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Fallahi MS, Sahebekhtiari K, Hosseini H, Aliasin MM, Noroozi M, Moghadam Fard A, Aarabi MH, Gulisashvili D, Shafie M, Mayeli M. Distinct patterns of hippocampal subfield volumes predict coping strategies, emotion regulation, and impulsivity in healthy adults. Brain Imaging Behav 2024:10.1007/s11682-024-00904-8. [PMID: 39103671 DOI: 10.1007/s11682-024-00904-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/18/2024] [Indexed: 08/07/2024]
Abstract
BACKGROUND Recent studies have suggested that the hippocampus (HC) is involved in cognitive and behavioral functions beyond memory. We aimed to investigate how the volume of each subfield of the HC is associated with distinct patterns of coping strategies, emotion regulation, and impulsivity in a healthy population. METHODS We studied a total of 218 healthy subjects using the Leipzig mind-brain-body dataset. Participants were assessed for coping strategies, emotion regulation, and impulsivity using the Cognitive Emotion Regulation Questionnaire (CERQ), Coping Orientations to Problems Experienced (COPE), Impulsive Behavior Scale (UPPS), and Behavioral Activation and Inhibition System (BAS/BIS). The associations between HC subfield volumes including CA1, CA2/3, CA4/DG, SR-SL-SM, and subiculum, and behavioral scores were examined using multiple linear regression models adjusted for possible confounders, including age, sex, years of education, handedness, total intracranial volume (ICV), and HC volume. RESULTS The use of emotional support, venting, and positive reframing coping strategies were significantly and positively correlated with total, total right, and total left HC volumes. Venting was significantly associated with CA1 after adjusting for age, sex, handedness, and education (P=0.001, B = 0.265, P-FDR = 0.005). No significant association was observed between CERQ subscales and HC subfield volumes after controlling for confounders and multiple analyses. However, sensation-seeking subscale of the UPPS-P was positively correlated with total and right CA2-CA3 volumes after adjustments for age, sex, handedness, ICV, and HC volumes (P=0.002, B = 0.266, P-FDR = 0.035). BAS and BIS subscales did not show significant relationship with HC subfield volumes. CONCLUSION Patterns of HC subfields volumes are associated with coping strategies, impulsivity, and emotion regulation. In particular, using emotional support, positive reframing, venting, and sensation seeking are significantly associated with certain HC subfield volumes. These findings suggest that the hippocampus may play a crucial role in modulating emotional responses and behavioral adaptations, offering potential targets for therapeutic interventions.
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Affiliation(s)
- Mohammad Sadegh Fallahi
- NeuroTRACT International Association, Tehran, Iran
- School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Kianoosh Sahebekhtiari
- NeuroTRACT International Association, Tehran, Iran
- School of Medicine, Hamadan University of Medical Sciences, Hamadan, Iran
| | - Helia Hosseini
- NeuroTRACT International Association, Tehran, Iran
- School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Mohammad Mahdi Aliasin
- NeuroTRACT International Association, Tehran, Iran
- School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Masoud Noroozi
- NeuroTRACT International Association, Tehran, Iran
- Department of Biomedical Engineering, Tarbiat Modares University, Tehran, Iran
| | - Atousa Moghadam Fard
- NeuroTRACT International Association, Tehran, Iran
- School of Medicine, Iran University of Medical Sciences, Tehran, Iran
| | - Mohammad Hadi Aarabi
- Department of Neuroscience (DNS), University of Padova, Padua, Italy
- Padova Neuroscience Center, University of Padova, Padua, Italy
| | - David Gulisashvili
- Department of Diagnostic Radiology and Nuclear Medicine, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Mahan Shafie
- School of Medicine, Tehran University of Medical Sciences, Tehran, Iran.
| | - Mahsa Mayeli
- NeuroTRACT International Association, Tehran, Iran.
- Department of Diagnostic Radiology and Nuclear Medicine, University of Maryland School of Medicine, Baltimore, MD, USA.
