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Sabbir MG. Cholinergic Receptor Muscarinic 1 Co-Localized with Mitochondria in Cultured Dorsal Root Ganglion Neurons, and Its Deletion Disrupted Mitochondrial Ultrastructure in Peripheral Neurons: Implications in Alzheimer's Disease. J Alzheimers Dis 2024; 98:247-264. [PMID: 38427478 DOI: 10.3233/jad-230883] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/03/2024]
Abstract
Background Loss of Cholinergic Receptor Muscarinic 1 (CHRM1) has been linked to the pathogenesis of Alzheimer's disease (AD). Our recent study found significantly lower CHRM1 protein levels in AD patient cortices, linked to reduced survival. Furthermore, using knockout mice (Chrm1-/-) we demonstrated that deletion of Chrm1 alters cortical mitochondrial structure and function, directly establishing a connection between its loss and mitochondrial dysfunction in the context of AD. While CHRM1's role in the brain has been extensively investigated, its impact on peripheral neurons in AD remains a crucial area of research, especially considering reported declines in peripheral nerve conduction among AD patients. Objective The objective was to characterize Chrm1 localization and mitochondrial deficits in Chrm1-/- dorsal root ganglion (DRG) neurons. Methods Recombinant proteins tagged with Green or Red Fluorescent Protein (GFP/RFP) were transiently expressed to investigate the localization of Chrm1 and mitochondria, as well as mitochondrial movement in the neurites of cultured primary mouse DRG neurons, using confocal time-lapse live cell imaging. Transmission electron microscopy was performed to examine the ultrastructure of mitochondria in both wild-type and Chrm1-/- DRGs. Results Fluorescence imaging revealed colocalization and comigration of N-terminal GFP-tagged Chrm1 and mitochondrial localization signal peptide-tagged RFP-labelled mitochondria in the DRGs neurons. A spectrum of mitochondrial structural abnormalities, including disruption and loss of cristae was observed in 87% neurons in Chrm1-/- DRGs. Conclusions This study suggests that Chrm1 may be localized in the neuronal mitochondria and loss of Chrm1 in peripheral neurons causes sever mitochondrial structural aberrations resembling AD pathology.
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Affiliation(s)
- Mohammad Golam Sabbir
- Department of Psychology and Neuroscience, Collegeof Psychology, Nova Southeastern University, Fort Lauderdale, FL, USA
- Alzo Biosciences Inc., San Diego, CA, USA
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Masoumi N, Ghollasi M, Raheleh Halabian, Eftekhari E, Ghiasi M. Carbachol, along with calcium, indicates new strategy in neural differentiation of human adipose tissue-derived mesenchymal stem cells in vitro. Regen Ther 2023; 23:60-66. [PMID: 37122359 PMCID: PMC10130343 DOI: 10.1016/j.reth.2023.04.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2022] [Revised: 02/25/2023] [Accepted: 04/06/2023] [Indexed: 08/27/2023] Open
Abstract
INTRODUCTION Over the past few years, stem cells have represented a promising treatment in neurological disorders due to the well-defined characteristics of their capability to proliferate and differentiate into any cell type, both in vitro and in vivo. Additionally, previous studies have shown that calcium signaling modulates the proliferation and differentiation of neural progenitor cells. The present study investigated the effect of carbachol (CCh), a cholinergic agonist activating acetylcholine receptors, with and without calcium, on the neural differentiation of human adipose tissue-derived mesenchymal stem cells (hADSCs) in neural media, including forskolin and 3-isobutyl-1-methyl-xanthine and retinoic acid. METHODS For this purpose, first, the MTT assay and acridine orange staining were studied to obtain the optimal concentration of CCh. Next, the differentiation tests, such as cellular calcium assay as well as evaluation of qualitative and quantitative expression of neuronal index markers through immunofluorescence staining and gene expression analysis, respectively, were performed on days 7 and 14 of the differentiation period. RESULTS According to the results, CCh at 1 μM concentration had no cytotoxicity on hADSCs and also induced cell proliferation. Furthermore, CCh with and without calcium increased the expression of neural-specific genes (NSE, MAP2, β-III-tubulin, and MAPK3) and proteins (γ-enolase, MAP2, and β-III-tubulin) as well as the amount of calcium in differentiated hADSCs at 7 and 14 days after induction. CONCLUSIONS In conclusion, the findings suggest that CCh acts as an influential therapeutic factor in the field of neural regenerative medicine and research.
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Affiliation(s)
- Niloofar Masoumi
- Department of Cell and Molecular Biology, Faculty of Biological Sciences, Kharazmi University, Tehran, Iran
| | - Marzieh Ghollasi
- Department of Cell and Molecular Biology, Faculty of Biological Sciences, Kharazmi University, Tehran, Iran
| | - Raheleh Halabian
- Applied Microbiology Research Center, Systems Biology and Poisonings Institute, Baqiyatallah University of Medical Sciences, Tehran, Iran
| | - Elahe Eftekhari
- Department of Biology, Science and Research Branch, Islamic Azad University, Tehran, Iran
| | - Mohsen Ghiasi
- Department of Cellular and Molecular Biology, Faculty of Advanced Science and Technology, Tehran Medical Sciences, Islamic Azad University, Tehran, Iran
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Sabbir MG, Swanson M, Speth RC, Albensi BC. Hippocampal versus cortical deletion of cholinergic receptor muscarinic 1 in mice differentially affects post-translational modifications and supramolecular assembly of respiratory chain-associated proteins, mitochondrial ultrastructure, and respiration: implications in Alzheimer's disease. Front Cell Dev Biol 2023; 11:1179252. [PMID: 37293125 PMCID: PMC10246746 DOI: 10.3389/fcell.2023.1179252] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2023] [Accepted: 05/02/2023] [Indexed: 06/10/2023] Open
Abstract
Introduction: In a previous retrospective study using postmortem human brain tissues, we demonstrated that loss of Cholinergic Receptor Muscarinic 1 (CHRM1) in the temporal cortex of a subset of Alzheimer's patients was associated with poor survival, whereas similar loss in the hippocampus showed no such association. Mitochondrial dysfunction underlies Alzheimer's pathogenesis. Therefore, to investigate the mechanistic basis of our findings, we evaluated cortical mitochondrial phenotypes in Chrm1 knockout (Chrm1-/-) mice. Cortical Chrm1 loss resulted in reduced respiration, reduced supramolecular assembly of respiratory protein complexes, and caused mitochondrial ultrastructural abnormalities. These mouse-based findings mechanistically linked cortical CHRM1 loss with poor survival of Alzheimer's patients. However, evaluation of the effect of Chrm1 loss on mouse hippocampal mitochondrial characteristics is necessary to fully understand our retrospective human tissue-based observations. This is the objective of this study. Methods: Enriched hippocampal and cortical mitochondrial fractions (EHMFs/ECMFs, respectively) derived from wild-type and Chrm1-/- mice were used to measure respiration by quantifying real-time oxygen consumption, supramolecular assembly of oxidative phosphorylation (OXPHOS)-associated proteins by blue native polyacrylamide gel electrophoresis, post-translational modifications (PTMs) by isoelectric focusing (IEF), and mitochondrial ultrastructure by electron microscopy. Results: In contrast to our previous observations in Chrm1-/- ECMFs, EHMFs of Chrm1-/- mice significantly increased respiration with a concomitant increase in the supramolecular assembly of OXPHOS-associated proteins, specifically Atp5a and Uqcrc2, with no mitochondrial ultrastructural alterations. IEF of ECMFs and EHMFs from Chrm1-/- mice showed a decrease and an increase, respectively in a negatively charged (pH∼3) fraction of Atp5a relative to the wild-type mice, with a corresponding decrease or increase in the supramolecular assembly of Atp5a and respiration indicating a tissue-specific signaling effect. Discussion: Our findings indicate that loss of Chrm1 in the cortex causes structural, and physiological alterations to mitochondria that compromise neuronal function, whereas Chrm1 loss in the hippocampus may benefit neuronal function by enhancing mitochondrial function. This brain region-specific differential effect of Chrm1 deletion on mitochondrial function supports our human brain region-based findings and Chrm1-/- mouse behavioral phenotypes. Furthermore, our study indicates that Chrm1-mediated brain region-specific differential PTMs of Atp5a may alter complex-V supramolecular assembly which in turn regulates mitochondrial structure-function.
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Affiliation(s)
- Mohammad Golam Sabbir
- Division of Neurodegenerative Disorders, St. Boniface Hospital Albrechtsen Research Centre, Winnipeg, MB, Canada
- Alzo Biosciences Inc., San Diego, CA, United States
- Canadian Centre for Agri-Food Research in Health and Medicine, St. Boniface Hospital Albrechtsen Research Centre, Winnipeg, MB, Canada
- Barry & Judy Silverman College of Pharmacy, Nova Southeastern University, Fort Lauderdale, FL, United States
| | - Mamiko Swanson
- Alzo Biosciences Inc., San Diego, CA, United States
- Barry & Judy Silverman College of Pharmacy, Nova Southeastern University, Fort Lauderdale, FL, United States
| | - Robert C. Speth
- Barry & Judy Silverman College of Pharmacy, Nova Southeastern University, Fort Lauderdale, FL, United States
- Department of Pharmacology and Physiology, School of Medicine, Georgetown University, Washington, DC, United States
| | - Benedict C. Albensi
- Division of Neurodegenerative Disorders, St. Boniface Hospital Albrechtsen Research Centre, Winnipeg, MB, Canada
- Barry & Judy Silverman College of Pharmacy, Nova Southeastern University, Fort Lauderdale, FL, United States
- Department of Pharmacology and Therapeutics, University of Manitoba, Winnipeg, MB, Canada
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Sabbir MG, Swanson M, Albensi BC. Loss of cholinergic receptor muscarinic 1 impairs cortical mitochondrial structure and function: implications in Alzheimer's disease. Front Cell Dev Biol 2023; 11:1158604. [PMID: 37274741 PMCID: PMC10233041 DOI: 10.3389/fcell.2023.1158604] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2023] [Accepted: 05/04/2023] [Indexed: 06/06/2023] Open
Abstract
Introduction: Cholinergic Receptor Muscarinic 1 (CHRM1) is a G protein-coupled acetylcholine (ACh) receptor predominantly expressed in the cerebral cortex. In a retrospective postmortem brain tissues-based study, we demonstrated that severely (≥50% decrease) reduced CHRM1 proteins in the temporal cortex of Alzheimer's patients significantly correlated with poor patient outcomes. The G protein-mediated CHRM1 signal transduction cannot sufficiently explain the mechanistic link between cortical CHRM1 loss and the appearance of hallmark Alzheimer's pathophysiologies, particularly mitochondrial structural and functional abnormalities. Therefore, the objective of this study was to analyze the molecular, ultrastructural, and functional properties of cortical mitochondria using CHRM1 knockout (Chrm1-/-) and wild-type mice to identify mitochondrial abnormalities. Methods: Isolated and enriched cortical mitochondrial fractions derived from wild-type and Chrm1-/- mice were assessed for respiratory deficits (oxygen consumption) following the addition of different substrates. The supramolecular assembly of mitochondrial oxidative phosphorylation (OXPHOS)-associated protein complexes (complex I-V) and cortical mitochondrial ultrastructure were investigated by blue native polyacrylamide gel electrophoresis and transmission electron microscopy (TEM), respectively. A cocktail of antibodies, specific to Ndufb8, Sdhb, Uqcrc2, Mtco1, and Atp5a proteins representing different subunits of complexes I-V, respectively was used to characterize different OXPHOS-associated protein complexes. Results: Loss of Chrm1 led to a significant reduction in cortical mitochondrial respiration (oxygen consumption) concomitantly associated with reduced oligomerization of ATP synthase (complex V) and supramolecular assembly of complexes I-IV (Respirasome). Overexpression of Chrm1 in transformed cells (lacking native Chrm1) significantly increased complex V oligomerization and respirasome assembly leading to enhanced respiration. TEM analysis revealed that Chrm1 loss led to mitochondrial ultrastructural defects and alteration in the tinctorial properties of cortical neurons causing a significant increase in the abundance of dark cortical neurons (Chrm1-/- 85% versus wild-type 2%). Discussion: Our findings indicate a hitherto unknown effect of Chrm1 deletion in cortical neurons affecting mitochondrial function by altering multiple interdependent factors including ATP synthase oligomerization, respirasome assembly, and mitochondrial ultrastructure. The appearance of dark neurons in Chrm1-/- cortices implies potentially enhanced glutamatergic signaling in pyramidal neurons under Chrm1 loss condition. The findings provide novel mechanistic insights into Chrm1 loss with the appearance of mitochondrial pathophysiological deficits in Alzheimer's disease.
