1
|
Simmons SC, Flerlage WJ, Langlois LD, Shepard RD, Bouslog C, Thomas EH, Gouty KM, Sanderson JL, Gouty S, Cox BM, Dell'Acqua ML, Nugent FS. AKAP150-anchored PKA regulates synaptic transmission and plasticity, neuronal excitability and CRF neuromodulation in the mouse lateral habenula. Commun Biol 2024; 7:345. [PMID: 38509283 PMCID: PMC10954712 DOI: 10.1038/s42003-024-06041-8] [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: 12/06/2023] [Accepted: 03/08/2024] [Indexed: 03/22/2024] Open
Abstract
The scaffolding A-kinase anchoring protein 150 (AKAP150) is critically involved in kinase and phosphatase regulation of synaptic transmission/plasticity, and neuronal excitability. Emerging evidence also suggests that AKAP150 signaling may play a key role in brain's processing of rewarding/aversive experiences, however its role in the lateral habenula (LHb, as an important brain reward circuitry) is completely unknown. Using whole cell patch clamp recordings in LHb of male wildtype and ΔPKA knockin mice (with deficiency in AKAP-anchoring of PKA), here we show that the genetic disruption of PKA anchoring to AKAP150 significantly reduces AMPA receptor-mediated glutamatergic transmission and prevents the induction of presynaptic endocannabinoid-mediated long-term depression in LHb neurons. Moreover, ΔPKA mutation potentiates GABAA receptor-mediated inhibitory transmission while increasing LHb intrinsic excitability through suppression of medium afterhyperpolarizations. ΔPKA mutation-induced suppression of medium afterhyperpolarizations also blunts the synaptic and neuroexcitatory actions of the stress neuromodulator, corticotropin releasing factor (CRF), in mouse LHb. Altogether, our data suggest that AKAP150 complex signaling plays a critical role in regulation of AMPA and GABAA receptor synaptic strength, glutamatergic plasticity and CRF neuromodulation possibly through AMPA receptor and potassium channel trafficking and endocannabinoid signaling within the LHb.
Collapse
Affiliation(s)
- Sarah C Simmons
- Uniformed Services University of the Health Sciences, Department of Pharmacology and Molecular Therapeutics, Bethesda, MD, 20814, USA
| | - William J Flerlage
- Uniformed Services University of the Health Sciences, Department of Pharmacology and Molecular Therapeutics, Bethesda, MD, 20814, USA
| | - Ludovic D Langlois
- Uniformed Services University of the Health Sciences, Department of Pharmacology and Molecular Therapeutics, Bethesda, MD, 20814, USA
| | - Ryan D Shepard
- Uniformed Services University of the Health Sciences, Department of Pharmacology and Molecular Therapeutics, Bethesda, MD, 20814, USA
| | - Christopher Bouslog
- Uniformed Services University of the Health Sciences, Department of Pharmacology and Molecular Therapeutics, Bethesda, MD, 20814, USA
| | - Emily H Thomas
- Uniformed Services University of the Health Sciences, Department of Pharmacology and Molecular Therapeutics, Bethesda, MD, 20814, USA
| | - Kaitlyn M Gouty
- Uniformed Services University of the Health Sciences, Department of Pharmacology and Molecular Therapeutics, Bethesda, MD, 20814, USA
| | - Jennifer L Sanderson
- Department of Pharmacology, University of Colorado School of Medicine, Anschutz Medical Campus, Aurora, CO, 80045, USA
| | - Shawn Gouty
- Uniformed Services University of the Health Sciences, Department of Pharmacology and Molecular Therapeutics, Bethesda, MD, 20814, USA
| | - Brian M Cox
- Uniformed Services University of the Health Sciences, Department of Pharmacology and Molecular Therapeutics, Bethesda, MD, 20814, USA
| | - Mark L Dell'Acqua
- Department of Pharmacology, University of Colorado School of Medicine, Anschutz Medical Campus, Aurora, CO, 80045, USA.
| | - Fereshteh S Nugent
- Uniformed Services University of the Health Sciences, Department of Pharmacology and Molecular Therapeutics, Bethesda, MD, 20814, USA.
| |
Collapse
|
2
|
Holguin-Cruz JA, Bui JM, Jha A, Na D, Gsponer J. Widespread alteration of protein autoinhibition in human cancers. Cell Syst 2024; 15:246-263.e7. [PMID: 38366601 DOI: 10.1016/j.cels.2024.01.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Revised: 06/20/2023] [Accepted: 01/26/2024] [Indexed: 02/18/2024]
Abstract
Autoinhibition is a prevalent allosteric regulatory mechanism in signaling proteins. Reduced autoinhibition underlies the tumorigenic effect of some known cancer drivers, but whether autoinhibition is altered generally in cancer remains elusive. Here, we demonstrate that cancer-associated missense mutations, in-frame insertions/deletions, and fusion breakpoints are enriched within inhibitory allosteric switches (IASs) across all cancer types. Selection for IASs that are recurrently mutated in cancers identifies established and unknown cancer drivers. Recurrent missense mutations in IASs of these drivers are associated with distinct, cancer-specific changes in molecular signaling. For the specific case of PPP3CA, the catalytic subunit of calcineurin, we provide insights into the molecular mechanisms of altered autoinhibition by cancer mutations using biomolecular simulations, and demonstrate that such mutations are associated with transcriptome changes consistent with increased calcineurin signaling. Our integrative study shows that autoinhibition-modulating genetic alterations are positively selected for by cancer cells.
Collapse
Affiliation(s)
- Jorge A Holguin-Cruz
- Michael Smith Laboratories, University of British Columbia, Vancouver, BC V6T 1Z4, Canada; Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - Jennifer M Bui
- Michael Smith Laboratories, University of British Columbia, Vancouver, BC V6T 1Z4, Canada; Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - Ashwani Jha
- Michael Smith Laboratories, University of British Columbia, Vancouver, BC V6T 1Z4, Canada; Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - Dokyun Na
- School of Integrative Engineering, Chung-Ang University, 84 Heukseok-ro, Dongjak-gu, Seoul 156-756, Republic of Korea
| | - Jörg Gsponer
- Michael Smith Laboratories, University of British Columbia, Vancouver, BC V6T 1Z4, Canada; Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, BC V6T 1Z4, Canada.
| |
Collapse
|
3
|
Martinez TP, Larsen ME, Sullivan E, Woolfrey KM, Dell’Acqua ML. Amyloid-β-induced dendritic spine elimination requires Ca 2+-permeable AMPA receptors, AKAP-Calcineurin-NFAT signaling, and the NFAT target gene Mdm2. eNeuro 2024; 11:ENEURO.0175-23.2024. [PMID: 38331575 PMCID: PMC10925900 DOI: 10.1523/eneuro.0175-23.2024] [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: 05/25/2023] [Revised: 01/26/2024] [Accepted: 02/01/2024] [Indexed: 02/10/2024] Open
Abstract
Alzheimer's Disease (AD) is associated with brain accumulation of synaptotoxic amyloid-β (Aβ) peptides produced by the proteolytic processing of amyloid precursor protein (APP). Cognitive impairments associated with AD correlate with dendritic spine and excitatory synapse loss, particularly within the hippocampus. In rodents, soluble Aβ oligomers impair hippocampus-dependent learning and memory, promote dendritic spine loss, inhibit NMDA-type glutamate receptor (NMDAR)-dependent long-term potentiation (LTP), and promote synaptic depression (LTD), at least in part through activation of the Ca2+-CaM-dependent phosphatase calcineurin (CaN). Yet, questions remain regarding Aβ-dependent postsynaptic CaN signaling specifically at the synapse to mediate its synaptotoxicity. Here, we use pharmacologic and genetic approaches to demonstrate a role for postsynaptic signaling via A kinase-anchoring protein 150 (AKAP150)-scaffolded CaN in mediating Aβ-induced dendritic spine loss in hippocampal neurons from rats and mice of both sexes. In particular, we found that Ca2+-permeable AMPA-type glutamate receptors (CP-AMPARs), which were previously shown to signal through AKAP-anchored CaN to promote both LTD and Aβ-dependent inhibition of LTP, are also required upstream of AKAP-CaN signaling to mediate spine loss via overexpression of APP containing multiple mutations linked to familial, early-onset AD and increased Aβ production. In addition, we found that the CaN-dependent nuclear factor of activated T-cells (NFAT) transcription factors are required downstream to promote Aβ-mediated dendritic spine loss. Finally, we identified the E3-ubiquitin ligase Mdm2, which was previously linked to LTD and developmental synapse elimination, as a downstream NFAT target gene upregulated by Aβ whose enzymatic activity is required for Aβ-mediated spine loss.Significance Statement Impaired hippocampal function and synapse loss are hallmarks of AD linked to Aβ oligomers. Aβ exposure acutely blocks hippocampal LTP and enhances LTD and chronically leads to dendritic spine synapse loss. In particular, Aβ hijacks normal plasticity mechanisms, biasing them toward synapse weakening/elimination, with previous studies broadly linking CaN phosphatase signaling to this synaptic dysfunction. However, we do not understand how Aβ engages signaling specifically at synapses. Here we elucidate a synapse-to-nucleus signaling pathway coordinated by the postsynaptic scaffold protein AKAP150 that is activated by Ca2+ influx through CP-AMPARs and transduced to nucleus by CaN-NFAT signaling to transcriptionally upregulate the E3-ubiquitin ligase Mdm2 that is required for Aβ-mediated spine loss. These findings identify Mdm2 as potential therapeutic target for AD.
Collapse
Affiliation(s)
- Tyler P. Martinez
- Pharmacology PhD Program, University of Colorado Anschutz Medical Campus, Aurora, Colorado 80045
- Department of Pharmacology, University of Colorado Anschutz Medical Campus, Aurora, Colorado 80045
- Linda Crnic Institute for Down Syndrome, University of Colorado Anschutz Medical Campus, Aurora, Colorado 80045
| | - Matthew E. Larsen
- Department of Pharmacology, University of Colorado Anschutz Medical Campus, Aurora, Colorado 80045
- Neuroscience PhD Program, University of Colorado Anschutz Medical Campus, Aurora, Colorado 80045
| | - Emily Sullivan
- Department of Pharmacology, University of Colorado Anschutz Medical Campus, Aurora, Colorado 80045
| | - Kevin M. Woolfrey
- Department of Pharmacology, University of Colorado Anschutz Medical Campus, Aurora, Colorado 80045
| | - Mark L. Dell’Acqua
- Department of Pharmacology, University of Colorado Anschutz Medical Campus, Aurora, Colorado 80045
- Linda Crnic Institute for Down Syndrome, University of Colorado Anschutz Medical Campus, Aurora, Colorado 80045
- Neurotechnology Center, University of Colorado Anschutz Medical Campus, Aurora, Colorado 80045
- Alzheimer’s and Cognition Center, University of Colorado Anschutz Medical Campus, Aurora, Colorado 80045
| |
Collapse
|
4
|
Bothe MS, Kohl T, Felmy F, Gallant J, Chagnaud BP. Timing and precision of rattlesnake spinal motoneurons are determined by the KV7 2/3 potassium channel. Curr Biol 2024; 34:286-297.e5. [PMID: 38157862 DOI: 10.1016/j.cub.2023.11.062] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2023] [Revised: 10/11/2023] [Accepted: 11/29/2023] [Indexed: 01/03/2024]
Abstract
The evolution of novel motor behaviors requires modifications in the central pattern generators (CPGs) controlling muscle activity. How such changes gradually lead to novel behaviors remains enigmatic due to the long time course of evolution. Rattlesnakes provide a unique opportunity to investigate how a locomotor CPG was evolutionarily modified to generate a novel behavior-in this case, acoustic signaling. We show that motoneurons (MNs) in the body and tail spinal cord of rattlesnakes possess fundamentally different physiological characteristics, which allow MNs in the tail to integrate and transmit CPG output for controlling superfast muscles with high temporal precision. Using patch-clamp electrophysiology, we demonstrate that these differences in locomotor and rattle MNs are mainly determined by KV72/3 potassium channels. However, although KV72/3 exerted a significantly different influence on locomotor and rattle MN physiology, single-cell RNA-seq unexpectedly did not reveal any differences in KV72/3 channels' expression. VIDEO ABSTRACT.
Collapse
Affiliation(s)
| | - Tobias Kohl
- TUM School of Life Science, Technical University of Munich, 85354 Munich, Germany
| | - Felix Felmy
- Institute of Zoology, University of Veterinary Medicine Hannover, 30559 Hannover, Germany
| | - Jason Gallant
- Department of Integrative Biology, Michigan State University, East Lansing, MI 48824, USA
| | - Boris P Chagnaud
- Institute of Biology, University of Graz, 8010 Graz, Austria; Department of Biology II, Ludwig-Maximilians-University Munich, 82152 Planegg-Martinsried, Germany
| |
Collapse
|
5
|
Simmons S, Flerlage W, Langlois L, Shepard R, Bouslog C, Thomas E, Gouty K, Sanderson J, Gouty S, Cox B, Dell’Acqua M, Nugent F. AKAP150-anchored PKA regulation of synaptic transmission and plasticity, neuronal excitability and CRF neuromodulation in the lateral habenula. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.12.06.570160. [PMID: 38106086 PMCID: PMC10723374 DOI: 10.1101/2023.12.06.570160] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2023]
Abstract
Numerous studies of hippocampal synaptic function in learning and memory have established the functional significance of the scaffolding A-kinase anchoring protein 150 (AKAP150) in kinase and phosphatase regulation of synaptic receptor and ion channel trafficking/function and hence synaptic transmission/plasticity, and neuronal excitability. Emerging evidence also suggests that AKAP150 signaling may play a critical role in brain's processing of rewarding/aversive experiences. Here we focused on an unexplored role of AKAP150 in the lateral habenula (LHb), a diencephalic brain region that integrates and relays negative reward signals from forebrain striatal and limbic structures to midbrain monoaminergic centers. LHb aberrant activity (specifically hyperactivity) is also linked to depression. Using whole cell patch clamp recordings in LHb of male wildtype (WT) and ΔPKA knockin mice (with deficiency in AKAP-anchoring of PKA), we found that the genetic disruption of PKA anchoring to AKAP150 significantly reduced AMPA receptor (AMPAR)-mediated glutamatergic transmission and prevented the induction of presynaptic endocannabinoid (eCB)-mediated long-term depression (LTD) in LHb neurons. Moreover, ΔPKA mutation potentiated GABAA receptor (GABAAR)-mediated inhibitory transmission postsynaptically while increasing LHb intrinsic neuronal excitability through suppression of medium afterhyperpolarizations (mAHPs). Given that LHb is a highly stress-responsive brain region, we further tested the effects of corticotropin releasing factor (CRF) stress neuromodulator on synaptic transmission and intrinsic excitability of LHb neurons in WT and ΔPKA mice. As in our earlier study in rat LHb, CRF significantly suppressed GABAergic transmission onto LHb neurons and increased intrinsic excitability by diminishing small-conductance potassium (SK) channel-mediated mAHPs. ΔPKA mutation-induced suppression of mAHPs also blunted the synaptic and neuroexcitatory actions of CRF in mouse LHb. Altogether, our data suggest that AKAP150 complex signaling plays a critical role in regulation of AMPAR and GABAAR synaptic strength, glutamatergic plasticity and CRF neuromodulation possibly through AMPAR and potassium channel trafficking and eCB signaling within the LHb.
