greengard, P.

    1988-03-01

    Chromaffin cells were isolated from bovine adrenal medullae and maintained in primary culture. After prelabeling with /sup 32/PO/sub 4/, exposure of the chromaffin cells to acetylcholine increased the phosphorylation of a M/sub r/ approx. = 100,000 protein and a M/sub r/ approx. = 60,000 protein (tyrosine hydroxylase), visualized after separation of total cellular proteins in NaDodSO/sub 4//polyacrylamide gels. Immunoprecipitation with antibodies to three known phosphoproteins (100-kDa, 87-kDa, and protein III) revealed an acetylcholine-dependent phosphorylation of these proteins. These three proteins were also shown to be present in bovine adrenal chromaffin cells by immunolabeling techniques. 100-kDa is a M/sub r/ approx. = 100,000 protein selectively phosphorylated by calcium/calmodulin-dependent protein kinase III, 87-kDa is a M/sub r/ approx. = 87,000 protein selectively phosphorylated by protein kinase C, and protein III is a phosphoprotein doublet of M/sub r/ approx. = 74,000 (IIIa) and M/sub r/ approx. = 55,000 (IIIb) phosphorylated by cAMP-dependent protein kinase and calcium/calmodulin-dependent protein kinase I. The data demonstrate that cholinergic activation of chromaffin cells increases the phosphorylation of several proteins and that several protein kinase systems may be involved in these effects.

  11. The Nicotinic Receptor of Cochlear Hair Cells: A Possible Pharmacotherapeutic Target?

    PubMed Central

    Elgoyhen, Ana Belén; Katz, Eleonora; Fuchs, Paul A.

    2009-01-01

    Mechanosensory hair cells of the organ of Corti transmit information regarding sound to the central nervous system by way of peripheral afferent neurons. In return, the central nervous system provides feedback and modulates the afferent stream of information through efferent neurons. The medial olivocochlear efferent system makes direct synaptic contacts with outer hair cells and inhibits amplification brought about by the active mechanical process inherent to these cells. This feedback system offers the potential to improve the detection of signals in background noise, to selectively attend to particular signals, and to protect the periphery from damage caused by overly loud sounds. Acetylcholine released at the synapse between efferent terminals and outer hair cells activates a peculiar nicotinic cholinergic receptor subtype, the α9α10 receptor. At present no pharmacotherapeutic approaches have been designed that target this cholinergic receptor to treat pathologies of the auditory system. The potential use of α9α10 selective drugs in conditions such as noise-induced hearing loss, tinnitus and auditory processing disorders is discussed. PMID:19481062

  12. Cholinergic regulation of the vasopressin neuroendocrine system

    SciTech Connect

    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.

  13. Higher sensitivity to cadmium induced cell death of basal forebrain cholinergic neurons: a cholinesterase dependent mechanism.

    PubMed

    Del Pino, Javier; Zeballos, Garbriela; Anadon, María José; Capo, Miguel Andrés; Díaz, María Jesús; García, Jimena; Frejo, María Teresa

    2014-11-01

    Cadmium is an environmental pollutant, which is a cause of concern because it can be greatly concentrated in the organism causing severe damage to a variety of organs including the nervous system which is one of the most affected. Cadmium has been reported to produce learning and memory dysfunctions and Alzheimer like symptoms, though the mechanism is unknown. On the other hand, cholinergic system in central nervous system (CNS) is implicated on learning and memory regulation, and it has been reported that cadmium can affect cholinergic transmission and it can also induce selective toxicity on cholinergic system at peripheral level, producing cholinergic neurons loss, which may explain cadmium effects on learning and memory processes if produced on central level. The present study is aimed at researching the selective neurotoxicity induced by cadmium on cholinergic system in CNS. For this purpose we evaluated, in basal forebrain region, the cadmium toxic effects on neuronal viability and the cholinergic mechanisms related to it on NS56 cholinergic mourine septal cell line. This study proves that cadmium induces a more pronounced, but not selective, cell death on acetylcholinesterase (AChE) on cholinergic neurons. Moreover, MTT and LDH assays showed a dose dependent decrease of cell viability in NS56 cells. The ACh treatment of SN56 cells did not revert cell viability reduction induced by cadmium, but siRNA transfection against AChE partially reduced it. Our present results provide new understanding of the mechanisms contributing to the harmful effects of cadmium on the function and viability of neurons, and the possible relevance of cadmium in the pathogenesis of neurodegenerative diseases. PMID:25201352

  14. A two-layer biophysical model of cholinergic neuromodulation in olfactory bulb

    PubMed Central

    Li, Guoshi; Cleland, Thomas A.

    2013-01-01

    Cholinergic inputs from the basal forebrain regulate multiple olfactory bulb (OB) functions including odor discrimination, perceptual learning, and short term memory. Previous studies have shown that nicotinic cholinergic receptor activation sharpens mitral cell chemoreceptive fields, likely via intraglomerular circuitry. Muscarinic cholinergic activation is less well understood, though muscarinic receptors are implicated in olfactory learning and in the regulation of synchronized oscillatory dynamics in hippocampus and cortex. To understand the mechanisms underlying cholinergic neuromodulation in OB, we developed a biophysical model of the OB neuronal network including both glomerular layer and external plexiform layer (EPL) computations and incorporating both nicotinic and muscarinic neuromodulatory effects. Our simulations show how nicotinic activation within glomerular circuits sharpens mitral cell chemoreceptive fields, even in the absence of EPL circuitry, but does not facilitate intrinsic oscillations or spike synchronization. In contrast, muscarinic receptor activation increases mitral cell spike synchronization and field oscillatory power by potentiating granule cell excitability and lateral inhibitory interactions within the EPL, but has little effect on mitral cell firing rates and hence will not sharpen olfactory representations under a rate metric. These results are consistent with the theory that EPL interactions regulate the timing, rather than the existence, of mitral cell action potentials, and perform their computations with respect to a spike timing-based metric. This general model suggests that the roles of nicotinic and muscarinic receptors in olfactory bulb are both distinct and complementary to one another, together regulating the effects of ascending cholinergic inputs on olfactory bulb transformations. PMID:23407960

  15. Serotonin 5-HT4 receptors and forebrain cholinergic system: receptor expression in identified cell populations.

    PubMed

    Peñas-Cazorla, Raúl; Vilaró, M Teresa

    2015-11-01

    Activation of serotonin 5-HT4 receptors has pro-cognitive effects on memory performance. The proposed underlying neurochemical mechanism is the enhancement of acetylcholine release in frontal cortex and hippocampus elicited by 5-HT4 agonists. Although 5-HT4 receptors are present in brain areas related to cognition, e.g., hippocampus and cortex, the cellular localization of the receptors that might modulate acetylcholine release is unknown at present. We have analyzed, using dual label in situ hybridization, the cellular localization of 5-HT4 receptor mRNA in identified neuronal populations of the rat basal forebrain, which is the source of the cholinergic innervation to cortex and hippocampus. 5-HT4 receptor mRNA was visualized with isotopically labeled oligonucleotide probes, whereas cholinergic, glutamatergic, GABAergic and parvalbumin-synthesizing neurons were identified with digoxigenin-labeled oligonucleotide probes. 5-HT4 receptor mRNA was not detected in the basal forebrain cholinergic cell population. In contrast, basal forebrain GABAergic, parvalbumin synthesizing, and glutamatergic cells contained 5-HT4 receptor mRNA. Hippocampal and cortical glutamatergic neurons also express this receptor. These results indicate that 5-HT4 receptors are not synthesized by cholinergic cells, and thus would be absent from cholinergic terminals. In contrast, several non-cholinergic cell populations within the basal forebrain and its target hippocampal and cortical areas express these receptors and are thus likely to mediate the enhancement of acetylcholine release elicited by 5-HT4 agonists. PMID:25183542

  16. Muscarinic signaling influences the patterning and phenotype of cholinergic amacrine cells in the developing chick retina

    PubMed Central

    Stanke, Jennifer J; Lehman, Bret; Fischer, Andy J

    2008-01-01

    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. PMID:18254959

  17. Prenatal Ablation of Nicotinic Receptor alpha7 Cell Lineages Produces Lumbosacral Spina Bifida the Severity of Which is Modified by Choline and Nicotine Exposure

    PubMed Central

    Rogers, Scott W; Tvrdik, Petr; Capecchi, Mario R; Gahring, Lorise C

    2012-01-01

    Lumbosacral spina bifida is a common debilitating birth defect whose multiple causes are poorly understood. Here, we provide the first genetic delineation of cholinergic nicotinic receptor alpha7 (Chrna7) expression and link the ablation of the Chrna7 cell lineage to this condition in the mouse. Using homologous recombination, an IRES-Cre bi-cistronic cassette was introduced into the 3′ noncoding region of Chrna7 (Chrna7:Cre) for identifying cell lineages expressing this gene. This lineage first appears at embryonic day E9.0 in rhombomeres 3 and 5 of the neural tube and extends to cell subsets in most tissues by E14.5. Ablation of the Chrna7:Cre cell lineage in embryos from crosses with conditionally expressed attenuated diphtheria toxin results in precise developmental defects including omphalocele (89%) and open spina bifida (SB; 80%). We hypothesized that like humans, this defect would be modified by environmental compounds not only folic acid or choline but also nicotine. Prenatal chronic oral nicotine administration substantially worsened the defect to often include the rostral neural tube. In contrast, supplementation of the maternal diet with 2% choline decreased SB prevalence to 38% and dramatically reduced the defect severity. Folic acid supplementation only trended towards a reduced SB frequency. The omphalocele was unaffected by these interventions. These studies identify the Chrna7 cell lineage as participating in posterior neuropore closure and present a novel model of lower SB that can be substantially modified by the prenatal environment. © 2012 Wiley Periodicals, Inc. PMID:22473653

  18. Cholinergic pesticides cause mushroom body neuronal inactivation in honeybees

    PubMed Central

    Palmer, Mary J.; Moffat, Christopher; Saranzewa, Nastja; Harvey, Jenni; Wright, Geraldine A.; Connolly, Christopher N.

    2013-01-01

    Pesticides that target cholinergic neurotransmission are highly effective, but their use has been implicated in insect pollinator population decline. Honeybees are exposed to two widely used classes of cholinergic pesticide: neonicotinoids (nicotinic receptor agonists) and organophosphate miticides (acetylcholinesterase inhibitors). Although sublethal levels of neonicotinoids are known to disrupt honeybee learning and behaviour, the neurophysiological basis of these effects has not been shown. Here, using recordings from mushroom body Kenyon cells in acutely isolated honeybee brain, we show that the neonicotinoids imidacloprid and clothianidin, and the organophosphate miticide coumaphos oxon, cause a depolarization-block of neuronal firing and inhibit nicotinic responses. These effects are observed at concentrations that are encountered by foraging honeybees and within the hive, and are additive with combined application. Our findings demonstrate a neuronal mechanism that may account for the cognitive impairments caused by neonicotinoids, and predict that exposure to multiple pesticides that target cholinergic signalling will cause enhanced toxicity to pollinators. PMID:23535655

  19. Impact of nicotine on the interplay between human periodontal ligament cells and CD4+ T cells.

    PubMed

    Ge, Xin; Liu, Ying-Feng; Wong, Yong; Wu, Li-Zheng; Tan, Ling; Liu, Fen; Wang, Xiao-Jing

    2016-09-01

    Periodontitis is a common infectious disease associated with destruction of periodontal ligaments and alveolar bones. CD4(+) T cell-mediated immune response is involved in the progression of periodontitis. Tobacco consumption increases the risk of periodontal disease. However, the impact of nicotine on the interaction between human periodontal ligament (PDL) cells and CD4(+) T cells remains unrevealed. Our study aims to investigate the effect of nicotine on PDL cells and the cocultured CD4(+) T cells. The PDL cell cultures were established by explants from healthy individuals, exposed to nicotine or α-bungarotoxin (α-BTX), and incubated solely or in combination with CD4(+) T cells. Afterwards, cell viability, secreted cytokines, and matrix metalloproteinases (MMPs) were evaluated. In monoculture of PDL cells, nicotine dramatically repressed cell viability and increased apoptosis. Meanwhile, α-BTX largely reversed the nicotine-induced apoptosis and increased viability of PDL cells. Compared with the monoculture, MMP-1, MMP-3, interleukin (IL)-1β, IL-6, IL-17, and IL-21 in supernatant of cocultures were markedly elevated after treatment with nicotine. Moreover, α-BTX significantly attenuated nicotine-triggered production of these components either in mono- or co-cultures. In addition, PDL cell-derived CXCL12 following nicotine treatment recruited CD4(+) T cells. Above all, nicotine deteriorated periodontitis partially by promoting PDL cell-CD4(+) T cell-mediated inflammatory response and matrix degradation. PMID:26553320

  20. Sox2 Regulates Cholinergic Amacrine Cell Positioning and Dendritic Stratification in the Retina

    PubMed Central

    Whitney, Irene E.; Keeley, Patrick W.; St. John, Ace J.; Kautzman, Amanda G.; Kay, Jeremy N.

    2014-01-01

    The retina contains two populations of cholinergic amacrine cells, one positioned in the ganglion cell layer (GCL) and the other in the inner nuclear layer (INL), that together comprise ∼1/2 of a percent of all retinal neurons. The present study examined the genetic control of cholinergic amacrine cell number and distribution between these two layers. The total number of cholinergic amacrine cells was quantified in the C57BL/6J and A/J inbred mouse strains, and in 25 recombinant inbred strains derived from them, and variations in their number and ratio (GCL/INL) across these strains were mapped to genomic loci. The total cholinergic amacrine cell number was found to vary across the strains, from 27,000 to 40,000 cells, despite little variation within individual strains. The number of cells was always lower within the GCL relative to the INL, and the sizes of the two populations were strongly correlated, yet there was variation in their ratio between the strains. Approximately 1/3 of that variation in cell ratio was mapped to a locus on chromosome 3, where Sex determining region Y box 2 (Sox2) was identified as a candidate gene due to the presence of a 6-nucleotide insertion in the protein-coding sequence in C57BL/6J and because of robust and selective expression in cholinergic amacrine cells. Conditionally deleting Sox2 from the population of nascent cholinergic amacrine cells perturbed the normal ratio of cells situated in the GCL versus the INL and induced a bistratifying morphology, with dendrites distributed to both ON and OFF strata within the inner plexiform layer. PMID:25057212

  1. Striatal cholinergic interneurons drive GABA release from dopamine terminals

    PubMed Central

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

    2014-01-01

    Summary 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. PMID:24613418

  2. Acetylcholine induces GABA release onto rod bipolar cells through heteromeric nicotinic receptors expressed in A17 amacrine cells

    PubMed Central

    Elgueta, Claudio; Vielma, Alex H.; Palacios, Adrian G.; Schmachtenberg, Oliver

    2015-01-01

    Acetylcholine (ACh) is a major retinal neurotransmitter that modulates visual processing through a large repertoire of cholinergic receptors expressed on different retinal cell types. ACh is released from starburst amacrine cells (SACs) under scotopic conditions, but its effects on cells of the rod pathway have not been investigated. Using whole-cell patch clamp recordings in slices of rat retina, we found that ACh application triggers GABA release onto rod bipolar (RB) cells. GABA was released from A17 amacrine cells and activated postsynaptic GABAA and GABAC receptors in RB cells. The sensitivity of ACh-induced currents to nicotinic ACh receptor (nAChR) antagonists (TMPH ~ mecamylamine > erysodine > DhβE > MLA) together with the differential potency of specific agonists to mimic ACh responses (cytisine >> RJR2403 ~ choline), suggest that A17 cells express heteromeric nAChRs containing the β4 subunit. Activation of nAChRs induced GABA release after Ca2+ accumulation in A17 cell dendrites and varicosities mediated by L-type voltage-gated calcium channels (VGCCs) and intracellular Ca2+ stores. Inhibition of acetylcholinesterase depolarized A17 cells and increased spontaneous inhibitory postsynaptic currents in RB cells, indicating that endogenous ACh enhances GABAergic inhibition of RB cells. Moreover, injection of neostigmine or cytisine reduced the b-wave of the scotopic flash electroretinogram (ERG), suggesting that cholinergic modulation of GABA release controls RB cell activity in vivo. These results describe a novel regulatory mechanism of RB cell inhibition and complement our understanding of the neuromodulatory control of retinal signal processing. PMID:25709566

  3. Nicotine induces mitochondrial fission through mitofusin degradation in human multipotent embryonic carcinoma cells.

    PubMed

    Hirata, Naoya; Yamada, Shigeru; Asanagi, Miki; Sekino, Yuko; Kanda, Yasunari

    2016-02-01

    Nicotine is considered to contribute to the health risks associated with cigarette smoking. Nicotine exerts its cellular functions by acting on nicotinic acetylcholine receptors (nAChRs), and adversely affects normal embryonic development. However, nicotine toxicity has not been elucidated in human embryonic stage. In the present study, we examined the cytotoxic effects of nicotine in human multipotent embryonal carcinoma cell line NT2/D1. We found that exposure to 10 μM nicotine decreased intracellular ATP levels and inhibited proliferation of NT2/D1 cells. Because nicotine suppressed energy production, which is a critical mitochondrial function, we further assessed the effects of nicotine on mitochondrial dynamics. Staining with MitoTracker revealed that 10 μM nicotine induced mitochondrial fragmentation. The levels of the mitochondrial fusion proteins, mitofusins 1 and 2, were also reduced in cells exposed to nicotine. These nicotine effects were blocked by treatment with mecamylamine, a nonselective nAChR antagonist. These data suggest that nicotine degrades mitofusin in NT2/D1 cells and thus induces mitochondrial dysfunction and cell growth inhibition in a nAChR-dependent manner. Thus, mitochondrial function in embryonic cells could be used to assess the developmental toxicity of chemicals. PMID:26774337

  4. A novel cholinergic epithelial cell with chemosensory traits in the murine conjunctiva.

    PubMed

    Wiederhold, Stephanie; Papadakis, Tamara; Chubanov, Vladimir; Gudermann, Thomas; Krasteva-Christ, Gabriela; Kummer, Wolfgang

    2015-11-01

    We recently identified a specialized cholinergic cell type in tracheal and urethral epithelium that utilizes molecules of the canonical taste transduction signaling cascade to sense potentially harmful substances in the luminal content. Upon stimulation, this cell initiates protective reflexes. Assuming a sentinel role of such cells at mucosal surfaces exposed to bacteria, we hypothesized their occurrence also in ocular mucosal surfaces. Utilizing a mouse strain expressing eGFP under the promoter of the acetylcholine synthesizing enzyme, choline acetyltransferase (ChAT-eGFP), we observed a cholinergic cell in the murine conjunctiva. Singular cholinergic cells reaching the epithelial surface with slender processes were detected in fornical, but neither in bulbar nor palpebral epithelia. These cells were found neither in the lacrimal canaliculi, nor in the lacrimal sac and the nasolacrimal duct. Cholinergic conjunctival epithelial cells were immunoreactive for components of the canonical taste transduction signaling cascade, i.e. α-gustducin, phospholipase Cβ2 and the monovalent cation channel TRPM5. Calcitonin gene-related peptide- and substance P-immunoreactive sensory nerve fibers were observed extending into the conjunctival epithelium approaching slender ChAT-eGFP-positive cells. In addition, we noted both ChAT-eGFP expression and α-gustducin-immunoreactivity, albeit in different cell populations, in occasionally occurring lymphoid follicles of the nictitating membrane. The data show a previously unidentified cholinergic cell in murine conjunctiva with chemosensory traits that presumably utilizes acetylcholine for signaling. In analogy to similar cells described in the respiratory and urethral epithelium, it might serve to detect bacterial products and to initiate protective reflexes. PMID:26119492

  5. Functional chromaffin cell plasticity in response to stress: focus on nicotinic, gap junction, and voltage-gated Ca2+ channels.

    PubMed

    Guérineau, Nathalie C; Desarménien, Michel G; Carabelli, Valentina; Carbone, Emilio

    2012-10-01

    An increase in circulating catecholamines constitutes one of the mechanisms whereby human body responds to stress. In response to chronic stressful situations, the adrenal medullary tissue exhibits crucial morphological and functional changes that are consistent with an improvement of chromaffin cell stimulus-secretion coupling efficiency. Stimulus-secretion coupling encompasses multiple intracellular (chromaffin cell excitability, Ca(2+) signaling, exocytosis, endocytosis) and intercellular pathways (splanchnic nerve-mediated synaptic transmission, paracrine and endocrine communication, gap junctional coupling), each of them being potentially subjected to functional remodeling upon stress. This review focuses on three chromaffin cell incontrovertible actors, the cholinergic nicotinic receptors and the voltage-dependent T-type Ca(2+) channels that are directly involved in Ca(2+)-dependent events controlling catecholamine secretion and electrical activity, and the gap junctional communication involved in the modulation of catecholamine secretion. We show here that these three actors react differently to various stressors, sometimes independently, sometimes in concert or in opposition. PMID:22252244

  6. Functional chromaffin cell plasticity in response to stress: focus on nicotinic, gap junction, and voltage-gated Ca2+ channels

    PubMed Central

    Guérineau, Nathalie C.; Desarménien, Michel G.; Carabelli, Valentina; Carbone, Emilio

    2012-01-01

    An increase in circulating catecholamines constitutes one of the mechanisms whereby human body responds to stress. In response to chronic stressful situations, the adrenal medullary tissue exhibits crucial morphological and functional changes that are consistent with an improvement of chromaffin cell stimulus-secretion coupling efficiency. Stimulus-secretion coupling encompasses multiple intracellular (chromaffin cell excitability, Ca2+ signaling, exocytosis, endocytosis) and intercellular pathways (splanchnic nerve-mediated synaptic transmission, paracrine and endocrine communication, gap junctional coupling), each of them being potentially subjected to functional remodeling upon stress. This review focuses on three chromaffin cell incontrovertible actors, the cholinergic nicotinic receptors and the voltage-dependent T-type Ca2+ channels that are directly involved in Ca2+-dependent events controlling catecholamine secretion and electrical activity, and the gap junctional communication involved in the modulation of catecholamine secretion. We show here that these three actors react differently to various stressors, sometimes independently, sometimes in concert or in opposition. PMID:22252244

  7. Cellular basis for the olfactory response to nicotine.

    PubMed

    Bryant, Bruce; Xu, Jiang; Audige, Valery; Lischka, Fritz W; Rawson, Nancy E

    2010-03-17

    Smokers regulate their smoking behavior on the basis of sensory stimuli independently of the pharmacological effects of nicotine (Rose J. E., et al. (1993) Pharmacol., Biochem. Behav.44 (4), 891-900). A better understanding of sensory mechanisms underlying smoking behavior may help to develop more effective smoking alternatives. Olfactory stimulation by nicotine makes up a considerable part of the flavor of tobacco smoke, yet our understanding of the cellular mechanisms responsible for olfactory detection of nicotine remains incomplete. We used biophysical methods to characterize the nicotine sensitivity and response mechanisms of neurons from olfactory epithelium. In view of substantial differences in the olfactory receptor repertoire between rodent and human (Mombaerts P. (1999) Annu. Rev. Neurosci.22, 487-509), we studied biopsied human olfactory sensory neurons (OSNs), cultured human olfactory cells (Gomez G., et al. (2000) J. Neurosci. Res.62 (5), 737-749), and rat olfactory neurons. Rat and human OSNs responded to S(-)-nicotine with a concentration dependent influx of calcium and activation of adenylate cyclase. Some rat OSNs displayed some stereoselectivity, with neurons responding to either enantiomer alone or to both. Freshly biopsied and primary cultured human olfactory neurons were less stereoselective. Nicotinic cholinergic antagonists had no effect on the responses of rat or human OSNs to nicotine. Patch clamp recording of rat OSNs revealed a nicotine-activated, calcium-sensitive nonspecific cation channel. These results indicate that nicotine activates a canonical olfactory receptor pathway rather than nicotinic cholinergic receptors on OSNs. Further, because the nicotine-sensitive mechanisms of rodents appear generally similar to those of humans, this animal model is an appropriate one for studies of nicotine sensation. PMID:22777075

  8. Cellular Basis for the Olfactory Response to Nicotine

    PubMed Central

    2010-01-01

    Smokers regulate their smoking behavior on the basis of sensory stimuli independently of the pharmacological effects of nicotine (RoseJ. E., et al. (1993) Pharmacol., Biochem. Behav.1 (3), 891−9008469698). A better understanding of sensory mechanisms underlying smoking behavior may help to develop more effective smoking alternatives. Olfactory stimulation by nicotine makes up a considerable part of the flavor of tobacco smoke, yet our understanding of the cellular mechanisms responsible for olfactory detection of nicotine remains incomplete. We used biophysical methods to characterize the nicotine sensitivity and response mechanisms of neurons from olfactory epithelium. In view of substantial differences in the olfactory receptor repertoire between rodent and human (MombaertsP. (1999) Annu. Rev. Neurosci.1, 487−50910202546), we studied biopsied human olfactory sensory neurons (OSNs), cultured human olfactory cells (GomezG., et al. (2000) J. Neurosci. Res.1 (3), 737−74911104513), and rat olfactory neurons. Rat and human OSNs responded to S(−)-nicotine with a concentration dependent influx of calcium and activation of adenylate cyclase. Some rat OSNs displayed some stereoselectivity, with neurons responding to either enantiomer alone or to both. Freshly biopsied and primary cultured human olfactory neurons were less stereoselective. Nicotinic cholinergic antagonists had no effect on the responses of rat or human OSNs to nicotine. Patch clamp recording of rat OSNs revealed a nicotine-activated, calcium-sensitive nonspecific cation channel. These results indicate that nicotine activates a canonical olfactory receptor pathway rather than nicotinic cholinergic receptors on OSNs. Further, because the nicotine-sensitive mechanisms of rodents appear generally similar to those of humans, this animal model is an appropriate one for studies of nicotine sensation. PMID:22777075

  9. Identification of cholinergic chemosensory cells in mouse tracheal and laryngeal glandular ducts.

    PubMed

    Krasteva-Christ, G; Soultanova, A; Schütz, B; Papadakis, T; Weiss, C; Deckmann, K; Chubanov, V; Gudermann, T; Voigt, A; Meyerhof, W; Boehm, U; Weihe, E; Kummer, W

    2015-11-01

    Specialized epithelial cells in the respiratory tract such as solitary chemosensory cells and brush cells sense the luminal content and initiate protective reflexes in response to the detection of potentially harmful substances. The majority of these cells are cholinergic and utilize the canonical taste signal transduction cascade to detect "bitter" substances such as bacterial quorum sensing molecules. Utilizing two different mouse strains reporting expression of choline acetyltransferase (ChAT), the synthesizing enzyme of acetylcholine (ACh), we detected cholinergic cells in the submucosal glands of the murine larynx and trachea. These cells were localized in the ciliated glandular ducts and were neither found in the collecting ducts nor in alveolar or tubular segments of the glands. ChAT expression in tracheal gland ducts was confirmed by in situ hybridization. The cholinergic duct cells expressed the brush cell marker proteins, villin and cytokeratin-18, and were immunoreactive for components of the taste signal transduction cascade (Gα-gustducin, transient receptor potential melastatin-like subtype 5 channel = TRPM5, phospholipase C(β2)), but not for carbonic anhydrase IV. Furthermore, these cells expressed the bitter taste receptor Tas2r131, as demonstrated utilizing an appropriate reporter mouse strain. Our study identified a previously unrecognized presumptive chemosensory cell type in the duct of the airway submucosal glands that likely utilizes ACh for paracrine signaling. We propose that these cells participate in infection-sensing mechanisms and initiate responses assisting bacterial clearance from the lower airways. PMID:26033492

  10. Immunodominant regions for T helper-cell sensitization on the human nicotinic receptor alpha subunit in myasthenia gravis.

    PubMed Central

    Protti, M P; Manfredi, A A; Straub, C; Howard, J F; Conti-Tronconi, B M

    1990-01-01

    In myasthenia gravis an autoimmune response against the nicotinic acetylcholine receptor (AChR) occurs. The alpha subunit of the AChR contains both the epitope(s) that dominates the antibody response (main immunogenic region) and epitopes involved in T helper cell sensitization. In this study, overlapping synthetic peptides corresponding to the complete AChR alpha-subunit sequence were used to propagate polyclonal AChR-specific T helper cell lines from four myasthenic patients of different HLA types. Response of the T helper lines to the individual peptides was studied. Four immunodominant sequence segments were identified--i.e., residues 48-67, 101-120, 304-322, and 419-437. These regions did not include residues known to form the main immunogenic region or the cholinergic binding site, and they frequently contained sequence motifs that have been proposed to be related to T-epitope formation. Images PMID:2145582

  11. Prostate stem cell antigen interacts with nicotinic acetylcholine receptors and is affected in Alzheimer's disease.

    PubMed

    Jensen, Majbrit M; Arvaniti, Maria; Mikkelsen, Jens D; Michalski, Dominik; Pinborg, Lars H; Härtig, Wolfgang; Thomsen, Morten S

    2015-04-01

    Alzheimer's disease (AD) is a neurodegenerative disorder involving impaired cholinergic neurotransmission and dysregulation of nicotinic acetylcholine receptors (nAChRs). Ly-6/neurotoxin (Lynx) proteins have been shown to modulate cognition and neural plasticity by binding to nAChR subtypes and modulating their function. Hence, changes in nAChR regulatory proteins such as Lynx proteins could underlie the dysregulation of nAChRs in AD. Using Western blotting, we detected bands corresponding to the Lynx proteins prostate stem cell antigen (PSCA) and Lypd6 in human cortex indicating that both proteins are present in the human brain. We further showed that PSCA forms stable complexes with the α4 nAChR subunit and decreases nicotine-induced extracellular-signal regulated kinase phosphorylation in PC12 cells. In addition, we analyzed protein levels of PSCA and Lypd6 in postmortem tissue of medial frontal gyrus from AD patients and found significantly increased PSCA levels (approximately 70%). In contrast, no changes in Lypd6 levels were detected. In concordance with our findings in AD patients, PSCA levels were increased in the frontal cortex of triple transgenic mice with an AD-like pathology harboring human transgenes that cause both age-dependent β-amyloidosis and tauopathy, whereas Tg2576 mice, which display β-amyloidosis only, had unchanged PSCA levels compared to wild-type animals. These findings identify PSCA as a nAChR-binding protein in the human brain that is affected in AD, suggesting that PSCA-nAChR interactions may be involved in the cognitive dysfunction observed in AD. PMID:25680266

  12. Nicotine promotes cell proliferation via {alpha}7-nicotinic acetylcholine receptor and catecholamine-synthesizing enzymes-mediated pathway in human colon adenocarcinoma HT-29 cells

    SciTech Connect

    Wong, Helen Pui Shan; Yu Le; Lam, Emily Kai Yee; Tai, Emily Kin Ki; Wu, William Ka Kei; Cho, Chi Hin . E-mail: chcho@cuhk.edu.hk

    2007-06-15

    Cigarette smoking has been implicated in colon cancer. Nicotine is a major alkaloid in cigarette smoke. In the present study, we showed that nicotine stimulated HT-29 cell proliferation and adrenaline production in a dose-dependent manner. The stimulatory action of nicotine was reversed by atenolol and ICI 118,551, a {beta}{sub 1}- and {beta}{sub 2}-selective antagonist, respectively, suggesting the role of {beta}-adrenoceptors in mediating the action. Nicotine also significantly upregulated the expression of the catecholamine-synthesizing enzymes [tyrosine hydroxylase (TH), dopamine-{beta}-hydroxylase (D{beta}H) and phenylethanolamine N-methyltransferase]. Inhibitor of TH, a rate-limiting enzyme in the catecholamine-biosynthesis pathway, reduced the actions of nicotine on cell proliferation and adrenaline production. Expression of {alpha}7-nicotinic acetylcholine receptor ({alpha}7-nAChR) was demonstrated in HT-29 cells. Methyllycaconitine, an {alpha}7-nAChR antagonist, reversed the stimulatory actions of nicotine on cell proliferation, TH and D{beta}H expression as well as adrenaline production. Taken together, through the action on {alpha}7-nAChR nicotine stimulates HT-29 cell proliferation via the upregulation of the catecholamine-synthesis pathway and ultimately adrenaline production and {beta}-adrenergic activation. These data reveal the contributory role {alpha}7-nAChR and {beta}-adrenoceptors in the tumorigenesis of colon cancer cells and partly elucidate the carcinogenic action of cigarette smoke on colon cancer.

  13. Cholinergic chemosensory cells of the thymic medulla express the bitter receptor Tas2r131.

    PubMed

    Soultanova, Aichurek; Voigt, Anja; Chubanov, Vladimir; Gudermann, Thomas; Meyerhof, Wolfgang; Boehm, Ulrich; Kummer, Wolfgang

    2015-11-01

    The thymus is the site of T cell maturation which includes positive selection in the cortex and negative selection in the medulla. Acetylcholine is locally produced in the thymus and cholinergic signaling influences the T cell development. We recently described a distinct subset of medullary epithelial cells in the murine thymus which express the acetylcholine-synthesizing enzyme choline acetyltransferase (ChAT) and components of the canonical taste transduction cascade, i.e. transient receptor potential melastatin-like subtype 5 channel (TRPM5), phospholipase Cβ(2), and Gα-gustducin. Such a chemical phenotype is characteristic for chemosensory cells of mucosal surfaces which utilize bitter receptors for detection of potentially hazardous compounds and cholinergic signaling to initiate avoidance reflexes. We here demonstrate mRNA expression of bitter receptors Tas2r105, Tas2r108, and Tas2r131 in the murine thymus. Using a Tas2r131-tauGFP reporter mouse we localized the expression of this receptor to cholinergic cells expressing the downstream elements of the taste transduction pathway. These cells are distinct from the medullary thymic epithelial cells which promiscuously express tissue-restricted self-antigens during the process of negative selection, since double-labeling immunofluorescence showed no colocalization of autoimmune regulator (AIRE), the key mediator of negative selection, and TRPM5. These data demonstrate the presence of bitter taste-sensing signaling in cholinergic epithelial cells in the thymic medulla and opens a discussion as to what is the physiological role of this pathway. PMID:26102274

  14. Generation of Human Embryonic Stem Cell Line Expressing zsGreen in Cholinergic Neurons Using CRISPR/Cas9 System.

    PubMed

    Zhou, Jing; Wang, Chencheng; Zhang, Kunshan; Wang, Yingying; Gong, Xi; Wang, Yanlu; Li, Siguang; Luo, Yuping

    2016-08-01

    Lineage specific human embryonic stem cell (hESC) reporter cell line is a versatile tool for biological studies on real time monitoring of differentiation, physiological and biochemical features of special cell types and pathological mechanism of disease. Here we report the generation of ChAT-zsGreen reporter hESC line that express zsGreen under the control of the choline acetyltransferase (ChAT) promoter using CRISPR (Clustered Regularly Interspersed Short Palindromic Repeats)/Cas9 system. We show that the ChAT-zsGreen hESC reporter cell lines retain the features of undifferentiated hESC. After cholinergic neuronal differentiation, cholinergic neurons were clearly labeled with green fluorescence protein (zsGreen). The ChAT-zsGreen reporter hESC lines are invaluable not only for the monitoring cholinergic neuronal differentiation but also for study physiological and biochemical hallmarks of cholinergic neurons. PMID:27113041

  15. Cellular and molecular basis of cholinergic function

    SciTech Connect

    Dowdall, M.J.; Hawthorne, J.N.

