1
|
Bouhassira D, Tesfaye S, Sarkar A, Soisalon-Soininen S, Stemper B, Baron R. Efficacy and safety of eliapixant in diabetic neuropathic pain and prediction of placebo responders with an exploratory novel algorithm: results from the randomized controlled phase 2a PUCCINI study. Pain 2024; 165:785-795. [PMID: 37851336 DOI: 10.1097/j.pain.0000000000003085] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2023] [Accepted: 08/18/2023] [Indexed: 10/19/2023]
Abstract
ABSTRACT Phase 2a of the PUCCINI study was a placebo-controlled, double-blind, parallel-group, multicenter, proof-of-concept study evaluating the efficacy and safety of the selective P2X3 antagonist eliapixant in patients with diabetic neuropathic pain (DNP) ( ClinicalTrials.gov NCT04641273). Adults with type 1 or type 2 diabetes mellitus with painful distal symmetric sensorimotor neuropathy of >6 months' duration and neuropathic pain were enrolled and randomized 1:1 to 150 mg oral eliapixant twice daily or placebo for 8 weeks. The primary endpoint was change from baseline in weekly mean 24-hour average pain intensity score at week 8. In total, 135 participants completed treatment, 67 in the eliapixant group and 68 in the placebo group. At week 8, the change from baseline in posterior mean 24-hour average pain intensity score (90% credible interval) in the eliapixant group was -1.56 (-1.95, -1.18) compared with -2.17 (-2.54, -1.80) for the placebo group. The mean treatment difference was 0.60 (0.06, 1.14) in favor of placebo. The use of a model-based framework suggests that various factors may contribute to the placebo-responder profile. Adverse events were mostly mild or moderate in severity and occurred in 51% of the eliapixant group and 48% of the placebo group. As the primary endpoint was not met, the PUCCINI study was terminated after completion of phase 2a and did not proceed to phase 2b. In conclusion, selective P2X3 antagonism in patients with DNP did not translate to any relevant improvement in different pain intensity outcomes compared with placebo. Funding: Bayer AG.
Collapse
Affiliation(s)
- Didier Bouhassira
- INSERM U987, APHP, CHU Ambroise Paré, UVSQ, Paris-Saclay, Boulogne-Billancourt, France
| | - Solomon Tesfaye
- Diabetes Research Unit, Sheffield Teaching Hospitals NHS Foundation Trust, Sheffield, United Kingdom
| | - Arnab Sarkar
- Research & Development, Pharmaceuticals, Bayer AG, Berlin, Germany
| | | | - Brigitte Stemper
- Research & Development, Pharmaceuticals, Bayer AG, Berlin, Germany
- Department of Neurology, University Erlangen Nürnberg, Erlangen, Germany
| | - Ralf Baron
- Division of Neurological Pain Research and Therapy, Department of Neurology, University Hospital Schleswig-Holstein, Kiel, Germany
| |
Collapse
|
2
|
Ai Y, Wang H, Liu L, Qi Y, Tang S, Tang J, Chen N. Purine and purinergic receptors in health and disease. MedComm (Beijing) 2023; 4:e359. [PMID: 37692109 PMCID: PMC10484181 DOI: 10.1002/mco2.359] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2023] [Revised: 08/07/2023] [Accepted: 08/10/2023] [Indexed: 09/12/2023] Open
Abstract
Purines and purinergic receptors are widely distributed throughout the human body. Purine molecules within cells play crucial roles in regulating energy metabolism and other cellular processes, while extracellular purines transmit signals through specific purinergic receptors. The ubiquitous purinergic signaling maintains normal neural excitability, digestion and absorption, respiratory movement, and other complex physiological activities, and participates in cell proliferation, differentiation, migration, and death. Pathological dysregulation of purinergic signaling can result in the development of various diseases, including neurodegeneration, inflammatory reactions, and malignant tumors. The dysregulation or dysfunction of purines and purinergic receptors has been demonstrated to be closely associated with tumor progression. Compared with other subtypes of purinergic receptors, the P2X7 receptor (P2X7R) exhibits distinct characteristics (i.e., a low affinity for ATP, dual functionality upon activation, the mediation of ion channels, and nonselective pores formation) and is considered a promising target for antitumor therapy, particularly in patients with poor response to immunotherapy This review summarizes the physiological and pathological significance of purinergic signaling and purinergic receptors, analyzes their complex relationship with tumors, and proposes potential antitumor immunotherapy strategies from tumor P2X7R inhibition, tumor P2X7R overactivation, and host P2X7R activation. This review provides a reference for clinical immunotherapy and mechanism investigation.
Collapse
Affiliation(s)
- Yanling Ai
- Department of OncologyHospital of Chengdu University of Traditional Chinese MedicineChengduChina
| | - Hengyi Wang
- Department of Infectious DiseasesHospital of Chengdu University of Traditional Chinese MedicineChengduChina
| | - Lu Liu
- School of PharmacyChengdu University of Traditional Chinese MedicineChengduChina
| | - Yulin Qi
- Department of OphthalmologyThe First Affiliated Hospital of Guangzhou University of Chinese MedicineGuangzhou University of Chinese MedicineGuangzhouChina
- Postdoctoral Research Station of Guangzhou University of Chinese MedicineGuangzhouChina
| | - Shiyun Tang
- Hospital of Chengdu University of Traditional Chinese MedicineChengduChina
| | - Jianyuan Tang
- TCM Regulating Metabolic Diseases Key Laboratory of Sichuan ProvinceHospital of Chengdu University of Traditional Chinese MedicineChengduChina
| | - Nianzhi Chen
- State Key Laboratory of Ultrasound in Medicine and EngineeringCollege of Biomedical EngineeringChongqing Medical UniversityChongqingChina
| |
Collapse
|
3
|
Inoue K. Overview for the study of P2 receptors: From P2 receptor history to neuropathic pain studies. J Pharmacol Sci 2022; 149:73-80. [DOI: 10.1016/j.jphs.2022.04.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2021] [Revised: 04/06/2022] [Accepted: 04/07/2022] [Indexed: 11/25/2022] Open
|
4
|
Madaan P, Behl T, Sehgal A, Singh S, Sharma N, Yadav S, Kaur S, Bhatia S, Al-Harrasi A, Abdellatif AAH, Ashraf GM, Abdel-Daim MM, Dailah HG, Anwer MK, Bungau S. Exploring the Therapeutic Potential of Targeting Purinergic and Orexinergic Receptors in Alcoholic Neuropathy. Neurotox Res 2022; 40:646-669. [DOI: 10.1007/s12640-022-00477-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2021] [Revised: 01/13/2022] [Accepted: 01/19/2022] [Indexed: 12/11/2022]
|
5
|
Lei X, Zeng J, Yan Y, Liu X. Blockage of HCN Channels Inhibits the Function of P2X Receptors in Rat Dorsal Root Ganglion Neurons. Neurochem Res 2022; 47:1083-1096. [PMID: 35064517 DOI: 10.1007/s11064-021-03509-5] [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: 07/14/2021] [Revised: 12/06/2021] [Accepted: 12/14/2021] [Indexed: 12/12/2022]
Abstract
Hyperpolarization-activated cyclic nucleotide-gated channels and purinergic P2X receptors play critical roles in the nerve injury-induced pain hypersensitivity. Both HCN channels and P2XR are expressed in dorsal root ganglia sensory neurons. However, it is not clear whether the expression and function of P2X2 and P2X3 receptors can be modulated by HCN channel activity. For this reason, in rats with chronic constriction injury of sciatic nerve, we evaluated the effect of intrathecal administration of HCN channel blocker ZD7288 on nociceptive behavior and the expression of P2X2 and P2X3 in rat DRG. The mechanical withdrawal threshold was measured to evaluate pain behavior in rats. The protein expression of P2X2 and P2X3 receptor in rat DRG was observed by using Western Blot. The level of cAMP in rat DRG was measured by ELISA. As a result, decreased MWT was observed in CCI rats on 1 d after surgery, and the allodynia was sustained throughout the experimental period. In addition, CCI rats presented increased expression of P2X2 and P2X3 receptor in the ipsilateral DRG at 7 d and 14 d after CCI operation. Intrathecal injection of ZD7288 significantly reversed CCI-induced mechanical hyperalgesia, and attenuated the increased expression of P2X2 and P2X3 receptor in rat DRG, which open up the possibility that the expression of P2X2 and P2X3 receptor in DRG is down-regulated by HCN channel blocker ZD7288 in CCI rats. Furthermore, the level of cAMP in rat DRG significantly increased after nerve injury. Intrathecal administration of ZD7288 attenuated the increase of cAMP in DRG caused by nerve injury. Subsequently, effects of HCN channel activity on ATP-induced current (IATP) in rat DRG neurons were explored by using whole-cell patch-clamp techniques. ATP (100 μM) elicited three types of currents (fast, slow and mixed IATP) in cultured DRG neurons. Pretreatment with ZD7288 concentration-dependently inhibited three types of ATP-activated currents. On the other hand, pretreatment with 8-Br-cAMP (a cell-permeable cAMP analog, also known as an activator of PKA) significantly increased the amplitude of fast, slow and mixed IATP in DRG neurons. The enhanced effect of 8-Br-cAMP on ATP-activated currents could be reversed by ZD7288. In a summary, our observations suggest that the opening of HCN channels could enhance the expression and function of P2X2 and P2X3 receptor via the cAMP-PKA signaling pathway. This may be important for pathophysiological events occurring within the DRG, for where it is implicated in nerve injury-induced pain hypersensitivity.
Collapse
Affiliation(s)
- Xiaolu Lei
- Key Laboratory of Brain Science, Zunyi Medical University, Zunyi, 563000, China
| | - Junwei Zeng
- Department of Physiology, Zunyi Medical University, No. 6, Xuefu west road, Zunyi, 563000, Guizhou province, China
| | - Yan Yan
- Key Laboratory of Brain Science, Zunyi Medical University, Zunyi, 563000, China
| | - Xiaohong Liu
- Department of Physiology, Zunyi Medical University, No. 6, Xuefu west road, Zunyi, 563000, Guizhou province, China.
| |
Collapse
|
6
|
Inoue K, Tsuda M. Nociceptive signaling mediated by P2X3, P2X4 and P2X7 receptors. Biochem Pharmacol 2020; 187:114309. [PMID: 33130129 DOI: 10.1016/j.bcp.2020.114309] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2020] [Revised: 10/22/2020] [Accepted: 10/27/2020] [Indexed: 12/18/2022]
Abstract
Chronic pain is a debilitating condition that often occurs following peripheral tissue inflammation and nerve injury. This pain, especially neuropathic pain, is a significant clinical problem because of the ineffectiveness of clinically available drugs. Since Burnstock proposed new roles of nucleotides as neurotransmitters, the roles of extracellular ATP and P2 receptors (P2Rs) in pain signaling have been extensively studied, and ATP-P2R signaling has subsequently received much attention as it can provide clues toward elucidating the mechanisms underlying chronic pain and serve as a potential therapeutic target. This review summarizes the literature regarding the role of ATP signaling via P2X3Rs (as well as P2X2/3Rs) in primary afferent neurons and via P2X4Rs and P2X7Rs in spinal cord microglia in chronic pain, and discusses their respective therapeutic potentials.
Collapse
Affiliation(s)
- Kazuhide Inoue
- Department of Molecular and System Pharmacology, Graduate School of Pharmaceutical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi, Fukuoka 812-8582, Japan
| | - Makoto Tsuda
- Department of Molecular and System Pharmacology, Graduate School of Pharmaceutical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi, Fukuoka 812-8582, Japan; Department of Life Innovation, Graduate School of Pharmaceutical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi, Fukuoka 812-8582, Japan
| |
Collapse
|
7
|
Krajewski JL. P2X3-Containing Receptors as Targets for the Treatment of Chronic Pain. Neurotherapeutics 2020; 17:826-838. [PMID: 33009633 PMCID: PMC7609758 DOI: 10.1007/s13311-020-00934-2] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/17/2020] [Indexed: 02/06/2023] Open
Abstract
Current therapies for the treatment of chronic pain provide inadequate relief for millions of suffering patients, demonstrating the need for better therapies that will treat pain effectively and improve the quality of patient's lives. Better understanding of the mechanisms that mediate chronic pain is critical for developing drugs with improved clinical outcomes. Adenosine triphosphate (ATP) is a key modulator in nociceptive pathways. Release of ATP from injured tissue or sympathetic efferents has sensitizing effects on sensory neurons in the periphery, and presynaptic vesicular release of ATP from the central terminals can increase glutamate release thereby potentiating downstream central sensitization mechanisms, a condition thought to underlie many chronic pain conditions. The purinergic receptors on sensory nerves primarily responsible for ATP signaling are P2X3 and P2X2/3. Selective knockdown experiments, or inhibition with small molecules, demonstrate P2X3-containing receptors are key targets to modulate nociceptive signals. Preclinical studies have identified that P2X3-containing receptors are critical for sensory transduction for bladder function, and clinical studies have shown promise in treatment for bladder pain and pain associated with osteoarthritis. Further clinical characterization of antagonists to P2X3-containing receptors may lead to improved therapies in the treatment of chronic pain.
