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Bouron A. Neuronal Store-Operated Calcium Channels. Mol Neurobiol 2023:10.1007/s12035-023-03352-5. [PMID: 37118324 DOI: 10.1007/s12035-023-03352-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Accepted: 04/13/2023] [Indexed: 04/30/2023]
Abstract
The endoplasmic reticulum (ER) is the major intracellular calcium (Ca2+) storage compartment in eukaryotic cells. In most instances, the mobilization of Ca2+ from this store is followed by a delayed and sustained uptake of Ca2+ through Ca2+-permeable channels of the cell surface named store-operated Ca2+ channels (SOCCs). This gives rise to a store-operated Ca2+ entry (SOCE) that has been thoroughly investigated in electrically non-excitable cells where it is the principal regulated Ca2+ entry pathway. The existence of this Ca2+ route in neurons has long been a matter of debate. However, a growing body of experimental evidence indicates that the recruitment of Ca2+ from neuronal ER Ca2+ stores generates a SOCE. The present review summarizes the main studies supporting the presence of a depletion-dependent Ca2+ entry in neurons. It also addresses the question of the molecular composition of neuronal SOCCs, their expression, pharmacological properties, as well as their physiological relevance.
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Affiliation(s)
- Alexandre Bouron
- Université Grenoble Alpes, CNRS, CEA, Inserm UA13 BGE, 38000, Grenoble, France.
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2
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Abstract
Calcein, a fluorescent fluid phase marker, has been used to track and visualize cellular processes such as synaptic vesicle fusion. It is also the fluorophore for live cells in the commonly used Live/Dead viability assay. In pilot studies designed to determine fusion pore open size and vesicle movement in secretory cells, imaging analysis revealed that calcein reduced the number of vesicles released from the cells when stimulated with nicotine. Using amperometry to detect individual vesicle release events, we show that when calcein is present in the media, the number of vesicles that fuse with the cellular membrane is reduced when cells are stimulated with either nicotine or high K+. Experimentally, amperometric electrodes are not undergoing fouling in the presence of calcein. We hypothesized that calcein, when activated by light, releases reactive oxygen species that cause a reduction in secreted vesicles. We show that when calcein is protected from light during experimentation, little to no reduction of vesicle secretion occurred. Therefore, photoactivated calcein can cause deleterious results for measurements of cellular processes, likely to be the result of release of reactive oxygen species.
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Affiliation(s)
- Brooke A. Miller
- Department
of Pharmacology and Physiology, Saint Louis University, St. Louis, Missouri 63104, United States
| | - Jason B. Papke
- Department
of Pharmacology and Physiology, Saint Louis University, St. Louis, Missouri 63104, United States
| | - Vytas P. Bindokas
- Department
of Pharmacological and Physiological Sciences, University of Chicago, Chicago, Illinois 60637, United States
| | - Amy B. Harkins
- Department
of Pharmacology and Physiology, Saint Louis University, St. Louis, Missouri 63104, United States
- Department
of Biomedical Engineering, Saint Louis University, St. Louis, Missouri 63103, United States
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3
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He LL, Zhang QF, Wang LC, Dai JX, Wang CH, Zheng LH, Zhou Z. Muscarinic inhibition of nicotinic transmission in rat sympathetic neurons and adrenal chromaffin cells. Philos Trans R Soc Lond B Biol Sci 2016; 370:rstb.2014.0188. [PMID: 26009767 DOI: 10.1098/rstb.2014.0188] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Little is known about the interactions between nicotinic and muscarinic acetylcholine receptors (nAChRs and mAChRs). Here we report that methacholine (MCh), a selective agonist of mAChRs, inhibited up to 80% of nicotine-induced nAChR currents in sympathetic superior cervical ganglion neurons and adrenal chromaffin cells. The muscarine-induced inhibition (MiI) substantially reduced ACh-induced membrane currents through nAChRs and quantal neurotransmitter release. The MiI was time- and temperature-dependent. The slow recovery of nAChR current after washout of MCh, as well as the high value of Q10 (3.2), suggested, instead of a direct open-channel blockade, an intracellular metabotropic process. The effects of GTP-γ-S, GDP-β-S and pertussis toxin suggested that MiI was mediated by G-protein signalling. Inhibitors of protein kinase C (bisindolymaleimide-Bis), protein kinase A (H89) and PIP2 depletion attenuated the MiI, indicating that a second messenger pathway is involved in this process. Taken together, these data suggest that mAChRs negatively modulated nAChRs via a G-protein-mediated second messenger pathway. The time dependence suggests that MiI may provide a novel mechanism for post-synaptic adaptation in all cells/neurons and synapses expressing both types of AChRs.
