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Tam SW, Huffer K, Li M, Swartz KJ. Ion permeation pathway within the internal pore of P2X receptor channels. eLife 2023; 12:84796. [PMID: 36940138 PMCID: PMC10027316 DOI: 10.7554/elife.84796] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2022] [Accepted: 03/07/2023] [Indexed: 03/21/2023] Open
Abstract
P2X receptor channels are trimeric ATP-activated ion channels expressed in neuronal and non-neuronal cells that are attractive therapeutic targets for human disorders. Seven subtypes of P2X receptor channels have been identified in mammals that can form both homomeric and heteromeric channels. P2X1-4 and P2X7 receptor channels are cation-selective, whereas P2X5 has been reported to have both cation and anion permeability. P2X receptor channel structures reveal that each subunit is comprised of two transmembrane helices, with both N-and C-termini on the intracellular side of the membrane and a large extracellular domain that contains the ATP binding sites at subunit interfaces. Recent structures of ATP-bound P2X receptors with the activation gate open reveal the unanticipated presence of a cytoplasmic cap over the central ion permeation pathway, leaving lateral fenestrations that may be largely buried within the membrane as potential pathways for ions to permeate the intracellular end of the pore. In the present study, we identify a critical residue within the intracellular lateral fenestrations that is readily accessible to thiol-reactive compounds from both sides of the membrane and where substitutions influence the relative permeability of the channel to cations and anions. Taken together, our results demonstrate that ions can enter or exit the internal pore through lateral fenestrations that play a critical role in determining the ion selectivity of P2X receptor channels.
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Affiliation(s)
- Stephanie W Tam
- Molecular Physiology and Biophysics Section, Porter Neuroscience Research Center, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, United States
| | - Kate Huffer
- Molecular Physiology and Biophysics Section, Porter Neuroscience Research Center, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, United States
- Department of Biology, Johns Hopkins University, Baltimore, United States
| | - Mufeng Li
- Molecular Physiology and Biophysics Section, Porter Neuroscience Research Center, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, United States
| | - Kenton J Swartz
- Molecular Physiology and Biophysics Section, Porter Neuroscience Research Center, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, United States
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Hu Q, Li G. Role of purinergic receptors in cardiac sympathetic nerve injury in diabetes mellitus. Neuropharmacology 2023; 226:109406. [PMID: 36586475 DOI: 10.1016/j.neuropharm.2022.109406] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Revised: 12/13/2022] [Accepted: 12/23/2022] [Indexed: 12/30/2022]
Abstract
Diabetic cardiac autonomic neuropathy is a common and serious chronic complication of diabetes, which can lead to sympathetic and parasympathetic nerve imbalance and a relative excitation of the sympathetic nerve. Purinergic receptors play a crucial role in this process. Diabetic cardiac sympathetic nerve injury affects the expression of purinergic receptors, and activated purinergic receptors affect the phosphorylation of different signaling pathways and the regulation of inflammatory processes. This paper introduces the abnormal changes of sympathetic nerve in diabetes mellitus and summarizes the recently published studies on the role of several purinergic receptor subtypes in diabetic cardiac sympathetic nerve injury. These studies suggest that purinergic receptors as novel drug targets are of great significance for the treatment of diabetic autonomic neuropathy. This article is part of the Special Issue on "Purinergic Signaling: 50 years".
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Affiliation(s)
- Qixing Hu
- Department of Physiology, Medical School of Nanchang University, 461 Bayi Road, Nanchang, Jiangxi, 330006, PR China.
| | - Guilin Li
- Department of Physiology, Medical School of Nanchang University, 461 Bayi Road, Nanchang, Jiangxi, 330006, PR China.
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Wang Z, Zhu S, Tan S, Zeng Y, Zeng H. The P2 purinoceptors in prostate cancer. Purinergic Signal 2023; 19:255-263. [PMID: 35771310 PMCID: PMC9984634 DOI: 10.1007/s11302-022-09874-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2022] [Accepted: 05/25/2022] [Indexed: 02/08/2023] Open
Abstract
P2 purinoceptors are composed of ligand-gated ion channel type (P2X receptor) and G protein-coupled metabolite type (P2Y receptor). Both these receptors have played important roles in the prostate cancer microenvironment in recent years. P2X and P2Y receptors can contribute to prostate cancer's growth and invasiveness. However, the comprehensive mechanisms have yet to be identified. By summarizing the relevant studies, we believe that P2X and P2Y receptors play a dual role in cancer cell growth depending on the prostate cancer microenvironment and different downstream signalling pathways. We also summarized how different signalling pathways contribute to tumor invasiveness and metastasis through P2X and P2Y receptors, focusing on understanding the specific mechanisms led by P2X4, P2X7, and P2Y2. Statins may reduce and prevent tumor progression through P2X7 so that P2X purinergic receptors may have clinical implications in the management of prostate cancer. Furthermore, P2X7 receptors can aid in the early detection of prostate cancer. We hope that this review will provide new insights for future mechanistic and clinical investigations into the role of P2 purinergic receptors in prostate cancer.
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Affiliation(s)
- Zilin Wang
- The Department of Urology, Institute of Urology, West China Hospital, Sichuan University, Chengdu, China
| | - Sha Zhu
- The Department of Urology, Institute of Urology, West China Hospital, Sichuan University, Chengdu, China
| | - Sirui Tan
- Department of Abdominal Cancer, Medical School, West China Hospital, Sichuan University, Cancer Center, Chengdu, West China, China
| | - Yuhao Zeng
- The Department of Urology, Institute of Urology, West China Hospital, Sichuan University, Chengdu, China
| | - Hao Zeng
- The Department of Urology, Institute of Urology, West China Hospital, Sichuan University, Chengdu, China.
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von Mücke-Heim IA, Deussing JM. The P2X7 receptor in mood disorders: Emerging target in immunopsychiatry, from bench to bedside. Neuropharmacology 2023; 224:109366. [PMID: 36470368 DOI: 10.1016/j.neuropharm.2022.109366] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Revised: 11/09/2022] [Accepted: 11/29/2022] [Indexed: 12/03/2022]
Abstract
Psychiatric disorders are among the most burdensome disorders worldwide. Though therapies have evolved over the last decades, treatment resistance still affects many patients. Recently, neuroimmune systems have been identified as important factors of mood disorder biology. The underlying dysregulation in neuroimmune cross-talk is driven by genetic risk factors and accumulating adverse environmental influences like chronic psychosocial stress. These result in a cluster of proinflammatory cytokines and quantitative and functional changes of immune cell populations (e.g., microglia, monocytes, T cells), varying by disease entity and state. Among the emerging immune targets, purinergic signalling revolving around the membranous and ATP specific P2X7 receptor (P2X7R) has gained wider attention and clinical studies making use of antagonistic drugs are on-going. Still, no clinically meaningful applications have been identified so far. A major problem is the often overly simplified approach taken to translate findings from bench to bedside. Therefore, the present review focuses on purinergic signalling via P2X7R in the context of recent advances in immunopsychiatric mood disorder research. Our aim is to provide an overview of the current P2X7R-related findings, from bench to bedside. First, we summarize the characteristics of purinergic signalling and P2X7R, followed by a depiction of genetic and clinical data connecting P2X7R to mood disorders. We close with our perspective on current developments and discuss changes necessary to translate the evident potential of P2X7R signalling modulation into meaningful clinical application. This article is part of the Special Issue on 'Purinergic Signaling: 50 years'.
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Affiliation(s)
| | - Jan M Deussing
- Max Planck Institute for Psychiatry, Molecular Neurogenetics, Munich, Germany.
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Pasqualetto G, Zuanon M, Brancale A, Young MT. Identification of the molecular determinants of antagonist potency in the allosteric binding pocket of human P2X4. Front Pharmacol 2023; 14:1101023. [PMID: 36843952 PMCID: PMC9947563 DOI: 10.3389/fphar.2023.1101023] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2022] [Accepted: 01/31/2023] [Indexed: 02/11/2023] Open
Abstract
P2X receptors are a family of ATP-gated cation channels comprising seven subtypes in mammals, which play key roles in nerve transmission, pain sensation and inflammation. The P2X4 receptor in particular has attracted significant interest from pharmaceutical companies due to its physiological roles in neuropathic pain and modulation of vascular tone. A number of potent small-molecule P2X4 receptor antagonists have been developed, including the allosteric P2X4 receptor antagonist BX430, which is approximately 30-fold more potent at human P2X4 compared with the rat isoform. A single amino-acid difference between human and rat P2X4 (I312T), located in an allosteric pocket, has previously been identified as critical for BX430 sensitivity, implying that BX430 binds in this pocket. Using a combination of mutagenesis, functional assay in mammalian cells and in silico docking we confirmed these findings. Induced-fit docking, permitting the sidechains of the amino-acids of P2X4 to move, showed that BX430 could access a deeper portion of the allosteric pocket, and that the sidechain of Lys-298 was important for shaping the cavity. We then performed blind docking of 12 additional P2X4 antagonists into the receptor extracellular domain, finding that many of these compounds favored the same pocket as BX430 from their calculated binding energies. Induced-fit docking of these compounds in the allosteric pocket enabled us to show that antagonists with high potency (IC50 ≤ 100 nM) bind deep in the allosteric pocket, disrupting a network of interacting amino acids including Asp-85, Ala-87, Asp-88, and Ala-297, which are vital for transmitting the conformational change following ATP binding to channel gating. Our work confirms the importance of Ile-312 for BX430 sensitivity, demonstrates that the allosteric pocket where BX430 binds is a plausible binding pocket for a series of P2X4 antagonists, and suggests a mode of action for these allosteric antagonists involving disruption of a key structural motif required for the conformational change induced in P2X4 when ATP binds.
