1
|
Stover L, Zhu Y, Schrecke S, Laganowsky A. TREK2 Lipid Binding Preferences Revealed by Native Mass Spectrometry. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2024; 35:1516-1522. [PMID: 38843438 DOI: 10.1021/jasms.4c00112] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/04/2024]
Abstract
TREK2, a two-pore domain potassium channel, is recognized for its regulation by various stimuli, including lipids. While previous members of the TREK subfamily, TREK1 and TRAAK, have been investigated to elucidate their lipid affinity and selectivity, TREK2 has not been similarly studied in this regard. Our findings indicate that while TRAAK and TREK2 exhibit similarities in terms of electrostatics and share an overall structural resemblance, there are notable distinctions in their interaction with lipids. Specifically, SAPI(4,5)P2,1-stearoyl-2-arachidonoyl-sn-glycero-3-phospho-(1'-myo-inositol-4',5'-bisphosphate) exhibits a strong affinity for TREK2, surpassing that of dOPI(4,5)P2,1,2-dioleoyl-sn-glycero-3-phospho-(1'-myo-inositol-4',5'-bisphosphate), which differs in its acyl chains. TREK2 displays lipid binding preferences not only for the headgroup of lipids but also toward the acyl chains. Functional studies draw a correlation for lipid binding affinity and activity of the channel. These findings provide important insight into elucidating the molecular prerequisites for specific lipid binding to TREK2 important for function.
Collapse
Affiliation(s)
- Lauren Stover
- Department of Chemistry, Texas A&M University, College Station, Texas 77843, United States
| | - Yun Zhu
- Department of Chemistry, Texas A&M University, College Station, Texas 77843, United States
| | - Samantha Schrecke
- Department of Chemistry, Texas A&M University, College Station, Texas 77843, United States
| | - Arthur Laganowsky
- Department of Chemistry, Texas A&M University, College Station, Texas 77843, United States
| |
Collapse
|
2
|
Xie L, Zhang M, Liu Q, Wei R, Sun M, Zhang Q, Hao L, Xue Z, Wang Q, Yang L, Wang H, Pan Z. Downregulation of ciRNA-Kat6b in dorsal spinal horn is required for neuropathic pain by regulating Kcnk1 in miRNA-26a-dependent manner. CNS Neurosci Ther 2023; 29:2955-2971. [PMID: 37144575 PMCID: PMC10493661 DOI: 10.1111/cns.14235] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2023] [Revised: 04/03/2023] [Accepted: 04/10/2023] [Indexed: 05/06/2023] Open
Abstract
AIMS Nerve injury-induced maladaptive changes in gene expression in the spinal neurons are essential for neuropathic pain genesis. Circular RNAs (ciRNA) are emerging as key regulators of gene expression. Here, we identified a nervous-system-tissues-specific ciRNA-Kat6 with conservation in humans and mice. We aimed to investigate whether and how spinal dorsal horn ciRNA-Kat6b participates in neuropathic pain. METHODS Unilateral sciatic nerve chronic constrictive injury (CCI) surgery was used to prepare the neuropathic pain model. The differentially expressed ciRNAs were obtained by RNA-Sequencing. The identification of nervous-system-tissues specificity of ciRNA-Kat6b and the measurement of ciRNA-Kat6b and microRNA-26a (miRNA-26a) expression level were carried out by quantitative RT-PCR. The ciRNA-Kat6b that targets miRNA-26a and miRNA-26a that targets Kcnk1 were predicted by bioinformatics analysis and verified by in vitro luciferase reports test and in vivo experiments including Western-blot, immunofluorescence, and RNA-RNA immunoprecipitation. The correlation between neuropathic pain and ciRNA-Kat6b, miRNA-26a, or Kcnk1 was examined by the hypersensitivity response to heat and mechanical stimulus. RESULTS Peripheral nerve injury downregulated ciRNA-Kat6b in the dorsal spinal horn of male mice. Rescuing this downregulation blocked nerve injury-induced increase of miRNA-26a, reversed the miRNA-26a-triggered decrease of potassium channel Kcnk1, a key neuropathic pain player, in the dorsal horn, and alleviates CCI-induced pain hypersensitivities. On the contrary, mimicking this downregulation increased the miRNA-26a level and decreased Kcnk1 in the spinal cord, resulting in neuropathic pain-like syndrome in naïve mice. Mechanistically, the downregulation of ciRNA-Kat6b reduced the accounts of miRNA-26a binding to ciRNA-Kat6b, and elevated the binding accounts of miRNA-26a to the 3' untranslated region of Kcnk1 mRNA and degeneration of Kcnk1 mRNA, triggering in the reduction of KCNK1 protein in the dorsal horn of neuropathic pain mice. CONCLUSION The ciRNA-Kat6b/miRNA-26a/Kcnk1 pathway in dorsal horn neurons regulates the development and maintenance of neuropathic pain, ciRNA-Kat6b may be a potential new target for analgesic and treatment strategies.
Collapse
Affiliation(s)
- Ling Xie
- Jiangsu Province Key Laboratory of AnesthesiologyXuzhou Medical UniversityXuzhouChina
- Jiangsu Province Key Laboratory of Anesthesia and Analgesia Application TechnologyXuzhou Medical UniversityXuzhouChina
- NMPA Key Laboratory for Research and Evaluation of Narcotic and Psychotropic DrugsXuzhouChina
- Department of AnesthesiologyThe Obstetrics and Gynecology Hospital of Fudan UniversityShanghaiChina
| | - Ming Zhang
- Jiangsu Province Key Laboratory of AnesthesiologyXuzhou Medical UniversityXuzhouChina
- Jiangsu Province Key Laboratory of Anesthesia and Analgesia Application TechnologyXuzhou Medical UniversityXuzhouChina
- NMPA Key Laboratory for Research and Evaluation of Narcotic and Psychotropic DrugsXuzhouChina
| | - Qiaoqiao Liu
- Jiangsu Province Key Laboratory of AnesthesiologyXuzhou Medical UniversityXuzhouChina
- Jiangsu Province Key Laboratory of Anesthesia and Analgesia Application TechnologyXuzhou Medical UniversityXuzhouChina
- NMPA Key Laboratory for Research and Evaluation of Narcotic and Psychotropic DrugsXuzhouChina
| | - Runa Wei
- Jiangsu Province Key Laboratory of AnesthesiologyXuzhou Medical UniversityXuzhouChina
- Jiangsu Province Key Laboratory of Anesthesia and Analgesia Application TechnologyXuzhou Medical UniversityXuzhouChina
- NMPA Key Laboratory for Research and Evaluation of Narcotic and Psychotropic DrugsXuzhouChina
| | - Menglan Sun
- Jiangsu Province Key Laboratory of AnesthesiologyXuzhou Medical UniversityXuzhouChina
- Jiangsu Province Key Laboratory of Anesthesia and Analgesia Application TechnologyXuzhou Medical UniversityXuzhouChina
- NMPA Key Laboratory for Research and Evaluation of Narcotic and Psychotropic DrugsXuzhouChina
| | - Qi Zhang
- Jiangsu Province Key Laboratory of AnesthesiologyXuzhou Medical UniversityXuzhouChina
- Jiangsu Province Key Laboratory of Anesthesia and Analgesia Application TechnologyXuzhou Medical UniversityXuzhouChina
- NMPA Key Laboratory for Research and Evaluation of Narcotic and Psychotropic DrugsXuzhouChina
| | - Lingyun Hao
- Jiangsu Province Key Laboratory of AnesthesiologyXuzhou Medical UniversityXuzhouChina
- Jiangsu Province Key Laboratory of Anesthesia and Analgesia Application TechnologyXuzhou Medical UniversityXuzhouChina
- NMPA Key Laboratory for Research and Evaluation of Narcotic and Psychotropic DrugsXuzhouChina
| | - Zhouya Xue
- Department of AnesthesiologyThe Yancheng First People's Hospital Affiliated to Xuzhou Medical UniversityYanchengChina
| | - Qihui Wang
- Jiangsu Province Key Laboratory of AnesthesiologyXuzhou Medical UniversityXuzhouChina
- Jiangsu Province Key Laboratory of Anesthesia and Analgesia Application TechnologyXuzhou Medical UniversityXuzhouChina
- NMPA Key Laboratory for Research and Evaluation of Narcotic and Psychotropic DrugsXuzhouChina
| | - Li Yang
- Jiangsu Province Key Laboratory of AnesthesiologyXuzhou Medical UniversityXuzhouChina
- Jiangsu Province Key Laboratory of Anesthesia and Analgesia Application TechnologyXuzhou Medical UniversityXuzhouChina
- NMPA Key Laboratory for Research and Evaluation of Narcotic and Psychotropic DrugsXuzhouChina
| | - Hongjun Wang
- Jiangsu Province Key Laboratory of AnesthesiologyXuzhou Medical UniversityXuzhouChina
- Jiangsu Province Key Laboratory of Anesthesia and Analgesia Application TechnologyXuzhou Medical UniversityXuzhouChina
- NMPA Key Laboratory for Research and Evaluation of Narcotic and Psychotropic DrugsXuzhouChina
| | - Zhiqiang Pan
- Jiangsu Province Key Laboratory of AnesthesiologyXuzhou Medical UniversityXuzhouChina
- Jiangsu Province Key Laboratory of Anesthesia and Analgesia Application TechnologyXuzhou Medical UniversityXuzhouChina
- NMPA Key Laboratory for Research and Evaluation of Narcotic and Psychotropic DrugsXuzhouChina
| |
Collapse
|
3
|
Fan X, Lu Y, Du G, Liu J. Advances in the Understanding of Two-Pore Domain TASK Potassium Channels and Their Potential as Therapeutic Targets. MOLECULES (BASEL, SWITZERLAND) 2022; 27:molecules27238296. [PMID: 36500386 PMCID: PMC9736439 DOI: 10.3390/molecules27238296] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/10/2022] [Revised: 11/09/2022] [Accepted: 11/15/2022] [Indexed: 11/29/2022]
Abstract
TWIK-related acid-sensitive K+ (TASK) channels, including TASK-1, TASK-3, and TASK-5, are important members of the two-pore domain potassium (K2P) channel family. TASK-5 is not functionally expressed in the recombinant system. TASK channels are very sensitive to changes in extracellular pH and are active during all membrane potential periods. They are similar to other K2P channels in that they can create and use background-leaked potassium currents to stabilize resting membrane conductance and repolarize the action potential of excitable cells. TASK channels are expressed in both the nervous system and peripheral tissues, including excitable and non-excitable cells, and are widely engaged in pathophysiological phenomena, such as respiratory stimulation, pulmonary hypertension, arrhythmia, aldosterone secretion, cancers, anesthesia, neurological disorders, glucose homeostasis, and visual sensitivity. Therefore, they are important targets for innovative drug development. In this review, we emphasized the recent advances in our understanding of the biophysical properties, gating profiles, and biological roles of TASK channels. Given the different localization ranges and biologically relevant functions of TASK-1 and TASK-3 channels, the development of compounds that selectively target TASK-1 and TASK-3 channels is also summarized based on data reported in the literature.
