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Huang Y, Chen SR, Pan HL. Calcineurin Regulates Synaptic Plasticity and Nociceptive Transmission at the Spinal Cord Level. Neuroscientist 2022; 28:628-638. [PMID: 34791930 DOI: 10.1177/10738584211046888] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Calcineurin, the predominant Ca2+/calmodulin-dependent serine/threonine protein phosphatase (also known as protein phosphatase 2B), is highly expressed in immune T cells and the nervous system, including the dorsal root ganglion and spinal cord. It controls synaptic transmission and plasticity by maintaining the appropriate phosphorylation status of many ion channels present at presynaptic and postsynaptic sites. As such, normal calcineurin activity in neurons and synapses is mainly involved in negative feedback regulation in response to increased neuronal activity and intracellular Ca2+ levels. Calcineurin inhibitors (e.g., cyclosporine and tacrolimus) are widely used as immunosuppressants in tissue and organ transplantation recipients and for treating autoimmune diseases but can cause severe pain in some patients. Furthermore, diminished calcineurin activity at the spinal cord level may play a major role in the transition from acute to chronic neuropathic pain after nerve injury. Restoring calcineurin activity at the spinal cord level produces long-lasting pain relief in animal models of neuropathic pain. In this article, we provide an overview of recent studies on the critical roles of calcineurin in regulating glutamate NMDA and AMPA receptors, voltage-gated Ca2+ channels, potassium channels, and transient receptor potential channels expressed in the spinal dorsal horn and primary sensory neurons.
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Affiliation(s)
- Yuying Huang
- Center for Neuroscience and Pain Research, Department of Anesthesiology and Perioperative Medicine, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Shao-Rui Chen
- Center for Neuroscience and Pain Research, Department of Anesthesiology and Perioperative Medicine, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Hui-Lin Pan
- Center for Neuroscience and Pain Research, Department of Anesthesiology and Perioperative Medicine, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
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2
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Barker KH, Higham JP, Pattison LA, Taylor TS, Chessell IP, Welsh F, Smith ESJ, Bulmer DC. Sensitisation of colonic nociceptors by TNFα is dependent on TNFR1 expression and p38 MAPK activity. J Physiol 2022; 600:3819-3836. [PMID: 35775903 PMCID: PMC9543404 DOI: 10.1113/jp283170] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2022] [Accepted: 06/28/2022] [Indexed: 11/23/2022] Open
Abstract
Abstract Visceral pain is a leading cause of morbidity in gastrointestinal diseases, which is exacerbated by the gut‐related side‐effects of many analgesics. New treatments are needed and further understanding of the mediators and mechanisms underpinning visceral nociception in disease states is required to facilitate this. The pro‐inflammatory cytokine TNFα is linked to pain in both patients with inflammatory bowel disease and irritable bowel syndrome, and has been shown to sensitize colonic sensory neurons. Somatic, TNFα‐triggered thermal and mechanical hypersensitivity is mediated by TRPV1 signalling and p38 MAPK activity respectively, downstream of TNFR1 receptor activation. We therefore hypothesized that TNFR1‐evoked p38 MAPK activity may also be responsible for TNFα sensitization of colonic afferent responses to the TRPV1 agonist capsaicin, and noxious distension of the bowel. Using Ca2+ imaging of dorsal root ganglion sensory neurons, we observed TNFα‐mediated increases in intracellular [Ca2+] and sensitization of capsaicin responses. The sensitizing effects of TNFα were dependent on TNFR1 expression and attenuated by p38 MAPK inhibition. Consistent with these findings, ex vivo colonic afferent fibre recordings demonstrated an enhanced response to noxious ramp distention of the bowel and bath application of capsaicin following TNFα pre‐treatment. Responses were reversed by p38 MAPK inhibition and absent in tissue from TNFR1 knockout mice. Our findings demonstrate a contribution of TNFR1, p38 MAPK and TRPV1 to TNFα‐induced sensitization of colonic afferents, highlighting the potential utility of these drug targets for the treatment of visceral pain in gastrointestinal disease.
![]() Key points The pro‐inflammatory cytokine TNFα is elevated in gastrointestinal disease and sensitizes colonic afferents via modulation of TRPA1 and NaV1.8 activity. We further develop this understanding by demonstrating a role for p38 MAPK and TRPV1 in TNFα‐mediated colonic afferent sensitization. Specifically, we show that: TNFα sensitizes sensory neurons and colonic afferents to the TRPV1 agonist capsaicin. TNFα‐mediated sensitization of sensory neurons and colonic nociceptors is dependent on TNFR1 expression. TNFα sensitization of sensory neurons and colonic afferents to capsaicin and noxious ramp distension is abolished by inhibition of p38 MAPK. Collectively these data support the utility of targeting TNFα, TNFR1 and their downstream signalling via p38 MAPK for the treatment of visceral pain in gastrointestinal disease.