Collapse
|
8
|
Dal Ben D, Antonioli L, Lambertucci C, Spinaci A, Fornai M, D'Antongiovanni V, Pellegrini C, Blandizzi C, Volpini R. Approaches for designing and discovering purinergic drugs for gastrointestinal diseases. Expert Opin Drug Discov 2020; 15:687-703. [PMID: 32228110 DOI: 10.1080/17460441.2020.1743673] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
INTRODUCTION Purines finely modulate physiological motor, secretory, and sensory functions in the gastrointestinal tract. Their activity is mediated by the purinergic signaling machinery, including receptors and enzymes regulating their synthesis, release, and degradation. Several gastrointestinal dysfunctions are characterized by alterations affecting the purinergic system. AREAS COVERED The authors provide an overview on the purinergic receptor signaling machinery, the molecules and proteins involved, and a summary of medicinal chemistry efforts aimed at developing novel compounds able to modulate the activity of each player involved in this machinery. The involvement of purinergic signaling in gastrointestinal motor, secretory, and sensory functions and dysfunctions, and the potential therapeutic applications of purinergic signaling modulators, are then described. EXPERT OPINION A number of preclinical and clinical studies demonstrate that the pharmacological manipulation of purinergic signaling represents a viable way to counteract several gastrointestinal diseases. At present, the paucity of purinergic therapies is related to the lack of receptor-subtype-specific agonists and antagonists that are effective in vivo. In this regard, the development of novel therapeutic strategies should be focused to include tools able to control the P1 and P2 receptor expression as well as modulators of the breakdown or transport of purines.
Collapse
Affiliation(s)
- Diego Dal Ben
- School of Pharmacy, Medicinal Chemistry Unit, University of Camerino , Camerino, Italy
| | - Luca Antonioli
- Unit of Pharmacology and Pharmacovigilance, Department of Clinical and Experimental Medicine, University of Pisa , Pisa, Italy
| | - Catia Lambertucci
- School of Pharmacy, Medicinal Chemistry Unit, University of Camerino , Camerino, Italy
| | - Andrea Spinaci
- School of Pharmacy, Medicinal Chemistry Unit, University of Camerino , Camerino, Italy
| | - Matteo Fornai
- Unit of Pharmacology and Pharmacovigilance, Department of Clinical and Experimental Medicine, University of Pisa , Pisa, Italy
| | - Vanessa D'Antongiovanni
- Unit of Pharmacology and Pharmacovigilance, Department of Clinical and Experimental Medicine, University of Pisa , Pisa, Italy
| | | | - Corrado Blandizzi
- Unit of Pharmacology and Pharmacovigilance, Department of Clinical and Experimental Medicine, University of Pisa , Pisa, Italy
| | - Rosaria Volpini
- School of Pharmacy, Medicinal Chemistry Unit, University of Camerino , Camerino, Italy
| |
Collapse
|
9
|
Leng C, Chen L, Li C. Alteration of P2X1-6 receptor expression in retrograde Fluorogold-labeled DRG neurons from rat chronic neuropathic pain model. Biomed Rep 2019; 10:225-230. [PMID: 31001422 PMCID: PMC6439428 DOI: 10.3892/br.2019.1197] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2018] [Accepted: 02/28/2019] [Indexed: 12/25/2022] Open
Abstract
Accumulating evidence indicates that P2X receptors may serve an important role in pain and nociceptive sensations. However, recent studies of regulation of P2X receptor expression following nerve injury have produced variable or conflicting results. In the present study the alteration of expression of P2X1-6 receptor subunits in retrograde Flurorogold (FG)-labeled L4+L5 dorsal root ganglion (DRG) neurons were evaluated following unilateral chronic constriction injury (CCI) of the rat sciatic nerve using immunohistochemistry combined with a retrograde fluorescence-tracing method. It was demonstrated that there was no significant difference in the proportion of FG-labeled DRG neurons between the sham and CCI groups (P>0.5). The percentages of P2X1-immunoreactive (IR) and P2X2-IR FG-labeled DRG neurons were not significantly different between the sham and CCI groups (41.5±8.2 vs. 45.2±7.4% and 58.1±6.2 vs. 69.1±3.5%, P>0.05). The percentages of P2X3-IR and P2X6-IR FG-labeled DRG neurons significantly increased in the CCI group compared with the sham group (51.6±4.1 vs. 28.5±3.4% and 41.8±2.2 vs. 22.6±3.3%, P>0.01). By contrast, the percentage of P2X4-IR FG-labeled DRG neurons significantly decreased in the CCI group compared with the sham group (29.4±3.3 vs. 45.0±3.7%, P<0.01). The P2X5-IR positive FG-labeled neurons were not detected in the CCI and sham groups. The results of the present study provided the first evidence regarding the regulation of the expression of the P2X1-6 receptor in sensory neurons being directly associated with chronic nerve injury in rats and also suggest that compared with the P2X3 receptor, the P2X2/3 heteromeric receptor is not the major receptor involved in peripheral neuropathic pain sensation. In addition, the possible functional role of P2X6 receptors in peripheral neuropathic pain requires further investigation.
Collapse
Affiliation(s)
- Changlong Leng
- Wuhan Institutes of Biomedical Sciences, Jianghan University, Wuhan, Hubei 430056, P.R. China
| | - Lin Chen
- Wuhan Institutes of Biomedical Sciences, Jianghan University, Wuhan, Hubei 430056, P.R. China
| | - Chaoying Li
- Wuhan Institutes of Biomedical Sciences, Jianghan University, Wuhan, Hubei 430056, P.R. China
| |
Collapse
|
10
|
Kanaya K, Iba K, Abe Y, Dohke T, Okazaki S, Matsumura T, Yamashita T. Acid-sensing ion channel 3 or P2X2/3 is involved in the pain-like behavior under a high bone turnover state in ovariectomized mice. J Orthop Res 2016; 34:566-73. [PMID: 26340235 DOI: 10.1002/jor.23047] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/06/2015] [Accepted: 08/28/2015] [Indexed: 02/04/2023]
Abstract
We have recently demonstrated that pathological changes leading to increased bone resorption by osteoclast activation are related to the induction of pain-like behavior in ovariectomized (OVX) mice. In addition, bisphosphonate and the antagonist of transient receptor potential vanilloid type 1 (TRPV1), an acid-sensing nociceptor, improved the threshold value of pain-like behaviors accompanying an improvement in the acidic environment in the bone tissue based on osteoclast inactivation. The aim of this study was to evaluate the effect of (i) an inhibitor of vacuolar H(+) -ATPase, known as an proton pump, (ii) an antagonist of acid-sensing ion channel (ASIC) 3, as another acid-sensing nociceptor, and (iii) the P2X2/3 receptor, as an ATP-ligand nociceptor, on pain-like behavior in OVX mice. This inhibitor and antagonists were found to improve the threshold value of pain-like behavior in OVX mice. These results indicated that the skeletal pain accompanying osteoporosis is possibly associated with the acidic microenvironment and increased ATP level caused by osteoclast activation under a high bone turnover state.
Collapse
Affiliation(s)
- Kumiko Kanaya
- Department of Orthopaedic Surgery, Sapporo Medical University School of Medicine, Sapporo, Japan
| | - Kousuke Iba
- Department of Orthopaedic Surgery, Sapporo Medical University School of Medicine, Sapporo, Japan
| | - Yasuhisa Abe
- Department of Orthopaedic Surgery, Sapporo Medical University School of Medicine, Sapporo, Japan
| | - Takayuki Dohke
- Department of Orthopaedic Surgery, Sapporo Medical University School of Medicine, Sapporo, Japan
| | - Shunichiro Okazaki
- Department of Orthopaedic Surgery, Sapporo Medical University School of Medicine, Sapporo, Japan
| | - Tadaki Matsumura
- Department of Orthopaedic Surgery, Sapporo Medical University School of Medicine, Sapporo, Japan
| | - Toshihiko Yamashita
- Department of Orthopaedic Surgery, Sapporo Medical University School of Medicine, Sapporo, Japan
| |
Collapse
|
11
|
Prokineticin 2 facilitates mechanical allodynia induced by α,β-methylene ATP in rats. Eur J Pharmacol 2015; 767:24-9. [PMID: 26435025 DOI: 10.1016/j.ejphar.2015.09.047] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2015] [Revised: 09/25/2015] [Accepted: 09/29/2015] [Indexed: 01/19/2023]
Abstract
Prokineticin 2 (PK2), a new chemokine, causes mechanical hypersensitivity in the rat hind paw, but little is known about the molecular mechanism. Here, we have found that ionotropic P2X receptor is essential to mechanical allodynia induced by PK2. First, intraplantar injection of high dose (3 or 10 pmol) of PK2 significantly increased paw withdrawal response frequency (%) to innocuous mechanical stimuli (mechanical allodynia). And the mechanical allodynia induced by PK2 was prevented by co-administration of TNP-ATP, a selective P2X receptor antagonist. Second, although low dose (0.3 or 1 pmol) of PK2 itself did not produce an allodynic response, it significantly facilitated the mechanical allodynia evoked by intraplantar injection of α,β-methylene ATP (α,β-meATP). Third, PK2 concentration-dependently potentiated α,β-meATP-activated currents in rat dorsal root ganglion (DRG) neurons. Finally, PK2 receptors and intracellular signal transduction were involved in PK2 potentiation of α,β-meATP-induced mechanical allodynia and α,β-meATP-activated currents, since the potentiation were blocked by PK2 receptor antagonist PKRA and selective PKC inhibitor GF 109203X. These results suggested that PK2 facilitated mechanical allodynia induced by α,β-meATP through a mechanism involved in sensitization of cutaneous P2X receptors expressed by nociceptive nerve endings.
Collapse
|
12
|
Wieskopf JS, Mathur J, Limapichat W, Post MR, Al-Qazzaz M, Sorge RE, Martin LJ, Zaykin DV, Smith SB, Freitas K, Austin JS, Dai F, Zhang J, Marcovitz J, Tuttle AH, Slepian PM, Clarke S, Drenan RM, Janes J, Al Sharari S, Segall SK, Aasvang EK, Lai W, Bittner R, Richards CI, Slade GD, Kehlet H, Walker J, Maskos U, Changeux JP, Devor M, Maixner W, Diatchenko L, Belfer I, Dougherty DA, Su AI, Lummis SCR, Imad Damaj M, Lester HA, Patapoutian A, Mogil JS. The nicotinic α6 subunit gene determines variability in chronic pain sensitivity via cross-inhibition of P2X2/3 receptors. Sci Transl Med 2015; 7:287ra72. [PMID: 25972004 PMCID: PMC5018401 DOI: 10.1126/scitranslmed.3009986] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Chronic pain is a highly prevalent and poorly managed human health problem. We used microarray-based expression genomics in 25 inbred mouse strains to identify dorsal root ganglion (DRG)-expressed genetic contributors to mechanical allodynia, a prominent symptom of chronic pain. We identified expression levels of Chrna6, which encodes the α6 subunit of the nicotinic acetylcholine receptor (nAChR), as highly associated with allodynia. We confirmed the importance of α6* (α6-containing) nAChRs by analyzing both gain- and loss-of-function mutants. We find that mechanical allodynia associated with neuropathic and inflammatory injuries is significantly altered in α6* mutants, and that α6* but not α4* nicotinic receptors are absolutely required for peripheral and/or spinal nicotine analgesia. Furthermore, we show that Chrna6's role in analgesia is at least partially due to direct interaction and cross-inhibition of α6* nAChRs with P2X2/3 receptors in DRG nociceptors. Finally, we establish the relevance of our results to humans by the observation of genetic association in patients suffering from chronic postsurgical and temporomandibular pain.