Collapse
Affiliation(s)
- Xueming Fan
- Laboratory of Anesthesia and Critical Care Medicine, National-Local Joint Engineering Research Center of Translational Medicine of Anesthesiology, Department of Anesthesiology, West China Hospital, Sichuan University, Chengdu 610041, China
- Department of Anesthesiology, Guizhou Provincial People’s Hospital, Guiyang 550002, China
| | - Yongzhi Lu
- Guangdong Provincial Key Laboratory of Biocomputing, Guangzhou Institute of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou 510700, China
| | - Guizhi Du
- Laboratory of Anesthesia and Critical Care Medicine, National-Local Joint Engineering Research Center of Translational Medicine of Anesthesiology, Department of Anesthesiology, West China Hospital, Sichuan University, Chengdu 610041, China
- Correspondence: (G.D.); (J.L.)
| | - Jin Liu
- Laboratory of Anesthesia and Critical Care Medicine, National-Local Joint Engineering Research Center of Translational Medicine of Anesthesiology, Department of Anesthesiology, West China Hospital, Sichuan University, Chengdu 610041, China
- Correspondence: (G.D.); (J.L.)
| |
Collapse
|
4
|
Benarroch E. What Is the Role of 2-Pore Domain Potassium Channels (K2P) in Pain? Neurology 2022; 99:516-521. [PMID: 36123135 DOI: 10.1212/wnl.0000000000201197] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2022] [Accepted: 07/15/2022] [Indexed: 11/15/2022] Open
|
5
|
Kwatra SG, Misery L, Clibborn C, Steinhoff M. Molecular and cellular mechanisms of itch and pain in atopic dermatitis and implications for novel therapeutics. Clin Transl Immunology 2022; 11:e1390. [PMID: 35582626 PMCID: PMC9082890 DOI: 10.1002/cti2.1390] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2022] [Revised: 04/07/2022] [Accepted: 04/11/2022] [Indexed: 12/03/2022] Open
Abstract
Atopic dermatitis is a chronic inflammatory skin disease. Patients with atopic dermatitis experience inflammatory lesions associated with intense itch and pain, which lead to sleep disturbance and poor mental health and quality of life. We review the molecular mechanisms underlying itch and pain symptoms in atopic dermatitis and discuss the current clinical development of treatments for moderate‐to‐severe atopic dermatitis. The molecular pathology of atopic dermatitis includes aberrant immune activation involving significant cross‐talk among the skin and immune and neuronal cells. Exogenous and endogenous triggers modulate stimulation of mediators including cytokine/chemokine expression/release by the skin and immune cells, which causes inflammation, skin barrier disruption, activation and growth of sensory neurons, itch and pain. These complex interactions among cell types are mediated primarily by cytokines, but also involve chemokines, neurotransmitters, lipids, proteases, antimicrobial peptides, agonists of ion channels or various G protein–coupled receptors. Patients with atopic dermatitis have a cytokine profile characterised by abnormal levels of interleukins 4, 12, 13, 18, 22, 31 and 33; thymic stromal lymphopoietin; and interferon gamma. Cytokine receptors mainly signal through the Janus kinase/signal transducer and activator of transcription pathway. Among emerging novel therapeutics, several Janus kinase inhibitors are being developed for topical or systemic treatment of moderate‐to‐severe atopic dermatitis because of their potential to modulate cytokine expression and release. Janus kinase inhibitors lead to changes in gene expression that have favourable effects on local and systemic cytokine release, and probably other mediators, thus successfully modulating molecular mechanisms responsible for itch and pain in atopic dermatitis.
Collapse
Affiliation(s)
- Shawn G Kwatra
- Department of Dermatology Johns Hopkins University School of Medicine Baltimore MD USA
| | - Laurent Misery
- Department of Dermatology University Hospital of Brest Brest France
| | | | - Martin Steinhoff
- Department of Dermatology and Venereology Hamad Medical Corporation Doha Qatar.,Translational Research Institute Academic Health System Hamad Medical Corporation Doha Qatar.,Dermatology Institute Academic Health System Hamad Medical Corporation Doha Qatar.,Department of Dermatology Weill Cornell Medicine-Qatar Doha Qatar.,Qatar University, College of Medicine Doha Qatar.,Department of Dermatology Weill Cornell Medicine New York NY USA
| |
Collapse
|
6
|
Jia S, Wei G, Bono J, Pan Z, Zheng B, Wang B, Adaralegbe A, Tenorio C, Bekker A, Tao YX. TET1 overexpression attenuates paclitaxel-induced neuropathic pain through rescuing K 2p1.1 expression in primary sensory neurons of male rats. Life Sci 2022; 297:120486. [PMID: 35304127 PMCID: PMC8976761 DOI: 10.1016/j.lfs.2022.120486] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2022] [Revised: 03/03/2022] [Accepted: 03/11/2022] [Indexed: 10/18/2022]
Abstract
AIMS Paclitaxel-induced downregulation of two-pore domain K+ channel 1.1 (K2p1.1) caused by increasing DNA methylation within its gene promoter in the dorsal root ganglion (DRG) contributes to neuropathic pain. Given that ten-eleven translocation methylcytosine dioxygenase 1 (TET1) promotes DNA demethylation and gene transcription, the present study investigated whether DRG overexpression of TET1 produces an antinociceptive effect on the paclitaxel-induced nociceptive hypersensitivity. MAIN METHODS TET1 was overexpressed in the DRG through unilateral microinjection of the herpes simplex virus expressing full-length Tet1 mRNA into the fourth and fifth lumbar DRGs of male rats. Behavioral tests were carried out to examine the effect of this overexpression on the paclitaxel-induced nociceptive hypersensitivity. Western blot analysis, chromatin immunoprecipitation assay and 5-hydroxymethylcytosine detection assay were performed to assess the levels of TET1/K2p1.1, 5-methylcytosine and 5-hydroxymethylcytosine, respectively. KEY FINDINGS DRG overexpression of TET1 mitigated the paclitaxel-induced mechanical allodynia, heat hyperalgesia and cold hyperalgesia on the ipsilateral side during the development and maintenance periods. Locomotor function or basal (acute) responses to mechanical, heat or cold stimuli were not affected. Mechanistically, DRG overexpression of TET1 rescued the expression of K2p1.1 by blocking the paclitaxel-induced increase in the level of 5-methylcytosine and correspondingly reversing the paclitaxel-induced decreases in the amount of 5-hydroxymethylcytosine within the K2p1.1 promoter region in the microinjected DRGs of male rats. SIGNIFICANCE Our findings suggest that DRG overexpression of TET1 alleviated chemotherapy-induced neuropathic pain likely through rescuing DRG K2p1.1 expression. Our findings may provide a potential avenue for the management of this disorder.
Collapse
Affiliation(s)
- Shushan Jia
- Department of Anesthesiology, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ 07103, USA
| | - Guihua Wei
- Department of Anesthesiology, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ 07103, USA
| | - Jamie Bono
- Department of Anesthesiology, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ 07103, USA,Rutgers School of Graduate Studies, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ07103, USA
| | - Zhiqiang Pan
- Department of Anesthesiology, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ 07103, USA
| | - Bixin Zheng
- Department of Anesthesiology, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ 07103, USA
| | - Bing Wang
- Department of Anesthesiology, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ 07103, USA
| | - Adejuyigbe Adaralegbe
- Department of Anesthesiology, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ 07103, USA
| | - Christopher Tenorio
- Department of Anesthesiology, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ 07103, USA
| | - Alex Bekker
- Department of Anesthesiology, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ 07103, USA
| | - Yuan-Xiang Tao
- Department of Anesthesiology, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ 07103, USA; Department of Cell Biology & Molecular Medicine, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark NJ07103, USA; Department of Physiology, Pharmacology & Neuroscience, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark NJ07103, USA.
