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Alexander RPD, Bender KJ. Delta opioid receptors engage multiple signaling cascades to differentially modulate prefrontal GABA release with input and target specificity. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.08.08.607246. [PMID: 39149233 PMCID: PMC11326311 DOI: 10.1101/2024.08.08.607246] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 08/17/2024]
Abstract
Opioids regulate circuits associated with motivation and reward across the brain. Of the opioid receptor types, delta opioid receptors (DORs) appear to have a unique role in regulating the activity of circuits related to reward without a liability for abuse. In neocortex, DORs are expressed primarily in interneurons, including parvalbumin- and somatostatin-expressing interneurons that inhibit somatic and dendritic compartments of excitatory pyramidal cells, respectively. But how DORs regulate transmission from these key interneuron classes is unclear. We found that DORs regulate inhibition from these interneuron classes using different G-protein signaling pathways that both converge on presynaptic calcium channels, but regulate distinct aspects of calcium channel function. This imposes different temporal filtering effects, via short-term plasticity, that depend on how calcium channels are regulated. Thus, DORs engage differential signaling cascades to regulate inhibition depending on the postsynaptic target compartment, with different effects on synaptic information transfer in somatic and dendritic domains.
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Affiliation(s)
- Ryan P. D. Alexander
- Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA, USA
- Department of Neurology, University of California, San Francisco, San Francisco, CA, USA
| | - Kevin J. Bender
- Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA, USA
- Department of Neurology, University of California, San Francisco, San Francisco, CA, USA
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2
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Busceti CL, Di Menna L, Castaldi S, D'Errico G, Taddeucci A, Bruno V, Fornai F, Pittaluga A, Battaglia G, Nicoletti F. Adaptive Changes in Group 2 Metabotropic Glutamate Receptors Underlie the Deficit in Recognition Memory Induced by Methamphetamine in Mice. eNeuro 2024; 11:ENEURO.0523-23.2024. [PMID: 38969501 PMCID: PMC11298959 DOI: 10.1523/eneuro.0523-23.2024] [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: 12/11/2023] [Revised: 05/27/2024] [Accepted: 06/04/2024] [Indexed: 07/07/2024] Open
Abstract
Cognitive dysfunction is associated with methamphetamine use disorder (MUD). Here, we used genetic and pharmacological approaches to examine the involvement of either Group 2 metabotropic glutamate (mGlu2) or mGlu3 receptors in memory deficit induced by methamphetamine in mice. Methamphetamine treatment (1 mg/kg, i.p., once a day for 5 d followed by 7 d of withdrawal) caused an impaired performance in the novel object recognition test in wild-type mice, but not in mGlu2-/- or mGlu3-/- mice. Memory deficit in wild-type mice challenged with methamphetamine was corrected by systemic treatment with selectively negative allosteric modulators of mGlu2 or mGlu3 receptors (compounds VU6001966 and VU0650786, respectively). Methamphetamine treatment in wild-type mice caused large increases in levels of mGlu2/3 receptors, the Type 3 activator of G-protein signaling (AGS3), Rab3A, and the vesicular glutamate transporter, vGlut1, in the prefrontal cortex (PFC). Methamphetamine did not alter mGlu2/3-mediated inhibition of cAMP formation but abolished the ability of postsynaptic mGlu3 receptors to boost mGlu5 receptor-mediated inositol phospholipid hydrolysis in PFC slices. Remarkably, activation of presynaptic mGlu2/3 receptors did not inhibit but rather amplified depolarization-induced [3H]-D-aspartate release in synaptosomes prepared from the PFC of methamphetamine-treated mice. These findings demonstrate that exposure to methamphetamine causes changes in the expression and function of mGlu2 and mGlu3 receptors, which might alter excitatory synaptic transmission in the PFC and raise the attractive possibility that selective inhibitors of mGlu2 or mGlu3 receptors (or both) may be used to improve cognitive dysfunction in individuals affected by MUD.
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Affiliation(s)
| | - Luisa Di Menna
- Department of Molecular Pathology, IRCCS Neuromed, Pozzilli 86077, Italy
| | - Sonia Castaldi
- Department of Physiology and Pharmacology, University Sapienza, Roma 00185, Italy
| | - Giovanna D'Errico
- Department of Molecular Pathology, IRCCS Neuromed, Pozzilli 86077, Italy
| | - Alice Taddeucci
- Department of Pharmacy, University of Genova, Genova 16148, Italy
| | - Valeria Bruno
- Department of Molecular Pathology, IRCCS Neuromed, Pozzilli 86077, Italy
- Department of Physiology and Pharmacology, University Sapienza, Roma 00185, Italy
| | - Francesco Fornai
- Department of Molecular Pathology, IRCCS Neuromed, Pozzilli 86077, Italy
- Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, Pisa 56126, Italy
| | - Anna Pittaluga
- Department of Pharmacy, University of Genova, Genova 16148, Italy
- IRCCS Ospedale Policlinico San Martino, Genova 16145, Italy
| | - Giuseppe Battaglia
- Department of Molecular Pathology, IRCCS Neuromed, Pozzilli 86077, Italy
- Department of Physiology and Pharmacology, University Sapienza, Roma 00185, Italy
| | - Ferdinando Nicoletti
- Department of Molecular Pathology, IRCCS Neuromed, Pozzilli 86077, Italy
- Department of Physiology and Pharmacology, University Sapienza, Roma 00185, Italy
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3
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Sanchez GA, Smrcka AV, Jutkiewicz EM. Biasing G βγ Downstream Signaling with Gallein Inhibits Development of Morphine Tolerance and Potentiates Morphine-Induced Nociception in a Tolerant State. Mol Pharmacol 2024; 106:47-55. [PMID: 38769020 PMCID: PMC11187686 DOI: 10.1124/molpharm.124.000875] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2024] [Revised: 05/03/2024] [Accepted: 05/09/2024] [Indexed: 05/22/2024] Open
Abstract
Opioid analgesics are widely used as a treatment option for pain management and relief. However, the misuse of opioid analgesics has contributed to the current opioid epidemic in the United States. Prescribed opioids such as morphine, codeine, oxycodone, and fentanyl are mu-opioid receptor (MOR) agonists primarily used in the clinic to treat pain or during medical procedures, but development of tolerance limits their utility for treatment of chronic pain. Here we explored the effects of biasing Gβγ signaling on tolerance development after chronic morphine treatment in vivo. We hypothesized that biasing Gβγ signaling with gallein could prevent activation of regulatory signaling pathways that result in tolerance to antinociceptive effects of MOR agonists. Gallein has been shown to bind to Gβγ and inhibit interactions of Gβγ with phospholipase-Cβ3 (PLCβ3) or G-protein-coupled receptor kinase 2 (GRK2) but not G-protein inwardly rectifying potassium (GIRK) channels. In mice, morphine-induced antinociception was evaluated in the 55°C warm water tail withdrawal assay. We used two paradigms for gallein treatment: administration during and after three times-daily morphine administration. Our results show that gallein cotreatment during repeated administration of morphine decreased opioid tolerance development and that gallein treatment in an opioid-tolerant state enhanced the potency of morphine. Mechanistically, our data suggest that PLCβ3 is necessary for potentiating effects of gallein in an opioid-tolerant state but not in preventing the development of tolerance. These studies demonstrate that small molecules that target Gβγ signaling could reduce the need for large doses of opioid analgesics to treat pain by producing an opioid-sparing effect. SIGNIFICANCE STATEMENT: Biasing Gβγ signaling prevents tolerance to repeated morphine administration in vivo and potentiates the antinociceptive effects of morphine in an opioid-tolerant state. Mechanistically, phospholipase-Cβ is necessary for potentiating effects of gallein in an opioid-tolerant state but not in preventing the development of tolerance. This study identifies a novel treatment strategy to decrease the development of tolerance to the analgesic effects of mu-opioid receptor agonists, which are necessary to improve pain treatment and decrease the incidence of opioid use disorder.
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Affiliation(s)
- Gissell A Sanchez
- Department of Pharmacology, University of Michigan, Ann Arbor, Michigan
| | - Alan V Smrcka
- Department of Pharmacology, University of Michigan, Ann Arbor, Michigan
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4
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Thiel G, Rössler OG. Signal Transduction of Transient Receptor Potential TRPM8 Channels: Role of PIP5K, Gq-Proteins, and c-Jun. Molecules 2024; 29:2602. [PMID: 38893478 PMCID: PMC11174004 DOI: 10.3390/molecules29112602] [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: 04/30/2024] [Revised: 05/24/2024] [Accepted: 05/26/2024] [Indexed: 06/21/2024] Open
Abstract
Transient receptor potential melastatin-8 (TRPM8) is a cation channel that is activated by cold and "cooling agents" such as menthol and icilin, which induce a cold sensation. The stimulation of TRPM8 activates an intracellular signaling cascade that ultimately leads to a change in the gene expression pattern of the cells. Here, we investigate the TRPM8-induced signaling pathway that links TRPM8 channel activation to gene transcription. Using a pharmacological approach, we show that the inhibition of phosphatidylinositol 4-phosphate 5 kinase α (PIP5K), an enzyme essential for the biosynthesis of phosphatidylinositol 4,5-bisphosphate, attenuates TRPM8-induced gene transcription. Analyzing the link between TRPM8 and Gq proteins, we show that the pharmacological inhibition of the βγ subunits impairs TRPM8 signaling. In addition, genetic studies show that TRPM8 requires an activated Gα subunit for signaling. In the nucleus, the TRPM8-induced signaling cascade triggers the activation of the transcription factor AP-1, a complex consisting of a dimer of basic region leucine zipper (bZIP) transcription factors. Here, we identify the bZIP protein c-Jun as an essential component of AP-1 within the TRPM8-induced signaling cascade. In summary, with PIP5K, Gq subunits, and c-Jun, we identified key molecules in TRPM8-induced signaling from the plasma membrane to the nucleus.
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Affiliation(s)
- Gerald Thiel
- Department of Medical Biochemistry and Molecular Biology, Medical Faculty, Saarland University, 66421 Homburg, Germany;
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5
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Dolejší E, Janoušková A, Jakubík J. Muscarinic Receptors in Cardioprotection and Vascular Tone Regulation. Physiol Res 2024; 73:S389-S400. [PMID: 38634650 DOI: 10.33549/physiolres.935270] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/04/2024] Open
Abstract
Muscarinic acetylcholine receptors are metabotropic G-protein coupled receptors. Muscarinic receptors in the cardiovascular system play a central role in its regulation. Particularly M2 receptors slow down the heart rate by reducing the impulse conductivity through the atrioventricular node. In general, activation of muscarinic receptors has sedative effects on the cardiovascular system, including vasodilation, negative chronotropic and inotropic effects on the heart, and cardioprotective effects, including antifibrillatory effects. First, we review the signaling of individual subtypes of muscarinic receptors and their involvement in the physiology and pathology of the cardiovascular system. Then we review age and disease-related changes in signaling via muscarinic receptors in the cardiovascular system. Finally, we review molecular mechanisms involved in cardioprotection mediated by muscarinic receptors leading to negative chronotropic and inotropic and antifibrillatory effects on heart and vasodilation, like activation of acetylcholine-gated inward-rectifier K+-currents and endothelium-dependent and -independent vasodilation. We relate this knowledge with well-established cardioprotective treatments by vagal stimulation and muscarinic agonists. It is well known that estrogen exerts cardioprotective effects against atherosclerosis and ischemia-reperfusion injury. Recently, some sex hormones and neurosteroids have been shown to allosterically modulate muscarinic receptors. Thus, we outline possible treatment by steroid-based positive allosteric modulators of acetylcholine as a novel pharmacotherapeutic tactic. Keywords: Muscarinic receptors, Muscarinic agonists, Allosteric modulation, Cardiovascular system, Cardioprotection, Steroids.
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Affiliation(s)
- E Dolejší
- Laboratory of Neurochemistry, Institute of Physiology, Czech Academy of Sciences, Prague, Czech Republic.
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6
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Stott JB, Greenwood IA. G protein βγ regulation of KCNQ-encoded voltage-dependent K channels. Front Physiol 2024; 15:1382904. [PMID: 38655029 PMCID: PMC11035767 DOI: 10.3389/fphys.2024.1382904] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2024] [Accepted: 03/25/2024] [Indexed: 04/26/2024] Open
Abstract
The KCNQ family is comprised of five genes and the expression products form voltage-gated potassium channels (Kv7.1-7.5) that have a major impact upon cellular physiology in many cell types. Each functional Kv7 channel forms as a tetramer that often associates with proteins encoded by the KCNE gene family (KCNE1-5) and is critically reliant upon binding of phosphatidylinositol bisphosphate (PIP2) and calmodulin. Other modulators like A-kinase anchoring proteins, ubiquitin ligases and Ca-calmodulin kinase II alter Kv7 channel function and trafficking in an isoform specific manner. It has now been identified that for Kv7.4, G protein βγ subunits (Gβγ) can be added to the list of key regulators and is paramount for channel activity. This article provides an overview of this nascent field of research, highlighting themes and directions for future study.
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Affiliation(s)
| | - Iain A. Greenwood
- Vascular Biology Research Group, Institute of Molecular and Clinical Sciences, St George’s University of London, London, United Kingdom
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7
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Hettiarachchi P, Niyangoda S, Shigemoto A, Solowiej IJ, Burdette SC, Johnson MA. Caged Zn 2+ Photolysis in Zebrafish Whole Brains Reveals Subsecond Modulation of Dopamine Uptake. ACS Chem Neurosci 2024; 15:772-782. [PMID: 38301116 PMCID: PMC11036533 DOI: 10.1021/acschemneuro.3c00668] [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] [Indexed: 02/03/2024] Open
Abstract
Free, ionic zinc (Zn2+) modulates neurotransmitter dynamics in the brain. However, the sub-s effects of transient concentration changes of Zn2+ on neurotransmitter release and uptake are not well understood. To address this lack of knowledge, we have combined the photolysis of the novel caged Zn2+ compound [Zn(DPAdeCageOMe)]+ with fast scan cyclic voltammetry (FSCV) at carbon fiber microelectrodes in live, whole brain preparations from zebrafish (Danio rerio). After treating the brain with [Zn(DPAdeCageOMe)]+, Zn2+ was released by application of light that was gated through a computer-controlled shutter synchronized with the FSCV measurements and delivered through a 1 mm fiber optic cable. We systematically optimized the photocage concentration and light application parameters, including the total duration and light-to-electrical stimulation delay time. While sub-s Zn2+ application with this method inhibited DA reuptake, assessed by the first-order rate constant (k) and half-life (t1/2), it had no effect on the electrically stimulated DA overflow ([DA]STIM). Increasing the photocage concentration and light duration progressively inhibited uptake, with maximal effects occurring at 100 μM and 800 ms, respectively. Furthermore, uptake was inhibited 200 ms after Zn2+ photorelease, but no measurable effect occurred after 800 ms. We expect that application of this method to the zebrafish whole brain and other preparations will help expand the current knowledge of how Zn2+ affects neurotransmitter release/uptake in select neurological disease states.
