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Wang X, Su Y, Yan H, Huang Z, Huang Y, Yue W. Association Study of KCNH7 Polymorphisms and Individual Responses to Risperidone Treatment in Schizophrenia. Front Psychiatry 2019; 10:633. [PMID: 31543842 PMCID: PMC6728906 DOI: 10.3389/fpsyt.2019.00633] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/03/2018] [Accepted: 08/06/2019] [Indexed: 12/31/2022] Open
Abstract
Risperidone has been used to treat the symptoms of schizophrenia and to reduce its relapse. However, the responses to treatment show great variability among patients. The potassium channel has been reported as an effective target for antipsychotics. KCNH7, a member of the voltage-gated K+ channel Kv11 family, is primarily expressed in the brain. Here, we assessed the genetic association of KCNH7 with risperidone responses in 393 schizophrenia patients. The patients were treated with risperidone for 6 weeks. The reduction rates of Positive and Negative Syndrome Scale (PANSS) scores were determined to quantify drug response. We also examined the associations between six single-nucleotide polymorphisms (SNPs) of KCNH7 and the risperidone responses for a total of 6 weeks. The SNP rs77699177 (C > T) in the KCNH7 gene intron was significantly associated with the treatment response reflected by the PANSS reduction rate (CC, 55.8 ± 23.0; TC, 70.9 ± 20.3, P = 0.000110), indicating that patients with the TC genotype have better efficacy for antipsychotic therapy. The rs2241240 SNP also showed a significant association with treatment responses after 6 weeks of treatment (P = 0.00256). The findings indicate that the voltage-gated K+ channel KCNH7 is a potential functional marker for the identification of the response to risperidone treatment in schizophrenia patients. Note: The study was registered under clinical trial number ChiCTR-RNC-09000522 (http://www.chictr.org/).
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Affiliation(s)
- Xueping Wang
- Peking University Sixth Hospital, Institute of Mental Health, Beijing, China.,NHC Key Laboratory of Mental Health, Peking University, Beijing, China.,National Clinical Research Center for Mental Disorders, Peking University Sixth Hospital, Beijing, China
| | - Yi Su
- Peking University Sixth Hospital, Institute of Mental Health, Beijing, China.,NHC Key Laboratory of Mental Health, Peking University, Beijing, China.,National Clinical Research Center for Mental Disorders, Peking University Sixth Hospital, Beijing, China
| | - Hao Yan
- Peking University Sixth Hospital, Institute of Mental Health, Beijing, China.,NHC Key Laboratory of Mental Health, Peking University, Beijing, China.,National Clinical Research Center for Mental Disorders, Peking University Sixth Hospital, Beijing, China
| | - Zhuo Huang
- State Key Laboratory of Natural and Biomimetic Drugs, Department of Molecular and Cellular Pharmacology, School of Pharmaceutical Sciences, Peking University Health Science Center, Beijing, China.,Key Laboratory for Neuroscience, Ministry of Education, Beijing, China
| | - Yu Huang
- National Engineering Research Center for Software Engineering, Peking University, Beijing, China
| | - Weihua Yue
- Peking University Sixth Hospital, Institute of Mental Health, Beijing, China.,NHC Key Laboratory of Mental Health, Peking University, Beijing, China.,National Clinical Research Center for Mental Disorders, Peking University Sixth Hospital, Beijing, China
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2
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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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3
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Balaraman Y, Lahiri DK, Nurnberger JI. Variants in Ion Channel Genes Link Phenotypic Features of Bipolar Illness to Specific Neurobiological Process Domains. MOLECULAR NEUROPSYCHIATRY 2015; 1:23-35. [PMID: 27602355 DOI: 10.1159/000371886] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/08/2014] [Accepted: 01/05/2015] [Indexed: 11/19/2022]
Abstract
Recent advances in genome-wide association studies are pointing towards a major role for voltage-gated ion channels in neuropsychiatric disorders and, in particular, bipolar disorder (BD). The phenotype of BD is complex, with symptoms during mood episodes and deficits persisting between episodes. We have tried to elucidate the common neurobiological mechanisms associated with ion channel signaling in order to provide a new perspective on the clinical symptoms and possible endophenotypes seen in BD patients. We propose a model in which the multiple variants in genes coding for ion channel proteins would perturb motivational circuits, synaptic plasticity, myelination, hypothalamic-pituitary-adrenal axis function, circadian neuronal rhythms, and energy regulation. These changes in neurobiological mechanisms would manifest in endophenotypes of aberrant reward processing, white matter hyperintensities, deficits in executive function, altered frontolimbic connectivity, increased amygdala activity, increased melatonin suppression, decreased REM latency, and aberrant myo-inositol/ATP shuttling. The endophenotypes result in behaviors of poor impulse control, motivational changes, cognitive deficits, abnormal stress response, sleep disturbances, and energy changes involving different neurobiological process domains. The hypothesis is that these disturbances start with altered neural circuitry during development, following which multiple environmental triggers may disrupt the neuronal excitability balance through an activity-dependent molecular process, resulting in clinical mood episodes.
