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Zhang L, Chen X, Li M, Lv R, Gu B, Chen Z. Activation of the adenosine A1 receptor in the lumbosacral spinal cord improves bladder overactivity in rats with cystitis induced by cyclophosphamide. Int Urol Nephrol 2023; 55:2183-2191. [PMID: 37330931 DOI: 10.1007/s11255-023-03659-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2023] [Accepted: 06/02/2023] [Indexed: 06/20/2023]
Abstract
PURPOSE To investigate the effect of intrathecal administration of CCPA, an adenosine A1 receptor agonist, on voiding function in rats with cystitis induced by cyclophosphamide (CYP). METHODS Thirty 8-week-old Sprague Dawley rats were randomly divided into a control group (n = 15) and a cystitis group (n = 15). Cystitis was induced by a single intraperitoneal injection of CYP (200 mg/kg, dissolved in physiological saline) in rats. Control rats were injected intraperitoneally with physiological saline. The PE10 catheter reached the level of L6-S1 spinal cord through L3-4 intervertebral space for intrathecal injection. Forty-eight hours after intraperitoneal injection, urodynamic tests were conducted to observe the effect of intrathecal administration of 10% dimethylsulfoxide (vehicle) and 1 nmol CCPA on micturition parameters, including basal pressure (BP), threshold pressure (TP), maximal voiding pressure (MVP), intercontraction interval (ICI), voided volume (VV), residual volume (RV), bladder capacity (BC), and voiding efficiency (VE). Histological changes of the bladder of cystitis rats were studied through hematoxylin-eosin staining (HE staining). Moreover, Western blot and immunofluorescence were used to study the expression of adenosine A1 receptor in the L6-S1 dorsal spinal cord in both groups of rats. RESULTS HE staining revealed submucosal hemorrhage, edema, and inflammatory cell infiltration in the bladder wall of cystitis rats. The urodynamic test showed significant increase in BP, TP, MVP and RV in cystitis rats, while ICI, VV, BC and VE decreased significantly, indicating bladder overactivity. CCPA inhibited the micturition reflex in both control and cystitis rats, and significantly increased TP, ICI, VV, BC, and VE, but had no significant effect on BP, MVP and RV. Western blot and immunofluorescence showed that there was no significant difference in the expression of adenosine A1 receptor in the L6-S1 dorsal spinal cord between the control and cystitis rats. CONCLUSION The findings of this study suggest that intrathecal administration of the adenosine A1 receptor agonist CCPA alleviates CYP-induced bladder overactivity. Furthermore, our results indicate that the adenosine A1 receptor in the lumbosacral spinal cord may be a promising target for treatment of bladder overactivity.
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Affiliation(s)
- Lin Zhang
- Department of Urology, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, 600 Yishan Road, Shanghai, 200233, China
| | - Xun Chen
- Department of Urology, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, 600 Yishan Road, Shanghai, 200233, China
| | - Mingzhuo Li
- Department of Urology, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, 600 Yishan Road, Shanghai, 200233, China
| | - Rong Lv
- Department of Urology, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, 600 Yishan Road, Shanghai, 200233, China
| | - Baojun Gu
- Department of Urology, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, 600 Yishan Road, Shanghai, 200233, China.
| | - Zhong Chen
- Department of Urology, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, 600 Yishan Road, Shanghai, 200233, China.
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Breitinger U, Breitinger HG. Excitatory and inhibitory neuronal signaling in inflammatory and diabetic neuropathic pain. Mol Med 2023; 29:53. [PMID: 37069517 PMCID: PMC10111846 DOI: 10.1186/s10020-023-00647-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2022] [Accepted: 03/27/2023] [Indexed: 04/19/2023] Open
Abstract
Pain, although unpleasant, is an essential warning mechanism against injury and damage of the organism. An intricate network of specialised sensors and transmission systems contributes to reception, transmission and central sensitization of pain. Here, we briefly introduce some of the main aspects of pain signal transmission, including nociceptors and nociceptive signals, mechanisms of inflammatory and neuropathic pain, and the situation of diabetes-associated neuropathic pain. The role of glia-astrocytes, microglia, satellite glia cells-and their specific channels, transporters and signaling pathways is described. A focus is on the contribution of inhibitory synaptic signaling to nociception and a possible role of glycine receptors in glucose-mediated analgesia and treatment-induced diabetic neuropathy. Inhibitory receptors such as GABAA- and glycine receptors are important contributors to nociceptive signaling; their contribution to altered pain sensation in diabetes may be of clinical relevance, and they could be promising therapeutic targets towards the development of novel analgesics.
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Affiliation(s)
- Ulrike Breitinger
- Department of Biochemistry, German University in Cairo, New Cairo, 11835, Egypt
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3
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Perkins ME, Girard BM, Campbell SE, Vizzard MA. Imatinib Mesylate Reduces Voiding Frequency in Female Mice With Acute Cyclophosphamide-Induced Cystitis. Front Syst Neurosci 2022; 16:867875. [PMID: 35645740 PMCID: PMC9135974 DOI: 10.3389/fnsys.2022.867875] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2022] [Accepted: 04/19/2022] [Indexed: 01/28/2023] Open
Abstract
Lamina propria interstitial cells that express the tyrosine kinase receptor, platelet-derived growth factor receptor alpha (PDGFRα) may play a role in urinary sensory signaling. Imatinib mesylate, also referred to as imatinib, is a tyrosine kinase inhibitor that can inhibit PDGFRα and has been widely used in urological research. We evaluated the functional effects of imatinib administration (via oral gavage or intravesical infusion) with two different experimental designs (prevention and treatment), in a cyclophosphamide (CYP)-induced cystitis (acute, intermediate, and chronic), male and female rodent model using conscious cystometry and somatic sensitivity testing. Imatinib significantly (0.0001 ≤ p ≤ 0.05) decreased voiding frequency and increased bladder capacity in acute CYP-induced cystitis, by the prevention (females) and treatment (females and males) designs. Imatinib was not effective in preventing or treating intermediate or chronic CYP-induced cystitis in either sex. Interestingly, in the prevention experiments, imatinib administration increased (0.0001 ≤ p ≤ 0.01) voiding frequency and decreased bladder capacity in control mice. However, in the treatment experiments, imatinib administration decreased (0.01 ≤ p ≤ 0.05) voiding frequency and increased bladder capacity in control mice. Bladder function improvements observed with imatinib treatment in acute CYP-induced cystitis mice remained and additionally improved with a second dose of imatinib 24 hours after CYP treatment. Imatinib administration did not affect pelvic somatic sensitivity in female mice with acute CYP-induced cystitis. Our studies suggest that (1) imatinib improves bladder function in mice with acute CYP-induced cystitis with a prevention and treatment design and (2) interstitial cells may be a useful target to improve bladder function in cystitis.
