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Qiu J, Voliotis M, Bosch MA, Li XF, Zweifel LS, Tsaneva-Atanasova K, O’Byrne KT, Rønnekleiv OK, Kelly MJ. Estradiol elicits distinct firing patterns in arcuate nucleus kisspeptin neurons of females through altering ion channel conductances. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.02.20.581121. [PMID: 38915596 PMCID: PMC11195100 DOI: 10.1101/2024.02.20.581121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/26/2024]
Abstract
Hypothalamic kisspeptin (Kiss1) neurons are vital for pubertal development and reproduction. Arcuate nucleus Kiss1 (Kiss1ARH) neurons are responsible for the pulsatile release of Gonadotropin-releasing Hormone (GnRH). In females, the behavior of Kiss1ARH neurons, expressing Kiss1, Neurokinin B (NKB), and Dynorphin (Dyn), varies throughout the ovarian cycle. Studies indicate that 17β-estradiol (E2) reduces peptide expression but increases Vglut2 mRNA and glutamate neurotransmission in these neurons, suggesting a shift from peptidergic to glutamatergic signaling. To investigate this shift, we combined transcriptomics, electrophysiology, and mathematical modeling. Our results demonstrate that E2 treatment upregulates the mRNA expression of voltage-activated calcium channels, elevating the whole-cell calcium current and that contribute to high-frequency burst firing. Additionally, E2 treatment decreased the mRNA levels of Canonical Transient Receptor Potential (TPRC) 5 and G protein-coupled K+ (GIRK) channels. When TRPC5 channels in Kiss1ARH neurons were deleted using CRISPR, the slow excitatory postsynaptic potential (sEPSP) was eliminated. Our data enabled us to formulate a biophysically realistic mathematical model of the Kiss1ARH neuron, suggesting that E2 modifies ionic conductances in Kiss1ARH neurons, enabling the transition from high frequency synchronous firing through NKB-driven activation of TRPC5 channels to a short bursting mode facilitating glutamate release. In a low E2 milieu, synchronous firing of Kiss1ARH neurons drives pulsatile release of GnRH, while the transition to burst firing with high, preovulatory levels of E2 would facilitate the GnRH surge through its glutamatergic synaptic connection to preoptic Kiss1 neurons.
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Affiliation(s)
- Jian Qiu
- Department of Chemical Physiology and Biochemistry, Oregon Health and Science University, Portland, OR 97239, USA
| | - Margaritis Voliotis
- Department of Mathematics and Statistics, University of Exeter, Stocker Rd, Exeter, EX4 4PY, UK
- Living Systems Institute, University of Exeter, Stocker Rd, Exeter, EX4 4PY, UK
| | - Martha A. Bosch
- Department of Chemical Physiology and Biochemistry, Oregon Health and Science University, Portland, OR 97239, USA
| | - Xiao Feng Li
- Department of Women and Children’s Health, School of Life Course and Population Sciences, King’s College London, Guy’s Campus, London SE1 1UL, UK
| | - Larry S. Zweifel
- Department of Psychiatry and Behavioral Sciences, University of Washington, Seattle, WA 98195, USA
- Depatment of Pharmacology, University of Washington, Seattle, WA 98195, USA
| | - Krasimira Tsaneva-Atanasova
- Department of Mathematics and Statistics, University of Exeter, Stocker Rd, Exeter, EX4 4PY, UK
- Living Systems Institute, University of Exeter, Stocker Rd, Exeter, EX4 4PY, UK
| | - Kevin T. O’Byrne
- Department of Women and Children’s Health, School of Life Course and Population Sciences, King’s College London, Guy’s Campus, London SE1 1UL, UK
| | - Oline K. Rønnekleiv
- Department of Chemical Physiology and Biochemistry, Oregon Health and Science University, Portland, OR 97239, USA
- Division of Neuroscience, Oregon National Primate Research Center, Beaverton, OR 97006, USA
| | - Martin J. Kelly
- Department of Chemical Physiology and Biochemistry, Oregon Health and Science University, Portland, OR 97239, USA
- Division of Neuroscience, Oregon National Primate Research Center, Beaverton, OR 97006, USA
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Baron J, Groschner K, Tiapko O. Calcium transport and sensing in TRPC channels - New insights into a complex feedback regulation. Cell Calcium 2023; 116:102816. [PMID: 37897981 DOI: 10.1016/j.ceca.2023.102816] [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: 09/07/2023] [Revised: 10/16/2023] [Accepted: 10/17/2023] [Indexed: 10/30/2023]
Abstract
Canonical TRP (TRPC) channels are a still enigmatic family of signaling molecules with multimodal sensing features. These channels enable Ca2+ influx through the plasma membrane to control a diverse range of cellular functions. Based on both regulatory- and recently uncovered structural features, TRPC channels are considered to coordinate Ca2+ and other divalent cations not only within the permeation path but also at additional sensory sites. Analysis of TRPC structures by cryo-EM identified multiple regulatory ion binding pockets. With this review, we aim at an overview and a critical discussion of the current concepts of divalent sensing by TRPC channels.
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Affiliation(s)
- Jasmin Baron
- Gottfried-Schatz-Research-Center Medical Physics and Biophysics, Medical University of Graz, Neue Stiftingtalstrasse 6/H03, 8010 Graz, Austria
| | - Klaus Groschner
- Gottfried-Schatz-Research-Center Medical Physics and Biophysics, Medical University of Graz, Neue Stiftingtalstrasse 6/H03, 8010 Graz, Austria
| | - Oleksandra Tiapko
- Gottfried-Schatz-Research-Center Medical Physics and Biophysics, Medical University of Graz, Neue Stiftingtalstrasse 6/H03, 8010 Graz, Austria.
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Jiang ZJ, Gong LW. The SphK1/S1P Axis Regulates Synaptic Vesicle Endocytosis via TRPC5 Channels. J Neurosci 2023; 43:3807-3824. [PMID: 37185099 PMCID: PMC10217994 DOI: 10.1523/jneurosci.1494-22.2023] [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: 08/03/2022] [Revised: 04/13/2023] [Accepted: 04/17/2023] [Indexed: 05/17/2023] Open
Abstract
Sphingosine-1-phosphate (S1P), a bioactive sphingolipid concentrated in the brain, is essential for normal brain functions, such as learning and memory and feeding behaviors. Sphingosine kinase 1 (SphK1), the primary kinase responsible for S1P production in the brain, is abundant within presynaptic terminals, indicating a potential role of the SphK1/S1P axis in presynaptic physiology. Altered S1P levels have been highlighted in many neurologic diseases with endocytic malfunctions. However, it remains unknown whether the SphK1/S1P axis may regulate synaptic vesicle endocytosis in neurons. The present study evaluates potential functions of the SphK1/S1P axis in synaptic vesicle endocytosis by determining effects of a dominant negative catalytically inactive SphK1. Our data for the first time identify a critical role of the SphK1/S1P axis in endocytosis in both neuroendocrine chromaffin cells and neurons from mice of both sexes. Furthermore, our Ca2+ imaging data indicate that the SphK1/S1P axis may be important for presynaptic Ca2+ increases during prolonged stimulations by regulating the Ca2+ permeable TRPC5 channels, which per se regulate synaptic vesicle endocytosis. Collectively, our data point out a critical role of the regulation of TRPC5 by the SphK1/S1P axis in synaptic vesicle endocytosis.SIGNIFICANCE STATEMENT Sphingosine kinase 1 (SphK1), the primary kinase responsible for brain sphingosine-1-phosphate (S1P) production, is abundant within presynaptic terminals. Altered SphK1/S1P metabolisms has been highlighted in many neurologic disorders with defective synaptic vesicle endocytosis. However, whether the SphK1/S1P axis may regulate synaptic vesicle endocytosis is unknown. Here, we identify that the SphK1/S1P axis regulates the kinetics of synaptic vesicle endocytosis in neurons, in addition to controlling fission-pore duration during single vesicle endocytosis in neuroendocrine chromaffin cells. The regulation of the SphK1/S1P axis in synaptic vesicle endocytosis is specific since it has a distinguished signaling pathway, which involves regulation of Ca2+ influx via TRPC5 channels. This discovery may provide novel mechanistic implications for the SphK1/S1P axis in brain functions under physiological and pathologic conditions.
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Affiliation(s)
- Zhong-Jiao Jiang
- Department of Biological Sciences, University of Illinois Chicago, Chicago, Illinois 60607
| | - Liang-Wei Gong
- Department of Biological Sciences, University of Illinois Chicago, Chicago, Illinois 60607
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4
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Won J, Kim J, Jeong H, Kim J, Feng S, Jeong B, Kwak M, Ko J, Im W, So I, Lee HH. Molecular architecture of the Gα i-bound TRPC5 ion channel. Nat Commun 2023; 14:2550. [PMID: 37137991 PMCID: PMC10156788 DOI: 10.1038/s41467-023-38281-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2023] [Accepted: 04/21/2023] [Indexed: 05/05/2023] Open
Abstract
G-protein coupled receptors (GPCRs) and ion channels serve as key molecular switches through which extracellular stimuli are transformed into intracellular effects, and it has long been postulated that ion channels are direct effector molecules of the alpha subunit of G-proteins (Gα). However, no complete structural evidence supporting the direct interaction between Gα and ion channels is available. Here, we present the cryo-electron microscopy structures of the human transient receptor potential canonical 5 (TRPC5)-Gαi3 complexes with a 4:4 stoichiometry in lipid nanodiscs. Remarkably, Gαi3 binds to the ankyrin repeat edge of TRPC5 ~ 50 Å away from the cell membrane. Electrophysiological analysis shows that Gαi3 increases the sensitivity of TRPC5 to phosphatidylinositol 4,5-bisphosphate (PIP2), thereby rendering TRPC5 more easily opened in the cell membrane, where the concentration of PIP2 is physiologically regulated. Our results demonstrate that ion channels are one of the direct effector molecules of Gα proteins triggered by GPCR activation-providing a structural framework for unraveling the crosstalk between two major classes of transmembrane proteins: GPCRs and ion channels.
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Affiliation(s)
- Jongdae Won
- Department of Chemistry, College of Natural Sciences, Seoul National University, Seoul, 08826, Republic of Korea
| | - Jinsung Kim
- Department of Physiology, College of Medicine, Seoul National University, Seoul, 03080, Republic of Korea
| | - Hyeongseop Jeong
- Center for Research Equipment, Korea Basic Science Institute, Chungcheongbuk-do, 28119, Republic of Korea
| | - Jinhyeong Kim
- Department of Physiology, College of Medicine, Seoul National University, Seoul, 03080, Republic of Korea
| | - Shasha Feng
- Department of Biological Sciences and Chemistry, Lehigh University, Bethlehem, PA, 18015, USA
| | - Byeongseok Jeong
- Department of Physiology, College of Medicine, Seoul National University, Seoul, 03080, Republic of Korea
| | - Misun Kwak
- Department of Physiology, College of Medicine, Seoul National University, Seoul, 03080, Republic of Korea
| | - Juyeon Ko
- Department of Physiology, College of Medicine, Seoul National University, Seoul, 03080, Republic of Korea
- Department of Physiology, University of California, San Francisco, San Francisco, CA, 94158, USA
| | - Wonpil Im
- Department of Biological Sciences and Chemistry, Lehigh University, Bethlehem, PA, 18015, USA
| | - Insuk So
- Department of Physiology, College of Medicine, Seoul National University, Seoul, 03080, Republic of Korea.
| | - Hyung Ho Lee
- Department of Chemistry, College of Natural Sciences, Seoul National University, Seoul, 08826, Republic of Korea.
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Ko J, Kim J, Myeong J, Kwak M, So I. Negative self-regulation of transient receptor potential canonical 4 by the specific interaction with phospholipase C-δ1. THE KOREAN JOURNAL OF PHYSIOLOGY & PHARMACOLOGY : OFFICIAL JOURNAL OF THE KOREAN PHYSIOLOGICAL SOCIETY AND THE KOREAN SOCIETY OF PHARMACOLOGY 2023; 27:187-196. [PMID: 36815258 PMCID: PMC9968946 DOI: 10.4196/kjpp.2023.27.2.187] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/26/2022] [Revised: 12/27/2022] [Accepted: 12/29/2022] [Indexed: 02/24/2023]
Abstract
Transient receptor potential canonical (TRPC) channels are non-selective calcium-permeable cation channels. It is suggested that TRPC4β is regulated by phospholipase C (PLC) signaling and is especially maintained by phosphatidylinositol 4,5-bisphosphate (PIP2). In this study, we present the regulation mechanism of the TRPC4 channel with PIP2 hydrolysis which is mediated by a channel-bound PLCδ1 but not by the GqPCR signaling pathway. Our electrophysiological recordings demonstrate that the Ca2+ via an open TRPC4 channel activates PLCδ1 in the physiological range, and it causes the decrease of current amplitude. The existence of PLCδ1 accelerated PIP2 depletion when the channel was activated by an agonist. Interestingly, PLCδ1 mutants which have lost the ability to regulate PIP2 level failed to reduce the TRPC4 current amplitude. Our results demonstrate that TRPC4 self-regulates its activity by allowing Ca2+ ions into the cell and promoting the PIP2 hydrolyzing activity of PLCδ1.
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Affiliation(s)
- Juyeon Ko
- Department of Physiology, Seoul National University College of Medicine, Seoul 03080, Korea
| | - Jinhyeong Kim
- Department of Physiology, Seoul National University College of Medicine, Seoul 03080, Korea
| | - Jongyun Myeong
- Department of Physiology, Seoul National University College of Medicine, Seoul 03080, Korea
| | - Misun Kwak
- Department of Physiology, Seoul National University College of Medicine, Seoul 03080, Korea
| | - Insuk So
- Department of Physiology, Seoul National University College of Medicine, Seoul 03080, Korea,Correspondence Insuk So, E-mail:
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Manning D, Barrett-Jolley R, Evans RL, Dart C. TRPC1 channel clustering during store-operated Ca 2+ entry in keratinocytes. Front Physiol 2023; 14:1141006. [PMID: 36950299 PMCID: PMC10025536 DOI: 10.3389/fphys.2023.1141006] [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: 01/09/2023] [Accepted: 02/20/2023] [Indexed: 03/08/2023] Open
Abstract
Skin is the largest organ in the human body with ∼95% of its surface made up of keratinocytes. These cells maintain a healthy skin barrier through regulated differentiation driven by Ca2+-transcriptional coupling. Many important skin conditions arise from disruption of this process although not all stages are fully understood. We know that elevated extracellular Ca2+ at the skin surface is detected by keratinocyte Gαq-coupled receptors that signal to empty endoplasmic reticulum Ca2+ stores. Orai channel store-operated Ca2+ entry (SOCE) and Ca2+ influx via "canonical" transient receptor potential (TRPC)-composed channels then activates transcription factors that drive differentiation. While STIM-mediated activation of Orai channels following store depletion is well defined, how TRPC channels are activated is less clear. Multiple modes of TRPC channel activation have been proposed, including 1) independent TRPC activation by STIM, 2) formation of Orai-TRPC-STIM complexes, and 3) the insertion of constitutively-active TRPC channels into the membrane during SOCE. To help distinguish between these models, we used high-resolution microscopy of intact keratinocyte (HaCaT) cells and immunogold transmission electron microscopy (TEM) of HaCaT plasma membrane sheets. Our data shows no evidence of significant insertion of Orai1 or TRPC subunits into the membrane during SOCE. Analysis of transmission electron microscopy data shows that during store-depletion and SOCE, Orai1 and TRPC subunits form separate membrane-localized clusters that migrate towards each other. This clustering of TRPC channel subunits in keratinocytes may support the formation of TRPC-STIM interactions at ER-plasma membrane junctions that are distinct from Orai-STIM junctions.
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Affiliation(s)
- Declan Manning
- Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool, United Kingdom
| | - Richard Barrett-Jolley
- Institute of Life Course and Medical Sciences, University of Liverpool, Liverpool, United Kingdom
| | - Richard L. Evans
- Unilever Research & Development, Port Sunlight Laboratory, Wirral, United Kingdom
| | - Caroline Dart
- Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool, United Kingdom
- *Correspondence: Caroline Dart,
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7
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Kollewe A, Schwarz Y, Oleinikov K, Raza A, Haupt A, Wartenberg P, Wyatt A, Boehm U, Ectors F, Bildl W, Zolles G, Schulte U, Bruns D, Flockerzi V, Fakler B. Subunit composition, molecular environment, and activation of native TRPC channels encoded by their interactomes. Neuron 2022; 110:4162-4175.e7. [PMID: 36257322 DOI: 10.1016/j.neuron.2022.09.029] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Revised: 08/15/2022] [Accepted: 09/23/2022] [Indexed: 12/24/2022]
Abstract
In the mammalian brain TRPC channels, a family of Ca2+-permeable cation channels, are involved in a variety of processes from neuronal growth and synapse formation to transmitter release, synaptic transmission and plasticity. The molecular appearance and operation of native TRPC channels, however, remained poorly understood. Here, we used high-resolution proteomics to show that TRPC channels in the rodent brain are macro-molecular complexes of more than 1 MDa in size that result from the co-assembly of the tetrameric channel core with an ensemble of interacting proteins (interactome). The core(s) of TRPC1-, C4-, and C5-containing channels are mostly heteromers with defined stoichiometries for each subtype, whereas TRPC3, C6, and C7 preferentially form homomers. In addition, TRPC1/C4/C5 channels may co-assemble with the metabotropic glutamate receptor mGluR1, thus guaranteeing both specificity and reliability of channel activation via the phospholipase-Ca2+ pathway. Our results unveil the subunit composition of native TRPC channels and resolve the molecular details underlying their activation.