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2
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Lyman KA, Han Y, Robinson AP, Weinberg SE, Fisher DW, Heuermann RJ, Lyman RE, Kim DK, Ludwig A, Chandel NS, Does MD, Miller SD, Chetkovich DM. Characterization of hyperpolarization-activated cyclic nucleotide-gated channels in oligodendrocytes. Front Cell Neurosci 2024; 18:1321682. [PMID: 38469353 PMCID: PMC10925711 DOI: 10.3389/fncel.2024.1321682] [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: 10/14/2023] [Accepted: 02/08/2024] [Indexed: 03/13/2024] Open
Abstract
Mature oligodendrocytes (OLG) are the myelin-forming cells of the central nervous system. Recent work has shown a dynamic role for these cells in the plasticity of neural circuits, leading to a renewed interest in voltage-sensitive currents in OLG. Hyperpolarization-activated cyclic nucleotide-gated (HCN) channels and their respective current (Ih) were recently identified in mature OLG and shown to play a role in regulating myelin length. Here we provide a biochemical and electrophysiological characterization of HCN channels in cells of the oligodendrocyte lineage. We observed that mice with a nonsense mutation in the Hcn2 gene (Hcn2ap/ap) have less white matter than their wild type counterparts with fewer OLG and fewer oligodendrocyte progenitor cells (OPCs). Hcn2ap/ap mice have severe motor impairments, although these deficits were not observed in mice with HCN2 conditionally eliminated only in oligodendrocytes (Cnpcre/+; Hcn2F/F). However, Cnpcre/+; Hcn2F/F mice develop motor impairments more rapidly in response to experimental autoimmune encephalomyelitis (EAE). We conclude that HCN2 channels in OLG may play a role in regulating metabolism.
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Affiliation(s)
- Kyle A. Lyman
- Department of Neurology, Massachusetts General Hospital, Boston, MA, United States
| | - Ye Han
- Department of Neurology, Vanderbilt University Medical Center, Nashville, TN, United States
| | - Andrew P. Robinson
- Department of Microbiology-Immunology and Interdepartmental Immunobiology Center, Northwestern University, Chicago, IL, United States
| | - Samuel E. Weinberg
- Department of Medicine, Northwestern University, Chicago, IL, United States
| | - Daniel W. Fisher
- Department of Psychiatry, University of Washington, Seattle, WA, United States
| | - Robert J. Heuermann
- Department of Neurology, Washington University, St. Louis, MO, United States
| | - Reagan E. Lyman
- Heritage College of Osteopathic Medicine, Ohio University, Dublin, OH, United States
| | - Dong Kyu Kim
- Department of Biomedical Engineering, Vanderbilt University, Nashville, TN, United States
- Vanderbilt University Institute of Imaging Science, Vanderbilt University, Nashville, TN, United States
- Department of Radiology and Radiological Sciences, Vanderbilt University School of Medicine, Nashville, TN, United States
- Department of Electrical Engineering, Vanderbilt University, Nashville, TN, United States
| | - Andreas Ludwig
- Institut fur Experimentelle und Klinische Pharmakologie und Toxikologie, Friedrich-Alexander-Universitat Erlangen-Nurnberg, Erlangen, Germany
| | - Navdeep S. Chandel
- Department of Medicine, Northwestern University, Chicago, IL, United States
| | - Mark D. Does
- Department of Biomedical Engineering, Vanderbilt University, Nashville, TN, United States
- Vanderbilt University Institute of Imaging Science, Vanderbilt University, Nashville, TN, United States
- Department of Radiology and Radiological Sciences, Vanderbilt University School of Medicine, Nashville, TN, United States
- Department of Electrical Engineering, Vanderbilt University, Nashville, TN, United States
| | - Stephen D. Miller
- Department of Microbiology-Immunology and Interdepartmental Immunobiology Center, Northwestern University, Chicago, IL, United States
| | - Dane M. Chetkovich
- Department of Neurology, Vanderbilt University Medical Center, Nashville, TN, United States
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3
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Mishra P, Narayanan R. The enigmatic HCN channels: A cellular neurophysiology perspective. Proteins 2023. [PMID: 37982354 DOI: 10.1002/prot.26643] [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: 08/03/2023] [Revised: 10/24/2023] [Accepted: 11/09/2023] [Indexed: 11/21/2023]
Abstract