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Çakıcı ÖU, Dinçer S. The effect of amino acids on the bladder cycle: a concise review. Amino Acids 2021; 54:13-31. [PMID: 34853916 DOI: 10.1007/s00726-021-03113-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2021] [Accepted: 11/25/2021] [Indexed: 11/26/2022]
Abstract
The human bladder maintains a cycle of filling, storing, and micturating throughout an individual's lifespan. The cycle relies on the ability of the bladder to expand without increasing the intravesical pressure, which is only possible with the controlled relaxation of well-complaint muscles and the congruously organized construction of the bladder wall. A competent bladder outlet, which functions in a synchronous fashion with the bladder, is also necessary for this cycle to be completed successfully without deterioration. In this paper, we aimed to review the contemporary physiological findings on bladder physiology and examine the effects of amino acids on clinical conditions affecting the bladder, with special emphasis on the available therapeutic evidence and possible future roles of the amino acids in the treatment of the bladder-related disorders.
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Affiliation(s)
- Özer Ural Çakıcı
- Attending Urologist, Private Practice, Ankara, Turkey.
- PhD Candidate in Physiology, Department of Physiology, Gazi University, Ankara, Turkey.
| | - Sibel Dinçer
- Professor in Physiology, Department of Physiology, Gazi University, Ankara, Turkey
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Ishida K, Mbanefo EC, Le L, Lamanna O, Pennington LF, Finkel JC, Jardetzky TS, Falcone FH, Hsieh MH. IPSE, a parasite-derived, host immunomodulatory infiltrin protein, alleviates resiniferatoxin-induced bladder pain. Mol Pain 2021; 16:1744806920970099. [PMID: 33342372 PMCID: PMC7756320 DOI: 10.1177/1744806920970099] [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] [Indexed: 11/16/2022] Open
Abstract
The transient receptor potential cation channel subfamily V member 1 (TRPV1)
receptor is an important mediator of nociception and its expression is enriched
in nociceptive neurons. TRPV1 signaling has been implicated in bladder pain and
is a potential analgesic target. Resiniferatoxin is the most potent known
agonist of TRPV1. Acute exposure of the rat bladder to resiniferatoxin has been
demonstrated to result in pain-related freezing and licking behaviors that are
alleviated by virally encoded IL-4. The interleukin-4-inducing principle of
Schistosoma mansoni eggs (IPSE) is a powerful inducer of
IL-4 secretion, and is also known to alter host cell transcription through a
nuclear localization sequence-based mechanism. We previously reported that IPSE
ameliorates ifosfamide-induced bladder pain in an IL-4- and nuclear localization
sequence-dependent manner. We hypothesized that pre-administration of IPSE to
resiniferatoxin-challenged mice would dampen pain-related behaviors. IPSE indeed
lessened resiniferatoxin-triggered freezing behaviors in mice. This was a
nuclear localization sequence-dependent phenomenon, since administration of a
nuclear localization sequence mutant version of IPSE abrogated IPSE’s analgesic
effect. In contrast, IPSE’s analgesic effect did not seem IL-4-dependent, since
use of anti-IL-4 antibody in mice given both IPSE and resiniferatoxin did not
significantly affect freezing behaviors. RNA-Seq analysis of resiniferatoxin-
and IPSE-exposed bladders revealed differential expression of TNF/NF-κb-related
signaling pathway genes. In vitro testing of IPSE uptake by
urothelial cells and TRPV1-expressing neuronal cells showed uptake by both cell
types. Thus, IPSE’s nuclear localization sequence-dependent therapeutic effects
on TRPV1-mediated bladder pain may act on TRPV1-expressing neurons and/or may
rely upon urothelial mechanisms.
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Affiliation(s)
- Kenji Ishida
- Division of Urology, Department of Surgery, Children's National Hospital, Washington, DC, USA
| | - Evaristus C Mbanefo
- Division of Urology, Department of Surgery, Children's National Hospital, Washington, DC, USA
| | - Loc Le
- Biomedical Research Institute, Rockville, MD, USA
| | - Olivia Lamanna
- Division of Urology, Department of Surgery, Children's National Hospital, Washington, DC, USA
| | - Luke F Pennington
- Department of Structural Biology, Stanford University, Stanford, CA, USA
| | - Julia C Finkel
- Department of Anesthesiology, Pain and Perioperative Medicine, Children's National Hospital, Washington, DC, USA
| | | | - Franco H Falcone
- Institute of Parasitology, Justus-Liebig-Universität Gießen, Gießen, Germany
| | - Michael H Hsieh
- Division of Urology, Department of Surgery, Children's National Hospital, Washington, DC, USA
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6
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Inhibition of Glycine Re-Uptake: A Potential Approach for Treating Pain by Augmenting Glycine-Mediated Spinal Neurotransmission and Blunting Central Nociceptive Signaling. Biomolecules 2021; 11:biom11060864. [PMID: 34200954 PMCID: PMC8230656 DOI: 10.3390/biom11060864] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Revised: 06/07/2021] [Accepted: 06/08/2021] [Indexed: 12/23/2022] Open
Abstract
Among the myriad of cellular and molecular processes identified as contributing to pathological pain, disinhibition of spinal cord nociceptive signaling to higher cortical centers plays a critical role. Importantly, evidence suggests that impaired glycinergic neurotransmission develops in the dorsal horn of the spinal cord in inflammatory and neuropathic pain models and is a key maladaptive mechanism causing mechanical hyperalgesia and allodynia. Thus, it has been hypothesized that pharmacological agents capable of augmenting glycinergic tone within the dorsal horn may be able to blunt or block aberrant nociceptor signaling to the brain and serve as a novel class of analgesics for various pathological pain states. Indeed, drugs that enhance dysfunctional glycinergic transmission, and in particular inhibitors of the glycine transporters (GlyT1 and GlyT2), are generating widespread interest as a potential class of novel analgesics. The GlyTs are Na+/Cl−-dependent transporters of the solute carrier 6 (SLC6) family and it has been proposed that the inhibition of them presents a possible mechanism by which to increase spinal extracellular glycine concentrations and enhance GlyR-mediated inhibitory neurotransmission in the dorsal horn. Various inhibitors of both GlyT1 and GlyT2 have demonstrated broad analgesic efficacy in several preclinical models of acute and chronic pain, providing promise for the approach to deliver a first-in-class non-opioid analgesic with a mechanism of action differentiated from current standard of care. This review will highlight the therapeutic potential of GlyT inhibitors as a novel class of analgesics, present recent advances reported for the field, and discuss the key challenges associated with the development of a GlyT inhibitor into a safe and effective agent to treat pain.