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Affiliation(s)
- Piyanka Hettiarachchi
- Department of Chemistry and R.N. Adams Institute for Bioanalytical Chemistry, University of Kansas, Lawrence, Kansas 66045
| | - Sayuri Niyangoda
- Department of Chemistry and R.N. Adams Institute for Bioanalytical Chemistry, University of Kansas, Lawrence, Kansas 66045
| | - Austin Shigemoto
- Department of Chemistry and Biochemistry, Worcester Polytechnic Institute, Worcester, MA 01609
| | - Isabel J. Solowiej
- Department of Chemistry and R.N. Adams Institute for Bioanalytical Chemistry, University of Kansas, Lawrence, Kansas 66045
| | - Shawn C. Burdette
- Department of Chemistry and Biochemistry, Worcester Polytechnic Institute, Worcester, MA 01609
| | - Michael A. Johnson
- Department of Chemistry and R.N. Adams Institute for Bioanalytical Chemistry, University of Kansas, Lawrence, Kansas 66045
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8
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Miller WE, O'Connor CM. CMV-encoded GPCRs in infection, disease, and pathogenesis. Adv Virus Res 2024; 118:1-75. [PMID: 38461029 DOI: 10.1016/bs.aivir.2024.01.001] [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] [Indexed: 03/11/2024]
Abstract
G protein coupled receptors (GPCRs) are seven-transmembrane domain proteins that modulate cellular processes in response to external stimuli. These receptors represent the largest family of membrane proteins, and in mammals, their signaling regulates important physiological functions, such as vision, taste, and olfaction. Many organisms, including yeast, slime molds, and viruses encode GPCRs. Cytomegaloviruses (CMVs) are large, betaherpesviruses, that encode viral GPCRs (vGPCRs). Human CMV (HCMV) encodes four vGPCRs, including UL33, UL78, US27, and US28. Each of these vGPCRs, as well as their rodent and primate orthologues, have been investigated for their contributions to viral infection and disease. Herein, we discuss how the CMV vGPCRs function during lytic and latent infection, as well as our understanding of how they impact viral pathogenesis.
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Affiliation(s)
- William E Miller
- Department of Molecular and Cellular Bioscience, University of Cincinnati College of Medicine, Cincinnati, OH, United States
| | - Christine M O'Connor
- Infection Biology, Sheikha Fatima bint Mubarak Global Center for Pathogen and Human Health Research, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, United States; Molecular Medicine, Cleveland Clinic Lerner College of Medicine of Case Western Reserve University, Cleveland Clinic, Cleveland, OH, United States; Case Comprehensive Cancer Center, Cleveland, OH, United States.
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9
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Goudsward HJ, Ruiz-Velasco V, Stella SL, Willing LB, Holmes GM. Coexpressed δ-, μ-, and κ-Opioid Receptors Modulate Voltage-Gated Ca 2+ Channels in Gastric-Projecting Vagal Afferent Neurons. Mol Pharmacol 2024; 105:250-259. [PMID: 38182431 PMCID: PMC10877734 DOI: 10.1124/molpharm.123.000774] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Revised: 12/12/2023] [Accepted: 12/19/2023] [Indexed: 01/07/2024] Open
Abstract
Opioid analgesics are frequently associated with gastrointestinal side effects, including constipation, nausea, dysphagia, and reduced gastric motility. Though it has been shown that stimulation of opioid receptors expressed in enteric motor neurons contributes to opioid-induced constipation, it remains unclear whether activation of opioid receptors in gastric-projecting nodose ganglia neurons contributes to the reduction in gastric motility and emptying associated with opioid use. In the present study, whole-cell patch-clamp recordings were performed to determine the mechanism underlying opioid receptor-mediated modulation of Ca2+ currents in acutely isolated gastric vagal afferent neurons. Our results demonstrate that CaV2.2 channels provide the majority (71% ± 16%) of Ca2+ currents in gastric vagal afferent neurons. Furthermore, we found that application of oxycodone, U-50488, or deltorphin II on gastric nodose ganglia neurons inhibited Ca2+ currents through a voltage-dependent mechanism by coupling to the Gα i/o family of heterotrimeric G-proteins. Because previous studies have demonstrated that the nodose ganglia expresses low levels of δ-opioid receptors, we also determined the deltorphin II concentration-response relationship and assessed deltorphin-mediated Ca2+ current inhibition following exposure to the δ-opioid receptor antagonist ICI 174,864 (0.3 µM). The peak mean Ca2+ current inhibition following deltorphin II application was 47% ± 24% (EC50 = 302.6 nM), and exposure to ICI 174,864 blocked deltorphin II-mediated Ca2+ current inhibition (4% ± 4% versus 37% ± 20%). Together, our results suggest that analgesics targeting any opioid receptor subtype can modulate gastric vagal circuits. SIGNIFICANCE STATEMENT: This study demonstrated that in gastric nodose ganglia neurons, agonists targeting all three classical opioid receptor subtypes (μ, δ, and κ) inhibit voltage-gated Ca2+ channels in a voltage-dependent mechanism by coupling to Gαi/o. These findings suggest that analgesics targeting any opioid receptor subtype would modulate gastric vagal circuits responsible for regulating gastric reflexes.
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Affiliation(s)
- Hannah J Goudsward
- Departments of Neural and Behavioral Sciences (H.J.G., S.L.S., L.B.W., G.M.H.) and Anesthesiology and Perioperative Medicine (V.R.-V.), Penn State University College of Medicine, Hershey, Pennsylvania
| | - Victor Ruiz-Velasco
- Departments of Neural and Behavioral Sciences (H.J.G., S.L.S., L.B.W., G.M.H.) and Anesthesiology and Perioperative Medicine (V.R.-V.), Penn State University College of Medicine, Hershey, Pennsylvania
| | - Salvatore L Stella
- Departments of Neural and Behavioral Sciences (H.J.G., S.L.S., L.B.W., G.M.H.) and Anesthesiology and Perioperative Medicine (V.R.-V.), Penn State University College of Medicine, Hershey, Pennsylvania
| | - Lisa B Willing
- Departments of Neural and Behavioral Sciences (H.J.G., S.L.S., L.B.W., G.M.H.) and Anesthesiology and Perioperative Medicine (V.R.-V.), Penn State University College of Medicine, Hershey, Pennsylvania
| | - Gregory M Holmes
- Departments of Neural and Behavioral Sciences (H.J.G., S.L.S., L.B.W., G.M.H.) and Anesthesiology and Perioperative Medicine (V.R.-V.), Penn State University College of Medicine, Hershey, Pennsylvania
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10
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Szabo B. Presynaptic Adrenoceptors. Handb Exp Pharmacol 2024; 285:185-245. [PMID: 38755350 DOI: 10.1007/164_2024_714] [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] [Indexed: 05/18/2024]
Abstract
Presynaptic α2-adrenoceptors are localized on axon terminals of many noradrenergic and non-noradrenergic neurons in the peripheral and central nervous systems. Their activation by exogenous agonists leads to inhibition of the exocytotic release of noradrenaline and other transmitters from the neurons. Most often, the α2A-receptor subtype is involved in this inhibition. The chain of molecular events between receptor occupation and inhibition of the exocytotic release of transmitters has been determined. Physiologically released endogenous noradrenaline elicits retrograde autoinhibition of its own release. Some clonidine-like α2-receptor agonists have been used to treat hypertension. Dexmedetomidine is used for prolonged sedation in the intensive care; It also has a strong analgesic effect. The α2-receptor antagonist mirtazapine increases the noradrenaline concentration in the synaptic cleft by interrupting physiological autoinhibion of release. It belongs to the most effective antidepressive drugs. β2-Adrenoceptors are also localized on axon terminals in the peripheral and central nervous systems. Their activation leads to enhanced transmitter release, however, they are not activated by endogenous adrenaline.
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MESH Headings
- Animals
- Humans
- Receptors, Adrenergic, alpha-2/metabolism
- Receptors, Adrenergic, alpha-2/drug effects
- Receptors, Adrenergic, alpha-2/physiology
- Presynaptic Terminals/drug effects
- Presynaptic Terminals/metabolism
- Adrenergic alpha-2 Receptor Agonists/pharmacology
- Receptors, Presynaptic/drug effects
- Receptors, Presynaptic/physiology
- Receptors, Presynaptic/metabolism
- Synaptic Transmission/drug effects
- Receptors, Adrenergic, beta-2/metabolism
- Receptors, Adrenergic, beta-2/drug effects
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Affiliation(s)
- Bela Szabo
- Institut für Experimentelle und Klinische Pharmakologie und Toxikologie, Albert-Ludwigs-Universität Freiburg, Freiburg, Germany.
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11
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Quiroz-Acosta T, Bermeo K, Arenas I, Garcia DE. G-protein tonic inhibition of calcium channels in pancreatic β-cells. Am J Physiol Cell Physiol 2023; 325:C592-C598. [PMID: 37458440 DOI: 10.1152/ajpcell.00447.2022] [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: 10/07/2022] [Revised: 06/30/2023] [Accepted: 07/03/2023] [Indexed: 08/17/2023]
Abstract
Voltage-gated calcium channels (CaV) conduct Ca2+ influx promoting neurotransmitters and hormone release. CaV are finely regulated by voltage-dependent and independent pathways either by G-protein-coupled receptors (GPCRs) or intramembrane lipids, respectively, in neurons and glands. Interestingly, pancreatic β-cells are abundantly innervated by both sympathetic and parasympathetic neurons, while a variety of high-voltage activated (HVA) Ca2+ channels are present in these cells. Thus, autonomic system seems to exert a tonic inhibition on HVA Ca2+ channels throughout GPCRs, constitutively preventing hormone secretion. Therefore, this work aimed to investigate noradrenergic and cholinergic inhibition of HVA Ca2+ channels in pancreatic β-cells. Experiments were conducted in pancreatic β-cells of rat by using patch-clamping methods, immunocytochemistry, pharmacological probes, and biochemical reagents. A voltage-clamp protocol with a strong depolarizing prepulse was used to unmask tonic inhibition. Herein, we consistently find a basal tonic inhibition of HVA Ca2+ channels according to a GPCRs regulation. Facilitation ratio is enhanced by noradrenaline (NA) according to a voltage-dependent regulation and a membrane-delimited mechanism, while no facilitation changes are observed with carbachol or phosphatidylinositol 4,5-bisphosphate (PIP2). Furthermore, carbachol or intramembrane lipids, such as PIP2, do not change facilitation ratio according to a voltage-independent regulation. Together, HVA Ca2+ channels of pancreatic β-cells are constitutively inhibited by GPCRs, suggesting a natural brake preventing cells from exhaustive insulin secretion.NEW & NOTEWORTHY Our results support the hypothesis that GPCRs tonically inhibit HVA Ca2+ channels in pancreatic β-cells. A voltage-clamp protocol with a strong depolarizing prepulse was used to unmask voltage-dependent inhibition of Ca2+ channels. The novelty of these results strengthens the critical role of Gβγ's in Ca2+ channel regulation, highlighting kinetic slowing and increased facilitation ratio. Together, HVA Ca2+ channels of pancreatic β-cells are constitutively inhibited by GPCRs underlying fine-tuning modulation of insulin secretion.
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Affiliation(s)
- Tayde Quiroz-Acosta
- Department of Physiology, Faculty of Medicine, Universidad Nacional Autónoma de México, UNAM, Ciudad de México, Mexico
| | - Karina Bermeo
- Department of Physiology, Faculty of Medicine, Universidad Nacional Autónoma de México, UNAM, Ciudad de México, Mexico
| | - Isabel Arenas
- Department of Physiology, Faculty of Medicine, Universidad Nacional Autónoma de México, UNAM, Ciudad de México, Mexico
| | - David E Garcia
- Department of Physiology, Faculty of Medicine, Universidad Nacional Autónoma de México, UNAM, Ciudad de México, Mexico
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12
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Jiang W, Wang W, Kong Y, Zheng S. Structural basis for the ubiquitination of G protein βγ subunits by KCTD5/Cullin3 E3 ligase. SCIENCE ADVANCES 2023; 9:eadg8369. [PMID: 37450587 PMCID: PMC10348674 DOI: 10.1126/sciadv.adg8369] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/24/2023] [Accepted: 06/14/2023] [Indexed: 07/18/2023]
Abstract
G protein-coupled receptor (GPCR) signaling is precisely controlled to avoid overstimulation that results in detrimental consequences. Gβγ signaling is negatively regulated by a Cullin3 (Cul3)-dependent E3 ligase, KCTD5, which triggers ubiquitination and degradation of free Gβγ. Here, we report the cryo-electron microscopy structures of the KCTD5-Gβγ fusion complex and the KCTD7-Cul3 complex. KCTD5 in pentameric form engages symmetrically with five copies of Gβγ through its C-terminal domain. The unique pentameric assembly of the KCTD5/Cul3 E3 ligase places the ubiquitin-conjugating enzyme (E2) and the modification sites of Gβγ in close proximity and allows simultaneous transfer of ubiquitin from E2 to five Gβγ subunits. Moreover, we show that ubiquitination of Gβγ by KCTD5 is important for fine-tuning cyclic adenosine 3´,5´-monophosphate signaling of GPCRs. Our studies provide unprecedented insights into mechanisms of substrate recognition by unusual pentameric E3 ligases and highlight the KCTD family as emerging regulators of GPCR signaling.
