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Kim D, Roh H, Lee HM, Kim SJ, Im M. Localization of hyperpolarization-activated cyclic nucleotide-gated channels in the vertebrate retinas across species and their physiological roles. Front Neuroanat 2024; 18:1385932. [PMID: 38562955 PMCID: PMC10982330 DOI: 10.3389/fnana.2024.1385932] [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: 02/14/2024] [Accepted: 03/06/2024] [Indexed: 04/04/2024] Open
Abstract
Transmembrane proteins known as hyperpolarization-activated cyclic nucleotide-gated (HCN) channels control the movement of Na+ and K+ ions across cellular membranes. HCN channels are known to be involved in crucial physiological functions in regulating neuronal excitability and rhythmicity, and pacemaker activity in the heart. Although HCN channels have been relatively well investigated in the brain, their distribution and function in the retina have received less attention, remaining their physiological roles to be comprehensively understood. Also, because recent studies reported HCN channels have been somewhat linked with the dysfunction of photoreceptors which are affected by retinal diseases, investigating HCN channels in the retina may offer valuable insights into disease mechanisms and potentially contribute to identifying novel therapeutic targets for retinal degenerative disorders. This paper endeavors to summarize the existing literature on the distribution and function of HCN channels reported in the vertebrate retinas of various species and discuss the potential implications for the treatment of retinal diseases. Then, we recapitulate current knowledge regarding the function and regulation of HCN channels, as well as their relevance to various neurological disorders.
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Affiliation(s)
- Daniel Kim
- Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul, Republic of Korea
- Department of Biomedical Sciences, College of Medicine, Seoul National University (SNU), Seoul, Republic of Korea
| | - Hyeonhee Roh
- School of Electrical Engineering, College of Engineering, Korea University, Seoul, Republic of Korea
| | - Hyung-Min Lee
- School of Electrical Engineering, College of Engineering, Korea University, Seoul, Republic of Korea
| | - Sang Jeong Kim
- Department of Biomedical Sciences, College of Medicine, Seoul National University (SNU), Seoul, Republic of Korea
| | - Maesoon Im
- Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul, Republic of Korea
- Division of Bio-Medical Science & Technology, KIST School, University of Science & Technology (UST), Seoul, Republic of Korea
- KHU-KIST Department of Converging Science and Technology, Kyung Hee University, Seoul, Republic of Korea
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2
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Bi-directional modulation of hyperpolarization-activated cation currents (I h) by ethanol in rat hippocampal CA3 pyramidal neurons. Neuropharmacology 2023; 227:109423. [PMID: 36690323 DOI: 10.1016/j.neuropharm.2023.109423] [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: 09/09/2022] [Revised: 01/12/2023] [Accepted: 01/15/2023] [Indexed: 01/22/2023]
Abstract
It is widely acknowledged that ethanol (EtOH) can alter many neuronal functions, including synaptic signaling, firing discharge, and membrane excitability, through its interaction with multiple membrane proteins and intracellular pathways. Previous work has demonstrated that EtOH enhances the firing rate of hippocampal GABAergic interneurons and thus the presynaptic GABA release at CA1 and CA3 inhibitory synapses through a positive modulation of the hyperpolarization-activated cyclic nucleotide-gated cation (HCN) channels. Activation of HCN channels produce an inward current, commonly called Ih, which plays an essential role in generating/regulating specific neuronal activities in GABAergic interneurons and principal glutamatergic pyramidal neurons such as those in the CA3 subregion. Since the direct effect of EtOH on HCN channels expressed in CA3 pyramidal neurons was not thoroughly elucidated, we investigated the possible interaction between EtOH and HCN channels and the impact on excitability and postsynaptic integration of these neurons. Patch-clamp recordings were performed in single CA3 pyramidal neurons from acute male rat coronal hippocampal slices. Our results show that EtOH modulates HCN-mediated Ih in a concentration-dependent and bi-directional manner, with a positive modulation at lower (20 mM) and an inhibitory action at higher (60-80 mM) concentrations. The modulation of Ih by EtOH was mimicked by forskolin, antagonized by different drugs that selectively interfere with the AC/cAMP/PKA intracellular pathway, as well as by the selective HCN inhibitor ZD7288. Altogether, these data further support the evidence that HCN channels may represent an important molecular target through which EtOH may regulate neuronal activity.
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3
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Ledonne A, Massaro Cenere M, Paldino E, D'Angelo V, D'Addario SL, Casadei N, Nobili A, Berretta N, Fusco FR, Ventura R, Sancesario G, Guatteo E, Mercuri NB. Morpho-Functional Changes of Nigral Dopamine Neurons in an α-Synuclein Model of Parkinson's Disease. Mov Disord 2023; 38:256-266. [PMID: 36350188 DOI: 10.1002/mds.29269] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2022] [Accepted: 10/17/2022] [Indexed: 11/11/2022] Open
Abstract
BACKGROUND The accumulation of α-synuclein (α-syn) fibrils in intraneuronal inclusions called Lewy bodies and Lewy neurites is a pathological signature of Parkinson's disease (PD). Although several aspects linked to α-syn-dependent pathology (concerning its spreading, aggregation, and activation of inflammatory and neurodegenerative processes) have been under intense investigation, less attention has been devoted to the real impact of α-syn overexpression on structural and functional properties of substantia nigra pars compacta (SNpc) dopamine (DA) neurons, particularly at tardive stages of α-syn buildup, despite this has obvious relevance to comprehending mechanisms beyond PD progression. OBJECTIVES We aimed to determine the consequences of a prolonged α-syn overexpression on somatodendritic morphology and functions of SNpc DA neurons. METHODS We performed immunohistochemistry, stereological DA cell counts, analyses of dendritic arborization, ex vivo patch-clamp recordings, and in vivo DA microdialysis measurements in a 12- to 13-month-old transgenic rat model overexpressing the full-length human α-syn (Snca+/+ ) and age-matched wild-type rats. RESULTS Aged Snca+/+ rats have mild loss of SNpc DA neurons and decreased basal DA levels in the SN. Residual nigral DA neurons display smaller soma and compromised dendritic arborization and, in parallel, increased firing activity, switch in firing mode, and hyperexcitability associated with hypofunction of fast activating/inactivating voltage-gated K+ channels and Ca2+ - and voltage-activated large conductance K+ channels. These intrinsic currents underlie the repolarization/afterhyperpolarization phase of action potentials, thus affecting neuronal excitability. CONCLUSIONS Besides clarifying α-syn-induced pathological landmarks, such evidence reveals compensatory functional mechanisms that nigral DA neurons could adopt during PD progression to counteract neurodegeneration. © 2022 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.