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Affiliation(s)
- Katie H Barker
- Department of Pharmacology, University of Cambridge, Cambridge, CB2 1PD, UK
| | - James P Higham
- Department of Pharmacology, University of Cambridge, Cambridge, CB2 1PD, UK
| | - Luke A Pattison
- Department of Pharmacology, University of Cambridge, Cambridge, CB2 1PD, UK
| | - Toni S Taylor
- Department of Pharmacology, University of Cambridge, Cambridge, CB2 1PD, UK
| | - Iain P Chessell
- Neuroscience, BioPharmaceuticals R&D, AstraZeneca, Cambridge, UK
| | - Fraser Welsh
- Neuroscience, BioPharmaceuticals R&D, AstraZeneca, Cambridge, UK
| | - Ewan St J Smith
- Department of Pharmacology, University of Cambridge, Cambridge, CB2 1PD, UK
| | - David C Bulmer
- Department of Pharmacology, University of Cambridge, Cambridge, CB2 1PD, UK
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3
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Scorpion Venom peptide, AGAP inhibits TRPV1 and potentiates the analgesic effect of lidocaine. Heliyon 2021; 7:e08560. [PMID: 35005265 PMCID: PMC8715296 DOI: 10.1016/j.heliyon.2021.e08560] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Revised: 07/04/2021] [Accepted: 12/01/2021] [Indexed: 11/20/2022] Open
Abstract
The current study was designed to test the hypothesis that BmK AGAP (AGAP) potentiates the analgesic effect of lidocaine. The chronic constrictive injury was performed on 72 rats to induce a rapid onset and long-lasting pain. The rats were randomly assigned to one of six groups; Group A (n = 12) received an intrathecal administration of saline, Group B (n = 12) received an intrathecal injection of lidocaine, Group C (n = 12) received an intrathecal administration of AGAP, Group D, E, and F (n = 12 each) received an intrathecal administration of lidocaine 0.005 mg/ml + AGAP 25, 50, 100 μg/kg respectively. The von Frey filaments were used to assess mechanical allodynia. Nav1.7 and TRPV1 currents were recorded by the whole-cell aspiration patch-clamp technique, and KCNQ2/3 currents were recorded by the whole-cell drilling patch-clamp technique. The whole-cell aspiration patch-clamp technique showed that AGAP inhibited TRPV1and KCNQ2/3 currents and increased the analgesic effect of lidocaine. AGAP may have a synergistic effect with lidocaine which demonstrates a potential therapeutic approach for optimizing post-operative analgesia.
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Zhang D, Men H, Zhang L, Gao X, Wang J, Li L, Zhu Q, Zhang H, Jia Z. Inhibition of M/K v7 Currents Contributes to Chloroquine-Induced Itch in Mice. Front Mol Neurosci 2020; 13:105. [PMID: 32694980 PMCID: PMC7339983 DOI: 10.3389/fnmol.2020.00105] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2019] [Accepted: 05/20/2020] [Indexed: 01/31/2023] Open
Abstract
M/Kv7 potassium channels play a key role in regulation of neuronal excitability. Modulation of neuronal excitability of primary sensory neurons determines the itch sensation induced by a variety of itch-causing substances including chloroquine (CQ). In the present study, we demonstrate that suppression of M/Kv7 channel activity contributes to generation of itch in mice. CQ enhances excitability of the primary sensory neurons through inhibiting M/Kv7 potassium currents in a Ca2+ influx-dependent manner. Specific M/Kv7 channel opener retigabine (RTG) or tannic acid (TA) not only reverses the CQ-induced enhancement of neuronal excitability but also suppresses the CQ-induced itch behavior. Systemic application of RTG or TA also significantly inhibits the itch behavior induced by a variety of pruritogens. Taken together, our findings provide novel insight into the molecular basis of CQ-induced itch sensation in mammals that can be applied to the development of strategies to mitigate itch behavior.