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Affiliation(s)
- Wentong Jiang
- Graduate School of Peking Union Medical College, Beijing 100730, China
- National Institute of Biological Sciences, Beijing 102206, China
| | - Wei Wang
- National Institute of Biological Sciences, Beijing 102206, China
- School of Life Sciences, Peking University, Beijing 100871, China
| | - Yinfei Kong
- Peking-Tsinghua Center for Life Sciences, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871, China
| | - Sanduo Zheng
- Graduate School of Peking Union Medical College, Beijing 100730, China
- National Institute of Biological Sciences, Beijing 102206, China
- Tsinghua Institute of Multidisciplinary Biomedical Research, Tsinghua University, Beijing 100084, China
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13
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Colombo S, Reddy HP, Petri S, Williams DJ, Shalomov B, Dhindsa RS, Gelfman S, Krizay D, Bera AK, Yang M, Peng Y, Makinson CD, Boland MJ, Frankel WN, Goldstein DB, Dascal N. Epilepsy in a mouse model of GNB1 encephalopathy arises from altered potassium (GIRK) channel signaling and is alleviated by a GIRK inhibitor. Front Cell Neurosci 2023; 17:1175895. [PMID: 37275776 PMCID: PMC10232839 DOI: 10.3389/fncel.2023.1175895] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Accepted: 04/12/2023] [Indexed: 06/07/2023] Open
Abstract
De novo mutations in GNB1, encoding the Gβ1 subunit of G proteins, cause a neurodevelopmental disorder with global developmental delay and epilepsy, GNB1 encephalopathy. Here, we show that mice carrying a pathogenic mutation, K78R, recapitulate aspects of the disorder, including developmental delay and generalized seizures. Cultured mutant cortical neurons also display aberrant bursting activity on multi-electrode arrays. Strikingly, the antiepileptic drug ethosuximide (ETX) restores normal neuronal network behavior in vitro and suppresses spike-and-wave discharges (SWD) in vivo. ETX is a known blocker of T-type voltage-gated Ca2+ channels and G protein-coupled potassium (GIRK) channels. Accordingly, we present evidence that K78R results in a gain-of-function (GoF) effect by increasing the activation of GIRK channels in cultured neurons and a heterologous model (Xenopus oocytes)-an effect we show can be potently inhibited by ETX. This work implicates a GoF mechanism for GIRK channels in epilepsy, identifies a new mechanism of action for ETX in preventing seizures, and establishes this mouse model as a pre-clinical tool for translational research with predicative value for GNB1 encephalopathy.
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Affiliation(s)
- Sophie Colombo
- Institute for Genomic Medicine, Columbia University Irving Medical Center, New York, NY, United States
| | - Haritha P. Reddy
- Department of Physiology and Pharmacology, School of Medicine, Tel Aviv University, Tel Aviv, Israel
- Department of Biotechnology, Bhupat and Jyoti Mehta School of Biosciences, Indian Institute of Technology Madras, Chennai, India
| | - Sabrina Petri
- Institute for Genomic Medicine, Columbia University Irving Medical Center, New York, NY, United States
| | - Damian J. Williams
- Institute for Genomic Medicine, Columbia University Irving Medical Center, New York, NY, United States
| | - Boris Shalomov
- Department of Physiology and Pharmacology, School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Ryan S. Dhindsa
- Institute for Genomic Medicine, Columbia University Irving Medical Center, New York, NY, United States
| | - Sahar Gelfman
- Institute for Genomic Medicine, Columbia University Irving Medical Center, New York, NY, United States
| | - Daniel Krizay
- Institute for Genomic Medicine, Columbia University Irving Medical Center, New York, NY, United States
| | - Amal K. Bera
- Department of Biotechnology, Bhupat and Jyoti Mehta School of Biosciences, Indian Institute of Technology Madras, Chennai, India
| | - Mu Yang
- Institute for Genomic Medicine, Columbia University Irving Medical Center, New York, NY, United States
- Mouse NeuroBehavior Core Facility, Columbia University Irving Medical Center, New York, NY, United States
| | - Yueqing Peng
- Institute for Genomic Medicine, Columbia University Irving Medical Center, New York, NY, United States
- Department of Pathology and Cell Biology, Columbia University Irving Medical Center, New York, NY, United States
| | - Christopher D. Makinson
- Institute for Genomic Medicine, Columbia University Irving Medical Center, New York, NY, United States
- Department of Neurology, Columbia University Irving Medical Center, New York, NY, United States
- Department of Neuroscience, Columbia University, New York, NY, United States
| | - Michael J. Boland
- Institute for Genomic Medicine, Columbia University Irving Medical Center, New York, NY, United States
- Department of Neurology, Columbia University Irving Medical Center, New York, NY, United States
| | - Wayne N. Frankel
- Institute for Genomic Medicine, Columbia University Irving Medical Center, New York, NY, United States
- Department of Genetics and Development, Columbia University Irving Medical Center, New York, NY, United States
| | - David B. Goldstein
- Institute for Genomic Medicine, Columbia University Irving Medical Center, New York, NY, United States
- Department of Genetics and Development, Columbia University Irving Medical Center, New York, NY, United States
| | - Nathan Dascal
- Department of Physiology and Pharmacology, School of Medicine, Tel Aviv University, Tel Aviv, Israel
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14
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Choudhary S, Kaur R, Waziri A, Garg A, Kadian R, Alam MS. N-type calcium channel blockers: a new approach towards the treatment of chronic neuropathic pain. EXPLORATION OF MEDICINE 2023. [DOI: 10.37349/emed.2023.00126] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/04/2023] Open
Abstract
Neuropathic pain (NP) remains maltreated for a wide number of patients by the currently available treatments and little research has been done in finding new drugs for treating NP. Ziconotide (PrialtTM) had been developed as the new drug, which belongs to the class of ω-conotoxin MVIIA. It inhibits N-type calcium channels. Ziconotide is under the last phase of the clinical trial, a new non-narcotic drug for the management of NP. Synthetically it has shown the similarities with ω-conotoxin MVIIA, a constituent of poison found in fish hunting snails (Conus magus). Ziconotide acts by selectively blocking neural N-type voltage-sensitized Ca2+ channels (NVSCCs). Certain herbal drugs also have been studied but no clinical result is there and the study is only limited to preclinical data. This review emphasizes the N-type calcium channel inhibitors, and their mechanisms for blocking calcium channels with their remedial prospects for treating chronic NP.
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Affiliation(s)
- Shikha Choudhary
- School of Medical and Allied Sciences, K.R. Mangalam University, Gurugram 122103, Haryana, India
| | - Raminderjit Kaur
- School of Medical and Allied Sciences, K.R. Mangalam University, Gurugram 122103, Haryana, India
| | - Aafrin Waziri
- University School of Biotechnology, Guru Gobind Singh Indraprastha University, Delhi, 110078, India
| | - Arun Garg
- Department of Pharmacology, NIMS Institute of Pharmacy, NIMS University, Jaipur 303121, Rajasthan, India
| | - Renu Kadian
- Ram Gopal College of Pharmacy, Gurugram 122506, Haryana, India
| | - Md Sabir Alam
- SGT College of Pharmacy, SGT University, Gurugram 122505, Haryana, India
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15
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Manz KM, Zepeda JC, Zurawski Z, Hamm HE, Grueter BA. SNAP25 differentially contributes to G i/o-coupled receptor function at glutamatergic synapses in the nucleus accumbens. Front Cell Neurosci 2023; 17:1165261. [PMID: 37206665 PMCID: PMC10188356 DOI: 10.3389/fncel.2023.1165261] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2023] [Accepted: 04/10/2023] [Indexed: 05/21/2023] Open
Abstract
The nucleus accumbens (NAc) guides reward-related motivated behavior implicated in pathological behavioral states, including addiction and depression. These behaviors depend on the precise neuromodulatory actions of Gi/o-coupled G-protein-coupled receptors (GPCRs) at glutamatergic synapses onto medium spiny projection neurons (MSNs). Previous work has shown that discrete classes of Gi/o-coupled GPCR mobilize Gβγ to inhibit vesicular neurotransmitter release via t-SNARE protein, SNAP25. However, it remains unknown which Gαi/o systems in the NAc utilize Gβγ-SNARE signaling to dampen glutamatergic transmission. Utilizing patch-clamp electrophysiology and pharmacology in a transgenic mouse line with a C-terminal three-residue deletion of SNAP25 (SNAP25Δ3) weaking the Gβγ-SNARE interaction, we surveyed a broad cohort of Gi/o-coupled GPCRs with robust inhibitory actions at glutamatergic synapses in the NAc. We find that basal presynaptic glutamate release probability is reduced in SNAP25Δ3 mice. While κ opioid, CB1, adenosine A1, group II metabotropic glutamate receptors, and histamine H3 receptors inhibit glutamatergic transmission onto MSNs independent of SNAP25, we report that SNAP25 contributes significantly to the actions of GABAB, 5-HT1B/D, and μ opioid receptors. These findings demonstrate that presynaptic Gi/o-coupled GPCRs recruit heterogenous effector mechanisms at glutamatergic synapses in the NAc, with a subset requiring SNA25-dependent Gβγ signaling.
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Affiliation(s)
- Kevin M. Manz
- Department of Anesthesiology, Vanderbilt University Medical Center, Nashville, TN, United States
| | - José C. Zepeda
- Department of Pharmacology, Vanderbilt University, Nashville, TN, United States
| | - Zack Zurawski
- Department of Pharmacology, Vanderbilt University, Nashville, TN, United States
| | - Heidi E. Hamm
- Department of Pharmacology, Vanderbilt University, Nashville, TN, United States
| | - Brad A. Grueter
- Department of Anesthesiology, Vanderbilt University Medical Center, Nashville, TN, United States
- Department of Pharmacology, Vanderbilt University, Nashville, TN, United States
- Vanderbilt Brain Institute, Vanderbilt University, Nashville, TN, United States
- Vanderbilt Center for Addiction Research, Vanderbilt University, Nashville, TN, United States
- *Correspondence: Brad A. Grueter,
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16
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Yoon JY, Ho WK. Involvement of Ca2+ in Signaling Mechanisms Mediating Muscarinic Inhibition of M Currents in Sympathetic Neurons. Cell Mol Neurobiol 2022:10.1007/s10571-022-01303-7. [DOI: 10.1007/s10571-022-01303-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Accepted: 10/31/2022] [Indexed: 11/13/2022]
Abstract
AbstractAcetylcholine can excite neurons by suppressing M-type (KCNQ) potassium channels. This effect is mediated by M1 muscarinic receptors coupled to the Gq protein. Although PIP2 depletion and PKC activation have been strongly suggested to contribute to muscarinic inhibition of M currents (IM), direct evidence is lacking. We investigated the mechanism involved in muscarinic inhibition of IM with Ca2+ measurement and electrophysiological studies in both neuronal (rat sympathetic neurons) and heterologous (HEK cells expressing KCNQ2/KCNQ3) preparations. We found that muscarinic inhibition of IM was not blocked either by PIP2 or by calphostin C, a PKC inhibitor. We then examined whether muscarinic inhibition of IM uses multiple signaling pathways by blocking both PIP2 depletion and PKC activation. This maneuver, however, did not block muscarinic inhibition of IM. Additionally, muscarinic inhibition of IM was not prevented either by sequestering of G-protein βγ subunits from Gα-transducin or anti-Gβγ antibody or by preventing intracellular trafficking of channel proteins with blebbistatin, a class-II myosin inhibitor. Finally, we re-examined the role of Ca2+ signals in muscarinic inhibition of IM. Ca2+ measurements showed that muscarinic stimulation increased intracellular Ca2+ and was comparable to the Ca2+ mobilizing effect of bradykinin. Accordingly, 20-mM of BAPTA significantly suppressed muscarinic inhibition of IM. In contrast, muscarinic inhibition of IM was completely insensitive to 20-mM EGTA. Taken together, these data suggest a role of Ca2+ signaling in muscarinic modulation of IM. The differential effects of EGTA and BAPTA imply that Ca2+ microdomains or spatially local Ca2+ signals contribute to inhibition of IM.
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17
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Sukhanova KY, Koirala A, Elmslie KS. Na V1.9 current in muscle afferent neurons is enhanced by substances released during muscle activity. J Neurophysiol 2022; 128:739-750. [PMID: 36043704 PMCID: PMC9512110 DOI: 10.1152/jn.00116.2022] [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: 03/22/2022] [Revised: 08/26/2022] [Accepted: 08/29/2022] [Indexed: 11/22/2022] Open
Abstract
Skeletal muscle contraction triggers the exercise pressor reflex (EPR) to regulate the cardiovascular system response to exercise. During muscle contraction, substances are released that generate action potential activity in group III and IV afferents that mediate the EPR. Some of these substances increase afferent activity via G-protein-coupled receptor (GPCR) activation, but the mechanisms are incompletely understood. We were interested in determining if tetrodotoxin-resistant (TTX-R) voltage-dependent sodium channels (NaV) were involved and investigated the effect of a mixture of such compounds (bradykinin, prostaglandin, norepinephrine, and ATP, called muscle metabolites). Using whole cell patch-clamp electrophysiology, we show that the muscle metabolites significantly increased TTX-R NaV currents. The rise time of this enhancement averaged ∼2 min, which suggests the involvement of a diffusible second messenger pathway. The effect of muscle metabolites on the current-voltage relationship, channel activation and inactivation kinetics support NaV1.9 channels as the target for this enhancement. When applied individually at the concentration used in the mixture, only prostaglandin and bradykinin significantly enhanced NaV current, but the sum of these enhancements was <1/3 that observed when the muscle metabolites were applied together. This suggests synergism between the activated GPCRs to enhance NaV1.9 current. When applied at a higher concentration, all four substances could enhance the current, which demonstrates that the GPCRs activated by each metabolite can enhance channel activity. The enhancement of NaV1.9 channel activity is a likely mechanism by which GPCR activation increases action potential activity in afferents generating the EPR.NEW & NOTEWORTHY G-protein-coupled receptor (GPCR) activation increases action potential activity in muscle afferents to produce the exercise pressor reflex (EPR), but the mechanisms are incompletely understood. We provide evidence that NaV1.9 current is synergistically enhanced by application of a mixture of metabolites potentially released during muscle contraction. The enhancement of NaV1.9 current is likely one mechanism by which GPCR activation generates the EPR and the inappropriate activation of the EPR in patients with cardiovascular disease.
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Affiliation(s)
- Khrystyna Yu Sukhanova
- The Baker Laboratory of Pharmacology, Department of Pharmacology, Kirksville College of Osteopathic Medicine, A.T. Still University of Health Sciences, Kirksville, Missouri
| | - Ankeeta Koirala
- The Baker Laboratory of Pharmacology, Department of Pharmacology, Kirksville College of Osteopathic Medicine, A.T. Still University of Health Sciences, Kirksville, Missouri
| | - Keith S Elmslie
- The Baker Laboratory of Pharmacology, Department of Pharmacology, Kirksville College of Osteopathic Medicine, A.T. Still University of Health Sciences, Kirksville, Missouri
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18
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Abstract
Optogenetic actuators enable highly precise spatiotemporal interrogation of biological processes at levels ranging from the subcellular to cells, circuits and behaving organisms. Although their application in neuroscience has traditionally focused on the control of spiking activity at the somatodendritic level, the scope of optogenetic modulators for direct manipulation of presynaptic functions is growing. Presynaptically localized opsins combined with light stimulation at the terminals allow light-mediated neurotransmitter release, presynaptic inhibition, induction of synaptic plasticity and specific manipulation of individual components of the presynaptic machinery. Here, we describe presynaptic applications of optogenetic tools in the context of the unique cell biology of axonal terminals, discuss their potential shortcomings and outline future directions for this rapidly developing research area.
