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Furutani K. Facilitation of hERG Activation by Its Blocker: A Mechanism to Reduce Drug-Induced Proarrhythmic Risk. Int J Mol Sci 2023; 24:16261. [PMID: 38003453 PMCID: PMC10671758 DOI: 10.3390/ijms242216261] [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: 10/24/2023] [Revised: 11/08/2023] [Accepted: 11/12/2023] [Indexed: 11/26/2023] Open
Abstract
Modulation of the human Ether-à-go-go-Related Gene (hERG) channel, a crucial voltage-gated potassium channel in the repolarization of action potentials in ventricular myocytes of the heart, has significant implications on cardiac electrophysiology and can be either antiarrhythmic or proarrhythmic. For example, hERG channel blockade is a leading cause of long QT syndrome and potentially life-threatening arrhythmias, such as torsades de pointes. Conversely, hERG channel blockade is the mechanism of action of Class III antiarrhythmic agents in terminating ventricular tachycardia and fibrillation. In recent years, it has been recognized that less proarrhythmic hERG blockers with clinical potential or Class III antiarrhythmic agents exhibit, in addition to their hERG-blocking activity, a second action that facilitates the voltage-dependent activation of the hERG channel. This facilitation is believed to reduce the proarrhythmic potential by supporting the final repolarizing of action potentials. This review covers the pharmacological characteristics of hERG blockers/facilitators, the molecular mechanisms underlying facilitation, and their clinical significance, as well as unresolved issues and requirements for research in the fields of ion channel pharmacology and drug-induced arrhythmias.
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Affiliation(s)
- Kazuharu Furutani
- Department of Pharmacology, Faculty of Pharmaceutical Sciences, Tokushima Bunri University, 180 Nishihama-Boji, Yamashiro-cho, Tokushima 770-8514, Japan
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T-Type Calcium Channels: A Mixed Blessing. Int J Mol Sci 2022; 23:ijms23179894. [PMID: 36077291 PMCID: PMC9456242 DOI: 10.3390/ijms23179894] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2022] [Revised: 08/26/2022] [Accepted: 08/29/2022] [Indexed: 11/17/2022] Open
Abstract
The role of T-type calcium channels is well established in excitable cells, where they preside over action potential generation, automaticity, and firing. They also contribute to intracellular calcium signaling, cell cycle progression, and cell fate; and, in this sense, they emerge as key regulators also in non-excitable cells. In particular, their expression may be considered a prognostic factor in cancer. Almost all cancer cells express T-type calcium channels to the point that it has been considered a pharmacological target; but, as the drugs used to reduce their expression are not completely selective, several complications develop, especially within the heart. T-type calcium channels are also involved in a specific side effect of several anticancer agents, that act on microtubule transport, increase the expression of the channel, and, thus, the excitability of sensory neurons, and make the patient more sensitive to pain. This review puts into context the relevance of T-type calcium channels in cancer and in chemotherapy side effects, considering also the cardiotoxicity induced by new classes of antineoplastic molecules.
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Guardiola-Ripoll M, Almodóvar-Payá C, Lubeiro A, Salvador R, Salgado-Pineda P, Gomar JJ, Guerrero-Pedraza A, Sarró S, Maristany T, Fernández-Linsenbarth I, Hernández-García M, Papiol S, Molina V, Pomarol-Clotet E, Fatjó-Vilas M. New insights of the role of the KCNH2 gene in schizophrenia: An fMRI case-control study. Eur Neuropsychopharmacol 2022; 60:38-47. [PMID: 35635995 DOI: 10.1016/j.euroneuro.2022.04.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Revised: 04/14/2022] [Accepted: 04/19/2022] [Indexed: 11/04/2022]
Abstract
The KCNH2 gene, encoding for a subunit of a voltage-gated potassium channel, has been identified as a key element of neuronal excitability and a promising novel therapeutic target for schizophrenia (SZ). Nonetheless, evidence highlighting the role of KCNH2 on cognitive and brain activity phenotypes comes mainly from studies based on healthy controls (HC). Therefore, we aimed to study the role of KCNH2 on the brain functional differences between patients with SZ and HC. The fMRI sample comprised 78 HC and 79 patients with SZ (matched for age, sex and premorbid IQ). We studied the effect of the polymorphism KCNH2-rs3800779 on attention and working memory-related brain activity, evaluated through the N-back task, in regions with detected diagnostic differences (regression model, controlled for age, sex and premorbid IQ, FEAT-FSL). We report a significant diagnosis x KCNH2 interaction on brain activity (1-back vs baseline contrast) at the medial superior prefrontal cortex (Zmax=3.55, p = 0.00861). In this region, patients with SZ carrying the risk genotype (AA) show a deactivation failure, while HC depict the opposite pattern towards deactivation. The brain region with significant diagnosis x KCNH2 interaction has been previously associated with SZ. The results of this study, in which the role of KCNH2 on fMRI response is analysed for the first time in patients, suggest that KCNH2 variability contributes to inefficient brain activity modulation during the N-back task in affected subjects. These data may pave the way to further understand how KCNH2 genetic variability is related to the pathophysiological mechanisms underlying schizophrenia.
