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da Silva Ferreira NC, Alves LA, Soares-Bezerra RJ. Potential Therapeutic Applications of P2 Receptor Antagonists: From Bench to Clinical Trials. Curr Drug Targets 2020; 20:919-937. [PMID: 30760187 DOI: 10.2174/1389450120666190213095923] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2018] [Revised: 01/30/2019] [Accepted: 02/06/2019] [Indexed: 12/12/2022]
Abstract
BACKGROUND Extracellular purines and pyrimidines have important physiological functions in mammals. Purines and pyrimidines act on P1 and P2 purinergic receptors, which are widely expressed in the plasma membrane in various cell types. P2 receptors act as important therapeutic targets and are associated with several disorders, such as pain, neurodegeneration, cancer, inflammation, and thrombosis. However, the use of antagonists for P2 receptors in clinical therapy, with the exception of P2Y12, is a great challenge. Currently, many research groups and pharmaceutical companies are working on the development of specific antagonist molecules for each receptor subtype that could be used as new medicines to treat their respective disorders. OBJECTIVE The present review compiles some interesting findings on the application of P2 receptor antagonists in different in vitro and in vivo experimental models as well as the progress of advanced clinical trials with these compounds. CONCLUSION Despite all of the exciting results obtained on the bench, few antagonists of P2 receptors advanced to the clinical trials, and once they reach this stage, the effectiveness of the therapy is not guaranteed, as in the example of P2X7 antagonists. Despite this, P2Y12 receptor antagonists have a history of success and have been used in therapy for at least two decades to prevent thrombosis in patients at risk for myocardial infarctions. This breakthrough is the motivation for scientists to develop new drugs with antagonistic activity for the other P2 receptors; thus, in a matter of years, we will have an evolution in the field of purinergic therapy.
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Affiliation(s)
- Natiele C da Silva Ferreira
- Laboratory of Cellular Communication, Oswaldo Cruz Institute, Oswaldo Cruz Foundation, Rio de Janeiro, 21040- 360, Brazil
| | - Luiz A Alves
- Laboratory of Cellular Communication, Oswaldo Cruz Institute, Oswaldo Cruz Foundation, Rio de Janeiro, 21040- 360, Brazil
| | - Rômulo J Soares-Bezerra
- Laboratory of Technological Development in Virology, Oswaldo Cruz Institute, Oswaldo Cruz Foundation, Rio de Janeiro, 21040-360, Brazil
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2
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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.
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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
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3
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He YQ, Lang XQ, Lin L, Ji L, Yuan XY, Chen Q, Ran YM, Chen HS, Li L, Wang JM, Wang ZG, Gregersen H, Zou DW, Liang HP, Yang M. P2X3 receptor-mediated visceral hyperalgesia and neuronal sensitization following exposure to PTSD-like stress in the dorsal root ganglia of rats. Neurogastroenterol Motil 2017; 29. [PMID: 27781340 DOI: 10.1111/nmo.12976] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/01/2015] [Accepted: 09/22/2016] [Indexed: 12/18/2022]
Abstract
BACKGROUND Patients with posttraumatic stress disorder (PTSD) often share co-morbidity with chronic pain conditions. Recent studies suggest a role of P2X3 receptors and ATP signaling in pain conditions. However, the underlying mechanisms of visceral hyperalgesia following exposure to PTSD-like stress conditions remain unclarified. METHODS The behavior and hormones relevant for PTSD were studied. Visceromotor responses (VMR) and the abdominal withdrawal reflexes (AWR) to colorectal distention (CRD) were recorded to determine P2X3-receptor-mediated alteration of hyperalgesia following single-prolonged stress (SPS) exposure. Immunofluorescence, Western blotting, and patch-clamp were used. KEY RESULTS The escape latency, adrenocorticotropic hormone and cortisol were increased on days 7-14. Visceromotor responses and AWR was reduced at day 1 in SPS rats but increased to higher levels than in controls after exposure to day 7. Intrathecal administration of the P2X3-receptor antagonist TNP-ATP abolished the CRD response. Based on immunofluorescence and Western blotting analysis, SPS-treated rats exhibited reduced P2X3 expression in dorsal root ganglia (DRG) after day 1 compared with controls. P2X3 expression in DRG was enhanced on day 7 after SPS and the increase of the P2X3 expression was maintained on day 14 and 21 compared with controls. The P2X3-receptor agonist α,β-me ATP (10 μM) induced a fast desensitizing inward current in DRG neurons of both control and SPS-treated rats. The average peak current densities in SPS-treated group were increased 3.6-fold. TNP-ATP (100 nM) markedly blocked all fast α,β-me ATP-induced inward currents in the DRG neurons both in control and SPS-treated rats. CONCLUSIONS & INFERENCES The data indicate an important role of P2X3 signaling in visceral hyperalgesia following PTSD-like stress.