Collapse
Affiliation(s)
- Jeffrey S Wieskopf
- Department of Psychology and Alan Edwards Centre for Research on Pain, McGill University, Montreal, Quebec H3A 1B1, Canada
| | - Jayanti Mathur
- Genomic Institute of the Novartis Research Foundation, San Diego, CA 92121, USA
| | - Walrati Limapichat
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA 91125, USA
| | - Michael R Post
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA 91125, USA
| | - Mona Al-Qazzaz
- Department of Biochemistry, University of Cambridge, Cambridge CB2 1QW, UK
| | - Robert E Sorge
- Department of Psychology and Alan Edwards Centre for Research on Pain, McGill University, Montreal, Quebec H3A 1B1, Canada
| | - Loren J Martin
- Department of Psychology and Alan Edwards Centre for Research on Pain, McGill University, Montreal, Quebec H3A 1B1, Canada
| | - Dmitri V Zaykin
- National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709, USA
| | - Shad B Smith
- Center for Neurosensory Disorders, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Kelen Freitas
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, VA 23219, USA
| | - Jean-Sebastien Austin
- Department of Psychology and Alan Edwards Centre for Research on Pain, McGill University, Montreal, Quebec H3A 1B1, Canada
| | - Feng Dai
- Departments of Anesthesiology and Human Genetics, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Jie Zhang
- Genomic Institute of the Novartis Research Foundation, San Diego, CA 92121, USA
| | - Jaclyn Marcovitz
- Department of Psychology and Alan Edwards Centre for Research on Pain, McGill University, Montreal, Quebec H3A 1B1, Canada
| | - Alexander H Tuttle
- Department of Psychology and Alan Edwards Centre for Research on Pain, McGill University, Montreal, Quebec H3A 1B1, Canada
| | - Peter M Slepian
- Department of Psychology and Alan Edwards Centre for Research on Pain, McGill University, Montreal, Quebec H3A 1B1, Canada
| | - Sarah Clarke
- Department of Psychology and Alan Edwards Centre for Research on Pain, McGill University, Montreal, Quebec H3A 1B1, Canada
| | - Ryan M Drenan
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, IN 47907, USA
| | - Jeff Janes
- Genomic Institute of the Novartis Research Foundation, San Diego, CA 92121, USA
| | - Shakir Al Sharari
- Department of Pharmacology, King Saud University, P. O. Box 2457, Riyadh 11451, Saudi Arabia
| | - Samantha K Segall
- Center for Neurosensory Disorders, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Eske K Aasvang
- Section for Surgical Pathophysiology, Rigshospitalet, Copenhagen University, 2100 Copenhagen, Denmark
| | - Weike Lai
- Departments of Anesthesiology and Human Genetics, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Reinhard Bittner
- Department of Surgery, Marienhospital Stuttgart, 70199 Stuttgart, Germany
| | | | - Gary D Slade
- Department of Dental Ecology, School of Dentistry, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Henrik Kehlet
- Section for Surgical Pathophysiology, Rigshospitalet, Copenhagen University, 2100 Copenhagen, Denmark
| | - John Walker
- Genomic Institute of the Novartis Research Foundation, San Diego, CA 92121, USA
| | - Uwe Maskos
- Neurobiologie Intégrative des Systèmes Cholinergiques, CNRS UMR 3571, Département de Neuroscience, Institute Pasteur, 75724 Paris, France
| | - Jean-Pierre Changeux
- Neurobiologie Intégrative des Systèmes Cholinergiques, CNRS UMR 3571, Département de Neuroscience, Institute Pasteur, 75724 Paris, France
| | - Marshall Devor
- Department of Cell and Developmental Biology, Institute of Life Sciences and Center for Research on Pain, Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - William Maixner
- Center for Neurosensory Disorders, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Luda Diatchenko
- Center for Neurosensory Disorders, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA. Faculty of Dentistry, Department of Anesthesia, and Alan Edwards Centre for Research on Pain, McGill University, Montreal, Quebec H3A 1G1, Canada
| | - Inna Belfer
- Departments of Anesthesiology and Human Genetics, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Dennis A Dougherty
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA 91125, USA
| | - Andrew I Su
- Department of Molecular and Experimental Medicine, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Sarah C R Lummis
- Department of Biochemistry, University of Cambridge, Cambridge CB2 1QW, UK
| | - M Imad Damaj
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, VA 23219, USA
| | - Henry A Lester
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA
| | - Ardem Patapoutian
- Department of Molecular and Cellular Neuroscience, The Scripps Research Institute, and Howard Hughes Medical Institute, La Jolla, CA 92037, USA
| | - Jeffrey S Mogil
- Department of Psychology and Alan Edwards Centre for Research on Pain, McGill University, Montreal, Quebec H3A 1B1, Canada.
| |
Collapse
|
13
|
Deiteren A, van der Linden L, de Wit A, Ceuleers H, Buckinx R, Timmermans JP, Moreels TG, Pelckmans PA, De Man JG, De Winter BY. P2X3 receptors mediate visceral hypersensitivity during acute chemically-induced colitis and in the post-inflammatory phase via different mechanisms of sensitization. PLoS One 2015; 10:e0123810. [PMID: 25885345 PMCID: PMC4401691 DOI: 10.1371/journal.pone.0123810] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2014] [Accepted: 03/07/2015] [Indexed: 01/08/2023] Open
Abstract
Objectives Experiments using P2X3 knock-out mice or more general P2X receptor antagonists suggest that P2X3 receptors contribute to visceral hypersensitivity. We aimed to investigate the effect of the selective P2X3 antagonist A-317491 on visceral sensitivity under physiological conditions, during acute colitis and in the post-inflammatory phase of colitis. Methods Trinitrobenzene sulphonic-acid colitis was monitored by colonoscopy: on day 3 to confirm the presence of colitis and then every 4 days, starting from day 10, to monitor convalescence and determine the exact timepoint of endoscopic healing in each rat. Visceral sensitivity was assessed by quantifying visceromotor responses to colorectal distension in controls, rats with acute colitis and post-colitis rats. A-317491 was administered 30 min prior to visceral sensitivity testing. Expression of P2X3 receptors (RT-PCR and immunohistochemistry) and the intracellular signalling molecules cdk5, csk and CASK (RT-PCR) were quantified in colonic tissue and dorsal root ganglia. ATP release in response to colorectal distension was measured by luminiscence. Results Rats with acute TNBS-colitis displayed significant visceral hypersensitivity that was dose-dependently, but not fully, reversed by A-317491. Hypersenstivity was accompanied by an increased colonic release of ATP. Post-colitis rats also displayed visceral hypersensitivity that was dose-dependently reduced and fully normalized by A-317491 without increased release of ATP. A-317491 did not modify visceral sensitivity in controls. P2X3 mRNA and protein expression in the colon and dorsal root ganglia were similar in control, acute colitis and post-colitis groups, while colonic mRNA expression of cdk5, csk and CASK was increased in the post-colitis group only. Conclusions These findings indicate that P2X3 receptors are not involved in sensory signaling under physiological conditions whereas they modulate visceral hypersensitivity during acute TNBS-colitis and even more so in the post-inflammatory phase, albeit via different mechanisms of sensitization, validating P2X3 receptors as potential new targets in the treatment of abdominal pain syndromes.
Collapse
Affiliation(s)
- Annemie Deiteren
- Laboratory of Experimental Medicine and Pediatrics, Division of Gastroenterology, University of Antwerp, Antwerp, Belgium
| | - Laura van der Linden
- Laboratory of Experimental Medicine and Pediatrics, Division of Gastroenterology, University of Antwerp, Antwerp, Belgium
| | - Anouk de Wit
- Laboratory of Experimental Medicine and Pediatrics, Division of Gastroenterology, University of Antwerp, Antwerp, Belgium
| | - Hannah Ceuleers
- Laboratory of Experimental Medicine and Pediatrics, Division of Gastroenterology, University of Antwerp, Antwerp, Belgium
| | - Roeland Buckinx
- Laboratory of Cell Biology and Histology, University of Antwerp, Antwerp, Belgium
| | | | - Tom G. Moreels
- Laboratory of Experimental Medicine and Pediatrics, Division of Gastroenterology, University of Antwerp, Antwerp, Belgium
- Antwerp University Hospital, Department of Gastroenterology and Hepatology, Antwerp, Belgium
| | - Paul A. Pelckmans
- Laboratory of Experimental Medicine and Pediatrics, Division of Gastroenterology, University of Antwerp, Antwerp, Belgium
- Antwerp University Hospital, Department of Gastroenterology and Hepatology, Antwerp, Belgium
| | - Joris G. De Man
- Laboratory of Experimental Medicine and Pediatrics, Division of Gastroenterology, University of Antwerp, Antwerp, Belgium
| | - Benedicte Y. De Winter
- Laboratory of Experimental Medicine and Pediatrics, Division of Gastroenterology, University of Antwerp, Antwerp, Belgium
- * E-mail:
| |
Collapse
|
14
|
Matsuda T, Kubo A, Taguchi T, Mizumura K. ATP decreases mechanical sensitivity of muscle thin-fiber afferents in rats. Neurosci Res 2015; 97:36-44. [PMID: 25862944 DOI: 10.1016/j.neures.2015.04.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2014] [Revised: 02/23/2015] [Accepted: 04/01/2015] [Indexed: 10/23/2022]
Abstract
ATP is an energy rich substance contained in cells in the order of mM. It is released when cells are damaged and when muscle is compressed or contracted. Subcutaneous injection of ATP induces pain-related behavior and hyperalgesia to mechanical and heat stimulation in rats. However, the effects of ATP in muscle have not been fully studied. In the present study we examined the effects of ATP on muscle C-fiber afferent activities using single fiber recordings, and on nociceptive behavior. Muscle C-fiber activities were recorded in vitro using extensor digitorum longus muscle-common peroneal nerve preparations excised from rats deeply anesthetized with pentobarbital. ATP (100 μM and 1 mM, but not 1 μM) superfused for 5 min before the mechanical stimulation suppressed the mechanical responses of muscle thin fibers irrespective of whether they excited the fiber. This suppressive effect was reversed by P2X receptor antagonists PPADS (100 μM) and suramin (300 μM). We also found that subcutaneous injection of ATP (10 mM) induced nociceptive behavior, whereas intramuscular injection had no effect. These findings showed that effects of ATP on muscle afferents differ from those on cutaneous afferents.
Collapse
Affiliation(s)
- Teru Matsuda
- Department of Neuroscience II, Research Institute of Environmental Medicine, Nagoya University, Nagoya, Japan; Department of Physical Therapy, College of Life and Health Sciences, Chubu University, Kasugai, Japan
| | - Asako Kubo
- Department of Neuroscience II, Research Institute of Environmental Medicine, Nagoya University, Nagoya, Japan; Department of Physical Therapy, College of Life and Health Sciences, Chubu University, Kasugai, Japan
| | - Toru Taguchi
- Department of Neuroscience II, Research Institute of Environmental Medicine, Nagoya University, Nagoya, Japan
| | - Kazue Mizumura
- Department of Neuroscience II, Research Institute of Environmental Medicine, Nagoya University, Nagoya, Japan; Department of Physical Therapy, College of Life and Health Sciences, Chubu University, Kasugai, Japan.
| |
Collapse
|
15
|
Xanthos DN, Beiersdorf JW, Thrun A, Ianosi B, Orr-Urtreger A, Huck S, Scholze P. Role of α5-containing nicotinic receptors in neuropathic pain and response to nicotine. Neuropharmacology 2015; 95:37-49. [PMID: 25725336 DOI: 10.1016/j.neuropharm.2015.02.012] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2014] [Revised: 02/03/2015] [Accepted: 02/10/2015] [Indexed: 11/26/2022]
Abstract
Nicotinic receptors in the central nervous system (nAChRs) are known to play important roles in pain processing and modulate behavioral responses to analgesic drugs, including nicotine. The presence of the α5-neuronal nicotinic accessory subunit in the nicotinic receptor complex is increasingly understood to modulate reward and aversive states, addiction, and possibly pathological pain. In the current study, using α5-knockout (KO) mice and subunit-specific antibodies, we assess the role of α5-containing neuronal nicotinic receptors in neuropathic pain and in the analgesic response to nicotine. After chronic constriction injury (CCI) or partial sciatic nerve ligation (PSNL), no differences in mechanical, heat, or cold hyperalgesia were found in wild-type (WT) versus α5-KO littermate mice. The number of α5-containing nAChRs was decreased (rather than increased) after CCI in the spinal cord and in the thalamus. Nevertheless, thermal analgesic response to nicotine was marginally reduced in CCI α5-KO mice at 4 days after CCI, but not at later timepoints or after PSNL. Interestingly, upon daily intermittent nicotine injections in unoperated mice, WT animals developed tolerance to nicotine-induced analgesia to a larger extent than α5-KO mice. Our results suggest that α5-containing nAChRs mediate analgesic tolerance to nicotine but do not play a major role in neuropathic pain.