    1987-01-01

    This book contains 105 selections. Some of the titles are: Functional correlates of brain nicotine receptors; Muscarinic receptor subclasses; Cholinergic innervation and levels of nerve growth factor and its mRNA in the central nervous system; Developmentally regulated neurontrophic activities of Torpedo electric organ tissue; and Association of a regulatory peptide with cholinergic neurons.

  16. Functional expression of human α7 nicotinic acetylcholine receptor in human embryonic kidney 293 cells.

    PubMed

    Gong, Yuan; Jiang, Ji-Hong; Li, Shi-Tong

    2016-09-01

    The functional expression of recombinant α7 nicotinic acetylcholine receptors in human embryonic kidney (HEK) 293 cells has presented a challenge. Resistance to inhibitors of cholinesterase 3 (RIC‑3) has been confirmed to act as a molecular chaperone of nicotinic acetylcholine receptors. The primary objectives of the present study were to investigate whether the co‑expression of human (h)RIC‑3 with human α7 nicotinic acetylcholine receptor in HEK 293 cells facilitates functional expression of the α7 nicotinic acetylcholine receptor. Subsequent to transfection, western blotting and polymerase chain reaction were used to test the expression of α7 nicotinic acetylcholine receptor and RIC-3. The α7 nicotinic acetylcholine receptor was expressed alone or co‑expressed with hRIC‑3 in the HEK 293 cells. Drug‑containing solution was then applied to the cells via a gravity‑driven perfusion system. Calcium influx in the cells was analyzed using calcium imaging. Nicotine did not induce calcium influx in the HEK 293 cells expressing human α7 nicotinic acetylcholine receptor only. However, in the cells co‑expressing human RIC‑3 and α7 nicotinic acetylcholine receptor, nicotine induced calcium influx via the α7 nicotinic acetylcholine receptor in a concentration‑dependent manner (concentration required to elicit 50% of the maximal effect=29.21 µM). Taken together, the results of the present study suggested that the co‑expression of RIC‑3 in HEK 293 cells facilitated the functional expression of the α7 nicotinic acetylcholine receptor. PMID:27430244

  17. Chagas’ disease parasite-derived neurotrophic factor activates cholinergic gene expression in neuronal PC12 cells

    PubMed Central

    Akpan, Nsikan; Caradonna, Kacey; Chuenkova, Marina V.; PereiraPerrin, Mercio

    2008-01-01

    A parasite-derived neurotrophic factor (PDNF) produced by the Chagas’ disease parasite Trypanosoma cruzi binds nerve growth factor (NGF) receptor TrkA, increasing receptor autophosphorylation, activating phosphatidylinositol 3-kinase (PI3K) and mitogen-activated protein kinase (MAPK/Erk) pathways, and transcription factor CREB. The end-result is enhanced survival and neuritogenesis of various types of neurons. PDNF also enhances the expression and activity of tyrosine hydroxylase, a rate limiting enzyme in the synthesis of dopamine and other catecholamine neurotransmitters. It remains unknown, however, if PDNF alters expression and metabolism of acetylcholine (ACh), a neurotransmitter thought to play a role in Chagas’ disease progression. Here we demonstrate that PDNF stimulates mRNA and protein expression of choline acetyltransferase (ChAT) and vesicular acetylcholine transporter (VAChT), which are critical for synthesis and storage of ACh. Stimulation requires functional TrkA because it did not occur in cell mutants that lack the receptor and in TrkA-expressing wild-type cells treated with K252a, an inhibitor of TrkA kinase activity. It also requires TrkA-dependent PI3K and MAPK/Erk signaling pathways because PDNF stimulation of cholinergic transcripts is abolished by specific pharmacological inhibitors. Furthermore, the cholinergic actions of PDNF were reproduced by PDNF-expressing extracellular T. cruzi trypomastigotes at the start of host cell invasion. In contrast, host cells bearing intracellular T. cruzi showed decreased, rather than increased, cholinergic gene expression. These results suggest that T. cruzi invasion of the nervous system alters cholinergic gene expression and that could play a role in neuropathology, and/or lack thereof, in Chagas’ disease patients. PMID:18502403

  18. Chagas' disease parasite-derived neurotrophic factor activates cholinergic gene expression in neuronal PC12 cells.

    PubMed

    Akpan, Nsikan; Caradonna, Kacey; Chuenkova, Marina V; PereiraPerrin, Mercio

    2008-06-27

    A parasite-derived neurotrophic factor (PDNF) produced by the Chagas' disease parasite Trypanosoma cruzi binds nerve growth factor (NGF) receptor TrkA, increasing receptor autophosphorylation, and activating phosphatidylinositol 3-kinase (PI3K) and mitogen-activated protein kinase (MAPK/Erk) pathways, and transcription factor CREB. The end-result is enhanced survival and neuritogenesis of various types of neurons. PDNF also enhances the expression and activity of tyrosine hydroxylase, a rate limiting enzyme in the synthesis of dopamine and other catecholamine neurotransmitters. It remains unknown, however, if PDNF alters expression and metabolism of acetylcholine (ACh), a neurotransmitter thought to play a role in Chagas' disease progression. Here we demonstrate that PDNF stimulates mRNA and protein expression of choline acetyltransferase (ChAT) and vesicular acetylcholine transporter (VAChT), which are critical for synthesis and storage of ACh. Stimulation requires functional TrkA because it did not occur in cell mutants that lack the receptor and in TrkA-expressing wild-type cells treated with K252a, an inhibitor of TrkA kinase activity. It also requires TrkA-dependent PI3K and MAPK/Erk signaling pathways because PDNF stimulation of cholinergic transcripts is abolished by specific pharmacological inhibitors. Furthermore, the cholinergic actions of PDNF were reproduced by PDNF-expressing extracellular T. cruzi trypomastigotes at the start of host cell invasion. In contrast, host cells bearing intracellular T. cruzi showed decreased, rather than increased, cholinergic gene expression. These results suggest that T. cruzi invasion of the nervous system alters cholinergic gene expression and that could play a role in neuropathology, and/or lack thereof, in Chagas' disease patients. PMID:18502403

  19. Mesopontine organization of cholinergic and catecholaminergic cell groups in the normal and narcoleptic dog.

    PubMed

    Tafti, M; Nishino, S; Liao, W; Dement, W C; Mignot, E

    1997-03-10

    Canine narcolepsy is a unique experimental model of a human sleep disorder characterized by excessive daytime sleepiness and cataplexy. There is a consensus recognition of an imbalance between cholinergic and catecholaminergic systems in narcolepsy although the underlying mechanisms remain poorly understood. Possible substrates could be an abnormal organization, numbers and/or ratio of cholinergic to catecholaminergic cells in the brain of narcoleptic dogs. Therefore, we sought to characterize the corresponding neuronal populations in normal and narcoleptic dogs (Doberman Pinscher) by using choline acetyltransferase (ChAT), nicotinamide adenosine dinucleotide phosphate (NADPH)-diaphorase, tyrosine hydroxylase (TH), and dopamine beta-hydroxylase (DBH). Cholinergic cell groups were found in an area extending from the central to the gigantocellular tegmental field and the periventricular gray corresponding to the pedunculopontine tegmental nucleus (PPT), the laterodorsal tegmental nucleus (LDT), and the parabrachial nucleus. An almost perfect co-localization of ChAT and NADPH-diaphorase was also observed. Catecholaminergic cell groups detected included the ventral tegmental area, the substantia nigra, and the locus coeruleus nucleus (LC). The anatomical distribution of catecholaminergic neurons was unusual in the dog in two important aspects: i) TH- and/or DBH-immunoreactive neurons of the LC were found almost exclusively in the reticular formation and not within the periventricular gray, ii) very few, if any TH-positive neurons were found in the central gray and dorsal raphe. Quantitative analysis did not reveal any significant differences in the organization and the number of cells identified in the LDT, PPT, and LC of normal and narcoleptic dogs. Moreover, the cholinergic to catecholaminergic ratio was found identical in the two groups. In conclusion, the present results do not support the hypothesis that the neurochemical imbalance in narcolepsy could result from

  20. Bromoenol Lactone Attenuates Nicotine-Induced Breast Cancer Cell Proliferation and Migration

    PubMed Central

    Calderon, Lindsay E.; Liu, Shu; Arnold, Nova; Breakall, Bethany; Rollins, Joseph; Ndinguri, Margaret

    2015-01-01

    Objectives Calcium independent group VIA phospholipase A2 (iPLA2β) and Matrix Metalloproteinase-9 (MMP-9) are upregulated in many disease states; their involvement with cancer cell migration has been a recent subject for study. Further, the molecular mechanisms mediating nicotine-induced breast cancer cell progression have not been fully investigated. This study aims to investigate whether iPLA2β mediates nicotine-induced breast cancer cell proliferation and migration through both in-vitro and in-vivo techniques. Subsequently, the ability of Bromoenol Lactone (BEL) to attenuate the severity of nicotine-induced breast cancer was examined. Method and Results We found that BEL significantly attenuated both basal and nicotine-induced 4T1 breast cancer cell proliferation, via an MTT proliferation assay. Breast cancer cell migration was examined by both a scratch and transwell assay, in which, BEL was found to significantly decrease both basal and nicotine-induced migration. Additionally, nicotine-induced MMP-9 expression was found to be mediated in an iPLA2β dependent manner. These results suggest that iPLA2β plays a critical role in mediating both basal and nicotine-induced breast cancer cell proliferation and migration in-vitro. In an in-vivo mouse breast cancer model, BEL treatment was found to significantly reduce both basal (p<0.05) and nicotine-induced tumor growth (p<0.01). Immunohistochemical analysis showed BEL decreased nicotine-induced MMP-9, HIF-1alpha, and CD31 tumor tissue expression. Subsequently, BEL was observed to reduce nicotine-induced lung metastasis. Conclusion The present study indicates that nicotine-induced migration is mediated by MMP-9 production in an iPLA2β dependent manner. Our data suggests that BEL is a possible chemotherapeutic agent as it was found to reduce both nicotine-induced breast cancer tumor growth and lung metastasis. PMID:26588686

  1. Nicotine-Mediated Ca(2+)-Influx Induces IL-8 Secretion in Oral Squamous Cell Carcinoma Cell.

    PubMed

    Tsunoda, Kou; Tsujino, Ichiro; Koshi, Ryosuke; Sugano, Naoyuki; Sato, Shuichi; Asano, Masatake

    2016-04-01

    Cigarette smoking is one of the most important risk factors for the development of various diseases. Nicotine is the most extensively investigated component of cigarette smoke, and a comprehensive analysis of the genes induced by nicotine stimulation revealed that interleukin-8 (IL-8) was induced in oral squamous cell carcinoma cell (OSCC). Based on this background, the signaling mechanisms of nicotine-mediated IL-8 induction in OSCC was investigated. Augmented IL-8 secretion by Ca9-22 cells was blocked by the NF-κB inhibitor L-1-4'-tosylamino-phenylethyl-chloromethyl ketone (TPCK) and the nicotinic acetylcholine receptor (nAChR)-specific inhibitor α-bungarotoxin (αBtx). The downstream signaling pathway was further examined by pre-incubating the cells with inhibitors against mitogen-activated protein kinase (MEK), protein kinase C (PKC), and Ca(2+)/calmodulin-dependent kinase II (CaMK II). Only the CaMK II inhibitor was found to exert an inhibitory effect on nicotine-mediated IL-8 secretion. Pre-treatment of the Ca9-22 cells with the Ca(2+) chelator BAPTA-AM drastically inhibited IL-8 secretion. Although nicotine stimulation induced the phosphorylation of the NF-κB p65 subunit, pre-treatment with BAPTA-AM was found to inhibit this activity significantly. CaMK II-dependent p65 phosphorylation was confirmed by pre-incubation of the cells with CaMK II inhibitor. The results from this study indicate that the binding of nicotine to nAChR induces Ca(2+) influx, which results in the activation and phosphorylation of CaMK II and NF-κB p65, respectively. Nicotine-mediated IL-8 induction should be a trigger for the initiation of various diseases. PMID:26418512

  2. A Cell Line Producing Recombinant Nerve Growth Factor Evokes Growth Responses in Intrinsic and Grafted Central Cholinergic Neurons

    NASA Astrophysics Data System (ADS)

    Ernfors, Patrik; Ebendal, Ted; Olson, Lars; Mouton, Peter; Stromberg, Ingrid; Persson, Hakan

    1989-06-01

    The rat β nerve growth factor (NGF) gene was inserted into a mammalian expression vector and cotransfected with a plasmid conferring resistance to neomycin into mouse 3T3 fibroblasts. From this transfection a stable cell line was selected that contains several hundred copies of the rat NGF gene and produces excess levels of recombinant NGF. Such genetically modified cells were implanted into the rat brain as a probe for in vivo effects of NGF on central nervous system neurons. In a model of the cortical cholinergic deficits in Alzheimer disease, we demonstrate a marked increase in the survival of, and fiber outgrowth from, grafts of fetal basal forebrain cholinergic neurons, as well as stimulation of fiber formation by intact adult intrinsic cholinergic circuits in the cerebral cortex. Adult cholinergic interneurons in intact striatum also sprout vigorously toward implanted fibroblasts. Our results suggest that this model has implications for future treatment of neurodegenerative diseases.

  3. The distribution and morphological characteristics of cholinergic cells in the brain of monotremes as revealed by ChAT immunohistochemistry.

    PubMed

    Manger, P R; Fahringer, H M; Pettigrew, J D; Siegel, J M

    2002-01-01

    The present study employs choline acetyltransferase (ChAT) immunohistochemistry to identify the cholinergic neuronal population in the central nervous system of the monotremes. Two of the three extant species of monotreme were studied: the platypus (Ornithorhynchus anatinus) and the short-beaked echidna (Tachyglossus aculeatus). The distribution of cholinergic cells in the brain of these two species was virtually identical. Distinct groups of cholinergic cells were observed in the striatum, basal forebrain, habenula, pontomesencephalon, cranial nerve motor nuclei, and spinal cord. In contrast to other tetrapods studied with this technique, we failed to find evidence for cholinergic cells in the hypothalamus, the parabigeminal nucleus (or nucleus isthmus), or the cerebral cortex. The lack of hypothalamic cholinergic neurons creates a hiatus in the continuous antero-posterior aggregation of cholinergic neurons seen in other tetrapods. This hiatus might be functionally related to the phenomenology of monotreme sleep and to the ontogeny of sleep in mammals, as juvenile placental mammals exhibit a similar combination of sleep elements to that found in adult monotremes. PMID:12476054

  4. Cholinergic innervation and receptors in the cerebellum.

    PubMed

    Jaarsma, D; Ruigrok, T J; Caffé, R; Cozzari, C; Levey, A I; Mugnaini, E; Voogd, J

    1997-01-01

    We have studied the source and ultrastructural characteristics of ChAT-immunoreactive fibers in the cerebellum of the rat, and the distribution of muscarinic and nicotinic receptors in the cerebellum of the rat, rabbit, cat and monkey, in order to define which of the cerebellar afferents may use ACh as a neurotransmitter, what target structures are they, and which cholinergic receptor mediate the actions of these pathways. Our data confirm and extend previous observations that cholinergic markers occur at relatively low density in the cerebellum and show not only interspecies variability, but also heterogeneity between cerebellar lobules in the same species. As previously demonstrated by Barmack et al. (1992a,b), the predominant fiber system in the cerebellum that might use ACh as a transmitter or a co-transmitter is formed by mossy fibers originating in the vestibular nuclei and innervating the nodulus and ventral uvula. Our results show that these fibers innervate both granule cells and unipolar brush cells, and that the presumed cholinergic action of these fibers most likely is mediated by nicotinic receptors. In addition to cholinergic mossy fibers, the rat cerebellum is innervated by beaded ChAT-immunoreactive fibers. We have demonstrated that these fibers originate in the pedunculopontine tegmental nucleus (PPTg), the lateral paragigantocellular nucleus (LPGi), and to a lesser extent in various raphe nuclei. In both the cerebellar cortex and the cerebellar nuclei these fibers make asymmetric synaptic junctions with small and medium-sized dendritic profiles. Both muscarinic and nicotinic receptor could mediate the action of these diffuse beaded fibers. In the cerebellar nuclei the beaded cholinergic fibers form a moderately dense network, and could in principle have a significant effect on neuronal activity. For instance, the cholinergic fibers arising in the PPTg may modulate the excitability of the cerebellonuclear neurons in relation to sleep and arousal (e

  5. Effects of estrogen on beta-amyloid-induced cholinergic cell death in the nucleus basalis magnocellularis.

    PubMed

    Szego, Eva M; Csorba, Attila; Janáky, Tamás; Kékesi, Katalin A; Abrahám, István M; Mórotz, Gábor M; Penke, Botond; Palkovits, Miklós; Murvai, Unige; Kellermayer, Miklós S Z; Kardos, József; Juhász, Gábor D

    2011-01-01

    Alzheimer disease is characterized by accumulation of β-amyloid (Aβ) and cognitive dysfunctions linked to early loss of cholinergic neurons. As estrogen-based hormone replacement therapy has beneficial effects on cognition of demented patients, and it may prevent memory impairments, we investigated the effect of estrogen-pretreatment on Aβ-induced cholinergic neurodegeneration in the nucleus basalis magnocellularis (NBM). We tested which Aβ species induces the more pronounced cholinotoxic effect in vivo. We injected different Aβ assemblies in the NBM of mice, and measured cholinergic cell and cortical fiber loss. Spherical Aβ oligomers had the most toxic effect. Pretreatment of ovariectomized mice with estrogen before Aβ injection decreased cholinergic neuron loss and partly prevented fiber degeneration. By using proteomics, we searched for proteins involved in estrogen-mediated protection and in Aβ toxicity 24 h following injection. The change in expression of, e.g., DJ-1, NADH ubiquinone oxidoreductase, ATP synthase, phosphatidylethanolamine-binding protein 1, protein phosphatase 2A and dimethylarginine dimethylaminohydrolase 1 support our hypothesis that Aβ induces mitochondrial dysfunction, decreases MAPK signaling, and increases NOS activation in NBM. On the other hand, altered expression of, e.g., MAP kinase kinase 1 and 2, protein phosphatase 1 and 2A by Aβ might increase MAPK suppression and NOS signaling in the cortical target area. Estrogen pretreatment reversed most of the changes in the proteome in both areas. Our experiments suggest that regulation of the MAPK pathway, mitochondrial pH and NO production may all contribute to Aβ toxicity, and their regulation can be prevented partly by estrogen pretreatment. PMID:20938166

  6. Nicotine-Induced Apoptosis in Human Renal Proximal Tubular Epithelial Cells

    PubMed Central

    Joo, Soo Yeon; Bae, Eun Hui; Ma, Seong Kwon; Lee, JongUn; Kim, Soo Wan

    2016-01-01

    Background Nicotine is, to a large extent, responsible for smoking-mediated renal dysfunction. This study investigated nicotine’s effects on renal tubular epithelial cell apoptosis in vitro and it explored the mechanisms underlying its effects. Methods Human proximal tubular epithelial (HK-2) cells were treated with nicotine. Cell viability was examined by using the WST-1 assay. Intracellular levels of reactive oxygen species (ROS) and the expression of mitogen-activated protein kinase (MAPK) and nuclear factor-κB (NF-κB) proteins were determined. The messenger ribonucleic acid and the protein expression associated with the nicotine acetylcholine receptors (nAChRs) in HK-2 cells was examined, and apoptosis was detected using flow cytometry, cell cycle analysis, and immunoblot analysis. Results The HK-2 cells were endowed with nAChRs. Nicotine treatment reduced cell viability dose dependently, increased ROS levels, and increased extracellular signal-regulated kinase (ERK), c-Jun N-terminal kinase (JNK), and p38 MAPK expression. Nicotine increased NF-κB activation, which was attenuated by N-acetyl-L-cysteine, and ERK and JNK inhibitors, but was not affected by a p38 MAPK inhibitor. Nicotine increased the Bax/Bcl-2 ratio, which was attenuated by N-acetyl-L-cysteine, the NF-κB inhibitor, Bay 11–7082, and hexamethonium, a non-specific nAChR blocker. Flow cytometry revealed nicotine-induced G2/M phase arrest. While nicotine treatment increased the expression of phosphorylated cdc2 and histone H3, a marker of G2/M phase arrest, hexamethonium and Bay 11–7082 pretreatment reduced their expression. Conclusions Nicotine caused apoptosis in HK-2 cells by inducing ROS generation that activated the NF-κB signaling pathway via the MAPK pathway and it arrested the cell cycle at the G2/M phase. Nicotine-induced apoptosis in HK-2 cells involves the nAChRs. PMID:27028622

  7. Recurrent exposure to nicotine differentiates human bronchial epithelial cells via epidermal growth factor receptor activation

    SciTech Connect

    Martinez-Garcia, Eva; Irigoyen, Marta; Anso, Elena; Martinez-Irujo, Juan Jose; Rouzaut, Ana

    2008-05-01

    Cigarette smoking is the major preventable cause of lung cancer in developed countries. Nicotine (3-(1-methyl-2-pyrrolidinyl)-pyridine) is one of the major alkaloids present in tobacco. Besides its addictive properties, its effects have been described in panoply of cell types. In fact, recent studies have shown that nicotine behaves as a tumor promoter in transformed epithelial cells. This research focuses on the effects of acute repetitive nicotine exposure on normal human bronchial epithelial cells (NHBE cells). Here we show that treatment of NHBE cells with recurrent doses of nicotine up to 500 {mu}M triggered cell differentiation towards a neuronal-like phenotype: cells emitted filopodia and expressed neuronal markers such as neuronal cell adhesion molecule, neurofilament-M and the transcription factors neuronal N and Pax-3. We also demonstrate that nicotine treatment induced NF-kB translocation to the nucleus, phosphorylation of the epidermal growth factor receptor (EGFR), and accumulation of heparin binding-EGF in the extracellular medium. Moreover, addition of AG1478, an inhibitor of EGFR tyrosine phosphorylation, or cetuximab, a monoclonal antibody that precludes ligand binding to the same receptor, prevented cell differentiation by nicotine. Lastly, we show that differentiated cells increased their adhesion to the extracellular matrix and their protease activity. Given that several lung pathologies are strongly related to tobacco consumption, these results may help to better understand the damaging consequences of nicotine exposure.

  8. Protein kinase C-α attenuates cholinergically stimulated gastric acid secretion of rabbit parietal cells

    PubMed Central

    Fährmann, Michael; Kaufhold, Marc; Pfeiffer, Andreas F; Seidler, Ursula

    2003-01-01

    The phorbolester 12-O-tetradecanoyl phorbol-13-acetate (TPA), an activator of protein kinase C (PKC), inhibits cholinergic stimulation of gastric acid secretion. We observed that this effect strongly correlated with the inhibition of Ca2+/calmodulin-dependent protein kinase II (CaMKII) activity in rabbit parietal cells. The aim of this study was to specify the function of PKC-α in cholinergically stimulated H+ secretion. PKC-α represents the only calcium-dependent PKC isoenzyme that has been detected in rabbit parietal cells. Gö 6976, an inhibitor of calcium-dependent PKC, concentration-dependently antagonized the inhibitory effect of TPA, and, therefore, revealed the action of PKC-α on carbachol-induced acid secretion in rabbit parietal cells. TPA exerted no additive inhibition of carbachol-stimulated acid secretion if acid secretion was partially inhibited by the potent CaMKII inhibitor 1-[N,O-bis(5-isoquinolinsulfonyl)-N-methyl-L-tyrosyl]-4-phenyl-piperazine (KN-62). Since both kinase modulators, TPA and KN-62, affected no divergent signal transduction pathways in the parietal cell, an in vitro model has been used to study if PKC directly targets CaMKII. CaMKII purified from parietal cell-containing gastric mucosa of pig, was transphosphorylated by purified cPKC containing PKC-α up to 1.8 mol Pi per mol CaMKII in vitro. The autonomy site of CaMKII was not transphosphorylated by PKC. The phosphotransferase activity of the purified CaMKII was in vitro inhibited after transphosphorylation by PKC if calmodulin was absent during transphosphorylation. Attenuation of CaMKII activity by PKC showed strong similarity to the downregulation of CaMKII by basal autophosphorylation. Our results suggest that PKC-α and CaMKII are closely functionally linked in a cholinergically induced signalling pathway in rabbit parietal cells. We assume that in cholinergically stimulated parietal cells PKC-α transinhibits CaMKII activity, resulting in an attenuation of acid secretion

  9. Effects of nicotine on cellular proliferation, macromolecular synthesis and cell cycle phase distribution in human and murine cells

    SciTech Connect

    Konno, S.; Chiao, J.; Rossi, J.; Wang, C.H.; Wu, J.M.

    1986-05-01

    Addition of nicotine causes a dose- and time-dependent inhibition of cell growth in established human and murine cells. In the human promyelocytic HL-60 leukemic cells, 3 mM nicotine results in a 50% inhibition of cellular proliferation after 80 h. Nicotine was also found to affect the cell cycle distribution of HL-60 cells. Treatment with 4 mM nicotine for 20 h causes an increase in proportion of Gl-phase cells (from 49% to 57%) and a significant decrease in the proportion of S-phase cells (from 41% to 32%). These results suggest that nicotine causes cell arrest in the Gl-phase which may in part account for its effects on cell growth. To determine whether nicotine has a primary effect on the uptake/transport of macromolecular precursors into cells, HL-60 cells were treated with 2-6 mM nicotine for 30 h/sub 3/ at the end of which time cells were labeled with (/sup 3/H)thymidine, (/sup 3/H)uridine, (/sup 14/C)lysine and (/sup 35/S)methionine, the trichloroacetic acid (TCA) soluble and insoluble radioactivities from each of the labeling conditions were determined. These studies show that nicotine primarily affect the synthesis of proteins.

  10. Nicotine prevents the apoptosis induced by menadione in human lung cancer cells

    SciTech Connect

    Zhang Tao; Lu Heng; Shang Xuan; Tian Yihao; Zheng Congyi; Wang Shiwen; Cheng Hanhua . E-mail: hhcheng@whu.edu.cn; Zhou Rongjia . E-mail: rjzhou@whu.edu.cn

    2006-04-14

    Approximately 50% of long-term cigarette smokers die prematurely from the adverse effects of smoking, including on lung cancer and other illnesses. Nicotine is a main component in tobacco and has been implicated as a potential factor in the pathogenesis of human lung cancer. However, the mechanism of nicotine action in the development of lung cancer remains largely unknown. In the present study, we designed a nicotine-apoptosis system, by pre-treatment of nicotine making lung cancer cell A549 to be in a physiological nicotine environment, and observed that nicotine promoted cell proliferation and prevented the menadione-induced apoptosis, and exerts its role of anti-apoptosis by shift of apoptotic stage induced by menadione from late apoptotic stage to early apoptotic stage, in which NF-{kappa}B was up-regulated. Interference analysis of NF-{kappa}B in A549 cells showed that knock down of NF-{kappa}B resulted in apoptosis promotion and counteracted the protective effect of nicotine. The findings suggest that nicotine has potential effect in lung cancer genesis, especially in patients with undetectable early tumor development and development of specific NF-{kappa}B inhibitors would represent a potentially exciting new pharmacotherapy for tobacco-related lung cancer.

  11. Functional interaction between Lypd6 and nicotinic acetylcholine receptors.

    PubMed

    Arvaniti, Maria; Jensen, Majbrit M; Soni, Neeraj; Wang, Hong; Klein, Anders B; Thiriet, Nathalie; Pinborg, Lars H; Muldoon, Pretal P; Wienecke, Jacob; Imad Damaj, M; Kohlmeier, Kristi A; Gondré-Lewis, Marjorie C; Mikkelsen, Jens D; Thomsen, Morten S

    2016-09-01

    Nicotinic acetylcholine receptors (nAChRs) affect multiple physiological functions in the brain and their functions are modulated by regulatory proteins of the Lynx family. Here, we report for the first time a direct interaction of the Lynx protein LY6/PLAUR domain-containing 6 (Lypd6) with nAChRs in human brain extracts, identifying Lypd6 as a novel regulator of nAChR function. Using protein cross-linking and affinity purification from human temporal cortical extracts, we demonstrate that Lypd6 is a synaptically enriched membrane-bound protein that binds to multiple nAChR subtypes in the human brain. Additionally, soluble recombinant Lypd6 protein attenuates nicotine-induced hippocampal inward currents in rat brain slices and decreases nicotine-induced extracellular signal-regulated kinase phosphorylation in PC12 cells, suggesting that binding of Lypd6 is sufficient to inhibit nAChR-mediated intracellular signaling. We further show that perinatal nicotine exposure in rats (4 mg/kg/day through minipumps to dams from embryonic day 7 to post-natal day 21) significantly increases Lypd6 protein levels in the hippocampus in adulthood, which did not occur after exposure to nicotine in adulthood only. Our findings suggest that Lypd6 is a versatile inhibitor of cholinergic signaling in the brain, and that Lypd6 is dysregulated by nicotine exposure during early development. Regulatory proteins of the Lynx family modulate the function of nicotinic receptors (nAChRs). We report for the first time that the Lynx protein Lypd6 binds to nAChRs in human brain extracts, and that recombinant Lypd6 decreases nicotine-induced ERK phosphorylation and attenuates nicotine-induced hippocampal inward currents. Our findings suggest that Lypd6 is a versatile inhibitor of cholinergic signaling in the brain. PMID:27344019

  12. Opioid and nicotine receptors affect growth regulation of human lung cancer cell lines

    SciTech Connect

    Maneckjee, R.; Minna, J.D. Uniformed Services Univ. of the Health Sciences, Bethesda, MD )

    1990-05-01

    Using specific radioactively-labeled ligands, the authors find that lung cancer cell lines of diverse histologic types express multiple, high-affinity membrane receptors for {mu}, {delta}, and {kappa} opioid agonists and for nicotine and {alpha}-bungarotoxin. These receptors are biologically active because cAMP levels decreased in lung cancer cells after opioid and nicotine application. Nicotine at concentrations found in the blood of smokers had no effect on in vitro lung cancer cell growth, whereas {mu}, {delta}, and {kappa} opioid agonists at low concentrations inhibited lung cancer growth in vitro. They also found that lung cancer cells expressed various combinations of immunoreactive opioid peptides ({beta}-endorphin, enkephalin, or dynorphin), suggesting the participation of opioids in a negative autocrine loop or tumor-suppressing system. Due to the almost universal exposure of patients with lung cancer to nicotine, they tested whether nicotine affected the response of lung cancer cell growth to opioids and found that nicotine at concentrations of 100-200 nM partially or totally reversed opioid-induced growth inhibition in 9/14 lung cancer cell lines. These in vitro results for lung cancer cells suggest that opioids could function as part of a tumor suppressor system and that nicotine can function to circumvent this system in the pathogenesis of lung cancer.

  13. Islet-1 Controls the Differentiation of Retinal Bipolar and Cholinergic Amacrine Cells

    PubMed Central

    Elshatory, Yasser; Everhart, Drew; Deng, Min; Xie, Xiaoling; Barlow, Robert B.; Gan, Lin

    2010-01-01

    Whereas the mammalian retina possesses a repertoire of factors known to establish general retinal cell types, these factors alone cannot explain the vast diversity of neuronal subtypes. In other CNS regions, the differentiation of diverse neuronal pools is governed by coordinately acting LIM-homeodomain proteins including the Islet-class factor Islet-1 (Isl1). We report that deletion of Isl1 profoundly disrupts retinal function as assessed by electroretinograms and vision as assessed by optomotor behavior. These deficits are coupled with marked reductions in mature ON- and OFF-bipolar (>76%), cholinergic amacrine (93%), and ganglion (71%) cells. Mosaic deletion of Isl1 permitted a chimeric analysis of “wild-type” cells in a predominantly Isl1-null environment, demonstrating a cell-autonomous role for Isl1 in rod bipolar and cholinergic amacrine development. Furthermore, the effects on bipolar cell development appear to be dissociable from the preceding retinal ganglion cell loss, because Pou4f2-null mice are devoid of similar defects in bipolar cell marker expression. Expression of the ON- and OFF-bipolar cell differentiation factors Bhlhb4 and Vsx1, respectively, requires the presence of Isl1, whereas the early bipolar cell marker Prox1 initially did not. Thus, Isl1 is required for engaging bipolar differentiation pathways but not for general bipolar cell specification. Spatiotemporal expression analysis of additional LIM-homeobox genes identifies a LIM-homeobox gene network during bipolar cell development that includes Lhx3 and Lhx4. We conclude that Isl1 has an indispensable role in retinal neuron differentiation within restricted cell populations and this function may reflect a broader role for other LIM-homeobox genes in retinal development, and perhaps in establishing neuronal subtypes. PMID:18003851

  14. Multiple roles of nicotine on cell proliferation and inhibition of apoptosis: implications on lung carcinogenesis.

    PubMed

    Catassi, A; Servent, D; Paleari, L; Cesario, A; Russo, P

    2008-01-01

    The genotoxic effects of tobacco carcinogens have long been recognized, the contribution of tobacco components to cancerogenesis by cell surface receptor signaling is relatively unexplored. Nicotine, the principal tobacco alkaloid, acts through nicotinic acetylcholine receptor (nAChR). nAChR are functionally present on human lung airway epithelial cells, on lung carcinoma [SCLC and NSCLC] and on mesothelioma and build a part of an autocrine-proliferative network that facilitates the growth of neoplastic cells. Different nAChR subunit gene expression patterns are expressed between NSCLC from smokers and non-smokers. Although there is no evidence that nicotine itself could induce cancer, different studies established that nicotine promotes in vivo the growth of cancer cells and the proliferation of endothelial cells suggesting that nicotine might contribute to the progression of tumors already initiated. These observations led to the hypothesis that nicotine might be playing a direct role in the promotion and progression of human lung cancers. Here, we briefly overview the role and the effects of nicotine on pulmonary cell growth and physiology and its feasible implications in lung carcinogenesis. PMID:18495523

  15. Modulation of spontaneous intracellular Ca²⁺ fluctuations and spontaneous cholinergic transmission in rat chromaffin cells in situ by endogenous GABA acting on GABAA receptors.