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Affiliation(s)
- Mohammad Golam Sabbir
- Division of Neurodegenerative Disorders, St. Boniface Hospital Albrechtsen Research Centre, Winnipeg, MB, Canada
- Alzo Biosciences Inc, SanDiego, CA, United States
- Canadian Centre for Agri-Food Research in Health and Medicine, St. Boniface Hospital Albrechtsen Research Centre, Winnipeg, MB, Canada
- Barry & Judy Silverman College of Pharmacy, Nova Southeastern University, Fort Lauderdale, FL, United States
| | - Mamiko Swanson
- Alzo Biosciences Inc, SanDiego, CA, United States
- Barry & Judy Silverman College of Pharmacy, Nova Southeastern University, Fort Lauderdale, FL, United States
| | - Benedict C. Albensi
- Division of Neurodegenerative Disorders, St. Boniface Hospital Albrechtsen Research Centre, Winnipeg, MB, Canada
- Barry & Judy Silverman College of Pharmacy, Nova Southeastern University, Fort Lauderdale, FL, United States
- Department of Pharmacology & Therapeutics, University of Manitoba, Winnipeg, MB, Canada
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Motawi TK, El-Maraghy SA, Kamel AS, Said SE, Kortam MA. Modulation of p38 MAPK and Nrf2/HO-1/NLRP3 inflammasome signaling and pyroptosis outline the anti-neuroinflammatory and remyelinating characters of Clemastine in EAE rat model. Biochem Pharmacol 2023; 209:115435. [PMID: 36720356 DOI: 10.1016/j.bcp.2023.115435] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2022] [Revised: 01/23/2023] [Accepted: 01/23/2023] [Indexed: 01/31/2023]
Abstract
There is vast evidence for the effect of NOD-like receptor protein-3 (NLRP3) inflammasome on multiple sclerosis (MS) pathogenesis. Clemastine (CLM) targets NLRP3 in hypoxic brain injury and promotes oligodendrocyte differentiation. However, no previous study pointed to the link of CLM with inflammasome components in MS. Herein, the study aimed to verify the action of CLM on NLRP3 signaling in experimental autoimmune encephalomyelitis (EAE) as an MS rat model. Homogenate of spinal cord with complete Freund's adjuvant was administered on days 0 and 7 to induce EAE. Rats received either CLM (5 mg/kg/day; p.o.) or MCC950 (2.5 mg/kg/day; i.p) for 15 days starting from the first immunization day. In EAEs' brains, NLRP3 pathway components; total and phosphorylated p38 mitogen-activated protein kinase (MAPK), apoptosis-associated speck-like protein containing a CARD (ASC), caspase-1, interleukins 1β and -18 along with pyroptotic marker; gasdermin D (GSDMD) were upregulated. These were accompanied with diminished nuclear factor erythroid 2-related factor 2 (Nrf2), heme oxygenase-1 (HO-1) and total antioxidant capacity levels. CLM improved these perturbations as well as signs of MS; weight loss, clinical scores, and motor disorders observed in the open field, hanging wire and rotarod tests. Histopathological examinations revealed improvement in H&E abnormalities and axonal demyelination as shown by luxol fast blue stain in lumbar sections of spinal cord. These CLM's actions were studied in comparison to MCC950 as a well-established selective blocker of the NLRP3 inflammasome. Conclusively, CLM has a protective role against neuroinflammation and demyelination in EAE via its anti-inflammatory and anti-pyroptotic actions.
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Affiliation(s)
- Tarek K Motawi
- Department of Biochemistry, Faculty of Pharmacy, Cairo University, Kasr El Ainy st., 11562 Cairo, Egypt.
| | - Shohda A El-Maraghy
- Department of Biochemistry, Faculty of Pharmacy, Cairo University, Kasr El Ainy st., 11562 Cairo, Egypt.
| | - Ahmed S Kamel
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Cairo University, Kasr El Ainy st., 11562 Cairo, Egypt.
| | - Salma E Said
- Department of Biochemistry, Faculty of Pharmacy, Cairo University, Kasr El Ainy st., 11562 Cairo, Egypt.
| | - Mona A Kortam
- Department of Biochemistry, Faculty of Pharmacy, Cairo University, Kasr El Ainy st., 11562 Cairo, Egypt.
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Rosa J, de Carvalho Myskiw J, Fiorenza NG, Furini CRG, Sapiras GG, Izquierdo I. Hippocampal cholinergic receptors and the mTOR participation in fear-motivated inhibitory avoidance extinction memory. Behav Brain Res 2023; 437:114129. [PMID: 36179804 DOI: 10.1016/j.bbr.2022.114129] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2022] [Revised: 09/07/2022] [Accepted: 09/24/2022] [Indexed: 10/14/2022]
Abstract
Evidence has demonstrated the hippocampal cholinergic system and the mammalian target of rapamycin (mTOR) participation during the memory formation of aversive events. This study assessed the role of these systems in the hippocampus for the extinction memory process by submitting male Wistar rats to fear-motivated step-down inhibitory avoidance (IA). The post-extinction session administration of the nicotinic and muscarinic cholinergic receptor antagonists, mecamylamine and scopolamine, respectively, both at doses of 2 µg/µl/side, and rapamycin, an mTOR inhibitor (0.02 µg/µl/side), into the CA1 region of the dorsal hippocampus, impaired the IA extinction memory. Furthermore, the nicotinic and muscarinic cholinergic receptor agonists, nicotine and muscarine, respectively, had a dose-dependent effect on the IA extinction memory when administered intra-CA1, immediately after the extinction session. Nicotine (0.6 µg/µl/side) and muscarine (0.02 µg/µl/side), respectively, had no effect, while the higher doses (6 and 2 µg/µl/side, respectively) impaired the IA extinction memory. Interestingly, the co-administration of muscarine at the lower dose blocked the impairment that was induced by rapamycin. This effect was not observed when nicotine at the lower dose was co-administered. These results have demonstrated the participation of the cholinergic receptors and mTOR in the hippocampus for IA extinction, and that the cholinergic agonists had a dose-dependent effect on the IA extinction memory. This study provides insights related to the behavioural aspects and the neurobiological properties underlying the early stage of fear-motivated IA extinction memory consolidation and suggests that there is hippocampal muscarinic receptor participation independent of mTOR in this memory process.
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Affiliation(s)
- Jessica Rosa
- Memory Center, Brain Institute of Rio Grande do Sul, Pontifical Catholic University of Rio Grande do Sul (PUCRS), Ipiranga 6690, Floor 2, 90610-600 Porto Alegre, RS, Brazil; Department of Pharmacology, School of Medicine of Ribeirao Preto, University of Sao Paulo (USP), Bandeirantes 3900, 14049-900 Ribeirao Preto, SP, Brazil.
| | - Jociane de Carvalho Myskiw
- Memory Center, Brain Institute of Rio Grande do Sul, Pontifical Catholic University of Rio Grande do Sul (PUCRS), Ipiranga 6690, Floor 2, 90610-600 Porto Alegre, RS, Brazil; National Institute of Translational Neuroscience (INNT), National Research Council of Brazil, Federal University of Rio de Janeiro, 21941-902 Rio de Janeiro, RJ, Brazil; Department of Biophysics, Institute of Biosciences, Federal University of Rio Grande do Sul (UFRGS), Bento Gonçalves 9500, Building 43422, Room 208 A, 91501-970 Porto Alegre, RS, Brazil
| | - Natalia Gindri Fiorenza
- Memory Center, Brain Institute of Rio Grande do Sul, Pontifical Catholic University of Rio Grande do Sul (PUCRS), Ipiranga 6690, Floor 2, 90610-600 Porto Alegre, RS, Brazil; Oswaldo Cruz Foundation (FIOCRUZ), Branch Ceara, 60760-000 Eusebio, CE, Brazil
| | - Cristiane Regina Guerino Furini
- Memory Center, Brain Institute of Rio Grande do Sul, Pontifical Catholic University of Rio Grande do Sul (PUCRS), Ipiranga 6690, Floor 2, 90610-600 Porto Alegre, RS, Brazil; National Institute of Translational Neuroscience (INNT), National Research Council of Brazil, Federal University of Rio de Janeiro, 21941-902 Rio de Janeiro, RJ, Brazil; Laboratory of Cognition and Memory Neurobiology, Brain Institute, Pontifical Catholic University of Rio Grande do Sul (PUCRS), Ipiranga 6690, 3rd Floor, 90610-000 Porto Alegre, RS, Brazil
| | - Gerson Guilherme Sapiras
- Memory Center, Brain Institute of Rio Grande do Sul, Pontifical Catholic University of Rio Grande do Sul (PUCRS), Ipiranga 6690, Floor 2, 90610-600 Porto Alegre, RS, Brazil; Clinical Hospital of Passo Fundo (HCPF), Tiradentes 295, 99010-260 Passo Fundo, RS, Brazil
| | - Ivan Izquierdo
- Memory Center, Brain Institute of Rio Grande do Sul, Pontifical Catholic University of Rio Grande do Sul (PUCRS), Ipiranga 6690, Floor 2, 90610-600 Porto Alegre, RS, Brazil; National Institute of Translational Neuroscience (INNT), National Research Council of Brazil, Federal University of Rio de Janeiro, 21941-902 Rio de Janeiro, RJ, Brazil
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Dean B, Bakker G, Ueda HR, Tobin AB, Brown A, Kanaan RAA. A growing understanding of the role of muscarinic receptors in the molecular pathology and treatment of schizophrenia. Front Cell Neurosci 2023; 17:1124333. [PMID: 36909280 PMCID: PMC9992992 DOI: 10.3389/fncel.2023.1124333] [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: 12/15/2022] [Accepted: 02/06/2023] [Indexed: 02/24/2023] Open
Abstract
Pre-clinical models, postmortem and neuroimaging studies all support a role for muscarinic receptors in the molecular pathology of schizophrenia. From these data it was proposed that activation of the muscarinic M1 and/or M4 receptor would reduce the severity of the symptoms of schizophrenia. This hypothesis is now supported by results from two clinical trials which indicate that activating central muscarinic M1 and M4 receptors can reduce the severity of positive, negative and cognitive symptoms of the disorder. This review will provide an update on a growing body of evidence that argues the muscarinic M1 and M4 receptors have critical roles in CNS functions that are dysregulated by the pathophysiology of schizophrenia. This realization has been made possible, in part, by the growing ability to visualize and quantify muscarinic M1 and M4 receptors in the human CNS using molecular neuroimaging. We will discuss how these advances have provided evidence to support the notion that there is a sub-group of patients within the syndrome of schizophrenia that have a unique molecular pathology driven by a marked loss of muscarinic M1 receptors. This review is timely, as drugs targeting muscarinic receptors approach clinical use for the treatment of schizophrenia and here we outline the background biology that supported development of such drugs to treat the disorder.
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Affiliation(s)
- Brian Dean
- Synaptic Biology and Cognition Laboratory, The Florey Institute of Neuroscience and Mental Health, Parkville, VIC, Australia
| | | | - Hiroki R Ueda
- Department of Systems Pharmacology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.,Laboratory for Synthetic Biology, RIKEN Center for Biosystems Dynamics Research, Osaka, Japan
| | - Andrew B Tobin
- Advanced Research Centre (ARC), School of Molecular Bioscience, University of Glasgow, Glasgow, United Kingdom
| | | | - Richard A A Kanaan
- Department of Psychiatry, Austin Health, The University of Melbourne, Heidelberg, VIC, Australia
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Slater C, Liu Y, Weiss E, Yu K, Wang Q. The Neuromodulatory Role of the Noradrenergic and Cholinergic Systems and Their Interplay in Cognitive Functions: A Focused Review. Brain Sci 2022; 12:890. [PMID: 35884697 PMCID: PMC9320657 DOI: 10.3390/brainsci12070890] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2022] [Revised: 06/28/2022] [Accepted: 06/30/2022] [Indexed: 12/15/2022] Open
Abstract
The noradrenergic and cholinergic modulation of functionally distinct regions of the brain has become one of the primary organizational principles behind understanding the contribution of each system to the diversity of neural computation in the central nervous system. Decades of work has shown that a diverse family of receptors, stratified across different brain regions, and circuit-specific afferent and efferent projections play a critical role in helping such widespread neuromodulatory systems obtain substantial heterogeneity in neural information processing. This review briefly discusses the anatomical layout of both the noradrenergic and cholinergic systems, as well as the types and distributions of relevant receptors for each system. Previous work characterizing the direct and indirect interaction between these two systems is discussed, especially in the context of higher order cognitive functions such as attention, learning, and the decision-making process. Though a substantial amount of work has been done to characterize the role of each neuromodulator, a cohesive understanding of the region-specific cooperation of these two systems is not yet fully realized. For the field to progress, new experiments will need to be conducted that capitalize on the modular subdivisions of the brain and systematically explore the role of norepinephrine and acetylcholine in each of these subunits and across the full range of receptors expressed in different cell types in these regions.
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Affiliation(s)
- Cody Slater
- Department of Biomedical Engineering, Columbia University, ET 351, 500 W. 120th Street, New York, NY 10027, USA; (C.S.); (Y.L.); (E.W.); (K.Y.)
- Vagelos College of Physicians and Surgeons, Columbia University, 630 West 168th Street, New York, NY 10032, USA
| | - Yuxiang Liu
- Department of Biomedical Engineering, Columbia University, ET 351, 500 W. 120th Street, New York, NY 10027, USA; (C.S.); (Y.L.); (E.W.); (K.Y.)
| | - Evan Weiss
- Department of Biomedical Engineering, Columbia University, ET 351, 500 W. 120th Street, New York, NY 10027, USA; (C.S.); (Y.L.); (E.W.); (K.Y.)
| | - Kunpeng Yu
- Department of Biomedical Engineering, Columbia University, ET 351, 500 W. 120th Street, New York, NY 10027, USA; (C.S.); (Y.L.); (E.W.); (K.Y.)
| | - Qi Wang
- Department of Biomedical Engineering, Columbia University, ET 351, 500 W. 120th Street, New York, NY 10027, USA; (C.S.); (Y.L.); (E.W.); (K.Y.)