Collapse
Affiliation(s)
- S.C. Simmons
- Uniformed Services University of the Health Sciences, Department of Pharmacology, Bethesda, Maryland 20814, USA
| | - W.J. Flerlage
- Uniformed Services University of the Health Sciences, Department of Pharmacology, Bethesda, Maryland 20814, USA
| | - L.D. Langlois
- Uniformed Services University of the Health Sciences, Department of Pharmacology, Bethesda, Maryland 20814, USA
| | - R.D. Shepard
- Uniformed Services University of the Health Sciences, Department of Pharmacology, Bethesda, Maryland 20814, USA
| | - C. Bouslog
- Uniformed Services University of the Health Sciences, Department of Pharmacology, Bethesda, Maryland 20814, USA
| | - E.H. Thomas
- Uniformed Services University of the Health Sciences, Department of Pharmacology, Bethesda, Maryland 20814, USA
| | - K.M. Gouty
- Uniformed Services University of the Health Sciences, Department of Pharmacology, Bethesda, Maryland 20814, USA
| | - J.L. Sanderson
- Department of Pharmacology, University of Colorado School of Medicine, Anschutz Medical Campus, Aurora, CO 80045, USA
| | - S. Gouty
- Uniformed Services University of the Health Sciences, Department of Pharmacology, Bethesda, Maryland 20814, USA
| | - B.M. Cox
- Uniformed Services University of the Health Sciences, Department of Pharmacology, Bethesda, Maryland 20814, USA
| | - M.L. Dell’Acqua
- Department of Pharmacology, University of Colorado School of Medicine, Anschutz Medical Campus, Aurora, CO 80045, USA
| | - F.S. Nugent
- Uniformed Services University of the Health Sciences, Department of Pharmacology, Bethesda, Maryland 20814, USA
| |
Collapse
|
6
|
Puhl CJ, Wefelmeyer W, Burrone J. Cholinergic Stimulation Modulates the Functional Composition of CA3 Cell Types in the Hippocampus. J Neurosci 2023; 43:4972-4983. [PMID: 37277177 PMCID: PMC10324996 DOI: 10.1523/jneurosci.0966-22.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2022] [Revised: 03/03/2023] [Accepted: 03/07/2023] [Indexed: 06/07/2023] Open
Abstract
The functional heterogeneity of hippocampal CA3 pyramidal neurons has emerged as a key aspect of circuit function. Here, we explored the effects of long-term cholinergic activity on the functional heterogeneity of CA3 pyramidal neurons in organotypic slices obtained from male rat brains. Application of agonists to either AChRs generally, or mAChRs specifically, induced robust increases in network activity in the low-gamma range. Prolonged AChR stimulation for 48 h uncovered a population of hyperadapting CA3 pyramidal neurons that typically fired a single, early action potential in response to current injection. Although these neurons were present in control networks, their proportions were dramatically increased following long-term cholinergic activity. Characterized by the presence of a strong M-current, the hyperadaptation phenotype was abolished by acute application of either M-channel antagonists or the reapplication of AChR agonists. We conclude that long-term mAChR activation modulates the intrinsic excitability of a subset of CA3 pyramidal cells, uncovering a highly plastic cohort of neurons that are sensitive to chronic ACh modulation. Our findings provide evidence for the activity-dependent plasticity of functional heterogeneity in the hippocampus.SIGNIFICANCE STATEMENT The large heterogeneity of neuron types in the brain, each with its own specific functional properties, provides the rich cellular tapestry needed to account for the vast diversity of behaviors. By studying the functional properties of neurons in the hippocampus, a region of the brain involved in learning and memory, we find that exposure to the neuromodulator acetylcholine can alter the relative number of functionally defined neuron types. Our findings suggest that the heterogeneity of neurons in the brain is not a static feature but can be modified by the ongoing activity of the circuits to which they belong.
Collapse
Affiliation(s)
- Christopher Jon Puhl
- Centre for Developmental Neurobiology, Kings College London, New Hunts House, Guys Hospital Campus, London, SE1 1UL, United Kingdom
- MRC Centre for Neurodevelopmental Disorders, Kings College London, New Hunts House, Guys Hospital Campus, London, SE1 1UL, United Kingdom
| | - Winnie Wefelmeyer
- Centre for Developmental Neurobiology, Kings College London, New Hunts House, Guys Hospital Campus, London, SE1 1UL, United Kingdom
- MRC Centre for Neurodevelopmental Disorders, Kings College London, New Hunts House, Guys Hospital Campus, London, SE1 1UL, United Kingdom
| | - Juan Burrone
- Centre for Developmental Neurobiology, Kings College London, New Hunts House, Guys Hospital Campus, London, SE1 1UL, United Kingdom
- MRC Centre for Neurodevelopmental Disorders, Kings College London, New Hunts House, Guys Hospital Campus, London, SE1 1UL, United Kingdom
| |
Collapse
|
7
|
Garrido JJ. Contribution of Axon Initial Segment Structure and Channels to Brain Pathology. Cells 2023; 12:cells12081210. [PMID: 37190119 DOI: 10.3390/cells12081210] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2023] [Revised: 04/17/2023] [Accepted: 04/20/2023] [Indexed: 05/17/2023] Open
Abstract
Brain channelopathies are a group of neurological disorders that result from genetic mutations affecting ion channels in the brain. Ion channels are specialized proteins that play a crucial role in the electrical activity of nerve cells by controlling the flow of ions such as sodium, potassium, and calcium. When these channels are not functioning properly, they can cause a wide range of neurological symptoms such as seizures, movement disorders, and cognitive impairment. In this context, the axon initial segment (AIS) is the site of action potential initiation in most neurons. This region is characterized by a high density of voltage-gated sodium channels (VGSCs), which are responsible for the rapid depolarization that occurs when the neuron is stimulated. The AIS is also enriched in other ion channels, such as potassium channels, that play a role in shaping the action potential waveform and determining the firing frequency of the neuron. In addition to ion channels, the AIS contains a complex cytoskeletal structure that helps to anchor the channels in place and regulate their function. Therefore, alterations in this complex structure of ion channels, scaffold proteins, and specialized cytoskeleton may also cause brain channelopathies not necessarily associated with ion channel mutations. This review will focus on how the AISs structure, plasticity, and composition alterations may generate changes in action potentials and neuronal dysfunction leading to brain diseases. AIS function alterations may be the consequence of voltage-gated ion channel mutations, but also may be due to ligand-activated channels and receptors and AIS structural and membrane proteins that support the function of voltage-gated ion channels.
Collapse
Affiliation(s)
- Juan José Garrido
- Instituto Cajal, CSIC, 28002 Madrid, Spain
- Alzheimer's Disease and Other Degenerative Dementias, Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas (CIBERNED), 28002 Madrid, Spain
| |
Collapse
|
8
|
Paclitaxel Inhibits KCNQ Channels in Primary Sensory Neurons to Initiate the Development of Painful Peripheral Neuropathy. Cells 2022; 11:cells11244067. [PMID: 36552832 PMCID: PMC9776748 DOI: 10.3390/cells11244067] [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: 11/29/2022] [Revised: 12/11/2022] [Accepted: 12/13/2022] [Indexed: 12/23/2022] Open
Abstract
Cancer patients undergoing paclitaxel infusion usually experience peripheral nerve degeneration and serious neuropathic pain termed paclitaxel-induced peripheral neuropathy (PIPN). However, alterations in the dose or treatment schedule for paclitaxel do not eliminate PIPN, and no therapies are available for PIPN, despite numerous studies to uncover the mechanisms underlying the development/maintenance of this condition. Therefore, we aimed to uncover a novel mechanism underlying the pathogenesis of PIPN. Clinical studies suggest that acute over excitation of primary sensory neurons is linked to the pathogenesis of PIPN. We found that paclitaxel-induced acute hyperexcitability of primary sensory neurons results from the paclitaxel-induced inhibition of KCNQ potassium channels (mainly KCNQ2), found abundantly in sensory neurons and axons. We found that repeated application of XE-991, a specific KCNQ channel blocker, induced PIPN-like alterations in rats, including mechanical hypersensitivity and degeneration of peripheral nerves, as detected by both morphological and behavioral assays. In contrast, genetic deletion of KCNQ2 from peripheral sensory neurons in mice significantly attenuated the development of paclitaxel-induced peripheral sensory fiber degeneration and chronic pain. These findings may lead to a better understanding of the causes of PIPN and provide an impetus for developing new classes of KCNQ activators for its therapeutic treatment.
Collapse
|
9
|
Bar L, Shalom L, Lezmy J, Peretz A, Attali B. Excitatory and inhibitory hippocampal neurons differ in their homeostatic adaptation to chronic M-channel modulation. Front Mol Neurosci 2022; 15:972023. [PMID: 36311018 PMCID: PMC9614320 DOI: 10.3389/fnmol.2022.972023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2022] [Accepted: 09/27/2022] [Indexed: 12/03/2022] Open
Abstract
A large body of studies has investigated bidirectional homeostatic plasticity both in vitro and in vivo using numerous pharmacological manipulations of activity or behavioral paradigms. However, these experiments rarely explored in the same cellular system the bidirectionality of the plasticity and simultaneously on excitatory and inhibitory neurons. M-channels are voltage-gated potassium channels that play a crucial role in regulating neuronal excitability and plasticity. In cultured hippocampal excitatory neurons, we previously showed that chronic exposure to the M-channel blocker XE991 leads to adaptative compensations, thereby triggering at different timescales intrinsic and synaptic homeostatic plasticity. This plastic adaptation barely occurs in hippocampal inhibitory neurons. In this study, we examined whether this homeostatic plasticity induced by M-channel inhibition was bidirectional by investigating the acute and chronic effects of the M-channel opener retigabine on hippocampal neuronal excitability. Acute retigabine exposure decreased excitability in both excitatory and inhibitory neurons. Chronic retigabine treatment triggered in excitatory neurons homeostatic adaptation of the threshold current and spontaneous firing rate at a time scale of 4–24 h. These plastic changes were accompanied by a substantial decrease in the M-current density and by a small, though significant, proximal relocation of Kv7.3-FGF14 segment along the axon initial segment. Thus, bidirectional homeostatic changes were observed in excitatory neurons though not symmetric in kinetics and mechanisms. Contrastingly, in inhibitory neurons, the compensatory changes in intrinsic excitability barely occurred after 48 h, while no homeostatic normalization of the spontaneous firing rate was observed. Our results indicate that excitatory and inhibitory hippocampal neurons differ in their adaptation to chronic alterations in neuronal excitability induced by M-channel bidirectional modulation.
Collapse
|
10
|
Ketamine exerts its sustained antidepressant effects via cell-type-specific regulation of Kcnq2. Neuron 2022; 110:2283-2298.e9. [PMID: 35649415 DOI: 10.1016/j.neuron.2022.05.001] [Citation(s) in RCA: 37] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Revised: 03/01/2022] [Accepted: 05/02/2022] [Indexed: 12/20/2022]
Abstract
A single sub-anesthetic dose of ketamine produces a rapid and sustained antidepressant response, yet the molecular mechanisms responsible for this remain unclear. Here, we identified cell-type-specific transcriptional signatures associated with a sustained ketamine response in mice. Most interestingly, we identified the Kcnq2 gene as an important downstream regulator of ketamine action in glutamatergic neurons of the ventral hippocampus. We validated these findings through a series of complementary molecular, electrophysiological, cellular, pharmacological, behavioral, and functional experiments. We demonstrated that adjunctive treatment with retigabine, a KCNQ activator, augments ketamine's antidepressant-like effects in mice. Intriguingly, these effects are ketamine specific, as they do not modulate a response to classical antidepressants, such as escitalopram. These findings significantly advance our understanding of the mechanisms underlying the sustained antidepressant effects of ketamine, with important clinical implications.
Collapse
|
11
|
Costi S, Han MH, Murrough JW. The Potential of KCNQ Potassium Channel Openers as Novel Antidepressants. CNS Drugs 2022; 36:207-216. [PMID: 35258812 DOI: 10.1007/s40263-021-00885-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 11/28/2021] [Indexed: 12/12/2022]
Abstract
Major depressive disorder (MDD) is a leading cause of disability worldwide and less than one-third of patients with MDD achieve stable remission of symptoms, despite currently available treatments. Although MDD represents a serious health problem, a complete understanding of the neurobiological mechanisms underlying this condition continues to be elusive. Accumulating evidence from preclinical and animal studies provides support for the antidepressant potential of modulators of KCNQ voltage-gated potassium (K+) channels. KCNQ K+ channels, through regulation of neuronal excitability and activity, contribute to neurophysiological mechanisms underlying stress resilience, and represent potential targets of drug discovery for depression. The present article focuses on the pharmacology and efficacy of KCNQ2/3 K+ channel openers as novel therapeutic agents for depressive disorders from initial studies conducted on animal models showing depressive-like behaviors to recent work in humans that examines the potential for KCNQ2/3 channel modulators as novel antidepressants. Data from preclinical work suggest that KCNQ-type K+ channels are an active mediator of stress resilience and KCNQ2/3 K+ channel openers show antidepressant efficacy. Similarly, evidence from clinical trials conducted in patients with MDD using the KCNQ2/3 channel opener ezogabine (retigabine) showed significant improvements in depressive symptoms and anhedonia. Overall, KCNQ channel openers appear a promising target for the development of novel therapeutics for the treatment of psychiatric disorders and specifically for MDD.