    PubMed

    Tzitzitlini, Alejandre-García; Pedro, Segura-Chama; Martha, Pérez-Armendáriz E; Rodolfo, Delgado-Lezama; Arturo, Hernández-Cruz

    2016-02-01

    Using fluorescence [Ca(2+)]i imaging in rat adrenal slices, we characterized the effects of agonists and antagonists of the GABAA receptor (GABAA-R) on resting intracellular Ca(2+) ([Ca(2+)]i) and spontaneous [Ca(2+)]i fluctuations (SCFs) in hundreds of individual chromaffin cells (CCs) recorded simultaneously in situ. Muscimol, a GABAA-R agonist (20 μM; 25 s), induced an increase of resting [Ca(2+)]i in 43 ± 3 % of CCs, a decrease in 26 ± 2 %, and no response in 30 ± 5 %. In Ca(2+)-free external medium, SCFs ceased completely and muscimol failed to elicit [Ca(2+)]i rises. All muscimol-induced [Ca(2+)]i changes were blocked by the GABAA-R antagonist bicuculline, suggesting that they result from changes in membrane potential depending on the cell's Cl(-) equilibrium potential. Unexpectedly, bicuculline increased the amplitude and frequency of SCFs in 54 % of CCs, revealing a tonic inhibition of SCFs by ambient GABA acting through GABAA-R. Mecamylamine (a specific nicotinic cholinergic blocker) decreased basal SCF activity in 18 % of CCs and inhibited bicuculline-induced SCF intensification, suggesting that spontaneous acetylcholine (ACh) release from nerve endings contributes to SCF generation in CCs in situ and that blockade of presynaptic GABAA-Rs intensifies SCFs in part through the disinhibition of spontaneous cholinergic transmission. Electrophysiological experiments confirmed that spontaneous excitatory postsynaptic currents recorded from CCs in situ were enhanced by bicuculline. To our knowledge, this is the first description of a regulatory effect of endogenous GABA on synaptic currents and SCFs of adrenal CCs. These findings denote a novel GABA-mediated presynaptic and postsynaptic regulatory mechanism of CC activity which may participate in the control of catecholamine secretion. PMID:26490458

  16. Basic and clinical aspects of non-neuronal acetylcholine: overview of non-neuronal cholinergic systems and their biological significance.

    PubMed

    Kawashima, Koichiro; Fujii, Takeshi

    2008-02-01

    Acetylcholine (ACh) is a phylogenetically ancient molecule involved in cell-to-cell signaling in almost all life-forms on earth. Cholinergic components, including ACh, choline acetyltransferase, acetylcholinesterase, and muscarinic and nicotinic ACh receptors (mAChRs and nAChRs, respectively) have been identified in numerous non-neuronal cells and tissues, including keratinocytes, cancer cells, immune cells, urinary bladder, airway epithelial cells, vascular endothelial cells, and reproductive organs, among many others. Stimulation of the mAChRs and nAChRs elicits cell-specific functional and biochemical effects. These findings support the notion that non-neuronal cholinergic systems are expressed in certain cells and tissues and are involved in the regulation of their function and that cholinergic dysfunction is related to the pathophysiology of certain diseases. They also provide clues for development of drugs with novel mechanisms of action. PMID:18285657

  17. Nicotine Directly Induces Endoplasmic Reticulum Stress Response in Rat Placental Trophoblast Giant Cells.

    PubMed

    Wong, Michael K; Holloway, Alison C; Hardy, Daniel B

    2016-05-01

    Nicotine exposure during pregnancy leads to placental insufficiency impairing both fetal and neonatal development. Previous studies from our laboratory have demonstrated that in rats, nicotine augmented endoplasmic reticulum (ER) stress in association with placental insufficiency; however, the underlying mechanisms remain elusive. Therefore, we sought to investigate the possible direct effect of nicotine on ER stress in Rcho-1 rat placental trophoblast giant (TG) cells during differentiation. Protein and/or mRNA expression of markers involved in ER stress (eg, phosphorylated PERK, eIF2α, CHOP, and BiP/GRP78) and TG cell differentiation and function (eg, Pl-1, placental growth factor [Pgf], Hsd11b1, and Hsd11b2) were quantified via Western blot or real-time polymerase chain reaction. Nicotine treatment led to dose-dependent increases in the phosphorylation of PERK[Thr981] and eIF2α[Ser51], whereas pretreatment with a nicotinic acetylcholine receptor (nAChR) antagonist (mecamylamine hydrochloride) blocked the induction of PERK phosphorylation, verifying the direct involvement of nicotine and nAChR binding. We next investigated select target genes known to play essential roles in placental TG cell differentiation and function (Pl-1, Pgf, Hsd11b1, and Hsd11b2), and found that nicotine significantly augmented the mRNA levels of Hsd11b1 in a dose-dependent manner. Furthermore, using tauroursodeoxycholic acid, a safe bile acid known to improve protein chaperoning and folding, we were able to prevent nicotine-induced increases in both PERK phosphorylation and Hsd11b1 mRNA levels, revealing a potential novel therapeutic approach to reverse the deleterious effects of nicotine exposure in pregnancy. Collectively, these results implicate that nicotine, acting through its receptor, can directly augment ER stress and impair placental function. PMID:26803847

  18. Modulation of secretion by dopamine involves decreases in calcium and nicotinic currents in bovine chromaffin cells.

    PubMed Central

    Sontag, J M; Sanderson, P; Klepper, M; Aunis, D; Takeda, K; Bader, M F

    1990-01-01

    1. Catecholamine secretion from cultured bovine adrenal chromaffin cells was decreased in a dose-dependent manner by the D2 dopamine agonists apomorphine and LY 17 1555. 2. 45Ca2+ uptake was similarly inhibited and whole-cell Ca2+ currents were reduced by apomorphine. 3. These inhibitory effects of D2 agonists depended on the secretagogue used, being much more pronounced for nicotine-evoked responses compared to high K+ stimulation, indicating another possible site of action of apomorphine up-stream of Ca2+ entry. 4. Inhibition by apomorphine of nicotine-evoked responses could not be explained by competitive antagonism against nicotine or DMPP (1,1-dimethyl-4-phenyl-piperazinium iodide). 5. Apomorphine caused reductions of inward whole-cell nicotinic current evoked by ACh and nicotine. 6. Inhibition of nicotine-evoked secretion and 22Na+ influx by apomorphine were not affected by tetrodotoxin, and voltage-dependent, whole-cell Na+ currents were unaltered by apomorphine. 7. No evidence was obtained for increases in K+ conductance by apomorphine. 8. Action potentials recorded in whole-cell current clamp were blocked by apomorphine when they were triggered by nicotinic depolarization but not when they were elicited by direct electrical stimulation. 9. Inclusion of GDP-beta-S in the pipette internal solution did not affect apomorphine-dependent inhibition of nicotinic-evoked responses, while the decrease in whole-cell Ca2+ current induced by apomorphine was completely inhibited in the presence of GDP-beta-S. 10. Increases in cyclic AMP caused by cholera toxin and forskolin did not change the apomorphine-dependent inhibitory effects on nicotine-evoked secretion, indicating that changes in cyclic AMP levels caused by dopamine receptor stimulation are probably not involved. PMID:2170637

  19. Effects of Nicotine on Streptococcus gordonii Growth, Biofilm Formation, and Cell Aggregation.

    PubMed

    Huang, R; Li, M; Ye, M; Yang, K; Xu, X; Gregory, R L

    2014-12-01

    Streptococcus gordonii is a commensal species of human oral flora. It initiates dental biofilm formation and provides binding sites for later colonizers to attach to and generate mature biofilm. Smoking is the second highest risk factor for periodontal disease, and cigarette smoke extract has been reported to facilitate Porphyromonas gingivalis-S. gordonii dual-species biofilm formation. Our hypothesis is that nicotine, one of the most important and active components of tobacco, stimulates S. gordonii multiplication and aggregation. In the present study, S. gordonii planktonic cell growth (kinetic absorbance and CFU), biofilm formation (crystal violet stain and confocal laser scanning microscopy [CLSM]), aggregation with/without sucrose, and 11 genes that encode binding proteins or regulators of gene expression were investigated. Results demonstrated planktonic cell growth was stimulated by 1 to 4 mg/ml nicotine treatment. Biofilm formation was increased at 0.5 to 4 mg/ml nicotine. CLSM indicated bacterial cell mass was increased by 2 and 4 mg/ml nicotine, but biofilm extracellular polysaccharide was not significantly affected by nicotine. Cell aggregation was upregulated by 4, 8, and 16 mg/ml nicotine with sucrose and by 16 mg/ml nicotine without sucrose. Quantitative reverse transcriptase PCR indicated S. gordonii abpA, scaA, ccpA, and srtA were upregulated in planktonic cells by 2 mg/ml nicotine. In conclusion, nicotine stimulates S. gordonii planktonic cell growth, biofilm formation, aggregation, and gene expression of binding proteins. Those effects may promote later pathogen attachment to tooth surfaces, the accumulation of tooth calculus, and the development of periodontal disease in cigarette smokers. PMID:25217021

  20. Cholinergic afferent stimulation induces axonal function plasticity in adult hippocampal granule cells.

    PubMed

    Martinello, Katiuscia; Huang, Zhuo; Lujan, Rafael; Tran, Baouyen; Watanabe, Masahiko; Cooper, Edward C; Brown, David A; Shah, Mala M

    2015-01-21

    Acetylcholine critically influences hippocampal-dependent learning. Cholinergic fibers innervate hippocampal neuron axons, dendrites, and somata. The effects of acetylcholine on axonal information processing, though, remain unknown. By stimulating cholinergic fibers and making electrophysiological recordings from hippocampal dentate gyrus granule cells, we show that synaptically released acetylcholine preferentially lowered the action potential threshold, enhancing intrinsic excitability and synaptic potential-spike coupling. These effects persisted for at least 30 min after the stimulation paradigm and were due to muscarinic receptor activation. This caused sustained elevation of axonal intracellular Ca(2+) via T-type Ca(2+) channels, as indicated by two-photon imaging. The enhanced Ca(2+) levels inhibited an axonal KV7/M current, decreasing the spike threshold. In support, immunohistochemistry revealed muscarinic M1 receptor, CaV3.2, and KV7.2/7.3 subunit localization in granule cell axons. Since alterations in axonal signaling affect neuronal firing patterns and neurotransmitter release, this is an unreported cellular mechanism by which acetylcholine might, at least partly, enhance cognitive processing. PMID:25578363

  1. Acute and long-term exposure to chlorpyrifos induces cell death of basal forebrain cholinergic neurons through AChE variants alteration.

    PubMed

    del Pino, Javier; Moyano, Paula; Anadon, María José; García, José Manuel; Díaz, María Jesús; García, Jimena; Frejo, María Teresa

    2015-10-01

    Chlorpyrifos (CPF) is one of the most widely used organophosphates insecticides that has been reported to induce cognitive disorders both after acute and repeated administration similar to those induced in Alzheimer's disease (AD). However, the mechanisms through which it induces these effects are unknown. On the other hand, the cholinergic system, mainly basal forebrain cholinergic neurons, is involved in learning and memory regulation, and an alteration of cholinergic transmission or/and cholinergic cell loss could induce these effects. In this regard, it has been reported that CPF can affect cholinergic transmission, and alter AChE variants, which have been shown to be related with basal forebrain cholinergic neuronal loss. According to these data, we hypothesized that CPF could induce basal forebrain cholinergic neuronal loss through cholinergic transmission and AChE variants alteration. To prove this hypothesis, we evaluated in septal SN56 basal forebrain cholinergic neurons, the CPF toxic effects after 24h and 14 days exposure on neuronal viability and the cholinergic mechanisms related to it. This study shows that CPF impaired cholinergic transmission, induced AChE inhibition and, only after long-term exposure, increased CHT expression, which suggests that acetylcholine levels alteration could be mediated by these actions. Moreover, CPF induces, after acute and long-term exposure, cell death in cholinergic neurons in the basal forebrain and this effect is independent of AChE inhibition and acetylcholine alteration, but was mediated partially by AChE variants alteration. Our present results provide a new understanding of the mechanisms contributing to the harmful effects of CPF on neuronal function and viability, and the possible relevance of CPF in the pathogenesis of neurodegenerative diseases. PMID:26210949

  2. Acetylcholine-induced potassium current of guinea pig outer hair cells: its dependence on a calcium influx through nicotinic-like receptors.

    PubMed

    Blanchet, C; Eróstegui, C; Sugasawa, M; Dulon, D

    1996-04-15

    The cholinergic efferent inhibition of mammalian outer hair cells (OHCs) is mediated by a hyperpolarizing K+ current. We have made whole-cell tight-seal recordings from single OHCs isolated from the guinea pig cochlea to characterize the mechanism by which acetylcholine (ACh) activates K+ channels. After ACh application, OHCs exhibited a biphasic response: an early depolarizing current preceding the predominant hyperpolarizing K+ current. The current-voltage (I-V) relationship of the ACh-induced response displayed an N-shape, suggesting the involvement of Ca2+ influx. When whole-cell recording was combined with confocal calcium imaging, we simultaneously observed the ACh-induced K+ current (IK(ACh)) and a Ca2+ response restricted to the synaptic area of the cell. This IK(ACh) could be prevented by loading OHCs with 10 mM of the fast Ca2+ buffer bis(2-aminophenoxy)ethane-N,N,N',N'-tetra-acetic acid (or BAPTA), therefore allowing the observation of the ACh-induced early current in isolation. This early current revealed nicotinic features because it activated with an intrinsic delay in the millisecond range, reversed nearly in between potassium and sodium equilibrium potentials, and was blocked by curare. However, it was strongly reduced in the absence of external Ca2+, and its I-V relationship displayed an unusual outward rectification at positive membrane potentials and an inward rectification below -60 mV. The results indicate that the cholinergic response of mammalian OHCs involves a "nicotinic-like" nonspecific cation channel through which Ca2+ enters and triggers activation of nearby Ca2+-dependent K+ channels. PMID:8786433

  3. Cholinergic inhibition of short (outer) hair cells of the chick's cochlea.

    PubMed

    Fuchs, P A; Murrow, B W

    1992-03-01

    Cochlear hair cells are thought to be inhibited by the release of ACh from efferent neurons. Several studies have implicated Ca2+ as a postsynaptic intermediary in hair cell inhibition, but its role remains unproven. We have made whole-cell, tight-seal recordings from single short hair cells (the avian analog of outer hair cells in the mammalian cochlea), isolated from the chick's cochlea, to determine the mechanism of cholinergic inhibition. These cells hyperpolarized upon exposure to ACh, although a brief depolarization preceded the much larger, longer-lasting hyperpolarization. In voltage clamp ACh evoked an outward current that reversed in sign near the K+ equilibrium potential. A small, transient inward current preceded the predominant outward current. The ACh-evoked K+ current depended on Ca2+ in the external saline, or could be prevented when the cell was dialyzed with the rapid Ca2+ buffer BAPTA. In BAPTA-loaded cells a residual inward current was seen. This activated with very little delay upon exposure of the cell to ACh and reversed near 0 mV membrane potential. Thus, the hair cell ACh receptor appears to be a nonspecific cation channel through which Ca2+ enters and triggers the opening of nearby Ca(2+)-activated K+ channels. However, the ACh-evoked K+ channels are not the same as the "maxi" K+ channels activated by Ca2+ influx through voltage-gated Ca2+ channels in these same cells. PMID:1545240

  4. Fetal chlorpyrifos exposure: adverse effects on brain cell development and cholinergic biomarkers emerge postnatally and continue into adolescence and adulthood.

    PubMed Central

    Qiao, Dan; Seidler, Frederic J; Tate, Charlotte A; Cousins, Mandy M; Slotkin, Theodore A

    2003-01-01

    Fetal and childhood exposures to widely used organophosphate pesticides, especially chlorpyrifos (CPF), have raised concerns about developmental neurotoxicity. Previously, biomarkers for brain cell number, cell packing density, and cell size indicated that neonatal rats were more sensitive to CPF than were fetal rats, yet animals exposed prenatally still developed behavioral deficits in adolescence and adulthood. In the present study, we administered CPF to pregnant rats on gestational days 17-20, using regimens devoid of overt fetal toxicity. We then examined subsequent development of acetylcholine systems in forebrain regions involved in cognitive function and compared the effects with those on general biomarkers of cell development. Choline acetyltransferase, a constitutive marker for cholinergic nerve terminals, showed only minor CPF-induced changes during the period of rapid synaptogenesis. In contrast, hemicholinium-3 binding to the presynaptic choline transporter, which is responsive to nerve impulse activity, displayed marked suppression in the animals exposed to CPF; despite a return to nearly normal values by weaning, deficits were again apparent in adolescence and adulthood. There was no compensatory up-regulation of cholinergic receptors, as m2-muscarinic cholinergic receptor binding was unchanged. CPF also elicited delayed-onset alterations in biomarkers for general aspects of cell integrity, with reductions in cell packing density, increases in relative cell size, and contraction of neuritic extensions; however, neither the magnitude nor timing of these changes was predictive of the cholinergic defects. The present findings indicate a wide window of vulnerability of cholinergic systems to CPF, extending from prenatal through postnatal periods, occurring independently of adverse effects on general cellular neurotoxicity. PMID:12676612

  5. Central Insulin Action Activates Kupffer Cells by Suppressing Hepatic Vagal Activation via the Nicotinic Alpha 7 Acetylcholine Receptor.

    PubMed

    Kimura, Kumi; Tanida, Mamoru; Nagata, Naoto; Inaba, Yuka; Watanabe, Hitoshi; Nagashimada, Mayumi; Ota, Tsuguhito; Asahara, Shun-ichiro; Kido, Yoshiaki; Matsumoto, Michihiro; Toshinai, Koji; Nakazato, Masamitsu; Shibamoto, Toshishige; Kaneko, Shuichi; Kasuga, Masato; Inoue, Hiroshi

    2016-03-15

    Central insulin action activates hepatic IL-6/STAT3 signaling, which suppresses the gene expression of hepatic gluconeogenic enzymes. The vagus nerve plays an important role in this centrally mediated hepatic response; however, the precise mechanism underlying this brain-liver interaction is unclear. Here, we present our findings that the vagus nerve suppresses hepatic IL-6/STAT3 signaling via α7-nicotinic acetylcholine receptors (α7-nAchR) on Kupffer cells, and that central insulin action activates hepatic IL-6/STAT3 signaling by suppressing vagal activity. Indeed, central insulin-mediated hepatic IL-6/STAT3 activation and gluconeogenic gene suppression were impeded in mice with hepatic vagotomy, pharmacological cholinergic blockade, or α7-nAchR deficiency. In high-fat diet-induced obese and insulin-resistant mice, control of the vagus nerve by central insulin action was disturbed, inducing a persistent increase of inflammatory cytokines. These findings suggest that dysregulation of the α7-nAchR-mediated control of Kupffer cells by central insulin action may affect the pathogenesis of chronic hepatic inflammation in obesity. PMID:26947072

  6. Nicotine-mediated signals modulate cell death and survival of T lymphocytes

    SciTech Connect

    Oloris, Silvia C.S.; Frazer-Abel, Ashley A.; Jubala, Cristan M.; Fosmire, Susan P.; Helm, Karen M.; Robinson, Sally R.; Korpela, Derek M.; Duckett, Megan M.; Baksh, Shairaz; Modiano, Jaime F.

    2010-02-01

    The capacity of nicotine to affect the behavior of non-neuronal cells through neuronal nicotinic acetylcholine receptors (nAChRs) has been the subject of considerable recent attention. Previously, we showed that exposure to nicotine activates the nuclear factor of activated T cells (NFAT) transcription factor in lymphocytes and endothelial cells, leading to alterations in cellular growth and vascular endothelial growth factor production. Here, we extend these studies to document effects of nicotine on lymphocyte survival. The data show that nicotine induces paradoxical effects that might alternatively enforce survival or trigger apoptosis, suggesting that depending on timing and context, nicotine might act both as a survival factor or as an inducer of apoptosis in normal or transformed lymphocytes, and possibly other non-neuronal cells. In addition, our results show that, while having overlapping functions, low and high affinity nAChRs also transmit signals that promote distinct outcomes in lymphocytes. The sum of our data suggests that selective modulation of nAChRs might be useful to regulate lymphocyte activation and survival in health and disease.

  7. Global actions of nicotine on the striatal microcircuit

    PubMed Central

    Plata, Víctor; Duhne, Mariana; Pérez-Ortega, Jesús; Hernández-Martinez, Ricardo; Rueda-Orozco, Pavel; Galarraga, Elvira; Drucker-Colín, René; Bargas, José

    2013-01-01

    The question to solve in the present work is: what is the predominant action induced by the activation of cholinergic-nicotinic receptors (nAChrs) in the striatal network given that nAChrs are expressed by several elements of the circuit: cortical terminals, dopamine terminals, and various striatal GABAergic interneurons. To answer this question some type of multicellular recording has to be used without losing single cell resolution. Here, we used calcium imaging and nicotine. It is known that in the presence of low micromolar N-Methyl-D-aspartate (NMDA), the striatal microcircuit exhibits neuronal activity consisting in the spontaneous synchronization of different neuron pools that interchange their activity following determined sequences. The striatal circuit also exhibits profuse spontaneous activity in pathological states (without NMDA) such as dopamine depletion. However, in this case, most pathological activity is mostly generated by the same neuron pool. Here, we show that both types of activity are inhibited during the application of nicotine. Nicotine actions were blocked by mecamylamine, a non-specific antagonist of nAChrs. Interestingly, inhibitory actions of nicotine were also blocked by the GABAA-receptor antagonist bicuculline, in which case, the actions of nicotine on the circuit became excitatory and facilitated neuronal synchronization. We conclude that the predominant action of nicotine in the striatal microcircuit is indirect, via the activation of networks of inhibitory interneurons. This action inhibits striatal pathological activity in early Parkinsonian animals almost as potently as L-DOPA. PMID:24223538

  8. Prenatal and lactation nicotine exposure affects Sertoli cell and gonadotropin levels in rats.

    PubMed

    Paccola, C C; Miraglia, S M

    2016-02-01

    Nicotine is largely consumed in the world as a component of cigarettes. It can cross the placenta and reach the milk of smoking mothers. This drug induces apoptosis, affects sex hormone secretion, and leads to male infertility. To investigate the exposure to nicotine during the whole intrauterine and lactation phases in Sertoli cells, pregnant rats received nicotine (2 mg/kg per day) through osmotic minipumps. Male offsprings (30, 60, and 90 days old) had blood collected for hormonal analysis (FSH and LH) and their testes submitted for histophatological study, analysis of the frequency of the stages of seminiferous epithelium cycle, immunolabeling of apoptotic epithelial cells (TUNEL and Fas/FasL), analysis of the function and structure of Sertoli cells (respectively using transferrin and vimentin immunolabeling), and analysis of Sertoli-germ cell junctional molecule (β-catenin immunolabeling). The exposure to nicotine increased the FSH and LH plasmatic levels in adult rats. Although nicotine had not changed the number of apoptotic cells, neither in Fas nor FasL expression, it provoked an intense sloughing of epithelial cells and also altered the frequency of some stages of the seminiferous epithelium cycle. Transferrin and β-catenin expressions were not changed, but vimentin was significantly reduced in the early stages of the seminiferous cycle of the nicotine-exposed adult rats. Thus, we concluded that nicotine exposure during all gestational and lactation periods affects the structure of Sertoli cells by events causing intense germ cell sloughing observed in the tubular lumen and can compromise the fertility of the offspring. PMID:26556892

  9. Interaction of IFN-γ with Cholinergic Agonists to Modulate Rat and Human Goblet Cell Function

    PubMed Central

    García-Posadas, L; Hodges, RR; Li, D; Shatos, MA; Storr-Paulsen, T; Diebold, Y; Dartt, DA

    2015-01-01

    Goblet cells populate wet-surfaced mucosa including the conjunctiva of the eye, intestine, and nose, among others. These cells function as part of the innate immune system by secreting high molecular weight mucins that interact with environmental constituents including pathogens, allergens, and particulate pollutants. Herein we determined whether IFN-γ, a Th1 cytokine increased in dry eye, alters goblet cell function. Goblet cells from rat and human conjunctiva were cultured. Changes in intracellular [Ca2+] ([Ca2+]i), high molecular weight glycoconjugate secretion, and proliferation were measured after stimulation with IFN-γ with or without the cholinergic agonist carbachol. IFN-γ itself increased [Ca2+]i in rat and human goblet cells and prevented the increase in [Ca2+]i caused by carbachol. Carbachol prevented IFN-γ-mediated increase in [Ca2+]i. This cross-talk between IFN-γ and muscarinic receptors may be partially due to use of the same Ca2+i reservoirs, but also from interaction of signaling pathways proximal to the increase in [Ca2+]i. IFN-γ blocked carbachol-induced high molecular weight glycoconjugate secretion and reduced goblet cell proliferation. We conclude that increased levels of IFN-γ in dry eye disease could explain the lack of goblet cells and mucin deficiency typically found in this pathology. IFN-γ could also function similarly in respiratory and gastrointestinal tracts. PMID:26129651

  10. Nicotine recruits glutamate receptors to postsynaptic sites.

    PubMed

    Duan, Jing-Jing; Lozada, Adrian F; Gou, Chen-Yu; Xu, Jing; Chen, Yuan; Berg, Darwin K

    2015-09-01

    Cholinergic neurons project throughout the nervous system and activate nicotinic receptors to modulate synaptic function in ways that shape higher order brain function. The acute effects of nicotinic signaling on long-term synaptic plasticity have been well-characterized. Less well understood is how chronic exposure to low levels of nicotine, such as those encountered by habitual smokers, can alter neural connections to promote addiction and other lasting behavioral effects. We show here that chronic exposure of hippocampal neurons in culture to low levels of nicotine recruits AMPA and NMDA receptors to the cell surface and sequesters them at postsynaptic sites. The receptors include GluA2-containing AMPA receptors, which are responsible for most of the excitatory postsynaptic current mediated by AMPA receptors on the neurons, and include NMDA receptors containing GluN1 and GluN2B subunits. Moreover, we find that the nicotine treatment also increases expression of the presynaptic component synapsin 1 and arranges it in puncta juxtaposed to the additional AMPA and NMDA receptor puncta, suggestive of increases in synaptic contacts. Consistent with increased synaptic input, we find that the nicotine treatment leads to an increase in the excitatory postsynaptic currents mediated by AMPA and NMDA receptors. Further, the increases skew the ratio of excitatory-to-inhibitory input that the cell receives, and this holds both for pyramidal neurons and inhibitory neurons in the hippocampal CA1 region. The GluN2B-containing NMDA receptor redistribution at synapses is associated with a significant increase in GluN2B phosphorylation at Tyr1472, a site known to prevent GluN2B endocytosis. These results suggest that chronic exposure to low levels of nicotine not only alters functional connections but also is likely to change excitability levels across networks. Further, it may increase the propensity for synaptic plasticity, given the increase in synaptic NMDA receptors. PMID

  11. Heterogeneity of phasic cholinergic signaling in neocortical neurons.

    PubMed

    Gulledge, Allan T; Park, Susanna B; Kawaguchi, Yasuo; Stuart, Greg J

    2007-03-01

    Acetylcholine (ACh) is a neurotransmitter critical for normal cognition. Here we demonstrate heterogeneity of cholinergic signaling in neocortical neurons in the rat prefrontal, somatosensory, and visual cortex. Focal ACh application (100 muM) inhibited layer 5 pyramidal neurons in all cortical areas via activation of an apamin-sensitive SK-type calcium-activated potassium conductance. Cholinergic inhibition was most robust in prefrontal layer 5 neurons, where it relies on the same signal transduction mechanism (M1-like receptors, IP(3)-dependent calcium release, and SK-channels) as exists in somatosensory pyramidal neurons. Pyramidal neurons in layer 2/3 were less responsive to ACh, but substantial apamin-sensitive inhibitory responses occurred in deep layer 3 neurons of the visual cortex. ACh was only inhibitory when presented near the somata of layer 5 pyramidal neurons, where repetitive ACh applications generated discrete inhibitory events at frequencies of up to approximately 0.5 Hz. Fast-spiking (FS) nonpyramidal neurons in all cortical areas were unresponsive to ACh. When applied to non-FS interneurons in layers 2/3 and 5, ACh generated mecamylamine-sensitive nicotinic responses (38% of cells), apamin-insensitive hyperpolarizing responses, with or without initial nicotinic depolarization (7% of neurons), or no response at all (55% of cells). Responses in interneurons were similar across cortical layers and regions but were correlated with cellular physiology and the expression of biochemical markers associated with different classes of nonpyramidal neurons. Finally, ACh generated nicotinic responses in all layer 1 neurons tested. These data demonstrate that phasic cholinergic input can directly inhibit projection neurons throughout the cortex while sculpting intracortical processing, especially in superficial layers. PMID:17122323

  12. Global Analysis of Protein Expression and Phosphorylation Levels in Nicotine-Treated Pancreatic Stellate Cells.

    PubMed

    Paulo, Joao A; Gaun, Aleksandr; Gygi, Steven P

    2015-10-01

    Smoking is a risk factor in pancreatic disease; however, the biochemical mechanisms correlating smoking with pancreatic dysfunction remain poorly understood. Strategies using multiplexed isobaric tag-based mass spectrometry facilitate the study of drug-induced perturbations on biological systems. Here, we present the first large-scale analysis of the proteomic and phosphoproteomic alterations in pancreatic stellate cells following treatment with two nicotinic acetylcholine receptor (nAChR) ligands: nicotine and α-bungarotoxin. We treated cells with nicotine or α-bungarotoxin for 12 h in triplicate and compared alterations in protein expression and phosphorylation levels to mock-treated cells using a tandem mass tag (TMT9plex)-based approach. Over 8100 proteins were quantified across all nine samples, of which 46 were altered in abundance upon treatment with nicotine. Proteins with increased abundance included those associated with neurons, defense mechanisms, indicators of pancreatic disease, and lysosomal proteins. In addition, we measured differences for ∼16 000 phosphorylation sites across all nine samples using a titanium dioxide-based strategy, of which 132 sites were altered with nicotine and 451 with α-bungarotoxin treatment. Many altered phosphorylation sites were involved in nuclear function and transcriptional events. This study supports the development of future targeted investigations to establish a better understanding for the role of nicotine and associated receptors in pancreatic disease. PMID:26265067

  13. Global analysis of protein expression and phosphorylation levels in nicotine-treated pancreatic stellate cells

    PubMed Central

    Paulo, Joao A.; Gaun, Aleksandr; Gygi, Steven P.

    2016-01-01

    Smoking is a risk factor in pancreatic disease, however, the biochemical mechanisms correlating smoking with pancreatic dysfunction remain poorly understood. Strategies using multiplexed isobaric tag-based mass spectrometry facilitate the study of drug-induced perturbations on biological systems. Here, we present the first large scale analysis of the proteomic and phosphoproteomic alterations in pancreatic stellate cells following treatment with two nicotinic acetylcholine receptor (nAChR) ligands: nicotine and α-bungarotoxin. We treated cells with nicotine or α-bungarotoxin for 12hr in triplicate and compared alterations in protein expression and phosphorylation levels to mock treated cells using a tandem mass tag (TMT9plex)-based approach. Over 8,100 proteins were quantified across all nine samples of which 46 were altered in abundance upon treatment with nicotine. Proteins with increased abundance included those associated with neurons, defense mechanisms, indicators of pancreatic disease and lysosomal proteins. In addition, we measured differences for ∼16,000 phosphorylation sites across all nine samples using a titanium dioxide-based strategy, of which 132 sites were altered with nicotine and 451 with α-bungarotoxin treatment. Many altered phosphorylation sites were involved in nuclear function and transcriptional events. This study supports the development of future targeted investigations to establish a better understanding for the role of nicotine and associated receptors in pancreatic disease. PMID:26265067

  14. Cell-surface translational dynamics of nicotinic acetylcholine receptors

    PubMed Central

    Barrantes, Francisco J.

    2014-01-01

    Synapse efficacy heavily relies on the number of neurotransmitter receptors available at a given time. In addition to the equilibrium between the biosynthetic production, exocytic delivery and recycling of receptors on the one hand, and the endocytic internalization on the other, lateral diffusion and clustering of receptors at the cell membrane play key roles in determining the amount of active receptors at the synapse. Mobile receptors traffic between reservoir compartments and the synapse by thermally driven Brownian motion, and become immobilized at the peri-synaptic region or the synapse by: (a) clustering mediated by homotropic inter-molecular receptor–receptor associations; (b) heterotropic associations with non-receptor scaffolding proteins or the subjacent cytoskeletal meshwork, leading to diffusional “trapping,” and (c) protein-lipid interactions, particularly with the neutral lipid cholesterol. This review assesses the contribution of some of these mechanisms to the supramolecular organization and dynamics of the paradigm neurotransmitter receptor of muscle and neuronal cells -the nicotinic acetylcholine receptor (nAChR). Currently available information stemming from various complementary biophysical techniques commonly used to interrogate the dynamics of cell-surface components is critically discussed. The translational mobility of nAChRs at the cell surface differs between muscle and neuronal receptors in terms of diffusion coefficients and residence intervals at the synapse, which cover an ample range of time regimes. A peculiar feature of brain α7 nAChR is its ability to spend much of its time confined peri-synaptically, vicinal to glutamatergic (excitatory) and GABAergic (inhibitory) synapses. An important function of the α7 nAChR may thus be visiting the territories of other neurotransmitter receptors, differentially regulating the dynamic equilibrium between excitation and inhibition, depending on its residence time in each domain. PMID

  15. Nicotine Promotes Acquisition of Stem Cell and Epithelial-to-Mesenchymal Properties in Head and Neck Squamous Cell Carcinoma

    PubMed Central

    Rahimy, Elham; Haas, Martin; Yu, Vicky; Ellies, Lesley G.; Chen, Jing; Fan, Jian-Bing; Brumund, Kevin T.; Weisman, Robert A.; Ongkeko, Weg M.