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Affiliation(s)
- Dong Zhang
- Department of Pharmacology, Hebei Medical University, Shijiazhuang, China.,Center for Innovative Drug Research and Evaluation, Institute of Medical Science and Health, Hebei Medical University, Shijiazhuang, China.,The Key Laboratory of Neural and Vascular Biology, Ministry of Education, Shijiazhuang, China.,The Key Laboratory of New Drug Pharmacology and Toxicology, Shijiazhuang, China.,Department of Anesthesiology, Hebei General Hospital, Shijiazhuang, China
| | - Hongchao Men
- Department of Pharmacology, Hebei Medical University, Shijiazhuang, China.,Center for Innovative Drug Research and Evaluation, Institute of Medical Science and Health, Hebei Medical University, Shijiazhuang, China.,The Key Laboratory of Neural and Vascular Biology, Ministry of Education, Shijiazhuang, China.,The Key Laboratory of New Drug Pharmacology and Toxicology, Shijiazhuang, China.,Department of Anesthesiology, Hebei General Hospital, Shijiazhuang, China
| | - Ludi Zhang
- Department of Pharmacology, Hebei Medical University, Shijiazhuang, China.,Center for Innovative Drug Research and Evaluation, Institute of Medical Science and Health, Hebei Medical University, Shijiazhuang, China.,The Key Laboratory of Neural and Vascular Biology, Ministry of Education, Shijiazhuang, China.,The Key Laboratory of New Drug Pharmacology and Toxicology, Shijiazhuang, China
| | - Xiangxin Gao
- Department of Pharmacology, Hebei Medical University, Shijiazhuang, China.,Center for Innovative Drug Research and Evaluation, Institute of Medical Science and Health, Hebei Medical University, Shijiazhuang, China.,The Key Laboratory of Neural and Vascular Biology, Ministry of Education, Shijiazhuang, China.,The Key Laboratory of New Drug Pharmacology and Toxicology, Shijiazhuang, China
| | - Jingjing Wang
- Department of Pharmacology, Hebei Medical University, Shijiazhuang, China.,Center for Innovative Drug Research and Evaluation, Institute of Medical Science and Health, Hebei Medical University, Shijiazhuang, China.,The Key Laboratory of Neural and Vascular Biology, Ministry of Education, Shijiazhuang, China.,The Key Laboratory of New Drug Pharmacology and Toxicology, Shijiazhuang, China
| | - Leying Li
- Department of Pharmacology, Hebei Medical University, Shijiazhuang, China.,Center for Innovative Drug Research and Evaluation, Institute of Medical Science and Health, Hebei Medical University, Shijiazhuang, China.,The Key Laboratory of Neural and Vascular Biology, Ministry of Education, Shijiazhuang, China.,The Key Laboratory of New Drug Pharmacology and Toxicology, Shijiazhuang, China
| | - Qiaoying Zhu
- Department of Pharmacology, Hebei Medical University, Shijiazhuang, China.,Center for Innovative Drug Research and Evaluation, Institute of Medical Science and Health, Hebei Medical University, Shijiazhuang, China.,The Key Laboratory of Neural and Vascular Biology, Ministry of Education, Shijiazhuang, China.,The Key Laboratory of New Drug Pharmacology and Toxicology, Shijiazhuang, China
| | - Hailin Zhang
- Department of Pharmacology, Hebei Medical University, Shijiazhuang, China.,Center for Innovative Drug Research and Evaluation, Institute of Medical Science and Health, Hebei Medical University, Shijiazhuang, China.,The Key Laboratory of Neural and Vascular Biology, Ministry of Education, Shijiazhuang, China.,The Key Laboratory of New Drug Pharmacology and Toxicology, Shijiazhuang, China
| | - Zhanfeng Jia
- Department of Pharmacology, Hebei Medical University, Shijiazhuang, China.,Center for Innovative Drug Research and Evaluation, Institute of Medical Science and Health, Hebei Medical University, Shijiazhuang, China.,The Key Laboratory of Neural and Vascular Biology, Ministry of Education, Shijiazhuang, China.,The Key Laboratory of New Drug Pharmacology and Toxicology, Shijiazhuang, China
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5
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Ambrosino P, Soldovieri MV, Di Zazzo E, Paventi G, Iannotti FA, Mosca I, Miceli F, Franco C, Canzoniero LMT, Taglialatela M. Activation of Kv7 Potassium Channels Inhibits Intracellular Ca 2+ Increases Triggered By TRPV1-Mediated Pain-Inducing Stimuli in F11 Immortalized Sensory Neurons. Int J Mol Sci 2019; 20:ijms20184322. [PMID: 31487785 PMCID: PMC6769798 DOI: 10.3390/ijms20184322] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2019] [Revised: 09/01/2019] [Accepted: 09/02/2019] [Indexed: 12/11/2022] Open
Abstract
Kv7.2-Kv7.5 channels mediate the M-current (IKM), a K+-selective current regulating neuronal excitability and representing an attractive target for pharmacological therapy against hyperexcitability diseases such as pain. Kv7 channels interact functionally with transient receptor potential vanilloid 1 (TRPV1) channels activated by endogenous and/or exogenous pain-inducing substances, such as bradykinin (BK) or capsaicin (CAP), respectively; however, whether Kv7 channels of specific molecular composition provide a dominant contribution in BK- or CAP-evoked responses is yet unknown. To this aim, Kv7 transcripts expression and function were assessed in F11 immortalized sensorial neurons, a cellular model widely used to assess nociceptive molecular mechanisms. In these cells, the effects of the pan-Kv7 activator retigabine were investigated, as well as the effects of ICA-27243 and (S)-1, two Kv7 activators acting preferentially on Kv7.2/Kv7.3 and Kv7.4/Kv7.5 channels, respectively, on BK- and CAP-induced changes in intracellular Ca2+ concentrations ([Ca2+]i). The results obtained revealed the expression of transcripts of all Kv7 genes, leading to an IKM-like current. Moreover, all tested Kv7 openers inhibited BK- and CAP-induced responses by a similar extent (~60%); at least for BK-induced Ca2+ responses, the potency of retigabine (IC50~1 µM) was higher than that of ICA-27243 (IC50~5 µM) and (S)-1 (IC50~7 µM). Altogether, these results suggest that IKM activation effectively counteracts the cellular processes triggered by TRPV1-mediated pain-inducing stimuli, and highlight a possible critical contribution of Kv7.4 subunits.
