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Tejero R, Alsakkal M, Hennlein L, Lopez-Cabello AM, Jablonka S, Tabares L. Nifedipine Ameliorates Cellular Differentiation Defects of Smn-Deficient Motor Neurons and Enhances Neuromuscular Transmission in SMA Mice. Int J Mol Sci 2023; 24:ijms24087648. [PMID: 37108811 PMCID: PMC10146780 DOI: 10.3390/ijms24087648] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2023] [Revised: 04/11/2023] [Accepted: 04/18/2023] [Indexed: 04/29/2023] Open
Abstract
In spinal muscular atrophy (SMA), mutations in or loss of the Survival Motor Neuron 1 (SMN1) gene reduce full-length SMN protein levels, which leads to the degeneration of a percentage of motor neurons. In mouse models of SMA, the development and maintenance of spinal motor neurons and the neuromuscular junction (NMJ) function are altered. Since nifedipine is known to be neuroprotective and increases neurotransmission in nerve terminals, we investigated its effects on cultured spinal cord motor neurons and motor nerve terminals of control and SMA mice. We found that application of nifedipine increased the frequency of spontaneous Ca2+ transients, growth cone size, cluster-like formations of Cav2.2 channels, and it normalized axon extension in SMA neurons in culture. At the NMJ, nifedipine significantly increased evoked and spontaneous release at low-frequency stimulation in both genotypes. High-strength stimulation revealed that nifedipine increased the size of the readily releasable pool (RRP) of vesicles in control but not SMA mice. These findings provide experimental evidence about the ability of nifedipine to prevent the appearance of developmental defects in SMA embryonic motor neurons in culture and reveal to which extent nifedipine could still increase neurotransmission at the NMJ in SMA mice under different functional demands.
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Affiliation(s)
- Rocio Tejero
- Department of Medical Physiology and Biophysics, School of Medicine, University of Seville, 41009 Seville, Spain
| | - Mohammad Alsakkal
- Institute of Clinical Neurobiology, University Hospital Würzburg, 97078 Würzburg, Germany
| | - Luisa Hennlein
- Institute of Clinical Neurobiology, University Hospital Würzburg, 97078 Würzburg, Germany
| | - Ana M Lopez-Cabello
- Department of Medical Physiology and Biophysics, School of Medicine, University of Seville, 41009 Seville, Spain
| | - Sibylle Jablonka
- Institute of Clinical Neurobiology, University Hospital Würzburg, 97078 Würzburg, Germany
| | - Lucia Tabares
- Department of Medical Physiology and Biophysics, School of Medicine, University of Seville, 41009 Seville, Spain
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Uzieliene I, Bironaite D, Miksiunas R, Bagdonas E, Vaiciuleviciute R, Mobasheri A, Bernotiene E. The Effect of CaV1.2 Inhibitor Nifedipine on Chondrogenic Differentiation of Human Bone Marrow or Menstrual Blood-Derived Mesenchymal Stem Cells and Chondrocytes. Int J Mol Sci 2023; 24:ijms24076730. [PMID: 37047701 PMCID: PMC10095444 DOI: 10.3390/ijms24076730] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2023] [Revised: 02/27/2023] [Accepted: 03/29/2023] [Indexed: 04/07/2023] Open
Abstract
Cartilage is an avascular tissue and sensitive to mechanical trauma and/or age-related degenerative processes leading to the development of osteoarthritis (OA). Therefore, it is important to investigate the mesenchymal cell-based chondrogenic regenerating mechanisms and possible their regulation. The aim of this study was to investigate the role of intracellular calcium (iCa2+) and its regulation through voltage-operated calcium channels (VOCC) on chondrogenic differentiation of mesenchymal stem/stromal cells derived from human bone marrow (BMMSCs) and menstrual blood (MenSCs) in comparison to OA chondrocytes. The level of iCa2+ was highest in chondrocytes, whereas iCa2+ store capacity was biggest in MenSCs and they proliferated better as compared to other cells. The level of CaV1.2 channels was also highest in OA chondrocytes than in other cells. CaV1.2 antagonist nifedipine slightly suppressed iCa2+, Cav1.2 and the proliferation of all cells and affected iCa2+ stores, particularly in BMMSCs. The expression of the CaV1.2 gene during 21 days of chondrogenic differentiation was highest in MenSCs, showing the weakest chondrogenic differentiation, which was stimulated by the nifedipine. The best chondrogenic differentiation potential showed BMMSCs (SOX9 and COL2A1 expression); however, purposeful iCa2+ and VOCC regulation by blockers can stimulate a chondrogenic response at least in MenSCs.