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Changes in cortical gene expression in the muscarinic M1 receptor knockout mouse: potential relevance to schizophrenia, Alzheimer's disease and cognition. NPJ SCHIZOPHRENIA 2021; 7:44. [PMID: 34521861 PMCID: PMC8440523 DOI: 10.1038/s41537-021-00174-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Accepted: 07/14/2021] [Indexed: 11/08/2022]
Abstract
Postmortem and neuroimaging studies show low levels of cortical muscarinic M1 receptors (CHRM1) in patients with schizophrenia which is significant because CHRM signalling has been shown to change levels of gene expression and cortical gene expression is altered in schizophrenia. We decided to identify CHRM1-mediated changes in cortical gene expression by measuring levels of RNA in the cortex of the Chrm1-/- mouse (n = 10), where there would be no signalling by that receptor, and in wild type mouse (n = 10) using the Affymetrix Mouse Exon 1.0 ST Array. We detected RNA for 15,501 annotated genes and noncoding RNA of which 1,467 RNAs were higher and 229 RNAs lower in the cortex of the Chrm1-/- mouse. Pathways and proteins affected by the changes in cortical gene expression in the Chrm1-/- are linked to the molecular pathology of schizophrenia. Our human cortical gene expression data showed 47 genes had altered expression in Chrm1-/- mouse and the frontal pole from patients with schizophrenia with the change in expression of 44 genes being in opposite directions. In addition, genes with altered levels of expression in the Chrm1-/- mouse have been shown to affect amyloid precursor protein processing which is associated with the pathophysiology of Alzheimer's disease, and 69 genes with altered expression in the Chrm1-/- mouse are risk genes associated with human cognitive ability. Our findings argue CHRM1-mediated changes in gene expression are relevant to the pathophysiologies of schizophrenia and Alzheimer's disease and the maintenance of cognitive ability in humans.
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Kheradpezhouh E, Tang MF, Mattingley JB, Arabzadeh E. Enhanced Sensory Coding in Mouse Vibrissal and Visual Cortex through TRPA1. Cell Rep 2021; 32:107935. [PMID: 32698003 DOI: 10.1016/j.celrep.2020.107935] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2020] [Revised: 05/25/2020] [Accepted: 06/29/2020] [Indexed: 01/01/2023] Open
Abstract
Transient receptor potential ankyrin 1 (TRPA1) is a non-selective cation channel, broadly expressed throughout the body. Despite its expression in the mammalian brain, little is known about the contribution of TRPA1 to cortical function. Here, we characterize how TRPA1 affects sensory information processing in two cortical areas in mice: the primary vibrissal (whisker) somatosensory cortex (vS1) and the primary visual cortex (V1). In vS1, local activation of TRPA1 by allyl isothiocyanate (AITC) increases the ongoing activity of neurons and their evoked response to vibrissal stimulation, producing a positive gain modulation. The gain modulation is reversed by TRPA1 inhibitor HC-030031 and is absent in TRPA1 knockout mice. Similarly, in V1, TRPA1 activation increases the gain of direction and orientation selectivity. Linear decoding of V1 population activity confirms faster and more reliable encoding of visual signals under TRPA1 activation. Overall, our findings reveal a physiological role for TRPA1 in enhancing sensory signals in the mammalian cortex.
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Affiliation(s)
- Ehsan Kheradpezhouh
- Eccles Institute of Neuroscience, John Curtin School of Medical Research, The Australian National University, Canberra, ACT, Australia; The Australian Research Council Centre of Excellence for Integrative Brain Function, Australia.
| | - Matthew F Tang
- Eccles Institute of Neuroscience, John Curtin School of Medical Research, The Australian National University, Canberra, ACT, Australia; The Australian Research Council Centre of Excellence for Integrative Brain Function, Australia; Queensland Brain Institute, The University of Queensland, Brisbane, QLD, Australia
| | - Jason B Mattingley
- The Australian Research Council Centre of Excellence for Integrative Brain Function, Australia; Queensland Brain Institute, The University of Queensland, Brisbane, QLD, Australia; School of Psychology, The University of Queensland, Brisbane, QLD, Australia; Canadian Institute for Advanced Research (CIFAR), Toronto, ON, Canada
| | - Ehsan Arabzadeh
- Eccles Institute of Neuroscience, John Curtin School of Medical Research, The Australian National University, Canberra, ACT, Australia; The Australian Research Council Centre of Excellence for Integrative Brain Function, Australia
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11
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van der Westhuizen ET, Choy KHC, Valant C, McKenzie-Nickson S, Bradley SJ, Tobin AB, Sexton PM, Christopoulos A. Fine Tuning Muscarinic Acetylcholine Receptor Signaling Through Allostery and Bias. Front Pharmacol 2021; 11:606656. [PMID: 33584282 PMCID: PMC7878563 DOI: 10.3389/fphar.2020.606656] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Accepted: 11/30/2020] [Indexed: 12/18/2022] Open
Abstract
The M1 and M4 muscarinic acetylcholine receptors (mAChRs) are highly pursued drug targets for neurological diseases, in particular for Alzheimer's disease and schizophrenia. Due to high sequence homology, selective targeting of any of the M1-M5 mAChRs through the endogenous ligand binding site has been notoriously difficult to achieve. With the discovery of highly subtype selective mAChR positive allosteric modulators in the new millennium, selectivity through targeting an allosteric binding site has opened new avenues for drug discovery programs. However, some hurdles remain to be overcome for these promising new drug candidates to progress into the clinic. One challenge is the potential for on-target side effects, such as for the M1 mAChR where over-activation of the receptor by orthosteric or allosteric ligands can be detrimental. Therefore, in addition to receptor subtype selectivity, a drug candidate may need to exhibit a biased signaling profile to avoid such on-target adverse effects. Indeed, recent studies in mice suggest that allosteric modulators for the M1 mAChR that bias signaling toward specific pathways may be therapeutically important. This review brings together details on the signaling pathways activated by the M1 and M4 mAChRs, evidence of biased agonism at these receptors, and highlights pathways that may be important for developing new subtype selective allosteric ligands to achieve therapeutic benefit.
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Affiliation(s)
- Emma T. van der Westhuizen
- Drug Discovery Biology, Monash Institute for Pharmaceutical Research, Monash University, Parkville, VIC, Australia
| | - K. H. Christopher Choy
- Drug Discovery Biology, Monash Institute for Pharmaceutical Research, Monash University, Parkville, VIC, Australia
| | - Celine Valant
- Drug Discovery Biology, Monash Institute for Pharmaceutical Research, Monash University, Parkville, VIC, Australia
| | - Simon McKenzie-Nickson
- Drug Discovery Biology, Monash Institute for Pharmaceutical Research, Monash University, Parkville, VIC, Australia
| | - Sophie J. Bradley
- Centre for Translational Pharmacology, Institute of Molecular Cell and Systems Biology, University of Glasgow, Glasgow, United Kingdom
| | - Andrew B. Tobin
- Centre for Translational Pharmacology, Institute of Molecular Cell and Systems Biology, University of Glasgow, Glasgow, United Kingdom
| | - Patrick M. Sexton
- Drug Discovery Biology, Monash Institute for Pharmaceutical Research, Monash University, Parkville, VIC, Australia
| | - Arthur Christopoulos
- Drug Discovery Biology, Monash Institute for Pharmaceutical Research, Monash University, Parkville, VIC, Australia
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12
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Melis C, Beauvais G, Muntean BS, Cirnaru MD, Otrimski G, Creus-Muncunill J, Martemyanov KA, Gonzalez-Alegre P, Ehrlich ME. Striatal Dopamine Induced ERK Phosphorylation Is Altered in Mouse Models of Monogenic Dystonia. Mov Disord 2021; 36:1147-1157. [PMID: 33458877 DOI: 10.1002/mds.28476] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Revised: 12/02/2020] [Accepted: 12/04/2020] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND Similar to some monogenic forms of dystonia, levodopa-induced dyskinesia is a hyperkinetic movement disorder with abnormal nigrostriatal dopaminergic neurotransmission. Molecularly, it is characterized by hyper-induction of phosphorylation of extracellular signal-related kinase in response to dopamine in medium spiny neurons of the direct pathway. OBJECTIVES The objective of this study was to determine if mouse models of monogenic dystonia exhibit molecular features of levodopa-induced dyskinesia. METHODS Western blotting and quantitative immunofluorescence was used to assay baseline and/or dopamine-induced levels of the phosphorylated kinase in the striatum in mouse models of DYT1, DYT6, and DYT25 expressing a reporter in dopamine D1 receptor-expressing projection neurons. Cyclic adenosine monophosphate (cAMP) immunoassay and adenylyl cyclase activity assays were also performed. RESULTS In DYT1 and DYT6 models, blocking dopamine reuptake with cocaine leads to enhanced extracellular signal-related kinase phosphorylation in dorsomedial striatal medium spiny neurons in the direct pathway, which is abolished by pretreatment with the N-methyl-d-aspartate antagonist MK-801. Phosphorylation is decreased in a model of DYT25. Levels of basal and stimulated cAMP and adenylyl cyclase activity were normal in the DYT1 and DYT6 mice and decreased in the DYT25 mice. Oxotremorine induced increased abnormal movements in the DYT1 knock-in mice. CONCLUSIONS The increased dopamine induction of extracellular signal-related kinase phosphorylation in 2 genetic types of dystonia, similar to what occurs in levodopa-induced dyskinesia, and its decrease in a third, suggests that abnormal signal transduction in response to dopamine in the postsynaptic nigrostriatal pathway might be a point of convergence for dystonia and other hyperkinetic movement disorders, potentially offering common therapeutic targets. © 2021 International Parkinson and Movement Disorder Society.
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Affiliation(s)
- Chiara Melis
- Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Genevieve Beauvais
- Raymond G. Perelman Center for Cellular and Molecular Therapy, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
| | - Brian S Muntean
- Department of Neuroscience, The Scripps Research Institute, Jupiter, Florida, USA
| | - Maria-Daniela Cirnaru
- Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Garrett Otrimski
- Raymond G. Perelman Center for Cellular and Molecular Therapy, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
| | - Jordi Creus-Muncunill
- Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Kirill A Martemyanov
- Department of Neuroscience, The Scripps Research Institute, Jupiter, Florida, USA
| | - Pedro Gonzalez-Alegre
- Raymond G. Perelman Center for Cellular and Molecular Therapy, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA.,Department of Neurology, The University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Michelle E Ehrlich
- Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, New York, USA.,Departments of Pediatrics and Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, New York, USA
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13
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Cieślik P, Wierońska JM. Regulation of Glutamatergic Activity via Bidirectional Activation of Two Select Receptors as a Novel Approach in Antipsychotic Drug Discovery. Int J Mol Sci 2020; 21:ijms21228811. [PMID: 33233865 PMCID: PMC7699963 DOI: 10.3390/ijms21228811] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2020] [Revised: 11/10/2020] [Accepted: 11/16/2020] [Indexed: 12/14/2022] Open
Abstract
Schizophrenia is a mental disorder that affects approximately 1-2% of the population and develops in early adulthood. The disease is characterized by positive, negative, and cognitive symptoms. A large percentage of patients with schizophrenia have a treatment-resistant disease, and the risk of developing adverse effects is high. Many researchers have attempted to introduce new antipsychotic drugs to the clinic, but most of these treatments failed, and the diversity of schizophrenic symptoms is one of the causes of disappointing results. The present review summarizes the results of our latest papers, showing that the simultaneous activation of two receptors with sub-effective doses of their ligands induces similar effects as the highest dose of each compound alone. The treatments were focused on inhibiting the increased glutamate release responsible for schizophrenia arousal, without interacting with dopamine (D2) receptors. Ligands activating metabotropic receptors for glutamate, GABAB or muscarinic receptors were used, and the compounds were administered in several different combinations. Some combinations reversed all schizophrenia-related deficits in animal models, but others were active only in select models of schizophrenia symptoms (i.e., cognitive or negative symptoms).
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14
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Schechter M, Grigoletto J, Abd-Elhadi S, Glickstein H, Friedman A, Serrano GE, Beach TG, Sharon R. A role for α-Synuclein in axon growth and its implications in corticostriatal glutamatergic plasticity in Parkinson's disease. Mol Neurodegener 2020; 15:24. [PMID: 32228705 PMCID: PMC7104492 DOI: 10.1186/s13024-020-00370-y] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2019] [Accepted: 02/25/2020] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND α-Synuclein (α-Syn) is a protein implicated in the pathogenesis of Parkinson's disease (PD). α-Syn has been shown to associate with membranes and bind acidic phospholipids. However, the physiological importance of these associations to the integrity of axons is not fully clear. METHODS Biochemical, immunohistochemical and ultrastructural analyses in cultured neurons, transgenic mouse brains, PD and control human brains. RESULTS We analyzed the ultrastructure of cross-sectioned axons localized to white matter tracts (WMTs), within the dorsal striatum of old and symptomatic α-Syn transgenic mouse brains. The analysis indicated a higher density of axons of thinner diameter. Our findings in cultured cortical neurons indicate a role for α-Syn in elongation of the main axon and its collaterals, resulting in enhanced axonal arborization. We show that α-Syn effect to enhance axonal outgrowth is mediated through its activity to regulate membrane levels of the acidic phosphatidylinositol 4,5-bisphosphate (PI4,5P2). Moreover, our findings link α-Syn- enhanced axonal growth with evidence for axonal injury. In relevance to disease mechanisms, we detect in human brains evidence for a higher degree of corticostriatal glutamatergic plasticity within WMTs at early stages of PD. However, at later PD stages, the respective WMTs in the caudate are degenerated with accumulation of Lewy pathology. CONCLUSIONS Our results show that through regulating PI4,5P2 levels, α-Syn acts to elongate the main axon and collaterals, resulting in a higher density of axons in the striatal WMTs. Based on these results we suggest a role for α-Syn in compensating mechanisms, involving corticostriatal glutamatergic plasticity, taking place early in PD.