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Affiliation(s)
- Astrid Kollewe
- Institute of Physiology, Faculty of Medicine, University of Freiburg, Hermann-Herder-Str. 7, 79104 Freiburg, Germany
| | - Yvonne Schwarz
- Institute of Physiology, Center for Integrative Physiology and Molecular Medicine, Saarland University, 66421 Homburg, Germany
| | - Katharina Oleinikov
- Institute of Physiology, Center for Integrative Physiology and Molecular Medicine, Saarland University, 66421 Homburg, Germany
| | - Ahsan Raza
- Experimental and Clinical Pharmacology and Toxicology, PZMS, Saarland University, 66421 Homburg, Germany
| | - Alexander Haupt
- Institute of Physiology, Faculty of Medicine, University of Freiburg, Hermann-Herder-Str. 7, 79104 Freiburg, Germany
| | - Philipp Wartenberg
- Experimental and Clinical Pharmacology and Toxicology, PZMS, Saarland University, 66421 Homburg, Germany
| | - Amanda Wyatt
- Experimental and Clinical Pharmacology and Toxicology, PZMS, Saarland University, 66421 Homburg, Germany
| | - Ulrich Boehm
- Experimental and Clinical Pharmacology and Toxicology, PZMS, Saarland University, 66421 Homburg, Germany
| | - Fabien Ectors
- Transgenic facility, FARAH Research Center, Faculty of Veterinary Medicine, University of Liège, 4000 Liège, Belgium
| | - Wolfgang Bildl
- Institute of Physiology, Faculty of Medicine, University of Freiburg, Hermann-Herder-Str. 7, 79104 Freiburg, Germany
| | - Gerd Zolles
- Institute of Physiology, Faculty of Medicine, University of Freiburg, Hermann-Herder-Str. 7, 79104 Freiburg, Germany
| | - Uwe Schulte
- Institute of Physiology, Faculty of Medicine, University of Freiburg, Hermann-Herder-Str. 7, 79104 Freiburg, Germany; Signalling Research Centres BIOSS and CIBSS, Schänzlestr. 18, 79104 Freiburg, Germany
| | - Dieter Bruns
- Institute of Physiology, Center for Integrative Physiology and Molecular Medicine, Saarland University, 66421 Homburg, Germany
| | - Veit Flockerzi
- Experimental and Clinical Pharmacology and Toxicology, PZMS, Saarland University, 66421 Homburg, Germany.
| | - Bernd Fakler
- Institute of Physiology, Faculty of Medicine, University of Freiburg, Hermann-Herder-Str. 7, 79104 Freiburg, Germany; Signalling Research Centres BIOSS and CIBSS, Schänzlestr. 18, 79104 Freiburg, Germany; Center for Basics in NeuroModulation, Breisacherstr. 4, 79106 Freiburg, Germany.
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8
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Qiu J, Bosch MA, Stincic TL, Hunker AC, Zweifel LS, Rønnekleiv OK, Kelly MJ. CRISPR/SaCas9 mutagenesis of stromal interaction molecule 1 in proopiomelanocortin neurons increases glutamatergic excitability and protects against diet-induced obesity. Mol Metab 2022; 66:101645. [PMID: 36442744 PMCID: PMC9727646 DOI: 10.1016/j.molmet.2022.101645] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/13/2022] [Revised: 11/09/2022] [Accepted: 11/22/2022] [Indexed: 11/26/2022] Open
Abstract
OBJECTIVE Proopiomelanocortin (POMC) neurons are the key anorexigenic hypothalamic neuron for integrating metabolic cues to generate the appropriate output for maintaining energy homeostasis and express the requisite channels as a perfect synaptic integrator in this role. Similar to the metabolic hormones leptin and insulin, glutamate also excites POMC neurons via group I metabotropic glutamate receptors (mGluR1 and 5, mGluR1/5) that activate Transient Receptor Potential Canonical (TRPC 5) Channels to cause depolarization. A key modulator of TRPC 5 channel activity is stromal interaction molecule 1 (STIM1), which is involved in recruitment of TRPC 5 channels from receptor-operated to store-operated calcium entry following depletion of calcium from the endoplasmic reticulum. METHODS We used a single adeno-associated viral (AAV) vector containing a recombinase-dependent Staphylococcus aureus Cas9 (SaCas) and a single guide RNA (sgRNA) to mutate Stim1 in POMCCre neurons in male mice, verified by qPCR of Stim1 mRNA expression in single POMC neurons. Whole-cell patch clamp experiments were conducted to validate the effects of Stim1 mutagenesis. Body weight and food intake were measured in male mice to assess disruptions in energy balance. RESULTS Reduced Stim1 expression augmented the efficacy of the mGluR1/5 agonist 3, 5-Dihydroxyphenylglycine (DHPG) to depolarize POMC neurons via a Gαq-coupled signaling pathway, which is an essential part of excitatory glutamatergic input in regulating energy homeostasis. The TRPC 5 channel blockers HC070 and Pico145 antagonized the excitatory effects of DHPG. As proof of principle, mutagenesis of Stim1 in POMC neurons reduced food intake, attenuated weight gain, reduced body fat and fat pad mass in mice fed a high fat diet. CONCLUSIONS Using CRISPR technology we have uncovered a critical role of STIM1 in modulating glutamatergic activation of TRPC 5 channels in POMC neurons, which ultimately is important for maintaining energy balance.
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Affiliation(s)
- Jian Qiu
- Department of Chemical Physiology and Biochemistry, Oregon Health & Science University, Portland, OR 97239, USA,Corresponding author.Department of Chemical Physiology and Biochemistry, Oregon Health & Science University, Portland, OR 97239, USA
| | - Martha A. Bosch
- Department of Chemical Physiology and Biochemistry, Oregon Health & Science University, Portland, OR 97239, USA
| | - Todd L. Stincic
- Department of Chemical Physiology and Biochemistry, Oregon Health & Science University, Portland, OR 97239, USA
| | - Avery C. Hunker
- Department of Psychiatry and Behavioral Sciences, University of Washington, Seattle, WA 98195, USA
| | - Larry S. Zweifel
- Department of Psychiatry and Behavioral Sciences, University of Washington, Seattle, WA 98195, USA,Department of Pharmacology, University of Washington, Seattle, WA 98195, USA
| | - Oline K. Rønnekleiv
- Department of Chemical Physiology and Biochemistry, Oregon Health & Science University, Portland, OR 97239, USA,Division of Neuroscience, Oregon National Primate Research Center, Beaverton, OR 97006, USA
| | - Martin J. Kelly
- Department of Chemical Physiology and Biochemistry, Oregon Health & Science University, Portland, OR 97239, USA,Division of Neuroscience, Oregon National Primate Research Center, Beaverton, OR 97006, USA,Corresponding author.Department of Chemical Physiology and Biochemistry, Oregon Health & Science University, Portland, OR 97239, USA
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9
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Shang Y, Li Y, Yang Z, Zhou Z. Upregulation of TACAN in the trigeminal ganglion affects pain transduction in acute pulpitis. Arch Oral Biol 2022; 143:105530. [PMID: 36088852 DOI: 10.1016/j.archoralbio.2022.105530] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2022] [Revised: 07/28/2022] [Accepted: 08/23/2022] [Indexed: 11/02/2022]
Abstract
OBJECTIVE Acute pulpitis is one of the common causes of tooth pain. TACAN (Tmem120a) is a newly identified ion channel that senses mechanical pain. In this experiment, we studied the expression of the TACAN ion channel in the trigeminal ganglia in a rat model of pulpitis to explore the correlation between the expression of this ion channel and inflammatory pain. DESIGN Lipopolysaccharide was used to induce acute pulpitis in rats, and pulpitis was assessed histologically. The facial pain threshold of the rats was measured by the von Frey test. TACAN mRNA expression in rat dental pulp and the trigeminal nerve was measured by qPCR, and TACAN protein expression in the trigeminal ganglia was evaluated by western blot analysis and immunofluorescence. Antisense oligonucleotides were used to reduce TACAN protein expression in the trigeminal ganglia, and the change in the pain threshold in the rats with acute pulpitis was determined. RESULTS The results showed that the TACAN transcript level in rat pulp tissue increased under inflammatory conditions, and we proved that pulpitis increased TACAN protein expression in the rat ipsilateral trigeminal ganglia. The facial pain threshold was decreased in rats with pulpitis. A short-term decrease in TACAN protein expression could improve the pain threshold. CONCLUSIONS With the development of pulpitis after bacterial infection, the upregulation of TACAN expression in the trigeminal ganglia promoted pain sensitivity. A short-term reduction in TACAN expression relieved pain. Therefore, this study indicated that TACAN is a potential target channel for new analgesics.
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Affiliation(s)
- Yicong Shang
- College of Stomatology, Chongqing Medical University, Chongqing, China; Chongqing Key Laboratory of Oral Diseases and Biomedical Sciences, Chongqing, China; Chongqing Municipal Key Laboratory of Oral Biomedical Engineering of Higher Education, Chongqing, China
| | - Yueheng Li
- College of Stomatology, Chongqing Medical University, Chongqing, China; Chongqing Key Laboratory of Oral Diseases and Biomedical Sciences, Chongqing, China; Chongqing Municipal Key Laboratory of Oral Biomedical Engineering of Higher Education, Chongqing, China
| | - Zhengyan Yang
- College of Stomatology, Chongqing Medical University, Chongqing, China; Chongqing Key Laboratory of Oral Diseases and Biomedical Sciences, Chongqing, China.
| | - Zhi Zhou
- College of Stomatology, Chongqing Medical University, Chongqing, China.
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10
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Bera K, Kiepas A, Zhang Y, Sun SX, Konstantopoulos K. The interplay between physical cues and mechanosensitive ion channels in cancer metastasis. Front Cell Dev Biol 2022; 10:954099. [PMID: 36158191 PMCID: PMC9490090 DOI: 10.3389/fcell.2022.954099] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2022] [Accepted: 08/08/2022] [Indexed: 11/13/2022] Open
Abstract
Physical cues have emerged as critical influencers of cell function during physiological processes, like development and organogenesis, and throughout pathological abnormalities, including cancer progression and fibrosis. While ion channels have been implicated in maintaining cellular homeostasis, their cell surface localization often places them among the first few molecules to sense external cues. Mechanosensitive ion channels (MICs) are especially important transducers of physical stimuli into biochemical signals. In this review, we describe how physical cues in the tumor microenvironment are sensed by MICs and contribute to cancer metastasis. First, we highlight mechanical perturbations, by both solid and fluid surroundings typically found in the tumor microenvironment and during critical stages of cancer cell dissemination from the primary tumor. Next, we describe how Piezo1/2 and transient receptor potential (TRP) channels respond to these physical cues to regulate cancer cell behavior during different stages of metastasis. We conclude by proposing alternative mechanisms of MIC activation that work in tandem with cytoskeletal components and other ion channels to bestow cells with the capacity to sense, respond and navigate through the surrounding microenvironment. Collectively, this review provides a perspective for devising treatment strategies against cancer by targeting MICs that sense aberrant physical characteristics during metastasis, the most lethal aspect of cancer.
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Affiliation(s)
- Kaustav Bera
- Department of Chemical and Biomolecular Engineering, The Johns Hopkins University, Baltimore, MD, United States
- Johns Hopkins Institute for NanoBioTechnology, The Johns Hopkins University, Baltimore, MD, United States
| | - Alexander Kiepas
- Department of Chemical and Biomolecular Engineering, The Johns Hopkins University, Baltimore, MD, United States
- Johns Hopkins Institute for NanoBioTechnology, The Johns Hopkins University, Baltimore, MD, United States
- *Correspondence: Alexander Kiepas, ; Konstantinos Konstantopoulos,
| | - Yuqi Zhang
- Department of Chemical and Biomolecular Engineering, The Johns Hopkins University, Baltimore, MD, United States
- Johns Hopkins Institute for NanoBioTechnology, The Johns Hopkins University, Baltimore, MD, United States
| | - Sean X. Sun
- Department of Chemical and Biomolecular Engineering, The Johns Hopkins University, Baltimore, MD, United States
- Johns Hopkins Institute for NanoBioTechnology, The Johns Hopkins University, Baltimore, MD, United States
- Department of Biomedical Engineering, The Johns Hopkins University, Baltimore, MD, United States
- Department of Mechanical Engineering, The Johns Hopkins University, Baltimore, MD, United States
| | - Konstantinos Konstantopoulos
- Department of Chemical and Biomolecular Engineering, The Johns Hopkins University, Baltimore, MD, United States
- Johns Hopkins Institute for NanoBioTechnology, The Johns Hopkins University, Baltimore, MD, United States
- Department of Biomedical Engineering, The Johns Hopkins University, Baltimore, MD, United States
- Department of Oncology, The Johns Hopkins University, Baltimore, MD, United States
- *Correspondence: Alexander Kiepas, ; Konstantinos Konstantopoulos,
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11
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Yu Y, Li W, Jiang J. TRPC channels as emerging targets for seizure disorders. Trends Pharmacol Sci 2022; 43:787-798. [PMID: 35840362 PMCID: PMC9378536 DOI: 10.1016/j.tips.2022.06.007] [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: 03/30/2022] [Revised: 06/09/2022] [Accepted: 06/17/2022] [Indexed: 10/17/2022]
Abstract
Epilepsy is characterized by seizures of diverse types that affect about 1-2% of the population worldwide. Current antiseizure medications are unsatisfactory, as they merely provide symptomatic relief, are ineffective in about one-third of patients, and cause unbearable adverse effects. Transient receptor potential canonical (TRPC) channels are a group of nonselective cation channels involved in many physiological functions. In this review, we provide an overview of recent preclinical studies using both genetic and pharmacological strategies that reveal these receptor-operated calcium-permeable channels may also play fundamental roles in many aspects of epileptic seizures. We also propose that TRPC channels represent appealing targets for epilepsy treatment, with a goal of helping to advance the discovery and development of new antiseizure and/or antiepileptogenic therapies.
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Affiliation(s)
- Ying Yu
- Department of Pharmaceutical Sciences and Drug Discovery Center, College of Pharmacy, University of Tennessee Health Science Center, Memphis, TN 38163, USA
| | - Wei Li
- Department of Pharmaceutical Sciences and Drug Discovery Center, College of Pharmacy, University of Tennessee Health Science Center, Memphis, TN 38163, USA
| | - Jianxiong Jiang
- Department of Pharmaceutical Sciences and Drug Discovery Center, College of Pharmacy, University of Tennessee Health Science Center, Memphis, TN 38163, USA.
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12
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Bon RS, Wright DJ, Beech DJ, Sukumar P. Pharmacology of TRPC Channels and Its Potential in Cardiovascular and Metabolic Medicine. Annu Rev Pharmacol Toxicol 2022; 62:427-446. [PMID: 34499525 DOI: 10.1146/annurev-pharmtox-030121-122314] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Transient receptor potential canonical (TRPC) proteins assemble to form homo- or heterotetrameric, nonselective cation channels permeable to K+, Na+, and Ca2+. TRPC channels are thought to act as complex integrators of physical and chemical environmental stimuli. Although the understanding of essential physiological roles of TRPC channels is incomplete, their implication in various pathological mechanisms and conditions of the nervous system, kidneys, and cardiovascular system in combination with the lack of major adverse effects of TRPC knockout or TRPC channel inhibition is driving the search of TRPC channel modulators as potential therapeutics. Here, we review the most promising small-molecule TRPC channel modulators, the understanding of their mode of action, and their potential in the study and treatment of cardiovascular and metabolic disease.
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Affiliation(s)
- Robin S Bon
- Discovery and Translational Science Department, Leeds Institute of Cardiovascular and Metabolic Medicine, University of Leeds, Leeds LS2 9JT, United Kingdom;
| | - David J Wright
- Discovery and Translational Science Department, Leeds Institute of Cardiovascular and Metabolic Medicine, University of Leeds, Leeds LS2 9JT, United Kingdom;
| | - David J Beech
- Discovery and Translational Science Department, Leeds Institute of Cardiovascular and Metabolic Medicine, University of Leeds, Leeds LS2 9JT, United Kingdom;
| | - Piruthivi Sukumar
- Discovery and Translational Science Department, Leeds Institute of Cardiovascular and Metabolic Medicine, University of Leeds, Leeds LS2 9JT, United Kingdom;
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13
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Deletion of Stim1 in Hypothalamic Arcuate Nucleus Kiss1 Neurons Potentiates Synchronous GCaMP Activity and Protects against Diet-Induced Obesity. J Neurosci 2021; 41:9688-9701. [PMID: 34654752 DOI: 10.1523/jneurosci.0622-21.2021] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Revised: 06/29/2021] [Accepted: 10/07/2021] [Indexed: 12/17/2022] Open
Abstract
Kisspeptin (Kiss1) neurons are essential for reproduction, but their role in the control of energy balance and other homeostatic functions remains unclear. High-frequency firing of hypothalamic arcuate Kiss1 (Kiss1ARH) neurons releases kisspeptin into the median eminence, and neurokinin B (NKB) and dynorphin onto neighboring Kiss1ARH neurons to generate a slow EPSP mediated by TRPC5 channels that entrains intermittent, synchronous firing of Kiss1ARH neurons. High-frequency optogenetic stimulation of Kiss1ARH neurons also releases glutamate to excite the anorexigenic proopiomelanocortin (POMC) neurons and inhibit the orexigenic neuropeptide Y/agouti-related peptide (AgRP) neurons via metabotropic glutamate receptors. At the molecular level, the endoplasmic reticulum (ER) calcium-sensing protein stromal interaction molecule 1 (STIM1) is critically involved in the regulation of neuronal Ca2+ signaling and neuronal excitability through its interaction with plasma membrane (PM) calcium (e.g., TRPC) channels. Therefore, we hypothesized that deletion of Stim1 in Kiss1ARH neurons would increase neuronal excitability and their synchronous firing, which ultimately would affect energy homeostasis. Using optogenetics in combination with whole-cell recording and GCaMP6 imaging in slices, we discovered that deletion of Stim1 in Kiss1 neurons significantly increased the amplitude and duration of the slow EPSP and augmented synchronous [Ca2+]i oscillations in Kiss1ARH neurons. Deletion of Stim1 in Kiss1ARH neurons amplified the actions of NKB and protected ovariectomized female mice from developing obesity and glucose intolerance with high-fat dieting (HFD). Therefore, STIM1 appears to play a critical role in regulating synchronous firing of Kiss1ARH neurons, which ultimately affects the coordination between energy homeostasis and reproduction.SIGNIFICANCE STATEMENT Hypothalamic arcuate kisspeptin (Kiss1ARH) neurons are essential for stimulating the pulsatile release of gonadotropin-releasing hormone (GnRH) and maintaining fertility. However, Kiss1ARH neurons appear to be a key player in coordinating energy balance with reproduction. The regulation of calcium channels and hence calcium signaling is critically dependent on the endoplasmic reticulum (ER) calcium-sensing protein stromal interaction molecule 1 (STIM1), which interacts with the plasma membrane (PM) calcium channels. We have conditionally deleted Stim1 in Kiss1ARH neurons and found that it significantly increased the excitability of Kiss1ARH neurons and protected ovariectomized female mice from developing obesity and glucose intolerance with high-fat dieting (HFD).