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Affiliation(s)
- Paolo Ambrosino
- Department of Science and Technology, University of Sannio, 82100 Benevento, Italy
| | - Maria Virginia Soldovieri
- Department of Medicine and Health Sciences "V. Tiberio", University of Molise, 86100 Campobasso, Italy
| | - Erika Di Zazzo
- Department of Medicine and Health Sciences "V. Tiberio", University of Molise, 86100 Campobasso, Italy
| | - Gianluca Paventi
- Department of Medicine and Health Sciences "V. Tiberio", University of Molise, 86100 Campobasso, Italy
| | - Fabio Arturo Iannotti
- Institute of Biomolecular Chemistry, National Research Council, Pozzuoli, 80121 Naples, Italy
| | - Ilaria Mosca
- Department of Medicine and Health Sciences "V. Tiberio", University of Molise, 86100 Campobasso, Italy
| | - Francesco Miceli
- Division of Pharmacology, Department of Neuroscience, University of Naples "Federico II", 80131 Naples, Italy
| | - Cristina Franco
- Department of Science and Technology, University of Sannio, 82100 Benevento, Italy
| | | | - Maurizio Taglialatela
- Division of Pharmacology, Department of Neuroscience, University of Naples "Federico II", 80131 Naples, Italy.
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6
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Wild AR, Dell'Acqua ML. Potential for therapeutic targeting of AKAP signaling complexes in nervous system disorders. Pharmacol Ther 2017; 185:99-121. [PMID: 29262295 DOI: 10.1016/j.pharmthera.2017.12.004] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
A common feature of neurological and neuropsychiatric disorders is a breakdown in the integrity of intracellular signal transduction pathways. Dysregulation of ion channels and receptors in the cell membrane and the enzymatic mediators that link them to intracellular effectors can lead to synaptic dysfunction and neuronal death. However, therapeutic targeting of these ubiquitous signaling elements can lead to off-target side effects due to their widespread expression in multiple systems of the body. A-kinase anchoring proteins (AKAPs) are multivalent scaffolding proteins that compartmentalize a diverse range of receptor and effector proteins to streamline signaling within nanodomain signalosomes. A number of essential neurological processes are known to critically depend on AKAP-directed signaling and an understanding of the role AKAPs play in nervous system disorders has emerged in recent years. Selective targeting of AKAP protein-protein interactions may be a means to uncouple pathologically active signaling pathways in neurological disorders with a greater degree of specificity. In this review we will discuss the role of AKAPs in both regulating normal nervous system function and dysfunction associated with disease, and the potential for therapeutic targeting of AKAP signaling complexes.
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Affiliation(s)
- Angela R Wild
- Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - Mark L Dell'Acqua
- Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO 80045, USA.
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7
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Zhang J, Carver CM, Choveau FS, Shapiro MS. Clustering and Functional Coupling of Diverse Ion Channels and Signaling Proteins Revealed by Super-resolution STORM Microscopy in Neurons. Neuron 2016; 92:461-478. [PMID: 27693258 DOI: 10.1016/j.neuron.2016.09.014] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2016] [Revised: 06/24/2016] [Accepted: 08/26/2016] [Indexed: 11/25/2022]
Abstract
The fidelity of neuronal signaling requires organization of signaling molecules into macromolecular complexes, whose components are in intimate proximity. The intrinsic diffraction limit of light makes visualization of individual signaling complexes using visible light extremely difficult. However, using super-resolution stochastic optical reconstruction microscopy (STORM), we observed intimate association of individual molecules within signaling complexes containing ion channels (M-type K+, L-type Ca2+, or TRPV1 channels) and G protein-coupled receptors coupled by the scaffolding protein A-kinase-anchoring protein (AKAP)79/150. Some channels assembled as multi-channel supercomplexes. Surprisingly, we identified novel layers of interplay within macromolecular complexes containing diverse channel types at the single-complex level in sensory neurons, dependent on AKAP79/150. Electrophysiological studies revealed that such ion channels are functionally coupled as well. Our findings illustrate the novel role of AKAP79/150 as a molecular coupler of different channels that conveys crosstalk between channel activities within single microdomains in tuning the physiological response of neurons.
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Affiliation(s)
- Jie Zhang
- Department of Physiology, University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, USA
| | - Chase M Carver
- Department of Physiology, University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, USA
| | - Frank S Choveau
- Department of Physiology, University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, USA
| | - Mark S Shapiro
- Department of Physiology, University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, USA.