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Affiliation(s)
- Meir Schechter
- Department of Biochemistry and Molecular Biology, IMRIC, The Hebrew University-Hadassah Medical School, Ein Kerem, 9112001 Jerusalem, Israel
| | - Jessica Grigoletto
- Department of Biochemistry and Molecular Biology, IMRIC, The Hebrew University-Hadassah Medical School, Ein Kerem, 9112001 Jerusalem, Israel
| | - Suaad Abd-Elhadi
- Department of Biochemistry and Molecular Biology, IMRIC, The Hebrew University-Hadassah Medical School, Ein Kerem, 9112001 Jerusalem, Israel
| | - Hava Glickstein
- Electron Microscopy Unit, The Hebrew University-Hadassah Medical School, Ein Kerem, 9112001 Jerusalem, Israel
| | - Alexander Friedman
- McGovern Institute for Brain Research and Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139 USA
| | | | | | - Ronit Sharon
- Department of Biochemistry and Molecular Biology, IMRIC, The Hebrew University-Hadassah Medical School, Ein Kerem, 9112001 Jerusalem, Israel
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15
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Sabbir MG, Fernyhough P. Muscarinic receptor antagonists activate ERK-CREB signaling to augment neurite outgrowth of adult sensory neurons. Neuropharmacology 2018; 143:268-281. [PMID: 30248305 DOI: 10.1016/j.neuropharm.2018.09.020] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2018] [Revised: 08/09/2018] [Accepted: 09/12/2018] [Indexed: 01/09/2023]
Abstract
A major cellular effector activated by G protein coupled receptors is extracellular signal-regulated kinase (ERK). The ERK signaling cascade regulates a variety of cellular processes including growth and proliferation. Both G protein and β-arrestin-mediated signaling lead to ERK activation by phosphorylation through different kinases. Recently, we have shown muscarinic acetylcholine type 1 receptor (M1R) antagonists, muscarinic toxin 7 (MT7) and pirenzepine, elevated neurite outgrowth and protected from small and large fiber neuropathy in adult sensory neurons in various animal models. Thus, we tested the novel hypothesis that muscarinic antagonists could drive neurite outgrowth through altered M1R-ERK signaling. We have used two dimensional isoelectric focusing/SDS-PAGE combined with analysis using multiple phospho-epitope specific antibodies to study ERK1/2 phosphorylation and activation of its downstream nuclear effector cyclic response element binding protein (CREB). Activated CREB is known to exhibit neuroprotective and growth promoting effects. One hour of treatment with MT7 and pirenzepine activated ERK through M1R and induced a significant increase in levels of pCREB(S133) in cultured sensory neurons. Further, pharmacological blockade or siRNA based knockdown of ERK abolished the MT7 and pirenzepine mediated neuritogenic effect. In addition, we have shown drug-induced alterations of charged protein fractions that may possess additional post-translationally modified forms of ERK and CREB. For the first time we show that long-term treatment, e.g. 1 h, with muscarinic antagonists selective or specific for M1R can activate a biased β-arrestin dependent ERK-CREB signal cascade. Our study gives novel insight into muscarinic antagonist-mediated modulation of M1R-ERK-CREB signaling which could be exploited for therapy in neuropathic diseases.
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Affiliation(s)
- Mohammad Golam Sabbir
- Division of Neurodegenerative Disorders, St. Boniface Hospital Albrechtsen Research Centre, Winnipeg, MB, R2H 2A6, Canada.
| | - Paul Fernyhough
- Division of Neurodegenerative Disorders, St. Boniface Hospital Albrechtsen Research Centre, Winnipeg, MB, R2H 2A6, Canada; Dept of Pharmacology & Therapeutics, University of Manitoba, MB, R3T 2N2, Canada.
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16
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Yohn SE, Conn PJ. Positive allosteric modulation of M 1 and M 4 muscarinic receptors as potential therapeutic treatments for schizophrenia. Neuropharmacology 2018; 136:438-448. [PMID: 28893562 PMCID: PMC5844786 DOI: 10.1016/j.neuropharm.2017.09.012] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2017] [Revised: 09/06/2017] [Accepted: 09/08/2017] [Indexed: 01/22/2023]
Abstract
Current antipsychotic drugs provide symptomatic relief for positive symptoms of schizophrenia, but do not offer symptom management for negative and cognitive symptoms. In addition, many patients discontinue treatment due to adverse side effects. Therefore, there is a critical need to develop more effective and safe treatment options. Although the etiology of schizophrenia is unclear, considerable data from post-mortem, neuroimaging and neuropharmacology studies support a role of the muscarinic acetylcholine (mAChRs) in the pathophysiology of schizophrenia. Substantial evidence suggests that activation of mAChRs has the potential to treat all symptom domains of schizophrenia. Despite encouraging results in demonstrating efficacy, clinical trials of nonselective mAChR agonists were limited in their clinical utility due to dose-limiting peripheral side effects. Accordingly, efforts have been made to specifically target centrally located M1 and M4 mAChR subtypes devoid of adverse-effect liability. To circumvent this limitation, there have been tremendous advances in the discovery of ligands that bind at allosteric sites, binding sites distinct from the orthosteric site, which are structurally less conserved and thereby afford high levels of receptor subtype selectivity. The discovery of subtype-specific allosteric modulators has greatly advanced our understanding of the physiological role of various muscarinic receptor subtypes in schizophrenia and the potential utility of M1 and M4 mAChR subtypes as targets for the development of novel treatments for schizophrenia and related disorders. This article is part of the Special Issue entitled 'Neuropharmacology on Muscarinic Receptors'.
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Affiliation(s)
- Samantha E Yohn
- Department of Pharmacology, Vanderbilt University, Nashville, TN 37232, United States; Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University, Nashville, TN 37232, United States
| | - P Jeffrey Conn
- Department of Pharmacology, Vanderbilt University, Nashville, TN 37232, United States; Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University, Nashville, TN 37232, United States.
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17
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Sabbir MG, Calcutt NA, Fernyhough P. Muscarinic Acetylcholine Type 1 Receptor Activity Constrains Neurite Outgrowth by Inhibiting Microtubule Polymerization and Mitochondrial Trafficking in Adult Sensory Neurons. Front Neurosci 2018; 12:402. [PMID: 29997469 PMCID: PMC6029366 DOI: 10.3389/fnins.2018.00402] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2018] [Accepted: 05/24/2018] [Indexed: 11/13/2022] Open
Abstract
The muscarinic acetylcholine type 1 receptor (M1R) is a metabotropic G protein-coupled receptor. Knockout of M1R or exposure to selective or specific receptor antagonists elevates neurite outgrowth in adult sensory neurons and is therapeutic in diverse models of peripheral neuropathy. We tested the hypothesis that endogenous M1R activation constrained neurite outgrowth via a negative impact on the cytoskeleton and subsequent mitochondrial trafficking. We overexpressed M1R in primary cultures of adult rat sensory neurons and cell lines and studied the physiological and molecular consequences related to regulation of cytoskeletal/mitochondrial dynamics and neurite outgrowth. In adult primary neurons, overexpression of M1R caused disruption of the tubulin, but not actin, cytoskeleton and significantly reduced neurite outgrowth. Over-expression of a M1R-DREADD mutant comparatively increased neurite outgrowth suggesting that acetylcholine released from cultured neurons interacts with M1R to suppress neurite outgrowth. M1R-dependent constraint on neurite outgrowth was removed by selective (pirenzepine) or specific (muscarinic toxin 7) M1R antagonists. M1R-dependent disruption of the cytoskeleton also diminished mitochondrial abundance and trafficking in distal neurites, a disorder that was also rescued by pirenzepine or muscarinic toxin 7. M1R activation modulated cytoskeletal dynamics through activation of the G protein (Gα13) that inhibited tubulin polymerization and thus reduced neurite outgrowth. Our study provides a novel mechanism of M1R control of Gα13 protein-dependent modulation of the tubulin cytoskeleton, mitochondrial trafficking and neurite outgrowth in axons of adult sensory neurons. This novel pathway could be harnessed to treat dying-back neuropathies since anti-muscarinic drugs are currently utilized for other clinical conditions.
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Affiliation(s)
- Mohammad G Sabbir
- Division of Neurodegenerative Disorders, St. Boniface Hospital Research Centre, Winnipeg, MB, Canada
| | - Nigel A Calcutt
- Department of Pathology, University of California, San Diego, San Diego, CA, United States
| | - Paul Fernyhough
- Division of Neurodegenerative Disorders, St. Boniface Hospital Research Centre, Winnipeg, MB, Canada.,Department of Pharmacology and Therapeutics, University of Manitoba, Winnipeg, MB, Canada
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18
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Thomsen M, Sørensen G, Dencker D. Physiological roles of CNS muscarinic receptors gained from knockout mice. Neuropharmacology 2017; 136:411-420. [PMID: 28911965 DOI: 10.1016/j.neuropharm.2017.09.011] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2016] [Revised: 09/06/2017] [Accepted: 09/08/2017] [Indexed: 12/29/2022]
Abstract
Because the five muscarinic acetylcholine receptor subtypes have overlapping distributions in many CNS tissues, and because ligands with a high degree of selectivity for a given subtype long remained elusive, it has been difficult to determine the physiological functions of each receptor. Genetically engineered knockout mice, in which one or more muscarinic acetylcholine receptor subtype has been inactivated, have been instrumental in identifying muscarinic receptor functions in the CNS, at the neuronal, circuit, and behavioral level. These studies revealed important functions of muscarinic receptors modulating neuronal activity and neurotransmitter release in many brain regions, shaping neuronal plasticity, and affecting functions ranging from motor and sensory function to cognitive processes. As gene targeting technology evolves including the use of conditional, cell type specific strains, knockout mice are likely to continue to provide valuable insights into brain physiology and pathophysiology, and advance the development of new medications for a range of conditions such as Alzheimer's disease, Parkinson's disease, schizophrenia, and addictions, as well as non-opioid analgesics. This article is part of the Special Issue entitled 'Neuropharmacology on Muscarinic Receptors'.
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Affiliation(s)
- Morgane Thomsen
- Laboratory of Neuropsychiatry, Psychiatric Center Copenhagen and University of Copenhagen, Denmark; Alcohol and Drug Abuse Research Center, McLean Hospital/Harvard Medical School, 115 Mill Street, Belmont, MA 02478, USA.
| | - Gunnar Sørensen
- Alcohol and Drug Abuse Research Center, McLean Hospital/Harvard Medical School, 115 Mill Street, Belmont, MA 02478, USA
| | - Ditte Dencker
- Laboratory of Neuropsychiatry, Psychiatric Center Copenhagen and University of Copenhagen, Denmark
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19
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Abstract
Xanomeline (1) is an orthosteric muscarinic acetylcholine receptor (mAChR) agonist, often referred to as M1/M4-preferring, that received widespread attention for its clinical efficacy in schizophrenia and Alzheimer's disease (AD) patients. Despite the compound's promising initial clinical results, dose-limiting side effects limited further clinical development. While xanomeline, and related orthosteric muscarinic agonists, have yet to receive approval from the FDA for the treatment of these CNS disorders, interest in the compound's unique M1/M4-preferring mechanism of action is ongoing in the field of chemical neuroscience. Specifically, the promising cognitive and behavioral effects of xanomeline in both schizophrenia and AD have spurred a renewed interest in the development of safer muscarinic ligands with improved subtype selectivity for either M1 or M4. This Review will address xanomeline's overall importance in the field of neuroscience, with a specific focus on its chemical structure and synthesis, pharmacology, drug metabolism and pharmacokinetics (DMPK), and adverse effects.
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Affiliation(s)
- Aaron M. Bender
- Vanderbilt
Center for Neuroscience Drug Discovery, Vanderbilt University School of Medicine, Nashville, Tennessee 37232, United States
| | - Carrie K. Jones
- Vanderbilt
Center for Neuroscience Drug Discovery, Vanderbilt University School of Medicine, Nashville, Tennessee 37232, United States
- Department
of Pharmacology, Vanderbilt University School of Medicine, Nashville, Tennessee 37232, United States
| | - Craig W. Lindsley
- Vanderbilt
Center for Neuroscience Drug Discovery, Vanderbilt University School of Medicine, Nashville, Tennessee 37232, United States
- Department
of Pharmacology, Vanderbilt University School of Medicine, Nashville, Tennessee 37232, United States
- Department
of Chemistry, Vanderbilt Institute of Chemical Biology, Vanderbilt University, Nashville, Tennessee 37232, United States
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20
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Toth AB, Shum AK, Prakriya M. Regulation of neurogenesis by calcium signaling. Cell Calcium 2016; 59:124-34. [PMID: 27020657 DOI: 10.1016/j.ceca.2016.02.011] [Citation(s) in RCA: 101] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2015] [Revised: 02/17/2016] [Accepted: 02/18/2016] [Indexed: 12/22/2022]
Abstract
Calcium (Ca(2+)) signaling has essential roles in the development of the nervous system from neural induction to the proliferation, migration, and differentiation of neural cells. Ca(2+) signaling pathways are shaped by interactions among metabotropic signaling cascades, intracellular Ca(2+) stores, ion channels, and a multitude of downstream effector proteins that activate specific genetic programs. The temporal and spatial dynamics of Ca(2+) signals are widely presumed to control the highly diverse yet specific genetic programs that establish the complex structures of the adult nervous system. Progress in the last two decades has led to significant advances in our understanding of the functional architecture of Ca(2+) signaling networks involved in neurogenesis. In this review, we assess the literature on the molecular and functional organization of Ca(2+) signaling networks in the developing nervous system and its impact on neural induction, gene expression, proliferation, migration, and differentiation. Particular emphasis is placed on the growing evidence for the involvement of store-operated Ca(2+) release-activated Ca(2+) (CRAC) channels in these processes.