Collapse
Affiliation(s)
- Sara Costi
- Depression and Anxiety Center for Discovery and Treatment, Department of Psychiatry, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, Box 1230, New York, NY, 10029, USA
| | - Ming-Hu Han
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, USA.,Nash Family Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, USA.,Center for Affective Neuroscience, Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, USA.,Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA.,Department of Mental Health and Public Health, Faculty of Life and Health Sciences, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
| | - James W Murrough
- Depression and Anxiety Center for Discovery and Treatment, Department of Psychiatry, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, Box 1230, New York, NY, 10029, USA. .,Nash Family Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, USA. .,Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA.
| |
Collapse
|
12
|
Church TW, Tewatia P, Hannan S, Antunes J, Eriksson O, Smart TG, Hellgren Kotaleski J, Gold MG. AKAP79 enables calcineurin to directly suppress protein kinase A activity. eLife 2021; 10:e68164. [PMID: 34612814 PMCID: PMC8560092 DOI: 10.7554/elife.68164] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2021] [Accepted: 10/04/2021] [Indexed: 12/28/2022] Open
Abstract
Interplay between the second messengers cAMP and Ca2+ is a hallmark of dynamic cellular processes. A common motif is the opposition of the Ca2+-sensitive phosphatase calcineurin and the major cAMP receptor, protein kinase A (PKA). Calcineurin dephosphorylates sites primed by PKA to bring about changes including synaptic long-term depression (LTD). AKAP79 supports signaling of this type by anchoring PKA and calcineurin in tandem. In this study, we discovered that AKAP79 increases the rate of calcineurin dephosphorylation of type II PKA regulatory subunits by an order of magnitude. Fluorescent PKA activity reporter assays, supported by kinetic modeling, show how AKAP79-enhanced calcineurin activity enables suppression of PKA without altering cAMP levels by increasing PKA catalytic subunit capture rate. Experiments with hippocampal neurons indicate that this mechanism contributes toward LTD. This non-canonical mode of PKA regulation may underlie many other cellular processes.
Collapse
Affiliation(s)
- Timothy W Church
- Department of Neuroscience, Physiology & Pharmacology, University College LondonLondonUnited Kingdom
| | - Parul Tewatia
- Science for Life Laboratory, School of Electrical Engineering and Computer Science, KTH Royal Institute of TechnologyStockholmSweden
- Department of Neuroscience, Karolinska InstituteStockholmSweden
| | - Saad Hannan
- Department of Neuroscience, Physiology & Pharmacology, University College LondonLondonUnited Kingdom
| | - João Antunes
- Science for Life Laboratory, School of Electrical Engineering and Computer Science, KTH Royal Institute of TechnologyStockholmSweden
| | - Olivia Eriksson
- Science for Life Laboratory, School of Electrical Engineering and Computer Science, KTH Royal Institute of TechnologyStockholmSweden
| | - Trevor G Smart
- Department of Neuroscience, Physiology & Pharmacology, University College LondonLondonUnited Kingdom
| | - Jeanette Hellgren Kotaleski
- Science for Life Laboratory, School of Electrical Engineering and Computer Science, KTH Royal Institute of TechnologyStockholmSweden
- Department of Neuroscience, Karolinska InstituteStockholmSweden
| | - Matthew G Gold
- Department of Neuroscience, Physiology & Pharmacology, University College LondonLondonUnited Kingdom
| |
Collapse
|
13
|
Eadaim A, Hahm ET, Justice ED, Tsunoda S. Cholinergic Synaptic Homeostasis Is Tuned by an NFAT-Mediated α7 nAChR-K v4/Shal Coupled Regulatory System. Cell Rep 2021; 32:108119. [PMID: 32905767 PMCID: PMC7521586 DOI: 10.1016/j.celrep.2020.108119] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2019] [Revised: 06/23/2020] [Accepted: 08/17/2020] [Indexed: 11/26/2022] Open
Abstract
Homeostatic synaptic plasticity (HSP) involves compensatory mechanisms employed by neurons and circuits to preserve signaling when confronted with global changes in activity that may occur during physiological and pathological conditions. Cholinergic neurons, which are especially affected in some pathologies, have recently been shown to exhibit HSP mediated by nicotinic acetylcholine receptors (nAChRs). In Drosophila central neurons, pharmacological blockade of activity induces a homeostatic response mediated by the Drosophila α7 (Dα7) nAChR, which is tuned by a subsequent increase in expression of the voltage-dependent Kv4/Shal channel. Here, we show that an in vivo reduction of cholinergic signaling induces HSP mediated by Dα7 nAChRs, and this upregulation of Dα7 itself is sufficient to trigger transcriptional activation, mediated by nuclear factor of activated T cells (NFAT), of the Kv4/Shal gene, revealing a receptor-ion channel system coupled for homeostatic tuning in cholinergic neurons. Eadaim et al. show that in vivo reduction of cholinergic signaling in Drosophila neurons induces synaptic homeostasis mediated by Dα7 nAChRs. This upregulation of Dα7 induces Kv4/Shal gene expression mediated by nuclear factor of activated T cells (NFAT), revealing a receptor-ion channel system coupled for homeostatic tuning in cholinergic neurons.
Collapse
Affiliation(s)
- Abdunaser Eadaim
- Department of Biomedical Sciences, Colorado State University, Fort Collins, CO 80523, USA
| | - Eu-Teum Hahm
- Department of Biomedical Sciences, Colorado State University, Fort Collins, CO 80523, USA
| | - Elizabeth D Justice
- Department of Biomedical Sciences, Colorado State University, Fort Collins, CO 80523, USA
| | - Susan Tsunoda
- Department of Biomedical Sciences, Colorado State University, Fort Collins, CO 80523, USA.
| |
Collapse
|
14
|
Zhang J, Zhang C, Chen X, Wang B, Ma W, Yang Y, Zheng R, Huang Z. PKA-RIIβ autophosphorylation modulates PKA activity and seizure phenotypes in mice. Commun Biol 2021; 4:263. [PMID: 33649504 PMCID: PMC7921646 DOI: 10.1038/s42003-021-01748-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Accepted: 12/22/2020] [Indexed: 11/20/2022] Open
Abstract
Temporal lobe epilepsy (TLE) is one of the most common and intractable neurological disorders in adults. Dysfunctional PKA signaling is causally linked to the TLE. However, the mechanism underlying PKA involves in epileptogenesis is still poorly understood. In the present study, we found the autophosphorylation level at serine 114 site (serine 112 site in mice) of PKA-RIIβ subunit was robustly decreased in the epileptic foci obtained from both surgical specimens of TLE patients and seizure model mice. The p-RIIβ level was negatively correlated with the activities of PKA. Notably, by using a P-site mutant that cannot be autophosphorylated and thus results in the released catalytic subunit to exert persistent phosphorylation, an increase in PKA activities through transduction with AAV-RIIβ-S112A in hippocampal DG granule cells decreased mIPSC frequency but not mEPSC, enhanced neuronal intrinsic excitability and seizure susceptibility. In contrast, a reduction of PKA activities by RIIβ knockout led to an increased mIPSC frequency, a reduction in neuronal excitability, and mice less prone to experimental seizure onset. Collectively, our data demonstrated that the autophosphorylation of RIIβ subunit plays a critical role in controlling neuronal and network excitabilities by regulating the activities of PKA, providing a potential therapeutic target for TLE.
Collapse
Affiliation(s)
- Jingliang Zhang
- 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
| | - Chenyu Zhang
- Department of Anatomy, Histology and Embryology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, China
| | - Xiaoling Chen
- 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
| | - Bingwei Wang
- Department of Anatomy, Histology and Embryology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, China
| | - Weining Ma
- Department of Neurology, Shengjing Hospital Affiliated to China Medical University, Shenyang, China
| | - Yang Yang
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University College of Pharmacy, West Lafayette, IN, USA
| | - Ruimao Zheng
- Department of Anatomy, Histology and Embryology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, China.
- Neuroscience Research Institute, Peking University, Beijing, China.
- Key Laboratory for Neuroscience, Ministry of Education, Beijing, China.
- Key Laboratory for Neuroscience of National Health Commission, 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.
- Key Laboratory for Neuroscience of National Health Commission, Beijing, China.
| |
Collapse
|
15
|
Abstract
Kv7.1-Kv7.5 (KCNQ1-5) K+ channels are voltage-gated K+ channels with major roles in neurons, muscle cells and epithelia where they underlie physiologically important K+ currents, such as neuronal M current and cardiac IKs. Specific biophysical properties of Kv7 channels make them particularly well placed to control the activity of excitable cells. Indeed, these channels often work as 'excitability breaks' and are targeted by various hormones and modulators to regulate cellular activity outputs. Genetic deficiencies in all five KCNQ genes result in human excitability disorders, including epilepsy, arrhythmias, deafness and some others. Not surprisingly, this channel family attracts considerable attention as potential drug targets. Here we will review biophysical properties and tissue expression profile of Kv7 channels, discuss recent advances in the understanding of their structure as well as their role in various neurological, cardiovascular and other diseases and pathologies. We will also consider a scope for therapeutic targeting of Kv7 channels for treatment of the above health conditions.
Collapse
|
16
|
Ca v1.2 Activity and Downstream Signaling Pathways in the Hippocampus of An Animal Model of Depression. Cells 2020; 9:cells9122609. [PMID: 33291797 PMCID: PMC7762021 DOI: 10.3390/cells9122609] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2020] [Revised: 09/20/2020] [Accepted: 10/01/2020] [Indexed: 11/21/2022] Open
Abstract
Functional and morphological modifications in the brain caused by major mood disorders involve many brain areas, including the hippocampus, leading to cognitive and mood alterations. Cav1.2 channel expression has been found to increase in animals with depressive-like behaviors. Calcium influx through these channels is associated with changes in excitation-transcriptional coupling by several intracellular signal pathways that are regulated by its C-terminus region. However, which of these signaling pathways is activated during the development of depressive-like behaviors is not known. Here, we evaluate the phosphorylation and expression levels of crucial kinases and transcription factors at the hippocampus of rats after 21 days of chronic restraint stress. Our results show that rats subjected to CRS protocol achieve less body weight, have heavier adrenal glands, and exhibit depression-like behaviors such as anhedonia, behavioral despair and decreased social interaction. Cav1.2 mRNA and protein expression levels, plus l-type calcium current amplitude, are also increased in treated rats when compared with control animals. Out of the three main signaling pathways activated by l-type currents, we only observed an increment of CaM-NFAT axis activity with the concomitant increment in Fas ligand expression. Thus, our results suggest that CRS activates specific pathways, and the increased expression of Cav1.2 could lead to neuronal death in the hippocampus.
Collapse
|
17
|
Changes in expression of Kv7.5 and Kv7.2 channels in dorsal root ganglion neurons in the streptozotocin rat model of painful diabetic neuropathy. Neurosci Lett 2020; 736:135277. [PMID: 32739272 DOI: 10.1016/j.neulet.2020.135277] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Revised: 07/21/2020] [Accepted: 07/22/2020] [Indexed: 11/21/2022]
Abstract
Diabetic peripheral neuropathic pain (DPNP), the most debilitating complication of diabetes mellitus, is resistant to current therapy. The pathogenesis of DPNP is still elusive, but several mechanisms have been proposed including abnormal hyperexcitability of dorsal root ganglion (DRG) neurons. The underlying molecular mechanisms of such aberrant hyperexcitability are incompletely understood. Using the streptozotocin (STZ) rat model of DPNP, we have recently provided evidence implicating neuronal Kv7 channels that normally exert a powerful stabilizing influence on neuronal excitability, in the abnormal hyperexcitability of DRG neurons and in pain hypersensitivity associated with DPNP. In the present immunohistochemical study, we sought to determine whether Kv7.2 and/or Kv7.5 channel expression is altered in DRG neurons in STZ rats. We found 35 days post-STZ: (1) a significant decrease in Kv7.5-immunoreactivity in small (<30 μm) DRG neurons (both IB4 positive and IB4 negative) and medium-sized (30-40 μm) neurons, and (2) a significant increase in Kv7.2-immunoreactivity in small (<30 μm) neurons, and a non-significant increase in medium/large neurons. The decrease in Kv7.5 channel expression in small and medium-sized DRG neurons in STZ rats is likely to contribute to the mechanisms of hyperexcitability of these neurons and thereby to the resulting pain hypersensitivity associated with DPNP. The upregulation of Kv7.2 subunit in small DRG neurons may be an activity dependent compensatory mechanism to limit STZ-induced hyperexcitability of DRG neurons and the associated pain hypersensitivity. The findings support the notion that Kv7 channels may represent a novel target for DPNP treatment.
Collapse
|
18
|
Baculis BC, Zhang J, Chung HJ. The Role of K v7 Channels in Neural Plasticity and Behavior. Front Physiol 2020; 11:568667. [PMID: 33071824 PMCID: PMC7530275 DOI: 10.3389/fphys.2020.568667] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Accepted: 08/28/2020] [Indexed: 12/12/2022] Open
Abstract
Activity-dependent persistent changes in neuronal intrinsic excitability and synaptic strength are widely thought to underlie learning and memory. Voltage-gated KCNQ/Kv7 potassium channels have been of great interest as the potential targets for memory disorders due to the beneficial effects of their antagonists in cognition. Importantly, de novo dominant mutations in their neuronal subunits KCNQ2/Kv7.2 and KCNQ3/Kv7.3 are associated with epilepsy and neurodevelopmental disorder characterized by developmental delay and intellectual disability. The role of Kv7 channels in neuronal excitability and epilepsy has been extensively studied. However, their functional significance in neural plasticity, learning, and memory remains largely unknown. Here, we review recent studies that support the emerging roles of Kv7 channels in intrinsic and synaptic plasticity, and their contributions to cognition and behavior.
Collapse
Affiliation(s)
- Brian C Baculis
- Neuroscience Program, University of Illinois at Urbana-Champaign, Urbana, IL, United States
| | - Jiaren Zhang
- Department of Molecular Integrative Physiology, University of Illinois at Urbana-Champaign, Urbana, IL, United States
| | - Hee Jung Chung
- Neuroscience Program, University of Illinois at Urbana-Champaign, Urbana, IL, United States.,Department of Molecular Integrative Physiology, University of Illinois at Urbana-Champaign, Urbana, IL, United States
| |
Collapse
|
19
|
Saccà SC, Vernazza S, Iorio EL, Tirendi S, Bassi AM, Gandolfi S, Izzotti A. Molecular changes in glaucomatous trabecular meshwork. Correlations with retinal ganglion cell death and novel strategies for neuroprotection. PROGRESS IN BRAIN RESEARCH 2020; 256:151-188. [PMID: 32958211 DOI: 10.1016/bs.pbr.2020.06.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Glaucoma is a chronic neurodegenerative disease characterized by retinal ganglion cell loss. Although significant advances in ophthalmologic knowledge and practice have been made, some glaucoma mechanisms are not yet understood, therefore, up to now there is no effective treatment able to ensure healing. Indeed, either pharmacological or surgical approaches to this disease aim in lowering intraocular pressure, which is considered the only modifiable risk factor. However, it is well known that several factors and metabolites are equally (if not more) involved in glaucoma. Oxidative stress, for instance, plays a pivotal role in both glaucoma onset and progression because it is responsible for the trabecular meshwork cell damage and, consequently, for intraocular pressure increase as well as for glaucomatous damage cascade. This review at first shows accurately the molecular-derived dysfunctions in antioxidant system and in mitochondria homeostasis which due to both oxidative stress and aging, lead to a chronic inflammation state, the trabecular meshwork damage as well as the glaucoma neurodegeneration. Therefore, the main molecular events triggered by oxidative stress up to the proapoptotic signals that promote the ganglion cell death have been highlighted. The second part of this review, instead, describes some of neuroprotective agents such as polyphenols or polyunsaturated fatty acids as possible therapeutic source against the propagation of glaucomatous damage.
