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Dos Santos TM, Righetti RF, do Nascimento Camargo L, Leick EA, Fukuzaki S, de Campos EC, Galli TT, Saraiva-Romanholo BM, da Silva LLS, Barbosa JAS, João JMLG, Prado CM, de Rezende BG, Bourotte CLM, Dos Lopes FDTQS, Martins MA, Bensenor IM, de Oliveira Cirillo JV, Bezerra SKM, Silva FJA, Paulo MSL, Lotufo PA, Tibério IFLC. Effect of VAChT reduction on lung alterations induced by exposure to iron particles in an asthma model. J Inflamm (Lond) 2024; 21:24. [PMID: 38961398 PMCID: PMC11223391 DOI: 10.1186/s12950-024-00399-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2024] [Accepted: 06/21/2024] [Indexed: 07/05/2024] Open
Abstract
INTRODUCTION Pollution harms the health of people with asthma. The effect of the anti-inflammatory cholinergic pathway in chronic allergic inflammation associated to pollution is poorly understood. METHODS One hundred eight animals were divided into 18 groups (6 animals). Groups included: wild type mice (WT), genetically modified with reduced VAChT (VAChTKD), and those sensitized with ovalbumin (VAChTKDA), exposed to metal powder due to iron pelletizing in mining company (Local1) or 3.21 miles away from a mining company (Local2) in their locations for 2 weeks during summer and winter seasons. It was analyzed for hyperresponsivity, inflammation, remodeling, oxidative stress responses and the cholinergic system. RESULTS During summer, animals without changes in the cholinergic system revealed that Local1 exposure increased the hyperresponsiveness (%Rrs, %Raw), and inflammation (IL-17) relative to vivarium animals, while animals exposed to Local2 also exhibited elevated IL-17. During winter, animals without changes in the cholinergic system revealed that Local2 exposure increased the hyperresponsiveness (%Rrs) relative to vivarium animals. Comparing the exposure local of these animals during summer, animals exposed to Local1 showed elevated %Rrs, Raw, and IL-5 compared to Local 2, while in winter, Local2 exposure led to more IL-17 than Local1. Animals with VAChT attenuation displayed increased %Rrs, NFkappaB, IL-5, and IL-13 but reduced alpha-7 compared to animals without changes in the cholinergic system WT. Animals with VAChT attenuation and asthma showed increased the hyperresponsiveness, all inflammatory markers, remodeling and oxidative stress compared to animals without chronic lung inflammation. Exposure to Local1 exacerbated the hyperresponsiveness, oxidative stressand inflammation in animals with VAChT attenuation associated asthma, while Local2 exposure led to increased inflammation, remodeling and oxidative stress. CONCLUSIONS Reduced cholinergic signaling amplifies lung inflammation in a model of chronic allergic lung inflammation. Furthermore, when associated with pollution, it can aggravate specific responses related to inflammation, oxidative stress, and remodeling.
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Affiliation(s)
- Tabata Maruyama Dos Santos
- Faculdade de Medicina FMUSP, Universidade de Sao Paulo, São Paulo, SP, Brazil.
- Hospital Sírio Libanês, São Paulo, SP, Brazil.
| | - Renato Fraga Righetti
- Faculdade de Medicina FMUSP, Universidade de Sao Paulo, São Paulo, SP, Brazil
- Hospital Sírio Libanês, São Paulo, SP, Brazil
| | - Leandro do Nascimento Camargo
- Faculdade de Medicina FMUSP, Universidade de Sao Paulo, São Paulo, SP, Brazil
- Hospital Sírio Libanês, São Paulo, SP, Brazil
| | | | - Silvia Fukuzaki
- Faculdade de Medicina FMUSP, Universidade de Sao Paulo, São Paulo, SP, Brazil
- Hospital Alemão Oswaldo Cruz, São Paulo, Brazil
| | - Elaine Cristina de Campos
- Faculdade de Medicina FMUSP, Universidade de Sao Paulo, São Paulo, SP, Brazil
- Hospital Sírio Libanês, São Paulo, SP, Brazil
| | | | | | | | | | | | - Carla Máximo Prado
- Department of Biosciences, Universidade Federal de São Paulo, Santos, Brazil
| | | | | | | | | | - Isabela M Bensenor
- Faculdade de Medicina FMUSP, Universidade de Sao Paulo, São Paulo, SP, Brazil
| | | | | | | | | | - Paulo A Lotufo
- Faculdade de Medicina FMUSP, Universidade de Sao Paulo, São Paulo, SP, Brazil
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2
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Continuous cholinergic-dopaminergic updating in the nucleus accumbens underlies approaches to reward-predicting cues. Nat Commun 2022; 13:7924. [PMID: 36564387 PMCID: PMC9789106 DOI: 10.1038/s41467-022-35601-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2022] [Accepted: 12/13/2022] [Indexed: 12/25/2022] Open
Abstract
The ability to learn Pavlovian associations from environmental cues predicting positive outcomes is critical for survival, motivating adaptive behaviours. This cued-motivated behaviour depends on the nucleus accumbens (NAc). NAc output activity mediated by spiny projecting neurons (SPNs) is regulated by dopamine, but also by cholinergic interneurons (CINs), which can release acetylcholine and glutamate via the activity of the vesicular acetylcholine transporter (VAChT) or the vesicular glutamate transporter (VGLUT3), respectively. Here we investigated behavioural and neurochemical changes in mice performing a touchscreen Pavlovian approach task by recording dopamine, acetylcholine, and calcium dynamics from D1- and D2-SPNs using fibre photometry in control, VAChT or VGLUT3 mutant mice to understand how these signals cooperate in the service of approach behaviours toward reward-predicting cues. We reveal that NAc acetylcholine-dopaminergic signalling is continuously updated to regulate striatal output underlying the acquisition of Pavlovian approach learning toward reward-predicting cues.
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3
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Characterization of social behavior in young and middle-aged ChAT-IRES-Cre mouse. PLoS One 2022; 17:e0272141. [PMID: 35925937 PMCID: PMC9352053 DOI: 10.1371/journal.pone.0272141] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2022] [Accepted: 07/13/2022] [Indexed: 11/19/2022] Open
Abstract
The cholinergic system is an important modulator of brain processes. It contributes to the regulation of several cognitive functions and emotional states, hence altering behaviors. Previous works showed that cholinergic (nicotinic) receptors of the prefrontal cortex are needed for adapted social behaviors. However, these data were obtained in mutant mice that also present alterations of several neurotransmitter systems, in addition to the cholinergic system. ChAT-IRES-Cre mice, that express the Cre recombinase specifically in cholinergic neurons, are useful tools to investigate the role of the cholinergic circuits in behavior. However, their own behavioral phenotype has not yet been fully characterized, in particular social behavior. In addition, the consequences of aging on the cholinergic system of ChAT-IRES-Cre mice has never been studied, despite the fact that aging is known to compromise the cholinergic system efficiency. The aim of the current study was thus to characterize the social phenotype of ChAT-IRES-Cre mice both at young (2–3 months) and middle (10–11 months) ages. Our results reveal an alteration of the cholinergic system, evidenced by a decrease of ChAT, CHT and VAChT gene expression in the striatum of the mice, that was accompanied by mild social disturbances and a tendency towards anxiety. Aging decreased social dominance, without being amplified by the cholinergic alterations. Altogether, this study shows that ChAT-IRES-Cre mice are useful models for studying the cholinergic system‘s role in social behavior using appropriate modulating technics (optogenetic or DREADD).
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4
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González Sanabria J, Hurtado Paso M, Frontera T, Losavio A. Effect of endogenous purines on electrically evoked ACh release at the mouse neuromuscular junction. J Neurosci Res 2022; 100:1933-1950. [PMID: 35839285 DOI: 10.1002/jnr.25107] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Revised: 06/22/2022] [Accepted: 07/04/2022] [Indexed: 11/11/2022]
Abstract
At the mouse neuromuscular junction, adenosine triphosphate (ATP), which is co-released with the neurotransmitter acetylcholine (ACh), and its metabolite adenosine, modulate neurotransmitter release by activating presynaptic inhibitory P2Y13 receptors (a subtype of ATP/adenosine diphosphate [ADP] receptor), inhibitory A1 and A3 adenosine receptors, and excitatory A2A adenosine receptors. To study the effect of endogenous purines, when phrenic-diaphragm preparations are depolarized by different nerve stimulation patterns, we analyzed the effect of the antagonists for P2Y13 , A1 , A3 , and A2A receptors (AR-C69931MX, 8-cyclopentyl-1,3-dipropylxanthine, MRS-1191, and SCH-58261, respectively) on the amplitude of the end-plate potentials of the trains, and contrasted these results with those obtained with the selective agonists of these receptors (2-methylthioadenosine 5'-diphosphate trisodium salt hydrate, 2-chloro-N6 -cyclopentyl-adenosine, inosine, and PSB-0777, respectively). During continuous 0.5-Hz stimulation, the amount of endogenous purines was not enough to activate purinergic receptors, while at continuous 5-Hz stimulation, an incipient action of endogenous purines on P2Y13 , A1 and A3 receptors might be evident just at the end of the trains. During continuous 50-Hz stimulation, the concentration of endogenous ATP/ADP and adenosine exerted an inhibitory action on ACh release after of the initial phase of the train, but when the nerve was stimulated at intermittent 50 Hz (5 bursts), this behavior was not observed. Excitatory A2A receptors were only activated when continuous 100-Hz stimulation was applied. In conclusion, when motor nerve terminals are depolarized by repetitive stimulation of the phrenic nerve, endogenous ATP/ADP and adenosine are able to fine-tune neurosecretion depending on the frequency and pattern of stimulation.
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Affiliation(s)
- Javier González Sanabria
- Laboratorio de Neurofisiología, Instituto de Investigaciones Médicas Alfredo Lanari - Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Universidad de Buenos Aires (UBA), Ciudad Autónoma de Buenos Aires, Argentina
| | - Maximiliano Hurtado Paso
- Laboratorio de Neurofisiología, Instituto de Investigaciones Médicas Alfredo Lanari - Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Universidad de Buenos Aires (UBA), Ciudad Autónoma de Buenos Aires, Argentina
| | - Tamara Frontera
- Laboratorio de Neurofisiología, Instituto de Investigaciones Médicas Alfredo Lanari - Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Universidad de Buenos Aires (UBA), Ciudad Autónoma de Buenos Aires, Argentina
| | - Adriana Losavio
- Laboratorio de Neurofisiología, Instituto de Investigaciones Médicas Alfredo Lanari - Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Universidad de Buenos Aires (UBA), Ciudad Autónoma de Buenos Aires, Argentina
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5
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Suehiro CL, Souza NTS, da Silva EB, Cruz MM, Laia RM, de Oliveira Santos S, Santana-Novelli FPR, de Castro TBP, Lopes FD, Pinheiro NM, de FátimaLopes Calvo Tibério I, Olivo CR, Alonso-Vale MI, Prado MAM, Prado VF, de Toledo-Arruda AC, Prado CM. Aerobic exercise training engages cholinergic signaling to improve emphysema induced by cigarette smoke exposure in mice. Life Sci 2022; 301:120599. [DOI: 10.1016/j.lfs.2022.120599] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Revised: 04/16/2022] [Accepted: 04/26/2022] [Indexed: 11/25/2022]
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6
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Camargo WL, Kushmerick C, Pinto E, Souza N, Cavalcante W, Souza-Neto FP, Guatimosim S, Prado M, Guatimosim C, Naves LA. Homeostatic plasticity induced by increased acetylcholine release at the mouse neuromuscular junction. Neurobiol Aging 2021; 110:13-26. [PMID: 34844076 DOI: 10.1016/j.neurobiolaging.2021.10.010] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Revised: 10/21/2021] [Accepted: 10/22/2021] [Indexed: 02/07/2023]
Abstract
At the neuromuscular junction (NMJ), changes to the size of the postsynaptic potential induce homeostatic compensation. At the Drosophila NMJ, increased glutamate release causes a compensatory decrease in quantal content, but it is unknown if this mechanism operates at the cholinergic mammalian NMJ. We addressed this question by recording endplate potentials (EPP) and muscle contraction in 3-month and 24-month ChAT-ChR2-EYFP mice that overexpress vesicular acetylcholine transporter and release more acetylcholine per vesicle. At 3 months, the quantal content of EPPs from ChAT-ChR2-EYFP mice were not different from WT controls, however tetanic depression was greater, and quantal size during high-frequency stimulation and the size of the readily releasable pool (RRP) were decreased. At 24 months of age, quantal content was reduced in ChAT-ChR2-EYFP mice, which normalized synaptic depression despite smaller RRP. The effect of pancuronium on indirect evoked muscle twitch was not different between groups. These results indicate that an increase in the amount of acetylcholine per vesicle induces two distinct age-dependent homeostatic mechanisms compensating excessive acetylcholine release.
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Affiliation(s)
| | | | | | | | | | | | | | - Mam Prado
- Robarts Research Institute and Department of Physiology and Pharmacology and Anatomy & Cell Biology, University of Western Ontario, London, ON, Canada
| | | | - L A Naves
- Departments of Physiology and biophysics
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7
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Long-term endogenous acetylcholine deficiency potentiates pulmonary inflammation in a murine model of elastase-induced emphysema. Sci Rep 2021; 11:15918. [PMID: 34354132 PMCID: PMC8342425 DOI: 10.1038/s41598-021-95211-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Accepted: 07/19/2021] [Indexed: 02/07/2023] Open
Abstract
Acetylcholine (ACh), the neurotransmitter of the cholinergic system, regulates inflammation in several diseases including pulmonary diseases. ACh is also involved in a non-neuronal mechanism that modulates the innate immune response. Because inflammation and release of pro-inflammatory cytokines are involved in pulmonary emphysema, we hypothesized that vesicular acetylcholine transport protein (VAChT) deficiency, which leads to reduction in ACh release, can modulate lung inflammation in an experimental model of emphysema. Mice with genetical reduced expression of VAChT (VAChT KDHOM 70%) and wild-type mice (WT) received nasal instillation of 50 uL of porcine pancreatic elastase (PPE) or saline on day 0. Twenty-eight days after, animals were evaluated. Elastase instilled VAChT KDHOM mice presented an increase in macrophages, lymphocytes, and neutrophils in bronchoalveolar lavage fluid and MAC2-positive macrophages in lung tissue and peribronchovascular area that was comparable to that observed in WT mice. Conversely, elastase instilled VAChT KDHOM mice showed significantly larger number of NF-κB-positive cells and isoprostane staining in the peribronchovascular area when compared to elastase-instilled WT-mice. Moreover, elastase-instilled VAChT-deficient mice showed increased MCP-1 levels in the lungs. Other cytokines, extracellular matrix remodeling, alveolar enlargement, and lung function were not worse in elastase-instilled VAChT deficiency than in elastase-instilled WT-controls. These data suggest that decreased VAChT expression may contribute to the pathogenesis of emphysema, at least in part, through NF-κB activation, MCP-1, and oxidative stress pathways. This study highlights novel pathways involved in lung inflammation that may contribute to the development of chronic obstrutive lung disease (COPD) in cholinergic deficient individuals such as Alzheimer's disease patients.