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Affiliation(s)
- Lin-Ling He
- State Key Laboratory of Biomembrane and Membrane Biotechnology and Beijing Key Laboratory of Cardiometabolic Molecular Medicine, Institute of Molecular Medicine and PKU-IDG/McGovern Institute for Brain Research and Peking-Tsinghua Center for Life Sciences, Peking University, Beijing 100871, People's Republic of China Department of Immunology and Microbial Science, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Quan-Feng Zhang
- State Key Laboratory of Biomembrane and Membrane Biotechnology and Beijing Key Laboratory of Cardiometabolic Molecular Medicine, Institute of Molecular Medicine and PKU-IDG/McGovern Institute for Brain Research and Peking-Tsinghua Center for Life Sciences, Peking University, Beijing 100871, People's Republic of China
| | - Lie-Cheng Wang
- State Key Laboratory of Biomembrane and Membrane Biotechnology and Beijing Key Laboratory of Cardiometabolic Molecular Medicine, Institute of Molecular Medicine and PKU-IDG/McGovern Institute for Brain Research and Peking-Tsinghua Center for Life Sciences, Peking University, Beijing 100871, People's Republic of China
| | - Jing-Xia Dai
- State Key Laboratory of Biomembrane and Membrane Biotechnology and Beijing Key Laboratory of Cardiometabolic Molecular Medicine, Institute of Molecular Medicine and PKU-IDG/McGovern Institute for Brain Research and Peking-Tsinghua Center for Life Sciences, Peking University, Beijing 100871, People's Republic of China
| | - Chang-He Wang
- State Key Laboratory of Biomembrane and Membrane Biotechnology and Beijing Key Laboratory of Cardiometabolic Molecular Medicine, Institute of Molecular Medicine and PKU-IDG/McGovern Institute for Brain Research and Peking-Tsinghua Center for Life Sciences, Peking University, Beijing 100871, People's Republic of China
| | - Liang-Hong Zheng
- State Key Laboratory of Biomembrane and Membrane Biotechnology and Beijing Key Laboratory of Cardiometabolic Molecular Medicine, Institute of Molecular Medicine and PKU-IDG/McGovern Institute for Brain Research and Peking-Tsinghua Center for Life Sciences, Peking University, Beijing 100871, People's Republic of China
| | - Zhuan Zhou
- State Key Laboratory of Biomembrane and Membrane Biotechnology and Beijing Key Laboratory of Cardiometabolic Molecular Medicine, Institute of Molecular Medicine and PKU-IDG/McGovern Institute for Brain Research and Peking-Tsinghua Center for Life Sciences, Peking University, Beijing 100871, People's Republic of China
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4
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de Groot MW, Westerink RH. Chemically-induced oxidative stress increases the vulnerability of PC12 cells to rotenone-induced toxicity. Neurotoxicology 2014; 43:102-109. [DOI: 10.1016/j.neuro.2014.02.008] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2013] [Revised: 02/20/2014] [Accepted: 02/28/2014] [Indexed: 10/25/2022]
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Kayano T, Kitamura N, Miyazaki S, Ichiyanagi T, Shimomura N, Shibuya I, Aimi T. Gymnopilins, a product of a hallucinogenic mushroom, inhibit the nicotinic acetylcholine receptor. Toxicon 2014; 81:23-31. [DOI: 10.1016/j.toxicon.2014.01.014] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2013] [Revised: 12/21/2013] [Accepted: 01/23/2014] [Indexed: 10/25/2022]
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Abstract
BACKGROUND The α7 nicotinic acetylcholine receptor, a ligand-gated ion channel, is an attractive drug discovery target in schizophrenia and Alzheimer's disease. OBJECTIVE We have evaluated the various approaches to discovering ligands targeting the α7 nicotinic receptor to define the current paradigm driving drug discovery efforts in this area. METHODS Assays using functional read-outs as a consequence of α7 nicotinic receptor activation have been reviewed. CONCLUSION Functional assays using fluorescence-based optical methods in combination with direct electrophysiological recordings of channel function currently provide an integrated approach to the discovery of α7 nicotinic receptor targeted ligands.
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Affiliation(s)
- John Dunlop
- Neuroscience Discovery Research, Wyeth Research, CN-8000, Princeton, NJ 08543, USA +1 732 274 4193 ; +1 732 274 4755 ;
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7
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Prasai P, Stefos GC, Becker W. Extracellular ATP activates NFAT-dependent gene expression in neuronal PC12 cells via P2X receptors. BMC Neurosci 2011; 12:90. [PMID: 21943104 PMCID: PMC3189881 DOI: 10.1186/1471-2202-12-90] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2011] [Accepted: 09/23/2011] [Indexed: 02/04/2023] Open
Abstract
Background Treatment of neuronal PC12 cells with ATP induces depolarisation and increases intracellular calcium levels via purinergic receptors. In many cell types, sustained elevation of intracellular calcium levels cause changes in gene expression via activation of the transcription factor NFAT (nuclear factor of activated T cells). We have therefore characterised the signalling pathway by which ATP regulates NFAT-dependent gene expression in PC12 cells. Results The activation of NFAT transcriptional activity by extracellular ATP was characterised with the help of reporter gene assays. Treatment of PC12 cells with ATP elicited a dose-dependent increase in luciferase activity (EC50 = 78 μM). UTP, 4-benzoylbenzoyl ATP and α,β-methylene ATP did not mimic the effect of ATP, which was abolished by treatment with the P2X receptor antagonist pyridoxal-phosphate-6-azophenyl-2',4'-disulfonate (PPADS). This pharmacological characterisation provides evidence for a critical role of ionotropic P2X receptors. Blockade of L-type voltage-dependent calcium channels by nifedipine reduced the response of NFAT to ATP, indicating that a depolarisation-mediated calcium influx was required for maximal NFAT activation. Inhibition of store-operated calcium entry by the pyrazole derivative BTP2 also diminished ATP-dependent NFAT activation. Furthermore, ATP-induced NFAT activation was associated with the activation of the mitogen-activated protein kinases ERK1/2. Finally, treatment with ATP increased the levels of the NFAT target transcripts, RCAN1-4 (regulator of calcineurin) and BDNF (brain derived neurotrophic factor). Conclusion The present data show that ATP induces NFAT-dependent changes in gene expression in PC12 cells by acting on P2X receptors. Maximal NFAT activation depends on both depolarisation-induced calcium influx and store-operated calcium entry and requires the activity of the protein phosphatase calcineurin and the mitogen-activated protein kinase cascade.