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Affiliation(s)
- Ada Ledonne
- Department of Experimental Neuroscience, Santa Lucia Foundation IRCCS, Rome, Italy
| | - Mariangela Massaro Cenere
- Department of Experimental Neuroscience, Santa Lucia Foundation IRCCS, Rome, Italy.,Department of Systems Medicine, University of Rome Tor Vergata, Rome, Italy
| | - Emanuela Paldino
- Department of Systems Medicine, University of Rome Tor Vergata, Rome, Italy.,Laboratory of Neuroanatomy, Santa Lucia Foundation IRCCS, Rome, Italy
| | - Vincenza D'Angelo
- Department of Systems Medicine, University of Rome Tor Vergata, Rome, Italy
| | - Sebastian Luca D'Addario
- Department of Experimental Neuroscience, Santa Lucia Foundation IRCCS, Rome, Italy.,Department of Psychology and Center "Daniel Bovet, University of Rome La Sapienza, Rome, Italy
| | - Nicolas Casadei
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Tübingen, Germany
| | - Annalisa Nobili
- Department of Experimental Neuroscience, Santa Lucia Foundation IRCCS, Rome, Italy.,Department of Medicine and Surgery, University Campus Bio-Medico, Rome, Italy
| | - Nicola Berretta
- Department of Experimental Neuroscience, Santa Lucia Foundation IRCCS, Rome, Italy
| | - Francesca R Fusco
- Laboratory of Neuroanatomy, Santa Lucia Foundation IRCCS, Rome, Italy
| | - Rossella Ventura
- Department of Experimental Neuroscience, Santa Lucia Foundation IRCCS, Rome, Italy.,Department of Psychology and Center "Daniel Bovet, University of Rome La Sapienza, Rome, Italy
| | | | - Ezia Guatteo
- Department of Experimental Neuroscience, Santa Lucia Foundation IRCCS, Rome, Italy.,Department of Motor Science and Wellness, Parthenope University, Naples, Italy
| | - Nicola Biagio Mercuri
- Department of Experimental Neuroscience, Santa Lucia Foundation IRCCS, Rome, Italy.,Department of Systems Medicine, University of Rome Tor Vergata, Rome, Italy
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4
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Soti M, Ranjbar H, Kohlmeier KA, Razavinasab M, Masoumi-Ardakani Y, Shabani M. Probable role of the hyperpolarization-activated current in the dual effects of CB1R antagonism on behaviors in a Parkinsonism mouse model. Brain Res Bull 2022; 191:78-92. [DOI: 10.1016/j.brainresbull.2022.10.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2022] [Revised: 10/19/2022] [Accepted: 10/21/2022] [Indexed: 11/15/2022]
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5
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Guatteo E, Berretta N, Monda V, Ledonne A, Mercuri NB. Pathophysiological Features of Nigral Dopaminergic Neurons in Animal Models of Parkinson's Disease. Int J Mol Sci 2022; 23:ijms23094508. [PMID: 35562898 PMCID: PMC9102081 DOI: 10.3390/ijms23094508] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Revised: 04/16/2022] [Accepted: 04/18/2022] [Indexed: 12/21/2022] Open
Abstract
The degeneration of nigral dopaminergic neurons is considered the hallmark of Parkinson’s disease (PD), and it is triggered by different factors, including mitochondrial dysfunction, Lewy body accumulation, neuroinflammation, excitotoxicity and metal accumulation. Despite the extensive literature devoted to unravelling the signalling pathways involved in neuronal degeneration, little is known about the functional impairments occurring in these cells during illness progression. Of course, it is not possible to obtain direct information on the properties of the dopaminergic cells in patients. However, several data are available in the literature reporting changes in the function of these cells in PD animal models. In the present manuscript, we focus on dopaminergic neuron functional properties and summarize shared or peculiar features of neuronal dysfunction in different PD animal models at different stages of the disease in an attempt to design a picture of the functional modifications occurring in nigral dopaminergic neurons during disease progression preceding their eventual death.
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Affiliation(s)
- Ezia Guatteo
- Department of Motor Science and Wellness, University of Naples Parthenope, 80133 Naples, Italy; (E.G.); (V.M.)
- Experimental Neurology Laboratory, IRCCS Santa Lucia Foundation, 00143 Rome, Italy;
| | - Nicola Berretta
- Experimental Neurology Laboratory, IRCCS Santa Lucia Foundation, 00143 Rome, Italy;
| | - Vincenzo Monda
- Department of Motor Science and Wellness, University of Naples Parthenope, 80133 Naples, Italy; (E.G.); (V.M.)
| | - Ada Ledonne
- Experimental Neurology Laboratory, IRCCS Santa Lucia Foundation, 00143 Rome, Italy;
- Correspondence: (A.L.); (N.B.M.)
| | - Nicola Biagio Mercuri
- Experimental Neurology Laboratory, IRCCS Santa Lucia Foundation, 00143 Rome, Italy;
- Department of Systems Medicine, University of Rome Tor Vergata, 00143 Rome, Italy
- Correspondence: (A.L.); (N.B.M.)
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6
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Daniel NH, Aravind A, Thakur P. Are ion channels potential therapeutic targets for Parkinson's disease? Neurotoxicology 2021; 87:243-257. [PMID: 34699791 DOI: 10.1016/j.neuro.2021.10.008] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Revised: 10/15/2021] [Accepted: 10/21/2021] [Indexed: 01/31/2023]
Abstract
Parkinson's disease (PD) is primarily associated with the progressive neurodegeneration of the dopaminergic neurons in the substantia nigra region of the brain. The resulting motor symptoms are managed with the help of dopamine replacement therapies. However, these therapeutics do not prevent the neurodegeneration underlying the disease and therefore lose their effectiveness in managing disease symptoms over time. Thus, there is an urgent need to develop newer therapeutics for the benefit of patients. The release of dopamine and the firing activity of substantia nigra neurons is regulated by several ion channels that act in concert. Dysregulations of these channels cause the aberrant movement of various ions in the intracellular milieu. This eventually leads to disruption of intracellular signalling cascades, alterations in cellular homeostasis, and bioenergetic deficits. Therefore, ion channels play a central role in driving the high vulnerability of dopaminergic neurons to degenerate during PD. Targeting ion channels offers an attractive mechanistic strategy to combat the process of neurodegeneration. In this review, we highlight the evidence pointing to the role of various ion channels in driving the PD processes. In addition, we also discuss the various drugs or compounds that target the ion channels and have shown neuroprotective potential in the in-vitro and in-vivo models of PD. We also discuss the current clinical status of various drugs targeting the ion channels in the context of PD.
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Affiliation(s)
- Neha Hanna Daniel
- School of Biology, Indian Institute of Science Education and Research (IISER)-Thiruvananthapuram, Kerala, 695551, India
| | - Ananya Aravind
- School of Biology, Indian Institute of Science Education and Research (IISER)-Thiruvananthapuram, Kerala, 695551, India
| | - Poonam Thakur
- School of Biology, Indian Institute of Science Education and Research (IISER)-Thiruvananthapuram, Kerala, 695551, India.
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7
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Seutin V. Electrophysiological Quality Control of Human Dopaminergic Neurons: Are We Doing Enough? Front Cell Neurosci 2021; 15:715273. [PMID: 34483841 PMCID: PMC8414165 DOI: 10.3389/fncel.2021.715273] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Accepted: 07/19/2021] [Indexed: 11/13/2022] Open
Affiliation(s)
- Vincent Seutin
- Laboratory of Neurophysiology, GIGA Neurosciences, Liège University, Liège, Belgium
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8
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Chang X, Ma Z, Shi L, Xie J. Effects of ghrelin on the electrical activities of substantia nigra dopaminergic neurons treated with MPP .. Neurochem Int 2020; 138:104780. [PMID: 32569790 DOI: 10.1016/j.neuint.2020.104780] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2019] [Revised: 05/19/2020] [Accepted: 05/30/2020] [Indexed: 12/17/2022]
Abstract
Ghrelin, a 28 amino acid brain-gut peptide, has attracted increasing attention for its neuroprotective effect in Parkinson's disease (PD). In view of the pivotal role of excitability of dopaminergic neurons in substantia nigra pars compacta (SNc) in the function of nigrostriatal system, it is of great significance to elucidate the regulation of electrical activity of dopaminergic neurons by ghrelin, especially in PD pathogenesis. In this study, we tackled this issue by probing the effects of ghrelin on the electrophysiological properties of dopaminergic neurons in acute application of Methyl-4-phenylpyridinium (MPP+), a potent parkinsonizing agent in primates and rodents, with whole cell patch clamp technique. We first observed that MPP+ (10, 20 and 50 μM) inhibited the spontaneous firing activity of dopaminergic neurons with dose-dependent and time-dependent properties. MPP+ also hyperpolarized the membrane potential, inhibited the evoked firing activity and reduced the amplitude of the inward rectification characteristic (Sag) in dopaminergic neurons. Importantly, ghrelin (100 nM) could improve the above effects of MPP+ on the electrical activities of dopaminergic neurons. The potential mechanism of this phenomenon may be that ghrelin upregulated hyperpolarization-activated cyclic nucleotide-gated channel current (Ih) to antagonize the inhibition of MPP+ on Ih, thereby improving the electrical activities of dopaminergic neurons.