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Affiliation(s)
- Gaia Pasqualetto
- School of Biosciences, Cardiff University, Cardiff, United Kingdom
| | - Marika Zuanon
- School of Biosciences, Cardiff University, Cardiff, United Kingdom
| | - Andrea Brancale
- School of Pharmacy and Pharmaceutical Sciences, Cardiff University, Cardiff, United Kingdom,Department of Organic Chemistry, Vysoká škola chemicko-technologická v Praze, Prague, Czechia
| | - Mark T. Young
- School of Biosciences, Cardiff University, Cardiff, United Kingdom,*Correspondence: Mark T. Young,
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Kaur J, Dora S. Purinergic signaling: Diverse effects and therapeutic potential in cancer. Front Oncol 2023; 13:1058371. [PMID: 36741002 PMCID: PMC9889871 DOI: 10.3389/fonc.2023.1058371] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Accepted: 01/02/2023] [Indexed: 01/19/2023] Open
Abstract
Regardless of improved biological insights and therapeutic advances, cancer is consuming multiple lives worldwide. Cancer is a complex disease with diverse cellular, metabolic, and physiological parameters as its hallmarks. This instigates a need to uncover the latest therapeutic targets to advance the treatment of cancer patients. Purines are building blocks of nucleic acids but also function as metabolic intermediates and messengers, as part of a signaling pathway known as purinergic signaling. Purinergic signaling comprises primarily adenosine triphosphate (ATP) and adenosine (ADO), their analogous membrane receptors, and a set of ectonucleotidases, and has both short- and long-term (trophic) effects. Cells release ATP and ADO to modulate cellular function in an autocrine or paracrine manner by activating membrane-localized purinergic receptors (purinoceptors, P1 and P2). P1 receptors are selective for ADO and have four recognized subtypes-A1, A2A, A2B, and A3. Purines and pyrimidines activate P2 receptors, and the P2X subtype is ligand-gated ion channel receptors. P2X has seven subtypes (P2X1-7) and forms homo- and heterotrimers. The P2Y subtype is a G protein-coupled receptor with eight subtypes (P2Y1/2/4/6/11/12/13/14). ATP, its derivatives, and purinoceptors are widely distributed in all cell types for cellular communication, and any imbalance compromises the homeostasis of the cell. Neurotransmission, neuromodulation, and secretion employ fast purinergic signaling, while trophic purinergic signaling regulates cell metabolism, proliferation, differentiation, survival, migration, invasion, and immune response during tumor progression. Thus, purinergic signaling is a prospective therapeutic target in cancer and therapy resistance.
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Affiliation(s)
- Jasmeet Kaur
- Department of Biophysics, Postgraduate Institute of Medical Education and Research (PGIMER), Chandigarh, India
| | - Sanchit Dora
- Department of Biophysics, Postgraduate Institute of Medical Education and Research (PGIMER), Chandigarh, India
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57
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Pasqualetto G, Zuanon M, Brancale A, Young MT. Identification of a novel P2X7 antagonist using structure-based virtual screening. Front Pharmacol 2023; 13:1094607. [PMID: 36712671 PMCID: PMC9877316 DOI: 10.3389/fphar.2022.1094607] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2022] [Accepted: 12/12/2022] [Indexed: 01/15/2023] Open
Abstract
P2X4 and P2X7 receptors are ATP-gated ion channels, which play important roles in neuropathic and inflammatory pain, and as such they are important drug targets in diseases of inflammatory origin. While several compounds targeting P2X4 and P2X7 receptors have been developed using traditional high-throughput screening approaches, relatively few compounds have been developed using structure-based design. We initially set out to develop compounds targeting human P2X4, by performing virtual screening on the orthosteric (ATP-binding) pocket of a molecular model of human P2X4 based on the crystal structure of the Danio rerio receptor. The screening of a library of approximately 300,000 commercially available drug-like compounds led to the initial selection of 17 compounds; however, none of these compounds displayed a significant antagonist effect at P2X4 in a Fluo-4 ATP-induced calcium influx assay. When the same set of compounds was tested against human P2X7 in an ATP-stimulated Yo-Pro1 dye uptake assay, one compound (an indeno(1,2-b)pyridine derivative; GP-25) reduced the response by greater than 50% when applied at a concentration of 30 µM. GP-25 displayed an IC50 value of 8.7 μM at human P2X7 and 24.4 μM at rat P2X7, and was confirmed to be active using whole-cell patch clamp electrophysiology and not cytotoxic. Schild analysis suggested that mode of action of GP-25 was orthosteric. Screening of a further 16 commercially available analogues of GP-25 led to the discovery of five additional compounds with antagonist activity at human P2X7, enabling us to investigate the structure-activity relationship. Finally, docking of the R- and S-enantiomers of GP-25 into the orthosteric pocket of molecular models of human P2X4 and human P2X7 revealed that, while both enantiomers were able to make multiple interactions between their carboxyl moieties and conserved positively charged amino-acids in human P2X7, only the S-enantiomer of GP-25 was able to do this in human P2X4, potentially explaining the lack of activity of GP-25 at this receptor.
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Affiliation(s)
- Gaia Pasqualetto
- School of Biosciences, Cardiff University, Cardiff, United Kingdom
| | - Marika Zuanon
- School of Biosciences, Cardiff University, Cardiff, United Kingdom
| | - Andrea Brancale
- School of Pharmacy and Pharmaceutical Sciences, Cardiff University, Cardiff, United Kingdom,Department of Organic Chemistry, University of Chemistry and Technology, Prague, Czechia
| | - Mark T. Young
- School of Biosciences, Cardiff University, Cardiff, United Kingdom,*Correspondence: Mark T. Young,
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Durner A, Durner E, Nicke A. Improved ANAP incorporation and VCF analysis reveal details of P2X7 current facilitation and a limited conformational interplay between ATP binding and the intracellular ballast domain. eLife 2023; 12:82479. [PMID: 36598131 PMCID: PMC9859053 DOI: 10.7554/elife.82479] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Accepted: 01/03/2023] [Indexed: 01/05/2023] Open
Abstract
The large intracellular C-terminus of the pro-inflammatory P2X7 ion channel receptor (P2X7R) is associated with diverse P2X7R-specific functions. Cryo-EM structures of the closed and ATP-bound open full-length P2X7R recently identified a membrane-associated anchoring domain, an open-state stabilizing "cap" domain, and a globular "ballast domain" containing GTP/GDP and dinuclear Zn2+-binding sites with unknown functions. To investigate protein dynamics during channel activation, we improved incorporation of the environment-sensitive fluorescent unnatural amino acid L-3-(6-acetylnaphthalen-2-ylamino)-2-aminopropanoic acid (ANAP) into Xenopus laevis oocyte-expressed P2X7Rs and performed voltage clamp fluorometry. While we confirmed predicted conformational changes within the extracellular and the transmembrane domains, only 3 out of 41 mutants containing ANAP in the C-terminal domain resulted in ATP-induced fluorescence changes. We conclude that the ballast domain functions rather independently from the extracellular ATP binding domain and might require activation by additional ligands and/or protein interactions. Novel tools to study these are presented.
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Affiliation(s)
- Anna Durner
- Walther Straub Institute of Pharmacology and Toxicology, Faculty of Medicine, LMU MunichMunichGermany
| | - Ellis Durner
- Lehrstuhl für Angewandte Physik and Center for Nanoscience, LMU MunichMunichGermany
| | - Annette Nicke
- Walther Straub Institute of Pharmacology and Toxicology, Faculty of Medicine, LMU MunichMunichGermany
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59
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Advances in Antibody-Based Therapeutics for Cerebral Ischemia. Pharmaceutics 2022; 15:pharmaceutics15010145. [PMID: 36678774 PMCID: PMC9866586 DOI: 10.3390/pharmaceutics15010145] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2022] [Revised: 12/18/2022] [Accepted: 12/29/2022] [Indexed: 01/04/2023] Open
Abstract
Cerebral ischemia is an acute disorder characterized by an abrupt reduction in blood flow that results in immediate deprivation of both glucose and oxygen. The main types of cerebral ischemia are ischemic and hemorrhagic stroke. When a stroke occurs, several signaling pathways are activated, comprising necrosis, apoptosis, and autophagy as well as glial activation and white matter injury, which leads to neuronal cell death. Current treatments for strokes include challenging mechanical thrombectomy or tissue plasminogen activator, which increase the danger of cerebral bleeding, brain edema, and cerebral damage, limiting their usage in clinical settings. Monoclonal antibody therapy has proven to be effective and safe in the treatment of a variety of neurological disorders. In contrast, the evidence for stroke therapy is minimal. Recently, Clone MTS510 antibody targeting toll-like receptor-4 (TLR4) protein, ASC06-IgG1 antibody targeting acid sensing ion channel-1a (ASIC1a) protein, Anti-GluN1 antibodies targeting N-methyl-D-aspartate (NMDA) receptor associated calcium influx, GSK249320 antibody targeting myelin-associated glycoprotein (MAG), anti-High Mobility Group Box-1 antibody targeting high mobility group box-1 (HMGB1) are currently under clinical trials for cerebral ischemia treatment. In this article, we review the current antibody-based pharmaceuticals for neurological diseases, the use of antibody drugs in stroke, strategies to improve the efficacy of antibody therapeutics in cerebral ischemia, and the recent advancement of antibody drugs in clinical practice. Overall, we highlight the need of enhancing blood-brain barrier (BBB) penetration for the improvement of antibody-based therapeutics in the brain, which could greatly enhance the antibody medications for cerebral ischemia in clinical practice.
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Abstract
Within the family of purinergic receptors, the P2X1 receptor is a ligand-gated ion channel that plays a role in urogenital, immune and cardiovascular function. Specifically, the P2X1 receptor has been implicated in controlling smooth muscle contractions of the vas deferens and therefore has emerged as an exciting drug target for male contraception. In addition, the P2X1 receptor contributes to smooth muscle contractions of the bladder and is a target to treat bladder dysfunction. Finally, platelets and neutrophils have populations of P2X1 receptors that could be targeted for thrombosis and inflammatory conditions. Drugs that specifically target the P2X1 receptor have been challenging to develop, and only recently have small molecule antagonists of the P2X1 receptor been available. However, these ligands need further biological validation for appropriate selectivity and drug-like properties before they will be suitable for use in preclinical models of disease. Although the atomic structure of the P2X1 receptor has yet to be determined, the recent discovery of several other P2X receptor structures and improvements in the field of structural biology suggests that this is now a distinct possibility. Such efforts may significantly improve drug discovery efforts at the P2X1 receptor.