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Affiliation(s)
- Ilona Uzieliene
- Department of Regenerative Medicine, State Research Institute Centre for Innovative Medicine, 08406 Vilnius, Lithuania
| | - Daiva Bironaite
- Department of Regenerative Medicine, State Research Institute Centre for Innovative Medicine, 08406 Vilnius, Lithuania
| | - Rokas Miksiunas
- Department of Regenerative Medicine, State Research Institute Centre for Innovative Medicine, 08406 Vilnius, Lithuania
| | - Edvardas Bagdonas
- Department of Regenerative Medicine, State Research Institute Centre for Innovative Medicine, 08406 Vilnius, Lithuania
| | - Raminta Vaiciuleviciute
- Department of Regenerative Medicine, State Research Institute Centre for Innovative Medicine, 08406 Vilnius, Lithuania
| | - Ali Mobasheri
- Department of Regenerative Medicine, State Research Institute Centre for Innovative Medicine, 08406 Vilnius, Lithuania
- Research Unit of Health Sciences and Technology, Faculty of Medicine, University of Oulu, 90014 Oulu, Finland
- World Health Organization Collaborating Center for Public Health Aspects of Musculoskeletal Health and Aging, Université de Liège, B-4000 Liège, Belgium
- Department of Joint Surgery, First Affiliated Hospital of Sun Yat-sen University, Guangzhou 510080, China
| | - Eiva Bernotiene
- Department of Regenerative Medicine, State Research Institute Centre for Innovative Medicine, 08406 Vilnius, Lithuania
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Uzieliene I, Bernotiene E, Rakauskiene G, Denkovskij J, Bagdonas E, Mackiewicz Z, Porvaneckas N, Kvederas G, Mobasheri A. The Antihypertensive Drug Nifedipine Modulates the Metabolism of Chondrocytes and Human Bone Marrow-Derived Mesenchymal Stem Cells. Front Endocrinol (Lausanne) 2019; 10:756. [PMID: 31781032 PMCID: PMC6857108 DOI: 10.3389/fendo.2019.00756] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/12/2019] [Accepted: 10/18/2019] [Indexed: 11/30/2022] Open
Abstract
Aging is associated with the development of various chronic diseases, in which both cardiovascular disorders and osteoarthritis are dominant. Currently, there is no effective treatment for osteoarthritis, whereas hypertension is often treated with L-type voltage-operated calcium channel blocking drugs, nifedipine being among the most classical ones. Although nifedipine together with other L-type voltage-operated calcium channel inhibitors plays an important role in controlling hypertension, there are unresolved questions concerning its possible effect on cartilage tissue homeostasis and the development of osteoarthritis. The aim of this study was to analyse the effects of nifedipine on metabolic processes in human chondrocytes and bone marrow mesenchymal stem cells. To better understand whether the metabolic effects are mediated specifically through L-type voltage-operated calcium channel, effects of the agonist BayK8644 were analyzed in parallel. Nifedipine downregulated and mitochondrial respiration and ATP production in both cell types. Analysis of cartilage explants by electron microscopy also suggested that a small number of chondrocyte mitochondria's lose their activity in response to nifedipine. Conversely, nifedipine enhanced glycolytic capacity in chondrocytes, suggesting that these cells have the capacity to switch from oxidative phosphorylation to glycolysis and alter their metabolic activity in response to L-type voltage-operated calcium channel inhibition. Such a metabolic switch was not observed in bone marrow mesenchymal stem cells. Nitric oxide activity was upregulated by nifedipine in bone marrow mesenchymal stem cells and particularly in chondrocytes, implying its involvement in the effects of nifedipine on metabolism in both tested cell types. Furthermore, stimulation with nifedipine resulted in elevated production of collagen type II and glycosaminoglycans in micromass cultures under chondrogenic conditions. Taken together, we conclude that the antihypertensive drug nifedipine inhibits mitochondrial respiration in both chondrocytes and bone marrow mesenchymal stem cells and that these effects may be associated with the increased nitric oxide accumulation and pro-inflammatory activity. Nifedipine had positive effects on the production of collagen type II and proteoglycans in both cell types, implying potentially beneficial anabolic responses in articular cartilage. These results highlight a potential link between antihypertensive drugs and cartilage health.