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8
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TRPV1: A Target for Rational Drug Design. Pharmaceuticals (Basel) 2016; 9:ph9030052. [PMID: 27563913 PMCID: PMC5039505 DOI: 10.3390/ph9030052] [Citation(s) in RCA: 73] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2016] [Revised: 08/12/2016] [Accepted: 08/18/2016] [Indexed: 12/18/2022] Open
Abstract
Transient Receptor Potential Vanilloid 1 (TRPV1) is a non-selective, Ca2+ permeable cation channel activated by noxious heat, and chemical ligands, such as capsaicin and resiniferatoxin (RTX). Many compounds have been developed that either activate or inhibit TRPV1, but none of them are in routine clinical practice. This review will discuss the rationale for antagonists and agonists of TRPV1 for pain relief and other conditions, and strategies to develop new, better drugs to target this ion channel, using the newly available high-resolution structures.
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9
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Rohacs T. Phosphoinositide signaling in somatosensory neurons. Adv Biol Regul 2016; 61:2-16. [PMID: 26724974 PMCID: PMC4884561 DOI: 10.1016/j.jbior.2015.11.012] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2015] [Revised: 11/06/2015] [Accepted: 11/07/2015] [Indexed: 02/03/2023]
Abstract
Somatosensory neurons of the dorsal root ganglia (DRG) and trigeminal ganglia (TG) are responsible for detecting thermal and tactile stimuli. They are also the primary neurons mediating pain and itch. A large number of cell surface receptors in these neurons couple to phospholipase C (PLC) enzymes leading to the hydrolysis of phosphatidylinositol 4,5-bisphosphate [PI(4,5)P2] and the generation of downstream signaling molecules. These neurons also express many different ion channels, several of which are regulated by phosphoinositides. This review will summarize the knowledge on phosphoinositide signaling in DRG neurons, with special focus on effects on sensory and other ion channels.
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Affiliation(s)
- Tibor Rohacs
- Rutgers, New Jersey Medical School, Newark, NJ, USA.
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10
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Shudo Y, Shimojo M, Fukunaga M, Ito S. Pituitary adenylate cyclase-activating polypeptide is regulated by alternative splicing of transcriptional repressor REST/NRSF in nerve injury. Life Sci 2015; 143:174-81. [PMID: 26518165 DOI: 10.1016/j.lfs.2015.10.033] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2015] [Revised: 09/28/2015] [Accepted: 10/26/2015] [Indexed: 12/22/2022]
Abstract
AIMS The pathophysiological mechanism for neuropathic pain (NP), one of the most common types of intractable pain, remains largely unknown. We previously reported that pituitary adenylate-cyclase activating polypeptide (PACAP) is required for the development of spinal sensitization and induction of NP. Previous in vitro studies suggest that PACAP transcription unit has two RE1-like elements and that the transcriptional repressor REST controls expression of PACAP gene. However the regulation of PACAP gene through its RE1 sites in vivo has not been studied. We have analyzed the functional role of PACAP gene RE1 element following nerve injury. MAIN METHODS An L5-spinal nerve transection (L5-SNT) in mice was used as a model of spinal injury. DRGs after the L5-SNT were studied. KEY FINDINGS PACAP mRNA increased in the DRG following spinal nerve injury. REST4, an alternatively spliced isoform of REST was shown to be regulated by the splicing activator (nSR100) and nSR100 itself also increased. Overexpression of either REST4 or nSR100 in vitro increased PACAP expression, while overexpression of REST repressed PACAP mRNA production. Reporter gene analysis showed that a novel RE1 previously predicted by in silico analysis was indeed functional. ChIP analysis showed that REST bound significantly to this RE1 in the DRG of naïve mice, while REST binding to this RE1 was decreased following spinal nerve injury. The expression of REST was decreased by nSR100-dependent alternative splicing of the REST gene, leading to derepression of PACAP. SIGNIFICANCE PACAP expression in the DRG following spinal nerve injury is controlled through a novel RE1 by REST.
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Affiliation(s)
- Yoshie Shudo
- Department of Medical Chemistry, Kansai Medical University, Osaka, Japan; Department of Psychosomatic Medicine, Kansai Medical University, Osaka, Japan
| | - Masahito Shimojo
- Department of Medical Chemistry, Kansai Medical University, Osaka, Japan.