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19
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Mochida S. Mechanisms of Synaptic Vesicle Exo- and Endocytosis. Biomedicines 2022; 10:1593. [PMID: 35884898 PMCID: PMC9313035 DOI: 10.3390/biomedicines10071593] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2022] [Revised: 06/21/2022] [Accepted: 06/22/2022] [Indexed: 01/05/2023] Open
Abstract
Within 1 millisecond of action potential arrival at presynaptic terminals voltage-gated Ca2+ channels open. The Ca2+ channels are linked to synaptic vesicles which are tethered by active zone proteins. Ca2+ entrance into the active zone triggers: (1) the fusion of the vesicle and exocytosis, (2) the replenishment of the active zone with vesicles for incoming exocytosis, and (3) various types of endocytosis for vesicle reuse, dependent on the pattern of firing. These time-dependent vesicle dynamics are controlled by presynaptic Ca2+ sensor proteins, regulating active zone scaffold proteins, fusion machinery proteins, motor proteins, endocytic proteins, several enzymes, and even Ca2+ channels, following the decay of Ca2+ concentration after the action potential. Here, I summarize the Ca2+-dependent protein controls of synchronous and asynchronous vesicle release, rapid replenishment of the active zone, endocytosis, and short-term plasticity within 100 msec after the action potential. Furthermore, I discuss the contribution of active zone proteins to presynaptic plasticity and to homeostatic readjustment during and after intense activity, in addition to activity-dependent endocytosis.
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Affiliation(s)
- Sumiko Mochida
- Department of Physiology, Tokyo Medical University, Tokyo 160-8402, Japan
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20
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Lovinger DM, Mateo Y, Johnson KA, Engi SA, Antonazzo M, Cheer JF. Local modulation by presynaptic receptors controls neuronal communication and behaviour. Nat Rev Neurosci 2022; 23:191-203. [PMID: 35228740 PMCID: PMC10709822 DOI: 10.1038/s41583-022-00561-0] [Citation(s) in RCA: 28] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/19/2022] [Indexed: 12/15/2022]
Abstract
Central nervous system neurons communicate via fast synaptic transmission mediated by ligand-gated ion channel (LGIC) receptors and slower neuromodulation mediated by G protein-coupled receptors (GPCRs). These receptors influence many neuronal functions, including presynaptic neurotransmitter release. Presynaptic LGIC and GPCR activation by locally released neurotransmitters influences neuronal communication in ways that modify effects of somatic action potentials. Although much is known about presynaptic receptors and their mechanisms of action, less is known about when and where these receptor actions alter release, especially in vivo. This Review focuses on emerging evidence for important local presynaptic receptor actions and ideas for future studies in this area.
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Affiliation(s)
- David M Lovinger
- Laboratory for Integrative Neuroscience, National Institute on Alcohol Abuse and Alcoholism, Bethesda, MD, USA.
| | - Yolanda Mateo
- Laboratory for Integrative Neuroscience, National Institute on Alcohol Abuse and Alcoholism, Bethesda, MD, USA
| | - Kari A Johnson
- Department of Pharmacology, Uniformed Services University of the Health Sciences, Bethesda, MD, USA
| | - Sheila A Engi
- Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Mario Antonazzo
- Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Joseph F Cheer
- Department of Psychiatry, University of Maryland School of Medicine, Baltimore, MD, USA
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21
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Feng H, Yuan Y, Williams MR, Roy AJ, Leipprandt JR, Neubig RR. MICE WITH GNAO1-ASSOCIATED MOVEMENT DISORDER EXHIBIT REDUCED INHIBITORY SYNAPTIC INPUT TO CEREBELLAR PURKINJE CELLS. J Neurophysiol 2022; 127:607-622. [PMID: 35080448 DOI: 10.1152/jn.00720.2020] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
GNAO1 encodes Gαo, a heterotrimeric G protein alpha subunit in the Gi/o family. In this report, we used a Gnao1 mouse model "G203R" previously described as a "gain-of-function" Gnao1 mutant with movement abnormalities and enhanced seizure susceptibility. Here, we report an unexpected second mutation resulting in a loss-of-function Gαo protein and describe alterations in central synaptic transmission. Whole cell patch clamp recordings from Purkinje cells (PCs) in acute cerebellar slices from Gnao1 mutant mice showed significantly lower frequencies of spontaneous and miniature inhibitory postsynaptic currents (sIPSCs and mIPSCs) compared to WT mice. There was no significant change in sEPSCs or mEPSCs. Whereas mIPSC frequency was reduced, mIPSC amplitudes were not affected, suggesting a presynaptic mechanism of action. A modest decrease in the number of molecular layer interneurons was insufficient to explain the magnitude of IPSC suppression. Paradoxically, Gi/o inhibitors (pertussis toxin), enhanced the mutant-suppressed mIPSC frequency and eliminated the difference between WT and Gnao1 mice. While GABAB receptor regulates mIPSCs, neither agonists nor antagonists of this receptor altered function in the mutant mouse PCs. This study is the first electrophysiological investigation of the role of Gi/o proteinin cerebellar synaptic transmission using an animal model with a loss-of-function Gi/o protein.
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Affiliation(s)
- Huijie Feng
- Department of Pharmacology and Toxicology, Michigan State University, East Lansing, MI, United States
| | - Yukun Yuan
- Department of Pharmacology and Toxicology, Michigan State University, East Lansing, MI, United States
| | - Michael R Williams
- Department of Pediatrics and Human Development, Michigan State University, Grand Rapids, MI, United States
| | - Alex J Roy
- Department of Pharmacology and Toxicology, Michigan State University, East Lansing, MI, United States
| | - Jeffrey R Leipprandt
- Department of Pharmacology and Toxicology, Michigan State University, East Lansing, MI, United States
| | - Richard R Neubig
- Department of Pharmacology and Toxicology, Michigan State University, East Lansing, MI, United States
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22
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Alten B, Guzikowski NJ, Zurawski Z, Hamm HE, Kavalali ET. Presynaptic mechanisms underlying GABA B-receptor-mediated inhibition of spontaneous neurotransmitter release. Cell Rep 2022; 38:110255. [PMID: 35045279 PMCID: PMC8793855 DOI: 10.1016/j.celrep.2021.110255] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Revised: 06/15/2021] [Accepted: 12/21/2021] [Indexed: 01/08/2023] Open
Abstract
Inhibition of neurotransmitter release by neurotransmitter substances constitutes a fundamental means of neuromodulation. In contrast to well-delineated mechanisms that underlie inhibition of evoked release via suppression of voltage-gated Ca2+ channels, processes that underlie neuromodulatory inhibition of spontaneous release remain unclear. Here, we interrogated inhibition of spontaneous glutamate and GABA release by presynaptic metabotropic GABAB receptors. Our findings show that this inhibition relies on Gβγ subunit action at the membrane, and it is largely independent of presynaptic Ca2+ signaling for both forms of release. In the case of spontaneous glutamate release, inhibition requires Gβγ interaction with the C terminus of the key fusion machinery component SNAP25, and it is modulated by synaptotagmin-1. Inhibition of spontaneous GABA release, on the other hand, is independent of these pathways and likely requires alternative Gβγ targets at the presynaptic terminal.
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Affiliation(s)
- Baris Alten
- Department of Pharmacology, Vanderbilt University, 7130A MRB III 465 21st Avenue South, Nashville, TN 37240-7933, USA,Vanderbilt Brain Institute, Vanderbilt University, Nashville, TN 37240-7933, USA
| | - Natalie J. Guzikowski
- Department of Pharmacology, Vanderbilt University, 7130A MRB III 465 21st Avenue South, Nashville, TN 37240-7933, USA,Vanderbilt Brain Institute, Vanderbilt University, Nashville, TN 37240-7933, USA
| | - Zack Zurawski
- Department of Pharmacology, Vanderbilt University, 7130A MRB III 465 21st Avenue South, Nashville, TN 37240-7933, USA
| | - Heidi E. Hamm
- Department of Pharmacology, Vanderbilt University, 7130A MRB III 465 21st Avenue South, Nashville, TN 37240-7933, USA
| | - Ege T. Kavalali
- Department of Pharmacology, Vanderbilt University, 7130A MRB III 465 21st Avenue South, Nashville, TN 37240-7933, USA,Vanderbilt Brain Institute, Vanderbilt University, Nashville, TN 37240-7933, USA,Lead contact,Correspondence:
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23
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Simpson EH, Gallo EF, Balsam PD, Javitch JA, Kellendonk C. How changes in dopamine D2 receptor levels alter striatal circuit function and motivation. Mol Psychiatry 2022; 27:436-444. [PMID: 34385603 PMCID: PMC8837728 DOI: 10.1038/s41380-021-01253-4] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Revised: 07/27/2021] [Accepted: 07/29/2021] [Indexed: 02/07/2023]
Abstract
It was first posited, more than five decades ago, that the etiology of schizophrenia involves overstimulation of dopamine receptors. Since then, advanced clinical research methods, including brain imaging, have refined our understanding of the relationship between striatal dopamine and clinical phenotypes as well as disease trajectory. These studies point to striatal dopamine D2 receptors, the main target for all current antipsychotic medications, as being involved in both positive and negative symptoms. Simultaneously, animal models have been central to investigating causal relationships between striatal dopamine D2 receptors and behavioral phenotypes relevant to schizophrenia. We begin this article by reviewing the circuit, cell-type and subcellular locations of dopamine D2 receptors and their downstream signaling pathways. We then summarize results from several mouse models in which D2 receptor levels were altered in various brain regions, cell-types and developmental periods. Behavioral, electrophysiological and anatomical consequences of these D2 receptor perturbations are reviewed with a selective focus on striatal circuit function and alterations in motivated behavior, a core negative symptom of schizophrenia. These studies show that D2 receptors serve distinct physiological roles in different cell types and at different developmental time points, regulating motivated behaviors in sometimes opposing ways. We conclude by considering the clinical implications of this complex regulation of striatal circuit function by D2 receptors.
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Affiliation(s)
- Eleanor H. Simpson
- Division of Developmental Neuroscience, New York State Psychiatric Institute, 1051 Riverside Drive, New York, NY 10032, United States,Department of Psychiatry, Columbia University, 1051 Riverside Drive, New York, NY 10032, United States
| | - Eduardo F. Gallo
- Department of Biological Sciences, Fordham University, 441 East Fordham Road, Bronx, NY 10458
| | - Peter D. Balsam
- Division of Developmental Neuroscience, New York State Psychiatric Institute, 1051 Riverside Drive, New York, NY 10032, United States,Department of Psychiatry, Columbia University, 1051 Riverside Drive, New York, NY 10032, United States,Department of Psychology, Barnard College, 3009 Broadway, New York, NY 10027,Department of Psychology, Columbia University, 1190 Amsterdam Ave, New York, NY 10027
| | - Jonathan A. Javitch
- Department of Psychiatry, Columbia University, 1051 Riverside Drive, New York, NY 10032, United States,Division of Molecular Therapeutics, New York State Psychiatric Institute, 1051 Riverside Drive, New York, NY 10032,Department of Molecular Pharmacology and Therapeutics, Columbia University, 1051 Riverside Drive, New York, NY 10032
| | - Christoph Kellendonk
- Department of Psychiatry, Columbia University, New York, NY, USA. .,Division of Molecular Therapeutics, New York State Psychiatric Institute, New York, NY, USA. .,Department of Molecular Pharmacology and Therapeutics, Columbia University, New York, NY, USA.
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24
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Abstract
Biophysics is a way of approaching biological problems through numbers, physical laws, models, and quantitative logic. In a long scientific career, I have seen the formation and fruition of the ion channel concept through biophysical study. Marvelous discoveries were made as our instruments evolved from vacuum tubes to transistors; computers evolved from the size of an entire building to a few chips inside our instruments; and genome sequencing, gene expression, and atom-level structural biology became accessible to all laboratories. Science is rewarding and exhilarating. Expected final online publication date for the Annual Review of Biophysics, Volume 51 is May 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
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Affiliation(s)
- Bertil Hille
- Department of Physiology and Biophysics, University of Washington School of Medicine, Seattle, Washington, USA;
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25
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Yim YY, McDonald WH, Betke KM, Kaya A, Hyde K, Erreger K, Gilsbach R, Hein L, Hamm HE. Specificities of Gβγ subunits for the SNARE complex before and after stimulation of α 2a-adrenergic receptors. Sci Signal 2021; 14:eabc4970. [PMID: 34932372 DOI: 10.1126/scisignal.abc4970] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Ligand binding to G protein–coupled receptors (GPCRs), such as the α2a-adrenergic receptor (α2aAR), results in the activation of heterotrimeric G proteins, which consist of functionally distinct Gα subunits and Gβγ dimers. α2aAR-dependent inhibition of synaptic transmission regulates functions such as spontaneous locomotor activity, anesthetic sparing, and working memory enhancement and requires the soluble NSF attachment protein receptor (SNARE) complex, a Gβγ effector. To understand how the Gβγ-SNARE complex underlies the α2aAR-dependent inhibition of synaptic transmission, we examined the specificity of Gβγ subunits for the SNARE complex in adrenergic neurons, in which auto-α2aARs respond to epinephrine released from these neurons, and nonadrenergic neurons, in which hetero-α2aARs respond to epinephrine released from other neurons. We performed a quantitative, targeted multiple reaction monitoring proteomic analysis of Gβ and Gγ subunits bound to the SNARE complex in synaptosomes from mouse brains. In the absence of stimulation of auto-α2aARs, Gβ1 and Gγ3 interacted with the SNARE complex. However, Gβ1, Gβ2, and Gγ3 were found in the complex when auto-α2aARs were activated by epinephrine. Further understanding of the specific usage of distinct Gβγ subunits in vivo may provide insights into the homeostatic regulation of synaptic transmission and the mechanisms of dysfunction that occur in neurological diseases.