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Affiliation(s)
- Ilona Uzieliene
- Department of Regenerative Medicine, State Research Institute Centre for Innovative Medicine, Vilnius, Lithuania
| | - Eiva Bernotiene
- Department of Regenerative Medicine, State Research Institute Centre for Innovative Medicine, Vilnius, Lithuania
| | - Greta Rakauskiene
- Department of Regenerative Medicine, State Research Institute Centre for Innovative Medicine, Vilnius, Lithuania
| | - Jaroslav Denkovskij
- Department of Regenerative Medicine, State Research Institute Centre for Innovative Medicine, Vilnius, Lithuania
| | - Edvardas Bagdonas
- Department of Regenerative Medicine, State Research Institute Centre for Innovative Medicine, Vilnius, Lithuania
| | - Zygmunt Mackiewicz
- Department of Regenerative Medicine, State Research Institute Centre for Innovative Medicine, Vilnius, Lithuania
| | | | | | - Ali Mobasheri
- Department of Regenerative Medicine, State Research Institute Centre for Innovative Medicine, Vilnius, Lithuania
- Research Unit of Medical Imaging, Physics and Technology, Faculty of Medicine, University of Oulu, Oulu, Finland
- Centre for Sport, Exercise and Osteoarthritis Research Versus Arthritis, Queen's Medical Centre, Nottingham, United Kingdom
- Sheik Salem Bin Mahfouz Scientific Chair for Treatment of Osteoarthritis With Stem Cells, King Abdulaziz University, Jeddah, Saudi Arabia
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McCarthy CJ, Marangos C, Fry CH, Ikeda Y. ATP transients accompany spontaneous contractions in isolated guinea-pig detrusor smooth muscle. Exp Physiol 2019; 104:1717-1725. [PMID: 31464344 DOI: 10.1113/ep087960] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2019] [Accepted: 08/21/2019] [Indexed: 11/08/2022]
Abstract
NEW FINDINGS What is the central question of this study? Overactive bladder is associated with enhanced spontaneous contractions, but their origins are unclear. The aim of this study was to characterize the accompanying ATP transients. What is the main finding and its importance? Spontaneous detrusor contractions were accompanied by transient increases of ATP, and their appearance was delayed by previous activation of efferent nerves to the detrusor. This indicates that spontaneous ATP release from nerve terminals supports spontaneous contractions. ATP is a functional excitatory neurotransmitter in human bladder only in pathologies such as overactive bladder. A potential drug target is revealed to manage this condition. ABSTRACT Spontaneous contractions are characteristic of the bladder wall, but their origins remain unclear. Activity is reduced if the mucosa is removed but does not disappear, suggesting that a fraction arises from the detrusor. We tested the hypothesis that spontaneous detrusor contractions arise from spontaneous ATP release. Guinea-pig detrusor strips, without mucosa, were superfused with Tyrode solution at 36°C. Preparations were subjected to electrical field stimulation (EFS; 3 s trains at 90 s intervals) to produce nerve-mediated contractions, abolished by 1 µm TTX. Amperometric ATP electrodes on the preparation surface recorded any ATP released. Spontaneous contractions and ATP transients were recorded between EFS