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Zhang T, Liao X, Chen Y, Shu X, Liu D, Yao Y. Dexmedetomidine Prolongs Lidocaine Intravenous Regional Anesthesia in Rats by Blocking the Hyperpolarization-Activated Cation Current. Drug Des Devel Ther 2024; 18:1103-1114. [PMID: 38618283 PMCID: PMC11015855 DOI: 10.2147/dddt.s450971] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2023] [Accepted: 03/23/2024] [Indexed: 04/16/2024] Open
Abstract
Purpose Intravenous regional anesthesia (IVRA) using lidocaine provides effective localized analgesia but its duration is limited. The mechanism by which dexmedetomidine enhances lidocaine IVRA is unclear but may involve modulation of hyperpolarization-activated cyclic nucleotide-gated (HCN) channels. Materials and Methods Lidocaine IVRA with varying dexmedetomidine concentrations was performed in the tails of Sprague-Dawley rats. Tail-flick and tail-clamping tests assessed IVRA analgesia and anesthesia efficacy and duration. Contributions of α2 adrenergic receptors and HCN channels were evaluated by incorporating an α adrenergic receptor antagonist, the HCN channel inhibitor ZD7288, and the HCN channel agonist forskolin. Furthermore, whole-cell patch clamp electrophysiology quantified the effects of dexmedetomidine on HCN channels mediating hyperpolarization-activated cation current (Ih) in isolated dorsal root ganglion neurons. Results Dexmedetomidine dose-dependently extended lidocaine IVRA duration and analgesia, unaffected by α2 receptor blockade. The HCN channel inhibitor ZD7288 also prolonged lidocaine IVRA effects, while the HCN channel activator forskolin shortened effects. In dorsal root ganglion neurons, dexmedetomidine concentration-dependently inhibited Ih amplitude and shifted the voltage-dependence of HCN channel activation. Conclusion Dexmedetomidine prolongs lidocaine IVRA duration by directly inhibiting HCN channel activity, independent of α2 adrenergic receptor activation. This HCN channel inhibition represents a novel mechanism underlying the anesthetic and analgesic adjuvant effects of dexmedetomidine in IVRA.
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Affiliation(s)
- Tongtong Zhang
- Department of Anesthesiology, Mengchao Hepatobiliary Hospital of Fujian Medical University, Fuzhou, People’s Republic of China
| | - Xincheng Liao
- Department of Anesthesiology, The Second Affiliated Hospital of Fujian University of Traditional Chinese Medicine, Fuzhou, People’s Republic of China
| | - Yuzhi Chen
- Department of Anesthesiology, Shengli Clinical Medical College of Fujian Medical University, Fujian Provincial Hospital, Fuzhou, People’s Republic of China
| | - Xinru Shu
- Department of Anesthesiology, Shengli Clinical Medical College of Fujian Medical University, Fujian Provincial Hospital, Fuzhou, People’s Republic of China
| | - Deshan Liu
- Department of Neurology, Shengli Clinical Medical College of Fujian Medical University, Fujian Provincial Hospital, Fuzhou, People’s Republic of China
| | - Yusheng Yao
- Department of Anesthesiology, Shengli Clinical Medical College of Fujian Medical University, Fujian Provincial Hospital, Fuzhou, People’s Republic of China
- Fujian Provincial Key Laboratory of Critical Care Medicine, Fuzhou, People’s Republic of China
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Wang Q, Ye Y, Yang L, Xiao L, Liu J, Zhang W, Du G. Painful diabetic neuropathy: The role of ion channels. Biomed Pharmacother 2024; 173:116417. [PMID: 38490158 DOI: 10.1016/j.biopha.2024.116417] [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] [Received: 11/30/2023] [Revised: 03/06/2024] [Accepted: 03/06/2024] [Indexed: 03/17/2024] Open
Abstract
Painful diabetic neuropathy (PDN) is a common chronic complication of diabetes that causes neuropathic pain and negatively affects the quality of life. The management of PDN is far from satisfactory. At present, interventions are primarily focused on symptomatic treatment. Ion channel disorders are a major cause of PDN, and a complete understanding of their roles and mechanisms may provide better options for the clinical treatment of PDN. Therefore, this review summarizes the important role of ion channels in PDN and the current drug development targeting these ion channels.
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Affiliation(s)
- Qi Wang
- Department of Anesthesiology, Laboratory of Anesthesia and Critical Care Medicine, Translational Neuroscience Centre, West China Hospital, Sichuan University, Chengdu, China; National-Local Joint Engineering Research Center of Translational Medicine of Anesthesiology, West China Hospital, Sichuan University, Chengdu, China
| | - Yifei Ye
- Department of Anesthesiology, Laboratory of Anesthesia and Critical Care Medicine, Translational Neuroscience Centre, West China Hospital, Sichuan University, Chengdu, China; National-Local Joint Engineering Research Center of Translational Medicine of Anesthesiology, West China Hospital, Sichuan University, Chengdu, China
| | - Linghui Yang
- Department of Anesthesiology, Laboratory of Anesthesia and Critical Care Medicine, Translational Neuroscience Centre, West China Hospital, Sichuan University, Chengdu, China; National-Local Joint Engineering Research Center of Translational Medicine of Anesthesiology, West China Hospital, Sichuan University, Chengdu, China
| | - Lifan Xiao
- Department of Anesthesiology, Laboratory of Anesthesia and Critical Care Medicine, Translational Neuroscience Centre, West China Hospital, Sichuan University, Chengdu, China; National-Local Joint Engineering Research Center of Translational Medicine of Anesthesiology, West China Hospital, Sichuan University, Chengdu, China
| | - Jin Liu
- Department of Anesthesiology, Laboratory of Anesthesia and Critical Care Medicine, Translational Neuroscience Centre, West China Hospital, Sichuan University, Chengdu, China; National-Local Joint Engineering Research Center of Translational Medicine of Anesthesiology, West China Hospital, Sichuan University, Chengdu, China
| | - Wensheng Zhang
- Department of Anesthesiology, Laboratory of Anesthesia and Critical Care Medicine, Translational Neuroscience Centre, West China Hospital, Sichuan University, Chengdu, China; National-Local Joint Engineering Research Center of Translational Medicine of Anesthesiology, West China Hospital, Sichuan University, Chengdu, China.
| | - Guizhi Du
- Department of Anesthesiology, Laboratory of Anesthesia and Critical Care Medicine, Translational Neuroscience Centre, West China Hospital, Sichuan University, Chengdu, China; National-Local Joint Engineering Research Center of Translational Medicine of Anesthesiology, West China Hospital, Sichuan University, Chengdu, China.
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3
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Doldur-Balli F, Smieszek SP, Keenan BT, Zimmerman AJ, Veatch OJ, Polymeropoulos CM, Birznieks G, Polymeropoulos MH. Screening effects of HCN channel blockers on sleep/wake behavior in zebrafish. Front Neurosci 2024; 18:1375484. [PMID: 38567282 PMCID: PMC10986788 DOI: 10.3389/fnins.2024.1375484] [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: 01/23/2024] [Accepted: 02/29/2024] [Indexed: 04/04/2024] Open
Abstract
Hyperpolarization-activated cyclic nucleotide-gated (HCN) ion channels generate electrical rhythmicity in various tissues although primarily heart, retina and brain. The HCN channel blocker compound, Ivabradine (Corlanor), is approved by the US Food and Drug Administration (FDA) as a medication to lower heart rate by blocking hyperpolarization activated inward current in the sinoatrial node. In addition, a growing body of evidence suggests a role for HCN channels in regulation of sleep/wake behavior. Zebrafish larvae are ideal model organisms for high throughput drug screening, drug repurposing and behavioral phenotyping studies. We leveraged this model system to investigate effects of three HCN channel blockers (Ivabradine, Zatebradine Hydrochloride and ZD7288) at multiple doses on sleep/wake behavior in wild type zebrafish. Results of interest included shorter latency to daytime sleep at 0.1 μM dose of Ivabradine (ANOVA, p: 0.02), moderate reduction in average activity at 30 μM dose of Zatebradine Hydrochloride (ANOVA, p: 0.024) in daytime, and increased nighttime sleep at 4.5 μM dose of ZD7288 (ANOVA, p: 0.036). Taken together, shorter latency to daytime sleep, decrease in daytime activity and increased nighttime sleep indicate that different HCN channel antagonists affected different parameters of sleep and activity.
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Affiliation(s)
- Fusun Doldur-Balli
- Division of Sleep Medicine, Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States
| | | | - Brendan T. Keenan
- Division of Sleep Medicine, Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States
| | - Amber J. Zimmerman
- Division of Sleep Medicine, Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States
| | - Olivia J. Veatch
- Department of Psychiatry and Behavioral Sciences, University of Kansas Medical Center, Kansas City, KS, United States
| | | | - Gunther Birznieks
- Vanda Pharmaceuticals Inc., Pennsylvania, Washington, DC, United States
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4
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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
- Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul, Republic of Korea
- 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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5
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Morris PG, Taylor JD, Paton JFR, Nogaret A. Single shot detection of alterations across multiple ionic currents from assimilation of cell membrane dynamics. Sci Rep 2024; 14:6031. [PMID: 38472404 DOI: 10.1038/s41598-024-56576-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2023] [Accepted: 03/08/2024] [Indexed: 03/14/2024] Open
Abstract
The dysfunction of ion channels is a causative factor in a variety of neurological diseases, thereby defining the implicated channels as key drug targets. The detection of functional changes in multiple specific ionic currents currently presents a challenge, particularly when the neurological causes are either a priori unknown, or are unexpected. Traditional patch clamp electrophysiology is a powerful tool in this regard but is low throughput. Here, we introduce a single-shot method for detecting alterations amongst a range of ion channel types from subtle changes in membrane voltage in response to a short chaotically driven current clamp protocol. We used data assimilation to estimate the parameters of individual ion channels and from these we reconstructed ionic currents which exhibit significantly lower error than the parameter estimates. Such reconstructed currents thereby become sensitive predictors of functional alterations in biological ion channels. The technique correctly predicted which ionic current was altered, and by approximately how much, following pharmacological blockade of BK, SK, A-type K+ and HCN channels in hippocampal CA1 neurons. We anticipate this assay technique could aid in the detection of functional changes in specific ionic currents during drug screening, as well as in research targeting ion channel dysfunction.
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Affiliation(s)
- Paul G Morris
- Department of Physics, University of Bath, Claverton Down, Bath, UK
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, UK
| | - Joseph D Taylor
- Department of Physics, University of Bath, Claverton Down, Bath, UK
| | - Julian F R Paton
- Manaaki Manawa - the Centre for Heart Research, Department of Physiology, Faculty of Medical and Health Sciences, University of Auckland, Grafton, Auckland, New Zealand
| | - Alain Nogaret
- Department of Physics, University of Bath, Claverton Down, Bath, UK.
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6
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Han X, Pinto LG, Vilar B, McNaughton PA. Opioid-Induced Hyperalgesia and Tolerance Are Driven by HCN Ion Channels. J Neurosci 2024; 44:e1368232023. [PMID: 38124021 PMCID: PMC11059424 DOI: 10.1523/jneurosci.1368-23.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2023] [Revised: 10/24/2023] [Accepted: 11/19/2023] [Indexed: 12/23/2023] Open
Abstract
Prolonged exposure to opioids causes an enhanced sensitivity to painful stimuli (opioid-induced hyperalgesia, OIH) and a need for increased opioid doses to maintain analgesia (opioid-induced tolerance, OIT), but the mechanisms underlying both processes remain obscure. We found that pharmacological block or genetic deletion of HCN2 ion channels in primary nociceptive neurons of male mice completely abolished OIH but had no effect on OIT. Conversely, pharmacological inhibition of central HCN channels alleviated OIT but had no effect on OIH. Expression of C-FOS, a marker of neuronal activity, was increased in second-order neurons of the dorsal spinal cord by induction of OIH, and the increase was prevented by peripheral block or genetic deletion of HCN2, but block of OIT by spinal block of HCN channels had no impact on C-FOS expression in dorsal horn neurons. Collectively, these observations show that OIH is driven by HCN2 ion channels in peripheral nociceptors, while OIT is driven by a member of the HCN family located in the CNS. Induction of OIH increased cAMP in nociceptive neurons, and a consequent shift in the activation curve of HCN2 caused an increase in nociceptor firing. The shift in HCN2 was caused by expression of a constitutively active μ-opioid receptor (MOR) and was reversed by MOR antagonists. We identified the opioid-induced MOR as a six-transmembrane splice variant, and we show that it increases cAMP by coupling constitutively to Gs HCN2 ion channels therefore drive OIH, and likely OIT, and may be a novel therapeutic target for the treatment of addiction.
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Affiliation(s)
- Xue Han
- Wolfson Sensory, Pain and Regeneration Centre, King's College London, London SE1 1UL, United Kingdom
| | - Larissa Garcia Pinto
- Wolfson Sensory, Pain and Regeneration Centre, King's College London, London SE1 1UL, United Kingdom
| | - Bruno Vilar
- Wolfson Sensory, Pain and Regeneration Centre, King's College London, London SE1 1UL, United Kingdom
| | - Peter A McNaughton
- Wolfson Sensory, Pain and Regeneration Centre, King's College London, London SE1 1UL, United Kingdom
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7
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de Silva N, Lacko LA, Jamies EA, Evans T, Hurtado R. Atacama Clear for Complex 3D Imaging of Organs. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.01.22.576689. [PMID: 38328217 PMCID: PMC10849539 DOI: 10.1101/2024.01.22.576689] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/09/2024]
Abstract
3D reconstructive imaging is a powerful strategy to interrogate the global architecture of tissues. We developed Atacama Clear (ATC), a novel method that increases 3D imaging signal-to-noise ratios (SNRs) while simultaneously increasing the capacity of tissue to be cleared. ATC potentiated the clearing capacity of all tested chemical reagents currently used for optical clearing by an average of 68%, and more than doubled SNRs. This increased imaging efficacy enabled multiplex interrogation of tough fibrous tissue and specimens that naturally exhibit high levels of background noise, including the heart, kidney, and human biopsies. Indeed, ATC facilitated visualization of previously undocumented adjacent nephron segments that exhibit notoriously high autofluorescence, elements of the cardiac conduction system, and the distinct human glomerular tissue layers, at single cell resolution. Moreover, ATC was validated to be compatible with fluorescent reporter proteins in murine, zebrafish, and 3D stem cell model systems. These data establish ATC for 3D imaging studies of challenging tissue types.
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Affiliation(s)
| | - Lauretta A. Lacko
- Department of Medicine, Weill Cornell Medicine, New York, NY, USA
- Human Therapeutic Organoid Core Facility, Weill Cornell Medicine, New York, NY USA
| | - Edgar A. Jamies
- Department of Medicine, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Todd Evans
- Department of Surgery, Weill Cornell Medicine, New York, NY, USA
- Weill Cornell Center for Genomic Health
| | - Romulo Hurtado
- Department of Surgery, Weill Cornell Medicine, New York, NY, USA
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Vinnenberg L, Rychlik N, Oniani T, Williams B, White JA, Kovac S, Meuth SG, Budde T, Hundehege P. Assessing neuroprotective effects of diroximel fumarate and siponimod via modulation of pacemaker channels in an experimental model of remyelination. Exp Neurol 2024; 371:114572. [PMID: 37852467 DOI: 10.1016/j.expneurol.2023.114572] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2023] [Revised: 10/04/2023] [Accepted: 10/14/2023] [Indexed: 10/20/2023]
Abstract
Cuprizone (CPZ)-induced alterations in axonal myelination are associated with a period of neuronal hyperexcitability and increased activity of hyperpolarization-activated and cyclic nucleotide-gated (HCN) channels in the thalamocortical (TC) system. Substances used for the treatment of multiple sclerosis (MS) have been shown to normalize neuronal excitability in CPZ-treated mice. Therefore, we aimed to examine the effects of diroximel fumarate (DRF) and the sphingosine 1-phospate receptor (S1PR) modulator siponimod on action potential firing and the inward current (Ih) carried by HCN ion channels in naive conditions and during different stages of de- and remyelination. Here, DRF application reduced Ih current density in ex vivo patch clamp recordings from TC neurons of the ventrobasal thalamic complex (VB), thereby counteracting the increase of Ih during early remyelination. Siponimod reduced Ih in VB neurons under control conditions but had no effect in neurons of the auditory cortex (AU). Furthermore, siponimod increased and decreased AP firing properties of neurons in VB and AU, respectively. Computational modeling revealed that both DRF and siponimod influenced thalamic bursting during early remyelination by delaying the onset and decreasing the interburst frequency. Thus, substances used in MS treatment normalize excitability in the TC system by influencing AP firing and Ih.