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Affiliation(s)
- Yun Young Yim
- Department of Pharmacology, Vanderbilt University, Nashville, TN 37232, USA
| | - W Hayes McDonald
- Department of Biochemistry and Mass Spectrometry Research Center, Vanderbilt University, Nashville, TN 37232, USA
| | - Katherine M Betke
- Department of Pharmacology, Vanderbilt University, Nashville, TN 37232, USA
| | - Ali Kaya
- Department of Pharmacology, Vanderbilt University, Nashville, TN 37232, USA
| | - Karren Hyde
- Department of Pharmacology, Vanderbilt University, Nashville, TN 37232, USA
| | - Kevin Erreger
- Department of Pharmacology, Vanderbilt University, Nashville, TN 37232, USA
| | - Ralf Gilsbach
- Fachbereich Medizin, Institute for Cardiovascular Physiology, Goethe University, Theodor-Stern-Kai 7, 60590 Frankfurt, Germany
- Institute of Experimental and Clinical Pharmacology and Toxicology, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany
| | - Lutz Hein
- Institute of Experimental and Clinical Pharmacology and Toxicology, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany
| | - Heidi E Hamm
- Department of Pharmacology, Vanderbilt University, Nashville, TN 37232, USA
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26
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Mochida S. Stable and Flexible Synaptic Transmission Controlled by the Active Zone Protein Interactions. Int J Mol Sci 2021; 22:ijms222111775. [PMID: 34769208 PMCID: PMC8583982 DOI: 10.3390/ijms222111775] [Citation(s) in RCA: 3] [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: 09/30/2021] [Revised: 10/24/2021] [Accepted: 10/25/2021] [Indexed: 12/28/2022] Open
Abstract
An action potential triggers neurotransmitter release from synaptic vesicles docking to a specialized release site of the presynaptic plasma membrane, the active zone. The active zone is a highly organized structure with proteins that serves as a platform for synaptic vesicle exocytosis, mediated by SNAREs complex and Ca2+ sensor proteins, within a sub-millisecond opening of nearby Ca2+ channels with the membrane depolarization. In response to incoming neuronal signals, each active zone protein plays a role in the release-ready site replenishment with synaptic vesicles for sustainable synaptic transmission. The active zone release apparatus provides a possible link between neuronal activity and plasticity. This review summarizes the mostly physiological role of active zone protein interactions that control synaptic strength, presynaptic short-term plasticity, and homeostatic synaptic plasticity.
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Affiliation(s)
- Sumiko Mochida
- Department of Physiology, Tokyo Medical University, Tokyo 160-8402, Japan
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27
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Lee AS, Tiwari S, Bishop I, Matossian V, Romaneschi N, Miyazaki T, VanderVeen L, Zalevsky J, DeFea K, Cahill CM, Walwyn WM. In vivo and in vitro Characterization of a Partial Mu Opioid Receptor Agonist, NKTR-181, Supports Future Therapeutic Development. FRONTIERS IN PAIN RESEARCH 2021; 2:695962. [PMID: 35295409 PMCID: PMC8915576 DOI: 10.3389/fpain.2021.695962] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Accepted: 07/15/2021] [Indexed: 11/13/2022] Open
Abstract
Mu opioid receptor (MOPr) agonists are well-known and frequently used clinical analgesics but are also rewarding due to their highly addictive and often abusive properties. This may lead to opioid use disorder (OUD) a disorder that effects millions of people worldwide. Therefore, novel compounds are urgently needed to treat OUD. As opioids are effective analgesics and OUD often occurs in conjunction with chronic pain, these novel compounds may be opioids, but they must have a low abuse liability. This could be mediated by diminishing or slowing blood-brain barrier transport, slowing target receptor binding kinetics, and showing a long half-life. NKTR-181 is a PEGylated oxycodol and a MOPr agonist that has slowed blood-brain barrier transport, a long half-life, and diminished likeability in clinical trials. In this study, we examined the signaling and behavioral profile of NKTR-181 in comparison with oxycodone to determine whether further therapeutic development of this compound may be warranted. For this preclinical study, we used a number of in vitro and in vivo assays. The signaling profile of NKTR-181 was determined by the electrophysiological assessment of MOPr-Ca2+ channel inhibition in the nociceptive neurons of rodent dorsal root ganglia. Heterologous cell-based assays were used to assess biased agonism and receptor trafficking. Different rodent behavioral models were used to define the NKTR-181-induced relief of effective and reflexive nociception and drug-seeking behavior as assessed by an intravenous self-administration (IVSA) of NKTR-181. We found that NKTR-181 and oxycodone are partial agonists in G-protein signaling and Ca2+ channel inhibition assays and promote limited MOPr desensitization. However, NKTR-181 inhibits Ca2+ channels by a different mechanism than oxycodone and induces a different pattern of arrestin recruitment. In addition, NKTR-181 has a slower receptor on-rate and a slower rate of Ca2+ channel coupling than oxycodone. This signaling profile is coupled with a slower onset of antinociception and limited drug-seeking behavior in comparison with oxycodone. Together with its known long half-life and slow blood-brain barrier transport, these data suggest that NKTR-181 could be further studied as a pharmacotherapeutic treatment modality for OUD.
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Affiliation(s)
- Alex S. Lee
- Department of Psychiatry and Biobehavioral Sciences, University of California, Los Angeles, Los Angeles, CA, United States
| | - Suchi Tiwari
- Department of Psychiatry and Biobehavioral Sciences, University of California, Los Angeles, Los Angeles, CA, United States
| | - Isabel Bishop
- Department of Psychiatry and Biobehavioral Sciences, University of California, Los Angeles, Los Angeles, CA, United States
| | - Vartan Matossian
- Department of Psychiatry and Biobehavioral Sciences, University of California, Los Angeles, Los Angeles, CA, United States
| | - Nicole Romaneschi
- Department of Psychiatry and Biobehavioral Sciences, University of California, Los Angeles, Los Angeles, CA, United States
| | | | | | | | - Kathryn DeFea
- KiloDalton Consulting, Orinda, CA, United States
- Division of Biomedical Sciences, School of Medicine, University of California, Riverside, Riverside, CA, United States
| | - Catherine M. Cahill
- Department of Psychiatry and Biobehavioral Sciences, University of California, Los Angeles, Los Angeles, CA, United States
- Brain Research Institute, University of California, Los Angeles, Los Angeles, CA, United States
- Shirley & Stefen Hatos Center for Neuropharmacology, University of California, Los Angeles, Los Angeles, CA, United States
- Jane & Terry Semel Institute for Neuroscience and Human Behavior, University of California, Los Angeles, Los Angeles, CA, United States
| | - Wendy M. Walwyn
- Department of Psychiatry and Biobehavioral Sciences, University of California, Los Angeles, Los Angeles, CA, United States
- Brain Research Institute, University of California, Los Angeles, Los Angeles, CA, United States
- Shirley & Stefen Hatos Center for Neuropharmacology, University of California, Los Angeles, Los Angeles, CA, United States
- Jane & Terry Semel Institute for Neuroscience and Human Behavior, University of California, Los Angeles, Los Angeles, CA, United States
- *Correspondence: Wendy M. Walwyn
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28
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Copits BA, Gowrishankar R, O'Neill PR, Li JN, Girven KS, Yoo JJ, Meshik X, Parker KE, Spangler SM, Elerding AJ, Brown BJ, Shirley SE, Ma KKL, Vasquez AM, Stander MC, Kalyanaraman V, Vogt SK, Samineni VK, Patriarchi T, Tian L, Gautam N, Sunahara RK, Gereau RW, Bruchas MR. A photoswitchable GPCR-based opsin for presynaptic inhibition. Neuron 2021; 109:1791-1809.e11. [PMID: 33979635 PMCID: PMC8194251 DOI: 10.1016/j.neuron.2021.04.026] [Citation(s) in RCA: 55] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2021] [Revised: 04/21/2021] [Accepted: 04/26/2021] [Indexed: 12/12/2022]
Abstract
Optical manipulations of genetically defined cell types have generated significant insights into the dynamics of neural circuits. While optogenetic activation has been relatively straightforward, rapid and reversible synaptic inhibition has proven more elusive. Here, we leveraged the natural ability of inhibitory presynaptic GPCRs to suppress synaptic transmission and characterize parapinopsin (PPO) as a GPCR-based opsin for terminal inhibition. PPO is a photoswitchable opsin that couples to Gi/o signaling cascades and is rapidly activated by pulsed blue light, switched off with amber light, and effective for repeated, prolonged, and reversible inhibition. PPO rapidly and reversibly inhibits glutamate, GABA, and dopamine release at presynaptic terminals. Furthermore, PPO alters reward behaviors in a time-locked and reversible manner in vivo. These results demonstrate that PPO fills a significant gap in the neuroscience toolkit for rapid and reversible synaptic inhibition and has broad utility for spatiotemporal control of inhibitory GPCR signaling cascades.
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Affiliation(s)
- Bryan A Copits
- Washington University Pain Center, Washington University School of Medicine, St. Louis, MO, USA; Department of Anesthesiology, Washington University School of Medicine, St. Louis, MO, USA.
| | - Raaj Gowrishankar
- Center of Excellence in the Neurobiology of Addiction, Pain, and Emotion, Departments of Anesthesiology and Pain Medicine, and Pharmacology, University of Washington, Seattle, WA, USA
| | - Patrick R O'Neill
- Department of Anesthesiology, Washington University School of Medicine, St. Louis, MO, USA; Shirley and Stefan Hatos Center for Neuropharmacology, Semel Institute, Department of Psychiatry and Biobehavioral Sciences, University of California Los Angeles, Los Angeles, CA
| | - Jun-Nan Li
- Washington University Pain Center, Washington University School of Medicine, St. Louis, MO, USA; Department of Anesthesiology, Washington University School of Medicine, St. Louis, MO, USA
| | - Kasey S Girven
- Center of Excellence in the Neurobiology of Addiction, Pain, and Emotion, Departments of Anesthesiology and Pain Medicine, and Pharmacology, University of Washington, Seattle, WA, USA
| | - Judy J Yoo
- Washington University Pain Center, Washington University School of Medicine, St. Louis, MO, USA; Department of Anesthesiology, Washington University School of Medicine, St. Louis, MO, USA
| | - Xenia Meshik
- Department of Anesthesiology, Washington University School of Medicine, St. Louis, MO, USA
| | - Kyle E Parker
- Department of Anesthesiology, Washington University School of Medicine, St. Louis, MO, USA
| | - Skylar M Spangler
- Department of Anesthesiology, Washington University School of Medicine, St. Louis, MO, USA
| | - Abigail J Elerding
- Center of Excellence in the Neurobiology of Addiction, Pain, and Emotion, Departments of Anesthesiology and Pain Medicine, and Pharmacology, University of Washington, Seattle, WA, USA
| | - Bobbie J Brown
- Washington University Pain Center, Washington University School of Medicine, St. Louis, MO, USA; Department of Anesthesiology, Washington University School of Medicine, St. Louis, MO, USA
| | - Sofia E Shirley
- Center of Excellence in the Neurobiology of Addiction, Pain, and Emotion, Departments of Anesthesiology and Pain Medicine, and Pharmacology, University of Washington, Seattle, WA, USA
| | - Kelly K L Ma
- Washington University Pain Center, Washington University School of Medicine, St. Louis, MO, USA; Department of Anesthesiology, Washington University School of Medicine, St. Louis, MO, USA
| | - Alexis M Vasquez
- Department of Pharmacology, University of California San Diego, San Diego, CA, USA
| | - M Christine Stander
- Department of Anesthesiology, Washington University School of Medicine, St. Louis, MO, USA
| | - Vani Kalyanaraman
- Department of Anesthesiology, Washington University School of Medicine, St. Louis, MO, USA
| | - Sherri K Vogt
- Washington University Pain Center, Washington University School of Medicine, St. Louis, MO, USA; Department of Anesthesiology, Washington University School of Medicine, St. Louis, MO, USA
| | - Vijay K Samineni
- Washington University Pain Center, Washington University School of Medicine, St. Louis, MO, USA; Department of Anesthesiology, Washington University School of Medicine, St. Louis, MO, USA
| | - Tommaso Patriarchi
- Institute of Pharmacology and Toxicology, University of Zurich, Zurich, Switzerland
| | - Lin Tian
- Department of Biochemistry and Molecular Medicine, University of California Davis, Davis, CA, USA
| | - N Gautam
- Department of Anesthesiology, Washington University School of Medicine, St. Louis, MO, USA
| | - Roger K Sunahara
- Department of Pharmacology, University of California San Diego, San Diego, CA, USA
| | - Robert W Gereau
- Washington University Pain Center, Washington University School of Medicine, St. Louis, MO, USA; Department of Anesthesiology, Washington University School of Medicine, St. Louis, MO, USA; Department of Neuroscience, Washington University School of Medicine, St. Louis, MO, USA
| | - Michael R Bruchas
- Department of Anesthesiology, Washington University School of Medicine, St. Louis, MO, USA; Department of Neuroscience, Washington University School of Medicine, St. Louis, MO, USA; Center of Excellence in the Neurobiology of Addiction, Pain, and Emotion, Departments of Anesthesiology and Pain Medicine, and Pharmacology, University of Washington, Seattle, WA, USA.
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29
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Tennakoon M, Senarath K, Kankanamge D, Ratnayake K, Wijayaratna D, Olupothage K, Ubeysinghe S, Martins-Cannavino K, Hébert TE, Karunarathne A. Subtype-dependent regulation of Gβγ signalling. Cell Signal 2021; 82:109947. [PMID: 33582184 PMCID: PMC8026654 DOI: 10.1016/j.cellsig.2021.109947] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Revised: 02/01/2021] [Accepted: 02/02/2021] [Indexed: 01/04/2023]
Abstract
G protein-coupled receptors (GPCRs) transmit information to the cell interior by transducing external signals to heterotrimeric G protein subunits, Gα and Gβγ subunits, localized on the inner leaflet of the plasma membrane. Though the initial focus was mainly on Gα-mediated events, Gβγ subunits were later identified as major contributors to GPCR-G protein signalling. A broad functional array of Gβγ signalling has recently been attributed to Gβ and Gγ subtype diversity, comprising 5 Gβ and 12 Gγ subtypes, respectively. In addition to displaying selectivity towards each other to form the Gβγ dimer, numerous studies have identified preferences of distinct Gβγ combinations for specific GPCRs, Gα subtypes and effector molecules. Importantly, Gβ and Gγ subtype-dependent regulation of downstream effectors, representing a diverse range of signalling pathways and physiological functions have been found. Here, we review the literature on the repercussions of Gβ and Gγ subtype diversity on direct and indirect regulation of GPCR/G protein signalling events and their physiological outcomes. Our discussion additionally provides perspective in understanding the intricacies underlying molecular regulation of subtype-specific roles of Gβγ signalling and associated diseases.
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Affiliation(s)
- Mithila Tennakoon
- Department of Chemistry and Biochemistry, The University of Toledo, Toledo, OH 43606, USA
| | - Kanishka Senarath
- Genetics and Molecular Biology Unit, University of Sri Jayewardenepura, Nugegoda, Sri Lanka
| | - Dinesh Kankanamge
- Department of Chemistry and Biochemistry, The University of Toledo, Toledo, OH 43606, USA
| | - Kasun Ratnayake
- Department of Chemistry and Biochemistry, The University of Toledo, Toledo, OH 43606, USA; Department of Pharmacology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Dhanushan Wijayaratna
- Department of Chemistry and Biochemistry, The University of Toledo, Toledo, OH 43606, USA
| | - Koshala Olupothage
- Department of Chemistry and Biochemistry, The University of Toledo, Toledo, OH 43606, USA
| | - Sithurandi Ubeysinghe
- Department of Chemistry and Biochemistry, The University of Toledo, Toledo, OH 43606, USA
| | | | - Terence E Hébert
- Department of Pharmacology and Therapeutics, McGill University, Montréal, QC H3G 1Y6, Canada.
| | - Ajith Karunarathne
- Department of Chemistry and Biochemistry, The University of Toledo, Toledo, OH 43606, USA.