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8
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Kljakic O, Al-Onaizi M, Janíčková H, Chen KS, Guzman MS, Prado MAM, Prado VF. Cholinergic transmission from the basal forebrain modulates social memory in male mice. Eur J Neurosci 2021; 54:6075-6092. [PMID: 34308559 DOI: 10.1111/ejn.15400] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2020] [Revised: 07/06/2021] [Accepted: 07/21/2021] [Indexed: 01/02/2023]
Abstract
Disruptions in social behaviour are prevalent in many neuropsychiatric disorders such as schizophrenia, bipolar disorder and autism spectrum disorders. However, the underlying neurochemical regulation of social behaviour is still not well understood. The central cholinergic system has been proposed to contribute to the regulation of social behaviour. For instance, decreased global levels of acetylcholine release in the brain leads to decreased social interaction and an impairment of social memory in mice. Nonetheless, it has been difficult to ascertain the specific brain areas where cholinergic signalling influences social preference and social memory. In this study, we investigated the impact of different forebrain cholinergic regions on social behaviour by examining mouse lines that differ in their regional expression level of the vesicular acetylcholine transporter-the protein that regulates acetylcholine secretion. We found that when cholinergic signalling is highly disrupted in the striatum, hippocampus, cortex and amygdala mice have intact social preference but are impaired in social memory, as they cannot remember a familiar conspecific nor recognize a novel one. A similar pattern emerges when acetylcholine release is disrupted mainly in the striatum, cortex, and amygdala; however, the ability to recognize novel conspecifics is retained. In contrast, cholinergic signalling of the striatum and amygdala does not appear to significantly contribute to the modulation of social memory and social preference. Furthermore, we demonstrated that increasing global cholinergic tone does not increase social behaviours. Together, these data suggest that cholinergic transmission from the hippocampus and cortex are important for regulating social memory.
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Affiliation(s)
- Ornela Kljakic
- Robarts Research Institute, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Ontario, Canada.,Department of Anatomy and Cell Biology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Ontario, Canada
| | - Mohammed Al-Onaizi
- Robarts Research Institute, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Ontario, Canada.,Department of Anatomy and Cell Biology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Ontario, Canada.,Department of Anatomy, Faculty of Medicine, Kuwait University, Kuwait City, Kuwait
| | - Helena Janíčková
- Robarts Research Institute, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Ontario, Canada.,Department of Neurochemistry, Institute of Physiology, Czech Academy of Sciences, Prague, Czech Republic
| | - Kevin S Chen
- Robarts Research Institute, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Ontario, Canada
| | - Monica S Guzman
- Robarts Research Institute, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Ontario, Canada.,Toronto General Hospital Research Institute, University Health Network, Toronto, Ontario, Canada
| | - Marco A M Prado
- Robarts Research Institute, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Ontario, Canada.,Department of Anatomy and Cell Biology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Ontario, Canada.,Department of Physiology and Pharmacology, Schulich School of Medicine & Dentistry, University of Western Ontario, London, Ontario, Canada
| | - Vania F Prado
- Robarts Research Institute, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Ontario, Canada.,Department of Anatomy and Cell Biology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Ontario, Canada.,Department of Physiology and Pharmacology, Schulich School of Medicine & Dentistry, University of Western Ontario, London, Ontario, Canada
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9
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Pinheiro NM, Banzato R, Tibério I, Prado MAM, Prado VF, Hamouda AK, Prado CM. Acute Lung Injury in Cholinergic-Deficient Mice Supports Anti-Inflammatory Role of α7 Nicotinic Acetylcholine Receptor. Int J Mol Sci 2021; 22:ijms22147552. [PMID: 34299169 PMCID: PMC8303767 DOI: 10.3390/ijms22147552] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Revised: 07/05/2021] [Accepted: 07/07/2021] [Indexed: 11/16/2022] Open
Abstract
(1) Background: The lung cholinergic pathway is important for controlling pulmonary inflammation in acute lung injury, a condition that is characterized by a sudden onset and intense inflammation. This study investigated changes in the expression levels of nicotinic and muscarinic acetylcholine receptors (nAChR and mAChR) in the lung during acute lung injury. (2) Methods: acute lung injury (ALI) was induced in wild-type and cholinergic-deficient (VAChT-KDHOM) mice using intratracheal lipopolysaccharide (LPS) instillation with or without concurrent treatment with nicotinic ligands. Bronchoalveolar lavage fluid was collected to evaluate markers of inflammation, and then the lung was removed and processed for isolation of membrane fraction and determination of acetylcholine receptors level using radioligand binding assays. (3) Results: LPS-induced increase in lung inflammatory markers (e.g., neutrophils and IL-1β) was significantly higher in VAChT-KDHOM than wild-type mice. In contrast, LPS treatment resulted in a significant increase in lung’s α7 nicotinic receptor level in wild-type, but not in VAChT-KDHOM mice. However, treatment with PNU 282987, a selective α7 nicotinic receptor agonist, restored VAChT-KDHOM mice’s ability to increase α7 nicotinic receptor levels in response to LPS-induced acute lung injury and reduced lung inflammation. LPS also increased muscarinic receptors level in VAChT-KDHOM mice, and PNU 282987 treatment reduced this response. (4) Conclusions: Our data indicate that the anti-inflammatory effects of the lung cholinergic system involve an increase in the level of α7 nicotinic receptors. Pharmacological agents that increase the expression or the function of lung α7 nicotinic receptors have potential clinical uses for treating acute lung injury.
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Affiliation(s)
- Nathalia M. Pinheiro
- Department of Bioscience, Federal University of Sao Paulo, Santos 11015-020, SP, Brazil;
- College of Pharmacy, University of Texas at Tyler, Tyler, TX 75799, USA;
| | - Rosana Banzato
- Department of Medicine, School of Medicine, University of Sao Paulo, Sao Paulo 01246-903, SP, Brazil; (R.B.); (I.T.); (V.F.P.)
| | - Iolanda Tibério
- Department of Medicine, School of Medicine, University of Sao Paulo, Sao Paulo 01246-903, SP, Brazil; (R.B.); (I.T.); (V.F.P.)
| | - Marco A. M. Prado
- Molecular Medicine Group, Robarts Research Institute, London, ON N6A 5B7, Canada;
- Department of Physiology & Pharmacology, University of Western Ontario, London, ON N6A 5B7, Canada
- Department of Anatomy & Cell Biology, University of Western Ontario, London, ON N6A 5B7, Canada
| | - Vânia F. Prado
- Department of Medicine, School of Medicine, University of Sao Paulo, Sao Paulo 01246-903, SP, Brazil; (R.B.); (I.T.); (V.F.P.)
- Molecular Medicine Group, Robarts Research Institute, London, ON N6A 5B7, Canada;
| | - Ayman K. Hamouda
- College of Pharmacy, University of Texas at Tyler, Tyler, TX 75799, USA;
| | - Carla M. Prado
- Department of Bioscience, Federal University of Sao Paulo, Santos 11015-020, SP, Brazil;
- Correspondence: ; Tel.: +55-13-3229-0118
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10
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Joviano-Santos JV, Kljakic O, Magalhães-Gomes MPS, Valadão PAC, de Oliveira LR, Prado MAM, Prado VF, Guatimosim C. Motoneuron-specific loss of VAChT mimics neuromuscular defects seen in congenital myasthenic syndrome. FEBS J 2021; 288:5331-5349. [PMID: 33730374 DOI: 10.1111/febs.15825] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Revised: 03/03/2021] [Accepted: 03/16/2021] [Indexed: 11/28/2022]
Abstract
Motoneurons (MNs) control muscle activity by releasing the neurotransmitter acetylcholine (ACh) at the level of neuromuscular junctions. ACh is packaged into synaptic vesicles by the vesicular ACh transporter (VAChT), and disruptions in its release can impair muscle contraction, as seen in congenital myasthenic syndromes (CMS). Recently, VAChT gene mutations were identified in humans displaying varying degrees of myasthenia. Moreover, mice with a global deficiency in VAChT expression display several characteristics of CMS. Despite these findings, little is known about how a long-term decrease in VAChT expression in vivo affects MNs structure and function. Using Cre-loxP technology, we generated a mouse model where VAChT is deleted in select groups of MNs (mnVAChT-KD). Molecular analysis revealed that the VAChT deletion was specific to MNs and affected approximately 50% of its population in the brainstem and spinal cord, with alpha-MNs primarily targeted (70% in spinal cord). Within each animal, the cell body area of VAChT-deleted MNs was significantly smaller compared to MNs with VAChT preserved. Likewise, muscles innervated by VAChT-deleted MNs showed atrophy while muscles innervated by VAChT-containing neurons appeared normal. In addition, mnVAChT KD mice had decreased muscle strength, were hypoactive, leaner and exhibited kyphosis. This neuromuscular dysfunction was evident at 2 months of age and became progressively worse by 6 months. Treatment of mutants with a cholinesterase inhibitor was able to improve some of the motor deficits. As these observations mimic what is seen in CMS, this new line could be valuable for assessing the efficacy of potential CMS drugs.
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Affiliation(s)
- Julliane V Joviano-Santos
- Robarts Research Institute, Schulich School of Medicine & Dentistry, University of Western Ontario, London, Canada.,Departamento de Morfologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Ornela Kljakic
- Robarts Research Institute, Schulich School of Medicine & Dentistry, University of Western Ontario, London, Canada.,Department of Anatomy and Cell Biology, Schulich School of Medicine & Dentistry, University of Western Ontario, London, Canada
| | - Matheus P S Magalhães-Gomes
- Departamento de Morfologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil.,Departamento de Medicina, Faculdade Ciências Médicas de Minas Gerais, FCMMG, Belo Horizonte, Brasil
| | - Priscila Aparecida C Valadão
- Departamento de Morfologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Leonardo R de Oliveira
- Departamento de Morfologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Marco A M Prado
- Robarts Research Institute, Schulich School of Medicine & Dentistry, University of Western Ontario, London, Canada.,Department of Anatomy and Cell Biology, Schulich School of Medicine & Dentistry, University of Western Ontario, London, Canada.,Department of Physiology and Pharmacology, Schulich School of Medicine & Dentistry, University of Western Ontario, London, Canada.,Brain and Mind Institute, University of Western Ontario, London, Canada
| | - Vania F Prado
- Robarts Research Institute, Schulich School of Medicine & Dentistry, University of Western Ontario, London, Canada.,Department of Anatomy and Cell Biology, Schulich School of Medicine & Dentistry, University of Western Ontario, London, Canada.,Department of Physiology and Pharmacology, Schulich School of Medicine & Dentistry, University of Western Ontario, London, Canada.,Brain and Mind Institute, University of Western Ontario, London, Canada
| | - Cristina Guatimosim
- Departamento de Morfologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
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11
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Vesicular neurotransmitter transporters in Drosophila melanogaster. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2020; 1862:183308. [PMID: 32305263 DOI: 10.1016/j.bbamem.2020.183308] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2020] [Revised: 04/09/2020] [Accepted: 04/10/2020] [Indexed: 12/11/2022]
Abstract
Drosophila melanogaster express vesicular transporters for the storage of neurotransmitters acetylcholine, biogenic amines, GABA, and glutamate. The large array of powerful molecular-genetic tools available in Drosophila enhances the use of this model organism for studying transporter function and regulation.
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12
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Goncalves DF, Guzman MS, Gros R, Massensini AR, Bartha R, Prado VF, Prado MAM. Striatal Acetylcholine Helps to Preserve Functional Outcomes in a Mouse Model of Stroke. ASN Neuro 2020; 12:1759091420961612. [PMID: 32967452 PMCID: PMC7521057 DOI: 10.1177/1759091420961612] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Acetylcholine (ACh) has been suggested to facilitate plasticity and
improve functional recovery after different types of brain lesions.
Interestingly, numerous studies have shown that striatal cholinergic
interneurons are relatively resistant to acute ischemic insults, but
whether ACh released by these neurons enhances functional recovery
after stroke is unknown. We investigated the role of endogenous
striatal ACh in stroke lesion volume and functional outcomes following
middle cerebral artery occlusion to induce focal ischemia in
striatum-selective vesicular acetylcholine transporter-deficient mice
(stVAChT-KO). As transporter expression is almost completely
eliminated in the striatum of stVAChT-KO mice, ACh release is nearly
abolished in this area. Conversely, in other brain areas, VAChT
expression and ACh release are preserved. Our results demonstrate a
larger infarct size after ischemic insult in stVAChT-KO mice, with
more pronounced functional impairments and increased mortality than in
littermate controls. These changes are associated with increased
activation of GSK-3, decreased levels of β-catenin, and a higher
permeability of the blood–brain barrier in mice with loss of VAChT in
striatum neurons. These results support a framework in which
endogenous ACh secretion originating from cholinergic interneurons in
the striatum helps to protect brain tissue against ischemia-induced
damage and facilitates brain recovery by supporting blood–brain
barrier function.