Collapse
Affiliation(s)
- Dimitris N Xanthos
- Department of Neurophysiology, Center for Brain Research, Medical University of Vienna, Spitalgasse 4, 1090 Austria.
| | - Johannes W Beiersdorf
- Department of Pathobiology of the Nervous System, Center for Brain Research, Medical University of Vienna, Spitalgasse 4, 1090 Austria
| | - Ariane Thrun
- Department of Pathobiology of the Nervous System, Center for Brain Research, Medical University of Vienna, Spitalgasse 4, 1090 Austria
| | - Bogdan Ianosi
- Department of Pathobiology of the Nervous System, Center for Brain Research, Medical University of Vienna, Spitalgasse 4, 1090 Austria
| | - Avi Orr-Urtreger
- The Genetic Institute, Tel-Aviv Sourasky Medical Center, Tel-Aviv, Israel; The Sackler Faculty of Medicine, Tel-Aviv University, Tel-Aviv, Israel
| | - Sigismund Huck
- Department of Pathobiology of the Nervous System, Center for Brain Research, Medical University of Vienna, Spitalgasse 4, 1090 Austria
| | - Petra Scholze
- Department of Pathobiology of the Nervous System, Center for Brain Research, Medical University of Vienna, Spitalgasse 4, 1090 Austria.
| |
Collapse
|
16
|
Schiavuzzo JG, Teixeira JM, Melo B, da Silva dos Santos DF, Jorge CO, Oliveira-Fusaro MCG, Parada CA. Muscle hyperalgesia induced by peripheral P2X3 receptors is modulated by inflammatory mediators. Neuroscience 2014; 285:24-33. [PMID: 25446353 DOI: 10.1016/j.neuroscience.2014.11.020] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2014] [Revised: 11/06/2014] [Accepted: 11/11/2014] [Indexed: 11/25/2022]
Abstract
ATP, via activation of P2X3 receptors, has been highlighted as a key target in inflammatory hyperalgesia. Therefore, the aim of this study was to confirm whether the activation of P2X3 receptors in the gastrocnemius muscle of rats induces mechanical muscle hyperalgesia and, if so, to analyze the involvement of the classical inflammatory mediators (bradykinin, prostaglandins, sympathetic amines, pro-inflammatory cytokines and neutrophil migration) in this response. Intramuscular administration of the non-selective P2X3 receptor agonist α,β-meATP in the gastrocnemius muscle of rats induced mechanical muscle hyperalgesia, which, in turn, was prevented by the selective P2X3 and P2X2/3 receptors antagonist A-317491, the selective bradykinin B1-receptor antagonist Des-Arg9-[Leu8]-BK (DALBK), the cyclooxygenase inhibitor indomethacin, the β1- or β2-adrenoceptor antagonist atenolol and ICI 118,551, respectively. Also, the nonspecific selectin inhibitor fucoidan. α,β-meATP induced increases in the local concentration of the pro-inflammatory cytokines tumor necrosis factor-α (TNF-α) and interleukin 1β (IL-1β), which were reduced by bradykinin antagonist. Finally, α,β-meATP also induced neutrophil migration. Together, these findings suggest that α,β-meATP induced mechanical hyperalgesia in the gastrocnemius muscle of rats via activation of peripheral P2X3 receptors, which involves bradykinin, prostaglandins, sympathetic amines, pro-inflammatory cytokines release and neutrophil migration. It is also indicated that bradykinin is the key modulator of the mechanical muscle hyperalgesia induced by P2X3 receptors. Therefore, we suggest that P2X3 receptors are important targets to control muscle inflammatory pain.
Collapse
Affiliation(s)
- J G Schiavuzzo
- Laboratory of Studies of Pain and Inflammation, School of Applied Sciences - UNICAMP, Limeira, Sao Paulo, Brazil; Department of Structural and Functional Biology, Institute of Biology, State University of Campinas - UNICAMP, Campinas, Sao Paulo, Brazil
| | - J M Teixeira
- Department of Structural and Functional Biology, Institute of Biology, State University of Campinas - UNICAMP, Campinas, Sao Paulo, Brazil
| | - B Melo
- Laboratory of Studies of Pain and Inflammation, School of Applied Sciences - UNICAMP, Limeira, Sao Paulo, Brazil
| | - D F da Silva dos Santos
- Laboratory of Studies of Pain and Inflammation, School of Applied Sciences - UNICAMP, Limeira, Sao Paulo, Brazil
| | - C O Jorge
- Laboratory of Studies of Pain and Inflammation, School of Applied Sciences - UNICAMP, Limeira, Sao Paulo, Brazil
| | - M C G Oliveira-Fusaro
- Laboratory of Studies of Pain and Inflammation, School of Applied Sciences - UNICAMP, Limeira, Sao Paulo, Brazil.
| | - C A Parada
- Department of Structural and Functional Biology, Institute of Biology, State University of Campinas - UNICAMP, Campinas, Sao Paulo, Brazil
| |
Collapse
|
17
|
Wang WS, Tu WZ, Cheng RD, He R, Ruan LH, Zhang L, Gong YS, Fan XF, Hu J, Cheng B, Lai YP, Zou EM, Jiang SH. Electroacupuncture and A-317491 depress the transmission of pain on primary afferent mediated by the P2X3 receptor in rats with chronic neuropathic pain states. J Neurosci Res 2014; 92:1703-13. [PMID: 25041872 DOI: 10.1002/jnr.23451] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2013] [Revised: 06/04/2014] [Accepted: 06/10/2014] [Indexed: 12/14/2022]
Abstract
P2X is a family of ligand-gated ion channels that act through adenosine ATP. The P2X3 receptor plays a key role in the transmission of neuropathic pain at peripheral and spinal sites. Electroacupuncture (EA) has been used to treat neuropathic pain effectively. To determine the role of EA in neuropathic pain mediated through the P2X3 receptor in dorsal root ganglion neurons and the spinal cord, a chronic constriction injury (CCI) model was used. Sprague-Dawley rats were divided into four groups: sham CCI, CCI, CCI plus contralateral EA, and CCI plus ipsilateral EA. The mechanical withdrawal threshold (MWT) and thermal withdrawal latency (TWL) were recorded. Furthermore, the expression of the P2X3 receptor was evaluated through Western blotting and immunofluorescence. The effects of EA and A-317491 were investigated through the whole-cell patch-clamp method and intrathecal administration. Our results show that the MWT and TWL of EA groups were higher than those in the CCI group, whereas the expression of the P2X3 receptor was lower than that in the CCI group. However, no significant difference was detected between the two EA groups. EA depressed the currents created by ATP and the upregulation of the P2X3 receptor in CCI rats. Additionally, EA was more potent in reducing mechanical allodynia and thermal hyperalgesia when combined with A-317491 through intrathecal administration. These results show that both contralateral and ipsilateral EA might inhibit the primary afferent transmission of neuropathic pain induced through the P2X3 receptor. In addition, EA and A-317491 might have an additive effect in inhibiting the transmission of pain mediated by the P2X3 receptor.
Collapse
Affiliation(s)
- Wan-Sheng Wang
- Department of Physical Medicine and Rehabilitation, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, China
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
18
|
Barr TP, Hrnjic A, Khodorova A, Sprague JM, Strichartz GR. Sensitization of cutaneous neuronal purinergic receptors contributes to endothelin-1-induced mechanical hypersensitivity. Pain 2014; 155:1091-1101. [PMID: 24569146 DOI: 10.1016/j.pain.2014.02.014] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2013] [Revised: 02/05/2014] [Accepted: 02/18/2014] [Indexed: 10/25/2022]
Abstract
Endothelin (ET-1), an endogenous peptide with a prominent role in cutaneous pain, causes mechanical hypersensitivity in the rat hind paw, partly through mechanisms involving local release of algogenic molecules in the skin. The present study investigated involvement of cutaneous ATP, which contributes to pain in numerous animal models. Pre-exposure of ND7/104 immortalized sensory neurons to ET-1 (30nM) for 10min increased the proportion of cells responding to ATP (2μM) with an increase in intracellular calcium, an effect prevented by the ETA receptor-selective antagonist BQ-123. ET-1 (3nM) pre-exposure also increased the proportion of isolated mouse dorsal root ganglion neurons responding to ATP (0.2-0.4μM). Blocking ET-1-evoked increases in intracellular calcium with the IP3 receptor antagonist 2-APB did not inhibit sensitization to ATP, indicating a mechanism independent of ET-1-mediated intracellular calcium increases. ET-1-sensitized ATP calcium responses were largely abolished in the absence of extracellular calcium, implicating ionotropic P2X receptors. Experiments using quantitative polymerase chain reaction and receptor-selective ligands in ND7/104 showed that ET-1-induced sensitization most likely involves the P2X4 receptor subtype. ET-1-sensitized calcium responses to ATP were strongly inhibited by broad-spectrum (TNP-ATP) and P2X4-selective (5-BDBD) antagonists, but not antagonists for other P2X subtypes. TNP-ATP and 5-BDBD also significantly inhibited ET-1-induced mechanical sensitization in the rat hind paw, supporting a role for purinergic receptor sensitization in vivo. These data provide evidence that mechanical hypersensitivity caused by cutaneous ET-1 involves an increase in the neuronal sensitivity to ATP in the skin, possibly due to sensitization of P2X4 receptors.
Collapse
Affiliation(s)
- Travis P Barr
- Pain Research Center, Department of Anesthesiology, Perioperative and Pain Medicine, Brigham & Women's Hospital, Boston, MA, USA Department of Pharmaceutical Biosciences, Uppsala University, Uppsala, Sweden Neurobiology Department, Children's Hospital Boston, Harvard Medical School, Boston, MA, USA Harvard School of Dental Medicine, Boston, MA, USA Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA, USA
| | | | | | | | | |
Collapse
|
19
|
Cho JH, Jung KY, Jung Y, Kim MH, Ko H, Park CS, Kim YC. Design and synthesis of potent and selective P2X₃ receptor antagonists derived from PPADS as potential pain modulators. Eur J Med Chem 2013; 70:811-30. [PMID: 24246730 DOI: 10.1016/j.ejmech.2013.10.026] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2013] [Revised: 10/07/2013] [Accepted: 10/11/2013] [Indexed: 11/17/2022]
Abstract
Pyridoxalphosphate-6-azophenyl-2',4'-disulfonate (7a, PPADS), a nonselective P2X receptor antagonist, was extensively modified to develop more stable, potent, and selective P2X₃ receptor antagonists as potential antinociceptive agents. Based on the results of our previous report, all strong anionic groups in PPADS including phosphate and sulfonate groups were changed to carboxylic acids or deleted. The unstable azo (-NN-) linkage of 7a was transformed to more stable carbon-carbon, ether or amide linkages through the synthesis of the 5-hydroxyl-pyridine moieties with substituents at 2 position via a Diels-Alder reaction. This resulted in the retention of antagonistic activity (IC50 = 400 ∼ 700 nM) at the hP2X₃ receptor in the two-electrode voltage clamp (TEVC) assay system on the Xenopus oocytes. Introduction of bulky aromatic groups at the carbon linker, as in compounds 13 h-n, dramatically improved the selectivity profiles of hP2X₃ when compared with mP2X₁ and hP2X₇ receptors. Among the substituents tested at the 2-position, the m-phenoxybenzyl group showed optimum selectivity and potency at the hP2X₃ receptor. In searching for effective substituents at the 4- and 3-positions, we found that compound 36j, with 4-carboxaldehyde, 3-propenoic acid and 2-(m-phenoxy)benzyl groups, was the most potent and selective hP2X₃ receptor antagonist with an IC50 of 60 nM at hP2X₃ and marginal antagonistic activities of 10 μM at mP2X₁ and hP2X₇. Furthermore, using an ex-vivo assay system, we found that compound 36j potently inhibited pain signaling in the rat dorsal horn with 20 μM 36j displaying 65% inhibition while 20 μM pregabalin, a clinically available drug, showed only 31% inhibition.