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Affiliation(s)
- Y-Q He
- State Key Laboratory of Trauma, Burns and Combined Injury, Department of Gastroenterology, Daping Hospital, Third Military Medical University, Chongqing, China
| | - X-Q Lang
- State Key Laboratory of Trauma, Burns and Combined Injury, Department of Gastroenterology, Daping Hospital, Third Military Medical University, Chongqing, China
| | - L Lin
- State Key Laboratory of Trauma, Burns and Combined Injury, Department of Gastroenterology, Daping Hospital, Third Military Medical University, Chongqing, China
| | - L Ji
- State Key Laboratory of Trauma, Burns and Combined Injury, Department of Gastroenterology, Daping Hospital, Third Military Medical University, Chongqing, China
| | - X-Y Yuan
- Department of Gastroenterology, The Ninth People's Hospital of Chongqing, Chongqing, China
| | - Q Chen
- State Key Laboratory of Trauma, Burns and Combined Injury, Department of Gastroenterology, Daping Hospital, Third Military Medical University, Chongqing, China
| | - Y-M Ran
- State Key Laboratory of Trauma, Burns and Combined Injury, Department of Gastroenterology, Daping Hospital, Third Military Medical University, Chongqing, China
| | - H-S Chen
- Chongqing Key Laboratory of Translational Medical Research in Cognitive Development and Learning and Memory Disorders, Chongqing, China
| | - L Li
- Research Institute of Surgery, Daping Hospital, Third Military Medical University, Chongqing, China
| | - J-M Wang
- Research Institute of Surgery, Daping Hospital, Third Military Medical University, Chongqing, China
| | - Z-G Wang
- State Key Laboratory of Trauma, Burns and Combined Injury, Department of Gastroenterology, Daping Hospital, Third Military Medical University, Chongqing, China.,Research Institute of Surgery, Daping Hospital, Third Military Medical University, Chongqing, China
| | - H Gregersen
- GIOME and the Key Laboratory for Biorheological Science and Technology of Ministry of Education, Bioengineering College of Chongqing University, Chongqing, China
| | - D-W Zou
- Department of Gastroenterology, Changhai Hospital, Second Military Medical University, Shanghai, China
| | - H-P Liang
- State Key Laboratory of Trauma, Burns and Combined Injury, Department of Gastroenterology, Daping Hospital, Third Military Medical University, Chongqing, China.,Research Institute of Surgery, Daping Hospital, Third Military Medical University, Chongqing, China
| | - M Yang
- State Key Laboratory of Trauma, Burns and Combined Injury, Department of Gastroenterology, Daping Hospital, Third Military Medical University, Chongqing, China.,Research Institute of Surgery, Daping Hospital, Third Military Medical University, Chongqing, China
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4
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Viatchenko-Karpinski V, Novosolova N, Ishchenko Y, Azhar MA, Wright M, Tsintsadze V, Kamal A, Burnashev N, Miller AD, Voitenko N, Giniatullin R, Lozovaya N. Stable, synthetic analogs of diadenosine tetraphosphate inhibit rat and human P2X3 receptors and inflammatory pain. Mol Pain 2016; 12:1744806916637704. [PMID: 27030723 PMCID: PMC4955970 DOI: 10.1177/1744806916637704] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2015] [Accepted: 12/08/2015] [Indexed: 11/17/2022] Open
Abstract
BACKGROUND A growing body of evidence suggests that ATP-gated P2X3 receptors (P2X3Rs) are implicated in chronic pain. We address the possibility that stable, synthetic analogs of diadenosine tetraphosphate (Ap4A) might induce antinociceptive effects by inhibiting P2X3Rs in peripheral sensory neurons. RESULTS The effects of two stable, synthetic Ap4A analogs (AppNHppA and AppCH2ppA) are studied firstly in vitro on HEK293 cells expressing recombinant rat P2XRs (P2X2Rs, P2X3Rs, P2X4Rs, and P2X7Rs) and then using native rat brain cells (cultured trigeminal, nodose, or dorsal root ganglion neurons). Thereafter, the action of these stable, synthetic Ap4A analogs on inflammatory pain and thermal hyperalgesia is studied through the measurement of antinociceptive effects in formalin and Hargreaves plantar tests in rats in vivo. In vitro inhibition of rat P2X3Rs (not P2X2Rs, P2X4Rs nor P2X7Rs) is shown to take place mediated by high-affinity desensitization (at low concentrations; IC50 values 100-250 nM) giving way to only weak partial agonism at much higher concentrations (EC50 values ≥ 10 µM). Similar inhibitory activity is observed with human recombinant P2X3Rs. The inhibitory effects of AppNHppA on nodose, dorsal root, and trigeminal neuron whole cell currents suggest that stable, synthetic Ap4A analogs inhibit homomeric P2X3Rs in preference to heteromeric P2X2/3Rs. Both Ap4A analogs mediate clear inhibition of pain responses in both in vivo inflammation models. CONCLUSIONS Stable, synthetic Ap4A analogs (AppNHppA and AppCH2ppA) being weak partial agonist provoke potent high-affinity desensitization-mediated inhibition of homomeric P2X3Rs at low concentrations. Therefore, both analogs demonstrate clear potential as potent analgesic agents for use in the management of chronic pain associated with heightened P2X3R activation.