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Affiliation(s)
- Yokesh Balaraman
- Institute of Psychiatric Research, Department of Psychiatry, Neuroscience Research Center, Indiana University School of Medicine, Indianapolis, Ind., USA
| | - Debomoy K Lahiri
- Institute of Psychiatric Research, Department of Psychiatry, Neuroscience Research Center, Indiana University School of Medicine, Indianapolis, Ind., USA
| | - John I Nurnberger
- Institute of Psychiatric Research, Department of Psychiatry, Neuroscience Research Center, Indiana University School of Medicine, Indianapolis, Ind., USA
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Strauss KA, Markx S, Georgi B, Paul SM, Jinks RN, Hoshi T, McDonald A, First MB, Liu W, Benkert AR, Heaps AD, Tian Y, Chakravarti A, Bucan M, Puffenberger EG. A population-based study of KCNH7 p.Arg394His and bipolar spectrum disorder. Hum Mol Genet 2014; 23:6395-406. [PMID: 24986916 PMCID: PMC4222358 DOI: 10.1093/hmg/ddu335] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
We conducted blinded psychiatric assessments of 26 Amish subjects (52 ± 11 years) from four families with prevalent bipolar spectrum disorder, identified 10 potentially pathogenic alleles by exome sequencing, tested association of these alleles with clinical diagnoses in the larger Amish Study of Major Affective Disorder (ASMAD) cohort, and studied mutant potassium channels in neurons. Fourteen of 26 Amish had bipolar spectrum disorder. The only candidate allele shared among them was rs78247304, a non-synonymous variant of KCNH7 (c.1181G>A, p.Arg394His). KCNH7 c.1181G>A and nine other potentially pathogenic variants were subsequently tested within the ASMAD cohort, which consisted of 340 subjects grouped into controls subjects and affected subjects from overlapping clinical categories (bipolar 1 disorder, bipolar spectrum disorder and any major affective disorder). KCNH7 c.1181G>A had the highest enrichment among individuals with bipolar spectrum disorder (χ2 = 7.3) and the strongest family-based association with bipolar 1 (P = 0.021), bipolar spectrum (P = 0.031) and any major affective disorder (P = 0.016). In vitro, the p.Arg394His substitution allowed normal expression, trafficking, assembly and localization of HERG3/Kv11.3 channels, but altered the steady-state voltage dependence and kinetics of activation in neuronal cells. Although our genome-wide statistical results do not alone prove association, cumulative evidence from multiple independent sources (parallel genome-wide study cohorts, pharmacological studies of HERG-type potassium channels, electrophysiological data) implicates neuronal HERG3/Kv11.3 potassium channels in the pathophysiology of bipolar spectrum disorder. Such a finding, if corroborated by future studies, has implications for mental health services among the Amish, as well as development of drugs that specifically target HERG3/Kv11.3.