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Affiliation(s)
- Daniela F Goncalves
- Robarts Research Institute, The University of Western Ontario, London, Canada.,Neuroscience Centre, Department of Physiology and Biophysics, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Monica S Guzman
- Robarts Research Institute, The University of Western Ontario, London, Canada.,Department of Physiology and Pharmacology, The University of Western Ontario, London, Canada
| | - Robert Gros
- Robarts Research Institute, The University of Western Ontario, London, Canada.,Department of Physiology and Pharmacology, The University of Western Ontario, London, Canada
| | - André R Massensini
- Neuroscience Centre, Department of Physiology and Biophysics, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Robert Bartha
- Robarts Research Institute, The University of Western Ontario, London, Canada.,Department of Medical Biophysics, The University of Western Ontario, London, Canada
| | - Vania F Prado
- Robarts Research Institute, The University of Western Ontario, London, Canada.,Department of Physiology and Pharmacology, The University of Western Ontario, London, Canada.,Department of Anatomy and Cell Biology, The University of Western Ontario, London, Canada
| | - Marco A M Prado
- Robarts Research Institute, The University of Western Ontario, London, Canada.,Department of Physiology and Pharmacology, The University of Western Ontario, London, Canada.,Department of Anatomy and Cell Biology, The University of Western Ontario, London, Canada
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13
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Bogacheva P, Balezina O. Delayed increase of acetylcholine quantal size induced by the activity-dependent release of endogenous CGRP but not ATP in neuromuscular junctions. Synapse 2020; 74:e22175. [PMID: 32478912 DOI: 10.1002/syn.22175] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2020] [Revised: 05/07/2020] [Accepted: 05/23/2020] [Indexed: 11/09/2022]
Abstract
In mouse motor synapses tetanic neuromuscular activity (30 Hz, 2 min) led to a delayed posttetanic potentiation of amplitude and duration of spontaneous miniature endplate potentials (MEPPs). Microelectrode recordings of MEPPs before and after nerve stimulation showed an increase in MEPP amplitude and time course by 30% and 15%, respectively, without changes in their frequency. Peak effect was detected 20 min after tetanic activity and progressively faded throughout the next 40 min of recording. The revealed potentiation of MEPPs was fully preserved in preparations from pannexin 1 knockout mice. It means, that myogenic ATP released via pannexin 1 channels from contracting muscle fibers is not likely to participate in the described phenomenon. But posttetanic potentiation of MEPPs was fully prevented by competitive antagonist of calcitonin gene-related peptide (CGRP) receptors CGRP8-37 , ryanodine receptors inhibitor ryanodine and by vesicular acetylcholine transporter inhibitor vesamicol. It is suggested that the combination of intensive synaptic and contractile activity in neuromuscular junctions is required to induce Ca2+ -dependent exocytosis of endogenous CGRP. The accumulation of CGRP in the synaptic cleft and its presynaptic activity may induce posttetanic potentiation of MEPP amplitude due to CGRP-stimulated acetylcholine loading into vesicles and subsequent increase of quantal size.
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Affiliation(s)
- Polina Bogacheva
- Department of Human and Animal Physiology, Biological Faculty, Lomonosov Moscow State University, Moscow, Russia
| | - Olga Balezina
- Department of Human and Animal Physiology, Biological Faculty, Lomonosov Moscow State University, Moscow, Russia
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14
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Leite Schetino LP, Fonseca M, Magalhães Gomes MPS, Costa Valadão PA, Camargo WL, Rodrigues HA, Andrade JN, Arantes‐Costa FM, Naves LA, Prado CM, Prado VF, Prado MAM, Guatimosim C. Evaluation of the neuromuscular junction in a middle‐aged mouse model of congenital myasthenic syndrome. Muscle Nerve 2019; 60:790-800. [DOI: 10.1002/mus.26710] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2019] [Revised: 09/06/2019] [Accepted: 09/11/2019] [Indexed: 12/19/2022]
Affiliation(s)
| | - Matheus Fonseca
- Laboratório Nacional de BiociênciasCentro Nacional de Pesquisa em Energia e Materiais Campinas São Paulo Brazil
| | | | | | - Wallace Lucio Camargo
- Departamento de Fisiologia e BiofísicaUniversidade Federal de Minas Gerais Belo Horizonte Minas Gerais Brazil
| | - Hermann Alecsandro Rodrigues
- Departamento de Ciências Básicas da Vida, Instituto de Ciências da VidaUniversidade Federal de Juiz de Fora Campus Governador Valadares Minas Gerais Brazil
| | - Jéssica Neves Andrade
- Departamento de MorfologiaUniversidade Federal de Minas Gerais Belo Horizonte Minas Gerais Brazil
| | | | - Lígia Araujo Naves
- Departamento de Fisiologia e BiofísicaUniversidade Federal de Minas Gerais Belo Horizonte Minas Gerais Brazil
| | - Carla Máximo Prado
- Departmento de BiociênciasUniversidade Federal de São Paulo, Campus Baixada Santista São Paulo Brazil
| | - Vânia Ferreira Prado
- Robarts Research Institute and Department of Physiology and Pharmacology and Anatomy & Cell BiologyUniversity of Western Ontario London Ontario Canada
| | - Marco Antônio Máximo Prado
- Robarts Research Institute and Department of Physiology and Pharmacology and Anatomy & Cell BiologyUniversity of Western Ontario London Ontario Canada
| | - Cristina Guatimosim
- Departamento de MorfologiaUniversidade Federal de Minas Gerais Belo Horizonte Minas Gerais Brazil
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15
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Janickova H, Kljakic O, Rosborough K, Raulic S, Matovic S, Gros R, Saksida LM, Bussey TJ, Inoue W, Prado VF, Prado MAM. Selective decrease of cholinergic signaling from pedunculopontine and laterodorsal tegmental nuclei has little impact on cognition but markedly increases susceptibility to stress. FASEB J 2019; 33:7018-7036. [PMID: 30857416 DOI: 10.1096/fj.201802108r] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
The pedunculopontine tegmental nucleus (PPT) and laterodorsal tegmental nucleus (LDT) are heterogeneous brainstem structures that contain cholinergic, glutamatergic, and GABAergic neurons. PPT/LDT neurons are suggested to modulate both cognitive and noncognitive functions, yet the extent to which acetylcholine (ACh) signaling from the PPT/LDT is necessary for normal behavior remains uncertain. We addressed this issue by using a mouse model in which PPT/LDT cholinergic signaling is highly decreased by selective deletion of the vesicular ACh transporter (VAChT) gene. This approach interferes exclusively with ACh signaling, leaving signaling by other neurotransmitters from PPT/LDT cholinergic neurons intact and sparing other cells. VAChT mutants were examined on different PPT/LDT-associated cognitive domains. Interestingly, VAChT mutants showed no attentional deficits and only minor cognitive flexibility impairments while presenting large deficiencies in both spatial and cued Morris water maze (MWM) tasks. Conversely, working spatial memory determined with the Y-maze and spatial memory measured with the Barnes maze were not affected, suggesting that deficits in MWM were unrelated to spatial memory abnormalities. Supporting this interpretation, VAChT mutants exhibited alterations in anxiety-like behavior and increased corticosterone levels after exposure to the MWM, suggesting altered stress response. Thus, PPT/LDT VAChT-mutant mice present little cognitive impairment per se, yet they exhibit increased susceptibility to stress, which may lead to performance deficits in more stressful conditions.-Janickova, H., Kljakic, O., Rosborough, K., Raulic, S., Matovic, S., Gros, R., Saksida, L. M., Bussey, T. J., Inoue, W., Prado, V. F., Prado, M. A. M. Selective decrease of cholinergic signaling from pedunculopontine and laterodorsal tegmental nuclei has little impact on cognition but markedly increases susceptibility to stress.
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Affiliation(s)
- Helena Janickova
- Robarts Research Institute, Schulich School of Medicine & Dentistry, University of Western Ontario, London, Ontario, Canada
| | - Ornela Kljakic
- Robarts Research Institute, Schulich School of Medicine & Dentistry, University of Western Ontario, London, Ontario, Canada.,Department of Anatomy and Cell Biology, Schulich School of Medicine & Dentistry, University of Western Ontario, London, Ontario, Canada
| | - Kaie Rosborough
- Robarts Research Institute, Schulich School of Medicine & Dentistry, University of Western Ontario, London, Ontario, Canada.,Department of Anatomy and Cell Biology, Schulich School of Medicine & Dentistry, University of Western Ontario, London, Ontario, Canada
| | - Sanda Raulic
- Robarts Research Institute, Schulich School of Medicine & Dentistry, University of Western Ontario, London, Ontario, Canada
| | - Sara Matovic
- Robarts Research Institute, Schulich School of Medicine & Dentistry, University of Western Ontario, London, Ontario, Canada.,Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Ontario, Canada; and
| | - Robert Gros
- Robarts Research Institute, Schulich School of Medicine & Dentistry, University of Western Ontario, London, Ontario, Canada.,Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Ontario, Canada; and
| | - Lisa M Saksida
- Robarts Research Institute, Schulich School of Medicine & Dentistry, University of Western Ontario, London, Ontario, Canada.,Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Ontario, Canada; and.,Brain and Mind Institute, The University of Western Ontario, London, Ontario, Canada
| | - Timothy J Bussey
- Robarts Research Institute, Schulich School of Medicine & Dentistry, University of Western Ontario, London, Ontario, Canada.,Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Ontario, Canada; and.,Brain and Mind Institute, The University of Western Ontario, London, Ontario, Canada
| | - Wataru Inoue
- Robarts Research Institute, Schulich School of Medicine & Dentistry, University of Western Ontario, London, Ontario, Canada.,Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Ontario, Canada; and
| | - Vania F Prado
- Robarts Research Institute, Schulich School of Medicine & Dentistry, University of Western Ontario, London, Ontario, Canada.,Department of Anatomy and Cell Biology, Schulich School of Medicine & Dentistry, University of Western Ontario, London, Ontario, Canada.,Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Ontario, Canada; and.,Brain and Mind Institute, The University of Western Ontario, London, Ontario, Canada
| | - Marco A M Prado
- Robarts Research Institute, Schulich School of Medicine & Dentistry, University of Western Ontario, London, Ontario, Canada.,Department of Anatomy and Cell Biology, Schulich School of Medicine & Dentistry, University of Western Ontario, London, Ontario, Canada.,Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Ontario, Canada; and.,Brain and Mind Institute, The University of Western Ontario, London, Ontario, Canada
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16
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A Poly-Glutamine Region in the Drosophila VAChT Dictates Fill-Level of Cholinergic Synaptic Vesicles. eNeuro 2019; 6:eN-NWR-0477-18. [PMID: 30847389 PMCID: PMC6402538 DOI: 10.1523/eneuro.0477-18.2019] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2018] [Revised: 01/03/2019] [Accepted: 01/07/2019] [Indexed: 01/08/2023] Open
Abstract
While the primary role of vesicular transporters is to load neurotransmitters into synaptic vesicles (SVs), accumulating evidence suggests that these proteins also contribute to additional aspects of synaptic function, including vesicle release. In this study, we extend the role of the VAChT to include regulating the transmitter content of SVs. We report that manipulation of a C-terminal poly-glutamine (polyQ) region in the Drosophila VAChT is sufficient to influence transmitter content, and release frequency, of cholinergic vesicles from the terminals of premotor interneurons. Specifically, we find that reduction of the polyQ region, by one glutamine residue (13Q to 12Q), results in a significant increase in both amplitude and frequency of spontaneous cholinergic miniature EPSCs (mEPSCs) recorded in the aCC and RP2 motoneurons. Moreover, this truncation also results in evoked synaptic currents that show increased duration: consistent with increased ACh release. By contrast, extension of the polyQ region by one glutamine (13Q to 14Q) is sufficient to reduce mEPSC amplitude and frequency and, moreover, prevents evoked SV release. Finally, a complete deletion of the polyQ region (13Q to 0Q) has no obvious effects to mEPSCs, but again evoked synaptic currents show increased duration. The mechanisms that ensure SVs are filled to physiologically-appropriate levels remain unknown. Our study identifies the polyQ region of the insect VAChT to be required for correct vesicle transmitter loading and, thus, provides opportunity to increase understanding of this critical aspect of neurotransmission.
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17
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Magalhães-Gomes MPS, Motta-Santos D, Schetino LPL, Andrade JN, Bastos CP, Guimarães DAS, Vaughan SK, Martinelli PM, Guatimosim S, Pereira GS, Coimbra CC, Prado VF, Prado MAM, Valdez G, Guatimosim C. Fast and slow-twitching muscles are differentially affected by reduced cholinergic transmission in mice deficient for VAChT: A mouse model for congenital myasthenia. Neurochem Int 2018; 120:1-12. [PMID: 30003945 PMCID: PMC6421860 DOI: 10.1016/j.neuint.2018.07.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2018] [Revised: 06/27/2018] [Accepted: 07/07/2018] [Indexed: 12/15/2022]
Abstract
Congenital myasthenic syndromes (CMS) result from reduced cholinergic transmission at neuromuscular junctions (NMJs). While the etiology of CMS varies, the disease is characterized by muscle weakness. To date, it remains unknown if CMS causes long-term and irreversible changes to skeletal muscles. In this study, we examined skeletal muscles in a mouse line with reduced expression of Vesicular Acetylcholine Transporter (VAChT, mouse line herein called VAChT-KDHOM). We examined this mouse line for several reasons. First, VAChT plays a central function in loading acetylcholine (ACh) into synaptic vesicles and releasing it at NMJs, in addition to other cholinergic nerve endings. Second, loss of function mutations in VAChT causes myasthenia in humans. Importantly, VAChT-KDHOM present with reduced ACh and muscle weakness, resembling CMS. We evaluated the morphology, fiber type (myosin heavy chain isoforms), and expression of muscle-related genes in the extensor digitorum longus (EDL) and soleus muscles. This analysis revealed that while muscle fibers atrophy in the EDL, they hypertrophy in the soleus muscle of VAChT-KDHOM mice. Along with these cellular changes, skeletal muscles exhibit altered levels of markers for myogenesis (Pax-7, Myogenin, and MyoD), oxidative metabolism (PGC1-α and MTND1), and protein degradation (Atrogin1 and MuRF1) in VAChT-KDHOM mice. Importantly, we demonstrate that deleterious changes in skeletal muscles and motor deficits can be partially reversed following the administration of the cholinesterase inhibitor, pyridostigmine in VAChT-KDHOM mice. These findings reveal that fast and slow type muscles differentially respond to cholinergic deficits. Additionally, this study shows that the adverse effects of cholinergic transmission, as in the case of CMS, on fast and slow type skeletal muscles are reversible.