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30
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Kesner AJ, Lovinger DM. Cannabis use, abuse, and withdrawal: Cannabinergic mechanisms, clinical, and preclinical findings. J Neurochem 2021; 157:1674-1696. [PMID: 33891706 PMCID: PMC9291571 DOI: 10.1111/jnc.15369] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Revised: 04/12/2021] [Accepted: 04/12/2021] [Indexed: 12/14/2022]
Abstract
Cannabis sativa is the most widely used illicit drug in the world. Its main psychoactive component is delta-9-tetrahydrocannabinol (THC), one of over 100 phytocannabinoid compounds produced by the cannabis plant. THC is the primary compound that drives cannabis abuse potential and is also used and prescribed medically for therapeutic qualities. Despite its therapeutic potential, a significant subpopulation of frequent cannabis or THC users will develop a drug use syndrome termed cannabis use disorder. Individuals suffering from cannabis use disorder exhibit many of the hallmarks of classical addictions including cravings, tolerance, and withdrawal symptoms. Currently, there are no efficacious treatments for cannabis use disorder or withdrawal symptoms. This makes both clinical and preclinical research on the neurobiological mechanisms of these syndromes ever more pertinent. Indeed, basic research using animal models has provided valuable evidence of the neural molecular and cellular actions of cannabis that mediate its behavioral effects. One of the main components being central action on the cannabinoid type-one receptor and downstream intracellular signaling related to the endogenous cannabinoid system. Back-translational studies have provided insight linking preclinical basic and behavioral biology research to better understand symptoms observed at the clinical level. This narrative review aims to summarize major research elucidating the molecular, cellular, and behavioral manifestations of cannabis/THC use that play a role in cannabis use disorder and withdrawal.
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Affiliation(s)
- Andrew J. Kesner
- Laboratory for Integrative NeuroscienceNational Institute on Alcohol Abuse and AlcoholismCenter on Compulsive BehaviorsNational Institutes of HealthBethesdaMDUSA
| | - David M. Lovinger
- Laboratory for Integrative NeuroscienceNational Institute on Alcohol Abuse and AlcoholismCenter on Compulsive BehaviorsNational Institutes of HealthBethesdaMDUSA
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31
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Efficient optogenetic silencing of neurotransmitter release with a mosquito rhodopsin. Neuron 2021; 109:1621-1635.e8. [PMID: 33979634 DOI: 10.1016/j.neuron.2021.03.013] [Citation(s) in RCA: 64] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Revised: 03/02/2021] [Accepted: 03/09/2021] [Indexed: 12/21/2022]
Abstract
Information is carried between brain regions through neurotransmitter release from axonal presynaptic terminals. Understanding the functional roles of defined neuronal projection pathways requires temporally precise manipulation of their activity. However, existing inhibitory optogenetic tools have low efficacy and off-target effects when applied to presynaptic terminals, while chemogenetic tools are difficult to control in space and time. Here, we show that a targeting-enhanced mosquito homolog of the vertebrate encephalopsin (eOPN3) can effectively suppress synaptic transmission through the Gi/o signaling pathway. Brief illumination of presynaptic terminals expressing eOPN3 triggers a lasting suppression of synaptic output that recovers spontaneously within minutes in vitro and in vivo. In freely moving mice, eOPN3-mediated suppression of dopaminergic nigrostriatal afferents induces a reversible ipsiversive rotational bias. We conclude that eOPN3 can be used to selectively suppress neurotransmitter release at presynaptic terminals with high spatiotemporal precision, opening new avenues for functional interrogation of long-range neuronal circuits in vivo.
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32
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Ramirez JM, Burgraff NJ, Wei AD, Baertsch NA, Varga AG, Baghdoyan HA, Lydic R, Morris KF, Bolser DC, Levitt ES. Neuronal mechanisms underlying opioid-induced respiratory depression: our current understanding. J Neurophysiol 2021; 125:1899-1919. [PMID: 33826874 DOI: 10.1152/jn.00017.2021] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Opioid-induced respiratory depression (OIRD) represents the primary cause of death associated with therapeutic and recreational opioid use. Within the United States, the rate of death from opioid abuse since the early 1990s has grown disproportionally, prompting the classification as a nationwide "epidemic." Since this time, we have begun to unravel many fundamental cellular and systems-level mechanisms associated with opioid-related death. However, factors such as individual vulnerability, neuromodulatory compensation, and redundancy of opioid effects across central and peripheral nervous systems have created a barrier to a concise, integrative view of OIRD. Within this review, we bring together multiple perspectives in the field of OIRD to create an overarching viewpoint of what we know, and where we view this essential topic of research going forward into the future.
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Affiliation(s)
- Jan-Marino Ramirez
- Department of Neurological Surgery, University of Washington, Seattle, Washington.,Center for Integrative Brain Research, Seattle Children's Research Institute, Seattle, Washington
| | - Nicholas J Burgraff
- Center for Integrative Brain Research, Seattle Children's Research Institute, Seattle, Washington
| | - Aguan D Wei
- Center for Integrative Brain Research, Seattle Children's Research Institute, Seattle, Washington
| | - Nathan A Baertsch
- Center for Integrative Brain Research, Seattle Children's Research Institute, Seattle, Washington
| | - Adrienn G Varga
- Department of Pharmacology and Therapeutics, University of Florida, Gainesville, Florida.,Center for Respiratory Research and Rehabilitation, Department of Physical Therapy, University of Florida, Gainesville, Florida
| | - Helen A Baghdoyan
- Department of Psychology, University of Tennessee, Knoxville, Tennessee.,Oak Ridge National Laboratory, Oak Ridge, Tennessee
| | - Ralph Lydic
- Department of Psychology, University of Tennessee, Knoxville, Tennessee.,Oak Ridge National Laboratory, Oak Ridge, Tennessee
| | - Kendall F Morris
- Department of Molecular Pharmacology and Physiology, Morsani College of Medicine, University of South Florida, Tampa, Florida
| | - Donald C Bolser
- Department of Physiological Sciences, College of Veterinary Medicine, University of Florida, Gainesville, Florida
| | - Erica S Levitt
- Department of Pharmacology and Therapeutics, University of Florida, Gainesville, Florida.,Center for Respiratory Research and Rehabilitation, Department of Physical Therapy, University of Florida, Gainesville, Florida
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33
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Agahari FA, Stricker C. Serotonergic Modulation of Spontaneous and Evoked Transmitter Release in Layer II Pyramidal Cells of Rat Somatosensory Cortex. Cereb Cortex 2021; 31:1182-1200. [PMID: 33063109 DOI: 10.1093/cercor/bhaa285] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
As axons from the raphe nuclei densely innervate the somatosensory cortex, we investigated how serotonin (5-HT) modulates transmitter release in layer II pyramidal cells of rat barrel cortex. In the presence of tetrodotoxin and gabazine, 10 μM 5-HT caused a waxing and waning in the frequency of miniature excitatory postsynaptic currents (mEPSC) with no effect on amplitude. Specifically, within 15 min of recording the mEPSC frequency initially increased by 28 ± 7%, then dropped to below control (-15 ± 3%), before resurging back to 27 ± 7% larger than control. These changes were seen in 47% of pyramidal cells (responders) and were mediated by 5-HT2C receptors (5-HT2CR). Waxing resulted from phospholipase C activation, IP3 production, and Ca2+ release from presynaptic stores. Waning was prevented if PKC was blocked. In contrast, in paired recordings, the unitary EPSC amplitude was reduced by 50 ± 3% after 5-HT exposure in almost all cases with no significant effect on paired-pulse ratio and synaptic dynamics. This sustained EPSC reduction was also caused by 5-HT2R, but was mediated by presynaptic Gβγ subunits likely limiting influx through CaV2 channels. EPSC reduction, together with enhanced spontaneous noise in a restricted subset of inputs, could temporarily diminish the signal-to-noise ratio and affect the computation in the neocortical microcircuit.
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Affiliation(s)
- Fransiscus Adrian Agahari
- Neuronal Network Laboratory, Eccles Institute of Neuroscience, The John Curtin School of Medical Research, Australian National University, Acton ACT 2601, Australia.,Division of Cerebral Circuitry, National Institute for Physiological Sciences, Okazaki 444-8787, Japan.,Brain Science Institute, Tamagawa University, Tokyo 194-8610, Japan
| | - Christian Stricker
- Neuronal Network Laboratory, Eccles Institute of Neuroscience, The John Curtin School of Medical Research, Australian National University, Acton ACT 2601, Australia
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34
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Yang LK, Hou ZS, Tao YX. Biased signaling in naturally occurring mutations of G protein-coupled receptors associated with diverse human diseases. Biochim Biophys Acta Mol Basis Dis 2021; 1867:165973. [PMID: 32949766 PMCID: PMC7722056 DOI: 10.1016/j.bbadis.2020.165973] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Revised: 09/07/2020] [Accepted: 09/14/2020] [Indexed: 12/15/2022]
Abstract
G protein-coupled receptors (GPCRs) play critical roles in transmitting a variety of extracellular signals into the cells and regulate diverse physiological functions. Naturally occurring mutations that result in dysfunctions of GPCRs have been known as the causes of numerous diseases. Significant progresses have been made in elucidating the pathophysiology of diseases caused by mutations. The multiple intracellular signaling pathways, such as G protein-dependent and β-arrestin-dependent signaling, in conjunction with recent advances on biased agonism, have broadened the view on the molecular mechanism of disease pathogenesis. This review aims to briefly discuss biased agonism of GPCRs (biased ligands and biased receptors), summarize the naturally occurring GPCR mutations that cause biased signaling, and propose the potential pathophysiological relevance of biased mutant GPCRs associated with various endocrine diseases.
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Affiliation(s)
- Li-Kun Yang
- Department of Anatomy, Physiology and Pharmacology, College of Veterinary Medicine, Auburn University, Auburn, AL 36849, United States
| | - Zhi-Shuai Hou
- Department of Anatomy, Physiology and Pharmacology, College of Veterinary Medicine, Auburn University, Auburn, AL 36849, United States
| | - Ya-Xiong Tao
- Department of Anatomy, Physiology and Pharmacology, College of Veterinary Medicine, Auburn University, Auburn, AL 36849, United States.
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35
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Mochida S. Neurotransmitter Release Site Replenishment and Presynaptic Plasticity. Int J Mol Sci 2020; 22:ijms22010327. [PMID: 33396919 PMCID: PMC7794938 DOI: 10.3390/ijms22010327] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Revised: 12/23/2020] [Accepted: 12/27/2020] [Indexed: 12/19/2022] Open
Abstract
An action potential (AP) triggers neurotransmitter release from synaptic vesicles (SVs) docking to a specialized release site of presynaptic plasma membrane, the active zone (AZ). The AP simultaneously controls the release site replenishment with SV for sustainable synaptic transmission in response to incoming neuronal signals. Although many studies have suggested that the replenishment time is relatively slow, recent studies exploring high speed resolution have revealed SV dynamics with milliseconds timescale after an AP. Accurate regulation is conferred by proteins sensing Ca2+ entering through voltage-gated Ca2+ channels opened by an AP. This review summarizes how millisecond Ca2+ dynamics activate multiple protein cascades for control of the release site replenishment with release-ready SVs that underlie presynaptic short-term plasticity.
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Affiliation(s)
- Sumiko Mochida
- Department of Physiology, Tokyo Medical University, Tokyo 160-8402, Japan
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36
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Spanoghe J, Larsen LE, Craey E, Manzella S, Van Dycke A, Boon P, Raedt R. The Signaling Pathways Involved in the Anticonvulsive Effects of the Adenosine A 1 Receptor. Int J Mol Sci 2020; 22:ijms22010320. [PMID: 33396826 PMCID: PMC7794785 DOI: 10.3390/ijms22010320] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2020] [Revised: 12/22/2020] [Accepted: 12/27/2020] [Indexed: 12/20/2022] Open
Abstract
Adenosine acts as an endogenous anticonvulsant and seizure terminator in the brain. Many of its anticonvulsive effects are mediated through the activation of the adenosine A1 receptor, a G protein-coupled receptor with a wide array of targets. Activating A1 receptors is an effective approach to suppress seizures. This review gives an overview of the neuronal targets of the adenosine A1 receptor focusing in particular on signaling pathways resulting in neuronal inhibition. These include direct interactions of G protein subunits, the adenyl cyclase pathway and the phospholipase C pathway, which all mediate neuronal hyperpolarization and suppression of synaptic transmission. Additionally, the contribution of the guanyl cyclase and mitogen-activated protein kinase cascades to the seizure-suppressing effects of A1 receptor activation are discussed. This review ends with the cautionary note that chronic activation of the A1 receptor might have detrimental effects, which will need to be avoided when pursuing A1 receptor-based epilepsy therapies.
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Affiliation(s)
- Jeroen Spanoghe
- 4Brain, Department of Head and Skin, Ghent University, 9000 Ghent, Belgium; (J.S.); (L.E.L.); (E.C.); (S.M.); (P.B.)
| | - Lars E. Larsen
- 4Brain, Department of Head and Skin, Ghent University, 9000 Ghent, Belgium; (J.S.); (L.E.L.); (E.C.); (S.M.); (P.B.)
| | - Erine Craey
- 4Brain, Department of Head and Skin, Ghent University, 9000 Ghent, Belgium; (J.S.); (L.E.L.); (E.C.); (S.M.); (P.B.)
| | - Simona Manzella
- 4Brain, Department of Head and Skin, Ghent University, 9000 Ghent, Belgium; (J.S.); (L.E.L.); (E.C.); (S.M.); (P.B.)
| | - Annelies Van Dycke
- Department of Neurology, General Hospital Sint-Jan Bruges, 8000 Bruges, Belgium;
| | - Paul Boon
- 4Brain, Department of Head and Skin, Ghent University, 9000 Ghent, Belgium; (J.S.); (L.E.L.); (E.C.); (S.M.); (P.B.)
| | - Robrecht Raedt
- 4Brain, Department of Head and Skin, Ghent University, 9000 Ghent, Belgium; (J.S.); (L.E.L.); (E.C.); (S.M.); (P.B.)