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Extracellular binding sites of positive and negative allosteric P2X4 receptor modulators. Life Sci 2022; 311:121143. [DOI: 10.1016/j.lfs.2022.121143] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2022] [Revised: 10/13/2022] [Accepted: 10/27/2022] [Indexed: 11/18/2022]
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Cunliffe G, Lim YT, Chae W, Jung S. Alternative Pharmacological Strategies for the Treatment of Alzheimer's Disease: Focus on Neuromodulator Function. Biomedicines 2022; 10:3064. [PMID: 36551821 PMCID: PMC9776382 DOI: 10.3390/biomedicines10123064] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2022] [Revised: 11/23/2022] [Accepted: 11/24/2022] [Indexed: 11/30/2022] Open
Abstract
Alzheimer's disease (AD) is a neurodegenerative disorder, comprising 70% of dementia diagnoses worldwide and affecting 1 in 9 people over the age of 65. However, the majority of its treatments, which predominantly target the cholinergic system, remain insufficient at reversing pathology and act simply to slow the inevitable progression of the disease. The most recent neurotransmitter-targeting drug for AD was approved in 2003, strongly suggesting that targeting neurotransmitter systems alone is unlikely to be sufficient, and that research into alternate treatment avenues is urgently required. Neuromodulators are substances released by neurons which influence neurotransmitter release and signal transmission across synapses. Neuromodulators including neuropeptides, hormones, neurotrophins, ATP and metal ions display altered function in AD, which underlies aberrant neuronal activity and pathology. However, research into how the manipulation of neuromodulators may be useful in the treatment of AD is relatively understudied. Combining neuromodulator targeting with more novel methods of drug delivery, such as the use of multi-targeted directed ligands, combinatorial drugs and encapsulated nanoparticle delivery systems, may help to overcome limitations of conventional treatments. These include difficulty crossing the blood-brain-barrier and the exertion of effects on a single target only. This review aims to highlight the ways in which neuromodulator functions are altered in AD and investigate how future therapies targeting such substances, which act upstream to classical neurotransmitter systems, may be of potential therapeutic benefit in the sustained search for more effective treatments.
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Affiliation(s)
- Grace Cunliffe
- Institute of Molecular and Cell Biology (IMCB), Agency for Science, Technology and Research (A*STAR), Singapore 138667, Singapore
- Division of Neuroscience and Experimental Psychology, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester M13 9PL, UK
| | - Yi Tang Lim
- Institute of Molecular and Cell Biology (IMCB), Agency for Science, Technology and Research (A*STAR), Singapore 138667, Singapore
- Faculty of Science, National University of Singapore, Singapore 117546, Singapore
| | - Woori Chae
- Institute of Molecular and Cell Biology (IMCB), Agency for Science, Technology and Research (A*STAR), Singapore 138667, Singapore
- Department of BioNano Technology, Gachon University, 1342 Seongnam-daero, Seongnam-si 13120, Republic of Korea
| | - Sangyong Jung
- Institute of Molecular and Cell Biology (IMCB), Agency for Science, Technology and Research (A*STAR), Singapore 138667, Singapore
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117593, Singapore
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Alberto AVP, Ferreira NCDS, Bonavita AGC, Nihei OK, de Farias FP, Bisaggio RDC, de Albuquerque C, Savino W, Coutinho‐Silva R, Persechini PM, Alves LA. Physiologic roles of P2 receptors in leukocytes. J Leukoc Biol 2022; 112:983-1012. [PMID: 35837975 PMCID: PMC9796137 DOI: 10.1002/jlb.2ru0421-226rr] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2021] [Revised: 06/13/2022] [Indexed: 01/01/2023] Open
Abstract
Since their discovery in the 1970s, purinergic receptors have been shown to play key roles in a wide variety of biologic systems and cell types. In the immune system, purinergic receptors participate in innate immunity and in the modulation of the adaptive immune response. In particular, P2 receptors, which respond to extracellular nucleotides, are widely expressed on leukocytes, causing the release of cytokines and chemokines and the formation of inflammatory mediators, and inducing phagocytosis, degranulation, and cell death. The activity of these receptors is regulated by ectonucleotidases-expressed in these same cell types-which regulate the availability of nucleotides in the extracellular environment. In this article, we review the characteristics of the main purinergic receptor subtypes present in the immune system, focusing on the P2 family. In addition, we describe the physiologic roles of the P2 receptors already identified in leukocytes and how they can positively or negatively modulate the development of infectious diseases, inflammation, and pain.
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Affiliation(s)
- Anael Viana Pinto Alberto
- Laboratory of Cellular Communication, Oswaldo Cruz InstituteOswaldo Cruz FoundationRio de JaneiroRJBrazil
| | | | | | - Oscar Kenji Nihei
- Center of Education and LetterState University of the West of ParanáFoz do IguaçuPRBrazil
| | | | - Rodrigo da Cunha Bisaggio
- Laboratory of Cellular Communication, Oswaldo Cruz InstituteOswaldo Cruz FoundationRio de JaneiroRJBrazil,Federal Institute of Education, Science, and Technology of Rio de JaneiroRio de JaneiroRJBrazil
| | | | - Wilson Savino
- Laboratory on Thymus Research, Oswaldo Cruz InstituteOswaldo Cruz FoundationRio de JaneiroRJBrazil,Brazilian National Institute of Science and Technology on NeuroimmunomodulationRio de Janeiro Research Network on NeuroinflammationRio de JaneiroRJBrazil
| | - Robson Coutinho‐Silva
- Laboratory of Immunophysiology, Carlos Chagas Filho Biophysics InstituteFederal University of Rio de JaneiroRio de JaneiroRJBrazil
| | - Pedro Muanis Persechini
- Laboratory of Immunobiophysics, Carlos Chagas Filho Biophysics InstituteFederal University of Rio de JaneiroRio de JaneiroRJBrazil
| | - Luiz Anastacio Alves
- Laboratory of Cellular Communication, Oswaldo Cruz InstituteOswaldo Cruz FoundationRio de JaneiroRJBrazil
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Zelentsova AS, Deykin AV, Soldatov VO, Ulezko AA, Borisova AY, Belyaeva VS, Skorkina MY, Angelova PR. P2X7 Receptor and Purinergic Signaling: Orchestrating Mitochondrial Dysfunction in Neurodegenerative Diseases. eNeuro 2022; 9:ENEURO.0092-22.2022. [PMID: 36376084 PMCID: PMC9665882 DOI: 10.1523/eneuro.0092-22.2022] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2022] [Revised: 07/14/2022] [Accepted: 08/09/2022] [Indexed: 11/15/2022] Open
Abstract
Mitochondrial dysfunction is one of the basic hallmarks of cellular pathology in neurodegenerative diseases. Since the metabolic activity of neurons is highly dependent on energy supply, nerve cells are especially vulnerable to impaired mitochondrial function. Besides providing oxidative phosphorylation, mitochondria are also involved in controlling levels of second messengers such as Ca2+ ions and reactive oxygen species (ROS). Interestingly, the critical role of mitochondria as producers of ROS is closely related to P2XR purinergic receptors, the activity of which is modulated by free radicals. Here, we review the relationships between the purinergic signaling system and affected mitochondrial function. Purinergic signaling regulates numerous vital biological processes in the CNS. The two main purines, ATP and adenosine, act as excitatory and inhibitory neurotransmitters, respectively. Current evidence suggests that purinergic signaling best explains how neuronal activity is related to neuronal electrical activity and energy homeostasis, especially in the development of Alzheimer's and Parkinson's diseases. In this review, we focus on the mechanisms underlying the involvement of the P2RX7 purinoreceptor in triggering mitochondrial dysfunction during the development of neurodegenerative disorders. We also summarize various avenues by which the purine signaling pathway may trigger metabolic dysfunction contributing to neuronal death and the inflammatory activation of glial cells. Finally, we discuss the potential role of the purinergic system in the search for new therapeutic approaches to treat neurodegenerative diseases.
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Toti KS, Verma R, McGonnigle MJ, Gamiotea Turro D, Wen Z, Lewicki SA, Liang BT, Jacobson KA. Structure-Activity Relationship and Neuroprotective Activity of 1,5-Dihydro-2 H-naphtho[1,2- b][1,4]diazepine-2,4(3 H)-diones as P2X4 Receptor Antagonists. J Med Chem 2022; 65:13967-13987. [PMID: 36150180 PMCID: PMC9653265 DOI: 10.1021/acs.jmedchem.2c01197] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
We analyzed the P2X4 receptor structure-activity relationship of a known antagonist 5, a 1,5-dihydro-2H-naphtho[1,2-b][1,4]diazepine-2,4(3H)-dione. Following extensive modification of the reported synthetic route, 4-pyridyl 21u (MRS4719) and 6-methyl 22c (MRS4596) analogues were most potent at human (h) P2X4R (IC50 0.503 and 1.38 μM, respectively, and selective versus hP2X1R, hP2X2/3R, hP2X3R). Thus, the naphthalene 6-, but not 7-position was amenable to substitution, and an N-phenyl ring aza-scan identified 21u with 3-fold higher activity than 5. Compounds 21u and 22c showed neuroprotective and learning- and memory-enhancing activities in a mouse middle cerebral artery occlusion (MCAO) model of ischemic stroke, with potency of 21u > 22c. 21u dose-dependently reduced infarct volume and reduced brain atrophy at 3 and 35 days post-stroke, respectively. Relevant to clinical implication, 21u also reduced ATP-induced [Ca2+]i influx in primary human monocyte-derived macrophages. This study indicates the translational potential of P2X4R antagonists for treating ischemic stroke, including in aging populations.