Collapse
Affiliation(s)
- Joong-Heui Cho
- School of Life Sciences, Gwangju Institute of Science and Technology (GIST), Gwangju 500-712, Republic of Korea
| | | | | | | | | | | | | |
Collapse
|
20
|
Upregulation of P2X3 receptors by neuronal calcium sensor protein VILIP-1 in dorsal root ganglions contributes to the bone cancer pain in rats. Pain 2013; 154:1551-1568. [PMID: 23707265 DOI: 10.1016/j.pain.2013.04.022] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2013] [Revised: 03/24/2013] [Accepted: 04/11/2013] [Indexed: 01/27/2023]
Abstract
Primary and metastatic cancers that affect bone are frequently associated with severe and intractable pain. The mechanisms underlying the development of bone cancer pain are largely unknown. In this study, we first demonstrated that a functional upregulation of P2X3 receptors in dorsal root ganglion (DRG) neurons is closely associated with the neuronal hyperexcitability and the cancer-induced bone pain in MRMT-1 tumor cell-inoculated rats. Second, we revealed that visinin-like protein 1 (VILIP-1), a member of visinin-like proteins that belong to the family of neuronal calcium sensor proteins is responsible for the observed upregulation of P2X3 receptors in DRG neurons. The interaction between the amino terminus of VLIP-1 and the carboxyl terminus of the P2X3 receptor is critical for the surface expression and functional enhancement of the receptor. Finally, overexpression of VILIP-1 increases the expression of functional P2X3 receptors and enhances the neuronal excitability in naive rat DRG neurons. In contrast, knockdown of VILIP-1 inhibits the development of bone cancer pain via downregulation of P2X3 receptors and repression of DRG excitability in MRMT-1 rats. Taken together, these results suggest that functional upregulation of P2X3 receptors by VILIP-1 in DRG neurons contributes to the development of cancer-induced bone pain in MRMT-1 rats. Hence, P2X3 receptors and VILIP-1 could serve as potential targets for therapeutic interventions in cancer patients for pain management. Pharmacological blockade of P2X3 receptors or knockdown of VILIP-1 in DRGs would be used as innovative strategies for the treatment of bone cancer pain.
Collapse
|
21
|
Prado F, Araldi D, Vieira A, Oliveira-Fusaro M, Tambeli C, Parada C. Neuronal P2X3 receptor activation is essential to the hyperalgesia induced by prostaglandins and sympathomimetic amines released during inflammation. Neuropharmacology 2013. [DOI: 10.1016/j.neuropharm.2012.11.011] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
|
22
|
Barr TP, Albrecht PJ, Hou Q, Mongin AA, Strichartz GR, Rice FL. Air-stimulated ATP release from keratinocytes occurs through connexin hemichannels. PLoS One 2013; 8:e56744. [PMID: 23457608 PMCID: PMC3574084 DOI: 10.1371/journal.pone.0056744] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2012] [Accepted: 01/14/2013] [Indexed: 01/17/2023] Open
Abstract
Cutaneous ATP release plays an important role in both epidermal stratification and chronic pain, but little is known about ATP release mechanisms in keratinocytes that comprise the epidermis. In this study, we analyzed ATP release from cultured human neonatal keratinocytes briefly exposed to air, a process previously demonstrated to trigger ATP release from these cells. We show that exposing keratinocytes to air by removing media for 15 seconds causes a robust, long-lasting ATP release. This air-stimulated ATP release was increased in calcium differentiated cultures which showed a corresponding increase in connexin 43 mRNA, a major component of keratinocyte hemichannels. The known connexin hemichannel inhibitors 1-octanol and carbenoxolone both significantly reduced air-stimulated ATP release, as did two drugs traditionally used as ABC transporter inhibitors (glibenclamide and verapamil). These same 4 inhibitors also prevented an increase in the uptake of a connexin permeable dye induced by air exposure, confirming that connexin hemichannels are open during air-stimulated ATP release. In contrast, activity of the MDR1 ABC transporter was reduced by air exposure and the drugs that inhibited air-stimulated ATP release had differential effects on this transporter. These results indicate that air exposure elicits non-vesicular release of ATP from keratinocytes through connexin hemichannels and that drugs used to target connexin hemichannels and ABC transporters may cross-inhibit. Connexins represent a novel, peripheral target for the treatment of chronic pain and dermatological disease.
Collapse
Affiliation(s)
- Travis P. Barr
- Pain Research Center, Department of Anesthesiology, Perioperative and Pain Medicine, Brigham & Women's Hospital, Boston, Massachusetts, United States of America
| | - Phillip J. Albrecht
- Albany Medical College, Center for Neuroscience and Neuropharmacology, Albany, New York, United States of America
| | - Quanzhi Hou
- Albany Medical College, Center for Neuroscience and Neuropharmacology, Albany, New York, United States of America
| | - Alexander A. Mongin
- Albany Medical College, Center for Neuroscience and Neuropharmacology, Albany, New York, United States of America
| | - Gary R. Strichartz
- Pain Research Center, Department of Anesthesiology, Perioperative and Pain Medicine, Brigham & Women's Hospital, Boston, Massachusetts, United States of America
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Frank L. Rice
- Albany Medical College, Center for Neuroscience and Neuropharmacology, Albany, New York, United States of America
| |
Collapse
|
23
|
Abstract
Musculoskeletal pain conditions, particularly those associated with temporomandibular disorders (TMD) affect a large percentage of the population. Identifying mechanisms underlying hyperalgesia could contribute to the development of new treatment strategies for the management of TMD and other muscle pain conditions. In this study, we provide evidence of functional interactions between two ligand-gated channels, P2X₃ and transient receptor potential V1 (TRPV1), in trigeminal sensory neurons, and propose that the interactions serve as an underlying mechanism for the development of mechanical hyperalgesia. Mechanical sensitivity of the masseter muscle was assessed in lightly anesthetized rats via an electronic anesthesiometer (Ro et al., 2009). Direct intramuscular injection of a selective P2X₃ agonist, alpha,beta-methylene adenosine triphosphate (αβmeATP), induced a dose- and time-dependent hyperalgesia. Mechanical sensitivity in the contralateral muscle was unaffected suggesting local P2X₃ mediate hyperalgesia. Anesthetizing the overlying skin had no effect on αβmeATP-induced hyperalgesia confirming the contribution of P2X₃ from the muscle. Importantly, the αβmeATP-induced hyperalgesia was prevented by pretreatment of the muscle with a TRPV1 antagonist, AMG9810. P2X₃ was co-expressed with TRPV1 in the masseter muscle afferents confirming the possibility for intracellular interactions. Additionally, in a subpopulation of P2Xv/TRPV1 positive neurons, capsaicin-induced Ca(2+) transients were significantly amplified following P2X₃ activation. Finally, activation of P2X₃ induced phosphorylation of serine, but not threonine, residues in TRPV1 in trigeminal ganglia cultures. Significant phosphorylation was observed at 15 min, the time point at which behavioral hyperalgesia was prominent. Previously, activation of either P2X₃ or TRPV1 had been independently implicated in the development of mechanical hyperalgesia. Our data propose P2X₃ and TRPV1 interact in a facilitatory manner, which could contribute to the peripheral sensitization known to underlie masseter hyperalgesia.
Collapse
|
24
|
Hansen RR, Nasser A, Falk S, Baldvinsson SB, Ohlsson PH, Bahl JMC, Jarvis MF, Ding M, Heegaard AM. Chronic administration of the selective P2X3, P2X2/3 receptor antagonist, A-317491, transiently attenuates cancer-induced bone pain in mice. Eur J Pharmacol 2012; 688:27-34. [PMID: 22634164 DOI: 10.1016/j.ejphar.2012.05.008] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2011] [Revised: 04/24/2012] [Accepted: 05/15/2012] [Indexed: 12/16/2022]
Abstract
The purinergic P2X3 and P2X2/3 receptors are in the peripheral nervous system almost exclusively confined to afferent sensory neurons, where they are found both at peripheral and central synapses. The P2X3 receptor is implicated in both neuropathic and inflammatory pain. However, the role of the P2X3 receptor in chronic cancer-induced bone pain is less known. Here we investigated the effect of systemic acute and chronic administration of the selective P2X3, P2X2/3 receptor antagonist (5-[[[(3-Phenoxyphenyl)methyl][(1S)-1,2,3,4-tetrahydro-1-naphthalenyl]amino]carbonyl]-1,2,4-benzenetricarboxylic acid sodium salt hydrate) (A-317491) in a murine model of cancer-induced bone pain. Chronic administration of A-317491 (30 μmol/kgs.c., b.i.d.) resulted in a transient attenuation of pain related behaviours in the early stage of the bone cancer model, but had no effect in the late and more progressed stage of bone cancer. Also, acute administration of A-317491 (100 μmol/kgs.c.) had no effect in the progressed stage of the bone cancer pain model. Thus, systemically administered A-317491 did not demonstrate a robust effect in the present mouse model of cancer-induced bone pain.
Collapse
Affiliation(s)
- Rikke Rie Hansen
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, Universitetsparken 2, DK-2100 Copenhagen, Denmark
| | | | | | | | | | | | | | | | | |
Collapse
|
25
|
Inhibiting the breakdown of endogenous opioids and cannabinoids to alleviate pain. Nat Rev Drug Discov 2012; 11:292-310. [DOI: 10.1038/nrd3673] [Citation(s) in RCA: 139] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
|
26
|
Xu J, Chu KL, Brederson JD, Jarvis MF, McGaraughty S. Spontaneous firing and evoked responses of spinal nociceptive neurons are attenuated by blockade of P2X3 and P2X2/3 receptors in inflamed rats. J Neurosci Res 2012; 90:1597-606. [PMID: 22422599 DOI: 10.1002/jnr.23042] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2011] [Revised: 01/04/2012] [Accepted: 01/15/2012] [Indexed: 11/11/2022]
Abstract
P2X3 and P2X2/3 receptors are selectively expressed on primary afferent nociceptors and have been implicated in modulating nociception in different models of pathological pain, including inflammatory pain. In an effort to delineate further the role of P2X3 receptors (homomeric and heteromeric) in the modulation of nociceptive transmission after a chronic inflammation injury, A-317491, a potent and selective P2X3-P2X2/3 antagonist, was administered to CFA-inflamed rats in order to examine its effects on responses of spinal dorsal horn neurons to mechanical and thermal stimulation. Systemic injection of A-317491 (30 μmol/kg, i.v.) reduced the responses of wide-dynamic-range (WDR) and nociceptive specific (NS) neurons to both high-intensity mechanical (pinch) and heat (49°C) stimulation. A-317491 also decreased low-intensity (10 g von Frey hair) mechanically evoked activity of WDR neurons but did not alter WDR neuronal responses to cold stimulation (5°C). Spontaneous firing of WDR neurons in CFA-inflamed rats was also significantly attenuated by A-317491 injection. By using immunohistochemistry, P2X3 receptors were demonstrated to be enhanced in lamina II of the spinal dorsal horn after inflammation. In summary, blockade of P2X3 and P2X2/3 receptors dampens mechanical- and heat-related signaling, as well as nonevoked activity of key classes of spinal nociceptive neurons in inflamed animals. These data suggest that P2X3 and/or P2X2/3 receptors have a broad contribution to somatosensory/nociceptive transmission in rats with a chronic inflammatory injury and are consistent with previous behavioral data demonstrating antiallodynic and antihyperalgesic effects of receptor antagonists.