| |
Collapse
|
7
|
Alles SRA, Smith PA. Peripheral Voltage-Gated Cation Channels in Neuropathic Pain and Their Potential as Therapeutic Targets. FRONTIERS IN PAIN RESEARCH 2022; 2:750583. [PMID: 35295464 PMCID: PMC8915663 DOI: 10.3389/fpain.2021.750583] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Accepted: 11/10/2021] [Indexed: 11/25/2022] Open
Abstract
The persistence of increased excitability and spontaneous activity in injured peripheral neurons is imperative for the development and persistence of many forms of neuropathic pain. This aberrant activity involves increased activity and/or expression of voltage-gated Na+ and Ca2+ channels and hyperpolarization activated cyclic nucleotide gated (HCN) channels as well as decreased function of K+ channels. Because they display limited central side effects, peripherally restricted Na+ and Ca2+ channel blockers and K+ channel activators offer potential therapeutic approaches to pain management. This review outlines the current status and future therapeutic promise of peripherally acting channel modulators. Selective blockers of Nav1.3, Nav1.7, Nav1.8, Cav3.2, and HCN2 and activators of Kv7.2 abrogate signs of neuropathic pain in animal models. Unfortunately, their performance in the clinic has been disappointing; some substances fail to meet therapeutic end points whereas others produce dose-limiting side effects. Despite this, peripheral voltage-gated cation channels retain their promise as therapeutic targets. The way forward may include (i) further structural refinement of K+ channel activators such as retigabine and ASP0819 to improve selectivity and limit toxicity; use or modification of Na+ channel blockers such as vixotrigine, PF-05089771, A803467, PF-01247324, VX-150 or arachnid toxins such as Tap1a; the use of Ca2+ channel blockers such as TTA-P2, TTA-A2, Z 944, ACT709478, and CNCB-2; (ii) improving methods for assessing “pain” as opposed to nociception in rodent models; (iii) recognizing sex differences in pain etiology; (iv) tailoring of therapeutic approaches to meet the symptoms and etiology of pain in individual patients via quantitative sensory testing and other personalized medicine approaches; (v) targeting genetic and biochemical mechanisms controlling channel expression using anti-NGF antibodies such as tanezumab or re-purposed drugs such as vorinostat, a histone methyltransferase inhibitor used in the management of T-cell lymphoma, or cercosporamide a MNK 1/2 inhibitor used in treatment of rheumatoid arthritis; (vi) combination therapy using drugs that are selective for different channel types or regulatory processes; (vii) directing preclinical validation work toward the use of human or human-derived tissue samples; and (viii) application of molecular biological approaches such as clustered regularly interspaced short palindromic repeats (CRISPR) technology.
Collapse
Affiliation(s)
- Sascha R A Alles
- Department of Anesthesiology and Critical Care Medicine, University of New Mexico School of Medicine, Albuquerque, NM, United States
| | - Peter A Smith
- Department of Pharmacology, Neuroscience and Mental Health Institute, University of Alberta, Edmonton, AB, Canada
| |
Collapse
|
8
|
Regulation of Two-Pore-Domain Potassium TREK Channels and their Involvement in Pain Perception and Migraine. Neurosci Lett 2022; 773:136494. [DOI: 10.1016/j.neulet.2022.136494] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Revised: 01/25/2022] [Accepted: 01/26/2022] [Indexed: 02/07/2023]
|
9
|
Abstract
Neuropathic pain (NP) is a common symptom in many diseases of the somatosensory
nervous system, which severely affects the patient’s quality of life.
Epigenetics are heritable alterations in gene expression that do not cause
permanent changes in the DNA sequence. Epigenetic modifications can affect gene
expression and function and can also mediate crosstalk between genes and the
environment. Increasing evidence shows that epigenetic modifications, including
DNA methylation, histone modification, non-coding RNA, and RNA modification, are
involved in the development and maintenance of NP. In this review, we focus on
the current knowledge of epigenetic modifications in the development and
maintenance of NP. Then, we illustrate different facets of epigenetic
modifications that regulate gene expression and their crosstalk. Finally, we
discuss the burgeoning evidence supporting the potential of emerging epigenetic
therapies, which has been valuable in understanding mechanisms and offers novel
and potent targets for NP therapy.
Collapse
Affiliation(s)
- Danzhi Luo
- Department of Anesthesiology, The First People’s Hospital of
Foshan, Foshan, China
- Sun Yet-Sen Memorial Hospital of Sun
Yet-Sen University, Guangzhou, China
| | - Xiaohong Li
- Department of Anesthesiology, The First People’s Hospital of
Foshan, Foshan, China
| | - Simin Tang
- Department of Anesthesiology, The Third Affiliated Hospital of
Southern Medical University, Guangzhou, China
| | - Fuhu Song
- Department of Anesthesiology, The Third Affiliated Hospital of
Southern Medical University, Guangzhou, China
| | - Wenjun Li
- Department of Anesthesiology, The Third Affiliated Hospital of
Southern Medical University, Guangzhou, China
| | - Guiling Xie
- Department of Anesthesiology, The Third Affiliated Hospital of
Southern Medical University, Guangzhou, China
| | - Jinshu Liang
- Department of Anesthesiology, The Third Affiliated Hospital of
Southern Medical University, Guangzhou, China
| | - Jun Zhou
- Department of Anesthesiology, The Third Affiliated Hospital of
Southern Medical University, Guangzhou, China
- Jun Zhou, Department of Anesthesiology, The
Third Affiliated Hospital of Southern Medical University, Guangzhou 510630,
China.
| |
Collapse
|
10
|
Abstract
K+ channels enable potassium to flow across the membrane with great selectivity. There are four K+ channel families: voltage-gated K (Kv), calcium-activated (KCa), inwardly rectifying K (Kir), and two-pore domain potassium (K2P) channels. All four K+ channels are formed by subunits assembling into a classic tetrameric (4x1P = 4P for the Kv, KCa, and Kir channels) or tetramer-like (2x2P = 4P for the K2P channels) architecture. These subunits can either be the same (homomers) or different (heteromers), conferring great diversity to these channels. They share a highly conserved selectivity filter within the pore but show different gating mechanisms adapted for their function. K+ channels play essential roles in controlling neuronal excitability by shaping action potentials, influencing the resting membrane potential, and responding to diverse physicochemical stimuli, such as a voltage change (Kv), intracellular calcium oscillations (KCa), cellular mediators (Kir), or temperature (K2P).
Collapse
|
11
|
Huang L, Xu G, Jiang R, Luo Y, Zuo Y, Liu J. Development of Non-opioid Analgesics Targeting Two-pore Domain Potassium Channels. Curr Neuropharmacol 2021; 20:16-26. [PMID: 33827408 PMCID: PMC9199554 DOI: 10.2174/1570159x19666210407152528] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Revised: 03/14/2021] [Accepted: 03/24/2021] [Indexed: 02/08/2023] Open
Abstract
Two-pore domain potassium (K2P) channels are a diverse family of potassium channels. K2P channels generate background leak potassium currents to regulate cellular excitability and are thereby involved in a wide range of neurological disorders. K2P channels are modulated by a variety of physicochemical factors such as mechanical stretch, temperature, and pH. In the the peripheral nervous system (PNS), K2P channels are widely expressed in nociceptive neurons and play a critical roles in pain perception. In this review, we summarize the recent advances in the pharmacological properties of K2P channels, with a focus on the exogenous small-molecule activators targeting K2P channels. We emphasize the subtype-selectivity, cellular and in vivo pharmacological properties of all the reported small-molecule activators. The key underlying analgesic mechanisms mediated by K2P are also summarized based on the data in the literature from studies using small-molecule activators and genetic knock-out animals. We discuss advantages and limitations of the translational perspectives of K2P in pain medicine and provide outstanding questions for future studies in the end.
Collapse
Affiliation(s)
- Lu Huang
- Laboratory of Anesthesia and Critical Care Medicine, National-Local Joint Engineering Research Center of Translational Medicine of Anesthesiology, West China Hospital, Sichuan University, Chengdu 610000, Sichuan. China
| | - Guangyin Xu
- Department of Physiology and Neurobiology, Institute of Neuroscience, Medical College of Soochow University, Suzhou, 215123, Jiangsu. China
| | - Ruotian Jiang
- Laboratory of Anesthesia and Critical Care Medicine, National-Local Joint Engineering Research Center of Translational Medicine of Anesthesiology, West China Hospital, Sichuan University, Chengdu 610000, Sichuan. China
| | - Yuncheng Luo
- Laboratory of Anesthesia and Critical Care Medicine, National-Local Joint Engineering Research Center of Translational Medicine of Anesthesiology, West China Hospital, Sichuan University, Chengdu 610000, Sichuan. China
| | - Yunxia Zuo
- Laboratory of Anesthesia and Critical Care Medicine, National-Local Joint Engineering Research Center of Translational Medicine of Anesthesiology, West China Hospital, Sichuan University, Chengdu 610000, Sichuan. China
| | - Jin Liu
- Laboratory of Anesthesia and Critical Care Medicine, National-Local Joint Engineering Research Center of Translational Medicine of Anesthesiology, West China Hospital, Sichuan University, Chengdu 610000, Sichuan. China
| |
Collapse
|
12
|
Abstract
Two-pore domain potassium channels are formed by subunits that each contain two pore-loops moieties. Whether the channels are expressed in yeast or the human central nervous system, two subunits come together to form a single potassium selective pore. TOK1, the first two-domain channel was cloned from Saccharomyces cerevisiae in 1995 and soon thereafter, 15 distinct K2P subunits were identified in the human genome. The human K2P channels are stratified into six K2P subfamilies based on sequence as well as physiological or pharmacological similarities. Functional K2P channels pass background (or "leak") K+ currents that shape the membrane potential and excitability of cells in a broad range of tissues. In the years since they were first described, classical functional assays, latterly coupled with state-of-the-art structural and computational studies have revealed the mechanistic basis of K2P channel gating in response to specific physicochemical or pharmacological stimuli. The growing appreciation that K2P channels can play a pivotal role in the pathophysiology of a growing spectrum of diseases makes a compelling case for K2P channels as targets for drug discovery. Here, we summarize recent advances in unraveling the structure, function, and pharmacology of the K2P channels.