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14
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Song K, Wei M, Guo W, Quan L, Kang Y, Wu JX, Chen L. Structural basis for human TRPC5 channel inhibition by two distinct inhibitors. eLife 2021; 10:63429. [PMID: 33683200 PMCID: PMC7987348 DOI: 10.7554/elife.63429] [Citation(s) in RCA: 38] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Accepted: 03/05/2021] [Indexed: 02/06/2023] Open
Abstract
TRPC5 channel is a nonselective cation channel that participates in diverse physiological processes. TRPC5 inhibitors show promise in the treatment of anxiety disorder, depression, and kidney disease. However, the binding sites and inhibitory mechanism of TRPC5 inhibitors remain elusive. Here, we present the cryo-EM structures of human TRPC5 in complex with two distinct inhibitors, namely clemizole and HC-070, to the resolution of 2.7 Å. The structures reveal that clemizole binds inside the voltage sensor-like domain of each subunit. In contrast, HC-070 is wedged between adjacent subunits and replaces the glycerol group of a putative diacylglycerol molecule near the extracellular side. Moreover, we found mutations in the inhibitor binding pockets altered the potency of inhibitors. These structures suggest that both clemizole and HC-070 exert the inhibitory functions by stabilizing the ion channel in a nonconductive closed state. These results pave the way for further design and optimization of inhibitors targeting human TRPC5.
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Affiliation(s)
- Kangcheng Song
- State Key Laboratory of Membrane Biology, College of Future Technology, Institute of Molecular Medicine, Beijing Key Laboratory of Cardiometabolic Molecular Medicine, Peking University, Beijing, China
| | - Miao Wei
- State Key Laboratory of Membrane Biology, College of Future Technology, Institute of Molecular Medicine, Beijing Key Laboratory of Cardiometabolic Molecular Medicine, Peking University, Beijing, China
| | - Wenjun Guo
- State Key Laboratory of Membrane Biology, College of Future Technology, Institute of Molecular Medicine, Beijing Key Laboratory of Cardiometabolic Molecular Medicine, Peking University, Beijing, China
| | - Li Quan
- State Key Laboratory of Membrane Biology, College of Future Technology, Institute of Molecular Medicine, Beijing Key Laboratory of Cardiometabolic Molecular Medicine, Peking University, Beijing, China
| | - Yunlu Kang
- State Key Laboratory of Membrane Biology, College of Future Technology, Institute of Molecular Medicine, Beijing Key Laboratory of Cardiometabolic Molecular Medicine, Peking University, Beijing, China
| | - Jing-Xiang Wu
- State Key Laboratory of Membrane Biology, College of Future Technology, Institute of Molecular Medicine, Beijing Key Laboratory of Cardiometabolic Molecular Medicine, Peking University, Beijing, China.,Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, China.,Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, China
| | - Lei Chen
- State Key Laboratory of Membrane Biology, College of Future Technology, Institute of Molecular Medicine, Beijing Key Laboratory of Cardiometabolic Molecular Medicine, Peking University, Beijing, China.,Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, China.,Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, China
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15
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Bernal L, Sotelo-Hitschfeld P, König C, Sinica V, Wyatt A, Winter Z, Hein A, Touska F, Reinhardt S, Tragl A, Kusuda R, Wartenberg P, Sclaroff A, Pfeifer JD, Ectors F, Dahl A, Freichel M, Vlachova V, Brauchi S, Roza C, Boehm U, Clapham DE, Lennerz JK, Zimmermann K. Odontoblast TRPC5 channels signal cold pain in teeth. SCIENCE ADVANCES 2021; 7:7/13/eabf5567. [PMID: 33771873 PMCID: PMC7997515 DOI: 10.1126/sciadv.abf5567] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Accepted: 02/09/2021] [Indexed: 05/21/2023]
Abstract
Teeth are composed of many tissues, covered by an inflexible and obdurate enamel. Unlike most other tissues, teeth become extremely cold sensitive when inflamed. The mechanisms of this cold sensation are not understood. Here, we clarify the molecular and cellular components of the dental cold sensing system and show that sensory transduction of cold stimuli in teeth requires odontoblasts. TRPC5 is a cold sensor in healthy teeth and, with TRPA1, is sufficient for cold sensing. The odontoblast appears as the direct site of TRPC5 cold transduction and provides a mechanism for prolonged cold sensing via TRPC5's relative sensitivity to intracellular calcium and lack of desensitization. Our data provide concrete functional evidence that equipping odontoblasts with the cold-sensor TRPC5 expands traditional odontoblast functions and renders it a previously unknown integral cellular component of the dental cold sensing system.
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Affiliation(s)
- Laura Bernal
- Department of Anesthesiology, Erlangen University Hospital, Friedrich Alexander University of Erlangen-Nuremberg (FAU), Erlangen, Germany
- Departamento de Biología de Sistemas, Facultad de Medicina, Universidad de Alcalá, Alcalá de Henares, Madrid, Spain
| | - Pamela Sotelo-Hitschfeld
- Department of Anesthesiology, Erlangen University Hospital, Friedrich Alexander University of Erlangen-Nuremberg (FAU), Erlangen, Germany
- Institute of Physiology, Faculty of Medicine and Center for Interdisciplinary Studies on the Nervous System (CISNe), Universidad Austral de Chile, Valdivia, Chile
| | - Christine König
- Department of Anesthesiology, Erlangen University Hospital, Friedrich Alexander University of Erlangen-Nuremberg (FAU), Erlangen, Germany
| | - Viktor Sinica
- Department of Anesthesiology, Erlangen University Hospital, Friedrich Alexander University of Erlangen-Nuremberg (FAU), Erlangen, Germany
- Department of Cellular Neurophysiology, Institute of Physiology, Czech Academy of Sciences, Prague, Czech Republic
| | - Amanda Wyatt
- Experimental Pharmacology, Center for Molecular Signaling (PZMS), Saarland University School of Medicine, Homburg, Germany
| | - Zoltan Winter
- Department of Anesthesiology, Erlangen University Hospital, Friedrich Alexander University of Erlangen-Nuremberg (FAU), Erlangen, Germany
| | - Alexander Hein
- HHMI, Cardiovascular Division, Boston Children's Hospital, and Department of Neurobiology, Harvard Medical School, Boston, MA, USA
| | - Filip Touska
- Department of Anesthesiology, Erlangen University Hospital, Friedrich Alexander University of Erlangen-Nuremberg (FAU), Erlangen, Germany
- Department of Cellular Neurophysiology, Institute of Physiology, Czech Academy of Sciences, Prague, Czech Republic
| | - Susanne Reinhardt
- Center for Molecular and Cellular Bioengineering (CMCB), Technische Universität Dresden, Dresden, Germany
| | - Aaron Tragl
- Department of Anesthesiology, Erlangen University Hospital, Friedrich Alexander University of Erlangen-Nuremberg (FAU), Erlangen, Germany
| | - Ricardo Kusuda
- Department of Anesthesiology, Erlangen University Hospital, Friedrich Alexander University of Erlangen-Nuremberg (FAU), Erlangen, Germany
| | - Philipp Wartenberg
- Experimental Pharmacology, Center for Molecular Signaling (PZMS), Saarland University School of Medicine, Homburg, Germany
| | - Allen Sclaroff
- Department of Otolaryngology, Washington University School of Medicine, St Louis, MO, USA
| | - John D Pfeifer
- Department of Pathology, Washington University School of Medicine, St Louis, MO, USA
| | - Fabien Ectors
- FARAH Mammalian Transgenics Platform, Liège University, Liège, Belgium
| | - Andreas Dahl
- Center for Molecular and Cellular Bioengineering (CMCB), Technische Universität Dresden, Dresden, Germany
| | - Marc Freichel
- Institute of Pharmacology, University of Heidelberg, Heidelberg, Germany
| | - Viktorie Vlachova
- Department of Cellular Neurophysiology, Institute of Physiology, Czech Academy of Sciences, Prague, Czech Republic
| | - Sebastian Brauchi
- Institute of Physiology, Faculty of Medicine and Center for Interdisciplinary Studies on the Nervous System (CISNe), Universidad Austral de Chile, Valdivia, Chile
- Millennium Nucleus of Ion Channel-associated Diseases (MiNICAD), Santiago, Chile
| | - Carolina Roza
- Departamento de Biología de Sistemas, Facultad de Medicina, Universidad de Alcalá, Alcalá de Henares, Madrid, Spain
| | - Ulrich Boehm
- Experimental Pharmacology, Center for Molecular Signaling (PZMS), Saarland University School of Medicine, Homburg, Germany
| | - David E Clapham
- HHMI, Cardiovascular Division, Boston Children's Hospital, and Department of Neurobiology, Harvard Medical School, Boston, MA, USA.
| | - Jochen K Lennerz
- Center for Integrated Diagnostics, Department of Pathology, Massachusetts General Hospital/Harvard Medical School, Boston, MA, USA.
| | - Katharina Zimmermann
- Department of Anesthesiology, Erlangen University Hospital, Friedrich Alexander University of Erlangen-Nuremberg (FAU), Erlangen, Germany.
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16
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Siri-Angkul N, Song Z, Fefelova N, Gwathmey JK, Chattipakorn SC, Qu Z, Chattipakorn N, Xie LH. Activation of TRPC (Transient Receptor Potential Canonical) Channel Currents in Iron Overloaded Cardiac Myocytes. Circ Arrhythm Electrophysiol 2021; 14:e009291. [PMID: 33417472 DOI: 10.1161/circep.120.009291] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
BACKGROUND Arrhythmias and heart failure are common cardiac complications leading to substantial morbidity and mortality in patients with hemochromatosis, yet mechanistic insights remain incomplete. We investigated the effects of iron (Fe) on electrophysiological properties and intracellular Ca2+ (Ca2+i) handling in mouse left ventricular cardiomyocytes. METHODS Cardiomyocytes were isolated from the left ventricle of mouse hearts and were superfused with Fe3+/8-hydroxyquinoline complex (5-100 μM). Membrane potential and ionic currents including TRPC (transient receptor potential canonical) were recorded using the patch-clamp technique. Ca2+i was evaluated by using Fluo-4. Cell contraction was measured with a video-based edge detection system. The role of TRPCs in the genesis of arrhythmias was also investigated by using a mathematical model of a mouse ventricular myocyte with the incorporation of the TRPC component. RESULTS We observed prolongation of the action potential duration and induction of early and delayed afterdepolarizations in myocytes superfused with 15 µmol/L Fe3+/8-hydroxyquinoline complex. Iron treatment decreased the peak amplitude of the L-type Ca2+ current and total K+ current, altered Ca2+i dynamics, and decreased cell contractility. During the final phase of Fe treatment, sustained Ca2+i waves and repolarization failure occurred and ventricular cells became unexcitable. Gadolinium abolished Ca2+i waves and restored the resting membrane potential to the normal range. The involvement of TRPC activation was confirmed by TRPC channel current recordings in the absence or presence of functional TRPC channel antibodies. Computer modeling captured the same action potential and Ca2+i dynamics and provided additional mechanistic insights. CONCLUSIONS We conclude that iron overload induces cardiac dysfunction that is associated with TRPC channel activation and alterations in membrane potential and Ca2+i dynamics.
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Affiliation(s)
- Natthaphat Siri-Angkul
- Department of Cell Biology and Molecular Medicine, Rutgers University, New Jersey Medical School, Newark (N.S.-A., N.F., J.K.G., L.-H.X.).,Cardiac Electrophysiology Research and Training Center (N.S.-A., S.C.C., N.C.), Chiang Mai University, Thailand.,Department of Physiology, Faculty of Medicine (N.S.-A., N.C.), Chiang Mai University, Thailand
| | - Zhen Song
- Department of Medicine (Cardiology), University of California, Los Angeles (Z.S., Z.Q.)
| | - Nadezhda Fefelova
- Department of Cell Biology and Molecular Medicine, Rutgers University, New Jersey Medical School, Newark (N.S.-A., N.F., J.K.G., L.-H.X.)
| | - Judith K Gwathmey
- Department of Cell Biology and Molecular Medicine, Rutgers University, New Jersey Medical School, Newark (N.S.-A., N.F., J.K.G., L.-H.X.)
| | - Siriporn C Chattipakorn
- Cardiac Electrophysiology Research and Training Center (N.S.-A., S.C.C., N.C.), Chiang Mai University, Thailand
| | - Zhilin Qu
- Department of Medicine (Cardiology), University of California, Los Angeles (Z.S., Z.Q.)
| | - Nipon Chattipakorn
- Cardiac Electrophysiology Research and Training Center (N.S.-A., S.C.C., N.C.), Chiang Mai University, Thailand.,Department of Physiology, Faculty of Medicine (N.S.-A., N.C.), Chiang Mai University, Thailand
| | - Lai-Hua Xie
- Department of Cell Biology and Molecular Medicine, Rutgers University, New Jersey Medical School, Newark (N.S.-A., N.F., J.K.G., L.-H.X.)
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17
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How TRPC Channels Modulate Hippocampal Function. Int J Mol Sci 2020; 21:ijms21113915. [PMID: 32486187 PMCID: PMC7312571 DOI: 10.3390/ijms21113915] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2020] [Revised: 05/27/2020] [Accepted: 05/28/2020] [Indexed: 12/12/2022] Open
Abstract
Transient receptor potential canonical (TRPC) proteins constitute a group of receptor-operated calcium-permeable nonselective cationic membrane channels of the TRP superfamily. They are largely expressed in the hippocampus and are able to modulate neuronal functions. Accordingly, they have been involved in different hippocampal functions such as learning processes and different types of memories, as well as hippocampal dysfunctions such as seizures. This review covers the mechanisms of activation of these channels, how these channels can modulate neuronal excitability, in particular the after-burst hyperpolarization, and in the persistent activity, how they control synaptic plasticity including pre- and postsynaptic processes and how they can interfere with cell survival and neurogenesis.
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18
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Thakur DP, Wang Q, Jeon J, Tian JB, Zhu MX. Intracellular acidification facilitates receptor-operated TRPC4 activation through PLCδ1 in a Ca 2+ -dependent manner. J Physiol 2020; 598:2651-2667. [PMID: 32338378 DOI: 10.1113/jp279658] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2020] [Accepted: 04/20/2020] [Indexed: 12/28/2022] Open
Abstract
KEY POINTS Receptor-operated activation of TRPC4 cation channels requires Gi/o proteins and phospholipase-Cδ1 (PLCδ1) activation by intracellular Ca2+ . Concurrent stimulation of the Gq/11 pathway accelerates Gi/o activation of TRPC4, which is not mimicked by increasing cytosolic Ca2+ . The kinetic effect of Gq/11 was diminished by alkaline intracellular pH (pHi ) and increased pHi buffer capacity. Acidic pHi (6.75-6.25) together with the cytosolic Ca2+ rise accelerated Gi/o -mediated TRPC4 activation. Protons exert their facilitation effect through Ca2+ -dependent activation of PLCδ1. The data suggest that the Gq/11 -PLCβ pathway facilitates Gi/o activation of TRPC4 through hydrolysing phosphatidylinositol 4,5-bisphosphate (PIP2 ) to produce the initial proton signal that triggers a self-propagating PLCδ1 activity supported by regenerative H+ and Ca2+ . The findings provide novel mechanistic insights into receptor-operated TRPC4 activation by coincident Gq/11 and Gi/o pathways and shed light on how aberrant activation of TRPC4 may occur under pathological conditions to cause cell damage. ABSTRACT Transient Receptor Potential Canonical 4 (TRPC4) forms non-selective cation channels activated downstream from receptors that signal through G proteins. Our recent work suggests that TRPC4 channels are particularly coupled to pertussis toxin-sensitive Gi/o proteins, with a co-dependence on phospholipase-Cδ1 (PLCδ1). The Gi/o -mediated TRPC4 activation is dually dependent on and bimodally regulated by phosphatidylinositol 4,5-bisphosphate (PIP2 ), the substrate hydrolysed by PLC, and intracellular Ca2+ . As a byproduct of PLC-mediated PIP2 hydrolysis, protons have been shown to play an important role in the activation of Drosophila TRP channels. However, how intracellular pH affects mammalian TRPC channels remains obscure. Here, using patch-clamp recordings of HEK293 cells heterologously co-expressing mouse TRPC4β and the Gi/o -coupled μ opioid receptor, we investigated the role of intracellular protons on Gi/o -mediated TRPC4 activation. We found that acidic cytosolic pH greatly accelerated the rate of TRPC4 activation without altering the maximal current density and this effect was dependent on intracellular Ca2+ elevation. However, protons did not accelerate channel activation by directly acting upon TRPC4. We additionally demonstrated that protons exert their effect through sensitization of PLCδ1 to Ca2+ , which in turn promotes PLCδ1 activity and further potentiates TRPC4 via a positive feedback mechanism. The mechanism elucidated here helps explain how Gi/o and Gq/11 co-stimulation induces a faster activation of TRPC4 than Gi/o activation alone and highlights again the critical role of PLCδ1 in TRPC4 gating.