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Affiliation(s)
| | - Daisy Motta-Santos
- Departamento de Fisiologia e Biofísica, ICB, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil; Departamento de Esportes, EEFFTO, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
| | - Luana P L Schetino
- Departamento de Morfologia, ICB, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
| | - Jéssica N Andrade
- Departamento de Morfologia, ICB, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
| | - Cristiane P Bastos
- Departamento de Fisiologia e Biofísica, ICB, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
| | | | - Sydney K Vaughan
- Virginia Tech Carilion Research Institute, Roanoke, VA, USA; Graduate Program in Translational Biology, Medicine, and Health, Virginia Tech, Blacksburg, VA, USA
| | - Patrícia M Martinelli
- Departamento de Morfologia, ICB, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
| | - Silvia Guatimosim
- Departamento de Fisiologia e Biofísica, ICB, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
| | - Grace S Pereira
- Departamento de Fisiologia e Biofísica, ICB, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
| | - Candido C Coimbra
- Departamento de Fisiologia e Biofísica, ICB, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
| | - Vânia F Prado
- Robarts Research Institute and Department of Physiology and Pharmacology and Anatomy & Cell Biology, University of Western Ontario, London, ON, Canada
| | - Marco A M Prado
- Robarts Research Institute and Department of Physiology and Pharmacology and Anatomy & Cell Biology, University of Western Ontario, London, ON, Canada
| | - Gregorio Valdez
- Virginia Tech Carilion Research Institute, Roanoke, VA, USA; Department of Biological Sciences, Virginia Tech, Blacksburg, VA, USA
| | - Cristina Guatimosim
- Departamento de Morfologia, ICB, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil.
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18
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Vernon SW, Goodchild J, Baines RA. The VAChTY49N mutation provides insecticide-resistance but perturbs evoked cholinergic neurotransmission in Drosophila. PLoS One 2018; 13:e0203852. [PMID: 30204788 PMCID: PMC6133381 DOI: 10.1371/journal.pone.0203852] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2018] [Accepted: 08/28/2018] [Indexed: 12/05/2022] Open
Abstract
Global agriculture and the control of insect disease vectors have developed with a heavy reliance on insecticides. The increasing incidence of resistance, for virtually all insecticides, threatens both food supply and effective control of insect borne disease. CASPP ((5-chloro-1’-[(E)-3-(4-chlorophenyl)allyl]spiro[indoline-3,4’-piperidine]-1-yl}-(2-chloro-4-pyridyl)methanone)) compounds are a potential new class of neuroactive insecticide specifically targeting the Vesicular Acetylcholine Transporter (VAChT). Resistance to CASPP, under laboratory conditions, has been reported following either up-regulation of wildtype VAChT expression or the presence of a specific point mutation (VAChTY49N). However, the underlying mechanism of CASPP-resistance, together with the consequence to insect viability of achieving resistance, is unknown. In this study, we use electrophysiological characterisation of cholinergic release at Drosophila larval interneuron→motoneuron synapses to investigate the physiological implications of these two identified modes of CASPP resistance. We show that both VAChT up-regulation or the expression of VAChTY49N increases miniature (mini) release frequency. Mini frequency appears deterministic of CASPP activity. However, maintenance of SV release is not indicative of resistance in all cases. This is evidenced through expression of syntaxin or complexin mutants (sytx3-61/cpxSH1) that show similarly high mini release frequency but are not resistant to CASPP. The VAChTY49N mutation additionally disrupts action potential-evoked cholinergic release and fictive locomotor patterning through depletion of releasable synaptic vesicles. This observation suggests a functional trade-off for this point mutation, which is not seen when wildtype VAChT is up-regulated.
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Affiliation(s)
- Samuel W. Vernon
- Division of Neuroscience and Experimental Psychology, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester Academic Health Science Centre, Manchester, United Kingdom
| | - Jim Goodchild
- Syngenta Crop Protection Research, Bracknell, Berkshire, United Kingdom
| | - Richard A. Baines
- Division of Neuroscience and Experimental Psychology, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester Academic Health Science Centre, Manchester, United Kingdom
- * E-mail:
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19
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Pereira LM, Guimarães IM, Oliveira VE, Bastos CP, Ribeiro FM, Prado VF, Prado MA, Pereira GS. Estradiol effect on short-term object memory under hypocholinergic condition. Brain Res Bull 2018; 140:411-417. [DOI: 10.1016/j.brainresbull.2018.01.012] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2017] [Revised: 01/10/2018] [Accepted: 01/16/2018] [Indexed: 12/20/2022]
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20
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Kolisnyk B, Al-Onaizi M, Soreq L, Barbash S, Bekenstein U, Haberman N, Hanin G, Kish MT, Souza da Silva J, Fahnestock M, Ule J, Soreq H, Prado VF, Prado MAM. Cholinergic Surveillance over Hippocampal RNA Metabolism and Alzheimer's-Like Pathology. Cereb Cortex 2018; 27:3553-3567. [PMID: 27312991 DOI: 10.1093/cercor/bhw177] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
The relationship between long-term cholinergic dysfunction and risk of developing dementia is poorly understood. Here we used mice with deletion of the vesicular acetylcholine transporter (VAChT) in the forebrain to model cholinergic abnormalities observed in dementia. Whole-genome RNA sequencing of hippocampal samples revealed that cholinergic failure causes changes in RNA metabolism. Remarkably, key transcripts related to Alzheimer's disease are affected. BACE1, for instance, shows abnormal splicing caused by decreased expression of the splicing regulator hnRNPA2/B1. Resulting BACE1 overexpression leads to increased APP processing and accumulation of soluble Aβ1-42. This is accompanied by age-related increases in GSK3 activation, tau hyperphosphorylation, caspase-3 activation, decreased synaptic markers, increased neuronal death, and deteriorating cognition. Pharmacological inhibition of GSK3 hyperactivation reversed deficits in synaptic markers and tau hyperphosphorylation induced by cholinergic dysfunction, indicating a key role for GSK3 in some of these pathological changes. Interestingly, in human brains there was a high correlation between decreased levels of VAChT and hnRNPA2/B1 levels with increased tau hyperphosphorylation. These results suggest that changes in RNA processing caused by cholinergic loss can facilitate Alzheimer's-like pathology in mice, providing a mechanism by which decreased cholinergic tone may increase risk of dementia.
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Affiliation(s)
| | - Mohammed Al-Onaizi
- Robarts Research Institute.,Department of Anatomy and Cell Biology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Ontario, Canada N6A5K8
| | - Lilach Soreq
- Department of Molecular Neuroscience, UCL Institute of Neurology, Queen Square, London WC1N 3BG, UK
| | - Shahar Barbash
- The Edmond and Lily Safra Center for Brain Science and The Silberman Institute of Life Sciences, The Edmond J Safra Campus, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - Uriya Bekenstein
- The Edmond and Lily Safra Center for Brain Science and The Silberman Institute of Life Sciences, The Edmond J Safra Campus, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - Nejc Haberman
- Department of Molecular Neuroscience, UCL Institute of Neurology, Queen Square, London WC1N 3BG, UK
| | - Geula Hanin
- The Edmond and Lily Safra Center for Brain Science and The Silberman Institute of Life Sciences, The Edmond J Safra Campus, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - Maxine T Kish
- Robarts Research Institute.,Department of Physiology and Pharmacology
| | | | - Margaret Fahnestock
- Department of Psychiatry and Behavioural Neurosciences, McMaster University, Hamilton, Ontario, CanadaL8S 4K1
| | - Jernej Ule
- Department of Molecular Neuroscience, UCL Institute of Neurology, Queen Square, London WC1N 3BG, UK
| | - Hermona Soreq
- The Edmond and Lily Safra Center for Brain Science and The Silberman Institute of Life Sciences, The Edmond J Safra Campus, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - Vania F Prado
- Robarts Research Institute.,Graduate Program in Neuroscience.,Department of Physiology and Pharmacology.,Department of Anatomy and Cell Biology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Ontario, Canada N6A5K8
| | - Marco A M Prado
- Robarts Research Institute.,Graduate Program in Neuroscience.,Department of Physiology and Pharmacology.,Department of Anatomy and Cell Biology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Ontario, Canada N6A5K8
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21
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Janickova H, Prado VF, Prado MAM, El Mestikawy S, Bernard V. Vesicular acetylcholine transporter (VAChT) over-expression induces major modifications of striatal cholinergic interneuron morphology and function. J Neurochem 2017. [DOI: 10.1111/jnc.14105] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Affiliation(s)
- Helena Janickova
- Department of Physiology and Pharmacology and Department of Anatomy & Cell Biology; Robarts Research Institute; Molecular Medicine Laboratories; The University of Western Ontario; London Ontario Canada
| | - Vania F. Prado
- Department of Physiology and Pharmacology and Department of Anatomy & Cell Biology; Robarts Research Institute; Molecular Medicine Laboratories; The University of Western Ontario; London Ontario Canada
| | - Marco A. M. Prado
- Department of Physiology and Pharmacology and Department of Anatomy & Cell Biology; Robarts Research Institute; Molecular Medicine Laboratories; The University of Western Ontario; London Ontario Canada
| | - Salah El Mestikawy
- Sorbonne Universités; Université Pierre et Marie Curie UM 119 - CNRS UMR 8246 - INSERM U1130; Neurosciences Paris Seine - Institut de Biologie Paris Seine (NPS - IBPS); Paris France
- Department of Psychiatry; Douglas Mental Health University Institute; McGill University; Montreal Canada
| | - Véronique Bernard
- Sorbonne Universités; Université Pierre et Marie Curie UM 119 - CNRS UMR 8246 - INSERM U1130; Neurosciences Paris Seine - Institut de Biologie Paris Seine (NPS - IBPS); Paris France
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22
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Kljakic O, Janickova H, Prado VF, Prado MAM. Cholinergic/glutamatergic co-transmission in striatal cholinergic interneurons: new mechanisms regulating striatal computation. J Neurochem 2017; 142 Suppl 2:90-102. [PMID: 28421605 DOI: 10.1111/jnc.14003] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2016] [Revised: 02/28/2017] [Accepted: 03/01/2017] [Indexed: 01/22/2023]
Abstract
It is well established that neurons secrete neuropeptides and ATP with classical neurotransmitters; however, certain neuronal populations are also capable of releasing two classical neurotransmitters by a process named co-transmission. Although there has been progress in our understanding of the molecular mechanism underlying co-transmission, the individual regulation of neurotransmitter secretion and the functional significance of this neuronal 'bilingualism' is still unknown. Striatal cholinergic interneurons (CINs) have been shown to secrete glutamate (Glu) in addition to acetylcholine (ACh) and are recognized for their role in the regulation of striatal circuits and behavior. Our review highlights the recent research into identifying mechanisms that regulate the secretion and function of Glu and ACh released by CINs and the roles these neurons play in regulating dopamine secretion and striatal activity. In particular, we focus on how the transporters for ACh (VAChT) and Glu (VGLUT3) influence the storage of neurotransmitters in CINs. We further discuss how these individual neurotransmitters regulate striatal computation and distinct aspects of behavior that are regulated by the striatum. We suggest that understanding the distinct and complementary functional roles of these two neurotransmitters may prove beneficial in the development of therapies for Parkinson's disease and addiction. Overall, understanding how Glu and ACh secreted by CINs impacts striatal activity may provide insight into how different populations of 'bilingual' neurons are able to develop sophisticated regulation of their targets by interacting with multiple receptors but also by regulating each other's vesicular storage. This is an article for the special issue XVth International Symposium on Cholinergic Mechanisms.
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Affiliation(s)
- Ornela Kljakic
- Robarts Research Institute, Schulich School of Medicine & Dentistry, University of Western Ontario, London, Ontario, Canada.,Department of Anatomy and Cell Biology, Schulich School of Medicine & Dentistry, University of Western Ontario, London, Ontario, Canada
| | - Helena Janickova
- Robarts Research Institute, Schulich School of Medicine & Dentistry, University of Western Ontario, London, Ontario, Canada
| | - Vania F Prado
- Robarts Research Institute, Schulich School of Medicine & Dentistry, University of Western Ontario, London, Ontario, Canada.,Department of Anatomy and Cell Biology, Schulich School of Medicine & Dentistry, University of Western Ontario, London, Ontario, Canada.,Department of Physiology and Pharmacology, Schulich School of Medicine & Dentistry, University of Western Ontario, London, Ontario, Canada
| | - Marco A M Prado
- Robarts Research Institute, Schulich School of Medicine & Dentistry, University of Western Ontario, London, Ontario, Canada.,Department of Anatomy and Cell Biology, Schulich School of Medicine & Dentistry, University of Western Ontario, London, Ontario, Canada.,Department of Physiology and Pharmacology, Schulich School of Medicine & Dentistry, University of Western Ontario, London, Ontario, Canada
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23
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Aran A, Segel R, Kaneshige K, Gulsuner S, Renbaum P, Oliphant S, Meirson T, Weinberg-Shukron A, Hershkovitz Y, Zeligson S, Lee MK, Samson AO, Parsons SM, King MC, Levy-Lahad E, Walsh T. Vesicular acetylcholine transporter defect underlies devastating congenital myasthenia syndrome. Neurology 2017; 88:1021-1028. [PMID: 28188302 DOI: 10.1212/wnl.0000000000003720] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2016] [Accepted: 12/21/2016] [Indexed: 11/15/2022] Open
Abstract
OBJECTIVE To identify the genetic basis of a recessive congenital neurologic syndrome characterized by severe hypotonia, arthrogryposis, and respiratory failure. METHODS Identification of the responsible gene by exome sequencing and assessment of the effect of the mutation on protein stability in transfected rat neuronal-like PC12A123.7 cells. RESULTS Two brothers from a nonconsanguineous Yemeni Jewish family manifested at birth with severe hypotonia and arthrogryposis. The older brother died of respiratory failure at 5 days of age. The proband, now 4.5 years old, has been mechanically ventilated since birth with virtually no milestones achievement. Whole exome sequencing revealed homozygosity of SLC18A3 c.1078G>C, p.Gly360Arg in the affected brothers but not in other family members. SLC18A3 p.Gly360Arg is not reported in world populations but is present at a carrier frequency of 1:30 in healthy Yemeni Jews. SLC18A3 encodes the vesicular acetylcholine transporter (VAChT), which loads newly synthesized acetylcholine from the neuronal cytoplasm into synaptic vesicles. Mice that are VAChT-null have been shown to die at birth of respiratory failure. In human VAChT, residue 360 is located in a conserved region and substitution of arginine for glycine is predicted to disrupt proper protein folding and membrane embedding. Stable transfection of wild-type and mutant human VAChT into neuronal-like PC12A123.7 cells revealed similar mRNA levels, but undetectable levels of the mutant protein, suggesting post-translational degradation of mutant VAChT. CONCLUSION Loss of function of VAChT underlies severe arthrogryposis and respiratory failure. While most congenital myasthenic syndromes are caused by defects in postsynaptic proteins, VAChT deficiency is a presynaptic myasthenic syndrome.