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Affiliation(s)
- Kiran S Toti
- National Institute of Diabetes and Digestive and Kidney Diseases, NIH, Bethesda, Maryland 20892-0810, United States
| | - Rajkumar Verma
- Department of Neuroscience, UConn School of Medicine, Farmington, Connecticut 06032, United States
| | - Michael J McGonnigle
- Department of Neuroscience, UConn School of Medicine, Farmington, Connecticut 06032, United States
| | - Daylin Gamiotea Turro
- Department of Neuroscience, UConn School of Medicine, Farmington, Connecticut 06032, United States
| | - Zhiwei Wen
- National Institute of Diabetes and Digestive and Kidney Diseases, NIH, Bethesda, Maryland 20892-0810, United States
| | - Sarah A Lewicki
- National Institute of Diabetes and Digestive and Kidney Diseases, NIH, Bethesda, Maryland 20892-0810, United States
| | - Bruce T Liang
- Calhoun Cardiology Center, UConn School of Medicine, Farmington, Connecticut 06032, United States
| | - Kenneth A Jacobson
- National Institute of Diabetes and Digestive and Kidney Diseases, NIH, Bethesda, Maryland 20892-0810, United States
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Rehabilitation of the P2X5 receptor: a re-evaluation of structure and function. Purinergic Signal 2022:10.1007/s11302-022-09903-0. [DOI: 10.1007/s11302-022-09903-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2022] [Accepted: 10/03/2022] [Indexed: 11/28/2022] Open
Abstract
AbstractOf the extended family of ATP-gated P2X ion-channels, the P2X5 receptor has received comparatively little attention since first cloned over 25 years ago. Disinterest in studying this P2X subtype stems from two commonly held beliefs: (i) canonical human P2X5 is non-functional because the P2X5 subunit is truncated (hP2X5A, 422 aa) and missing the critical peptide sequence (22 aa) encoded by exon 10; (ii) rat and mouse P2X5 subunits are fully formed (455 aa) but the receptor is only weakly functional, and successive ATP responses rapidly run down in amplitude. However, newer studies have re-evaluated these notions. First, a low proportion (around 10%) of humans possess full-length P2X5 subunits (444 aa) and can form competent P2X5 receptors. Full-length P2X5 has been identified only in black Americans, but may occur in a wider population as more ethnicities are screened. Second, replacement of one of three amino acids in rat P2X5 subunits with corresponding residues in human P2X5 subunits (V67I, S191F, or F195H) significantly improves the responsiveness of rat P2X5 to ATP. Replaced residues exert an allosteric action on the left flipper, allowing the docking jaw for ATP to flex the lower body of the subunit and fully open the ion pore. This proposed action may drive the search for naturally occurring modulators which act allosterically on wildtype rat P2X5. This review collates the available information on the structure and function of human and rat P2X5 receptors, with the view to rehabilitating the reputation of these ATP-gated ion channels and stimulating future lines of research.
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Blocking P2X7 by intracerebroventricular injection of P2X7-specific nanobodies reduces stroke lesions. J Neuroinflammation 2022; 19:256. [PMID: 36224611 PMCID: PMC9559872 DOI: 10.1186/s12974-022-02601-z] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Accepted: 09/25/2022] [Indexed: 01/15/2023] Open
Abstract
BACKGROUND Previous studies have demonstrated that purinergic receptors could be therapeutic targets to modulate the inflammatory response in multiple models of brain diseases. However, tools for the selective and efficient targeting of these receptors are lacking. The development of new P2X7-specific nanobodies (nbs) has enabled us to effectively block the P2X7 channel. METHODS Temporary middle cerebral artery occlusion (tMCAO) in wild-type (wt) and P2X7 transgenic (tg) mice was used to model ischemic stroke. Adenosine triphosphate (ATP) release was assessed in transgenic ATP sensor mice. Stroke size was measured after P2X7-specific nbs were injected intravenously (iv) and intracerebroventricularly (icv) directly before tMCAO surgery. In vitro cultured microglia were used to investigate calcium influx, pore formation via 4,6-diamidino-2-phenylindole (DAPI) uptake, caspase 1 activation and interleukin (IL)-1β release after incubation with the P2X7-specific nbs. RESULTS Transgenic ATP sensor mice showed an increase in ATP release in the ischemic hemisphere compared to the contralateral hemisphere or the sham-treated mice up to 24 h after stroke. P2X7-overexpressing mice had a significantly greater stroke size 24 h after tMCAO surgery. In vitro experiments with primary microglial cells demonstrated that P2X7-specific nbs could inhibit ATP-triggered calcium influx and the formation of membrane pores, as measured by Fluo4 fluorescence or DAPI uptake. In microglia, we found lower caspase 1 activity and subsequently lower IL-1β release after P2X7-specific nb treatment. The intravenous injection of P2X7-specific nbs compared to isotype controls before tMCAO surgery did not result in a smaller stroke size. As demonstrated by fluorescence-activated cell sorting (FACS), after stroke, iv injected nbs bound to brain-infiltrated macrophages but not to brain resident microglia, indicating insufficient crossing of the blood-brain barrier of the nbs. Therefore, we directly icv injected the P2X7-specific nbs or the isotype nbs. After icv injection of 30 µg of P2X7 specific nbs, P2X7 specific nbs bound sufficiently to microglia and reduced stroke size. CONCLUSION Mechanistically, we can show that there is a substantial increase of ATP locally after stroke and that blockage of the ATP receptor P2X7 by icv injected P2X7-specific nbs can reduce ischemic tissue damage.
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Sykes DL, Zhang M, Morice AH. Treatment of chronic cough: P2X3 receptor antagonists and beyond. Pharmacol Ther 2022; 237:108166. [DOI: 10.1016/j.pharmthera.2022.108166] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2022] [Revised: 02/22/2022] [Accepted: 03/02/2022] [Indexed: 10/18/2022]
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Isaak A, Dobelmann C, Füsser FT, Erlitz KS, Koch O, Junker A. Unveiling the Structure-Activity Relationships at the Orthosteric Binding Site of P2X Ion Channels: The Route to Selectivity. J Med Chem 2022; 65:11291-11308. [PMID: 35930402 DOI: 10.1021/acs.jmedchem.2c00812] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The orthosteric ATP-binding site of the P2X receptors is poorly understood. Only a few compounds were well characterized for their P2X receptor functional activity and subtype selectivity. This study represents the first fully functional characterization of various ATP derivatives combined with in silico studies to advance the understanding of SARs at the orthosteric binding sites of P2X receptors leading to the identification of 2-chloro-3-trifluoromethylbenzoyl ATP ester as a novel pan-P2X receptor agonist and several subtype-selective P2X receptor agonists. Furthermore, esterification of both hydroxyl functions of ATP using 1-naphthoic acid has led to compound 26 acting as an antagonist at P2X1-4 and P2X2/3 receptors and an agonist at P2X7 receptors. This particular ATP derivative will allow interrogating the P2X7 receptor function while antagonizing all other P2X receptor subtypes and therefore serve as a valuable pharmacological tool in the future.
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Affiliation(s)
- Andreas Isaak
- European Institute for Molecular Imaging (EIMI), Waldeyerstr. 15, Münster 48149, Germany
| | - Clemens Dobelmann
- European Institute for Molecular Imaging (EIMI), Waldeyerstr. 15, Münster 48149, Germany
| | - Friederike Theresa Füsser
- Institut für Pharmazeutische und Medizinische Chemie der Universität Münster, Corrensstr. 48, Münster 48149, Germany
| | | | - Oliver Koch
- Institut für Pharmazeutische und Medizinische Chemie der Universität Münster, Corrensstr. 48, Münster 48149, Germany
| | - Anna Junker
- European Institute for Molecular Imaging (EIMI), Waldeyerstr. 15, Münster 48149, Germany
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De Salis SKF, Li L, Chen Z, Lam KW, Skarratt KK, Balle T, Fuller SJ. Alternatively Spliced Isoforms of the P2X7 Receptor: Structure, Function and Disease Associations. Int J Mol Sci 2022; 23:ijms23158174. [PMID: 35897750 PMCID: PMC9329894 DOI: 10.3390/ijms23158174] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Revised: 07/20/2022] [Accepted: 07/21/2022] [Indexed: 12/24/2022] Open
Abstract
The P2X7 receptor (P2X7R) is an ATP-gated membrane ion channel that is expressed by multiple cell types. Following activation by extracellular ATP, the P2X7R mediates a broad range of cellular responses including cytokine and chemokine release, cell survival and differentiation, the activation of transcription factors, and apoptosis. The P2X7R is made up of three P2X7 subunits that contain specific domains essential for the receptor’s varied functions. Alternative splicing produces P2X7 isoforms that exclude one or more of these domains and assemble in combinations that alter P2X7R function. The modification of the structure and function of the P2X7R may adversely affect cellular responses to carcinogens and pathogens, and alternatively spliced (AS) P2X7 isoforms have been associated with several cancers. This review summarizes recent advances in understanding the structure and function of AS P2X7 isoforms and their associations with cancer and potential role in modulating the inflammatory response.