Collapse
Affiliation(s)
- Sergio C Saccà
- Policlinico San Martino University Hospital, Department of Neuroscience and sense organs, Ophthalmology Unit, Genoa, Italy.
| | | | | | - Sara Tirendi
- Department of Experimental Medicine (DIMES), University of Genoa, Genoa, Italy; Inter-University Center for the Promotion of the 3Rs Principles in Teaching & Research (Centro 3R), Pisa, Italy
| | - Anna Maria Bassi
- Department of Experimental Medicine (DIMES), University of Genoa, Genoa, Italy; Inter-University Center for the Promotion of the 3Rs Principles in Teaching & Research (Centro 3R), Pisa, Italy
| | - Stefano Gandolfi
- Ophthalmology Unit, Department of Biological, Biotechnological and Translational Sciences, University of Parma, Parma, Italy
| | - Alberto Izzotti
- Department of Experimental Medicine (DIMES), University of Genoa, Genoa, Italy; Mutagenesis Unit, IRCCS Ospedale Policlinico San Martino, Genoa, Italy
| |
Collapse
|
20
|
van der Horst J, Greenwood IA, Jepps TA. Cyclic AMP-Dependent Regulation of Kv7 Voltage-Gated Potassium Channels. Front Physiol 2020; 11:727. [PMID: 32695022 PMCID: PMC7338754 DOI: 10.3389/fphys.2020.00727] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Accepted: 06/04/2020] [Indexed: 01/08/2023] Open
Abstract
Voltage-gated Kv7 potassium channels, encoded by KCNQ genes, have major physiological impacts cardiac myocytes, neurons, epithelial cells, and smooth muscle cells. Cyclic adenosine monophosphate (cAMP), a well-known intracellular secondary messenger, can activate numerous downstream effector proteins, generating downstream signaling pathways that regulate many functions in cells. A role for cAMP in ion channel regulation has been established, and recent findings show that cAMP signaling plays a role in Kv7 channel regulation. Although cAMP signaling is recognized to regulate Kv7 channels, the precise molecular mechanism behind the cAMP-dependent regulation of Kv7 channels is complex. This review will summarize recent research findings that support the mechanisms of cAMP-dependent regulation of Kv7 channels.
Collapse
Affiliation(s)
- Jennifer van der Horst
- Vascular Biology Group, Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Iain A Greenwood
- Molecular and Clinical Sciences Institute, St. George's University of London, London, United Kingdom
| | - Thomas A Jepps
- Vascular Biology Group, Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
| |
Collapse
|
21
|
Nappi P, Miceli F, Soldovieri MV, Ambrosino P, Barrese V, Taglialatela M. Epileptic channelopathies caused by neuronal Kv7 (KCNQ) channel dysfunction. Pflugers Arch 2020; 472:881-898. [PMID: 32506321 DOI: 10.1007/s00424-020-02404-2] [Citation(s) in RCA: 54] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2020] [Revised: 05/12/2020] [Accepted: 05/18/2020] [Indexed: 11/28/2022]
Abstract
Seizures are the most common neurological manifestation in the newborn period, with an estimated incidence of 1.8-3.5 per 1000 live births. Prolonged or intractable seizures have a detrimental effect on cognition and brain function in experimental animals and are associated with adverse long-term neurodevelopmental sequelae and an increased risk of post-neonatal epilepsy in humans. The developing brain is particularly susceptible to the potentially severe effects of epilepsy, and epilepsy, especially when refractory to medications, often results in a developmental and epileptic encephalopathy (DEE) with developmental arrest or regression. DEEs can be primarily attributed to genetic causes. Given the critical role of potassium (K+) currents with distinct subcellular localization, biophysical properties, modulation, and pharmacological profile in regulating intrinsic electrical properties of neurons and their responsiveness to synaptic inputs, it is not too surprising that genetic research in the past two decades has identified several K+ channel genes as responsible for a large fraction of DEE. In the present article, we review the genetically determined epileptic channelopathies affecting three members of the Kv7 family, namely Kv7.2 (KCNQ2), Kv7.3 (KCNQ3), and Kv7.5 (KCNQ5); we review the phenotypic spectrum of Kv7-related epileptic channelopathies, the different genetic and pathogenetic mechanisms, and the emerging genotype-phenotype correlations which may prove crucial for prognostic predictions, disease management, parental counseling, and individually tailored therapeutic attempts.
Collapse
Affiliation(s)
- Piera Nappi
- Section of Pharmacology, Department of Neuroscience, University of Naples, "Federico II", Via Pansini 5, 80131, Naples, Italy
| | - Francesco Miceli
- Section of Pharmacology, Department of Neuroscience, University of Naples, "Federico II", Via Pansini 5, 80131, Naples, Italy
| | | | - Paolo Ambrosino
- Department of Science and Technology (DST), University of Sannio, Benevento, Italy
| | - Vincenzo Barrese
- Section of Pharmacology, Department of Neuroscience, University of Naples, "Federico II", Via Pansini 5, 80131, Naples, Italy
| | - Maurizio Taglialatela
- Section of Pharmacology, Department of Neuroscience, University of Naples, "Federico II", Via Pansini 5, 80131, Naples, Italy.
| |
Collapse
|
22
|
Vigil FA, Bozdemir E, Bugay V, Chun SH, Hobbs M, Sanchez I, Hastings SD, Veraza RJ, Holstein DM, Sprague SM, M Carver C, Cavazos JE, Brenner R, Lechleiter JD, Shapiro MS. Prevention of brain damage after traumatic brain injury by pharmacological enhancement of KCNQ (Kv7, "M-type") K + currents in neurons. J Cereb Blood Flow Metab 2020; 40:1256-1273. [PMID: 31272312 PMCID: PMC7238379 DOI: 10.1177/0271678x19857818] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Nearly three million people in the USA suffer traumatic brain injury (TBI) yearly; however, there are no pre- or post-TBI treatment options available. KCNQ2-5 voltage-gated K+ channels underlie the neuronal "M current", which plays a dominant role in the regulation of neuronal excitability. Our strategy towards prevention of TBI-induced brain damage is predicated on the suggested hyper-excitability of neurons induced by TBIs, and the decrease in neuronal excitation upon pharmacological augmentation of M/KCNQ K+ currents. Seizures are very common after a TBI, making further seizures and development of epilepsy disease more likely. Our hypothesis is that TBI-induced hyperexcitability and ischemia/hypoxia lead to metabolic stress, cell death and a maladaptive inflammatory response that causes further downstream morbidity. Using the mouse controlled closed-cortical impact blunt TBI model, we found that systemic administration of the prototype M-channel "opener", retigabine (RTG), 30 min after TBI, reduces the post-TBI cascade of events, including spontaneous seizures, enhanced susceptibility to chemo-convulsants, metabolic stress, inflammatory responses, blood-brain barrier breakdown, and cell death. This work suggests that acutely reducing neuronal excitability and energy demand via M-current enhancement may be a novel model of therapeutic intervention against post-TBI brain damage and dysfunction.
Collapse
Affiliation(s)
- Fabio A Vigil
- Department of Cellular and Integrative Physiology, University of Texas Health San Antonio, San Antonio, TX, USA
| | - Eda Bozdemir
- Department of Cell Systems and Anatomy, University of Texas Health San Antonio, San Antonio, TX, USA
| | - Vladislav Bugay
- Department of Cellular and Integrative Physiology, University of Texas Health San Antonio, San Antonio, TX, USA
| | - Sang H Chun
- Department of Cell Systems and Anatomy, University of Texas Health San Antonio, San Antonio, TX, USA
| | - MaryAnn Hobbs
- Department of Cellular and Integrative Physiology, University of Texas Health San Antonio, San Antonio, TX, USA
| | - Isamar Sanchez
- Department of Cellular and Integrative Physiology, University of Texas Health San Antonio, San Antonio, TX, USA
| | - Shayne D Hastings
- Department of Cellular and Integrative Physiology, University of Texas Health San Antonio, San Antonio, TX, USA
| | - Rafael J Veraza
- Department of Cellular and Integrative Physiology, University of Texas Health San Antonio, San Antonio, TX, USA
| | - Deborah M Holstein
- Department of Cell Systems and Anatomy, University of Texas Health San Antonio, San Antonio, TX, USA
| | - Shane M Sprague
- Department of Neurosurgery, University of Texas Health San Antonio, San Antonio, TX, USA
| | - Chase M Carver
- Department of Cellular and Integrative Physiology, University of Texas Health San Antonio, San Antonio, TX, USA
| | - Jose E Cavazos
- Department of Neurology, University of Texas Health San Antonio, San Antonio, TX, USA
| | - Robert Brenner
- Department of Cellular and Integrative Physiology, University of Texas Health San Antonio, San Antonio, TX, USA
| | - James D Lechleiter
- Department of Cell Systems and Anatomy, University of Texas Health San Antonio, San Antonio, TX, USA
| | - Mark S Shapiro
- Department of Cellular and Integrative Physiology, University of Texas Health San Antonio, San Antonio, TX, USA
| |
Collapse
|
23
|
Wild AR, Sinnen BL, Dittmer PJ, Kennedy MJ, Sather WA, Dell'Acqua ML. Synapse-to-Nucleus Communication through NFAT Is Mediated by L-type Ca 2+ Channel Ca 2+ Spike Propagation to the Soma. Cell Rep 2020; 26:3537-3550.e4. [PMID: 30917310 PMCID: PMC6521872 DOI: 10.1016/j.celrep.2019.03.005] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2018] [Revised: 12/11/2018] [Accepted: 02/28/2019] [Indexed: 12/21/2022] Open
Abstract
Long-term information storage in the brain requires continual modification of the neuronal transcriptome. Synaptic inputs located hundreds of micrometers from the nucleus can regulate gene transcription, requiring high-fidelity, long-range signaling from synapses in dendrites to the nucleus in the cell soma. Here, we describe a synapse-to-nucleus signaling mechanism for the activity-dependent transcription factor NFAT. NMDA receptors activated on distal dendrites were found to initiate L-type Ca2+ channel (LTCC) spikes that quickly propagated the length of the dendrite to the soma. Surprisingly, LTCC propagation did not require voltage-gated Na+ channels or back-propagating action potentials. NFAT nuclear recruitment and transcriptional activation only occurred when LTCC spikes invaded the somatic compartment, and the degree of NFAT activation correlated with the number of somatic LTCC Ca2+ spikes. Together, these data support a model for synapse to nucleus communication where NFAT integrates somatic LTCC Ca2+ spikes to alter transcription during periods of heightened neuronal activity. Signaling from synapse to nucleus can alter transcription and consolidate long-term changes in neuronal function. Wild et al. uncover a mechanism for rapid long-distance signaling from distal dendrites to the nucleus that utilizes L-type voltage-gated Ca2+ channel Ca2+ spikes to activate the transcription factor NFAT.
Collapse
Affiliation(s)
- Angela R Wild
- Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - Brooke L Sinnen
- Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - Philip J Dittmer
- Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - Matthew J Kennedy
- Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - William A Sather
- Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - Mark L Dell'Acqua
- Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO 80045, USA.
| |
Collapse
|
24
|
Shepard RD, Langlois LD, Authement ME, Nugent FS. Histone deacetylase inhibition reduces ventral tegmental area dopamine neuronal hyperexcitability involving AKAP150 signaling following maternal deprivation in juvenile male rats. J Neurosci Res 2020; 98:1457-1467. [PMID: 32162391 DOI: 10.1002/jnr.24613] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Revised: 02/19/2020] [Accepted: 02/27/2020] [Indexed: 12/27/2022]
Abstract
Traumatic early life stress (ELS) is linked to dopamine (DA) dysregulation which increases the probability of developing psychiatric disorders in adolescence and adulthood. Our prior studies demonstrated that a severe early life stressor, a 24-hr maternal deprivation (MD) in juvenile male rats, could lead to altered DA signaling from the ventral tegmental area (VTA) due to impairment of GABAergic synaptic plasticity (promoting GABAergic long-term depression, LTD) with concomitant changes in the abundance of synaptic regulators including A-kinase anchoring protein (AKAP150). Importantly, these MD-induced synaptic changes in the VTA were accompanied by upregulation of histone deacetylase 2, histone hypoacetylation, and were reversible by HDAC inhibition. Using cell-attached and whole-cell patch clamp recordings, we found that MD stress also increased spontaneous VTA DA neuronal activity and excitability in juvenile male rats without affecting intrinsic excitability. Postsynaptic chemical disruption of AKAP150 and protein kinase A interaction increased VTA DA neuronal excitability in control non-MD rats mimicking the effects of MD on DA cell excitability with similar changes in membrane properties. Interestingly, this disruption decreased MD-induced VTA DA hyperexcitability. This MD-induced DA neuronal hyperexcitability could also be normalized at 24 hr after injection of the class 1 HDAC inhibitor, CI-994. Altogether, our data suggest that AKAP150 plays a critical role in the regulation of VTA DA neuronal excitability and that HDAC-mediated targeting of AKAP150 signaling could normalize VTA DA dysfunction following ELS thereby providing novel therapeutic targets for prevention of later life psychopathology.