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Affiliation(s)
- Prabin Prasai
- Institute of Pharmacology and Toxicology, Medical Faculty of RWTH Aachen University, Wendlingweg 2, 52074 Aachen, Germany
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8
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Oliveira EE, Pippow A, Salgado VL, Büschges A, Schmidt J, Kloppenburg P. Cholinergic Currents in Leg Motoneurons of Carausius morosus. J Neurophysiol 2010; 103:2770-82. [DOI: 10.1152/jn.00963.2009] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
We used patch-clamp recordings and fast optical Ca2+ imaging to characterize an acetylcholine-induced current ( IACh) in leg motoneurons of the stick insect Carausius morosus. Our long-term goal is to better understand the synaptic and integrative properties of the leg sensory-motor system, which has served extremely successfully as a model to study basic principles of walking and locomotion on the network level. The experiments were performed under biophysically controlled conditions on freshly dissociated leg motoneurons to avoid secondary effects from the network. To allow for unequivocal identification, the leg motoneurons were backfilled with a fluorescent label through the main leg nerve prior to cell dissociation. In 87% of the motoneurons, IACh consisted of a fast-desensitizing ( IACh1) and a slow-desensitizing component ( IACh2), both of which were concentration dependent, with EC50 values of 3.7 × 10−5 and 2.0 × 10−5 M, respectively. Ca2+ imaging revealed that a considerable portion of IACh (∼18%) is carried by Ca2+, suggesting that IACh, besides mediating fast synaptic transmission, could also induce Ca2+-dependent processes. Using specific nicotinic and muscarinic acetylcholine receptor ligands, we showed that IACh was exclusively mediated by nicotinic acetylcholine receptors. Distinct concentration–response relations of IACh1 and IACh2 for these ligands indicated that they are mediated by different types of nicotinic acetylcholine receptors.
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Affiliation(s)
- Eugênio E. Oliveira
- Institute for Zoology, Biocenter, and
- Center for Molecular Medicine Cologne (CMMC) and Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany; and
| | - Andreas Pippow
- Institute for Zoology, Biocenter, and
- Center for Molecular Medicine Cologne (CMMC) and Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany; and
| | - Vincent L. Salgado
- BASF Agricultural Products, BASF Corporation, Research Triangle Park, North Carolina
| | | | | | - Peter Kloppenburg
- Institute for Zoology, Biocenter, and
- Center for Molecular Medicine Cologne (CMMC) and Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany; and
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9
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Ariano P, Zamburlin P, D'Alessandro R, Meldolesi J, Lovisolo D. Differential repression by the transcription factor REST/NRSF of the various Ca2+ signalling mechanisms in pheochromocytoma PC12 cells. Cell Calcium 2010; 47:360-8. [PMID: 20171735 DOI: 10.1016/j.ceca.2010.01.007] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2009] [Revised: 01/21/2010] [Accepted: 01/26/2010] [Indexed: 01/20/2023]
Abstract
Expression of the nerve cell phenotype is orchestrated by the REST/NRSF transcription repressor, working on hundreds of genes recognized at a specific regulatory binding sequence. Most PC12 clones, the most frequently employed neuronal model, maintain low levels of REST; however a few, defective of neurosecretion, express high levels. To investigate the role of REST in Ca2+ signalling we studied the [Ca2+](i) changes in single cells of four clones, two wild-type and two defective, pre-treated for 5 days with NGF. We focused on Ca2+ influxes induced by depolarization and ATP. Only a subpopulation ( approximately 15%) of the defective, high REST cells responded to depolarization (Ca(V) expression approximately 10%). The ATP-induced intracellular Ca2+ release was little changed, whereas influx via ionotropic P2X receptors was decreased, in agreement with the decreased expression of P2X2 receptors. The percentage of defective cells expressing store-operated calcium entry (SOCE) following ATP stimulation was also lower. The responses of the defective clones were little affected by their differentiated state. In conclusion, our results revealed important new aspects of REST control of Ca2+ homeostasis, of potential physiological importance. The mechanisms of this control remain to be investigated.