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Affiliation(s)
- Xiaoli Chang
- Department of Physiology, Shandong Provincial Key Laboratory of Pathogenesis and Prevention of Neurological Disorders, School of Basic Medicine, Medical College of Qingdao University, Qingdao, 266071, China; Institute of Brain Science and Disease, Qingdao University, Qingdao, 266071, China; Institute of Acupuncture, Shandong University of Traditional Chinese Medicine, Jinan, 250355, China
| | - Zegang Ma
- Department of Physiology, Shandong Provincial Key Laboratory of Pathogenesis and Prevention of Neurological Disorders, School of Basic Medicine, Medical College of Qingdao University, Qingdao, 266071, China; Institute of Brain Science and Disease, Qingdao University, Qingdao, 266071, China
| | - Limin Shi
- Department of Physiology, Shandong Provincial Key Laboratory of Pathogenesis and Prevention of Neurological Disorders, School of Basic Medicine, Medical College of Qingdao University, Qingdao, 266071, China; Institute of Brain Science and Disease, Qingdao University, Qingdao, 266071, China.
| | - Junxia Xie
- Department of Physiology, Shandong Provincial Key Laboratory of Pathogenesis and Prevention of Neurological Disorders, School of Basic Medicine, Medical College of Qingdao University, Qingdao, 266071, China; Institute of Brain Science and Disease, Qingdao University, Qingdao, 266071, China.
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9
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Rivolta I, Binda A, Masi A, DiFrancesco JC. Cardiac and neuronal HCN channelopathies. Pflugers Arch 2020; 472:931-951. [PMID: 32424620 DOI: 10.1007/s00424-020-02384-3] [Citation(s) in RCA: 46] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2020] [Revised: 04/21/2020] [Accepted: 04/24/2020] [Indexed: 12/31/2022]
Abstract
Hyperpolarization-activated cyclic nucleotide-gated (HCN) channels are expressed as four different isoforms (HCN1-4) in the heart and in the central and peripheral nervous systems. In the voltage range of activation, HCN channels carry an inward current mediated by Na+ and K+, termed If in the heart and Ih in neurons. Altered function of HCN channels, mainly HCN4, is associated with sinus node dysfunction and other arrhythmias such as atrial fibrillation, ventricular tachycardia, and atrioventricular block. In recent years, several data have also shown that dysfunctional HCN channels, in particular HCN1, but also HCN2 and HCN4, can play a pathogenic role in epilepsy; these include experimental data from animal models, and data collected over genetic mutations of the channels identified and characterized in epileptic patients. In the central nervous system, alteration of the Ih current could predispose to the development of neurodegenerative diseases such as Parkinson's disease; since HCN channels are widely expressed in the peripheral nervous system, their dysfunctional behavior could also be associated with the pathogenesis of neuropathic pain. Given the fundamental role played by the HCN channels in the regulation of the discharge activity of cardiac and neuronal cells, the modulation of their function for therapeutic purposes is under study since it could be useful in various pathological conditions. Here we review the present knowledge of the HCN-related channelopathies in cardiac and neurological diseases, including clinical, genetic, therapeutic, and physiopathological aspects.
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Affiliation(s)
- Ilaria Rivolta
- School of Medicine and Surgery, Milan Center for Neuroscience (NeuroMI), University of Milano-Bicocca, Monza, Italy
| | - Anna Binda
- School of Medicine and Surgery, Milan Center for Neuroscience (NeuroMI), University of Milano-Bicocca, Monza, Italy
| | - Alessio Masi
- Department of Neuroscience, Psychology, Drug Research and Child Health (NEUROFARBA), section of Pharmacology and Toxicology, University of Florence, Florence, Italy
| | - Jacopo C DiFrancesco
- School of Medicine and Surgery, Milan Center for Neuroscience (NeuroMI), University of Milano-Bicocca, Monza, Italy. .,Department of Neurology, ASST San Gerardo Hospital, University of Milano-Bicocca, Via Pergolesi, 33, 20900, Monza, MB, Italy.
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10
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Gerace E, Zianni E, Landucci E, Scartabelli T, Berlinguer Palmini R, Iezzi D, Moroni F, Di Luca M, Mannaioni G, Gardoni F, Pellegrini-Giampietro DE. Differential mechanisms of tolerance induced by NMDA and 3,5-dihydroxyphenylglycine (DHPG) preconditioning. J Neurochem 2020; 155:638-649. [PMID: 32343420 DOI: 10.1111/jnc.15033] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2020] [Revised: 04/11/2020] [Accepted: 04/14/2020] [Indexed: 11/26/2022]
Abstract
We investigated the molecular events triggered by NMDA and 3,5-dihydroxyphenylglycine (DHPG) preconditioning, that lead to neuroprotection against excitotoxic insults (AMPA or oxygen and glucose deprivation) in rat organotypic hippocampal slices, with particular attention on glutamate receptors and on cannabinoid system. We firstly evaluated the protein expression of NMDA and AMPA receptor subunits after preconditioning using western blot analysis performed in post-synaptic densities. We observed that following NMDA, but not DHPG preconditioning, the expression of GluA1 was significantly reduced and this reduction appeared to be associated with the internalization of AMPA receptors. Whole-cell voltage clamp recordings on CA1 pyramidal neurons of organotypic slices show that 24 hr after exposure to NMDA and DHPG preconditioning, AMPA-induced currents were significantly reduced. To clarify the mechanisms induced by DHPG preconditioning, we then investigated the involvement of the endocannabinoid system. Exposure of slices to the CB1 antagonist AM251 prevented the development of tolerance to AMPA toxicity induced by DHPG but not NMDA. Accordingly, the MAG-lipase inhibitor URB602, that increases arachidonoylglycerol (2-AG) content, but not the FAAH inhibitor URB597, that limits the degradation of anandamide, was also able to induce tolerance versus AMPA and OGD toxicity, suggesting that 2-AG is responsible for the DHPG-induced tolerance. In conclusion, preconditioning with NMDA or DHPG promotes differential neuroprotective mechanisms: NMDA by internalization of GluA1-AMPA receptors, DHPG by producing the endocannabinoid 2-AG.