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Affiliation(s)
- Maria Guardiola-Ripoll
- FIDMAG Germanes Hospitalàries Research Foundation, Barcelona, Spain; CIBERSAM (Biomedical Research Network in Mental Health, Instituto de Salud Carlos III), Madrid, Spain
| | - Carmen Almodóvar-Payá
- FIDMAG Germanes Hospitalàries Research Foundation, Barcelona, Spain; CIBERSAM (Biomedical Research Network in Mental Health, Instituto de Salud Carlos III), Madrid, Spain
| | - Alba Lubeiro
- Psychiatry Department, School of Medicine, University of Valladolid, Valladolid, Spain
| | - Raymond Salvador
- FIDMAG Germanes Hospitalàries Research Foundation, Barcelona, Spain; CIBERSAM (Biomedical Research Network in Mental Health, Instituto de Salud Carlos III), Madrid, Spain
| | - Pilar Salgado-Pineda
- FIDMAG Germanes Hospitalàries Research Foundation, Barcelona, Spain; CIBERSAM (Biomedical Research Network in Mental Health, Instituto de Salud Carlos III), Madrid, Spain
| | - Jesús J Gomar
- FIDMAG Germanes Hospitalàries Research Foundation, Barcelona, Spain; The Litwin-Zucker Alzheimer's Research Center, NY, United States
| | - Amalia Guerrero-Pedraza
- FIDMAG Germanes Hospitalàries Research Foundation, Barcelona, Spain; Hospital Benito Menni-CASM, Sant Boi de Llobregat, Barcelona, Spain
| | - Salvador Sarró
- FIDMAG Germanes Hospitalàries Research Foundation, Barcelona, Spain; CIBERSAM (Biomedical Research Network in Mental Health, Instituto de Salud Carlos III), Madrid, Spain
| | - Teresa Maristany
- Diagnostic Imaging Department, Hospital Sant Joan de Déu Research Foundation, Barcelona, Spain
| | | | - Marta Hernández-García
- Neurosciences Institute of Castilla y León (INCYL), University of Salamanca, Salamanca, Spain
| | - Sergi Papiol
- CIBERSAM (Biomedical Research Network in Mental Health, Instituto de Salud Carlos III), Madrid, Spain; Institute of Psychiatric Phenomics and Genomics (IPPG), University Hospital, LMU Munich, Munich, Germany; Department of Psychiatry, University Hospital, Ludwig Maximilian University, Munich Germany
| | - Vicente Molina
- Psychiatry Department, School of Medicine, University of Valladolid, Valladolid, Spain; Neurosciences Institute of Castilla y León (INCYL), University of Salamanca, Salamanca, Spain; Psychiatry Service, University Hospital of Valladolid, Valladolid, Spain
| | - Edith Pomarol-Clotet
- FIDMAG Germanes Hospitalàries Research Foundation, Barcelona, Spain; CIBERSAM (Biomedical Research Network in Mental Health, Instituto de Salud Carlos III), Madrid, Spain.
| | - Mar Fatjó-Vilas
- FIDMAG Germanes Hospitalàries Research Foundation, Barcelona, Spain; CIBERSAM (Biomedical Research Network in Mental Health, Instituto de Salud Carlos III), Madrid, Spain; Departament de Biologia Evolutiva, Ecologia i Ciències Ambientals, Facultat de Biologia, Universitat de Barcelona; Barcelona, Spain.
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Sanchez-Conde FG, Jimenez-Vazquez EN, Auerbach DS, Jones DK. The ERG1 K+ Channel and Its Role in Neuronal Health and Disease. Front Mol Neurosci 2022; 15:890368. [PMID: 35600076 PMCID: PMC9113952 DOI: 10.3389/fnmol.2022.890368] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2022] [Accepted: 04/11/2022] [Indexed: 11/30/2022] Open
Abstract
The ERG1 potassium channel, encoded by KCNH2, has long been associated with cardiac electrical excitability. Yet, a growing body of work suggests that ERG1 mediates physiology throughout the human body, including the brain. ERG1 is a regulator of neuronal excitability, ERG1 variants are associated with neuronal diseases (e.g., epilepsy and schizophrenia), and ERG1 serves as a potential therapeutic target for neuronal pathophysiology. This review summarizes the current state-of-the-field regarding the ERG1 channel structure and function, ERG1’s relationship to the mammalian brain and highlights key questions that have yet to be answered.