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Affiliation(s)
- Sophie K. F. De Salis
- Sydney Pharmacy School, Faculty of Medicine and Health, The University of Sydney, Sydney, NSW 2006, Australia; (S.K.F.D.S.); (Z.C.); (T.B.)
| | - Lanxin Li
- Sydney Medical School Nepean, Faculty of Medicine and Health, The University of Sydney, Nepean Hospital, Penrith, NSW 2750, Australia; (L.L.); (K.W.L.); (K.K.S.)
| | - Zheng Chen
- Sydney Pharmacy School, Faculty of Medicine and Health, The University of Sydney, Sydney, NSW 2006, Australia; (S.K.F.D.S.); (Z.C.); (T.B.)
| | - Kam Wa Lam
- Sydney Medical School Nepean, Faculty of Medicine and Health, The University of Sydney, Nepean Hospital, Penrith, NSW 2750, Australia; (L.L.); (K.W.L.); (K.K.S.)
| | - Kristen K. Skarratt
- Sydney Medical School Nepean, Faculty of Medicine and Health, The University of Sydney, Nepean Hospital, Penrith, NSW 2750, Australia; (L.L.); (K.W.L.); (K.K.S.)
| | - Thomas Balle
- Sydney Pharmacy School, Faculty of Medicine and Health, The University of Sydney, Sydney, NSW 2006, Australia; (S.K.F.D.S.); (Z.C.); (T.B.)
- Brain and Mind Centre, The University of Sydney, Camperdown, NSW 2050, Australia
| | - Stephen J. Fuller
- Sydney Medical School Nepean, Faculty of Medicine and Health, The University of Sydney, Nepean Hospital, Penrith, NSW 2750, Australia; (L.L.); (K.W.L.); (K.K.S.)
- Correspondence: ; Tel.: +61-2-4734-3732
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71
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Hua SQ, Hu JL, Zou FL, Liu JP, Luo HL, Hu DX, Wu LD, Zhang WJ. P2X7 receptor in inflammation and pain. Brain Res Bull 2022; 187:199-209. [PMID: 35850190 DOI: 10.1016/j.brainresbull.2022.07.006] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Revised: 06/15/2022] [Accepted: 07/13/2022] [Indexed: 11/02/2022]
Abstract
Different studies have confirmed P2X7 receptor-mediated inflammatory mediators play a key role in the development of pain. P2X7 receptor activation can induce the development of pain by mediating the release of inflammatory mediators. In view of the fact that P2X7 receptor is expressed in the nervous system and immune system, it is closely related to the stability and maintenance of the nervous system function. ATP activates P2X7 receptor, opens non-selective cation channels, activates multiple intracellular signaling, releases multiple inflammatory cytokines, and induces pain. At present, the role of P2X7 receptor in inflammatory response and pain has been widely recognized and affirmed. Therefore, in this paper, we discussed the pathological mechanism of P2X7 receptor-mediated inflammation and pain, focused on the internal relationship between P2X7 receptor and pain. Moreover, we also described the effects of some antagonists on pain relief by inhibiting the activities of P2X7 receptor. Thus, targeting to inhibit activation of P2X7 receptor is expected to become another potential target for the relief of pain.
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Affiliation(s)
- Shi-Qi Hua
- Nanchang University, Nanchang City 343000, Jiangxi Province, China
| | - Jia-Ling Hu
- Emergency Department, The Second Affiliated Hospital, Nanchang University, Nanchang City 343000, Jiangxi Province, China
| | - Fei-Long Zou
- Gastrointestinal Surgery, The Second Affiliated Hospital, Nanchang University, Nanchang City 343000, Jiangxi Province, China
| | - Ji-Peng Liu
- Gastrointestinal Surgery, The Second Affiliated Hospital, Nanchang University, Nanchang City 343000, Jiangxi Province, China
| | - Hong-Liang Luo
- Gastrointestinal Surgery, The Second Affiliated Hospital, Nanchang University, Nanchang City 343000, Jiangxi Province, China
| | - Dong-Xia Hu
- Department of Rehabilitation Medicine, The Second Affiliated Hospital, Nanchang University, Nanchang City 343000, Jiangxi Province, China.
| | - Li-Dong Wu
- Emergency Department, The Second Affiliated Hospital, Nanchang University, Nanchang City 343000, Jiangxi Province, China.
| | - Wen-Jun Zhang
- Department of Rehabilitation Medicine, The Second Affiliated Hospital, Nanchang University, Nanchang City 343000, Jiangxi Province, China.
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72
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Dandamudi M, Hausen H, Lynagh T. Comparative analysis defines a broader FMRFamide-gated sodium channel family and determinants of neuropeptide sensitivity. J Biol Chem 2022; 298:102086. [PMID: 35636513 PMCID: PMC9234716 DOI: 10.1016/j.jbc.2022.102086] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2022] [Revised: 05/19/2022] [Accepted: 05/25/2022] [Indexed: 12/23/2022] Open
Abstract
FMRFamide (Phe-Met-Arg-Phe-amide, FMRFa) and similar neuropeptides are important physiological modulators in most invertebrates, but the molecular basis of FMRFa activity at its receptors is unknown. We therefore sought to identify the molecular determinants of FMRFa potency against one of its native targets, the excitatory FMRFa-gated sodium channel (FaNaC) from gastropod mollusks. Using molecular phylogenetics and electrophysiological measurement of neuropeptide activity, we identified a broad FaNaC family that includes mollusk and annelid channels gated by FMRFa, FVRIamides, and/or Wamides (or myoinhibitory peptides). A comparative analysis of this broader FaNaC family and other channels from the overarching degenerin (DEG)/epithelial sodium channel (ENaC) superfamily, incorporating mutagenesis and experimental dissection of channel function, identified a pocket of amino acid residues that determines activation of FaNaCs by neuropeptides. Although this pocket has diverged in distantly related DEG/ENaC channels that are activated by other ligands but enhanced by FMRFa, such as mammalian acid-sensing ion channels, we show that it nonetheless contains residues that determine enhancement of those channels by similar peptides. This study thus identifies amino acid residues that determine FMRFa neuropeptide activity at FaNaC receptor channels and illuminates the evolution of ligand recognition in one branch of the DEG/ENaC superfamily of ion channels.
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Affiliation(s)
- Mowgli Dandamudi
- Sars International Centre for Marine Molecular Biology, University of Bergen, Bergen, Norway
| | - Harald Hausen
- Sars International Centre for Marine Molecular Biology, University of Bergen, Bergen, Norway; Department of Earth Science, University of Bergen, Bergen, Norway
| | - Timothy Lynagh
- Sars International Centre for Marine Molecular Biology, University of Bergen, Bergen, Norway.
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73
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McDouall A, Zhou KQ, Bennet L, Green CR, Gunn AJ, Davidson JO. Connexins, Pannexins and Gap Junctions in Perinatal Brain Injury. Biomedicines 2022; 10:1445. [PMID: 35740466 PMCID: PMC9220888 DOI: 10.3390/biomedicines10061445] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Revised: 06/15/2022] [Accepted: 06/15/2022] [Indexed: 11/18/2022] Open
Abstract
Perinatal brain injury secondary to hypoxia-ischemia and/or infection/inflammation remains a major cause of disability. Therapeutic hypothermia significantly improves outcomes, but in randomized controlled trials nearly half of infants still died or survived with disability, showing that additional interventions are needed. There is growing evidence that brain injury spreads over time from injured to previously uninjured regions of the brain. At least in part, this spread is related to opening of connexin hemichannels and pannexin channels, both of which are large conductance membrane channels found in many brain cells. Opening of these membrane channels releases adenosine triphosphate (ATP), and other neuroactive molecules, into the extracellular space. ATP has an important role in normal signaling, but pathologically can trigger the assembly of the multi-protein inflammasome complex. The inflammasome complex promotes activation of inflammatory caspases, and release of inflammatory cytokines. Overall, the connexin hemichannel appears to play a primary role in propagation of injury and chronic disease, and connexin hemichannel blockade has been shown to be neuroprotective in multiple animal models. Thus, there is potential for some blockers of connexin or pannexin channels to be developed into targeted interventions that could be used in conjunction with or separate to therapeutic hypothermia.
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Affiliation(s)
- Alice McDouall
- U1 Department of Physiology, Faculty of Medical and Health Sciences, The University of Auckland, Auckland 1023, New Zealand; (A.M.); (K.Q.Z.); (L.B.); (A.J.G.)
| | - Kelly Q. Zhou
- U1 Department of Physiology, Faculty of Medical and Health Sciences, The University of Auckland, Auckland 1023, New Zealand; (A.M.); (K.Q.Z.); (L.B.); (A.J.G.)
| | - Laura Bennet
- U1 Department of Physiology, Faculty of Medical and Health Sciences, The University of Auckland, Auckland 1023, New Zealand; (A.M.); (K.Q.Z.); (L.B.); (A.J.G.)
| | - Colin R. Green
- Department of Ophthalmology, Faculty of Medical and Health Sciences, The University of Auckland, Auckland 1023, New Zealand;
| | - Alistair J. Gunn
- U1 Department of Physiology, Faculty of Medical and Health Sciences, The University of Auckland, Auckland 1023, New Zealand; (A.M.); (K.Q.Z.); (L.B.); (A.J.G.)
| | - Joanne O. Davidson
- U1 Department of Physiology, Faculty of Medical and Health Sciences, The University of Auckland, Auckland 1023, New Zealand; (A.M.); (K.Q.Z.); (L.B.); (A.J.G.)
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Oken AC, Krishnamurthy I, Savage JC, Lisi NE, Godsey MH, Mansoor SE. Molecular Pharmacology of P2X Receptors: Exploring Druggable Domains Revealed by Structural Biology. Front Pharmacol 2022; 13:925880. [PMID: 35784697 PMCID: PMC9248971 DOI: 10.3389/fphar.2022.925880] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Accepted: 05/10/2022] [Indexed: 11/18/2022] Open
Abstract
Extracellular ATP is a critical signaling molecule that is found in a wide range of concentrations across cellular environments. The family of nonselective cation channels that sense extracellular ATP, termed P2X receptors (P2XRs), is composed of seven subtypes (P2X1-P2X7) that assemble as functional homotrimeric and heterotrimeric ion channels. Each P2XR is activated by a distinct concentration of extracellular ATP, spanning from high nanomolar to low millimolar. P2XRs are implicated in a variety of physiological and pathophysiological processes in the cardiovascular, immune, and central nervous systems, corresponding to the spatiotemporal expression, regulation, and activation of each subtype. The therapeutic potential of P2XRs is an emerging area of research in which structural biology has seemingly exceeded medicinal chemistry, as there are several published P2XR structures but currently no FDA-approved drugs targeting these ion channels. Cryogenic electron microscopy is ideally suited to facilitate structure-based drug design for P2XRs by revealing and characterizing novel ligand-binding sites. This review covers structural elements in P2XRs including the extracellular orthosteric ATP-binding site, extracellular allosteric modulator sites, channel pore, and cytoplasmic substructures, with an emphasis on potential therapeutic ligand development.