Collapse
Affiliation(s)
- Jordie M Kamuene
- Department of Pharmaceutical Sciences, Northeastern University, Boston, MA, USA
| | - Yu Xu
- Department of Pharmaceutical Sciences, Northeastern University, Boston, MA, USA
| | - Leigh D Plant
- Department of Pharmaceutical Sciences, Northeastern University, Boston, MA, USA.
| |
Collapse
|
13
|
Smith PA. K + Channels in Primary Afferents and Their Role in Nerve Injury-Induced Pain. Front Cell Neurosci 2020; 14:566418. [PMID: 33093824 PMCID: PMC7528628 DOI: 10.3389/fncel.2020.566418] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Accepted: 08/21/2020] [Indexed: 12/12/2022] Open
Abstract
Sensory abnormalities generated by nerve injury, peripheral neuropathy or disease are often expressed as neuropathic pain. This type of pain is frequently resistant to therapeutic intervention and may be intractable. Numerous studies have revealed the importance of enduring increases in primary afferent excitability and persistent spontaneous activity in the onset and maintenance of peripherally induced neuropathic pain. Some of this activity results from modulation, increased activity and /or expression of voltage-gated Na+ channels and hyperpolarization-activated cyclic nucleotide–gated (HCN) channels. K+ channels expressed in dorsal root ganglia (DRG) include delayed rectifiers (Kv1.1, 1.2), A-channels (Kv1.4, 3.3, 3.4, 4.1, 4.2, and 4.3), KCNQ or M-channels (Kv7.2, 7.3, 7.4, and 7.5), ATP-sensitive channels (KIR6.2), Ca2+-activated K+ channels (KCa1.1, 2.1, 2.2, 2.3, and 3.1), Na+-activated K+ channels (KCa4.1 and 4.2) and two pore domain leak channels (K2p; TWIK related channels). Function of all K+ channel types is reduced via a multiplicity of processes leading to altered expression and/or post-translational modification. This also increases excitability of DRG cell bodies and nociceptive free nerve endings, alters axonal conduction and increases neurotransmitter release from primary afferent terminals in the spinal dorsal horn. Correlation of these cellular changes with behavioral studies provides almost indisputable evidence for K+ channel dysfunction in the onset and maintenance of neuropathic pain. This idea is underlined by the observation that selective impairment of just one subtype of DRG K+ channel can produce signs of pain in vivo. Whilst it is established that various mediators, including cytokines and growth factors bring about injury-induced changes in DRG function and excitability, evidence presently available points to a seminal role for interleukin 1β (IL-1β) in control of K+ channel function. Despite the current state of knowledge, attempts to target K+ channels for therapeutic pain management have met with limited success. This situation may change with the advent of personalized medicine. Identification of specific sensory abnormalities and genetic profiling of individual patients may predict therapeutic benefit of K+ channel activators.
Collapse
Affiliation(s)
- Peter A Smith
- Department of Pharmacology and Neuroscience and Mental Health Institute, University of Alberta, Edmonton, AB, Canada
| |
Collapse
|
14
|
Liao P, Qiu Y, Mo Y, Fu J, Song Z, Huang L, Bai S, Wang Y, Zhu JJ, Tian F, Chen Z, Pan N, Sun EY, Yang L, Lan X, Chen Y, Huang D, Sun P, Zhao L, Yang D, Lu W, Yang T, Xiao J, Li WG, Gao Z, Shen B, Zhang Q, Liu J, Jiang H, Jiang R, Yang H. Selective activation of TWIK-related acid-sensitive K + 3 subunit-containing channels is analgesic in rodent models. Sci Transl Med 2020; 11:11/519/eaaw8434. [PMID: 31748231 DOI: 10.1126/scitranslmed.aaw8434] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Revised: 06/27/2019] [Accepted: 09/19/2019] [Indexed: 02/05/2023]
Abstract
The paucity of selective agonists for TWIK-related acid-sensitive K+ 3 (TASK-3) channel, a member of two-pore domain K+ (K2P) channels, has contributed to our limited understanding of its biological functions. By targeting a druggable transmembrane cavity using a structure-based drug design approach, we discovered a biguanide compound, CHET3, as a highly selective allosteric activator for TASK-3-containing K2P channels, including TASK-3 homomers and TASK-3/TASK-1 heteromers. CHET3 displayed potent analgesic effects in vivo in a variety of acute and chronic pain models in rodents that could be abolished pharmacologically or by genetic ablation of TASK-3. We further found that TASK-3-containing channels anatomically define a unique population of small-sized, transient receptor potential cation channel subfamily M member 8 (TRPM8)-, transient receptor potential cation channel subfamily V member 1 (TRPV1)-, or tyrosine hydroxylase (TH)-positive nociceptive sensory neurons and functionally regulate their membrane excitability, supporting CHET3 analgesic effects in thermal hyperalgesia and mechanical allodynia under chronic pain. Overall, our proof-of-concept study reveals TASK-3-containing K2P channels as a druggable target for treating pain.
Collapse
Affiliation(s)
- Ping Liao
- Laboratory of Anesthesia and Critical Care Medicine, Department of Anesthesiology, National-Local Joint Engineering Research Center of Translational Medicine of Anesthesiology, West China Hospital of Sichuan University, Chengdu, Sichuan 610000, China
| | - Yunguang Qiu
- State Key Laboratory of Drug Research and CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China.,University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yiqing Mo
- Shanghai Key Laboratory of Regulatory Biology, Institute of Biomedical Sciences, School of Life Sciences, East China Normal University, Shanghai 200241, China
| | - Jie Fu
- Shanghai Key Laboratory of Regulatory Biology, Institute of Biomedical Sciences, School of Life Sciences, East China Normal University, Shanghai 200241, China
| | - Zhenpeng Song
- Laboratory of Anesthesia and Critical Care Medicine, Department of Anesthesiology, National-Local Joint Engineering Research Center of Translational Medicine of Anesthesiology, West China Hospital of Sichuan University, Chengdu, Sichuan 610000, China
| | - Lu Huang
- Laboratory of Anesthesia and Critical Care Medicine, Department of Anesthesiology, National-Local Joint Engineering Research Center of Translational Medicine of Anesthesiology, West China Hospital of Sichuan University, Chengdu, Sichuan 610000, China
| | - Suwen Bai
- Department of Physiology, Anhui Medical University, Hefei, Anhui 230032, China
| | - Yang Wang
- Department of Physiology, Anhui Medical University, Hefei, Anhui 230032, China
| | - Jia-Jie Zhu
- Collaborative Innovation Center for Brain Science, Department of Anatomy and Physiology, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Fuyun Tian
- State Key Laboratory of Drug Research and CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China
| | - Zhuo Chen
- Laboratory of Anesthesia and Critical Care Medicine, Department of Anesthesiology, National-Local Joint Engineering Research Center of Translational Medicine of Anesthesiology, West China Hospital of Sichuan University, Chengdu, Sichuan 610000, China
| | - Nanfang Pan
- Laboratory of Anesthesia and Critical Care Medicine, Department of Anesthesiology, National-Local Joint Engineering Research Center of Translational Medicine of Anesthesiology, West China Hospital of Sichuan University, Chengdu, Sichuan 610000, China
| | - Er-Yi Sun
- Laboratory of Anesthesia and Critical Care Medicine, Department of Anesthesiology, National-Local Joint Engineering Research Center of Translational Medicine of Anesthesiology, West China Hospital of Sichuan University, Chengdu, Sichuan 610000, China
| | - Linghui Yang
- Laboratory of Anesthesia and Critical Care Medicine, Department of Anesthesiology, National-Local Joint Engineering Research Center of Translational Medicine of Anesthesiology, West China Hospital of Sichuan University, Chengdu, Sichuan 610000, China
| | - Xi Lan
- State Key Laboratory of Drug Research and CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China
| | - Yinbin Chen
- Shanghai Key Laboratory of Regulatory Biology, Institute of Biomedical Sciences, School of Life Sciences, East China Normal University, Shanghai 200241, China
| | - Dongping Huang
- Shanghai Key Laboratory of Regulatory Biology, Institute of Biomedical Sciences, School of Life Sciences, East China Normal University, Shanghai 200241, China
| | - Peihua Sun
- Jiangsu Key Laboratory of Neuropsychiatric Diseases and College of Pharmaceutical Sciences, Soochow University, Suzhou, Jiangsu 215123, China
| | - Lifen Zhao
- State Key Laboratory of Drug Research and CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China
| | - Dehua Yang
- State Key Laboratory of Drug Research and CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China
| | - Weiqiang Lu
- Shanghai Key Laboratory of Regulatory Biology, Institute of Biomedical Sciences, School of Life Sciences, East China Normal University, Shanghai 200241, China
| | - Tingting Yang
- Cardiac Regeneration and Ageing Lab, School of Life Science, Shanghai University, Shanghai 200444, China
| | - Junjie Xiao
- Cardiac Regeneration and Ageing Lab, School of Life Science, Shanghai University, Shanghai 200444, China
| | - Wei-Guang Li
- Collaborative Innovation Center for Brain Science, Department of Anatomy and Physiology, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Zhaobing Gao
- State Key Laboratory of Drug Research and CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China
| | - Bing Shen
- Department of Physiology, Anhui Medical University, Hefei, Anhui 230032, China
| | - Qiansen Zhang
- Shanghai Key Laboratory of Regulatory Biology, Institute of Biomedical Sciences, School of Life Sciences, East China Normal University, Shanghai 200241, China
| | - Jin Liu
- Laboratory of Anesthesia and Critical Care Medicine, Department of Anesthesiology, National-Local Joint Engineering Research Center of Translational Medicine of Anesthesiology, West China Hospital of Sichuan University, Chengdu, Sichuan 610000, China
| | - Hualiang Jiang
- State Key Laboratory of Drug Research and CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China.,University of Chinese Academy of Sciences, Beijing 100049, China
| | - Ruotian Jiang
- Laboratory of Anesthesia and Critical Care Medicine, Department of Anesthesiology, National-Local Joint Engineering Research Center of Translational Medicine of Anesthesiology, West China Hospital of Sichuan University, Chengdu, Sichuan 610000, China.
| | - Huaiyu Yang
- Shanghai Key Laboratory of Regulatory Biology, Institute of Biomedical Sciences, School of Life Sciences, East China Normal University, Shanghai 200241, China.
| |
Collapse
|
15
|
Li H, Liu S, Wang Z, Zhang Y, Wang K. Hydrogen sulfide attenuates diabetic neuropathic pain through NO/cGMP/PKG pathway and μ-opioid receptor. Exp Biol Med (Maywood) 2020; 245:823-834. [PMID: 32268802 DOI: 10.1177/1535370220918193] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
IMPACT STATEMENT There are currently approximately 425 million diabetic patients worldwide, of which approximately 90% of patients with diabetes suffer from neuropathy. Diabetic neuropathic pain (DNP) is a common complication of diabetic neuropathy. Nearly half of the patients hospitalized with diabetes have pain symptoms or symptoms related to neurological injury, and the incidence increases with age and diabetic duration. Anti-DNP analgesics have either limited therapeutic effects or serious side effects or lack of clinical trials, which has limited their application. Physiopathological mechanisms and treatment of DNP remain a significant challenge. The present confirmed that inhalation of H2S may attenuate the diabetic neuropathic pain through NO/cGMP/PKG pathway and μ-opioid receptor. It provides us the animal study foundation for the application of H2S on the treatment of DNP and clarifies some target molecules in the pain modulation of DNP.