Collapse
Affiliation(s)
- Ryan D Shepard
- Edward Hebert School of Medicine, Department of Pharmacology, Uniformed Services University of the Health Sciences, Bethesda, MD, USA
| | - Ludovic D Langlois
- Edward Hebert School of Medicine, Department of Pharmacology, Uniformed Services University of the Health Sciences, Bethesda, MD, USA
| | - Michael E Authement
- Edward Hebert School of Medicine, Department of Pharmacology, Uniformed Services University of the Health Sciences, Bethesda, MD, USA
| | - Fereshteh S Nugent
- Edward Hebert School of Medicine, Department of Pharmacology, Uniformed Services University of the Health Sciences, Bethesda, MD, USA
| |
Collapse
|
25
|
Koo JW, Chaudhury D, Han MH, Nestler EJ. Role of Mesolimbic Brain-Derived Neurotrophic Factor in Depression. Biol Psychiatry 2019; 86:738-748. [PMID: 31327473 PMCID: PMC6814503 DOI: 10.1016/j.biopsych.2019.05.020] [Citation(s) in RCA: 71] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/28/2019] [Revised: 05/20/2019] [Accepted: 05/24/2019] [Indexed: 11/27/2022]
Abstract
Brain-derived neurotrophic factor (BDNF) is widely accepted as being critical for neural and synaptic plasticity throughout the nervous system. Recent work has shown that BDNF in the mesolimbic dopamine (DA) circuit, originating in ventral tegmental area DA neurons that project to the nucleus accumbens, is crucial in the development of depressive-like behaviors following exposure to chronic social defeat stress in mice. Whereas BDNF modulates DA signaling in encoding responses to acute defeat stress, BDNF signaling alone appears to be responsible for the behavioral effects after chronic social defeat stress. Very different patterns are seen with another widely used chronic stress paradigm in mice, chronic mild stress (also known as chronic variable or unpredictable stress), where DA signaling, but not BDNF signaling, is primarily responsible for the behavioral effects observed. This review discusses the molecular, cellular, and circuit basis of this dramatic discrepancy, which appears to involve the nature of the stress, its severity and duration, and its effects on distinct cell types within the ventral tegmental area-to-nucleus accumbens mesolimbic circuit.
Collapse
Affiliation(s)
- Ja Wook Koo
- Department of Neural Development and Disease, Korea Brain Research Institute (KBRI), 61, Cheomdan-ro, Dong-gu, Daegu, 41068, Republic of Korea
| | - Dipesh Chaudhury
- Division of Science, New York University Abu Dhabi (NYUAD), Saadiyat Island Campus, Abu Dhabi, PO Box 129188, United Arab Emirates
| | - Ming-Hu Han
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, New York; Nash Family Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, New York; Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, New York.
| | - Eric J. Nestler
- Departments of Pharmacological Sciences and of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA,Address correspondence to: Ming-Hu Han, Ph.D. and Eric J. Nestler, MD., Ph.D., Department of Neuroscience, Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; and
| |
Collapse
|
26
|
Carver CM, Hastings SD, Cook ME, Shapiro MS. Functional responses of the hippocampus to hyperexcitability depend on directed, neuron-specific KCNQ2 K + channel plasticity. Hippocampus 2019; 30:435-455. [PMID: 31621989 DOI: 10.1002/hipo.23163] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2019] [Revised: 07/24/2019] [Accepted: 08/30/2019] [Indexed: 12/14/2022]
Abstract
M-type (KCNQ2/3) K+ channels play dominant roles in regulation of active and passive neuronal discharge properties such as resting membrane potential, spike-frequency adaptation, and hyper-excitatory states. However, plasticity of M-channel expression and function in nongenetic forms of epileptogenesis are still not well understood. Using transgenic mice with an EGFP reporter to detect expression maps of KCNQ2 mRNA, we assayed hyperexcitability-induced alterations in KCNQ2 transcription across subregions of the hippocampus. Pilocarpine and pentylenetetrazol chemoconvulsant models of seizure induction were used, and brain tissue examined 48 hr later. We observed increases in KCNQ2 mRNA in CA1 and CA3 pyramidal neurons after chemoconvulsant-induced hyperexcitability at 48 hr, but no significant change was observed in dentate gyrus (DG) granule cells. Using chromogenic in situ hybridization assays, changes to KCNQ3 transcription were not detected after hyper-excitation challenge, but the results for KCNQ2 paralleled those using the KCNQ2-mRNA reporter mice. In mice 7 days after pilocarpine challenge, levels of KCNQ2 mRNA were similar in all regions to those from control mice. In brain-slice electrophysiology recordings, CA1 pyramidal neurons demonstrated increased M-current amplitudes 48 hr after hyperexcitability; however, there were no significant changes to DG granule cell M-current amplitude. Traumatic brain injury induced significantly greater KCNQ2 expression in the hippocampal hemisphere that was ipsilateral to the trauma. In vivo, after a secondary challenge with subconvulsant dose of pentylenetetrazole, control mice were susceptible to tonic-clonic seizures, whereas mice administered the M-channel opener retigabine were protected from such seizures. This study demonstrates that increased excitatory activity promotes KCNQ2 upregulation in the hippocampus in a cell-type specific manner. Such novel ion channel expressional plasticity may serve as a compensatory mechanism after a hyperexcitable event, at least in the short term. The upregulation described could be potentially leveraged in anticonvulsant enhancement of KCNQ2 channels as therapeutic target for preventing onset of epileptogenic seizures.
Collapse
Affiliation(s)
- Chase M Carver
- Department of Cellular and Integrative Physiology, University of Texas Health San Antonio, San Antonio, Texas
| | - Shayne D Hastings
- Department of Cellular and Integrative Physiology, University of Texas Health San Antonio, San Antonio, Texas
| | - Mileah E Cook
- Department of Cellular and Integrative Physiology, University of Texas Health San Antonio, San Antonio, Texas
| | - Mark S Shapiro
- Department of Cellular and Integrative Physiology, University of Texas Health San Antonio, San Antonio, Texas
| |
Collapse
|
27
|
Zakaria ZA, Abdul Rahim MH, Roosli RAJ, Mohd Sani MH, Marmaya NH, Omar MH, Teh LK, Salleh MZ. Antinociceptive Activity of Petroleum Ether Fraction of Clinacanthus nutans Leaves Methanolic Extract: Roles of Nonopioid Pain Modulatory Systems and Potassium Channels. BIOMED RESEARCH INTERNATIONAL 2019; 2019:6593125. [PMID: 31467905 PMCID: PMC6699298 DOI: 10.1155/2019/6593125] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/09/2019] [Revised: 05/22/2019] [Accepted: 07/09/2019] [Indexed: 12/13/2022]
Abstract
Methanolic extract of Clinacanthus nutans Lindau leaves (MECN) has been reported to exert antinociceptive activity. The present study aimed to elucidate the possible antinociceptive mechanisms of a lipid-soluble fraction of MECN, which was obtained after sequential extraction in petroleum ether. The petroleum ether fraction of C. nutans (PECN), administered orally to mice, was (i) subjected to capsaicin-, glutamate-, phorbol 12-myristate 13-acetate-, bradykinin-induced nociception model; (ii) prechallenged (intraperitoneal (i.p.)) with 0.15 mg/kg yohimbine, 1 mg/kg pindolol, 3 mg/kg caffeine, 0.2 mg/kg haloperidol, or 10 mg/kg atropine, which were the respective antagonist of α 2-adrenergic, β-adrenergic, adenosinergic, dopaminergic, or muscarinic receptors; and (iii) prechallenged (i.p.) with 10 mg/kg glibenclamide, 0.04 mg/kg apamin, 0.02 mg/kg charybdotoxin, or 4 mg/kg tetraethylammonium chloride, which were the respective inhibitor of ATP sensitive-, small conductance Ca2+-activated-, large conductance Ca2+-activated-, or nonselective voltage-activated-K+ channel. Results obtained demonstrated that PECN (100, 250, and 500 mg/kg) significantly (P<0.05) inhibited all models of nociception described earlier. The antinociceptive activity of 500 mg/kg PECN was significantly (P<0.05) attenuated when prechallenged with all antagonists or K+ channel blockers. However, only pretreatment with apamin and charybdotoxin caused full inhibition of PECN-induced antinociception. The rest of the K+ channel blockers and all antagonists caused only partial inhibition of PECN antinociception, respectively. Analyses on PECN's phytoconstituents revealed the presence of antinociceptive-bearing bioactive compounds of volatile (i.e., derivatives of γ-tocopherol, α-tocopherol, and lupeol) and nonvolatile (i.e., cinnamic acid) nature. In conclusion, PECN exerts a non-opioid-mediated antinociceptive activity involving mainly activation of adenosinergic and cholinergic receptors or small- and large-conductance Ca2+-activated-K+ channels.
Collapse
Affiliation(s)
- Zainul Amiruddin Zakaria
- Department of Biomedical Science, Faculty of Medicine and Health Science, Universiti Putra Malaysia, 43400 Serdang, Selangor, Malaysia
- Integrative Pharmacogenomics Institute (iPROMISE), Level 7, FF3, Faculty of Pharmacy, Universiti Teknologi MARA, Puncak Alam Campus, 42300 Bandar Puncak Alam, Selangor, Malaysia
| | - Mohammad Hafiz Abdul Rahim
- Department of Biomedical Science, Faculty of Medicine and Health Science, Universiti Putra Malaysia, 43400 Serdang, Selangor, Malaysia
| | - Rushduddin Al Jufri Roosli
- Department of Biomedical Science, Faculty of Medicine and Health Science, Universiti Putra Malaysia, 43400 Serdang, Selangor, Malaysia
| | - Mohd Hijaz Mohd Sani
- Department of Biomedical Sciences and Therapeutics, Faculty of Medicine and Health Science, Universiti Malaysia Sabah, 88400 Kota Kinabalu, Sabah, Malaysia
| | - Najihah Hanisah Marmaya
- Faculty of Business and Management, Universiti Teknologi MARA, Melaka Campus, 75300, Melaka, Malaysia
| | - Maizatul Hasyima Omar
- Phytochemistry Unit, Herbal Medicine Research Centre, Institute for Medical Research, Jalan Pahang, 50588 Kuala Lumpur, Malaysia
| | - Lay Kek Teh
- Integrative Pharmacogenomics Institute (iPROMISE), Level 7, FF3, Faculty of Pharmacy, Universiti Teknologi MARA, Puncak Alam Campus, 42300 Bandar Puncak Alam, Selangor, Malaysia
| | - Mohd. Zaki Salleh
- Integrative Pharmacogenomics Institute (iPROMISE), Level 7, FF3, Faculty of Pharmacy, Universiti Teknologi MARA, Puncak Alam Campus, 42300 Bandar Puncak Alam, Selangor, Malaysia
| |
Collapse
|
28
|
Abstract
Many diseases are related to age, among these neurodegeneration is particularly important. Alzheimer's disease Parkinson's and Glaucoma have many common pathogenic events including oxidative damage, Mitochondrial dysfunction, endothelial alterations and changes in the visual field. These are well known in the case of glaucoma, less in the case of neurodegeneration of the brain. Many other molecular aspects are common, such as the role of endoplasmic reticulum autophagy and neuronal apoptosis while others have been neglected due to lack of space such as inflammatory cytokine or miRNA. Moreover, the loss of specific neuronal populations, the induction of similar mechanisms of cell injury and the deposition of protein aggregates in specific anatomical areas are very similar events between these diseases. Intracellular and/or extracellular accumulation of protein aggregates is a key feature of many neurodegenerative disorders. The existence of abnormal protein aggregates has been documented in the RGCs of glaucomatous patients such as the anomalous Tau protein or the β-amyloid accumulations. Intra-cell catabolic processes also appear to be common in both glaucoma and neurodegeneration. They also help us to understand how the basis between these diseases is common and how the visual aspects can be a serious problem for those who are affected.
Collapse
Affiliation(s)
- Sergio Claudio Saccà
- Department of Head/Neck Pathologies, St Martino Hospital, Ophthalmology Unit, Genoa, Italy.
| | - Carlo Alberto Cutolo
- Department of Neuroscience, Rehabilitation, Ophthalmology, Genetics and Maternal and Child Science, University of Genoa, Policlinico San Martino Hospital, Eye Clinic Genoa, Genoa, Italy
| | - Tommaso Rossi
- Department of Head/Neck Pathologies, St Martino Hospital, Ophthalmology Unit, Genoa, Italy
| |
Collapse
|
29
|
Gq-Coupled Muscarinic Receptor Enhancement of KCNQ2/3 Channels and Activation of TRPC Channels in Multimodal Control of Excitability in Dentate Gyrus Granule Cells. J Neurosci 2018; 39:1566-1587. [PMID: 30593498 DOI: 10.1523/jneurosci.1781-18.2018] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2018] [Revised: 12/17/2018] [Accepted: 12/20/2018] [Indexed: 12/21/2022] Open
Abstract
KCNQ (Kv7, "M-type") K+ channels and TRPC (transient receptor potential, "canonical") cation channels are coupled to neuronal discharge properties and are regulated via Gq/11-protein-mediated signals. Stimulation of Gq/11-coupled receptors both consumes phosphatidylinositol 4,5-bisphosphate (PIP2) via phosphalipase Cβ hydrolysis and stimulates PIP2 synthesis via rises in Ca2+ i and other signals. Using brain-slice electrophysiology and Ca2+ imaging from male and female mice, we characterized threshold K+ currents in dentate gyrus granule cells (DGGCs) and CA1 pyramidal cells, the effects of Gq/11-coupled muscarinic M1 acetylcholine (M1R) stimulation on M current and on neuronal discharge properties, and elucidated the intracellular signaling mechanisms involved. We observed disparate signaling cascades between DGGCs and CA1 neurons. DGGCs displayed M1R enhancement of M-current, rather than suppression, due to stimulation of PIP2 synthesis, which was paralleled by increased PIP2-gated G-protein coupled inwardly rectifying K+ currents as well. Deficiency of KCNQ2-containing M-channels ablated the M1R-induced enhancement of M-current in DGGCs. Simultaneously, M1R stimulation in DGGCs induced robust increases in [Ca2+]i, mostly due to TRPC currents, consistent with, and contributing to, neuronal depolarization and hyperexcitability. CA1 neurons did not display such multimodal signaling, but rather M current was suppressed by M1R stimulation in these cells, similar to the previously described actions of M1R stimulation on M-current in peripheral ganglia that mostly involves PIP2 depletion. Therefore, these results point to a pleiotropic network of cholinergic signals that direct cell-type-specific, precise control of hippocampal function with strong implications for hyperexcitability and epilepsy.SIGNIFICANCE STATEMENT At the neuronal membrane, protein signaling cascades consisting of ion channels and metabotropic receptors govern the electrical properties and neurotransmission of neuronal networks. Muscarinic acetylcholine receptors are G-protein-coupled metabotropic receptors that control the excitability of neurons through regulating ion channels, intracellular Ca2+ signals, and other second-messenger cascades. We have illuminated previously unknown actions of muscarinic stimulation on the excitability of hippocampal principal neurons that include M channels, TRPC (transient receptor potential, "canonical") cation channels, and powerful regulation of lipid metabolism. Our results show that these signaling pathways, and mechanisms of excitability, are starkly distinct between peripheral ganglia and brain, and even between different principal neurons in the hippocampus.