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Affiliation(s)
- Anna B Toth
- Department of Pharmacology, Northwestern University, Feinberg School of Medicine, Chicago, IL 60611, United States
| | - Andrew K Shum
- Department of Pharmacology, Northwestern University, Feinberg School of Medicine, Chicago, IL 60611, United States
| | - Murali Prakriya
- Department of Pharmacology, Northwestern University, Feinberg School of Medicine, Chicago, IL 60611, United States.
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21
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Hopper S, Udawela M, Scarr E, Dean B. Allosteric modulation of cholinergic system: Potential approach to treating cognitive deficits of schizophrenia. World J Pharmacol 2016; 5:32-43. [DOI: 10.5497/wjp.v5.i1.32] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/19/2015] [Revised: 11/26/2015] [Accepted: 01/04/2016] [Indexed: 02/06/2023] Open
Abstract
Schizophrenia is a psychiatric disorder affecting approximately 1% of the population worldwide and is characterised by the presence of positive and negative symptoms and cognitive deficits. Whilst current therapeutics ameliorate positive symptoms, they are largely ineffective in improving negative symptoms and cognitive deficits. The cholinergic neurotransmitter system heavily influences cognitive function and there is evidence that implicates disruption of the central cholinergic system in schizophrenia. Historically, targeting the cholinergic system has been impeded by poor selectivity leading to intolerable side effects warranting the need to develop more targeted therapeutic compounds. In this review we will summarise evidence supporting the roles of the cholinergic system, particularly the muscarinic M1 receptor, in the pathophysiology of schizophrenia and discuss the potential of a promising new class of candidate compounds, allosteric ligands, for addressing the difficulties involved in targeting this system. The body of evidence presented here highlights the dysfunction of the cholinergic system in schizophrenia and that targeting this system by taking advantage of allosteric ligands is having clinically meaningful effect on cognitive deficits.
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22
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Kow RL, Cheng EM, Jiang K, Le JH, Stella N, Nathanson NM. Muscarinic M1 receptor and cannabinoid CB1 receptor do not modulate paraoxon-induced seizures. Pharmacol Res Perspect 2014; 3:e00100. [PMID: 25692018 PMCID: PMC4317231 DOI: 10.1002/prp2.100] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2014] [Revised: 08/19/2014] [Accepted: 09/16/2014] [Indexed: 11/24/2022] Open
Abstract
One of the major signs of severe organophosphate poisoning is seizures. Previous studies have shown that both muscarinic agonist- and organophosphate-induced seizures require activation of muscarinic acetylcholine receptors in the central nervous system. Seizures induced by the muscarinic agonist pilocarpine require the M1 receptor and are modulated by cannabinoid CB1 receptors. In this study, we determined whether M1 and CB1 receptors also regulated seizures induced by the organophosphate paraoxon. We found no differences in seizures induced by paraoxon in wild-type (WT) and M1 knockout (KO) mice, indicating that in contrast to pilocarpine seizures, M1 receptors are not required for paraoxon seizures. Furthermore, we found that pilocarpine administration resulted in seizure-independent activation of ERK in the hippocampus in a M1 receptor-dependent manner, while paraoxon did not induce seizure-independent activation of ERK in the mouse hippocampus. This shows that pilocarpine and paraoxon activated M1 receptors in the hippocampus to different extents. There were no differences in seizures induced by paraoxon in WT and CB1 KO mice, and neither CB1 agonist nor antagonist administration had significant effects on paraoxon seizures, indicating that, in contrast to pilocarpine seizures, paraoxon seizures are not modulated by CB1 receptors. These results demonstrate that there are fundamental molecular differences in the regulation of seizures induced by pilocarpine and paraoxon.
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Affiliation(s)
- Rebecca L Kow
- Department of Pharmacology, University of Washington Seattle, Washington
| | - Eugene M Cheng
- Department of Pharmacology, University of Washington Seattle, Washington
| | - Kelly Jiang
- Department of Pharmacology, University of Washington Seattle, Washington
| | - Joshua H Le
- Department of Pharmacology, University of Washington Seattle, Washington
| | - Nephi Stella
- Department of Pharmacology, University of Washington Seattle, Washington
| | - Neil M Nathanson
- Department of Pharmacology, University of Washington Seattle, Washington
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Wang YP, Li G, Ma LL, Zheng Y, Zhang SD, Zhang HX, Qiu M, Ma X. Penehyclidine hydrochloride ameliorates renal ischemia–reperfusion injury in rats. J Surg Res 2014; 186:390-7. [DOI: 10.1016/j.jss.2013.07.041] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2013] [Revised: 07/07/2013] [Accepted: 07/19/2013] [Indexed: 12/17/2022]
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Morishima S, Anisuzzaman ASM, Uwada J, Yoshiki H, Muramatsu I. Comparison of subcellular distribution and functions between exogenous and endogenous M1 muscarinic acetylcholine receptors. Life Sci 2013; 93:17-23. [DOI: 10.1016/j.lfs.2013.05.013] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2013] [Revised: 03/28/2013] [Accepted: 05/13/2013] [Indexed: 02/01/2023]
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Anisuzzaman ASM, Uwada J, Masuoka T, Yoshiki H, Nishio M, Ikegaya Y, Takahashi N, Matsuki N, Fujibayashi Y, Yonekura Y, Momiyama T, Muramatsu I. Novel contribution of cell surface and intracellular M1-muscarinic acetylcholine receptors to synaptic plasticity in hippocampus. J Neurochem 2013; 126:360-71. [DOI: 10.1111/jnc.12306] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2013] [Revised: 04/30/2013] [Accepted: 05/14/2013] [Indexed: 01/08/2023]
Affiliation(s)
- Abu Syed Md Anisuzzaman
- Division of Pharmacology; Department of Biochemistry and Bioinformative Sciences; School of Medicine; University of Fukui; Eiheiji Japan
| | - Junsuke Uwada
- Division of Pharmacology; Department of Biochemistry and Bioinformative Sciences; School of Medicine; University of Fukui; Eiheiji Japan
- Organization for Life Science Advancement Programs; University of Fukui; Eiheiji Japan
| | - Takayoshi Masuoka
- Department of Pharmacology; School of Medicine; Kanazawa Medical University; Uchinada Japan
| | - Hatsumi Yoshiki
- Division of Pharmacology; Department of Biochemistry and Bioinformative Sciences; School of Medicine; University of Fukui; Eiheiji Japan
| | - Matomo Nishio
- Department of Pharmacology; School of Medicine; Kanazawa Medical University; Uchinada Japan
| | - Yuji Ikegaya
- Laboratory of Chemical Pharmacology; Graduate School of Pharmaceutical Sciences; The University of Tokyo; Hongo Bunkyo-ku Japan
| | - Naoya Takahashi
- Laboratory of Chemical Pharmacology; Graduate School of Pharmaceutical Sciences; The University of Tokyo; Hongo Bunkyo-ku Japan
| | - Norio Matsuki
- Laboratory of Chemical Pharmacology; Graduate School of Pharmaceutical Sciences; The University of Tokyo; Hongo Bunkyo-ku Japan
| | | | | | - Toshihiko Momiyama
- Department of Pharmacology; Jikei University School of Medicine; Minato-ku Japan
| | - Ikunobu Muramatsu
- Division of Pharmacology; Department of Biochemistry and Bioinformative Sciences; School of Medicine; University of Fukui; Eiheiji Japan
- Organization for Life Science Advancement Programs; University of Fukui; Eiheiji Japan
- Child Development Research Center; Graduate School of Medicine; University of Fukui; Eiheiji Japan
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Lutz CC, Rodriguez-Zas SL, Fahrbach SE, Robinson GE. Transcriptional response to foraging experience in the honey bee mushroom bodies. Dev Neurobiol 2012; 72:153-66. [PMID: 21634017 DOI: 10.1002/dneu.20929] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Enriched environmental conditions induce neuroanatomical plasticity in a variety of vertebrate and invertebrate species. We explored the molecular processes associated with experience-induced plasticity, using naturally occurring foraging behavior in adult worker honey bees (Apis mellifera). In honey bees, the mushroom bodies exhibit neuroanatomical plasticity that is dependent on accumulated foraging experience. To investigate molecular processes associated with foraging experience, we performed a time-course microarray study to examine gene expression changes in the mushroom bodies as a function of days foraged. We found almost 500 genes that were regulated by duration of foraging experience. Bioinformatic analyses of these genes suggest that foraging experience is associated with multiple molecular processes in the mushroom bodies, including some that may contribute directly to neuropil growth, and others that could potentially protect the brain from the effects of aging and physiological stress.
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Affiliation(s)
- Claudia C Lutz
- Neuroscience Program, University of Illinois, Urbana, Illinois 61801, USA
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Chen YJ, Chang LS. Arecoline-induced death of human leukemia K562 cells is associated with surface up-modulation of TNFR2. J Cell Physiol 2012; 227:2240-51. [DOI: 10.1002/jcp.22963] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
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Abstract
Schizophrenia is a devastating disease with several broad symptom clusters and the current monoamine-based treatments do not adequately treat the disease, especially negative and cognitive symptoms. A proposed alternative approach for treating schizophrenia is through the use of compounds that activate certain muscarinic receptor subtypes, the so-called muscarinic cholinergic hypothesis theory. This theory has been revitalized with a number of recent and provocative findings including postmortem reports in schizophrenia patients showing decreased numbers of muscarinic M(1) and M(4) receptors in brain regions associated with schizophrenia as well as decreased muscarinic receptors in an in vivo imaging study. Studies with M(4) knockout mice have shown that there is a reciprocal relationship between M(4) and dopamine receptor function, and a number of muscarinic agonists have shown antidopaminergic activity in a variety of preclinical assays predictive of antipsychotic efficacy in the clinic. Furthermore, the M(1)/M(4) preferring partial agonist xanomeline has been shown to have antipsychotic-like and pro-cognitive activity in preclinical models and in clinical trials to decrease psychotic-like behaviors in Alzheimer's patients and positive, negative, and cognitive symptoms in patients with schizophrenia. Therefore, we propose that an agonist with M(1) and M(4) interactions would effectively treat core symptom clusters associated with schizophrenia. Currently, research is focused on developing subtype-selective muscarinic agonists and positive allosteric modulators that have reduced propensity for parasympathetic side-effects, but retain the therapeutic benefit observed with their less selective predecessors.
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Affiliation(s)
- David L McKinzie
- Lilly Research Laboratories, Eli Lilly and Co., Indianapolis, IN 46285, USA.
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Hulme EC, Lu ZL, Bee MS. Scanning Mutagenesis Studies of the M 1 Muscarinic Acetylcholine Receptor. ACTA ACUST UNITED AC 2011. [DOI: 10.3109/10606820308261] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Uwada J, Anisuzzaman ASM, Nishimune A, Yoshiki H, Muramatsu I. Intracellular distribution of functional M(1) -muscarinic acetylcholine receptors in N1E-115 neuroblastoma cells. J Neurochem 2011; 118:958-67. [PMID: 21740440 DOI: 10.1111/j.1471-4159.2011.07378.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Signaling by muscarinic agonists is thought to result from the activation of cell surface acetylcholine receptors (mAChRs) that transmit extracellular signals to intracellular systems. In N1E-115 neuroblastoma cells, we detected both plasma membrane and intracellular M(1) -mAChRs using both biochemical and pharmacological methods. In intact cells, both plasma membrane and intracellular M(1) -mAChRs were detected by the hydrophobic ligand probe, 1-quinuclidinyl-[phenyl-4-(3) H]-benzilate ([(3) H]-QNB) whereas the hydrophilic probe, 1-[N-methyl-(3) H] scopolamine ([(3) H]-NMS), detected only cell surface receptors. These probes detected comparable numbers of receptors in isolated membrane preparations. Immunohistochemical studies with M(1) -mAChR antibody also detected both cell-surface and intracellular M(1) -mAChRs. Carbachol-stimulated phosphatidylinositol hydrolysis and Ca(2+) mobilization were completely inhibited by a cell-impermeable M(1) antagonist, muscarinic toxin -7 and the G(q/11) inhibitor YM-254890. However, carbachol-stimulated extracellular-regulated kinase 1/2 activation was unaffected by muscarinic toxin-7, but was blocked by the cell-permeable antagonist, pirenzepine. extracellular regulated kinase 1/2 phosphorylation was resistant to blockade of G(q/11) (YM-254890) and protein kinase C (bisindolylmaleimide I). Our data suggest that the geographically distinct M(1) -mAChRs (cell surface versus intracellular) can signal via unique signaling pathways that are differentially sensitive to cell-impermeable versus cell-permeable antagonists. Our data are of potential physiological relevance to signaling that affects both cognitive and neurodegenerative processes.