    2012-01-01

    The ability of nicotine to enhance the malignancy of cancer cells is known; however, the possibility that nicotine could regulate a cancer stem cell phenotype remains to be well-established. In this study we sought to determine whether long-term exposure to nicotine could promote cancer stem cell-like properties in two head and neck squamous cell carcinoma cell lines, UMSCC-10B and HN-1. Nicotine treatment induced epithelial-to-mesenchymal transition (EMT) in both cell lines by repressing E-cadherin expression, and led to the induction of stem cell markers Oct-4, Nanog, CD44 and BMI-1, which was reversed upon ectopic re-expression of E-cadherin. Nicotine-treated cells formed spheres at a higher efficiency than non-treated cells, formed larger tumors when injected into mice, and formed tumors with 4-fold greater efficiency compared to control cells when injected at limiting doses. Consistent with previous literature, nicotine-treated cells demonstrated a greater capacity for survival and also a higher tendency to invade. Comparison of microRNA profiles between nicotine and control cells revealed the upregulation of miR-9, a repressor of E-cadherin, and the downregulation of miR-101, a repressor of EZH2. Taken together, these results suggest that nicotine may play a critical role in the development of tobacco-induced cancers by regulating cancer stem cell characteristics, and that these effects are likely mediated through EMT-promoting, microRNA-mediated pathways. Further characterization of such pathways remains a promising avenue for the understanding and treatment of tobacco-related cancers. PMID:23300583

  16. Nicotine mediates oxidative stress and apoptosis through cross talk between NOX1 and Bcl-2 in lung epithelial cells.

    PubMed

    Zanetti, Filippo; Giacomello, Marta; Donati, Yves; Carnesecchi, Stephanie; Frieden, Maud; Barazzone-Argiroffo, Constance

    2014-11-01

    Nicotine contributes to the onset and progression of several pulmonary diseases. Among the various pathophysiological mechanisms triggered by nicotine, oxidative stress and cell death are reported in several cell types. We found that chronic exposure to nicotine (48h) induced NOX1-dependent oxidative stress and apoptosis in primary pulmonary cells. In murine (MLE-12) and human (BEAS-2B) lung epithelial cell lines, nicotine acted as a sensitizer to cell death and synergistically enhanced apoptosis when cells were concomitantly exposed to hyperoxia. The precise signaling pathway was investigated in MLE-12 cells in which NOX1 was abrogated by a specific inhibitor or stably silenced by shRNA. In the early phase of exposure (1h), nicotine mediated intracellular Ca(2+) fluxes and activation of protein kinase C, which in its turn activated NOX1, leading to cellular and mitochondrial oxidative stress. The latter triggered the intrinsic apoptotic machinery by modulating the expression of Bcl-2 and Bax. Overexpression of Bcl-2 completely prevented nicotine's detrimental effects, suggesting Bcl-2as a downstream key regulator in nicotine/NOX1-induced cell damage. These results suggest that NOX1 is a major contributor to the generation of intracellular oxidative stress induced by nicotine and might be an important molecule to target in nicotine-related lung pathologies. PMID:25151121

  17. Cholinergic microvillous cells in the mouse main olfactory epithelium and effect of acetylcholine on olfactory sensory neurons and supporting cells

    PubMed Central

    Ogura, Tatsuya; Szebenyi, Steven A.; Krosnowski, Kurt; Sathyanesan, Aaron; Jackson, Jacqueline

    2011-01-01

    The mammalian olfactory epithelium is made up of ciliated olfactory sensory neurons (OSNs), supporting cells, basal cells, and microvillous cells. Previously, we reported that a population of nonneuronal microvillous cells expresses transient receptor potential channel M5 (TRPM5). Using transgenic mice and immunocytochemical labeling, we identify that these cells are cholinergic, expressing the signature markers of choline acetyltransferase (ChAT) and the vesicular acetylcholine transporter. This result suggests that acetylcholine (ACh) can be synthesized and released locally to modulate activities of neighboring supporting cells and OSNs. In Ca2+ imaging experiments, ACh induced increases in intracellular Ca2+ levels in 78% of isolated supporting cells tested in a concentration-dependent manner. Atropine, a muscarinic ACh receptor (mAChR) antagonist suppressed the ACh responses. In contrast, ACh did not induce or potentiate Ca2+ increases in OSNs. Instead ACh suppressed the Ca2+ increases induced by the adenylyl cyclase activator forskolin in some OSNs. Supporting these results, we found differential expression of mAChR subtypes in supporting cells and OSNs using subtype-specific antibodies against M1 through M5 mAChRs. Furthermore, we found that various chemicals, bacterial lysate, and cold saline induced Ca2+ increases in TRPM5/ChAT-expressing microvillous cells. Taken together, our data suggest that TRPM5/ChAT-expressing microvillous cells react to certain chemical or thermal stimuli and release ACh to modulate activities of neighboring supporting cells and OSNs via mAChRs. Our studies reveal an intrinsic and potentially potent mechanism linking external stimulation to cholinergic modulation of activities in the olfactory epithelium. PMID:21676931

  18. Nicotine exposure induces bronchial epithelial cell apoptosis and senescence via ROS mediated autophagy-impairment.

    PubMed

    Bodas, Manish; Van Westphal, Colin; Carpenter-Thompson, Rhett; K Mohanty, Dillip; Vij, Neeraj

    2016-08-01

    Waterpipe smoking and e-cigarette vaping, the non-combustible sources of inhaled nicotine exposure are increasingly becoming popular and marketed as safer alternative to cigarette smoking. Hence, this study was designed to investigate the impact of inhaled nicotine exposure on disease causing COPD-emphysema mechanisms. For in vitro studies, human bronchial epithelial cells (Beas2b) were treated with waterpipe smoke extract (WPSE, 5%), nicotine (5mM), and/or cysteamine (250μM, an autophagy inducer and anti-oxidant drug), for 6hrs. We observed significantly (p<0.05) increased ubiquitinated protein-accumulation in the insoluble protein fractions of Beas2b cells treated with WPSE or nicotine that could be rescued by cysteamine treatment, suggesting aggresome-formation and autophagy-impairment. Moreover, our data also demonstrate that both WPSE and nicotine exposure significantly (p<0.05) elevates Ub-LC3β co-localization to aggresome-bodies while inducing Ub-p62 co-expression/accumulation, verifying autophagy-impairment. We also found that WPSE and nicotine exposure impacts Beas2b cell viability by significantly (p<0.05) inducing cellular apoptosis/senescence via ROS-activation, as it could be controlled by cysteamine, which is known to have an anti-oxidant property. For murine studies, C57BL/6 mice were administered with inhaled nicotine (intranasal, 500μg/mouse/day for 5 days), as an experimental model of non-combustible nicotine exposure. The inhaled nicotine exposure mediated oxidative-stress induces autophagy-impairment in the murine lungs as seen by significant (p<0.05, n=4) increase in the expression levels of nitrotyrosine protein-adduct (oxidative-stress marker, soluble-fraction) and Ub/p62/VCP (impaired-autophagy marker, insoluble-fraction). Overall, our data shows that nicotine, a common component of WPS, e-cigarette vapor and cigarette smoke, induces bronchial epithelial cell apoptosis and senescence via ROS mediated autophagy-impairment as a potential

  19. Nicotine enhances invasion and metastasis of human colorectal cancer cells through the nicotinic acetylcholine receptor downstream p38 MAPK signaling pathway.

    PubMed

    Xiang, Tao; Fei, Rushan; Wang, Zhe; Shen, Zhonglei; Qian, Jing; Chen, Wenbin

    2016-01-01

    Nicotine as a cigarette component is an established risk factor for colorectal cancer tumorigenesis. The downstream signaling pathways of nicotinic acetylcholine receptors (nAchRs) are believed to be responsible for the cellular effects. In the present study, we evaluated the effects and novel mechanisms for nicotine on the capacity for colorectal cancer cell invasion and metastasis. LOVO and SW620 colorectal cancer cells were stimulated with nicotine in vitro. A Transwell chamber model was applied to detect the capacity for tumor cell invasion. Assays for gelatin zymography and western blotting were applied to detect the activity and expression of metastasis-related matrix metalloproteinases (MMPs), respectively. Signal transduction was assessed by immunoblotting for the phosphorylation of relevant signal molecules and the application of pharmaceutical inhibitors. We showed that nicotine increased LOVO and SW620 colorectal cancer cell invasion along with enhanced activity and expression of MMP-1, -2 and -9. Nicotine increased phosphorylation of p38, ERK, Akt and PI3K p85 but had no effect on phosphorylation of JNK, or NF-κB. Of the pharmaceutical inhibitors of U0126 (ERK1/2 inhibitor), LY294002 (Akt activation inhibitor), SB239063 (p38 MAPK activation inhibitor) and hexamethonium (Hex) (nAchRs inhibitor), the cellular and molecular effects were reduced by the applications of SB239063 and Hex. We concluded that nicotine stimulates the invasion and metastasis of colon cancer cells in vitro via activation of the nAchRs and the p38 MAPK downstream signaling pathway. Therefore, p38 MAPK may have potential as a therapeutic target for smoking-related human colorectal cancer metastasis. PMID:26530054

  20. Further proof of the existence of a non-neuronal cholinergic system in the human Achilles tendon: Presence of the AChRα7 receptor in tendon cells and cells in the peritendinous tissue.

    PubMed

    Forsgren, Sture; Alfredson, Håkan; Andersson, Gustav

    2015-11-01

    Human tendon cells have the capacity for acetylcholine (ACh) production. It is not known if the tendon cells also have the potential for ACh breakdown, nor if they show expression of the nicotinic acetylcholine receptor AChRα7 (α7nAChR). Therefore, tendon tissue specimens from patients with midportion Achilles tendinopathy/tendinosis and from normal midportion Achilles tendons were examined. Reaction for the degradative enzyme acetylcholinesterase (AChE) was found in some tenocytes in only a few tendinopathy tendons, and was never found in those of control tendons. Tenocytes displayed more regularly α7nAChR immunoreactivity. However, there was a marked heterogeneity in the degree of this reaction within and between the specimens. α7nAChR immunoreactivity was especially pronounced for tenocytes showing an oval/widened appearance. There was a tendency that the magnitude of α7nAChR immunoreactivity was higher in tendinopathy tendons as compared to control tendons. A stronger α7nAChR immunoreactivity than seen for tenocytes was observed for the cells in the peritendinous tissue. It is likely that the α7nAChR may be an important part of an auto-and paracrine loop of non-neuronal ACh that is released from the tendon cells. The effects may be related to proliferative and blood vessel regulatory functions as well as features related to collagen deposition. ACh can furthermore be of importance in leading to anti-inflammatory effects in the peritendinous tissue, a tissue nowadays considered to be of great relevance for the tendinopathy process. Overall, the findings show that tendon tissue, a tissue known to be devoid of cholinergic innervation, is a tissue in which there is a marked non-neuronal cholinergic system. PMID:25981114

  1. Protective Effects of Nicotine Against Aminochrome-Induced Toxicity in Substantia Nigra Derived Cells: Implications for Parkinson’s Disease

    PubMed Central

    Muñoz, Patricia; Huenchuguala, Sandro; Paris, Irmgard; Cuevas, Carlos; Villa, Monica; Caviedes, Pablo; Segura-Aguilar, Juan

    2013-01-01

    Parkinson’s disease is a debilitating progressive neurodegenerative disorder that results from the loss of or damage to dopaminergic cells containing neuromelanin in the substantia nigra (SN). The underlying neurodegenerative mechanism(s), however, remain elusive. Aminochrome, the precursor of neuromelanin is an endogenous substance capable of inducing selective neurotoxicity to dopaminergic neurons in SN. Nicotine, on the other hand, may offer protective effects against dopaminergic cell damage induced by various neurotoxins including MPTP and salsolinol. In this study, we sought to determine whether nicotine may also protect against aminochrome-induced toxicity in SN derived RCSN-3 cells. Exposure of RCSN-3 cells to a combination of aminochrome (50 μM) and dicoumarol (50 μM) for 48 h induced approximately 70 % cell death. Pretreatment with nicotine, dose-dependently blocked this toxicity. The effects of nicotine in turn were dose-dependently blocked by mecamylamine, a non-selective nicotinic receptor antagonist. These results suggest involvement of nicotinic receptors in protective effects of nicotine against aminochrome-induced toxicity and provide further evidence for possible therapeutic effects of nicotine or nicotinic agonists in Parkinson’s disease. PMID:22528249

  2. COMPARISON OF WEEKLY EXPOSURES TO ANATOXIN-A AND NICOTINE ON THE MOTOR ACTIVITY OF RATS.

    EPA Science Inventory

    Anatoxin-a is a nicotinic cholinergic agonist that is produced by several genera of cyanobacteria, and has been implicated in several poisoning episodes of wildlife, livestock, domestic animals and people. Previous research on nicotine has obtained tolerance and sensitization ...

  3. Nicotine-mediated cell proliferation and angiogenesis: new twists to an old story.

    PubMed

    Dasgupta, Piyali; Chellappan, Srikumar P

    2006-10-01

    Tobacco smoking is one of the major etiologic factors associated with cancer. While there are many carcinogenic compounds present in tobacco smoke, its main addictive component, nicotine, is not carcinogenic by itself. The addictive properties of nicotine are achieved through the nicotinic acetylcholine receptors (nAChRs) that are widely distributed in the brain and neuromuscular junctions; at the same time, they were found to be expressed in a variety of non-neuronal tissues in the body including those of the lung. Recent studies show that these non-neuronal nAChRs can induce cell proliferation and angiogenesis. Analysis of the molecular mechanisms underlying nicotine-mediated cell proliferation showed the involvement of Src kinase and the scaffolding protein beta-arrestin-1. Further, nAChRs were found to activate the basic components of the cell cycle machinery similar to growth factor receptors. This involved increased binding of Raf-1 kinase to the Rb protein, activation of cyclins D and E as well as induction of proliferative promoters. This article describes pathway involved in nicotine-induced cell proliferation and angiogenesis and the potential steps that are amenable for developing novel anti-cancer therapies. PMID:17102610

  4. Culture conditions affect the cholinergic development of an isolated subpopulation of chick mesencephalic neural crest cells.

    PubMed

    Barald, K F

    1989-10-01

    Although neural crest cells are known to be very responsive to environmental cues during their development, recent evidence indicates that at least some subpopulations may be committed to a specific differentiation program prior to migration. Because the neural crest is composed of a heterogeneous mixture of cells that contributes to many vertebrate cell lineages, assessing the properties of specific subpopulations and the effect of the environment on their development has been difficult. To address this problem, we have isolated a pure subpopulation of chick mesencephalic neural crest cells by fluorescence no-flow cytometry after labeling them with monoclonal antibodies (Mabs) to a 75-kDa cell surface antigen that is associated with high affinity choline uptake. When cultures of chick mesencephalic neural crest cells are labeled with these Mabs and a fluorescent second step antibody, approximately 5% of the cells are antigen-positive (A+). After sorting, 100% of the resulting cultured mesencephalic neural crest cells are A+. The Mabs we used also label all of the neurons of the embryonic chick and quail ciliary ganglion in vivo and in vitro. We have compared the effect of various cell culture media on the isolated neural crest subpopulation and the heterogeneous chick mesencephalic neural crest from which it was derived. A+ cells were passaged and grown in a variety of media, each of which differently affected its characteristics and development. A+ cells proliferated in the presence of 15% fetal bovine serum (FBS) and high concentrations (10-15%) of chick embryo extract, but did not differentiate, although they retained basal levels of choline acetyltransferase (ChAT) activity. However, in chick serum and high (25 mM as opposed to 7 mM) K+, and heart-, iris-, or lung-conditioned medium, all of which are known to promote survival and/or cholinergic development of ciliary ganglion neurons, the cells ceased to proliferate and all of the cells in the culture became

  5. Alpha5 nicotinic acetylcholine receptor mediates nicotine-induced HIF-1α and VEGF expression in non-small cell lung cancer

    SciTech Connect

    Ma, Xiaoli; Jia, Yanfei; Zu, Shanshan; Li, Ruisheng; Jia, Ying; Zhao, Yun; Xiao, Dongjie; Dang, Ningning; Wang, Yunshan

    2014-07-15

    By binding to nicotinic acetylcholine receptors (nAChRs), nicotine induces the proliferation and apoptosis of non-small cell lung cancer (NSCLC). Previous studies have indicated that α5-nAChR is highly associated with lung cancer risk and nicotine dependence. However, the mechanisms through which α5-nAChRs may influence lung carcinogenesis are far from clear. In the present study, we investigated the roles of α5-nAChR in the nicotine-induced expression of hypoxia-inducible factor-1α (HIF-1α) and vascular endothelial growth factor (VEGF). Immunohistochemistry was used to detect the expression of α5-nAChR and HIF-1α in 60 specimens of lung cancer and para-carcinoma tissue. The correlations between the expression levels of α5-nAChR and HIF-1α and other clinicopathological data were analyzed. In a cell line that highly expressed α5-nAChR, the loss of α5-nAChR function by siRNA was used to study whether α5-nAChR is involved in the nicotine-induced expression of HIF-1α and VEGF through the activation of the ERK1/2 and PI3K/Akt signaling pathways. Cell growth was detected using the cell counting kit-8 (CCK-8). α5-nAChR (78.3%) and HIF-1α (88.3%) were both overexpressed in NSCLC, and their expression levels were found to be correlated with each other (P < 0.05). In the A549 cell line, α5-nAChR and HIF-1α were found to be expressed under normal conditions, and their expression levels were significantly increased in response to nicotine treatment. The silencing of α5-nAChR significantly inhibited the nicotine-induced cell proliferation compared with the control group and attenuated the nicotine-induced upregulation of HIF-1α and VEGF, and these effects required the cooperation of the ERK1/2 and PI3K/Akt signaling pathways. These results show that the α5-nAChR/HIF-1α/VEGF axis is involved in nicotine-induced tumor cell proliferation, which suggests that α5-nAChR may serve as a potential anticancer target in nicotine-associated lung cancer. - Highlights

  6. Nicotine-induced resistance of non-small cell lung cancer to treatment--possible mechanisms.

    PubMed

    Czyżykowski, Rafał; Połowinczak-Przybyłek, Joanna; Potemski, Piotr

    2016-01-01

    Cigarette smoking is the leading risk factor of lung cancer. Data from several clinical studies suggest that continuation of smoking during therapy of tobacco-related cancers is associated with lower response rates to chemotherapy and/or radiotherapy, and even with decreased survival. Although nicotine--an addictive component of tobacco--is not a carcinogen, it may influence cancer development and progression or effectiveness of anti-cancer therapy. Several in vitro and in vivo trials have evaluated the influence of nicotine on lung cancer cells. The best known mechanisms by which nicotine impacts cancer biology involve suppression of apoptosis induced by certain drugs or radiation, promotion of proliferation, angiogenesis, invasion and migration of cancer cells. This effect is mainly mediated by membranous nicotinic acetylcholine receptors whose stimulation leads to sustained activation of such intracellular pathways as PI3K/Akt/mTOR, RAS/RAF/MEK/ERK and JAK/STAT, induction of NF-κB activity, enhanced transcription of mitogenic promoters, inhibition of the mitochondrial death pathway or stimulation of pro-angiogenic factors. We herein summarize the mechanisms underlying nicotine's influence on biology of lung cancer cells and the effectiveness of anti-cancer therapy. PMID:26943316

  7. Transplantation of NSC-derived cholinergic neuron-like cells improves cognitive function in APP/PS1 transgenic mice.

    PubMed

    Gu, G; Zhang, W; Li, M; Ni, J; Wang, P

    2015-04-16

    The ability to selectively control the differentiation of neural stem cells (NSCs) into cholinergic neurons in vivo would be an important step toward cell replacement therapy. First, green fluorescent protein (GFP)-NSCs were induced to differentiate into cholinergic neuron-like cells (CNLs) with retinoic acid (RA) pre-induction followed by nerve growth factor (NGF) induction. Then, these CNLs were transplanted into bilateral hippocampus of APP/PS1 transgenic mice. Behavioral parameters showed by Morris water maze (MWM) tests and the percentages of GFP-labeled cholinergic neurons of CNL transplanted mice were compared with those of controls. Brain levels of choline acetyltransferase (ChAT) mRNA and proteins were analyzed by quantitative real-time PCR and Western blotting, ChAT activity and acetylcholine (ACh) concentration were also evaluated by ChAT activity and ACh concentration assay kits. Immunofluorescence analysis showed that 80.3±1.5% NSCs differentiated into CNLs after RA pre-induction followed by NGF induction in vitro. Three months after transplantation, 82.4±6.3% CNLs differentiated into cholinergic neurons in vivo. APP/PS1 mice transplanted with CNLs showed a significant improvement in learning and memory ability compared with control groups at different time points. Furthermore, CNLs transplantation dramatically increased in the expressions of ChAT mRNA and protein, as well ChAT activity and ACh concentration in APP/PS1 mice. Our findings support the prospect of using NSC-derived CNLs in developing therapies for Alzheimer's disease (AD). PMID:25681520

  8. The Role of Cholinergic and GABAergic Medial Septal/Diagonal Band Cell Populations in the Emergence of Diencephalic amnesia

    PubMed Central

    Roland, Jessica J.; Savage, Lisa M.

    2010-01-01

    The septohippocampal pathway, which is mostly comprised of cholinergic and GABAergic projections between the medial septum/diagonal band (MS/DB) and the hippocampus, has an established role in learning, memory and disorders of cognition. In Wernicke-Korsakoff’s syndrome (WKS) and the animal model of the disorder, pyrithiamine-induced thiamine deficiency (PTD), there is both diencephalic damage and basal forebrain cell loss that could contribute to the amnesic state. In the current experiment, we used the PTD animal model to access both cholinergic (choline acetyltransferase [ChAT] immunopositive) and GABAergic (parvalbumin [PV]; calbindin [CaBP]) neuronal loss in the MS/DB in relationship to midline-thalamic pathology. In addition, to gain an understanding about the role of such neuropathology in behavioral dysfunction, animals were tested on a non-rewarded spontaneous alternation task and behavioral performance was correlated to neuropathology. Unbiased stereological assessment of neuronal populations revealed that ChAT-positive neurons were significantly reduced in PTD rats, relative to control pair-fed rats, and thalamic mass and behavioral performance correlated with ChAT neuronal estimates. In contrast, both the PV- and CaBP-positive neurons in the MS/DB were not affected by PTD treatment. These results support an interactive role of both thalamic pathology and cholinergic cell loss in diencephalic amnesia. PMID:19264109

  9. The role of cholinergic and GABAergic medial septal/diagonal band cell populations in the emergence of diencephalic amnesia.

    PubMed

    Roland, J J; Savage, L M

    2009-04-21

    The septohippocampal pathway, which is mostly composed of cholinergic and GABAergic projections between the medial septum/diagonal band (MS/DB) and the hippocampus, has an established role in learning, memory and disorders of cognition. In Wernicke-Korsakoff's syndrome (WKS) and the animal model of the disorder, pyrithiamine-induced thiamine deficiency (PTD), there is both diencephalic damage and basal forebrain cell loss that could contribute to the amnesic state. In the current experiment, we used the PTD animal model to access both cholinergic (choline acetyltransferase [ChAT] immunopositive) and GABAergic (parvalbumin [PV]; calbindin [CaBP]) neuronal loss in the MS/DB in relationship to midline-thalamic pathology. In addition, to gain an understanding about the role of such neuropathology in behavioral dysfunction, animals were tested on a non-rewarded spontaneous alternation task and behavioral performance was correlated to neuropathology. Unbiased stereological assessment of neuronal populations revealed that ChAT-positive neurons were significantly reduced in PTD rats, relative to control pair-fed rats, and thalamic mass and behavioral performance correlated with ChAT neuronal estimates. In contrast, both the PV- and CaBP-positive neurons in the MS/DB were not affected by PTD treatment. These results support an interactive role of both thalamic pathology and cholinergic cell loss in diencephalic amnesia. PMID:19264109

  10. Cholinergic receptor pathways involved in apoptosis, cell proliferation and neuronal differentiation

    PubMed Central

    Resende, Rodrigo R; Adhikari, Avishek

    2009-01-01

    Acetylcholine (ACh) has been shown to modulate neuronal differentiation during early development. Both muscarinic and nicotinic acetylcholine receptors (AChRs) regulate a wide variety of physiological responses, including apoptosis, cellular proliferation and neuronal differentiation. However, the intracellular mechanisms underlying these effects of AChR signaling are not fully understood. It is known that activation of AChRs increase cellular proliferation and neurogenesis and that regulation of intracellular calcium through AChRs may underlie the many functions of ACh. Intriguingly, activation of diverse signaling molecules such as Ras-mitogen-activated protein kinase, phosphatidylinositol 3-kinase-Akt, protein kinase C and c-Src is modulated by AChRs. Here we discuss the roles of ACh in neuronal differentiation, cell proliferation and apoptosis. We also discuss the pathways involved in these processes, as well as the effects of novel endogenous AChRs agonists and strategies to enhance neuronal-differentiation of stem and neural progenitor cells. Further understanding of the intracellular mechanisms underlying AChR signaling may provide insights for novel therapeutic strategies, as abnormal AChR activity is present in many diseases. PMID:19712465

  11. Intracerebellar behavioral interactions between nicotine, cotinine and ethanol in mice

    SciTech Connect

    Dar, M.S.; Li, C. )

    1992-02-26

    Using ethanol-induced motor incoordination as the test response as evaluated by rotorod, possible behavioral interactions between ethanol and (-)-nicotine in the cerebellum, one of the key motor area, were investigated. (-)-Nicotine, 5, 1.25, 0.625 ng/100nL intracerebellarly significantly attenuated motor incoordination due to ethanol in a dose-dependent manner. Similarly, (-)-cotinine, a major metabolite of nicotine, 5, 2.5, and 1.25 ng/100nL, significantly but less marked compared to (-)-nicotine attenuated ethanol-induced motor incoordination. The highest, 5 ng/100nL, dose of (-)-nicotine or (-)-cotinine followed by saline instead of ethanol did not alter normal motor coordination. The attenuation of ethanol-induced motor incoordination by (-)-nicotine and (-)- cotinine was blocked by intracerebellar hexamethonium 1 ug/100nL, a purported nicotinic cholinergic antagonist. The data obtained strongly suggest participation of cerebellar nicotinic cholinergic receptor in the ethanol-induced motor incoordination.

  12. Differentiation of LA-N-5 neuroblastoma cells into cholinergic neurons: methods for differentiation, immunohistochemistry and reporter gene introduction.

    PubMed

    Hill, D P; Robertson, K A

    1998-03-01

    The use of model systems derived from cell lines has been a valuable tool in understanding the molecules and cellular processes that govern differentiation processes (T.R. Breitman, S.E. Selonick, S.J. Collins, Induction of differentiation of the human promyelocytic leukemia cell line (HL-60) by retinoic acid, Proc. Natl. Acad. Sci. USA 77 (1980) 2936-2940 [2]; N. Gomez, S. Traverse, P. Cohen, Identification of a MAP kinase in phaeochromocytoma (PC12) cells, FEBS Lett. 314 (1992) 461-465 [4]). The use of such systems provides an inexpensive, quick and simple way to identify and test molecules that can be further studied in more complex in vivo experiments. Some cell lines such as embryonic stem cells can be induced to differentiate in vitro, however, the differentiation is difficult to control and most often leads to the generation of a wide variety of cell types. Cell lines derived from sources committed to a restricted cell fate provide an opportunity to examine cell growth and differentiation within a specific cell type (G.M. Keller, In vitro differentiation of embryonic stem cells, Curr. Opin. Cell Biol. 7 (1995) 862-869 [10]). In this article we describe a simple system for the differentiation of the human neuroblastoma cell line LA-N-5 into cholinergic neurons using all-trans retinoic acid (G. Han, B. Chang, M.J. Connor, N. Sidell, Enhanced potency of 9-cis versus all-trans retinoic acid to induce the differentiation of human neuroblastoma cells, Differentiation, 59 (1995) 61-69 [5]; D.P. Hill, K.R. Robertson, Characterization of the cholinergic neuronal differentiation of the human neuroblastoma cell line LA-N-5 after treatment with retinoic acid, Dev. Brain Res. 102 (1997) 53-67 [6]; J.A. Robson, N. Sidell, Ultrastructural features of a human neuroblastoma cell line treated with retinoic acid, Neuroscience 14 (1985) 1149-1162 [12]; N. Sidell, C.A. Lucas, G.W. Kreutzberg, Regulation of acetylcholinesterase activity by retinoic acid in a human neuroblastoma

  13. Analgesic and Antineuropathic Drugs Acting Through Central Cholinergic Mechanisms

    PubMed Central

    Bartolini, Alessandro; Cesare Mannelli, Lorenzo Di; Ghelardini, Carla

    2011-01-01

    The role of muscarinic and nicotinic cholinergic receptors in analgesia and neuropathic pain relief is relatively unknown. This review describes how such drugs induce analgesia or alleviate neuropathic pain by acting on the central cholinergic system. Several pharmacological strategies are discussed which increase synthesis and release of acetylcholine (ACh) from cholinergic neurons. The effects of their acute and chronic administration are described. The pharmacological strategies which facilitate the physiological functions of the cholinergic system without altering the normal modulation of cholinergic signals are highlighted. It is proposed that full agonists of muscarinic or nicotinic receptors should be avoided. Their activation is too intense and un-physiological because neuronal signals are distorted when these receptors are constantly activated. Good results can be achieved by using agents that are able to a) increase ACh synthesis, b) partially inhibit cholinesterase activity c) selectively block the autoreceptor or heteroreceptor feedback mechanisms. Activation of M1 subtype muscarinic receptors induces analgesia. Chronic stimulation of nicotinic (N1) receptors has neuronal protective effects. Recent experimental results indicate a relationship between repeated cholinergic stimulation and neurotrophic activation of the glial derived neurotrophic factor (GDNF) family. At least 9 patents covering novel chemicals for cholinergic system modulation and pain control are discussed. PMID:21585331

  14. Striatal cholinergic cell ablation attenuates L-DOPA induced dyskinesia in Parkinsonian mice.

    PubMed

    Won, Lisa; Ding, Yunmin; Singh, Pardeep; Kang, Un Jung

    2014-02-19

    3,4-Dihydroxyphenyl-L-alanine (L-DOPA)-induced dyskinesia (LID) is a debilitating side effect of long-term dopamine replacement therapy in Parkinson's Disease. At present, there are few therapeutic options for treatment of LID and mechanisms contributing to the development and maintenance of these drug-induced motor complications are not well understood. We have previously shown that pharmacological reduction of cholinergic tone attenuates the expression of LID in parkinsonian mice with established dyskinesia after chronic L-DOPA treatment. The present study was undertaken to provide anatomically specific evidence for the role of striatal cholinergic interneurons by ablating them before initiation of L-DOPA treatment and determining whether it decreases LID. We used a novel approach to ablate striatal cholinergic interneurons (ChIs) via Cre-dependent viral expression of the diphtheria toxin A subunit (DT-A) in hemiparkinsonian transgenic mice expressing Cre recombinase under control of the choline acetyltransferase promoter. We show that Cre recombinase-mediated DT-A ablation selectively eliminated ChIs when injected into striatum. The depletion of ChIs markedly attenuated LID without compromising the therapeutic efficacy of L-DOPA. These results provide evidence that ChIs play a key and selective role in LID and that strategies to reduce striatal cholinergic tone may represent a promising approach to decreasing L-DOPA-induced motor complications in Parkinson's disease. PMID:24553948

  15. Generation, Release, and Uptake of the NAD Precursor Nicotinic Acid Riboside by Human Cells.

    PubMed

    Kulikova, Veronika; Shabalin, Konstantin; Nerinovski, Kirill; Dölle, Christian; Niere, Marc; Yakimov, Alexander; Redpath, Philip; Khodorkovskiy, Mikhail; Migaud, Marie E; Ziegler, Mathias; Nikiforov, Andrey

    2015-11-01

    NAD is essential for cellular metabolism and has a key role in various signaling pathways in human cells. To ensure proper control of vital reactions, NAD must be permanently resynthesized. Nicotinamide and nicotinic acid as well as nicotinamide riboside (NR) and nicotinic acid riboside (NAR) are the major precursors for NAD biosynthesis in humans. In this study, we explored whether the ribosides NR and NAR can be generated in human cells. We demonstrate that purified, recombinant human cytosolic 5'-nucleotidases (5'-NTs) CN-II and CN-III, but not CN-IA, can dephosphorylate the mononucleotides nicotinamide mononucleotide and nicotinic acid mononucleotide (NAMN) and thus catalyze NR and NAR formation in vitro. Similar to their counterpart from yeast, Sdt1, the human 5'-NTs require high (millimolar) concentrations of nicotinamide mononucleotide or NAMN for efficient catalysis. Overexpression of FLAG-tagged CN-II and CN-III in HEK293 and HepG2 cells resulted in the formation and release of NAR. However, NAR accumulation in the culture medium of these cells was only detectable under conditions that led to increased NAMN production from nicotinic acid. The amount of NAR released from cells engineered for increased NAMN production was sufficient to maintain viability of surrounding cells unable to use any other NAD precursor. Moreover, we found that untransfected HeLa cells produce and release sufficient amounts of NAR and NR under normal culture conditions. Collectively, our results indicate that cytosolic 5'-NTs participate in the conversion of NAD precursors and establish NR and NAR as integral constituents of human NAD metabolism. In addition, they point to the possibility that different cell types might facilitate each other's NAD supply by providing alternative precursors. PMID:26385918

  16. Nicotine-Mediated Regulation of Nicotinic Acetylcholine Receptors in Non-Small Cell Lung Adenocarcinoma by E2F1 and STAT1 Transcription Factors

    PubMed Central

    Schaal, Courtney; Chellappan, Srikumar

    2016-01-01

    Cigarette smoking is the major risk factor for non-small cell lung cancer (NSCLC), which accounts for 80% of all lung cancers. Nicotine, the addictive component of tobacco smoke, can induce proliferation, migration, invasion, epithelial-mesenchymal transition (EMT), angiogenesis, and survival in NSCLC cell lines, as well as growth and metastasis of NSCLC in mice. This nicotine-mediated tumor progression is facilitated through activation of nicotinic acetylcholine receptors (nAChRs), specifically the α7 subunit; however, how the α7 nAChR gene is regulated in lung adenocarcinoma is not fully clear. Here we demonstrate that the α7 nAChR gene promoter is differentially regulated by E2F and STAT transcription factors through a competitive interplay; E2F1 induces the promoter, while STAT transcription factors repress it by binding to an overlapping site at a region -294 through -463bp upstream of the transcription start site. Treatment of cells with nicotine induced the mRNA and protein levels of α7 nAChR; this could be abrogated by treatment with inhibitors targeting Src, PI3K, MEK, α7 nAChR, CDK4/6 or a disruptor of the Rb-Raf-1 interaction. Further, nicotine–mediated induction of α7 nAChR was reduced when E2F1 was depleted and in contrast elevated when STAT1 was depleted by siRNAs. Interestingly, extracts from e-cigarettes, which have recently emerged as healthier alternatives to traditional cigarette smoking, can also induce α7 nAChR expression in a manner similar to nicotine. These results suggest an autoregulatory feed-forward loop that induces the levels of α7 nAChR upon exposure to nicotine, which enhances the strength of the signal. It can be imagined that such an induction of α7 nAChR contributes to the tumor-promoting functions of nicotine. PMID:27228072

  17. Nicotine: abused substance and therapeutic agent.

    PubMed Central

    Le Houezec, J

    1998-01-01

    Tobacco dependence is a complex phenomenon that is not fully understood. Nicotine is the main alkaloid in tobacco and the addictive compound of tobacco. It can improve both mood and cognitive functioning; these positive effects are strong reinforcements for smokers and contribute to their addiction. Opposite results also have been reported, however, and the effects of nicotine remain controversial. Recent epidemiological and empirical studies have indicated that smoking or nicotine or both may have protective effects against certain diseases. These findings have suggested that nicotine may be used as a therapeutic agent. However, because a variety of nicotinic cholinergic receptors are present in the brain, new agonist compounds may prove to be more effective than nicotine for therapeutic purposes. Studies are reviewed and the suggestion made that nicotine may prove useful as a tool to help us understand normal and pathological brain functioning. PMID:9549250

  18. Additive protective effects of donepezil and nicotine against salsolinol-induced cytotoxicity in SH-SY5Y cells.

    PubMed

    Das, Jharna R; Tizabi, Yousef

    2009-10-01

    Although the etiology of Parkinson's disease (PD) remains elusive, a number of toxins including elevated salsolinol, an endogenous metabolite of dopamine may contribute to its pathology. It was reported recently that nicotine may have protective effects against salsolinol-induced toxicity in human neuroblastoma derived SH-SY5Y cells and that these effects of nicotine are mediated by nicotinic receptors. Donepezil (Aricept) is a reversible non-competitive acetylcholinesterase inhibitor that is approved for use in mild to moderate Alzheimer's disease. The increase in acetylcholine concentrations is believed to be the major contributory factor in donepezil's therapeutic efficacy. However, cholinesterase inhibitors may also directly interact with nicotinic receptors and possess neuroprotective properties. In this study, we sought to determine whether donepezil may have protective effects against salsolinol-induced toxicity in SH-SY5Y cells and whether the combination of donepezil and nicotine may result in additive protection. Moreover, it was of interest to elucidate the role of nicotinic receptors as well as cell cycle and apoptosis in mechanism of action of these compounds. SH-SY5Y cells were exposed to 0.6 mM salsolinol with and without various drug pretreatments for 48 h. Nicotine (50 muM) resulted in approximately 54% protection and donepezil (5 muM) resulted in approximately 40% protection, and the combination of the two resulted in an additive (approximately 93%) protection against salsolinol-induced toxicity. Salsolinol caused an arrest of the cells in G(1)-phase of cell cycle and an increase in apoptotic indices that were blocked by the combination of donepezil and nicotine. Mecamylamine, a non-selective nicotinic receptor antagonist completely blocked the effects of nicotine and partially attenuated the effects of donepezil. A combination of atropine, a muscarinic receptor antagonist and mecamylamine completely blocked the effects of donepezil, indicating

  19. Is the input to a GABAergic or cholinergic synapse the sole asymmetry in rabbit's retinal directional selectivity?

    PubMed

    Grzywacz, N M; Tootle, J S; Amthor, F R

    1997-01-01

    We examined contrast, direction of motion, and concentration dependencies of the effects of GABAergic and cholinergic antagonists, and anticholinesterases on responses to movement of On-Off directionally selective (DS) ganglion cells of the rabbit's retina. The drugs tested were curare and hexamethonium bromide (cholinergic antagonists), physostigmine (anticholinesterase), and picrotoxin (GABAergic antagonist). They all reduced the cells' directional selectivity, while maintaining their preferred-null axis. However, cholinergic antagonists did not block directional selectivity completely even at saturating concentrations. The failure to eliminate directional selectivity was probably not due to an incomplete blockade of cholinergic receptors. In a extension of a Masland and Ames (1976) experiment, saturating concentrations of antagonists blocked the effects of exogenous acetylcholine or nicotine applied during synaptic blockade. Consequently, a noncholinergic pathway may be sufficient to account for at least some directional selectivity. This putative pathway interacts with the cholinergic pathway before spike generation, since physostigmine eliminated directional selectivity at contrasts lower than those saturating responses. This elimination apparently resulted from cholinergic-induced saturation, since reduction of contrast restored directional selectivity. Under picrotoxin, directional selectivity was lost in 33% of the cells regardless of contrast. However, 47% maintained their preferred direction despite saturating concentrations of picrotoxin, and 20% reversed the preferred and null directions. Therefore, models based solely on a GABAergic implementation of Barlow and Levick's asymmetric-inhibition model or solely on a cholinergic implementation of asymmetric-excitation models are not complete models of directional selectivity in the rabbit. We propose an alternate model for this retinal property. PMID:9057267

  20. Otilonium: a potent blocker of neuronal nicotinic ACh receptors in bovine chromaffin cells.

    PubMed Central

    Gandía, L.; Villarroya, M.; Lara, B.; Olmos, V.; Gilabert, J. A.; López, M. G.; Martínez-Sierra, R.; Borges, R.; García, A. G.