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Affiliation(s)
- Dhananjay P Thakur
- Department of Integrative Biology and Pharmacology, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, TX, 77030, USA
| | - Qiaochu Wang
- Department of Integrative Biology and Pharmacology, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, TX, 77030, USA
| | - Jaepyo Jeon
- Department of Integrative Biology and Pharmacology, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, TX, 77030, USA
| | - Jin-Bin Tian
- Department of Integrative Biology and Pharmacology, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, TX, 77030, USA
| | - Michael X Zhu
- Department of Integrative Biology and Pharmacology, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, TX, 77030, USA
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19
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Wen H, Gwathmey JK, Xie LH. Role of Transient Receptor Potential Canonical Channels in Heart Physiology and Pathophysiology. Front Cardiovasc Med 2020; 7:24. [PMID: 32158769 PMCID: PMC7052113 DOI: 10.3389/fcvm.2020.00024] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2019] [Accepted: 02/11/2020] [Indexed: 12/13/2022] Open
Abstract
Transient receptor potential canonical (TRPC) channels are involved in the regulation of cardiac function under (patho)physiological conditions and are closely associated with the pathogenesis of cardiac hypertrophy, arrhythmias, and myocardial infarction. Understanding the molecular mechanisms and the regulatory pathway/locus of TRPC channels in related heart diseases will provide potential new concepts for designing novel drugs targeting TRPC channels. We will present the properties and regulation of TRPC channels and their roles in the development of various forms of heart disease. This article provides a brief review on the role of TRPC channels in the regulation of myocardial function as well as how TRPC channels may serve as a therapeutic target in heart failure and cardiac arrhythmias including atrial fibrillation.
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Affiliation(s)
- Hairuo Wen
- Beijing Key Laboratory, National Center for Safety Evaluation of Drugs, National Institutes for Food and Drug Control, Beijing, China.,Department of Cell Biology and Molecular Medicine, Rutgers University-New Jersey Medical School, Newark, NJ, United States
| | - Judith K Gwathmey
- Department of Cell Biology and Molecular Medicine, Rutgers University-New Jersey Medical School, Newark, NJ, United States
| | - Lai-Hua Xie
- Department of Cell Biology and Molecular Medicine, Rutgers University-New Jersey Medical School, Newark, NJ, United States
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20
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Kepura F, Braun E, Dietrich A, Plant TD. TRPC1 Regulates the Activity of a Voltage-Dependent Nonselective Cation Current in Hippocampal CA1 Neurons. Cells 2020; 9:cells9020459. [PMID: 32085504 PMCID: PMC7072794 DOI: 10.3390/cells9020459] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2019] [Revised: 02/12/2020] [Accepted: 02/14/2020] [Indexed: 12/26/2022] Open
Abstract
The cation channel subunit TRPC1 is strongly expressed in central neurons including neurons in the CA1 region of the hippocampus where it forms complexes with TRPC4 and TRPC5. To investigate the functional role of TRPC1 in these neurons and in channel function, we compared current responses to group I metabotropic glutamate receptor (mGluR I) activation and looked for major differences in dendritic morphology in neurons from TRPC1+/+ and TRPC1-/- mice. mGluR I stimulation resulted in the activation of a voltage-dependent nonselective cation current in both genotypes. Deletion of TRPC1 resulted in a modification of the shape of the current-voltage relationship, leading to an inward current increase. In current clamp recordings, the percentage of neurons that responded to depolarization in the presence of an mGluR I agonist with a plateau potential was increased in TRPC1-/- mice. There was also a small increase in the minor population of CA1 neurons that have more than one apical dendrite in TRPC1-/- mice. We conclude that TRPC1 has an inhibitory effect on receptor-operated nonselective cation channels in hippocampal CA1 neurons probably as a result of heterotetramer formation with other TRPC isoforms, and that TRPC1 deletion has only minor effects on dendritic morphology.
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Affiliation(s)
- Frauke Kepura
- Pharmakologisches Institut, BPC-Marburg, Fachbereich Medizin, Philipps-Universität Marburg, Karl-von-Frisch-Straße 2, 35043 Marburg, Germany; (F.K.); (E.B.); (A.D.)
| | - Eva Braun
- Pharmakologisches Institut, BPC-Marburg, Fachbereich Medizin, Philipps-Universität Marburg, Karl-von-Frisch-Straße 2, 35043 Marburg, Germany; (F.K.); (E.B.); (A.D.)
| | - Alexander Dietrich
- Pharmakologisches Institut, BPC-Marburg, Fachbereich Medizin, Philipps-Universität Marburg, Karl-von-Frisch-Straße 2, 35043 Marburg, Germany; (F.K.); (E.B.); (A.D.)
- Walther-Straub-Institut für Pharmakologie und Toxikologie, Ludwig-Maximilians-Universität München, 80336 München, Germany
| | - Tim D. Plant
- Pharmakologisches Institut, BPC-Marburg, Fachbereich Medizin, Philipps-Universität Marburg, Karl-von-Frisch-Straße 2, 35043 Marburg, Germany; (F.K.); (E.B.); (A.D.)
- Center for Mind, Brain and Behavior, Philipps-Universität Marburg, 35032 Marburg, Germany
- Correspondence: ; Tel.: +49-6421-28-65038
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21
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Involvement of TRPC4 and 5 Channels in Persistent Firing in Hippocampal CA1 Pyramidal Cells. Cells 2020; 9:cells9020365. [PMID: 32033274 PMCID: PMC7072216 DOI: 10.3390/cells9020365] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2019] [Revised: 01/29/2020] [Accepted: 02/01/2020] [Indexed: 12/17/2022] Open
Abstract
Persistent neural activity has been observed in vivo during working memory tasks, and supports short-term (up to tens of seconds) retention of information. While synaptic and intrinsic cellular mechanisms of persistent firing have been proposed, underlying cellular mechanisms are not yet fully understood. In vitro experiments have shown that individual neurons in the hippocampus and other working memory related areas support persistent firing through intrinsic cellular mechanisms that involve the transient receptor potential canonical (TRPC) channels. Recent behavioral studies demonstrating the involvement of TRPC channels on working memory make the hypothesis that TRPC driven persistent firing supports working memory a very attractive one. However, this view has been challenged by recent findings that persistent firing in vitro is unchanged in TRPC knock out (KO) mice. To assess the involvement of TRPC channels further, we tested novel and highly specific TRPC channel blockers in cholinergically induced persistent firing in mice CA1 pyramidal cells for the first time. The application of the TRPC4 blocker ML204, TRPC5 blocker clemizole hydrochloride, and TRPC4 and 5 blocker Pico145, all significantly inhibited persistent firing. In addition, intracellular application of TRPC4 and TRPC5 antibodies significantly reduced persistent firing. Taken together these results indicate that TRPC4 and 5 channels support persistent firing in CA1 pyramidal neurons. Finally, we discuss possible scenarios causing these controversial observations on the role of TRPC channels in persistent firing.
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22
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Dattilo M, Penington NJ, Williams K. Regulation of TRPC5 currents by intracellular ATP: Single channel studies. J Cell Physiol 2020; 235:7056-7066. [PMID: 31994734 DOI: 10.1002/jcp.29602] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2019] [Accepted: 01/10/2020] [Indexed: 11/09/2022]
Abstract
TRPC5 channels are nonselective cation channels activated by G-protein-coupled receptors. It was previously found that recombinant TRPC5 currents are inhibited by intracellular ATP, when studied by whole-cell patch-clamp recording. In the present study, we investigated the mechanism of ATP inhibition at the single-channel level using patches from HEK-293 cells transiently transfected with TRPC5 and the M1 muscarinic receptor. In inside-out patches, application of ATP to the intracellular face of the membrane reduced TRPC5 channel activity at both positive and negative potentials without affecting the unitary current amplitude or open dwell time of the channel. The effect of ATP was rapidly reversible. These results suggest that ATP may bind to the channel protein and affect the ability of the channel to open or to remain in an open, nondesensitized state. The activity of TRPC5 channels may be influenced by cellular metabolism via changes in ATP levels.
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Affiliation(s)
- Michael Dattilo
- Department of Physiology and Pharmacology, State University of New York, Downstate Health Sciences University, Brooklyn, New York.,Program in Neural and Behavioral Science and Robert F. Furchgott, Center for Neural and Behavioral Science, State University of New York, Downstate Health Sciences University, Brooklyn, New York
| | - Nicholas J Penington
- Department of Physiology and Pharmacology, State University of New York, Downstate Health Sciences University, Brooklyn, New York.,Program in Neural and Behavioral Science and Robert F. Furchgott, Center for Neural and Behavioral Science, State University of New York, Downstate Health Sciences University, Brooklyn, New York
| | - Keith Williams
- Department of Physiology and Pharmacology, State University of New York, Downstate Health Sciences University, Brooklyn, New York.,Program in Neural and Behavioral Science and Robert F. Furchgott, Center for Neural and Behavioral Science, State University of New York, Downstate Health Sciences University, Brooklyn, New York
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23
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Wang H, Cheng X, Tian J, Xiao Y, Tian T, Xu F, Hong X, Zhu MX. TRPC channels: Structure, function, regulation and recent advances in small molecular probes. Pharmacol Ther 2020; 209:107497. [PMID: 32004513 DOI: 10.1016/j.pharmthera.2020.107497] [Citation(s) in RCA: 125] [Impact Index Per Article: 31.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2019] [Accepted: 01/14/2020] [Indexed: 02/08/2023]
Abstract
Transient receptor potential canonical (TRPC) channels constitute a group of receptor-operated calcium-permeable nonselective cation channels of the TRP superfamily. The seven mammalian TRPC members, which can be further divided into four subgroups (TRPC1, TRPC2, TRPC4/5, and TRPC3/6/7) based on their amino acid sequences and functional similarities, contribute to a broad spectrum of cellular functions and physiological roles. Studies have revealed complexity of their regulation involving several components of the phospholipase C pathway, Gi and Go proteins, and internal Ca2+ stores. Recent advances in cryogenic electron microscopy have provided several high-resolution structures of TRPC channels. Growing evidence demonstrates the involvement of TRPC channels in diseases, particularly the link between genetic mutations of TRPC6 and familial focal segmental glomerulosclerosis. Because TRPCs were discovered by the molecular identity first, their pharmacology had lagged behind. This is rapidly changing in recent years owning to great efforts from both academia and industry. A number of potent tool compounds from both synthetic and natural products that selective target different subtypes of TRPC channels have been discovered, including some preclinical drug candidates. This review will cover recent advancements in the understanding of TRPC channel regulation, structure, and discovery of novel TRPC small molecular probes over the past few years, with the goal of facilitating drug discovery for the study of TRPCs and therapeutic development.
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Affiliation(s)
- Hongbo Wang
- Key Laboratory of Molecular Pharmacology and Drug Evaluation (Yantai University), Ministry of Education; Collaborative Innovation Center of Advanced Drug Delivery System and Biotech Drugs in Universities of Shandong, Yantai University, Yantai 264005, China.
| | - Xiaoding Cheng
- State Key Laboratory of Virology, Key Laboratory of Combinatorial Biosynthesis and Drug Discovery (MOE) and Hubei Province Engineering and Technology Research Center for Fluorinated Pharmaceuticals, Wuhan University School of Pharmaceutical Sciences, Wuhan 430071, China
| | - Jinbin Tian
- Department of Integrative Biology and Pharmacology, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, TX 77030, USA
| | - Yuling Xiao
- State Key Laboratory of Virology, Key Laboratory of Combinatorial Biosynthesis and Drug Discovery (MOE) and Hubei Province Engineering and Technology Research Center for Fluorinated Pharmaceuticals, Wuhan University School of Pharmaceutical Sciences, Wuhan 430071, China
| | - Tian Tian
- Innovation Center for Traditional Tibetan Medicine Modernization and Quality Control, Medical College, Department of Chemistry and Environmental Science, School of Science, Tibet University, Lhasa 850000, China
| | - Fuchun Xu
- Innovation Center for Traditional Tibetan Medicine Modernization and Quality Control, Medical College, Department of Chemistry and Environmental Science, School of Science, Tibet University, Lhasa 850000, China
| | - Xuechuan Hong
- State Key Laboratory of Virology, Key Laboratory of Combinatorial Biosynthesis and Drug Discovery (MOE) and Hubei Province Engineering and Technology Research Center for Fluorinated Pharmaceuticals, Wuhan University School of Pharmaceutical Sciences, Wuhan 430071, China; Innovation Center for Traditional Tibetan Medicine Modernization and Quality Control, Medical College, Department of Chemistry and Environmental Science, School of Science, Tibet University, Lhasa 850000, China.
| | - Michael X Zhu
- Department of Integrative Biology and Pharmacology, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, TX 77030, USA.
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24
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Hydrogen Peroxide Gates a Voltage-Dependent Cation Current in Aplysia Neuroendocrine Cells. J Neurosci 2019; 39:9900-9913. [PMID: 31676600 DOI: 10.1523/jneurosci.1460-19.2019] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2019] [Revised: 10/07/2019] [Accepted: 10/27/2019] [Indexed: 11/21/2022] Open
Abstract
Nonselective cation channels promote persistent spiking in many neurons from a diversity of animals. In the hermaphroditic marine-snail, Aplysia californica, synaptic input to the neuroendocrine bag cell neurons triggers various cation channels, causing an ∼30 min afterdischarge of action potentials and the secretion of egg-laying hormone. During the afterdischarge, protein kinase C is also activated, which in turn elevates hydrogen peroxide (H2O2), likely by stimulating nicotinamide adenine dinucleotide phosphate oxidase. The present study investigated whether H2O2 regulates cation channels to drive the afterdischarge. In single, cultured bag cell neurons, H2O2 elicited a prolonged, concentration- and voltage-dependent inward current, associated with an increase in membrane conductance and a reversal potential of ∼+30 mV. Compared with normal saline, the presence of Ca2+-free, Na+-free, or Na+/Ca2+-free extracellular saline, lowered the current amplitude and left-shifted the reversal potential, consistent with a nonselective cationic conductance. Preventing H2O2 reduction with the glutathione peroxidase inhibitor, mercaptosuccinate, enhanced the H2O2-induced current, while boosting glutathione production with its precursor, N-acetylcysteine, or adding the reducing agent, dithiothreitol, lessened the response. Moreover, the current generated by the alkylating agent, N-ethylmaleimide, occluded the effect of H2O2 The H2O2-induced current was inhibited by tetrodotoxin as well as the cation channel blockers, 9-phenanthrol and clotrimazole. In current-clamp, H2O2 stimulated burst firing, but this was attenuated or prevented altogether by the channel blockers. Finally, H2O2 evoked an afterdischarge from whole bag cell neuron clusters recorded ex vivo by sharp-electrode. H2O2 may regulate a cation channel to influence long-term changes in activity and ultimately reproduction.SIGNIFICANCE STATEMENT Hydrogen peroxide (H2O2) is often studied in a pathological context, such as ischemia or inflammation. However, H2O2 also physiologically modulates synaptic transmission and gates certain transient receptor potential channels. That stated, the effect of H2O2 on neuronal excitability remains less well defined. Here, we examine how H2O2 influences Aplysia bag cell neurons, which elicit ovulation by releasing hormones during an afterdischarge. These neuroendocrine cells are uniquely identifiable and amenable to recording as individual cultured neurons or a cluster from the nervous system. In both culture and the cluster, H2O2 evokes prolonged, afterdischarge-like bursting by gating a nonselective voltage-dependent cationic current. Thus, H2O2, which is generated in response to afterdischarge-associated second messengers, may prompt the firing necessary for hormone secretion and procreation.
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25
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He Z, Gao Y, Lieu L, Afrin S, Cao J, Michael NJ, Dong Y, Sun J, Guo H, Williams KW. Direct and indirect effects of liraglutide on hypothalamic POMC and NPY/AgRP neurons - Implications for energy balance and glucose control. Mol Metab 2019; 28:120-134. [PMID: 31446151 PMCID: PMC6822260 DOI: 10.1016/j.molmet.2019.07.008] [Citation(s) in RCA: 60] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/29/2019] [Revised: 07/22/2019] [Accepted: 07/25/2019] [Indexed: 12/15/2022] Open
Abstract
OBJECTIVE The long-acting glucagon-like peptide-1 receptor (GLP-1R) agonist, liraglutide, stimulates insulin secretion and efficiently suppresses food intake to reduce body weight. As such, liraglutide is growing in popularity in the treatment of diabetes and chronic weight management. Within the brain, liraglutide has been shown to alter the activity of hypothalamic proopiomelanocortin (POMC) and Neuropeptide Y/Agouti-related peptide (NPY/AgRP) neurons. Moreover, the acute activities of POMC and NPY neurons have been directly linked to feeding behavior, body weight, and glucose metabolism. Despite the increased usage of liraglutide and other GLP-1 analogues as diabetic and obesity interventions, the cellular mechanisms by which liraglutide alters the activity of metabolically relevant neuronal populations are poorly understood. METHODS In order to resolve this issue, we utilized neuron-specific transgenic mouse models to identify POMC and NPY neurons for patch-clamp electrophysiology experiments. RESULTS We found that liraglutide directly activated arcuate POMC neurons via TrpC5 channels, sharing a similar mechanistic pathway to the adipose-derived peptide leptin. Liraglutide also indirectly increases excitatory tone to POMC neurons. In contrast, liraglutide inhibited NPY/AgRP neurons through post-synaptic GABAA receptors and enhanced activity of pre-synaptic GABAergic neurons, which required both TrpC5 subunits and K-ATP channels. In support of an additive role of leptin and liraglutide in suppressing food intake, leptin potentiated the acute effects of liraglutide to activate POMC neurons. TrpC5 subunits in POMC neurons were also required for the intact pharmacological effects of liraglutide on food intake and body weight. Thus, the current study adds to recent work from our group and others, which highlight potential mechanisms to amplify the effects of GLP-1 agonists in vivo. Moreover, these data highlight multiple sites of action (both pre- and post-synaptic) for GLP-1 agonists on this circuit. CONCLUSIONS Taken together, our results identify critical molecular mechanisms linking GLP-1 analogues in arcuate POMC and NPY/AgRP neurons with metabolism.