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Affiliation(s)
| | - Eric N. Jimenez-Vazquez
- Department of Pharmacology, University of Michigan Medical School, Ann Arbor, MI, United States
| | - David S. Auerbach
- Department of Pharmacology, State University of New York Upstate Medical University, Syracuse, NY, United States
- *Correspondence: David S. Auerbach,
| | - David K. Jones
- Department of Pharmacology, University of Michigan Medical School, Ann Arbor, MI, United States
- Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, MI, United States
- David K. Jones,
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Lee HJ, Choi BH, Choi JS, Hahn SJ. Effects of iloperidone on hERG 1A/3.1 heterotetrameric channels. Neuroreport 2021; 32:1299-1306. [PMID: 34605450 DOI: 10.1097/wnr.0000000000001724] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVES Iloperidone is an atypical antipsychotic drug that is widely used for the treatment of schizophrenia. hERG 3.1, alternatively spliced form of hERG 1A, is considered a potential target for an antipsychotic drug. The present study was designed to study the effects of iloperidone on hERG 1A/3.1 heterotetrameric channels. METHODS The interactions of iloperidone with hERG 1A/3.1 heterotetrameric channels stably expressed in HEK cells were investigated using the whole-cell patch-clamp technique and western blot analysis. RESULTS Iloperidone inhibited the hERG 1A/3.1 tail currents at -50 mV in a concentration-dependent manner with an IC50 value of 0.44 μM. The block of hERG 1A/3.1 currents by iloperidone was voltage-dependent and increased over a range of voltage for channel activation. However, the block by iloperidone was voltage-independent at more depolarized potentials where the channels were fully activated. A fast application of iloperidone inhibited the hERG 1A/3.1 current elicited by a 5-s depolarizing pulse to +60 mV to fully inactivate the hERG 1A/3.1 currents. Iloperidone also induced a rapid and reversible inhibition of hERG 1A/3.1 tail currents during repolarization. However, iloperidone had no effect on either hERG 1A or hERG 1A/3.1 channel trafficking to the cell membrane. CONCLUSIONS Our results indicated that iloperidone concentration-dependently inhibited hERG 1A/3.1 currents by preferentially interacting with the open states of channels, but not by the disruption of membrane trafficking or surface membrane expression of hERG 1A and hERG 1A/3.1 channel proteins.
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Affiliation(s)
- Hong Joon Lee
- Department of Physiology, College of Medicine, The Catholic University of Korea, Seoul
| | - Bok Hee Choi
- Department of Pharmacology, Institute for Medical Science, Jeonbuk National University Medical School, Jeonju
| | - Jin-Sung Choi
- College of Pharmacy, Integrated Research Institute of Pharmaceutical, The Catholic University of Korea, Bucheon, Korea
| | - Sang June Hahn
- Department of Physiology, College of Medicine, The Catholic University of Korea, Seoul
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Abashkin DA, Kurishev AO, Karpov DS, Golimbet VE. Cellular Models in Schizophrenia Research. Int J Mol Sci 2021; 22:ijms22168518. [PMID: 34445221 PMCID: PMC8395162 DOI: 10.3390/ijms22168518] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Revised: 08/04/2021] [Accepted: 08/05/2021] [Indexed: 12/11/2022] Open
Abstract
Schizophrenia (SZ) is a prevalent functional psychosis characterized by clinical behavioural symptoms and underlying abnormalities in brain function. Genome-wide association studies (GWAS) of schizophrenia have revealed many loci that do not directly identify processes disturbed in the disease. For this reason, the development of cellular models containing SZ-associated variations has become a focus in the post-GWAS research era. The application of revolutionary clustered regularly interspaced palindromic repeats CRISPR/Cas9 gene-editing tools, along with recently developed technologies for cultivating brain organoids in vitro, have opened new perspectives for the construction of these models. In general, cellular models are intended to unravel particular biological phenomena. They can provide the missing link between schizophrenia-related phenotypic features (such as transcriptional dysregulation, oxidative stress and synaptic dysregulation) and data from pathomorphological, electrophysiological and behavioural studies. The objectives of this review are the systematization and classification of cellular models of schizophrenia, based on their complexity and validity for understanding schizophrenia-related phenotypes.