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Affiliation(s)
- Viacheslav Viatchenko-Karpinski
- Laboratory of Sensory Signaling, Bogomoletz Institute of Physiology, Kiev, Ukraine International Center for Molecular Physiology, Kiev, Ukraine
| | | | | | - M Ameruddin Azhar
- Indian Institute of Chemical Technology, Hyderabad, India Imperial College Genetic Therapies Centre, Department of Chemistry, Imperial College London, London, UK
| | - Michael Wright
- Imperial College Genetic Therapies Centre, Department of Chemistry, Imperial College London, London, UK Institute of Pharmaceutical Science, King's College London, London, UK
| | - Vera Tsintsadze
- INSERM UMR901 Aix-Marseille Université, Marseille, France INMED, Institut de Neurobiologie de la Méditerranée, Marseille, France
| | - Ahmed Kamal
- Indian Institute of Chemical Technology, Hyderabad, India
| | - Nail Burnashev
- INSERM UMR901 Aix-Marseille Université, Marseille, France INMED, Institut de Neurobiologie de la Méditerranée, Marseille, France
| | - Andrew D Miller
- Institute of Pharmaceutical Science, King's College London, London, UK GlobalAcorn Ltd, London, UK
| | - Nana Voitenko
- Laboratory of Sensory Signaling, Bogomoletz Institute of Physiology, Kiev, Ukraine International Center for Molecular Physiology, Kiev, Ukraine
| | - Rashid Giniatullin
- Department of Neurobiology, A. I. Virtanen Institute, Kuopio, Finland Kazan Federal University, Kazan, Russia
| | - Natalia Lozovaya
- INSERM UMR901 Aix-Marseille Université, Marseille, France INMED, Institut de Neurobiologie de la Méditerranée, Marseille, France Neurochlore, Marseille, France
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5
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Abstract
There is a brief introductory summary of purinergic signaling involving ATP storage, release, and ectoenzymatic breakdown, and the current classification of receptor subtypes for purines and pyrimidines. The review then describes purinergic mechanosensory transduction involved in visceral, cutaneous, and musculoskeletal nociception and on the roles played by receptor subtypes in neuropathic and inflammatory pain. Multiple purinoceptor subtypes are involved in pain pathways both as an initiator and modulator. Activation of homomeric P2X3 receptors contributes to acute nociception and activation of heteromeric P2X2/3 receptors appears to modulate longer-lasting nociceptive sensitivity associated with nerve injury or chronic inflammation. In neuropathic pain activation of P2X4, P2X7, and P2Y12 receptors on microglia may serve to maintain nociceptive sensitivity through complex neural-glial cell interactions and antagonists to these receptors reduce neuropathic pain. Potential therapeutic approaches involving purinergic mechanisms will be discussed.
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6
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Pirt reduces bladder overactivity by inhibiting purinergic receptor P2X3. Nat Commun 2015; 6:7650. [PMID: 26151598 DOI: 10.1038/ncomms8650] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2015] [Accepted: 05/28/2015] [Indexed: 12/14/2022] Open
Abstract
Pirt is a transmembrane protein predominantly expressed in peripheral neurons. However, the physiological and pathological roles of Pirt in hollow viscus are largely unknown. Here we show that Pirt deficiency in mice causes bladder overactivity. The density of α,β-meATP-induced currents is significantly reinforced in Pirt-deficient dorsal root ganglion (DRG) neurons. Pirt and P2X3 receptor co-localize in bladder nerve fibres and heterologous Pirt expression significantly reduces P2X3-mediated currents. Pirt interacts with P2X3 through the N-terminal 14 amino-acid residues. TAT-conjugated Pirt(N14) peptide (Pirt(N14)) is sufficient to inhibit P2X3 activation in bladder DRG neurons and to alleviate bladder overactivity in Pirt(-/-) mice. Pirt expression is decreased in the bladder of cyclophosphamide (CYP)-treated mice, a commonly used model of bladder overactivity. Importantly, Pirt(N14) administration reduces the frequency of bladder voiding and restores the voided volume of CYP-treated mice. Therefore, our results demonstrate that Pirt is an endogenous regulator of P2X3 in bladder function.
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7
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Weng Z, Wu L, Lu Y, Wang L, Tan L, Dong M, Xin Y. Electroacupuncture diminishes P2X2 and P2X3 purinergic receptor expression in dorsal root ganglia of rats with visceral hypersensitivity. Neural Regen Res 2014; 8:802-8. [PMID: 25206727 PMCID: PMC4146084 DOI: 10.3969/j.issn.1673-5374.2013.09.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2012] [Accepted: 02/22/2013] [Indexed: 02/06/2023] Open
Abstract
Electroacupuncture at Shangjuxu (ST37) and Tianshu (ST25) can improve visceral hypersensitivity in rats. Colorectal distension was used to establish a rat model of chronic visceral hypersensitivity. Immunohistochemistry was used to detect P2X2 and P2X3 receptor expression in dorsal root ganglia from rats with chronic visceral hypersensitivity. Results demonstrated that abdominal withdrawal reflex scores obviously increased following establishment of the model, indicating visceral hypersensitivity. Simultaneously, P2X2 and P2X3 receptor expression increased in dorsal root ganglia. After bilateral electroacupuncture at Shangjuxu and Tianshu, abdominal withdrawal reflex scores and P2X2 and P2X3 receptor expression decreased in rats with visceral hypersensitivity. These results indicated that electroacupuncture treatment improved visceral hypersensitivity in rats with irritable bowel syndrome by reducing P2X2 and P2X3 receptor expression in dorsal root ganglia.