    1996-01-01

    1. Otilonium, a clinically useful spasmolytic, behaves as a potent blocker of neuronal nicotinic acetylcholine receptors (AChR) as well as a mild wide-spectrum Ca2+ channel blocker in bovine adrenal chromaffin cells. 2. 45Ca2+ uptake into chromaffin cells stimulated with high K+ (70 mM, 1 min) was blocked by otilonium with an IC50 of 7.6 microM. The drug inhibited the 45Ca2+ uptake stimulated by the nicotinic AChR agonist, dimethylphenylpiperazinium (DMPP) with a 79 fold higher potency (IC50 = 0.096 microM). 3. Whole-cell Ba2+ currents (IBa) through Ca2+ channels of voltage-clamped chromaffin cells were blocked by otilonium with an IC50 of 6.4 microM, very close to that of K(+)-evoked 45Ca2+ uptake. Blockade developed in 10-20 s, almost as a single step and was rapidly and almost fully reversible. 4. Whole-cell nicotinic AChR-mediated currents (250 ms pulses of 100 microM DMPP) applied at 30 s intervals were blocked by otilonium in a concentration-dependent manner, showing an IC50 of 0.36 microM. Blockade was induced in a step-wise manner. Wash out of otilonium allowed a slow recovery of the current, also in discrete steps. 5. In experiments with recordings in the same cells of whole-cell IDMPP, Na+ currents (INa) and Ca2+ currents (ICa), 1 microM otilonium blocked 87% IDMPP, 7% INa and 13% ICa. 6. Otilonium inhibited the K(+)-evoked catecholamine secretory response of superfused bovine chromaffin cells with an IC50 of 10 microM, very close to the IC50 for blockade of K(+)-induced 45Ca2+ uptake and IBa. 7. Otilonium inhibited the secretory responses induced by 10 s pulses of 50 microM DMPP with an IC50 of 7.4 nM. Hexamethonium blocked the DMPP-evoked responses with an IC50 of 29.8 microM, 4,000 fold higher than that of otilonium. 8. In conclusion, otilonium is a potent blocker of nicotinic AChR-mediated responses. The drugs also blocked various subtypes of neuronal voltage-dependent Ca2+ channels at a considerably lower potency. Na+ channels were unaffected by

  1. Cholinergic Machinery as Relevant Target in Acute Lymphoblastic T Leukemia

    PubMed Central

    Dobrovinskaya, Oxana; Valencia-Cruz, Georgina; Castro-Sánchez, Luis; Bonales-Alatorre, Edgar O.; Liñan-Rico, Liliana; Pottosin, Igor

    2016-01-01

    Various types of non-neuronal cells, including tumors, are able to produce acetylcholine (ACh), which acts as an autocrine/paracrine growth factor. T lymphocytes represent a key component of the non-neuronal cholinergic system. T cells-derived ACh is involved in a stimulation of their activation and proliferation, and acts as a regulator of immune response. The aim of the present work was to summarize the data about components of cholinergic machinery in T lymphocytes, with an emphasis on the comparison of healthy and leukemic T cells. Cell lines derived from acute lymphoblastic leukemias of T lineage (T-ALL) were found to produce a considerably higher amount of ACh than healthy T lymphocytes. Additionally, ACh produced by T-ALL is not efficiently hydrolyzed, because acetylcholinesterase (AChE) activity is drastically decreased in these cells. Up-regulation of muscarinic ACh receptors was also demonstrated at expression and functional level, whereas nicotinic ACh receptors seem to play a less important role and not form functional channels in cells derived from T-ALL. We hypothesized that ACh over-produced in T-ALL may act as an autocrine growth factor and play an important role in leukemic clonal expansion through shaping of intracellular Ca2+ signals. We suggest that cholinergic machinery may be attractive targets for new drugs against T-ALL. Specifically, testing of high affinity antagonists of muscarinic ACh receptors as well as antagomiRs, which interfere with miRNAs involved in the suppression of AChE expression, may be the first choice options.

  2. Nicotine induces self-renewal of pancreatic cancer stem cells via neurotransmitter-driven activation of sonic hedgehog signalling.

    PubMed

    Al-Wadei, Mohammed H; Banerjee, Jheelam; Al-Wadei, Hussein A N; Schuller, Hildegard M

    2016-01-01

    A small subpopulation of pancreatic cancer cells with characteristics of stem cells drive tumour initiation, progression and metastasis. A better understanding of the regulation of cancer stem cells may lead to more effective cancer prevention and therapy. We have shown that the proliferation and migration of pancreatic cancer cell lines is activated by the nicotinic receptor-mediated release of stress neurotransmitters, responses reversed by γ-aminobutyric acid (GABA). However, the observed cancer inhibiting effects of GABA will only succeed clinically if GABA inhibits pancreatic cancer stem cells (PCSCs) in addition to the more differentiated cancer cells that comprise the majority of cancer tissues and cell lines. Using PCSCs isolated from two pancreatic cancer patients by cell sorting and by spheroid formation assay from pancreatic cancer cell line Panc-1, we tested the hypothesis that nicotine induces the self-renewal of PCSCs. Nicotinic acetylcholine receptors (nAChRs) α3, α4, α5 and α7 were expressed and chronic exposure to nicotine increased the protein expression of these receptors. Immunoassays showed that PCSCs produced the stress neurotransmitters epinephrine and norepinephrine and the inhibitory neurotransmitter GABA. Chronic nicotine significantly increased the production of stress neurotransmitters and sonic hedgehog (SHH) while inducing Gli1 protein and decreasing GABA. GABA treatment inhibited the induction of SHH and Gli1. Spheroid formation and 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazoliumbromide assays showed significant nicotine-induced increases in self renewal and cell proliferation, responses blocked by GABA. Our data suggest that nicotine increases the SHH-mediated malignant potential of PCSCs and that GABA prevents these effects. PMID:26689865

  3. Mutual Control of Cholinergic and Low-Threshold Spike Interneurons in the Striatum

    PubMed Central

    Elghaba, Rasha; Vautrelle, Nicolas; Bracci, Enrico

    2016-01-01

    The striatum is the largest nucleus of the basal ganglia and is crucially involved in action selection and reward processing. Cortical and thalamic inputs to the striatum are processed by local networks in which several classes of interneurons play an important, but still poorly understood role. Here we investigated the interactions between cholinergic and low-threshold spike (LTS) interneurons. LTS interneurons were hyperpolarized by co-application of muscarinic and nicotinic receptor antagonists (atropine and mecamylamine, respectively). Mecamylamine alone also caused hyperpolarizations, while atropine alone caused depolarizations and increased firing. LTS interneurons were also under control of tonic GABA, as application of the GABAA receptor antagonist picrotoxin caused depolarizations and increased firing. Frequency of spontaneous GABAergic events in LTS interneurons was increased by co-application of atropine and mecamylamine or by atropine alone, but reduced by mecamylamine alone. In the presence of picrotoxin and tetrodotoxin (TTX), atropine and mecamylamine depolarized the LTS interneurons. We concluded that part of the excitatory effects of tonic acetylcholine (ACh) on LTS interneurons were due to cholinergic modulation of tonic GABA. We then studied the influence of LTS interneurons on cholinergic interneurons. Application of antagonists of somatostatin or neuropeptide Y (NPY) receptors or of an inhibitor of nitric oxide synthase (L-NAME) did not cause detectable effects in cholinergic interneurons. However, prolonged synchronized depolarizations of LTS interneurons (elicited with optogenetics tools) caused slow-onset depolarizations in cholinergic interneurons, which were often accompanied by strong action potential firing and were fully abolished by L-NAME. Thus, a mutual excitatory influence exists between LTS and cholinergic interneurons in the striatum, providing an opportunity for sustained activation of the two cell types. This activation may

  4. Basic and modern concepts on cholinergic receptor: A review

    PubMed Central

    Tiwari, Prashant; Dwivedi, Shubhangi; Singh, Mukesh Pratap; Mishra, Rahul; Chandy, Anish

    2013-01-01

    Cholinergic system is an important system and a branch of the autonomic nervous system which plays an important role in memory, digestion, control of heart beat, blood pressure, movement and many other functions. This article serves as both structural and functional sources of information regarding cholinergic receptors and provides a detailed understanding of the determinants governing specificity of muscarinic and nicotinic receptor to researchers. The study helps to give overall information about the fundamentals of the cholinergic system, its receptors and ongoing research in this field.

  5. Nicotine and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone induce cyclooxygenase-2 activity in human gastric cancer cells: Involvement of nicotinic acetylcholine receptor (nAChR) and {beta}-adrenergic receptor signaling pathways

    SciTech Connect

    Shin, Vivian Yvonne; Jin, H.C.; Ng, Enders K.O.; Yu Jun; Leung, W.K.; Cho, C.H.; Sung, J.J.Y.

    2008-12-01

    Induction of cyclooxygenase-2 (COX-2) associates with cigarette smoke exposure in many malignancies. Nicotine and its derivative, 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), are the two important components in cigarette smoke that contributes to cancer development. However, the molecular mechanism(s) by which nicotine or NNK promotes gastric carcinogenesis remains largely unknown. We found that nicotine and NNK significantly enhanced cell proliferation in AGS cells that expressed both alpha7 nicotinic acetylcholine receptor ({alpha}7 nAChR) and {beta}-adrenergic receptors. Treatment of cells with {alpha}-bungarotoxin ({alpha}-BTX, {alpha}7nAChR antagonist) or propranolol ({beta}-adrenergic receptor antagonist) blocked NNK-induced COX-2/PGE{sub 2} and cell proliferation, while nicotine-mediated cell growth and COX-2/PGE{sub 2} induction can only be suppressed by propranolol, but not {alpha}-BTX. Moreover, in contrast to the dependence of growth promoting effect of nicotine on Erk activation, inhibitor of p38 mitogen-activated protein kinase (MAPK) repressed NNK-induced COX-2 upregulation and resulted in suppression of cell growth. In addition, nicotine and NNK mediated COX-2 induction via different receptors to modulate several G1/S transition regulatory proteins and promote gastric cancer cell growth. Selective COX-2 inhibitor (SC-236) caused G1 arrest and abrogated nicotine/NNK-induced cell proliferation. Aberrant expression of cyclin D1 and other G1 regulatory proteins are reversed by blockade of COX-2. These results pointed to the importance of adrenergic and nicotinic receptors in gastric tumor growth through MAPK/COX-2 activation, which may perhaps provide a chemoprevention strategy for cigarette smoke-related gastric carcinogenesis.

  6. Nicotine inhibits collagen synthesis and alkaline phosphatase activity, but stimulates DNA synthesis in osteoblast-like cells

    SciTech Connect

    Ramp, W.K.; Lenz, L.G.; Galvin, R.J. )

    1991-05-01

    Use of smokeless tobacco is associated with various oral lesions including periodontal damage and alveolar bone loss. This study was performed to test the effects of nicotine on bone-forming cells at concentrations that occur in the saliva of smokeless tobacco users. Confluent cultures of osteoblast-like cells isolated from chick embryo calvariae were incubated for 2 days with nicotine added to the culture medium (25-600 micrograms/ml). Nicotine inhibited alkaline phosphatase in the cell layer and released to the medium, whereas glycolysis (as indexed by lactate production) was unaffected or slightly elevated. The effects on medium and cell layer alkaline phosphatase were concentration dependent with maximal inhibition occurring at 600 micrograms nicotine/ml. Nicotine essentially did not affect the noncollagenous protein content of the cell layer, but did inhibit collagen synthesis (hydroxylation of ({sup 3}H)proline and collagenase-digestible protein) at 100, 300, and 600 micrograms/ml. Release of ({sup 3}H)hydroxyproline to the medium was also decreased in a dose-dependent manner, as was the collagenase-digestible protein for both the medium and cell layer. In contrast, DNA synthesis (incorporation of ({sup 3}H)thymidine) was more than doubled by the alkaloid, whereas total DNA content was slightly inhibited at 600 micrograms/ml, suggesting stimulated cell turnover. Morphologic changes occurred in nicotine-treated cells including rounding up, detachment, and the occurrence of numerous large vacuoles. These results suggest that steps to reduce the salivary concentration of nicotine in smokeless tobacco users might diminish damaging effects of this product on alveolar bone.

  7. Intracellular ion concentrations and cell volume during cholinergic stimulation of eccrine secretory coil cells

    SciTech Connect

    Takemura, T.; Sato, F.; Saga, K.; Suzuki, Y.; Sato, K. )

    1991-02-01

    Methacholine (MCh)-induced changes in intracellular concentrations of Na, K, and Cl (( Na)i, (K)i, and (Cl)i, respectively) and in cellular dry mass (a measure of cell shrinkage) were examined in isolated monkey eccrine sweat secretory coils by electron probe X-ray microanalysis using the peripheral standard method. To further confirm the occurrence of cell shrinkage during MCh stimulation, the change in cell volume of dissociated clear and dark cells were directly determined under a light microscope equipped with differential interference contrast (DIC) optics. X-ray microanalysis revealed a biphasic increase in cellular dry mass in clear cells during continuous MCh stimulation; an initial increase of dry mass to 158% (of control) followed by a plateau at 140%, which correspond to the decrease in cell volume of 37 and 29%, respectively. The latter agrees with the MCh-induced cell shrinkage of 29% in dissociated clear cells. The MCh-induced increase in dry mass in myoepithelial cells was less than half that of clear cells. During the steady state of MCh stimulation, both (K+)i and (Cl)i of clear cells decreased by about 45%, whereas (Na)i increased in such a way to maintain the sum of (Na) i + (K)i constant. There was a small (12-15 mM) increase in (Na)i and a decrease in (K)i in myoepithelial cells during stimulation with MCh. Dissociated dark cells failed to significantly shrink during MCh stimulation. The decrease in (Cl)i in the face of constant (Na)i + (K)i suggests the accumulation of unknown anion(s) inside the clear cell during MCh stimulation.

  8. 6-hydroxy-nicotine-inducible multilevel transgene control in mammalian cells.

    PubMed

    Malphettes, Laetitia; Schoenmakers, Ronald G; Fussenegger, Martin

    2006-11-01

    The precise control of transgene expression is essential for biopharmaceutical manufacturing, gene therapy and tissue engineering. We have designed a novel conditional transcription technology, which enables reversible induction, repression and adjustment of desired transgene expression using the clinically inert 6-hydroxy-nicotine (6HNic). The 6-hydroxy-nicotine oxidase (6HNO) repressor (HdnoR), which manages nicotine metabolism in Arthrobacter nicotinovorans pAO1 by binding to a specific operator of the 6-hydroxy-nicotine oxidase (O(NIC)), was fused to the Krueppel-associated box protein of the human kox-1 gene (KRAB) to create a synthetic 6HNic-dependent transsilencer (NS) that controls chimeric mammalian promoters, which are assembled by cloning tandem O(NIC) operators 3' of a constitutive promoter. In the absence of 6HNic, NS binds to O(NIC) and silences the constitutive promoter, which otherwise drives high-level transgene expression when the NS-O(NIC) interaction stops in the presence of 6HNic. Generic NICE(ON) technology was compatible with a variety of constitutive viral and mammalian housekeeping promoters, each of which enabled specific induced, repressed, adjusted and reversible transgene expression profiles in Chinese hamster ovary (CHO-K1), baby hamster kidney (BHK-21) as well as in human fibrosarcoma (HT-1080) cells. NICE(ON) also proved successful in controlling multicistronic expression units for coordinated transcription of up to three transgenes and in the fine-tuning of transcription-translation networks, in which RNA polymerase II- and III-dependent promoters, engineered for 6HNic responsiveness, drove expression of siRNAs that triggered specific transgene knockdown. NICE(ON) represents a robust and versatile technology for the precise tuning of transgene expression in mammalian cells. PMID:16962351

  9. Maternal antioxidants prevent beta cell apoptosis and promote formation of dual hormone-expressing endocrine cells in male offspring following fetal and neonatal nicotine exposure

    PubMed Central

    BRUIN, Jennifer E; WOYNILLOWICZ, Amanda K; HETTINGA, Bart P; TARNOPOLSKY, Mark A; MORRISON, Katherine M; GERSTEIN, Hertzel C; HOLLOWAY, Alison C

    2013-01-01

    Aim Fetal and neonatal nicotine exposure causes beta cell oxidative stress and apoptosis in neonates, leading to adult-onset dysglycemia. The goal of this study was to determine whether an antioxidant intervention could prevent nicotine-induced beta cell loss. Methods Nulliparous female Wistar rats received daily subcutaneous injections of either saline or nicotine bitartrate (1.0 mg/kg/d) for 2 weeks prior to mating until weaning. Nicotine-exposed dams received either normal chow or diet containing antioxidants (1000 IU/kg vitamin E, 0.25% w/w coenzyme Q10 and 0.1% w/w alpha-lipoic acid) during mating, pregnancy and lactation; saline-exposed dams received normal chow. Pancreas tissue was collected from male offspring at 3 weeks of age to measure beta cell fraction, apoptosis, proliferation and the presence of cells co-expressing insulin and glucagon. Results The birth weight of the offspring born to nicotine-exposed dams receiving dietary antioxidants was significantly reduced. Most interestingly, the antioxidant intervention to nicotine-exposed dams prevented the beta cell loss and apoptosis observed in nicotine exposed male offspring whose mothers did not receive antioxidants. Male pups born to nicotine-treated mothers receiving antioxidants also had a trend towards increased beta cell proliferation and a significant increase in islets containing insulin/glucagon bi-hormonal cells relative to the other two treatment groups. Conclusion This study demonstrates that exposure to maternal antioxidants protects beta cells from the damaging effects of nicotine thus preserving beta cell mass. PMID:22385833

  10. Increase in cholinergic modulation with pyridostigmine induces anti-inflammatory cell recruitment soon after acute myocardial infarction in rats.

    PubMed

    Rocha, Juraci Aparecida; Ribeiro, Susan Pereira; França, Cristiane Miranda; Coelho, Otávio; Alves, Gisele; Lacchini, Silvia; Kallás, Esper Georges; Irigoyen, Maria Cláudia; Consolim-Colombo, Fernanda M

    2016-04-15

    We tested the hypothesis that an increase in the anti-inflammatory cholinergic pathway, when induced by pyridostigmine (PY), may modulate subtypes of lymphocytes (CD4+, CD8+, FOXP3+) and macrophages (M1/M2) soon after myocardial infarction (MI) in rats. Wistar rats, randomly allocated to receive PY (40 mg·kg(-1)·day(-1)) in drinking water or to stay without treatment, were followed for 4 days and then were subjected to ligation of the left coronary artery. The groups-denominated as the pyridostigmine-treated infarcted (IP) and infarcted control (I) groups-were submitted to euthanasia 3 days after MI; the heart was removed for immunohistochemistry, and the peripheral blood and spleen were collected for flow cytometry analysis. Noninfarcted and untreated rats were used as controls (C Group). Echocardiographic measurements were registered on the second day after MI, and heart rate variability was measured on the third day after MI. The infarcted groups had similar MI areas, degrees of systolic dysfunction, blood pressures, and heart rates. Compared with the I Group, the IP Group showed a significant higher parasympathetic modulation and a lower sympathetic modulation, which were associated with a small, but significant, increase in diastolic function. The IP Group showed a significant increase in M2 macrophages and FOXP3(+)cells in the infarcted and peri-infarcted areas, a significantly higher frequency of circulating Treg cells (CD4(+)CD25(+)FOXP3(+)), and a less extreme decrease in conventional T cells (CD25(+)FOXP3(-)) compared with the I Group. Therefore, increasing cholinergic modulation with PY induces greater anti-inflammatory cell recruitment soon after MY in rats. PMID:26791829

  11. Nicotine induces cell proliferation in association with cyclin D1 up-regulation and inhibits cell differentiation in association with p53 regulation in a murine pre-osteoblastic cell line

    SciTech Connect

    Sato, Tsuyoshi Abe, Takahiro; Nakamoto, Norimichi; Tomaru, Yasuhisa; Koshikiya, Noboru; Nojima, Junya; Kokabu, Shoichiro; Sakata, Yasuaki; Kobayashi, Akio; Yoda, Tetsuya

    2008-12-05

    Recent studies have suggested that nicotine critically affects bone metabolism. Many studies have examined the effects of nicotine on proliferation and differentiation, but the underlying molecular mechanisms remain unclear. We examined cell cycle regulators involved in the proliferation and differentiation of MC3T3-E1 cells. Nicotine induced cell proliferation in association with p53 down-regulation and cyclin D1 up-regulation. In differentiated cells, nicotine reduced alkaline phosphatase activity and mineralized nodule formation in dose-dependent manners. Furthermore, p53 expression was sustained in nicotine-treated cells during differentiation. These findings indicate that nicotine promotes the cell cycle and inhibits differentiation in association with p53 regulation in pre-osteoblastic cells.

  12. The Pro-Proliferative Effects of Nicotine and Its Underlying Mechanism on Rat Airway Smooth Muscle Cells

    PubMed Central

    He, Fang; Li, Bing; Zhao, Zhuxiang; Zhou, Yumin; Hu, Guoping; Zou, Weifeng; Hong, Wei; Zou, Yimin; Jiang, Changbin; Zhao, Dongxing; Ran, Pixin

    2014-01-01

    Recent studies have shown that nicotine, a major component of cigarette smoke, can stimulate the proliferation of non-neuronal cells. Cigarette smoking can promote a variety of pulmonary and cardiovascular diseases, such as chronic obstructive pulmonary disease (COPD), atherosclerosis, and cancer. A predominant feature of COPD is airway remodeling, which includes increased airway smooth muscle (ASM) mass. The mechanisms underlying ASM remodeling in COPD have not yet been fully elucidated. Here, we show that nicotine induces a profound and time-dependent increase in DNA synthesis in rat airway smooth muscle cells (RASMCs) in vitro. Nicotine also significantly increased the number of RASMCs, which was associated with the increased expression of Cyclin D1, phosphorylation of the retinoblastoma protein (RB) and was dependent on the activation of Akt. The activation of Akt by nicotine occurred within minutes and depended upon the nicotinic acetylcholine receptors (nAchRs). Activated Akt increased the phosphorylation of downstream substrates such as GSK3β. Our data suggest that the binding of nicotine to the nAchRs on RASMCs can regulate cellular proliferation by activating the Akt pathway. PMID:24690900

  13. Cholinergic Responses and Intrinsic Membrane Properties of Developing Thalamic Parafascicular Neurons

    PubMed Central

    Ye, Meijun; Hayar, Abdallah; Garcia-Rill, Edgar

    2009-01-01

    Parafascicular (Pf) neurons receive cholinergic input from the pedunculopontine nucleus (PPN), which is active during waking and REM sleep. There is a developmental decrease in REM sleep in humans between birth and puberty and 10–30 days in rat. Previous studies have established an increase in muscarinic and 5-HT1 serotonergic receptor–mediated inhibition and a transition from excitatory to inhibitory GABAA responses in the PPN during the developmental decrease in REM sleep. However, no studies have been conducted on the responses of Pf cells to the cholinergic input from the PPN during development, which is a major target of ascending cholinergic projections and may be an important mechanism for the generation of rhythmic oscillations in the cortex. Whole cell patch-clamp recordings were performed in 9- to 20-day-old rat Pf neurons in parasagittal slices, and responses to the cholinergic agonist carbachol (CAR) were determined. Three types of responses were identified: inhibitory (55.3%), excitatory (31.1%), and biphasic (fast inhibitory followed by slow excitatory, 6.8%), whereas 6.8% of cells showed no response. The proportion of CAR-inhibited Pf neurons increased with development. Experiments using cholinergic antagonists showed that M2 receptors mediated the inhibitory response, whereas excitatory modulation involved M1, nicotinic, and probably M3 or M5 receptors, and the biphasic response was caused by the activation of multiple types of muscarinic receptors. Compared with CAR-inhibited cells, CAR-excited Pf cells showed 1) a decreased membrane time constant, 2) higher density of hyperpolarization-activated channels (Ih), 3) lower input resistance (Rin), 4) lower action potential threshold, and 5) shorter half-width duration of action potentials. Some Pf cells exhibited spikelets, and all were excited by CAR. During development, we observed decreases in Ih density, Rin, time constant, and action potential half-width. These results suggest that cholinergic

  14. Cholinergic responses and intrinsic membrane properties of developing thalamic parafascicular neurons.

    PubMed

    Ye, Meijun; Hayar, Abdallah; Garcia-Rill, Edgar

    2009-08-01

    Parafascicular (Pf) neurons receive cholinergic input from the pedunculopontine nucleus (PPN), which is active during waking and REM sleep. There is a developmental decrease in REM sleep in humans between birth and puberty and 10-30 days in rat. Previous studies have established an increase in muscarinic and 5-HT1 serotonergic receptor-mediated inhibition and a transition from excitatory to inhibitory GABA(A) responses in the PPN during the developmental decrease in REM sleep. However, no studies have been conducted on the responses of Pf cells to the cholinergic input from the PPN during development, which is a major target of ascending cholinergic projections and may be an important mechanism for the generation of rhythmic oscillations in the cortex. Whole cell patch-clamp recordings were performed in 9- to 20-day-old rat Pf neurons in parasagittal slices, and responses to the cholinergic agonist carbachol (CAR) were determined. Three types of responses were identified: inhibitory (55.3%), excitatory (31.1%), and biphasic (fast inhibitory followed by slow excitatory, 6.8%), whereas 6.8% of cells showed no response. The proportion of CAR-inhibited Pf neurons increased with development. Experiments using cholinergic antagonists showed that M2 receptors mediated the inhibitory response, whereas excitatory modulation involved M1, nicotinic, and probably M3 or M5 receptors, and the biphasic response was caused by the activation of multiple types of muscarinic receptors. Compared with CAR-inhibited cells, CAR-excited Pf cells showed 1) a decreased membrane time constant, 2) higher density of hyperpolarization-activated channels (I(h)), 3) lower input resistance (R(in)), 4) lower action potential threshold, and 5) shorter half-width duration of action potentials. Some Pf cells exhibited spikelets, and all were excited by CAR. During development, we observed decreases in I(h) density, R(in), time constant, and action potential half-width. These results suggest that

  15. CYTOKINE-INDUCED ALTERATIONS OF α7 NICOTINIC RECEPTOR IN COLONIC CD4 T CELLS MEDIATE DICHOTOMOUS RESPONSE TO NICOTINE IN MURINE MODELS OF Th1/Th17 VS. Th2-MEDIATED COLITIS

    PubMed Central

    Galitovskiy, Valentin; Qian, Jing; Chernyavsky, Alexander I.; Marchenko, Steve; Gindi, Vivian; Edwards, Robert A.; Grando, Sergei A.