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Affiliation(s)
- Adi Aran
- From the Neuropediatric Unit (A.A.) and Medical Genetics (R.S., P.R., A.W.-S., S.Z., E.L.-L.), Shaare Zedek Medical Center; Hebrew University-Hadassah School of Medicine (A.A., R.S., A.W.-S., E.L.-L.), Jerusalem, Israel; Department of Chemistry and Biochemistry (K.K., S.O., S.M.P.), University of California, Santa Barbara; Faculty of Medicine (T.M., Y.H., A.O.S.), Bar Ilan University, Safed, Israel; and Departments of Medicine and Genome Sciences (S.G., M.K.L., M.-C.K., T.W.), University of Washington, Seattle
| | - Reeval Segel
- From the Neuropediatric Unit (A.A.) and Medical Genetics (R.S., P.R., A.W.-S., S.Z., E.L.-L.), Shaare Zedek Medical Center; Hebrew University-Hadassah School of Medicine (A.A., R.S., A.W.-S., E.L.-L.), Jerusalem, Israel; Department of Chemistry and Biochemistry (K.K., S.O., S.M.P.), University of California, Santa Barbara; Faculty of Medicine (T.M., Y.H., A.O.S.), Bar Ilan University, Safed, Israel; and Departments of Medicine and Genome Sciences (S.G., M.K.L., M.-C.K., T.W.), University of Washington, Seattle
| | - Kota Kaneshige
- From the Neuropediatric Unit (A.A.) and Medical Genetics (R.S., P.R., A.W.-S., S.Z., E.L.-L.), Shaare Zedek Medical Center; Hebrew University-Hadassah School of Medicine (A.A., R.S., A.W.-S., E.L.-L.), Jerusalem, Israel; Department of Chemistry and Biochemistry (K.K., S.O., S.M.P.), University of California, Santa Barbara; Faculty of Medicine (T.M., Y.H., A.O.S.), Bar Ilan University, Safed, Israel; and Departments of Medicine and Genome Sciences (S.G., M.K.L., M.-C.K., T.W.), University of Washington, Seattle
| | - Suleyman Gulsuner
- From the Neuropediatric Unit (A.A.) and Medical Genetics (R.S., P.R., A.W.-S., S.Z., E.L.-L.), Shaare Zedek Medical Center; Hebrew University-Hadassah School of Medicine (A.A., R.S., A.W.-S., E.L.-L.), Jerusalem, Israel; Department of Chemistry and Biochemistry (K.K., S.O., S.M.P.), University of California, Santa Barbara; Faculty of Medicine (T.M., Y.H., A.O.S.), Bar Ilan University, Safed, Israel; and Departments of Medicine and Genome Sciences (S.G., M.K.L., M.-C.K., T.W.), University of Washington, Seattle
| | - Paul Renbaum
- From the Neuropediatric Unit (A.A.) and Medical Genetics (R.S., P.R., A.W.-S., S.Z., E.L.-L.), Shaare Zedek Medical Center; Hebrew University-Hadassah School of Medicine (A.A., R.S., A.W.-S., E.L.-L.), Jerusalem, Israel; Department of Chemistry and Biochemistry (K.K., S.O., S.M.P.), University of California, Santa Barbara; Faculty of Medicine (T.M., Y.H., A.O.S.), Bar Ilan University, Safed, Israel; and Departments of Medicine and Genome Sciences (S.G., M.K.L., M.-C.K., T.W.), University of Washington, Seattle
| | - Scott Oliphant
- From the Neuropediatric Unit (A.A.) and Medical Genetics (R.S., P.R., A.W.-S., S.Z., E.L.-L.), Shaare Zedek Medical Center; Hebrew University-Hadassah School of Medicine (A.A., R.S., A.W.-S., E.L.-L.), Jerusalem, Israel; Department of Chemistry and Biochemistry (K.K., S.O., S.M.P.), University of California, Santa Barbara; Faculty of Medicine (T.M., Y.H., A.O.S.), Bar Ilan University, Safed, Israel; and Departments of Medicine and Genome Sciences (S.G., M.K.L., M.-C.K., T.W.), University of Washington, Seattle
| | - Tomer Meirson
- From the Neuropediatric Unit (A.A.) and Medical Genetics (R.S., P.R., A.W.-S., S.Z., E.L.-L.), Shaare Zedek Medical Center; Hebrew University-Hadassah School of Medicine (A.A., R.S., A.W.-S., E.L.-L.), Jerusalem, Israel; Department of Chemistry and Biochemistry (K.K., S.O., S.M.P.), University of California, Santa Barbara; Faculty of Medicine (T.M., Y.H., A.O.S.), Bar Ilan University, Safed, Israel; and Departments of Medicine and Genome Sciences (S.G., M.K.L., M.-C.K., T.W.), University of Washington, Seattle
| | - Ariella Weinberg-Shukron
- From the Neuropediatric Unit (A.A.) and Medical Genetics (R.S., P.R., A.W.-S., S.Z., E.L.-L.), Shaare Zedek Medical Center; Hebrew University-Hadassah School of Medicine (A.A., R.S., A.W.-S., E.L.-L.), Jerusalem, Israel; Department of Chemistry and Biochemistry (K.K., S.O., S.M.P.), University of California, Santa Barbara; Faculty of Medicine (T.M., Y.H., A.O.S.), Bar Ilan University, Safed, Israel; and Departments of Medicine and Genome Sciences (S.G., M.K.L., M.-C.K., T.W.), University of Washington, Seattle
| | - Yair Hershkovitz
- From the Neuropediatric Unit (A.A.) and Medical Genetics (R.S., P.R., A.W.-S., S.Z., E.L.-L.), Shaare Zedek Medical Center; Hebrew University-Hadassah School of Medicine (A.A., R.S., A.W.-S., E.L.-L.), Jerusalem, Israel; Department of Chemistry and Biochemistry (K.K., S.O., S.M.P.), University of California, Santa Barbara; Faculty of Medicine (T.M., Y.H., A.O.S.), Bar Ilan University, Safed, Israel; and Departments of Medicine and Genome Sciences (S.G., M.K.L., M.-C.K., T.W.), University of Washington, Seattle
| | - Sharon Zeligson
- From the Neuropediatric Unit (A.A.) and Medical Genetics (R.S., P.R., A.W.-S., S.Z., E.L.-L.), Shaare Zedek Medical Center; Hebrew University-Hadassah School of Medicine (A.A., R.S., A.W.-S., E.L.-L.), Jerusalem, Israel; Department of Chemistry and Biochemistry (K.K., S.O., S.M.P.), University of California, Santa Barbara; Faculty of Medicine (T.M., Y.H., A.O.S.), Bar Ilan University, Safed, Israel; and Departments of Medicine and Genome Sciences (S.G., M.K.L., M.-C.K., T.W.), University of Washington, Seattle
| | - Ming K Lee
- From the Neuropediatric Unit (A.A.) and Medical Genetics (R.S., P.R., A.W.-S., S.Z., E.L.-L.), Shaare Zedek Medical Center; Hebrew University-Hadassah School of Medicine (A.A., R.S., A.W.-S., E.L.-L.), Jerusalem, Israel; Department of Chemistry and Biochemistry (K.K., S.O., S.M.P.), University of California, Santa Barbara; Faculty of Medicine (T.M., Y.H., A.O.S.), Bar Ilan University, Safed, Israel; and Departments of Medicine and Genome Sciences (S.G., M.K.L., M.-C.K., T.W.), University of Washington, Seattle
| | - Abraham O Samson
- From the Neuropediatric Unit (A.A.) and Medical Genetics (R.S., P.R., A.W.-S., S.Z., E.L.-L.), Shaare Zedek Medical Center; Hebrew University-Hadassah School of Medicine (A.A., R.S., A.W.-S., E.L.-L.), Jerusalem, Israel; Department of Chemistry and Biochemistry (K.K., S.O., S.M.P.), University of California, Santa Barbara; Faculty of Medicine (T.M., Y.H., A.O.S.), Bar Ilan University, Safed, Israel; and Departments of Medicine and Genome Sciences (S.G., M.K.L., M.-C.K., T.W.), University of Washington, Seattle
| | - Stanley M Parsons
- From the Neuropediatric Unit (A.A.) and Medical Genetics (R.S., P.R., A.W.-S., S.Z., E.L.-L.), Shaare Zedek Medical Center; Hebrew University-Hadassah School of Medicine (A.A., R.S., A.W.-S., E.L.-L.), Jerusalem, Israel; Department of Chemistry and Biochemistry (K.K., S.O., S.M.P.), University of California, Santa Barbara; Faculty of Medicine (T.M., Y.H., A.O.S.), Bar Ilan University, Safed, Israel; and Departments of Medicine and Genome Sciences (S.G., M.K.L., M.-C.K., T.W.), University of Washington, Seattle
| | - Mary-Claire King
- From the Neuropediatric Unit (A.A.) and Medical Genetics (R.S., P.R., A.W.-S., S.Z., E.L.-L.), Shaare Zedek Medical Center; Hebrew University-Hadassah School of Medicine (A.A., R.S., A.W.-S., E.L.-L.), Jerusalem, Israel; Department of Chemistry and Biochemistry (K.K., S.O., S.M.P.), University of California, Santa Barbara; Faculty of Medicine (T.M., Y.H., A.O.S.), Bar Ilan University, Safed, Israel; and Departments of Medicine and Genome Sciences (S.G., M.K.L., M.-C.K., T.W.), University of Washington, Seattle
| | - Ephrat Levy-Lahad
- From the Neuropediatric Unit (A.A.) and Medical Genetics (R.S., P.R., A.W.-S., S.Z., E.L.-L.), Shaare Zedek Medical Center; Hebrew University-Hadassah School of Medicine (A.A., R.S., A.W.-S., E.L.-L.), Jerusalem, Israel; Department of Chemistry and Biochemistry (K.K., S.O., S.M.P.), University of California, Santa Barbara; Faculty of Medicine (T.M., Y.H., A.O.S.), Bar Ilan University, Safed, Israel; and Departments of Medicine and Genome Sciences (S.G., M.K.L., M.-C.K., T.W.), University of Washington, Seattle.
| | - Tom Walsh
- From the Neuropediatric Unit (A.A.) and Medical Genetics (R.S., P.R., A.W.-S., S.Z., E.L.-L.), Shaare Zedek Medical Center; Hebrew University-Hadassah School of Medicine (A.A., R.S., A.W.-S., E.L.-L.), Jerusalem, Israel; Department of Chemistry and Biochemistry (K.K., S.O., S.M.P.), University of California, Santa Barbara; Faculty of Medicine (T.M., Y.H., A.O.S.), Bar Ilan University, Safed, Israel; and Departments of Medicine and Genome Sciences (S.G., M.K.L., M.-C.K., T.W.), University of Washington, Seattle
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24
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Janickova H, Rosborough K, Al-Onaizi M, Kljakic O, Guzman MS, Gros R, Prado MAM, Prado VF. Deletion of the vesicular acetylcholine transporter from pedunculopontine/laterodorsal tegmental neurons modifies gait. J Neurochem 2017; 140:787-798. [DOI: 10.1111/jnc.13910] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2016] [Revised: 11/04/2016] [Accepted: 11/24/2016] [Indexed: 11/27/2022]
Affiliation(s)
- Helena Janickova
- Robarts Research Institute; Schulich School of Medicine & Dentistry; University of Western Ontario; London Ontario Canada
| | - Kaie Rosborough
- Robarts Research Institute; Schulich School of Medicine & Dentistry; University of Western Ontario; London Ontario Canada
- Department of Anatomy and Cell Biology; Schulich School of Medicine & Dentistry; University of Western Ontario; London Ontario Canada
| | - Mohammed Al-Onaizi
- Robarts Research Institute; Schulich School of Medicine & Dentistry; University of Western Ontario; London Ontario Canada
- Department of Anatomy and Cell Biology; Schulich School of Medicine & Dentistry; University of Western Ontario; London Ontario Canada
| | - Ornela Kljakic
- Robarts Research Institute; Schulich School of Medicine & Dentistry; University of Western Ontario; London Ontario Canada
- Department of Anatomy and Cell Biology; Schulich School of Medicine & Dentistry; University of Western Ontario; London Ontario Canada
| | - Monica S. Guzman
- Robarts Research Institute; Schulich School of Medicine & Dentistry; University of Western Ontario; London Ontario Canada
- Department of Anatomy and Cell Biology; Schulich School of Medicine & Dentistry; University of Western Ontario; London Ontario Canada
| | - Robert Gros
- Robarts Research Institute; Schulich School of Medicine & Dentistry; University of Western Ontario; London Ontario Canada
- Department of Physiology and Pharmacology; Schulich School of Medicine & Dentistry; University of Western Ontario; London Ontario Canada
| | - Marco A. M. Prado
- Robarts Research Institute; Schulich School of Medicine & Dentistry; University of Western Ontario; London Ontario Canada
- Department of Anatomy and Cell Biology; Schulich School of Medicine & Dentistry; University of Western Ontario; London Ontario Canada
- Department of Physiology and Pharmacology; Schulich School of Medicine & Dentistry; University of Western Ontario; London Ontario Canada
| | - Vania F. Prado
- Robarts Research Institute; Schulich School of Medicine & Dentistry; University of Western Ontario; London Ontario Canada
- Department of Anatomy and Cell Biology; Schulich School of Medicine & Dentistry; University of Western Ontario; London Ontario Canada
- Department of Physiology and Pharmacology; Schulich School of Medicine & Dentistry; University of Western Ontario; London Ontario Canada
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25
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Leite HR, Oliveira-Lima OCD, Pereira LDM, Oliveira VEDM, Prado VF, Prado MAM, Pereira GS, Massensini AR. Vesicular acetylcholine transporter knock down-mice are more susceptible to inflammation, c-Fos expression and sickness behavior induced by lipopolysaccharide. Brain Behav Immun 2016; 57:282-292. [PMID: 27179819 DOI: 10.1016/j.bbi.2016.05.005] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/13/2016] [Revised: 05/01/2016] [Accepted: 05/10/2016] [Indexed: 01/14/2023] Open
Abstract
In addition to the well-known functions as a neurotransmitter, acetylcholine (ACh) can modulate of the immune system. Nonetheless, how endogenous ACh release inflammatory responses is still not clear. To address this question, we took advantage of an animal model with a decreased ACh release due a reduction (knockdown) in vesicular acetylcholine transporter (VAChT) expression (VAChT-KD(HOM)). These animals were challenged with lipopolysaccharide (LPS). Afterwards, we evaluated sickness behavior and quantified systemic and cerebral inflammation as well as neuronal activation in the dorsal vagal complex (DVC). VAChT-KD(HOM) mice that were injected with LPS (10mg/kg) showed increased mortality rate as compared to control mice. In line with this result, a low dose of LPS (0.1mg/kg) increased the levels of pro-inflammatory (TNF-α, IL-1β, and IL-6) and anti-inflammatory (IL-10) cytokines in the spleen and brain of VAChT-KD(HOM) mice in comparison with controls. Similarly, serum levels of TNF-α and IL-6 were increased in VAChT-KD(HOM) mice. This excessive cytokine production was completely prevented by administration of a nicotinic receptor agonist (0.4mg/kg) prior to the LPS injection. Three hours after the LPS injection, c-Fos expression increased in the DVC region of VAChT-KD(HOM) mice compared to controls. In addition, VAChT-KD(HOM) mice showed behavioral changes such as lowered locomotor and exploratory activity and reduced social interaction after the LPS challenge, when compared to control mice. Taken together, our results show that the decreased ability to release ACh exacerbates systemic and cerebral inflammation and promotes neural activation and behavioral changes induced by LPS. In conclusion, our findings support the notion that activity of cholinergic pathways, which can be modulated by VAChT expression, controls inflammatory and neural responses to LPS challenge.