| | - Mikihiko Fukunaga
- Department of Psychosomatic Medicine, Kansai Medical University, Osaka, Japan
| | - Seiji Ito
- Department of Medical Chemistry, Kansai Medical University, Osaka, Japan
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11
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Li C, Huang P, Lu Q, Zhou M, Guo L, Xu X. KCNQ/Kv7 channel activator flupirtine protects against acute stress-induced impairments of spatial memory retrieval and hippocampal LTP in rats. Neuroscience 2014; 280:19-30. [PMID: 25234320 DOI: 10.1016/j.neuroscience.2014.09.009] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2013] [Revised: 09/03/2014] [Accepted: 09/05/2014] [Indexed: 12/17/2022]
Abstract
Spatial memory retrieval and hippocampal long-term potentiation (LTP) are impaired by stress. KCNQ/Kv7 channels are closely associated with memory and the KCNQ/Kv7 channel activator flupirtine represents neuroprotective effects. This study aims to test whether KCNQ/Kv7 channel activation prevents acute stress-induced impairments of spatial memory retrieval and hippocampal LTP. Rats were placed on an elevated platform in the middle of a bright room for 30 min to evoke acute stress. The expression of KCNQ/Kv7 subunits was analyzed at 1, 3 and 12 h after stress by Western blotting. Spatial memory was examined by the Morris water maze (MWM) and the field excitatory postsynaptic potential (fEPSP) in the hippocampal CA1 area was recorded in vivo. Acute stress transiently decreased the expression of KCNQ2 and KCNQ3 in the hippocampus. Acute stress impaired the spatial memory retrieval and hippocampal LTP, the KCNQ/Kv7 channel activator flupirtine prevented the impairments, and the protective effects of flupirtine were blocked by XE-991 (10,10-bis(4-Pyridinylmethyl)-9(10H)-anthracenone), a selective KCNQ channel blocker. Furthermore, acute stress decreased the phosphorylation of glycogen synthase kinase-3β (GSK-3β) at Ser9 in the hippocampus, and flupirtine inhibited the reduction. These results suggest that the KCNQ/Kv7 channels may be a potential target for protecting both hippocampal synaptic plasticity and spatial memory retrieval from acute stress influences.
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Affiliation(s)
- C Li
- Department of Pharmacology, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China
| | - P Huang
- Department of Pharmacology, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Q Lu
- Department of Pharmacology, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China; The Key Laboratory for Drug Target Researches and Pharmacodynamic Evaluation of Hubei Province, Wuhan 430030, China
| | - M Zhou
- Department of Pharmacology, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China
| | - L Guo
- Department of Pharmacology, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China; The Key Laboratory for Drug Target Researches and Pharmacodynamic Evaluation of Hubei Province, Wuhan 430030, China
| | - X Xu
- Department of Pharmacology, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China; The Key Laboratory for Drug Target Researches and Pharmacodynamic Evaluation of Hubei Province, Wuhan 430030, China.
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12
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Kornilov P, Peretz A, Lee Y, Son K, Lee JH, Refaeli B, Roz N, Rehavi M, Choi S, Attali B. Promiscuous gating modifiers target the voltage sensor of K(v)7.2, TRPV1, and H(v)1 cation channels. FASEB J 2014; 28:2591-602. [PMID: 24599966 DOI: 10.1096/fj.14-250647] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Some of the fascinating features of voltage-sensing domains (VSDs) in voltage-gated cation channels (VGCCs) are their modular nature and adaptability. Here we examined the VSD sensitivity of different VGCCs to 2 structurally related nontoxin gating modifiers, NH17 and NH29, which stabilize K(v)7.2 potassium channels in the closed and open states, respectively. The effects of NH17 and NH29 were examined in Chinese hamster ovary cells transfected with transient receptor potential vanilloid 1 (TRPV1) or K(v)7.2 channels, as well as in dorsal root ganglia neurons, using the whole-cell patch-clamp technique. NH17 and NH29 exert opposite effects on TRPV1 channels, operating, respectively, as an activator and a blocker of TRPV1 currents (EC50 and IC50 values ranging from 4 to 40 μM). Combined mutagenesis, electrophysiology, structural homology modeling, molecular docking, and molecular dynamics simulation indicate that both compounds target the VSDs of TRPV1 channels, which, like vanilloids, are involved in π-π stacking, H-bonding, and hydrophobic interactions. Reflecting their promiscuity, the drugs also affect the lone VSD proton channel mVSOP. Thus, the same gating modifier can promiscuously interact with different VGCCs, and subtle differences at the VSD-ligand interface will dictate whether the gating modifier stabilizes channels in either the closed or the open state.