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Affiliation(s)
- Zhenyan He
- The National Key Clinical Specialty, The Engineering Technology Research Center of Education Ministry of China, Guangdong Provincial Key Laboratory on Brain Function Repair and Regeneration, Department of Neurosurgery, Zhujiang Hospital, Southern Medical University, Guangzhou 510282, China; Division of Hypothalamic Research, the University of Texas Southwestern Medical Center at Dallas, Dallas, TX, USA
| | - Yong Gao
- Division of Hypothalamic Research, the University of Texas Southwestern Medical Center at Dallas, Dallas, TX, USA; National Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100005, China
| | - Linh Lieu
- Division of Hypothalamic Research, the University of Texas Southwestern Medical Center at Dallas, Dallas, TX, USA
| | - Sadia Afrin
- Division of Hypothalamic Research, the University of Texas Southwestern Medical Center at Dallas, Dallas, TX, USA
| | - Jianhong Cao
- Division of Hypothalamic Research, the University of Texas Southwestern Medical Center at Dallas, Dallas, TX, USA; Pi-wei Institute, Guangzhou University of Chinese Medicine, 12 Jichang Road, Guangzhou 510405, China
| | - Natalie J Michael
- Division of Hypothalamic Research, the University of Texas Southwestern Medical Center at Dallas, Dallas, TX, USA
| | - Yanbin Dong
- Division of Hypothalamic Research, the University of Texas Southwestern Medical Center at Dallas, Dallas, TX, USA; Pi-wei Institute, Guangzhou University of Chinese Medicine, 12 Jichang Road, Guangzhou 510405, China
| | - Jia Sun
- Division of Hypothalamic Research, the University of Texas Southwestern Medical Center at Dallas, Dallas, TX, USA
| | - Hongbo Guo
- The National Key Clinical Specialty, The Engineering Technology Research Center of Education Ministry of China, Guangdong Provincial Key Laboratory on Brain Function Repair and Regeneration, Department of Neurosurgery, Zhujiang Hospital, Southern Medical University, Guangzhou 510282, China
| | - Kevin W Williams
- Division of Hypothalamic Research, the University of Texas Southwestern Medical Center at Dallas, Dallas, TX, USA.
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26
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Schwarz Y, Oleinikov K, Schindeldecker B, Wyatt A, Weißgerber P, Flockerzi V, Boehm U, Freichel M, Bruns D. TRPC channels regulate Ca2+-signaling and short-term plasticity of fast glutamatergic synapses. PLoS Biol 2019; 17:e3000445. [PMID: 31536487 PMCID: PMC6773422 DOI: 10.1371/journal.pbio.3000445] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2019] [Revised: 10/01/2019] [Accepted: 08/29/2019] [Indexed: 11/18/2022] Open
Abstract
Transient receptor potential (TRP) proteins form Ca2+-permeable, nonselective cation channels, but their role in neuronal Ca2+ homeostasis is elusive. In the present paper, we show that TRPC channels potently regulate synaptic plasticity by changing the presynaptic Ca2+-homeostasis of hippocampal neurons. Specifically, loss of TRPC1/C4/C5 channels decreases basal-evoked secretion, reduces the pool size of readily releasable vesicles, and accelerates synaptic depression during high-frequency stimulation (HFS). In contrast, primary TRPC5 channel-expressing neurons, identified by a novel TRPC5–τ-green fluorescent protein (τGFP) knockin mouse line, show strong short-term enhancement (STE) of synaptic signaling during HFS, indicating a key role of TRPC5 in short-term plasticity. Lentiviral expression of either TRPC1 or TRPC5 turns classic synaptic depression of wild-type neurons into STE, demonstrating that TRPCs are instrumental in regulating synaptic plasticity. Presynaptic Ca2+ imaging shows that TRPC activity strongly boosts synaptic Ca2+ dynamics, showing that TRPC channels provide an additional presynaptic Ca2+ entry pathway, which efficiently regulates synaptic strength and plasticity. Transient receptor potential (TRP) proteins can form non-selective cation channels, but their role in synaptic transmission is poorly understood. This study shows that calcium-permeable TRPC channels provide an additional calcium entry pathway at presynaptic sites and are efficient regulators of synaptic strength and plasticity.
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Affiliation(s)
- Yvonne Schwarz
- Institute for Physiology, Saarland University, CIPMM, Homburg/Saar, Germany
| | | | | | - Amanda Wyatt
- Experimental and Clinical Pharmacology and Toxicology, PZMS, Saarland University, Homburg/Saar, Germany
| | - Petra Weißgerber
- Experimental and Clinical Pharmacology and Toxicology, PZMS, Saarland University, Homburg/Saar, Germany
| | - Veit Flockerzi
- Experimental and Clinical Pharmacology and Toxicology, PZMS, Saarland University, Homburg/Saar, Germany
| | - Ulrich Boehm
- Experimental and Clinical Pharmacology and Toxicology, PZMS, Saarland University, Homburg/Saar, Germany
| | - Marc Freichel
- Institute of Pharmacology, University of Heidelberg, Heidelberg, Germany
| | - Dieter Bruns
- Institute for Physiology, Saarland University, CIPMM, Homburg/Saar, Germany
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27
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Ko J, Myeong J, Kwak M, Jeon JH, So I. Identification of phospholipase C β downstream effect on transient receptor potential canonical 1/4, transient receptor potential canonical 1/5 channels. THE KOREAN JOURNAL OF PHYSIOLOGY & PHARMACOLOGY : OFFICIAL JOURNAL OF THE KOREAN PHYSIOLOGICAL SOCIETY AND THE KOREAN SOCIETY OF PHARMACOLOGY 2019; 23:357-366. [PMID: 31496873 PMCID: PMC6717798 DOI: 10.4196/kjpp.2019.23.5.357] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/17/2019] [Revised: 07/25/2019] [Accepted: 07/26/2019] [Indexed: 12/21/2022]
Abstract
Gαq-coupled receptor stimulation was implied in the activation process of transient receptor potential canonical (TRPC)1/4 and TRPC1/5 heterotetrameric channels. The inactivation occurs due to phosphatidylinositol 4,5-biphosphate (PI(4,5)P2) depletion. When PI(4,5)P2 depletion was induced by muscarinic stimulation or inositol polyphosphate 5-phosphatase (Inp54p), however, the inactivation by muscarinic stimulation was greater compared to that by Inp54p. The aim of this study was to investigate the complete inactivation mechanism of the heteromeric channels upon Gαq-phospholipase C β (Gαq-PLCβ) activation. We evaluated the activity of heteromeric channels with electrophysiological recording in HEK293 cells expressing TRPC channels. TRPC1/4 and TRPC1/5 heteromers undergo further inhibition in PLCβ activation and calcium/protein kinase C (PKC) signaling. Nevertheless, the key factors differ. For TRPC1/4, the inactivation process was facilitated by Ca2+ release from the endoplasmic reticulum, and for TRPC1/5, activation of PKC was concerned mostly. We conclude that the subsequent increase in cytoplasmic Ca2+ due to Ca2+ release from the endoplasmic reticulum and activation of PKC resulted in a second phase of channel inhibition following PI(4,5)P2 depletion.
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Affiliation(s)
- Juyeon Ko
- Department of Physiology, Seoul National University College of Medicine, Seoul 03080, Korea
| | - Jongyun Myeong
- Department of Physiology, Seoul National University College of Medicine, Seoul 03080, Korea.,Department of Physiology and Biophysics, University of Washington School of Medicine, Seattle, WA 98195, USA
| | - Misun Kwak
- Department of Physiology, Seoul National University College of Medicine, Seoul 03080, Korea
| | - Ju-Hong Jeon
- Department of Physiology, Seoul National University College of Medicine, Seoul 03080, Korea
| | - Insuk So
- Department of Physiology, Seoul National University College of Medicine, Seoul 03080, Korea
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28
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Polat OK, Uno M, Maruyama T, Tran HN, Imamura K, Wong CF, Sakaguchi R, Ariyoshi M, Itsuki K, Ichikawa J, Morii T, Shirakawa M, Inoue R, Asanuma K, Reiser J, Tochio H, Mori Y, Mori MX. Contribution of Coiled-Coil Assembly to Ca 2+/Calmodulin-Dependent Inactivation of TRPC6 Channel and its Impacts on FSGS-Associated Phenotypes. J Am Soc Nephrol 2019; 30:1587-1603. [PMID: 31266820 DOI: 10.1681/asn.2018070756] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2018] [Accepted: 04/23/2019] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND TRPC6 is a nonselective cation channel, and mutations of this gene are associated with FSGS. These mutations are associated with TRPC6 current amplitude amplification and/or delay of the channel inactivation (gain-of-function phenotype). However, the mechanism of the gain-of-function in TRPC6 activity has not yet been clearly solved. METHODS We performed electrophysiologic, biochemical, and biophysical experiments to elucidate the molecular mechanism underlying calmodulin (CaM)-mediated Ca2+-dependent inactivation (CDI) of TRPC6. To address the pathophysiologic contribution of CDI, we assessed the actin filament organization in cultured mouse podocytes. RESULTS Both lobes of CaM helped induce CDI. Moreover, CaM binding to the TRPC6 CaM-binding domain (CBD) was Ca2+-dependent and exhibited a 1:2 (CaM/CBD) stoichiometry. The TRPC6 coiled-coil assembly, which brought two CBDs into adequate proximity, was essential for CDI. Deletion of the coiled-coil slowed CDI of TRPC6, indicating that the coiled-coil assembly configures both lobes of CaM binding on two CBDs to induce normal CDI. The FSGS-associated TRPC6 mutations within the coiled-coil severely delayed CDI and often increased TRPC6 current amplitudes. In cultured mouse podocytes, FSGS-associated channels and CaM mutations led to sustained Ca2+ elevations and a disorganized cytoskeleton. CONCLUSIONS The gain-of-function mechanism found in FSGS-causing mutations in TRPC6 can be explained by impairments of the CDI, caused by disruptions of TRPC's coiled-coil assembly which is essential for CaM binding. The resulting excess Ca2+ may contribute to structural damage in the podocytes.
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Affiliation(s)
- Onur K Polat
- Laboratory of Molecular Biology, Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering
| | - Masatoshi Uno
- Department of Biophysics, Graduate School of Science.,Department of Molecular Engineering, Graduate School of Engineering
| | - Terukazu Maruyama
- Laboratory of Molecular Biology, Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering
| | - Ha Nam Tran
- Laboratory of Molecular Biology, Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering.,Department of Technology and Ecology, Laboratory of Environmental Systems Biology, Graduate School of Global Environmental Studies
| | - Kayo Imamura
- Department of Biophysics, Graduate School of Science
| | - Chee Fah Wong
- Laboratory of Molecular Biology, Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering.,Department of Biology, Faculty of Science and Mathematics, Universiti Pendidikan Sultan Idris, Perak, Malaysia
| | - Reiko Sakaguchi
- Laboratory of Molecular Biology, Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering.,Institute for Integrated Cell-Material Sciences, Kyoto University, Kyoto, Japan
| | - Mariko Ariyoshi
- Department of Molecular Engineering, Graduate School of Engineering
| | - Kyohei Itsuki
- Department of Physiology, Fukuoka University School of Medicine, Fukuoka, Japan
| | - Jun Ichikawa
- Department of Physiology, Fukuoka University School of Medicine, Fukuoka, Japan
| | - Takashi Morii
- Institute of Advanced Energy, Kyoto University, Kyoto, Japan
| | | | - Ryuji Inoue
- Department of Physiology, Fukuoka University School of Medicine, Fukuoka, Japan
| | - Katsuhiko Asanuma
- Department of Nephrology, School of Medicine, Chiba University, Chiba, Japan
| | - Jochen Reiser
- Department of Internal Medicine, Rush University Medical Center, Chicago, Illinois
| | | | - Yasuo Mori
- Laboratory of Molecular Biology, Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering
| | - Masayuki X Mori
- Laboratory of Molecular Biology, Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering,
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29
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Dryer SE, Roshanravan H, Kim EY. TRPC channels: Regulation, dysregulation and contributions to chronic kidney disease. Biochim Biophys Acta Mol Basis Dis 2019; 1865:1041-1066. [PMID: 30953689 DOI: 10.1016/j.bbadis.2019.04.001] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2018] [Revised: 12/20/2018] [Accepted: 01/06/2019] [Indexed: 12/13/2022]
Abstract
Mutations in the gene encoding canonical transient receptor potential-6 (TRPC6) channels result in severe nephrotic syndromes that typically lead to end-stage renal disease. Many but not all of these mutations result in a gain in the function of the resulting channel protein. Since those observations were first made, substantial work has supported the hypothesis that TRPC6 channels can also contribute to progression of acquired (non-genetic) glomerular diseases, including primary and secondary FSGS, glomerulosclerosis during autoimmune glomerulonephritis, and possibly in type-1 diabetes. Their regulation has been extensively studied, especially in podocytes, but also in mesangial cells and other cell types present in the kidney. More recent evidence has implicated TRPC6 in renal fibrosis and tubulointerstitial disease caused by urinary obstruction. Consequently TRPC6 is being extensively investigated as a target for drug discovery. Other TRPC family members are present in kidney. TRPC6 can form a functional heteromultimer with TRPC3, and it has been suggested that TRPC5 may also play a role in glomerular disease progression, although the evidence on this is contradictory. Here we review literature on the expression and regulation of TRPC6, TRPC3 and TRPC5 in various cell types of the vertebrate kidney, the evidence that these channels are dysregulated in disease models, and research showing that knock-out or pharmacological inhibition of these channels can reduce the severity of kidney disease. We also summarize several areas that remain controversial, and some of the large gaps of knowledge concerning the fundamental role of these proteins in regulation of renal function.
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Affiliation(s)
- Stuart E Dryer
- Department of Biology and Biochemistry, University of Houston, Houston, TX, USA; Department of Internal Medicine, Division of Nephrology, Baylor College of Medicine, Houston, TX, USA.
| | - Hila Roshanravan
- Department of Biology and Biochemistry, University of Houston, Houston, TX, USA
| | - Eun Young Kim
- Department of Biology and Biochemistry, University of Houston, Houston, TX, USA
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30
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Wong VSC, Meadows M, Goldberg D, Willis DE. Semaphorin 3A induces acute changes in membrane excitability in spiral ganglion neurons in vitro. Eur J Neurosci 2019; 50:1741-1758. [PMID: 30706560 DOI: 10.1111/ejn.14360] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2018] [Revised: 01/10/2019] [Accepted: 01/23/2019] [Indexed: 11/29/2022]
Abstract
The development and survival of spiral ganglion neurons (SGNs) are dependent on multiple trophic factors as well as membrane electrical activity. Semaphorins (Sema) constitute a family of membrane-associated and secreted proteins that have garnered significant attention as a potential SGN "navigator" during cochlea development. Previous studies using mutant mice demonstrated that Sema3A plays a role in the SGN pathfinding. The mechanisms, however, by which Sema3A shapes SGNs firing behavior are not known. In these studies, we found that Sema3A plays a novel role in regulating SGN resting membrane potential and excitability. Using dissociated SGN from pre-hearing (P3-P5) and post-hearing mice (P12-P15), we recorded membrane potentials using whole-cell patch clamp recording techniques in apical and basal SGN populations. Recombinant Sema3A was applied to examine the effects on intrinsic membrane properties and action potentials evoked by current injections. Apical and basal SGNs from newborn mice treated with recombinant Sema3A (100 ng/ml) displayed a higher resting membrane potential, higher threshold, decreased amplitude, and prolonged latency and duration of spikes. Although a similar phenomenon was observed in SGNs from post-hearing mice, the resting membrane potential was essentially indistinguishable before and after Sema3A exposure. Sema3A-mediated changes in membrane excitability were associated with a significant decrease in K+ and Ca2+ currents. Sema3A acts through linopirdine-sensitive K+ channels in apical, but not in the basal SGNs. Therefore, Sema3A induces differential effects in SGN membrane excitability that are dependent on age and location, and constitutes an additional early and novel effect of Sema3A SGNs in vitro.