Collapse
Affiliation(s)
- Jun Xu
- Neuroscience Research, Global Pharmaceutical Research and Development, Abbott Laboratories, Abbott Park, Illinois 60064-6118, USA
| | | | | | | | | |
Collapse
|
27
|
Jennings EA, Williams MC, Staikopoulos V, Ivanusic JJ. Neurobiology of Temporomandibular Joint Pain: Therapeutic Implications. Semin Orthod 2012. [DOI: 10.1053/j.sodo.2011.10.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
|
28
|
|
29
|
Abstract
The pharmacological concept of specifically targeting purinoceptors (receptors for ATP and related nucleotides) has emerged over the last two decades in the quest for novel, differentiated therapeutics. Investigations from many laboratories have established a prominent role for ATP in the functional regulation of most tissue and organ systems, including the urinary tract, under normal and pathophysiological conditions. In the particular case of the urinary tract, ATP signaling via P2X1 receptors participates in the efferent control of detrusor smooth muscle excitability, and this function may be heightened in disease and aging. Perhaps of greater interest, ATP also appears to be involved in bladder sensation, operating via activation of P2X3-containing receptors on sensory afferent neurones, both on peripheral terminals within the urinary tract tissues (e.g., ureters, bladder) and on central synapses in the dorsal horn of the spinal cord. Such findings are based on results from classical pharmacological and localization studies in nonhuman and human tissues, gene knockout mice, and studies using recently identified pharmacological antagonists - some of which have progressed as candidate drug molecules. Based on recent advances in this field, it is apparent that the development of selective antagonists for these receptors will occur that could lead to therapies offering better relief of storage, voiding, and sensory symptoms for patients, while minimizing the systemic side effects that curb the clinical effectiveness of current urologic medicines.
Collapse
|
30
|
Niane LM, Donnelly DF, Joseph V, Bairam A. Ventilatory and carotid body chemoreceptor responses to purinergic P2X receptor antagonists in newborn rats. J Appl Physiol (1985) 2010; 110:83-94. [PMID: 21051571 DOI: 10.1152/japplphysiol.00871.2010] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Adenosine triphosphate, acting through purinergic P2X receptors, has been shown to stimulate ventilation and increase carotid body chemoreceptor activity in adult rats. However, its role during postnatal development of the ventilatory response to hypoxia is yet unknown. Using whole body plethysmography, we measured ventilation in normoxia and in moderate hypoxia (12% fraction of inspired O₂, 20 min) before and after intraperitoneal injection of suramin (P2X₂ and P2X₃ receptor antagonist, 40 mg/kg) in 4-, 7-, 12-, and 21-day-old rats. Suramin reduced baseline breathing (∼20%) and the response to hypoxia (∼30%) in all rats, with a relatively constant effect across ages. We then tested the effect of the specific P2X₃ antagonist, A-317491 (150 mg/kg), in rats aged 4, 7, and 21 days. As with suramin, A-317491 reduced baseline ventilation (∼55%) and the hypoxic response (∼40%) at all ages studied. Single-unit carotid body chemoreceptor activity was recorded in vitro in 4-, 7-, and 21-day-old rats. Suramin (100 μM) and A-317491 (10 μM) significantly depressed the sinus nerve chemosensory discharge rate (∼80%) in normoxia (Po₂ ∼150 Torr) and hypoxia (Po₂ ∼60 Torr), and this decrease was constant across ages. We conclude that, in newborn rats, P2X purinergic receptors are involved in the regulation of breathing under basal and hypoxic condition, and P2X₃-containing receptors play a major role in carotid body function. However, these effects are not age dependent within the age range studied.
Collapse
Affiliation(s)
- Lalah M Niane
- Unité de Recherche en Périnatologie, Centre Hospitalier Universitaire de Québec, Hôpital Saint-François d’Assise, Département de Pédiatrie, Université Laval, Québec, Canada
| | | | | | | |
Collapse
|
31
|
Gever JR, Soto R, Henningsen RA, Martin RS, Hackos DH, Panicker S, Rubas W, Oglesby IB, Dillon MP, Milla ME, Burnstock G, Ford APDW. AF-353, a novel, potent and orally bioavailable P2X3/P2X2/3 receptor antagonist. Br J Pharmacol 2010; 160:1387-98. [PMID: 20590629 DOI: 10.1111/j.1476-5381.2010.00796.x] [Citation(s) in RCA: 97] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
BACKGROUND AND PURPOSE Purinoceptors containing the P2X3 subunit (P2X3 homotrimeric and P2X2/3 heterotrimeric) are members of the P2X family of ion channels gated by ATP and may participate in primary afferent sensitization in a variety of pain-related diseases. The current work describes the in vitro pharmacological characteristics of AF-353, a novel, orally bioavailable, highly potent and selective P2X3/P2X2/3 receptor antagonist. EXPERIMENTAL APPROACH The antagonistic potencies (pIC(50)) of AF-353 for rat and human P2X3 and human P2X2/3 receptors were determined using methods of radioligand binding, intracellular calcium flux and whole cell voltage-clamp electrophysiology. KEY RESULTS The pIC(50) estimates for these receptors ranged from 7.3 to 8.5, while concentrations 300-fold higher had little or no effect on other P2X channels or on an assortment of receptors, enzymes and transporter proteins. In contrast to A-317491 and TNP-ATP, competition binding and intracellular calcium flux experiments suggested that AF-353 inhibits activation by ATP in a non-competitive fashion. Favourable pharmacokinetic parameters were observed in rat, with good oral bioavailability (%F = 32.9), reasonable half-life (t(1/2) = 1.63 h) and plasma-free fraction (98.2% protein bound). CONCLUSIONS AND IMPLICATIONS The combination of a favourable pharmacokinetic profile with the antagonist potency and selectivity for P2X3 and P2X2/3 receptors suggests that AF-353 is an excellent in vivo tool compound for study of these channels in animal models and demonstrates the feasibility of identifying and optimizing molecules into potential clinical candidates, and, ultimately, into a novel class of therapeutics for the treatment of pain-related disorders.
Collapse
Affiliation(s)
- Joel R Gever
- Department of Inflammation Discovery, Roche Palo Alto, Palo Alto, CA, USA
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
32
|
Adachi K, Shimizu K, Hu JW, Suzuki I, Sakagami H, Koshikawa N, Sessle BJ, Shinoda M, Miyamoto M, Honda K, Iwata K. Purinergic receptors are involved in tooth-pulp evoked nocifensive behavior and brainstem neuronal activity. Mol Pain 2010; 6:59. [PMID: 20860800 PMCID: PMC3146069 DOI: 10.1186/1744-8069-6-59] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2010] [Accepted: 09/22/2010] [Indexed: 11/10/2022] Open
Abstract
Background To evaluate whether P2X receptors are involved in responses to noxious pulp stimulation, the P2X3 and P2X2/3 receptor agonist α,β-methyleneATP (α,β-meATP) was applied to the molar tooth pulp and nocifensive behavior and extracellular-signal regulated kinase (ERK) phosphorylation in trigeminal spinal subnucleus caudalis (Vc), trigeminal spinal subnucleus interpolaris (Vi), upper cervical spinal cord (C1/C2) and paratrigeminal nucleus (Pa5) neurons were analyzed in rats. Results Genioglossus (GG) muscle activity was evoked by pulpal application of 100 mM α,β-meATP and was significantly larger than GG activity following vehicle (phosphate-buffered saline PBS) application (p < 0.01). The enhanced GG muscle activity following 100 mM α,β-meATP was significantly reduced (p < 0.05) by co-application of 1 mM TNP-ATP (P2X1, P2X3 and, P2X2/3 antagonist). A large number of pERK-LI cells were expressed in the Vc, Vi/Vc, C1/C2 and Pa5 at 5 min following pulpal application of 100 mM α,β-meATP compared to PBS application to the pulp (p < 0.05). The pERK-LI cell expression and GG muscle activity induced by 100 mM α,β-meATP pulpal application were significantly reduced after intrathecal injection of the MAPK/ERK kinase (MEK) inhibitor PD 98059 and by pulpal co-application of 1 mM TNP-ATP (p < 0.05). Conclusions The present findings suggest that activation of P2X3 and P2X2/3 receptors in the tooth pulp is sufficient to elicit nociceptive behavioral responses and trigeminal brainstem neuronal activity.
Collapse
Affiliation(s)
- Kazunori Adachi
- Department of Physiology, Nihon University School of Dentistry, Nihon University School of Dentistry, 1-8-13 Kanda-Surugadai Chiyoda-ku, Tokyo, 101-8310, Japan
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
33
|
de Oliveira Fusaro MCG, Pelegrini-da-Silva A, Araldi D, Parada CA, Tambeli CH. P2X3 and P2X2/3 receptors mediate mechanical hyperalgesia induced by bradykinin, but not by pro-inflammatory cytokines, PGE₂ or dopamine. Eur J Pharmacol 2010; 649:177-82. [PMID: 20868656 DOI: 10.1016/j.ejphar.2010.09.037] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2010] [Revised: 08/11/2010] [Accepted: 09/14/2010] [Indexed: 12/19/2022]
Abstract
Activation of peripheral P2X3 and P2X2/3 receptors by endogenous ATP is essential to the development of inflammatory hyperalgesia. We have previously demonstrated that this essential role of P2X3 and P2X2/3 receptors in the development of mechanical hyperalgesia induced by the inflammatory agent carrageenan is mediated by an indirect sensitization of the primary afferent nociceptors dependent on the previous release of tumor necrosis factor alpha (TNF-α) and by a direct sensitization of the primary afferent nociceptors. Therefore, in this study we asked whether activation of P2X3 and P2X2/3 receptors contribute to the mechanical hyperalgesia induced by the inflammatory mediators involved in carrageenan-induced mechanical hyperalgesia, such as bradykinin, tumor necrosis factor alpha (TNF-α), interleukin-1 beta (IL-1β), interleukin-6 (IL-6), chemokine-induced chemoattractant-1 (CINC-1), prostaglandin E₂ (PGE₂) and dopamine. Co-administration of the non-selective P2X3 receptor antagonist TNP-ATP or the selective P2X3 and P2X2/3 receptor antagonist A-317491 with bradykinin, but not with TNF-α, IL-1β, IL-6, CINC-1, PGE₂ or dopamine, prevented in a dose-dependent manner the mechanical hyperalgesia. We also verified whether the activation of P2X3 and P2X2/3 receptors by endogenous ATP contributes to bradykinin-induced mechanical hyperalgesia via neutrophil migration and/or cytokine release. Co-administration of TNP-ATP or A-317491 did not affect either neutrophil migration or the increased concentration of TNF-α, IL-1β, IL-6 and CINC-1 induced by bradykinin. These findings demonstrate that the activation of P2X3 and P2X2/3 receptors by endogenous ATP mediates bradykinin-induced mechanical hyperalgesia by a mechanism that does not depend on neutrophil migration or cytokines release.
Collapse
|
34
|
Kaan TKY, Yip PK, Patel S, Davies M, Marchand F, Cockayne DA, Nunn PA, Dickenson AH, Ford APDW, Zhong Y, Malcangio M, McMahon SB. Systemic blockade of P2X3 and P2X2/3 receptors attenuates bone cancer pain behaviour in rats. ACTA ACUST UNITED AC 2010; 133:2549-64. [PMID: 20802203 DOI: 10.1093/brain/awq194] [Citation(s) in RCA: 99] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Pain remains an area of considerable unmet clinical need, and this is particularly true of pain associated with bone metastases, in part because existing analgesic drugs show only limited efficacy in many patients and in part because of the adverse side effects associated with these agents. An important issue is that the nature and roles of the algogens produced in bone that drive pain-signalling systems remain unknown. Here, we tested the hypothesis that adenosine triphosphate is one such key mediator through actions on P2X3 and P2X2/3 receptors, which are expressed selectively on primary afferent nocioceptors, including those innervating the bone. Using a well-established rat model of bone cancer pain, AF-353, a recently described potent and selective P2X3 and P2X2/3 receptor antagonist, was administered orally to rats and found to produce highly significant prevention and reversal of bone cancer pain behaviour. This attenuation occurred without apparent modification of the disease, since bone destruction induced by rat MRMT-1 carcinoma cells was not significantly altered by AF-353. Using in vivo electrophysiology, evidence for a central site of action was provided by dose-dependent reductions in electrical, mechanical and thermal stimuli-evoked dorsal horn neuronal hyperexcitability following direct AF-353 administration onto the spinal cord of bone cancer animals. A peripheral site of action was also suggested by studies on the extracellular release of adenosine triphosphate from MRMT-1 carcinoma cells. Moreover, elevated phosphorylated-extracellular signal-regulated kinase expression in dorsal root ganglion neurons, induced by co-cultured MRMT-1 carcinoma cells, was significantly reduced in the presence of AF-353. These data suggest that blockade of P2X3 and P2X2/3 receptors on both the peripheral and central terminals of nocioceptors contributes to analgesic efficacy in a model of bone cancer pain. Thus, systemic P2X3 and P2X2/3 receptor antagonists with central nervous system penetration may offer a promising therapeutic tool in treating bone cancer pain.