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Affiliation(s)
- Dmitrii A. Abashkin
- Mental Health Research Center, Clinical Genetics Laboratory, Kashirskoe Sh. 34, 115522 Moscow, Russia; (D.A.A.); (A.O.K.); (D.S.K.)
| | - Artemii O. Kurishev
- Mental Health Research Center, Clinical Genetics Laboratory, Kashirskoe Sh. 34, 115522 Moscow, Russia; (D.A.A.); (A.O.K.); (D.S.K.)
| | - Dmitry S. Karpov
- Mental Health Research Center, Clinical Genetics Laboratory, Kashirskoe Sh. 34, 115522 Moscow, Russia; (D.A.A.); (A.O.K.); (D.S.K.)
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Vavilov Str. 32, 119991 Moscow, Russia
| | - Vera E. Golimbet
- Mental Health Research Center, Clinical Genetics Laboratory, Kashirskoe Sh. 34, 115522 Moscow, Russia; (D.A.A.); (A.O.K.); (D.S.K.)
- Correspondence:
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Dysregulated Glial Differentiation in Schizophrenia May Be Relieved by Suppression of SMAD4- and REST-Dependent Signaling. Cell Rep 2020; 27:3832-3843.e6. [PMID: 31242417 DOI: 10.1016/j.celrep.2019.05.088] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2018] [Revised: 04/04/2019] [Accepted: 05/22/2019] [Indexed: 12/22/2022] Open
Abstract
Astrocytic differentiation is developmentally impaired in patients with childhood-onset schizophrenia (SCZ). To determine why, we used genetic gain- and loss-of-function studies to establish the contributions of differentially expressed transcriptional regulators to the defective differentiation of glial progenitor cells (GPCs) produced from SCZ patient-derived induced pluripotent cells (iPSCs). Negative regulators of the bone morphogenetic protein (BMP) pathway were upregulated in SCZ GPCs, including BAMBI, FST, and GREM1, whose overexpression retained SCZ GPCs at the progenitor stage. SMAD4 knockdown (KD) suppressed the production of these BMP inhibitors by SCZ GPCs and rescued normal astrocytic differentiation. In addition, the BMP-regulated transcriptional repressor REST was upregulated in SCZ GPCs, and its KD similarly restored normal glial differentiation. REST KD also rescued potassium-transport-associated gene expression and K+ uptake, which were otherwise deficient in SCZ glia. These data suggest that the glial differentiation defect in childhood-onset SCZ, and its attendant disruption in K+ homeostasis, may be rescued by targeting BMP/SMAD4- and REST-dependent transcription.
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Fu SJ, Hu MC, Peng YJ, Fang HY, Hsiao CT, Chen TY, Jeng CJ, Tang CY. CUL4-DDB1-CRBN E3 Ubiquitin Ligase Regulates Proteostasis of ClC-2 Chloride Channels: Implication for Aldosteronism and Leukodystrophy. Cells 2020; 9:cells9061332. [PMID: 32466489 PMCID: PMC7348978 DOI: 10.3390/cells9061332] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2020] [Revised: 05/20/2020] [Accepted: 05/25/2020] [Indexed: 12/27/2022] Open
Abstract
Voltage-gated ClC-2 channels are essential for chloride homeostasis. Complete knockout of mouse ClC-2 leads to testicular degeneration and neuronal myelin vacuolation. Gain-of-function and loss-of-function mutations in the ClC-2-encoding human CLCN2 gene are linked to the genetic diseases aldosteronism and leukodystrophy, respectively. The protein homeostasis (proteostasis) mechanism of ClC-2 is currently unclear. Here, we aimed to identify the molecular mechanism of endoplasmic reticulum-associated degradation of ClC-2, and to explore the pathophysiological significance of disease-associated anomalous ClC-2 proteostasis. In both heterologous expression system and native neuronal and testicular cells, ClC-2 is subject to significant regulation by cullin-RING E3 ligase-mediated polyubiquitination and proteasomal degradation. The cullin 4 (CUL4)-damage-specific DNA binding protein 1 (DDB1)-cereblon (CRBN) E3 ubiquitin ligase co-exists in the same complex with and promotes the degradation of ClC-2 channels. The CRBN-targeting immunomodulatory drug lenalidomide and the cullin E3 ligase inhibitor MLN4924 promotes and attenuates, respectively, proteasomal degradation of ClC-2. Analyses of disease-related ClC-2 mutants reveal that aldosteronism and leukodystrophy are associated with opposite alterations in ClC-2 proteostasis. Modifying CUL4 E3 ligase activity with lenalidomide and MLN4924 ameliorates disease-associated ClC-2 proteostasis abnormality. Our results highlight the significant role and therapeutic potential of CUL4 E3 ubiquitin ligase in regulating ClC-2 proteostasis.