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Affiliation(s)
- Zhijun Weng
- Shanghai Academy of Traditional Chinese Medicine, Shanghai 201203, China
| | - Luyi Wu
- Shanghai Academy of Traditional Chinese Medicine, Shanghai 201203, China
| | - Yuan Lu
- Shanghai Academy of Traditional Chinese Medicine, Shanghai 201203, China
| | - Lidong Wang
- Shanghai Academy of Traditional Chinese Medicine, Shanghai 201203, China
| | - Linying Tan
- Shanghai Academy of Traditional Chinese Medicine, Shanghai 201203, China
| | - Ming Dong
- Shanghai Academy of Traditional Chinese Medicine, Shanghai 201203, China
| | - Yuhu Xin
- Fudan University Shanghai Cancer Center, Shanghai 200032, China
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8
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Ochoa-Cortes F, Liñán-Rico A, Jacobson KA, Christofi FL. Potential for developing purinergic drugs for gastrointestinal diseases. Inflamm Bowel Dis 2014; 20:1259-87. [PMID: 24859298 PMCID: PMC4340257 DOI: 10.1097/mib.0000000000000047] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Treatments for inflammatory bowel disease (IBD), irritable bowel syndrome (IBS), functional dyspepsia, or motility disorders are not adequate, and purinergic drugs offer exciting new possibilities. Gastrointestinal symptoms that could be targeted for therapy include visceral pain, inflammatory pain, dysmotility, constipation, and diarrhea. The focus of this review is on the potential for developing purinergic drugs for clinical trials to treat gastrointestinal symptoms. Purinergic receptors are divided into adenosine P1 (A(1), A(2A), A(2B), A(3)), ionotropic ATP-gated P2X ion channel (P2X(1-7)), or metabotropic P2Y(1,2,4,6,11-14) receptors. There is good experimental evidence for targeting A(2A), A(2B), A(3), P2X(7), and P2X(3) receptors or increasing endogenous adenosine levels to treat IBD, inflammatory pain, IBS/visceral pain, inflammatory diarrhea, and motility disorders. Purine genes are also potential biomarkers of disease. Advances in medicinal chemistry have an accelerated pace toward clinical trials: Methotrexate and sulfasalazine, used to treat IBD, act by stimulating CD73-dependent adenosine production. ATP protects against NSAID-induced enteropathy and has pain-relieving properties in humans. A P2X(7)R antagonist AZD9056 is in clinical trials for Crohn's disease. A(3) adenosine receptor drugs target inflammatory diseases (e.g., CF101, CF102). Dipyridamole, a nucleoside uptake inhibitor, is in trials for endotoxemia. Drugs for pain in clinical trials include P2X(3)/P2X(2/3) (AF-219) and P2X(7) (GSK1482160) antagonists and A(1) (GW493838) or A(2A) (BVT.115959) agonists. Iberogast is a phytopharmacon targeting purine mechanisms with efficacy in IBS and functional dyspepsia. Purinergic drugs have excellent safety/efficacy profile for prospective clinical trials in IBD, IBS, functional dyspepsia, and inflammatory diarrhea. Genetic polymorphisms and caffeine consumption may affect susceptibility to treatment. Further studies in animals can clarify mechanisms and test new generation drugs. Finally, there is still a huge gap in our knowledge of human pathophysiology of purinergic signaling.
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Affiliation(s)
- Fernando Ochoa-Cortes
- Department of Anesthesiology, The Wexner Medical Center at The Ohio State University, Columbus, Ohio
| | - Andromeda Liñán-Rico
- Department of Anesthesiology, The Wexner Medical Center at The Ohio State University, Columbus, Ohio
| | - Kenneth A. Jacobson
- Laboratory of Bioorganic Chemistry & Molecular Recognition Section, National Institute of Diabetes & Digestive & Kidney Diseases, National Institutes of Health
| | - Fievos L. Christofi
- Department of Anesthesiology, The Wexner Medical Center at The Ohio State University, Columbus, Ohio
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9
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Abstract
The article begins with a review of the main conceptual steps involved in the development of our understanding of purinergic signalling, including non-adrenergic, non-cholinergic (NANC) neurotransmission; identification of ATP as a NANC transmitter; purinergic cotransmission; recognition of two families of purinoceptors [P1 (adenosine) and P2 (ATP/ADP)]; and, later, cloning and characterisation of P1 (G protein-coupled), P2X (ion channel) and P2Y (G protein-coupled) receptor subtypes. Further studies have established the involvement of ATP in synaptic neurotransmission in both ganglia and in the central nervous system; long-term (trophic) purinergic signalling in cell proliferation, differentiation and death occurring in development and regeneration; and short-term purinergic signalling in neurotransmission, neuromodulation and secretion. ATP is released from most cell types in response to gentle mechanical stimulation and is rapidly degraded to adenosine by ecto-nucleotidases. This review then focuses on the pathophysiology of purinergic signalling in a wide variety of systems, including urinogenital, cardiovascular, airway, musculoskeletal and gastrointestinal. Consideration is also given to the involvement of purinoceptors in pain, cancer and diseases of the central nervous system. Purinergic therapeutic approaches for the treatment of some of these diseases are discussed.
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10
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Rajagopalan P, Tracey H, Chen Z, Bandyopadhyaya A, Veeraraghavan S, Rajagopalan DR, Salvemini D, McPhee I, Viswanadha S, Rajagopalan R. DDD-028: a potent potential non-opioid, non-cannabinoid analgesic for neuropathic and inflammatory pain. Bioorg Med Chem Lett 2014; 24:3088-91. [PMID: 24863744 DOI: 10.1016/j.bmcl.2014.05.016] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2014] [Revised: 04/30/2014] [Accepted: 05/05/2014] [Indexed: 12/25/2022]
Abstract
DDD-028 (4), a novel pentacyclic pyridoindolobenzazepine derivative was evaluated in vitro for receptor binding affinity and in vivo for analgesic activity using rodent models of neuropathic and inflammatory pain. DDD-028 does not bind to opioid, cannabinoid, dopamine, or histamine receptors. DDD-028 is very active even at the low oral dose of 1-5 mg/kg in both neuropathic, (spinal nerve ligation and chronic constriction injury) and inflammatory (Complete Freund's Adjuvant Induced) models of pain. DDD-028 appears to be about 6-fold more potent than pregabalin and indomethacin. Visual observation of all the animals used in these studies indicated that DDD-028 is well tolerated without any sedation. Thus, DDD-028 seems to be a promising candidate for the treatment of neuropathic and inflammatory pain without the possible side effects or abuse potential associated with opioid or cannabinoid activities.