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Affiliation(s)
| | - Marc Meadows
- The Vollum Institute, Oregon Health and Science University, Portland, Oregon
| | - David Goldberg
- The Burke Neurological Institute, White Plains, New York
| | - Dianna E Willis
- The Burke Neurological Institute, White Plains, New York.,Brain and Mind Research Institute, Weill Cornell Medicine, New York, New York
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31
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Identification of Inhibitory Ca 2+ Binding Sites in the Upper Vestibule of the Yeast Vacuolar TRP Channel. iScience 2018; 11:1-12. [PMID: 30572205 PMCID: PMC6299153 DOI: 10.1016/j.isci.2018.11.037] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2018] [Revised: 10/30/2018] [Accepted: 11/29/2018] [Indexed: 01/28/2023] Open
Abstract
By vacuolar patch-clamp and Ca2+ imaging experiments, we show that the yeast vacuolar transient receptor potential (TRPY) channel 1 is activated by cytosolic Ca2+ and inhibited by Ca2+ from the vacuolar lumen. The channel is cooperatively affected by vacuolar Ca2+ (Hill coefficient, 1.5), suggesting that it may accommodate a Ca2+ receptor that can bind two calcium ions. Alanine scanning of six negatively charged amino acid residues in the transmembrane S5 and S6 linker, facing the vacuolar lumen, revealed that two aspartate residues, 401 and 405, are essential for current inhibition and direct binding of 45Ca2+. Expressed in HEK-293 cells, a significant fraction of TRPY1, present in the plasma membrane, retained its Ca2+ sensitivity. Based on these data and on homology with TRPV channels, we conclude that D401 and D405 are key residues within the vacuolar vestibule of the TRPY1 pore that decrease cation access or permeation after Ca2+ binding. The yeast vacuolar TRPY1 channel is inhibited by vacuolar Ca2+ Aspartate residues D401A and D405A are essential for Ca2+-mediated inhibition Aspartate residues D401 and D405 are essential for direct Ca2+ binding Ca2+ binding to D401 and D405 within vacuolar pore vestibule mediates inhibition
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32
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Smith MA, Katsouri L, Virtue S, Choudhury AI, Vidal-Puig A, Ashford MLJ, Withers DJ. Calcium Channel Ca V2.3 Subunits Regulate Hepatic Glucose Production by Modulating Leptin-Induced Excitation of Arcuate Pro-opiomelanocortin Neurons. Cell Rep 2018; 25:278-287.e4. [PMID: 30304668 PMCID: PMC6198286 DOI: 10.1016/j.celrep.2018.09.024] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2017] [Revised: 07/26/2018] [Accepted: 09/07/2018] [Indexed: 11/18/2022] Open
Abstract
Leptin acts on hypothalamic pro-opiomelanocortin (POMC) neurons to regulate glucose homeostasis, but the precise mechanisms remain unclear. Here, we demonstrate that leptin-induced depolarization of POMC neurons is associated with the augmentation of a voltage-gated calcium (CaV) conductance with the properties of the "R-type" channel. Knockdown of the pore-forming subunit of the R-type (CaV2.3 or Cacna1e) conductance in hypothalamic POMC neurons prevented sustained leptin-induced depolarization. In vivo POMC-specific Cacna1e knockdown increased hepatic glucose production and insulin resistance, while body weight, feeding, or leptin-induced suppression of food intake were not changed. These findings link Cacna1e function to leptin-mediated POMC neuron excitability and glucose homeostasis and may provide a target for the treatment of diabetes.
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Affiliation(s)
- Mark A Smith
- Metabolic Signalling Group, MRC London Institute of Medical Sciences, London W12 0NN, UK.
| | - Loukia Katsouri
- Metabolic Signalling Group, MRC London Institute of Medical Sciences, London W12 0NN, UK
| | - Samuel Virtue
- Metabolic Research Laboratories, Institute of Metabolic Science, University of Cambridge, Cambridge CB2 0QQ, UK
| | - Agharul I Choudhury
- Metabolic Signalling Group, MRC London Institute of Medical Sciences, London W12 0NN, UK
| | - Antonio Vidal-Puig
- Metabolic Research Laboratories, Institute of Metabolic Science, University of Cambridge, Cambridge CB2 0QQ, UK
| | - Michael L J Ashford
- Division of Molecular and Clinical Medicine, Ninewells Hospital and Medical School, University of Dundee, Dundee DD1 9SY, UK
| | - Dominic J Withers
- Metabolic Signalling Group, MRC London Institute of Medical Sciences, London W12 0NN, UK; Institute of Clinical Sciences, Imperial College London, Du Cane Road, London W12 0NN, UK.
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33
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Myeong J, Ko J, Kwak M, Kim J, Woo J, Ha K, Hong C, Yang D, Kim HJ, Jeon JH, So I. Dual action of the Gα q-PLCβ-PI(4,5)P 2 pathway on TRPC1/4 and TRPC1/5 heterotetramers. Sci Rep 2018; 8:12117. [PMID: 30108272 PMCID: PMC6092394 DOI: 10.1038/s41598-018-30625-0] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2017] [Accepted: 08/03/2018] [Indexed: 11/09/2022] Open
Abstract
The transient receptor potential canonical (TRPC) 1 channel is widely distributed in mammalian cells and is involved in many physiological processes. TRPC1 is primarily considered a regulatory subunit that forms heterotetrameric channels with either TRPC4 or TRPC5 subunits. Here, we suggest that the regulation of TRPC1/4 and TRPC1/5 heterotetrameric channels by the Gαq-PLCβ pathway is self-limited and dynamically mediated by Gαq and PI(4,5)P2. We provide evidence indicating that Gαq protein directly interacts with either TRPC4 or TRPC5 of the heterotetrameric channels to permit activation. Simultaneously, Gαq-coupled PLCβ activation leads to the breakdown of PI(4,5)P2, which inhibits activity of TRPC1/4 and 1/5 channels.
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Affiliation(s)
- Jongyun Myeong
- Department of Physiology, Seoul National University College of Medicine, Seoul, 03080, Republic of Korea.,Department of Physiology and Biophysics, University of Washington School of Medicine, Seattle, WA, 98195, USA
| | - Juyeon Ko
- Department of Physiology, Seoul National University College of Medicine, Seoul, 03080, Republic of Korea
| | - Misun Kwak
- Department of Physiology, Seoul National University College of Medicine, Seoul, 03080, Republic of Korea
| | - Jinsung Kim
- Department of Physiology, Seoul National University College of Medicine, Seoul, 03080, Republic of Korea
| | - Joohan Woo
- Department of Physiology, Seoul National University College of Medicine, Seoul, 03080, Republic of Korea
| | - Kotdaji Ha
- Department of Physiology, Seoul National University College of Medicine, Seoul, 03080, Republic of Korea
| | - Chansik Hong
- Department of Physiology, Chosun University School of Medicine, Kwangju, 61452, Republic of Korea
| | - Dongki Yang
- Department of Physiology, Gachon University College of Medicine, Incheon, 21936, Republic of Korea
| | - Hyun Jin Kim
- Department of Physiology, Sungkyunkwan University School of Medicine, Suwon, 16419, Republic of Korea.
| | - Ju-Hong Jeon
- Department of Physiology, Seoul National University College of Medicine, Seoul, 03080, Republic of Korea
| | - Insuk So
- Department of Physiology, Seoul National University College of Medicine, Seoul, 03080, Republic of Korea.
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Trebak M, Putney JW. ORAI Calcium Channels. Physiology (Bethesda) 2018; 32:332-342. [PMID: 28615316 DOI: 10.1152/physiol.00011.2017] [Citation(s) in RCA: 66] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2017] [Revised: 05/10/2017] [Accepted: 05/10/2017] [Indexed: 12/17/2022] Open
Abstract
In this review article, we discuss the different gene products and translational variants of ORAI proteins and their contribution to the makeup of different native calcium-conducting channels with distinct compositions and modes of activation. We also review the different modes of regulation of these distinct calcium channels and their impact on downstream cellular signaling controlling important physiological functions.
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Affiliation(s)
- Mohamed Trebak
- The Department of Cellular and Molecular Physiology, The Pennsylvania State University College of Medicine, Hershey, Pennsylvania; and
| | - James W Putney
- The National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, North Carolina
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35
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Pires PW, Earley S. Redox regulation of transient receptor potential channels in the endothelium. Microcirculation 2018; 24. [PMID: 27809396 DOI: 10.1111/micc.12329] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2016] [Accepted: 10/31/2016] [Indexed: 01/08/2023]
Abstract
ROS and RNS are important mediators of signaling pathways in the endothelium. Specific members of the TRP superfamily of cation channels act as important Ca2+ influx pathways in endothelial cells and are involved in endothelium-dependent vasodilation, regulation of barrier permeability, and angiogenesis. ROS and RNS can modulate the activity of certain TRP channels mainly by modifying specific cysteine residues or by stimulating the production of second messengers. In this review, we highlight the recent literature describing redox regulation of TRP channel activity in endothelial cells as well as the physiological importance of these pathways and implication for cardiovascular diseases.
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Affiliation(s)
- Paulo Wagner Pires
- Department of Pharmacology, Cardiovascular Research Center, Reno School of Medicine, University of Nevada, Reno, NV, USA
| | - Scott Earley
- Department of Pharmacology, Cardiovascular Research Center, Reno School of Medicine, University of Nevada, Reno, NV, USA
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36
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Just S, Chenard BL, Ceci A, Strassmaier T, Chong JA, Blair NT, Gallaschun RJ, del Camino D, Cantin S, D’Amours M, Eickmeier C, Fanger CM, Hecker C, Hessler DP, Hengerer B, Kroker KS, Malekiani S, Mihalek R, McLaughlin J, Rast G, Witek J, Sauer A, Pryce CR, Moran MM. Treatment with HC-070, a potent inhibitor of TRPC4 and TRPC5, leads to anxiolytic and antidepressant effects in mice. PLoS One 2018; 13:e0191225. [PMID: 29385160 PMCID: PMC5791972 DOI: 10.1371/journal.pone.0191225] [Citation(s) in RCA: 86] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2017] [Accepted: 12/30/2017] [Indexed: 12/28/2022] Open
Abstract
Background Forty million adults in the US suffer from anxiety disorders, making these the most common forms of mental illness. Transient receptor potential channel canonical subfamily (TRPC) members 4 and 5 are non-selective cation channels highly expressed in regions of the cortex and amygdala, areas thought to be important in regulating anxiety. Previous work with null mice suggests that inhibition of TRPC4 and TRPC5 may have anxiolytic effects. HC-070 in vitro To assess the potential of TRPC4/5 inhibitors as an avenue for treatment, we invented a highly potent, small molecule antagonist of TRPC4 and TRPC5 which we call HC-070. HC-070 inhibits recombinant TRPC4 and TRPC5 homomultimers in heterologous expression systems with nanomolar potency. It also inhibits TRPC1/5 and TRPC1/4 heteromultimers with similar potency and reduces responses evoked by cholecystokinin tetrapeptide (CCK-4) in the amygdala. The compound is >400-fold selective over a wide range of molecular targets including ion channels, receptors, and kinases. HC-070 in vivo Upon oral dosing in mice, HC-070 achieves exposure levels in the brain and plasma deemed sufficient to test behavioral activity. Treatment with HC-070 attenuates the anxiogenic effect of CCK-4 in the elevated plus maze (EPM). The compound recapitulates the phenotype observed in both null TRPC4 and TRPC5 mice in a standard EPM. Anxiolytic and anti-depressant effects of HC-070 are also observed in pharmacological in vivo tests including marble burying, tail suspension and forced swim. Furthermore, HC-070 ameliorates the increased fear memory induced by chronic social stress. A careful evaluation of the pharmacokinetic-pharmacodynamic relationship reveals that substantial efficacy is observed at unbound brain levels similar to, or even lower than, the 50% inhibitory concentration (IC50) recorded in vitro, increasing confidence that the observed effects are indeed mediated by TRPC4 and/or TRPC5 inhibition. Together, this experimental data set introduces a novel, high quality, small molecule antagonist of TRPC4 and TRPC5 containing channels and supports the targeting of TRPC4 and TRPC5 channels as a new mechanism of action for the treatment of psychiatric symptoms.
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Affiliation(s)
- Stefan Just
- Boehringer Ingelheim Pharma GmbH & Co. KG, Biberach an der Riss, Germany
| | | | - Angelo Ceci
- Boehringer Ingelheim Pharma GmbH & Co. KG, Biberach an der Riss, Germany
| | | | - Jayhong A. Chong
- Hydra Biosciences, Cambridge, Massachusetts, United States of America
| | | | | | - Donato del Camino
- Hydra Biosciences, Cambridge, Massachusetts, United States of America
| | - Susan Cantin
- Hydra Biosciences, Cambridge, Massachusetts, United States of America
| | - Marc D’Amours
- Hydra Biosciences, Cambridge, Massachusetts, United States of America
| | | | | | - Carsten Hecker
- Boehringer Ingelheim Pharma GmbH & Co. KG, Biberach an der Riss, Germany
| | - David P. Hessler
- Hydra Biosciences, Cambridge, Massachusetts, United States of America
| | - Bastian Hengerer
- Boehringer Ingelheim Pharma GmbH & Co. KG, Biberach an der Riss, Germany
| | - Katja S. Kroker
- Boehringer Ingelheim Pharma GmbH & Co. KG, Biberach an der Riss, Germany
| | - Sam Malekiani
- Hydra Biosciences, Cambridge, Massachusetts, United States of America
| | - Robert Mihalek
- Hydra Biosciences, Cambridge, Massachusetts, United States of America
| | - Joseph McLaughlin
- Hydra Biosciences, Cambridge, Massachusetts, United States of America
| | - Georg Rast
- Boehringer Ingelheim Pharma GmbH & Co. KG, Biberach an der Riss, Germany
| | - JoAnn Witek
- Hydra Biosciences, Cambridge, Massachusetts, United States of America
| | - Achim Sauer
- Boehringer Ingelheim Pharma GmbH & Co. KG, Biberach an der Riss, Germany
| | - Christopher R. Pryce
- Preclinical Laboratory for Translational Research into Affective Disorders, Department of Psychiatry, Psychotherapy & Psychosomatics, Psychiatric Hospital, University of Zurich, Zurich, Switzerland
| | - Magdalene M. Moran
- Hydra Biosciences, Cambridge, Massachusetts, United States of America
- * E-mail:
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37
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Nonlinear Relationship Between Spike-Dependent Calcium Influx and TRPC Channel Activation Enables Robust Persistent Spiking in Neurons of the Anterior Cingulate Cortex. J Neurosci 2018; 38:1788-1801. [PMID: 29335357 DOI: 10.1523/jneurosci.0538-17.2018] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2017] [Revised: 12/18/2017] [Accepted: 01/08/2018] [Indexed: 11/21/2022] Open
Abstract
Continuation of spiking after a stimulus ends (i.e. persistent spiking) is thought to support working memory. Muscarinic receptor activation enables persistent spiking among synaptically isolated pyramidal neurons in anterior cingulate cortex (ACC), but a detailed characterization of that spiking is lacking and the underlying mechanisms remain unclear. Here, we show that the rate of persistent spiking in ACC neurons is insensitive to the intensity and number of triggers, but can be modulated by injected current, and that persistent spiking can resume after several seconds of hyperpolarization-imposed quiescence. Using electrophysiology and calcium imaging in brain slices from male rats, we determined that canonical transient receptor potential (TRPC) channels are necessary for persistent spiking and that TRPC-activating calcium enters in a spike-dependent manner via voltage-gated calcium channels. Constrained by these biophysical details, we built a computational model that reproduced the observed pattern of persistent spiking. Nonlinear dynamical analysis of that model revealed that TRPC channels become fully activated by the small rise in intracellular calcium caused by evoked spikes. Calcium continues to rise during persistent spiking, but because TRPC channel activation saturates, firing rate stabilizes. By calcium rising higher than required for maximal TRPC channel activation, TRPC channels are able to remain active during periods of hyperpolarization-imposed quiescence (until calcium drops below saturating levels) such that persistent spiking can resume when hyperpolarization is discontinued. Our results thus reveal that the robust intrinsic bistability exhibited by ACC neurons emerges from the nonlinear positive feedback relationship between spike-dependent calcium influx and TRPC channel activation.SIGNIFICANCE STATEMENT Neurons use action potentials, or spikes, to encode information. Some neurons can store information for short periods (seconds to minutes) by continuing to spike after a stimulus ends, thus enabling working memory. This so-called "persistent" spiking occurs in many brain areas and has been linked to activation of canonical transient receptor potential (TRPC) channels. However, TRPC activation alone is insufficient to explain many aspects of persistent spiking such as resumption of spiking after periods of imposed quiescence. Using experiments and simulations, we show that calcium influx caused by spiking is necessary and sufficient to activate TRPC channels and that the ensuing positive feedback interaction between intracellular calcium and TRPC channel activation can account for many hitherto unexplained aspects of persistent spiking.
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38
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Götz V, Qiao S, Beck A, Boehm U. Transient receptor potential (TRP) channel function in the reproductive axis. Cell Calcium 2017; 67:138-147. [DOI: 10.1016/j.ceca.2017.04.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2017] [Revised: 04/19/2017] [Accepted: 04/19/2017] [Indexed: 10/19/2022]
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39
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Oda S, Numaga-Tomita T, Kitajima N, Toyama T, Harada E, Shimauchi T, Nishimura A, Ishikawa T, Kumagai Y, Birnbaumer L, Nishida M. TRPC6 counteracts TRPC3-Nox2 protein complex leading to attenuation of hyperglycemia-induced heart failure in mice. Sci Rep 2017; 7:7511. [PMID: 28790356 PMCID: PMC5548754 DOI: 10.1038/s41598-017-07903-4] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2017] [Accepted: 07/04/2017] [Indexed: 12/19/2022] Open
Abstract
Excess production of reactive oxygen species (ROS) caused by hyperglycemia is a major risk factor for heart failure. We previously reported that transient receptor potential canonical 3 (TRPC3) channel mediates pressure overload-induced maladaptive cardiac fibrosis by forming stably functional complex with NADPH oxidase 2 (Nox2). Although TRPC3 has been long suggested to form hetero-multimer channels with TRPC6 and function as diacylglycerol-activated cation channels coordinately, the role of TRPC6 in heart is still obscure. We here demonstrated that deletion of TRPC6 had no impact on pressure overload-induced heart failure despite inhibiting interstitial fibrosis in mice. TRPC6-deficient mouse hearts 1 week after transverse aortic constriction showed comparable increases in fibrotic gene expressions and ROS production but promoted inductions of inflammatory cytokines, compared to wild type hearts. Treatment of TRPC6-deficient mice with streptozotocin caused severe reduction of cardiac contractility with enhancing urinary and cardiac lipid peroxide levels, compared to wild type and TRPC3-deficient mice. Knockdown of TRPC6, but not TRPC3, enhanced basal expression levels of cytokines in rat cardiomyocytes. TRPC6 could interact with Nox2, but the abundance of TRPC6 was inversely correlated with that of Nox2. These results strongly suggest that Nox2 destabilization through disrupting TRPC3-Nox2 complex underlies attenuation of hyperglycemia-induced heart failure by TRPC6.