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Affiliation(s)
- Elisabetta Gerace
- Department of Neuroscience, Psychology, Drug Research and Child Health (NeuroFarBa), Section of Pharmacology and Toxicology, University of Florence, Florence, Italy.,Department of Health Sciences, Section of Clinical Pharmacology and Oncology, University of Florence, Florence, Italy
| | - Elisa Zianni
- Department of Pharmacological and Biomolecular Sciences (DiSFeB), University of Milan, Milan, Italy
| | - Elisa Landucci
- Department of Health Sciences, Section of Clinical Pharmacology and Oncology, University of Florence, Florence, Italy
| | - Tania Scartabelli
- Department of Health Sciences, Section of Clinical Pharmacology and Oncology, University of Florence, Florence, Italy
| | - Rolando Berlinguer Palmini
- Department of Neuroscience, Psychology, Drug Research and Child Health (NeuroFarBa), Section of Pharmacology and Toxicology, University of Florence, Florence, Italy
| | - Daniela Iezzi
- Department of Neuroscience, Psychology, Drug Research and Child Health (NeuroFarBa), Section of Pharmacology and Toxicology, University of Florence, Florence, Italy
| | - Flavio Moroni
- Department of Neuroscience, Psychology, Drug Research and Child Health (NeuroFarBa), Section of Pharmacology and Toxicology, University of Florence, Florence, Italy
| | - Monica Di Luca
- Department of Pharmacological and Biomolecular Sciences (DiSFeB), University of Milan, Milan, Italy
| | - Guido Mannaioni
- Department of Neuroscience, Psychology, Drug Research and Child Health (NeuroFarBa), Section of Pharmacology and Toxicology, University of Florence, Florence, Italy
| | - Fabrizio Gardoni
- Department of Pharmacological and Biomolecular Sciences (DiSFeB), University of Milan, Milan, Italy
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11
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Hao XM, Xu R, Chen AQ, Sun FJ, Wang Y, Liu HX, Chen H, Xue Y, Chen L. Endogenous HCN Channels Modulate the Firing Activity of Globus Pallidus Neurons in Parkinsonian Animals. Front Aging Neurosci 2019; 11:190. [PMID: 31402860 PMCID: PMC6670024 DOI: 10.3389/fnagi.2019.00190] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2019] [Accepted: 07/11/2019] [Indexed: 11/13/2022] Open
Abstract
The globus pallidus occupies a critical position in the indirect pathway of the basal ganglia motor control system. Hyperpolarization-activated cyclic-nucleotide gated (HCN) channels play an important role in the modulation of neuronal excitability. In vivo extracellular single unit recording, behavioral test and immunohistochemistry were performed to explore the possible modulation of endogenous HCN channels in the globus pallidus under parkinsonian states. In MPTP parkinsonian mice, micro-pressure application of the selective HCN channel antagonist, ZD7288, decreased the firing rate in 10 out of the 28 pallidal neurons, while increased the firing rate in another 15 out of the 28 neurons. In 6-OHDA parkinsonian rats, ZD7288 also bidirectionally regulated the spontaneous firing activity of the globus pallidus neurons. The proportion of pallidal neurons with ZD7288-induced slowing of firing rate tended to reduce in both parkinsonian animals. Morphological studies revealed a weaker staining of HCN channels in the globus pallidus under parkinsonian state. Finally, behavioral study demonstrated that intrapallidal microinjection of ZD7288 alleviated locomotor deficits in MPTP parkinsonian mice. These results suggest that endogenous HCN channels modulate the activities of pallidal neurons under parkinsonian states.
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Affiliation(s)
- Xiao-Meng Hao
- Department of Physiology, Qingdao University, Qingdao, China
| | - Rong Xu
- Department of Physiology, Qingdao University, Qingdao, China
| | - An-Qi Chen
- Department of Physiology, Qingdao University, Qingdao, China
| | - Feng-Jiao Sun
- Department of Physiology, Qingdao University, Qingdao, China
| | - Ying Wang
- Department of Physiology, Qingdao University, Qingdao, China
| | - Hong-Xia Liu
- Department of Physiology, Qingdao University, Qingdao, China
| | - Hua Chen
- Department of Pathology, Qingdao Municipal Hospital, Qingdao, China
| | - Yan Xue
- Department of Physiology, Qingdao University, Qingdao, China
| | - Lei Chen
- Department of Physiology, Qingdao University, Qingdao, China
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12
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Masi A, Narducci R, Mannaioni G. Harnessing ionic mechanisms to achieve disease modification in neurodegenerative disorders. Pharmacol Res 2019; 147:104343. [PMID: 31279830 DOI: 10.1016/j.phrs.2019.104343] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/08/2019] [Revised: 06/19/2019] [Accepted: 07/03/2019] [Indexed: 12/12/2022]
Abstract
Progressive neuronal death is the key pathogenic event leading to clinical symptoms in neurodegenerative disorders (NDDs). Neuroprotective treatments are virtually unavailable, partly because of the marked internal heterogeneity of the mechanisms underlying pathology. Targeted neuroprotection would require deep mechanistic knowledge across the entire aetiological spectrum of each NDD and the development of tailored treatments. Although ideal, this strategy appears challenging, as it would require a degree of characterization of both the disease and the patient that is currently unavailable. The alternate strategy is to search for commonalities across molecularly distinct NDD forms and exploit these for the development of drugs with broad-spectrum efficacy. In this view, mounting evidence points to ionic mechanisms (IMs) as targets with potential therapeutic efficacy across distinct NDD subtypes. The scope of this review is to present clinical and preclinical evidence supporting the link between disruption of IMs and neuronal death in specific NDDs and to critically revise past and ongoing attempts of harnessing IMs for the development of neuroprotective treatments.
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Affiliation(s)
- A Masi
- Department of Neuroscience, Psychology, Drug Research and Child Health (NEUROFARBA), Section of Pharmacology and Toxicology, University of Florence, Florence, Italy; School of Pharmacy, University of Camerino, Camerino, Italy.
| | - R Narducci
- Italian Institute of Technology (IIT), Department of Neuroscience and Brain Technologies, Genova, Italy
| | - G Mannaioni
- Department of Neuroscience, Psychology, Drug Research and Child Health (NEUROFARBA), Section of Pharmacology and Toxicology, University of Florence, Florence, Italy; Toxicology Unit, Azienda Ospedaliero-Universitaria Careggi, Florence, Italy
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13
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Chang X, Wang J, Jiang H, Shi L, Xie J. Hyperpolarization-Activated Cyclic Nucleotide-Gated Channels: An Emerging Role in Neurodegenerative Diseases. Front Mol Neurosci 2019; 12:141. [PMID: 31231190 PMCID: PMC6560157 DOI: 10.3389/fnmol.2019.00141] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2018] [Accepted: 05/13/2019] [Indexed: 12/13/2022] Open
Abstract
Neurodegenerative diseases such as Parkinson’s disease (PD), Alzheimer’s disease (AD), amyotrophic lateral sclerosis (ALS), and spinal muscular atrophy (SMA) are chronic, progressive, and age-associated neurological disorders characterized by neuronal deterioration in specific brain regions. Although the specific pathological mechanisms underlying these disorders have remained elusive, ion channel dysfunction has become increasingly accepted as a potential mechanism for neurodegenerative diseases. Hyperpolarization-activated cyclic nucleotide-gated (HCN) channels are encoded by the HCN1-4 gene family and conduct the hyperpolarization-activated current (Ih). These channels play important roles in modulating cellular excitability, rhythmic activity, dendritic integration, and synaptic transmission. In the present review, we first provide a comprehensive picture of the role of HCN channels in PD by summarizing their role in the regulation of neuronal activity in PD-related brain regions. Dysfunction of Ih may participate in 1-methyl-4-phenylpyridinium (MPP+)-induced toxicity and represent a pathogenic mechanism in PD. Given current reports of the critical role of HCN channels in neuroinflammation and depression, we also discussed the putative contribution of HCN channels in inflammatory processes and non-motor symptoms in PD. In the second section, we summarize how HCN channels regulate the formation of β-amyloid peptide in AD and the role of these channels in learning and memory. Finally, we briefly discuss the effects of HCN channels in ALS and SMA based on existing discoveries.