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Affiliation(s)
- Kevin A Strauss
- Clinic for Special Children, Strasburg, PA, USA, Franklin & Marshall College, Lancaster, PA, USA, Lancaster General Hospital, Lancaster, PA, USA,
| | - Sander Markx
- Department of Psychiatry, Columbia University, New York, New York, USA
| | | | - Steven M Paul
- Departments of Neuroscience, Psychiatry and Pharmacology, Weill Cornell Medical College of Cornell University, New York, New York, USA
| | - Robert N Jinks
- Biological Foundations of Behavior Program, Franklin & Marshall College, Lancaster, PA, USA and
| | - Toshinori Hoshi
- Department of Physiology, University of Pennsylvania, Philadelphia, PA, USA
| | - Ann McDonald
- Department of Psychiatry, Columbia University, New York, New York, USA
| | - Michael B First
- Department of Psychiatry, Columbia University, New York, New York, USA
| | - Wencheng Liu
- Departments of Neuroscience, Psychiatry and Pharmacology, Weill Cornell Medical College of Cornell University, New York, New York, USA
| | - Abigail R Benkert
- Clinic for Special Children, Strasburg, PA, USA, Biological Foundations of Behavior Program, Franklin & Marshall College, Lancaster, PA, USA and
| | | | - Yutao Tian
- Department of Physiology, University of Pennsylvania, Philadelphia, PA, USA
| | - Aravinda Chakravarti
- Center for Complex Disease Genomics, McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Maja Bucan
- Department of Genetics, Perelman School of Medicine and
| | - Erik G Puffenberger
- Clinic for Special Children, Strasburg, PA, USA, Franklin & Marshall College, Lancaster, PA, USA
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Christensen RK, Petersen AV, Schmitt N, Perrier JF. Fast detection of extrasynaptic GABA with a whole-cell sniffer. Front Cell Neurosci 2014; 8:133. [PMID: 24860433 PMCID: PMC4030185 DOI: 10.3389/fncel.2014.00133] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2014] [Accepted: 04/28/2014] [Indexed: 11/16/2022] Open
Abstract
Gamma-amino-butyric acid (GABA) is the main inhibitory transmitter of the brain. It operates by binding to specific receptors located both inside and outside synapses. The extrasynaptic receptors are activated by spillover from GABAergic synapses and by ambient GABA in the extracellular space. Ambient GABA is essential for adjusting the excitability of neurons. However, due to the lack of suitable methods, little is known about its dynamics. Here we describe a new technique that allows detection of GABA transients and measurement of the steady state GABA concentration with high spatial and temporal resolution. We used a human embryonic kidney (HEK) cell line that stably expresses GABAA receptors composed of α1, β2, and γ2 subunits. We recorded from such a HEK cell with the whole-cell patch-clamp technique. The presence of GABA near the HEK cell generated a measurable electric current whose magnitude increased with concentration. A fraction of the current did not inactivate during prolonged exposition to GABA. This technique, which we refer to as a “sniffer” allows the measurement of ambient GABA concentration inside nervous tissue with a resolution of few tens of nanomolars. In addition, the sniffer detects variations in the extrasynaptic GABA concentration with millisecond time resolution. Pilot experiments demonstrate that the sniffer is able to report spillover of GABA induced by synaptic activation in real time. This is the first report on a GABA sensor that combines the ability to detect fast transients and to measure steady concentrations.
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Affiliation(s)
- Rasmus K Christensen
- Department of Neuroscience and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen Copenhagen, Denmark
| | - Anders V Petersen
- Department of Neuroscience and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen Copenhagen, Denmark
| | - Nicole Schmitt
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen Copenhagen, Denmark
| | - Jean-François Perrier
- Department of Neuroscience and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen Copenhagen, Denmark
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Bilet A, Bauer CK. Effects of the small molecule HERG activator NS1643 on Kv11.3 channels. PLoS One 2012; 7:e50886. [PMID: 23226420 PMCID: PMC3511382 DOI: 10.1371/journal.pone.0050886] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2012] [Accepted: 10/26/2012] [Indexed: 01/15/2023] Open
Abstract
NS1643 is one of the small molecule HERG (Kv11.1) channel activators and has also been found to increase erg2 (Kv11.2) currents. We now investigated whether NS1643 is also able to act as an activator of Kv11.3 (erg3) channels expressed in CHO cells. Activation of rat Kv11.3 current occurred in a dose-dependent manner and maximal current increasing effects were obtained with 10 µM NS1643. At this concentration, steady-state outward current increased by about 80% and the current increase was associated with a significant shift in the voltage dependence of activation to more negative potentials by about 15 mV. In addition, activation kinetics were accelerated, whereas deactivation was slowed. There was no significant effect on the kinetics of inactivation and recovery from inactivation. The strong current-activating agonistic effect of NS1643 did not result from a shift in the voltage dependence of Kv11.3 channel inactivation and was independent from external Na+ or Ca2+. At the higher concentration of 20 µM, NS1643 induced clearly less current increase. The left shift in the voltage dependence of activation reversed and the voltage sensitivity of activation dramatically decreased along with a slowing of Kv11.3 channel activation. These data show that, in comparison to other Kv11 family members, NS1643 exerts distinct effects on Kv11.3 channels with especially pronounced partial antagonistic effects at higher concentration.