    2014-01-01

    Ulcerative colitis (UC) and Crohn’s disease (CD) are two forms of chronic inflammatory bowel disease. CD4 T cells play a central role in the pathogenesis of both diseases. Smoking affects both UC and CD but with opposite effects, ameliorating UC and worsening CD. We hypothesized that the severity of gut inflammation could be modulated through T-cell nicotinic acetylcholine receptors (nAChRs) and that the exact clinical outcome would depend on the repertoire of nAChRs on CD4 T cells mediating each form of colitis. We measured clinical and immunologic outcomes of treating BALB/c mice with oxazolone- and TNBS-induced colitides by nicotine. Nicotine attenuated oxazolone colitis, which was associated with increased percentage of colonic Tregs and a reduction of Th17 cells. TCR stimulation of naïve CD4+CD62L+ T cells in the presence of nicotine upregulated expression of Foxp3. In marked contrast, nicotine worsened TNBS colitis, and this was associated with increased Th17 cells among colonic CD4 T cells. Nicotine upregulated IL-10 and inhibited IL-17 production, which could be abolished by exogenous IL-12 that also abolished the nicotine-dependent upregulation of Tregs. The dichotomous action of nicotine resulted from the up- and downregulation of anti-inflammatory α7 nAChR on colonic CD4 T cells induced by cytokines characteristic of the inflammatory milieu in oxazolone (IL-4), and TNBS (IL-12) colitis, respectively. These findings help explain the dichotomous effect of smoking in patients with UC and CD, and underscore the potential for nicotinergic drugs in regulating colonic inflammation. PMID:21784975

  16. Harmful effects of nicotine

    PubMed Central

    Mishra, Aseem; Chaturvedi, Pankaj; Datta, Sourav; Sinukumar, Snita; Joshi, Poonam; Garg, Apurva

    2015-01-01

    With the advent of nicotine replacement therapy, the consumption of the nicotine is on the rise. Nicotine is considered to be a safer alternative of tobacco. The IARC monograph has not included nicotine as a carcinogen. However there are various studies which show otherwise. We undertook this review to specifically evaluate the effects of nicotine on the various organ systems. A computer aided search of the Medline and PubMed database was done using a combination of the keywords. All the animal and human studies investigating only the role of nicotine were included. Nicotine poses several health hazards. There is an increased risk of cardiovascular, respiratory, gastrointestinal disorders. There is decreased immune response and it also poses ill impacts on the reproductive health. It affects the cell proliferation, oxidative stress, apoptosis, DNA mutation by various mechanisms which leads to cancer. It also affects the tumor proliferation and metastasis and causes resistance to chemo and radio therapeutic agents. The use of nicotine needs regulation. The sale of nicotine should be under supervision of trained medical personnel. PMID:25810571

  17. Harmful effects of nicotine.

    PubMed

    Mishra, Aseem; Chaturvedi, Pankaj; Datta, Sourav; Sinukumar, Snita; Joshi, Poonam; Garg, Apurva

    2015-01-01

    With the advent of nicotine replacement therapy, the consumption of the nicotine is on the rise. Nicotine is considered to be a safer alternative of tobacco. The IARC monograph has not included nicotine as a carcinogen. However there are various studies which show otherwise. We undertook this review to specifically evaluate the effects of nicotine on the various organ systems. A computer aided search of the Medline and PubMed database was done using a combination of the keywords. All the animal and human studies investigating only the role of nicotine were included. Nicotine poses several health hazards. There is an increased risk of cardiovascular, respiratory, gastrointestinal disorders. There is decreased immune response and it also poses ill impacts on the reproductive health. It affects the cell proliferation, oxidative stress, apoptosis, DNA mutation by various mechanisms which leads to cancer. It also affects the tumor proliferation and metastasis and causes resistance to chemo and radio therapeutic agents. The use of nicotine needs regulation. The sale of nicotine should be under supervision of trained medical personnel. PMID:25810571

  18. Targeting leukemic side population cells by isatin derivatives of nicotinic acid amide.

    PubMed

    Naglah, A M; Shinwari, Z; Bhat, M A; Al-Tahhan, M; Al-Omar, M A; Al-Dhfyan, A

    2016-01-01

    Side population (SP) cells mediate chemoresistance in leukemia. However, chemical inhibition approach to target SP cells has been poorly studied. Herein, we report the discovery of isatin derivatives of nicotinic acid amide as potent side population cell inhibitors. The selected derivatives showed superior potency over the reference drug verapamil. Furthermore, the treatment increased chemosensitivity and inhibited the cell proliferation on three different leukemic cell lines, K562, THP-1 and U937, suggesting that both SP and the bulk of leukemic cells are affected. Moreover, treatment with the most potent compound Nic9 reduced the expression of ABCG2, demonstrating that side population inhibition effect of the target derivatives is at least via ABCG2 inhibition. Importantly, the target derivatives induced erythrocyte/dendritic differentiation to leukemic cells mainly through Musashi/Numb pathway modulation. PMID:27358121

  19. Nicotine stimulates urokinase-type plasminogen activator receptor expression and cell invasiveness through mitogen-activated protein kinase and reactive oxygen species signaling in ECV304 endothelial cells

    SciTech Connect

    Khoi, Pham Ngoc; Park, Jung Sun; Kim, Nam Ho; Jung, Young Do

    2012-03-01

    Urokinase-type plasminogen activator receptor (uPAR) expression is elevated during inflammation, tissue remodeling and in many human cancers. This study investigated the effect of nicotine, a major alkaloid in tobacco, on uPAR expression and cell invasiveness in ECV304 endothelial cells. Nicotine stimulated uPAR expression in a dose-dependent manner and activated extracellular signal-regulated kinases-1/2 (Erk-1/2), c-Jun amino-terminal kinase (JNK) and p38 mitogen activated protein kinase (MAPK). Specific inhibitors of MEK-1 (PD98059) and JNK (SP600125) inhibited the nicotine-induced uPAR expression, while the p38 MAPK inhibitor SB203580 did not. Expression vectors encoding dominant negative MEK-1 (pMCL-K97M) and JNK (TAM67) also prevented nicotine-induced uPAR promoter activity. The intracellular hydrogen peroxide (H{sub 2}O{sub 2}) content was increased by nicotine treatment. The antioxidant N-acetylcysteine prevented nicotine-activated production of reactive oxygen species (ROS) and uPAR expression. Furthermore, exogenous H{sub 2}O{sub 2} increased uPAR mRNA expression. Deleted and site-directed mutagenesis demonstrated the involvement of the binding sites of transcription factor nuclear factor-kappaB (NF-κB) and activator protein (AP)-1 in the nicotine-induced uPAR expression. Studies with expression vectors encoding mutated NF-κB signaling molecules and AP-1 decoy confirmed that NF-κB and AP-1 were essential for the nicotine-stimulated uPAR expression. MAPK (Erk-1/2 and JNK) and ROS functioned as upstream signaling molecules in the activation of AP-1 and NF-κB, respectively. In addition, ECV304 endothelial cells treated with nicotine displayed markedly enhanced invasiveness, which was partially abrogated by uPAR neutralizing antibodies. The data indicate that nicotine induces uPAR expression via the MAPK/AP-1 and ROS/NF-κB signaling pathways and, in turn, stimulates invasiveness in human ECV304 endothelial cells. -- Highlights: ► Endothelial cells

  20. Central cholinergic control of vasopressin release in conscious rats

    SciTech Connect

    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. Nicotine and the adolescent brain

    PubMed Central

    Yuan, Menglu; Cross, Sarah J; Loughlin, Sandra E; Leslie, Frances M

    2015-01-01

    Adolescence encompasses a sensitive developmental period of enhanced clinical vulnerability to nicotine, tobacco, and e-cigarettes. While there are sociocultural influences, data at preclinical and clinical levels indicate that this adolescent sensitivity has strong neurobiological underpinnings. Although definitions of adolescence vary, the hallmark of this period is a profound reorganization of brain regions necessary for mature cognitive and executive function, working memory, reward processing, emotional regulation, and motivated behavior. Regulating critical facets of brain maturation are nicotinic acetylcholine receptors (nAChRs). However, perturbations of cholinergic systems during this time with nicotine, via tobacco or e-cigarettes, have unique consequences on adolescent development. In this review, we highlight recent clinical and preclinical data examining the adolescent brain's distinct neurobiology and unique sensitivity to nicotine. First, we discuss what defines adolescence before reviewing normative structural and neurochemical alterations that persist until early adulthood, with an emphasis on dopaminergic systems. We review how acute exposure to nicotine impacts brain development and how drug responses differ from those seen in adults. Finally, we discuss the persistent alterations in neuronal signaling and cognitive function that result from chronic nicotine exposure, while highlighting a low dose, semi-chronic exposure paradigm that may better model adolescent tobacco use. We argue that nicotine exposure, increasingly occurring as a result of e-cigarette use, may induce epigenetic changes that sensitize the brain to other drugs and prime it for future substance abuse. PMID:26018031

  2. Light microscopic distribution of some cholinergic markers in the rat and rabbit locus coeruleus and the nucleus angularis grisea periventricularis of the domestic pig (Sus scrofa): a correlative electron microscopic investigation of cholinergic receptor proteins in the rabbit.

    PubMed

    Caffé, A R

    1994-10-15

    Cholinergic modulation of locus coeruleus (LC) neurons evokes a variety of neuronal and behavioural effects. In an attempt to understand the LC cholinergic circuit, several markers has been investigated and compared. (Immuno)-histochemical and autoradiographic methods have been used on rat, rabbit, and pig tissue. To identify the boundaries of the LC in each of these species, sections through the entire brainstem have been stained for tyrosine hydroxylase. The results indicate that the pig does not possess a LC proper that conforms to the accepted features of this cell group. However, in this location fusiform cells reminiscent of LC interneurons are still present. This group of fusiform neurons has been named the nucleus angularis grisea periventricularis (NAGP). LC cells of the rat and rabbit show strong acetylcholinesterase (AChE) activity. In the pig the NAGP is markedly free from AChE staining. Muscarinic binding sites are densely distributed over the rabbit LC and adjacent region. The rat and rabbit LC neurons synthesise both muscarinic (mAChR) and nicotinic receptor protein (nAChR). In the pig NAGP region mAChR and nAChR positive cell bodies are almost absent, while some nAChR immunoreactive dendrites are present. The light microscopic data in the rabbit have been confirmed by electron microscopic analysis. It is concluded that the general concept of a noradrenergic LC that is present throughout mammals is questionable. At present, choline acetyltransferase immunoreactive terminals that closely correspond to the other cholinergic components in the rat or rabbit LC have not been observed. However, in these species the cholinergic sensitivity of LC cells is mediated via both muscarinic and nicotinic receptors on somata and dendrites. PMID:7849322

  3. Nicotinate-Curcumin Impedes Foam Cell Formation from THP-1 Cells through Restoring Autophagy Flux.

    PubMed

    Gu, Hong-Feng; Li, Hai-Zhe; Tang, Ya-Ling; Tang, Xiao-Qing; Zheng, Xi-Long; Liao, Duan-Fang

    2016-01-01

    Our previous studies have indicated that a novel curcumin derivate nicotinate-curcumin (NC) has beneficial effects on the prevention of atherosclerosis, but the precise mechanisms are not fully understood. Given that autophagy regulates lipid metabolism, the present study was designed to investigate whether NC decreases foam cell formation through restoring autophagy flux in oxidized low-density lipoprotein (ox-LDL)-treated THP-1 cells. Our results showed that ox-LDL (100 μg/ml) was accumulated in THP-1 cells and impaired autophagy flux. Ox-LDL-induced impairment of autophagy was enhanced by treatment with the autophagy inhibitor chloroquine (CQ) and rescued by the autophagy inducer rapamycin. The aggregation of ox-LDL was increased by CQ, but decreased by rapamycin. In addition, colocalization of lipid droplets with LC3-II was remarkably reduced in ox-LDL group. In contrast, NC (10 μM) rescued the impaired autophagy flux by significantly increasing level of LC3-II, the number of autophagolysosomes, and the degradation of p62 in ox-LDL-treated THP-1 cells. Inhibition of the PI3K-Akt-mTOR signaling was required for NC-rescued autophagy flux. Notably, our results showed that NC remarkably promoted the colocalization of lipid droplets with autophagolysosomes, increased efflux of cholesterol, and reduced ox-LDL accumulation in THP-1 cells. However, treatment with 3-methyladenine (3-MA) or CQ reduced the protective effects of NC on lipid accumulation. Collectively, the findings suggest that NC decreases lipid accumulation in THP-1 cells through restoring autophagy flux, and further implicate that NC may be a potential therapeutic reagent to reverse atherosclerosis. PMID:27128486

  4. Nicotinate-Curcumin Impedes Foam Cell Formation from THP-1 Cells through Restoring Autophagy Flux

    PubMed Central

    Gu, Hong-Feng; Li, Hai-Zhe; Tang, Ya-Ling; Tang, Xiao-Qing; Zheng, Xi-Long; Liao, Duan-Fang

    2016-01-01

    Our previous studies have indicated that a novel curcumin derivate nicotinate-curcumin (NC) has beneficial effects on the prevention of atherosclerosis, but the precise mechanisms are not fully understood. Given that autophagy regulates lipid metabolism, the present study was designed to investigate whether NC decreases foam cell formation through restoring autophagy flux in oxidized low-density lipoprotein (ox-LDL)-treated THP-1 cells. Our results showed that ox-LDL (100 μg/ml) was accumulated in THP-1 cells and impaired autophagy flux. Ox-LDL-induced impairment of autophagy was enhanced by treatment with the autophagy inhibitor chloroquine (CQ) and rescued by the autophagy inducer rapamycin. The aggregation of ox-LDL was increased by CQ, but decreased by rapamycin. In addition, colocalization of lipid droplets with LC3-II was remarkably reduced in ox-LDL group. In contrast, NC (10 μM) rescued the impaired autophagy flux by significantly increasing level of LC3-II, the number of autophagolysosomes, and the degradation of p62 in ox-LDL-treated THP-1 cells. Inhibition of the PI3K-Akt-mTOR signaling was required for NC-rescued autophagy flux. Notably, our results showed that NC remarkably promoted the colocalization of lipid droplets with autophagolysosomes, increased efflux of cholesterol, and reduced ox-LDL accumulation in THP-1 cells. However, treatment with 3-methyladenine (3-MA) or CQ reduced the protective effects of NC on lipid accumulation. Collectively, the findings suggest that NC decreases lipid accumulation in THP-1 cells through restoring autophagy flux, and further implicate that NC may be a potential therapeutic reagent to reverse atherosclerosis. PMID:27128486

  5. Striatal cholinergic interneuron regulation and circuit effects

    PubMed Central

    Lim, Sean Austin O.; Kang, Un Jung; McGehee, Daniel S.

    2014-01-01

    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. PMID:25374536

  6. Regulation of Prostate Development and Benign Prostatic Hyperplasia by Autocrine Cholinergic Signaling via Maintaining the Epithelial Progenitor Cells in Proliferating Status.

    PubMed

    Wang, Naitao; Dong, Bai-Jun; Quan, Yizhou; Chen, Qianqian; Chu, Mingliang; Xu, Jin; Xue, Wei; Huang, Yi-Ran; Yang, Ru; Gao, Wei-Qiang

    2016-05-10

    Regulation of prostate epithelial progenitor cells is important in prostate development and prostate diseases. Our previous study demonstrated a function of autocrine cholinergic signaling (ACS) in promoting prostate cancer growth and castration resistance. However, whether or not such ACS also plays a role in prostate development is unknown. Here, we report that ACS promoted the proliferation and inhibited the differentiation of prostate epithelial progenitor cells in organotypic cultures. These results were confirmed by ex vivo lineage tracing assays and in vivo renal capsule recombination assays. Moreover, we found that M3 cholinergic receptor (CHRM3) was upregulated in a large subset of benign prostatic hyperplasia (BPH) tissues compared with normal tissues. Activation of CHRM3 also promoted the proliferation of BPH cells. Together, our findings identify a role of ACS in maintaining prostate epithelial progenitor cells in the proliferating state, and blockade of ACS may have clinical implications for the management of BPH. PMID:27167157

  7. Effects of amyloid-beta on cholinergic and acetylcholinesterase-positive cells in cultured basal forebrain neurons of embryonic rat brain.

    PubMed

    Kasa, Peter; Papp, Henrietta; Kasa, Peter; Pakaski, Magdolna; Balaspiri, Lajos

    2004-02-13

    The neurotoxic effects of amyloid-beta(1-42) and amyloid-beta(25-35) (A beta) on cholinergic and acetylcholinesterase-positive neurons were investigated in primary cultures derived from embryonic 18-day-old rat basal forebrain. After various time intervals, the cultures were treated with 1, 5, 10 or 20 microM A beta for different time periods. The cholinergic neurons and their axon terminals were revealed by vesicular acetylcholine transporter immunohistochemistry and the cholinoceptive cells by acetylcholinesterase histochemical staining. To assess the toxic effects of these A beta peptides on the cholinergic neurons, image analysis was applied for quantitative determination of the numbers of axon varicosities/terminals and cells. The results demonstrate that, following treatment with 1 or 5 microM A beta for 5, 10, 30, 60 or 120 min, no changes in vesicular acetylcholine transporter immunohistochemical staining were observed. However, after treatment for 30 min with 10 or 20 microM A beta, the number of stained axon varicosities was reduced, and treatment for 2 h they had disappeared. In contrast, vesicular acetylcholine transporter-positivity could be seen in some of the neuronal perikarya even after 3 days after treatment. The acetylcholinesterase staining was homogeneously distributed in the control neurons. After A beta treatment, the histochemical reaction end-product was detected in some of the neuronal perikarya or in the dendritic processes near to the soma. It is concluded that the neurotoxic effects of A beta appear more rapidly in the cholinergic axon terminals than in the cholinergic and acetylcholinesterase-positive neuronal perikarya. PMID:14725970

  8. Novel aspects of cholinergic regulation of colonic ion transport.

    PubMed

    Bader, Sandra; Diener, Martin

    2015-06-01

    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 (I sc) 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 I sc 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

  9. Novel aspects of cholinergic regulation of colonic ion transport

    PubMed Central

    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

  10. Medial Habenula Output Circuit Mediated by α5 Nicotinic Receptor-Expressing GABAergic Neurons in the Interpeduncular Nucleus

    PubMed Central

    Hsu, Yun-Wei A.; Tempest, Lynne; Quina, Lely A.; Wei, Aguan D.; Zeng, Hongkui

    2013-01-01

    The Chrna5 gene encodes the α5 nicotinic acetylcholine receptor subunit, an “accessory” subunit of pentameric nicotinic receptors, that has been shown to play a role in nicotine-related behaviors in rodents and is genetically linked to smoking behavior in humans. Here we have used a BAC transgenic mouse line, α5GFP, to examine the cellular phenotype, connectivity, and function of α5-expressing neurons. Although the medial habenula (MHb) has been proposed as a site of α5 function, α5GFP is not detectable in the MHb, and α5 mRNA is expressed there only at very low levels. However, α5GFP is strongly expressed in a subset of neurons in the interpeduncular nucleus (IP), median raphe/paramedian raphe (MnR/PMnR), and dorsal tegmental area (DTg). Double-label fluorescence in situ hybridization reveals that these neurons are exclusively GABAergic. Transgenic and conventional tract tracing show that α5GFP neurons in the IP project principally to the MnR/PMnR and DTg/interfascicular dorsal raphe, both areas rich in serotonergic neurons. The α5GFP neurons in the IP are located in a region that receives cholinergic fiber inputs from the ventral MHb, and optogenetically assisted circuit mapping demonstrates a monosynaptic connection between these cholinergic neurons and α5GFP IP neurons. Selective inhibitors of both α4β2- and α3β4-containing nicotinic receptors were able to reduce nicotine-evoked inward currents in α5GFP neurons in the IP, suggesting a mixed nicotinic receptor profile in these cells. Together, these findings show that the α5-GABAergic interneurons form a link from the MHb to serotonergic brain centers, which is likely to mediate some of the behavioral effects of nicotine. PMID:24227714

  11. Medial habenula output circuit mediated by α5 nicotinic receptor-expressing GABAergic neurons in the interpeduncular nucleus.

    PubMed

    Hsu, Yun-Wei A; Tempest, Lynne; Quina, Lely A; Wei, Aguan D; Zeng, Hongkui; Turner, Eric E

    2013-11-13

    The Chrna5 gene encodes the α5 nicotinic acetylcholine receptor subunit, an "accessory" subunit of pentameric nicotinic receptors, that has been shown to play a role in nicotine-related behaviors in rodents and is genetically linked to smoking behavior in humans. Here we have used a BAC transgenic mouse line, α5(GFP), to examine the cellular phenotype, connectivity, and function of α5-expressing neurons. Although the medial habenula (MHb) has been proposed as a site of α5 function, α5(GFP) is not detectable in the MHb, and α5 mRNA is expressed there only at very low levels. However, α5(GFP) is strongly expressed in a subset of neurons in the interpeduncular nucleus (IP), median raphe/paramedian raphe (MnR/PMnR), and dorsal tegmental area (DTg). Double-label fluorescence in situ hybridization reveals that these neurons are exclusively GABAergic. Transgenic and conventional tract tracing show that α5(GFP) neurons in the IP project principally to the MnR/PMnR and DTg/interfascicular dorsal raphe, both areas rich in serotonergic neurons. The α5(GFP) neurons in the IP are located in a region that receives cholinergic fiber inputs from the ventral MHb, and optogenetically assisted circuit mapping demonstrates a monosynaptic connection between these cholinergic neurons and α5(GFP) IP neurons. Selective inhibitors of both α4β2- and α3β4-containing nicotinic receptors were able to reduce nicotine-evoked inward currents in α5(GFP) neurons in the IP, suggesting a mixed nicotinic receptor profile in these cells. Together, these findings show that the α5-GABAergic interneurons form a link from the MHb to serotonergic brain centers, which is likely to mediate some of the behavioral effects of nicotine. PMID:24227714

  12. Effects of diazinon on the lymphocytic cholinergic system of Nile tilapia fish (Oreochromis niloticus).

    PubMed

    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. PMID:27260186

  13. Nicotine, acetylcholine and bombesin are trophic growth factors in neuroendocrine cell lines derived from experimental hamster lung tumors

    SciTech Connect

    Schueller, H.M.; Nylen, E.; Park, P.; Becker, K.L. George Washington Univ., Washington, DC )

    1990-01-01

    Neuroendocrine hamster lung tumors, induced by exposure to 60% hyperoxia and subcutaneous administration of the tobacco-specific nitrosamine 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) for 12 weeks, were placed in cell culture. By subsequent selective transfer of epithelial cells and maintenance in an atmosphere of 8% CO{sub 2}, cell lines with characteristics of neuroendocrine cells were established. The neuroendocrine markers expressed by these cell lines included electron dense neuroendocrine secretion granules as well as secretion of calcitonin and mammalian bombesin. In keeping with data previously reported for a human neuroendocrine lung tumor cell line, nicotine, acetylcholien, and mammalian bombesin (MB) acted as strongrowth factors in these neuroendocrine hamster tumor lines. The mitogenic effect of nicotine an acetylcholine was abolished by nicotinic receptor inhibition while the effects of mammalian bombesin were inhibited by an antagonist of MB receptors. Our data suggest that a receptor-mediated mitogenic effect of nicotine on neuroendocrine lung cells may be instrumental in the induction of smoking-associated small cell lung cancer.

  14. Nicotine Inhibits Cisplatin-Induced Apoptosis via Regulating α5-nAChR/AKT Signaling in Human Gastric Cancer Cells.

    PubMed

    Jia, Yanfei; Sun, Haiji; Wu, Hongqiao; Zhang, Huilin; Zhang, Xiuping; Xiao, Dongjie; Ma, Xiaoli; Wang, Yunshan

    2016-01-01

    Gastric cancer incidence demonstrates a strong etiologic association with smoking. Nicotine, the major component in tobacco, is a survival agonist that inhibits apoptosis induced by certain chemotherapeutic agents, but the precise mechanisms involved remain largely unknown. Recently studies have indicated that α5-nicotinic acetylcholine receptor (α5-nAChR) is highly associated with lung cancer risk and nicotine dependence. Nevertheless, no information has been available about whether nicotine also affects proliferation of human gastric cancer cells through regulation of α5-nAChR. To evaluate the hypothesis that α5-nAChR may play a role in gastric cancer, we investigated its expression in gastric cancer tissues and cell lines. The expression of α5-nAChR increased in gastric cancer tissue compared with para-carcinoma tissues. In view of the results, we proceeded to investigate whether nicotine inhibits cisplatin-induced apoptosis via regulating α5-nAChR in gastric cancer cell. The results showed that nicotine significantly promoted cell proliferation in a dose and time-dependent manner through α5-nAChR activation in human gastric cells. Furthermore, nicotine inhibited apoptosis induced by cisplatin. Silence of α5-nAChR ablated the protective effects of nicotine. However, when co-administrating LY294002, an inhibitor of PI3K/AKT pathway, an increased apoptosis was observed. This effect correlated with the induction of Bcl-2, Bax, Survivin and Caspase-3 by nicotine in gastric cell lines. These results suggest that exposure to nicotine might negatively impact the apoptotic potential of chemotherapeutic drugs and that α5-nAChR/AKT signaling plays a key role in the anti-apoptotic activity of nicotine induced by cisplatin. PMID:26909550

  15. Polymer-encapsulated cells genetically modified to secrete human nerve growth factor promote the survival of axotomized septal cholinergic neurons.

    PubMed Central

    Winn, S R; Hammang, J P; Emerich, D F; Lee, A; Palmiter, R D; Baetge, E E

    1994-01-01

    Effective treatments for neurodegenerative disorders are limited by our inability to alter the progression of the diseases. A number of proteins have specific neuroprotective activities in vitro; however, the delivery of these factors into the central nervous system over the long term at therapeutic levels has been difficult to achieve. BHK cells engineered to express and release human nerve growth factor were encapsulated in an immunoisolation polymeric device and transplanted into both fimbria-fornix-lesioned rat brains and naive controls. In the lesioned rat brain, chronic delivery of human nerve growth factor by the encapsulated BHK cells provided nearly complete protection of axotomized medial septal cholinergic neurons. Human nerve growth factor continued to be released by encapsulated cells upon removal from the aspirative site after 3 weeks or from normal rat striatum after 3 and 6 months in vivo. Long-term encapsulated cell survival was confirmed by histologic analysis. This encapsulated xenogeneic system may provide therapeutically effective amounts of a number of neurotrophic factors, alone or in combination, to virtually any site within the body. Images PMID:8134395

  16. Cadmium-induced cell death of basal forebrain cholinergic neurons mediated by muscarinic M1 receptor blockade, increase in GSK-3β enzyme, β-amyloid and tau protein levels.

    PubMed

    Del Pino, Javier; Zeballos, Gabriela; Anadón, María José; Moyano, Paula; Díaz, María Jesús; García, José Manuel; Frejo, María Teresa

    2016-05-01

    Cadmium is a neurotoxic compound which induces cognitive alterations similar to those produced by Alzheimer's disease (AD). However, the mechanism through which cadmium induces this effect remains unknown. In this regard, we described in a previous work that cadmium blocks cholinergic transmission and induces a more pronounced cell death on cholinergic neurons from basal forebrain which is partially mediated by AChE overexpression. Degeneration of basal forebrain cholinergic neurons, as happens in AD, results in memory deficits attributable to the loss of cholinergic modulation of hippocampal synaptic circuits. Moreover, cadmium has been described to activate GSK-3β, induce Aβ protein production and tau filament formation, which have been related to a selective loss of basal forebrain cholinergic neurons and development of AD. The present study is aimed at researching the mechanisms of cell death induced by cadmium on basal forebrain cholinergic neurons. For this purpose, we evaluated, in SN56 cholinergic mourine septal cell line from basal forebrain region, the cadmium toxic effects on neuronal viability through muscarinic M1 receptor, AChE splice variants, GSK-3β enzyme, Aβ and tau proteins. This study proves that cadmium induces cell death on cholinergic neurons through blockade of M1 receptor, overexpression of AChE-S and GSK-3β, down-regulation of AChE-R and increase in Aβ and total and phosphorylated tau protein levels. Our present results provide new understanding of the mechanisms contributing to the harmful effects of cadmium on cholinergic neurons and suggest that cadmium could mediate these mechanisms by M1R blockade through AChE splices altered expression. PMID:26026611

  17. Role of [Na+]i and [Ca2+]i in nicotine-induced norepinephrine release from bovine adrenal chromaffin cells.

    PubMed

    Gerber, S H; Haunstetter, A; Krüger, C; Kaufmann, A; Nobiling, R; Haass, M

    1995-09-01

    Intracellular free sodium ([Na+]i) and calcium ([Ca2+]i) concentrations were determined by sodium-binding benzofuran isophthalate (SBFI) and fura 2 microfluorimetry, respectively, in bovine adrenal chromaffin cells (BCC). Validation of SBFI microfluorimetry by in vitro and in vivo calibration revealed a reliable assessment of [Na+]i within a range of 1-30 mM in single BCC. Nicotine (0.1-10 microM) induced concentration-dependent increases of both [Na+]i (from 3.3 +/- 0.1 to 25.6 +/- 0.4 mM, n = 76, P < 0.001) and [Ca2+]i (from 64 +/- 1 to 467 +/- 16 nM, n = 87, P < 0.001), which were accompanied by an increase in [3H]norepinephrine (NE) release. Consistent with an exocytotic release mechanism, nicotine-induced increments of [Ca2+]i and [3H]NE release were reduced under calcium-free conditions and by gadolinium chloride (40 microM), whereas [Na+]i was not affected. In contrast, a parallel attenuation of nicotine-evoked changes in [Na+]i, [Ca2+]i, and [3H]NE release was observed during reduction of the extracellular sodium concentration. The nicotine-evoked responses were neutralized by the nicotinic receptor antagonist hexamethonium (100 microM) but not by blockade of voltage-dependent sodium channels (1 microM tetrodotoxin). In conclusion, the nicotine-induced exocytotic release of [3H]NE is triggered by an increase in [Ca2+]i, which is facilitated by sodium influx through the nicotinic receptor ionophore. PMID:7573386

  18. Nicotine and tobacco

    MedlinePlus

    Withdrawal from nicotine; Smoking - nicotine addiction and withdrawal; Smokeless tobacco - nicotine addiction; Cigar smoking; Pipe smoking; Smokeless snuff; Tobacco use; Chewing tobacco; Nicotine addiction and tobacco

  19. Synaptic modulation of excitatory synaptic transmission by nicotinic acetylcholine receptors in spinal ventral horn neurons.

    PubMed

    Mine, N; Taniguchi, W; Nishio, N; Izumi, N; Miyazaki, N; Yamada, H; Nakatsuka, T; Yoshida, M

    2015-04-01

    Nicotinic acetylcholine receptors (nAChRs) are distributed widely in the central nervous system and play important roles in higher brain functions, including learning, memory, and recognition. However, functions of the cholinergic system in spinal motoneurons remain poorly understood. In this study, we investigated the actions of presynaptic and postsynaptic nAChRs in spinal ventral horn neurons by performing whole-cell patch-clamp recordings on lumbar slices from male rats. The application of nicotine or acetylcholine generated slow inward currents and increased the frequency and amplitude of spontaneous excitatory postsynaptic currents (sEPSCs). Slow inward currents by acetylcholine or nicotine were not inhibited by tetrodotoxin (TTX) or glutamate receptor antagonists. In the presence of TTX, the frequency and amplitude of miniature excitatory postsynaptic currents (mEPSCs) were also increased by acetylcholine or nicotine. A selective α4β2 nicotinic receptor antagonist, dihydro-β-erythroidine hydrobromide (DhβE), significantly decreased nicotine-induced inward currents without affecting the enhancement of sEPSCs and mEPSCs. In addition, a selective α7 nicotinic receptor antagonist, methyllycaconitine, did not affect either nicotine-induced inward currents or the enhancement of sEPSCs and mEPSCs. These results suggest that α4β2 AChRs are localized at postsynaptic sites in the spinal ventral horn, non-α4β2 and non-α7 nAChRs are located presynaptically, and nAChRs enhance excitatory synaptic transmission in the spinal ventral horn. PMID:25613686

  20. Epigallocatechin-3-gallate inhibits nicotine-induced migration and invasion by the suppression of angiogenesis and epithelial-mesenchymal transition in non-small cell lung cancer cells.

    PubMed

    Shi, Jingli; Liu, Fei; Zhang, Wenzhang; Liu, Xin; Lin, Bihua; Tang, Xudong

    2015-06-01

    Epigallocatechin-3-gallate (EGCG), the most abundant polyphenol in green tea extract, has been found to have anticancer activities in various types of cancer. However, the underlying mechanisms are not completely clear. In the present study, the effects of EGCG on migration, invasion, angiogenesis and epithelial-mesenchymal transition (EMT) induced by nicotine in A549 non-small cell lung cancer (NSCLC) cells were investigated, and the underlying molecular mechanisms were preliminarily examined. The results showed that different concentrations of EGCG significantly inhibited nicotine-induced migration and invasion. Moreover, EGCG reversed the upregulation of HIF-1α, vascular endothelial growth factor (VEGF), COX-2, p-Akt, p-ERK and vimentin protein levels and the downregulation of p53 and β-catenin protein levels mediated by nicotine in A549 cells, but had no significant effect on their mRNA levels. Furthermore, EGCG markedly inhibited HIF-1α-dependent angiogenesis induced by nicotine in vitro and in vivo, and suppressed HIF-1α and VEGF protein expression induced by nicotine in A549 xenografts of nude mice. Taken together, the results indicated that EGCG inhibited nicotine-induced angiogenesis and EMT, leading to migration and invasion in A549 cells. The results of the present study suggested that EGCG can be developed into a potential agent for the prevention and treatment of smoking-associated NSCLC. PMID:25845434

  1. Activation of the cholinergic anti-inflammatory system in peripheral blood mononuclear cells from patients with borderline personality disorder.

    PubMed

    Díaz-Marsá, Marina; Macdowell, Karina S; Guemes, Itziar; Rubio, Víctor; Carrasco, José L; Leza, Juan C

    2012-12-01

    A case-control study including patients (n = 20) with Borderline Personality Disorder (BPD) and healthy controls (n = 33) was carried out. To avoid interferences of other clinical conditions on biological findings, patients were free of current major depressive episodes or substance dependence disorders, and had no life history of schizophrenia, bipolar or neuropsychiatric disorders. Patients were free of medication for at least two weeks at the time of the study. Studies carried out in peripheral mononuclear blood cells and plasma evidence a systemic inflammatory condition in unstable-impulsive BPD patients. Specifically, a significant increase in some intracellular components of two main pro-inflammatory pathways such as iNOS and COX-2, as well as an increase in the plasma levels of the inflammatory cytokine IL1β. Interestingly, patients have an increase in the protein expression of the anti-inflammatory subtype of nicotinic receptor α7nAChR. This finding may reflect a possible mechanism trying to maintain intracellular inflammation pathways under control. All together, these results describe an imbalanced, pro-inflammatory and oxidant phenotype in BPD patients independent of plasma cotinine levels. Although more scientific evidence is needed, the determination of multiple components of pro- and anti-inflammatory cellular pathways have interesting potential as biological markers for BPD and other generalized impulsive syndromes, specially data obtained with α7nAChR and its lack of correlation with plasma levels of nicotine metabolites. Their pharmacological modulation with receptor modulators can be a promising therapeutic target to take into account in mental health conditions associated with inflammatory or oxido/nitrosative consequences. Also, identifying at-risk individuals would be of importance for early detection and intervention in adolescent subjects before they present severe behavioural problems. PMID:23083519

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

    PubMed

    Couesnon, Aurélie; Molgó, Jordi; Connan, Chloé; Popoff, Michel R

    2012-01-01

    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. PMID:22438808

  3. Cholinergic modulation of fast inhibitory and excitatory transmission to pedunculopontine thalamic projecting neurons.

    PubMed

    Ye, Meijun; Hayar, Abdallah; Strotman, Beau; Garcia-Rill, Edgar

    2010-05-01

    The pedunculopontine nucleus (PPN) is part of the cholinergic arm of the reticular activating system, which is mostly active during waking and rapid-eye movement sleep. The PPN projects to the thalamus and receives cholinergic inputs from the laterodorsal tegmental nucleus and contralateral PPN. We employed retrograde labeling and whole cell recordings to determine the modulation of GABAergic, glycinergic, and glutamatergic transmission to PPN thalamic projecting neurons, and their postsynaptic responses to the nonspecific cholinergic agonist carbachol. M2 and M4 muscarinic receptor-modulated inhibitory postsynaptic responses were observed in 73% of PPN output neurons; in 12.9%, M1 and nicotinic receptor-mediated excitation was detected; and muscarinic and nicotinic-modulated fast inhibitory followed by slow excitatory biphasic responses were evident in 6.7% of cells. A significant increase in the frequency of spontaneous excitatory postsynaptic currents (EPSCs) and inhibitory postsynaptic currents during carbachol application was observed in 66.2% and 65.2% of efferent neurons, respectively. This effect was blocked by a M1 antagonist or nonselective muscarinic blocker, indicating that glutamatergic, GABAergic, and/or glycinergic neurons projecting to PPN output neurons are excited through muscarinic receptors. Decreases in the frequency of miniature EPSCs, and amplitude of electrical stimulation-evoked EPSCs, were blocked by a M2 antagonist, suggesting the presence of M2Rs at terminals of presynaptic glutamatergic neurons. Carbachol-induced multiple types of postsynaptic responses, enhancing both inhibitory and excitatory fast transmission to PPN thalamic projecting neurons through muscarinic receptors. These results provide possible implications for the generation of different frequency oscillations in PPN thalamic projecting neurons during distinct sleep-wake states. PMID:20181729

  4. Quinuclidine compounds differently act as agonists of Kenyon cell nicotinic acetylcholine receptors and induced distinct effect on insect ganglionic depolarizations.

    PubMed

    Mathé-Allainmat, Monique; Swale, Daniel; Leray, Xavier; Benzidane, Yassine; Lebreton, Jacques; Bloomquist, Jeffrey R; Thany, Steeve H

    2013-12-01

    We have recently demonstrated that a new quinuclidine benzamide compound named LMA10203 acted as an agonist of insect nicotinic acetylcholine receptors. Its specific pharmacological profile on cockroach dorsal unpaired median neurons (DUM) helped to identify alpha-bungarotoxin-insensitive nAChR2 receptors. In the present study, we tested its effect on cockroach Kenyon cells. We found that it induced an inward current demonstrating that it bounds to nicotinic acetylcholine receptors expressed on Kenyon cells. Interestingly, LMA10203-induced currents were completely blocked by the nicotinic antagonist α-bungarotoxin. We suggested that LMA10203 effect occurred through the activation of α-bungarotoxin-sensitive receptors and did not involve α-bungarotoxin-insensitive nAChR2, previously identified in DUM neurons. In addition, we have synthesized two new compounds, LMA10210 and LMA10211, and compared their effects on Kenyon cells. These compounds were members of the 3-quinuclidinyl benzamide or benzoate families. Interestingly, 1 mM LMA10210 was not able to induce an inward current on Kenyon cells compared to LMA10211. Similarly, we did not find any significant effect of LMA10210 on cockroach ganglionic depolarization, whereas these three compounds were able to induce an effect on the central nervous system of the third instar M. domestica larvae. Our data suggested that these three compounds could bind to distinct cockroach nicotinic acetylcholine receptors. PMID:23884575

  5. Nicotinic Mechanisms Modulate Ethanol Withdrawal and Modify Time Course and Symptoms Severity of Simultaneous Withdrawal from Alcohol and Nicotine.