- Correspondence:
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Calebiro D, Koszegi Z, Lanoiselée Y, Miljus T, O'Brien S. G protein-coupled receptor-G protein interactions: a single-molecule perspective. Physiol Rev 2020; 101:857-906. [PMID: 33331229 DOI: 10.1152/physrev.00021.2020] [Citation(s) in RCA: 50] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
G protein-coupled receptors (GPCRs) regulate many cellular and physiological processes, responding to a diverse range of extracellular stimuli including hormones, neurotransmitters, odorants, and light. Decades of biochemical and pharmacological studies have provided fundamental insights into the mechanisms of GPCR signaling. Thanks to recent advances in structural biology, we now possess an atomistic understanding of receptor activation and G protein coupling. However, how GPCRs and G proteins interact in living cells to confer signaling efficiency and specificity remains insufficiently understood. The development of advanced optical methods, including single-molecule microscopy, has provided the means to study receptors and G proteins in living cells with unprecedented spatio-temporal resolution. The results of these studies reveal an unexpected level of complexity, whereby GPCRs undergo transient interactions among themselves as well as with G proteins and structural elements of the plasma membrane to form short-lived signaling nanodomains that likely confer both rapidity and specificity to GPCR signaling. These findings may provide new strategies to pharmaceutically modulate GPCR function, which might eventually pave the way to innovative drugs for common diseases such as diabetes or heart failure.
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Affiliation(s)
- Davide Calebiro
- Institute of Metabolism and Systems Research, University of Birmingham, Birmingham, United Kingdom; Centre of Membrane Proteins and Receptors (COMPARE), Universities of Nottingham and Birmingham, Birmingham, United Kingdom
| | - Zsombor Koszegi
- Institute of Metabolism and Systems Research, University of Birmingham, Birmingham, United Kingdom; Centre of Membrane Proteins and Receptors (COMPARE), Universities of Nottingham and Birmingham, Birmingham, United Kingdom
| | - Yann Lanoiselée
- Institute of Metabolism and Systems Research, University of Birmingham, Birmingham, United Kingdom; Centre of Membrane Proteins and Receptors (COMPARE), Universities of Nottingham and Birmingham, Birmingham, United Kingdom
| | - Tamara Miljus
- Institute of Metabolism and Systems Research, University of Birmingham, Birmingham, United Kingdom; Centre of Membrane Proteins and Receptors (COMPARE), Universities of Nottingham and Birmingham, Birmingham, United Kingdom
| | - Shannon O'Brien
- Institute of Metabolism and Systems Research, University of Birmingham, Birmingham, United Kingdom; Centre of Membrane Proteins and Receptors (COMPARE), Universities of Nottingham and Birmingham, Birmingham, United Kingdom
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Zhang Y, Jeske NA. GRK2 Dictates a Functional Switch of the Peripheral Mu-Opioid Receptor. ACS Chem Neurosci 2020; 11:4376-4386. [PMID: 33174729 DOI: 10.1021/acschemneuro.0c00622] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
The peripheral mu-opioid receptor (MOR) has been recognized as a potential target to provide safer analgesia with reduced central side effects. Although analgesic incompetence of the peripheral MOR in the absence of inflammation was initially identified more than a decade ago, there has been very limited investigation into the underlying signaling mechanisms. Here we identify that G protein-coupled receptor kinase 2 (GRK2) constitutively interacts with the MOR in peripheral sensory neurons to suppress peripheral MOR activity. Brief exposure to bradykinin (BK) causes uncoupling of GRK2 from the MOR and subsequent restoration of MOR functionality in dorsal root ganglion (DRG) neurons. Interestingly, prolonged BK treatment induces constitutive activation of the MOR through a mechanism that involves protein kinase C (PKC) activation. After silencing Raf kinase inhibitory protein (RKIP) by RNA interference, BK-induced constitutive MOR activation is completely abrogated, which agrees with previous findings that BK activates PKC signaling to initiate GRK2 sequestration by RKIP. Furthermore, we demonstrate that constitutive, peripheral MOR activity requires GRK2 uncoupling and that the FDA-approved SSRI paroxetine promotes this state of uncoupling. Collectively, these results indicate that GRK2 tightly regulates MOR functional states and controls constitutive MOR activity in peripheral sensory neurons, supporting the potential for targeting the kinase to provide safer analgesia.
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Tsentsevitsky A, Nurullin L, Tyapkina O, Bukharaeva E. Sympathomimetics regulate quantal acetylcholine release at neuromuscular junctions through various types of adrenoreceptors. Mol Cell Neurosci 2020; 108:103550. [PMID: 32890729 DOI: 10.1016/j.mcn.2020.103550] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Revised: 07/26/2020] [Accepted: 08/27/2020] [Indexed: 01/01/2023] Open
Abstract
The studies of the interaction between the sympathetic and motor nervous systems are extremely relevant due to therapy for many neurodegenerative and cardiovascular disorders involving adrenergic compounds. Evidences indicate close contact between sympathetic varicosities and neuromuscular synapses. This raises questions about the effects of catecholamines on synaptic transmission. The currently available information is contradictory, and the types of adrenoreceptors responsible for modulation of neurotransmitter release have not been identified in mammalian neuromuscular synapses. Our results have shown that the α1A, α1B, α2A, α2B, α2C, and β1 adrenoreceptor subtypes are expressed in mouse diaphragm muscle containing neuromuscular synapses and sympathetic varicosities. Pharmacological stimulation of adrenoreceptors affects both spontaneous and evoked acetylcholine quantal secretion. Agonists of the α1, α2 and β1 adrenoreceptors decrease spontaneous release. Activation of the α2 and β1 adrenoreceptors reduces the number of acetylcholine quanta released in response to a nerve stimulus (quantal content), but an agonist of the β2 receptors increases quantal content. Activation of α2 and β2 adrenoreceptors alters the kinetics of acetylcholine quantal release by desynchronizing the neurosecretory process. Specific blockers of these receptors eliminate the effects of the specific agonists. The action of blockers on quantal acetylcholine secretion indicates possible action of endogenous catecholamines on neuromuscular transmission. Elucidating the molecular mechanisms by which clinically utilized adrenomimetics and adrenoblockers regulate synaptic vesicle release at the motor axon terminal will lead to the creation of improved and safer sympathomimetics for the treatment of various neurodegenerative diseases with synaptic defects.
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Affiliation(s)
- Andrei Tsentsevitsky
- Kazan Institute of Biochemistry and Biophysics FRC Kazan Scientific Center of RAS, PB 30, Kazan 420111, Russia
| | - Leniz Nurullin
- Kazan Institute of Biochemistry and Biophysics FRC Kazan Scientific Center of RAS, PB 30, Kazan 420111, Russia
| | - Oksana Tyapkina
- Kazan Institute of Biochemistry and Biophysics FRC Kazan Scientific Center of RAS, PB 30, Kazan 420111, Russia
| | - Ellya Bukharaeva
- Kazan Institute of Biochemistry and Biophysics FRC Kazan Scientific Center of RAS, PB 30, Kazan 420111, Russia.
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Arrestin recruitment to dopamine D2 receptor mediates locomotion but not incentive motivation. Mol Psychiatry 2020; 25:2086-2100. [PMID: 30120413 PMCID: PMC6378141 DOI: 10.1038/s41380-018-0212-4] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/01/2018] [Revised: 06/20/2018] [Accepted: 06/25/2018] [Indexed: 01/11/2023]
Abstract
The dopamine (DA) D2 receptor (D2R) is an important target for the treatment of neuropsychiatric disorders such as schizophrenia and Parkinson's disease. However, the development of improved therapeutic strategies has been hampered by our incomplete understanding of this receptor's downstream signaling processes in vivo and how these relate to the desired and undesired effects of drugs. D2R is a G protein-coupled receptor (GPCR) that activates G protein-dependent as well as non-canonical arrestin-dependent signaling pathways. Whether these effector pathways act alone or in concert to facilitate specific D2R-dependent behaviors is unclear. Here, we report on the development of a D2R mutant that recruits arrestin but is devoid of G protein activity. When expressed virally in "indirect pathway" medium spiny neurons (iMSNs) in the ventral striatum of D2R knockout mice, this mutant restored basal locomotor activity and cocaine-induced locomotor activity in a manner indistinguishable from wild-type D2R, indicating that arrestin recruitment can drive locomotion in the absence of D2R-mediated G protein signaling. In contrast, incentive motivation was enhanced only by wild-type D2R, signifying a dissociation in the mechanisms that underlie distinct D2R-dependent behaviors, and opening the door to more targeted therapeutics.
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41
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Yang L, Sun Q, Wang Y, Chan Z. Global transcriptomic network of melatonin regulated root growth in Arabidopsis. Gene 2020; 764:145082. [PMID: 32858176 DOI: 10.1016/j.gene.2020.145082] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Revised: 08/17/2020] [Accepted: 08/20/2020] [Indexed: 12/12/2022]
Abstract
Melatonin functions as a plant growth regulator in a concentration-dependent manner. In this study, we investigated the effects of melatonin on root growth and dissected underlined mechanisms. The results showed that melatonin up to 1000 μM inhibited primary root growth, but promoted lateral root development. Through RNA sequencing analysis, functions of differentially expressed genes were mainly involved in stress response, signaling transduction, transport, hormone metabolism and amino acid metabolism. Genes involving in jasmonate (JA), brassinosteroid (BR) and cytokinin (CK) biosynthesis were inhibited, but these in ethylene (ET), strigolactone (SL) and gibberellins (GA) biosynthetic pathways were activated after melatonin treatment. The majority of zinc finger proteins (ZFPs), Calmodulin-like (CMLs), NAM, ATAF1/2, and CUC2 (NACs) and ubiquitination related genes (RING/U-box and F-box) were upregulated, which possibly acted downstream of integrated hormone signals to mediate root growth. This study characterized melatonin modulated networks in regulating root growth.
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Affiliation(s)
- Li Yang
- Key Laboratory of Horticultural Plant Biology, Ministry of Education, College of Horticulture and Forestry Sciences, Huazhong Agricultural University, Wuhan, Hubei 430070, China
| | - Qi Sun
- Key Laboratory of Horticultural Plant Biology, Ministry of Education, College of Horticulture and Forestry Sciences, Huazhong Agricultural University, Wuhan, Hubei 430070, China
| | - Yanping Wang
- Key Laboratory of Horticultural Plant Biology, Ministry of Education, College of Horticulture and Forestry Sciences, Huazhong Agricultural University, Wuhan, Hubei 430070, China.
| | - Zhulong Chan
- Key Laboratory of Horticultural Plant Biology, Ministry of Education, College of Horticulture and Forestry Sciences, Huazhong Agricultural University, Wuhan, Hubei 430070, China.
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Thompson Gray AD, Simonetti J, Adegboye F, Jones CK, Zurawski Z, Hamm HE. Sexual Dimorphism in Stress-induced Hyperthermia in SNAP25Δ3 mice, a mouse model with disabled Gβγ regulation of the exocytotic fusion apparatus. Eur J Neurosci 2020; 52:2815-2826. [PMID: 32449556 DOI: 10.1111/ejn.14836] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2019] [Revised: 05/14/2020] [Accepted: 05/18/2020] [Indexed: 11/28/2022]
Abstract
Behavioral assays in the mouse can show marked differences between male and female animals of a given genotype. These differences identified in such preclinical studies may have important clinical implications. We recently made a mouse model with impaired presynaptic inhibition through Gβγ-SNARE signaling. Here, we examine the role of sexual dimorphism in the severity of the phenotypes of this model, the SNAP25Δ3 mouse. In males, we already reported that SNAP25Δ3 homozygotes demonstrated phenotypes in motor coordination, nociception, spatial memory and stress processing. We now report that while minimal sexually dimorphic effects were observed for the nociceptive, motor or memory phenotypes, large differences were observed in the stress-induced hyperthermia paradigm, with male SNAP25Δ3 homozygotes exhibiting an increase in body temperature subsequent to handling relative to wild-type littermates, while no such genotype-dependent effect was observed in females. This suggests sexually dimorphic mechanisms of Gβγ-SNARE signaling for stress processing or thermoregulation within the mouse. Second, we examined the effects of heterozygosity with respect to the SNAP25Δ3 mutation. Heterozygote SNAP25Δ3 animals were tested alongside homozygote and wild-type littermates in all of the aforementioned paradigms and displayed phenotypes similar to wild-type animals or an intermediate state. From this, we conclude that the SNAP25Δ3 mutation does not behave in an autosomal dominant manner, but rather displays incomplete dominance for many phenotypes.
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Affiliation(s)
| | - Justice Simonetti
- Department of Pharmacology, Vanderbilt University, Nashville, TN, USA
| | - Feyisayo Adegboye
- Department of Pharmacology, Vanderbilt University, Nashville, TN, USA
| | - Carrie K Jones
- Department of Pharmacology, Vanderbilt University, Nashville, TN, USA.,Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University, Nashville, TN, USA
| | - Zack Zurawski
- Department of Pharmacology, Vanderbilt University, Nashville, TN, USA.,Department of Anatomy and Cell Biology, University of Illinois at Chicago, Chicago, IL, USA
| | - Heidi E Hamm
- Department of Pharmacology, Vanderbilt University, Nashville, TN, USA
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43
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Habib AM, Nagi K, Thillaiappan NB, Sukumaran V, Akhtar S. Vitamin D and Its Potential Interplay With Pain Signaling Pathways. Front Immunol 2020; 11:820. [PMID: 32547536 PMCID: PMC7270292 DOI: 10.3389/fimmu.2020.00820] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2019] [Accepted: 04/09/2020] [Indexed: 12/12/2022] Open
Abstract
About 50 million of the U.S. adult population suffer from chronic pain. It is a complex disease in its own right for which currently available analgesics have been deemed woefully inadequate since ~20% of the sufferers derive no benefit. Vitamin D, known for its role in calcium homeostasis and bone metabolism, is thought to be of clinical benefit in treating chronic pain without the side-effects of currently available analgesics. A strong correlation between hypovitaminosis D and incidence of bone pain is known. However, the potential underlying mechanisms by which vitamin D might exert its analgesic effects are poorly understood. In this review, we discuss pathways involved in pain sensing and processing primarily at the level of dorsal root ganglion (DRG) neurons and the potential interplay between vitamin D, its receptor (VDR) and known specific pain signaling pathways including nerve growth factor (NGF), glial-derived neurotrophic factor (GDNF), epidermal growth factor receptor (EGFR), and opioid receptors. We also discuss how vitamin D/VDR might influence immune cells and pain sensitization as well as review the increasingly important topic of vitamin D toxicity. Further in vitro and in vivo experimental studies will be required to study these potential interactions specifically in pain models. Such studies could highlight the potential usefulness of vitamin D either alone or in combination with existing analgesics to better treat chronic pain.