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Affiliation(s)
- P Ariano
- Department of Animal and Human Biology, University of Turin, via Accademia Albertina 13, I-10123 and NIS Centre of Excellence, Turin, Italy
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10
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Chernyavsky AI, Arredondo J, Qian J, Galitovskiy V, Grando SA. Coupling of ionic events to protein kinase signaling cascades upon activation of alpha7 nicotinic receptor: cooperative regulation of alpha2-integrin expression and Rho kinase activity. J Biol Chem 2009; 284:22140-22148. [PMID: 19549780 DOI: 10.1074/jbc.m109.011395] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Defining the signaling mechanisms and effector proteins mediating phenotypic and mechanical plasticity of keratinocytes (KCs) during wound epithelialization is one of the major goals in epithelial cell biology. The acetylcholine (ACh)-gated ion channels, or nicotinic ACh receptors (nAChRs), mediate the nicotinergic signaling that controls crawling locomotion of KCs. To elucidate relative contributions of the ionic and protein kinase-mediated events elicited due to activation of alpha7 nAChRs, we quantitated expression of alpha2-integrin gene at the mRNA and protein levels and also measured Rho kinase activity in KCs stimulated with the alpha7 agonist AR-R17779 while blocking the Na+ or Ca2+ entry and/or inhibiting signaling kinases. The results demonstrated the existence of the two-component signaling systems coupling the ionic events and protein kinase signaling cascades downstream of alpha7 nAChR to simultaneous up-regulation of alpha2-integrin expression and activation of Rho kinase. The Raf/MEK1/ERK1/2 cascade up-regulating alpha2-integrin was activated due to both Ca2+-dependent recruitment of Ca2+/calmodulin-dependent protein kinase II and protein kinase C and Ca2+-independent activation of Ras. Likewise the phosphatidylinositol 3-kinase-mediated activation of Rho kinase was elicited due to both Ca2+ entry-dependent involvement of Ca2+/calmodulin-dependent protein kinase II and Ca2+-independent activation of Jak2. Thus, although the initial signals emanating from activated alpha7 nAChR are different in nature the pathways intersect at common effector molecules providing for a common end point effect. This novel paradigm of nAChR-mediated coordination of the ionic and metabolic signaling events can allow an auto/paracrine ACh to simultaneously alter gene expression and induce reciprocal changes in the cytoskeleton and contractile system of KCs required to compete a particular step of wound epithelialization.
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Affiliation(s)
- Alexander I Chernyavsky
- Departments of Dermatology and Biological Chemistry, University of California, Irvine, California 92697
| | - Juan Arredondo
- Departments of Dermatology and Biological Chemistry, University of California, Irvine, California 92697
| | - Jing Qian
- Departments of Dermatology and Biological Chemistry, University of California, Irvine, California 92697
| | - Valentin Galitovskiy
- Departments of Dermatology and Biological Chemistry, University of California, Irvine, California 92697
| | - Sergei A Grando
- Departments of Dermatology and Biological Chemistry, University of California, Irvine, California 92697
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11
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De Proost I, Pintelon I, Wilkinson WJ, Goethals S, Brouns I, Van Nassauw L, Riccardi D, Timmermans JP, Kemp PJ, Adriaensen D. Purinergic signaling in the pulmonary neuroepithelial body microenvironment unraveled by live cell imaging. FASEB J 2008; 23:1153-60. [PMID: 19050048 DOI: 10.1096/fj.08-109579] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Pulmonary neuroepithelial bodies (NEBs) are densely innervated groups of complex sensory airway receptors involved in the regulation of breathing. Together with their surrounding Clara-like cells, they exhibit stem cell potential through their capacity to regenerate depopulated areas of the epithelium following lung injury. We have employed confocal live cell imaging microscopy and novel electrophysiological techniques in a new ex vivo lung slice model to unravel potential purinergic signaling pathways within the NEB microenvironment. Quinacrine histochemistry indicated high amounts of vesicular ATP in NEB cells. Using a "reporter-patching" method adapted to create a uniquely sensitive and selective biosensor for the direct detection of ATP release from NEBs ex vivo, we demonstrated quantal ATP release from NEBs following their depolarization. Enhancing enzymatic extracellular ATP hydrolysis or inhibiting P2 receptors confirmed the central role of ATP in paracrine interactions between NEB cells and Clara-like cells. Combined calcium imaging, pharmacology, and immunohistochemistry showed that ligand-binding to functional P2Y(2) receptors underpins the activation of Clara-like cells. Hence, NEB cells communicate with their cellular neighbors in the NEB microenvironment by releasing ATP, which rapidly evokes purinergic activation of surrounding Clara-like cells. Besides ATP acting on the P2X(3) receptor expressing vagal sensory nerve terminals between NEB cells, local paracrine purinergic signaling within this potential stem cell niche may be important to both normal airway function, airway epithelial regeneration after injury, and/or the pathogenesis of small cell lung carcinomas.