Collapse
Affiliation(s)
- Timothy K Y Kaan
- Neurorestoration Group, Wolfson Centre for Age-Related Diseases, King’s College London, London, UK.
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
35
|
McCord JL, Tsuchimochi H, Kaufman MP. P2X2/3 and P2X3 receptors contribute to the metaboreceptor component of the exercise pressor reflex. J Appl Physiol (1985) 2010; 109:1416-23. [PMID: 20798273 DOI: 10.1152/japplphysiol.00774.2010] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
The exercise pressor reflex is due to activation of thin fiber afferents within contracting muscle. These afferents are in part stimulated by ATP activation of purinergic 2X (P2X) receptors during contraction. Which of the P2X receptors contribute to the reflex is unknown; however, P2X2/3 and P2X3 receptor subtypes are good candidates because they are located on thin fiber afferents and are involved in sensory neurotransmission. To determine if P2X2/3 and P2X3 receptors evoke the metabolic component of the exercise pressor reflex, we examined the effect of two P2X2/3 and P2X3 antagonists, A-317491 (10 mg/kg) and RO-3 (10 mg/kg), on the pressor response to injections of α,β-methylene ATP (α,β-MeATP; 50 μg/kg), freely perfused static contraction, contraction of the triceps surae muscles while the circulation was occluded, and postcontraction circulatory occlusion in decerebrate cats. We found that the antagonists reduced the pressor response to α,β-MeATP injection (before Δ 20 ± 3 mmHg; drug Δ 11 ± 3 mmHg; P < 0.05), suggesting the antagonists were effective in blocking P2X2/3 and P2X3 receptors. P2X2/3 and P2X3 receptor blockade reduced the pressor response to freely perfused contraction (before Δ 33 ± 5 mmHg; drug Δ 15 ± 5 mmHg; P < 0.05), contraction with the circulation occluded (before Δ 52 ± 7 mmHg; drug Δ 20 ± 4 mmHg; P < 0.05), and during postcontraction circulatory occlusion (before Δ 15 ± 1 mmHg; drug Δ 5 ± 1 mmHg; P < 0.05). Our findings suggest that P2X2/3 and P2X3 receptors contribute to the metabolic component of the exercise pressor reflex in decerebrate cats.
Collapse
Affiliation(s)
- Jennifer L McCord
- Penn State Heart and Vascular Institute, Pennsylvania State University College of Medicine, Hershey, PA 17033, USA.
| | | | | |
Collapse
|
36
|
Teixeira JM, Oliveira MCG, Nociti FH, Clemente-Napimoga JT, Pelegrini-da-Silva A, Parada CA, Tambeli CH. Involvement of temporomandibular joint P2X3 and P2X2/3 receptors in carrageenan-induced inflammatory hyperalgesia in rats. Eur J Pharmacol 2010; 645:79-85. [PMID: 20558155 DOI: 10.1016/j.ejphar.2010.06.008] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2010] [Revised: 05/13/2010] [Accepted: 06/07/2010] [Indexed: 11/28/2022]
Abstract
The aim of this study was to investigate the role of P2X3, P2X2/3 and P2X7 receptors in the development of TMJ hyperalgesia induced by carrageenan. We also investigated the expression of mRNA of P2X7 receptors in the trigeminal ganglia and the existence of functional P2X7 receptors in the rat's TMJ. The P2X1, P2X3 and P2X2/3 receptor antagonist TNP-ATP, but not the selective P2X7 receptor antagonist A-438079, significantly reduced carrageenan-induced TMJ inflammatory hyperalgesia. The qPCR assay showed that mRNA of P2X7 receptors are expressed in the trigeminal ganglia but this expression is not increased by the inflammation induced by carrageenan in the TMJ region. The P2X7 receptor agonist BzATP induced TMJ inflammatory hyperalgesia that was significantly reduced by pretreatment with dexamethasone. These results indicate that P2X3 and P2X2/3 but not P2X7 receptors are involved in carrageenan-induced TMJ inflammatory hyperalgesia. However, functional P2X7 receptors are expressed in the TMJ region. The activation of these receptors by BzATP sensitizes the primary afferent nociceptors in the TMJ through the previous release of inflammatory mediators. The findings of this study point out P2X3 and P2X2/3 receptors, but not P2X7 receptors, as potential targets for the development of new analgesic drugs to control TMJ inflammatory pain.
Collapse
Affiliation(s)
- Juliana Maia Teixeira
- Department of Physiological Sciences, Laboratory of Orofacial Pain, Piracicaba Dental School, State University of Campinas - UNICAMP, Piracicaba, Sao Paulo, Brazil
| | | | | | | | | | | | | |
Collapse
|
37
|
Endogenous purinergic control of bladder activity via presynaptic P2X3 and P2X2/3 receptors in the spinal cord. J Neurosci 2010; 30:4503-7. [PMID: 20335487 DOI: 10.1523/jneurosci.6132-09.2010] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
P2X(3) and P2X(2/3) receptors are localized on sensory afferents both peripherally and centrally and have been implicated in various sensory functions. However, the physiological role of these receptors expressed presynaptically in the spinal cord in regulating sensory transmission remains to be elucidated. Here, a novel selective P2X(3) and P2X(2/3) antagonist, AF-792 [5-(5-ethynyl-2-isopropyl-4-methoxy-phenoxy)-pyrimidine-2,4-diamine, previously known as RO-5], in addition to less selective purinoceptor ligands, was applied intrathecally in vivo. Cystometry recordings were made to assess changes in the micturition reflex contractions after drug treatments. We found that AF-792 inhibited micturition reflex activity significantly (300 nmol; from baseline contraction intervals of 1.18 +/- 0.07 to 9.33 +/- 2.50 min). Furthermore, inhibition of P2X(3) and P2X(2/3) receptors in the spinal cord significantly attenuated spinal activation of extracellular-signal regulated kinases induced by acute peripheral stimulation of the bladder with 1% acetic acid by 46.4 +/- 12.0% on average. Hence, the data suggest that afferent signals originating from the bladder are regulated by spinal P2X(3) and P2X(2/3) receptors and establish directly an endogenous central presynaptic purinergic mechanism to regulate visceral sensory transmission. Identification of this spinal purinergic control in visceral activities may help the development of P2X(3) and P2X(2/3) antagonist to treat urological dysfunction, such as overactive bladder, and possibly other debilitating sensory disorders, including chronic pain states.
Collapse
|
38
|
Novel strategies for the treatment of inflammatory hyperalgesia. Eur J Clin Pharmacol 2010; 66:429-44. [DOI: 10.1007/s00228-010-0784-7] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2009] [Accepted: 01/11/2010] [Indexed: 12/24/2022]
|
39
|
González-Rodríguez S, Pevida M, Roques BP, Fournié-Zaluski MC, Hidalgo A, Menéndez L, Baamonde A. Involvement of enkephalins in the inhibition of osteosarcoma-induced thermal hyperalgesia evoked by the blockade of peripheral P2X3 receptors. Neurosci Lett 2009; 465:285-9. [DOI: 10.1016/j.neulet.2009.09.015] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2009] [Revised: 09/10/2009] [Accepted: 09/11/2009] [Indexed: 12/26/2022]
|
40
|
Pan AH, Lu DH, Luo XG, Chen L, Li ZY. FORMALIN-INDUCED INCREASE IN P2X3RECEPTOR EXPRESSION IN DORSAL ROOT GANGLIA: IMPLICATIONS FOR NOCICEPTION. Clin Exp Pharmacol Physiol 2009; 36:e6-11. [DOI: 10.1111/j.1440-1681.2009.05179.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
41
|
|
42
|
Ambalavanar R, Dessem D. Emerging peripheral receptor targets for deep-tissue craniofacial pain therapies. J Dent Res 2009; 88:201-11. [PMID: 19329451 DOI: 10.1177/0022034508330176] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
While effective therapies are available for some types of craniofacial pain, treatments for deep-tissue craniofacial pain such as temporomandibular disorders are less efficacious. Several ion channels and receptors which are prominent in craniofacial nociceptive mechanisms have been identified on trigeminal primary afferent neurons. Many of these receptors and channels exhibit unusual distributions compared with extracranial regions. For example, expression of the ATP receptor P2X(3) is strongly implicated in nociception and is more abundant on trigeminal primary afferent neurons than analogous extracranial neurons, making them potentially productive targets specifically for craniofacial pain therapies. The initial part of this review therefore focuses on P2X(3) as a potential therapeutic target to treat deep-tissue craniofacial pain. In the trigeminal ganglion, P2X(3) receptors are often co-expressed with the nociceptive neuropeptides CGRP and SP. Therefore, we discuss the role of CGRP and SP in deep-tissue craniofacial pain and suggest that neuropeptide antagonists, which have shown promise for the treatment of migraine, may have wider therapeutic potential, including the treatment of deep-tissue craniofacial pain. P2X(3), TRPV1, and ASIC3 are often co-expressed in trigeminal neurons, implying the formation of functional complexes that allow craniofacial nociceptive neurons to respond synergistically to altered ATP and pH in pain. Future therapeutics for craniofacial pain thus might be more efficacious if targeted at combinations of P2X(3), CGRP, TRPV1, and ASIC3.
Collapse
Affiliation(s)
- R Ambalavanar
- Department of Neural and Pain Sciences and Program in Neuroscience, University of Maryland, Baltimore, MD 21201, USA
| | | |
Collapse
|
43
|
Tsai TL, Chang SY, Ho CY, Kou YR. Role of ATP in the ROS-mediated laryngeal airway hyperreactivity induced by laryngeal acid-pepsin insult in anesthetized rats. J Appl Physiol (1985) 2009; 106:1584-92. [PMID: 19246655 DOI: 10.1152/japplphysiol.91517.2008] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The pathogenetic mechanisms of laryngeal airway hyperreactivity (LAH) in patients with extraesophageal reflux are unclear. We recently reported that a laryngeal acid-pepsin insult produces LAH that is mediated through sensitization of the capsaicin-sensitive laryngeal afferent fibers by reactive oxygen species (ROS) in rats. Since ROS may promote the release of ATP from cells, we hypothesized that activation of P2X purinoceptors by ATP subsequent to an increase in ROS induces LAH in an inflamed larynx that has been insulted by acid-pepsin or H(2)O(2) (a major type of ROS). The larynxes of 208 anesthetized rats were functionally isolated while the animals breathed spontaneously. Ammonia vapor was delivered into the larynx to measure laryngeal reflex reactivity. Laryngeal insult with acid-pepsin or H(2)O(2) produced LAH with similar characteristics. The H(2)O(2)-induced LAH was prevented by laryngeal pretreatment with dimethylthiourea (a hydroxyl radical scavenger), suggesting a critical role for ROS. The LAH induced by both insults were completely prevented by ATP scavengers (a combination of apyrase and adenosine deaminase) or a P2X receptor antagonist (iso-pyridoxalphosphate-6-azophenyl-2',5'-disulfonate). Laryngeal application of a P2X receptor agonist (alpha,beta-methylene-ATP) also produced LAH. An insult with either acid-pepsin or H(2)O(2) similarly promoted an increase in the levels of ATP, lipid peroxidation, and inflammation in the larynx. Our findings suggest that laryngeal insult with acid-pepsin or H(2)O(2) induces inflammation and produces excess ROS in the rat's larynx. The latter may in turn promote the release of ATP to activate P2X receptors, resulting in sensitization of capsaicin-sensitive laryngeal afferent fibers and LAH.