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Benito-Muñoz C, Perona A, Felipe R, Pérez-Siles G, Núñez E, Aragón C, López-Corcuera B. Structural Determinants of the Neuronal Glycine Transporter 2 for the Selective Inhibitors ALX1393 and ORG25543. ACS Chem Neurosci 2021; 12:1860-1872. [PMID: 34003005 PMCID: PMC8691691 DOI: 10.1021/acschemneuro.0c00602] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
![]()
The
neuronal glycine transporter GlyT2 modulates inhibitory glycinergic
neurotransmission by controlling the extracellular concentration of
synaptic glycine and the supply of neurotransmitter to the presynaptic
terminal. Spinal cord glycinergic neurons present in the dorsal horn
diminish their activity in pathological pain conditions and behave
as gate keepers of the touch-pain circuitry. The pharmacological blockade
of GlyT2 reduces the progression of the painful signal to rostral
areas of the central nervous system by increasing glycine extracellular
levels, so it has analgesic action. O-[(2-benzyloxyphenyl-3-fluorophenyl)methyl]-l-serine (ALX1393) and N-[[1-(dimethylamino)cyclopentyl]methyl]-3,5-dimethoxy-4-(phenylmethoxy)benzamide
(ORG25543) are two selective GlyT2 inhibitors with nanomolar affinity
for the transporter and analgesic effects in pain animal models, although
with deficiencies which preclude further clinical development. In
this report, we performed a comparative ligand docking of ALX1393
and ORG25543 on a validated GlyT2 structural model including all ligand
sites constructed by homology with the crystallized dopamine transporter
from Drosophila melanogaster. Molecular dynamics
simulations and energy analysis of the complex and functional analysis
of a series of point mutants permitted to determine the structural
determinants of ALX1393 and ORG25543 discrimination by GlyT2. The
ligands establish simultaneous contacts with residues present in transmembrane
domains 1, 3, 6, and 8 and block the transporter in outward-facing
conformation and hence inhibit glycine transport. In addition, differential
interactions of ALX1393 with the cation bound at Na1 site and ORG25543
with TM10 define the differential sites of the inhibitors and explain
some of their individual features. Structural information about the
interactions with GlyT2 may provide useful tools for new drug discovery.
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Affiliation(s)
- Cristina Benito-Muñoz
- Departamento de Biología Molecular, Universidad Autónoma de Madrid, 28049 Madrid, Spain
- Centro de Biología Molecular “Severo Ochoa” Consejo Superior de Investigaciones Científicas, Universidad Autónoma de Madrid, 28049 Madrid, Spain
| | - Almudena Perona
- Departamento de Química en Ciencias Farmacéuticas, Universidad Complutense de Madrid, 28040 Madrid, Spain
| | - Raquel Felipe
- Departamento de Biología Molecular, Universidad Autónoma de Madrid, 28049 Madrid, Spain
- Centro de Biología Molecular “Severo Ochoa” Consejo Superior de Investigaciones Científicas, Universidad Autónoma de Madrid, 28049 Madrid, Spain
| | - Gonzalo Pérez-Siles
- Departamento de Biología Molecular, Universidad Autónoma de Madrid, 28049 Madrid, Spain
- Centro de Biología Molecular “Severo Ochoa” Consejo Superior de Investigaciones Científicas, Universidad Autónoma de Madrid, 28049 Madrid, Spain
| | - Enrique Núñez
- Departamento de Biología Molecular, Universidad Autónoma de Madrid, 28049 Madrid, Spain
- Centro de Biología Molecular “Severo Ochoa” Consejo Superior de Investigaciones Científicas, Universidad Autónoma de Madrid, 28049 Madrid, Spain
| | - Carmen Aragón
- Departamento de Biología Molecular, Universidad Autónoma de Madrid, 28049 Madrid, Spain
- Centro de Biología Molecular “Severo Ochoa” Consejo Superior de Investigaciones Científicas, Universidad Autónoma de Madrid, 28049 Madrid, Spain
- IdiPAZ-Hospital Universitario La Paz, Universidad Autónoma de Madrid, 28049 Madrid, Spain
| | - Beatriz López-Corcuera
- Departamento de Biología Molecular, Universidad Autónoma de Madrid, 28049 Madrid, Spain
- Centro de Biología Molecular “Severo Ochoa” Consejo Superior de Investigaciones Científicas, Universidad Autónoma de Madrid, 28049 Madrid, Spain
- IdiPAZ-Hospital Universitario La Paz, Universidad Autónoma de Madrid, 28049 Madrid, Spain
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8
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Andersson KE, Fry C, Panicker J, Rademakers K. Which molecular targets do we need to focus on to improve lower urinary tract dysfunction? ICI-RS 2017. Neurourol Urodyn 2019; 37:S117-S126. [PMID: 30133792 DOI: 10.1002/nau.23516] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2017] [Accepted: 12/26/2017] [Indexed: 12/18/2022]
Abstract
AIMS Update on some molecular targets for new drugs to improve lower urinary tract (LUT) dysfunction. METHODS Using PubMed, a search for literature on molecular targets in the LUT was performed to identify relevant clinical and animal studies. Keywords were entered as Medical Subject Headings (MeSH) or as text words. The Mesh terms were used in various combinations and usually included the terms lower urinary AND pharmacology. Other Mesh term included: bladder, urethra, CNS, physiology, afferent activity, ATP, prostanoids, cannabinoids, fibrosis. Search results were assessed for their overall relevance to this review. RESULTS In a normal bladder, ATP contributes little to detrusor contraction, but in a diseased bladder ATP may contribute to OAB. Selective decrease of ATP release via adenosine A1 receptor stimulation offers a potential treatment possibility. Candidates for relaxation of the smooth muscle of the urethra can be found among, for example, the receptor subtypes of PGE2 , and PGD2 . Drugs for relaxation of the striated sphincter can target the muscle directly or the spinal sphincter control. Fibrosis is a major problem in LUT dysfunction and agents with an inhibitory effect on the TGFβ pathway, for example relaxin and BMP7, may be promising avenues. Available drugs with a CNS site of action are often limited by low efficacy or adverse effects. Inhibitors of the glycine receptor Gly-T2 or antagonists of the adenosine A2 receptor may be new alternatives. CONCLUSION New molecular targets for drugs aiming at improvement of voiding function can be identified, but their translational impact remains to be established.