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Affiliation(s)
- Laura Vinnenberg
- Department of Neurology with Institute of Translational Neurology, Münster University, Albert-Schweitzer-Campus 1, D-48149 Münster, Germany
| | - Nicole Rychlik
- Institute of Physiology I, Münster University, Robert-Koch-Str. 27a, D-48149 Münster, Germany.
| | - Tengiz Oniani
- Institute of Physiology I, Münster University, Robert-Koch-Str. 27a, D-48149 Münster, Germany
| | - Brandon Williams
- Department of Biomedical Engineering, Center for Systems Neuroscience, Neurophotonics Center, Boston University, 610 Commonwealth Ave, Boston MA-02215, USA
| | - John A White
- Department of Biomedical Engineering, Center for Systems Neuroscience, Neurophotonics Center, Boston University, 610 Commonwealth Ave, Boston MA-02215, USA
| | - Stjepana Kovac
- Department of Neurology with Institute of Translational Neurology, Münster University, Albert-Schweitzer-Campus 1, D-48149 Münster, Germany
| | - Sven G Meuth
- Neurology Clinic, Medical Faculty, University Clinic Düsseldorf, Moorenstraße 5, D-40225 Düsseldorf, Germany
| | - Thomas Budde
- Institute of Physiology I, Münster University, Robert-Koch-Str. 27a, D-48149 Münster, Germany
| | - Petra Hundehege
- Department of Neurology with Institute of Translational Neurology, Münster University, Albert-Schweitzer-Campus 1, D-48149 Münster, Germany
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9
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Vasylyev DV, Liu S, Waxman SG. I h current stabilizes excitability in rodent DRG neurons and reverses hyperexcitability in a nociceptive neuron model of inherited neuropathic pain. J Physiol 2023; 601:5341-5366. [PMID: 37846879 PMCID: PMC10843455 DOI: 10.1113/jp284999] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2023] [Accepted: 09/25/2023] [Indexed: 10/18/2023] Open
Abstract
We show here that hyperpolarization-activated current (Ih ) unexpectedly acts to inhibit the activity of dorsal root ganglion (DRG) neurons expressing WT Nav1.7, the largest inward current and primary driver of DRG neuronal firing, and hyperexcitable DRG neurons expressing a gain-of-function Nav1.7 mutation that causes inherited erythromelalgia (IEM), a human genetic model of neuropathic pain. In this study we created a kinetic model of Ih and used it, in combination with dynamic-clamp, to study Ih function in DRG neurons. We show, for the first time, that Ih increases rheobase and reduces the firing probability in small DRG neurons, and demonstrate that the amplitude of subthreshold oscillations is reduced by Ih . Our results show that Ih , due to slow gating, is not deactivated during action potentials (APs) and has a striking damping action, which reverses from depolarizing to hyperpolarizing, close to the threshold for AP generation. Moreover, we show that Ih reverses the hyperexcitability of DRG neurons expressing a gain-of-function Nav1.7 mutation that causes IEM. In the aggregate, our results show that Ih unexpectedly has strikingly different effects in DRG neurons as compared to previously- and well-studied cardiac cells. Within DRG neurons where Nav1.7 is present, Ih reduces depolarizing sodium current inflow due to enhancement of Nav1.7 channel fast inactivation and creates additional damping action by reversal of Ih direction from depolarizing to hyperpolarizing close to the threshold for AP generation. These actions of Ih limit the firing of DRG neurons expressing WT Nav1.7 and reverse the hyperexcitability of DRG neurons expressing a gain-of-function Nav1.7 mutation that causes IEM. KEY POINTS: Hyperpolarization-activated cyclic nucleotide-gated (HCN) channels, the molecular determinants of hyperpolarization-activated current (Ih ) have been characterized as a 'pain pacemaker', and thus considered to be a potential molecular target for pain therapeutics. Dorsal root ganglion (DRG) neurons express Nav1.7, a channel that is not present in central neurons or cardiac tissue. Gain-of-function mutations (GOF) of Nav1.7 identified in inherited erythromelalgia (IEM), a human genetic model of neuropathic pain, produce DRG neuron hyperexcitability, which in turn produces severe pain. We found that Ih increases rheobase and reduces firing probability in small DRG neurons expressing WT Nav1.7, and demonstrate that the amplitude of subthreshold oscillations is reduced by Ih . We also demonstrate that Ih reverses the hyperexcitability of DRG neurons expressing a GOF Nav1.7 mutation (L858H) that causes IEM. Our results show that, in contrast to cardiac cells and CNS neurons, Ih acts to stabilize DRG neuron excitability and prevents excessive firing.
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Affiliation(s)
- Dmytro V. Vasylyev
- Department of Neurology and Center for Neuroscience & Regeneration Research, Yale University School of Medicine, New Haven, CT 06510
- Rehabilitation Research Center, Veterans Affairs Connecticut Healthcare System, West Haven, CT 06516
| | - Shujun Liu
- Department of Neurology and Center for Neuroscience & Regeneration Research, Yale University School of Medicine, New Haven, CT 06510
- Rehabilitation Research Center, Veterans Affairs Connecticut Healthcare System, West Haven, CT 06516
| | - Stephen G. Waxman
- Department of Neurology and Center for Neuroscience & Regeneration Research, Yale University School of Medicine, New Haven, CT 06510
- Rehabilitation Research Center, Veterans Affairs Connecticut Healthcare System, West Haven, CT 06516
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10
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Tibbs GR, Uprety R, Warren JD, Beyer NP, Joyce RL, Ferrer MA, Mellado W, Wong VSC, Goldberg DC, Cohen MW, Costa CJ, Li Z, Zhang G, Dephoure NE, Barman DN, Sun D, Ingólfsson HI, Sauve AA, Willis DE, Goldstein PA. An anchor-tether 'hindered' HCN1 inhibitor is antihyperalgesic in a rat spared nerve injury neuropathic pain model. Br J Anaesth 2023; 131:745-763. [PMID: 37567808 PMCID: PMC10541997 DOI: 10.1016/j.bja.2023.06.067] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2023] [Revised: 06/20/2023] [Accepted: 06/29/2023] [Indexed: 08/13/2023] Open
Abstract
BACKGROUND Neuropathic pain impairs quality of life, is widely prevalent, and incurs significant costs. Current pharmacological therapies have poor/no efficacy and significant adverse effects; safe and effective alternatives are needed. Hyperpolarisation-activated cyclic nucleotide-regulated (HCN) channels are causally implicated in some forms of peripherally mediated neuropathic pain. Whilst 2,6-substituted phenols, such as 2,6-di-tert-butylphenol (26DTB-P), selectively inhibit HCN1 gating and are antihyperalgesic, the development of therapeutically tolerable, HCN-selective antihyperalgesics based on their inverse agonist activity requires that such drugs spare the cardiac isoforms and do not cross the blood-brain barrier. METHODS In silico molecular dynamics simulation, in vitro electrophysiology, and in vivo rat spared nerve injury methods were used to test whether 'hindered' variants of 26DTB-P (wherein a hydrophilic 'anchor' is attached in the para-position of 26DTB-P via an acyl chain 'tether') had the desired properties. RESULTS Molecular dynamics simulation showed that membrane penetration of hindered 26DTB-Ps is controlled by a tethered diol anchor without elimination of head group rotational freedom. In vitro and in vivo analysis showed that BP4L-18:1:1, a variant wherein a diol anchor is attached to 26DTB-P via an 18-carbon tether, is an HCN1 inverse agonist and an orally available antihyperalgesic. With a CNS multiparameter optimisation score of 2.25, a >100-fold lower drug load in the brain vs blood, and an absence of adverse cardiovascular or CNS effects, BP4L-18:1:1 was shown to be poorly CNS penetrant and cardiac sparing. CONCLUSIONS These findings provide a proof-of-concept demonstration that anchor-tethered drugs are a new chemotype for treatment of disorders involving membrane targets.
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Affiliation(s)
- Gareth R Tibbs
- Department of Anesthesiology, Weill Cornell Medicine, New York, NY, USA
| | - Rajendra Uprety
- Department of Pharmacology, Weill Cornell Medicine, New York, NY, USA
| | - J David Warren
- Department of Biochemistry, Weill Cornell Medicine, New York, NY, USA
| | - Nicole P Beyer
- Department of Anesthesiology, Weill Cornell Medicine, New York, NY, USA
| | - Rebecca L Joyce
- Department of Anesthesiology, Weill Cornell Medicine, New York, NY, USA
| | - Matthew A Ferrer
- Department of Anesthesiology, Weill Cornell Medicine, New York, NY, USA
| | | | | | | | | | | | - Zhucui Li
- Department of Biochemistry, Weill Cornell Medicine, New York, NY, USA
| | - Guoan Zhang
- Department of Biochemistry, Weill Cornell Medicine, New York, NY, USA
| | - Noah E Dephoure
- Department of Biochemistry, Weill Cornell Medicine, New York, NY, USA; Sandra and Edward Meyer Cancer Center, Weill Cornell Medicine, New York, NY, USA
| | - Dipti N Barman
- Department of Biochemistry, Weill Cornell Medicine, New York, NY, USA
| | - Delin Sun
- Lawrence Livermore National Laboratory, Livermore, CA, USA
| | | | - Anthony A Sauve
- Department of Pharmacology, Weill Cornell Medicine, New York, NY, USA
| | - Dianna E Willis
- Burke Neurological Institute, White Plains, NY, USA; Feil Family Brain & Mind Research Institute, Weill Cornell Medicine, New York, NY, USA.
| | - Peter A Goldstein
- Department of Anesthesiology, Weill Cornell Medicine, New York, NY, USA; Feil Family Brain & Mind Research Institute, Weill Cornell Medicine, New York, NY, USA; Department of Medicine, Weill Cornell Medicine, New York, NY, USA.
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11
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Ślęczkowska M, Misra K, Santoro S, Gerrits MM, Hoeijmakers JGJ. Ion Channel Genes in Painful Neuropathies. Biomedicines 2023; 11:2680. [PMID: 37893054 PMCID: PMC10604193 DOI: 10.3390/biomedicines11102680] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2023] [Accepted: 09/28/2023] [Indexed: 10/29/2023] Open
Abstract
Neuropathic pain (NP) is a typical symptom of peripheral nerve disorders, including painful neuropathy. The biological mechanisms that control ion channels are important for many cell activities and are also therapeutic targets. Disruption of the cellular mechanisms that govern ion channel activity can contribute to pain pathophysiology. The voltage-gated sodium channel (VGSC) is the most researched ion channel in terms of NP; however, VGSC impairment is detected in only <20% of painful neuropathy patients. Here, we discuss the potential role of the other peripheral ion channels involved in sensory signaling (transient receptor potential cation channels), neuronal excitation regulation (potassium channels), involuntary action potential generation (hyperpolarization-activated cyclic nucleotide-gated channels), thermal pain (anoctamins), pH modulation (acid sensing ion channels), and neurotransmitter release (calcium channels) related to pain and their prospective role as therapeutic targets for painful neuropathy.
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Affiliation(s)
- Milena Ślęczkowska
- Department of Toxicogenomics, Maastricht University, 6229 ER Maastricht, The Netherlands;
- Department of Neurology, School of Mental Health and Neuroscience, Maastricht University Medical Centre+, 6229 ER Maastricht, The Netherlands
| | - Kaalindi Misra
- Laboratory of Human Genetics of Neurological Disorders, IRCCS San Raffaele Scientific Institute, INSPE, 20132 Milan, Italy; (K.M.); (S.S.)
| | - Silvia Santoro
- Laboratory of Human Genetics of Neurological Disorders, IRCCS San Raffaele Scientific Institute, INSPE, 20132 Milan, Italy; (K.M.); (S.S.)
| | - Monique M. Gerrits
- Department of Clinical Genetics, Maastricht University Medical Centre+, 6229 HX Maastricht, The Netherlands;
| | - Janneke G. J. Hoeijmakers
- Department of Neurology, School of Mental Health and Neuroscience, Maastricht University Medical Centre+, 6229 ER Maastricht, The Netherlands
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12
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Chen CS, So EC, Wu SN. Modulating Hyperpolarization-Activated Cation Currents through Small Molecule Perturbations: Magnitude and Gating Control. Biomedicines 2023; 11:2177. [PMID: 37626674 PMCID: PMC10452073 DOI: 10.3390/biomedicines11082177] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2023] [Revised: 07/10/2023] [Accepted: 07/27/2023] [Indexed: 08/27/2023] Open
Abstract
The hyperpolarization-activated cation current (Ih) exhibits a slowly activating time course of the current (Ih) when the cell membrane is hyperpolarized for an extended duration. It is involved in generating electrical activity in various excitable cells. Numerous structurally distinct compounds or herbal drugs have the potential to impact both the magnitude and gating kinetics of this current. Brivaracetam, a chemical analog of levetiracetam known to be a ligand for synaptic vesicle protein 2A, could directly suppress the Ih magnitude. Carisbamate, an anticonvulsant agent, not only inhibited the Ih amplitude but also reduced the strength of voltage-dependent hysteresis (Hys(V)) associated with Ih. Cilobradine, similar to ivabradine, inhibited the amplitude of Ih; however, it also suppressed the amplitude of delayed-rectifier K+ currents. Dexmedetomidine, an agonist of α2-adrenergic receptor, exerted a depressant action on Ih in a concentration-dependent fashion. Suppression of Ih amplitude was observed when GAL-021, a breathing control modulator, was present at a concentration exceeding 30 μM. Lutein, one of the few xanthophyll carotenoids, was able to suppress the Ih amplitude as well as to depress Hys(V)'s strength of Ih. Pirfenidone, a pyridine derivative known to be an anti-fibrotic agent, depressed the Ih magnitude in a concentration- and voltage-dependent fashion. Tramadol, a synthetic centrally active analgesic, was shown to reduce the Ih magnitude, independent of its interaction with opioid receptors. Various herbal drugs, including ent-kaurane-type diterpenoids from Croton tonkinensis, Ganoderma triterpenoids, honokiol, and pterostilbene, demonstrated efficacy in reducing the magnitude of Ih. Conversely, oxaliplatin, a platinum-based chemotherapeutic compound, was observed to effectively increase the Ih amplitude. Collectively, the regulatory effects of these compounds or herbal drugs on cellular function can be partly attributed to their perturbations on Ih.