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Affiliation(s)
- Ssu-Ju Fu
- Department of Physiology, College of Medicine, National Taiwan University, Taipei 10051, Taiwan; (S.-J.F.); (M.-C.H.); (Y.-J.P.); (H.-Y.F.); (C.-T.H.)
| | - Meng-Chun Hu
- Department of Physiology, College of Medicine, National Taiwan University, Taipei 10051, Taiwan; (S.-J.F.); (M.-C.H.); (Y.-J.P.); (H.-Y.F.); (C.-T.H.)
| | - Yi-Jheng Peng
- Department of Physiology, College of Medicine, National Taiwan University, Taipei 10051, Taiwan; (S.-J.F.); (M.-C.H.); (Y.-J.P.); (H.-Y.F.); (C.-T.H.)
| | - Hsin-Yu Fang
- Department of Physiology, College of Medicine, National Taiwan University, Taipei 10051, Taiwan; (S.-J.F.); (M.-C.H.); (Y.-J.P.); (H.-Y.F.); (C.-T.H.)
| | - Cheng-Tsung Hsiao
- Department of Physiology, College of Medicine, National Taiwan University, Taipei 10051, Taiwan; (S.-J.F.); (M.-C.H.); (Y.-J.P.); (H.-Y.F.); (C.-T.H.)
- Department of Neurology, Taipei Veterans General Hospital, Taipei 12217, Taiwan
| | - Tsung-Yu Chen
- Center for Neuroscience and Department of Neurology, University of California, Davis, CA 95616, USA;
| | - Chung-Jiuan Jeng
- Institute of Anatomy and Cell Biology, School of Medicine, National Yang-Ming University, Taipei 12212, Taiwan
- Brain Research Center, National Yang-Ming University, Taipei 12212, Taiwan
- Correspondence: (C.-J.J.); (C.-Y.T.)
| | - Chih-Yung Tang
- Department of Physiology, College of Medicine, National Taiwan University, Taipei 10051, Taiwan; (S.-J.F.); (M.-C.H.); (Y.-J.P.); (H.-Y.F.); (C.-T.H.)
- Graduate Institute of Brain and Mind Sciences, College of Medicine, National Taiwan University, Taipei 10051, Taiwan
- Correspondence: (C.-J.J.); (C.-Y.T.)
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KCNH2-3.1 mediates aberrant complement activation and impaired hippocampal-medial prefrontal circuitry associated with working memory deficits. Mol Psychiatry 2020; 25:206-229. [PMID: 31570775 DOI: 10.1038/s41380-019-0530-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/16/2018] [Revised: 09/03/2019] [Accepted: 09/17/2019] [Indexed: 12/19/2022]
Abstract
Increased expression of the 3.1 isoform of the KCNH2 potassium channel has been associated with cognitive dysfunction and with schizophrenia, yet little is known about the underlying pathophysiological mechanisms. Here, by using in vivo wireless local field potential recordings during working memory processing, in vitro brain slice whole-cell patching recordings and in vivo stereotaxic hippocampal injection of AAV-encoded expression, we identified specific and delayed disruption of hippocampal-mPFC synaptic transmission and functional connectivity associated with reductions of SERPING1, CFH, and CD74 in the KCNH2-3.1 overexpression transgenic mice. The differentially expressed genes in mice are enriched in neurons and microglia, and reduced expression of these genes dysregulates the complement cascade, which has been previously linked to synaptic plasticity. We find that knockdown of these genes in primary neuronal-microglial cocultures from KCNH2-3.1 mice impairs synapse formation, and replenishing reduced CFH gene expression rescues KCNH2-3.1-induced impaired synaptogenesis. Translating to humans, we find analogous dysfunctional interactions between hippocampus and prefrontal cortex in coupling of the fMRI blood oxygen level-dependent (BOLD) signal during working memory in healthy subjects carrying alleles associated with increased KCNH2-3.1 expression in brain. Our data uncover a previously unrecognized role of the truncated KCNH2-3.1 potassium channel in mediating complement activation, which may explain its association with altered hippocampal-prefrontal connectivity and synaptic function. These results provide a potential molecular link between increased KCNH2-3.1 expression, synapse alterations, and hippocampal-prefrontal circuit abnormalities implicated in schizophrenia.