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Affiliation(s)
- Karl-Erik Andersson
- Institute for Regenerative Medicine, Wake Forest University School of Medicine, Winston Salem NC, and Institute of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | - Christopher Fry
- Department of Uro-Neurology, The National Hospital for Neurology and Neurosurgery and UCL Institute of Neurology, London, United Kingdom
| | - Jalesh Panicker
- Department of urology, Maastricht University Medical Center, Maastricht, The Netherlands
| | - Kevin Rademakers
- Department of urology, Maastricht University Medical Center, Maastricht, The Netherlands
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Zeilhofer HU, Acuña MA, Gingras J, Yévenes GE. Glycine receptors and glycine transporters: targets for novel analgesics? Cell Mol Life Sci 2018; 75:447-465. [PMID: 28791431 PMCID: PMC11105467 DOI: 10.1007/s00018-017-2622-x] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2017] [Revised: 07/14/2017] [Accepted: 08/04/2017] [Indexed: 01/29/2023]
Abstract
Glycinergic neurotransmission has long been known for its role in spinal motor control. During the last two decades, additional functions have become increasingly recognized-among them is a critical contribution to spinal pain processing. Studies in rodent pain models provide proof-of-concept evidence that enhancing inhibitory glycinergic neurotransmission reduces chronic pain symptoms. Apparent strategies for pharmacological intervention include positive allosteric modulators of glycine receptors and modulators or inhibitors of the glial and neuronal glycine transporters GlyT1 and GlyT2. These prospects have led to drug discovery efforts in academia and in industry aiming at compounds that target glycinergic neurotransmission with high specificity. Available data show promising analgesic efficacy. Less is currently known about potential unwanted effects but the presence of glycinergic innervation in CNS areas outside the nociceptive system prompts for a careful evaluation not only of motor function, but also of potential respiratory impairment and addictive properties.
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Affiliation(s)
- Hanns Ulrich Zeilhofer
- Institute of Pharmacology and Toxicology, University of Zurich, Winterthurerstrasse 190, 8057, Zurich, Switzerland.
- Institute of Pharmaceutical Sciences, Swiss Federal Institute of Technology (ETH) Zürich, Vladimir-Prelog-Weg 1-5/10, 8093, Zurich, Switzerland.
| | - Mario A Acuña
- Institute of Pharmacology and Toxicology, University of Zurich, Winterthurerstrasse 190, 8057, Zurich, Switzerland
| | | | - Gonzalo E Yévenes
- Department of Physiology, University of Concepción, Concepción, Chile
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10
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Cioffi CL. Modulation of Glycine-Mediated Spinal Neurotransmission for the Treatment of Chronic Pain. J Med Chem 2017; 61:2652-2679. [PMID: 28876062 DOI: 10.1021/acs.jmedchem.7b00956] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Chronic pain constitutes a significant and expanding worldwide health crisis. Currently available analgesics poorly serve individuals suffering from chronic pain, and new therapeutic agents that are more effective, safer, and devoid of abuse liabilities are desperately needed. Among the myriad of cellular and molecular processes contributing to chronic pain, spinal disinhibition of pain signaling to higher cortical centers plays a critical role. Accumulating evidence shows that glycinergic inhibitory neurotransmission in the spinal cord dorsal horn gates nociceptive signaling, is essential in maintaining physiological pain sensitivity, and is diminished in pathological pain states. Thus, it is hypothesized that agents capable of enhancing glycinergic tone within the dorsal horn could obtund nociceptor signaling to the brain and serve as analgesics for persistent pain. This Perspective highlights the potential that pharmacotherapies capable of increasing inhibitory spinal glycinergic neurotransmission hold in providing new and transformative analgesic therapies for the treatment of chronic pain.
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Affiliation(s)
- Christopher L Cioffi
- Departments of Basic and Clinical Sciences and Pharmaceutical Sciences , Albany College of Pharmacy and Health Sciences , 106 New Scotland Avenue , Albany , New York 12208 United States
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Nedeljkovic SS, Correll DJ, Bao X, Zamor N, Zeballos JL, Zhang Y, Young MJ, Ledley J, Sorace J, Eng K, Hamsher CP, Maniam R, Chin JW, Tsui B, Cho S, Lee DH. Randomised, double-blind, parallel group, placebo-controlled study to evaluate the analgesic efficacy and safety of VVZ-149 injections for postoperative pain following laparoscopic colorectal surgery. BMJ Open 2017; 7:e011035. [PMID: 28213593 PMCID: PMC5318554 DOI: 10.1136/bmjopen-2016-011035] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/13/2016] [Revised: 06/02/2016] [Accepted: 08/03/2016] [Indexed: 12/23/2022] Open
Abstract
INTRODUCTION In spite of advances in understanding and technology, postoperative pain remains poorly treated for a significant number of patients. In colorectal surgery, the need for developing novel analgesics is especially important. Patients after bowel surgery are assessed for rapid return of bowel function and opioids worsen ileus, nausea and constipation. We describe a prospective, double-blind, parallel group, placebo-controlled randomised controlled trial testing the hypothesis that a novel analgesic drug, VVZ -149, is safe and effective in improving pain compared with providing opioid analgesia alone among adults undergoing laparoscopic colorectal surgery. METHODS AND ANALYSIS Based on sample size calculations for primary outcome, we plan to enrol 120 participants. Adult patients without significant medical comorbidities or ongoing opioid use and who are undergoing laparoscopic colorectal surgery will be enrolled. Participants are randomly assigned to receive either VVZ-149 with intravenous (IV) hydromorphone patient-controlled analgesia (PCA) or the control intervention (IV PCA alone) in the postoperative period. The primary outcome is the Sum of Pain Intensity Difference over 8 hours (SPID-8 postdose). Participants receive VVZ-149 for 8 hours postoperatively to the primary study end point, after which they continue to be assessed for up to 24 hours. We measure opioid consumption, record pain intensity and pain relief, and evaluate the number of rescue doses and requests for opioid. To assess safety, we record sedation, nausea and vomiting, respiratory depression, laboratory tests and ECG readings after study drug administration. We evaluate for possible confounders of analgesic response, such as anxiety, depression and catastrophising behaviours. The study will also collect blood sample data and evaluate for pharmacokinetic and pharmacodynamic relationships. ETHICS AND DISSEMINATION Ethical approval of the study protocol has been obtained from Institutional Review Boards at the participating institutions. Trial results will be disseminated through scientific conference presentations and by publication in scientific journals. TRIAL REGISTRATION NUMBER NCT02489526; pre-results.