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Affiliation(s)
- Sayaka Oda
- Division of Cardiocirculatory Signaling, National Institute for Physiological Sciences (Okazaki Institute for Integrative Bioscience), National Institutes of Natural Sciences, Aichi, 444-8787, Japan.,Department of Physiological Sciences, SOKENDAI (School of Life Science, The Graduate University for Advanced Studies), Aichi, 444-8787, Japan
| | - Takuro Numaga-Tomita
- Division of Cardiocirculatory Signaling, National Institute for Physiological Sciences (Okazaki Institute for Integrative Bioscience), National Institutes of Natural Sciences, Aichi, 444-8787, Japan.,Department of Physiological Sciences, SOKENDAI (School of Life Science, The Graduate University for Advanced Studies), Aichi, 444-8787, Japan
| | - Naoyuki Kitajima
- Division of Cardiocirculatory Signaling, National Institute for Physiological Sciences (Okazaki Institute for Integrative Bioscience), National Institutes of Natural Sciences, Aichi, 444-8787, Japan.,Department of Translational Pharmaceutical Sciences, Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka, 812-8582, Japan
| | - Takashi Toyama
- Division of Cardiocirculatory Signaling, National Institute for Physiological Sciences (Okazaki Institute for Integrative Bioscience), National Institutes of Natural Sciences, Aichi, 444-8787, Japan.,Department of Translational Pharmaceutical Sciences, Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka, 812-8582, Japan.,Environmental Biology Laboratory, Faculty of Medicine and Graduate School of Comprehensive Human Sciences, University of Tsukuba, Tsukuba, 305-8575, Japan
| | - Eri Harada
- Ajinomoto Co. Inc., Tokyo, 104-8315, Japan.,EA Pharma Co., Ltd., Tokyo, 104-0042, Japan
| | - Tsukasa Shimauchi
- Division of Cardiocirculatory Signaling, National Institute for Physiological Sciences (Okazaki Institute for Integrative Bioscience), National Institutes of Natural Sciences, Aichi, 444-8787, Japan.,Department of Translational Pharmaceutical Sciences, Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka, 812-8582, Japan
| | - Akiyuki Nishimura
- Division of Cardiocirculatory Signaling, National Institute for Physiological Sciences (Okazaki Institute for Integrative Bioscience), National Institutes of Natural Sciences, Aichi, 444-8787, Japan.,Department of Physiological Sciences, SOKENDAI (School of Life Science, The Graduate University for Advanced Studies), Aichi, 444-8787, Japan
| | - Tatsuya Ishikawa
- Department of Translational Pharmaceutical Sciences, Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka, 812-8582, Japan.,Ajinomoto Co. Inc., Tokyo, 104-8315, Japan.,EA Pharma Co., Ltd., Tokyo, 104-0042, Japan
| | - Yoshito Kumagai
- Environmental Biology Laboratory, Faculty of Medicine and Graduate School of Comprehensive Human Sciences, University of Tsukuba, Tsukuba, 305-8575, Japan
| | - Lutz Birnbaumer
- Laboratory of Neuroscience, NIEHS, NIH, Research Triangle Park, NC, 27709, USA.,Institute for Biomedical Research (BIOMED), Catholic University of Argentina, C1107AFF, Buenos, Aires, Argentina
| | - Motohiro Nishida
- Division of Cardiocirculatory Signaling, National Institute for Physiological Sciences (Okazaki Institute for Integrative Bioscience), National Institutes of Natural Sciences, Aichi, 444-8787, Japan. .,Department of Physiological Sciences, SOKENDAI (School of Life Science, The Graduate University for Advanced Studies), Aichi, 444-8787, Japan. .,Department of Translational Pharmaceutical Sciences, Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka, 812-8582, Japan. .,PRESTO, JST, 4-1-8 Honcho, Kawaguchi, Saitama, 332-0012, Japan.
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Bröker-Lai J, Kollewe A, Schindeldecker B, Pohle J, Nguyen Chi V, Mathar I, Guzman R, Schwarz Y, Lai A, Weißgerber P, Schwegler H, Dietrich A, Both M, Sprengel R, Draguhn A, Köhr G, Fakler B, Flockerzi V, Bruns D, Freichel M. Heteromeric channels formed by TRPC1, TRPC4 and TRPC5 define hippocampal synaptic transmission and working memory. EMBO J 2017; 36:2770-2789. [PMID: 28790178 DOI: 10.15252/embj.201696369] [Citation(s) in RCA: 85] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2016] [Revised: 07/01/2017] [Accepted: 07/07/2017] [Indexed: 12/30/2022] Open
Abstract
Canonical transient receptor potential (TRPC) channels influence various neuronal functions. Using quantitative high-resolution mass spectrometry, we demonstrate that TRPC1, TRPC4, and TRPC5 assemble into heteromultimers with each other, but not with other TRP family members in the mouse brain and hippocampus. In hippocampal neurons from Trpc1/Trpc4/Trpc5-triple-knockout (Trpc1/4/5-/-) mice, lacking any TRPC1-, TRPC4-, or TRPC5-containing channels, action potential-triggered excitatory postsynaptic currents (EPSCs) were significantly reduced, whereas frequency, amplitude, and kinetics of quantal miniature EPSC signaling remained unchanged. Likewise, evoked postsynaptic responses in hippocampal slice recordings and transient potentiation after tetanic stimulation were decreased. In vivo, Trpc1/4/5-/- mice displayed impaired cross-frequency coupling in hippocampal networks and deficits in spatial working memory, while spatial reference memory was unaltered. Trpc1/4/5-/- animals also exhibited deficiencies in adapting to a new challenge in a relearning task. Our results indicate the contribution of heteromultimeric channels from TRPC1, TRPC4, and TRPC5 subunits to the regulation of mechanisms underlying spatial working memory and flexible relearning by facilitating proper synaptic transmission in hippocampal neurons.
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Affiliation(s)
- Jenny Bröker-Lai
- Institute of Pharmacology, Heidelberg University, Heidelberg, Germany
| | - Astrid Kollewe
- Institute of Physiology, University of Freiburg, Freiburg, Germany
| | - Barbara Schindeldecker
- Center for Integrative Physiology and Molecular Medicine, Saarland University, Homburg, Germany
| | - Jörg Pohle
- Institute of Pharmacology, Heidelberg University, Heidelberg, Germany.,Physiology of Neural Networks, Psychiatry/Psychopharmacology, Central Institute of Mental Health, J5, Heidelberg University, Mannheim, Germany
| | - Vivan Nguyen Chi
- Institute of Physiology and Pathophysiology, Heidelberg University, Heidelberg, Germany
| | - Ilka Mathar
- Institute of Pharmacology, Heidelberg University, Heidelberg, Germany
| | - Raul Guzman
- Center for Integrative Physiology and Molecular Medicine, Saarland University, Homburg, Germany
| | - Yvonne Schwarz
- Center for Integrative Physiology and Molecular Medicine, Saarland University, Homburg, Germany
| | - Alan Lai
- Institute of Pharmacology, Heidelberg University, Heidelberg, Germany
| | - Petra Weißgerber
- Experimental and Clinical Pharmacology and Toxicology, Saarland University, Homburg, Germany
| | | | - Alexander Dietrich
- Walther-Straub-Institute for Pharmacology and Toxicology, Ludwig-Maximilians-University München, München, Germany
| | - Martin Both
- Institute of Physiology and Pathophysiology, Heidelberg University, Heidelberg, Germany
| | - Rolf Sprengel
- Max Planck Research Group of the Max Planck Institute for Medical Research at the Institute for Anatomy and Cell Biology, Heidelberg University, Heidelberg, Germany
| | - Andreas Draguhn
- Institute of Physiology and Pathophysiology, Heidelberg University, Heidelberg, Germany
| | - Georg Köhr
- Physiology of Neural Networks, Psychiatry/Psychopharmacology, Central Institute of Mental Health, J5, Heidelberg University, Mannheim, Germany
| | - Bernd Fakler
- Institute of Physiology, University of Freiburg, Freiburg, Germany.,BIOSS, Center for Biological Signaling Studies, University of Freiburg, Freiburg, Germany‡
| | - Veit Flockerzi
- Experimental and Clinical Pharmacology and Toxicology, Saarland University, Homburg, Germany
| | - Dieter Bruns
- Center for Integrative Physiology and Molecular Medicine, Saarland University, Homburg, Germany
| | - Marc Freichel
- Institute of Pharmacology, Heidelberg University, Heidelberg, Germany
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Lin EC, Combe CL, Gasparini S. Differential Contribution of Ca 2+-Dependent Mechanisms to Hyperexcitability in Layer V Neurons of the Medial Entorhinal Cortex. Front Cell Neurosci 2017; 11:182. [PMID: 28713246 PMCID: PMC5491848 DOI: 10.3389/fncel.2017.00182] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2016] [Accepted: 06/13/2017] [Indexed: 11/13/2022] Open
Abstract
Temporal lobe epilepsy is characterized by recurrent seizures in one or both temporal lobes of the brain; some in vitro models show that epileptiform discharges initiate in entorhinal layer V neurons and then spread into other areas of the temporal lobe. We previously found that, in the presence of GABAA receptor antagonists, stimulation of afferent fibers, terminating both at proximal and distal dendritic locations, initiated hyperexcitable bursts in layer V medial entorhinal neurons. We investigated the differential contribution of Ca2+-dependent mechanisms to the plateaus underlying these bursts at proximal and distal synapses. We found that the NMDA glutamatergic antagonist D,L-2-amino-5-phosphonovaleric acid (APV; 50 μM) reduced both the area and duration of the bursts at both proximal and distal synapses by about half. The L-type Ca2+ channel blocker nimodipine (10 μM) and the R- and T-type Ca2+ channel blocker NiCl2 (200 μM) decreased the area of the bursts to a lesser extent; none of these effects appeared to be location-dependent. Remarkably, the perfusion of flufenamic acid (FFA; 100 μM), to block Ca2+-activated non-selective cation currents (ICAN) mediated by transient receptor potential (TRP) channels, had a location-dependent effect, by abolishing burst firing and switching the suprathreshold response to a single action potential (AP) for proximal stimulation, but only minimally affecting the bursts evoked by distal stimulation. A similar outcome was found when FFA was pressure-applied locally around the proximal dendrite of the recorded neurons and in the presence of a selective blocker of melastatin TRP (TRPM) channels, 9-phenanthrol (100 μM), whereas a selective blocker of canonical TRP (TRPC) channels, SKF 96365, did not affect the bursts. These results indicate that different mechanisms might contribute to the initiation of hyperexcitability in layer V neurons at proximal and distal synapses and could shed light on the initiation of epileptiform activity in the entorhinal cortex.
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Affiliation(s)
- Eric C Lin
- Neuroscience Center of Excellence, Louisiana State University Health Sciences CenterNew Orleans, LA, United States
| | - Crescent L Combe
- Neuroscience Center of Excellence, Louisiana State University Health Sciences CenterNew Orleans, LA, United States
| | - Sonia Gasparini
- Neuroscience Center of Excellence, Louisiana State University Health Sciences CenterNew Orleans, LA, United States.,Department of Cell Biology and Anatomy, Louisiana State University Health Sciences CenterNew Orleans, LA, United States
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Beck A, Götz V, Qiao S, Weissgerber P, Flockerzi V, Freichel M, Boehm U. Functional Characterization of Transient Receptor Potential (TRP) Channel C5 in Female Murine Gonadotropes. Endocrinology 2017; 158:887-902. [PMID: 28324107 DOI: 10.1210/en.2016-1810] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/02/2016] [Accepted: 01/25/2017] [Indexed: 12/22/2022]
Abstract
Gonadotrope cells in the anterior pituitary gland secrete gonadotropins regulating gonadal function in mammals. Recent results have implicated transient receptor potential (TRP) cation channels in pituitary physiology; however, if and how TRP channels contribute to gonadotrope function is not known. Here, we report that 14 out of 28 TRP channels encoded in the mouse genome are expressed in murine gonadotropes with highest expression levels found for canonical TRP (TRPC) channel 5 in juvenile females. We show that TRP channel expression in these cells exhibits considerable plasticity and that it depends on the sex and the developmental and hormonal status of the animal. We then combine different genetic strategies including genetic confocal Ca2+ imaging in whole-mount pituitary gland preparations to characterize TRPC5 channel function in gonadotropes from juvenile females. We show that the TRPC5 agonist Englerin A activates a cytosolic Ca2+ signal and a whole-cell current in these cells, which is absent in TRPC5-deficient mice, and demonstrate that TRPC5 forms functional heteromultimers with TRPC1 in gonadotropes. We further show that the Englerin A-activated TRPC5-dependent Ca2+ signal is mediated by Ca2+ influx both via TRPC5 and via l-type voltage-gated Ca2+ channels, activated by the depolarization through TRPC5-mediated cation influx. Finally, we demonstrate that the gonadotropin-releasing hormone (GnRH)-mediated net depolarization is significantly reduced in gonadotropes isolated from TRPC5-deficient mice. In conclusion, our data suggest that TRPC5 contributes to depolarization of the plasma membrane in gonadotropes upon GnRH stimulation and increases the intracellular Ca2+ concentration via its own Ca2+ permeability and via the activation of voltage-gated Ca2+ channels.
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Affiliation(s)
- Andreas Beck
- Pharmacology and Toxicology, Center for Molecular Signaling (PZMS), Saarland University School of Medicine, Homburg, Germany
- Center of Human and Molecular Biology (ZHMB), Saarland University, Homburg, Germany
| | - Viktoria Götz
- Pharmacology and Toxicology, Center for Molecular Signaling (PZMS), Saarland University School of Medicine, Homburg, Germany
| | - Sen Qiao
- Pharmacology and Toxicology, Center for Molecular Signaling (PZMS), Saarland University School of Medicine, Homburg, Germany
| | - Petra Weissgerber
- Pharmacology and Toxicology, Center for Molecular Signaling (PZMS), Saarland University School of Medicine, Homburg, Germany
| | - Veit Flockerzi
- Pharmacology and Toxicology, Center for Molecular Signaling (PZMS), Saarland University School of Medicine, Homburg, Germany
| | - Marc Freichel
- Institute of Pharmacology, Heidelberg University, Heidelberg, Germany
| | - Ulrich Boehm
- Pharmacology and Toxicology, Center for Molecular Signaling (PZMS), Saarland University School of Medicine, Homburg, Germany
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MORI Y, TAKAHASHI N, KUROKAWA T, KIYONAKA S. TRP channels in oxygen physiology: distinctive functional properties and roles of TRPA1 in O 2 sensing. PROCEEDINGS OF THE JAPAN ACADEMY. SERIES B, PHYSICAL AND BIOLOGICAL SCIENCES 2017; 93:464-482. [PMID: 28769017 PMCID: PMC5713176 DOI: 10.2183/pjab.93.028] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/23/2017] [Accepted: 04/20/2017] [Indexed: 05/22/2023]
Abstract
Transient Receptor Potential (TRP) proteins form cation channels characterized by a wide variety of activation triggers. Here, we overview a group of TRP channels that respond to reactive redox species to transduce physiological signals, with a focus on TRPA1 and its role in oxygen physiology. Our systematic evaluation of oxidation sensitivity using cysteine-selective reactive disulphides with different redox potentials reveals that TRPA1 has the highest sensitivity to oxidants/electrophiles among the TRP channels, which enables it to sense O2. Proline hydroxylation by O2-dependent hydroxylases also regulates the O2-sensing function by inhibiting TRPA1 in normoxia; TRPA1 is activated by hypoxia through relief from the inhibition and by hyperoxia through cysteine oxidation that overrides the inhibition. TRPA1 enhances neuronal discharges induced by hyperoxia and hypoxia in the vagus to underlie respiratory adaptation to changes in O2 availability. This importance of TRPA1 in non-carotid body O2 sensors can be extended to the universal significance of redox-sensitive TRP channels in O2 adaptation.
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Affiliation(s)
- Yasuo MORI
- Laboratory of Molecular Biology, Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Kyoto, Japan
- Correspondence should be addressed: Y. Mori, Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Kyoto 615-8510, Japan (e-mail: )
| | - Nobuaki TAKAHASHI
- Laboratory of Molecular Biology, Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Kyoto, Japan
| | - Tatsuki KUROKAWA
- Laboratory of Molecular Biology, Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Kyoto, Japan
| | - Shigeki KIYONAKA
- Laboratory of Molecular Biology, Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Kyoto, Japan
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Ko J, Myeong J, Yang D, So I. Calcium permeability of transient receptor potential canonical (TRPC) 4 channels measured by TRPC4-GCaMP6s. THE KOREAN JOURNAL OF PHYSIOLOGY & PHARMACOLOGY : OFFICIAL JOURNAL OF THE KOREAN PHYSIOLOGICAL SOCIETY AND THE KOREAN SOCIETY OF PHARMACOLOGY 2016; 21:133-140. [PMID: 28066150 PMCID: PMC5214905 DOI: 10.4196/kjpp.2017.21.1.133] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/10/2016] [Revised: 11/24/2016] [Accepted: 11/24/2016] [Indexed: 12/16/2022]
Abstract
Conflicting evidence has been obtained regarding whether transient receptor potential cation channels (TRPC) are store-operated channels (SOCs) or receptor-operated channels (ROCs). Moreover, the Ca/Na permeability ratio differs depending on whether the current-voltage (I-V) curve has a doubly rectifying shape or inward rectifying shape. To investigate the calcium permeability of TRPC4 channels, we attached GCaMP6s to TRPC4 and simultaneously measured the current and calcium signals. A TRPC4 specific activator, (–)-englerin A, induced both current and calcium fluorescence with the similar time course. Muscarinic receptor stimulator, carbachol, also induced both current and calcium fluorescence with the similar time course. By forming heteromers with TRPC4, TRPC1 significantly reduced the inward current with outward rectifying I-V curve, which also caused the decrease of calcium fluorescence intensity. These results suggest that GCaMP6s attached to TRPC4 can detect slight calcium changes near TRPC4 channels. Consequently, TRPC4-GCaMP6s can be a useful tool for testing the calcium permeability of TRPC4 channels.