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Affiliation(s)
- Parthasarathi Rajagopalan
- Daya Drug Discoveries, Inc., University of Missouri, St. Louis, One University Blvd., St. Louis, MO 63121, USA
| | - Heather Tracey
- SB Drug Discovery, Ltd, Todd Campus, West of Scotland Science Park, Glasgow, Scotland G20 0XA, UK
| | - Zhoumou Chen
- Department of Pharmacological and Physiological Sciences, St. Louis University School of Medicine, 1402 South Grand Blvd., St. Louis, MO 63104, USA
| | - Acintya Bandyopadhyaya
- Daya Drug Discoveries, Inc., University of Missouri, St. Louis, One University Blvd., St. Louis, MO 63121, USA
| | - Sridhar Veeraraghavan
- Incozen Therapeutics, Ltd, 450 Alexandria Knowledge Park, Hyderabad 500078, Andhra Pradesh, India
| | - Desikan R Rajagopalan
- Daya Drug Discoveries, Inc., University of Missouri, St. Louis, One University Blvd., St. Louis, MO 63121, USA
| | - Daniela Salvemini
- Department of Pharmacological and Physiological Sciences, St. Louis University School of Medicine, 1402 South Grand Blvd., St. Louis, MO 63104, USA
| | - Ian McPhee
- SB Drug Discovery, Ltd, Todd Campus, West of Scotland Science Park, Glasgow, Scotland G20 0XA, UK
| | - Srikant Viswanadha
- Incozen Therapeutics, Ltd, 450 Alexandria Knowledge Park, Hyderabad 500078, Andhra Pradesh, India
| | - Raghavan Rajagopalan
- Daya Drug Discoveries, Inc., University of Missouri, St. Louis, One University Blvd., St. Louis, MO 63121, USA.
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11
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Abstract
This lecture is about the history of the purinergic signalling concept. It begins with reference to the paper by Paton & Vane published in 1963, which identified non-cholinergic relaxation in response to vagal nerve stimulation in several species, although they suggested that it might be due to sympathetic adrenergic nerves in the vagal nerve trunk. Using the sucrose gap technique for simultaneous mechanical and electrical recordings in smooth muscle (developed while in Feldberg's department in the National Institute for Medical Research) of the guinea-pig taenia coli preparation (learned when working in Edith Bülbring's smooth muscle laboratory in Oxford Pharmacology), we showed that the hyperpolarizations recorded in the presence of antagonists to the classical autonomic neurotransmitters, acetylcholine and noradrenaline, were inhibitory junction potentials in response to non-adrenergic, non-cholinergic neurotransmission, mediated by intrinsic enteric nerves controlled by vagal and sacral parasympathetic nerves. We then showed that ATP satisfied the criteria needed to identify a neurotransmitter released by these nerves. Subsequently, it was shown that ATP is a cotransmitter in all nerves in the peripheral and central nervous systems. The receptors for purines and pyrimidines were cloned and characterized in the early 1990 s, and immunostaining showed that most non-neuronal cells as well as nerve cells expressed these receptors. The physiology and pathophysiology of purinergic signalling is discussed.
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Affiliation(s)
- Geoffrey Burnstock
- G. Burnstock: University College Medical School, Autonomic Neuroscience Centre, Rowland Hill Street, London NW3 2PF, UK and Department of Pharmacology, The University of Melbourne, Australia.
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12
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Birder LA. Urinary bladder, cystitis and nerve/urothelial interactions. Auton Neurosci 2013; 182:89-94. [PMID: 24412640 DOI: 10.1016/j.autneu.2013.12.005] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2013] [Accepted: 12/12/2013] [Indexed: 12/20/2022]
Abstract
A hallmark of functional pain syndromes, such as bladder pain syndrome/interstitial cystitis (BPS/IC) is pain in the absence of demonstrable infection or pathology of the viscera or associated nerves. There are no clear definitions of this syndrome, no proven etiologies and no effective treatments able to eradicate the symptoms. This condition is characterized by suprapubic pain, associated with bladder filling and can also be accompanied by a persistent strong desire to void, increased frequency of urination and nocturia. Severe cases of this disorder, which affects primarily women, can have considerable impact on the quality of life of patients due to extreme pain and urinary frequency, which are often difficult to treat. In addition, BPS/IC patients may also suffer co-morbid conditions where pain is a common symptom (such as irritable bowel syndrome, fibromyalgia). Theories explaining the pathology of bladder pain syndrome are many and include an altered bladder lining and possible contribution of a bacterial agent.
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Affiliation(s)
- Lori A Birder
- Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, PA, United States; Department Pharmacology & Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, United States.