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Affiliation(s)
- Cheng-Shih Chen
- Department of Anesthesia, An Nan Hospital, China Medical University, Tainan 70965, Taiwan; (C.-S.C.); (E.C.S.)
| | - Edmund Cheung So
- Department of Anesthesia, An Nan Hospital, China Medical University, Tainan 70965, Taiwan; (C.-S.C.); (E.C.S.)
| | - Sheng-Nan Wu
- School of Medicine, National Sun Yat Sen University College of Medicine, Kaohsiung 804, Taiwan
- Department of Medical Education & Research, An Nan Hospital, China Medical University, Tainan 70965, Taiwan
- Department of Physiology, National Cheng Kung University Medical College, Tainan 701, Taiwan
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13
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Kola JB, Turarova B, Csige D, Sipos Á, Varga L, Gergely B, Refai FA, Uray IP, Docsa T, Uray K. Stretch-Induced Down-Regulation of HCN2 Suppresses Contractile Activity. Molecules 2023; 28:molecules28114359. [PMID: 37298834 DOI: 10.3390/molecules28114359] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2023] [Revised: 05/12/2023] [Accepted: 05/24/2023] [Indexed: 06/12/2023] Open
Abstract
Although hyperpolarization-activated and cyclic nucleotide-gated 2 channels (HCN2) are expressed in multiple cell types in the gut, the role of HCN2 in intestinal motility is poorly understood. HCN2 is down-regulated in intestinal smooth muscle in a rodent model of ileus. Thus, the purpose of this study was to determine the effects of HCN inhibition on intestinal motility. HCN inhibition with ZD7288 or zatebradine significantly suppressed both spontaneous and agonist-induced contractile activity in the small intestine in a dose-dependent and tetrodotoxin-independent manner. HCN inhibition significantly suppressed intestinal tone but not contractile amplitude. The calcium sensitivity of contractile activity was significantly suppressed by HCN inhibition. Inflammatory mediators did not affect the suppression of intestinal contractile activity by HCN inhibition but increased stretch of the intestinal tissue partially attenuated the effects of HCN inhibition on agonist-induced intestinal contractile activity. HCN2 protein and mRNA levels in intestinal smooth muscle tissue were significantly down-regulated by increased mechanical stretch compared to unstretched tissue. Increased cyclical stretch down-regulated HCN2 protein and mRNA levels in primary human intestinal smooth muscle cells and macrophages. Overall, our results suggest that decreased HCN2 expression induced by mechanical signals, such as intestinal wall distension or edema development, may contribute to the development of ileus.
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Affiliation(s)
- Job Baffin Kola
- Department of Medical Chemistry, School of Medicine, University of Debrecen, 4032 Debrecen, Hungary
| | - Botagoz Turarova
- Department of Medical Chemistry, School of Medicine, University of Debrecen, 4032 Debrecen, Hungary
| | - Dora Csige
- Department of Medical Chemistry, School of Medicine, University of Debrecen, 4032 Debrecen, Hungary
| | - Ádám Sipos
- Department of Medical Chemistry, School of Medicine, University of Debrecen, 4032 Debrecen, Hungary
| | - Luca Varga
- Department of Medical Chemistry, School of Medicine, University of Debrecen, 4032 Debrecen, Hungary
| | - Bence Gergely
- Department of Medical Chemistry, School of Medicine, University of Debrecen, 4032 Debrecen, Hungary
| | - Farah Al Refai
- Department of Medical Chemistry, School of Medicine, University of Debrecen, 4032 Debrecen, Hungary
| | - Iván P Uray
- Department of Clinical Oncology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary
| | - Tibor Docsa
- Department of Medical Chemistry, School of Medicine, University of Debrecen, 4032 Debrecen, Hungary
| | - Karen Uray
- Department of Medical Chemistry, School of Medicine, University of Debrecen, 4032 Debrecen, Hungary
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14
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Zorn A, Baillie G. Phosphodiesterase 7 as a therapeutic target - Where are we now? Cell Signal 2023; 108:110689. [PMID: 37120115 DOI: 10.1016/j.cellsig.2023.110689] [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: 02/03/2023] [Revised: 04/14/2023] [Accepted: 04/24/2023] [Indexed: 05/01/2023]
Abstract
Cyclic nucleotide phosphodiesterases (PDEs) are a superfamily of enzymes that hydrolyse the intracellular second messengers cAMP and cGMP to their inactive forms 5'AMP and 5'GMP. Some members of the PDE family display specificity towards a single cyclic nucleotide messenger, and PDE4, PDE7, and PDE8 specifically hydrolyse cAMP. While the role of PDE4 and its use as a therapeutic target have been well studied, less is known about PDE7 and PDE8. This review aims to collate the present knowledge on human PDE7 and outline its potential use as a therapeutic target. Human PDE7 exists as two isoforms PDE7A and PDE7B that display different expression patterns but are predominantly found in the central nervous system, immune cells, and lymphoid tissue. As a result, PDE7 is thought to play a role in T cell activation and proliferation, inflammation, and regulate several physiological processes in the central nervous system, such as neurogenesis, synaptogenesis, and long-term memory formation. Increased expression and activity of PDE7 has been detected in several disease states, including neurodegenerative diseases such as Parkinson's, Alzheimer's and Huntington's disease, autoimmune diseases such as multiple sclerosis and COPD, and several types of cancer. Early studies have shown that administration of PDE7 inhibitors may ameliorate the clinical state of these diseases. Targeting PDE7 may therefore provide a novel therapeutic strategy for targeting a broad range of disease and possibly provide a complementary alternative to inhibitors of other cAMP-selective PDEs, such as PDE4, which are severely limited by their side-effects.
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Affiliation(s)
- Alina Zorn
- University of Glasgow, 535 Wolfson Link Building, G12 8QQ Glasgow, United Kingdom.
| | - George Baillie
- University of Glasgow, 535 Wolfson Link Building, G12 8QQ Glasgow, United Kingdom.
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15
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Yang L, Arbona RJR, Smith CS, Banks KM, Thomas VK, Palmer L, Evans T, Hurtado R. An evolutionarily conserved pacemaker role for HCN ion channels in smooth muscle. J Physiol 2023; 601:1225-1246. [PMID: 36930567 PMCID: PMC10065941 DOI: 10.1113/jp283701] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Accepted: 02/14/2023] [Indexed: 03/18/2023] Open
Abstract
Although hyperpolarization-activated cation (HCN) ion channels are well established to underlie cardiac pacemaker activity, their role in smooth muscle organs remains controversial. HCN-expressing cells are localized to renal pelvic smooth muscle (RPSM) pacemaker tissues of the murine upper urinary tract and HCN channel conductance is required for peristalsis. To date, however, the Ih pacemaker current conducted by HCN channels has never been detected in these cells, raising questions on the identity of RPSM pacemakers. Indeed, the RPSM pacemaker mechanisms of the unique multicalyceal upper urinary tract exhibited by humans remains unknown. Here, we developed immunopanning purification protocols and demonstrate that 96% of isolated HCN+ cells exhibit Ih . Single-molecule STORM to whole-tissue imaging showed HCN+ cells express single HCN channels on their plasma membrane and integrate into the muscular syncytium. By contrast, PDGFR-α+ cells exhibiting the morphology of ICC gut pacemakers were shown to be vascular mural cells. Translational studies in the homologous human and porcine multicalyceal upper urinary tracts showed that contractions and pacemaker depolarizations originate in proximal calyceal RPSM. Critically, HCN+ cells were shown to integrate into calyceal RPSM pacemaker tissues, and HCN channel block abolished electrical pacemaker activity and peristalsis of the multicalyceal upper urinary tract. Cumulatively, these studies demonstrate that HCN ion channels play a broad, evolutionarily conserved pacemaker role in both cardiac and smooth muscle organs and have implications for channelopathies as putative aetiologies of smooth muscle disorders. KEY POINTS: Pacemakers trigger contractions of involuntary muscles. Hyperpolarization-activated cation (HCN) ion channels underpin cardiac pacemaker activity, but their role in smooth muscle organs remains controversial. Renal pelvic smooth muscle (RPSM) pacemakers trigger contractions that propel waste away from the kidney. HCN+ cells localize to murine RPSM pacemaker tissue and HCN channel conductance is required for peristalsis. The HCN (Ih ) current has never been detected in RPSM cells, raising doubt whether HCN+ cells are bona fide pacemakers. Moreover, the pacemaker mechanisms of the unique multicalyceal RPSM of higher order mammals remains unknown. In total, 97% of purified HCN+ RPSM cells exhibit Ih . HCN+ cells integrate into the RPSM musculature, and pacemaker tissue peristalsis is dependent on HCN channels. Translational studies in human and swine demonstrate HCN channels are conserved in the multicalyceal RPSM and that HCN channels underlie pacemaker activity that drives peristalsis. These studies provide insight into putative channelopathies that can underlie smooth muscle dysfunction.
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Affiliation(s)
- Lei Yang
- Department of Physiology and Biophysics, Weill Medical College of Cornell University, New York, NY, USA
| | - Rodolfo J. Ricart Arbona
- Center of Comparative Medicine and Pathology, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Carl S. Smith
- Department of Urologic Surgery, University of Minnesota School of Medicine, Minneapolis, MN, USA
| | - Kelly M. Banks
- Department of Surgery, Weill Medical College of Cornell University, New York, NY, USA
| | - V. Kaye Thomas
- Bio-Imaging Resource Center, The Rockefeller University, New York, NY, USA
| | - Lawrence Palmer
- Department of Physiology and Biophysics, Weill Medical College of Cornell University, New York, NY, USA
| | - Todd Evans
- Department of Surgery, Weill Medical College of Cornell University, New York, NY, USA
| | - Romulo Hurtado
- Department of Surgery, Weill Medical College of Cornell University, New York, NY, USA
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16
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Yu C, Deng XJ, Xu D. Gene mutations in comorbidity of epilepsy and arrhythmia. J Neurol 2023; 270:1229-1248. [PMID: 36376730 DOI: 10.1007/s00415-022-11430-2] [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] [Received: 07/31/2022] [Revised: 10/14/2022] [Accepted: 10/15/2022] [Indexed: 11/16/2022]
Abstract
Epilepsy is one of the most common neurological disorders, and sudden unexpected death in epilepsy (SUDEP) is the most severe outcome of refractory epilepsy. Arrhythmia is one of the heterogeneous factors in the pathophysiological mechanism of SUDEP with a high incidence in patients with refractory epilepsy, increasing the risk of premature death. The gene co-expressed in the brain and heart is supposed to be the genetic basis between epilepsy and arrhythmia, among which the gene encoding ion channel contributes to the prevalence of "cardiocerebral channelopathy" theory. Nevertheless, this theory could only explain the molecular mechanism of comorbid arrhythmia in part of patients with epilepsy (PWE). Therefore, we summarized the mutant genes that can induce comorbidity of epilepsy and arrhythmia and the possible corresponding treatments. These variants involved the genes encoding sodium, potassium, calcium and HCN channels, as well as some non-ion channel coding genes such as CHD4, PKP2, FHF1, GNB5, and mitochondrial genes. The relationship between genotype and clinical phenotype was not simple linear. Indeed, genes co-expressed in the brain and heart could independently induce epilepsy and/or arrhythmia. Mutant genes in brain could affect cardiac rhythm through central or peripheral regulation, while in the heart it could also affect cerebral electrical activity by changing the hemodynamics or internal environment. Analysis of mutations in comorbidity of epilepsy and arrhythmia could refine and expand the theory of "cardiocerebral channelopathy" and provide new insights for risk stratification of premature death and corresponding precision therapy in PWE.
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Affiliation(s)
- Cheng Yu
- Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1277 Jiefang Avenue, Wuhan, 430022, Hubei Province, China
| | - Xue-Jun Deng
- Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1277 Jiefang Avenue, Wuhan, 430022, Hubei Province, China
| | - Da Xu
- Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1277 Jiefang Avenue, Wuhan, 430022, Hubei Province, China.
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17
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Kamisah Y, Che Hassan HH. Therapeutic Use and Molecular Aspects of Ivabradine in Cardiac Remodeling: A Review. Int J Mol Sci 2023; 24:ijms24032801. [PMID: 36769115 PMCID: PMC9917668 DOI: 10.3390/ijms24032801] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2022] [Revised: 01/24/2023] [Accepted: 01/31/2023] [Indexed: 02/05/2023] Open
Abstract
Cardiac remodeling can cause ventricular dysfunction and progress to heart failure, a cardiovascular disease that claims many lives globally. Ivabradine, a funny channel (If) inhibitor, is used in patients with chronic heart failure as an adjunct to other heart failure medications. This review aims to gather updated information regarding the therapeutic use and mechanism of action of ivabradine in heart failure. The drug reduces elevated resting heart rate, which is linked to increased morbidity and mortality in patients with heart failure. Its use is associated with improved cardiac function, structure, and quality of life in the patients. Ivabradine exerts several pleiotropic effects, including an antiremodeling property, which are independent of its principal heart-rate-reducing effects. Its suppressive effects on cardiac remodeling have been demonstrated in animal models of cardiac remodeling and heart failure. It reduces myocardial fibrosis, apoptosis, inflammation, and oxidative stress as well as increases autophagy in the animals. It also modulates myocardial calcium homeostasis, neurohumoral systems, and energy metabolism. However, its role in improving heart failure remains unclear. Therefore, elucidating its molecular mechanisms is imperative and would aid in the design of future studies.
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Affiliation(s)
- Yusof Kamisah
- Department of Pharmacology, Faculty of Medicine, Universiti Kebangsaan Malaysia, Kuala Lumpur 56000, Malaysia
- Correspondence:
| | - Hamat H. Che Hassan
- Department of Medicine, Faculty of Medicine, Universiti Kebangsaan Malaysia, Kuala Lumpur 56000, Malaysia
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18
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Yu JM, Hu R, Mao Y, Tai Y, Qun S, Zhang Z, Chen D, Jin Y. Up-regulation of HCN2 channels in a thalamocortical circuit mediates allodynia in mice. Natl Sci Rev 2022; 10:nwac275. [PMID: 36846300 PMCID: PMC9945406 DOI: 10.1093/nsr/nwac275] [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: 04/07/2022] [Revised: 09/09/2022] [Accepted: 10/25/2022] [Indexed: 12/05/2022] Open
Abstract
Chronic pain is a significant problem that afflicts individuals and society, and for which the current clinical treatment is inadequate. In addition, the neural circuit and molecular mechanisms subserving chronic pain remain largely uncharacterized. Herein we identified enhanced activity of a glutamatergic neuronal circuit that encompasses projections from the ventral posterolateral nucleus (VPLGlu) to the glutamatergic neurons of the hindlimb primary somatosensory cortex (S1HLGlu), driving allodynia in mouse models of chronic pain. Optogenetic inhibition of this VPLGlu→S1HLGlu circuit reversed allodynia, whereas the enhancement of its activity provoked hyperalgesia in control mice. In addition, we found that the expression and function of the HCN2 (hyperpolarization-activated cyclic nucleotide-gated channel 2) were increased in VPLGlu neurons under conditions of chronic pain. Using in vivo calcium imaging, we demonstrated that downregulation of HCN2 channels in the VPLGlu neurons abrogated the rise in S1HLGlu neuronal activity while alleviating allodynia in mice with chronic pain. With these data, we propose that dysfunction in HCN2 channels in the VPLGlu→S1HLGlu thalamocortical circuit and their upregulation occupy essential roles in the development of chronic pain.