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Affiliation(s)
- Hércules Ribeiro Leite
- Laboratório de Inflamação e Metabolismo (LIM), Programa de Pós-graduação em Ciências Fisiológicas, Centro Integrado de Pesquisa e Pós-Graduação em Saúde - CIPq-Saúde, Universidade Federal dos Vales do Jequitinhonha e Mucuri (UFVJM), Campus JK, Alto da Jacuba, Minas Gerais 39100 000, Brazil; Núcleo de Neurociências (NNC), Departamento de Fisiologia e Biofísica, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais (UFMG), Avenida Antônio Carlos, Pampulha, n° 6627, Belo Horizonte, Minas Gerais 31270 901, Brazil.
| | - Onésia Cristina de Oliveira-Lima
- Núcleo de Neurociências (NNC), Departamento de Fisiologia e Biofísica, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais (UFMG), Avenida Antônio Carlos, Pampulha, n° 6627, Belo Horizonte, Minas Gerais 31270 901, Brazil
| | - Luciana de Melo Pereira
- Núcleo de Neurociências (NNC), Departamento de Fisiologia e Biofísica, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais (UFMG), Avenida Antônio Carlos, Pampulha, n° 6627, Belo Horizonte, Minas Gerais 31270 901, Brazil
| | - Vinícius Elias de Moura Oliveira
- Núcleo de Neurociências (NNC), Departamento de Fisiologia e Biofísica, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais (UFMG), Avenida Antônio Carlos, Pampulha, n° 6627, Belo Horizonte, Minas Gerais 31270 901, Brazil
| | - Vania Ferreira Prado
- Molecular Medicine, Robarts Research Institute, Department of Physiology and Pharmacology, Department of Anatomy & Cell Biology, Schulich School of Medicine & Dentistry, University of Western Ontario, London, Ontario N6A 5K8, Canada
| | - Marco Antônio Máximo Prado
- Molecular Medicine, Robarts Research Institute, Department of Physiology and Pharmacology, Department of Anatomy & Cell Biology, Schulich School of Medicine & Dentistry, University of Western Ontario, London, Ontario N6A 5K8, Canada
| | - Grace Schenatto Pereira
- Núcleo de Neurociências (NNC), Departamento de Fisiologia e Biofísica, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais (UFMG), Avenida Antônio Carlos, Pampulha, n° 6627, Belo Horizonte, Minas Gerais 31270 901, Brazil
| | - André Ricardo Massensini
- Núcleo de Neurociências (NNC), Departamento de Fisiologia e Biofísica, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais (UFMG), Avenida Antônio Carlos, Pampulha, n° 6627, Belo Horizonte, Minas Gerais 31270 901, Brazil.
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26
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da Silva AJ, Trindade MAS, Santos DOC, Lima RF. Maximum-likelihood q-estimator uncovers the role of potassium at neuromuscular junctions. BIOLOGICAL CYBERNETICS 2016; 110:31-40. [PMID: 26721559 DOI: 10.1007/s00422-015-0673-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2013] [Accepted: 12/05/2015] [Indexed: 06/05/2023]
Abstract
Recently, we demonstrated the existence of nonextensive behavior in neuromuscular transmission (da Silva et al. in Phys Rev E 84:041925, 2011). In this letter, we first obtain a maximum-likelihood q-estimator to calculate the scale factor ([Formula: see text]) and the q-index of q-Gaussian distributions. Next, we use the indexes to analyze spontaneous miniature end plate potentials in electrophysiological recordings from neuromuscular junctions. These calculations were performed assuming both normal and high extracellular potassium concentrations [Formula: see text]. This protocol was used to test the validity of Tsallis statistics under electrophysiological conditions closely resembling physiological stimuli. The analysis shows that q-indexes are distinct depending on the extracellular potassium concentration. Our letter provides a general way to obtain the best estimate of parameters from a q-Gaussian distribution function. It also expands the validity of Tsallis statistics in realistic physiological stimulus conditions. In addition, we discuss the physical and physiological implications of these findings.
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Affiliation(s)
- A J da Silva
- Departamento de Física, Instituto de Ciências Exatas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, CEP 31270-901, Brazil.
- Instituto de Humanidades, Artes e Ciências, Universidade Federal do Sul da Bahia, Itabuna, Bahia, CEP 45613-204, Brazil.
| | - M A S Trindade
- Departamento de Ciências Exatas e da Terra, Universidade do Estado da Bahia, Alagoinhas, Bahia, CEP 48040-210, Brazil
| | - D O C Santos
- Instituto de Humanidades, Artes e Ciências, Universidade Federal do Sul da Bahia, Itabuna, Bahia, CEP 31270-901, Brazil
| | - R F Lima
- Departamento de Fisiologia e Farmacologia, Faculdade de Medicina, Universidade Federal do Ceará, Fortaleza, Ceará, CEP 60430-270, Brazil
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Cash F, Vernon SW, Phelan P, Goodchild J, Baines RA. Central cholinergic synaptic vesicle loading obeys the set-point model in Drosophila. J Neurophysiol 2016; 115:843-50. [PMID: 26655826 DOI: 10.1152/jn.01053.2015] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2015] [Accepted: 12/09/2015] [Indexed: 11/22/2022] Open
Abstract
Experimental evidence shows that neurotransmitter release, from presynaptic terminals, can be regulated by altering transmitter load per synaptic vesicle (SV) and/or through change in the probability of vesicle release. The vesicular acetylcholine transporter (VAChT) loads acetylcholine into SVs at cholinergic synapses. We investigated how the VAChT affects SV content and release frequency at central synapses in Drosophila melanogaster by using an insecticidal compound, 5Cl-CASPP, to block VAChT and by transgenic overexpression of VAChT in cholinergic interneurons. Decreasing VAChT activity produces a decrease in spontaneous SV release with no change to quantal size and no decrease in the number of vesicles at the active zone. This suggests that many vesicles are lacking in neurotransmitter. Overexpression of VAChT leads to increased frequency of SV release, but again with no change in quantal size or vesicle number. This indicates that loading of central cholinergic SVs obeys the "set-point" model, rather than the "steady-state" model that better describes loading at the vertebrate neuromuscular junction. However, we show that expression of a VAChT polymorphism lacking one glutamine residue in a COOH-terminal polyQ domain leads to increased spontaneous SV release and increased quantal size. This effect spotlights the poly-glutamine domain as potentially being important for sensing the level of neurotransmitter in cholinergic SVs.
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Affiliation(s)
- Francesca Cash
- Faculty of Life Sciences, University of Manchester, Manchester, United Kingdom
| | - Samuel W Vernon
- Faculty of Life Sciences, University of Manchester, Manchester, United Kingdom
| | - Pauline Phelan
- School of Biosciences, University of Kent, Kent, United Kingdom; and
| | - Jim Goodchild
- Syngenta Crop Protection Research, Bracknell, Berkshire, United Kingdom
| | - Richard A Baines
- Faculty of Life Sciences, University of Manchester, Manchester, United Kingdom;
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28
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Jeremias IC, Victorino VJ, Barbeiro HV, Kubo SA, Prado CM, Lima TM, Soriano FG. The Role of Acetylcholine in the Inflammatory Response in Animals Surviving Sepsis Induced by Cecal Ligation and Puncture. Mol Neurobiol 2015; 53:6635-6643. [DOI: 10.1007/s12035-015-9538-y] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2015] [Accepted: 11/09/2015] [Indexed: 01/14/2023]
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29
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Stensrud MJ, Sogn CJ, Gundersen V. Immunogold characteristics of VGLUT3-positive GABAergic nerve terminals suggest corelease of glutamate. J Comp Neurol 2015; 523:2698-713. [PMID: 26010578 DOI: 10.1002/cne.23811] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2014] [Revised: 05/18/2015] [Accepted: 05/18/2015] [Indexed: 12/20/2022]
Abstract
There is compelling evidence that glutamate can act as a cotransmitter in the mammalian brain. Interestingly, the third vesicular glutamate transporter (VGLUT3) is primarily found in neurons that were anticipated to be nonglutamatergic. Whereas the function of VGLUT3 in acetylcholinergic and serotoninergic neurons has been elucidated, the role of VGLUT3 in neurons releasing gamma-aminobutyric acid (GABA) is not settled. We have previously shown that VGLUT3 is found together with the vesicular GABA transporter (VIAAT) on synaptic vesicle membranes in the hippocampus. Now we provide novel electron microscopic data from the rat hippocampus suggesting that glutamate is enriched in inhibitory nerve terminals containing VGLUT3 compared to those lacking VGLUT3. The opposite was found for GABA; VGLUT3-positive inhibitory terminals contained lower density of GABA labeling compared to VGLUT3-negative inhibitory terminals. In addition, semiquantitative confocal immunofluorescence showed that N-methyl-D-aspartate (NMDA)-receptor labeling was present more frequently in VGLUT3-positive/VIAAT-positive synapses versus in VGLUT3-negative/VIAAT-positive synapses. Electron microscopic immunogold data further suggest that NMDA receptors are enriched in VGLUT3 containing inhibitory terminals. Our data reveal new chemical characteristics of a subset of GABAergic interneurons in the hippocampus. The analyses suggest that glutamate is coreleased with GABA from hippocampal basket cell-synapses to act on NMDA receptors.
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Affiliation(s)
- Mats Julius Stensrud
- Department of Anatomy and Healthy Brain Ageing Centre Regional Research Network, Institute of Basic Medical Sciences, University of Oslo, Norway
| | - Carl Johan Sogn
- Department of Anatomy and Healthy Brain Ageing Centre Regional Research Network, Institute of Basic Medical Sciences, University of Oslo, Norway
| | - Vidar Gundersen
- Department of Anatomy and Healthy Brain Ageing Centre Regional Research Network, Institute of Basic Medical Sciences, University of Oslo, Norway.,Department of Neurology, Oslo University Hospital, Rikshospitalet, Oslo, Norway
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Pinheiro NM, Miranda CJCP, Perini A, Câmara NOS, Costa SKP, Alonso-Vale MIC, Caperuto LC, Tibério IFLC, Prado MAM, Martins MA, Prado VF, Prado CM. Pulmonary inflammation is regulated by the levels of the vesicular acetylcholine transporter. PLoS One 2015; 10:e0120441. [PMID: 25816137 PMCID: PMC4376856 DOI: 10.1371/journal.pone.0120441] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2014] [Accepted: 01/22/2015] [Indexed: 01/02/2023] Open
Abstract
Acetylcholine (ACh) plays a crucial role in physiological responses of both the central and the peripheral nervous system. Moreover, ACh was described as an anti-inflammatory mediator involved in the suppression of exacerbated innate response and cytokine release in various organs. However, the specific contributions of endogenous release ACh for inflammatory responses in the lung are not well understood. To address this question we have used mice with reduced levels of the vesicular acetylcholine transporter (VAChT), a protein required for ACh storage in secretory vesicles. VAChT deficiency induced airway inflammation with enhanced TNF-α and IL-4 content, but not IL-6, IL-13 and IL-10 quantified by ELISA. Mice with decreased levels of VAChT presented increased collagen and elastic fibers deposition in airway walls which was consistent with an increase in inflammatory cells positive to MMP-9 and TIMP-1 in the lung. In vivo lung function evaluation showed airway hyperresponsiveness to methacholine in mutant mice. The expression of nuclear factor-kappa B (p65-NF-kB) in lung of VAChT-deficient mice were higher than in wild-type mice, whereas a decreased expression of janus-kinase 2 (JAK2) was observed in the lung of mutant animals. Our findings show the first evidence that cholinergic deficiency impaired lung function and produce local inflammation. Our data supports the notion that cholinergic system modulates airway inflammation by modulation of JAK2 and NF-kB pathway. We proposed that intact cholinergic pathway is necessary to maintain the lung homeostasis.