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Affiliation(s)
- Xiaoli Chang
- Department of Physiology, Shandong Provincial Key Laboratory of Pathogenesis and Prevention of Neurological Disorders and State Key Disciplines: Physiology, Medical College of Qingdao University, Qingdao, China.,Institute of Brain Science and Disease, Qingdao University, Qingdao, China
| | - Jun Wang
- Department of Physiology, Shandong Provincial Key Laboratory of Pathogenesis and Prevention of Neurological Disorders and State Key Disciplines: Physiology, Medical College of Qingdao University, Qingdao, China.,Institute of Brain Science and Disease, Qingdao University, Qingdao, China
| | - Hong Jiang
- Department of Physiology, Shandong Provincial Key Laboratory of Pathogenesis and Prevention of Neurological Disorders and State Key Disciplines: Physiology, Medical College of Qingdao University, Qingdao, China.,Institute of Brain Science and Disease, Qingdao University, Qingdao, China
| | - Limin Shi
- Department of Physiology, Shandong Provincial Key Laboratory of Pathogenesis and Prevention of Neurological Disorders and State Key Disciplines: Physiology, Medical College of Qingdao University, Qingdao, China.,Institute of Brain Science and Disease, Qingdao University, Qingdao, China
| | - Junxia Xie
- Department of Physiology, Shandong Provincial Key Laboratory of Pathogenesis and Prevention of Neurological Disorders and State Key Disciplines: Physiology, Medical College of Qingdao University, Qingdao, China.,Institute of Brain Science and Disease, Qingdao University, Qingdao, China
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14
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Zhao Z, Li L, Gu H. Dynamical Mechanism of Hyperpolarization-Activated Non-specific Cation Current Induced Resonance and Spike-Timing Precision in a Neuronal Model. Front Cell Neurosci 2018; 12:62. [PMID: 29568262 PMCID: PMC5852126 DOI: 10.3389/fncel.2018.00062] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2017] [Accepted: 02/20/2018] [Indexed: 01/23/2023] Open
Abstract
Hyperpolarization-activated cyclic nucleotide-gated cation current (Ih) plays important roles in the achievement of many physiological/pathological functions in the nervous system by modulating the electrophysiological activities, such as the rebound (spike) to hyperpolarization stimulations, subthreshold membrane resonance to sinusoidal currents, and spike-timing precision to stochastic factors. In the present paper, with increasing gh (conductance of Ih), the rebound (spike) and subthreshold resonance appear and become stronger, and the variability of the interspike intervals (ISIs) becomes lower, i.e., the enhancement of spike-timing precision, which are simulated in a conductance-based theoretical model and well explained by the nonlinear concept of bifurcation. With increasing gh, the stable node to stable focus, to coexistence behavior, and to firing via the codimension-1 bifurcations (Hopf bifurcation, saddle-node bifurcation, saddle-node bifurcations on an invariant circle, and saddle homoclinic orbit) and codimension-2 bifurcations such as Bogdanov-Takens (BT) point related to the transition between saddle-node and Hopf bifurcations, are acquired with 1- and 2-parameter bifurcation analysis. The decrease of variability of ISIs with increasing gh is induced by the fast decrease of the standard deviation of ISIs, which is related to the increase of the capacity of resisting noisy disturbance due to the firing becomes far away from the bifurcation point. The enhancement of the rebound (spike) with increasing gh builds up a relationship to the decrease of the capacity of resisting disturbance like the hyperpolarization stimulus as the resting state approaches the bifurcation point. The “typical”-resonance and non-resonance appear in the parameter region of the stable focus and node far away from the bifurcation points, respectively. The complex or “strange” dynamics, such as the “weak”-resonance for the stable node near the transition point between the stable node and focus and the non-resonance for the stable focus close to the codimension-1 and −2 bifurcation points, are discussed.
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Affiliation(s)
- Zhiguo Zhao
- School of Aerospace Engineering and Applied Mechanics, Tongji University, Shanghai, China.,School of Basic Science, Henan Institute of Technology, Xinxiang, China
| | - Li Li
- School of Aerospace Engineering and Applied Mechanics, Tongji University, Shanghai, China
| | - Huaguang Gu
- School of Aerospace Engineering and Applied Mechanics, Tongji University, Shanghai, China
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15
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Sartiani L, Mannaioni G, Masi A, Novella Romanelli M, Cerbai E. The Hyperpolarization-Activated Cyclic Nucleotide-Gated Channels: from Biophysics to Pharmacology of a Unique Family of Ion Channels. Pharmacol Rev 2017; 69:354-395. [PMID: 28878030 DOI: 10.1124/pr.117.014035] [Citation(s) in RCA: 82] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2017] [Accepted: 07/07/2017] [Indexed: 12/22/2022] Open
Abstract
Hyperpolarization-activated, cyclic nucleotide-gated (HCN) channels are important members of the voltage-gated pore loop channels family. They show unique features: they open at hyperpolarizing potential, carry a mixed Na/K current, and are regulated by cyclic nucleotides. Four different isoforms have been cloned (HCN1-4) that can assemble to form homo- or heterotetramers, characterized by different biophysical properties. These proteins are widely distributed throughout the body and involved in different physiologic processes, the most important being the generation of spontaneous electrical activity in the heart and the regulation of synaptic transmission in the brain. Their role in heart rate, neuronal pacemaking, dendritic integration, learning and memory, and visual and pain perceptions has been extensively studied; these channels have been found also in some peripheral tissues, where their functions still need to be fully elucidated. Genetic defects and altered expression of HCN channels are linked to several pathologies, which makes these proteins attractive targets for translational research; at the moment only one drug (ivabradine), which specifically blocks the hyperpolarization-activated current, is clinically available. This review discusses current knowledge about HCN channels, starting from their biophysical properties, origin, and developmental features, to (patho)physiologic role in different tissues and pharmacological modulation, ending with their present and future relevance as drug targets.
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Affiliation(s)
- Laura Sartiani
- Department of Neurosciences, Psychology, Drug Research, and Child Health, University of Florence, Firenze, Italy
| | - Guido Mannaioni
- Department of Neurosciences, Psychology, Drug Research, and Child Health, University of Florence, Firenze, Italy
| | - Alessio Masi
- Department of Neurosciences, Psychology, Drug Research, and Child Health, University of Florence, Firenze, Italy
| | - Maria Novella Romanelli
- Department of Neurosciences, Psychology, Drug Research, and Child Health, University of Florence, Firenze, Italy
| | - Elisabetta Cerbai
- Department of Neurosciences, Psychology, Drug Research, and Child Health, University of Florence, Firenze, Italy
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16
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Carbone C, Costa A, Provensi G, Mannaioni G, Masi A. The Hyperpolarization-Activated Current Determines Synaptic Excitability, Calcium Activity and Specific Viability of Substantia Nigra Dopaminergic Neurons. Front Cell Neurosci 2017; 11:187. [PMID: 28701928 PMCID: PMC5487410 DOI: 10.3389/fncel.2017.00187] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2017] [Accepted: 06/16/2017] [Indexed: 12/28/2022] Open
Abstract
Differential vulnerability between Substantia Nigra pars compacta (SNpc) and Ventral Tegmental Area (VTA) dopaminergic (DAergic) neurons is a hallmark of Parkinson’s disease (PD). Understanding the molecular bases of this key histopathological aspect would foster the development of much-needed disease-modifying therapies. Non-heterogeneous DAergic degeneration is present in both toxin-based and genetic animal models, suggesting that cellular specificity, rather than causing factors, constitutes the background for differential vulnerability. In this regard, we previously demonstrated that MPP+, a neurotoxin able to cause selective nigrostriatal degeneration in animal rodents and primates, inhibits the Hyperpolarization-activated current (Ih) in SNpc DAergic neurons and that pharmacological Ih antagonism causes potentiation of evoked Excitatory post-synaptic potentials (EPSPs). Of note, the magnitude of such potentiation is greater in the SNpc subfield, consistent with higher Ih density. In the present work, we show that Ih block-induced synaptic potentiation leads to the amplification of somatic calcium responses (SCRs) in vitro. This effect is specific for the SNpc subfield and largely mediated by L-Type calcium channels, as indicated by sensitivity to the CaV 1 blocker isradipine. Furthermore, Ih is downregulated by low intracellular ATP and determines the efficacy of GABAergic inhibition in SNpc DAergic neurons. Finally, we show that stereotaxic administration of Ih blockers causes SNpc-specific neurodegeneration and hemiparkinsonian motor phenotype in rats. During PD progression, Ih downregulation may result from mitochondrial dysfunction and, in concert with PD-related disinhibition of excitatory inputs, determine a SNpc-specific disease pathway.