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Affiliation(s)
| | | | | | - Yingju Tai
- Department of Biophysics and Neurobiology, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230036, China
| | - Sen Qun
- Stroke Center and Department of Neurology, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230036, China
| | | | | | - Yan Jin
- Corresponding author. E-mail:
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19
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Munoz B, Fritz BM, Yin F, Atwood BK. HCN1 channels mediate mu opioid receptor long-term depression at insular cortex inputs to the dorsal striatum. J Physiol 2022; 600:4917-4938. [PMID: 36181477 DOI: 10.1113/jp283513] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2022] [Accepted: 09/26/2022] [Indexed: 12/24/2022] Open
Abstract
Mu opioid receptors (MORs) are expressed in the dorsal striatum, a brain region that mediates goal-directed (via the dorsomedial striatum) and habitual (via the dorsolateral striatum, DLS) behaviours. Our previous work indicates that glutamate transmission is depressed when MORs are activated in the dorsal striatum, inducing MOR-mediated long-term synaptic depression (MOR-LTD) or short-term depression (MOR-STD), depending on the input. In the DLS, MOR-LTD is produced by MORs on anterior insular cortex (AIC) inputs and MOR-STD occurs at thalamic inputs, suggesting input-specific MOR plasticity mechanisms. Here, we evaluated the mechanisms of induction of MOR-LTD and MOR-STD in the DLS using pharmacology and optogenetics combined with patch-clamp electrophysiology. We found that cAMP/PKA signalling and protein synthesis are necessary for MOR-LTD expression, similar to previous studies of cannabinoid-mediated LTD in DLS. MOR-STD does not utilize these same mechanisms. We also demonstrated that cannabinoid-LTD occurs at AIC inputs to DLS. However, while cannabinoid-LTD requires mTOR signalling in DLS, MOR-LTD does not. We characterized the role of presynaptic HCN1 channels in MOR-LTD induction as HCN1 channels expressed in AIC are necessary for MOR-LTD expression in the DLS. These results suggest a mechanism in which MOR activation requires HCN1 to induce MOR-LTD, suggesting a new target for pharmacological modulation of synaptic plasticity, providing new opportunities to develop novel drugs to treat alcohol and opioid use disorders. KEY POINTS: Mu opioid receptor-mediated long-term depression at anterior insular cortex inputs to dorsolateral striatum involves presynaptic cAMP/PKA signalling and protein translation, similar to known mechanisms of cannabinoid long-term depression. Dorsal striatal cannabinoid long-term depression also occurs at anterior insular cortex inputs to the dorsolateral striatum. Dorsal striatal cannabinoid long-term depression requires mTOR signalling, similar to hippocampal cannabinoid long-term depression, but dorsal striatal mu opioid long-term depression does not require mTOR signalling. Mu opioid long-term depression requires presynaptic HCN1 channels at anterior insular cortex inputs to dorsolateral striatum.
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Affiliation(s)
- Braulio Munoz
- Department of Pharmacology & Toxicology, Indiana University School of Medicine, Indianapolis, Indiana, USA
| | - Brandon M Fritz
- Department of Pharmacology & Toxicology, Indiana University School of Medicine, Indianapolis, Indiana, USA
| | - Fuqin Yin
- Department of Pharmacology & Toxicology, Indiana University School of Medicine, Indianapolis, Indiana, USA
| | - Brady K Atwood
- Department of Pharmacology & Toxicology, Indiana University School of Medicine, Indianapolis, Indiana, USA
- Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis, Indiana, USA
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20
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Majgaard J, Skov FG, Kim S, Hjortdal VE, Boedtkjer DMB. Positive chronotropic action of HCN channel antagonism in human collecting lymphatic vessels. Physiol Rep 2022; 10:e15401. [PMID: 35980021 PMCID: PMC9387113 DOI: 10.14814/phy2.15401] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2022] [Revised: 06/16/2022] [Accepted: 07/09/2022] [Indexed: 06/15/2023] Open
Abstract
Spontaneous action potentials precede phasic contractile activity in human collecting lymphatic vessels. In this study, we investigated the expression of hyperpolarization-activated cyclic nucleotide-gated (HCN) channels in human collecting lymphatics and by pharmacological inhibition ex vivo tested their potential role in controlling contractile function. Spontaneous and agonist-evoked tension changes of isolated thoracic duct and mesenteric lymphatic vessels-obtained from surgical patients with informed consent-were investigated by isometric myography, and ivabradine, ZD7288 or cesium were used to inhibit HCN. Analysis of HCN isoforms by RT-PCR and immunofluorescence revealed HCN2 to be the predominantly expressed mRNA isoform in human thoracic duct and mesenteric lymphatic vessels and HCN2-immunoreactivity confirmed protein expression in both vessel types. However, in functional experiments ex vivo the HCN inhibitors ivabradine, ZD7288, and cesium failed to lower contraction frequency: conversely, all three antagonists induced a positive chronotropic effect with concurrent negative inotropic action, though these effects first occurred at concentrations regarded as supramaximal for HCN inhibition. Based on these results, we conclude that human collecting vessels express HCN channel proteins but under the ex vivo experimental conditions described here HCN channels have little involvement in regulating contraction frequency in human collecting lymphatic vessels. Furthermore, HCN antagonists can produce concentration-dependent positive chronotropic and negative inotropic effects, which are apparently unrelated to HCN antagonism.
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Affiliation(s)
- Jens Majgaard
- Department of BiomedicineAarhus UniversityAarhusDenmark
| | | | - Sukhan Kim
- Department of BiomedicineAarhus UniversityAarhusDenmark
| | - Vibeke Elisabeth Hjortdal
- Department of Clinical MedicineAarhus UniversityAarhusDenmark
- Department of Cardiothoracic and Vascular SurgeryAarhus University HospitalAarhusDenmark
| | - Donna M. B. Boedtkjer
- Department of BiomedicineAarhus UniversityAarhusDenmark
- Department of Clinical MedicineAarhus UniversityAarhusDenmark
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21
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Plasticity of neuronal excitability and synaptic balance in the anterior nucleus of paraventricular thalamus after nerve injury. Brain Res Bull 2022; 188:1-10. [PMID: 35850188 DOI: 10.1016/j.brainresbull.2022.07.008] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2022] [Revised: 06/20/2022] [Accepted: 07/14/2022] [Indexed: 11/22/2022]
Abstract
The anterior nucleus of the paraventricular thalamus (aPVT) integrates various synaptic inputs and conveys information to the downstream brain regions for arousal and pain regulation. Recent studies have indicated that the PVT plays a crucial role in the regulation of chronic pain, but the plasticity mechanism of neuronal excitability and synaptic inputs for aPVT neurons in neuropathic pain remains unclear. Here, we report that spinal nerve ligation (SNL) significantly increased the neuronal excitability and reset the excitatory/inhibitory (E/I) synaptic inputs ratio of aPVT neurons in mice. SNL significantly increased the membrane input resistance, firing frequency, and the half-width of action potential. Additionally, SNL enlarged the area of afterdepolarization and prolonged the rebound low-threshold spike following a hyperpolarized current injection. Further results indicate that an inwardly rectifying current density was decreased in SNL animals. SNL also decreased the amplitude, but not the frequency of spontaneous excitatory postsynaptic currents (sEPSCs), nor the amplitude or frequency of spontaneous inhibitory postsynaptic currents (sIPSCs) of aPVT neurons. Moreover, SNL disrupted the E/I synaptic ratio, caused a decrease in weighted tau and half-width of averaged sIPSCs, but did not change these physiological properties of averaged sEPSCs. Finally, pharmacological activation of the GABAA receptor at aPVT could effective relieve SNL-induced mechanical allodynia in mice. These results reveal the plasticity of intrinsic neuronal excitability and E/I synaptic balance in the aPVT neurons after nerve injury and it may play an important role in the development of pain sensitization.
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22
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Nordström T, Andersson LC, Åkerman KEO. Role of hyperpolarization-activated cyclic nucleotide-gated channel HCN2 in embryonic neural stem cell proliferation and differentiation. Neurochem Int 2022; 159:105387. [PMID: 35835292 DOI: 10.1016/j.neuint.2022.105387] [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: 03/14/2022] [Revised: 06/06/2022] [Accepted: 07/03/2022] [Indexed: 10/17/2022]
Abstract
Hyperpolarization-activated cyclic nucleotide-gated channels (HCN channels) are involved in spontaneous activity in many electrically active cell types such as cardiomyocytes and neurons. In this study, the role of HCN channels in proliferation and migration of Nestin and Sox2 expressing embryonic neural progenitor cells (NPC) originating from the subventricular zone (SVZ) was examined. Immunostaining and PCR data showed that the HCN2 subtype was highly expressed in these cells. Patch clamp recordings revealed a hyperpolarization-activated current, which was sensitive to inhibitors of HCN channels. Using the fluorescence dye bis-(1,3-dibutylbarbituric acid)-trimethineoxonol (DiBAC(4)(3)) we found that a prompt reduction of the extracellular K+ concentration, or exposing the cells to acute hypoxia, induced an instant hyperpolarization in the whole cell population. Recovery from low K+ induced hyperpolarization after extracellular calcium removal, or by re-oxygenation of hypoxic cells, was sensitive to ZD7288, a HCN channel inhibitor. Treatment of neurosphere cultures from the SVZ with ZD7288 caused a significant and reversible inhibition of neurosphere formation from single cells indicating that proliferation of progenitor cells was reduced. Furthermore, the migration of neuronal cells from neurospheres was considerably retarded in the presence of ZD7288. The results suggest that HCN2 channels are involved in controlling the proliferation of NPC and that HCN2 channel-induced spontaneous electrical activity may trigger the motility response of neurosphere-derived neurons in concert with other ion channels. Furthermore, the response to hypoxia suggests that HCN2 channels may trigger the chemotactic response of NPC to ischemic brain regions seen in many studies.
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Affiliation(s)
- Tommy Nordström
- Faculty of Medicine, Medicum, Division of Physiology, P.O. Box 63, University of Helsinki, FIN-00014, Helsinki, Finland.
| | - Leif C Andersson
- Department of Pathology, Haartmaninkatu 3 (PB 21), 00014 University of Helsinki, Helsinki, Finland
| | - Karl E O Åkerman
- Faculty of Medicine, Medicum, Division of Physiology, P.O. Box 63, University of Helsinki, FIN-00014, Helsinki, Finland
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Analgesic effect of ivabradine against inflammatory pain mediated by hyperpolarization-activated cyclic nucleotide–gated cation channels expressed on primary afferent terminals in the spinal dorsal horn. Pain 2022; 163:1356-1369. [DOI: 10.1097/j.pain.0000000000002523] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Accepted: 10/14/2021] [Indexed: 11/25/2022]
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Liu J, Kasuya G, Zempo B, Nakajo K. Two HCN4 Channels Play Functional Roles in the Zebrafish Heart. Front Physiol 2022; 13:901571. [PMID: 35846012 PMCID: PMC9281569 DOI: 10.3389/fphys.2022.901571] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2022] [Accepted: 05/31/2022] [Indexed: 11/13/2022] Open
Abstract
The HCN4 channel is essential for heart rate regulation in vertebrates by generating pacemaker potentials in the sinoatrial node. HCN4 channel abnormality may cause bradycardia and sick sinus syndrome, making it an important target for clinical research and drug discovery. The zebrafish is a popular animal model for cardiovascular research. They are potentially suitable for studying inherited heart diseases, including cardiac arrhythmia. However, it has not been determined how similar the ion channels that underlie cardiac automaticity are in zebrafish and humans. In the case of HCN4, humans have one gene, whereas zebrafish have two ortholog genes (DrHCN4 and DrHCN4L; ‘Dr’ referring to Danio rerio). However, it is not known whether the two HCN4 channels have different physiological functions and roles in heart rate regulation. In this study, we characterized the biophysical properties of the two zebrafish HCN4 channels in Xenopus oocytes and compared them to those of the human HCN4 channel. We found that they showed different gating properties: DrHCN4L currents showed faster activation kinetics and a more positively shifted G-V curve than did DrHCN4 and human HCN4 currents. We made chimeric channels of DrHCN4 and DrHCN4L and found that cytoplasmic domains were determinants for the faster activation and the positively shifted G-V relationship in DrHCN4L. The use of a dominant-negative HCN4 mutant confirmed that DrHCN4 and DrHCN4L can form a heteromultimeric channel in Xenopus oocytes. Next, we confirmed that both are sensitive to common HCN channel inhibitors/blockers including Cs+, ivabradine, and ZD7288. These HCN inhibitors successfully lowered zebrafish heart rate during early embryonic stages. Finally, we knocked down the HCN4 genes using antisense morpholino and found that knocking down either or both of the HCN4 channels caused a temporal decrease in heart rate and tended to cause pericardial edema. These findings suggest that both DrHCN4 and DrHCN4L play a significant role in zebrafish heart rate regulation.
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Oniani T, Vinnenberg L, Chaudhary R, Schreiber JA, Riske K, Williams B, Pape HC, White JA, Junker A, Seebohm G, Meuth SG, Hundehege P, Budde T, Zobeiri M. Effects of Axonal Demyelination, Inflammatory Cytokines and Divalent Cation Chelators on Thalamic HCN Channels and Oscillatory Bursting. Int J Mol Sci 2022; 23:ijms23116285. [PMID: 35682964 PMCID: PMC9181513 DOI: 10.3390/ijms23116285] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2022] [Revised: 05/31/2022] [Accepted: 05/31/2022] [Indexed: 12/13/2022] Open
Abstract
Multiple sclerosis (MS) is a demyelinating disease of the central nervous system that is characterized by the progressive loss of oligodendrocytes and myelin and is associated with thalamic dysfunction. Cuprizone (CPZ)-induced general demyelination in rodents is a valuable model for studying different aspects of MS pathology. CPZ feeding is associated with the altered distribution and expression of different ion channels along neuronal somata and axons. However, it is largely unknown whether the copper chelator CPZ directly influences ion channels. Therefore, we assessed the effects of different divalent cations (copper; zinc) and trace metal chelators (EDTA; Tricine; the water-soluble derivative of CPZ, BiMPi) on hyperpolarization-activated cyclic nucleotide-gated (HCN) channels that are major mediators of thalamic function and pathology. In addition, alterations of HCN channels induced by CPZ treatment and MS-related proinflammatory cytokines (IL-1β; IL-6; INF-α; INF-β) were characterized in C57Bl/6J mice. Thus, the hyperpolarization-activated inward current (Ih) was recorded in thalamocortical (TC) neurons and heterologous expression systems (mHCN2 expressing HEK cells; hHCN4 expressing oocytes). A number of electrophysiological characteristics of Ih (potential of half-maximal activation (V0.5); current density; activation kinetics) were unchanged following the extracellular application of trace metals and divalent cation chelators to native neurons, cell cultures or oocytes. Mice were fed a diet containing 0.2% CPZ for 35 days, resulting in general demyelination in the brain. Withdrawal of CPZ from the diet resulted in rapid remyelination, the effects of which were assessed at three time points after stopping CPZ feeding (Day1, Day7, Day25). In TC neurons, Ih was decreased on Day1 and Day25 and revealed a transient increased availability on Day7. In addition, we challenged naive TC neurons with INF-α and IL-1β. It was found that Ih parameters were differentially altered by the application of the two cytokines to thalamic cells, while IL-1β increased the availability of HCN channels (depolarized V0.5; increased current density) and the excitability of TC neurons (depolarized resting membrane potential (RMP); increased the number of action potentials (APs); produced a larger voltage sag; promoted higher input resistance; increased the number of burst spikes; hyperpolarized the AP threshold), INF-α mediated contrary effects. The effect of cytokine modulation on thalamic bursting was further assessed in horizontal slices and a computational model of slow thalamic oscillations. Here, IL-1β and INF-α increased and reduced oscillatory bursting, respectively. We conclude that HCN channels are not directly modulated by trace metals and divalent cation chelators but are subject to modulation by different MS-related cytokines.