Collapse
|
30
|
Tarasova EO, Gaydukov AE, Balezina OP. Calcineurin and Its Role in Synaptic Transmission. BIOCHEMISTRY (MOSCOW) 2018; 83:674-689. [PMID: 30195324 DOI: 10.1134/s0006297918060056] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Calcineurin (CaN) is a serine/threonine phosphatase widely expressed in different cell types and structures including neurons and synapses. The most studied role of CaN is its involvement in the functioning of postsynaptic structures of central synapses. The role of CaN in the presynaptic structures of central and peripheral synapses is less understood, although it has generated a considerable interest and is a subject of a growing number of studies. The regulatory role of CaN in synaptic vesicle endocytosis in the synapse terminals is actively studied. In recent years, new targets of CaN have been identified and its role in the regulation of enzymes and neurotransmitter secretion in peripheral neuromuscular junctions has been revealed. CaN is the only phosphatase that requires calcium and calmodulin for activation. In this review, we present details of CaN molecular structure and give a detailed description of possible mechanisms of CaN activation involving calcium, enzymes, and endogenous and exogenous inhibitors. Known and newly discovered CaN targets at pre- and postsynaptic levels are described. CaN activity in synaptic structures is discussed in terms of functional involvement of this phosphatase in synaptic transmission and neurotransmitter release.
Collapse
Affiliation(s)
- E O Tarasova
- Lomonosov Moscow State University, Faculty of Biology, Moscow, 119991, Russia
| | - A E Gaydukov
- Lomonosov Moscow State University, Faculty of Biology, Moscow, 119991, Russia. .,Pirogov Russian National Research Medical University, Moscow, 117997, Russia
| | - O P Balezina
- Lomonosov Moscow State University, Faculty of Biology, Moscow, 119991, Russia
| |
Collapse
|
31
|
Control of Homeostatic Synaptic Plasticity by AKAP-Anchored Kinase and Phosphatase Regulation of Ca 2+-Permeable AMPA Receptors. J Neurosci 2018; 38:2863-2876. [PMID: 29440558 DOI: 10.1523/jneurosci.2362-17.2018] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2017] [Revised: 01/17/2018] [Accepted: 02/06/2018] [Indexed: 12/31/2022] Open
Abstract
Neuronal information processing requires multiple forms of synaptic plasticity mediated by NMDARs and AMPA-type glutamate receptors (AMPARs). These plasticity mechanisms include long-term potentiation (LTP) and long-term depression (LTD), which are Hebbian, homosynaptic mechanisms locally regulating synaptic strength of specific inputs, and homeostatic synaptic scaling, which is a heterosynaptic mechanism globally regulating synaptic strength across all inputs. In many cases, LTP and homeostatic scaling regulate AMPAR subunit composition to increase synaptic strength via incorporation of Ca2+-permeable receptors (CP-AMPAR) containing GluA1, but lacking GluA2, subunits. Previous work by our group and others demonstrated that anchoring of the kinase PKA and the phosphatase calcineurin (CaN) to A-kinase anchoring protein (AKAP) 150 play opposing roles in regulation of GluA1 Ser845 phosphorylation and CP-AMPAR synaptic incorporation during hippocampal LTP and LTD. Here, using both male and female knock-in mice that are deficient in PKA or CaN anchoring, we show that AKAP150-anchored PKA and CaN also play novel roles in controlling CP-AMPAR synaptic incorporation during homeostatic plasticity in hippocampal neurons. We found that genetic disruption of AKAP-PKA anchoring prevented increases in Ser845 phosphorylation and CP-AMPAR synaptic recruitment during rapid homeostatic synaptic scaling-up induced by combined blockade of action potential firing and NMDAR activity. In contrast, genetic disruption of AKAP-CaN anchoring resulted in basal increases in Ser845 phosphorylation and CP-AMPAR synaptic activity that blocked subsequent scaling-up by preventing additional CP-AMPAR recruitment. Thus, the balanced, opposing phospho-regulation provided by AKAP-anchored PKA and CaN is essential for control of both Hebbian and homeostatic plasticity mechanisms that require CP-AMPARs.SIGNIFICANCE STATEMENT Neuronal circuit function is shaped by multiple forms of activity-dependent plasticity that control excitatory synaptic strength, including LTP/LTD that adjusts strength of individual synapses and homeostatic plasticity that adjusts overall strength of all synapses. Mechanisms controlling LTP/LTD and homeostatic plasticity were originally thought to be distinct; however, recent studies suggest that CP-AMPAR phosphorylation regulation is important during both LTP/LTD and homeostatic plasticity. Here we show that CP-AMPAR regulation by the kinase PKA and phosphatase CaN coanchored to the scaffold protein AKAP150, a mechanism previously implicated in LTP/LTD, is also crucial for controlling synaptic strength during homeostatic plasticity. These novel findings significantly expand our understanding of homeostatic plasticity mechanisms and further emphasize how intertwined they are with LTP and LTD.
Collapse
|
32
|
Ling J, Erol F, Gu JG. Role of KCNQ2 channels in orofacial cold sensitivity: KCNQ2 upregulation in trigeminal ganglion neurons after infraorbital nerve chronic constrictive injury. Neurosci Lett 2018; 664:84-90. [PMID: 29133175 PMCID: PMC5817018 DOI: 10.1016/j.neulet.2017.11.026] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2017] [Revised: 11/08/2017] [Accepted: 11/09/2017] [Indexed: 11/17/2022]
Abstract
Sensitivity to cooling temperatures often becomes heightened in orofacial regions leading to orofacial cold allodynia/hyperalgesia after chronic trigeminal nerve injury. KCNQ2 channels are involved in controlling excitability of primary afferent neurons and thereby regulate sensory functions under both physiological and pathological conditions. In the present study, we sought to determine whether KCNQ2 channels in trigeminal nerves are involved in regulating orofacial operant behavioral responses to cooling stimulation. We also sought to examine whether chronic trigeminal nerve injury may alter KCNQ2 channel expression in trigeminal ganglions. Using the orofacial operant tests, animals show cold allodynia/hyperalgesia in orofacial regions following infraorbital nerve chronic constrictive injury (ION-CCI), which could be alleviated by subcutaneous administration of retigabine, a KCNQ2 activator. In contrast, subcutaneous administration of the KCNQ2 inhibitor XE991 directly elicits cold allodynia/hyperalgesia in sham animals. Using immunostaining, we show that KCNQ2 channels are primarily expressed in small-sized TG neurons. Interestingly, KCNQ2 channel expression becomes significantly upregulated in TG neurons following the ION-CCI. Our results suggest that KCNQ2 channels are involved in regulating orofacial cold sensitivity. Upregulation of KCNQ2 channels may be a compensatory change in attempting to limit injury-induced trigeminal hyperexcitability.
Collapse
Affiliation(s)
- Jennifer Ling
- Department of Anesthesiology and Perioperative Medicine, University of Alabama at Birmingham, Birmingham, AL, 35294, United States
| | - Ferhat Erol
- Department of Anesthesiology and Perioperative Medicine, University of Alabama at Birmingham, Birmingham, AL, 35294, United States
| | - Jianguo G Gu
- Department of Anesthesiology and Perioperative Medicine, University of Alabama at Birmingham, Birmingham, AL, 35294, United States.
| |
Collapse
|
33
|
Wild AR, Dell'Acqua ML. Potential for therapeutic targeting of AKAP signaling complexes in nervous system disorders. Pharmacol Ther 2017; 185:99-121. [PMID: 29262295 DOI: 10.1016/j.pharmthera.2017.12.004] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
A common feature of neurological and neuropsychiatric disorders is a breakdown in the integrity of intracellular signal transduction pathways. Dysregulation of ion channels and receptors in the cell membrane and the enzymatic mediators that link them to intracellular effectors can lead to synaptic dysfunction and neuronal death. However, therapeutic targeting of these ubiquitous signaling elements can lead to off-target side effects due to their widespread expression in multiple systems of the body. A-kinase anchoring proteins (AKAPs) are multivalent scaffolding proteins that compartmentalize a diverse range of receptor and effector proteins to streamline signaling within nanodomain signalosomes. A number of essential neurological processes are known to critically depend on AKAP-directed signaling and an understanding of the role AKAPs play in nervous system disorders has emerged in recent years. Selective targeting of AKAP protein-protein interactions may be a means to uncouple pathologically active signaling pathways in neurological disorders with a greater degree of specificity. In this review we will discuss the role of AKAPs in both regulating normal nervous system function and dysfunction associated with disease, and the potential for therapeutic targeting of AKAP signaling complexes.
Collapse
Affiliation(s)
- Angela R Wild
- Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - Mark L Dell'Acqua
- Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO 80045, USA.
| |
Collapse
|
34
|
Brown DA. Regulation of neural ion channels by muscarinic receptors. Neuropharmacology 2017; 136:383-400. [PMID: 29154951 DOI: 10.1016/j.neuropharm.2017.11.024] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2016] [Revised: 10/26/2017] [Accepted: 11/13/2017] [Indexed: 12/20/2022]
Abstract
The excitable behaviour of neurons is determined by the activity of their endogenous membrane ion channels. Since muscarinic receptors are not themselves ion channels, the acute effects of muscarinic receptor stimulation on neuronal function are governed by the effects of the receptors on these endogenous neuronal ion channels. This review considers some principles and factors determining the interaction between subtypes and classes of muscarinic receptors with neuronal ion channels, and summarizes the effects of muscarinic receptor stimulation on a number of different channels, the mechanisms of receptor - channel transduction and their direct consequences for neuronal activity. Ion channels considered include potassium channels (voltage-gated, inward rectifier and calcium activated), voltage-gated calcium channels, cation channels and chloride channels. This article is part of the Special Issue entitled 'Neuropharmacology on Muscarinic Receptors'.
Collapse
Affiliation(s)
- David A Brown
- Department of Neuroscience, Physiology & Pharmacology, University College London, Gower Street, London, WC1E 6BT, UK.
| |
Collapse
|
35
|
Fukuchi M. Studies of Neuronal Gene Regulation Controlling the Molecular Mechanisms Underlying Neural Plasticity. YAKUGAKU ZASSHI 2017; 137:1103-1115. [PMID: 28867697 DOI: 10.1248/yakushi.17-00107] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The regulation of the development and function of the nervous system is not preprogramed but responds to environmental stimuli to change neural development and function flexibly. This neural plasticity is a characteristic property of the nervous system. For example, strong synaptic activation evoked by environmental stimuli leads to changes in synaptic functions (known as synaptic plasticity). Long-lasting synaptic plasticity is one of the molecular mechanisms underlying long-term learning and memory. Since discovering the role of the transcription factor cAMP-response element-binding protein in learning and memory, it has been widely accepted that gene regulation in neurons contributes to long-lasting changes in neural functions. However, it remains unclear how synaptic activation is converted into gene regulation that results in long-lasting neural functions like long-term memory. We continue to address this question. This review introduces our recent findings on the gene regulation of brain-derived neurotrophic factor and discusses how regulation of the gene participates in long-lasting changes in neural functions.
Collapse
Affiliation(s)
- Mamoru Fukuchi
- Department of Biological Chemistry, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama
| |
Collapse
|
36
|
Isbrandt D. A mechanistic link between glia and neuronal excitability in acute neuroinflammation. J Physiol 2017; 595:603-604. [PMID: 28145018 DOI: 10.1113/jp273252] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Affiliation(s)
- Dirk Isbrandt
- German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany.,University of Cologne, Cologne, Germany
| |
Collapse
|
37
|
Liu H, Chaudhury D. Understanding Mood Disorders Using Electrophysiology and Circuit Breaking. DECODING NEURAL CIRCUIT STRUCTURE AND FUNCTION 2017:343-370. [DOI: 10.1007/978-3-319-57363-2_14] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/19/2023]
|
38
|
Li L, Li J, Drum BM, Chen Y, Yin H, Guo X, Luckey SW, Gilbert ML, McKnight GS, Scott JD, Santana LF, Liu Q. Loss of AKAP150 promotes pathological remodelling and heart failure propensity by disrupting calcium cycling and contractile reserve. Cardiovasc Res 2016; 113:147-159. [PMID: 27856611 DOI: 10.1093/cvr/cvw221] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/23/2016] [Revised: 08/15/2016] [Accepted: 10/11/2016] [Indexed: 01/18/2023] Open
Abstract
AIMS Impaired Ca2 + cycling and myocyte contractility are a hallmark of heart failure triggered by pathological stress such as hemodynamic overload. The A-Kinase anchoring protein AKAP150 has been shown to coordinate key aspects of adrenergic regulation of Ca2+ cycling and excitation-contraction in cardiomyocytes. However, the role of the AKAP150 signalling complexes in the pathogenesis of heart failure has not been investigated. METHODS AND RESULTS Here we examined how AKAP150 signalling complexes impact Ca2+ cycling, myocyte contractility, and heart failure susceptibility following pathological stress. We detected a significant reduction of AKAP150 expression in the failing mouse heart induced by pressure overload. Importantly, cardiac-specific AKAP150 knockout mice were predisposed to develop dilated cardiomyopathy with severe cardiac dysfunction and fibrosis after pressure overload. Loss of AKAP150 also promoted pathological remodelling and heart failure progression following myocardial infarction. However, ablation of AKAP150 did not affect calcineurin-nuclear factor of activated T cells signalling in cardiomyocytes or pressure overload- or agonist-induced cardiac hypertrophy. Immunoprecipitation studies showed that AKAP150 was associated with SERCA2, phospholamban, and ryanodine receptor-2, providing a targeted control of sarcoplasmic reticulum Ca2+ regulatory proteins. Mechanistically, loss of AKAP150 led to impaired Ca2+ cycling and reduced myocyte contractility reserve following adrenergic stimulation or pressure overload. CONCLUSIONS These findings define a critical role for AKAP150 in regulating Ca2+ cycling and myocardial ionotropy following pathological stress, suggesting the AKAP150 signalling pathway may serve as a novel therapeutic target for heart failure.