trains. Nerve-mediated contractions were attenuated by atropine and α,β-methylene ATP; in combination, they nearly abolished contractions, as did nifedipine. Contractions were accompanied by ATP transients that were unaffected by atropine but inhibited by TTX and greatly attenuated by nifedipine. Spontaneous contractions were accompanied by ATP transients, with a close correlation between the magnitudes of both transients. ATP and contractile transients persisted with TTX, atropine and nifedipine. Immediately after a nerve-mediated contraction and ATP transient, there was a longer interval than normal before spontaneous activity resumed. Spontaneous contractions and ATP transients are proposed to arise from ATP leakage from nerve terminals innervating the detrusor. Extracellular ATP has a greater functional significance in humans who suffer from detrusor overactivity (spontaneous bladder contractions associated with incontinence) owing to its reduced hydrolysis at the nerve-muscle interface. This study shows the origin of spontaneous activity that might be exploited to develop a therapeutic management of this condition.
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Affiliation(s)
- Carly J McCarthy
- Instituto de Investigaciones en Medicina Traslacional (IIMT), Facultad de Ciencias Biomédicas, Austral University, Pilar Centro, Buenos Aires, Argentina
| | | | - Christopher H Fry
- School of Physiology, Pharmacology & Neuroscience, University of Bristol, Bristol, UK.,Institute of Child Health, University College London, London, UK
| | - Youko Ikeda
- Department of Medicine, University of Pittsburgh, Pittsburgh, PA, USA
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Attili S, Hughes SM. Anaesthetic tricaine acts preferentially on neural voltage-gated sodium channels and fails to block directly evoked muscle contraction. PLoS One 2014; 9:e103751. [PMID: 25090007 PMCID: PMC4121177 DOI: 10.1371/journal.pone.0103751] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2014] [Accepted: 06/30/2014] [Indexed: 12/15/2022] Open
Abstract
Movements in animals arise through concerted action of neurons and skeletal muscle. General anaesthetics prevent movement and cause loss of consciousness by blocking neural function. Anaesthetics of the amino amide-class are thought to act by blockade of voltage-gated sodium channels. In fish, the commonly used anaesthetic tricaine methanesulphonate, also known as 3-aminobenzoic acid ethyl ester, metacaine or MS-222, causes loss of consciousness. However, its role in blocking action potentials in distinct excitable cells is unclear, raising the possibility that tricaine could act as a neuromuscular blocking agent directly causing paralysis. Here we use evoked electrical stimulation to show that tricaine efficiently blocks neural action potentials, but does not prevent directly evoked muscle contraction. Nifedipine-sensitive L-type Cav channels affecting movement are also primarily neural, suggesting that muscle Nav channels are relatively insensitive to tricaine. These findings show that tricaine used at standard concentrations in zebrafish larvae does not paralyse muscle, thereby diminishing concern that a direct action on muscle could mask a lack of general anaesthesia.