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Affiliation(s)
- Tengiz Oniani
- Institute of Physiology I, Westfälische Wilhelms-Universität, Robert-Koch-Str. 27a, D-48149 Münster, Germany; (T.O.); (R.C.); (H.-C.P.); (M.Z.)
| | - Laura Vinnenberg
- Department of Neurology with Institute of Translational Neurology, Albert-Schweitzer-Campus 1, D-48149 Münster, Germany; (L.V.); (P.H.)
| | - Rahul Chaudhary
- Institute of Physiology I, Westfälische Wilhelms-Universität, Robert-Koch-Str. 27a, D-48149 Münster, Germany; (T.O.); (R.C.); (H.-C.P.); (M.Z.)
| | - Julian A. Schreiber
- Institute of Pharmaceutical and Medicinal Chemistry, Westfälische Wilhelms-Universität, Corren-Str. 48, D-48149 Münster, Germany;
- Cellular Electrophysiology and Molecular Biology, Department of Cardiovascular Medicine, Institute for Genetics of Heart Diseases (IfGH), University Hospital Münster, Robert-Koch-Str. 45, D-48149 Münster, Germany;
| | - Kathrin Riske
- European Institute for Molecular Imaging (EIMI), Westfälische Wilhelms-Universität, Waldeyer-Str. 15, D-48149 Münster, Germany; (K.R.); (A.J.)
| | - Brandon Williams
- Center for Systems Neuroscience, Neurophotonics Center, Department of Biomedical Engineering, Boston University, 610 Commonwealth Ave., Boston, MA 02215, USA; (B.W.); (J.A.W.)
| | - Hans-Christian Pape
- Institute of Physiology I, Westfälische Wilhelms-Universität, Robert-Koch-Str. 27a, D-48149 Münster, Germany; (T.O.); (R.C.); (H.-C.P.); (M.Z.)
| | - John A. White
- Center for Systems Neuroscience, Neurophotonics Center, Department of Biomedical Engineering, Boston University, 610 Commonwealth Ave., Boston, MA 02215, USA; (B.W.); (J.A.W.)
| | - Anna Junker
- European Institute for Molecular Imaging (EIMI), Westfälische Wilhelms-Universität, Waldeyer-Str. 15, D-48149 Münster, Germany; (K.R.); (A.J.)
| | - Guiscard Seebohm
- Cellular Electrophysiology and Molecular Biology, Department of Cardiovascular Medicine, Institute for Genetics of Heart Diseases (IfGH), University Hospital Münster, Robert-Koch-Str. 45, D-48149 Münster, Germany;
| | - Sven G. Meuth
- Neurology Clinic, University Clinic Düsseldorf, Moorenstraße 5, D-40225 Düsseldorf, Germany;
| | - Petra Hundehege
- Department of Neurology with Institute of Translational Neurology, Albert-Schweitzer-Campus 1, D-48149 Münster, Germany; (L.V.); (P.H.)
| | - Thomas Budde
- Institute of Physiology I, Westfälische Wilhelms-Universität, Robert-Koch-Str. 27a, D-48149 Münster, Germany; (T.O.); (R.C.); (H.-C.P.); (M.Z.)
- Correspondence:
| | - Mehrnoush Zobeiri
- Institute of Physiology I, Westfälische Wilhelms-Universität, Robert-Koch-Str. 27a, D-48149 Münster, Germany; (T.O.); (R.C.); (H.-C.P.); (M.Z.)
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Kessi M, Peng J, Duan H, He H, Chen B, Xiong J, Wang Y, Yang L, Wang G, Kiprotich K, Bamgbade OA, He F, Yin F. The Contribution of HCN Channelopathies in Different Epileptic Syndromes, Mechanisms, Modulators, and Potential Treatment Targets: A Systematic Review. Front Mol Neurosci 2022; 15:807202. [PMID: 35663267 PMCID: PMC9161305 DOI: 10.3389/fnmol.2022.807202] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Accepted: 04/06/2022] [Indexed: 12/04/2022] Open
Abstract
Background Hyperpolarization-activated cyclic nucleotide-gated (HCN) current reduces dendritic summation, suppresses dendritic calcium spikes, and enables inhibitory GABA-mediated postsynaptic potentials, thereby suppressing epilepsy. However, it is unclear whether increased HCN current can produce epilepsy. We hypothesized that gain-of-function (GOF) and loss-of-function (LOF) variants of HCN channel genes may cause epilepsy. Objectives This systematic review aims to summarize the role of HCN channelopathies in epilepsy, update genetic findings in patients, create genotype–phenotype correlations, and discuss animal models, GOF and LOF mechanisms, and potential treatment targets. Methods The review was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement, for all years until August 2021. Results We identified pathogenic variants of HCN1 (n = 24), HCN2 (n = 8), HCN3 (n = 2), and HCN4 (n = 6) that were associated with epilepsy in 74 cases (43 HCN1, 20 HCN2, 2 HCN3, and 9 HCN4). Epilepsy was associated with GOF and LOF variants, and the mechanisms were indeterminate. Less than half of the cases became seizure-free and some developed drug-resistant epilepsy. Of the 74 cases, 12 (16.2%) died, comprising HCN1 (n = 4), HCN2 (n = 2), HCN3 (n = 2), and HCN4 (n = 4). Of the deceased cases, 10 (83%) had a sudden unexpected death in epilepsy (SUDEP) and 2 (16.7%) due to cardiopulmonary failure. SUDEP affected more adults (n = 10) than children (n = 2). HCN1 variants p.M234R, p.C329S, p.V414M, p.M153I, and p.M305L, as well as HCN2 variants p.S632W and delPPP (p.719–721), were associated with different phenotypes. HCN1 p.L157V and HCN4 p.R550C were associated with genetic generalized epilepsy. There are several HCN animal models, pharmacological targets, and modulators, but precise drugs have not been developed. Currently, there are no HCN channel openers. Conclusion We recommend clinicians to include HCN genes in epilepsy gene panels. Researchers should explore the possible underlying mechanisms for GOF and LOF variants by identifying the specific neuronal subtypes and neuroanatomical locations of each identified pathogenic variant. Researchers should identify specific HCN channel openers and blockers with high binding affinity. Such information will give clarity to the involvement of HCN channelopathies in epilepsy and provide the opportunity to develop targeted treatments.
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Affiliation(s)
- Miriam Kessi
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, China
- Hunan Intellectual and Developmental Disabilities Research Center, Changsha, China
- Department of Pediatrics, Kilimanjaro Christian Medical University College, Moshi, Tanzania
| | - Jing Peng
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, China
- Hunan Intellectual and Developmental Disabilities Research Center, Changsha, China
| | - Haolin Duan
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, China
- Hunan Intellectual and Developmental Disabilities Research Center, Changsha, China
| | - Hailan He
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, China
- Hunan Intellectual and Developmental Disabilities Research Center, Changsha, China
| | - Baiyu Chen
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, China
- Hunan Intellectual and Developmental Disabilities Research Center, Changsha, China
| | - Juan Xiong
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, China
- Hunan Intellectual and Developmental Disabilities Research Center, Changsha, China
| | - Ying Wang
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, China
- Hunan Intellectual and Developmental Disabilities Research Center, Changsha, China
| | - Lifen Yang
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, China
- Hunan Intellectual and Developmental Disabilities Research Center, Changsha, China
| | - Guoli Wang
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, China
- Hunan Intellectual and Developmental Disabilities Research Center, Changsha, China
| | - Karlmax Kiprotich
- Department of Epidemiology and Medical Statistics, School of Public Health, Moi University, Eldoret, Kenya
| | - Olumuyiwa A. Bamgbade
- Department of Anesthesiology and Pharmacology, University of British Columbia, Vancouver, BC, Canada
| | - Fang He
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, China
- Hunan Intellectual and Developmental Disabilities Research Center, Changsha, China
| | - Fei Yin
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, China
- Hunan Intellectual and Developmental Disabilities Research Center, Changsha, China
- *Correspondence: Fei Yin
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Effect of Riluzole on the Expression of HCN2 in Dorsal Root Ganglion Neurons of Diabetic Neuropathic Pain Rats. JOURNAL OF HEALTHCARE ENGINEERING 2022; 2022:8313415. [PMID: 35432830 PMCID: PMC9007632 DOI: 10.1155/2022/8313415] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/23/2022] [Revised: 03/09/2022] [Accepted: 03/12/2022] [Indexed: 11/18/2022]
Abstract
Neuropathic pain since early diabetes swamps patients' lives, and diabetes mellitus has become an increasingly worldwide epidemic. No agent, so far, can terminate the ongoing diabetes. Therefore, strategies that delay the process and the further complications are preferred, such as diabetic neuropathic pain (DNP). Dysfunction of ion channels is generally accepted as the central mechanism of diabetic associated neuropathy, of which hyperpolarization-activated cyclic nucleotide-gated 2 (HCN2) ion channel has been verified the involvement of neuropathic pain in dorsal root ganglion (DRG) neurons. Riluzole is a benzothiazole compound with neuroprotective properties on intervention to various ion channels, including hyperpolarization-activated voltage-dependent channels. To investigate the effect of riluzole within lumbar (L3-5) DRG neurons from DNP models, streptozocin (STZ, 70 mg/kg) injection was recruited subcutaneously followed by paw withdrawal mechanical threshold (PWMT) and paw withdrawal thermal latency (PWTL), which both show significant reduction, whilst relieved by riluzole (4 mg/kg/d) administration, which was performed once daily for 7 consecutive days for 14 days. HCN2 expression was also decreased in line with alleviated behavioral tests. Our results indicate riluzole as the alleviator to STZ-induced DNP with involvement of downregulated HCN2 in lumbar DRG by continual systemic administration in rats.
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Alles SRA, Smith PA. Peripheral Voltage-Gated Cation Channels in Neuropathic Pain and Their Potential as Therapeutic Targets. FRONTIERS IN PAIN RESEARCH 2022; 2:750583. [PMID: 35295464 PMCID: PMC8915663 DOI: 10.3389/fpain.2021.750583] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Accepted: 11/10/2021] [Indexed: 11/25/2022] Open
Abstract
The persistence of increased excitability and spontaneous activity in injured peripheral neurons is imperative for the development and persistence of many forms of neuropathic pain. This aberrant activity involves increased activity and/or expression of voltage-gated Na+ and Ca2+ channels and hyperpolarization activated cyclic nucleotide gated (HCN) channels as well as decreased function of K+ channels. Because they display limited central side effects, peripherally restricted Na+ and Ca2+ channel blockers and K+ channel activators offer potential therapeutic approaches to pain management. This review outlines the current status and future therapeutic promise of peripherally acting channel modulators. Selective blockers of Nav1.3, Nav1.7, Nav1.8, Cav3.2, and HCN2 and activators of Kv7.2 abrogate signs of neuropathic pain in animal models. Unfortunately, their performance in the clinic has been disappointing; some substances fail to meet therapeutic end points whereas others produce dose-limiting side effects. Despite this, peripheral voltage-gated cation channels retain their promise as therapeutic targets. The way forward may include (i) further structural refinement of K+ channel activators such as retigabine and ASP0819 to improve selectivity and limit toxicity; use or modification of Na+ channel blockers such as vixotrigine, PF-05089771, A803467, PF-01247324, VX-150 or arachnid toxins such as Tap1a; the use of Ca2+ channel blockers such as TTA-P2, TTA-A2, Z 944, ACT709478, and CNCB-2; (ii) improving methods for assessing “pain” as opposed to nociception in rodent models; (iii) recognizing sex differences in pain etiology; (iv) tailoring of therapeutic approaches to meet the symptoms and etiology of pain in individual patients via quantitative sensory testing and other personalized medicine approaches; (v) targeting genetic and biochemical mechanisms controlling channel expression using anti-NGF antibodies such as tanezumab or re-purposed drugs such as vorinostat, a histone methyltransferase inhibitor used in the management of T-cell lymphoma, or cercosporamide a MNK 1/2 inhibitor used in treatment of rheumatoid arthritis; (vi) combination therapy using drugs that are selective for different channel types or regulatory processes; (vii) directing preclinical validation work toward the use of human or human-derived tissue samples; and (viii) application of molecular biological approaches such as clustered regularly interspaced short palindromic repeats (CRISPR) technology.
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Affiliation(s)
- Sascha R A Alles
- Department of Anesthesiology and Critical Care Medicine, University of New Mexico School of Medicine, Albuquerque, NM, United States
| | - Peter A Smith
- Department of Pharmacology, Neuroscience and Mental Health Institute, University of Alberta, Edmonton, AB, Canada
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Tian C, Zhu X, Wang Q, Lv T, Cheng S, Yang D. Bibliometric analysis of hyperpolarization-activated cyclic nucleotide-gated (HCN)channels research (2004-2020). Channels (Austin) 2022; 16:49-59. [PMID: 35235763 PMCID: PMC8896186 DOI: 10.1080/19336950.2021.2020005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Affiliation(s)
- Chuanxi Tian
- Graduate School of Beijing University of Chinese Medicine, Beijing, China.,Department of Traditional Chinese Medicine for Pulmonary Diseases, China-Japan Friendship Hospital, Beijing, China
| | - Xueping Zhu
- Cardiovascular Department, Guanganmen Hosptial, China Academy of Chinese Medical Sciences, Beijing, China
| | - Qiuyuan Wang
- Graduate School of Beijing University of Chinese Medicine, Beijing, China
| | - Tianyi Lv
- Graduate School of Beijing University of Chinese Medicine, Beijing, China
| | - Siyi Cheng
- Graduate School of Beijing University of Chinese Medicine, Beijing, China
| | - Daowen Yang
- Department of Traditional Chinese Medicine for Pulmonary Diseases, China-Japan Friendship Hospital, Beijing, China
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Wrzosek A, Gałecka S, Żochowska M, Olszewska A, Kulawiak B. Alternative Targets for Modulators of Mitochondrial Potassium Channels. Molecules 2022; 27:299. [PMID: 35011530 PMCID: PMC8746388 DOI: 10.3390/molecules27010299] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2021] [Revised: 12/30/2021] [Accepted: 12/31/2021] [Indexed: 12/17/2022] Open
Abstract
Mitochondrial potassium channels control potassium influx into the mitochondrial matrix and thus regulate mitochondrial membrane potential, volume, respiration, and synthesis of reactive oxygen species (ROS). It has been found that pharmacological activation of mitochondrial potassium channels during ischemia/reperfusion (I/R) injury activates cytoprotective mechanisms resulting in increased cell survival. In cancer cells, the inhibition of these channels leads to increased cell death. Therefore, mitochondrial potassium channels are intriguing targets for the development of new pharmacological strategies. In most cases, however, the substances that modulate the mitochondrial potassium channels have a few alternative targets in the cell. This may result in unexpected or unwanted effects induced by these compounds. In our review, we briefly present the various classes of mitochondrial potassium (mitoK) channels and describe the chemical compounds that modulate their activity. We also describe examples of the multidirectional activity of the activators and inhibitors of mitochondrial potassium channels.
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Affiliation(s)
- Antoni Wrzosek
- Laboratory of Intracellular Ion Channels, Nencki Institute of Experimental Biology, Polish Academy of Sciences, 02-093 Warsaw, Poland; (A.W.); (S.G.); (M.Ż.)
| | - Shur Gałecka
- Laboratory of Intracellular Ion Channels, Nencki Institute of Experimental Biology, Polish Academy of Sciences, 02-093 Warsaw, Poland; (A.W.); (S.G.); (M.Ż.)
| | - Monika Żochowska
- Laboratory of Intracellular Ion Channels, Nencki Institute of Experimental Biology, Polish Academy of Sciences, 02-093 Warsaw, Poland; (A.W.); (S.G.); (M.Ż.)
| | - Anna Olszewska
- Department of Histology, Medical University of Gdansk, 1a Debinki, 80-211 Gdansk, Poland;
| | - Bogusz Kulawiak
- Laboratory of Intracellular Ion Channels, Nencki Institute of Experimental Biology, Polish Academy of Sciences, 02-093 Warsaw, Poland; (A.W.); (S.G.); (M.Ż.)