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Affiliation(s)
- Adam C. Oken
- Department of Chemical Physiology and Biochemistry, Oregon Health & Science University, Portland, OR, United States
| | - Ipsita Krishnamurthy
- Department of Chemical Physiology and Biochemistry, Oregon Health & Science University, Portland, OR, United States
| | - Jonathan C. Savage
- Department of Chemical Physiology and Biochemistry, Oregon Health & Science University, Portland, OR, United States
| | - Nicolas E. Lisi
- Department of Chemical Physiology and Biochemistry, Oregon Health & Science University, Portland, OR, United States
| | - Michael H. Godsey
- Department of Chemical Physiology and Biochemistry, Oregon Health & Science University, Portland, OR, United States
| | - Steven E. Mansoor
- Department of Chemical Physiology and Biochemistry, Oregon Health & Science University, Portland, OR, United States
- Knight Cardiovascular Institute, Oregon Health & Science University, Portland, OR, United States
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75
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You R, He X, Zeng Z, Zhan Y, Xiao Y, Xiao R. Pyroptosis and Its Role in Autoimmune Disease: A Potential Therapeutic Target. Front Immunol 2022; 13:841732. [PMID: 35693810 PMCID: PMC9174462 DOI: 10.3389/fimmu.2022.841732] [Citation(s) in RCA: 51] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Accepted: 04/29/2022] [Indexed: 12/13/2022] Open
Abstract
Autoimmune diseases are a group of heterogeneous diseases with diverse clinical manifestations that can be divided into systemic and organ-specific. The common etiology of autoimmune diseases is the destruction of immune tolerance and the production of autoantibodies, which attack specific tissues and/or organs in the body. The pathogenesis of autoimmune diseases is complicated, and genetic, environmental, infectious, and even psychological factors work together to cause aberrant innate and adaptive immune responses. Although the exact mechanisms are unclear, recently, excessive exacerbation of pyroptosis, as a bond between innate and adaptive immunity, has been proven to play a crucial role in the development of autoimmune disease. Pyroptosis is characterized by pore formation on cell membranes, as well as cell rupture and the excretion of intracellular contents and pro-inflammatory cytokines, such as IL-1β and IL-18. This overactive inflammatory programmed cell death disrupts immune system homeostasis and promotes autoimmunity. This review examines the molecular structure of classical inflammasomes, including NLRP3, AIM2, and P2X7-NLRP3, as the switches of pyroptosis, and their molecular regulation mechanisms. The sophisticated pyroptosis pathways, including the canonical caspase-1-mediated pathway, the noncanonical caspase-4/5/11-mediated pathway, the emerging caspase-3-mediated pathway, and the caspase-independent pathway, are also described. We highlight the recent advances in pyroptosis in autoimmune diseases, such as systemic lupus erythematosus, rheumatoid arthritis, inflammatory bowel disease, Sjögren's syndrome and dermatomyositis, and attempt to identify its potential advantages as a therapeutic target or prognostic marker in these diseases.
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Affiliation(s)
- Ruixuan You
- Department of Dermatology, The Second Xiangya Hospital of Central South University, Changsha, China.,Hunan Key Laboratory of Medical Epigenetics, The Second Xiangya Hospital of Central South University, Changsha, China
| | - Xinglan He
- Department of Dermatology, The Second Xiangya Hospital of Central South University, Changsha, China.,Hunan Key Laboratory of Medical Epigenetics, The Second Xiangya Hospital of Central South University, Changsha, China
| | - Zhuotong Zeng
- Department of Dermatology, The Second Xiangya Hospital of Central South University, Changsha, China.,Hunan Key Laboratory of Medical Epigenetics, The Second Xiangya Hospital of Central South University, Changsha, China
| | - Yi Zhan
- Department of Dermatology, The Second Xiangya Hospital of Central South University, Changsha, China.,Hunan Key Laboratory of Medical Epigenetics, The Second Xiangya Hospital of Central South University, Changsha, China
| | - Yangfan Xiao
- Clinical Nursing Teaching and Research Section, The Second Xiangya Hospital of Central South University, Changsha, China.,Department of Anesthesiology, The Second Xiangya Hospital of Central South University, Changsha, China
| | - Rong Xiao
- Department of Dermatology, The Second Xiangya Hospital of Central South University, Changsha, China.,Hunan Key Laboratory of Medical Epigenetics, The Second Xiangya Hospital of Central South University, Changsha, China
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76
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Ma XF, Wang TT, Wang WH, Guan L, Guo CR, Li XH, Lei YT, Fan YZ, Yang XN, Hattori M, Nureki O, Zhu MX, Yu Y, Tian Y, Wang J. The long β2,3-sheets encoded by redundant sequences play an integral role in the channel function of P2X7 receptors. J Biol Chem 2022; 298:102002. [PMID: 35504351 PMCID: PMC9163701 DOI: 10.1016/j.jbc.2022.102002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2021] [Revised: 04/23/2022] [Accepted: 04/27/2022] [Indexed: 11/26/2022] Open
Abstract
P2X receptors are a class of nonselective cation channels widely distributed in the immune and nervous systems, and their dysfunction is a significant cause of tumors, inflammation, leukemia, and immune diseases. P2X7 is a unique member of the P2X receptor family with many properties that differ from other subtypes in terms of primary sequence, the architecture of N- and C-terminals, and channel function. Here, we suggest that the observed lengthened β2- and β3-sheets and their linker (loop β2,3), encoded by redundant sequences, play an indispensable role in the activation of the P2X7 receptor. We show that deletion of this longer structural element leads to the loss of P2X7 function. Furthermore, by combining mutagenesis, chimera construction, surface expression, and protein stability analysis, we found that the deletion of the longer β2,3-loop affects P2X7 surface expression but, more importantly, that this loop affects channel gating of P2X7. We propose that the longer β2,3-sheets may have a negative regulatory effect on a loop on the head domain and on the structural element formed by E171 and its surrounding regions. Understanding the role of the unique structure of the P2X7 receptor in the gating process will aid in the development of selective drugs targeting this subtype.
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Affiliation(s)
- Xue-Fei Ma
- College of Bioscience and Biotechnology, Hunan Agricultural University, Changsha, China; School of Basic Medicine and Clinical Pharmacy and State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing, China
| | - Ting-Ting Wang
- School of Basic Medicine and Clinical Pharmacy and State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing, China
| | - Wen-Hui Wang
- School of Basic Medicine and Clinical Pharmacy and State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing, China
| | - Li Guan
- School of Basic Medicine and Clinical Pharmacy and State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing, China
| | - Chang-Run Guo
- School of Basic Medicine and Clinical Pharmacy and State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing, China
| | - Xing-Hua Li
- School of Basic Medicine and Clinical Pharmacy and State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing, China
| | - Yun-Tao Lei
- School of Basic Medicine and Clinical Pharmacy and State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing, China
| | - Ying-Zhe Fan
- Putuo Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Xiao-Na Yang
- School of Basic Medicine and Clinical Pharmacy and State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing, China
| | - Motoyuki Hattori
- State Key Laboratory of Genetic Engineering, Collaborative Innovation Center of Genetics and Development, Shanghai Key Laboratory of Bioactive Small Molecules, Department of Physiology and Neurobiology, School of Life Sciences, Fudan University, Shanghai, China
| | - Osamu Nureki
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
| | - Michael X Zhu
- Department of Integrative Biology and Pharmacology, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, Texas, USA
| | - Ye Yu
- School of Basic Medicine and Clinical Pharmacy and State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing, China.
| | - Yun Tian
- College of Bioscience and Biotechnology, Hunan Agricultural University, Changsha, China.
| | - Jin Wang
- School of Basic Medicine and Clinical Pharmacy and State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing, China.
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Bae J, Mook Kang K, Kim YC. Discovery of 5-methyl-1H-benzo[d]imidazole derivatives as novel P2X3 Receptor antagonists. Bioorg Med Chem Lett 2022; 72:128820. [PMID: 35644300 DOI: 10.1016/j.bmcl.2022.128820] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2022] [Revised: 05/17/2022] [Accepted: 05/22/2022] [Indexed: 11/02/2022]
Abstract
Drug discovery programs targeting P2X3 receptors (P2X3R), an extracellular adenosine 5'-triphosphate (ATP) gated cation channel family, have been actively investigated for several CNS-related diseases. The current unmet need in the field of P2X3R targeted drugs is to avoid a side effect, the loss of taste, that could be reduced by increase of the P2X3R selectivity vs P2X2/3R. In this study, 5-methyl-1H-benzo[d]imidazole derivatives were designed and synthesized from the analysis of key pharmacophores of current antagonists. In the structure-activity relationship study, the most potent compounds 17a-b was discovered as potent P2X3R antagonists with IC50 values of 145 and 206 nM, and selectivity index of 60 and 41, respectively. In addition, 17a-b showed the not-competitive antagonism, but poor binding score in the docking study at the known allosteric binding site of Gefapixant binding site, indicating that another allosteric binding site might be existing for the novel P2X3R antagonists.
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Affiliation(s)
- Jinsu Bae
- Department of Biomedical Science and Engineering, Gwangju Institute of Science and Technology (GIST) 61005, Republic of Korea
| | - Koon Mook Kang
- School of Life Sciences, Gwangju Institute of Science and Technology (GIST) 61005, Republic of Korea
| | - Yong-Chul Kim
- Department of Biomedical Science and Engineering, Gwangju Institute of Science and Technology (GIST) 61005, Republic of Korea; School of Life Sciences, Gwangju Institute of Science and Technology (GIST) 61005, Republic of Korea.