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Affiliation(s)
- Carmen Carbone
- Department of Neuroscience, Psychology, Drug Research and Child Health (NEUROFARBA), Section of Pharmacology and Toxicology, University of FlorenceFlorence, Italy
| | - Alessia Costa
- Department of Neuroscience, Psychology, Drug Research and Child Health (NEUROFARBA), Section of Pharmacology and Toxicology, University of FlorenceFlorence, Italy
| | - Gustavo Provensi
- Department of Neuroscience, Psychology, Drug Research and Child Health (NEUROFARBA), Section of Pharmacology and Toxicology, University of FlorenceFlorence, Italy
| | - Guido Mannaioni
- Department of Neuroscience, Psychology, Drug Research and Child Health (NEUROFARBA), Section of Pharmacology and Toxicology, University of FlorenceFlorence, Italy.,Toxicology Unit, Azienda Ospedaliero-Universitaria CareggiFlorence, Italy
| | - Alessio Masi
- Department of Neuroscience, Psychology, Drug Research and Child Health (NEUROFARBA), Section of Pharmacology and Toxicology, University of FlorenceFlorence, Italy.,Toxicology Unit, Azienda Ospedaliero-Universitaria CareggiFlorence, Italy
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17
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Functional alterations of the dopaminergic and glutamatergic systems in spontaneous α-synuclein overexpressing rats. Exp Neurol 2016; 287:21-33. [PMID: 27771352 DOI: 10.1016/j.expneurol.2016.10.009] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2016] [Revised: 10/17/2016] [Accepted: 10/18/2016] [Indexed: 12/15/2022]
Abstract
The presence of α-synuclein (α-syn) in Lewy bodies and Lewy neurites is an important characteristic of the neurodegenerative processes of substantia nigra pars compacta (SNpc) dopaminergic (DAergic) neurons in Parkinson's disease (PD) and other synucleinopathies. Here we report that Berlin-Druckrey rats carrying a spontaneous mutation in the 3' untranslated region of α-syn mRNA (m/m rats) display a marked accumulation of α-syn in the mesencephalic area, striatum and frontal cortex, accompanied to severe dysfunctions in the dorsolateral striatum. Despite a small reduction in the number of SNpc and ventral tegmental area DAergic cells, the surviving dopaminergic neurons of the m/m rats do not show clear-cut alterations of the spontaneous and evoked firing activity, DA responses and somatic amphetamine-induced firing inhibition. Interestingly, mutant DAergic neurons display diminished whole-cell Ih conductance and a reduced frequency of spontaneous excitatory synaptic currents. By contrast, m/m rats show a severe impairment of DA and glutamate release in the dorsolateral striatum, as revealed by amperometric measure of DA currents and by electrophysiological recordings of glutamatergic synaptic events in striatal medium spiny neurons. These functional impairments are paralleled by a decreased expression of the DA transporter and VGluT1 proteins in the same area. Thus, together with α-syn overload in the mesencephalic region, striatum and frontal cortex, the main functional alterations occur in the DAergic and glutamatergic terminals in the dorsal striatum of the m/m rats.
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18
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Resta F, Masi A, Sili M, Laurino A, Moroni F, Mannaioni G. Kynurenic acid and zaprinast induce analgesia by modulating HCN channels through GPR35 activation. Neuropharmacology 2016; 108:136-43. [PMID: 27131920 DOI: 10.1016/j.neuropharm.2016.04.038] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2015] [Revised: 02/11/2016] [Accepted: 04/26/2016] [Indexed: 12/30/2022]
Abstract
Hyperpolarization-activated cyclic nucleotide-gated (HCN) channels have a key role in the control of cellular excitability. HCN2, a subgroup of the HCN family channels, are heavily expressed in small dorsal root ganglia (DRG) neurons and their activation seems to be important in the determination of pain intensity. Intracellular elevation of cAMP levels activates HCN-mediated current (Ih) and small DRG neurons excitability. GPR35, a Gi/o coupled receptor, is highly expressed in small DRG neurons, and we hypothesized that its activation, mediated by endogenous or exogenous ligands, could lead to pain control trough a reduction of Ih current. Patch clamp recordings were carried out in primary cultures of rat DRG neurons and the effects of GPR35 activation on Ih current and neuronal excitability were studied in control conditions and after adenylate cyclase activation with either forskolin or prostaglandin E2 (PGE2). We found that both kynurenic acid (KYNA) and zaprinast, the endogenous and synthetic GPR35 agonist respectively, were able to antagonize the forskolin-induced depolarization of resting membrane potential by reducing Ih-mediated depolarization. Similar results were obtained when PGE2 was used to activate adenylate cyclase and to increase Ih current and the overall neuronal excitability. Finally, we tested the analgesic effect of both GPR35 agonists in an in vivo model of PGE2-induced thermal hyperalgesia. In accord with the hypothesis, both KYNA and zaprinast showed a dose dependent analgesic effect. In conclusion, GPR35 activation leads to a reduced excitability of small DRG neurons in vitro and causes a dose-dependent analgesia in vivo. GPR35 agonists, by reducing adenylate cyclase activity and inhibiting Ih in DRG neurons may represent a promising new group of analgesic drugs.
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Affiliation(s)
- Francesco Resta
- Department of Neurosciences, Psychology, Drug Research and Child Health, University of Florence, Viale Pieraccini 6, 50139 Florence, Italy.
| | - Alessio Masi
- Department of Neurosciences, Psychology, Drug Research and Child Health, University of Florence, Viale Pieraccini 6, 50139 Florence, Italy; Azienda Ospedaliero-Universitaria Careggi, Toxicology Unit, Largo Brambilla 1, 50139, Florence, Italy.
| | - Maria Sili
- Department of Neurosciences, Psychology, Drug Research and Child Health, University of Florence, Viale Pieraccini 6, 50139 Florence, Italy.
| | - Annunziatina Laurino
- Department of Neurosciences, Psychology, Drug Research and Child Health, University of Florence, Viale Pieraccini 6, 50139 Florence, Italy.
| | - Flavio Moroni
- Department of Neurosciences, Psychology, Drug Research and Child Health, University of Florence, Viale Pieraccini 6, 50139 Florence, Italy.
| | - Guido Mannaioni
- Department of Neurosciences, Psychology, Drug Research and Child Health, University of Florence, Viale Pieraccini 6, 50139 Florence, Italy; Azienda Ospedaliero-Universitaria Careggi, Toxicology Unit, Largo Brambilla 1, 50139, Florence, Italy.
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Novella Romanelli M, Sartiani L, Masi A, Mannaioni G, Manetti D, Mugelli A, Cerbai E. HCN Channels Modulators: The Need for Selectivity. Curr Top Med Chem 2016; 16:1764-91. [PMID: 26975509 PMCID: PMC5374843 DOI: 10.2174/1568026616999160315130832] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2015] [Revised: 08/04/2015] [Accepted: 08/05/2015] [Indexed: 12/27/2022]
Abstract
Hyperpolarization-activated, cyclic nucleotide-gated (HCN) channels, the molecular correlate of the hyperpolarization-activated current (If/Ih), are membrane proteins which play an important role in several physiological processes and various pathological conditions. In the Sino Atrial Node (SAN) HCN4 is the target of ivabradine, a bradycardic agent that is, at the moment, the only drug which specifically blocks If. Nevertheless, several other pharmacological agents have been shown to modulate HCN channels, a property that may contribute to their therapeutic activity and/or to their side effects. HCN channels are considered potential targets for developing drugs to treat several important pathologies, but a major issue in this field is the discovery of isoform-selective compounds, owing to the wide distribution of these proteins into the central and peripheral nervous systems, heart and other peripheral tissues. This survey is focused on the compounds that have been shown, or have been designed, to interact with HCN channels and on their binding sites, with the aim to summarize current knowledge and possibly to unveil useful information to design new potent and selective modulators.
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Affiliation(s)
- Maria Novella Romanelli
- University of Florence, Department of Neurosciences, Psychology, Drug Research and Child's Health, Section of Pharmaceutical and Nutraceutical Sciences, via Ugo Schiff 6, 50019 Sesto Fiorentino, Italy.