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13
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Naviaux RK. Metabolic features of the cell danger response. Mitochondrion 2013; 16:7-17. [PMID: 23981537 DOI: 10.1016/j.mito.2013.08.006] [Citation(s) in RCA: 136] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2013] [Revised: 08/12/2013] [Accepted: 08/16/2013] [Indexed: 12/12/2022]
Abstract
The cell danger response (CDR) is the evolutionarily conserved metabolic response that protects cells and hosts from harm. It is triggered by encounters with chemical, physical, or biological threats that exceed the cellular capacity for homeostasis. The resulting metabolic mismatch between available resources and functional capacity produces a cascade of changes in cellular electron flow, oxygen consumption, redox, membrane fluidity, lipid dynamics, bioenergetics, carbon and sulfur resource allocation, protein folding and aggregation, vitamin availability, metal homeostasis, indole, pterin, 1-carbon and polyamine metabolism, and polymer formation. The first wave of danger signals consists of the release of metabolic intermediates like ATP and ADP, Krebs cycle intermediates, oxygen, and reactive oxygen species (ROS), and is sustained by purinergic signaling. After the danger has been eliminated or neutralized, a choreographed sequence of anti-inflammatory and regenerative pathways is activated to reverse the CDR and to heal. When the CDR persists abnormally, whole body metabolism and the gut microbiome are disturbed, the collective performance of multiple organ systems is impaired, behavior is changed, and chronic disease results. Metabolic memory of past stress encounters is stored in the form of altered mitochondrial and cellular macromolecule content, resulting in an increase in functional reserve capacity through a process known as mitocellular hormesis. The systemic form of the CDR, and its magnified form, the purinergic life-threat response (PLTR), are under direct control by ancient pathways in the brain that are ultimately coordinated by centers in the brainstem. Chemosensory integration of whole body metabolism occurs in the brainstem and is a prerequisite for normal brain, motor, vestibular, sensory, social, and speech development. An understanding of the CDR permits us to reframe old concepts of pathogenesis for a broad array of chronic, developmental, autoimmune, and degenerative disorders. These disorders include autism spectrum disorders (ASD), attention deficit hyperactivity disorder (ADHD), asthma, atopy, gluten and many other food and chemical sensitivity syndromes, emphysema, Tourette's syndrome, bipolar disorder, schizophrenia, post-traumatic stress disorder (PTSD), chronic traumatic encephalopathy (CTE), traumatic brain injury (TBI), epilepsy, suicidal ideation, organ transplant biology, diabetes, kidney, liver, and heart disease, cancer, Alzheimer and Parkinson disease, and autoimmune disorders like lupus, rheumatoid arthritis, multiple sclerosis, and primary sclerosing cholangitis.
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Affiliation(s)
- Robert K Naviaux
- The Mitochondrial and Metabolic Disease Center, Departments of Medicine, Pediatrics, and Pathology, University of California, San Diego School of Medicine, 214 Dickinson St., Bldg CTF, Rm C102, San Diego, CA 92103-8467, USA; Veterans Affairs Center for Excellence in Stress and Mental Health (CESAMH), La Jolla, CA, USA.
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Volonté C, Burnstock G. P2X3 receptor: a novel ‘CASKade’ of signaling? J Neurochem 2013; 126:1-3. [DOI: 10.1111/jnc.12282] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2013] [Accepted: 04/25/2013] [Indexed: 11/28/2022]
Affiliation(s)
- Cinzia Volonté
- CNR-IBCN/S. Lucia Foundation; Via Del Fosso di Fiorano 65; Rome Italy
| | - Geoffrey Burnstock
- Autonomic Neuroscience Centre; University College Medical School; London UK
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Gnanasekaran A, Sundukova M, Hullugundi S, Birsa N, Bianchini G, Hsueh YP, Nistri A, Fabbretti E. Calcium/calmodulin-dependent serine protein kinase (CASK) is a new intracellular modulator of P2X3 receptors. J Neurochem 2013; 126:102-12. [PMID: 23600800 DOI: 10.1111/jnc.12272] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2013] [Revised: 04/02/2013] [Accepted: 04/03/2013] [Indexed: 12/20/2022]
Abstract
ATP-gated P2X3 receptors of sensory ganglion neurons are important transducers of painful stimuli and are modulated by extracellular algogenic substances, via changes in the receptor phosphorylation state. The present study investigated the role of calcium/calmodulin-dependent serine protein kinase (CASK) in interacting and controlling P2X3 receptor expression and function in mouse trigeminal ganglia. Most ganglion neurons in situ or in culture co-expressed P2X3 and CASK. CASK was immunoprecipitated with P2X3 receptors from trigeminal ganglia and from P2X3/CASK-cotransfected human embryonic kidney (HEK) cells. Recombinant P2X3/CASK expression in HEK cells increased serine phosphorylation of P2X3 receptors, typically associated with receptor upregulation. CASK deletion mutants also enhanced P2X3 subunit expression. After silencing CASK, cell surface P2X3 receptor expression was decreased, which is consistent with depressed P2X3 currents. The reduction in P2X3 expression levels was reversed by the proteasomal inhibitor MG-132. Moreover, neuronal CASK/P2X3 interaction was up-regulated by nerve growth factor (NGF) signaling and down-regulated by P2X3 agonist-induced desensitization. These data suggest a novel interaction between CASK and P2X3 receptors with positive outcome for receptor stability and function. As CASK-mediated control of P2X3 receptors was dependent on the receptor activation state, CASK represents an intracellular gateway to regulate purinergic nociceptive signaling.