    PubMed

    Perez, Erika; Quijano-Cardé, Natalia; De Biasi, Mariella

    2015-09-01

    Alcohol and nicotine are among the top causes of preventable death in the United States. Unfortunately, people who are dependent on alcohol are more likely to smoke than individuals in the general population. Similarly, smokers are more likely to abuse alcohol. Alcohol and nicotine codependence affects health in many ways and leads to poorer treatment outcomes in subjects who want to quit. This study examined the interaction of alcohol and nicotine during withdrawal and compared abstinence symptoms during withdrawal from one of the two drugs only vs both. Our results indicate that simultaneous withdrawal from alcohol and nicotine produces physical symptoms that are more severe and last longer than those experienced during withdrawal from one of the two drugs alone. In animals experiencing withdrawal after chronic ethanol treatment, acute nicotine exposure was sufficient to prevent abstinence symptoms. Similarly, symptoms were prevented when alcohol was injected acutely in mice undergoing nicotine withdrawal. These experiments provide evidence for the involvement of the nicotinic cholinergic system in alcohol withdrawal. Furthermore, the outcomes of intracranial microinfusions of mecamylamine, a nonselective nicotinic receptor antagonist, highlight a major role for the nicotinic receptors expressed in medial habenula and interpeduncular nucleus during withdrawal. Overall, the data support the notion that modulating the nicotinic cholinergic system might help to maintain long-term abstinence from alcohol. PMID:25790020

  6. Enhancement of cancer stem-like and epithelial−mesenchymal transdifferentiation property in oral epithelial cells with long-term nicotine exposure: Reversal by targeting SNAIL

    SciTech Connect

    Yu, Cheng-Chia; Chang, Yu-Chao

    2013-02-01

    Cigarette smoking is one of the major risk factors in the development and further progression of tumorigenesis, including oral squamous cell carcinoma (OSCC). Recent studies suggest that interplay cancer stem-like cells (CSCs) and epithelial−mesenchymal transdifferentiation (EMT) properties are responsible for the tumor maintenance and metastasis in OSCC. The aim of the present study was to investigate the effects of long-term exposure with nicotine, a major component in cigarette, on CSCs and EMT characteristics. The possible reversal regulators were further explored in nicotine-induced CSCs and EMT properties in human oral epithelial (OE) cells. Long-term exposure with nicotine was demonstrated to up-regulate ALDH1 population in normal gingival and primary OSCC OE cells dose-dependently. Moreover, long-term nicotine treatment was found to enhance the self-renewal sphere-forming ability and stemness gene signatures expression and EMT regulators in OE cells. The migration/cell invasiveness/anchorage independent growth and in vivo tumor growth by nude mice xenotransplantation assay was enhanced in long-term nicotine-stimulated OE cells. Knockdown of Snail in long-term nicotine-treated OE cells was found to reduce their CSCs properties. Therapeutic delivery of Si-Snail significantly blocked the xenograft tumorigenesis of long-term nicotine-treated OSCC cells and largely significantly improved the recipient survival. The present study demonstrated that the enrichment of CSCs coupled EMT property in oral epithelial cells induced by nicotine is critical for the development of OSCC tumorigenesis. Targeting Snail might offer a new strategy for the treatment of OSCC patients with smoking habit. -- Highlights: ► Sustained nicotine treatment induced CSCs properties of oral epithelial cells. ► Long-term nicotine treatment enhance EMT properties of oral epithelial cells. ► Long-term nicotine exposure increased tumorigenicity of oral epithelial cells. ► Si

  7. cGMP/cGMP-dependent protein kinase pathway modulates nicotine-induced currents through the activation of α-bungarotoxin-insensitive nicotinic acetylcholine receptors from insect neurosecretory cells.

    PubMed

    Mannai, Safa; Bitri, Lofti; Thany, Steeve H

    2016-06-01

    Insect neurosecretory cells, called dorsal unpaired median neurons, are known to express two α-bungarotoxin-insensitive nicotinic acetylcholine receptor (nAChR) subtypes, nAChR1 and nAChR2. It was demonstrated that nAChR1 was sensitive to cAMP/cAMP-dependent protein kinase (PKA) regulation, resulting in a modulation of nicotine currents. In this study, we show that cyclic guanosine monophosphate (cGMP)/cGMP-dependent protein kinase (PKG) pathway modulates nicotine-induced currents, as increased cGMP affects the second compound of the biphasic current-voltage curve, corresponding to the nAChR2 receptors. Indeed, maintaining the guanosine triphosphate level with 100 μM guanosine triphosphate-γ-S increased nicotine currents through nAChR2. We also demonstrated that inhibition of PKG activity with 0.2 μM (8R,9S,11S)-(-)-9-methoxy-carbamyl-8-methyl-2,3,9,10-tetrahydro-8,11-epoxy-1H,8H,11H-2,7b,11a-trizadibenzo-(a,g)-cycloocta-(c,d,e)-trinden-1-one (KT5823), a PKG specific inhibitor, reduced nicotine-induced current amplitudes. KT5823 effect on nicotine currents is associated with calcium (Ca(2+) ) activity because inhibition of Ca(2+) concentration with cadmium chloride (CdCl2 ) abolished KT5823-induced inhibition mediated by nAChR2. However, specific inhibition of nitric oxide-guanylyl cyclase (GC) complex by 10 μM 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ) significantly increased nicotine-induced current amplitudes on both nAChR1 and nAChR2. These results suggest that nicotine-induced currents mediated by both α-bungarotoxin-insensitive nAChR1 and nAChR2 are coupled to the cGMP/PKG pathway. We propose that nicotinic acetylcholine receptor activation induces an increase in intracellular calcium (Ca(2+) ) concentration. Elevation of intracellular Ca(2+) results in the formation of Ca(2+) -calmodulin (CaM) complex, which activates guanylyl cyclase (GC) and/or adenylyl cyclase (AC). Ca(2+) -CaM complex could activate Ca(2+) calmodulin kinase II which

  8. Dynamics of cholinergic function

    SciTech Connect

    Hanin, I.

    1986-01-01

    This book presents information on the following topics; cholinergic pathways - anatomy of the central nervous system; aging, DSAT and other clinical conditions; cholinergic pre- and post-synaptic receptors; acetylcholine release; cholinesterases, anticholinesterases and reactivators; acetylcholine synthesis, metabolism and precursors; second messenger messenger mechanisms; interaction of acetylcholine with other neurotransmitter systems; cholinergic mechanisms in physiological function, including cardiovascular events; and neurotoxic agents and false transmitters.

  9. Binding of /sup 3/H-acetylcholine to cholinergic receptors in bovine cerebral arteries

    SciTech Connect

    Shimohama, S.; Tsukahara, T.; Taniguchi, T.; Fujiwara, M.

    1985-11-18

    Cholinergic receptor sites in bovine cerebral arteries were analyzed using radioligand binding techniques with the cholinergic agonist, /sup 3/H-acetylcholine (ACh), as the ligand. Specific binding of /sup 3/H-ACh to membrane preparations of bovine cerebral arteries was saturable, of two binding sites, with dissociation constant (K/sub D/) values of 0.32 and 23.7 nM, and maximum binding capacity (Bmax) values of 67 and 252 fmol/mg protein, respectively. Specific binding of /sup 3/H-ACh was displaced effectively by muscarinic cholinergic agents and less effectively by nicotinic cholinergic agents. IC/sub 50/ values of cholinergic drugs for /sup 3/H-ACh binding were as follows: atropine, 38.5 nM; ACh, 59.8 nM; oxotremorine, 293 nM; scopolamine 474 nM; carbamylcholine, 990 nM. IC/sub 50/ values of nicotinic cholinergic agents such as nicotine, cytisine and ..cap alpha..-bungarotoxin exceeded 50 ..mu..M. Choline acetyltransferase activity was 1.09 nmol/mg protein/hour in the cerebral arteries. These findings suggest that the cholinergic nerves innervate the bovine cerebral arteries and that there are at least two classes of ACh binding sites of different affinities on muscarinic reporters in these arteries. 18 references, 2 figures, 2 tables.

  10. Direct muscarinic and nicotinic receptor-mediated excitation of rat medial vestibular nucleus neurons in vitro

    NASA Technical Reports Server (NTRS)

    Phelan, K. D.; Gallagher, J. P.

    1992-01-01

    We have utilized intracellular recording techniques to investigate the cholinoceptivity of rat medial vestibular nucleus (MVN) neurons in a submerged brain slice preparation. Exogenous application of the mixed cholinergic agonists, acetylcholine (ACh) or carbachol (CCh), produced predominantly membrane depolarization, induction of action potential firing, and decreased input resistance. Application of the selective muscarinic receptor agonist muscarine (MUSC), or the selective nicotinic receptor agonists nicotine (NIC) or 1,1-dimethyl-4-phenylpiperazinium (DMPP) also produced membrane depolarizations. The MUSC-induced depolarization was accompanied by decreased conductance, while an increase in conductance appeared to underlie the NIC- and DMPP-induced depolarizations. The muscarinic and nicotinic receptor mediated depolarizations persisted in tetrodotoxin and/or low Ca2+/high Mg2+ containing media, suggesting direct postsynaptic receptor activation. The MUSC-induced depolarization could be reversibly blocked by the selective muscarinic-receptor antagonist, atropine, while the DMPP-induced depolarization could be reversibly suppressed by the selective ganglionic nicotinic-receptor antagonist, mecamylamine. Some neurons exhibited a transient membrane hyperpolarization during the depolarizing response to CCh or MUSC application. This transient inhibition could be reversibly blocked by the gamma-aminobutyric acid (GABA) antagonist, bicuculline, suggesting that the underlying hyperpolarization results indirectly from the endogenous release of GABA acting at GABA receptors. This study confirms the cholinoceptivity of MVN neurons and establishes that individual MVN cells possess muscarinic as well as nicotinic receptors. The data provide support for a prominent role of cholinergic mechanisms in the direct and indirect regulation of the excitability of MVN neurons.

  11. Endogenous Cholinergic Neurotransmission Contributes to Behavioral Sensitization to Morphine

    PubMed Central

    Bajic, Dusica; Soiza-Reilly, Mariano; Spalding, Allegra L.; Berde, Charles B.; Commons, Kathryn G.

    2015-01-01

    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. PMID:25647082

  12. Cholinergic Functioning in Stimulant Addiction: Implications for Medications Development

    PubMed Central

    Sofuoglu, Mehmet; Mooney, Marc

    2009-01-01

    Acetylcholine (ACh), the first neurotransmitter discovered, participates in many CNS functions including sensory and motor processing, sleep, nociception, mood, stress response, attention, arousal, memory, motivation and reward. These diverse cholinergic effects are mediated by nicotinic (nAChR) and muscarinic (mAChR) type cholinergic receptors. The goal of this review is to synthesize a growing literature that supports the potential role of ACh as a treatment target for stimulant addiction. ACh interacts with the dopaminergic reward system in the ventral tegmental area (VTA), nucleus accumbens (NAc) and prefrontal cortex (PFC). In the VTA, both nAChR and mAChR stimulate the dopaminergic system. In the NAc, cholinergic interneurons integrate cortical and subcortical information related to reward. In the PFC, the cholinergic system contributes to the cognitive aspects of addiction. Preclinical studies support a facilitative role of nicotinic agonists in the development of stimulant addiction. Muscarinic agonists seem to have an inhibitory role depending on the subtype of mAChR. In human studies acetylcholine esterase (AChE) inhibitors, which increase synaptic ACh levels, have shown promise for the treatment of stimulant addiction. Further studies testing the efficacy of cholinergic medications for stimulant addiction are warranted. PMID:19845415

  13. Positive allosteric modulation of alpha-7 nicotinic receptors promotes cell death by inducing Ca(2+) release from the endoplasmic reticulum.

    PubMed

    Guerra-Álvarez, María; Moreno-Ortega, Ana J; Navarro, Elisa; Fernández-Morales, José Carlos; Egea, Javier; López, Manuela G; Cano-Abad, María F

    2015-05-01

    Positive allosteric modulation of α7 isoform of nicotinic acetylcholine receptors (α7-nAChRs) is emerging as a promising therapeutic approach for central nervous system disorders such as schizophrenia or Alzheimer's disease. However, its effect on Ca(2+) signaling and cell viability remains controversial. This study focuses on how the type II positive allosteric modulator (PAM II) PNU120596 affects intracellular Ca(2+) signaling and cell viability. We used human SH-SY5Y neuroblastoma cells overexpressing α7-nAChRs (α7-SH) and their control (C-SH). We monitored cytoplasmic and endoplasmic reticulum (ER) Ca(2+) with Fura-2 and the genetically encoded cameleon targeting the ER, respectively. Nicotinic inward currents were measured using patch-clamp techniques. Viability was assessed using methylthiazolyl blue tetrazolium bromide or propidium iodide staining. We observed that in the presence of a nicotinic agonist, PNU120596 (i) reduced viability of α7-SH but not of C-SH cells; (ii) significantly increased inward nicotinic currents and cytosolic Ca(2+) concentration; (iii) released Ca(2+) from the ER by a Ca(2+) -induced Ca(2+) release mechanism only in α7-SH cells; (iv) was cytotoxic in rat organotypic hippocampal slice cultures; and, lastly, all these effects were prevented by selective blockade of α7-nAChRs, ryanodine receptors, or IP3 receptors. In conclusion, positive allosteric modulation of α7-nAChRs with the PAM II PNU120596 can lead to dysregulation of ER Ca(2+) , overloading of intracellular Ca(2+) , and neuronal cell death. This study focuses on how the type II positive allosteric modulator PNU120596 (PAM II PNU12) affects intracellular Ca(2+) signaling and cell viability. Using SH-SY5Y neuroblastoma cells overexpressing α7-nAChRs (α7-SH) and their control (C-SH), we find that PAM of α7-nAChRs with PNU120596: (i) increases inward calcium current (ICa ) and cytosolic Ca(2+) concentration ([Ca(2+) ]cyt ); (ii) releases Ca(2+) from the ER ([Ca(2

  14. New Etiology of Cholinergic Urticaria.

    PubMed

    Tokura, Yoshiki

    2016-01-01

    Cholinergic urticaria (CholU) is characterized by pinpoint-sized, highly pruritic wheals occurring upon sweating. Both direct and indirect theories in the interaction of acetylcholine (ACh) with mast cells have been put forward in the sweating-associated histamine release from mast cells. In the mechanism of indirect involvement of ACh, patients are hypersensitive to sweat antigen(s) and develop wheals in response to sweat substances leaking from the syringeal ducts to the dermis, possibly by obstruction of the ducts. Some patients with CholU exhibit a positive reaction to intradermal injection of their own diluted sweat, representing 'sweat allergy (hypersensitivity)'. Regarding the direct interaction theory between ACh and mast cells, we found that CholU with anhidrosis and hypohidrosis lacks cholinergic receptor M3 (CHRM3) expression in eccrine sweat gland epithelial cells. The expression of CHRM3 is completely absent in the anhidrotic areas and lowly expressed in the hypohidrotic areas. In the hypohidrotic area, where CholU occurs, it is hypothesized that ACh released from nerves cannot be completely trapped by cholinergic receptors of eccrine glands and overflows to the adjacent mast cells, leading to wheals. PMID:27584968

  15. Short-term plasticity and modulation of synaptic transmission at mammalian inhibitory cholinergic olivocochlear synapses

    PubMed Central

    Katz, Eleonora; Elgoyhen, Ana Belén

    2014-01-01

    The organ of Corti, the mammalian sensory epithelium of the inner ear, has two types of mechanoreceptor cells, inner hair cells (IHCs) and outer hair cells (OHCs). In this sensory epithelium, vibrations produced by sound waves are transformed into electrical signals. When depolarized by incoming sounds, IHCs release glutamate and activate auditory nerve fibers innervating them and OHCs, by virtue of their electromotile property, increase the amplification and fine tuning of sound signals. The medial olivocochlear (MOC) system, an efferent feedback system, inhibits OHC activity and thereby reduces the sensitivity and sharp tuning of cochlear afferent fibers. During neonatal development, IHCs fire Ca2+ action potentials which evoke glutamate release promoting activity in the immature auditory system in the absence of sensory stimuli. During this period, MOC fibers also innervate IHCs and are thought to modulate their firing rate. Both the MOC-OHC and the MOC-IHC synapses are cholinergic, fast and inhibitory and mediated by the α9α10 nicotinic cholinergic receptor (nAChR) coupled to the activation of calcium-activated potassium channels that hyperpolarize the hair cells. In this review we discuss the biophysical, functional and molecular data which demonstrate that at the synapses between MOC efferent fibers and cochlear hair cells, modulation of transmitter release as well as short term synaptic plasticity mechanisms, operating both at the presynaptic terminal and at the postsynaptic hair-cell, determine the efficacy of these synapses and shape the hair cell response pattern. PMID:25520631

  16. Neuronal-type alpha-bungarotoxin receptors and the alpha 5-nicotinic receptor subunit gene are expressed in neuronal and nonneuronal human cell lines.

    PubMed Central

    Chini, B; Clementi, F; Hukovic, N; Sher, E

    1992-01-01

    alpha-Bungarotoxin (alpha Bgtx) is a toxin known to interact with muscle nicotinic receptors and with some neuronal nicotinic receptors. We show that alpha Bgtx binding sites are also expressed in nonmuscle and nonneuronal human cells, including small cell lung carcinoma and several epithelial cell lines. These receptors are immunologically related to the alpha Bgtx receptors of unknown function described in the nervous system and in the IMR32 neuroblastoma cell line and are distinct from muscle nicotinic receptors. We have also cloned from IMR32 cells the human alpha 5-nicotinic receptor subunit, which is supposed to participate in the formation of alpha Bgtx receptors. Transcripts corresponding to the alpha 5-subunit gene were found not only in neuroblastoma cells but also in all the cell lines expressing alpha Bgtx receptors, with the exception of the TE671 cell line, whose nicotinic receptor subunits are of the muscle type. We conclude that both alpha Bgtx receptors and the alpha 5-nicotinic subunit gene are not neuron-specific, as previously thought, but are expressed in a number of human cell lines of various origin. Images PMID:1542648

  17. Cirri of the stalked crinoid Metacrinus rotundus: neural elements and the effect of cholinergic agonists on mechanical properties.

    PubMed Central

    Birenheide, R; Yokoyama, K; Motokawa, T

    2000-01-01

    Sea lilies are enigmatic animals due to their scarcity and their biology is comparatively neglected. Cirri, arranged in whorls of five along the sea lily stalk, anchor and support the animal. They consist of ossicles interconnected by collagenous ligaments and by a central canal. Cirri have a well-developed nervous system but lack muscular cells. A light and electron microscopic study was performed to clarify the morphology of the nervous system of the cirri. Two cellular networks were found, one of neuron-like cells and one of cells filled with bullet-shaped organelles. Both networks ramify throughout the cirral ossicles up to the interossicle ligaments. Mechanical tests were performed to analyse the influence of cholinergic agonists on the mechanical properties of these ligaments. In the tests, the cirral ligaments softened after the application of acetylcholine, muscarinic agonists and nicotinic agonists. The reaction time to muscarinic agonists was much slower than to acetylcholine and nicotinic agonists. At low concentrations, muscarinic agonists caused active development of force. No reaction to stimuli was observed in anaesthetized cirri. The data clearly establish the existence of catch connective tissue which can change its mechanical properties under nervous control mediated via nerves with cholinergic receptors. The possible sources of the observed force production are discussed and it is concluded that active contraction of collagenous ligaments causes movement of cirri. PMID:10670946

  18. Purinergic and Cholinergic Drugs Mediate Hyperventilation in Zebrafish: Evidence from a Novel Chemical Screen.

    PubMed

    Rahbar, Saman; Pan, Wen; Jonz, Michael G

    2016-01-01

    A rapid test to identify drugs that affect autonomic responses to hypoxia holds therapeutic and ecologic value. The zebrafish (Danio rerio) is a convenient animal model for investigating peripheral O2 chemoreceptors and respiratory reflexes in vertebrates; however, the neurotransmitters and receptors involved in this process are not adequately defined. The goals of the present study were to demonstrate purinergic and cholinergic control of the hyperventilatory response to hypoxia in zebrafish, and to develop a procedure for screening of neurochemicals that affect respiration. Zebrafish larvae were screened in multi-well plates for sensitivity to the cholinergic receptor agonist, nicotine, and antagonist, atropine; and to the purinergic receptor antagonists, suramin and A-317491. Nicotine increased ventilation frequency (fV) maximally at 100 μM (EC50 = 24.5 μM). Hypoxia elevated fV from 93.8 to 145.3 breaths min-1. Atropine reduced the hypoxic response only at 100 μM. Suramin and A-317491 maximally reduced fV at 50 μM (EC50 = 30.4 and 10.8 μM) and abolished the hyperventilatory response to hypoxia. Purinergic P2X3 receptors were identified in neurons and O2-chemosensory neuroepithelial cells of the gills using immunohistochemistry and confocal microscopy. These studies suggest a role for purinergic and nicotinic receptors in O2 sensing in fish and implicate ATP and acetylcholine in excitatory neurotransmission, as in the mammalian carotid body. We demonstrate a rapid approach for screening neuroactive chemicals in zebrafish with implications for respiratory medicine and carotid body disease in humans; as well as for preservation of aquatic ecosystems. PMID:27100625

  19. Purinergic and Cholinergic Drugs Mediate Hyperventilation in Zebrafish: Evidence from a Novel Chemical Screen

    PubMed Central

    Rahbar, Saman; Pan, Wen; Jonz, Michael G.

    2016-01-01

    A rapid test to identify drugs that affect autonomic responses to hypoxia holds therapeutic and ecologic value. The zebrafish (Danio rerio) is a convenient animal model for investigating peripheral O2 chemoreceptors and respiratory reflexes in vertebrates; however, the neurotransmitters and receptors involved in this process are not adequately defined. The goals of the present study were to demonstrate purinergic and cholinergic control of the hyperventilatory response to hypoxia in zebrafish, and to develop a procedure for screening of neurochemicals that affect respiration. Zebrafish larvae were screened in multi-well plates for sensitivity to the cholinergic receptor agonist, nicotine, and antagonist, atropine; and to the purinergic receptor antagonists, suramin and A-317491. Nicotine increased ventilation frequency (fV) maximally at 100 μM (EC50 = 24.5 μM). Hypoxia elevated fV from 93.8 to 145.3 breaths min-1. Atropine reduced the hypoxic response only at 100 μM. Suramin and A-317491 maximally reduced fV at 50 μM (EC50 = 30.4 and 10.8 μM) and abolished the hyperventilatory response to hypoxia. Purinergic P2X3 receptors were identified in neurons and O2-chemosensory neuroepithelial cells of the gills using immunohistochemistry and confocal microscopy. These studies suggest a role for purinergic and nicotinic receptors in O2 sensing in fish and implicate ATP and acetylcholine in excitatory neurotransmission, as in the mammalian carotid body. We demonstrate a rapid approach for screening neuroactive chemicals in zebrafish with implications for respiratory medicine and carotid body disease in humans; as well as for preservation of aquatic ecosystems. PMID:27100625

  20. Promoter polymorphisms and transcript levels of nicotinic receptor CHRNA5.

    PubMed

    Falvella, Felicia S; Galvan, Antonella; Colombo, Francesca; Frullanti, Elisa; Pastorino, Ugo; Dragani, Tommaso A

    2010-09-01

    Chromosomal locus 15q25, implicated in lung cancer risk and nicotine dependence, shows extensive linkage disequilibrium that complicates identification of causal variation. Cholinergic receptor nicotinic alpha5 (CHRNA5) has been identified as a lung cancer risk factor. We identified by sequence analysis three haplotypes (delTTC, insATC, and insTGG) in the 5' promoter region and three at the 3'-untranslated region of CHRNA5. Linkage disequilibrium analysis of the 5' variants showed that the insTGG haplotype is associated with three tightly linked risk alleles (nicotine dependence, lung cancer, and chronic obstructive pulmonary disease). The three CHRNA5 promoter haplotypes were statistically significantly associated with lung CHRNA5 transcript levels, determined by real-time polymerase chain reaction. In nontumor lung parenchyma from 68 patients who underwent lung lobectomy, the delTTC haplotype was associated with the highest CHRNA5 transcript levels (relative quantification units = 1.82), whereas the insTGG haplotype was associated with the lowest (0.88 units, P(diff) < .001, Welch t test; all statistical tests were two-sided). Luciferase reporter assays in human lung cancer cell lines A549, H460, H520, and H596 also showed that the 5' region haplotypes were statistically significantly associated with changes in CHRNA5 promoter activity, whereas the 3'-untranslated region variants were not. PMID:20733116

  1. Chemical coding and chemosensory properties of cholinergic brush cells in the mouse gastrointestinal and biliary tract

    PubMed Central

    Schütz, Burkhard; Jurastow, Innokentij; Bader, Sandra; Ringer, Cornelia; von Engelhardt, Jakob; Chubanov, Vladimir; Gudermann, Thomas; Diener, Martin; Kummer, Wolfgang; Krasteva-Christ, Gabriela; Weihe, Eberhard

    2015-01-01

    The mouse gastro-intestinal and biliary tract mucosal epithelia harbor choline acetyltransferase (ChAT)-positive brush cells with taste cell-like traits. With the aid of two transgenic mouse lines that express green fluorescent protein (EGFP) under the control of the ChAT promoter (EGFPChAT) and by using in situ hybridization and immunohistochemistry we found that EGFPChAT cells were clustered in the epithelium lining the gastric groove. EGFPChAT cells were numerous in the gall bladder and bile duct, and found scattered as solitary cells along the small and large intestine. While all EGFPChAT cells were also ChAT-positive, expression of the high-affinity choline transporter (ChT1) was never detected. Except for the proximal colon, EGFPChAT cells also lacked detectable expression of the vesicular acetylcholine transporter (VAChT). EGFPChAT cells were found to be separate from enteroendocrine cells, however they were all immunoreactive for cytokeratin 18 (CK18), transient receptor potential melastatin-like subtype 5 channel (TRPM5), and for cyclooxygenases 1 (COX1) and 2 (COX2). The ex vivo stimulation of colonic EGFPChAT cells with the bitter substance denatonium resulted in a strong increase in intracellular calcium, while in other epithelial cells such an increase was significantly weaker and also timely delayed. Subsequent stimulation with cycloheximide was ineffective in both cell populations. Given their chemical coding and chemosensory properties, EGFPChAT brush cells thus may have integrative functions and participate in induction of protective reflexes and inflammatory events by utilizing ACh and prostaglandins for paracrine signaling. PMID:25852573

  2. Chemical coding and chemosensory properties of cholinergic brush cells in the mouse gastrointestinal and biliary tract.

    PubMed

    Schütz, Burkhard; Jurastow, Innokentij; Bader, Sandra; Ringer, Cornelia; von Engelhardt, Jakob; Chubanov, Vladimir; Gudermann, Thomas; Diener, Martin; Kummer, Wolfgang; Krasteva-Christ, Gabriela; Weihe, Eberhard

    2015-01-01

    The mouse gastro-intestinal and biliary tract mucosal epithelia harbor choline acetyltransferase (ChAT)-positive brush cells with taste cell-like traits. With the aid of two transgenic mouse lines that express green fluorescent protein (EGFP) under the control of the ChAT promoter (EGFP (ChAT) ) and by using in situ hybridization and immunohistochemistry we found that EGFP (ChAT) cells were clustered in the epithelium lining the gastric groove. EGFP (ChAT) cells were numerous in the gall bladder and bile duct, and found scattered as solitary cells along the small and large intestine. While all EGFP (ChAT) cells were also ChAT-positive, expression of the high-affinity choline transporter (ChT1) was never detected. Except for the proximal colon, EGFP (ChAT) cells also lacked detectable expression of the vesicular acetylcholine transporter (VAChT). EGFP (ChAT) cells were found to be separate from enteroendocrine cells, however they were all immunoreactive for cytokeratin 18 (CK18), transient receptor potential melastatin-like subtype 5 channel (TRPM5), and for cyclooxygenases 1 (COX1) and 2 (COX2). The ex vivo stimulation of colonic EGFP (ChAT) cells with the bitter substance denatonium resulted in a strong increase in intracellular calcium, while in other epithelial cells such an increase was significantly weaker and also timely delayed. Subsequent stimulation with cycloheximide was ineffective in both cell populations. Given their chemical coding and chemosensory properties, EGFP (ChAT) brush cells thus may have integrative functions and participate in induction of protective reflexes and inflammatory events by utilizing ACh and prostaglandins for paracrine signaling. PMID:25852573

  3. Cholinergic imaging in dementia spectrum disorders.

    PubMed

    Roy, Roman; Niccolini, Flavia; Pagano, Gennaro; Politis, Marios

    2016-07-01

    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 [(11)C]MP4A and [(11)C]PMP PET for acetylcholinesterase (AChE), [(123)I]5IA SPECT for the α4β2 nicotinic acetylcholine receptor and [(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. PMID:26984612

  4. The Regulatory Role of Rolipram on Inflammatory Mediators and Cholinergic/Adrenergic Stimulation-Induced Signals in Isolated Primary Mouse Submandibular Gland Cells

    PubMed Central

    Lee, Dong Un; Shin, Dong Min; Hong, Jeong Hee

    2016-01-01

    Exposure to bacterial lipopolysaccharides (LPS) induces inflammatory signals in salivary glands. We investigated the regulatory role of phosphodiesterase 4 (PDE4) inhibitor rolipram on inflammatory mediators and cholinergic/adrenergic stimulation-induced intracellular Ca2+ signaling in salivary acinar and ductal cells. Submandibular gland (SMG) expressed PDE4A through 4D mRNA and PDE4 was localized in the luminal membrane of SMG. LPS induced Ca2+ signaling and ROS production in SMG. Treatment with rolipram blocked LPS-induced Ca2+ increase and ROS production. The application of histamine evoked Ca2+ signals and ROS production, which were attenuated by rolipram in SMG cells. Moreover, LPS-induced NLRP3 inflammasome and cleaved caspase-1 were inhibited by rolipram. The inhibitory role of rolipram in ROS-induced Ca2+ signaling was mainly observed in acinar cells and not in ductal cells. Rolipram also protected SMG acinar but not ductal cells from LPS-induced cell membrane damage. In the case of cholinergic/adrenergic stimulation, carbachol/isoproterenol-induced Ca2+ signals were upregulated by the treatment of rolipram in SMG. In the case of cAMP-dependent ductal bicarbonate secretion by rolipram, no effect was observed on the modulation of ductal chloride/bicarbonate exchange activity. Rolipram could suppress the inflammatory signals and could be a potential therapeutic strategy against LPS-induced inflammation to protect the salivary gland cells. PMID:27143817

  5. [Probable mechanism of recognition of cholinergic ligands by acetylcholine receptors].

    PubMed

    Demushkin, V P; Kotelevtsev, Iu V; Pliashkevich, Iu G; Khramtsov, N V

    1982-01-01

    Dryding's models were used for the conformational analysis of compounds affecting muscarin-specific acetylcholine receptor and nicotin-specific acetylcholine receptor. Ammonium group and ether oxygen (3.6 A apart from the ammonium group) specifically oriented to each other were shown to be necessary structural elements to reveal muscarin-type cholinergic activity. Ammonium group along with carbonyl oxygen or its substituent (5 A distance) are the necessary structural units providing nicotin-type cholinergic activity. The presence of two hydrophobic substituents (one in the ammonium area and the other neighbouring the second active grouping) is the additional factor. The developed principles were justified by the use of a series of synthetic samples. The compounds were obtained likely favouring affinitive modification of acetylcholine receptor (dissociation constants of acetylcholine receptor complexes equalling to 10(-4)--10(-7) M-1). PMID:7070378

  6. Chronic Nicotine Exposure In Vivo and In Vitro Inhibits Vitamin B1 (Thiamin) Uptake by Pancreatic Acinar Cells.

    PubMed

    Srinivasan, Padmanabhan; Thrower, Edwin C; Loganathan, Gopalakrishnan; Balamurugan, A N; Subramanian, Veedamali S; Gorelick, Fred S; Said, Hamid M

    2015-01-01

    Thiamin (vitamin B1), a member of the water-soluble family of vitamins, is essential for normal cellular functions; its deficiency results in oxidative stress and mitochondrial dysfunction. Pancreatic acinar cells (PAC) obtain thiamin from the circulation using a specific carrier-mediated process mediated by both thiamin transporters -1 and -2 (THTR-1 and THTR-2; encoded by the SLC19A2 and SLC19A3 genes, respectively). The aim of the current study was to examine the effect of chronic exposure of mouse PAC in vivo and human PAC in vitro to nicotine (a major component of cigarette smoke that has been implicated in pancreatic diseases) on thiamin uptake and to delineate the mechanism involved. The results showed that chronic exposure of mice to nicotine significantly inhibits thiamin uptake in murine PAC, and that this inhibition is associated with a marked decrease in expression of THTR-1 and THTR-2 at the protein, mRNA and hnRNAs level. Furthermore, expression of the important thiamin-metabolizing enzyme, thiamin pyrophosphokinase (TPKase), was significantly reduced in PAC of mice exposed to nicotine. Similarly, chronic exposure of cultured human PAC to nicotine (0.5 μM, 48 h) significantly inhibited thiamin uptake, which was also associated with a decrease in expression of THTR-1 and THTR-2 proteins and mRNAs. This study demonstrates that chronic exposure of PAC to nicotine impairs the physiology and the molecular biology of the thiamin uptake process. Furthermore, the study suggests that the effect is, in part, mediated through transcriptional mechanism(s) affecting the SLC19A2 and SLC19A3 genes. PMID:26633299

  7. Chronic Nicotine Exposure In Vivo and In Vitro Inhibits Vitamin B1 (Thiamin) Uptake by Pancreatic Acinar Cells

    PubMed Central

    Srinivasan, Padmanabhan; Thrower, Edwin C.; Loganathan, Gopalakrishnan; Balamurugan, A. N.; Subramanian, Veedamali S.; Gorelick, Fred S.; Said, Hamid M.