Collapse
Affiliation(s)
- Tung-Lung Tsai
- Institute of Physiology, School of Medicine, National Yang-Ming Univ., Taipei 11221, Taiwan
| | | | | | | |
Collapse
|
44
|
Peripheral mechanisms underlying the essential role of P2X3,2/3 receptors in the development of inflammatory hyperalgesia. Pain 2008; 141:127-34. [PMID: 19081189 DOI: 10.1016/j.pain.2008.10.024] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2008] [Revised: 10/23/2008] [Accepted: 10/29/2008] [Indexed: 01/29/2023]
Abstract
Activation of P2X3,2/3 receptors by endogenous ATP contributes to the development of inflammatory hyperalgesia. Given the clinical importance of mechanical hyperalgesia in inflammatory states, we hypothesized that the activation of P2X3,2/3 receptors by endogenous ATP contributes to carrageenan-induced mechanical hyperalgesia and that this contribution is mediated by an indirect and/or a direct sensitization of the primary afferent nociceptors. Co-administration of the selective P2X3,2/3 receptors antagonist A-317491, or the non-selective P2X3 receptor antagonist, TNP-ATP, with carrageenan blocked the mechanical hyperalgesia induced by carrageenan, and significantly reduced the increased concentration of tumor necrosis factor alpha (TNF-alpha) and chemokine-induced chemoattractant-1 (CINC-1) but not of interleukin-1 beta (IL-1 beta) induced by carrageenan. Co-administration of the selective P2X3,2/3 receptors antagonist A-317491 with carrageenan did not affect the neutrophil migration induced by carrageenan. Intrathecal administration of oligonucleotides antisense against P2X3 receptors for seven days significantly reduced the expression of P2X3 receptors in the saphenous nerve and significantly reduced the mechanical hyperalgesia induced by carrageenan. We concluded that the activation of P2X3,2/3 receptors by endogenous ATP is essential to the development of the mechanical hyperalgesia induced by carrageenan. Furthermore, we showed that this essential role of P2X3,2/3 receptors in the development of carrageenan-induced mechanical hyperalgesia is mediated by an indirect sensitization of the primary afferent nociceptors dependent on the previous release of TNF-alpha and by a direct sensitization of the primary afferent nociceptors.
Collapse
|
45
|
Lu ZM, Xie F, Fu H, Liu MG, Cao FL, Hao J, Chen J. Roles of peripheral P2X and P2Y receptors in the development of melittin-induced nociception and hypersensitivity. Neurochem Res 2008; 33:2085-91. [PMID: 18404374 DOI: 10.1007/s11064-008-9689-6] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2007] [Accepted: 03/26/2008] [Indexed: 01/16/2023]
Abstract
A recent report from our laboratory shows that subcutaneous (s.c.) injection of melittin could induce persistent spontaneous nociception (PSN) and primary thermal or mechanical hyperalgesia. However, the exact peripheral mechanisms underlying melittin-induced multiple pain-related behaviors remain unclear. In this study, behavioral tests combined with pharmacological manipulations were used to explore potential roles of local P2X and P2Y receptors in melittin-induced inflammatory pain and hyperalgesia. Post-treatment of the primary injury site with s.c. injection of A-317491 (a potent P2X(3)/P2X(2/3) receptor antagonist) and Reactive Blue 2 (a potent P2Y receptor antagonist) could significantly suppress the development of melittin-evoked PSN and hypersensitivity (thermal and mechanical). Our control experiments demonstrated that local administration of either antagonist into the contralateral hindpaw produced no significant effect on any kind of pain-associated behaviors. Taken together, these data indicate that activation of P2X and P2Y receptors might be essential to the maintenance of melittin-induced primary thermal and mechanical hyperalgesia as well as on-going pain.
Collapse
Affiliation(s)
- Zhuo-Min Lu
- Institute for Biomedical Sciences of Pain and Institute for Functional Brain Disorders, Tangdu Hospital, Fourth Military Medical University, #1 Xinsi Road, Baqiao, Xi'an 710038, People's Republic of China
| | | | | | | | | | | | | |
Collapse
|
46
|
Tsuda M, Hasegawa S, Inoue K. P2X receptors-mediated cytosolic phospholipase A2activation in primary afferent sensory neurons contributes to neuropathic pain. J Neurochem 2007; 103:1408-16. [PMID: 17725579 DOI: 10.1111/j.1471-4159.2007.04861.x] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Activation of P2X(3) and P2X(2/3) receptors (P2X(3)R/P2X(2/3)R), ionotropic ATP receptor subtypes, in primary sensory neurons is involved in neuropathic pain, a debilitating chronic pain that occurs after peripheral nerve injury. However, the underlying mechanisms remain unknown. We investigated the role of cytosolic phospholipase A(2) (cPLA(2)) as a downstream molecule that mediates the P2X(3)R/P2X(2/3)R-dependent neuropathic pain. We found that applying ATP to cultured dorsal root ganglion (DRG) neurons increased the level of Ser505-phosphorylated cPLA(2) and caused translocation of Ser505-phosphorylated cPLA(2) to the plasma membrane. The ATP-induced cPLA(2) activation was inhibited by a selective antagonist of P2X(3)R/P2X(2/3)R and by a selective inhibitor of cPLA(2). In the DRG in vivo, the number of cPLA(2)-activated neurons was strikingly increased after peripheral nerve injury but not after peripheral inflammation produced by complete Freund's adjuvant. Pharmacological blockade of P2X(3)R/P2X(2/3)R reversed the nerve injury-induced cPLA(2) activation in DRG neurons. Moreover, administering the cPLA(2) inhibitor near the DRG suppressed nerve injury-induced tactile allodynia, a hallmark of neuropathic pain. Our results suggest that P2X(3)R/P2X(2/3)R-dependent cPLA(2) activity in primary sensory neurons is a key event in neuropathic pain and that cPLA(2) might be a potential target for treating neuropathic pain.
Collapse
Affiliation(s)
- Makoto Tsuda
- Department of Molecular and System Pharmacology, Graduate School of Pharmaceutical Sciences, Kyushu University, Higashi, Fukuoka, Japan
| | | | | |
Collapse
|
47
|
Ito K, Iwami A, Katsura H, Ikeda M. Therapeutic effects of the putative P2X3/P2X2/3 antagonist A-317491 on cyclophosphamide-induced cystitis in rats. Naunyn Schmiedebergs Arch Pharmacol 2007; 377:483-90. [PMID: 17917716 DOI: 10.1007/s00210-007-0197-z] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2007] [Accepted: 09/24/2007] [Indexed: 12/31/2022]
Abstract
It is suggested that ATP and purinergic P2X receptors are involved in overactive bladder. In this study, we investigated the effect of the recently developed P2X3 and P2X2/3 receptor antagonist A-317491 on cyclophosphamide (CYP)-induced cystitis to determine whether a P2X receptor antagonist could be beneficial for the treatment of bladder overactivity induced by CYP. Female Sprague-Dawley (SD) rats were given 150 mg/kg CYP (i.p.). When the micturition activity was observed for 24 h in a conscious and unrestrained condition, CYP-treated rats exhibited increased urinary frequency. Two days after CYP injection, cystometry was performed in conscious rats, in which the bladder was continuously infused with saline (5 ml/h). In CYP-treated rats, non-voiding contractions were interposed between micturitions, suggestive of hyper-reflexia. Intravenous administration of A-317491 (20 or 50 mg/kg) or pyridoxal phosphate-6-azo (benzene-2,4-disulfonic acid) tetrasodium (PPADS; a nonselective purinergic receptor antagonist, 10 mg/kg) prolonged the interval of voiding contraction and reduced the non-voiding contractions. On the other hand, oxybutynin (1 mg/kg), a muscarinic receptor antagonist, did not affect the frequency of non-voiding or voiding contractions in CYP-treated rats. A-317491 at the higher dose decreased the amplitude of voiding contractions, but increased the micturition volume. The residual urine in the bladder increased after treatment with CYP; A-317491 and PPADS reduced this, whereas oxybutynin had no effect. These data suggest that A-317491 is effective at improving the signs of CYP-induced cystitis and that the P2X3 or P2X2/3 receptor pathway is involved in bladder overactivity observed during CYP-induced cystitis.
Collapse
Affiliation(s)
- Katsuaki Ito
- Department of Veterinary Pharmacology, Faculty of Agriculture, University of Miyazaki, Miyazaki, 889-2192, Japan.
| | | | | | | |
Collapse
|
48
|
Huang WJ. ATP and spinal cord injury-related neurogenic bladder. J Chin Med Assoc 2007; 70:433-4. [PMID: 17962142 DOI: 10.1016/s1726-4901(08)70033-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
|
49
|
Zhang C, Li G, Liang S, Xu C, Zhu G, Wang Y, Zhang A, Wan F. Myocardial ischemic nociceptive signaling mediated by P2X3 receptor in rat stellate ganglion neurons. Brain Res Bull 2007; 75:77-82. [PMID: 18158099 DOI: 10.1016/j.brainresbull.2007.07.031] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2007] [Revised: 07/12/2007] [Accepted: 07/25/2007] [Indexed: 11/30/2022]
Abstract
Adenosine 5'-triphosphate (ATP) is implicated in peripheral pain signaling through activation of P2X receptors. P2X(3) receptors have a high level of expression in, and selective location on sensory afferents. P2X receptors, particularly the P2X(3) subtype, are identified as targets for novel analgesics. The stellate ganglion (SG) is peripheral sympathetic ganglia involved in heart function. Surgical interventions of sympathetic afferent pathways abolish or relieve angina pectoris, so it is showed that cardiac pain is mediated by the activation of afferents in sympathetic nerves. The cervicothoracic sympathetic ganglia, including the stellate ganglion, are implicated in sensations associated with myocardial ischemia or cardiac pain. In the present study we have examined P2X(3) involvement in cardiac nociceptive transmission. P2X receptor agonists activated currents (I(ATP)) in SG neurons. The I(ATP) amplitude and P2X(3) mRNA expression in myocardial ischemic injury group were much larger than those obtained in control group. Prostaglandin E(2) (PGE(2)) and substance P (SP) increased ATP-activated currents. P2X(3) receptor antagonist A-317491 reduced P2X agonist activated currents and P2X(3) mRNA expression. The results revealed that the myocardial ischemia induced the upregulation of P2X(3) receptor in function and morphous and P2X(3) receptor antagonist A-317491 inhibited P2X agonist activated currents and P2X(3) mRNA expression. The facts indicated that P2X(3) receptor in SG neurons was involved in cardiac nociceptive transmission.
Collapse
Affiliation(s)
- Chunping Zhang
- Department of Physiology, Medical College of Nanchang University, Nanchang, Jiangxi 330006, PR China
| | | | | | | | | | | | | | | |
Collapse
|
50
|
Nagakura Y, Kakimoto S, Matsuoka N. Purinergic P2X receptor activation induces emetic responses in ferrets and Suncus murinus (house musk shrews). Br J Pharmacol 2007; 152:464-70. [PMID: 17700716 PMCID: PMC2050822 DOI: 10.1038/sj.bjp.0707418] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND AND PURPOSE Despite the rapid progress made in understanding the significant role played by signalling via extracellular ATP in physiology and pathology, there has been no clear information generated on its involvement in the emetic response. EXPERIMENTAL APPROACH In the present study, the emetogenic potential of extracellular ATP signalling in mammalian species was examined using ferrets and Suncus murinus (house musk shrews). A slowly degradable ATP analogue, alpha,beta-methyleneATP (alpha,beta-meATP), was used to activate the P2X receptors, and either the non-selective P2 receptor antagonist, pyridoxal phosphate-6-azophenyl-2',4'-disulphonic acid (PPADS), or the specific P2X(3) homomer and P2X(2/3) heteromer antagonist, A-317491, were tested against the agonist-induced response. KEY RESULTS Intraperitoneal injection of alpha,beta-meATP produced significant emetic responses in ferrets (1 - 30 mg kg(-1)) and in Suncus murinus (5 - 50 mg kg(-1)). The responses occurred frequently within the first 10 min after administration, much less frequently from 11 to 60 min and no responses occurred later than 60 min. The emetic responses were completely inhibited by intraperitoneal pre-treatment with PPADS (100 mg kg(-1)) or A-317491 (100 mg kg(-1)). Abdominal surgical vagotomy did not reduce the emetic response in Suncus murinus significantly. CONCLUSIONS AND IMPLICATIONS These results for the first time indicate that the activation of P2X receptors evokes emetic responses in mammalian species. The P2X(3) homomer and.or P2X(2/3) heteromer in the area postrema could be responsible for the emetic response. This finding contributes to the elucidation of the roles played by extracellular ATP signalling in various emetic symptoms.
Collapse
Affiliation(s)
- Y Nagakura
- Drug Discovery Research, Astellas Pharma Inc., Tsukuba, Ibaraki, Japan.
| | | | | |
Collapse
|