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20
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Masi A, Narducci R, Resta F, Carbone C, Kobayashi K, Mannaioni G. Differential contribution of Ih to the integration of excitatory synaptic inputs in substantia nigra pars compacta and ventral tegmental area dopaminergic neurons. Eur J Neurosci 2015; 42:2699-706. [DOI: 10.1111/ejn.13066] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2015] [Revised: 08/05/2015] [Accepted: 09/04/2015] [Indexed: 01/23/2023]
Affiliation(s)
- Alessio Masi
- Department of Neuroscience, Psychology, Drug Research and Child Health (NEUROFARBA); Section of Pharmacology and Toxicology; University of Florence; Viale G Pieraccini 6 50139 Florence Italy
- Toxicology Unit; Azienda Ospedaliero-Universitaria Careggi; Florence Italy
| | - Roberto Narducci
- Department of Neuroscience, Psychology, Drug Research and Child Health (NEUROFARBA); Section of Pharmacology and Toxicology; University of Florence; Viale G Pieraccini 6 50139 Florence Italy
| | - Francesco Resta
- Department of Neuroscience, Psychology, Drug Research and Child Health (NEUROFARBA); Section of Pharmacology and Toxicology; University of Florence; Viale G Pieraccini 6 50139 Florence Italy
| | - Carmen Carbone
- Department of Neuroscience, Psychology, Drug Research and Child Health (NEUROFARBA); Section of Pharmacology and Toxicology; University of Florence; Viale G Pieraccini 6 50139 Florence Italy
| | - Kazuto Kobayashi
- Department of Molecular Genetics; Institute of Biomedical Sciences; Fukushima Medical University School of Medicine; Fukushima Japan
| | - Guido Mannaioni
- Department of Neuroscience, Psychology, Drug Research and Child Health (NEUROFARBA); Section of Pharmacology and Toxicology; University of Florence; Viale G Pieraccini 6 50139 Florence Italy
- Toxicology Unit; Azienda Ospedaliero-Universitaria Careggi; Florence Italy
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21
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Engel D, Seutin V. High dendritic expression of Ih in the proximity of the axon origin controls the integrative properties of nigral dopamine neurons. J Physiol 2015; 593:4905-22. [PMID: 26350173 DOI: 10.1113/jp271052] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2015] [Accepted: 08/26/2015] [Indexed: 11/08/2022] Open
Abstract
KEY POINTS The hyperpolarization-activated cation current Ih is expressed in dopamine neurons of the substantia nigra, but the subcellular distribution of the current and its role in synaptic integration remain unknown. We used cell-attached patch recordings to determine the localization profile of Ih along the somatodendritic axis of nigral dopamine neurons in slices from young rats. Ih density is higher in axon-bearing dendrites, in a membrane area close to the axon origin, than in the soma and axon-lacking dendrites. Dual current-clamp recordings revealed a similar contribution of Ih to the waveform of single excitatory postsynaptic potentials throughout the somatodendritic domain. The Ih blocker ZD 7288 increased the temporal summation in all dendrites with a comparable effect in axon- and non-axon dendrites. The strategic position of Ih in the proximity of the axon may influence importantly transitions between pacemaker and bursting activities and consequently the downstream release of dopamine. ABSTRACT Dendrites of most neurons express voltage-gated ion channels in their membrane. In combination with passive properties, active currents confer to dendrites a high computational potential. The hyperpolarization-activated cation current Ih present in the dendrites of some pyramidal neurons affects their membrane and integration properties, synaptic plasticity and higher functions such as memory. A gradient of increasing h-channel density towards distal dendrites has been found to be responsible for the location independence of excitatory postsynaptic potential (EPSP) waveform and temporal summation in cortical and hippocampal pyramidal cells. However, reports on other cell types revealed that smoother gradients or even linear distributions of Ih can achieve homogeneous temporal summation. Although the existence of a robust, slowly activating Ih current has been repeatedly demonstrated in nigral dopamine neurons, its subcellular distribution and precise role in synaptic integration are unknown. Using cell-attached patch-clamp recordings, we find a higher Ih current density in the axon-bearing dendrite than in the soma or in dendrites without axon in nigral dopamine neurons. Ih is mainly concentrated in the dendritic membrane area surrounding the axon origin and decreases with increasing distances from this site. Single EPSPs and temporal summation are similarly affected by blockade of Ih in axon- and non-axon-bearing dendrites. The presence of Ih close to the axon is pivotal to control the integrative functions and the output signal of dopamine neurons and may consequently influence the downstream coding of movement.
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Affiliation(s)
- Dominique Engel
- GIGA-Neurosciences, Neurophysiology Unit, University of Liège, SartTilman, B-4000, Liège, Belgium
| | - Vincent Seutin
- GIGA-Neurosciences, Neurophysiology Unit, University of Liège, SartTilman, B-4000, Liège, Belgium
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DiFrancesco JC, DiFrancesco D. Dysfunctional HCN ion channels in neurological diseases. Front Cell Neurosci 2015; 6:174. [PMID: 25805968 PMCID: PMC4354400 DOI: 10.3389/fncel.2015.00071] [Citation(s) in RCA: 86] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2014] [Accepted: 02/18/2015] [Indexed: 11/25/2022] Open
Abstract
Hyperpolarization-activated cyclic nucleotide-gated (HCN) channels are expressed as four different isoforms (HCN1-4) in the heart and in the central and peripheral nervous systems. HCN channels are activated by membrane hyperpolarization at voltages close to resting membrane potentials and carry the hyperpolarization-activated current, dubbed If (funny current) in heart and Ih in neurons. HCN channels contribute in several ways to neuronal activity and are responsible for many important cellular functions, including cellular excitability, generation, and modulation of rhythmic activity, dendritic integration, transmission of synaptic potentials, and plasticity phenomena. Because of their role, defective HCN channels are natural candidates in the search for potential causes of neurological disorders in humans. Several data, including growing evidence that some forms of epilepsy are associated with HCN mutations, support the notion of an involvement of dysfunctional HCN channels in different experimental models of the disease. Additionally, some anti-epileptic drugs are known to modify the activity of the Ih current. HCN channels are widely expressed in the peripheral nervous system and recent evidence has highlighted the importance of the HCN2 isoform in the transmission of pain. HCN channels are also present in the midbrain system, where they finely regulate the activity of dopaminergic neurons, and a potential role of these channels in the pathogenesis of Parkinson’s disease has recently emerged. The function of HCN channels is regulated by specific accessory proteins, which control the correct expression and modulation of the neuronal Ih current. Alteration of these proteins can severely interfere with the physiological channel function, potentially predisposing to pathological conditions. In this review we address the present knowledge of the association between HCN dysfunctions and neurological diseases, including clinical, genetic, and physiopathological aspects.