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Affiliation(s)
- Seetharamaiah Attili
- Randall Division of Cell and Molecular Biophysics, Guy's Campus, King's College London, London, United Kingdom
| | - Simon M. Hughes
- Randall Division of Cell and Molecular Biophysics, Guy's Campus, King's College London, London, United Kingdom
- * E-mail:
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McPartland JM, Simons DG. Myofascial Trigger Points: Translating Molecular Theory into Manual Therapy. J Man Manip Ther 2013. [DOI: 10.1179/106698106790819982] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
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Balezina OP, Bogacheva PO. Suppression of mediator secretion in murine neogenic motor synapses with the participation of L-type Ca2+-channels and ryanodine receptors. BIOL BULL+ 2009. [DOI: 10.1134/s1062359009050112] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Pinato G, Pegoraro S, Iacono G, Ruaro ME, Torre V. Calcium control of gene regulation in rat hippocampal neuronal cultures. J Cell Physiol 2009; 220:727-47. [PMID: 19441076 DOI: 10.1002/jcp.21820] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Blockage of GABA-A receptors in hippocampal neuronal cultures triggers synchronous bursts of spikes initiating neuronal plasticity, partly mediated by changes of gene expression. By using specific pharmacological blockers, we have investigated which sources of Ca2+ entry primarily control changes of gene expression induced by 20 microM gabazine applied for 30 min (GabT). Intracellular Ca2+ transients were monitored with Ca2+ imaging while recording electrical activity with patch clamp microelectrodes. Concomitant transcription profiles were obtained using Affymetrix oligonucleotide microarrays and confirmed with quantitative RT-PCR. Blockage of NMDA receptors with 2-amino-5-phosphonovaleric acid (APV) did not reduce significantly somatic Ca2+ transients, which, on the contrary, were reduced by selective blockage of L, N, and P/Q types voltage gated calcium channels (VGCCs). Therefore, we investigated changes of gene expression in the presence of blockers of NMDA receptors and L, N, and P/Q VGCCs. Our results show that: (i) among genes upregulated by GabT, there are genes selectively dependent on NMDA activation, genes selectively dependent on L-type VGCCs and genes dependent on the activation of both channels; (ii) the majority of genes requires the concomitant activation of NMDA receptors and Ca2+ entry through VGCCs; (iii) blockage of N and P/Q VGCCs has an effect similar but not identical to blockage of L-type VGCCs.
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Copello JA, Zima AV, Diaz-Sylvester PL, Fill M, Blatter LA. Ca2+ entry-independent effects of L-type Ca2+ channel modulators on Ca2+ sparks in ventricular myocytes. Am J Physiol Cell Physiol 2007; 292:C2129-40. [PMID: 17314267 PMCID: PMC2094215 DOI: 10.1152/ajpcell.00437.2006] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
During the cardiac action potential, Ca(2+) entry through dyhidropyridine receptor L-type Ca(2+) channels (DHPRs) activates ryanodine receptors (RyRs) Ca(2+)-release channels, resulting in massive Ca(2+) mobilization from the sarcoplasmic reticulum (SR). This global Ca(2+) release arises from spatiotemporal summation of many localized elementary Ca(2+)-release events, Ca(2+) sparks. We tested whether DHPRs modulate Ca(2+)sparks in a Ca(2+) entry-independent manner. Negative modulation by DHPR of RyRs via physical interactions is accepted in resting skeletal muscle but remains controversial in the heart. Ca(2+) sparks were studied in cat cardiac myocytes permeabilized with saponin or internally perfused via a patch pipette. Bathing and pipette solutions contained low Ca(2+) (100 nM). Under these conditions, Ca(2+) sparks were detected with a stable frequency of 3-5 sparks.s(-1).100 microm(-1). The DHPR blockers nifedipine, nimodipine, FS-2, and calciseptine decreased spark frequency, whereas the DHPR agonists Bay-K8644 and FPL-64176 increased it. None of these agents altered the spatiotemporal characteristics of Ca(2+) sparks. The DHPR modulators were also without effect on SR Ca(2+) load (caffeine-induced Ca(2+) transients) or sarco(endo)plasmic reticulum Ca(2+)-ATPase (SERCA) activity (Ca(2+) loading rates of isolated SR microsomes) and did not change cardiac RyR channel gating (planar lipid bilayer experiments). In summary, DHPR modulators affected spark frequency in the absence of DHPR-mediated Ca(2+) entry. This action could not be attributed to a direct action of DHPR modulators on SERCA or RyRs. Our results suggest that the activity of RyR Ca(2+)-release units in ventricular myocytes is modulated by Ca(2+) entry-independent conformational changes in neighboring DHPRs.