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Affiliation(s)
- Polina Kornilov
- Department of Physiology and Pharmacology, The Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel; and
| | - Asher Peretz
- Department of Physiology and Pharmacology, The Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel; and
| | - Yoonji Lee
- National Leading Research Laboratory of Molecular Modeling and Drug Design, College of Pharmacy, Graduate School of Pharmaceutical Sciences, and Global Top5 Research Program, Ewha Womans University, Seoul, Korea
| | - Karam Son
- National Leading Research Laboratory of Molecular Modeling and Drug Design, College of Pharmacy, Graduate School of Pharmaceutical Sciences, and Global Top5 Research Program, Ewha Womans University, Seoul, Korea
| | - Jin Hee Lee
- National Leading Research Laboratory of Molecular Modeling and Drug Design, College of Pharmacy, Graduate School of Pharmaceutical Sciences, and Global Top5 Research Program, Ewha Womans University, Seoul, Korea
| | - Bosmat Refaeli
- Department of Physiology and Pharmacology, The Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel; and
| | - Netta Roz
- Department of Physiology and Pharmacology, The Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel; and
| | - Moshe Rehavi
- Department of Physiology and Pharmacology, The Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel; and
| | - Sun Choi
- National Leading Research Laboratory of Molecular Modeling and Drug Design, College of Pharmacy, Graduate School of Pharmaceutical Sciences, and Global Top5 Research Program, Ewha Womans University, Seoul, Korea
| | - Bernard Attali
- Department of Physiology and Pharmacology, The Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel; and
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13
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Kim YS, Chu Y, Han L, Li M, Li Z, LaVinka PC, Sun S, Tang Z, Park K, Caterina MJ, Ren K, Dubner R, Wei F, Dong X. Central terminal sensitization of TRPV1 by descending serotonergic facilitation modulates chronic pain. Neuron 2014; 81:873-887. [PMID: 24462040 DOI: 10.1016/j.neuron.2013.12.011] [Citation(s) in RCA: 233] [Impact Index Per Article: 23.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/02/2013] [Indexed: 01/05/2023]
Abstract
The peripheral terminals of primary nociceptive neurons play an essential role in pain detection mediated by membrane receptors like TRPV1, a molecular sensor of heat and capsaicin. However, the contribution of central terminal TRPV1 in the dorsal horn to chronic pain has not been investigated directly. Combining primary sensory neuron-specific GCaMP3 imaging with a trigeminal neuropathic pain model, we detected robust neuronal hyperactivity in injured and uninjured nerves in the skin, soma in trigeminal ganglion, and central terminals in the spinal trigeminal nucleus. Extensive TRPV1 hyperactivity was observed in central terminals innervating all dorsal horn laminae. The central terminal TRPV1 sensitization was maintained by descending serotonergic (5-HT) input from the brainstem. Central blockade of TRPV1 or 5-HT/5-HT3A receptors attenuated central terminal sensitization, excitatory primary afferent inputs, and mechanical hyperalgesia in the territories of injured and uninjured nerves. Our results reveal central mechanisms facilitating central terminal sensitization underlying chronic pain.
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Affiliation(s)
- Yu Shin Kim
- Department of Neuroscience, Center of Sensory Biology, the Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Yuxia Chu
- Department of Neural and Pain Sciences, Program in Neuroscience, Dental School, University of Maryland, Baltimore, Maryland 21201
| | - Liang Han
- Department of Neuroscience, Center of Sensory Biology, the Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Man Li
- Department of Neural and Pain Sciences, Program in Neuroscience, Dental School, University of Maryland, Baltimore, Maryland 21201.,Department of Anesthesiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Zhe Li
- Department of Neuroscience, Center of Sensory Biology, the Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Pamela Colleen LaVinka
- Department of Neuroscience, Center of Sensory Biology, the Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Shuohao Sun
- Department of Neuroscience, Center of Sensory Biology, the Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | | | - Kyoungsook Park
- Department of Neuroscience, Center of Sensory Biology, the Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Michael J Caterina
- Department of Neuroscience, Center of Sensory Biology, the Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.,Department of Biological Chemistry, the Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Ke Ren
- Department of Neural and Pain Sciences, Program in Neuroscience, Dental School, University of Maryland, Baltimore, Maryland 21201
| | - Ronald Dubner
- Department of Neural and Pain Sciences, Program in Neuroscience, Dental School, University of Maryland, Baltimore, Maryland 21201
| | - Feng Wei
- Department of Neural and Pain Sciences, Program in Neuroscience, Dental School, University of Maryland, Baltimore, Maryland 21201
| | - Xinzhong Dong
- Department of Neuroscience, Center of Sensory Biology, the Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.,Howard Hughes Medical Institute, the Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
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14
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Kv7/M-type potassium channels in rat skin keratinocytes. Pflugers Arch 2013; 465:1371-81. [PMID: 23592175 PMCID: PMC3745621 DOI: 10.1007/s00424-013-1276-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2013] [Revised: 03/19/2013] [Accepted: 03/22/2013] [Indexed: 11/25/2022]
Abstract
Skin keratinocytes fulfil important signalling and protective functions. Immunocytochemical experiments revealed the unexpected presence of immunoreactivity for the M-type potassium channel subunit Kv7.2 in the keratinocyte layer of intact rat paw skin and in keratinocytes isolated from the skin of 1-day-old rats and cultured in vitro for 3–10 days. Application of the M-channel enhancer retigabine (3–10 μM) to isolated cultured rat keratinocytes: (a) increased outward membrane currents recorded under voltage clamp, (b) produced ~3 mV hyperpolarization at rest, (c) enhanced ~3-fold the release of ATP induced by the TRPV3 agonist carvacrol (1 mM) and (d) increased the amplitude of the carvacrol-induced intracellular Ca2+ transient measured with Fura-2. The effect of retigabine on ATP release was prevented by the M-channel blocking agent XE991. We conclude that rat skin keratinocytes possess M-channels that, when activated, can modify their physiological properties, with potential significance for their sensory and other biological functions.