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Affiliation(s)
- Nathalia M. Pinheiro
- Department of Medicine, School of Medicine, University of Sao Paulo, São Paulo, Brazil
| | | | - Adenir Perini
- Department of Medicine, School of Medicine, University of Sao Paulo, São Paulo, Brazil
| | - Niels O. S. Câmara
- Department of Immunology, Institute of Biomedical Sciences, University of Sao Paulo, São Paulo, Brazil
| | - Soraia K. P. Costa
- Department of Pharmacology Institute of Biomedical Sciences, University of Sao Paulo, São Paulo, Brazil
| | | | - Luciana C. Caperuto
- Department of Biological Science, Federal University of Sao Paulo, Diadema, Brazil
| | | | - Marco Antônio M. Prado
- Molecular Medicine Group, Robarts Research Institute, Department of Physiology & Pharmacology and Department of Anatomy & Cell Biology, University of Western Ontario, London, Canada
| | - Mílton A. Martins
- Department of Medicine, School of Medicine, University of Sao Paulo, São Paulo, Brazil
| | - Vânia F. Prado
- Molecular Medicine Group, Robarts Research Institute, Department of Physiology & Pharmacology and Department of Anatomy & Cell Biology, University of Western Ontario, London, Canada
| | - Carla M. Prado
- Department of Medicine, School of Medicine, University of Sao Paulo, São Paulo, Brazil
- Department of Biological Science, Federal University of Sao Paulo, Diadema, Brazil
- * E-mail:
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31
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Tan J, Xu J, Xing Y, Chen L, Li S. Effect of rocuronium on the level and mode of pre-synaptic acetylcholine release by facial and somatic nerves, and changes following facial nerve injury in rabbits. INTERNATIONAL JOURNAL OF CLINICAL AND EXPERIMENTAL PATHOLOGY 2015; 8:1479-1490. [PMID: 25973033 PMCID: PMC4396282] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 11/18/2014] [Accepted: 12/24/2014] [Indexed: 06/04/2023]
Abstract
Muscles innervated by the facial nerve show differential sensitivities to muscle relaxants than muscles innervated by somatic nerves. The evoked electromyography (EEMG) response is also proportionally reduced after facial nerve injury. This forms the theoretical basis for proper utilization of muscle relaxants to balance EEMG monitoring and immobility under general anesthesia. (1) To observe the relationships between the level and mode of acetylcholine (ACh) release and the duration of facial nerve injury, and the influence of rocuronium in an in vitro rabbit model. (2) To explore the pre-synaptic mechanisms of discrepant responses to a muscle relaxant. Quantal and non-quantal ACh release were measured by using intracellular microelectrode recording in the orbicularis oris 1 to 42 days after graded facial nerve injury and in the gastrocnemius with/without rocuronium. Quantal ACh release was significantly decreased by rocuronium in the orbicularis oris and gastrocnemius, but significantly more so in gastrocnemius. Quantal release was reduced after facial nerve injury, which was significantly correlated with the severity of nerve injury in the absence but not in the presence of rocuronium. Non-quantal ACh release was reduced after facial nerve injury, with many relationships observed depending on the extent of the injury. The extent of inhibition of non-quantal release by rocuronium correlated with the grade of facial nerve injury. These findings may explain why EEMG amplitude might be diminished after acute facial nerve injury but relatively preserved after chronic injury and differential responses in sensitivity to rocuronium.
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Affiliation(s)
- Jinghua Tan
- Department of Anesthesiology, Eye and ENT hospital of Fudan UniversityShanghai 200031, China
| | - Jing Xu
- Department of Anesthesiology, Eye and ENT hospital of Fudan UniversityShanghai 200031, China
| | - Yian Xing
- Shanghai First People’s Hospital, Shanghai Jiao Tong UniversityShanghai 200080, China
| | - Lianhua Chen
- Shanghai First People’s Hospital, Shanghai Jiao Tong UniversityShanghai 200080, China
| | - Shitong Li
- Shanghai First People’s Hospital, Shanghai Jiao Tong UniversityShanghai 200080, China
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32
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Patra K, Lyons DJ, Bauer P, Hilscher MM, Sharma S, Leão RN, Kullander K. A role for solute carrier family 10 member 4, or vesicular aminergic-associated transporter, in structural remodelling and transmitter release at the mouse neuromuscular junction. Eur J Neurosci 2014; 41:316-27. [DOI: 10.1111/ejn.12790] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2014] [Revised: 10/14/2014] [Accepted: 10/17/2014] [Indexed: 12/27/2022]
Affiliation(s)
| | - David J. Lyons
- Department of Neuroscience; Uppsala University; Uppsala Sweden
| | - Pavol Bauer
- Department of Neuroscience; Uppsala University; Uppsala Sweden
| | - Markus M. Hilscher
- Department of Neuroscience; Uppsala University; Uppsala Sweden
- The Beijer Laboratory for Gene and Neurosciences; Uppsala Sweden
- Brain Institute; Federal University of Rio Grande do Norte; Natal Brazil
| | - Swati Sharma
- Department of Neuroscience; Uppsala University; Uppsala Sweden
| | - Richardson N. Leão
- Department of Neuroscience; Uppsala University; Uppsala Sweden
- The Beijer Laboratory for Gene and Neurosciences; Uppsala Sweden
- Brain Institute; Federal University of Rio Grande do Norte; Natal Brazil
| | - Klas Kullander
- Department of Neuroscience; Uppsala University; Uppsala Sweden
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33
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Vesicular glutamate transporter expression level affects synaptic vesicle release probability at hippocampal synapses in culture. J Neurosci 2014; 34:11781-91. [PMID: 25164673 DOI: 10.1523/jneurosci.1444-14.2014] [Citation(s) in RCA: 65] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The vesicular glutamate transporter (VGLUT) plays an essential role in synaptic transmission by filling vesicles with glutamate. At mammalian synapses, VGLUT expression level determines the amount of glutamate packaged into vesicles, and the specific paralog of VGLUT expressed affects the release probability. In this study, we investigate whether there is a link between the number of VGLUTs on vesicles and release probability. We used a combination of electrophysiology and imaging techniques in cultured mouse hippocampal neurons where the VGLUT expression level has been severely altered. We found that vesicles with drastically reduced VGLUT expression were released with a lower probability. This deficit in release could only be rescued by a functional transporter, suggesting that the transport function, and not the molecular interactions, of the protein affects vesicle release. Based on these data, we propose a novel means of presynaptic vesicle release regulation--the intravesicular glutamate fill state of the vesicle.
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34
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Akasheh N, Walsh MT, Costello RW. Eosinophil peroxidase induces expression of cholinergic genes via cell surface neural interactions. Mol Immunol 2014; 62:37-45. [PMID: 24937179 DOI: 10.1016/j.molimm.2014.05.014] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2014] [Revised: 05/21/2014] [Accepted: 05/29/2014] [Indexed: 01/21/2023]
Abstract
Eosinophils localize to and release their granule proteins in close association with nerves in patients with asthma and rhinitis. These conditions are associated with increased neural function. In this study the effect of the individual granule proteins on cholinergic neurotransmitter expression was investigated. Eosinophil peroxidase (EPO) upregulated choline acetyltransferase (ChAT) and vesicular acetylcholine transporter (VAChT) gene expression. Fluorescently labeled EPO was seen to bind to the IMR-32 cell surface. Both Poly-L-Glutamate (PLG) and Heparinase-1 reversed the up-regulatory effect of EPO on ChAT and VAChT expression and prevented EPO adhesion to the cell surface. Poly-L-arginine (PLA) had no effect on expression of either gene, suggesting that charge is necessary but insufficient to alter gene expression. EPO induced its effects via the activation of NF-κB. MEK inhibition led to reversal of all up-regulatory effects of EPO. These data indicate a preferential role of EPO signaling via a specific surface receptor that leads to neural plasticity.
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Affiliation(s)
- Nadim Akasheh
- Department of Medicine, Royal College of Surgeons in Ireland, Smurfit Building, Beaumont Hospital, Dublin 9, Ireland.
| | - Marie-Therese Walsh
- Department of Medicine, Royal College of Surgeons in Ireland, Smurfit Building, Beaumont Hospital, Dublin 9, Ireland
| | - Richard W Costello
- Department of Medicine, Royal College of Surgeons in Ireland, Smurfit Building, Beaumont Hospital, Dublin 9, Ireland
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35
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Drosophila melanogaster as a genetic model system to study neurotransmitter transporters. Neurochem Int 2014; 73:71-88. [PMID: 24704795 DOI: 10.1016/j.neuint.2014.03.015] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2013] [Revised: 03/20/2014] [Accepted: 03/24/2014] [Indexed: 12/30/2022]
Abstract
The model genetic organism Drosophila melanogaster, commonly known as the fruit fly, uses many of the same neurotransmitters as mammals and very similar mechanisms of neurotransmitter storage, release and recycling. This system offers a variety of powerful molecular-genetic methods for the study of transporters, many of which would be difficult in mammalian models. We review here progress made using Drosophila to understand the function and regulation of neurotransmitter transporters and discuss future directions for its use.
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36
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Rodrigues HA, Fonseca MDC, Camargo WL, Lima PMA, Martinelli PM, Naves LA, Prado VF, Prado MAM, Guatimosim C. Reduced expression of the vesicular acetylcholine transporter and neurotransmitter content affects synaptic vesicle distribution and shape in mouse neuromuscular junction. PLoS One 2013; 8:e78342. [PMID: 24260111 PMCID: PMC3832638 DOI: 10.1371/journal.pone.0078342] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2013] [Accepted: 09/18/2013] [Indexed: 12/03/2022] Open
Abstract
In vertebrates, nerve muscle communication is mediated by the release of the neurotransmitter acetylcholine packed inside synaptic vesicles by a specific vesicular acetylcholine transporter (VAChT). Here we used a mouse model (VAChT KDHOM) with 70% reduction in the expression of VAChT to investigate the morphological and functional consequences of a decreased acetylcholine uptake and release in neuromuscular synapses. Upon hypertonic stimulation, VAChT KDHOM mice presented a reduction in the amplitude and frequency of miniature endplate potentials, FM 1–43 staining intensity, total number of synaptic vesicles and altered distribution of vesicles within the synaptic terminal. In contrast, under electrical stimulation or no stimulation, VAChT KDHOM neuromuscular junctions did not differ from WT on total number of vesicles but showed altered distribution. Additionally, motor nerve terminals in VAChT KDHOM exhibited small and flattened synaptic vesicles similar to that observed in WT mice treated with vesamicol that blocks acetylcholine uptake. Based on these results, we propose that decreased VAChT levels affect synaptic vesicle biogenesis and distribution whereas a lower ACh content affects vesicles shape.
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Affiliation(s)
- Hermann A. Rodrigues
- Departamento de Morfologia, ICB, Universidade Federal de Minas Gerais, Belo Horizonte, Brasil
| | - Matheus de C. Fonseca
- Departamento de Morfologia, ICB, Universidade Federal de Minas Gerais, Belo Horizonte, Brasil
| | - Wallace L. Camargo
- Departamento de Fisiologia e Biofísica, ICB, Universidade Federal de Minas Gerais, Belo Horizonte, Brasil
| | - Patrícia M. A. Lima
- Departamento de Engenharia de Biossistemas, Universidade Federal de São João Del Rei, São João Del Rei, Brasil
| | - Patrícia M. Martinelli
- Departamento de Morfologia, ICB, Universidade Federal de Minas Gerais, Belo Horizonte, Brasil
| | - Lígia A. Naves
- Departamento de Fisiologia e Biofísica, ICB, Universidade Federal de Minas Gerais, Belo Horizonte, Brasil
| | - Vânia F. Prado
- Robarts Research Institute and Department of Physiology and Pharmacology and Anatomy & Cell Biology, University of Western Ontario, London, ON, Canada
| | - Marco A. M. Prado
- Robarts Research Institute and Department of Physiology and Pharmacology and Anatomy & Cell Biology, University of Western Ontario, London, ON, Canada
| | - Cristina Guatimosim
- Departamento de Morfologia, ICB, Universidade Federal de Minas Gerais, Belo Horizonte, Brasil
- * E-mail:
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37
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Abstract
Acetylcholine, the first chemical to be identified as a neurotransmitter, is packed in synaptic vesicles by the activity of VAChT (vesicular acetylcholine transporter). A decrease in VAChT expression has been reported in a number of diseases, and this has consequences for the amount of acetylcholine loaded in synaptic vesicles as well as for neurotransmitter release. Several genetically modified mice targeting the VAChT gene have been generated, providing novel models to understand how changes in VAChT affect transmitter release. A surprising finding is that most cholinergic neurons in the brain also can express a second type of vesicular neurotransmitter transporter that allows these neurons to secrete two distinct neurotransmitters. Thus a given neuron can use two neurotransmitters to regulate different physiological functions. In addition, recent data indicate that non-neuronal cells can also express the machinery used to synthesize and release acetylcholine. Some of these cells rely on VAChT to secrete acetylcholine with potential physiological consequences in the periphery. Hence novel functions for the oldest neurotransmitter known are emerging with the potential to provide new targets for the treatment of several pathological conditions.
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38
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Guzman MS, De Jaeger X, Drangova M, Prado MAM, Gros R, Prado VF. Mice with selective elimination of striatal acetylcholine release are lean, show altered energy homeostasis and changed sleep/wake cycle. J Neurochem 2013; 124:658-69. [PMID: 23240572 DOI: 10.1111/jnc.12128] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2012] [Revised: 11/20/2012] [Accepted: 12/07/2012] [Indexed: 01/21/2023]
Abstract
Cholinergic neurons are known to regulate striatal circuits; however, striatal-dependent physiological outcomes influenced by acetylcholine (ACh) are still poorly under;?>stood. Here, we used vesicular acetylcholine transporter (VAChT)(D2-Cre-flox/flox) mice, in which we selectively ablated the vesicular acetylcholine transporter in the striatum to dissect the specific roles of striatal ACh in metabolic homeostasis. We report that VAChT(D) (2-Cre-flox/flox) mice are lean at a young age and maintain this lean phenotype with time. The reduced body weight observed in these mutant mice is not attributable to reduced food intake or to a decrease in growth rate. In addition, changed activity could not completely explain the lean phenotype, as only young VAChT(D) (2-Cre-flox/flox) mice showed increased physical activity. Interestingly, VAChT(D) (2-Cre-flox/flox) mice show several metabolic changes, including increased plasma levels of insulin and leptin. They also show increased periods of wakefulness when compared with littermate controls. Taken together, our data suggest that striatal ACh has an important role in the modulation of metabolism and highlight the importance of striatum cholinergic tone in the regulation of energy expenditure. These new insights on how cholinergic neurons influence homeostasis open new avenues for the search of drug targets to treat obesity.
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Affiliation(s)
- Monica S Guzman
- Robarts Research Institute, Schulich School of Medicine & Dentistry, University of Western Ontario, London, Ontario, Canada
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39
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De Jaeger X, Cammarota M, Prado MAM, Izquierdo I, Prado VF, Pereira GS. Decreased acetylcholine release delays the consolidation of object recognition memory. Behav Brain Res 2012; 238:62-8. [PMID: 23089649 DOI: 10.1016/j.bbr.2012.10.016] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2012] [Revised: 09/18/2012] [Accepted: 10/11/2012] [Indexed: 10/27/2022]
Abstract
Acetylcholine (ACh) is important for different cognitive functions such as learning, memory and attention. The release of ACh depends on its vesicular loading by the vesicular acetylcholine transporter (VAChT). It has been demonstrated that VAChT expression can modulate object recognition memory. However, the role of VAChT expression on object recognition memory persistence still remains to be understood. To address this question we used distinct mouse lines with reduced expression of VAChT, as well as pharmacological manipulations of the cholinergic system. We showed that reduction of cholinergic tone impairs object recognition memory measured at 24h. Surprisingly, object recognition memory, measured at 4 days after training, was impaired by substantial, but not moderate, reduction in VAChT expression. Our results suggest that levels of acetylcholine release strongly modulate object recognition memory consolidation and appear to be of particular importance for memory persistence 4 days after training.