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Affiliation(s)
| | | | | | | | - Saghir Akhtar
- College of Medicine, QU Health, Qatar University, Doha, Qatar
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Targeting the CaVα-CaVβ interaction yields an antagonist of the N-type CaV2.2 channel with broad antinociceptive efficacy. Pain 2020; 160:1644-1661. [PMID: 30933958 DOI: 10.1097/j.pain.0000000000001524] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Inhibition of voltage-gated calcium (CaV) channels is a potential therapy for many neurological diseases including chronic pain. Neuronal CaV1/CaV2 channels are composed of α, β, γ and α2δ subunits. The β subunits of CaV channels are cytoplasmic proteins that increase the surface expression of the pore-forming α subunit of CaV. We targeted the high-affinity protein-protein interface of CaVβ's pocket within the CaVα subunit. Structure-based virtual screening of 50,000 small molecule library docked to the β subunit led to the identification of 2-(3,5-dimethylisoxazol-4-yl)-N-((4-((3-phenylpropyl)amino)quinazolin-2-yl)methyl)acetamide (IPPQ). This small molecule bound to CaVβ and inhibited its coupling with N-type voltage-gated calcium (CaV2.2) channels, leading to a reduction in CaV2.2 currents in rat dorsal root ganglion sensory neurons, decreased presynaptic localization of CaV2.2 in vivo, decreased frequency of spontaneous excitatory postsynaptic potentials and miniature excitatory postsynaptic potentials, and inhibited release of the nociceptive neurotransmitter calcitonin gene-related peptide from spinal cord. IPPQ did not target opioid receptors nor did it engage inhibitory G protein-coupled receptor signaling. IPPQ was antinociceptive in naive animals and reversed allodynia and hyperalgesia in models of acute (postsurgical) and neuropathic (spinal nerve ligation, chemotherapy- and gp120-induced peripheral neuropathy, and genome-edited neuropathy) pain. IPPQ did not cause akinesia or motor impairment, a common adverse effect of CaV2.2 targeting drugs, when injected into the brain. IPPQ, a quinazoline analog, represents a novel class of CaV2.2-targeting compounds that may serve as probes to interrogate CaVα-CaVβ function and ultimately be developed as a nonopioid therapeutic for chronic pain.
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45
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Dolphin AC, Lee A. Presynaptic calcium channels: specialized control of synaptic neurotransmitter release. Nat Rev Neurosci 2020; 21:213-229. [PMID: 32161339 PMCID: PMC7873717 DOI: 10.1038/s41583-020-0278-2] [Citation(s) in RCA: 112] [Impact Index Per Article: 28.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/12/2020] [Indexed: 11/09/2022]
Abstract
Chemical synapses are heterogeneous junctions formed between neurons that are specialized for the conversion of electrical impulses into the exocytotic release of neurotransmitters. Voltage-gated Ca2+ channels play a pivotal role in this process as they are the major conduits for the Ca2+ ions that trigger the fusion of neurotransmitter-containing vesicles with the presynaptic membrane. Alterations in the intrinsic function of these channels and their positioning within the active zone can profoundly alter the timing and strength of synaptic output. Advances in optical and electron microscopic imaging, structural biology and molecular techniques have facilitated recent breakthroughs in our understanding of the properties of voltage-gated Ca2+ channels that support their presynaptic functions. Here we examine the nature of these channels, how they are trafficked to and anchored within presynaptic boutons, and the mechanisms that allow them to function optimally in shaping the flow of information through neural circuits.
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Affiliation(s)
- Annette C Dolphin
- Department of Neuroscience, Physiology and Pharmacology, University College London, London, UK.
| | - Amy Lee
- Department of Molecular Physiology and Biophysics, University of Iowa, Iowa City, IA, USA.
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46
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Castro H, Bermeo K, Arenas I, Garcia DE. Maintenance of Ca V2.2 channel-current by PIP 2 unveiled by neomycin in sympathetic neurons of the rat. Arch Biochem Biophys 2020; 682:108261. [PMID: 31923392 DOI: 10.1016/j.abb.2020.108261] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2019] [Revised: 12/13/2019] [Accepted: 01/06/2020] [Indexed: 02/01/2023]
Abstract
Membrane lipids are key determinants in the regulation of voltage-gated ion channels. Phosphatidylinositol 4,5-bisphosphate (PIP2), a native membrane phospholipid, has been involved in the maintenance of the current amplitude and in the voltage-independent regulation of voltage-gated calcium channels (VGCC). However, the nature of the PIP2 regulation on VGCC has not been fully elucidated. This work aimed to investigate whether the interacting PIP2 electrostatic charges may account for maintaining the current amplitude of CaV2.2 channels. Furthermore, we tested whether charge shielding of PIP2 mimics the voltage-independent inhibition induced by M1 muscarinic acetylcholine receptor (M1R) activation. Therefore, neomycin, a polycation that has been shown to block electrostatic interactions of PIP2, was intracellularly dialyzed in superior cervical ganglion (SCG) neurons of the rat. Consistently, neomycin time-dependently diminished the calcium current amplitude letting the channel exhibit the hallmarks of the voltage-independent regulation. These results support that interacting PIP2 charges not only underly the maintenance of the channel-current but also that charge screening of PIP2 by itself unveils the voltage-independent features of CaV2.2 channels in SCG neurons.
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Affiliation(s)
- Hector Castro
- Department of Physiology, School of Medicine, Universidad Nacional Autónoma de México (UNAM), Apartado Postal 70250, C.P. 04510, CdMx, México
| | - Karina Bermeo
- Department of Physiology, School of Medicine, Universidad Nacional Autónoma de México (UNAM), Apartado Postal 70250, C.P. 04510, CdMx, México
| | - Isabel Arenas
- Department of Physiology, School of Medicine, Universidad Nacional Autónoma de México (UNAM), Apartado Postal 70250, C.P. 04510, CdMx, México
| | - David E Garcia
- Department of Physiology, School of Medicine, Universidad Nacional Autónoma de México (UNAM), Apartado Postal 70250, C.P. 04510, CdMx, México.
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47
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Birdsong WT, Williams JT. Recent Progress in Opioid Research from an Electrophysiological Perspective. Mol Pharmacol 2020; 98:401-409. [PMID: 32198208 PMCID: PMC7562972 DOI: 10.1124/mol.119.119040] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2019] [Accepted: 03/12/2020] [Indexed: 02/06/2023] Open
Abstract
Electrophysiological approaches provide powerful tools to further our understanding of how different opioids affect signaling through opioid receptors; how opioid receptors modulate circuitry involved in processes such as pain, respiration, addiction, and feeding; and how receptor signaling and circuits are altered by physiologic challenges, such as injury, stress, and chronic opioid treatment. The use of genetic manipulations to alter or remove μ-opioid receptors (MORs) with anatomic and cell type specificity and the ability to activate or inhibit specific circuits through opto- or chemogenetic approaches are being used in combination with electrophysiological, pharmacological, and systems-level physiology experiments to expand our understanding of the beneficial and maladaptive roles of opioids and opioid receptor signaling. New approaches for studying endogenous opioid peptide signaling and release and the dynamics of these systems in response to chronic opioid use, pain, and stress will add another layer to our understanding of the intricacies of opioid modulation of brain circuits. This understanding may lead to new targets or approaches for drug development or treatment regimens that may affect both acute and long-term effects of manipulating the activity of circuits involved in opioid-mediated physiology and behaviors. This review will discuss recent advancements in our understanding of the role of phosphorylation in regulating MOR signaling, as well as our understanding of circuits and signaling pathways mediating physiologic behaviors such as respiratory control, and discuss how electrophysiological tools combined with new technologies have and will continue to advance the field of opioid research.
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Affiliation(s)
- William T Birdsong
- Department of Pharmacology, University of Michigan, Ann Arbor, Michigan (W.T.B.) and Vollum Institute, Oregon Health & Science University, Portland, Oregon (J.T.W.)
| | - John T Williams
- Department of Pharmacology, University of Michigan, Ann Arbor, Michigan (W.T.B.) and Vollum Institute, Oregon Health & Science University, Portland, Oregon (J.T.W.)
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48
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Gandini MA, Souza IA, Raval D, Xu J, Pan YX, Zamponi GW. Differential regulation of Cav2.2 channel exon 37 variants by alternatively spliced μ-opioid receptors. Mol Brain 2019; 12:98. [PMID: 31775826 PMCID: PMC6880636 DOI: 10.1186/s13041-019-0524-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2019] [Accepted: 11/14/2019] [Indexed: 12/15/2022] Open
Abstract
We have examined the regulation of mutually exclusive Cav2.2 exon 37a and b variants by the mouse μ-opioid receptor (mMOR) C-terminal splice variants 1, 1C and 1O in tsA-201 cells. Electrophysiological analyses revealed that both channel isoforms exhibit DAMGO-induced voltage-dependent (Gβγ-mediated) inhibition and its recovery by voltage pre-pulses, as well as a voltage-independent component. However, the two channel isoforms differ in their relative extent of voltage-dependent and independent inhibition, with Cav2.2-37b showing significantly more voltage-dependent inhibition upon activation of the three mMOR receptors studied. In addition, coexpression of either mMOR1 or mMOR1C results in an agonist-independent reduction in the peak current density of Cav2.2-37a channels, whereas the peak current density of Cav2.2-37b does not appear to be affected. Interestingly, this decrease is not due to an effect on channel expression at the plasma membrane, as demonstrated by biotinylation experiments. We further examined the mechanism underlying the agonist-independent modulation of Cav2.2-37a by mMOR1C. Incubation of cells with pertussis toxin did not affect the mMOR1C mediated inhibition of Cav2.2-37a currents, indicating a lack of involvement of Gi/o signaling. However, when a Src tyrosine kinase inhibitor was applied, the effect of mMOR1C was lost. Moreover, when we recorded currents using a Cav2.2-37a mutant in which tyrosine 1747 was replaced with phenylalanine (Y1747F), the agonist independent effects of mMOR1C were abolished. Altogether our findings show that Cav2.2-37a and Cav2.2-37b isoforms are subject to differential regulation by C-terminal splice variants of mMORs, and that constitutive mMOR1C activity and downstream tyrosine kinase activity exert a selective inhibition of the Cav2.2-37a splice variant, an N-type channel isoform that is highly enriched in nociceptors. Our study provides new insights into the roles of the MOR full-length C-terminal variants in modulating Cav2.2 channel isoform activities.
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Affiliation(s)
- Maria A Gandini
- Department of Physiology and Pharmacology, Alberta Children's Hospital Research Institute, Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Ivana A Souza
- Department of Physiology and Pharmacology, Alberta Children's Hospital Research Institute, Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Dvij Raval
- Department of Physiology and Pharmacology, Alberta Children's Hospital Research Institute, Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Jin Xu
- Department of Neurology and the Molecular Pharmacology Program, Memorial Sloan-Kettering Cancer Center, New York, NY, USA
| | - Ying-Xian Pan
- Department of Neurology and the Molecular Pharmacology Program, Memorial Sloan-Kettering Cancer Center, New York, NY, USA
| | - Gerald W Zamponi
- Department of Physiology and Pharmacology, Alberta Children's Hospital Research Institute, Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada.
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Wei AD, Ramirez JM. Presynaptic Mechanisms and KCNQ Potassium Channels Modulate Opioid Depression of Respiratory Drive. Front Physiol 2019; 10:1407. [PMID: 31824331 PMCID: PMC6882777 DOI: 10.3389/fphys.2019.01407] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2019] [Accepted: 10/31/2019] [Indexed: 01/02/2023] Open
Abstract
Opioid-induced respiratory depression (OIRD) is the major cause of death associated with opioid analgesics and drugs of abuse, but the underlying cellular and molecular mechanisms remain poorly understood. We investigated opioid action in vivo in unanesthetized mice and in in vitro medullary slices containing the preBötzinger Complex (preBötC), a locus critical for breathing and inspiratory rhythm generation. Although hypothesized as a primary mechanism, we found that mu-opioid receptor (MOR1)-mediated GIRK activation contributed only modestly to OIRD. Instead, mEPSC recordings from genetically identified Dbx1-derived interneurons, essential for rhythmogenesis, revealed a prevalent presynaptic mode of action for OIRD. Consistent with MOR1-mediated suppression of presynaptic release as a major component of OIRD, Cacna1a KO slices lacking P/Q-type Ca2+ channels enhanced OIRD. Furthermore, OIRD was mimicked and reversed by KCNQ potassium channel activators and blockers, respectively. In vivo whole-body plethysmography combined with systemic delivery of GIRK- and KCNQ-specific potassium channel drugs largely recapitulated these in vitro results, and revealed state-dependent modulation of OIRD. We propose that respiratory failure from OIRD results from a general reduction of synaptic efficacy, leading to a state-dependent collapse of rhythmic network activity.
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Affiliation(s)
- Aguan D. Wei
- Seattle Children’s Research Institute, Center for Integrative Brain Research, Seattle, WA, United States
- Department of Neurological Surgery, University of Washington School of Medicine, Seattle, WA, United States
| | - Jan-Marino Ramirez
- Seattle Children’s Research Institute, Center for Integrative Brain Research, Seattle, WA, United States
- Department of Neurological Surgery, University of Washington School of Medicine, Seattle, WA, United States
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Dong N, Lee DWK, Sun HS, Feng ZP. Dopamine-mediated calcium channel regulation in synaptic suppression in L. stagnalis interneurons. Channels (Austin) 2019; 12:153-173. [PMID: 29589519 PMCID: PMC5972806 DOI: 10.1080/19336950.2018.1457897] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
D2 dopamine receptor-mediated suppression of synaptic transmission from interneurons plays a key role in neurobiological functions across species, ranging from respiration to memory formation. In this study, we investigated the mechanisms of D2 receptor-dependent suppression using soma-soma synapse between respiratory interneuron VD4 and LPeD1 in the mollusk Lymnaea stagnalis (L. stagnalis). We studied the effects of dopamine on voltage-dependent Ca2+ current and synaptic vesicle release from the VD4. We report that dopamine inhibits voltage-dependent Ca2+ current in the VD4 by both voltage-dependent and -independent mechanisms. Dopamine also suppresses synaptic vesicle release downstream of activity-dependent Ca2+ influx. Our study demonstrated that dopamine acts through D2 receptors to inhibit interneuron synaptic transmission through both voltage-dependent Ca2+ channel-dependent and -independent pathways. Taken together, these findings expand our understanding of dopamine function and fundamental mechanisms that shape the dynamics of neural circuit.
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Affiliation(s)
- Nancy Dong
- a Department of Physiology, Faculty of Medicine , University of Toronto , Toronto , ON , Canada
| | - David W K Lee
- a Department of Physiology, Faculty of Medicine , University of Toronto , Toronto , ON , Canada
| | - Hong-Shuo Sun
- a Department of Physiology, Faculty of Medicine , University of Toronto , Toronto , ON , Canada
| | - Zhong-Ping Feng
- a Department of Physiology, Faculty of Medicine , University of Toronto , Toronto , ON , Canada
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