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Affiliation(s)
- Julio A Copello
- Dept. of Pharmacology, Southern Illinois University School of Medicine, Springfield, IL 62794-9629, USA.
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De Lorenzo S, Veggetti M, Muchnik S, Losavio A. Presynaptic inhibition of spontaneous acetylcholine release mediated by P2Y receptors at the mouse neuromuscular junction. Neuroscience 2006; 142:71-85. [PMID: 16843602 DOI: 10.1016/j.neuroscience.2006.05.062] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2006] [Revised: 05/15/2006] [Accepted: 05/29/2006] [Indexed: 11/20/2022]
Abstract
At the neuromuscular junction, ATP is co-released with the neurotransmitter acetylcholine (ACh) and once in the synaptic space, it is degraded to the presynaptically active metabolite adenosine. Intracellular recordings were performed on diaphragm fibers of CF1 mice to determine the action of extracellular ATP (100 muM) and the slowly hydrolysable ATP analog 5'-adenylylimidodiphosphate lithium (betagamma-imido ATP) (30 muM) on miniature end-plate potential (MEPP) frequency. We found that application of ATP and betagamma-imido ATP decreased spontaneous secretion by 45.3% and 55.9% respectively. 8-Cyclopentyl-1,3-dipropylxanthine (DPCPX), a selective A(1) adenosine receptor antagonist and alpha,beta-methylene ADP sodium salt (alphabeta-MeADP), which is an inhibitor of ecto-5'-nucleotidase, did not prevent the inhibitory effect of ATP, demonstrating that the nucleotide is able to modulate spontaneous ACh release through a mechanism independent of the action of adenosine. Blockade of Ca(2+) channels by both, Cd(2+) or the combined application of nitrendipine and omega-conotoxin GVIA (omega-CgTx) (L-type and N-type Ca(2+) channel antagonists, respectively) prevented the effect of betagamma-imido ATP, indicating that the nucleotide modulates Ca(2+) influx through the voltage-dependent Ca(2+) channels related to spontaneous secretion. betagamma-Imido ATP-induced modulation was antagonized by the non-specific P2 receptor antagonist suramin and the P2Y receptor antagonist 1-amino-4-[[4-[[4-chloro-6-[[3(or4)-sulfophenyl] amino]-1,3,5-triazin-2-yl]amino]-3-sulfophenyl] amino]-9,10-dihydro-9,10-dioxo-2-anthracenesulfonic acid (reactive blue-2), but not by pyridoxal phosphate-6-azo(benzene-2,4-disulfonic acid) tetrasodium salt (PPADS), which has a preferential antagonist effect on P2X receptors. Pertussis toxin and N-ethylmaleimide (NEM), which are blockers of G(i/o) proteins, prevented the action of the nucleotide, suggesting that the effect is mediated by P2Y receptors coupled to G(i/o) proteins. The protein kinase C (PKC) antagonist chelerythrine and the calmodulin antagonist N-(6-aminohexil)-5-chloro-1-naphthalenesulfonamide hydrochloride (W-7) occluded the effect of betagamma-imido ATP, while the protein kinase A (PKA) antagonist KT-5720 and the inhibitor of the calcium/calmodulin-dependent protein kinase II (CAMKII) KN-62 failed to do so. betagamma-Imido ATP did not affect 10, 15 and 20 mM K(+)-evoked release and application of reactive blue-2 before incubation in high K(+) induced a higher asynchronous secretion. Thus, our results show that at mammalian neuromuscular junctions, ATP induces presynaptic inhibition of spontaneous ACh release due to the modulation of Ca(2+) channels related to tonic secretion through the activation of P2Y receptors coupled to G(i/o) proteins. We also demonstrated that at increasing degrees of membrane depolarization evoked by K(+), endogenously released ATP induces presynaptic inhibition as a means of preventing excessive neurotransmitter secretion.