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A second S4 movement opens hyperpolarization-activated HCN channels. Proc Natl Acad Sci U S A 2021; 118:2102036118. [PMID: 34504015 DOI: 10.1073/pnas.2102036118] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/27/2021] [Indexed: 11/18/2022] Open
Abstract
Rhythmic activity in pacemaker cells, as in the sino-atrial node in the heart, depends on the activation of hyperpolarization-activated cyclic nucleotide-gated (HCN) channels. As in depolarization-activated K+ channels, the fourth transmembrane segment S4 functions as the voltage sensor in hyperpolarization-activated HCN channels. But how the inward movement of S4 in HCN channels at hyperpolarized voltages couples to channel opening is not understood. Using voltage clamp fluorometry, we found here that S4 in HCN channels moves in two steps in response to hyperpolarizations and that the second S4 step correlates with gate opening. We found a mutation in sea urchin HCN channels that separate the two S4 steps in voltage dependence. The E356A mutation in S4 shifts the main S4 movement to positive voltages, but channel opening remains at negative voltages. In addition, E356A reveals a second S4 movement at negative voltages that correlates with gate opening. Cysteine accessibility and molecular models suggest that the second S4 movement opens up an intracellular crevice between S4 and S5 that would allow radial movement of the intracellular ends of S5 and S6 to open HCN channels.
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The HCN channel as a pharmacological target: Why, where, and how to block it. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2021; 166:173-181. [PMID: 34303730 DOI: 10.1016/j.pbiomolbio.2021.07.010] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2021] [Revised: 06/22/2021] [Accepted: 07/20/2021] [Indexed: 12/19/2022]
Abstract
Hyperpolarization-activated, cyclic nucleotide-gated (HCN) channels, expressed in a variety of cell types and in all tissues, control excitation and rhythm. Since their discovery in neurons and cardiac pacemaker cells, they attracted the attention of medicinal chemistry and pharmacology as novel targets to shape (patho)physiological mechanisms. To date, ivabradine represents the first-in-class drug as specific bradycardic agent in cardiac diseases; however, new applications are emerging in parallel with the demonstration of the involvement of different HCN isoforms in central and peripheral nervous system. Hence, the possibility to target specific isoforms represents an attractive development in this field; indeed, HCN1, HCN2 or HCN4 specific blockers have shown promising features in vitro and in vivo, with remarkable pharmacological differences likely depending on the diverse functional role and tissue distribution. Here, we show a recently developed compound with high potency as HCN2-HCN4 blocker; because of its unique profile, this compound may deserve further investigation.
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Abstract
The physiological heart function is controlled by a well-orchestrated interplay of different ion channels conducting Na+, Ca2+ and K+. Cardiac K+ channels are key players of cardiac repolarization counteracting depolarizating Na+ and Ca2+ currents. In contrast to Na+ and Ca2+, K+ is conducted by many different channels that differ in activation/deactivation kinetics as well as in their contribution to different phases of the action potential. Together with modulatory subunits these K+ channel α-subunits provide a wide range of repolarizing currents with specific characteristics. Moreover, due to expression differences, K+ channels strongly influence the time course of the action potentials in different heart regions. On the other hand, the variety of different K+ channels increase the number of possible disease-causing mutations. Up to now, a plethora of gain- as well as loss-of-function mutations in K+ channel forming or modulating proteins are known that cause severe congenital cardiac diseases like the long-QT-syndrome, the short-QT-syndrome, the Brugada syndrome and/or different types of atrial tachyarrhythmias. In this chapter we provide a comprehensive overview of different K+ channels in cardiac physiology and pathophysiology.
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Barravecchia I, Demontis GC. HCN1 channels: A versatile tool for signal processing by primary sensory neurons. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2021; 166:133-146. [PMID: 34197835 DOI: 10.1016/j.pbiomolbio.2021.06.009] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Revised: 06/11/2021] [Accepted: 06/25/2021] [Indexed: 12/20/2022]
Abstract
Most primary sensory neurons (PSNs) generate a slowly-activating inward current in response to membrane hyperpolarization (Ih) and express HCN1 along with additional isoforms coding for hyperpolarization-activated channels (HCN). Changes in HCN expression may affect the excitability and firing patterns of PSNs, but retinal and inner ear PSNs do not fire action potentials, suggesting HCN channel roles may extend beyond excitability and cell firing control. In patients taking Ih blockers, photopsia triggered in response to abrupt changes in luminance correlates with impaired visual signal processing via parallel rod and cone pathways. Furthermore, in a mouse model of inherited retinal degeneration, HCN blockers or Hcn1 genetic ablation may worsen photoreceptors' demise. PSN's use of HCN channels to adjust either their firing rate or process signals generated by sensory transduction in non-spiking PSNs indicates HCN1 channels as a versatile tool with a novel role in sensory processing beyond firing control.
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Affiliation(s)
- Ivana Barravecchia
- Department of Pharmacy, Università di Pisa, Italy, Via Bonanno, 6, 56126, Pisa, Italy; Istitute of Life Science, Scuola Superiore Sant' Anna, 56127, Pisa, Italy.
| | - Gian Carlo Demontis
- Department of Pharmacy, Università di Pisa, Italy, Via Bonanno, 6, 56126, Pisa, Italy.
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35
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Combe CL, Gasparini S. I h from synapses to networks: HCN channel functions and modulation in neurons. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2021; 166:119-132. [PMID: 34181891 DOI: 10.1016/j.pbiomolbio.2021.06.002] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Revised: 05/25/2021] [Accepted: 06/03/2021] [Indexed: 01/16/2023]
Abstract
Hyperpolarization-activated cyclic nucleotide gated (HCN) channels and the current they carry, Ih, are widely and diversely distributed in the central nervous system (CNS). The distribution of the four subunits of HCN channels is variable within the CNS, within brain regions, and often within subcellular compartments. The precise function of Ih can depend heavily on what other channels are co-expressed. In this review, we give an overview of HCN channel structure, distribution, and modulation by cyclic adenosine monophosphate (cAMP). We then discuss HCN channel and Ih functions, where we have parsed the roles into two main effects: a steady effect on maintaining the resting membrane potential at relatively depolarized values, and slow channel dynamics. Within this framework, we discuss Ih involvement in resonance, synaptic integration, transmitter release, plasticity, and point out a special case, where the effects of Ih on the membrane potential and its slow channel dynamics have dual roles in thalamic neurons.
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Affiliation(s)
- Crescent L Combe
- Neuroscience Center of Excellence, Louisiana State University Health Sciences Center, New Orleans, LA, 70112, USA
| | - Sonia Gasparini
- Neuroscience Center of Excellence, Louisiana State University Health Sciences Center, New Orleans, LA, 70112, USA.
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36
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Loss of HCN2 in Dorsal Hippocampus of Young Adult Mice Induces Specific Apoptosis of the CA1 Pyramidal Neuron Layer. Int J Mol Sci 2021; 22:ijms22136699. [PMID: 34206649 PMCID: PMC8269412 DOI: 10.3390/ijms22136699] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2021] [Revised: 06/08/2021] [Accepted: 06/18/2021] [Indexed: 11/20/2022] Open
Abstract
Neurons inevitably rely on a proper repertoire and distribution of membrane-bound ion-conducting channels. Among these proteins, the family of hyperpolarization-activated and cyclic nucleotide-gated (HCN) channels possesses unique properties giving rise to the corresponding Ih-current that contributes to various aspects of neural signaling. In mammals, four genes (hcn1-4) encode subunits of HCN channels. These subunits can assemble as hetero- or homotetrameric ion-conducting channels. In order to elaborate on the specific role of the HCN2 subunit in shaping electrical properties of neurons, we applied an Adeno-associated virus (AAV)-mediated, RNAi-based knock-down strategy of hcn2 gene expression both in vitro and in vivo. Electrophysiological measurements showed that HCN2 subunit knock-down resulted in specific yet anticipated changes in Ih-current properties in primary hippocampal neurons and, in addition, corroborated that the HCN2 subunit participates in postsynaptic signal integration. To further address the role of the HCN2 subunit in vivo, we injected recombinant (r)AAVs into the dorsal hippocampus of young adult male mice. Behavioral and biochemical analyses were conducted to assess the contribution of HCN2-containing channels in shaping hippocampal network properties. Surprisingly, knock-down of hcn2 expression resulted in a severe degeneration of the CA1 pyramidal cell layer, which did not occur in mice injected with control rAAV constructs. This finding might pinpoint to a vital and yet unknown contribution of HCN2 channels in establishing or maintaining the proper function of CA1 pyramidal neurons of the dorsal hippocampus.
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37
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Nakashima K, Nakao K, Matsui H. Discovery of Novel HCN4 Blockers with Unique Blocking Kinetics and Binding Properties. SLAS DISCOVERY 2021; 26:896-908. [PMID: 34041946 PMCID: PMC8293762 DOI: 10.1177/24725552211013824] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The hyperpolarization-activated cyclic nucleotide-gated 4 (HCN4) channel underlies the pacemaker currents, called “If,” in sinoatrial nodes (SANs), which regulate heart rhythm. Some HCN4 blockers such as ivabradine have been extensively studied for treating various heart diseases. Studies have shown that these blockers have diverse state dependencies and binding sites, suggesting the existence of potential chemical and functional diversity among HCN4 blockers. Here we report approaches for the identification of novel HCN4 blockers through a random screening campaign among 16,000 small-molecule compounds using an automated patch-clamp system. These molecules exhibited various blockade profiles, and their blocking kinetics and associating amino acids were determined by electrophysiological studies and site-directed mutagenesis analysis, respectively. The profiles of these blockers were distinct from those of the previously reported HCN channel blockers ivabradine and ZD7288. Notably, the mutagenesis analysis showed that blockers with potencies that were increased when the channel was open involved a C478 residue, located at the pore cavity region near the cellular surface of the plasma membrane, while those with potencies that were decreased when the channel was open involved residues Y506 and I510, located at the intracellular region of the pore gate. Thus, this study reported for the first time the discovery of novel HCN4 blockers by screening, and their profiling analysis using an automated patch-clamp system provided chemical tools that will be useful to obtain unique molecular insights into the drug-binding modes of HCN4 and may contribute to the expansion of therapeutic options in the future.
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Affiliation(s)
- Kosuke Nakashima
- Neuroscience Drug Discovery Unit, Research, Takeda Pharmaceutical Company Limited, Fujisawa, Kanagawa, Japan
| | - Kenji Nakao
- Biomolecular Research Laboratories, Research, Takeda Pharmaceutical Company Limited, Fujisawa, Kanagawa, Japan.,Seedsupply Inc., Fujisawa, Kanagawa, Japan
| | - Hideki Matsui
- Neuroscience Drug Discovery Unit, Research, Takeda Pharmaceutical Company Limited, Fujisawa, Kanagawa, Japan
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38
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Giannetti F, Benzoni P, Campostrini G, Milanesi R, Bucchi A, Baruscotti M, Dell'Era P, Rossini A, Barbuti A. A detailed characterization of the hyperpolarization-activated "funny" current (I f) in human-induced pluripotent stem cell (iPSC)-derived cardiomyocytes with pacemaker activity. Pflugers Arch 2021; 473:1009-1021. [PMID: 33934225 PMCID: PMC8245366 DOI: 10.1007/s00424-021-02571-w] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2020] [Revised: 04/01/2021] [Accepted: 04/19/2021] [Indexed: 01/09/2023]
Abstract
Properties of the funny current (If) have been studied in several animal and cellular models, but so far little is known concerning its properties in human pacemaker cells. This work provides a detailed characterization of If in human-induced pluripotent stem cell (iPSC)–derived pacemaker cardiomyocytes (pCMs), at different time points. Patch-clamp analysis showed that If density did not change during differentiation; however, after day 30, it activates at more negative potential and with slower time constants. These changes are accompanied by a slowing in beating rate. If displayed the voltage-dependent block by caesium and reversed (Erev) at − 22 mV, compatibly with the 3:1 K+/Na+ permeability ratio. Lowering [Na+]o (30 mM) shifted the Erev to − 39 mV without affecting conductance. Increasing [K+]o (30 mM) shifted the Erev to − 15 mV with a fourfold increase in conductance. pCMs express mainly HCN4 and HCN1 together with the accessory subunits CAV3, KCR1, MiRP1, and SAP97 that contribute to the context-dependence of If. Autonomic agonists modulated the diastolic depolarization, and thus rate, of pCMs. The adrenergic agonist isoproterenol induced rate acceleration and a positive shift of If voltage-dependence (EC50 73.4 nM). The muscarinic agonists had opposite effects (Carbachol EC50, 11,6 nM). Carbachol effect was however small but it could be increased by pre-stimulation with isoproterenol, indicating low cAMP levels in pCMs. In conclusion, we demonstrated that pCMs display an If with the physiological properties expected by pacemaker cells and may thus represent a suitable model for studying human If-related sinus arrhythmias.
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Affiliation(s)
- Federica Giannetti
- The Cell Physiology MiLab, Department of Biosciences, Università degli Studi di Milano, Via Celoria 26, 20133, Milano, Italy
| | - Patrizia Benzoni
- The Cell Physiology MiLab, Department of Biosciences, Università degli Studi di Milano, Via Celoria 26, 20133, Milano, Italy
| | - Giulia Campostrini
- The Cell Physiology MiLab, Department of Biosciences, Università degli Studi di Milano, Via Celoria 26, 20133, Milano, Italy
- Department of Anatomy and Embryology, Leiden University Medical Center, Einthovenweg 20, 2333ZC, Leiden, The Netherlands
| | - Raffaella Milanesi
- The Cell Physiology MiLab, Department of Biosciences, Università degli Studi di Milano, Via Celoria 26, 20133, Milano, Italy
- Dipartimento di Medicina Veterinaria, Università degli Studi di Milano, Via dell'Università 6, 26900, Lodi, Italy
| | - Annalisa Bucchi
- The Cell Physiology MiLab, Department of Biosciences, Università degli Studi di Milano, Via Celoria 26, 20133, Milano, Italy
| | - Mirko Baruscotti
- The Cell Physiology MiLab, Department of Biosciences, Università degli Studi di Milano, Via Celoria 26, 20133, Milano, Italy
| | - Patrizia Dell'Era
- Cellular Fate Reprogramming Unit, Department of Molecular and Translational Medicine, University of Brescia, viale Europa 11, 25123, Brescia, Italy
| | - Alessandra Rossini
- Institute for Biomedicine, Eurac Research, Affiliated Institute of the University of Lübeck, Viale Druso 1, 39100, Bolzano, Italy
| | - Andrea Barbuti
- The Cell Physiology MiLab, Department of Biosciences, Università degli Studi di Milano, Via Celoria 26, 20133, Milano, Italy.
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Scridon A, Halaţiu VB, Balan AI, Cozac DA, Moldovan V, Bănescu C, Perian M, Şerban RC. Long-Term Effects of Ivabradine on Cardiac Vagal Parasympathetic Function in Normal Rats. Front Pharmacol 2021; 12:596956. [PMID: 33897414 PMCID: PMC8061748 DOI: 10.3389/fphar.2021.596956] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Accepted: 02/26/2021] [Indexed: 01/08/2023] Open
Abstract
Background: The complex interactions that exist between the pacemaker current, I f, and the parasympathetic nervous system could significantly influence the course of patients undergoing chronic therapy with the I f blocker ivabradine. We thus aimed to assess the effects of chronic ivabradine therapy on autonomic modulation and on the cardiovascular response to in situ and in vitro parasympathetic stimulation. The right atrial expression of HCN genes, encoding proteins for I f, was also evaluated. Methods: Sympathetic and parasympathetic heart rate variability parameters and right atrial HCN(1-4) RNA levels were analyzed in 6 Control and 10 ivabradine-treated male Wistar rats (IVA; 3 weeks, 10 mg/kg/day). The heart rate (HR) and systolic blood pressure (SBP) responses to in situ electrical stimulation of the vagus nerve (2-20 Hz) were assessed in 6 additional Control and 10 IVA rats. The spontaneous sinus node discharge rate (SNDR) response to in vitro cholinergic receptors stimulation using carbamylcholine (10-9-10-6 mol/L) was also assessed in these later rats. Results: Ivabradine significantly increased vagal modulation and shifted the sympatho-vagal balance toward vagal dominance. In Control, in situ vagus nerve stimulation induced progressive decrease in both the SBP (p = 0.0001) and the HR (p< 0.0001). Meanwhile, in IVA, vagal stimulation had no effect on the HR (p = 0.16) and induced a significantly lower drop in SBP (p< 0.05). IVA also displayed a significantly lower SNDR drop in response to carbamylcholine (p< 0.01) and significantly higher right atrial HCN4 expression (p = 0.02). Conclusion: Chronic ivabradine administration enhanced vagal modulation in healthy rats. In addition, ivabradine reduced the HR response to direct muscarinic receptors stimulation, canceled the cardioinhibitory response and blunted the hemodynamic response to in situ vagal stimulation. These data bring new insights into the mechanisms of ivabradine-related atrial proarrhythmia and suggest that long-term I f blockade may protect against excessive bradycardia induced by acute vagal activation.