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Affiliation(s)
- Srdjan S Nedeljkovic
- Department of Anesthesiology, Perioperative and Pain Medicine, Brigham and Women's Hospital, Boston, Massachusetts, USA
| | - Darin J Correll
- Department of Anesthesiology, Perioperative and Pain Medicine, Brigham and Women's Hospital, Boston, Massachusetts, USA
| | - Xiaodong Bao
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Boston, Massachusetts, USA
| | - Natacha Zamor
- Department of Anesthesia, Critical Care and Pain Medicine, Beth Israel Deaconess Medical Center, Boston, Massachusetts, USA
| | - Jose L Zeballos
- Department of Anesthesiology, Perioperative and Pain Medicine, Brigham and Women's Hospital, Boston, Massachusetts, USA
| | - Yi Zhang
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Boston, Massachusetts, USA
| | - Mark J Young
- Department of Anesthesia, Critical Care and Pain Medicine, Beth Israel Deaconess Medical Center, Boston, Massachusetts, USA
| | - Johanna Ledley
- Department of Anesthesiology, Perioperative and Pain Medicine, Brigham and Women's Hospital, Boston, Massachusetts, USA
| | - Jessica Sorace
- Department of Anesthesiology, Perioperative and Pain Medicine, Brigham and Women's Hospital, Boston, Massachusetts, USA
| | - Kristen Eng
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Boston, Massachusetts, USA
| | - Carlyle P Hamsher
- Department of Anesthesiology, Perioperative and Pain Medicine, Brigham and Women's Hospital, Boston, Massachusetts, USA
| | - Rajivan Maniam
- Department of Anesthesiology, Perioperative and Pain Medicine, Brigham and Women's Hospital, Boston, Massachusetts, USA
| | - Jonathan W Chin
- Department of Anesthesiology, Perioperative and Pain Medicine, Brigham and Women's Hospital, Boston, Massachusetts, USA
| | - Becky Tsui
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Boston, Massachusetts, USA
| | | | - Doo H Lee
- Vivozon, Inc. Seoul, Seoul, South Korea
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12
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Glycinergic transmission: glycine transporter GlyT2 in neuronal pathologies. Neuronal Signal 2016; 1:NS20160009. [PMID: 32714574 PMCID: PMC7377260 DOI: 10.1042/ns20160009] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2016] [Revised: 11/04/2016] [Accepted: 11/09/2016] [Indexed: 11/17/2022] Open
Abstract
Glycinergic neurons are major contributors to the regulation of neuronal excitability, mainly in caudal areas of the nervous system. These neurons control fluxes of sensory information between the periphery and the CNS and diverse motor activities like locomotion, respiration or vocalization. The phenotype of a glycinergic neuron is determined by the expression of at least two proteins: GlyT2, a plasma membrane transporter of glycine, and VIAAT, a vesicular transporter shared by glycine and GABA. In this article, we review recent advances in understanding the role of GlyT2 in the pathophysiology of inhibitory glycinergic neurotransmission. GlyT2 mutations are associated to decreased glycinergic function that results in a rare movement disease termed hyperekplexia (HPX) or startle disease. In addition, glycinergic neurons control pain transmission in the dorsal spinal cord and their function is reduced in chronic pain states. A moderate inhibition of GlyT2 may potentiate glycinergic inhibition and constitutes an attractive target for pharmacological intervention against these devastating conditions.
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Spinal glycine transporter-1 inhibition influences the micturition reflex in urethane-anesthetized rats. Int Urol Nephrol 2016; 48:349-54. [PMID: 26843416 DOI: 10.1007/s11255-015-1148-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2015] [Accepted: 10/23/2015] [Indexed: 10/22/2022]
Abstract
PURPOSE Glycine is an inhibitory neurotransmitter in the central nervous system. So far, two types of glycine transporters (GlyTs), GlyT-1 and GlyT-2, have been cloned. The aim of this study is to investigate the effects of a selective GlyT-1 inhibitor that can increase endogenous glycine concentration on the micturition reflex in urethane-anesthetized rats. METHODS Continuous cystometrograms (0.04 ml/min) were performed in female Sprague-Dawley rats (232-265 g) under urethane anesthesia. After stable micturition cycles were established, ALX5407, a selective GlyT-1 inhibitor, was administered intrathecally or intracerebroventricularly to evaluate changes in bladder activity. Cystometric parameters were recorded and compared before and after drug administration. RESULTS Intrathecal administration of ALX5407 (1, 3, 10 and 30 μg) increased intercontraction intervals at doses of 3 μg or higher in a dose-dependent fashion. Intrathecal administration of ALX5407 (1, 3, 10 and 30 μg) also increased pressure threshold at doses of 3 μg or higher in a dose-dependent fashion. However, when ALX5407 (1, 3, 10 and 30 μg) was administered intracerebroventricularly, there were no significant changes in intercontraction intervals, pressure threshold, maximum voiding pressure or baseline pressure or post-void residual urine volume at any doses tested. CONCLUSION The results of our study indicate that GlyT-1 plays an important role in the modulation of micturition. Furthermore, these findings indicate that in urethane-anesthetized rats suppression of GlyT-1 can inhibit the micturition reflex at the spinal cord level. Thus, GlyT-1 could be a potential target for the treatment of bladder dysfunction such as overactive bladder.
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Ogawa T, Ishizuka O, Ueda T, Tyagi P, Chancellor MB, Yoshimura N. Current and emerging drugs for interstitial cystitis/bladder pain syndrome (IC/BPS). Expert Opin Emerg Drugs 2015; 20:555-70. [DOI: 10.1517/14728214.2015.1105216] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
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Lin L, Yee SW, Kim RB, Giacomini KM. SLC transporters as therapeutic targets: emerging opportunities. Nat Rev Drug Discov 2015; 14:543-60. [PMID: 26111766 DOI: 10.1038/nrd4626] [Citation(s) in RCA: 512] [Impact Index Per Article: 56.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Solute carrier (SLC) transporters - a family of more than 300 membrane-bound proteins that facilitate the transport of a wide array of substrates across biological membranes - have important roles in physiological processes ranging from the cellular uptake of nutrients to the absorption of drugs and other xenobiotics. Several classes of marketed drugs target well-known SLC transporters, such as neurotransmitter transporters, and human genetic studies have provided powerful insight into the roles of more-recently characterized SLC transporters in both rare and common diseases, indicating a wealth of new therapeutic opportunities. This Review summarizes knowledge on the roles of SLC transporters in human disease, describes strategies to target such transporters, and highlights current and investigational drugs that modulate SLC transporters, as well as promising drug targets.