What physiological role does a slow hyperpolarization-activated ion channel with mixed cation selectivity play in the fast world of neuronal action potentials that are driven by depolarization? That puzzling question has piqued the curiosity of physiology enthusiasts about the hyperpolarization-activated cyclic nucleotide-gated (HCN) channels, which are widely expressed across the body and especially in neurons. In this review, we emphasize the need to assess HCN channels from the perspective of how they respond to time-varying signals, while also accounting for their interactions with other co-expressing channels and receptors. First, we illustrate how the unique structural and functional characteristics of HCN channels allow them to mediate a slow negative feedback loop in the neurons that they express in. We present the several physiological implications of this negative feedback loop to neuronal response characteristics including neuronal gain, voltage sag and rebound, temporal summation, membrane potential resonance, inductive phase lead, spike triggered average, and coincidence detection. Next, we argue that the overall impact of HCN channels on neuronal physiology critically relies on their interactions with other co-expressing channels and receptors. Interactions with other channels allow HCN channels to mediate intrinsic oscillations, earning them the "pacemaker channel" moniker, and to regulate spike frequency adaptation, plateau potentials, neurotransmitter release from presynaptic terminals, and spike initiation at the axonal initial segment. We also explore the impact of spatially non-homogeneous subcellular distributions of HCN channels in different neuronal subtypes and their interactions with other channels and receptors. Finally, we discuss how plasticity in HCN channels is widely prevalent and can mediate different encoding, homeostatic, and neuroprotective functions in a neuron. In summary, we argue that HCN channels form an important class of channels that mediate a diversity of neuronal functions owing to their unique gating kinetics that made them a puzzle in the first place.
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Affiliation(s)
- Poonam Mishra
- Department of Neuroscience, Yale School of Medicine, Yale University, New Haven, Connecticut, USA
| | - Rishikesh Narayanan
- Cellular Neurophysiology Laboratory, Molecular Biophysics Unit, Indian Institute of Science, Bangalore, India
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4
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Kraeuter AK. The use of integrated behavioural z-scoring in behavioural neuroscience - A perspective article. J Neurosci Methods 2023; 384:109751. [PMID: 36435327 DOI: 10.1016/j.jneumeth.2022.109751] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2022] [Revised: 11/16/2022] [Accepted: 11/22/2022] [Indexed: 11/24/2022]
Abstract
Complex pathophysiology in psychiatric disorders results in difficulties interpreting pre-clinical data. Guilloux et al. (2011b), proposed an integrated behavioural z-scoring procedure to improve the predictive validity of animal models by converging evidence similarly used to diagnose mental health conditions in humans. Here, I set out to give a brief review of the current methodology and literature using integrated behavioural z-scoring. Secondly, I will discuss the benefits and downfalls of integrated behavioural z-scoring and its potential future applications. Integrated behavioural z-scoring is a methodology used most frequently within animal models of depression and anxiety. Here, I am suggesting broadening the application of integrated behavioural z-scoring beyond the field of depression and anxiety to a three-step methodology to obtain disease-specific behavioural z-scores (i.e Schizophrenia index, Alzheimer's disease index) to aid translatability and interpretation of data. Lastly, I suggest integrating not only behaviour but also biological variables to create converging psychological and physiological evidence to sustain face and construct validity, while improving predict validity.
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Affiliation(s)
- Ann-Katrin Kraeuter
- Faculty of Health and Life Sciences, Psychology, Northumbria University, Newcastle upon Tyne, UK.
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5
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Petković A, Chaudhury D. Encore: Behavioural animal models of stress, depression and mood disorders. Front Behav Neurosci 2022; 16:931964. [PMID: 36004305 PMCID: PMC9395206 DOI: 10.3389/fnbeh.2022.931964] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Accepted: 06/28/2022] [Indexed: 11/17/2022] Open
Abstract
Animal studies over the past two decades have led to extensive advances in our understanding of pathogenesis of depressive and mood disorders. Among these, rodent behavioural models proved to be of highest informative value. Here, we present a comprehensive overview of the most popular behavioural models with respect to physiological, circuit, and molecular biological correlates. Behavioural stress paradigms and behavioural tests are assessed in terms of outcomes, strengths, weaknesses, and translational value, especially in the domain of pharmacological studies.