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Affiliation(s)
- Alina Scridon
- University of Medicine, Pharmacy, Science and Technology "George Emil Palade" of Târgu Mureş, Târgu Mureş, Romania.,Center for Advanced Medical and Pharmaceutical Research, Târgu Mureş, Romania
| | - Vasile Bogdan Halaţiu
- University of Medicine, Pharmacy, Science and Technology "George Emil Palade" of Târgu Mureş, Târgu Mureş, Romania
| | - Alkora Ioana Balan
- University of Medicine, Pharmacy, Science and Technology "George Emil Palade" of Târgu Mureş, Târgu Mureş, Romania
| | - Dan Alexandru Cozac
- University of Medicine, Pharmacy, Science and Technology "George Emil Palade" of Târgu Mureş, Târgu Mureş, Romania.,Emergency Institute for Cardiovascular Diseases and Transplantation Târgu Mureş, Târgu Mureş, Romania
| | - Valeriu Moldovan
- University of Medicine, Pharmacy, Science and Technology "George Emil Palade" of Târgu Mureş, Târgu Mureş, Romania.,Center for Advanced Medical and Pharmaceutical Research, Târgu Mureş, Romania
| | - Claudia Bănescu
- University of Medicine, Pharmacy, Science and Technology "George Emil Palade" of Târgu Mureş, Târgu Mureş, Romania.,Center for Advanced Medical and Pharmaceutical Research, Târgu Mureş, Romania
| | - Marcel Perian
- University of Medicine, Pharmacy, Science and Technology "George Emil Palade" of Târgu Mureş, Târgu Mureş, Romania.,Center for Advanced Medical and Pharmaceutical Research, Târgu Mureş, Romania
| | - Răzvan Constantin Şerban
- Emergency Institute for Cardiovascular Diseases and Transplantation Târgu Mureş, Târgu Mureş, Romania
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40
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Jansen LAR, Forster LA, Smith XL, Rubaharan M, Murphy AZ, Baro DJ. Changes in peripheral HCN2 channels during persistent inflammation. Channels (Austin) 2021; 15:165-179. [PMID: 33423595 PMCID: PMC7808421 DOI: 10.1080/19336950.2020.1870086] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Nociceptor sensitization following nerve injury or inflammation leads to chronic pain. An increase in the nociceptor hyperpolarization-activated current, Ih, is observed in many models of pathological pain. Pharmacological blockade of Ih prevents the mechanical and thermal hypersensitivity that occurs during pathological pain. Alterations in the Hyperpolarization-activated Cyclic Nucleotide-gated ion channel 2 (HCN2) mediate Ih-dependent thermal and mechanical hyperalgesia. Limited knowledge exists regarding the nature of these changes during chronic inflammatory pain. Modifications in HCN2 expression and post-translational SUMOylation have been observed in the Complete Freund’s Adjuvant (CFA) model of chronic inflammatory pain. Intra-plantar injection of CFA into the rat hindpaw induces unilateral hyperalgesia that is sustained for up to 14 days following injection. The hindpaw is innervated by primary afferents in lumbar DRG, L4-6. Adjustments in HCN2 expression and SUMOylation have been well-documented for L5 DRG during the first 7 days of CFA-induced inflammation. Here, we examine bilateral L4 and L6 DRG at day 1 and day 3 post-CFA. Using L4 and L6 DRG cryosections, HCN2 expression and SUMOylation were measured with immunohistochemistry and proximity ligation assays, respectively. Our findings indicate that intra-plantar injection of CFA elicited a bilateral increase in HCN2 expression in L4 and L6 DRG at day 1, but not day 3, and enhanced HCN2 SUMOylation in ipsilateral L6 DRG at day 1 and day 3. Changes in HCN2 expression and SUMOylation were transient over this time course. Our study suggests that HCN2 is regulated by multiple mechanisms during CFA-induced inflammation.
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Affiliation(s)
- L-A R Jansen
- Department of Biology, Georgia State University , Atlanta, Georgia
| | - L A Forster
- Department of Biology, Georgia State University , Atlanta, Georgia.,Neuroscience Institute, Georgia State University , Atlanta, Georgia
| | - X L Smith
- Department of Biology, Georgia State University , Atlanta, Georgia
| | - M Rubaharan
- Neuroscience Institute, Georgia State University , Atlanta, Georgia
| | - A Z Murphy
- Neuroscience Institute, Georgia State University , Atlanta, Georgia
| | - D J Baro
- Department of Biology, Georgia State University , Atlanta, Georgia.,Neuroscience Institute, Georgia State University , Atlanta, Georgia
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41
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Lipase-Catalyzed Kinetic Resolution of Alcohols as Intermediates for the Synthesis of Heart Rate Reducing Agent Ivabradine. Catalysts 2021. [DOI: 10.3390/catal11010053] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Ivabradine (Corlanor®), is a chiral benzocycloalkane currently employed and commercialized for the treatment of chronic stable angina pectoris and for the reduction in sinus tachycardia. The eutomer (S)-ivabradine is usually produced via chiral resolution of intermediates, by employing enantiopure auxiliary molecules or through preparative chiral HPLC separations. Recently, more sustainable biocatalytic approaches have been reported in literature for the preparation of the chiral amine precursor. In this work, we report on a novel biocatalyzed pathway, via a resolution study of a key alcohol intermediate used as a precursor of the chiral amine. After screening several enzymatic reaction conditions, employing different lipases and esterases both for the esterification and hydrolysis reactions, the best result was achieved with Pseudomonas cepacia Lipase and the final product was obtained in up to 96:4 enantiomeric ratio (e.r.) of an ivabradine alcohol precursor. This enantiomer was then efficiently converted into the desired amine in a facile three step synthetic sequence.
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42
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Hulme AJ, McArthur JR, Maksour S, Miellet S, Ooi L, Adams DJ, Finol-Urdaneta RK, Dottori M. Molecular and Functional Characterization of Neurogenin-2 Induced Human Sensory Neurons. Front Cell Neurosci 2020; 14:600895. [PMID: 33362470 PMCID: PMC7761588 DOI: 10.3389/fncel.2020.600895] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Accepted: 11/13/2020] [Indexed: 01/15/2023] Open
Abstract
Sensory perception is fundamental to everyday life, yet understanding of human sensory physiology at the molecular level is hindered due to constraints on tissue availability. Emerging strategies to study and characterize peripheral neuropathies in vitro involve the use of human pluripotent stem cells (hPSCs) differentiated into dorsal root ganglion (DRG) sensory neurons. However, neuronal functionality and maturity are limited and underexplored. A recent and promising approach for directing hPSC differentiation towards functionally mature neurons involves the exogenous expression of Neurogenin-2 (NGN2). The optimized protocol described here generates sensory neurons from hPSC-derived neural crest (NC) progenitors through virally induced NGN2 expression. NC cells were derived from hPSCs via a small molecule inhibitor approach and enriched for migrating NC cells (66% SOX10+ cells). At the protein and transcript level, the resulting NGN2 induced sensory neurons (NGN2iSNs) express sensory neuron markers such as BRN3A (82% BRN3A+ cells), ISLET1 (91% ISLET1+ cells), TRKA, TRKB, and TRKC. Importantly, NGN2iSNs repetitively fire action potentials (APs) supported by voltage-gated sodium, potassium, and calcium conductances. In-depth analysis of the molecular basis of NGN2iSN excitability revealed functional expression of ion channels associated with the excitability of primary afferent neurons, such as Nav1.7, Nav1.8, Kv1.2, Kv2.1, BK, Cav2.1, Cav2.2, Cav3.2, ASICs and HCN among other ion channels, for which we provide functional and transcriptional evidence. Our characterization of stem cell-derived sensory neurons sheds light on the molecular basis of human sensory physiology and highlights the suitability of using hPSC-derived sensory neurons for modeling human DRG development and their potential in the study of human peripheral neuropathies and drug therapies.
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Affiliation(s)
- Amy J Hulme
- Illawarra Health and Medical Research Institute, Wollongong, NSW, Australia.,School of Medicine, University of Wollongong, Wollongong, NSW, Australia
| | - Jeffrey R McArthur
- Illawarra Health and Medical Research Institute, Wollongong, NSW, Australia.,School of Medicine, University of Wollongong, Wollongong, NSW, Australia
| | - Simon Maksour
- Illawarra Health and Medical Research Institute, Wollongong, NSW, Australia.,School of Medicine, University of Wollongong, Wollongong, NSW, Australia
| | - Sara Miellet
- Illawarra Health and Medical Research Institute, Wollongong, NSW, Australia.,School of Medicine, University of Wollongong, Wollongong, NSW, Australia
| | - Lezanne Ooi
- Illawarra Health and Medical Research Institute, Wollongong, NSW, Australia.,School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, NSW, Australia.,Molecular Horizons, University of Wollongong, Wollongong, NSW, Australia
| | - David J Adams
- Illawarra Health and Medical Research Institute, Wollongong, NSW, Australia.,School of Medicine, University of Wollongong, Wollongong, NSW, Australia.,Molecular Horizons, University of Wollongong, Wollongong, NSW, Australia
| | - Rocio K Finol-Urdaneta
- Illawarra Health and Medical Research Institute, Wollongong, NSW, Australia.,School of Medicine, University of Wollongong, Wollongong, NSW, Australia
| | - Mirella Dottori
- Illawarra Health and Medical Research Institute, Wollongong, NSW, Australia.,School of Medicine, University of Wollongong, Wollongong, NSW, Australia.,Molecular Horizons, University of Wollongong, Wollongong, NSW, Australia
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43
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Cuddy SR, Schinlever AR, Dochnal S, Seegren PV, Suzich J, Kundu P, Downs TK, Farah M, Desai BN, Boutell C, Cliffe AR. Neuronal hyperexcitability is a DLK-dependent trigger of herpes simplex virus reactivation that can be induced by IL-1. eLife 2020; 9:e58037. [PMID: 33350386 PMCID: PMC7773336 DOI: 10.7554/elife.58037] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Accepted: 12/14/2020] [Indexed: 12/12/2022] Open
Abstract
Herpes simplex virus-1 (HSV-1) establishes a latent infection in neurons and periodically reactivates to cause disease. The stimuli that trigger HSV-1 reactivation have not been fully elucidated. We demonstrate HSV-1 reactivation from latently infected mouse neurons induced by forskolin requires neuronal excitation. Stimuli that directly induce neurons to become hyperexcitable also induced HSV-1 reactivation. Forskolin-induced reactivation was dependent on the neuronal pathway of DLK/JNK activation and included an initial wave of viral gene expression that was independent of histone demethylase activity and linked to histone phosphorylation. IL-1β is released under conditions of stress, fever and UV exposure of the epidermis; all known triggers of clinical HSV reactivation. We found that IL-1β induced histone phosphorylation and increased the excitation in sympathetic neurons. Importantly, IL-1β triggered HSV-1 reactivation, which was dependent on DLK and neuronal excitability. Thus, HSV-1 co-opts an innate immune pathway resulting from IL-1 stimulation of neurons to induce reactivation.
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Affiliation(s)
- Sean R Cuddy
- Department of Microbiology, Immunology and Cancer Biology, University of VirginiaCharlottesvilleUnited States
- Neuroscience Graduate Program, University of VirginiaCharlottesvilleUnited States
| | - Austin R Schinlever
- Department of Microbiology, Immunology and Cancer Biology, University of VirginiaCharlottesvilleUnited States
| | - Sara Dochnal
- Department of Microbiology, Immunology and Cancer Biology, University of VirginiaCharlottesvilleUnited States
| | - Philip V Seegren
- Department of Pharmacology, University of VirginiaCharlottesvilleUnited States
| | - Jon Suzich
- Department of Microbiology, Immunology and Cancer Biology, University of VirginiaCharlottesvilleUnited States
| | - Parijat Kundu
- Department of Microbiology, Immunology and Cancer Biology, University of VirginiaCharlottesvilleUnited States
| | - Taylor K Downs
- Department of Pharmacology, University of VirginiaCharlottesvilleUnited States
| | - Mina Farah
- Department of Microbiology, Immunology and Cancer Biology, University of VirginiaCharlottesvilleUnited States
| | - Bimal N Desai
- Department of Pharmacology, University of VirginiaCharlottesvilleUnited States
| | - Chris Boutell
- MRC-University of Glasgow Centre for Virus Research (CVR), Garscube CampusGlasgowUnited Kingdom
| | - Anna R Cliffe
- Department of Microbiology, Immunology and Cancer Biology, University of VirginiaCharlottesvilleUnited States
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44
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Han Y, Lyman KA, Foote KM, Chetkovich DM. The structure and function of TRIP8b, an auxiliary subunit of hyperpolarization-activated cyclic-nucleotide gated channels. Channels (Austin) 2020; 14:110-122. [PMID: 32189562 PMCID: PMC7153792 DOI: 10.1080/19336950.2020.1740501] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2020] [Revised: 02/18/2020] [Accepted: 02/21/2020] [Indexed: 02/08/2023] Open
Abstract
Hyperpolarization-activated cyclic nucleotide-gated (HCN) channels are expressed throughout the mammalian central nervous system (CNS). These channels have been implicated in a wide range of diseases, including Major Depressive Disorder and multiple subtypes of epilepsy. The diversity of functions that HCN channels perform is in part attributable to differences in their subcellular localization. To facilitate a broad range of subcellular distributions, HCN channels are bound by auxiliary subunits that regulate surface trafficking and channel function. One of the best studied auxiliary subunits is tetratricopeptide-repeat containing, Rab8b-interacting protein (TRIP8b). TRIP8b is an extensively alternatively spliced protein whose only known function is to regulate HCN channels. TRIP8b binds to HCN pore-forming subunits at multiple interaction sites that differentially regulate HCN channel function and subcellular distribution. In this review, we summarize what is currently known about the structure and function of TRIP8b isoforms with an emphasis on the role of this auxiliary subunit in health and disease.