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Affiliation(s)
- Lawrence Lin
- Department of Bioengineering and Therapeutic Sciences, Schools of Pharmacy and Medicine, University of California San Francisco, San Francisco, California 94158, USA
| | - Sook Wah Yee
- Department of Bioengineering and Therapeutic Sciences, Schools of Pharmacy and Medicine, University of California San Francisco, San Francisco, California 94158, USA
| | - Richard B Kim
- Division of Clinical Pharmacology, Department of Medicine, University of Western Ontario, London Health Science Centre, London, Ontario N6A 5A5, Canada
| | - Kathleen M Giacomini
- 1] Department of Bioengineering and Therapeutic Sciences, Schools of Pharmacy and Medicine, University of California San Francisco, San Francisco, California 94158, USA. [2] Institute for Human Genetics, University of California San Francisco, San Francisco, California 94158, USA
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Sacco E, Recupero S, Bientinesi R, Palermo G, D’Agostino D, Currò D, Bassi P. Pioneering drugs for overactive bladder and detrusor overactivity: Ongoing research and future directions. World J Obstet Gynecol 2015; 4:24-39. [DOI: 10.5317/wjog.v4.i2.24] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/20/2014] [Revised: 01/31/2015] [Accepted: 04/14/2015] [Indexed: 02/05/2023] Open
Abstract
The ongoing research on pioneering drug candidates for the overactive bladder (OAB) aimed to overcome the limitations of currently licensed pharmacotherapies, such as antimuscarinics, β3-adrenergic agents, and botulinum neurotoxin, has been reviewed performing a systematic literature review and web search. The review covers the exploratory agents alternative to available medications for OAB and that may ultimately prove to be therapeutically useful in the future management of OAB patients based on preclinical and early clinical data. It emerges that many alternative pharmacological strategies have been discovered or are under investigation in disease-oriented studies. Several potential therapeutics are known for years but still find obstacles to pass the clinical stages of development, while other completely novel compounds, targeting new pharmacological targets, have been recently discovered and show potential to translate into clinical therapeutic agents for idiopathic and neurogenic OAB syndrome. The global scenario of investigational drugs for OAB gives promise for the development of innovative therapeutics that may ultimately prove effective as first, combined or second-line treatments within a realistic timescale of ten years.
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Yoshimura N, Oguchi T, Yokoyama H, Funahashi Y, Yoshikawa S, Sugino Y, Kawamorita N, Kashyap MP, Chancellor MB, Tyagi P, Ogawa T. Bladder afferent hyperexcitability in bladder pain syndrome/interstitial cystitis. Int J Urol 2015; 21 Suppl 1:18-25. [PMID: 24807488 DOI: 10.1111/iju.12308] [Citation(s) in RCA: 82] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2013] [Accepted: 08/27/2013] [Indexed: 12/30/2022]
Abstract
Bladder pain syndrome/interstitial cystitis is a disease with lower urinary tract symptoms, such as bladder pain and urinary frequency, which results in seriously impaired quality of life of patients. The extreme pain and urinary frequency are often difficult to treat. Although the etiology of bladder pain syndrome/interstitial cystitis is still not known, there is increasing evidence showing that afferent hyperexcitability as a result of neurogenic bladder inflammation and urothelial dysfunction is important to the pathophysiological basis of symptom development. Further investigation of the pathophysiology will lead to the effective treatment of patients with bladder pain syndrome/interstitial cystitis.
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Affiliation(s)
- Naoki Yoshimura
- Department of Urology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
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Omori Y, Nakajima M, Nishimura K, Takahashi E, Arai T, Akahira M, Suzuki T, Kainoh M. Analgesic effect of GT-0198, a structurally novel glycine transporter 2 inhibitor, in a mouse model of neuropathic pain. J Pharmacol Sci 2015; 127:377-81. [PMID: 25837937 DOI: 10.1016/j.jphs.2015.02.010] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2014] [Revised: 02/02/2015] [Accepted: 02/19/2015] [Indexed: 11/15/2022] Open
Abstract
This study was conducted to identify the characteristic pharmacological features of GT-0198 that is phenoxymethylbenzamide derivatives. GT-0198 inhibited the function of glycine transporter 2 (GlyT2) in human GlyT2-expressing HEK293 cells and did not bind various major transporters or receptors of neurotransmitters in a competitive manner. Thus, GT-0198 is considered to be a comparatively selective GlyT2 inhibitor. Intravenous, oral, and intrathecal injections of GT-0198 decreased the pain-related response in a model of neuropathic pain with partial sciatic nerve ligation. This result suggests that GT-0198 has an analgesic effect. The analgesic effect of GT-0198 was abolished by the intrathecal injection of strychnine, a glycine receptor antagonist. Therefore, GT-0198 is considered to exhibit its analgesic effect via the activation of a glycine receptor by glycine following presynaptic GlyT2 inhibition in the spinal cord. In summary, GT-0198 is a structurally novel GlyT2 inhibitor bearing a phenoxymethylbenzamide moiety with in vivo efficacy in behavioral models of neuropathic pain.
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Affiliation(s)
- Yu Omori
- Toray Industries, Inc., Pharmaceutical Research Laboratories, 10-1, Tebiro 6-chome, Kamakura, Kanagawa 248-8555, Japan.
| | - Mayumi Nakajima
- Toray Industries, Inc., Pharmaceutical Research Laboratories, 10-1, Tebiro 6-chome, Kamakura, Kanagawa 248-8555, Japan
| | - Kazumi Nishimura
- Toray Industries, Inc., Pharmaceutical Research Laboratories, 10-1, Tebiro 6-chome, Kamakura, Kanagawa 248-8555, Japan
| | - Eiki Takahashi
- Toray Industries, Inc., Pharmaceutical Research Laboratories, 10-1, Tebiro 6-chome, Kamakura, Kanagawa 248-8555, Japan
| | - Tadamasa Arai
- Toray Industries, Inc., Pharmaceutical Research Laboratories, 10-1, Tebiro 6-chome, Kamakura, Kanagawa 248-8555, Japan
| | - Masato Akahira
- Toray Industries, Inc., Pharmaceutical Research Laboratories, 10-1, Tebiro 6-chome, Kamakura, Kanagawa 248-8555, Japan
| | - Tomohiko Suzuki
- Toray Industries, Inc., Pharmaceutical Research Laboratories, 10-1, Tebiro 6-chome, Kamakura, Kanagawa 248-8555, Japan
| | - Mie Kainoh
- Toray Industries, Inc., Pharmaceutical Research Laboratories, 10-1, Tebiro 6-chome, Kamakura, Kanagawa 248-8555, Japan
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Abstract
This article summarizes anatomical, neurophysiological, pharmacological, and brain imaging studies in humans and animals that have provided insights into the neural circuitry and neurotransmitter mechanisms controlling the lower urinary tract. The functions of the lower urinary tract to store and periodically eliminate urine are regulated by a complex neural control system in the brain, spinal cord, and peripheral autonomic ganglia that coordinates the activity of smooth and striated muscles of the bladder and urethral outlet. The neural control of micturition is organized as a hierarchical system in which spinal storage mechanisms are in turn regulated by circuitry in the rostral brain stem that initiates reflex voiding. Input from the forebrain triggers voluntary voiding by modulating the brain stem circuitry. Many neural circuits controlling the lower urinary tract exhibit switch-like patterns of activity that turn on and off in an all-or-none manner. The major component of the micturition switching circuit is a spinobulbospinal parasympathetic reflex pathway that has essential connections in the periaqueductal gray and pontine micturition center. A computer model of this circuit that mimics the switching functions of the bladder and urethra at the onset of micturition is described. Micturition occurs involuntarily in infants and young children until the age of 3 to 5 years, after which it is regulated voluntarily. Diseases or injuries of the nervous system in adults can cause the re-emergence of involuntary micturition, leading to urinary incontinence. Neuroplasticity underlying these developmental and pathological changes in voiding function is discussed.