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Affiliation(s)
- Junsuke Uwada
- Division of Pharmacology, Department of Biochemistry and Bioinformative Sciences, and Organization for Life Science Advancement Programs, School of Medicine, University of Fukui, Eiheiji, Fukui, Japan
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31
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Medeiros R, Kitazawa M, Caccamo A, Baglietto-Vargas D, Estrada-Hernandez T, Cribbs DH, Fisher A, LaFerla FM. Loss of muscarinic M1 receptor exacerbates Alzheimer's disease-like pathology and cognitive decline. THE AMERICAN JOURNAL OF PATHOLOGY 2011; 179:980-91. [PMID: 21704011 PMCID: PMC3157199 DOI: 10.1016/j.ajpath.2011.04.041] [Citation(s) in RCA: 89] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/05/2011] [Revised: 03/29/2011] [Accepted: 04/22/2011] [Indexed: 02/03/2023]
Abstract
Alzheimer's disease (AD) is pathologically characterized by tau-laden neurofibrillary tangles and β-amyloid deposits. Dysregulation of cholinergic neurotransmission has been implicated in AD pathogenesis, contributing to the associated memory impairments; yet, the exact mechanisms remain to be defined. Activating the muscarinic acetylcholine M(1) receptors (M(1)Rs) reduces AD-like pathological features and enhances cognition in AD transgenic models. To elucidate the molecular mechanisms by which M(1)Rs affect AD pathophysiological features, we crossed the 3xTgAD and transgenic mice expressing human Swedish, Dutch, and Iowa triple-mutant amyloid precursor protein (Tg-SwDI), two widely used animal models, with the M(1)R(-/-) mice. Our data show that M(1)R deletion in the 3xTgAD and Tg-SwDI mice exacerbates the cognitive impairment through mechanisms dependent on the transcriptional dysregulation of genes required for memory and through acceleration of AD-related synaptotoxicity. Ablating the M(1)R increased plaque and tangle levels in the brains of 3xTgAD mice and elevated cerebrovascular deposition of fibrillar Aβ in Tg-SwDI mice. Notably, tau hyperphosphorylation and potentiation of amyloidogenic processing in the mice with AD lacking M(1)R were attributed to changes in the glycogen synthase kinase 3β and protein kinase C activities. Finally, deleting the M(1)R increased the astrocytic and microglial response associated with Aβ plaques. Our data highlight the significant role that disrupting the M(1)R plays in exacerbating AD-related cognitive decline and pathological features and provide critical preclinical evidence to justify further development and evaluation of selective M(1)R agonists for treating AD.
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Affiliation(s)
- Rodrigo Medeiros
- Institute for Memory Impairments and Neurological Disorders, University of California, Irvine, California
- Department of Neurobiology and Behavior, University of California, Irvine, California
| | - Masashi Kitazawa
- Institute for Memory Impairments and Neurological Disorders, University of California, Irvine, California
- Department of Neurobiology and Behavior, University of California, Irvine, California
| | - Antonella Caccamo
- Institute for Memory Impairments and Neurological Disorders, University of California, Irvine, California
- Department of Neurobiology and Behavior, University of California, Irvine, California
| | - David Baglietto-Vargas
- Institute for Memory Impairments and Neurological Disorders, University of California, Irvine, California
- Department of Neurobiology and Behavior, University of California, Irvine, California
| | - Tatiana Estrada-Hernandez
- Institute for Memory Impairments and Neurological Disorders, University of California, Irvine, California
- Department of Neurobiology and Behavior, University of California, Irvine, California
| | - David H. Cribbs
- Institute for Memory Impairments and Neurological Disorders, University of California, Irvine, California
- Department of Neurology, University of California, Irvine, California
| | - Avraham Fisher
- Israel Institute for Biological Research, Ness-Ziona, Israel
| | - Frank M. LaFerla
- Institute for Memory Impairments and Neurological Disorders, University of California, Irvine, California
- Department of Neurobiology and Behavior, University of California, Irvine, California
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Wang Y, Ma T, Li M, Sun X, Wang Y, Gu S. Regulated hypoxia/reperfusion-dependent modulation of ERK1/2, cPLA2, and Bcl-2/Bax: a potential mechanism of neuroprotective effect of penehyclidine hydrochloride. Int J Neurosci 2011; 121:442-9. [PMID: 21545309 DOI: 10.3109/00207454.2011.570611] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The activation of event-related kinase 1/2 (ERK1/2) and cytosolic phospholipaseA2 (cPLA2), which can aggravate hypoxia/reoxygenation (H/R) damage related to their downstream Bcl-2/Bax and Caspase-3 pathway, plays a key role in H/R. The M1 receptors could be responsible for activation of ERK1/2. Thus, it seems that the regulation of M1 receptors mediated the ERK1/2; cPLA2-mediated Bcl-2/Bax pathway may be a significant responsive signal in H/R. Penehyclidine hydrochloride (PHC) is an anticholinergic agent with high degree of selectivity for M1 and M3 receptor subtypes, it is reported that PHC has a protective effect against H/R damage. Here we hypothesize and demonstrate that PHC could downregulate the expression of pERK1/2, cPLA2, and Caspase-3, increased the ratio of Bcl-2/Bax. This study may widen the application of PHC and therapeutic agents of stroke.
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Affiliation(s)
- Yun Wang
- Department of Pharmacology, XuZhou Medical College, XuZhou, Jiangsu, China
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33
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Shideler KK, Yan J. M1 muscarinic receptor for the development of auditory cortical function. Mol Brain 2010; 3:29. [PMID: 20964868 PMCID: PMC2972260 DOI: 10.1186/1756-6606-3-29] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2010] [Accepted: 10/22/2010] [Indexed: 02/02/2023] Open
Abstract
The sensory cortex is subject to continuous remodelling during early development and throughout adulthood. This process is important for establishing normal brain function and is dependent on cholinergic modulation via muscarinic receptors. Five muscarinic receptor genes encode five unique receptor subtypes (M1-5). The distributions and functions of each subtype vary in central and peripheral systems. In the brain, the M1 receptor is most abundant in the cerebral cortex, where its immunoreactivity peaks transiently during early development. This likely signifies the importance of M1 receptor in the development and maintenance of normal cortical function. Several lines of study have outlined the roles of M1 receptors in the development and plasticity of the auditory cortex. For example, M1-knockout reduces experience-dependent plasticity and disrupts tonotopic mapping in the adult mouse auditory cortex. Further evidence demonstrates a role for M1 in neurite outgrowth and hence determining the structure of cortical neurons. The disruption of tonotopic maps in M1-knockout mice may be linked to alterations in thalamocortical connectivity, because the targets of thalamocortical afferents (layer IV cortical neurons) appear less mature in M1 knockouts. Herein we review the literature to date concerning M1 receptors in the auditory cortex and consider some future directions that will contribute to our understanding.
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Affiliation(s)
- Karalee K Shideler
- Department of Physiology and Pharmacology, Hotchkiss Brain Institute, Faculty of Medicine, University of Calgary, Calgary, Alberta, Canada
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Zhan J, Liu Y, Zhang Z, Chen C, Chen K, Wang Y. Effect of penehyclidine hydrochloride on expressions of MAPK in mice with CLP-induced acute lung injury. Mol Biol Rep 2010; 38:1909-14. [PMID: 20845074 DOI: 10.1007/s11033-010-0310-0] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2009] [Accepted: 09/03/2010] [Indexed: 02/06/2023]
Abstract
Penehyclidine hydrochloride (PHC) is a new anticholinergic drug. PHC has been shown to have a good curative effect for sepsis. Mitogen-activated protein kinase (MAPK) has recently been considered to play an important role in sepsis. In this study, the role of MAPK signal pathways in protective effects of PHC preconditioning on acute lung injury in cecal ligation and puncture (CLP)-induced sepsis was investigated. Healthy female mice were randomly divided into 4 groups: sham control, CLP, and 0.3 or 0.45 mg/kg PHC. At 12 h after surgery, arterial blood was drawn for blood gas analysis, and lung tissue samples were collected to examine pulmonary microvascular permeability, IL-6 levels and myeloperoxidase (MPO) activity. MAPK protein expressions were measured using western blot technique. Compared with sham control mice, acute lung injury was induced in CLP group, which was indicated by decreased PaO(2)/FiO(2), increased pulmonary microvascular permeability, IL-6 levels and MPO activity. Furthermore, mice' exposure to CLP induced the increased protein levels of MAPK. Treatment of 0.45 mg/kg PHC markedly improved PaO(2)/FiO(2), decreased pulmonary microvascular permeability, IL-6 levels and MPO activity, and inhibited expressions of extracellular signal-regulated kinase (ERK1/2) and p38 MAPK. Taken together, these results suggest that PHC ameliorated acute lung injury through the inhibition of extracellular signal-regulated kinase (ERK1/2) and p38 MAPK activation in septic mice.
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Affiliation(s)
- Jia Zhan
- Department of Anesthesiology, Zhongnan Hospital of Wuhan University, East-lake Road 169, Wuhan, 430071 Hubei, China
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35
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Davis AA, Heilman CJ, Brady AE, Miller NR, Fuerstenau-Sharp M, Hanson BJ, Lindsley CW, Conn PJ, Lah JJ, Levey AI. Differential effects of allosteric M(1) muscarinic acetylcholine receptor agonists on receptor activation, arrestin 3 recruitment, and receptor downregulation. ACS Chem Neurosci 2010; 1:542-551. [PMID: 20835371 DOI: 10.1021/cn100011e] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Muscarinic acetylcholine receptors (mAChRs) are drug targets for multiple neurodegenerative and neuropsychiatric disorders, but the full therapeutic potential of mAChR-targeted drugs has not been realized, mainly because of a lack of subtype-selective agonists. Recent advances have allowed the development of highly selective agonists that bind to an allosteric site on the M(1) mAChR that is spatially distinct from the orthosteric acetylcholine binding site, but less is known about the profile of intracellular signals activated by orthosteric versus allosteric M(1) mAChR agonists. We investigated the activation and regulatory mechanisms of two structurally distinct allosteric M(1) mAChR agonists, AC260584 and TBPB. We show that allosteric agonists potently activate multiple signal transduction pathways linked to the M(1) mAChR receptor but, compared to orthosteric agonists, much less efficiently recruit arrestin 3, a protein involved in regulation of G-protein coupled receptor signaling. Consistent with decreased arrestin recruitment, both allosteric agonists showed blunted responses in measurements of receptor desensitization, internalization, and downregulation. These results advance the understanding of mAChR biology and may shed light on unanticipated differences in the pharmacology of orthosteric vs. allosteric agonists that might be capitalized upon for drug development for the treatment of CNS diseases.
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Affiliation(s)
- Albert A. Davis
- Center for Neurodegenerative Disease and Department of Neurology, Emory University School of Medicine, Atlanta, Georgia 30322
| | - Craig J. Heilman
- Center for Neurodegenerative Disease and Department of Neurology, Emory University School of Medicine, Atlanta, Georgia 30322
| | - Ashley E. Brady
- Department of Pharmacology, Vanderbilt University Medical Center, Nashville, Tennessee 37232
| | - Nicole R. Miller
- Department of Pharmacology, Vanderbilt University Medical Center, Nashville, Tennessee 37232
| | | | | | - Craig W. Lindsley
- Department of Pharmacology, Vanderbilt University Medical Center, Nashville, Tennessee 37232
- Department of Chemistry, Vanderbilt University Medical Center, Nashville, Tennessee 37232
- Vanderbilt Program in Drug Discovery, Vanderbilt University Medical Center, Nashville, Tennessee 37232
| | - P. Jeffrey Conn
- Department of Pharmacology, Vanderbilt University Medical Center, Nashville, Tennessee 37232
- Department of Chemistry, Vanderbilt University Medical Center, Nashville, Tennessee 37232
| | - James J. Lah
- Center for Neurodegenerative Disease and Department of Neurology, Emory University School of Medicine, Atlanta, Georgia 30322
| | - Allan I. Levey
- Center for Neurodegenerative Disease and Department of Neurology, Emory University School of Medicine, Atlanta, Georgia 30322
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Digby GJ, Shirey JK, Conn PJ. Allosteric activators of muscarinic receptors as novel approaches for treatment of CNS disorders. MOLECULAR BIOSYSTEMS 2010; 6:1345-54. [PMID: 20582339 PMCID: PMC4780333 DOI: 10.1039/c002938f] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Muscarinic acetylcholine receptors (mAChRs) represent exciting therapeutic targets for the treatment of multiple CNS disorders. The high degree of conservation of amino acids comprising the orthosteric acetylcholine (ACh) binding site between individual mAChR subtypes has hindered the development of subtype-selective compounds that bind to this site. As a result, many academic and industry researchers are now focusing on developing allosteric activators of mAChRs including both positive allosteric modulators (PAMs) and allosteric agonists. In the past 10 years major advances have been achieved in the discovery of allosteric ligands that possess much greater selectivity for individual mAChR subtypes when compared to previously developed orthosteric agents. These novel allosteric modulators of mAChRs may provide therapeutic potential for treatment of a number of CNS disorders such as Alzheimer's disease and schizophrenia.
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Affiliation(s)
- Gregory J. Digby
- 1215 Light Hall, 2215B Garland Ave., Nashville, TN 37237-0575, USA. ; Fax: +1 615 343 3088; Tel: +1 615 322 6730
| | - Jana K. Shirey
- 8410E Medical Research Building IV, 2215B Garland Ave., Nashville, TN 37237-0575, USA. ; Fax: +1 615 936-2661; Tel: +1 615 936-8424
| | - P. Jeffrey Conn
- 2215B Garland Ave., Nashville, TN 37237-0575, USA. ; Fax: +1 615 343 3088; Tel: +1 615 322 6730
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Abreu-Villaça Y, Filgueiras CC, Manhães AC. Developmental aspects of the cholinergic system. Behav Brain Res 2010; 221:367-78. [PMID: 20060019 DOI: 10.1016/j.bbr.2009.12.049] [Citation(s) in RCA: 111] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2009] [Accepted: 12/26/2009] [Indexed: 01/19/2023]
Abstract
Beyond its importance in sustaining or modulating different aspects of the activity of the central nervous system (CNS), the cholinergic system plays important roles during development. In the current review, we focus on the developmental aspects associated with major components of the cholinergic system: Acetylcholine, choline acetyltransferase, vesicular acetylcholine transporter, high-affinity choline transporter, acetylcholinesterase, nicotinic and muscarinic receptors. We describe when and where each one of these components is first identified in the CNS and the changes in their levels that occur during the course of prenatal and postnatal development. We also describe how these components are relevant to many events that occur during the development of the CNS, including progenitor cells proliferation and differentiation, neurogenesis, gliogenesis, neuronal maturation and plasticity, axonal pathfinding, regulation of gene expression and cell survival. It will be noticed that evidence regarding the developmental aspects of the cholinergic system comes mostly from studies that used agonists, such as nicotine, and antagonists, such as hemicholinium-3. Studies using immunohistochemistry and genetically altered mice also provided valuable information.