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Affiliation(s)
- Jacopo C DiFrancesco
- Department of Neurophysiology, Foundation Neurological Institute C. Besta Milano, Italy ; Department of Neurology, San Gerardo Hospital and Laboratory of Neurobiology, Milan Center for Neuroscience, University of Milano-Bicocca Monza, Italy
| | - Dario DiFrancesco
- The PaceLab, Department of Biosciences, University of Milano Milano, Italy
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Roselli F, Caroni P. From Intrinsic Firing Properties to Selective Neuronal Vulnerability in Neurodegenerative Diseases. Neuron 2015; 85:901-10. [DOI: 10.1016/j.neuron.2014.12.063] [Citation(s) in RCA: 75] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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24
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Yee AG, Lee SM, Hunter MR, Glass M, Freestone PS, Lipski J. Effects of the Parkinsonian toxin MPP+ on electrophysiological properties of nigral dopaminergic neurons. Neurotoxicology 2014; 45:1-11. [DOI: 10.1016/j.neuro.2014.08.009] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2014] [Revised: 08/22/2014] [Accepted: 08/25/2014] [Indexed: 10/24/2022]
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25
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Gerace E, Masi A, Resta F, Felici R, Landucci E, Mello T, Pellegrini-Giampietro DE, Mannaioni G, Moroni F. PARP-1 activation causes neuronal death in the hippocampal CA1 region by increasing the expression of Ca(2+)-permeable AMPA receptors. Neurobiol Dis 2014; 70:43-52. [PMID: 24954469 DOI: 10.1016/j.nbd.2014.05.023] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2014] [Revised: 05/07/2014] [Accepted: 05/17/2014] [Indexed: 01/22/2023] Open
Abstract
An excessive activation of poly(ADP-ribose) polymerases (PARPs) may trigger a form of neuronal death similar to that occurring in neurodegenerative disorders. To investigate this process, we exposed organotypic hippocampal slices to N-methyl-N'-nitro-N'-nitrosoguanidine (MNNG, 100μM for 5min), an alkylating agent widely used to activate PARP-1. MNNG induced a pattern of degeneration of the CA1 pyramidal cells morphologically similar to that observed after a brief period of oxygen and glucose deprivation (OGD). MNNG exposure was also associated with a dramatic increase in PARP-activity and a robust decrease in NAD(+) and ATP content. These effects were prevented by PARP-1 but not PARP-2 inhibitors. In our experimental conditions, cell death was not mediated by AIF translocation (parthanatos) or caspase-dependent apoptotic processes. Furthermore, we found that PARP activation was followed by a significant deterioration of neuronal membrane properties. Using electrophysiological recordings we firstly investigated the suggested ability of ADP-ribose to open TRPM2 channels in MNNG-induced cells death, but the results we obtained showed that TRPM2 channels are not involved. We then studied the involvement of glutamate receptor-ion channel complex and we found that NBQX, a selective AMPA receptor antagonist, was able to effectively prevent CA1 neuronal loss while MK801, a NMDA antagonist, was not active. Moreover, we observed that MNNG treatment increased the ratio of GluA1/GluA2 AMPAR subunit expression, which was associated with an inward rectification of the IV relationship of AMPA sEPSCs in the CA1 but not in the CA3 subfield. Accordingly, 1-naphthyl acetyl spermine (NASPM), a selective blocker of Ca(2+)-permeable GluA2-lacking AMPA receptors, reduced MNNG-induced CA1 pyramidal cell death. In conclusion, our results show that activation of the nuclear enzyme PARP-1 may change the expression of membrane proteins and Ca(2+) permeability of AMPA channels, thus affecting the function and survival of CA1 pyramidal cells.
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Affiliation(s)
- E Gerace
- Department of Health Sciences, Section of Clinical Pharmacology and Oncology, University of Florence, Viale Pieraccini 6, 50139 Florence, Italy
| | - A Masi
- Department of Neuroscience, Section of Pharmacology, University of Florence, Viale Pieraccini 6, 50139 Florence, Italy
| | - F Resta
- Department of Neuroscience, Section of Pharmacology, University of Florence, Viale Pieraccini 6, 50139 Florence, Italy
| | - R Felici
- Department of Health Sciences, Section of Clinical Pharmacology and Oncology, University of Florence, Viale Pieraccini 6, 50139 Florence, Italy
| | - E Landucci
- Department of Health Sciences, Section of Clinical Pharmacology and Oncology, University of Florence, Viale Pieraccini 6, 50139 Florence, Italy
| | - T Mello
- Department of Experimental and Biomedical Sciences, University of Florence, Viale Pieraccini 6, 50139 Florence, Italy
| | - D E Pellegrini-Giampietro
- Department of Health Sciences, Section of Clinical Pharmacology and Oncology, University of Florence, Viale Pieraccini 6, 50139 Florence, Italy
| | - G Mannaioni
- Department of Neuroscience, Section of Pharmacology, University of Florence, Viale Pieraccini 6, 50139 Florence, Italy
| | - F Moroni
- Department of Neuroscience, Section of Pharmacology, University of Florence, Viale Pieraccini 6, 50139 Florence, Italy.
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Berlinguer-Palmini R, Masi A, Narducci R, Cavone L, Maratea D, Cozzi A, Sili M, Moroni F, Mannaioni G. GPR35 activation reduces Ca2+ transients and contributes to the kynurenic acid-dependent reduction of synaptic activity at CA3-CA1 synapses. PLoS One 2013; 8:e82180. [PMID: 24312407 PMCID: PMC3843712 DOI: 10.1371/journal.pone.0082180] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2013] [Accepted: 10/22/2013] [Indexed: 12/19/2022] Open
Abstract
Limited information is available on the brain expression and role of GPR35, a Gi/o coupled receptor activated by kynurenic acid (KYNA). In mouse cultured astrocytes, we detected GPR35 transcript using RT-PCR and we found that KYNA (0.1 to 100 µM) decreased forskolin (FRSK)-induced cAMP production (p<0.05). Both CID2745687 (3 µM, CID), a recently described GPR35 antagonist, and GPR35 gene silencing significantly prevented the action of KYNA on FRSK-induced cAMP production. In these cultures, we then evaluated whether GPR35 activation was able to modulate intracellular Ca2+ concentration ([Ca2+]i ) and [Ca2+]i fluxes. We found that both KYNA and zaprinast, a phosphodiesterase (PDE) inhibitor and GPR35 agonist, did not modify either basal or peaks of [Ca2+]i induced by challenging the cells with ATP (30 µM). However, the [Ca2+]i plateau phase following peak was significantly attenuated by these compounds in a store-operated Ca2+ channel (SOC)-independent manner. The activation of GPR35 by KYNA and zaprinast was also studied at the CA3-CA1 synapse in the rat hippocampus. Evoked excitatory post synaptic currents (eEPSCs) were recorded from CA1 pyramidal neurons in acute brain slices. The action of KYNA on GPR35 was pharmacologically isolated by using NMDA and α7 nicotinic receptor blockers and resulted in a significant reduction of eEPSC amplitude. This effect was prevented in the presence of CID. Moreover, zaprinast reduced eEPSC amplitude in a PDE5- and cGMP-independent mechanism, thus suggesting that glutamatergic transmission in this area is modulated by GPR35. In conclusion, GPR35 is expressed in cultured astrocytes and its activation modulates cAMP production and [Ca2+]i. GPR35 activation may contribute to KYNA effects on the previously reported decrease of brain extracellular glutamate levels and reduction of excitatory transmission.
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Affiliation(s)
- Rolando Berlinguer-Palmini
- Department of Neuroscience, Psychology, Drug Research and Child Health, Section of Pharmacology and Toxicology, University of Florence, Florence, Italy
| | - Alessio Masi
- Department of Neuroscience, Psychology, Drug Research and Child Health, Section of Pharmacology and Toxicology, University of Florence, Florence, Italy
| | - Roberto Narducci
- Department of Neuroscience, Psychology, Drug Research and Child Health, Section of Pharmacology and Toxicology, University of Florence, Florence, Italy
| | - Leonardo Cavone
- Department of Health Science, Section of Clinical Pharmacology and Oncology, University of Florence, Florence, Italy
| | - Dario Maratea
- Department of Neuroscience, Psychology, Drug Research and Child Health, Section of Pharmacology and Toxicology, University of Florence, Florence, Italy
| | - Andrea Cozzi
- Department of Neuroscience, Psychology, Drug Research and Child Health, Section of Pharmacology and Toxicology, University of Florence, Florence, Italy
| | - Maria Sili
- Department of Neuroscience, Psychology, Drug Research and Child Health, Section of Pharmacology and Toxicology, University of Florence, Florence, Italy
| | - Flavio Moroni
- Department of Neuroscience, Psychology, Drug Research and Child Health, Section of Pharmacology and Toxicology, University of Florence, Florence, Italy
| | - Guido Mannaioni
- Department of Neuroscience, Psychology, Drug Research and Child Health, Section of Pharmacology and Toxicology, University of Florence, Florence, Italy
- * E-mail:
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