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Effects of cariprazine on hERG 1A and hERG 1A/3.1 potassium channels. Eur J Pharmacol 2019; 854:92-100. [DOI: 10.1016/j.ejphar.2019.04.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2018] [Revised: 04/01/2019] [Accepted: 04/02/2019] [Indexed: 12/28/2022]
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Bauer CK, Schwarz JR. Ether-à-go-go K + channels: effective modulators of neuronal excitability. J Physiol 2018; 596:769-783. [PMID: 29333676 DOI: 10.1113/jp275477] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2017] [Accepted: 12/18/2017] [Indexed: 12/22/2022] Open
Abstract
Mammalian ether-à-go-go (EAG) channels are voltage-gated K+ channels. They are encoded by the KCNH gene family and divided into three subfamilies, eag (Kv10), erg (eag-related gene; Kv11) and elk (eag-like; Kv12). All EAG channel subtypes are expressed in the brain where they effectively modulate neuronal excitability. This Topical Review describes the biophysical properties of each of the EAG channel subtypes, their function in neurons and the neurological diseases induced by EAG channel mutations. In contrast to the function of erg currents in the heart, where they contribute to repolarization of the cardiac action potential, erg currents in neurons are involved in the maintenance of the resting potential, setting of action potential threshold and frequency accommodation. They can even support high frequency firing by preventing a depolarization-induced Na+ channel block. EAG channels are modulated differentially, e.g. eag channels by intracellular Ca2+ , erg channels by extracellular K+ and GPCRs, and elk channels by changes in pH. So far, only currents mediated by erg channels have been recorded in neurons with the help of selective blockers. Neuronal eag and elk currents have not been isolated due to the lack of suitable channel blockers. However, findings in KO mice indicate a physiological role of eag1 currents in synaptic transmission and an involvement of elk2 currents in cognitive performance. Human eag1 and eag2 gain-of-function mutations underlie syndromes associated with epileptic seizures.
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Affiliation(s)
- Christiane K Bauer
- Department of Cellular and Integrative Physiology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Jürgen R Schwarz
- Institute of Molecular Neurogenetics, Center of Molecular Neurobiology Hamburg (ZMNH), University Medical Center Hamburg-Eppendorf, Hamburg, Germany
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Page SC, Hamersky GR, Gallo RA, Rannals MD, Calcaterra NE, Campbell MN, Mayfield B, Briley A, Phan BN, Jaffe AE, Maher BJ. The schizophrenia- and autism-associated gene, transcription factor 4 regulates the columnar distribution of layer 2/3 prefrontal pyramidal neurons in an activity-dependent manner. Mol Psychiatry 2018; 23:304-315. [PMID: 28289282 PMCID: PMC5599320 DOI: 10.1038/mp.2017.37] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/22/2016] [Revised: 01/05/2017] [Accepted: 01/26/2017] [Indexed: 01/18/2023]
Abstract
Disruption of the laminar and columnar organization of the brain is implicated in several psychiatric disorders. Here, we show in utero gain-of-function of the psychiatric risk gene transcription factor 4 (TCF4) severely disrupts the columnar organization of medial prefrontal cortex (mPFC) in a transcription- and activity-dependent manner. This morphological phenotype was rescued by co-expression of TCF4 plus calmodulin in a calcium-dependent manner and by dampening neuronal excitability through co-expression of an inwardly rectifying potassium channel (Kir2.1). For we believe the first time, we show that N-methyl-d-aspartate (NMDA) receptor-dependent Ca2+ transients are instructive to minicolumn organization because Crispr/Cas9-mediated mutation of NMDA receptors rescued TCF4-dependent morphological phenotypes. Furthermore, we demonstrate that the transcriptional regulation by the psychiatric risk gene TCF4 enhances NMDA receptor-dependent early network oscillations. Our novel findings indicate that TCF4-dependent transcription directs the proper formation of prefrontal cortical minicolumns by regulating the expression of genes involved in early spontaneous neuronal activity, and thus our results provides insights into potential pathophysiological mechanisms of TCF4-associated psychiatric disorders.