Collapse
Affiliation(s)
- Hao Li
- Medical Management Department, Shandong Cancer Hospital and Institute, Shandong First Medical University and Shandong Academy of Medical Sciences, Shandong 250117, China
| | - Shulin Liu
- Department of Aviation Medicine, Naval Medical Institute, Second Military Medical University, Shanghai 200433, China
| | - Zheng Wang
- Pre Hospital Emergency Department, Shandong Otolaryngology Hospital Affiliated to Shandong University (West Hospital of Shandong Provincial Hospital), Shandong 250117, China
| | - Yonglai Zhang
- Department of Anesthesiology, Shandong Cancer Hospital and Institute, Shandong First Medical University and Shandong Academy of Medical Sciences, Shandong 250117, China
| | - Kaiguo Wang
- Department of Anesthesiology, Shandong Cancer Hospital and Institute, Shandong First Medical University and Shandong Academy of Medical Sciences, Shandong 250117, China
| |
Collapse
|
16
|
Pattison LA, Callejo G, St John Smith E. Evolution of acid nociception: ion channels and receptors for detecting acid. Philos Trans R Soc Lond B Biol Sci 2019; 374:20190291. [PMID: 31544616 PMCID: PMC6790391 DOI: 10.1098/rstb.2019.0291] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/27/2019] [Indexed: 12/13/2022] Open
Abstract
Nociceptors, i.e. sensory neurons tuned to detect noxious stimuli, are found in numerous phyla of the Animalia kingdom and are often polymodal, responding to a variety of stimuli, e.g. heat, cold, pressure and chemicals, such as acid. Owing to the ability of protons to have a profound effect on ionic homeostasis and damage macromolecular structures, it is no wonder that the ability to detect acid is conserved across many species. To detect changes in pH, nociceptors are equipped with an assortment of different acid sensors, some of which can detect mild changes in pH, such as the acid-sensing ion channels, proton-sensing G protein-coupled receptors and several two-pore potassium channels, whereas others, such as the transient receptor potential vanilloid 1 ion channel, require larger shifts in pH. This review will discuss the evolution of acid sensation and the different mechanisms by which nociceptors can detect acid. This article is part of the Theo Murphy meeting issue 'Evolution of mechanisms and behaviour important for pain'.
Collapse
Affiliation(s)
| | | | - Ewan St John Smith
- Department of Pharmacology, University of Cambridge, Tennis Court Road, Cambridge CB2 1PD, UK
| |
Collapse
|
17
|
García G, Noriega-Navarro R, Martínez-Rojas VA, Gutiérrez-Lara EJ, Oviedo N, Murbartián J. Spinal TASK-1 and TASK-3 modulate inflammatory and neuropathic pain. Eur J Pharmacol 2019; 862:172631. [DOI: 10.1016/j.ejphar.2019.172631] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2019] [Revised: 08/09/2019] [Accepted: 08/27/2019] [Indexed: 12/13/2022]
|
18
|
Sandercock DA, Barnett MW, Coe JE, Downing AC, Nirmal AJ, Di Giminiani P, Edwards SA, Freeman TC. Transcriptomics Analysis of Porcine Caudal Dorsal Root Ganglia in Tail Amputated Pigs Shows Long-Term Effects on Many Pain-Associated Genes. Front Vet Sci 2019; 6:314. [PMID: 31620455 PMCID: PMC6760028 DOI: 10.3389/fvets.2019.00314] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2018] [Accepted: 09/03/2019] [Indexed: 12/24/2022] Open
Abstract
Tail amputation by tail docking or as an extreme consequence of tail biting in commercial pig production potentially has serious implications for animal welfare. Tail amputation causes peripheral nerve injury that might be associated with lasting chronic pain. The aim of this study was to investigate the short- and long-term effects of tail amputation in pigs on caudal DRG gene expression at different stages of development, particularly in relation to genes associated with nociception and pain. Microarrays were used to analyse whole DRG transcriptomes from tail amputated and sham-treated pigs 1, 8, and 16 weeks following tail treatment at either 3 or 63 days of age (8 pigs/treatment/age/time after treatment; n = 96). Tail amputation induced marked changes in gene expression (up and down) compared to sham-treated intact controls for all treatment ages and time points after tail treatment. Sustained changes in gene expression in tail amputated pigs were still evident 4 months after tail injury. Gene correlation network analysis revealed two co-expression clusters associated with amputation: Cluster A (759 down-regulated) and Cluster B (273 up-regulated) genes. Gene ontology (GO) enrichment analysis identified 124 genes in Cluster A and 61 genes in Cluster B associated with both “inflammatory pain” and “neuropathic pain.” In Cluster A, gene family members of ion channels e.g., voltage-gated potassium channels (VGPC) and receptors e.g., GABA receptors, were significantly down-regulated compared to shams, both of which are linked to increased peripheral nerve excitability after axotomy. Up-regulated gene families in Cluster B were linked to transcriptional regulation, inflammation, tissue remodeling, and regulatory neuropeptide activity. These findings, demonstrate that tail amputation causes sustained transcriptomic expression changes in caudal DRG cells involved in inflammatory and neuropathic pain pathways.
Collapse
Affiliation(s)
- Dale A Sandercock
- Animal and Veterinary Science Research Group, Scotland's Rural College, Roslin Institute Building, Edinburgh, United Kingdom
| | - Mark W Barnett
- The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Edinburgh, United Kingdom
| | - Jennifer E Coe
- Animal and Veterinary Science Research Group, Scotland's Rural College, Roslin Institute Building, Edinburgh, United Kingdom
| | - Alison C Downing
- Edinburgh Genomics, The University of Edinburgh, Edinburgh, United Kingdom
| | - Ajit J Nirmal
- The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Edinburgh, United Kingdom
| | - Pierpaolo Di Giminiani
- School of Natural and Environmental Sciences, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Sandra A Edwards
- School of Natural and Environmental Sciences, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Tom C Freeman
- The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Edinburgh, United Kingdom
| |
Collapse
|
19
|
Fischer RA, Roux AL, Wareham LK, Sappington RM. Pressure-dependent modulation of inward-rectifying K + channels: implications for cation homeostasis and K + dynamics in glaucoma. Am J Physiol Cell Physiol 2019; 317:C375-C389. [PMID: 31166711 DOI: 10.1152/ajpcell.00444.2018] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Glaucoma is the leading cause of blindness worldwide, resulting from degeneration of retinal ganglion cells (RGCs), which form the optic nerve. Prior to structural degeneration, RGCs exhibit physiological deficits. Müller glia provide homeostatic regulation of ions that supports RGC physiology through a process called K+ siphoning. Recent studies suggest that several retinal conditions, including glaucoma, involve changes in the expression of K+ channels in Müller glia. To clarify whether glaucoma-related stressors directly alter expression and function of K+ channels in Müller glia, we examined changes in the expression of inwardly rectifying K+ (Kir) channels and two-pore domain (K2P) channels in response to elevated intraocular pressure (IOP) in vivo and in vitro in primary cultures of Müller glia exposed to elevated hydrostatic pressure. We then measured outcomes of cell health, cation homeostasis, and cation flux in Müller glia cultures. Transcriptome analysis in a murine model of microbead-induced glaucoma revealed pressure-dependent downregulation of Kir and K2P channels in vivo. Changes in the expression and localization of Kir and K2P channels in response to elevated pressure were also found in Müller glia in vitro. Finally, we found that elevated pressure compromises the plasma membrane of Müller glia and induces cation dyshomeostasis that involves changes in ion flux through cation channels. Pressure-induced changes in cation flux precede both cation dyshomeostasis and membrane compromise. Our findings have implications for Müller glia responses to pressure-related conditions, i.e., glaucoma, and identify cation dyshomeostasis as a potential contributor to electrophysiological impairment observed in RGCs of glaucomatous retina.
Collapse
Affiliation(s)
- Rachel A Fischer
- Department of Pharmacology, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Abigail L Roux
- Vanderbilt Eye Institute, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Lauren K Wareham
- Vanderbilt Eye Institute, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Rebecca M Sappington
- Department of Pharmacology, Vanderbilt University School of Medicine, Nashville, Tennessee.,Vanderbilt Eye Institute, Vanderbilt University Medical Center, Nashville, Tennessee.,Department of Ophthalmology and Visual Sciences, Vanderbilt University School of Medicine, Nashville, Tennessee
| |
Collapse
|
20
|
García G, Gutiérrez-Lara EJ, Centurión D, Granados-Soto V, Murbartián J. Fructose-Induced Insulin Resistance as a Model of Neuropathic Pain in Rats. Neuroscience 2019; 404:233-245. [DOI: 10.1016/j.neuroscience.2019.01.063] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2018] [Revised: 01/29/2019] [Accepted: 01/30/2019] [Indexed: 12/21/2022]
|
21
|
Mao Q, Wu S, Gu X, Du S, Mo K, Sun L, Cao J, Bekker A, Chen L, Tao YX. DNMT3a-triggered downregulation of K 2p 1.1 gene in primary sensory neurons contributes to paclitaxel-induced neuropathic pain. Int J Cancer 2019; 145:2122-2134. [PMID: 30684388 DOI: 10.1002/ijc.32155] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2018] [Revised: 12/18/2018] [Accepted: 01/21/2019] [Indexed: 12/26/2022]
Abstract
Antineoplastic drugs induce dramatic transcriptional changes in dorsal root ganglion (DRG) neurons, which may contribute to chemotherapy-induced neuropathic pain. K2p 1.1 controls neuronal excitability by setting the resting membrane potential. Here, we report that systemic injection of the chemotherapy agent paclitaxel time-dependently downregulates the expression of K 2p 1.1 mRNA and its coding K2p 1.1 protein in the DRG neurons. Rescuing this downregulation mitigates the development and maintenance of paclitaxel-induced mechanical allodynia and heat hyperalgesia. Conversely, in the absence of paclitaxel administration, mimicking this downregulation decreases outward potassium current and increases excitability in the DRG neurons, leading to the enhanced responses to mechanical and heat stimuli. Mechanically, the downregulation of DRG K 2p 1.1 mRNA is attributed to paclitaxel-induced increase in DRG DNMT3a, as blocking this increase reverses the paclitaxel-induced the decrease of DRG K2p 1.1 and mimicking this increase reduces DRG K2p 1.1 expression. In addition, paclitaxel injection increases the binding of DNMT3a to the K 2p 1.1 gene promoter region and elevates the level of DNA methylation within this region in the DRG. These findings suggest that DNMT3a-triggered downregulation of DRG K2p 1.1 may contribute to chemotherapy-induced neuropathic pain.