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Affiliation(s)
- Yael Abreu-Villaça
- Laboratório de Neurofisiologia, Departamento de Ciências Fisiológicas, Instituto de Biologia Roberto Alcantara Gomes, Centro Biomédico, Universidade do Estado do Rio de Janeiro, Av. Prof. Manoel de Abreu 444, 5 andar, Vila Isabel, Rio de Janeiro, RJ 20550-170, Brazil.
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38
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Resende RR, Adhikari A. Cholinergic receptor pathways involved in apoptosis, cell proliferation and neuronal differentiation. Cell Commun Signal 2009; 7:20. [PMID: 19712465 PMCID: PMC2744676 DOI: 10.1186/1478-811x-7-20] [Citation(s) in RCA: 138] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2009] [Accepted: 08/27/2009] [Indexed: 11/14/2022] Open
Abstract
Acetylcholine (ACh) has been shown to modulate neuronal differentiation during early development. Both muscarinic and nicotinic acetylcholine receptors (AChRs) regulate a wide variety of physiological responses, including apoptosis, cellular proliferation and neuronal differentiation. However, the intracellular mechanisms underlying these effects of AChR signaling are not fully understood. It is known that activation of AChRs increase cellular proliferation and neurogenesis and that regulation of intracellular calcium through AChRs may underlie the many functions of ACh. Intriguingly, activation of diverse signaling molecules such as Ras-mitogen-activated protein kinase, phosphatidylinositol 3-kinase-Akt, protein kinase C and c-Src is modulated by AChRs. Here we discuss the roles of ACh in neuronal differentiation, cell proliferation and apoptosis. We also discuss the pathways involved in these processes, as well as the effects of novel endogenous AChRs agonists and strategies to enhance neuronal-differentiation of stem and neural progenitor cells. Further understanding of the intracellular mechanisms underlying AChR signaling may provide insights for novel therapeutic strategies, as abnormal AChR activity is present in many diseases.
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Affiliation(s)
- Rodrigo R Resende
- Department of Physics, Institute of Exact Sciences, Federal University of Minas Gerais, Belo Horizonte, MG, 31270-901, Brazil.
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Identification of an Ascaris G protein-coupled acetylcholine receptor with atypical muscarinic pharmacology. Int J Parasitol 2009; 39:1215-22. [PMID: 19327362 DOI: 10.1016/j.ijpara.2009.03.001] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2009] [Revised: 02/26/2009] [Accepted: 03/02/2009] [Indexed: 11/23/2022]
Abstract
Acetylcholine (ACh) is a neurotransmitter/neuromodulator in the nematode nervous system and induces its effects through interaction with both ligand-gated ion channels (LGICs) and G protein-coupled receptors (GPCRs). The structure, pharmacology and physiological importance of LGICs have been appreciably elucidated in model nematodes, including parasitic species where they are targets for anthelmintic drugs. Significantly less, however, is understood about nematode ACh GPCRs, termed GARs (G protein-linked ACh receptors). What is known comes from the free-living Caenorhabditis elegans as no GARs have been characterized from parasitic species. Here we clone a putative GAR from the pig gastrointestinal nematode Ascaris suum with high structural homology to the C. elegans receptor GAR-1. Our GPCR, dubbed AsGAR-1, is alternatively spliced and expressed in the head and tail of adult worms but not in dorsal or ventral body wall muscle, or the ovijector. ACh activated AsGAR-1 in a concentration-dependent manner but the receptor was not activated by other small neurotransmitters. The classical muscarinic agonists carbachol, arecoline, oxotremorine M and bethanechol were also AsGAR-1 agonists but pilocarpine was ineffective. AsGAR-1 activation by ACh was partially antagonized by the muscarinic blocker atropine but pirenzepine and scopolamine were largely ineffective. Certain biogenic amine GPCR antagonists were also found to block AsGAR-1. Our conclusion is that Ascaris possesses G protein-coupled ACh receptors that are homologous in structure to those present in C. elegans, and that although they have some sequence homology to vertebrate muscarinic receptors, their pharmacology is atypically muscarinic.
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40
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Luo L, Chen WH, Wang M, Zhu DM, She JQ, Ruan DY. Modulation of long-term potentiation by individual subtypes of muscarinic acetylcholine receptor in the rat dentate gyrus. Hippocampus 2008; 18:989-95. [PMID: 18548582 DOI: 10.1002/hipo.20461] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The roles of the muscarinic acetylcholine (ACh) receptors (mAChRs) in long-term potentiation (LTP) at many areas of the central nervous system including the hippocampus, have been extensively studied. However, not much is known about the modulation of LTP through individual subtypes of mAChR (M(1)-M(5) subtype). In this study, we investigated the involvement of each individual subtypes of mAChR in LTP induction by intrahippocampal administration of cholinergic ligands at the dentate gyrus (DG) of anesthetized rats. We found atropine, an antagonist of mAChRs, suppressed the induction of LTP. This observation confirmed that the muscarinic system is involved in LTP. We then examined the effects of M(1)AChR antagonists (pirenzepine and telenzepine), M(2/4)AChR antagonists (Methoctramine and {11-[[2-[(diethylamino)methyl]-1-piperidinyl]acetyl]-5,11-dihydro-6H-pyrido[2,3-b][1,4]benzodiazepin-6-one}(AFDX-116)), and M(3/5)AChR antagonist (4-diphenylacetoxy-N-methylpiperidine methiodide (4-DAMP)) on LTP. Our results showed that both M(1)AChR and M(2/4)AChR antagonists but not M(3/5)AChR antagonist suppressed the amplitude of LTP. We also examined the effects of these cholinergic ligands on basal synaptic transmission and found that only pirenzepine augmented the amplitude of population spike. This study suggests that individual mAChR subtypes play different modulation roles in LTP induction in the DG of rats.
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Affiliation(s)
- Le Luo
- School of Life Sciences, University of Science and Technology of China, Hefei, Anhui, People's Republic of China 230027
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Lin AL, Zhu B, Zhang W, Dang H, Zhang BX, Katz MS, Yeh CK. Distinct pathways of ERK activation by the muscarinic agonists pilocarpine and carbachol in a human salivary cell line. Am J Physiol Cell Physiol 2008; 294:C1454-64. [PMID: 18385290 DOI: 10.1152/ajpcell.00151.2007] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Cholinergic-muscarinic receptor agonists are used to alleviate mouth dryness, although the cellular signals mediating the actions of these agents on salivary glands have not been identified. We examined the activation of ERK1/2 by two muscarinic agonists, pilocarpine and carbachol, in a human salivary cell line (HSY). Immunoblot analysis revealed that both agonists induced transient activation of ERK1/2. Whereas pilocarpine induced phosphorylation of the epidermal growth factor (EGF) receptor, carbachol did not. Moreover, ERK activation by pilocarpine, but not carbachol, was abolished by the EGF receptor inhibitor AG-1478. Downregulation of PKC by prolonged treatment of cells with the phorbol ester PMA diminished carbachol-induced ERK phosphorylation but had no effect on pilocarpine responsiveness. Depletion of intracellular Ca2+ ([Ca2+]i by EGTA did not affect ERK activation by either agent. In contrast to carbachol, pilocarpine did not elicit [Ca2+]i mobilization in HSY cells. Treatment of cells with the muscarinic receptor subtype 3 (M3) antagonist N-(3-chloropropyl)-4-piperidnyl diphenylacetate decreased ERK responsiveness to both agents, whereas the subtype 1 (M1) antagonist pirenzepine reduced only the carbachol response. Stimulation of ERKs by pilocarpine was also decreased by M3, but not M1, receptor small interfering RNA. The Src inhibitor PP2 blocked pilocarpine-induced ERK activation and EGF receptor phosphorylation, without affecting ERK activation by carbachol. Our results demonstrate that the actions of pilocarpine and carbachol in salivary cells are mediated through two distinct signaling mechanisms-pilocarpine acting via M3 receptors and Src-dependent transactivation of EGF receptors, and carbachol via M1/M3 receptors and PKC-converging on the ERK pathway.
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Affiliation(s)
- Alan L Lin
- Department of Dental Diagnostic Science, University of Texas Health Science Center, San Antonio, TX, USA
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42
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Resende R, Alves A, Britto L, Ulrich H. Role of acetylcholine receptors in proliferation and differentiation of P19 embryonal carcinoma cells. Exp Cell Res 2008; 314:1429-43. [DOI: 10.1016/j.yexcr.2008.01.003] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2007] [Revised: 12/26/2007] [Accepted: 01/06/2008] [Indexed: 11/27/2022]
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43
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Chen FL, Wang XZ, Li JY, Yu JP, Huang CY, Chen ZX. 12-lipoxygenase induces apoptosis of human gastric cancer AGS cells via the ERK1/2 signal pathway. Dig Dis Sci 2008; 53:181-7. [PMID: 17522976 DOI: 10.1007/s10620-007-9841-1] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/02/2007] [Accepted: 04/05/2007] [Indexed: 12/09/2022]
Abstract
12-Lipoxygenase (12-LOX) is over-expressed in a variety of human tumors, but its exact effect on the tumorogenesis of gastric cancer remains largely obscure. To investigate the effect of 12-LOX and its inhibitor baicalein on proliferation and apoptosis of human gastric cancer, AGS cells were separately treated with 12-hydroxyeicosatetraenoic acid (12-HETE, a metabolite of 12-LOX) and baicalein. MTT assay revealed that the absorbance of the 12-HETE-treated group was significantly (P < 0.01) higher than that of control group and that the absorbance of baicalein-treated group was significantly (P < 0.01) less than that of the control group, and that 48 h after treatment the apoptosis index of the baicalein-treated group was significantly (P < 0.01) higher than that of the untreated group and was significantly (P < 0.01) lower in the 12-HETE-treated group. Western blotting analysis was used to investigate the mechanism of these effects. The results revealed that the concentration of phosphorylated ERK in cells treated with 100 nmol L(-1) 12-HETE was significantly (P < 0.05) higher than in the untreated group and that the concentration of phosphorylated ERK1/2 in cells treated with 40 micromol L(-1) baicalein was significantly (P < 0.05) lower than in the untreated group. The expression level of bcl-2 was up-regulated and down-regulated after separate treatment with 12-HETE and baicalein, respectively, and both of these effects could be blocked by PD98059. Protein kinase C (PKC) activity was increased by treatment with 12-HETE and reduced by treatment with baicalein (P < 0.05). The PKC inhibitor BIM (bisindolymaleimide-I) blocked the phosphorylation of ERK1/2 and activation of PKC induced by 12-LOX. When pretreated with BIM, the concentration of phospho-ERK1/2 or bcl-2 in the BIM + 12-HETE-treated group was significantly (P < 0.05) lower than in that treated with 12-HETE only, and the concentration in the BIM + baicalein-treated group was significantly (P < 0.05) higher than in that treated with baicalein only. On the basis of these data we conclude that, via its metabolite 12-HETE, 12-LOX abolishes proliferation of AGS cells and protect cells from apoptosis by activating the ERK1/2 pathway and, eventually, enhances expression of bcl-2. Because PKC is also involved in the activation of ERK1/2 induced by 12-LOX, 12-LOX inhibitors would be potentially powerful anticancer agents for prevention and cure of human gastric cancer.
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Affiliation(s)
- Feng-Lin Chen
- Department of Gastroenterology, Renmin Hospital of Wuhan University, Wuhan, Hubei Province, PR China.
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Wess J, Eglen RM, Gautam D. Muscarinic acetylcholine receptors: mutant mice provide new insights for drug development. Nat Rev Drug Discov 2007; 6:721-33. [PMID: 17762886 DOI: 10.1038/nrd2379] [Citation(s) in RCA: 457] [Impact Index Per Article: 26.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Muscarinic acetylcholine receptors (mAChRs), M(1)-M(5), regulate the activity of numerous fundamental central and peripheral functions. The lack of small-molecule ligands that can block or activate specific mAChR subtypes with high selectivity has remained a major obstacle in defining the roles of the individual receptor subtypes and in the development of novel muscarinic drugs. Recently, phenotypic analysis of mutant mouse strains deficient in each of the five mAChR subtypes has led to a wealth of new information regarding the physiological roles of the individual receptor subtypes. Importantly, these studies have identified specific mAChR-regulated pathways as potentially novel targets for the treatment of various important disorders including Alzheimer's disease, schizophrenia, pain, obesity and diabetes.
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Affiliation(s)
- Jürgen Wess
- Molecular Signaling Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892-0810, USA.