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Affiliation(s)
| | - Gregory R. Hamersky
- Lieber Institute for Brain Development, Johns Hopkins Medical Campus, Baltimore, MD
| | - Ryan A. Gallo
- Lieber Institute for Brain Development, Johns Hopkins Medical Campus, Baltimore, MD
| | - Matthew D. Rannals
- Lieber Institute for Brain Development, Johns Hopkins Medical Campus, Baltimore, MD
| | | | - Morganne N. Campbell
- Lieber Institute for Brain Development, Johns Hopkins Medical Campus, Baltimore, MD
| | - Brent Mayfield
- Lieber Institute for Brain Development, Johns Hopkins Medical Campus, Baltimore, MD
| | - Aaron Briley
- Lieber Institute for Brain Development, Johns Hopkins Medical Campus, Baltimore, MD
| | - BaDoi N. Phan
- Lieber Institute for Brain Development, Johns Hopkins Medical Campus, Baltimore, MD
| | - Andrew E. Jaffe
- Lieber Institute for Brain Development, Johns Hopkins Medical Campus, Baltimore, MD,Department of Biostatistics and Department of Mental Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD
| | - Brady J. Maher
- Lieber Institute for Brain Development, Johns Hopkins Medical Campus, Baltimore, MD,Department of Psychiatry and Behavioral Sciences and Department of Neuroscience, Johns Hopkins School of Medicine, Baltimore, MD,To Whom Correspondence Should Be Addressed: Brady J. Maher, Ph. D., Lieber Institute for Brain Development, 855 N. Wolfe Street, Suite 300, Baltimore, MD 21205, Telephone: 410-955-0865, Fax: 410-955-1044,
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Khademi E, Alehabib E, Shandiz EE, Ahmadifard A, Andarva M, Jamshidi J, Rahimi-Aliabadi S, Pouriran R, Nejad FR, Mansoori N, Shahmohammadibeni N, Taghavi S, Shokraeian P, Akhavan-Niaki H, Paisán-Ruiz C, Darvish H, Ohadi M. Support for "Disease-Only" Genotypes and Excess of Homozygosity at the CYTH4 Primate-Specific GTTT-Repeat in Schizophrenia. Genet Test Mol Biomarkers 2017; 21:485-490. [PMID: 28723299 DOI: 10.1089/gtmb.2016.0422] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
OBJECTIVE The role of short tandem repeats (STRs) in the control of gene expression among species is being increasingly understood following the identification of several instances in which certain STRs occur identically, or expand differentially, in primates versus nonprimates. These STRs may regulate genes that participate in characteristics that are associated with the divergence of primates from sibling orders (e.g., brain higher order functions). The CYTH4 gene contains the longest tetranucleotide STR in its core promoter, at 7-repeats, and links to the evolution of human and nonhuman primates. Allele and genotype distribution of this STR were studied in patients affected by schizophrenia (SCZ) and controls. METHODS High-resolution data were obtained on the allele and genotype distribution of the CYTH4 STR and a novel C > T single-nucleotide polymorphism (SNP) at its immediate upstream sequence in 255 patients with SCZ and 249 controls. Each sample was sequenced twice using the fluorescent dye termination method. RESULTS Novel alleles were detected at the long extreme of the GTTT-repeat, at 10- and 11-repeats, in the SCZ cases and controls. Excess of homozygosity was observed for the entire range of alleles across the GTTT-repeat and the C > T SNP in the SCZ patients in comparison with the controls (Yates corrected p < 0.011). Three genotypes consisting of the 11-repeat allele (i.e., 11/11, 10/11, and 7/11) were detected only in the SCZ patients (i.e., disease-only genotypes), and contributed to 2.3% of the SCZ genotypes (Mid p exact <0.007). The frequency of the 11-repeat allele was estimated at 0.02 and 0.006 in the SCZ patients and controls, respectively (Mid p exact <0.006). CONCLUSION This indicates that STR genotypes that are absent in the control group may be risk factors for SCZ. Future studies are warranted to test the significance of our findings.