Collapse
Affiliation(s)
- Qingxiang Mao
- Department of Anesthesiology, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ.,Department of Anesthesiology, Daping Hospital, Institute of Surgery Research, Third Military Medical University (Army Medical University), Chongqing, China
| | - Shaogen Wu
- Department of Anesthesiology, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ
| | - Xiyao Gu
- Department of Anesthesiology, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ
| | - Shibin Du
- Department of Anesthesiology, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ
| | - Kai Mo
- Department of Anesthesiology, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ
| | - Linlin Sun
- Department of Anesthesiology, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ
| | - Jing Cao
- Department of Anesthesiology, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ.,Neuroscience Research Institute, Zhengzhou University Academy of Medical Sciences, Zhengzhou, Henan, China
| | - Alex Bekker
- Department of Anesthesiology, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ
| | - Liyong Chen
- Department of Anesthesiology, Daping Hospital, Institute of Surgery Research, Third Military Medical University (Army Medical University), Chongqing, China
| | - Yuan-Xiang Tao
- Department of Anesthesiology, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ
| |
Collapse
|
22
|
Gada K, Plant LD. Two-pore domain potassium channels: emerging targets for novel analgesic drugs: IUPHAR Review 26. Br J Pharmacol 2018; 176:256-266. [PMID: 30325008 DOI: 10.1111/bph.14518] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2018] [Revised: 07/23/2018] [Accepted: 08/18/2018] [Indexed: 01/02/2023] Open
Abstract
Chronic pain is a debilitating and increasingly common medical problem with few effective treatments. In addition to the direct and indirect economic burden of pain syndromes, the concomitant increase in prescriptions for narcotics has contributed to a sharp rise in deaths associated with drug misuse - the 'opioid crisis'. Together, these issues highlight the unmet clinical and social need for a new generation of safe, efficacious analgesics. The detection and transmission of pain stimuli is largely mediated by somatosensory afferent fibres of the dorsal root ganglia. These nociceptive cells express an array of membrane proteins that have received significant attention as attractive targets for new pain medications. Among these, a growing body of evidence supports a role for the two-pore domain potassium (K2P) family of K+ channels. Here, we provide a concise review of the K2P channels, their role in pain biology and their potential as targets for novel analgesic agents.
Collapse
Affiliation(s)
- Kirin Gada
- Department of Pharmaceutical Sciences in the School of Pharmacy, Bouvé College of Health Sciences, Northeastern University, Boston, MA, USA
| | - Leigh D Plant
- Department of Pharmaceutical Sciences in the School of Pharmacy, Bouvé College of Health Sciences, Northeastern University, Boston, MA, USA
| |
Collapse
|
23
|
Mao Q, Yuan J, Ming X, Wu S, Chen L, Bekker A, Yang T, Tao YX. Role of dorsal root ganglion K2p1.1 in peripheral nerve injury-induced neuropathic pain. Mol Pain 2018; 13:1744806917701135. [PMID: 28326939 PMCID: PMC5367768 DOI: 10.1177/1744806917701135] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Peripheral nerve injury-caused hyperexcitability and abnormal ectopic discharges in the primary sensory neurons of dorsal root ganglion (DRG) play a key role in neuropathic pain development and maintenance. The two-pore domain background potassium (K2P) channels have been identified as key determinants of the resting membrane potential and neuronal excitability. However, whether K2P channels contribute to neuropathic pain is still elusive. We reported here that K2P1.1, the first identified mammalian K2P channel, was highly expressed in mouse DRG and distributed in small-, medium-, and large-sized DRG neurons. Unilateral lumbar (L) 4 spinal nerve ligation led to a significant and time-dependent reduction of K2P1.1 mRNA and protein in the ipsilateral L4 DRG, but not in the contralateral L4 or ipsilateral L3 DRG. Rescuing this reduction through microinjection of adeno-associated virus-DJ expressing full-length K2P1.1 mRNA into the ipsilateral L4 DRG blocked spinal nerve ligation-induced mechanical, thermal, and cold pain hypersensitivities during the development and maintenance periods. This DRG viral microinjection did not affect acute pain and locomotor function. Our findings suggest that K2P1.1 participates in neuropathic pain development and maintenance and may be a potential target in the management of this disorder.
Collapse
Affiliation(s)
- Qingxiang Mao
- Xinqiao Hospital, The Third Military Medical University
| | | | | | | | - Liyong Chen
- Daping Hospital, Institute of Surgery Research, The Third Military Medical University
| | | | - Tiande Yang
- Xinqiao Hospital, The Third Military Medical University
| | | |
Collapse
|
24
|
Abstract
Acute and chronic pain complaints, although common, are generally poorly served by existing therapies. This unmet clinical need reflects a failure to develop novel classes of analgesics with superior efficacy, diminished adverse effects and a lower abuse liability than those currently available. Reasons for this include the heterogeneity of clinical pain conditions, the complexity and diversity of underlying pathophysiological mechanisms, and the unreliability of some preclinical pain models. However, recent advances in our understanding of the neurobiology of pain are beginning to offer opportunities for developing novel therapeutic strategies and revisiting existing targets, including modulating ion channels, enzymes and G-protein-coupled receptors.
Collapse
|
25
|
Reversal of TRESK Downregulation Alleviates Neuropathic Pain by Inhibiting Activation of Gliocytes in the Spinal Cord. Neurochem Res 2017; 42:1288-1298. [PMID: 28160200 DOI: 10.1007/s11064-016-2170-z] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2016] [Revised: 11/03/2016] [Accepted: 12/28/2016] [Indexed: 10/20/2022]
Abstract
Despite the consensus that activation of TWIK-related spinal cord K+ (TRESK) might contribute to the pathogenesis of chronic pain, the specific mechanisms underlying the transfer and development of pain signals still remain obscure. In the present study, we validated that TRESK was expressed in neurons instead of glial cells. Furthermore, in the SNI model of neuropathic pain (NP), downregulation of TRESK in spinal cord neurons resulted in upregulation of connexin 36 (Cx36) and connexin 43 (Cx43), both being subtypes of gap junctions in the spinal cord, with gliocytes in the spinal cord activated ultimately. Compared with SNI rats, intrathecal injection of TRESK gene recombinant adenovirus significantly downregulated the expression levels of Cx36 and Cx43 and suppressed the activation of gliocytes in the spinal cord, with hyperalgesia significantly reduced. In conclusion, TRESK contributes to the pathogenesis of NP by upregulation of synaptic transmission and activation of gliocytes.
Collapse
|
26
|
Oxytocin alleviates orofacial mechanical hypersensitivity associated with infraorbital nerve injury through vasopressin-1A receptors of the rat trigeminal ganglia. Pain 2017; 158:649-659. [DOI: 10.1097/j.pain.0000000000000808] [Citation(s) in RCA: 54] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
|
27
|
Lolignier S, Gkika D, Andersson D, Leipold E, Vetter I, Viana F, Noël J, Busserolles J. New Insight in Cold Pain: Role of Ion Channels, Modulation, and Clinical Perspectives. J Neurosci 2016; 36:11435-11439. [PMID: 27911746 PMCID: PMC6601718 DOI: 10.1523/jneurosci.2327-16.2016] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2016] [Revised: 09/05/2016] [Accepted: 09/07/2016] [Indexed: 11/21/2022] Open
Abstract
Cold temperature detection involves the process of sensory transduction in cutaneous primary sensory nerve terminals, which converts thermal stimuli into depolarizations of the membrane. This transformation into electrical signals is followed by the subsequent propagation of action potentials in cold-sensitive afferent nerve fibers. A large array of ion channels shapes this process; however, the precise contribution of specific ion channel subtypes to cold perception and cold pain remains elusive. This review aims at giving an update on our current understanding of the role played by TRPs, leak K+ and voltage-gated Na+ and K+ channels in the transduction of cold by nociceptors and in cold-induced pain.