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Affiliation(s)
- Juyeon Ko
- Department of Physiology, Seoul National University College of Medicine, Seoul 03080, Korea
| | - Jongyun Myeong
- Department of Physiology, Seoul National University College of Medicine, Seoul 03080, Korea
| | - Dongki Yang
- Department of Physiology, College of Medicine, Gachon University, Incheon 21936, Korea
| | - Insuk So
- Department of Physiology, Seoul National University College of Medicine, Seoul 03080, Korea
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Chen X, Li W, Riley AM, Soliman M, Chakraborty S, Stamatkin CW, Obukhov AG. Molecular Determinants of the Sensitivity to Gq/11-Phospholipase C-dependent Gating, Gd3+ Potentiation, and Ca2+ Permeability in the Transient Receptor Potential Canonical Type 5 (TRPC5) Channel. J Biol Chem 2016; 292:898-911. [PMID: 27920205 DOI: 10.1074/jbc.m116.755470] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2016] [Revised: 11/24/2016] [Indexed: 11/06/2022] Open
Abstract
Transient receptor potential canonical type 5 (TRPC5) is a Ca2+-permeable cation channel that is highly expressed in the brain and is implicated in motor coordination, innate fear behavior, and seizure genesis. The channel is activated by a signal downstream of the G-protein-coupled receptor (GPCR)-Gq/11-phospholipase C (PLC) pathway. In this study we aimed to identify the molecular mechanisms involved in regulating TRPC5 activity. We report that Arg-593, a residue located in the E4 loop near the TRPC5 extracellular Gd3+ binding site, is critical for conferring the sensitivity to GPCR-Gq/11-PLC-dependent gating on TRPC5. Indeed, guanosine 5'-O-(thiotriphosphate) and GPCR agonists only weakly activate the TRPC5R593A mutant, whereas the addition of Gd3+ rescues the mutant's sensitivity to GPCR-Gq/11-PLC-dependent gating. Computer modeling suggests that Arg-593 may cross-bridge the E3 and E4 loops, forming the "molecular fulcrum." While validating the model using site-directed mutagenesis, we found that the Tyr-542 residue is critical for establishing a functional Gd3+ binding site, the Tyr-541 residue participates in fine-tuning Gd3+-sensitivity, and that the Asn-584 residue determines Ca2+ permeability of the TRPC5 channel. This is the first report providing molecular insights into the molecular mechanisms regulating the sensitivity to GPCR-Gq/11-PLC-dependent gating of a receptor-operated channel.
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Affiliation(s)
- Xingjuan Chen
- From the Department of Cellular and Integrative Physiology, Indiana University School of Medicine, Indianapolis, Indiana 46202
| | - Wennan Li
- From the Department of Cellular and Integrative Physiology, Indiana University School of Medicine, Indianapolis, Indiana 46202
| | - Ashley M Riley
- From the Department of Cellular and Integrative Physiology, Indiana University School of Medicine, Indianapolis, Indiana 46202
| | - Mario Soliman
- From the Department of Cellular and Integrative Physiology, Indiana University School of Medicine, Indianapolis, Indiana 46202
| | - Saikat Chakraborty
- From the Department of Cellular and Integrative Physiology, Indiana University School of Medicine, Indianapolis, Indiana 46202
| | - Christopher W Stamatkin
- From the Department of Cellular and Integrative Physiology, Indiana University School of Medicine, Indianapolis, Indiana 46202
| | - Alexander G Obukhov
- From the Department of Cellular and Integrative Physiology, Indiana University School of Medicine, Indianapolis, Indiana 46202
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Ogawa N, Kurokawa T, Mori Y. Sensing of redox status by TRP channels. Cell Calcium 2016; 60:115-22. [PMID: 26969190 DOI: 10.1016/j.ceca.2016.02.009] [Citation(s) in RCA: 315] [Impact Index Per Article: 39.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2016] [Revised: 02/17/2016] [Accepted: 02/17/2016] [Indexed: 11/17/2022]
Abstract
Cellular redox status is maintained by the balance between series of antioxidant systems and production of reactive oxygen/nitrogenous species. Cells utilize this redox balance to mediate diverse physiological functions. Transient receptor potential (TRP) channels are non-selective cation channels that act as biosensors for environmental and noxious stimuli, such as capsaicin and allicin, as well as changes in temperature and conditions inside the cell. TRP channels also have an emerging role as essential players in detecting cellular redox status to regulate cellular signals mediating physiological phenomena. Reactive species activate TRP channels either directly through oxidative amino acid modifications or indirectly through second messengers. For instance, TRPA1, TRPV1 and TRPC5 channels are directly activated by oxidizing agents through cysteine modification; whereas, TRPM2 channel is indirectly activated by production of ADP-ribose. One intriguing property of several TRP channels is susceptibility to both oxidizing and reducing stimuli, suggesting TRP channels could potentially act as a bidirectional sensor for detecting deviations in redox status. In this review, we discuss the unique chemical physiologies of redox sensitive TRP channels and their physiological significance in Ca(2+) signaling.
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Affiliation(s)
- Nozomi Ogawa
- Laboratory of Molecular Biology, Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Kyoto 615-8510, Japan
| | - Tatsuki Kurokawa
- Laboratory of Molecular Biology, Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Kyoto 615-8510, Japan
| | - Yasuo Mori
- Laboratory of Molecular Biology, Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Kyoto 615-8510, Japan; Laboratory of Environmental Systems Biology, Department of Technology and Ecology, Hall of Global Environmental Studies, Kyoto University, Kyoto 615-8510, Japan.
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47
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Critical roles of Gi/o proteins and phospholipase C-δ1 in the activation of receptor-operated TRPC4 channels. Proc Natl Acad Sci U S A 2016; 113:1092-7. [PMID: 26755577 DOI: 10.1073/pnas.1522294113] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Transient Receptor Potential Canonical (TRPC) proteins form nonselective cation channels commonly known to be activated downstream from receptors that signal through phospholipase C (PLC). Although TRPC3/C6/C7 can be directly activated by diacylglycerols produced by PLC breakdown of phosphatidylinositol 4,5-bisphosphate (PIP2), the mechanism by which the PLC pathway activates TRPC4/C5 remains unclear. We show here that TRPC4 activation requires coincident stimulation of Gi/o subgroup of G proteins and PLCδ, with a preference for PLCδ1 over PLCδ3, but not necessarily the PLCβ pathway commonly thought to be involved in receptor-operated TRPC activation. In HEK293 cells coexpressing TRPC4 and Gi/o-coupled µ opioid receptor, µ agonist elicited currents biphasically, with an initial slow phase preceding a rapidly developing phase. The currents were dependent on intracellular Ca(2+) and PIP2. Reducing PIP2 through phosphatases abolished the biphasic kinetics and increased the probability of channel activation by weak Gi/o stimulation. In both HEK293 cells heterologously expressing TRPC4 and renal carcinoma-derived A-498 cells endogenously expressing TRPC4, channel activation was inhibited by knocking down PLCδ1 levels and almost completely eliminated by a dominant-negative PLCδ1 mutant and a constitutively active RhoA mutant. Conversely, the slow phase of Gi/o-mediated TRPC4 activation was diminished by inhibiting RhoA or enhancing PLCδ function. Our data reveal an integrative mechanism of TRPC4 on detection of coincident Gi/o, Ca(2+), and PLC signaling, which is further modulated by the small GTPase RhoA. This mechanism is not shared with the closely related TRPC5, implicating unique roles of TRPC4 in signal integration in brain and other systems.
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48
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Carson C, Raman P, Tullai J, Xu L, Henault M, Thomas E, Yeola S, Lao J, McPate M, Verkuyl JM, Marsh G, Sarber J, Amaral A, Bailey S, Lubicka D, Pham H, Miranda N, Ding J, Tang HM, Ju H, Tranter P, Ji N, Krastel P, Jain RK, Schumacher AM, Loureiro JJ, George E, Berellini G, Ross NT, Bushell SM, Erdemli G, Solomon JM. Englerin A Agonizes the TRPC4/C5 Cation Channels to Inhibit Tumor Cell Line Proliferation. PLoS One 2015; 10:e0127498. [PMID: 26098886 PMCID: PMC4476799 DOI: 10.1371/journal.pone.0127498] [Citation(s) in RCA: 79] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2015] [Accepted: 04/14/2015] [Indexed: 01/19/2023] Open
Abstract
Englerin A is a structurally unique natural product reported to selectively inhibit growth of renal cell carcinoma cell lines. A large scale phenotypic cell profiling experiment (CLiP) of englerin A on ¬over 500 well characterized cancer cell lines showed that englerin A inhibits growth of a subset of tumor cell lines from many lineages, not just renal cell carcinomas. Expression of the TRPC4 cation channel was the cell line feature that best correlated with sensitivity to englerin A, suggesting the hypothesis that TRPC4 is the efficacy target for englerin A. Genetic experiments demonstrate that TRPC4 expression is both necessary and sufficient for englerin A induced growth inhibition. Englerin A induces calcium influx and membrane depolarization in cells expressing high levels of TRPC4 or its close ortholog TRPC5. Electrophysiology experiments confirmed that englerin A is a TRPC4 agonist. Both the englerin A induced current and the englerin A induced growth inhibition can be blocked by the TRPC4/C5 inhibitor ML204. These experiments confirm that activation of TRPC4/C5 channels inhibits tumor cell line proliferation and confirms the TRPC4 target hypothesis generated by the cell line profiling. In selectivity assays englerin A weakly inhibits TRPA1, TRPV3/V4, and TRPM8 which suggests that englerin A may bind a common feature of TRP ion channels. In vivo experiments show that englerin A is lethal in rodents near doses needed to activate the TRPC4 channel. This toxicity suggests that englerin A itself is probably unsuitable for further drug development. However, since englerin A can be synthesized in the laboratory, it may be a useful chemical starting point to identify novel modulators of other TRP family channels.
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Affiliation(s)
- Cheryl Carson
- Novartis Institutes for Biomedical Research, Cambridge, Massachusetts, United States of America
| | - Pichai Raman
- Novartis Institutes for Biomedical Research, Cambridge, Massachusetts, United States of America
| | - Jennifer Tullai
- Novartis Institutes for Biomedical Research, Cambridge, Massachusetts, United States of America
| | - Lei Xu
- Novartis Institutes for Biomedical Research, Cambridge, Massachusetts, United States of America
| | - Martin Henault
- Novartis Institutes for Biomedical Research, Cambridge, Massachusetts, United States of America
| | - Emily Thomas
- Novartis Institutes for Biomedical Research, Cambridge, Massachusetts, United States of America
| | - Sarita Yeola
- Novartis Institutes for Biomedical Research, Cambridge, Massachusetts, United States of America
| | - Jianmin Lao
- Genomics Institute of the Novartis Research Foundation, San Diego, California, United States of America
| | - Mark McPate
- Novartis Institutes for Biomedical Research, Horsham, United Kingdom
| | - J. Martin Verkuyl
- Novartis Institutes for Biomedical Research, Horsham, United Kingdom
| | - George Marsh
- Novartis Institutes for Biomedical Research, Cambridge, Massachusetts, United States of America
| | - Jason Sarber
- Novartis Institutes for Biomedical Research, Cambridge, Massachusetts, United States of America
| | - Adam Amaral
- Novartis Institutes for Biomedical Research, Cambridge, Massachusetts, United States of America
| | - Scott Bailey
- Novartis Institutes for Biomedical Research, Cambridge, Massachusetts, United States of America
| | - Danuta Lubicka
- Novartis Institutes for Biomedical Research, Cambridge, Massachusetts, United States of America
| | - Helen Pham
- Novartis Institutes for Biomedical Research, Cambridge, Massachusetts, United States of America
| | - Nicolette Miranda
- Novartis Institutes for Biomedical Research, Cambridge, Massachusetts, United States of America
| | - Jian Ding
- Novartis Institutes for Biomedical Research, Cambridge, Massachusetts, United States of America
| | - Hai-Ming Tang
- Novartis Institutes for Biomedical Research, East Hanover, New Jersey, United States of America
| | - Haisong Ju
- Novartis Institutes for Biomedical Research, East Hanover, New Jersey, United States of America
| | - Pamela Tranter
- Novartis Institutes for Biomedical Research, Horsham, United Kingdom
| | - Nan Ji
- Novartis Institutes for Biomedical Research, Cambridge, Massachusetts, United States of America
| | - Philipp Krastel
- Novartis Institutes for Biomedical Research, Basel, Switzerland
| | - Rishi K. Jain
- Novartis Institutes for Biomedical Research, Cambridge, Massachusetts, United States of America
| | - Andrew M. Schumacher
- Genomics Institute of the Novartis Research Foundation, San Diego, California, United States of America
| | - Joseph J. Loureiro
- Novartis Institutes for Biomedical Research, Cambridge, Massachusetts, United States of America
| | - Elizabeth George
- Novartis Institutes for Biomedical Research, Cambridge, Massachusetts, United States of America
| | - Giuliano Berellini
- Novartis Institutes for Biomedical Research, Cambridge, Massachusetts, United States of America
| | - Nathan T. Ross
- Novartis Institutes for Biomedical Research, Cambridge, Massachusetts, United States of America
| | - Simon M. Bushell
- Novartis Institutes for Biomedical Research, Cambridge, Massachusetts, United States of America
| | - Gül Erdemli
- Novartis Institutes for Biomedical Research, Cambridge, Massachusetts, United States of America
| | - Jonathan M. Solomon
- Novartis Institutes for Biomedical Research, Cambridge, Massachusetts, United States of America
- * E-mail:
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Shen B, Wong CO, Lau OC, Woo T, Bai S, Huang Y, Yao X. Plasma membrane mechanical stress activates TRPC5 channels. PLoS One 2015; 10:e0122227. [PMID: 25849346 PMCID: PMC4388645 DOI: 10.1371/journal.pone.0122227] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2014] [Accepted: 02/19/2015] [Indexed: 01/14/2023] Open
Abstract
Mechanical forces exerted on cells impose stress on the plasma membrane. Cells sense this stress and elicit a mechanoelectric transduction cascade that initiates compensatory mechanisms. Mechanosensitive ion channels in the plasma membrane are responsible for transducing the mechanical signals to electrical signals. However, the mechanisms underlying channel activation in response to mechanical stress remain incompletely understood. Transient Receptor Potential (TRP) channels serve essential functions in several sensory modalities. These channels can also participate in mechanotransduction by either being autonomously sensitive to mechanical perturbation or by coupling to other mechanosensory components of the cell. Here, we investigated the response of a TRP family member, TRPC5, to mechanical stress. Hypoosmolarity triggers Ca2+ influx and cationic conductance through TRPC5. Importantly, for the first time we were able to record the stretch-activated TRPC5 current at single-channel level. The activation threshold for TRPC5 was found to be 240 mOsm for hypoosmotic stress and between −20 and −40 mmHg for pressure applied to membrane patch. In addition, we found that disruption of actin filaments suppresses TRPC5 response to hypoosmotic stress and patch pipette pressure, but does not prevent the activation of TRPC5 by stretch-independent mechanisms, indicating that actin cytoskeleton is an essential transduction component that confers mechanosensitivity to TRPC5. In summary, our findings establish that TRPC5 can be activated at the single-channel level when mechanical stress on the cell reaches a certain threshold.
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Affiliation(s)
- Bing Shen
- School of Biomedical Sciences, Faculty of Medicine, the Chinese University of Hong Kong, Shatin, Hong Kong, China
- Department of Physiology, Anhui Medical University, Hefei, China
| | - Ching-On Wong
- School of Biomedical Sciences, Faculty of Medicine, the Chinese University of Hong Kong, Shatin, Hong Kong, China
- * E-mail: (XY); (CW)
| | - On-Chai Lau
- School of Biomedical Sciences, Faculty of Medicine, the Chinese University of Hong Kong, Shatin, Hong Kong, China
| | - Theodosia Woo
- School of Biomedical Sciences, Faculty of Medicine, the Chinese University of Hong Kong, Shatin, Hong Kong, China
| | - Suwen Bai
- Department of Physiology, Anhui Medical University, Hefei, China
| | - Yu Huang
- School of Biomedical Sciences, Faculty of Medicine, the Chinese University of Hong Kong, Shatin, Hong Kong, China
| | - Xiaoqiang Yao
- School of Biomedical Sciences, Faculty of Medicine, the Chinese University of Hong Kong, Shatin, Hong Kong, China
- * E-mail: (XY); (CW)
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50
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Dual depolarization responses generated within the same lateral septal neurons by TRPC4-containing channels. Pflugers Arch 2015; 466:1301-16. [PMID: 24121765 DOI: 10.1007/s00424-013-1362-5] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2013] [Accepted: 09/11/2013] [Indexed: 10/26/2022]
Abstract
In the central nervous system, canonical transient receptor potential (TRPC) channels have been implicated in mediating neuronal excitation induced by stimulating metabotropic receptors, including group 1 metabotropic glutamate receptors (mGluRs). Lateral septal (LS) neurons express high levels of TRPC4 and group I mGluRs. However, to what extent native TRPC4-containing channels (TRPC4-cc) are activated as well as the impact of different levels of TRPC4-cc activation on neuronal excitability remain elusive. Here, we report that stimulating LS neurons with group I mGluR agonist, (S)-3,5-DHPG, causes either an immediate increase in firing rate or an initial burst followed by a pause of firing, which can be correlated with below-threshold-depolarization (BTD) or above-threshold-plateau-depolarization (ATPD), respectively, in whole-cell recordings. The early phase of BTD and the entire ATPD are completely absent in neurons from TRPC4−/− mice. Moreover, in the same LS neurons, BTD can be converted to ATPD at more depolarized potentials or with a brief current injection, suggesting that BTD and ATPD may represent partial and full activations of TRPC4-cc, respectively. We show that coincident mGluR stimulation and depolarization is required to evoke strong TRPC4-cc current, and Na+ and Ca2+ influx, together with dynamic changes of intracellular Ca(2+), are essential for ATPD induction. Our results suggest that TRPC4-cc integrates metabotropic receptor stimulation with intracellular Ca(2+) signals to generate two interconvertible depolarization responses to affect excitability of LS neurons in distinct fashions.
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