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78
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Sophocleous RA, Ooi L, Sluyter R. The P2X4 Receptor: Cellular and Molecular Characteristics of a Promising Neuroinflammatory Target. Int J Mol Sci 2022; 23:ijms23105739. [PMID: 35628550 PMCID: PMC9147237 DOI: 10.3390/ijms23105739] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Revised: 05/18/2022] [Accepted: 05/18/2022] [Indexed: 02/07/2023] Open
Abstract
The adenosine 5′-triphosphate-gated P2X4 receptor channel is a promising target in neuroinflammatory disorders, but the ability to effectively target these receptors in models of neuroinflammation has presented a constant challenge. As such, the exact role of P2X4 receptors and their cell signalling mechanisms in human physiology and pathophysiology still requires further elucidation. To this end, research into the molecular mechanisms of P2X4 receptor activation, modulation, and inhibition has continued to gain momentum in an attempt to further describe the role of P2X4 receptors in neuroinflammation and other disease settings. Here we provide an overview of the current understanding of the P2X4 receptor, including its expression and function in cells involved in neuroinflammatory signalling. We discuss the pharmacology of P2X4 receptors and provide an overview of P2X4-targeting molecules, including agonists, positive allosteric modulators, and antagonists. Finally, we discuss the use of P2X4 receptor modulators and antagonists in models of neuroinflammatory cell signalling and disease.
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Affiliation(s)
- Reece Andrew Sophocleous
- Illawarra Health and Medical Research Institute, Wollongong, NSW 2522, Australia; (R.A.S.); (L.O.)
- Molecular Horizons and School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, NSW 2522, Australia
| | - Lezanne Ooi
- Illawarra Health and Medical Research Institute, Wollongong, NSW 2522, Australia; (R.A.S.); (L.O.)
- Molecular Horizons and School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, NSW 2522, Australia
| | - Ronald Sluyter
- Illawarra Health and Medical Research Institute, Wollongong, NSW 2522, Australia; (R.A.S.); (L.O.)
- Molecular Horizons and School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, NSW 2522, Australia
- Correspondence: ; Tel.: +612-4221-5508
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79
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Caufriez A, Tabernilla A, Van Campenhout R, Cooreman A, Leroy K, Sanz Serrano J, Kadam P, dos Santos Rodrigues B, Lamouroux A, Ballet S, Vinken M. Effects of Drugs Formerly Suggested for COVID-19 Repurposing on Pannexin1 Channels. Int J Mol Sci 2022; 23:ijms23105664. [PMID: 35628472 PMCID: PMC9146942 DOI: 10.3390/ijms23105664] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2022] [Revised: 05/12/2022] [Accepted: 05/17/2022] [Indexed: 02/01/2023] Open
Abstract
Although many efforts have been made to elucidate the pathogenesis of COVID-19, the underlying mechanisms are yet to be fully uncovered. However, it is known that a dysfunctional immune response and the accompanying uncontrollable inflammation lead to troublesome outcomes in COVID-19 patients. Pannexin1 channels are put forward as interesting drug targets for the treatment of COVID-19 due to their key role in inflammation and their link to other viral infections. In the present study, we selected a panel of drugs previously tested in clinical trials as potential candidates for the treatment of COVID-19 early on in the pandemic, including hydroxychloroquine, chloroquine, azithromycin, dexamethasone, ribavirin, remdesivir, favipiravir, lopinavir, and ritonavir. The effect of the drugs on pannexin1 channels was assessed at a functional level by means of measurement of extracellular ATP release. Immunoblot analysis and real-time quantitative reversetranscription polymerase chain reaction analysis were used to study the potential of the drugs to alter pannexin1 protein and mRNA expression levels, respectively. Favipiravir, hydroxychloroquine, lopinavir, and the combination of lopinavir with ritonavir were found to inhibit pannexin1 channel activity without affecting pannexin1 protein or mRNA levels. Thusthree new inhibitors of pannexin1 channels were identified that, though currently not being used anymore for the treatment of COVID-19 patients, could be potential drug candidates for other pannexin1-related diseases.
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Affiliation(s)
- Anne Caufriez
- Department of Pharmaceutical and Pharmacological Sciences, Vrije Universiteit Brussel, Laarbeeklaan 103, 1090 Brussels, Belgium; (A.C.); (A.T.); (R.V.C.); (A.C.); (K.L.); (J.S.S.); (P.K.); (B.d.S.R.)
- Departments of Chemistry and Bioengineering Sciences, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussels, Belgium; (A.L.); (S.B.)
| | - Andrés Tabernilla
- Department of Pharmaceutical and Pharmacological Sciences, Vrije Universiteit Brussel, Laarbeeklaan 103, 1090 Brussels, Belgium; (A.C.); (A.T.); (R.V.C.); (A.C.); (K.L.); (J.S.S.); (P.K.); (B.d.S.R.)
| | - Raf Van Campenhout
- Department of Pharmaceutical and Pharmacological Sciences, Vrije Universiteit Brussel, Laarbeeklaan 103, 1090 Brussels, Belgium; (A.C.); (A.T.); (R.V.C.); (A.C.); (K.L.); (J.S.S.); (P.K.); (B.d.S.R.)
| | - Axelle Cooreman
- Department of Pharmaceutical and Pharmacological Sciences, Vrije Universiteit Brussel, Laarbeeklaan 103, 1090 Brussels, Belgium; (A.C.); (A.T.); (R.V.C.); (A.C.); (K.L.); (J.S.S.); (P.K.); (B.d.S.R.)
| | - Kaat Leroy
- Department of Pharmaceutical and Pharmacological Sciences, Vrije Universiteit Brussel, Laarbeeklaan 103, 1090 Brussels, Belgium; (A.C.); (A.T.); (R.V.C.); (A.C.); (K.L.); (J.S.S.); (P.K.); (B.d.S.R.)
| | - Julen Sanz Serrano
- Department of Pharmaceutical and Pharmacological Sciences, Vrije Universiteit Brussel, Laarbeeklaan 103, 1090 Brussels, Belgium; (A.C.); (A.T.); (R.V.C.); (A.C.); (K.L.); (J.S.S.); (P.K.); (B.d.S.R.)
| | - Prashant Kadam
- Department of Pharmaceutical and Pharmacological Sciences, Vrije Universiteit Brussel, Laarbeeklaan 103, 1090 Brussels, Belgium; (A.C.); (A.T.); (R.V.C.); (A.C.); (K.L.); (J.S.S.); (P.K.); (B.d.S.R.)
| | - Bruna dos Santos Rodrigues
- Department of Pharmaceutical and Pharmacological Sciences, Vrije Universiteit Brussel, Laarbeeklaan 103, 1090 Brussels, Belgium; (A.C.); (A.T.); (R.V.C.); (A.C.); (K.L.); (J.S.S.); (P.K.); (B.d.S.R.)
| | - Arthur Lamouroux
- Departments of Chemistry and Bioengineering Sciences, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussels, Belgium; (A.L.); (S.B.)
| | - Steven Ballet
- Departments of Chemistry and Bioengineering Sciences, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussels, Belgium; (A.L.); (S.B.)
| | - Mathieu Vinken
- Department of Pharmaceutical and Pharmacological Sciences, Vrije Universiteit Brussel, Laarbeeklaan 103, 1090 Brussels, Belgium; (A.C.); (A.T.); (R.V.C.); (A.C.); (K.L.); (J.S.S.); (P.K.); (B.d.S.R.)
- Correspondence: ; Tel.: +32-2477-4587
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Mahmood A, Iqbal J. Purinergic receptors modulators: An emerging pharmacological tool for disease management. Med Res Rev 2022; 42:1661-1703. [PMID: 35561109 DOI: 10.1002/med.21888] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2021] [Revised: 03/16/2022] [Accepted: 05/04/2022] [Indexed: 11/10/2022]
Abstract
Purinergic signaling is mediated through extracellular nucleotides (adenosine 5'-triphosphate, uridine-5'-triphosphate, adenosine diphosphate, uridine-5'-diphosphate, and adenosine) that serve as signaling molecules. In the early 1990s, purines and pyrimidine receptors were cloned and characterized drawing the attention of scientists toward this aspect of cellular signaling. This signaling pathway is comprised of four subtypes of adenosine receptors (P1), eight subtypes of G-coupled protein receptors (P2YRs), and seven subtypes of ligand-gated ionotropic receptors (P2XRs). In current studies, the pathophysiology and therapeutic potentials of these receptors have been focused on. Various ligands, modulating the functions of purinergic receptors, are in current clinical practices for the treatment of various neurodegenerative disorders and cardiovascular diseases. Moreover, several purinergic receptors ligands are in advanced phases of clinical trials as a remedy for depression, epilepsy, autism, osteoporosis, atherosclerosis, myocardial infarction, diabetes, irritable bowel syndrome, and cancers. In the present study, agonists and antagonists of purinergic receptors have been summarized that may serve as pharmacological tools for drug design and development.