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Affiliation(s)
- Ian De Proost
- Department of Veterinary Sciences, University of Antwerp, Antwerp, Belgium
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12
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Amatore C, Arbault S, Guille M, Lemaître F. Electrochemical Monitoring of Single Cell Secretion: Vesicular Exocytosis and Oxidative Stress. Chem Rev 2008; 108:2585-621. [DOI: 10.1021/cr068062g] [Citation(s) in RCA: 316] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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13
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Arredondo J, Chernyavsky AI, Jolkovsky DL, Pinkerton KE, Grando SA. Receptor-mediated tobacco toxicity: acceleration of sequential expression of alpha5 and alpha7 nicotinic receptor subunits in oral keratinocytes exposed to cigarette smoke. FASEB J 2008; 22:1356-68. [PMID: 18450646 DOI: 10.1096/fj.07-9965.com] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Tobacco products and nicotine alter the cell cycle and lead to squamatization of oral keratinocytes (KCs) and squamous cell carcinoma. Activation of nicotinic acetylcholine receptors (nAChRs) elicits Ca(2+) influx that varies in magnitude between different nAChR subtypes. Normal differentiation of KCs is associated with sequential expression of the nAChR subtypes with increasing Ca(2+) permeability, such as alpha5-containing alpha3 nAChR and alpha7 nAChR. Exposure to environmental tobacco smoke (ETS) or an equivalent concentration of nicotine accelerated by severalfold the alpha5 and alpha7 expression in KCs, which could be abolished by mecamylamine and alpha-bungarotoxin with different efficacies, suggesting the following sequence of autoregulation of the expression of nAChR subtypes: alpha3(beta2/beta4) > alpha3(beta2/beta4)alpha5 > alpha7 > alpha7. This conjecture was corroborated by results of quantitative assays of subunit mRNA and protein levels, using nAChR-specific pharmacologic antagonists and small interfering RNAs. The genomic effects of ETS and nicotine involved the transcription factor GATA-2 that showed a multifold increase in quantity and activity in exposed KCs. Using protein kinase inhibitors and dominant negative and constitutively active constructs, we characterized the principal signaling cascades mediating a switch in the nAChR subtype. Cumulative results indicated that the alpha3(beta2/beta4) to alpha3(beta2/beta4)alpha5 nAChR transition predominantly involved protein kinase C, alpha3(beta2/beta4)alpha5 to alpha7 nAChR transition-Ca(2+)/calmodulin-dependent protein kinase II and p38 MAPK, and alpha7 self-up-regulation-the p38 MAPK/Akt pathway, and JAK-2. These results provide a mechanistic insight into the genomic effects of ETS and nicotine on KCs and characterize signaling pathways mediating autoregulation of stepwise overexpression of nAChR subtypes with increasing Ca(2+) permeability in exposed cells. These observations have salient clinical implications, because a switch in the nAChR subunit composition can bring about a corresponding switch in receptor function, leading to profound pathobiologic effects observed in KCs exposed to tobacco products.
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Affiliation(s)
- Juan Arredondo
- Department of Dermatology, University of California, Irvine, C340 Medical Sciences I, Irvine, CA 92697, USA
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14
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Ebihara T, Guo F, Zhang L, Kim JY, Saffen D. Muscarinic acetylcholine receptors stimulate Ca2+ influx in PC12D cells predominantly via activation of Ca2+ store-operated channels. J Biochem 2007; 139:449-58. [PMID: 16567410 DOI: 10.1093/jb/mvj064] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Activation of muscarinic acetylcholine receptors (mAChRs) causes the rapid release of Ca2+ from intracellular stores and a sustained influx of external Ca2+ in PC12D cells, a subline of the widely studied cell line PC12. Release of Ca2+ from intracellular stores and a sustained influx of Ca2+ are also observed following exposure to thapsigargin, a sesquiterpene lactone that depletes intracellular Ca2+ pools by irreversibly inhibiting the Ca2+ pump of the endoplasmic reticulum. In this study, we show that carbachol and thapsigargin empty the same intracellular Ca2+ stores, and that these stores are a subset of intracellular stores depleted by the Ca2+ ionophore ionomycin. Intracellular Ca2+ stores remain depleted during continuous stimulation of mAChR with carbachol in medium containing 2 mM extracellular Ca2+, but rapidly refill following inhibition of mAChRs with atropine. Addition of atropine to carbachol-stimulated cells causes intracellular Ca2+ levels to return to baseline levels in two steps: a rapid decrease that correlates with the reuptake of Ca2+ into internal stores and a delayed decrease that correlates with the inhibition of a Mn2+-permeable Ca2+ channel. Several lines of evidence suggest that carbachol and thapsigargin stimulate Ca2+ influx by a common mechanism: (i) pretreatment with thapsigargin occludes atropine-mediated inhibition of Ca2+ influx, (ii) carbachol and thapsigargin applied individually or together are equally efficient at stimulating the influx of Mn2+, and (iii) identical rates of Ca2+ influx are observed when Ca2+ is added to cells pretreated with carbachol, thapsigargin, or both agents in the absence of extracellular Ca2+. Taken together, these data suggest that the sustained influx of extracellular Ca2+ observed following activation of mAChRs in PC12D cells is mediated primarily by activation of a Mn2+-permeable, Ca2+ store-operated Ca2+ channel.