Collapse
Affiliation(s)
- Stéphane Lolignier
- Clermont Université, Université d'Auvergne, Pharmacologie fondamentale et clinique de la douleur, 63000 Clermont-Ferrand, France
- Inserm, U 1107, Neuro-Dol, 63000 Clermont-Ferrand, France
| | - Dimitra Gkika
- Laboratoire de Physiologie cellulaire, Inserm U1003, Laboratory of Excellence, Ion Channels Science and Therapeutics, Université Lille 1, 59655 Villeneuve d'Ascq Cedex, France
| | - David Andersson
- King's College London, Wolfson Centre for Age-Related Diseases Wolfson Wing, SE1 1UL London, United Kingdom
| | - Enrico Leipold
- Institut für Biochemie und Biophysik, D-07745 Jena, Germany
| | - Irina Vetter
- Institute for Molecular Bioscience and School of Pharmacy, University of Queensland, Brisbane, Queensland 4072, Australia
| | - Felix Viana
- Instituto de Neurociencias de Alicante Universidad Miguel Hernandez/CSIC Avda. S. Ramón y Cajal s.n. San Juan de Alicante, 03550 Alicante, Spain
| | - Jacques Noël
- Université Côte d'Azur, CNRS UMR 7275, Institut de Pharmacologie Moléculaire et Cellulaire, France, and
- LabEx Ion Channel Science and Therapeutics, 06560 Valbonne, France
| | - Jérôme Busserolles
- Clermont Université, Université d'Auvergne, Pharmacologie fondamentale et clinique de la douleur, 63000 Clermont-Ferrand, France,
- Inserm, U 1107, Neuro-Dol, 63000 Clermont-Ferrand, France
| |
Collapse
|
28
|
|
29
|
Szklarczyk R, Megchelenbrink W, Cizek P, Ledent M, Velemans G, Szklarczyk D, Huynen MA. WeGET: predicting new genes for molecular systems by weighted co-expression. Nucleic Acids Res 2015; 44:D567-73. [PMID: 26582928 PMCID: PMC4702868 DOI: 10.1093/nar/gkv1228] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2015] [Accepted: 10/30/2015] [Indexed: 01/04/2023] Open
Abstract
We have developed the Weighted Gene Expression Tool and database (WeGET, http://weget.cmbi.umcn.nl) for the prediction of new genes of a molecular system by correlated gene expression. WeGET utilizes a compendium of 465 human and 560 murine gene expression datasets that have been collected from multiple tissues under a wide range of experimental conditions. It exploits this abundance of expression data by assigning a high weight to datasets in which the known genes of a molecular system are harmoniously up- and down-regulated. WeGET ranks new candidate genes by calculating their weighted co-expression with that system. A weighted rank is calculated for human genes and their mouse orthologs. Then, an integrated gene rank and p-value is computed using a rank-order statistic. We applied our method to predict novel genes that have a high degree of co-expression with Gene Ontology terms and pathways from KEGG and Reactome. For each query set we provide a list of predicted novel genes, computed weights for transcription datasets used and cell and tissue types that contributed to the final predictions. The performance for each query set is assessed by 10-fold cross-validation. Finally, users can use the WeGET to predict novel genes that co-express with a custom query set.
Collapse
Affiliation(s)
- Radek Szklarczyk
- Maastricht University Medical Centre, P. Debyelaan 25, 6226XM Maastricht, The Netherlands Centre for Molecular and Biomolecular Informatics (CMBI), Radboud University Medical Centre, Geert Grooteplein Zuid 26-28, 6525 GA Nijmegen, Nijmegen, The Netherlands
| | - Wout Megchelenbrink
- Centre for Molecular and Biomolecular Informatics (CMBI), Radboud University Medical Centre, Geert Grooteplein Zuid 26-28, 6525 GA Nijmegen, Nijmegen, The Netherlands Institute for Computing and Information Sciences (ICIS), Radboud University, Toernooiveld 212, 6525 EC Nijmegen, The Netherlands Centre for Systems Biology and Bioenergetics (CSBB), Radboud University Medical Centre, Geert Grooteplein Zuid 10, 6500 HB Nijmegen, Nijmegen, The Netherlands
| | - Pavel Cizek
- Centre for Molecular and Biomolecular Informatics (CMBI), Radboud University Medical Centre, Geert Grooteplein Zuid 26-28, 6525 GA Nijmegen, Nijmegen, The Netherlands
| | - Marie Ledent
- Maastricht University Medical Centre, P. Debyelaan 25, 6226XM Maastricht, The Netherlands
| | - Gonny Velemans
- Centre for Molecular and Biomolecular Informatics (CMBI), Radboud University Medical Centre, Geert Grooteplein Zuid 26-28, 6525 GA Nijmegen, Nijmegen, The Netherlands
| | - Damian Szklarczyk
- Institute of Molecular Life Sciences and Swiss Institute of Bioinformatics, University of Zurich, 8057 Zurich, Switzerland
| | - Martijn A Huynen
- Centre for Molecular and Biomolecular Informatics (CMBI), Radboud University Medical Centre, Geert Grooteplein Zuid 26-28, 6525 GA Nijmegen, Nijmegen, The Netherlands Centre for Systems Biology and Bioenergetics (CSBB), Radboud University Medical Centre, Geert Grooteplein Zuid 10, 6500 HB Nijmegen, Nijmegen, The Netherlands
| |
Collapse
|
30
|
Kerr N, Holmes FE, Hobson SA, Vanderplank P, Leard A, Balthasar N, Wynick D. The generation of knock-in mice expressing fluorescently tagged galanin receptors 1 and 2. Mol Cell Neurosci 2015; 68:258-71. [PMID: 26292267 PMCID: PMC4604734 DOI: 10.1016/j.mcn.2015.08.006] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2015] [Revised: 08/06/2015] [Accepted: 08/10/2015] [Indexed: 12/12/2022] Open
Abstract
The neuropeptide galanin has diverse roles in the central and peripheral nervous systems, by activating the G protein-coupled receptors Gal1, Gal2 and the less studied Gal3 (GalR1-3 gene products). There is a wealth of data on expression of Gal1-3 at the mRNA level, but not at the protein level due to the lack of specificity of currently available antibodies. Here we report the generation of knock-in mice expressing Gal1 or Gal2 receptor fluorescently tagged at the C-terminus with, respectively, mCherry or hrGFP (humanized Renilla green fluorescent protein). In dorsal root ganglia (DRG) neurons expressing the highest levels of Gal1-mCherry, localization to the somatic cell membrane was detected by live-cell fluorescence and immunohistochemistry, and that fluorescence decreased upon addition of galanin. In spinal cord, abundant Gal1-mCherry immunoreactive processes were detected in the superficial layers of the dorsal horn, and highly expressing intrinsic neurons of the lamina III/IV border showed both somatic cell membrane localization and outward transport of receptor from the cell body, detected as puncta within cell processes. In brain, high levels of Gal1-mCherry immunofluorescence were detected within thalamus, hypothalamus and amygdala, with a high density of nerve endings in the external zone of the median eminence, and regions with lesser immunoreactivity included the dorsal raphe nucleus. Gal2-hrGFP mRNA was detected in DRG, but live-cell fluorescence was at the limits of detection, drawing attention to both the much lower mRNA expression than to Gal1 in mice and the previously unrecognized potential for translational control by upstream open reading frames (uORFs).
Collapse
MESH Headings
- Animals
- Brain/metabolism
- Cells, Cultured
- Ganglia, Spinal/cytology
- Green Fluorescent Proteins/genetics
- Green Fluorescent Proteins/metabolism
- Luminescent Proteins/genetics
- Luminescent Proteins/metabolism
- Mice
- Mice, Transgenic
- Microscopy, Confocal
- Neurons/physiology
- RNA, Messenger/metabolism
- Receptor, Galanin, Type 1/genetics
- Receptor, Galanin, Type 1/metabolism
- Receptor, Galanin, Type 2/genetics
- Receptor, Galanin, Type 2/metabolism
- Spinal Cord/metabolism
- Red Fluorescent Protein
Collapse
Affiliation(s)
- Niall Kerr
- Schools of Physiology and Pharmacology and Clinical Sciences, Medical Sciences Building, University Walk, Bristol BS8 1TD, UK
| | - Fiona E Holmes
- Schools of Physiology and Pharmacology and Clinical Sciences, Medical Sciences Building, University Walk, Bristol BS8 1TD, UK
| | - Sally-Ann Hobson
- Schools of Physiology and Pharmacology and Clinical Sciences, Medical Sciences Building, University Walk, Bristol BS8 1TD, UK
| | - Penny Vanderplank
- Schools of Physiology and Pharmacology and Clinical Sciences, Medical Sciences Building, University Walk, Bristol BS8 1TD, UK
| | - Alan Leard
- Wolfson Bioimaging Facility, Medical Sciences Building, University Walk, Bristol BS8 1TD, UK
| | - Nina Balthasar
- Schools of Physiology and Pharmacology and Clinical Sciences, Medical Sciences Building, University Walk, Bristol BS8 1TD, UK
| | - David Wynick
- Schools of Physiology and Pharmacology and Clinical Sciences, Medical Sciences Building, University Walk, Bristol BS8 1TD, UK.
| |
Collapse
|
31
|
Li XY, Toyoda H. Role of leak potassium channels in pain signaling. Brain Res Bull 2015; 119:73-9. [PMID: 26321392 DOI: 10.1016/j.brainresbull.2015.08.007] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2015] [Revised: 08/04/2015] [Accepted: 08/24/2015] [Indexed: 01/05/2023]
Abstract
Potassium (K(+)) channels are membrane proteins that allow rapid and selective flow of K(+) ions across the cell membrane, generating electrical signals in neurons. Thus, K(+) channels play a critical role in determining the neuronal excitability. Two-pore domain (K2P) "leak" K(+) channels give rise to leak K(+) currents that are responsible for the resting membrane potential and input resistance. The wide expression of leak K(+) channels in the central and peripheral nervous system suggests that these channels are critically involved in pain signaling and behavior. Indeed, it has become apparent in the past decade that the leak K(+) channels play essential roles in the development of pain. In this review, we describe evidence for the roles of TASK1, TASK3, TREK1, TREK2, TRAAK and TRESK channels in pain signaling and behavior. Furthermore, we describe the possible involvement of TASK2 and TWIK1 channels in pain.