    2015-01-01

    Thiamin (vitamin B1), a member of the water-soluble family of vitamins, is essential for normal cellular functions; its deficiency results in oxidative stress and mitochondrial dysfunction. Pancreatic acinar cells (PAC) obtain thiamin from the circulation using a specific carrier-mediated process mediated by both thiamin transporters -1 and -2 (THTR-1 and THTR-2; encoded by the SLC19A2 and SLC19A3 genes, respectively). The aim of the current study was to examine the effect of chronic exposure of mouse PAC in vivo and human PAC in vitro to nicotine (a major component of cigarette smoke that has been implicated in pancreatic diseases) on thiamin uptake and to delineate the mechanism involved. The results showed that chronic exposure of mice to nicotine significantly inhibits thiamin uptake in murine PAC, and that this inhibition is associated with a marked decrease in expression of THTR-1 and THTR-2 at the protein, mRNA and hnRNAs level. Furthermore, expression of the important thiamin-metabolizing enzyme, thiamin pyrophosphokinase (TPKase), was significantly reduced in PAC of mice exposed to nicotine. Similarly, chronic exposure of cultured human PAC to nicotine (0.5 μM, 48 h) significantly inhibited thiamin uptake, which was also associated with a decrease in expression of THTR-1 and THTR-2 proteins and mRNAs. This study demonstrates that chronic exposure of PAC to nicotine impairs the physiology and the molecular biology of the thiamin uptake process. Furthermore, the study suggests that the effect is, in part, mediated through transcriptional mechanism(s) affecting the SLC19A2 and SLC19A3 genes. PMID:26633299

  8. Comparative non-cholinergic neurotoxic effects of paraoxon and diisopropyl fluorophosphate (DFP) on human neuroblastoma and astrocytoma cell lines

    SciTech Connect

    Qian Yongchang; Venkatraj, Jijayanagaram; Barhoumi, Rola; Pal, Ranadip; Datta, Aniruddha; Wild, James R.; Tiffany-Castiglioni, Evelyn . E-mail: ecastiglioni@cvm.tamu.edu

    2007-03-15

    The objective of this study was to evaluate the comparative non-cholinergic neurotoxic effects of paraoxon, which is acutely neurotoxic, and diisopropyl fluorophosphate (DFP), which induces OPIDN, in the human neuroblastoma SY5Y and the human astrocytoma cell line CCF-STTG1. SY5Y cells have been studied extensively as a model for OP-induced neurotoxicity, but CCF cells have not previously been studied. We conducted a preliminary human gene array assay of OP-treated SY5Y cells in order to assess at the gene level whether these cells can distinguish between OP compounds that do and do not cause OPIDN. Paraoxon and DFP induced dramatically different profiles of gene expression. Two genes were upregulated and 13 downregulated by at least 2-fold in paraoxon-treated cells. In contrast, one gene was upregulated by DFP and none was downregulated at the 2-fold threshold. This finding is consistent with current and previous observations that SY5Y cells can distinguish between OPs that do or do not induce OPIDN. We also examined gene array results for possible novel target proteins or metabolic pathways for OP neurotoxicity. Protein levels of glucose regulated protein 78 (GRP78) revealed that paraoxon exposure at 3 {mu}M for 24 h significantly reduced GRP78 levels by 30% in neuroblastoma cells, whereas DFP treatment had no effect. In comparison with SY5Y neuroblastoma cells, paraoxon and DFP (3 {mu}M for 24 h) each significantly increased GRP78 levels by 23-24% in CCF astrocytoma cells. As we have previously evaluated intracellular changes in Ca{sup 2+} levels in SY5Y cells, we investigated the effects of paraoxon and DFP on cellular Ca{sup 2+} homeostasis in CCF by studying cytosolic and mitochondrial basal calcium levels. A significant decrease in the ratio of mitochondrial to cytosolic Ca{sup 2+} fluorescence was detected in CCF cultures treated for either 1 or 3 days with 1, 3, 10, or 30 {mu}M paraoxon. In contrast, treatment with DFP for 1 day had no significant effect

  9. Memory-Relevant Mushroom Body Output Synapses Are Cholinergic

    PubMed Central

    Barnstedt, Oliver; Owald, David; Felsenberg, Johannes; Brain, Ruth; Moszynski, John-Paul; Talbot, Clifford B.; Perrat, Paola N.; Waddell, Scott

    2016-01-01

    Summary Memories are stored in the fan-out fan-in neural architectures of the mammalian cerebellum and hippocampus and the insect mushroom bodies. However, whereas key plasticity occurs at glutamatergic synapses in mammals, the neurochemistry of the memory-storing mushroom body Kenyon cell output synapses is unknown. Here we demonstrate a role for acetylcholine (ACh) in Drosophila. Kenyon cells express the ACh-processing proteins ChAT and VAChT, and reducing their expression impairs learned olfactory-driven behavior. Local ACh application, or direct Kenyon cell activation, evokes activity in mushroom body output neurons (MBONs). MBON activation depends on VAChT expression in Kenyon cells and is blocked by ACh receptor antagonism. Furthermore, reducing nicotinic ACh receptor subunit expression in MBONs compromises odor-evoked activation and redirects odor-driven behavior. Lastly, peptidergic corelease enhances ACh-evoked responses in MBONs, suggesting an interaction between the fast- and slow-acting transmitters. Therefore, olfactory memories in Drosophila are likely stored as plasticity of cholinergic synapses. PMID:26948892

  10. Counting Bungarotoxin Binding Sites of Nicotinic Acetylcholine Receptors in Mammalian Cells with High Signal/Noise Ratios

    PubMed Central

    Simonson, Paul D.; DeBerg, Hannah A.; Ge, Pinghua; Alexander, John K.; Jeyifous, Okunola; Green, William N.; Selvin, Paul R.

    2010-01-01

    Nicotinic acetylcholine receptors are some of the most studied synaptic proteins; however, many questions remain that can only be answered using single molecule approaches. Here we report our results from single α7 and neuromuscular junction type nicotinic acetylcholine receptors in mammalian cell membranes. By labeling the receptors with fluorophore-labeled bungarotoxin, we can image individual receptors and count the number of bungarotoxin-binding sites in receptors expressed in HEK 293 cells. Our results indicate that there are two bungarotoxin-binding sites in neuromuscular junction receptors, as expected, and five in α7 receptors, clarifying previous uncertainty. This demonstrates a valuable technique for counting subunits in membrane-bound proteins at the single molecule level, with nonspecialized optics and with higher signal/noise ratios than previous fluorescent protein-based techniques. PMID:21081055

  11. Pu-erh Tea Extract Attenuates Nicotine-Induced Foam Cell Formation in Primary Cultured Monocytes: An in Vitro Mechanistic Study.

    PubMed

    Tu, Shih-Hsin; Chen, Ming-Yao; Chen, Li-Ching; Mao, Yi-Ting; Ho, Chi-Hou; Lee, Wen-Jui; Lin, Yen-Kuang; Pan, Min-Hsiung; Lo, Chih-Yu; Chen, Chi-Long; Yen, Yun; Whang-Peng, Jacqueline; Ho, Chi-Tang; Wu, Chih-Hsiung; Ho, Yuan-Soon

    2016-04-27

    In this study, the mechanisms by which pu-erh tea extract (PETE) attenuates nicotine-induced foam cell formation were investigated. Monocytes were purified from healthy individuals using commercial antibodies coated with magnetic beads. We found that the nicotine-induced (1-10 μM) expression of oxidized low-density lipoprotein receptors (ox-LDLRs) and α9-nAchRs in monocytes was significantly attenuated by 24 h of PETE (10 μg/mL; ∗, p < 0.05) cotreatment. Nicotine (1 μM for 24 h) significantly induced the expression of the surface adhesion molecule ICAM-1 and the monocyte integrin adhesion molecule (CD11b) by human umbilical vein endothelial cells (HUVECs) and triggered monocytes to differentiate into macrophages via interactions with the endothelium. After treatment with nicotine (0.1-10 μM for 24 h), the HUVECs released chemotactic factors (IL-8) to attract monocytes into the tunica intima of the artery, and the monocytes then transformed into foam cells. We demonstrated that PETE treatment (>1 μg/mL for 24 h; ∗, p < 0.05) significantly attenuates nicotine-induced (1 μM) monocyte migration toward HUVECs and foam cell formation. This study suggests that tea components effectively attenuate the initial step (foam cell formation) of nicotine-induced atherosclerosis in circulating monocytes. PMID:27001463

  12. Striatal cholinergic neurotransmission requires VGLUT3.

    PubMed

    Nelson, Alexandra B; Bussert, Timothy G; Kreitzer, Anatol C; Seal, Rebecca P

    2014-06-25

    It is now clear that many neuronal populations release more than one classical neurotransmitter, yet in most cases the functional role of corelease is unknown. Striatal cholinergic interneurons release both glutamate and acetylcholine, and vesicular loading of glutamate has been shown to enhance acetylcholine content. Using a combination of optogenetics and whole-cell recordings in mice, we now provide physiological evidence that optogenetic stimulation of cholinergic interneurons triggers monosynaptic glutamate- and acetylcholine-mediated currents in striatal fast-spiking interneurons (FSIs), both of which depend on the expression of the vesicular glutamate transporter 3 (VGLUT3). In contrast to corticostriatal glutamatergic inputs onto FSIs, which are mediated primarily by AMPA-type glutamate receptors, glutamate release by cholinergic interneurons activates both AMPA- and NMDA-type glutamate receptors, suggesting a unique role for these inputs in the modulation of FSI activity. Importantly, we find that the loss of VGLUT3 not only markedly attenuates glutamatergic and cholinergic inputs on FSIs, but also significantly decreases disynaptic GABAergic input onto medium spiny neurons (MSNs), the major output neurons of the striatum. Our data demonstrate that VGLUT3 is required for normal cholinergic signaling onto FSIs, as well as for acetylcholine-dependent disynaptic inhibition of MSNs. Thus, by supporting fast glutamatergic transmission as well as by modulating the strength of cholinergic signaling, VGLUT3 has the capacity to exert widespread influence on the striatal network. PMID:24966377

  13. Striatal Cholinergic Neurotransmission Requires VGLUT3

    PubMed Central

    Nelson, Alexandra B.; Bussert, Timothy G.

    2014-01-01

    It is now clear that many neuronal populations release more than one classical neurotransmitter, yet in most cases the functional role of corelease is unknown. Striatal cholinergic interneurons release both glutamate and acetylcholine, and vesicular loading of glutamate has been shown to enhance acetylcholine content. Using a combination of optogenetics and whole-cell recordings in mice, we now provide physiological evidence that optogenetic stimulation of cholinergic interneurons triggers monosynaptic glutamate- and acetylcholine-mediated currents in striatal fast-spiking interneurons (FSIs), both of which depend on the expression of the vesicular glutamate transporter 3 (VGLUT3). In contrast to corticostriatal glutamatergic inputs onto FSIs, which are mediated primarily by AMPA-type glutamate receptors, glutamate release by cholinergic interneurons activates both AMPA- and NMDA-type glutamate receptors, suggesting a unique role for these inputs in the modulation of FSI activity. Importantly, we find that the loss of VGLUT3 not only markedly attenuates glutamatergic and cholinergic inputs on FSIs, but also significantly decreases disynaptic GABAergic input onto medium spiny neurons (MSNs), the major output neurons of the striatum. Our data demonstrate that VGLUT3 is required for normal cholinergic signaling onto FSIs, as well as for acetylcholine-dependent disynaptic inhibition of MSNs. Thus, by supporting fast glutamatergic transmission as well as by modulating the strength of cholinergic signaling, VGLUT3 has the capacity to exert widespread influence on the striatal network. PMID:24966377

  14. Evidence of Nicotine-Induced, Curare-Insensitive, Behavior in Planarians.

    PubMed

    Pagán, Oné R; Montgomery, Erica; Deats, Sean; Bach, Daniel; Baker, Debra

    2015-10-01

    Planarians are rapidly developing into very useful research subjects in pharmacology and neuroscience research. Here we report that curare, a cholinergic nicotinic receptor antagonist, alleviates the nicotine-induced planarian seizure-like movements (pSLM) by up to 50 % at equimolar concentrations of nicotine and curare (1 mM), while curare alone does not induce significant pSLMs. The simplest interpretation of our data is that there are nicotine induced behaviors insensitive to curare in our experimental organism. To the best of our knowledge, this is the first report on curare-insensitive, nicotine-induced effects in any organism. PMID:25614180

  15. Alzheimer's Disease: Targeting the Cholinergic System

    PubMed Central

    Ferreira-Vieira, Talita H.; Guimaraes, Isabella M.; Silva, Flavia R.; Ribeiro, Fabiola M.

    2016-01-01

    Acetylcholine (ACh) has a crucial role in the peripheral and central nervous systems. The enzyme choline acetyltransferase (ChAT) is responsible for synthesizing ACh from acetyl-CoA and choline in the cytoplasm and the vesicular acetylcholine transporter (VAChT) uptakes the neurotransmitter into synaptic vesicles. Following depolarization, ACh undergoes exocytosis reaching the synaptic cleft, where it can bind its receptors, including muscarinic and nicotinic receptors. ACh present at the synaptic cleft is promptly hydrolyzed by the enzyme acetylcholinesterase (AChE), forming acetate and choline, which is recycled into the presynaptic nerve terminal by the high-affinity choline transporter (CHT1). Cholinergic neurons located in the basal forebrain, including the neurons that form the nucleus basalis of Meynert, are severely lost in Alzheimer’s disease (AD). AD is the most ordinary cause of dementia affecting 25 million people worldwide. The hallmarks of the disease are the accumulation of neurofibrillary tangles and amyloid plaques. However, there is no real correlation between levels of cortical plaques and AD-related cognitive impairment. Nevertheless, synaptic loss is the principal correlate of disease progression and loss of cholinergic neurons contributes to memory and attention deficits. Thus, drugs that act on the cholinergic system represent a promising option to treat AD patients. PMID:26813123

  16. Nicotine-induced exocytotic norepinephrine release in guinea-pig heart, human atrium and bovine adrenal chromaffin cells: modulation by single components of ischaemia.

    PubMed

    Krüger, C; Haunstetter, A; Gerber, S; Serf, C; Kaufmann, A; Kübler, W; Haass, M

    1995-08-01

    The influence of single components of myocardial ischaemia, such as anoxia, substrate withdrawal, hyperkalemia and extracellular acidosis, on nicotine-induced norepinephrine (NE) release was investigated in the isolated perfused guinea-pig heart, in incubated human atrial tissue and in cultured bovine adrenal chromaffin cells (BCC). In normoxia, nicotine (1-1000 mumol/l) evoked a concentration-dependent release of NE (determined by high pressure liquid chromatography and electrochemical detection) from guinea-pig heart and human atrium. In contrast to selective anoxia (Po2 < 5 mmHg) or glucose withdrawal, respectively, anoxia in combination with glucose withdrawal (5-40 min) markedly potentiated nicotine-induced NE release both in guinea-pig heart and human atrium. The sensitization of cardiac sympathetic nerve endings to nicotine was characterized by a lower threshold concentration and an approximate two-fold increase of maximum NE release, peaking after 10 min of anoxia and glucose withdrawal. Cyanide intoxication (1 mmol/l) combined with glucose withdrawal resulted in a similar increase of nicotine-induced sympathetic transmitter release both in guinea-pig heart and human atrium. In contrast, the nicotine-induced (10 mumol/l) NE overflow was only slightly potentiated by 10 min of global ischaemia in guinea-pig heart. Both hyperkalemia ([K+] 16 mmol/l) and acidosis (pH 6.8-6.0) distinctly attenuated the stimulatory effect of nicotine in guinea-pig heart and human atrium under normoxic conditions. Consistent with an exocytotic release mechanism, NE release was dependent on the presence of extracellular calcium under all conditions tested. Furthermore, NE overflow from guinea-pig heart was accompanied by a release of the exocytosis marker neuropeptide Y (NPY; determined by radioimmunoassay). In BCC, nicotine (1-10 mumol/l) evoked a release of NE and NPY and a transient rise of [Ca2+]i (determined with fura-2) during normoxia which were both dependent on the

  17. The α7-nicotinic acetylcholine receptor mediates the sensitivity of gastric cancer cells to taxanes.

    PubMed

    Tu, Chao-Chiang; Huang, Chien-Yu; Cheng, Wan-Li; Hung, Chin-Sheng; Uyanga, Batzorig; Wei, Po-Li; Chang, Yu-Jia

    2016-04-01

    Gastric cancer is difficult to cure because most patients are diagnosed at an advanced disease stage. Systemic chemotherapy remains an important therapy for gastric cancer, but both progression-free survival and disease-free survival associated with various combination regimens are limited because of refractoriness and chemoresistance. Accumulating evidence has revealed that the homomeric α7-nicotinic acetylcholine receptor (A7-nAChR) promotes human gastric cancer by driving cancer cell proliferation, migration, and metastasis. Therefore, A7-nAChR may serve as a potential therapeutic target for gastric cancer. However, the role of A7-nAChR in taxane therapy for gastric cancer was unclear. Cells were subjected to A7-nAChR knockdown (A7-nAChR KD) using short interfering RNA (siRNA). The anti-proliferative effects of taxane were assessed via 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT), terminal deoxynucleotidyl transferase-mediated nick-end labeling (TUNEL), and cell cycle distribution assays. A7-nAChR-KD cells exhibited low resistance to docetaxel and paclitaxel treatment, as measured by the MTT assay. Following paclitaxel treatment, the proportion of apoptotic cells was higher among A7-nAChR-KD cells than among scrambled control cells, as measured by cell cycle distribution and TUNEL assays. Further molecular analyses showed a reduction in the pAKT levels and a dramatic increase in the Bad levels in paclitaxel-treated A7-nAChR-KD cells but not in scrambled control cells. Following paclitaxel treatment, the level of Bax was slightly increased in both cell populations, whereas Poly (ADP-ribose) polymerase (PARP) cleavage was increased only in A7-nAChR-KD cells. These findings indicate that A7-nAChR-KD cells are more sensitive to paclitaxel treatment. We conclude that A7-nAChR may be a key biomarker for assessing the chemosensitivity of gastric cancer cells to taxane. PMID:26499946

  18. Purification of L-( sup 3 H) Nicotine eliminates low affinity binding

    SciTech Connect

    Romm, E.; Marks, M.J.; Collins, A.C. ); Lippiello, P.M. )

    1990-01-01

    Some studies of L-({sup 3}H) nicotine binding to rodent and human brain tissue have detected two binding sites as evidenced by nonlinear Scatchard plots. Evidence presented here indicated that the low affinity binding site is not stereospecific, is not inhibited by low concentrations of cholinergic agonists and is probably due to breakdown products of nicotine since purification of the L-({sup 3}H)nicotine eliminates the low affinity site.

  19. Basal ganglia cholinergic and dopaminergic function in progressive supranuclear palsy.

    PubMed

    Warren, Naomi M; Piggott, Margaret A; Greally, Elizabeth; Lake, Michelle; Lees, Andrew J; Burn, David J

    2007-08-15

    Progressive Supranuclear Palsy (PSP) is a progressive neurodegenerative disorder. In contrast to Parkinson's disease (PD) and dementia with Lewy bodies (DLB), replacement therapy with dopaminergic and cholinergic agents in PSP has been disappointing. The neurochemical basis for this is unclear. Our objective was to measure dopaminergic and cholinergic receptors in the basal ganglia of PSP and control brains. We measured, autoradiographically, dopaminergic (dopamine transporter, 125I PE2I and dopamine D2 receptors, 125I epidepride) and cholinergic (nicotinic alpha4beta2 receptors, 125I 5IA85380 and muscarinic M1 receptors, 3H pirenzepine) parameters in the striatum and pallidum of pathologically confirmed PSP cases (n=15) and controls (n=32). In PSP, there was a marked loss of dopamine transporter and nicotinic alpha4beta2 binding in the striatum and pallidum, consistent with loss of nigrostriatal neurones. Striatal D2 receptors were increased in the caudate and muscarinic M1 receptors were unchanged compared with controls. These results do not account for the poor response to dopaminergic and cholinergic replacement therapies in PSP, and suggest relative preservation of postsynaptic striatal projection neurones bearing D2/M1 receptors. PMID:17534953

  20. Where attention falls: Increased risk of falls from the converging impact of cortical cholinergic and midbrain dopamine loss on striatal function.

    PubMed

    Sarter, Martin; Albin, Roger L; Kucinski, Aaron; Lustig, Cindy

    2014-07-01

    Falls are a major source of hospitalization, long-term institutionalization, and death in older adults and patients with Parkinson's disease (PD). Limited attentional resources are a major risk factor for falls. In this review, we specify cognitive-behavioral mechanisms that produce falls and map these mechanisms onto a model of multi-system degeneration. Results from PET studies in PD fallers and findings from a recently developed animal model support the hypothesis that falls result from interactions between loss of basal forebrain cholinergic projections to the cortex and striatal dopamine loss. Striatal dopamine loss produces inefficient, low-vigor gait, posture control, and movement. Cortical cholinergic deafferentation impairs a wide range of attentional processes, including monitoring of gait, posture and complex movements. Cholinergic cell loss reveals the full impact of striatal dopamine loss on motor performance, reflecting loss of compensatory attentional supervision of movement. Dysregulation of dorsomedial striatal circuitry is an essential, albeit not exclusive, mediator of falls in this dual-system model. Because cholinergic neuromodulatory activity influences cortical circuitry primarily via stimulation of α4β2* nicotinic acetylcholine receptors, and because agonists at these receptors are known to benefit attentional processes in animals and humans, treating PD fallers with such agonists, as an adjunct to dopaminergic treatment, is predicted to reduce falls. Falls are an informative behavioral endpoint to study attentional-motor integration by striatal circuitry. PMID:24805070

  1. Optical methods in modeling nicotine effect on the surface water of cell membranes

    NASA Astrophysics Data System (ADS)

    Alexandrova, Tatyana V.; Rogacheva, Svetlana M.; Kuznetsov, Pavel E.; Gubina, Tamara I.

    2005-06-01

    Fluorescence and spectrophotometric methods have been used for investigation of nicotine action on the state and mobility of the surface water. The surfaces of membranes and proteins were simulated with the help of liposomes and ultradispersive diamonds consequently. Nicotine was shown to reduce the stability of liposomes and to change the aggregative ability of ultradispersive diamonds. The wave-like curves for the nicotine concentration dependences of the pointed features were observed. Such shape of responses was suggested to be due to the changing in structure and dynamics of water hydrogen bonds net near the surface of the model systems induced by nicotine molecules. The surface water phase was supposed to be one of signal elements ofthe ligand receptor recognition process.

  2. Nicotine Withdrawal

    PubMed Central

    McLaughlin, Ian; Dani, John A.; De Biasi, Mariella

    2015-01-01

    An aversive abstinence syndrome manifests 4–24 h following cessation of chronic use of nicotine-containing products. Symptoms peak on approximately the 3rd day and taper off over the course of the following 3–4 weeks. While the severity of withdrawal symptoms is largely determined by how nicotine is consumed, certain short nucleotide polymorphisms (SNPs) have been shown to predispose individuals to consume larger amounts of nicotine more frequently—as well as to more severe symptoms of withdrawal when trying to quit. Additionally, rodent behavioral models and transgenic mouse models have revealed that specific nicotinic acetylcholine receptor (nAChR) subunits, cellular components, and neuronal circuits are critical to the expression of withdrawal symptoms. Consequently, by continuing to map neuronal circuits and nAChR subpopulations that underlie the nicotine withdrawal syndrome—and by continuing to enumerate genes that predispose carriers to nicotine addiction and exacerbated withdrawal symptoms—it will be possible to pursue personalized therapeutics that more effectively treat nicotine addiction. PMID:25638335

  3. Chlorpyrifos promotes colorectal adenocarcinoma H508 cell growth through the activation of EGFR/ERK1/2 signaling pathway but not cholinergic pathway.

    PubMed

    Suriyo, Tawit; Tachachartvanich, Phum; Visitnonthachai, Daranee; Watcharasit, Piyajit; Satayavivad, Jutamaad

    2015-12-01

    Aside from the effects on neuronal cholinergic system, epidemiological studies suggest an association between chlorpyrifos (CPF) exposure and cancer risk. This in vitro study examined the effects of CPF and its toxic metabolite, chlorpyrifos oxon (CPF-O), on the growth of human colorectal adenocarcinoma H508, colorectal adenocarcinoma HT-29, normal colon epithelial CCD841, liver hepatocellular carcinoma HepG2, and normal liver hepatocyte THLE-3 cells. The results showed that CPF (5-100 μM) concentration-dependently increased viability of H508 and CCD841 cells in serum-free conditions. This increasing trend was not found in HT-29, HepG2 and THLE-3 cells. In contrast, CPF-O (50-100 μM) reduced the viability of all cell lines. Cell cycle analysis showed the induction of cells in the S phase, and EdU incorporation assay revealed the induction of DNA synthesis in CPF-treated H508 cells indicating that CPF promotes cell cycle progression. Despite the observation of acetylcholinesterase activity inhibition and reactive oxygen species (ROS) generation, atropine (a non-selective muscarinic acetylcholine receptor antagonist) and N-acetylcysteine (a potent antioxidant) failed to inhibit the growth-promoting effect of CPF. CPF increased the phosphorylation of epidermal growth factor receptor (EGFR) and its downstream effector, extracellular signal regulated kinase (ERK1/2), in H508 cells. AG-1478 (a specific EGFR tyrosine kinase inhibitor) and U0126 (a specific MEK inhibitor) completely mitigated the growth promoting effect of CPF. Altogether, these results suggest that EGFR/ERK1/2 signaling pathway but not cholinergic pathway involves in CPF-induced colorectal adenocarcinoma H508 cell growth. PMID:26514924

  4. Glutamatergic synapse formation is promoted by α7-containing nicotinic acetylcholine receptors.

    PubMed

    Lozada, Adrian F; Wang, Xulong; Gounko, Natalia V; Massey, Kerri A; Duan, Jingjing; Liu, Zhaoping; Berg, Darwin K

    2012-05-30

    Glutamate is the primary excitatory transmitter in adult brain, acting through synapses on dendritic spines and shafts. Early in development, however, when glutamatergic synapses are only beginning to form, nicotinic cholinergic excitation is already widespread; it is mediated by acetylcholine activating nicotinic acetylcholine receptors (nAChRs) that generate waves of activity across brain regions. A major class of nAChRs contributing at this time is a species containing α7 subunits (α7-nAChRs). These receptors are highly permeable to calcium, influence a variety of calcium-dependent events, and are diversely distributed throughout the developing CNS. Here we show that α7-nAChRs unexpectedly promote formation of glutamatergic synapses during development. The dependence on α7-nAChRs becomes clear when comparing wild-type (WT) mice with mice constitutively lacking the α7-nAChR gene. Ultrastructural analysis, immunostaining, and patch-clamp recording all reveal synaptic deficits when α7-nAChR input is absent. Similarly, nicotinic activation of α7-nAChRs in WT organotypic culture, as well as cell culture, increases the number of glutamatergic synapses. RNA interference demonstrates that the α7-nAChRs must be expressed in the neuron being innervated for normal innervation to occur. Moreover, the deficits persist throughout the developmental period of major de novo synapse formation and are still fully apparent in the adult. GABAergic synapses, in contrast, are undiminished in number under such conditions. As a result, mice lacking α7-nAChRs have an altered balance in the excitatory/inhibitory input they receive. This ratio represents a fundamental feature of neural networks and shows for the first time that endogenous nicotinic cholinergic signaling plays a key role in network construction. PMID:22649244

  5. Estrogen down-regulates nicotine-induced adhesion molecule expression via nongenomic signal pathway in endothelial cells.

    PubMed

    Wang, Yajing; Wang, Zhaoxia; Wang, Lianyun; Zhou, Ying; Zhao, Yangxing; Liu, Liming; Yao, Chenjiang; Qiao, Zhongdong

    2006-06-01

    Although gonadal hormone mostly causes genotropic actions through the members of nuclear receptor family, it also can regulate these actions via membrane receptor. To explore the possibility of plasma membrane estrogen receptors (mER) mediating genotropic events, we have investigated estrogen's effect on nicotine-stimulated adhesion molecule expression and evaluated whether this effect depends on calcium, MAPK signal pathway. Fluorescence Spectroscopy analysis of Ca2+ from human umbilical vein endothelial cells (HUVECs) showed through mER, estrogen induced a rapid rise of intracellular free Ca2+ concentration and this rise could not be inhibited by tamoxifen (classic ER inhibitor). In the context of nicotine stimulating, however, estrogen attenuated phosphorylation of mitogen-activated protein kinase (MAPK) family members, extracellular signal regulated kinase 1/2 (ERK1/2), p38 but not c-Jun-N-terminal kinase (JNK) in HUVECs and this effect could not still be prevented by tamoxifen. In the meantime, estrogen also down-regulated surface/soluble vascular cell adhesion molecule (VCAM-1, sVCAM-1) and endothelial selectin (E-selectin, sE-selectin) levels, which was not abolished by tamoxifen either. Moreover, calcium chelator BAPTA, ERK1/2 inhibitor PD98059, p38 inhibitor SB203580 significantly reduced the production of nicotine-activated surface/soluble VCAM-1 and E-selectin and both of the remained levels were no longer regulated by estrogen. Our study here provides the information of decrease effect of mER-mediated estrogen through Ca2+ and ERK1/2, p38 MAPK signaling pathway on nicotine-stimulated expression of surface/soluble VCAM-1 and E-selectin in HUVECs. PMID:16644474

  6. Brain Region–Specific Alterations in the Gene Expression of Cytokines, Immune Cell Markers and Cholinergic System Components during Peripheral Endotoxin–Induced Inflammation

    PubMed Central

    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

    2014-01-01

    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. PMID:25299421

  7. Developmental exposure of aflatoxin B1 reversibly affects hippocampal neurogenesis targeting late-stage neural progenitor cells through suppression of cholinergic signaling in rats.

    PubMed

    Tanaka, Takeshi; Mizukami, Sayaka; Hasegawa-Baba, Yasuko; Onda, Nobuhiko; Sugita-Konishi, Yoshiko; Yoshida, Toshinori; Shibutani, Makoto

    2015-10-01

    To elucidate the maternal exposure effects of aflatoxin B1 (AFB1) and its metabolite aflatoxin M1, which is transferred into milk, on postnatal hippocampal neurogenesis, pregnant Sprague-Dawley rats were provided a diet containing AFB1 at 0, 0.1, 0.3, or 1.0 ppm from gestational day 6 to day 21 after delivery on weaning. Offspring were maintained through postnatal day (PND) 77 without AFB1 exposure. Following exposure to 1.0 ppm AFB1, offspring showed no apparent systemic toxicity at weaning, whereas dams showed increased liver weight and DNA repair gene upregulation in the liver. In the hippocampal dentate gyrus of male PND 21 offspring, the number of doublecortin(+) progenitor cells were decreased, which was associated with decreased proliferative cell population in the subgranular zone at ≥ 0.3 ppm, although T-box brain 2(+) cells, tubulin beta III(+) cells, gamma-H2A histone family, member X(+) cells, and cyclin-dependent kinase inhibitor 1A(+) cells did not fluctuate in number. AFB1 exposure examined at 1.0 ppm also resulted in transcript downregulation of the cholinergic receptor subunit Chrna7 and dopaminergic receptor Drd2 in the dentate gyrus, although there was no change in transcript levels of DNA repair genes. In the hippocampal dentate hilus, interneurons expressing CHRNA7 or phosphorylated tropomyosin receptor kinase B (TRKB) decreased at ≥ 0.3 ppm. On PND 77, there were no changes in neurogenesis-related parameters. These results suggested that maternal AFB1 exposure reversibly affects hippocampal neurogenesis targeting type-3 progenitor cells. This mechanism likely involves suppression of cholinergic signals on hilar GABAergic interneurons and brain-derived neurotrophic factor-TRKB signaling from granule cells. The no-observed-adverse-effect level for offspring neurogenesis was determined to be 0.1 ppm (7.1-13.6 mg/kg body weight/day). PMID:26260870

  8. MicroRNA-124 mediates the cholinergic anti-inflammatory action through inhibiting the production of pro-inflammatory cytokines

    PubMed Central

    Sun, Yang; Li, Qi; Gui, Huan; Xu, Dong-Ping; Yang, Yi-Li; Su, Ding-Feng; Liu, Xia

    2013-01-01

    The vagus nerve can control inflammatory response through a 'cholinergic anti-inflammatory pathway', which is mediated by the α7-nicotinic acetylcholine receptor (α7nAChR) on macrophages. However, the intracellular mechanisms that link α7nAChR activation and pro-inflammatory cytokine production remain not well understood. In this study, we found that miR-124 is upregulated by cholinergic agonists in LPS-exposed cells and mice. Utilizing miR-124 mimic and siRNA knockdown, we demonstrated that miR-124 is a critical mediator for the cholinergic anti-inflammatory action. Furthermore, our data indicated that miR-124 modulates LPS-induced cytokine production by targeting signal transducer and activator of transcription 3 (STAT3) to decrease IL-6 production and TNF-α converting enzyme (TACE) to reduce TNF-α release. These results also indicate that miR-124 is a potential therapeutic target for the treatment of inflammatory diseases. PMID:23979021

  9. Nicotine Gum

    MedlinePlus

    ... gum is used to help people stop smoking cigarettes. Nicotine chewing gum should be used together with ... by your doctor.If you smoke your first cigarette more than 30 minutes after waking up, use ...

  10. Transient Cholesterol Effects on Nicotinic Acetylcholine Receptor Cell-Surface Mobility

    PubMed Central

    Almarza, Gonzalo; Sánchez, Francisco; Barrantes, Francisco J.

    2014-01-01

    To what extent do cholesterol-rich lipid platforms modulate the supramolecular organization of the nicotinic acetylcholine receptor (AChR)? To address this question, the dynamics of AChR particles at high density and its cholesterol dependence at the surface of mammalian cells were studied by combining total internal reflection fluorescence microscopy and single-particle tracking. AChR particles tagged with a monovalent ligand, fluorescent α-bungarotoxin (αBTX), exhibited two mobile pools: i) a highly mobile one undergoing simple Brownian motion (16%) and ii) one with restricted motion (∼50%), the rest being relatively immobile (∼44%). Depletion of membrane cholesterol by methyl-α-cyclodextrin increased the fraction of the first pool to 22% and 33% after 15 and 40 min, respectively; the pool undergoing restricted motion diminished from 50% to 44% and 37%, respectively. Monoclonal antibody binding results in AChR crosslinking-internalization after 2 h; here, antibody binding immobilized within minutes ∼20% of the totally mobile AChR. This proportion dramatically increased upon cholesterol depletion, especially during the initial 10 min (83.3%). Thus, antibody crosslinking and cholesterol depletion exhibited a mutually synergistic effect, increasing the average lifetime of cell-surface AChRs∼10 s to ∼20 s. The instantaneous (microscopic) diffusion coefficient D2–4 of the AChR obtained from the MSD analysis diminished from ∼0.001 µm2 s−1 to ∼0.0001–0.00033 µm2 s−1 upon cholesterol depletion, ∼30% of all particles falling into the stationary mode. Thus, muscle-type AChR exhibits heterogeneous motional regimes at the cell surface, modulated by the combination of intrinsic (its supramolecular organization) and extrinsic (membrane cholesterol content) factors. PMID:24971757