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Affiliation(s)
- Tatsuhiko Ebihara
- Department of Neurochemistry, Faculty of Medicine, University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113-0033
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15
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Hwang SR, Garza C, Mosier C, Toneff T, Wunderlich E, Goldsmith P, Hook V. Cathepsin L expression is directed to secretory vesicles for enkephalin neuropeptide biosynthesis and secretion. J Biol Chem 2007; 282:9556-9563. [PMID: 17244622 DOI: 10.1074/jbc.m605510200] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Proteases within secretory vesicles are required for conversion of neuropeptide precursors into active peptide neurotransmitters and hormones. This study demonstrates the novel cellular role of the cysteine protease cathepsin L for producing the (Met)enkephalin peptide neurotransmitter from proenkephalin (PE) in the regulated secretory pathway of neuroendocrine PC12 cells. These findings were achieved by coexpression of PE and cathepsin L cDNAs in PC12 cells with analyses of PE-derived peptide products. Expression of cathepsin L resulted in highly increased cellular levels of (Met)enkephalin, resulting from the conversion of PE to enkephalin-containing intermediates of 23, 18-19, 8-9, and 4.5 kDa that were similar to those present in vivo. Furthermore, expression of cathepsin L with PE resulted in increased amounts of nicotine-induced secretion of (Met)enkephalin. These results indicate increased levels of (Met)enkephalin within secretory vesicles of the regulated secretory pathway. Importantly, cathespin L expression was directed to secretory vesicles, demonstrated by colocalization of cathepsin L-DsRed fusion protein with enkephalin and chromogranin A neuropeptides that are present in secretory vesicles. In vivo studies also showed that cathepsin L in vivo was colocalized with enkephalin. The newly defined secretory vesicle function of cathepsin L for biosynthesis of active enkephalin opioid peptide contrasts with its function in lysosomes for protein degradation. These findings demonstrate cathepsin L as a distinct cysteine protease pathway for producing the enkephalin member of neuropeptides.
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Affiliation(s)
- Shin-Rong Hwang
- Skaggs School of Pharmacy and Pharmaceutical Sciences and Departments of Pharmacology, Neuroscience, and Medicine, School of Medicine, University of California, San Diego, La Jolla, California 92093
| | - Christina Garza
- Skaggs School of Pharmacy and Pharmaceutical Sciences and Departments of Pharmacology, Neuroscience, and Medicine, School of Medicine, University of California, San Diego, La Jolla, California 92093
| | - Charles Mosier
- Skaggs School of Pharmacy and Pharmaceutical Sciences and Departments of Pharmacology, Neuroscience, and Medicine, School of Medicine, University of California, San Diego, La Jolla, California 92093
| | - Thomas Toneff
- Skaggs School of Pharmacy and Pharmaceutical Sciences and Departments of Pharmacology, Neuroscience, and Medicine, School of Medicine, University of California, San Diego, La Jolla, California 92093
| | | | - Paul Goldsmith
- College of Pharmacy, Touro University, Vallejo, California 94592
| | - Vivian Hook
- Skaggs School of Pharmacy and Pharmaceutical Sciences and Departments of Pharmacology, Neuroscience, and Medicine, School of Medicine, University of California, San Diego, La Jolla, California 92093.
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Arredondo J, Chernyavsky AI, Jolkovsky DL, Pinkerton KE, Grando SA. Receptor-mediated tobacco toxicity: cooperation of the Ras/Raf-1/MEK1/ERK and JAK-2/STAT-3 pathways downstream of alpha7 nicotinic receptor in oral keratinocytes. FASEB J 2006; 20:2093-101. [PMID: 17012261 DOI: 10.1096/fj.06-6191com] [Citation(s) in RCA: 156] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The use of tobacco products is associated with an increased incidence of periodontal disease, poor response to periodontal therapy, and a high risk for developing head and neck cancer. Nicotine and tobacco-derived nitrosamines have been shown to exhibit their pathobiologic effects due in part to activation of the nicotinic acetylcholine (ACh) receptors (nAChRs), mainly alpha7 nAChR, expressed by oral keratinocytes (KCs). This study was designed to gain mechanistic insight into alpha7-mediated morbidity of tobacco products in the oral cavity. We investigated the signaling pathways downstream of alpha7 nAChR in monolayers of oral KCs exposed for 24 h to aged and diluted sidestream cigarette smoke (ADSS) or an equivalent concentration of pure nicotine. By both real-time polymerase chain reaction (PCR) and In-cell Western, the KCs stimulated with ADSS or nicotine showed multifold increases of STAT-3. These effects could be completely blocked or significantly (P<0.05) diminished if the cells were pretreated with the alpha7 antagonist alpha-bungarotoxin (alphaBTX) or transfected with anti-alpha7 small interfering RNA (siRNA-alpha7). The use of pathway inhibitors revealed that signaling through the Ras/Raf-1/MEK1/ERK steps mediated alpha7-dependent up-regulation of STAT-3. Targeted mutation of the alpha7 gene prevented ERK1/2 activation by nicotine. Using the gel mobility shift assay, we demonstrated that an increased protein binding activity of STAT-3 caused by ADSS or pure nicotine was mediated by janus-activated kinase (JAK)-2. Activation of JAK-2/STAT-3 pathway could be prevented by alphaBTX or siRNA-alpha7. Thus, nuclear transactivation of STAT-3 in KCs exposed to tobacco products is mediated via intracellular signaling downstream from alpha7, which proceeds via two complementary pathways. The Ras/Raf-1/MEK1/ERK cascade culminates in up-regulated expression of the gene encoding STAT-3, whereas recruitment and activation of tyrosine kinase JAK-2 phosphorylates it. Elucidation of this novel mechanism of nicotine-dependent nuclear transactivation of STAT-3 identifies oral alpha7 nAChR as a promising molecular target to prevent, reverse, or retard tobacco-related periodontal disease and progression of head and neck cancer by receptor inhibitors.