Collapse
Affiliation(s)
- Xiang-Yao Li
- Institute of Neuroscience, School of Medicine, Zhejiang University, Zhejiang, China
| | - Hiroki Toyoda
- Department of Neuroscience and Oral Physiology, Osaka University Graduate School of Dentistry, 1-8, Yamadaoka, Suita, Japan.
| |
Collapse
|
32
|
Ru F, jr BP, Kollarik M. Acid sensitivity of the spinal dorsal root ganglia C-fiber nociceptors innervating the guinea pig esophagus. Neurogastroenterol Motil 2015; 27:865-74. [PMID: 25846134 PMCID: PMC4446164 DOI: 10.1111/nmo.12561] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/20/2014] [Accepted: 03/05/2015] [Indexed: 12/13/2022]
Abstract
BACKGROUND Gastroesophageal reflux can cause high acidity in the esophagus and trigger heartburn and pain. However, because of the esophageal mucosal barrier, the acidity at the nerve terminals of pain-mediating C-fibers in esophageal mucosa is predicted to be substantially lower. We hypothesized that the esophageal dorsal root ganglia (DRG) C-fibers are activated by mild acid (compared to acidic reflux), and express receptors and ion channels highly sensitive to acid. METHODS Extracellular single unit recordings of activity originating in esophageal DRG C-fiber nerve terminals were performed in the innervated esophagus preparation ex vivo. Acid was delivered in a manner that bypassed the esophageal mucosal barrier. The expression of mRNA for selected receptors in esophagus-specific DRG neurons was evaluated using single cell RT-PCR. KEY RESULTS Mild acid (pH = 6.5-5.5) activated esophageal DRG C-fibers in a pH-dependent manner. The response to mild acid at pH = 6 was not affected by the TRPV1 selective antagonist iodo-resiniferatoxin. The majority (70-95%) of esophageal DRG C-fiber neurons (TRPV1-positive) expressed mRNA for acid sensing ion channels (ASIC1a, ASIC1b, ASIC2b, and/or ASIC3), two-pore-domain (K2P) potassium channel TASK1, and the proton-sensing G-protein coupled receptor OGR1. Other evaluated targets (PKD2L1, TRPV4, TASK3, TALK1, G2A, GPR4, and TDAG8) were expressed rarely. CONCLUSIONS & INFERENCES Guinea pig esophageal DRG C-fibers are activated by mild acid via a TRPV1-independent mechanism, and express mRNA for several receptors and ion channels highly sensitive to acid. The high acid sensitivity of esophageal C-fibers may contribute to heartburn and pain in conditions of reduced mucosal barrier function.
Collapse
Affiliation(s)
- F Ru
- Medicine, The Johns Hopkins University School of Medicine, Baltimore, USA
| | - Banovcin P jr
- Pathophysiology, Comenius University in Bratislava, Jessenius Faculty of Medicine, Martin, Slovakia,Gastroenterology, Comenius University in Bratislava, Jessenius Faculty of Medicine, Martin, Slovakia
| | - M Kollarik
- Medicine, The Johns Hopkins University School of Medicine, Baltimore, USA
| |
Collapse
|
33
|
Sharif-Naeini R. Contribution of mechanosensitive ion channels to somatosensation. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2015; 131:53-71. [PMID: 25744670 DOI: 10.1016/bs.pmbts.2014.11.011] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Mechanotransduction, the conversion of a mechanical stimulus into an electrical signal, is a central mechanism to several physiological functions in mammals. It relies on the function of mechanosensitive ion channels (MSCs). Although the first single-channel recording from MSCs dates back to 30 years ago, the identity of the genes encoding MSCs has remained largely elusive. Because these channels have an important role in the development of mechanical hypersensitivity, a better understanding of their function may lead to the identification of selective inhibitors and generate novel therapeutic pathways in the treatment of chronic pain. Here, I will describe our current understanding of the role MSCs may play in somatosensation and the potential candidate genes proposed to encode them.
Collapse
Affiliation(s)
- Reza Sharif-Naeini
- Department of Physiology and Cell Information Systems Group, McGill University, Montreal, Quebec, Canada.
| |
Collapse
|
34
|
Mathie A, Veale EL. Two-pore domain potassium channels: potential therapeutic targets for the treatment of pain. Pflugers Arch 2014; 467:931-43. [DOI: 10.1007/s00424-014-1655-3] [Citation(s) in RCA: 63] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2014] [Revised: 11/11/2014] [Accepted: 11/13/2014] [Indexed: 01/01/2023]
|
35
|
Enyedi P, Czirják G. Properties, regulation, pharmacology, and functions of the K₂p channel, TRESK. Pflugers Arch 2014; 467:945-58. [PMID: 25366493 DOI: 10.1007/s00424-014-1634-8] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2014] [Revised: 10/09/2014] [Accepted: 10/12/2014] [Indexed: 12/21/2022]
Abstract
TWIK-related spinal cord K(+) channel (TRESK) is the gene product of KCNK18, the last discovered leak potassium K2P channel gene. Under resting conditions, TRESK is constitutively phosphorylated at two regulatory regions. Protein kinase A (PKA) and microtubule affinity-regulating (MARK) kinases can be applied in experiments to phosphorylate these sites of TRESK expressed in Xenopus oocytes, respectively. Upon generation of a calcium signal, TRESK is dephosphorylated and thereby activated by calcineurin. In this process, the binding of calcineurin to the channel by non-catalytic interacting sites is essential. The phosphorylation/dephosphorylation regulatory process is modified by 14-3-3 proteins. Human, but not murine TRESK is also activated by protein kinase C. TRESK is expressed most abundantly in sensory neurons of the dorsal root ganglia (DRG) and trigeminal ganglia, and the channel modifies certain forms of nociceptive afferentation. In a large pedigree, a dominant negative mutant TRESK allele was found to co-segregate perfectly with migraine phenotype. While this genetic defect may be responsible only for a very small fraction of migraine cases, specific TRESK activation is expected to exert beneficial effect in common forms of the disease.
Collapse
Affiliation(s)
- Péter Enyedi
- Department of Physiology, Semmelweis University, P.O. Box 259, 1444, Budapest, Hungary,
| | | |
Collapse
|
36
|
Wang F, Stefano GB, Kream RM. Epigenetic modification of DRG neuronal gene expression subsequent to nerve injury: etiological contribution to complex regional pain syndromes (Part II). Med Sci Monit 2014; 20:1188-200. [PMID: 25027291 PMCID: PMC4106931 DOI: 10.12659/msm.890707] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Cumulating evidence indicated that nerve injury-associated cellular and molecular changes play an essential role in contributing to the development of pathological pain, and more recent findings implicated the critical role of epigenetic mechanisms in pain-related sensitization in the DRG subsequent to nerve injury. In this part of the dyad review (Part II), we reviewed and paid special attention on the etiological contribution of DGR gene expression modulated by epigenetic mechanisms of CRPS. As essential effectors to different molecular activation, we first discussed the activation of various signaling pathways that subsequently from nerve injury, and in further illustrated the fundamental and functional underpinnings of nerve injury-induced pain, in which we argued for the potential epigenetic mechanisms in response to sensitizing stimuli or injury. Therefore, understanding the specific mediating factors that influence individual epigenetic differences contributing to pain sensitivity and responsiveness to analgesics possesses crucial clinical implications.
Collapse
Affiliation(s)
- Fuzhou Wang
- Department of Anesthesiology and Critical Care Medicine, Affiliated Nanjing Maternity and Child Health Care Hospital, Nanjing Medical University, Nanjing, China (mainland)
| | - George B Stefano
- Neuroscience Research Institute, State University of New York at Old Westbury, Old Westbury, China (mainland)
| | - Richard M Kream
- Neuroscience Research Institute, State University of New York at Old Westbury, Old Westbury, China (mainland)
| |
Collapse
|
37
|
Sousa-Valente J, Varga A, Ananthan K, Khajuria A, Nagy I. Anandamide in primary sensory neurons: too much of a good thing? Eur J Neurosci 2014; 39:409-18. [DOI: 10.1111/ejn.12467] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2013] [Revised: 11/22/2013] [Accepted: 12/02/2013] [Indexed: 01/01/2023]
Affiliation(s)
- João Sousa-Valente
- Section of Anaesthetics, Pain Medicine and Intensive Care; Department of Surgery and Cancer; Imperial College London; 369 Fulham Road London SW10 9NH UK
| | - Angelika Varga
- Section of Anaesthetics, Pain Medicine and Intensive Care; Department of Surgery and Cancer; Imperial College London; 369 Fulham Road London SW10 9NH UK
| | - Kajaluxy Ananthan
- Section of Anaesthetics, Pain Medicine and Intensive Care; Department of Surgery and Cancer; Imperial College London; 369 Fulham Road London SW10 9NH UK
| | - Ankur Khajuria
- Section of Anaesthetics, Pain Medicine and Intensive Care; Department of Surgery and Cancer; Imperial College London; 369 Fulham Road London SW10 9NH UK
| | - Istvan Nagy
- Section of Anaesthetics, Pain Medicine and Intensive Care; Department of Surgery and Cancer; Imperial College London; 369 Fulham Road London SW10 9NH UK
| |
Collapse
|
38
|
Opening paths to novel analgesics: the role of potassium channels in chronic pain. Trends Neurosci 2014; 37:146-58. [PMID: 24461875 PMCID: PMC3945816 DOI: 10.1016/j.tins.2013.12.002] [Citation(s) in RCA: 183] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2013] [Revised: 12/13/2013] [Accepted: 12/17/2013] [Indexed: 01/02/2023]
Abstract
Potassium (K+) channels are crucial determinants of neuronal excitability. Nerve injury or inflammation alters K+ channel activity in neurons of the pain pathway. These changes can render neurons hyperexcitable and cause chronic pain. Therapies targeting K+ channels may provide improved pain relief in these states.
Chronic pain is associated with abnormal excitability of the somatosensory system and remains poorly treated in the clinic. Potassium (K+) channels are crucial determinants of neuronal activity throughout the nervous system. Opening of these channels facilitates a hyperpolarizing K+ efflux across the plasma membrane that counteracts inward ion conductance and therefore limits neuronal excitability. Accumulating research has highlighted a prominent involvement of K+ channels in nociceptive processing, particularly in determining peripheral hyperexcitability. We review salient findings from expression, pharmacological, and genetic studies that have untangled a hitherto undervalued contribution of K+ channels in maladaptive pain signaling. These emerging data provide a framework to explain enigmatic pain syndromes and to design novel pharmacological treatments for these debilitating states.
Collapse
|