Collapse
Affiliation(s)
- Lei Li
- Department of Physiology and Biophysics, University of Washington, 1705 NE Pacific Street, Seattle, WA 98195, USA
| | - Jing Li
- Department of Physiology and Biophysics, University of Washington, 1705 NE Pacific Street, Seattle, WA 98195, USA
| | - Benjamin M Drum
- Department of Physiology and Biophysics, University of Washington, 1705 NE Pacific Street, Seattle, WA 98195, USA
| | - Yi Chen
- Department of Physiology and Biophysics, University of Washington, 1705 NE Pacific Street, Seattle, WA 98195, USA
| | - Haifeng Yin
- Department of Physiology and Biophysics, University of Washington, 1705 NE Pacific Street, Seattle, WA 98195, USA
| | - Xiaoyun Guo
- Department of Physiology and Biophysics, University of Washington, 1705 NE Pacific Street, Seattle, WA 98195, USA
| | - Stephen W Luckey
- Department of Biology, Seattle University, 901 12th Ave., Seattle, WA 98122, USA
| | - Merle L Gilbert
- Department of Pharmacology, University of Washington, 1705 NE Pacific Street, Seattle, WA 98195, USA
| | - G Stanley McKnight
- Department of Pharmacology, University of Washington, 1705 NE Pacific Street, Seattle, WA 98195, USA
| | - John D Scott
- Department of Pharmacology, University of Washington, 1705 NE Pacific Street, Seattle, WA 98195, USA.,Howard Hughes Medical Institute, University of Washington, 1705 NE Pacific Street, Seattle, WA 98195, USA
| | - L Fernando Santana
- Deparment of Physiology & Membrane Biology, University of California, One Shields Ave., Davis, CA 95616, USA
| | - Qinghang Liu
- Department of Physiology and Biophysics, University of Washington, 1705 NE Pacific Street, Seattle, WA 98195, USA;
| |
Collapse
|
39
|
Xia X, Qu B, Li YM, Yang LB, Fan KX, Zheng H, Huang HD, Gu JW, Kuang YQ, Ma Y. NFAT5 protects astrocytes against oxygen-glucose-serum deprivation/restoration damage via the SIRT1/Nrf2 pathway. J Mol Neurosci 2016; 61:96-104. [PMID: 27838821 DOI: 10.1007/s12031-016-0849-x] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2016] [Accepted: 09/22/2016] [Indexed: 01/05/2023]
Abstract
Nuclear factor of activated T cells (NFAT) is a multifunctional cytokine family. NFAT5 was recently reported to be involved in many neuronal functions, but its specific function remains unclear. In this study, our aim is to investigate whether NFAT5 overexpression can protect astrocytes against oxygen-glucose-serum deprivation/restoration (OGSD/R) damage. In vivo, rats were subjected to ischemia-reperfusion injury, resulting in increased water content, infarct volume, and expression of NFAT5 protein in rat spinal cord. After primary culture for spinal cord astrocytes, the in vitro OGSD/R model was established. The results of the CCK8 assay and flow cytometry showed that, in the OGSD/R group, astrocyte cell viability was downregulated, but astrocyte apoptosis increased. Caspase 3 activity increased as well. Levels of NFAT5, as detected by real-time quantitative PCR and western blot, decreased under OGSD/R, as did SIRT1. Commercial kits for activity assays were used to show that OGSD/R inhibited SIRT1 activation but accelerated SOD activation after OGSD/R. Next, pcDNA-NFAT5 or NFAT5 siRNA was transfected into astrocytes. Overexpression of NFAT5 not only promoted the survival of the astrocytes and SIRT1 activation under OGSD/R but also inhibited cell apoptosis and SOD activation. Moreover, overexpression of NFAT5 apparently diminished histone acetylation and promoted the nuclear transport of Nrf2. Our results show that NFAT5 protects spinal astrocytes in a manner that depends on activation of the SIRT1/Nrf2 pathway. These findings present a novel potential molecular mechanism for NFAT5 therapy in the context of spinal cord injury.
Collapse
Affiliation(s)
- Xun Xia
- Department of Neurological Surgery, Chengdu Military General Hospital, Chengdu, 610083, China
| | - Bo Qu
- Department of Orthopaedics, Chengdu Military General Hospital, Chengdu, 610083, China
| | - Yun-Ming Li
- Department of Neurological Surgery, Chengdu Military General Hospital, Chengdu, 610083, China
| | - Li-Bin Yang
- Department of Neurological Surgery, Chengdu Military General Hospital, Chengdu, 610083, China
| | - Ke-Xia Fan
- Department of Neurological Surgery, Chengdu Military General Hospital, Chengdu, 610083, China
| | - Hui Zheng
- Department of Neurological Surgery, Chengdu Military General Hospital, Chengdu, 610083, China
| | - Hai-Dong Huang
- Department of Neurological Surgery, Chengdu Military General Hospital, Chengdu, 610083, China
| | - Jian-Wen Gu
- Department of Neurological Surgery, The 306th Hospital of PLA, No. 9 Anxiangbeili, Chaoyang District, Beijing, 100101, China.
| | - Yong-Qin Kuang
- Department of Neurological Surgery, Chengdu Military General Hospital, Chengdu, 610083, China.
| | - Yuan Ma
- Department of Neurological Surgery, Chengdu Military General Hospital, Chengdu, 610083, China.
| |
Collapse
|
40
|
Greene DL, Hoshi N. Modulation of Kv7 channels and excitability in the brain. Cell Mol Life Sci 2016; 74:495-508. [PMID: 27645822 DOI: 10.1007/s00018-016-2359-y] [Citation(s) in RCA: 108] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2016] [Revised: 08/25/2016] [Accepted: 09/06/2016] [Indexed: 11/26/2022]
Abstract
Neuronal Kv7 channels underlie a voltage-gated non-inactivating potassium current known as the M-current. Due to its particular characteristics, Kv7 channels show pronounced control over the excitability of neurons. We will discuss various factors that have been shown to drastically alter the activity of this channel such as protein and phospholipid interactions, phosphorylation, calcium, and numerous neurotransmitters. Kv7 channels locate to key areas for the control of action potential initiation and propagation. Moreover, we will explore the dynamic surface expression of the channel modulated by neurotransmitters and neural activity. We will also focus on known principle functions of neural Kv7 channels: control of resting membrane potential and spiking threshold, setting the firing frequency, afterhyperpolarization after burst firing, theta resonance, and transient hyperexcitability from neurotransmitter-induced suppression of the M-current. Finally, we will discuss the contribution of altered Kv7 activity to pathologies such as epilepsy and cognitive deficits.
Collapse
Affiliation(s)
- Derek L Greene
- Department of Pharmacology, University of California, 360 Med Surge II, Irvine, CA, 92697, USA
| | - Naoto Hoshi
- Department of Pharmacology, University of California, 360 Med Surge II, Irvine, CA, 92697, USA.
- Department of Physiology and Biophysics, University of California, Irvine, USA.
| |
Collapse
|
41
|
Frazier HN, Maimaiti S, Anderson KL, Brewer LD, Gant JC, Porter NM, Thibault O. Calcium's role as nuanced modulator of cellular physiology in the brain. Biochem Biophys Res Commun 2016; 483:981-987. [PMID: 27553276 DOI: 10.1016/j.bbrc.2016.08.105] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2016] [Revised: 08/04/2016] [Accepted: 08/18/2016] [Indexed: 12/22/2022]
Abstract
Neuroscientists studying normal brain aging, spinal cord injury, Alzheimer's disease (AD) and other neurodegenerative diseases have focused considerable effort on carefully characterizing intracellular perturbations in calcium dynamics or levels. At the cellular level, calcium is known for controlling life and death and orchestrating most events in between. For many years, intracellular calcium has been recognized as an essential ion associated with nearly all cellular functions from cell growth to degeneration. Often the emphasis is on the negative impact of calcium dysregulation and the typical worse-case-scenario leading inevitably to cell death. However, even high amplitude calcium transients, when executed acutely, can alter neuronal communication and synaptic strength in positive ways, without necessarily killing neurons. Here, we focus on the evidence that calcium has a subtle and distinctive role in shaping and controlling synaptic events that underpin neuronal communication and that these subtle changes in aging or AD may contribute to cognitive decline. We emphasize that calcium imaging in dendritic components is ultimately necessary to directly test for the presence of age- or disease-associated alterations during periods of synaptic activation.
Collapse
Affiliation(s)
- Hilaree N Frazier
- UKMC, MS-313, Department of Pharmacology and Nutritional Sciences, University of Kentucky Medical Center, 800 Rose Street, Lexington, KY 40536, USA
| | - Shaniya Maimaiti
- UKMC, MS-313, Department of Pharmacology and Nutritional Sciences, University of Kentucky Medical Center, 800 Rose Street, Lexington, KY 40536, USA
| | - Katie L Anderson
- UKMC, MS-313, Department of Pharmacology and Nutritional Sciences, University of Kentucky Medical Center, 800 Rose Street, Lexington, KY 40536, USA
| | - Lawrence D Brewer
- UKMC, MS-313, Department of Pharmacology and Nutritional Sciences, University of Kentucky Medical Center, 800 Rose Street, Lexington, KY 40536, USA
| | - John C Gant
- UKMC, MS-313, Department of Pharmacology and Nutritional Sciences, University of Kentucky Medical Center, 800 Rose Street, Lexington, KY 40536, USA
| | - Nada M Porter
- UKMC, MS-313, Department of Pharmacology and Nutritional Sciences, University of Kentucky Medical Center, 800 Rose Street, Lexington, KY 40536, USA
| | - Olivier Thibault
- UKMC, MS-313, Department of Pharmacology and Nutritional Sciences, University of Kentucky Medical Center, 800 Rose Street, Lexington, KY 40536, USA.
| |
Collapse
|
42
|
The Emerging Roles of the Calcineurin-Nuclear Factor of Activated T-Lymphocytes Pathway in Nervous System Functions and Diseases. J Aging Res 2016; 2016:5081021. [PMID: 27597899 PMCID: PMC5002468 DOI: 10.1155/2016/5081021] [Citation(s) in RCA: 64] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2016] [Accepted: 07/21/2016] [Indexed: 12/27/2022] Open
Abstract
The ongoing epidemics of metabolic diseases and increase in the older population have increased the incidences of neurodegenerative diseases. Evidence from murine and cell line models has implicated calcineurin-nuclear factor of activated T-lymphocytes (NFAT) signaling pathway, a Ca2+/calmodulin-dependent major proinflammatory pathway, in the pathogenesis of these diseases. Neurotoxins such as amyloid-β, tau protein, and α-synuclein trigger abnormal calcineurin/NFAT signaling activities. Additionally increased activities of endogenous regulators of calcineurin like plasma membrane Ca2+-ATPase (PMCA) and regulator of calcineurin 1 (RCAN1) also cause neuronal and glial loss and related functional alterations, in neurodegenerative diseases, psychotic disorders, epilepsy, and traumatic brain and spinal cord injuries. Treatment with calcineurin/NFAT inhibitors induces some degree of neuroprotection and decreased reactive gliosis in the central and peripheral nervous system. In this paper, we summarize and discuss the current understanding of the roles of calcineurin/NFAT signaling in physiology and pathologies of the adult and developing nervous system, with an emphasis on recent reports and cutting-edge findings. Calcineurin/NFAT signaling is known for its critical roles in the developing and adult nervous system. Its role in physiological and pathological processes is still controversial. However, available data suggest that its beneficial and detrimental effects are context-dependent. In view of recent reports calcineurin/NFAT signaling is likely to serve as a potential therapeutic target for neurodegenerative diseases and conditions. This review further highlights the need to characterize better all factors determining the outcome of calcineurin/NFAT signaling in diseases and the downstream targets mediating the beneficial and detrimental effects.
Collapse
|
43
|
Saccà SC, Gandolfi S, Bagnis A, Manni G, Damonte G, Traverso CE, Izzotti A. From DNA damage to functional changes of the trabecular meshwork in aging and glaucoma. Ageing Res Rev 2016; 29:26-41. [PMID: 27242026 DOI: 10.1016/j.arr.2016.05.012] [Citation(s) in RCA: 90] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2015] [Revised: 05/25/2016] [Accepted: 05/26/2016] [Indexed: 12/24/2022]
Abstract
Glaucoma is a degenerative disease of the eye. Both the anterior and posterior segments of the eye are affected, extensive damage being detectable in the trabecular meshwork and the inner retina-central visual pathway complex. Oxidative stress is claimed to be mainly responsible for molecular damage in the anterior chamber. Indeed, oxidation harms the trabecular meshwork, leading eventually to endothelial cell decay, tissue malfunction, subclinical inflammation, changes in the extracellular matrix and cytoskeleton, altered motility, reduced outflow facility and (ultimately) increased IOP. Moreover, free radicals are involved in aging and can be produced in the brain (as well as in the eye) as a result of ischemia, leading to oxidation of the surrounding neurons. Glaucoma-related cell death occurs by means of apoptosis, and apoptosis is triggered by oxidative stress via (a) mitochondrial damage, (b) inflammation, (c) endothelial dysregulation and dysfunction, and (d) hypoxia. The proteomics of the aqueous humor is significantly altered in glaucoma as a result of oxidation-induced trabecular damage. Those proteins whose aqueous humor levels are increased in glaucoma are biomarkers of trabecular meshwork impairment. Their diffusion from the anterior to the posterior segment of the eye may be relevant in the cascade of events triggering apoptosis in the inner retinal layers, including the ganglion cells.
Collapse
Affiliation(s)
- Sergio Claudio Saccà
- IRCCS San Martino University Hospital, Department of Neuroscience and Sense Organs, San Martino Hospital, Ophthalmology Unit, Viale Benedetto XV, 16132 Genoa, Italy.
| | - Stefano Gandolfi
- Ophthalmology Unit, Department of Biological, Biotechnological and Translational Sciences, University of Parma, Parma, Italy
| | - Alessandro Bagnis
- University of Genoa, Eye Clinic, Department of Neuroscience and Sense Organs, Viale Benedetto XV, 5, 16148 Genoa, Italy
| | - Gianluca Manni
- Dept. of Clinical Science and Translational Medicine, University Tor Vergata, Rome, Italy
| | - Gianluca Damonte
- Dept. of Experimental Medicine, Section of Biochemistry and Center of Excellence for Biomedical Research, University of Genoa, Viale Benedetto XV 1, 16132 Genoa, Italy
| | - Carlo Enrico Traverso
- University of Genoa, Eye Clinic, Department of Neuroscience and Sense Organs, Viale Benedetto XV, 5, 16148 Genoa, Italy
| | - Alberto Izzotti
- Mutagenesis Unit, IRCCS San Martino University Hospital, IST National Institute for Cancer Research, Department of Health Sciences, University of Genoa, Via A. Pastore 1, Genoa I-16132, Italy
| |
Collapse
|
44
|
Yao JJ, Zhao QR, Liu DD, Chow CW, Mei YA. Neuritin Up-regulates Kv4.2 α-Subunit of Potassium Channel Expression and Affects Neuronal Excitability by Regulating the Calcium-Calcineurin-NFATc4 Signaling Pathway. J Biol Chem 2016; 291:17369-81. [PMID: 27307045 PMCID: PMC5016134 DOI: 10.1074/jbc.m115.708883] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2015] [Indexed: 11/06/2022] Open
Abstract
Neuritin is an important neurotrophin that regulates neural development, synaptic plasticity, and neuronal survival. Elucidating the downstream molecular signaling is important for potential therapeutic applications of neuritin in neuronal dysfunctions. We previously showed that neuritin up-regulates transient potassium outward current (IA) subunit Kv4.2 expression and increases IA densities, in part by activating the insulin receptor signaling pathway. Molecular mechanisms of neuritin-induced Kv4.2 expression remain elusive. Here, we report that the Ca(2+)/calcineurin (CaN)/nuclear factor of activated T-cells (NFAT) c4 axis is required for neuritin-induced Kv4.2 transcriptional expression and potentiation of IA densities in cerebellum granule neurons. We found that neuritin elevates intracellular Ca(2+) and increases Kv4.2 expression and IA densities; this effect was sensitive to CaN inhibition and was eliminated in Nfatc4(-/-) mice but not in Nfatc2(-/-) mice. Stimulation with neuritin significantly increased nuclear accumulation of NFATc4 in cerebellum granule cells and HeLa cells, which expressed IR. Furthermore, NFATc4 was recruited to the Kv4.2 gene promoter loci detected by luciferase reporter and chromatin immunoprecipitation assays. More importantly, data obtained from cortical neurons following adeno-associated virus-mediated overexpression of neuritin indicated that reduced neuronal excitability and increased formation of dendritic spines were abrogated in the Nfatc4(-/-) mice. Together, these data demonstrate an indispensable role for the CaN/NFATc4 signaling pathway in neuritin-regulated neuronal functions.