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Affiliation(s)
- Arne Bilet
- Institute of Cellular and Integrative Physiology, University Medical Center Hamburg-Eppendorf (UKE), Hamburg, Germany
| | - Christiane K. Bauer
- Institute of Cellular and Integrative Physiology, University Medical Center Hamburg-Eppendorf (UKE), Hamburg, Germany
- * E-mail:
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Fano S, Çalışkan G, Heinemann U. Differential effects of blockade of ERG channels on gamma oscillations and excitability in rat hippocampal slices. Eur J Neurosci 2012; 36:3628-35. [DOI: 10.1111/ejn.12015] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2012] [Revised: 08/30/2012] [Accepted: 09/11/2012] [Indexed: 11/28/2022]
Affiliation(s)
- Silvia Fano
- Institute for Neurophysiology; Charité Universitätsmedizin Berlin; Berlin; Germany
| | - Gürsel Çalışkan
- Institute for Neurophysiology; Charité Universitätsmedizin Berlin; Berlin; Germany
| | - Uwe Heinemann
- Institute for Neurophysiology; Charité Universitätsmedizin Berlin; Berlin; Germany
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Atalar F, Acuner TT, Cine N, Oncu F, Yesilbursa D, Ozbek U, Turkcan S. Two four-marker haplotypes on 7q36.1 region indicate that the potassium channel gene HERG1 (KCNH2, Kv11.1) is related to schizophrenia: a case control study. Behav Brain Funct 2010; 6:27. [PMID: 20507645 PMCID: PMC2890623 DOI: 10.1186/1744-9081-6-27] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2009] [Accepted: 05/28/2010] [Indexed: 11/10/2022] Open
Abstract
Background The pathobiology of schizophrenia is still unclear. Its current treatment mainly depends on antipsychotic drugs. A leading adverse effect of these medications is the acquired long QT syndrome, which results from the blockade of cardiac HERG1 channels (human ether-a-go-go-related gene potassium channels 1) by antipsychotic agents. The HERG1 channel is encoded by HERG1 (KCNH2, Kv11.1) gene and is most highly expressed in heart and brain. Genetic variations in HERG1 predispose to acquired long QT syndrome. We hypothesized that the blockade of HERG1 channels by antipsychotics might also be significant for their therapeutic mode of action, indicating a novel mechanism in the pathogenesis of schizophrenia. Methods We genotyped four single nucleotide polymorphisms (SNPs) in 7q36.1 region (two SNPs, rs1805123 and rs3800779, located on HERG1, and two SNPs, rs885684 and rs956642, at the 3'-downstream intergenic region) and then performed single SNP and haplotype association analyses in 84 patients with schizophrenia and 74 healthy controls after the exclusion of individuals having prolonged or shortened QT interval on electrocardiogram. Results Our analyses revealed that both genotype and allele frequencies of rs3800779 (c.307+585G>T) were significantly different between populations (P = 0.023 and P = 0.018, respectively). We also identified that two previously undescribed four-marker haplotypes which are nearly allelic opposite of each other and located in chr7:150225599-150302147bp position encompassing HERG1 were either overrepresented (A-A-A-T, the at-risk haplotype, P = 0.0007) or underrepresented (C-A-C-G, the protective haplotype, P = 0.005) in patients compared to controls. Conclusions Our results indicate that the potassium channel gene HERG1 is related to schizophrenia. Our findings may also implicate the whole family of HERG channels (HERG1, HERG2 and HERG3) in the pathogenesis of psychosis and its treatment.
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Affiliation(s)
- Fatmahan Atalar
- Endocrinology Laboratory, Department of Growth, Development and Pediatric Endocrinology, Child Health Institute, Istanbul University, Istanbul, Turkey.
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Grunnet M. Repolarization of the cardiac action potential. Does an increase in repolarization capacity constitute a new anti-arrhythmic principle? Acta Physiol (Oxf) 2010; 198 Suppl 676:1-48. [PMID: 20132149 DOI: 10.1111/j.1748-1716.2009.02072.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The cardiac action potential can be divided into five distinct phases designated phases 0-4. The exact shape of the action potential comes about primarily as an orchestrated function of ion channels. The present review will give an overview of ion channels involved in generating the cardiac action potential with special emphasis on potassium channels involved in phase 3 repolarization. In humans, these channels are primarily K(v)11.1 (hERG1), K(v)7.1 (KCNQ1) and K(ir)2.1 (KCNJ2) being the responsible alpha-subunits for conducting I(Kr), I(Ks) and I(K1). An account will be given about molecular components, biophysical properties, regulation, interaction with other proteins and involvement in diseases. Both loss and gain of function of these currents are associated with different arrhythmogenic diseases. The second part of this review will therefore elucidate arrhythmias and subsequently focus on newly developed chemical entities having the ability to increase the activity of I(Kr), I(Ks) and I(K1). An evaluation will be given addressing the possibility that this novel class of compounds have the ability to constitute a new anti-arrhythmic principle. Experimental evidence from in vitro, ex vivo and in vivo settings will be included. Furthermore, conceptual differences between the short QT syndrome and I(Kr) activation will be accounted for.
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Affiliation(s)
- M Grunnet
- NeuroSearch A/S, Ballerup, and Danish National Research Foundation Centre for Cardiac Arrhythmia, University of Copenhagen, Denmark.
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