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Affiliation(s)
- Aswini Gnanasekaran
- Neuroscience Department, International School for Advanced Studies-SISSA, Trieste, Italy
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Antonioli L, Colucci R, Pellegrini C, Giustarini G, Tuccori M, Blandizzi C, Fornai M. The role of purinergic pathways in the pathophysiology of gut diseases: pharmacological modulation and potential therapeutic applications. Pharmacol Ther 2013; 139:157-88. [PMID: 23588157 DOI: 10.1016/j.pharmthera.2013.04.002] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2013] [Accepted: 03/15/2013] [Indexed: 02/08/2023]
Abstract
Gut homeostasis results from complex neuro-immune interactions aimed at triggering stereotypical and specific programs of coordinated mucosal secretion and powerful motor propulsion. A prominent role in the regulation of this highly integrated network, comprising a variety of immune/inflammatory cells and the enteric nervous system, is played by purinergic mediators. The cells of the digestive tract are literally plunged into a "biological sea" of functionally active nucleotides and nucleosides, which carry out the critical task of driving regulatory interventions on cellular functions through the activation of P1 and P2 receptors. Intensive research efforts are being made to achieve an integrated view of the purinergic system, since it is emerging that the various components of purinergic pathways (i.e., enzymes, transporters, mediators and receptors) are mutually linked entities, deputed to finely modulating the magnitude and the duration of purinergic signaling, and that alterations occurring in this balanced network could be intimately involved in the pathophysiology of several gut disorders. This review article intends to provide a critical appraisal of current knowledge on the purinergic system role in the regulation of gastrointestinal functions, considering these pathways as a whole integrated network, which is capable of finely controlling the levels of bioactive nucleotides and nucleosides in the biophase of their respective receptors. Special attention is paid to the mechanisms through which alterations in the various compartments of the purinergic system could contribute to the pathophysiology of gut disorders, and to the possibility of counteracting such dysfunctions by means of pharmacological interventions on purinergic molecular targets.
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Affiliation(s)
- Luca Antonioli
- Department of Clinical and Experimental Medicine, University of Pisa, Italy.
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17
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Abstract
The urothelium, which lines the inner surface of the renal pelvis, the ureters, and the urinary bladder, not only forms a high-resistance barrier to ion, solute and water flux, and pathogens, but also functions as an integral part of a sensory web which receives, amplifies, and transmits information about its external milieu. Urothelial cells have the ability to sense changes in their extracellular environment, and respond to chemical, mechanical and thermal stimuli by releasing various factors such as ATP, nitric oxide, and acetylcholine. They express a variety of receptors and ion channels, including P2X3 purinergic receptors, nicotinic and muscarinic receptors, and TRP channels, which all have been implicated in urothelial-neuronal interactions, and involved in signals that via components in the underlying lamina propria, such as interstitial cells, can be amplified and conveyed to nerves, detrusor muscle cells, and ultimately the central nervous system. The specialized anatomy of the urothelium and underlying structures, and the possible communication mechanisms from urothelial cells to various cell types within the bladder wall are described. Changes in the urothelium/lamina propria ("mucosa") produced by different bladder disorders are discussed, as well as the mucosa as a target for therapeutic interventions.
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Affiliation(s)
- Lori Birder
- Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15261, USA.
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18
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Purinergic mechanisms and pain--an update. Eur J Pharmacol 2013; 716:24-40. [PMID: 23524093 DOI: 10.1016/j.ejphar.2013.01.078] [Citation(s) in RCA: 94] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2012] [Revised: 12/11/2012] [Accepted: 01/09/2013] [Indexed: 12/12/2022]
Abstract
There is a brief summary of the background literature about purinergic signalling. The review then considers purinergic mechanosensory transduction involved in visceral, cutaneous and musculoskeletal nociception and on the roles played by P2X3, P2X2/3, P2X4, P2X7 and P2Y₁₂ receptors in neuropathic and inflammatory pain. Current developments of compounds for the therapeutic treatment of both visceral and neuropathic pain are discussed.
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Stark TD, Mtui DJ, Balemba OB. Ethnopharmacological Survey of Plants Used in the Traditional Treatment of Gastrointestinal Pain, Inflammation and Diarrhea in Africa: Future Perspectives for Integration into Modern Medicine. Animals (Basel) 2013; 3:158-227. [PMID: 26487315 PMCID: PMC4495512 DOI: 10.3390/ani3010158] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2013] [Revised: 02/06/2013] [Accepted: 02/07/2013] [Indexed: 11/19/2022] Open
Abstract
There is a growing need to find the most appropriate and effective treatment options for a variety of painful syndromes, including conditions affecting the gastrointestinal tract, for treating both veterinary and human patients. The most successful regimen may come through integrated therapies including combining current and novel western drugs with acupuncture and botanical therapies or their derivatives. There is an extensive history and use of plants in African traditional medicine. In this review, we have highlighted botanical remedies used for treatment of pain, diarrheas and inflammation in traditional veterinary and human health care in Africa. These preparations are promising sources of new compounds comprised of flavonoids, bioflavanones, xanthones, terpenoids, sterols and glycosides as well as compound formulas and supplements for future use in multimodal treatment approaches to chronic pain, gastrointestinal disorders and inflammation. The advancement of plant therapies and their derivative compounds will require the identification and validation of compounds having specific anti-nociceptive neuromodulatory and/or anti-inflammatory effects. In particular, there is need for the identification of the presence of compounds that affect purinergic, GABA, glutamate, TRP, opioid and cannabinoid receptors, serotonergic and chloride channel systems through bioactivity-guided, high-throughput screening and biotesting. This will create new frontiers for obtaining novel compounds and herbal supplements to relieve pain and gastrointestinal disorders, and suppress inflammation.