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15
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Zhang XF, Zhang D, Surowy CS, Yao B, Jarvis MF, McGaraughty S, Neelands TR. Development and validation of a medium-throughput electrophysiological assay for KCNQ2/3 channel openers using QPatch HT. Assay Drug Dev Technol 2012; 11:17-24. [PMID: 23002961 DOI: 10.1089/adt.2012.446] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The KCNQ2/3 channel has emerged as a drug target for a number of neurological disorders including pain and epilepsy. Known KCNQ2/3 openers have effects on two distinct biophysical properties of the channel: (1) a hyperpolarizing shift in the voltage dependence of channel activation (V(1/2)), and (2) an increase in channel open probability or peak whole-cell current. The current high-throughput screening assays for KCNQ2/3 openers measure changes of channel activity at sub-peak conductances and the output measure is a combination of effects on V(1/2) shift and peak current. Here, we describe a medium-throughput electrophysiological assay for screening KCNQ2/3 openers using the QPatch HT platform. We employed a double-pulse protocol that measures the shift in V(1/2) and the change in current amplitude at peak conductance voltage. Retigabine along with novel KCNQ2/3 openers were evaluated in this assay. Three classes of KCNQ2/3 openers were identified based on the hyperpolarizing shift in V(1/2) and the change in peak current. All three classes of compounds caused a hyperpolarizing shift in V(1/2), but they were differentiated by their respective effects on peak current amplitude (increase, decrease, or only modestly affecting peak current amplitude). KCNQ2/3 blockers were also identified with this assay. These compounds blocked currents without affecting voltage-dependent activation. In summary, we have developed a medium-throughput assay that can reliably detect changes in the biophysical properties of the KCNQ2/3 channel, V(1/2), and peak current amplitude, and therefore may serve as a reliable assay to evaluate KCNQ2/3 openers and blockers.
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Affiliation(s)
- Xu-Feng Zhang
- Neuroscience Research, Global Pharmaceutical Research and Development, Abbott Laboratories, Abbott Park, Illinois 60064-6125, USA.
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16
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Baumgärtel K, Mansuy IM. Neural functions of calcineurin in synaptic plasticity and memory. Learn Mem 2012; 19:375-84. [PMID: 22904368 DOI: 10.1101/lm.027201.112] [Citation(s) in RCA: 127] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Major brain functions depend on neuronal processes that favor the plasticity of neuronal circuits while at the same time maintaining their stability. The mechanisms that regulate brain plasticity are complex and engage multiple cascades of molecular components that modulate synaptic efficacy. Protein kinases (PKs) and phosphatases (PPs) are among the most important of these components that act as positive and negative regulators of neuronal signaling and plasticity, respectively. In these cascades, the PP protein phosphatase 2B or calcineurin (CaN) is of particular interest because it is the only Ca(2+)-activated PP in the brain and a major regulator of key proteins essential for synaptic transmission and neuronal excitability. This review describes the primary properties of CaN and illustrates its functions and modes of action by focusing on several representative targets, in particular glutamate receptors, striatal enriched protein phosphatase (STEP), and neuromodulin (GAP43), and their functional significance for synaptic plasticity and memory.
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Affiliation(s)
- Karsten Baumgärtel
- Dorris Neuroscience Center, Department of Cell Biology, The Scripps Research Institute, La Jolla, California 92037-1000, USA
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17
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Calcium-dependent inhibition of T-type calcium channels by TRPV1 activation in rat sensory neurons. Pflugers Arch 2011; 462:709-22. [PMID: 21904821 DOI: 10.1007/s00424-011-1023-5] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2011] [Revised: 08/23/2011] [Accepted: 08/24/2011] [Indexed: 10/17/2022]
Abstract
We studied the inhibitory effects of transient receptor potential vanilloid-1 (TRPV1) activation by capsaicin on low-voltage-activated (LVA, T-type) Ca(2+) channel and high-voltage-activated (HVA; L, N, P/Q, R) currents in rat DRG sensory neurons, as a potential mechanism underlying capsaicin-induced analgesia. T-type and HVA currents were elicited in whole-cell clamped DRG neurons using ramp commands applied before and after 30-s exposures to 1 μM capsaicin. T-type currents were estimated at the first peak of the I-V characteristics and HVA at the second peak, occurring at more positive potentials. Small and medium-sized DRG neurons responded to capsaicin producing transient inward currents of variable amplitudes, mainly carried by Ca(2+). In those cells responding to capsaicin with a large Ca(2+) influx (59% of the total), a marked inhibition of both T-type and HVA Ca(2+) currents was observed. The percentage of T-type and HVA channel inhibition was prevented by replacing Ca(2+) with Ba(2+) during capsaicin application or applying high doses of intracellular BAPTA (20 mM), suggesting that TRPV1-mediated inhibition of T-type and HVA channels is Ca(2+)-dependent and likely confined to membrane nano-microdomains. Our data are consistent with the idea that TRPV1-induced analgesia may derive from indirect inhibition of both T-type and HVA channels which, in turn, would reduce the threshold of nociceptive signals generation (T-type channel inhibition) and nociceptive synaptic transmission (HVA-channels inhibition).
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