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45
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Hulme EC, Bee MS, Goodwin JA. Phenotypic classification of mutants: a tool for understanding ligand binding and activation of muscarinic acetylcholine receptors. Biochem Soc Trans 2007; 35:742-5. [PMID: 17635138 DOI: 10.1042/bst0350742] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
GPCRs (G-protein-coupled receptors) such as the M(1) muscarinic receptor have so far proved recalcitrant to direct structure determination. Nevertheless systematic mutagenesis, particularly alanine scanning, has advanced our understanding of their structure-function relationships. GPCRs exhibit multiple conformational states with different affinities for and abilities to activate their cognate G-proteins. Ligand binding alters these conformational equilibria, thus promoting or inhibiting signalling. Alanine-scanning mutagenesis probes the relative contributions of a particular amino acid side chain to the stability of the ground and activated states of the receptor and its complexes. These determine the phenotype of the mutant receptor. Classification of the phenotypes suggests functional roles for particular amino acid side chains, allowing us to group them accordingly. From a rhodopsin-based homology model of the M(1) mAChR, a coherent view emerges of how these clusters of residues function in ligand anchoring, transduction of binding energy, global structural stabilization and selective stabilization of the ground state or the activated state of the receptor. We can identify differences in ligand-binding modes, and suggest inter- and intra-molecular interactions that are weakened or broken, or formed or intensified during acetylcholine-induced activation. In due course, we may be able to extend these insights to activation by unconventional agonists.
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Affiliation(s)
- E C Hulme
- Division of Physical Biochemistry, MRC National Institute for Medical Research, Mill Hill, London NW7 1AA, UK.
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46
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Bee MS, Hulme EC. Functional analysis of transmembrane domain 2 of the M1 muscarinic acetylcholine receptor. J Biol Chem 2007; 282:32471-9. [PMID: 17823120 DOI: 10.1074/jbc.m703909200] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Ala substitution scanning mutagenesis has been used to probe the functional role of amino acids in transmembrane (TM) domain 2 of the M1 muscarinic acetylcholine receptor, and of the highly conserved Asn43 in TM1. The mutation of Asn43, Asn61, and Leu64 caused an enhanced ACh affinity phenotype. Interpreted using a rhodopsin-based homology model, these results suggest the presence of a network of specific contacts between this group of residues and Pro415 and Tyr418 in the highly conserved NPXXY motif in TM7 that exhibit a similar mutagenic phenotype. These contacts may be rearranged or broken when ACh binds. D71A, like N414A, was devoid of signaling activity. We suggest that formation of a direct hydrogen bond between the highly conserved side chains of Asp71 and Asn414 may be a critical feature stabilizing the activated state of the M1 receptor. Mutation of Leu67, Ala70, and Ile74 also reduced the signaling efficacy of the ACh-receptor complex. The side chains of these residues are modeled as an extended surface that may help to orient and insulate the proposed hydrogen bond between Asp71 and Asn414. Mutation of Leu72, Gly75, and Met79 in the outer half of TM2 primarily reduced the expression of functional receptor binding sites. These residues may mediate contacts with TM1 and TM7 that are preserved throughout the receptor activation cycle. Thermal inactivation measurements confirmed that a reduction in structural stability followed the mutation of Met79 as well as Asp71.
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Affiliation(s)
- Mark S Bee
- Division of Physical Biochemistry, MRC National Institute for Medical Research, The Ridgeway, Mill Hill, London NW7 1AA, United Kingdom
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47
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O'Brien JJ, Nathanson NM. Retrograde activation of STAT3 by leukemia inhibitory factor in sympathetic neurons. J Neurochem 2007; 103:288-302. [PMID: 17608645 DOI: 10.1111/j.1471-4159.2007.04736.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Leukemia inhibitory factor (LIF) is a member of the interleukin-6 family of cytokines and signals through the glycoprotein 130 and LIF receptor beta subunits. Binding of cytokines to these subunits activates multiple signaling cascades, including the Janus kinase (Jak)/signal transducers and activators of transcription (STAT) pathway. We used compartmentalized cultures of sympathetic neurons and immunocytochemical analyses of STAT3 to examine the mechanisms involved in retrograde signaling of LIF from distal neurites (DN) to cell bodies. Addition of LIF to the DN of these neurons triggers the activation and nuclear translocation of STAT3. Inhibition of Jak activity in the cell bodies prevented LIF-induced retrograde activation of STAT3, while block of Jak activity in the DN had no effect on the appearance of activated STAT3 in the nucleus. These results show that the transport of activated Jak is not the main mechanism mediating retrograde signaling. Although there is an increase in phosphorylated STAT3 in the neurites after distal stimulation, the transport of activated STAT3 is not necessary for retrograde signaling. Our results are consistent with a signaling endosome model for retrograde signaling, in which the LIF/glycoprotein 130/LIF receptor/Jak complex is internalized and transported to activate STAT3 in the cell body.
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Affiliation(s)
- Jennifer J O'Brien
- Department of Pharmacology, University of Washington, Seattle, Washington, USA
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Alfa Cissé M, Sunyach C, Slack BE, Fisher A, Vincent B, Checler F. M1 and M3 muscarinic receptors control physiological processing of cellular prion by modulating ADAM17 phosphorylation and activity. J Neurosci 2007; 27:4083-92. [PMID: 17428986 PMCID: PMC6672535 DOI: 10.1523/jneurosci.5293-06.2007] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The cellular prion protein (PrP(c)) undergoes a physiological processing yielding the N-terminal fragment referred to as N1, the production of which can be constitutive or protein kinase C regulated. We show that activation of endogenous muscarinic receptors by carbachol and by the M1-selective agonist AF267B increases N1 recovery in an atropine-sensitive manner, in mouse embryonic primary neurons. To identify the muscarinic receptor subtype involved, we used human embryonic kidney HEK293 (HEK) cells stably overexpressing M1, M2, M3, or M4 receptor subtype. Carbachol and the selective M1 agonist AF267B dose dependently increased N1 release by HEK-M3 and HEK-M1 cells, respectively, whereas carbachol did not modify N1 production by HEK-M2 or HEK-M4 cells. We demonstrate that the increase of N1 was not attributable to modified trafficking to the membrane of either PrP(c) or the disintegrin metalloproteases ADAM10 or ADAM17. Furthermore, we establish that carbachol affects the overall phosphorylation of ADAM17 on its threonine and tyrosine but not serine residues, whereas levels of phosphorylated ADAM9 were not affected. Interestingly, carbachol also increases the hydrolysis of the fluorimetric substrate JMV2770, which mimicked the sequence encompassing the N1 site cleavage and was shown previously to behave as an ADAM protease substrate. Mutations of threonine 735 but not of tyrosine 702 of the ADAM17 cytoplasmic tail abolishes the carbachol-induced increase of N1, ADAM17 phosphorylation, and JMV2770-hydrolyzing activity in M1- and M3-expressing HEK293 cells. Thus, our data provide strong evidence that muscarinic receptor activation increases the physiological processing of PrP(c) by upregulating the phosphorylation state and activity of ADAM17 protease.
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Affiliation(s)
| | - Claire Sunyach
- Institut de Pharmacologie Moleculaire et Cellulaire, 06560 Valbonne, France
| | - Barbara E. Slack
- Boston University School of Medicine, Boston, Massachusetts 02118, and
| | - Abraham Fisher
- Israel Institute for Biological Research, 74100 Ness-Ziona, Israel
| | - Bruno Vincent
- Institut de Pharmacologie Moleculaire et Cellulaire, 06560 Valbonne, France
| | - Frédéric Checler
- Institut de Pharmacologie Moleculaire et Cellulaire, 06560 Valbonne, France
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Li GQ, Kevetter GA, Leonard RB, Prusak DJ, Wood TG, Correia MJ. Muscarinic acetylcholine receptor subtype expression in avian vestibular hair cells, nerve terminals and ganglion cells. Neuroscience 2007; 146:384-402. [PMID: 17391855 PMCID: PMC1986736 DOI: 10.1016/j.neuroscience.2007.02.019] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2007] [Revised: 01/31/2007] [Accepted: 02/08/2007] [Indexed: 10/23/2022]
Abstract
Muscarinic acetylcholine receptors (mAChRs) are widely expressed in the CNS and peripheral nervous system and play an important role in modulating the cell activity and function. We have shown that the cholinergic agonist carbachol reduces the pigeon's inwardly rectifying potassium channel (pKir2.1) ionic currents in native vestibular hair cells. We have cloned and sequenced pigeon mAChR subtypes M2-M5 and we have studied the expression of all five mAChR subtypes (M1-M5) in the pigeon vestibular end organs (semicircular canal ampullary cristae and utricular maculae), vestibular nerve fibers and the vestibular (Scarpa's) ganglion using tissue immunohistochemistry (IH), dissociated single cell immunocytochemistry (IC) and Western blotting (WB). We found that vestibular hair cells, nerve fibers and ganglion cells each expressed all five (M1-M5) mAChR subtypes. Two of the three odd-numbered mAChRs (M1, M5) were present on the hair cell cilia, supporting cells and nerve terminals. And all three odd numbered mAChRs (M1, M3 and M5) were expressed on cuticular plates, myelin sheaths and Schwann cells. Even-numbered mAChRs were seen on the nerve terminals. M2 was also shown on the cuticular plates and supporting cells. Vestibular efferent fibers and terminals were not identified in our studies. Results from WB of the dissociated vestibular epithelia, nerve fibers and vestibular ganglia were consistent with the results from IH and IC. Our findings suggest that there is considerable co-expression of the subtypes on the neural elements of the labyrinth. Further electrophysiological and pharmacological studies should delineate the mechanisms of action of muscarinic acetylcholine receptors on structures in the labyrinth.
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Affiliation(s)
- Gang Q. Li
- Department of Otolaryngologyy, University of Texas Medical Branch at Galveston, Galveston Texas, 77550-1063 U.S.A
- Department of Neuroscience and Cell Biologyy, University of Texas Medical Branch at Galveston, Galveston Texas, 77550-1063 U.S.A
| | - Golda A. Kevetter
- Department of Otolaryngologyy, University of Texas Medical Branch at Galveston, Galveston Texas, 77550-1063 U.S.A
- Department of Neuroscience and Cell Biologyy, University of Texas Medical Branch at Galveston, Galveston Texas, 77550-1063 U.S.A
| | - Robert B. Leonard
- Department of Otolaryngologyy, University of Texas Medical Branch at Galveston, Galveston Texas, 77550-1063 U.S.A
- Department of Neuroscience and Cell Biologyy, University of Texas Medical Branch at Galveston, Galveston Texas, 77550-1063 U.S.A
| | - Deborah J Prusak
- Sealy Center for Molecular Medicine, University of Texas Medical Branch at Galveston, Galveston Texas, 77550-1063 U.S.A
| | - Thomas G. Wood
- Sealy Center for Molecular Medicine, University of Texas Medical Branch at Galveston, Galveston Texas, 77550-1063 U.S.A
- Department of Molecular Biology and Biochemistry, University of Texas Medical Branch at Galveston, Galveston Texas, 77550-1063 U.S.A
| | - Manning J. Correia
- Department of Otolaryngologyy, University of Texas Medical Branch at Galveston, Galveston Texas, 77550-1063 U.S.A
- Department of Neuroscience and Cell Biologyy, University of Texas Medical Branch at Galveston, Galveston Texas, 77550-1063 U.S.A
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Li S, Cullen WK, Anwyl R, Rowan MJ. Muscarinic acetylcholine receptor-dependent induction of persistent synaptic enhancement in rat hippocampus in vivo. Neuroscience 2007; 144:754-61. [PMID: 17101232 DOI: 10.1016/j.neuroscience.2006.10.001] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2006] [Revised: 09/30/2006] [Accepted: 10/02/2006] [Indexed: 11/23/2022]
Abstract
Presynaptic terminal autoinhibitory muscarinic acetylcholine (ACh) receptors are predominantly of the M2/M4 subtypes and antagonists at these receptors may facilitate cognitive processes by increasing ACh release. The present study examined the ability of the M2/M4 muscarinic ACh receptor antagonist N,N'-bis [6-[[(2-methoxyphenyl)methyl]amino]hexyl]-1,8-octane diamine tetrahydrochloride (methoctramine) to induce and modulate synaptic plasticity in the CA1 area of the hippocampus in urethane-anesthetized rats. Both methoctramine and another M2/M4 antagonist, {11-[[2-[(diethylamino)methyl]-1-piperidinyl]acetyl]-5,11-dihydro-6H-pyrido[2,3-b][1,4]benzodiazepin-6-one} (AF-DX 116), caused a rapid onset and persistent increase in baseline synaptic transmission after i.c.v. injection. Consistent with a requirement for activation of non-M2 receptors by endogenously released ACh, the M1/M3 receptor selective antagonists 4-diphenylacetoxy-N-methylpiperidine methiodide (4-DAMP) and 4,9-dihydro-3-methyl-4-[(4-methyl-1-piperazinyl)acetyl]-10H-thieno[3,4-b][1,5]benzodiazepin-10-one dihydrochloride (telenzepine) prevented the induction of the persistent synaptic enhancement by methoctramine. The requirement for cholinergic activation was transient and independent of nicotinic ACh receptor stimulation. The synaptic enhancement was inhibited by the prior induction of long-term potentiation (LTP) by high frequency stimulation but induction of the synaptic enhancement by methoctramine before high frequency stimulation did not inhibit LTP. Unlike high frequency stimulation-evoked LTP, the synaptic enhancement induced by methoctramine appeared to be NMDA receptor-independent. The present studies provide evidence for the rapid induction of a persistent potentiation at hippocampal glutamatergic synapses by endogenous ACh in vivo following disinhibition of inhibitory M2 muscarinic autoreceptors.
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Affiliation(s)
- S Li
- Department of Pharmacology and Therapeutics, Biotechnology Building, Trinity College Institute of Neuroscience, Trinity College, Dublin 2, Ireland
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