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Affiliation(s)
| | - Dipesh Chaudhury
- Laboratory of Neural Systems and Behaviour, Department of Biology, New York University Abu Dhabi, Abu Dhabi, United Arab Emirates
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6
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Han Y, Iyamu ID, Clutter MR, Mishra RK, Lyman KA, Zhou C, Michailidis I, Xia MY, Sharma H, Luan CH, Schiltz GE, Chetkovich DM. Discovery of a small-molecule inhibitor of the TRIP8b-HCN interaction with efficacy in neurons. J Biol Chem 2022; 298:102069. [PMID: 35623388 PMCID: PMC9243175 DOI: 10.1016/j.jbc.2022.102069] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2022] [Revised: 05/17/2022] [Accepted: 05/22/2022] [Indexed: 10/27/2022] Open
Abstract
Major depressive disorder is a critical public health problem with a lifetime prevalence of nearly 17% in the United States. One potential therapeutic target is the interaction between hyperpolarization-activated cyclic nucleotide-gated (HCN) channels and an auxiliary subunit of the channel named tetratricopeptide repeat-containing Rab8b-interacting protein (TRIP8b). HCN channels regulate neuronal excitability in the mammalian hippocampus, and recent work has established that antagonizing HCN function rescues cognitive impairment caused by chronic stress. Here, we utilize a high-throughput virtual screen to find small molecules capable of disrupting the TRIP8b-HCN interaction. We found that the hit compound NUCC-0200590 disrupts the TRIP8b-HCN interaction in vitro and in vivo. These results provide a compelling strategy for developing new small molecules capable of disrupting the TRIP8b-HCN interaction.
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Affiliation(s)
- Ye Han
- Department of Neurology, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Iredia D Iyamu
- Center for Molecular Innovation and Drug Discovery, Northwestern University, Evanston, Illinois, USA
| | - Matthew R Clutter
- High Throughput Analysis Laboratory and Department of Molecular Biosciences, Northwestern University, Evanston, Illinois, USA
| | - Rama K Mishra
- Department of Biochemistry and Molecular Genetics, Northwestern University, Chicago, Illinois, USA
| | - Kyle A Lyman
- Department of Neurology, Stanford University, Palo Alto, California, USA
| | - Chengwen Zhou
- Department of Neurology, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Ioannis Michailidis
- Department of Neurology, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Maya Y Xia
- Department of Neurology, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Horrick Sharma
- Center for Molecular Innovation and Drug Discovery, Northwestern University, Evanston, Illinois, USA
| | - Chi-Hao Luan
- High Throughput Analysis Laboratory and Department of Molecular Biosciences, Northwestern University, Evanston, Illinois, USA; Robert H. Lurie Comprehensive Cancer Center, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
| | - Gary E Schiltz
- Robert H. Lurie Comprehensive Cancer Center, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA; Department of Pharmacology, Northwestern University, Chicago, Illinois, USA; Department of Chemistry, Northwestern University, Evanston, Illinois, USA.
| | - Dane M Chetkovich
- Department of Neurology, Vanderbilt University Medical Center, Nashville, Tennessee, USA.
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7
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Peters CH, Singh RK, Bankston JR, Proenza C. Regulation of HCN Channels by Protein Interactions. Front Physiol 2022; 13:928507. [PMID: 35795651 PMCID: PMC9251338 DOI: 10.3389/fphys.2022.928507] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Accepted: 06/01/2022] [Indexed: 11/30/2022] Open
Abstract
Hyperpolarization-activated, cyclic nucleotide-sensitive (HCN) channels are key regulators of subthreshold membrane potentials in excitable cells. The four mammalian HCN channel isoforms, HCN1-HCN4, are expressed throughout the body, where they contribute to diverse physiological processes including cardiac pacemaking, sleep-wakefulness cycles, memory, and somatic sensation. While all HCN channel isoforms produce currents when expressed by themselves, an emerging list of interacting proteins shape HCN channel excitability to influence the physiologically relevant output. The best studied of these regulatory proteins is the auxiliary subunit, TRIP8b, which binds to multiple sites in the C-terminus of the HCN channels to regulate expression and disrupt cAMP binding to fine-tune neuronal HCN channel excitability. Less is known about the mechanisms of action of other HCN channel interaction partners like filamin A, Src tyrosine kinase, and MinK-related peptides, which have a range of effects on HCN channel gating and expression. More recently, the inositol trisphosphate receptor-associated cGMP-kinase substrates IRAG1 and LRMP (also known as IRAG2), were discovered as specific regulators of the HCN4 isoform. This review summarizes the known protein interaction partners of HCN channels and their mechanisms of action and identifies gaps in our knowledge.