Collapse
Affiliation(s)
- Jin-Jing Yao
- From the Institutes of Brain Science, School of Life Sciences and State Key Laboratory of Medical Neurobiology, Fudan University, Shanghai 200433, China and
| | - Qian-Ru Zhao
- From the Institutes of Brain Science, School of Life Sciences and State Key Laboratory of Medical Neurobiology, Fudan University, Shanghai 200433, China and
| | - Dong-Dong Liu
- From the Institutes of Brain Science, School of Life Sciences and State Key Laboratory of Medical Neurobiology, Fudan University, Shanghai 200433, China and
| | - Chi-Wing Chow
- the Department of Molecular Pharmacology, Albert Einstein College of Medicine, New York, New York 10461
| | - Yan-Ai Mei
- From the Institutes of Brain Science, School of Life Sciences and State Key Laboratory of Medical Neurobiology, Fudan University, Shanghai 200433, China and
| |
Collapse
|
45
|
Lehnert S, Hartmann S, Hessler S, Adelsberger H, Huth T, Alzheimer C. Ion channel regulation by β-secretase BACE1 - enzymatic and non-enzymatic effects beyond Alzheimer's disease. Channels (Austin) 2016; 10:365-378. [PMID: 27253079 DOI: 10.1080/19336950.2016.1196307] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
β-site APP-cleaving enzyme 1 (BACE1) has become infamous for its pivotal role in the pathogenesis of Alzheimer's disease (AD). Consequently, BACE1 represents a prime target in drug development. Despite its detrimental involvement in AD, it should be quite obvious that BACE1 is not primarily present in the brain to drive mental decline. In fact, additional functions have been identified. In this review, we focus on the regulation of ion channels, specifically voltage-gated sodium and KCNQ potassium channels, by BACE1. These studies provide evidence for a highly unexpected feature in the functional repertoire of BACE1. Although capable of cleaving accessory channel subunits, BACE1 exerts many of its physiologically significant effects through direct, non-enzymatic interactions with main channel subunits. We discuss how the underlying mechanisms can be conceived and develop scenarios how the regulation of ion conductances by BACE1 might shape electric activity in the intact and diseased brain and heart.
Collapse
Affiliation(s)
- Sandra Lehnert
- a Institute of Physiology and Pathophysiology , Friedrich-Alexander-Universität Erlangen-Nürnberg , Erlangen , Germany
| | - Stephanie Hartmann
- a Institute of Physiology and Pathophysiology , Friedrich-Alexander-Universität Erlangen-Nürnberg , Erlangen , Germany
| | - Sabine Hessler
- b School of Psychology , University of Sussex , Brighton , UK
| | - Helmuth Adelsberger
- c Institute of Neuroscience, Technische Universität München , München , Germany
| | - Tobias Huth
- a Institute of Physiology and Pathophysiology , Friedrich-Alexander-Universität Erlangen-Nürnberg , Erlangen , Germany
| | - Christian Alzheimer
- a Institute of Physiology and Pathophysiology , Friedrich-Alexander-Universität Erlangen-Nürnberg , Erlangen , Germany
| |
Collapse
|
46
|
Friedman AK, Juarez B, Ku SM, Zhang H, Calizo RC, Walsh JJ, Chaudhury D, Zhang S, Hawkins A, Dietz DM, Murrough JW, Ribadeneira M, Wong EH, Neve RL, Han MH. KCNQ channel openers reverse depressive symptoms via an active resilience mechanism. Nat Commun 2016; 7:11671. [PMID: 27216573 PMCID: PMC4890180 DOI: 10.1038/ncomms11671] [Citation(s) in RCA: 102] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2016] [Accepted: 04/18/2016] [Indexed: 02/01/2023] Open
Abstract
Less than half of patients suffering from major depressive disorder, a leading cause of disability worldwide, achieve remission with current antidepressants, making it imperative to develop more effective treatment. A new therapeutic direction is emerging from the increased understanding of natural resilience as an active stress-coping process. It is known that potassium (K(+)) channels in the ventral tegmental area (VTA) are an active mediator of resilience. However, no druggable targets have been identified to potentiate active resilience mechanisms. In the chronic social defeat stress model of depression, we report that KCNQ-type K(+) channel openers, including FDA-approved drug retigabine (ezogabine), show antidepressant efficacy. We demonstrate that overexpression of KCNQ channels in the VTA dopaminergic neurons and either local infusion or systemic administration of retigabine normalized neuronal hyperactivity and depressive behaviours. These findings identify KCNQ as a target for conceptually novel antidepressants that function through the potentiation of active resilience mechanisms.
Collapse
Affiliation(s)
- Allyson K Friedman
- Department of Pharmacology and Systems Therapeutics, Icahn School of Medicine at Mount Sinai, New York, New York 10029, USA.,Department of Biological Sciences, Hunter College, Biology and Biochemistry PhD Program, Graduate Center, The City University of New York, New York, New York 10065, USA
| | - Barbara Juarez
- Department of Pharmacology and Systems Therapeutics, Icahn School of Medicine at Mount Sinai, New York, New York 10029, USA.,Graduate School of Biomedical Sciences, Icahn School of Medicine at Mount Sinai, New York, New York 10029, USA
| | - Stacy M Ku
- Department of Pharmacology and Systems Therapeutics, Icahn School of Medicine at Mount Sinai, New York, New York 10029, USA.,Graduate School of Biomedical Sciences, Icahn School of Medicine at Mount Sinai, New York, New York 10029, USA
| | - Hongxing Zhang
- Department of Pharmacology and Systems Therapeutics, Icahn School of Medicine at Mount Sinai, New York, New York 10029, USA
| | - Rhodora C Calizo
- Department of Pharmacology and Systems Therapeutics, Icahn School of Medicine at Mount Sinai, New York, New York 10029, USA
| | - Jessica J Walsh
- Department of Pharmacology and Systems Therapeutics, Icahn School of Medicine at Mount Sinai, New York, New York 10029, USA.,Graduate School of Biomedical Sciences, Icahn School of Medicine at Mount Sinai, New York, New York 10029, USA
| | - Dipesh Chaudhury
- Department of Pharmacology and Systems Therapeutics, Icahn School of Medicine at Mount Sinai, New York, New York 10029, USA
| | - Song Zhang
- Department of Pharmacology and Systems Therapeutics, Icahn School of Medicine at Mount Sinai, New York, New York 10029, USA
| | - Angel Hawkins
- Department of Pharmacology and Systems Therapeutics, Icahn School of Medicine at Mount Sinai, New York, New York 10029, USA
| | - David M Dietz
- Fishberg Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, New York 10029, USA
| | - James W Murrough
- Fishberg Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, New York 10029, USA.,Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, New York 10029, USA.,Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, New York 10029, USA
| | - Maria Ribadeneira
- CNS Pain Innovative Medicine Unit, AstraZeneca Pharmaceuticals, Wilmington, Delaware 19850, USA
| | - Erik H Wong
- CNS Pain Innovative Medicine Unit, AstraZeneca Pharmaceuticals, Wilmington, Delaware 19850, USA
| | - Rachael L Neve
- McGovern Institute for Brain Research, Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - Ming-Hu Han
- Department of Pharmacology and Systems Therapeutics, Icahn School of Medicine at Mount Sinai, New York, New York 10029, USA.,Fishberg Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, New York 10029, USA.,Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, New York 10029, USA
| |
Collapse
|
47
|
Vihma H, Luhakooder M, Pruunsild P, Timmusk T. Regulation of different human NFAT isoforms by neuronal activity. J Neurochem 2016; 137:394-408. [PMID: 26851544 DOI: 10.1111/jnc.13568] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2015] [Revised: 01/04/2016] [Accepted: 01/29/2016] [Indexed: 12/30/2022]
Abstract
Nuclear factor of activated T-cells (NFAT) is a family of transcription factors comprising four calcium-regulated members: NFATc1, NFATc2, NFATc3, and NFATc4. Upon activation by the calcium-dependent phosphatase calcineurin (CaN), NFATs translocate from cytosol to the nucleus and regulate their target genes, which in the nervous system are involved in axon growth, synaptic plasticity, and neuronal survival. We have shown previously that there are a number of different splice variants of NFAT genes expressed in the brain. Here, we studied the subcellular localizations and transactivation capacities of alternative human NFAT isoforms in rat primary cortical or hippocampal neurons in response to membrane depolarization and compared the induced transactivation levels in neurons to those obtained from HEK293 cells in response to calcium signaling. We confirm that in neurons the translocation to the nucleus of all NFAT isoforms is reliant on the activity of CaN. However, our results suggest that both the regulation of subcellular localization and transcriptional activity of NFAT proteins in neurons is isoform specific. We show that in primary hippocampal neurons NFATc2 isoforms have very fast translocation kinetics, whereas NFATc4 isoforms translocate relatively slowly to the nucleus. Moreover, we demonstrate that the strongest transcriptional activators in HEK293 cells are NFATc1 and NFATc3, but in neurons NFATc3 and NFATc4 lead to the highest induction, and NFATc2 and NFATc1 display isoform-specific transcription activation capacities. Altogether, our results indicate that the effects of calcium signaling on the action of NFAT proteins are isoform-specific and can differ between cell types. We show that the effects of calcium signaling on the action of NFAT proteins are isoform-specific and differ between cell types. Although nuclear localization of all NFAT isoforms in neurons requires calcineurin, the subcellular distributions, neuronal activity-induced nuclear translocation extent and kinetics, and transcription activation capacities of alternative NFAT proteins vary.
Collapse
Affiliation(s)
- Hanna Vihma
- Department of Gene Technology, Tallinn University of Technology, Tallinn, Estonia
| | - Mirjam Luhakooder
- Department of Gene Technology, Tallinn University of Technology, Tallinn, Estonia
| | - Priit Pruunsild
- Department of Gene Technology, Tallinn University of Technology, Tallinn, Estonia
| | - Tõnis Timmusk
- Department of Gene Technology, Tallinn University of Technology, Tallinn, Estonia
| |
Collapse
|
48
|
Ohya S, Kito H, Hatano N, Muraki K. Recent advances in therapeutic strategies that focus on the regulation of ion channel expression. Pharmacol Ther 2016; 160:11-43. [PMID: 26896566 DOI: 10.1016/j.pharmthera.2016.02.001] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
A number of different ion channel types are involved in cell signaling networks, and homeostatic regulatory mechanisms contribute to the control of ion channel expression. Profiling of global gene expression using microarray technology has recently provided novel insights into the molecular mechanisms underlying the homeostatic and pathological control of ion channel expression. It has demonstrated that the dysregulation of ion channel expression is associated with the pathogenesis of neural, cardiovascular, and immune diseases as well as cancers. In addition to the transcriptional, translational, and post-translational regulation of ion channels, potentially important evidence on the mechanisms controlling ion channel expression has recently been accumulated. The regulation of alternative pre-mRNA splicing is therefore a novel therapeutic strategy for the treatment of dominant-negative splicing disorders. Epigenetic modification plays a key role in various pathological conditions through the regulation of pluripotency genes. Inhibitors of pre-mRNA splicing and histone deacetyalase/methyltransferase have potential as potent therapeutic drugs for cancers and autoimmune and inflammatory diseases. Moreover, membrane-anchoring proteins, lysosomal and proteasomal degradation-related molecules, auxiliary subunits, and pharmacological agents alter the protein folding, membrane trafficking, and post-translational modifications of ion channels, and are linked to expression-defect channelopathies. In this review, we focused on recent insights into the transcriptional, spliceosomal, epigenetic, and proteasomal regulation of ion channel expression: Ca(2+) channels (TRPC/TRPV/TRPM/TRPA/Orai), K(+) channels (voltage-gated, KV/Ca(2+)-activated, KCa/two-pore domain, K2P/inward-rectifier, Kir), and Ca(2+)-activated Cl(-) channels (TMEM16A/TMEM16B). Furthermore, this review highlights expression of these ion channels in expression-defect channelopathies.
Collapse
Affiliation(s)
- Susumu Ohya
- Department of Pharmacology, Division of Pathological Sciences, Kyoto Pharmaceutical University, Kyoto 607-8414, Japan.
| | - Hiroaki Kito
- Department of Pharmacology, Division of Pathological Sciences, Kyoto Pharmaceutical University, Kyoto 607-8414, Japan
| | - Noriyuki Hatano
- Laboratory of Cellular Pharmacology, School of Pharmacy, Aichi-Gakuin University, Nagoya 464-8650, Japan
| | - Katsuhiko Muraki
- Laboratory of Cellular Pharmacology, School of Pharmacy, Aichi-Gakuin University, Nagoya 464-8650, Japan.
| |
Collapse
|
49
|
Gamper N. Localised intracellular signalling in neurons. J Physiol 2016; 594:7-8. [PMID: 26724480 DOI: 10.1113/jp271357] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2015] [Accepted: 11/06/2015] [Indexed: 11/08/2022] Open
Affiliation(s)
- Nikita Gamper
- Faculty of Biological Sciences, University of Leeds, Leeds, UK.,Department of Pharmacology, Hebei Medical University, Shijiazhuang, China
| |
Collapse
|
50
|
Radwan B, Liu H, Chaudhury D. Regulation and Modulation of Depression-Related Behaviours: Role of Dopaminergic Neurons. DOPAMINE AND SLEEP 2016:147-190. [DOI: 10.1007/978-3-319-46437-4_8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/19/2023]
|