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Affiliation(s)
- William C. de Groat
- Department of Pharmacology and Chemical Biology, University of Pittsburgh, School of Medicine Pittsburgh, Pennsylvania
| | - Derek Griffiths
- Department of Medicine (Geriatrics), University of Pittsburgh, School of Medicine Pittsburgh, Pennsylvania
| | - Naoki Yoshimura
- Department of Pharmacology and Chemical Biology, University of Pittsburgh, School of Medicine Pittsburgh, Pennsylvania
- Department of Urology, University of Pittsburgh, School of Medicine Pittsburgh, Pennsylvania
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Motoyama N, Morita K, Shiraishi S, Kitayama T, Kanematsu T, Uezono Y, Dohi T. Relief of cancer pain by glycine transporter inhibitors. Anesth Analg 2014; 119:988-995. [PMID: 25076101 DOI: 10.1213/ane.0000000000000388] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
BACKGROUND Recent studies have revealed the antinociceptive effects of glycine transporter (GlyT) inhibitors in neuropathic pain models such as sciatic nerve-injured and diabetic animals. Bone cancer can cause the most severe pain according to complex mechanisms in which a neuropathic element is included. Bone cancer modifies the analgesic action of opioids and limits their effectiveness, and thus novel medicament for bone cancer pain is desired. METHODS For the femur bone cancer model, NCTC 2472 tumor cells were injected into the medullary cavity of the distal femur of C3H/HeN mice. Effects of GlyT2 inhibitors, ORG 25543 and ALX 1393, and GlyT1 inhibitors, ORG 25935, and knockdown of the expression of spinal GlyTs protein by GlyTs siRNA on pain-like behaviors, such as allodynia, withdrawal threshold, guarding behavior, and limb-use abnormality, were examined in the femur bone cancer model mice. Effects of morphine in combination with GlyT inhibitor were examined. RESULTS GlyT2 inhibitors, ORG 25543 and ALX 1393, and GlyT1 inhibitor ORG 25935 by IV or oral administration or knockdown of the expression of spinal GlyTs protein improved pain-like behaviors at 11 days after tumor transplantation. The pain-relief activity was potent and long lasting. Morphine at a dose with no analgesic activity combined with ORG 25543 further promoted the ORG 25543-induced pain-relief activity. Injection of ORG 25543 on the second day after tumor implantation caused 3 phases of pain responses; pain-like behaviors were initially accelerated (at 2-4 days) and subsequently almost disappeared (5-7 days) and then reappeared. Intrathecal injection of strychnine 1 day after injection of ORG 25543 transiently antagonized the pain-relief activity of ORG 25543. In control mice, strychnine improved pain-like behaviors 4 days after tumor implantation and aggravated the behaviors between 4 and 5 days. The evidence suggests that the different mechanisms are phase-dependently involved. CONCLUSIONS GlyT inhibitors with or without morphine may be a new strategy for the treatment of bone cancer pain and lead to further investigations of the mechanisms underlying the development of bone cancer pain.
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Affiliation(s)
- Naoyo Motoyama
- From the Department of Dental Science for Health Promotion, Division of Integrated Health Sciences, Institute of Biomedical & Health Sciences, Hiroshima University, Hiroshima, Japan; Cancer Pathophysiology Division, National Cancer Center Research Institute, Tokyo, Japan; Department of Pharmacology, Faculty of Nursing, Hiroshima Bunka Gakuen University, Hiroshima, Japan; Department of Cell & Molecular Pharmacology, Division of Basic Life Science, Institute of Biomedical & Health Sciences, Hiroshima University, Hiroshima, Japan; Pharmaceutical Education Support Center, Mukogawa Women's University, Nishinomiya, Hyogo, Japan; and Department of Pharmacotherapy, Pharmaceutical Sciences, Nihon Pharmaceutical University, Saitama, Japan
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Tsai CH, Huang HC, Liu BL, Li CI, Lu MK, Chen X, Tsai MC, Yang YW, Lane HY. Activation of N-methyl-D-aspartate receptor glycine site temporally ameliorates neuropsychiatric symptoms of Parkinson's disease with dementia. Psychiatry Clin Neurosci 2014; 68:692-700. [PMID: 24612097 DOI: 10.1111/pcn.12175] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/25/2013] [Revised: 01/18/2014] [Accepted: 02/18/2014] [Indexed: 01/08/2023]
Abstract
AIM We have previously found that sarcosine, a glycine transporter I inhibitor, can improve the psychiatric symptoms of schizophrenia. In this study, we aimed to investigate whether the agent can also ameliorate neuropsychiatric symptoms of Parkinson's disease (PD) patients with dementia. METHODS An 8-week, double-blind, placebo-controlled trial was conducted in patients who had PD with dementia (PD-D). Neuropsychiatric manifestations were measured before and at week 2 (V1), week 4 (V2) and week 8 (V3) after treatment. Linear regression with the generalized estimating equations was applied for data analysis. RESULTS Fifteen patients were randomized into a sarcosine group; the other 15 into a placebo group. The generalized estimating equations model revealed significant differences in Hamilton Depression Rating Scale score (P = 0.049) at V1 and Neuropsychiatry Inventory (P = 0.039) at V2 between the treatment and placebo groups. By excluding the advanced patients from analysis, there were significant differences in Unified Parkinson's Disease Rating Scale V2 (P = 0.004) and V3 (P = 0.040), Hamilton Depression Rating Scale V1 (P = 0.014) and V2 (P = 0.047), Neuropsychiatry Inventory V1 (P = 0.002) and V2 (P < 0.001) and Behavior Pathology in Alzheimer's Disease Rating Scale V2 (P = 0.025) in favor of sarcosine. CONCLUSION Sarcosine temporally improved depression and neuropsychiatric symptoms in PD-D patients without exacerbating the motor or cognitive features; the beneficial effects were more prominent in patients with mild-moderate severity. Enhancement of N-methyl-D-aspartate receptor-glycine cascade may lead to a novel path for the management of PD-D.