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Affiliation(s)
- Juan Arredondo
- Department of Dermatology, University of California Davis, Sacramento, CA, USA
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17
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18
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Zalewski PD, Truong-Tran AQ, Grosser D, Jayaram L, Murgia C, Ruffin RE. Zinc metabolism in airway epithelium and airway inflammation: basic mechanisms and clinical targets. A review. Pharmacol Ther 2004; 105:127-49. [PMID: 15670623 DOI: 10.1016/j.pharmthera.2004.09.004] [Citation(s) in RCA: 122] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/29/2004] [Indexed: 12/22/2022]
Abstract
In addition to basic housekeeping roles in metalloenzymes and transcription factors, dietary zinc (Zn) is an important immunoregulatory agent, growth cofactor, and cytoprotectant with anti-oxidant, anti-apoptotic, and anti-inflammatory roles. These properties of Zn are of particular importance in maintaining homeostasis of epithelial tissues which are at the front line of defense. This review is about the role of Zn in airway epithelium (AE). The first part focuses on the cellular biology of Zn, and what is known about its distribution and function in AE. The second part of the review considers evidence for altered Zn metabolism in asthma and other chronic diseases of airway inflammation. Important issues arise from a potential therapeutic perspective as to the optimal ways to monitor circulating and epithelial Zn levels in patients and the most effective means of supplementing these levels.
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Affiliation(s)
- Peter D Zalewski
- Department of Medicine, University of Adelaide, The Queen Elizabeth Hospital, Woodville, South Australia 5011, Australia.
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19
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Chudapongse N, Kim SY, Sasaki K, Kramer RE, Ho IK. Nonopioid receptor-mediated effects of U-50,488H on [Ca2+]i and extracellular dopamine in PC12 cells. J Neurosci Res 2003; 74:598-604. [PMID: 14598304 DOI: 10.1002/jnr.10801] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
The present studies were carried out to determine the effects of a kappa-opioid receptor agonist on cytosolic Ca(2+) concentration, [Ca(2+)](i), and extracellular dopamine in undifferentiated PC12 cells. The kappa-opioid receptor agonist U-50,488H caused concentration-dependent increases in [Ca(2+)](i) and extracellular dopamine. Neither effect was blocked by the selective kappa-opioid receptor antagonist nor-binaltorphimine. Increases in extracellular dopamine content and [Ca(2+)](i) caused by U-50,488H were correlated positively in the presence of extracellular Ca(2+); however, reduction of extracellular Ca(2+) abolished the increase in [Ca(2+)](i), but not that in dopamine. The latter observation suggests that stimulation of exocytotic release is not the primary mechanism involved in the increase in extracellular dopamine caused by U-50,488H. Effects on dopamine synthesis or catabolism also seem unlikely because the enhancement of extracellular dopamine occurred rapidly, and the amount of a major metabolite of dopamine, 3,4-dihydroxyphenylacetic acid (DOPAC), was not affected. In any event, neither the increase in [Ca(2+)](i) nor the increase in extracellular dopamine caused by U-50,488H is mediated by the kappa-opioid receptor.
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Affiliation(s)
- Nuannoi Chudapongse
- Department of Pharmacology and Toxicology, University of Mississippi Medical Center, Jackson, MS 39216-4505, USA
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Truong-Tran AQ, Ruffin RE, Foster PS, Koskinen AM, Coyle P, Philcox JC, Rofe AM, Zalewski PD. Altered zinc homeostasis and caspase-3 activity in murine allergic airway inflammation. Am J Respir Cell Mol Biol 2002; 27:286-96. [PMID: 12204890 DOI: 10.1165/rcmb.2001-0014oc] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Zn may have an important protective role in the respiratory epithelium and Zn deficiency may enhance airway inflammation and epithelial damage. The effects of mild nutritional Zn deficiency on airway hyperresponsiveness (AHR) and airway inflammation in mice sensitized and challenged with ovalbumin (OVA) to induce an allergic response were investigated. Balb/c mice were given Zn normal (ZN, 50 mg/kg Zn) or Zn limited diets (ZL, 14 mg/kg Zn) before and during induction of allergic airway inflammation, with appropriate controls (saline-treated, SAL). ZL mice had greater levels of AHR than ZN mice, regardless of presence or absence of allergic inflammation. These mice also had increased eosinophilia and mucus cell hyperplasia compared with ZN mice. Second, ZN and ZL OVA-treated mice had significant decreases in airway epithelial Zinquin fluorescence, indicating a lowered availability of Zn compared with their SAL-treated counterparts. In contrast, the pro-apoptotic protein caspase-3, which was co-localized with Zn in the apical epithelium, was significantly increased in both ZN and ZL OVA-treated mice. Immunologically active caspase-3 and apoptosis were increased in OVA-treated mice, especially the ZL group. These findings provide the first data for adverse effects of Zn deficiency on the respiratory epithelium and support a role for altered Zn homeostasis and caspase upregulation in asthma.