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Affiliation(s)
- Timo D Stark
- Lehrstuhl für Lebensmittelchemie und Molekulare Sensorik, Technische Universität München, Lise-Meitner Str. 34, D-85354, Freising, Germany.
| | - Dorah J Mtui
- Department of Biological Sciences, University of Idaho, Moscow, ID 83844, USA.
| | - Onesmo B Balemba
- Department of Biological Sciences, University of Idaho, Moscow, ID 83844, USA.
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Liu M, Xu YF, Feng Y, Yang FQ, Luo J, Zhai W, Che JP, Wang GC, Zheng JH. Epigallocatechin gallate attenuates interstitial cystitis in human bladder urothelium cells by modulating purinergic receptors. J Surg Res 2012; 183:397-404. [PMID: 23260235 DOI: 10.1016/j.jss.2012.11.041] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2012] [Revised: 11/14/2012] [Accepted: 11/20/2012] [Indexed: 11/18/2022]
Abstract
BACKGROUND Epigallocatechin gallate (EGCG) has exhibited antitumor properties against bladder cancer. However, its effects in interstitial cystitis (IC) have not been investigated. METHODS Here, we performed repeated cystoscopy and re-biopsy of bladder mucosa before and after intravesical irrigation of EGCG in eight patients diagnosed with IC based on clinical and histopathologic assessments. Six normal bladder tissue samples were obtained from age-, race-, and sex-matched asymptomatic control subjects. IC symptom index was used to compare the therapeutic effect in IC patients. Patient-derived bladder epithelial cells were cultured and cell stretch experiments and ATP assays were performed. The expression of purinergic receptors X1, X2, and X3, and Y1, Y2, and Y11, in biopsied samples was detected by Western blotting and real-time polymerase chain reaction, respectively. Moreover, the expression of inducible NO synthase, phosphorylated Akt, and phosphorylated NF-κB was also assessed. RESULTS All EGCG-treated patients demonstrated different extents of remission of symptoms. We found a significant upregulation in P2X1, P2X2, and P2X3 receptor proteins and P2Y1, P2Y2, and P2Y11 receptor transcripts in IC patients. However, EGCG therapy attenuated the expression of all purinergic receptors. In addition, EGCG demonstrated prominent antioxidative and antiinflammatory effects via inhibition of the upregulation of iNOS and phosphorylated NF-κB. Furthermore, the stretch-activated release of ATP in cultured bladder urothelial cells was greater in cells derived from IC patients, compared with those from the control patients, but EGCG, at all concentrations tested, effectively abolished the increase in ATP release from stretched IC patient-derived cells. CONCLUSIONS Our study suggests that inhibition of the expression of purinergic receptors and ATP release in urothelial cells by EGCG supports further development of EGCG as a novel therapeutic option for IC.
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Affiliation(s)
- Min Liu
- Department of Urology & Surgery, Shanghai Tenth People's Hospital, Tongji University, Shanghai, PR China.
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21
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Birder LA. Nervous network for lower urinary tract function. Int J Urol 2012; 20:4-12. [PMID: 23088378 DOI: 10.1111/j.1442-2042.2012.03210.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2012] [Accepted: 09/25/2012] [Indexed: 12/21/2022]
Abstract
Traditionally, sensory signaling in the urinary bladder has been largely attributed to direct activation of bladder afferents. There is substantive evidence that sensory systems can be influenced by non-neuronal cells, such as the urothelium, which are able to respond to various types of stimuli that can include physiological, psychological and disease-related factors. The corresponding release of chemical mediators (through activation of a number of receptors/ion channels) can initiate signaling mechanisms between and within urothelial cells, as well as other cell types within the bladder wall including bladder nerves. However, the mechanisms underlying how various cell types in the bladder wall respond to normal filling and emptying, and are challenged by a variety of stressors (physical and chemical) are still not well understood. Alterations or defects in signaling mechanisms are likely to contribute to the pathophysiology of bladder disease with symptoms including urinary urgency, increased voiding frequency and pain. This review will discuss some of the components involved in control of lower urinary tract function, with an emphasis on the sensor and transducer roles of the urothelium.
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Affiliation(s)
- Lori A Birder
- Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15261, USA.
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Burnstock G. Discovery of purinergic signalling, the initial resistance and current explosion of interest. Br J Pharmacol 2012; 167:238-55. [PMID: 22537142 PMCID: PMC3481036 DOI: 10.1111/j.1476-5381.2012.02008.x] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2012] [Revised: 04/03/2012] [Accepted: 04/12/2012] [Indexed: 01/23/2023] Open
Abstract
There has been a remarkable growth of papers published about purinergic signalling via ATP since 1972. I am most grateful to the wonderful PhD students and postdoctoral fellows who have worked with me over the years to pursue the purinergic hypothesis despite early opposition and to the many outstanding scientists around the world who are currently extending the story. Recently, therapeutic approaches to pathological disorders include the development of selective P1 and P2 receptor subtype agonists and antagonists, as well as of inhibitors of extracellular ATP breakdown and of ATP transport enhancers and inhibitors. Medicinal chemists are starting to develop small molecule purinergic drugs that are orally bioavailable and stable in vivo.
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Affiliation(s)
- G Burnstock
- Autonomic Neuroscience Centre, Royal Free and University College Medical School, Rowland Hill Street, London, UK.
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