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Affiliation(s)
- Xavier De Jaeger
- Molecular Brain Research Group, Robarts Research Institute, Schulich School of Medicine & Dentistry, University of Western Ontario, London, Ontario, N6A 5K8 Canada.
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40
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Skup M, Gajewska-Wozniak O, Grygielewicz P, Mankovskaya T, Czarkowska-Bauch J. Different effects of spinalization and locomotor training of spinal animals on cholinergic innervation of the soleus and tibialis anterior motoneurons. Eur J Neurosci 2012; 36:2679-88. [PMID: 22708650 DOI: 10.1111/j.1460-9568.2012.08182.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Cholinergic input modulates excitability of motoneurons and plays an important role in the control of locomotion in both intact and spinalized animals. However, spinal cord transection in adult rats affects cholinergic innervation of only some hindlimb motoneurons, suggesting that specificity of this response is related to functional differences between motoneurons. Our aim was therefore to compare cholinergic input to motoneurons innervating the soleus (Sol) and tibialis anterior (TA) motoneurons following spinal cord transection at a low-thoracic level. The second aim was to investigate whether deficits in cholinergic input to these motoneurons could be modified by locomotor training. The Sol and TA motoneurons were identified by retrograde labelling with fluorescent dyes injected intramuscularly. Cholinergic terminals were detected using anti-vesicular acetylcholine transporter (VAChT) antibody. Overall innervation of motoneurons was evaluated with anti-synaptophysin antibody. After spinalization we found a decrease in the number of VAChT-positive boutons apposing perikarya of the Sol (to 49%) but not TA motoneurons. Locomotor training, resulting in moderate functional improvement, partly reduced the deficit in cholinergic innervation of Sol motoneurons by increasing the number of VAChT-positive boutons. However, the optical density of VAChT-positive boutons terminating on various motoneurons, which decreased after spinalization, continued to decrease despite the training, suggesting an impairment of acetylcholine availability in the terminals. Different effects of spinal cord transection on cholinergic innervation of motoneurons controlling the ankle extensor and flexor muscles point to different functional states of these muscles in paraplegia as a possible source of activity-dependent signaling regulating cholinergic input to the motoneurons.
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Affiliation(s)
- Malgorzata Skup
- Department of Neurophysiology, Nencki Institute of Experimental Biology, Warsaw, Poland.
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41
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Abreu BJ, Leite LF, Oliveira DL, Amaral E. Synaptic vesicle cycling is not impaired in a glutamatergic and a cholinergic synapse that exhibit deficits in acidification and filling. BRAZ J PHARM SCI 2012. [DOI: 10.1590/s1984-82502012000100017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The purpose of the present work was to investigate synaptic vesicle trafficking when vesicles exhibit alterations in filling and acidification in two different synapses: a cholinergic frog neuromuscular junction and a glutamatergic ribbon-type nerve terminal in the retina. These synapses display remarkable structural and functional differences, and the mechanisms regulating synaptic vesicle cycling might also differ between them. The lipophilic styryl dye FM1-43 was used to monitor vesicle trafficking. Both preparations were exposed to pharmacological agents that collapse ΔpH (NH4Cl and methylamine) or the whole ΔµH+ (bafilomycin), a necessary situation to provide the driving force for neurotransmitter accumulation into synaptic vesicles. The results showed that FM1-43 loading and unloading in neuromuscular junctions did not differ statistically between control and experimental conditions (P > 0.05). Also, FM1-43 labeling in bipolar cell terminals proved highly similar under all conditions tested. Despite remarkable differences in both experimental models, the present findings show that acidification and filling are not required for normal vesicle trafficking in either synapse.
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42
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Blakely RD, Edwards RH. Vesicular and plasma membrane transporters for neurotransmitters. Cold Spring Harb Perspect Biol 2012; 4:a005595. [PMID: 22199021 PMCID: PMC3281572 DOI: 10.1101/cshperspect.a005595] [Citation(s) in RCA: 100] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The regulated exocytosis that mediates chemical signaling at synapses requires mechanisms to coordinate the immediate response to stimulation with the recycling needed to sustain release. Two general classes of transporter contribute to release, one located on synaptic vesicles that loads them with transmitter, and a second at the plasma membrane that both terminates signaling and serves to recycle transmitter for subsequent rounds of release. Originally identified as the target of psychoactive drugs, these transport systems have important roles in transmitter release, but we are only beginning to understand their contribution to synaptic transmission, plasticity, behavior, and disease. Recent work has started to provide a structural basis for their activity, to characterize their trafficking and potential for regulation. The results indicate that far from the passive target of psychoactive drugs, neurotransmitter transporters undergo regulation that contributes to synaptic plasticity.
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Affiliation(s)
- Randy D Blakely
- Department of Pharmacology and Psychiatry, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-8548, USA
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43
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Elimination of the vesicular acetylcholine transporter in the striatum reveals regulation of behaviour by cholinergic-glutamatergic co-transmission. PLoS Biol 2011; 9:e1001194. [PMID: 22087075 PMCID: PMC3210783 DOI: 10.1371/journal.pbio.1001194] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2011] [Accepted: 09/29/2011] [Indexed: 11/30/2022] Open
Abstract
A novel mouse model that eliminates cholinergic neurotransmission in the striatum while leaving glutamate release intact reveals differential effects on cocaine-induced behavior and dopaminergic responses. Cholinergic neurons in the striatum are thought to play major regulatory functions in motor behaviour and reward. These neurons express two vesicular transporters that can load either acetylcholine or glutamate into synaptic vesicles. Consequently cholinergic neurons can release both neurotransmitters, making it difficult to discern their individual contributions for the regulation of striatal functions. Here we have dissected the specific roles of acetylcholine release for striatal-dependent behaviour in mice by selective elimination of the vesicular acetylcholine transporter (VAChT) from striatal cholinergic neurons. Analysis of several behavioural parameters indicates that elimination of VAChT had only marginal consequences in striatum-related tasks and did not affect spontaneous locomotion, cocaine-induced hyperactivity, or its reward properties. However, dopaminergic sensitivity of medium spiny neurons (MSN) and the behavioural outputs in response to direct dopaminergic agonists were enhanced, likely due to increased expression/function of dopamine receptors in the striatum. These observations indicate that previous functions attributed to striatal cholinergic neurons in spontaneous locomotor activity and in the rewarding responses to cocaine are mediated by glutamate and not by acetylcholine release. Our experiments demonstrate how one population of neurons can use two distinct neurotransmitters to differentially regulate a given circuitry. The data also raise the possibility of using VAChT as a target to boost dopaminergic function and decrease high striatal cholinergic activity, common neurochemical alterations in individuals affected with Parkinson's disease. The neurotransmitters dopamine and acetylcholine play opposite roles in the striatum (a brain region involved in motor control and reward-related behaviour), and their balance is thought to be critical for striatal function. Acetylcholine in the striatum has been linked to a number of functions, including control of locomotor activity and response to drugs of abuse. However, striatal cholinergic interneurons can also release glutamate (in addition to acetylcholine) and it is presently unclear how these two neurotransmitters regulate striatal-dependent behaviour. Previous work has attempted to resolve this issue by ablating cholinergic neurons in the striatum, but this causes loss of both cholinergic and glutamatergic neurotransmission. In this study, we created a novel genetic mouse model which allowed us to selectively interfere with secretion of acetylcholine in the striatum, while leaving total striatal glutamate release intact. In these mice, we observed minimally altered behavioural responses to cocaine, suggesting that striatal glutamate, rather than acetylcholine, is critical for cocaine-induced behavioural manifestations. Furthermore, elimination of striatal acetylcholine release affects how striatal output neurons respond to dopamine, by up-regulating dopaminergic receptors and changing behavioural responses to dopaminergic agonists. Our experiments highlight a previously unappreciated physiological role of cholinergic-glutamatergic co-transmission and demonstrate how a population of neurons can use two distinct neurotransmitters to differentially regulate behaviour.
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44
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da Silva AJ, Lima RF, Moret MA. Nonextensivity and self-affinity in the mammalian neuromuscular junction. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2011; 84:041925. [PMID: 22181193 DOI: 10.1103/physreve.84.041925] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2011] [Revised: 07/05/2011] [Indexed: 05/31/2023]
Abstract
We study time series and the spontaneous miniature end-plate potentials (MEPPs) of mammals recorded at neuromuscular junctions using two different approaches: generalized thermostatistics and detrended fluctuation analysis (DFA). Classical concepts establish that the magnitude of these potentials is characterized by Gaussian statistics and that their intervals are randomly displayed. First we show that MEPP distributions adequately satisfy the q-Gaussian distributions that maximize the Tsallis entropy, indicating their nonextensive and nonequilibrium behavior. We then examine the intervals between the miniature potentials via DFA, where the profile of the intervals between events configures a deviation from the expected random behavior. Some possible physiological substrates for these findings are discussed.
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Affiliation(s)
- A J da Silva
- Departamento de Fisiologia e Biofísica, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, CEP 31270-910 Belo Horizonte, Minas Gerais, Brazil.
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45
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Cleavage of the vesicular GABA transporter under excitotoxic conditions is followed by accumulation of the truncated transporter in nonsynaptic sites. J Neurosci 2011; 31:4622-35. [PMID: 21430162 DOI: 10.1523/jneurosci.3541-10.2011] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
GABA is the major inhibitory neurotransmitter in the CNS and changes in GABAergic neurotransmission affect the overall activity of neuronal networks. The uptake of GABA into synaptic vesicles is mediated by the vesicular GABA transporter (VGAT), and changes in the expression of the transporter directly regulate neurotransmitter release. In this work we investigated the changes in VGAT protein levels during ischemia and in excitotoxic conditions, which may affect the demise process. We found that VGAT is cleaved by calpains following excitotoxic stimulation of hippocampal neurons with glutamate, giving rise to a stable truncated cleavage product (tVGAT). VGAT cleavage was also observed after transient middle cerebral artery occlusion in mice, a cerebral ischemia model, and following intrahippocampal injection of kainate, but no effect was observed in transgenic mice overexpressing calpastatin, a calpain inhibitor. Incubation of isolated cerebrocortical synaptic vesicles with recombinant calpain also induced the cleavage of VGAT and formation of stable tVGAT. Immunoblot experiments using antibodies targeting different regions of VGAT and N-terminal sequencing analysis showed that calpain cleaves the transporter in the N-terminal region, at amino acids 52 and 60. Immunocytochemistry of GABAergic striatal neurons expressing GFP fusion proteins with the full-length VGAT or tVGAT showed that cleavage of the transporter induces a loss of synaptic delivery, leading to a homogeneous distribution of the protein along neurites. Our results show that excitotoxicity downregulates full-length VGAT, with a concomitant generation of tVGAT, which is likely to affect GABAergic neurotransmission and may influence cell death during ischemia.
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Petrov AM, Naumenko NV, Uzinskaya KV, Giniatullin AR, Urazaev AK, Zefirov AL. Increased non-quantal release of acetylcholine after inhibition of endocytosis by methyl-β-cyclodextrin: the role of vesicular acetylcholine transporter. Neuroscience 2011; 186:1-12. [PMID: 21557989 DOI: 10.1016/j.neuroscience.2011.04.051] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2011] [Revised: 04/04/2011] [Accepted: 04/21/2011] [Indexed: 10/18/2022]
Abstract
We investigated the role of the vesicular acetylcholine transporter in the mechanism of non-quantal (non-vesicular) secretion of neurotransmitter in the neuromuscular synapse of the rat diaphragm muscle. Non-quantal secretion was estimated electrophysiologically by the amplitude of end-plate hyperpolarization after inhibition of cholinesterase and nicotinic receptors (H-effect) or measured by the optical detection of acetylcholine in the bathing solution. It was shown that 1 mM methyl-β-cyclodextrin (MCD) reduced both endocytosis and, to much lesser extent, exocytosis of synaptic vesicles (SV) thereby increasing non-quantal secretion of acetylcholine with a concurrent decrease in axoplasm pH. During high-frequency stimulation of the motor nerve, that substantially increases vesicles exocytosis, the non-quantal secretion was further enhanced if the endocytosis of SV was blocked by MCD. In contrast, non-quantal secretion of acetylcholine did not increase when the MCD-treated neuromuscular preparations were superfused with either vesamicol, an inhibitor of vesicular transporter of acetylcholine, or sodium propionate, which decreases intracellular pH. These results suggest that the proton-dependent, vesamicol-sensitive vesicular transporters of acetylcholine, which become inserted into the presynaptic membrane during SV exocytosis and removed during endocytotic recycling of SV, play the major role in the process of non-quantal secretion of neurotransmitter.
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Affiliation(s)
- A M Petrov
- Department of Physiology, Medical University, Kazan 420012, Russia
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Schmid S, Azzopardi E, De Jaeger X, Prado MAM, Prado VF. VAChT knock-down mice show normal prepulse inhibition but disrupted long-term habituation. GENES BRAIN AND BEHAVIOR 2011; 10:457-64. [DOI: 10.1111/j.1601-183x.2011.00686.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Novel strains of mice deficient for the vesicular acetylcholine transporter: insights on transcriptional regulation and control of locomotor behavior. PLoS One 2011; 6:e17611. [PMID: 21423695 PMCID: PMC3053374 DOI: 10.1371/journal.pone.0017611] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2010] [Accepted: 01/31/2011] [Indexed: 12/19/2022] Open
Abstract
Defining the contribution of acetylcholine to specific behaviors has been challenging, mainly because of the difficulty in generating suitable animal models of cholinergic dysfunction. We have recently shown that, by targeting the vesicular acetylcholine transporter (VAChT) gene, it is possible to generate genetically modified mice with cholinergic deficiency. Here we describe novel VAChT mutant lines. VAChT gene is embedded within the first intron of the choline acetyltransferase (ChAT) gene, which provides a unique arrangement and regulation for these two genes. We generated a VAChT allele that is flanked by loxP sequences and carries the resistance cassette placed in a ChAT intronic region (FloxNeo allele). We show that mice with the FloxNeo allele exhibit differential VAChT expression in distinct neuronal populations. These mice show relatively intact VAChT expression in somatomotor cholinergic neurons, but pronounced decrease in other cholinergic neurons in the brain. VAChT mutant mice present preserved neuromuscular function, but altered brain cholinergic function and are hyperactive. Genetic removal of the resistance cassette rescues VAChT expression and the hyperactivity phenotype. These results suggest that release of ACh in the brain is normally required to “turn down” neuronal circuits controlling locomotion.
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