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Affiliation(s)
- Chon-Haw Tsai
- Department of Neurology, China Medical University Hospital, Taichung, Taiwan; Graduate Institute of Neural and Cognitive Sciences, China Medical University, Taichung, Taiwan; School of Medicine, Medical College, China Medical University, Taichung, Taiwan
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Long-term application of glycine transporter inhibitors acts antineuropathic and modulates spinal N-methyl-D-aspartate receptor subunit NR-1 expression in rats. Anesthesiology 2014; 121:160-9. [PMID: 24598217 DOI: 10.1097/aln.0000000000000203] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
BACKGROUND Dysfunction of spinal glycinergic neurotransmission is a major pathogenetic factor in neuropathic pain. The synaptic glycine concentration is controlled by the two glycine transporters (GlyT) 1 and 2. GlyT inhibitors act antinociceptive in various animal pain models when applied as bolus. Yet, in some studies, severe neuromotor side effects were reported. The aim of the current study was to elucidate whether continuous inhibition of GlyT ameliorates neuropathic pain without side effects and whether protein expression of GlyT1, GlyT2, or N-methyl-D-aspartate receptor subunit NR-1 in the spinal cord is affected. METHODS In the chronic constriction injury model of neuropathic pain, male Wistar rats received specific GlyT1 and GlyT2 inhibitors (ALX5407 and ALX1393; Sigma-Aldrich, St. Louis, MO) or vehicle for 14 days via subcutaneous osmotic infusion pumps (n = 6). Mechanical allodynia and thermal hyperalgesia were assessed before, after chronic constriction injury, and every 2 days during substance application. At the end of behavioral assessment, the expression of GlyT1, GlyT2, and NR-1 in the spinal cord was determined by Western blot analysis. RESULTS Both ALX5407 and ALX1393 ameliorated thermal hyperalgesia and mechanical allodynia in a time- and dose-dependent manner. Respiratory or neuromotor side effects were not observed. NR-1 expression in the ipsilateral spinal cord was significantly reduced by ALX5407, but not by ALX1393. The expression of GlyT1 and GlyT2 remained unchanged. CONCLUSIONS Continuous systemic inhibition of GlyT significantly ameliorates neuropathic pain in rats. Thus, GlyT represent promising targets in pain research. Modulation of N-methyl-D-aspartate receptor expression might represent a novel mechanism for the antinociceptive action of GyT1 inhibitors.
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Effects of sensory neuron-specific receptor agonist on bladder function in a rat model of cystitis induced by cyclophosphamide. Int Urol Nephrol 2014; 46:1953-9. [PMID: 24824147 DOI: 10.1007/s11255-014-0734-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2014] [Accepted: 05/02/2014] [Indexed: 10/25/2022]
Abstract
PURPOSE To investigate the effects of activation of sensory neuron-specific receptors (SNSRs) on cyclophosphamide (CYP) bladder overactivity in rats. METHODS Female Sprague-Dawley rats (235-258 g) were used. Rats were injected with either CYP (200 mg/kg, intraperitoneally) or saline (control). Continuous cystometrograms (0.04 ml/min) were recorded 48 h after CYP or saline injection under urethane anesthesia. After stable micturition cycles were established, a selective rat SNSR1 agonist, bovine adrenal medulla 8-22 (BAM8-22), was administered intravenously or intrathecally. RESULTS Cyclophosphamide treatment-induced higher baseline pressure and shorter intercontraction intervals compared with the control group. Intravenous administration of BAM8-22 at 10, 30 and 100 μg/kg significantly increased intercontraction intervals in the CYP-treated group. Intrathecal administration of BAM8-22 at 0.03, 0.1 and 0.3 μg also significantly increased intercontraction intervals in the CYP-treated group. Intravenous or intrathecal administration of BAM8-22 did not change baseline pressure or maximum voiding pressure in the CYP-treated group. CONCLUSIONS These findings indicate that activation of SNSRs can suppress CYP-induced bladder overactivity, probably due to suppression of bladder afferent activity.
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Glycine transporters as novel therapeutic targets in schizophrenia, alcohol dependence and pain. Nat Rev Drug Discov 2014; 12:866-85. [PMID: 24172334 DOI: 10.1038/nrd3893] [Citation(s) in RCA: 154] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Glycine transporters are endogenous regulators of the dual functions of glycine, which acts as a classical inhibitory neurotransmitter at glycinergic synapses and as a modulator of neuronal excitation mediated by NMDA (N-methyl-D-aspartate) receptors at glutamatergic synapses. The two major subtypes of glycine transporters, GlyT1 and GlyT2, have been linked to the pathogenesis and/or treatment of central and peripheral nervous system disorders, including schizophrenia and related affective and cognitive disturbances, alcohol dependence, pain, epilepsy, breathing disorders and startle disease (also known as hyperekplexia). This Review examines the rationale for the therapeutic potential of GlyT1 and GlyT2 inhibition, and surveys the latest advances in the biology of glycine reuptake and transport as well as the drug discovery and clinical development of compounds that block glycine transporters.
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Yoshimura N, Miyazato M, Kitta T, Yoshikawa S. Central nervous targets for the treatment of bladder dysfunction. Neurourol Urodyn 2013; 33:59-66. [PMID: 23832777 DOI: 10.1002/nau.22455] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2013] [Accepted: 06/05/2013] [Indexed: 12/28/2022]
Abstract
BACKGROUND The functions of the lower urinary tract, to store and periodically release urine, are dependent on the activity of smooth and striated muscles in the urinary bladder, urethra, and external urethral sphincter. This activity is in turn controlled by neural circuits in the brain, spinal cord, and peripheral ganglia. AIMS This paper will review recent advances in our understanding of the pathophysiology of voiding disorders, especially focusing on the central nervous system. METHODS Various neurotransmitters, including acetylcholine, norepinephrine, dopamine, serotonin, excitatory and inhibitory amino acids, adenosine triphosphate, nitric oxide, and neuropeptides, have been implicated in the neural regulation of the lower urinary tract. RESULTS Injuries or diseases of the nervous system, as well as drugs and disorders of the peripheral organs, can produce voiding dysfunctions such as urinary frequency, urgency, or incontinence. CONCLUSION We discuss the potential targets in the central nervous system and new modalities for the treatment of voiding dysfunction.
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Affiliation(s)
- Naoki Yoshimura
- Department of Urology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
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