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Affiliation(s)
- Colin H. Peters
- Department of Physiology and Biophysics, University of Colorado Anschutz Medical Campus, Aurora, CO, United States
| | - Rohit K. Singh
- Department of Physiology and Biophysics, University of Colorado Anschutz Medical Campus, Aurora, CO, United States
| | - John R. Bankston
- Department of Physiology and Biophysics, University of Colorado Anschutz Medical Campus, Aurora, CO, United States
| | - Catherine Proenza
- Department of Physiology and Biophysics, University of Colorado Anschutz Medical Campus, Aurora, CO, United States
- Department of Cardiology, University of Colorado Anschutz Medical Campus, Aurora, CO, United States
- *Correspondence: Catherine Proenza,
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8
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Lyman KA, Han Y, Zhou C, Renteria I, Besing GL, Kurz JE, Chetkovich DM. Hippocampal cAMP regulates HCN channel function on two time scales with differential effects on animal behavior. Sci Transl Med 2021; 13:eabl4580. [PMID: 34818058 DOI: 10.1126/scitranslmed.abl4580] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
[Figure: see text].
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Affiliation(s)
- Kyle A Lyman
- Department of Neurology, Northwestern University Feinberg School of Medicine, 303 E. Chicago Ave., Chicago, IL 60611, USA.,Department of Neurology, Vanderbilt University Medical Center, 1161 21st Avenue South, Nashville, TN 37232, USA.,Department of Neurology, Stanford University, 453 Quarry Road, Palo Alto, CA 94304, USA
| | - Ye Han
- Department of Neurology, Vanderbilt University Medical Center, 1161 21st Avenue South, Nashville, TN 37232, USA
| | - Chengwen Zhou
- Department of Neurology, Vanderbilt University Medical Center, 1161 21st Avenue South, Nashville, TN 37232, USA
| | - Isabelle Renteria
- Department of Neurology, Vanderbilt University Medical Center, 1161 21st Avenue South, Nashville, TN 37232, USA
| | - Gai-Linn Besing
- Department of Neurology, Vanderbilt University Medical Center, 1161 21st Avenue South, Nashville, TN 37232, USA
| | - Jonathan E Kurz
- Department of Pediatrics, Northwestern University Feinberg School of Medicine, 225 E. Chicago Ave., Chicago, IL 60611, USA
| | - Dane M Chetkovich
- Department of Neurology, Vanderbilt University Medical Center, 1161 21st Avenue South, Nashville, TN 37232, USA
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9
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Dwivedi D, Bhalla US. Physiology and Therapeutic Potential of SK, H, and M Medium AfterHyperPolarization Ion Channels. Front Mol Neurosci 2021; 14:658435. [PMID: 34149352 PMCID: PMC8209339 DOI: 10.3389/fnmol.2021.658435] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Accepted: 04/13/2021] [Indexed: 12/19/2022] Open
Abstract
SK, HCN, and M channels are medium afterhyperpolarization (mAHP)-mediating ion channels. The three channels co-express in various brain regions, and their collective action strongly influences cellular excitability. However, significant diversity exists in the expression of channel isoforms in distinct brain regions and various subcellular compartments, which contributes to an equally diverse set of specific neuronal functions. The current review emphasizes the collective behavior of the three classes of mAHP channels and discusses how these channels function together although they play specialized roles. We discuss the biophysical properties of these channels, signaling pathways that influence the activity of the three mAHP channels, various chemical modulators that alter channel activity and their therapeutic potential in treating various neurological anomalies. Additionally, we discuss the role of mAHP channels in the pathophysiology of various neurological diseases and how their modulation can alleviate some of the symptoms.