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Affiliation(s)
- S De Lorenzo
- Instituto de Investigaciones Médicas Alfredo Lanari, Facultad de Medicina, Universidad de Buenos Aires, Combatientes de Malvinas 3150, 1427 Buenos Aires, Argentina
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Giuliani D, Giaroni C, Zanetti E, Canciani L, Borroni P, Lecchini S, Frigo G. Involvement of glutamate receptors of the NMDA type in the modulation of acetylcholine and glutamate overflow from the guinea pig ileum during in vitro hypoxia and hypoglycaemia. Neurochem Int 2006; 48:191-200. [PMID: 16290263 DOI: 10.1016/j.neuint.2005.10.005] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2005] [Accepted: 10/05/2005] [Indexed: 01/14/2023]
Abstract
The involvement of NMDA glutamate receptors in the effects of glucose/oxygen deprivation (in vitro ischaemia) on spontaneous endogenous acetylcholine and glutamate overflow from the guinea pig ileum was studied. Neurotransmitter overflow was measured by HPLC. Deprivation of glucose in the medium slightly reduced acetylcholine overflow, and did not significantly influence glutamate overflow. During oxygen deprivation and glucose/oxygen deprivation, acetylcholine overflow augmented with a biphasic modality: an early peak was followed by a long lasting increase, whereas glutamate overflow increased with a rapid and sustained modality. The effects of glucose/oxygen deprivation on both acetylcholine and glutamate overflow were abolished after reperfusion with normal oxygenated medium. Acetylcholine and glutamate overflow induced by glucose/oxygen deprivation were significantly reduced in the absence of external Ca(2+) as well as by the addition of the mitochondrial Na(+)-Ca(2+) exchanger blocker, CGP 37157, and of the endoplasmic reticulum Ca(2+)/ATPase blocker, thapsigargin. +/-AP5, an NMDA receptor antagonist, and 5,7-diCl-kynurenic acid, an antagonist of the glycine site associated to NMDA receptor, markedly depressed glucose/oxygen deprivation-induced acetylcholine and glutamate overflow as well. Our results suggest that in vitro simulated ischaemia evokes acetylcholine and glutamate overflow from the guinea pig ileum, which is partly linked to an increase in intracellular Ca(2+) concentration dependent on both Ca(2+) influx from the extracellular space and Ca(2+) mobilization from the endoplasmic reticulum and mitochondrial stores. During glucose/oxygen deprivation, ionotropic glutamate receptors of the NMDA type exert both a positive feedback modulation of glutamate output and contribute to increased acetylcholine overflow.
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Affiliation(s)
- Daniela Giuliani
- Clinical and Applied Pharmacology Centre, University of Insubria and University of Pavia, via O. Rossi 9, I-21100 Varese, Italy
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Verkhratsky A. Physiology and Pathophysiology of the Calcium Store in the Endoplasmic Reticulum of Neurons. Physiol Rev 2005; 85:201-79. [PMID: 15618481 DOI: 10.1152/physrev.00004.2004] [Citation(s) in RCA: 560] [Impact Index Per Article: 29.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
The endoplasmic reticulum (ER) is the largest single intracellular organelle, which is present in all types of nerve cells. The ER is an interconnected, internally continuous system of tubules and cisterns, which extends from the nuclear envelope to axons and presynaptic terminals, as well as to dendrites and dendritic spines. Ca2+release channels and Ca2+pumps residing in the ER membrane provide for its excitability. Regulated ER Ca2+release controls many neuronal functions, from plasmalemmal excitability to synaptic plasticity. Enzymatic cascades dependent on the Ca2+concentration in the ER lumen integrate rapid Ca2+signaling with long-lasting adaptive responses through modifications in protein synthesis and processing. Disruptions of ER Ca2+homeostasis are critically involved in various forms of neuropathology.
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Affiliation(s)
- Alexei Verkhratsky
- The University of Manchester, Faculty of Biological Sciences, United Kingdom.
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