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Affiliation(s)
- Ai Q Truong-Tran
- Department of Medicine, University of Adelaide, The Queen Elizabeth Hospital, Woodville, South Australia, Australia
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Bonfante-cabarcas R, Bravo I, Nello C, Gutiérrez-reyes E, Loureiro Dos Santos NE, Moreno-yanes JA. Pharmacological doses of Zn2+ induce a muscarinic cholinergic supersensitivity. J Biomed Sci 2002; 9:639-44. [DOI: 10.1007/bf02254992] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
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Koizumi S, Rosa P, Willars GB, Challiss RAJ, Taverna E, Francolini M, Bootman MD, Lipp P, Inoue K, Roder J, Jeromin A. Mechanisms underlying the neuronal calcium sensor-1-evoked enhancement of exocytosis in PC12 cells. J Biol Chem 2002; 277:30315-24. [PMID: 12034721 DOI: 10.1074/jbc.m201132200] [Citation(s) in RCA: 77] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Neuronal calcium sensor-1 (NCS-1) or the originally identified homologue frequenin belongs to a superfamily of EF-hand calcium binding proteins. Although NCS-1 is thought to enhance synaptic efficacy or exocytosis mainly by activating ion channel function, the detailed molecular basis for the enhancement is still a matter of debate. Here, mechanisms underlying the NCS-1-evoked enhancement of exocytosis were investigated using PC12 cells overexpressing NCS-1. NCS-1 was found to have a broad distribution in the cells being partially distributed in the cytosol and associated to vesicles and tubular-like structures. Biochemical and immunohistochemical studies indicated that NCS-1 partially colocalized with the light synaptic vesicle marker synaptophysin. When stimulated with UTP or bradykinin, agonists to phospholipase C-linked receptors, NCS-1 enhanced the agonist-mediated elementary and global Ca2+ signaling and increased the levels of downstream signals of phosphatidylinositol 4-kinase. NCS-1 enhanced the UTP-evoked exocytosis but not the depolarization-evoked Ca2+ responses or exocytosis, suggesting that the enhancement by NCS-1 should involve phospholipase C-linked receptor-mediated signals rather than the Ca2+ channels or exocytotic machinery per se. Taken together, NCS-1 enhances phosphoinositide turnover, resulting in enhancement of Ca2+ signaling and exocytosis. This is a novel regulatory mechanism of exocytosis that might involve the activation of phosphatidylinositol 4-kinase.
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Affiliation(s)
- Schuichi Koizumi
- Section of Neuropharmacology, Division of Pharmacology, National Institute of Health Sciences, 1-18-1 Kamiyoga, Setagaya, Tokyo 158-8501, Japan.
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Abstract
There have been few reports on the mechanism(s) of action of oxethazaine (OXZ) despite its potent local anesthetic action. Generally, local anesthetics (LAs) not only inhibit Na(+) channels but also affect various membrane functions. In the present study, using PC12 cells as a nerve cell model, the effects of OXZ on intracellular Ca(2+) concentration ([Ca(2+)](i)) were examined in relation to cytotoxicity and dopamine release. [Ca(2+)](i) was determined by the quin2 method. In resting cells, (6-10)x10(-5)M OXZ produced lactate dehydrogenase leakage, which was Ca(2+)-dependent, inhibited by metal Ca(2+) channel blockers, and preceded by a marked increase in [Ca(2+)](i). Some other LAs showed no cytotoxicity at these concentrations. In K(+)-depolarized cells, however, lower concentrations of OXZ (10(-6)-10(-7)M), that had no effect on resting [Ca(2+)](i), inhibited both the dopamine release and the increase of [Ca(2+)](i) in parallel. The inhibitory potency against the [Ca(2+)](i) increase was in the order of nifedipine>OXZ approximately verapamil>diltiazem, and OXZ acted additively on the Ca(2+) channel blockers. OXZ showed the least effect on K(+)-depolarization as determined by bisoxonol uptake. OXZ also inhibited the increase in [Ca(2+)](i) induced by S(-)-BAY K 8644, a Ca(2+) channel agonist. These observations suggested that low concentrations of OXZ interact with L-type Ca(2+) channels. The biphasic effects of OXZ on Ca(2+) movement may be due to a unique chemical structure, and may participate in and complicate the understanding of the potent pharmacological and toxicological actions of OXZ.
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Affiliation(s)
- Yasusuke Masuda
- Division of Toxicology, Niigata College of Pharmacy, 5-13-2, Kamishin'ei-cho, Japan.
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Krjukova J, Akerman KE. Mechanisms of nicotine mediated communication between NGF-differentiated PC12 and HEL cells. Neuroreport 2002; 13:1157-61. [PMID: 12151760 DOI: 10.1097/00001756-200207020-00017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
HEL 92.1.7 cells were immobilized among nerve growth factor (NGF)-differentiated PC12 cells. Nicotine caused an immediate Ca2+ mobilisation in the PC12 cells followed by a delayed secondary Ca2+ response in the HEL 92.1.7 cells. The Ca2+ elevation in response to nicotine in PC12 cells was abolished by Na+ removal. The response was diminished by omega-contoxin GVIA (omega-CTx-GVIA) in PC12 cell neurites and by nifedipine in the cell bodies, respectively. The secondary response in HEL 92.1.7 cells was blocked by omega-CTx-GVIA. The results suggest that nicotinic receptor-mediated depolarisation and subsequent activation of voltage dependent Ca2+ channels (VDCC) are sufficient to induce transmitter release from NGF-differentiated PC12 cell varicosities without requirement for additional Ca2+ influx via nicotinic receptor ion channels.
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Affiliation(s)
- Jelena Krjukova
- Division of the Cell Physiology, Department of Physiology, BMC, Uppsala University, Husargatan 3, Sweden
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