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Affiliation(s)
- Deepanjali Dwivedi
- National Centre for Biological Sciences, Tata Institute of Fundamental Research, GKVK Campus, Bengaluru, India.,Department of Neurobiology, Harvard Medical School, Boston, MA, United States.,Stanley Center at the Broad, Cambridge, MA, United States
| | - Upinder S Bhalla
- National Centre for Biological Sciences, Tata Institute of Fundamental Research, GKVK Campus, Bengaluru, India
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10
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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: 19] [Impact Index Per Article: 4.8] [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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11
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Foote KM, Lyman KA, Han Y, Michailidis IE, Heuermann RJ, Mandikian D, Trimmer JS, Swanson GT, Chetkovich DM. Phosphorylation of the HCN channel auxiliary subunit TRIP8b is altered in an animal model of temporal lobe epilepsy and modulates channel function. J Biol Chem 2019; 294:15743-15758. [PMID: 31492750 DOI: 10.1074/jbc.ra119.010027] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2019] [Revised: 08/30/2019] [Indexed: 12/14/2022] Open
Abstract
Temporal lobe epilepsy (TLE) is a prevalent neurological disorder with many patients experiencing poor seizure control with existing anti-epileptic drugs. Thus, novel insights into the mechanisms of epileptogenesis and identification of new drug targets can be transformative. Changes in ion channel function have been shown to play a role in generating the aberrant neuronal activity observed in TLE. Previous work demonstrates that hyperpolarization-activated cyclic nucleotide-gated (HCN) channels regulate neuronal excitability and are mislocalized within CA1 pyramidal cells in a rodent model of TLE. The subcellular distribution of HCN channels is regulated by an auxiliary subunit, tetratricopeptide repeat-containing Rab8b-interacting protein (TRIP8b), and disruption of this interaction correlates with channel mislocalization. However, the molecular mechanisms responsible for HCN channel dysregulation in TLE are unclear. Here we investigated whether changes in TRIP8b phosphorylation are sufficient to alter HCN channel function. We identified a phosphorylation site at residue Ser237 of TRIP8b that enhances binding to HCN channels and influences channel gating by altering the affinity of TRIP8b for the HCN cytoplasmic domain. Using a phosphospecific antibody, we demonstrate that TRIP8b phosphorylated at Ser237 is enriched in CA1 distal dendrites and that phosphorylation is reduced in the kainic acid model of TLE. Overall, our findings indicate that the TRIP8b-HCN interaction can be modulated by changes in phosphorylation and suggest that loss of TRIP8b phosphorylation may affect HCN channel properties during epileptogenesis. These results highlight the potential of drugs targeting posttranslational modifications to restore TRIP8b phosphorylation to reduce excitability in TLE.
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Affiliation(s)
- Kendall M Foote
- Davee Department of Neurology and Clinical Neurosciences, Northwestern University, Chicago, Illinois 60611.,Department of Pharmacology, Northwestern University, Chicago, Illinois 60611.,Vanderbilt University Medical Center Department of Neurology, Nashville, Tennessee 37232
| | - Kyle A Lyman
- Davee Department of Neurology and Clinical Neurosciences, Northwestern University, Chicago, Illinois 60611.,Vanderbilt University Medical Center Department of Neurology, Nashville, Tennessee 37232.,Department of Medicine, Stanford University, Palo Alto, California 94305
| | - Ye Han
- Davee Department of Neurology and Clinical Neurosciences, Northwestern University, Chicago, Illinois 60611.,Vanderbilt University Medical Center Department of Neurology, Nashville, Tennessee 37232
| | - Ioannis E Michailidis
- Vanderbilt University Medical Center Department of Neurology, Nashville, Tennessee 37232
| | - Robert J Heuermann
- Department of Neurology, Washington University School of Medicine, St. Louis, Missouri 63110
| | - Danielle Mandikian
- Department of Neurobiology, Physiology, and Behavior, University of California, Davis, California 95616
| | - James S Trimmer
- Department of Neurobiology, Physiology, and Behavior, University of California, Davis, California 95616.,Department of Physiology and Membrane Biology, University of California, Davis, California 95616
| | - Geoffrey T Swanson
- Department of Pharmacology, Northwestern University, Chicago, Illinois 60611.,Department of Neurobiology, Northwestern University, Evanston, Illinois 60208
| | - Dane M Chetkovich
- Vanderbilt University Medical Center Department of Neurology, Nashville, Tennessee 37232
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12
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Abstract
Using a short peptide to regulate the activity of HCN ion channels illustrates how physiological modulators could inspire new drugs.
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Affiliation(s)
- Catherine Proenza
- Department of Physiology and Biophysics, University of Colorado Anschutz Medical Campus, Aurora, United States.,Department of Medicine, Division of Cardiology, University of Colorado Anschutz Medical Campus, Aurora, United States
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