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Affiliation(s)
- Ehteram Khademi
- 1 Cellular and Molecular Biology Research Center, Babol University of Medical Sciences , Babol, Iran
| | - Elham Alehabib
- 2 Department of Medical Genetics, Shahid Beheshti University of Medical Sciences , Tehran, Iran
| | - Ehsan Esmaili Shandiz
- 3 Department of Neurology, Ganjavian Hospital, Dezful University of Medical Sciences , Dezful, Iran
| | - Azadeh Ahmadifard
- 2 Department of Medical Genetics, Shahid Beheshti University of Medical Sciences , Tehran, Iran
| | - Monavvar Andarva
- 2 Department of Medical Genetics, Shahid Beheshti University of Medical Sciences , Tehran, Iran
| | - Javad Jamshidi
- 4 Noncommunicable Diseases Research Center, Fasa University of Medical Sciences , Fasa, Iran
| | - Simin Rahimi-Aliabadi
- 2 Department of Medical Genetics, Shahid Beheshti University of Medical Sciences , Tehran, Iran
| | - Ramin Pouriran
- 2 Department of Medical Genetics, Shahid Beheshti University of Medical Sciences , Tehran, Iran
| | - Farhad Ramezani Nejad
- 5 The Charitable Institute for Protecting of Social Victims (Saray-e-Ehsan) , Tehran, Iran
| | - Nader Mansoori
- 5 The Charitable Institute for Protecting of Social Victims (Saray-e-Ehsan) , Tehran, Iran
| | - Neda Shahmohammadibeni
- 1 Cellular and Molecular Biology Research Center, Babol University of Medical Sciences , Babol, Iran
| | - Shaghyegh Taghavi
- 2 Department of Medical Genetics, Shahid Beheshti University of Medical Sciences , Tehran, Iran
| | - Parasto Shokraeian
- 6 Tehran Medical Sciences Branch, Islamic Azad University , Tehran, Iran
| | - Haleh Akhavan-Niaki
- 1 Cellular and Molecular Biology Research Center, Babol University of Medical Sciences , Babol, Iran
| | - Coro Paisán-Ruiz
- 7 Departments of Neurology, Psychiatry and Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai , New York, New York.,8 Mindich Child Health and Development Institute, Icahn School of Medicine at Mount Sinai , New York, New York.,9 Friedman Brain Institute , Icahn School of Medicine at Mount Sinai, New York, New York
| | - Hossein Darvish
- 1 Cellular and Molecular Biology Research Center, Babol University of Medical Sciences , Babol, Iran .,2 Department of Medical Genetics, Shahid Beheshti University of Medical Sciences , Tehran, Iran
| | - Mina Ohadi
- 10 Iranian Research Center on Aging, University of Social Welfare and Rehabilitation Sciences , Tehran, Iran
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Huang CS, Wang GH, Tai CH, Hu CC, Yang YC. Antiarrhythmics cure brain arrhythmia: The imperativeness of subthalamic ERG K + channels in parkinsonian discharges. SCIENCE ADVANCES 2017; 3:e1602272. [PMID: 28508055 PMCID: PMC5425237 DOI: 10.1126/sciadv.1602272] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/18/2016] [Accepted: 03/15/2017] [Indexed: 06/07/2023]
Abstract
ERG K+ channels have long been known to play a crucial role in shaping cardiac action potentials and, thus, appropriate heart rhythms. The functional role of ERG channels in the central nervous system, however, remains elusive. We demonstrated that ERG channels exist in subthalamic neurons and have similar gating characteristics to those in the heart. ERG channels contribute crucially not only to the setting of membrane potential and, consequently, the firing modes, but also to the configuration of burst discharges and, consequently, the firing frequency and automaticity of the subthalamic neurons. Moreover, modulation of subthalamic discharges via ERG channels effectively modulates locomotor behaviors. ERG channel inhibitors ameliorate parkinsonian symptoms, whereas enhancers render normal animals hypokinetic. Thus, ERG K+ channels could be vital to the regulation of both cardiac and neuronal rhythms and may constitute an important pathophysiological basis and pharmacotherapeutic target for the growing list of neurological disorders related to "brain arrhythmias."
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Affiliation(s)
- Chen-Syuan Huang
- Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Tao-Yuan, Taiwan
- Department of Biomedical Sciences, College of Medicine, Chang Gung University, Tao-Yuan, Taiwan
| | - Guan-Hsun Wang
- Department of Biomedical Sciences, College of Medicine, Chang Gung University, Tao-Yuan, Taiwan
- School of Medicine, College of Medicine, Chang Gung University, Tao-Yuan, Taiwan
| | - Chun-Hwei Tai
- Department of Neurology, National Taiwan University Hospital, Taipei, Taiwan
| | - Chun-Chang Hu
- Department of Biomedical Sciences, College of Medicine, Chang Gung University, Tao-Yuan, Taiwan
| | - Ya-Chin Yang
- Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Tao-Yuan, Taiwan
- Department of Biomedical Sciences, College of Medicine, Chang Gung University, Tao-Yuan, Taiwan
- Neuroscience Research Center, Chang Gung Memorial Hospital, Linkou Medical Center, Tao-Yuan, Taiwan
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Inhibition of cloned hERG potassium channels by risperidone and paliperidone. Naunyn Schmiedebergs Arch Pharmacol 2017; 390:633-642. [DOI: 10.1007/s00210-017-1364-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2016] [Accepted: 02/24/2017] [Indexed: 12/31/2022]
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