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Affiliation(s)
- Ye Han
- Department of Neurology, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Kyle A. Lyman
- Department of Neurology, Stanford University, Palo Alto, CA, USA
| | - Kendall M. Foote
- Feinberg School of Medicine, Northwestern University, Chicago, IL, USA
| | - Dane M. Chetkovich
- Department of Neurology, Vanderbilt University Medical Center, Nashville, TN, USA
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45
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Luque M, Schrott-Fischer A, Dudas J, Pechriggl E, Brenner E, Rask-Andersen H, Liu W, Glueckert R. HCN channels in the mammalian cochlea: Expression pattern, subcellular location, and age-dependent changes. J Neurosci Res 2020; 99:699-728. [PMID: 33181864 PMCID: PMC7839784 DOI: 10.1002/jnr.24754] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Revised: 10/20/2020] [Accepted: 10/22/2020] [Indexed: 01/03/2023]
Abstract
Neuronal diversity in the cochlea is largely determined by ion channels. Among voltage‐gated channels, hyperpolarization‐activated cyclic nucleotide‐gated (HCN) channels open with hyperpolarization and depolarize the cell until the resting membrane potential. The functions for hearing are not well elucidated and knowledge about localization is controversial. We created a detailed map of subcellular location and co‐expression of all four HCN subunits across different mammalian species including CBA/J, C57Bl/6N, Ly5.1 mice, guinea pigs, cats, and human subjects. We correlated age‐related hearing deterioration in CBA/J and C57Bl/6N with expression levels of HCN1, −2, and −4 in individual auditory neurons from the same cohort. Spatiotemporal expression during murine postnatal development exposed HCN2 and HCN4 involvement in a critical phase of hair cell innervation. The huge diversity of subunit composition, but lack of relevant heteromeric pairing along the perisomatic membrane and axon initial segments, highlighted an active role for auditory neurons. Neuron clusters were found to be the hot spots of HCN1, −2, and −4 immunostaining. HCN channels were also located in afferent and efferent fibers of the sensory epithelium. Age‐related changes on HCN subtype expression were not uniform among mice and could not be directly correlated with audiometric data. The oldest mice groups revealed HCN channel up‐ or downregulation, depending on the mouse strain. The unexpected involvement of HCN channels in outer hair cell function where HCN3 overlaps prestin location emphasized the importance for auditory function. A better understanding may open up new possibilities to tune neuronal responses evoked through electrical stimulation by cochlear implants.
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Affiliation(s)
- Maria Luque
- Department of Otorhinolaryngology, Medical University of Innsbruck, Innsbruck, Austria
| | | | - Jozsef Dudas
- Department of Otorhinolaryngology, Medical University of Innsbruck, Innsbruck, Austria
| | - Elisabeth Pechriggl
- Department of Anatomy, Histology & Embryology, Division of Clinical & Functional Anatomy, Medical University of Innsbruck, Innsbruck, Austria
| | - Erich Brenner
- Department of Anatomy, Histology & Embryology, Division of Clinical & Functional Anatomy, Medical University of Innsbruck, Innsbruck, Austria
| | - Helge Rask-Andersen
- Department of Surgical Sciences, Head and Neck Surgery, Section of Otolaryngology, Uppsala University Hospital, Uppsala, Sweden
| | - Wei Liu
- Department of Surgical Sciences, Head and Neck Surgery, Section of Otolaryngology, Uppsala University Hospital, Uppsala, Sweden
| | - Rudolf Glueckert
- Department of Otorhinolaryngology, Medical University of Innsbruck, Innsbruck, Austria.,Tirol Kliniken, University Clinics Innsbruck, Innsbruck, Austria
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Lelle M, Otte M, Bonus M, Gohlke H, Benndorf K. Fluorophore-Labeled Cyclic Nucleotides as Potent Agonists of Cyclic Nucleotide-Regulated Ion Channels. Chembiochem 2020; 21:2311-2320. [PMID: 32227403 PMCID: PMC7497086 DOI: 10.1002/cbic.202000116] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Revised: 03/26/2020] [Indexed: 12/22/2022]
Abstract
High-affinity fluorescent derivatives of cyclic adenosine and guanosine monophosphate are powerful tools for investigating their natural targets. Cyclic nucleotide-regulated ion channels belong to these targets and are vital for many signal transduction processes, such as vision and olfaction. The relation of ligand binding to activation gating is still challenging, and there is a need for fluorescent probes that enable the process to be broken down to the single-molecule level. This inspired us to prepare fluorophore-labeled cyclic nucleotides, which are composed of a bright dye and a nucleotide derivative with a thiophenol motif at position 8 that has already been shown to enable superior binding affinity. These bioconjugates were prepared by a novel cross-linking strategy that involves substitution of the nucleobase with a modified thiophenolate in good yield. Both fluorescent nucleotides are potent activators of different cyclic nucleotide-regulated ion channels with respect to the natural ligand and previously reported substances. Molecular docking of the probes excluding the fluorophore reveals that the high potency can be attributed to additional hydrophobic and cation-π interactions between the ligand and the protein. Moreover, the introduced substances have the potential to investigate related target proteins, such as cAMP- and cGMP-dependent protein kinases, exchange proteins directly activated by cAMP or phosphodiesterases.
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Affiliation(s)
- Marco Lelle
- Institute of Physiology IIUniversity Hospital JenaKollegiengasse 907743JenaGermany
| | - Maik Otte
- Institute of Physiology IIUniversity Hospital JenaKollegiengasse 907743JenaGermany
| | - Michele Bonus
- Institute for Pharmaceutical and Medicinal ChemistryHeinrich Heine University DüsseldorfUniversitätsstrasse 140225DüsseldorfGermany
| | - Holger Gohlke
- Institute for Pharmaceutical and Medicinal ChemistryHeinrich Heine University DüsseldorfUniversitätsstrasse 140225DüsseldorfGermany
- John von Neumann Institute for Computing (NIC)Jülich Supercomputing Centre (JSC) andInstitute of Biological Information Processing (IBI-7: Structural Biochemistry)Forschungszentrum Jülich GmbHWilhelm-Johnen-Strasse52425JülichGermany
| | - Klaus Benndorf
- Institute of Physiology IIUniversity Hospital JenaKollegiengasse 907743JenaGermany
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HCN2 activation modulation: An electrophysiological and molecular study of the well-preserved LCI sequence in the pore channel. Arch Biochem Biophys 2020; 689:108436. [DOI: 10.1016/j.abb.2020.108436] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2020] [Revised: 05/21/2020] [Accepted: 05/25/2020] [Indexed: 11/17/2022]
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Chen C, Liu L, Shu YQ, Jing P, Lu Y, Zhang XX, Zong XG, Guo LJ, Li CJ. Blockade of HCN2 Channels Provides Neuroprotection Against Ischemic Injury via Accelerating Autophagic Degradation in Hippocampal Neurons. Neurosci Bull 2020; 36:875-894. [PMID: 32519067 PMCID: PMC7410947 DOI: 10.1007/s12264-020-00513-7] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2019] [Accepted: 02/16/2020] [Indexed: 01/25/2023] Open
Abstract
In the central nervous system, hyperpolarization-activated cyclic nucleotide-gated (HCN) channels are essential to maintain normal neuronal function. Recent studies have shown that HCN channels may be involved in the pathological process of ischemic brain injury, but the mechanisms remain unclear. Autophagy is activated in cerebral ischemia, but its role in cell death/survival remains controversial. In this study, our results showed that the HCN channel blocker ZD7288 remarkably decreased the percentage of apoptotic neurons and corrected the excessive autophagy induced by oxygen-glucose deprivation followed by reperfusion (OGD/R) in hippocampal HT22 neurons. Furthermore, in the OGD/R group, p-mTOR, p-ULK1 (Ser757), and p62 were significantly decreased, while p-ULK1 (Ser317), atg5, and beclin1 were remarkably increased. ZD7288 did not change the expression of p-ULK1 (Ser757), ULK1 (Ser317), p62, Beclin1, and atg5, which are involved in regulating autophagosome formation. Besides, we found that OGD/R induced a significant increase in Cathepsin D expression, but not LAMP-1. Treatment with ZD7288 at 10 μmol/L in the OGD/R group did not change the expression of cathepsin D and LAMP-1. However, chloroquine (CQ), which decreases autophagosome-lysosome fusion, eliminated the correction of excessive autophagy and neuroprotection by ZD7288. Besides, shRNA knockdown of HCN2 channels significantly reduced the accumulation of LC3-II and increased neuron survival in the OGD/R and transient global cerebral ischemia (TGCI) models, and CQ also eliminated the effects of HCN2-shRNA. Furthermore, we found that the percentage of LC3-positive puncta that co-localized with LAMP-1-positive lysosomes decreased in Con-shRNA-transfected HT22 neurons exposed to OGD/R or CQ. In HCN2-shRNA-transfected HT22 neurons, the percentage of LC3-positive puncta that co-localized with LAMP-1-positive lysosomes increased under OGD/R; however, the percentage was significantly decreased by the addition of CQ to HCN2-shRNA-transfected HT22 neurons. The present results demonstrated that blockade of HCN2 channels provides neuroprotection against OGD/R and TGCI by accelerating autophagic degradation attributable to the promotion of autophagosome and lysosome fusion.
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Affiliation(s)
- Cheng Chen
- Department of Pharmacology, School of Basic Medical Sciences, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Li Liu
- Office of Academic Research, The Central Hospital of Wuhan, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Ya-Qiao Shu
- Department of Pharmacology, School of Basic Medical Sciences, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Ping Jing
- Department of Neurology, The Central Hospital of Wuhan, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Yun Lu
- Department of Pharmacy, Zhongnan Hospital of Wuhan University, Wuhan, 430030, China
| | - Xiao-Xue Zhang
- Department of Clinical Laboratory, Wuhan PuAi Hospital, Wuhan, 430033, China
| | - Xian-Gang Zong
- Center for Integrated Protein Science and Zentrum für Pharmaforschung, Department Pharmazie, Ludwig-Maximilians-Universität München, 80539, Munich, Germany
| | - Lian-Jun Guo
- Department of Pharmacology, School of Basic Medical Sciences, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China.
- Key Laboratory of Drug Target Research and Pharmacodynamic Evaluation, Wuhan, 430030, China.
| | - Chang-Jun Li
- Department of Neurology, The Central Hospital of Wuhan, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China.
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Kharouf Q, Phillips AM, Bleakley LE, Morrisroe E, Oyrer J, Jia L, Ludwig A, Jin L, Nicolazzo JA, Cerbai E, Romanelli MN, Petrou S, Reid CA. The hyperpolarization-activated cyclic nucleotide-gated 4 channel as a potential anti-seizure drug target. Br J Pharmacol 2020; 177:3712-3729. [PMID: 32364262 DOI: 10.1111/bph.15088] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2019] [Revised: 03/24/2020] [Accepted: 04/16/2020] [Indexed: 01/03/2023] Open
Abstract
BACKGROUND AND PURPOSE Hyperpolarization-activated cyclic nucleotide-gated (HCN) channels are encoded by four genes (HCN1-4) with distinct biophysical properties and functions within the brain. HCN4 channels activate slowly at robust hyperpolarizing potentials, making them more likely to be engaged during hyperexcitable neuronal network activity seen during seizures. HCN4 channels are also highly expressed in thalamic nuclei, a brain region implicated in seizure generalization. Here, we assessed the utility of targeting the HCN4 channel as an anti-seizure strategy using pharmacological and genetic approaches. EXPERIMENTAL APPROACH The impact of reducing HCN4 channel function on seizure susceptibility and neuronal network excitability was studied using an HCN4 channel preferring blocker (EC18) and a conditional brain specific HCN4 knockout mouse model. KEY RESULTS EC18 (10 mg·kg-1 ) and brain-specific HCN4 channel knockout reduced seizure susceptibility and proconvulsant-mediated cortical spiking recorded using electrocorticography, with minimal effects on other mouse behaviours. EC18 (10 μM) decreased neuronal network bursting in mouse cortical cultures. Importantly, EC18 was not protective against proconvulsant-mediated seizures in the conditional HCN4 channel knockout mouse and did not reduce bursting behaviour in AAV-HCN4 shRNA infected mouse cortical cultures. CONCLUSIONS AND IMPLICATIONS These data suggest the HCN4 channel as a potential pharmacologically relevant target for anti-seizure drugs that is likely to have a low side-effect liability in the CNS.
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Affiliation(s)
- Qays Kharouf
- Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, Victoria, Australia
| | - A Marie Phillips
- Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, Victoria, Australia.,School of Biosciences, University of Melbourne, Parkville, Victoria, Australia
| | - Lauren E Bleakley
- Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, Victoria, Australia
| | - Emma Morrisroe
- Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, Victoria, Australia
| | - Julia Oyrer
- Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, Victoria, Australia
| | - Linghan Jia
- Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, Victoria, Australia
| | - Andreas Ludwig
- Institut für Experimentelle und Klinische Pharmakologie und Toxikologie, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Liang Jin
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia
| | - Joseph A Nicolazzo
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia
| | - Elisabetta Cerbai
- Department of Neurosciences, Psychology, Drug Research and Child Health, (NEUROFARBA), University of Florence, Florence, Italy
| | - M Novella Romanelli
- Department of Neurosciences, Psychology, Drug Research and Child Health, (NEUROFARBA), University of Florence, Florence, Italy
| | - Steven Petrou
- Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, Victoria, Australia
| | - Christopher A Reid
- Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, Victoria, Australia
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50
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Forster LA, Jansen LAR, Rubaharan M, Murphy AZ, Baro DJ. Alterations in SUMOylation of the hyperpolarization-activated cyclic nucleotide-gated ion channel 2 during persistent inflammation. Eur J Pain 2020; 24:1517-1536. [PMID: 32446289 PMCID: PMC7496191 DOI: 10.1002/ejp.1606] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2020] [Revised: 04/28/2020] [Accepted: 05/15/2020] [Indexed: 01/08/2023]
Abstract
Background Unilateral injection of Complete Freund's Adjuvant (CFA) into the intra‐plantar surface of the rodent hindpaw elicits chronic inflammation and hyperalgesia in the ipsilateral hindlimb. Mechanisms contributing to this hyperalgesia may act over multiple time courses and can include changes in ion channel expression and post‐translational SUMOylation. Hyperpolarization‐activated, cyclic nucleotide‐gated (HCN) channels mediate the hyperpolarization‐activated current, Ih. An HCN2‐mediated increase in C‐nociceptor Ih contributes to mechanical hyperalgesia in the CFA model of inflammatory pain. Changes in HCN2 post‐translational SUMOylation and protein expression have not been systematically documented for a given dorsal root ganglia (DRG) throughout the time course of inflammation. Methods This study examined HCN2 protein expression and post‐translational SUMOylation in a rat model of CFA‐induced hindpaw inflammation. L5 DRG cryosections were used in immunohistochemistry experiments and proximity ligation assays to investigate HCN2 expression and SUMOylation, respectively, on days 1 and 3 post‐CFA. Results Unilateral CFA injection elicited a significant bilateral increase in HCN2 staining intensity in small diameter DRG neurons on day 1 post‐CFA, and a significant bilateral increase in the number of small neurons expressing HCN2 but not staining intensity on day 3 post‐CFA. HCN2 channels were hyper‐SUMOylated in small diameter neurons of ipsilateral relative to contralateral DRG on days 1 and 3 post‐CFA. Conclusions Unilateral CFA injection elicits unilateral mechanical hyperalgesia, a bilateral increase in HCN2 expression and a unilateral increase in post‐translational SUMOylation. This suggests that enhanced HCN2 expression in L5 DRG is not sufficient for mechanical hyperalgesia in the early stages of inflammation and that hyper‐SUMOylation of HCN2 channels may also be necessary. Significance Nociceptor HCN2 channels mediate an increase in Ih that is necessary for mechanical hyperalgesia in a CFA model of chronic pain, but the mechanisms producing the increase in nociceptor Ih have not been resolved. The data presented here suggest that the increase in Ih during the early stages of inflammation may be mediated by an increase in HCN2 protein expression and post‐translational SUMOylation.
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Affiliation(s)
- Lori A Forster
- Department of Biology, Georgia State University, Atlanta, GA, USA.,Neuroscience Institute, Georgia State University, Atlanta, GA, USA
| | | | | | - Anne Z Murphy
- Neuroscience Institute, Georgia State University, Atlanta, GA, USA
| | - Deborah J Baro
- Department of Biology, Georgia State University, Atlanta, GA, USA.,Neuroscience Institute, Georgia State University, Atlanta, GA, USA
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