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Affiliation(s)
- Abid Mahmood
- Centre for Advanced Drug Research, COMSATS University Islamabad, Abbottabad, Pakistan
| | - Jamshed Iqbal
- Centre for Advanced Drug Research, COMSATS University Islamabad, Abbottabad, Pakistan
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81
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Immadisetty K, Alenciks J, Kekenes-Huskey PM. Modulation of P2X4 pore closure by magnesium, potassium, and ATP. Biophys J 2022; 121:1134-1142. [PMID: 35248546 PMCID: PMC9034312 DOI: 10.1016/j.bpj.2022.02.038] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2021] [Revised: 10/12/2021] [Accepted: 02/22/2022] [Indexed: 11/30/2022] Open
Abstract
The P2X4 receptor plays a prominent role in cellular responses to extracellular ATP. Through classical all-atom molecular dynamics (MD) simulations totaling 24 μs we have investigated how metal-complexed ATP stabilizes the channel's open state and prevents its closing. We have identified two metal-binding sites, Mg2+ and potassium K+, one at the intersection of the three subunits in the ectodomain (MBS1) and the second one near the ATP-binding site (MBS2), similar to those characterized in Gulf Coast P2X. Our data indicate that when Mg2+ and K+ ions are complexed with ATP, the channel is locked into an open state. Interestingly, irrespective of the number of bound ATP molecules, Mg2+ ions bound to the MBS2 impeded the collapse of the open-state protein to a closed state by stabilizing the ATP-protein interactions. However, when Mg2+ in the MBS2 was replaced with K+ ions, as might be expected when in equilibrium with an extracellular solution, the interactions between the subunits were weakened and the pore collapsed. This collapse was apparent when fewer than two ATPs were bound to MBS2 in the presence of K+. Therefore, the different capacities of common cations to stabilize the channel may underlie a mechanism governing P2X4 channel gating in physiological systems. This study therefore provides structural insights into the differential modulation of ATP activation of P2X4 by Mg2+ and K+.
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82
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Urbina-Treviño L, von Mücke-Heim IA, Deussing JM. P2X7 Receptor-Related Genetic Mouse Models – Tools for Translational Research in Psychiatry. Front Neural Circuits 2022; 16:876304. [PMID: 35422688 PMCID: PMC9001905 DOI: 10.3389/fncir.2022.876304] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Accepted: 03/07/2022] [Indexed: 11/20/2022] Open
Abstract
Depression is a common psychiatric disorder and the leading cause of disability worldwide. Although treatments are available, only about 60% of treated patients experience a significant improvement in disease symptoms. Numerous clinical and rodent studies have identified the purinergic P2X7 receptor (P2X7R) as one of the genetic factors potentially contributing to the disease risk. In this respect, genetically engineered mouse models targeting the P2X7R have become increasingly important in studying designated immunological features and subtypes of depression in vivo. This review provides an overview of the P2X7R -related mouse lines currently available for translational psychiatric research and discusses their strengths, weaknesses, and potentials.
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Affiliation(s)
- Lidia Urbina-Treviño
- Max Planck Institute of Psychiatry, Molecular Neurogenetics, Munich, Germany
- Graduate School of Systemic Neurosciences, Ludwig Maximilian University of Munich, Munich, Germany
| | - Iven-Alex von Mücke-Heim
- Max Planck Institute of Psychiatry, Molecular Neurogenetics, Munich, Germany
- International Max Planck Research School for Translational Psychiatry, Munich, Germany
| | - Jan M. Deussing
- Max Planck Institute of Psychiatry, Molecular Neurogenetics, Munich, Germany
- *Correspondence: Jan M. Deussing,
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83
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Gasparri F, Sarkar D, Bielickaite S, Poulsen MH, Hauser AS, Pless SA. P2X2 receptor subunit interfaces are missense variant hotspots where mutations tend to increase apparent ATP affinity. Br J Pharmacol 2022; 179:3859-3874. [PMID: 35285517 PMCID: PMC9314836 DOI: 10.1111/bph.15830] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2021] [Revised: 01/31/2022] [Accepted: 02/09/2022] [Indexed: 11/30/2022] Open
Abstract
Background and Purpose P2X receptors are trimeric ligand‐gated ion channels that open a cation‐selective pore in response to ATP binding to their large extracellular domain. The seven known P2X subtypes can assemble as homotrimeric or heterotrimeric complexes and contribute to numerous physiological functions, including nociception, inflammation and hearing. The overall structure of P2X receptors is well established, but little is known about the range and prevalence of human genetic variations and the functional implications of specific domains. Experimental Approach Here, we examine the impact of P2X2 receptor inter‐subunit interface missense variants identified in the human population or by structural predictions. We test both single and double mutants through electrophysiological and biochemical approaches. Key Results We demonstrate that predicted extracellular domain inter‐subunit interfaces display a higher‐than‐expected density of missense variations and that the majority of mutations that disrupt putative inter‐subunit interactions result in channels with higher apparent ATP affinity. Lastly, we show that double mutants at the subunit interface show significant energetic coupling, especially if located in close proximity. Conclusion and Implications We provide the first structural mapping of the mutational distribution across the human population in a ligand‐gated ion channel and show that the density of missense mutations is constrained between protein domains, indicating evolutionary selection at the domain level. Our data may indicate that, unlike other ligand‐gated ion channels, P2X2 receptors have evolved an intrinsically high threshold for activation, possibly to allow for additional modulation or as a cellular protection mechanism against overstimulation.
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Affiliation(s)
- Federica Gasparri
- Department of Drug Design and Pharmacology, University of Copenhagen, Copenhagen, Denmark
| | - Debayan Sarkar
- Department of Drug Design and Pharmacology, University of Copenhagen, Copenhagen, Denmark
| | - Sarune Bielickaite
- Department of Drug Design and Pharmacology, University of Copenhagen, Copenhagen, Denmark
| | - Mette Homann Poulsen
- Department of Drug Design and Pharmacology, University of Copenhagen, Copenhagen, Denmark
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84
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Cui WW, Wang SY, Zhang YQ, Wang Y, Fan YZ, Guo CR, Li XH, Lei YT, Wang WH, Yang XN, Hattori M, Li CZ, Wang J, Yu Y. P2X3-selective mechanism of Gefapixant, a drug candidate for the treatment of refractory chronic cough. Comput Struct Biotechnol J 2022; 20:1642-1653. [PMID: 35465163 PMCID: PMC9014320 DOI: 10.1016/j.csbj.2022.03.030] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2021] [Revised: 03/16/2022] [Accepted: 03/27/2022] [Indexed: 11/25/2022] Open
Abstract
The mechanism by which Gefapixant/AF-219 selectively acts on the P2X3 receptor is unclear. The negative allosteric site of AF-219 at P2X3 is also a potent allosteric site for other P2X subtypes. The selectivity of AF-219 for P2X3 is determined by the accessibility of binding site and the internal shape of this pocket. The finding will provide new perspectives for drug design against P2X3-mediated diseases such as RCC.
Gefapixant/AF-219, a selective inhibitor of the P2X3 receptor, is the first new drug other than dextromethorphan to be approved for the treatment of refractory chronic cough (RCC) in nearly 60 years. To date, seven P2X subtypes (P2X1-7) activated by extracellular ATP have been cloned, and subtype selectivity of P2X inhibitors is a prerequisite for reducing side effects. We previously identified the site and mechanism of action of Gefapixant/AF-219 on the P2X3 receptor, which occupies a pocket consisting of the left flipper (LF) and lower body (LB) domains. However, the mechanism by which AF-219 selectively acts on the P2X3 receptor is unknown. Here, we combined mutagenesis, chimera construction, molecular simulations, covalent occupation and chemical synthesis, and find that the negative allosteric site of AF-219 at P2X3 is also present in other P2X subtypes, at least for P2X1, P2X2 and P2X4. By constructing each chimera of AF-219 sensitive P2X3 and insensitive P2X2 subtypes, the insensitive P2X2 subtype was made to acquire the inhibitory properties of AF-219 and AF-353, an analog of AF-219 with higher affinity. Our results suggest that the selectivity of AF-219/AF-353 for P2X3 over the other P2X subtypes is determined by a combination of the accessibility of P2X3 binding site and the internal shape of this pocket, a finding that could provide new perspectives for drug design against P2X3-mediated diseases such as RCC, idiopathic pulmonary fibrosis, hypertension and overactive bladder disorder.
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85
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Sattler C, Benndorf K. Enlightening activation gating in P2X receptors. Purinergic Signal 2022; 18:177-191. [PMID: 35188598 PMCID: PMC9123132 DOI: 10.1007/s11302-022-09850-w] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Accepted: 02/04/2022] [Indexed: 12/20/2022] Open
Abstract
P2X receptors are trimeric nonselective cation channels gated by ATP. They assemble from seven distinct subunit isoforms as either homo- or heteromeric complexes and contain three extracellularly located binding sites for ATP. P2X receptors are expressed in nearly all tissues and are there involved in physiological processes like synaptic transmission, pain, and inflammation. Thus, they are a challenging pharmacological target. The determination of crystal and cryo-EM structures of several isoforms in the last decade in closed, open, and desensitized states has provided a firm basis for interpreting the huge amount of functional and biochemical data. Electrophysiological characterization in conjugation with optical approaches has generated significant insights into structure–function relationships of P2X receptors. This review focuses on novel optical and related approaches to better understand the conformational changes underlying the activation of these receptors.
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Affiliation(s)
- Christian Sattler
- Institut Für Physiologie II, Universitätsklinikum Jena, Friedrich-Schiller-Universität Jena, 07740, Jena, Germany.
| | - Klaus Benndorf
- Institut Für Physiologie II, Universitätsklinikum Jena, Friedrich-Schiller-Universität Jena, 07740, Jena, Germany.
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86
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Synthesis and Structure-Activity Relationship Studies of Benzimidazole-4,7-dione-Based P2X3 Receptor Antagonists as Novel Anti-Nociceptive Agents. MOLECULES (BASEL, SWITZERLAND) 2022; 27:molecules27041337. [PMID: 35209126 PMCID: PMC8877008 DOI: 10.3390/molecules27041337] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Revised: 02/11/2022] [Accepted: 02/14/2022] [Indexed: 11/24/2022]
Abstract
P2X3 receptors (P2X3R) are ATP-gated ion channels predominantly expressed in C- and Aδ-fiber primary afferent neurons and have been introduced as a novel therapeutic target for neurological disorders, including neuropathic pain and chronic cough. Because of its localized distribution, antagonism of P2X3R has been thoroughly considered, and the avoidance of issues related to CNS side effects has been proven in clinical trials. In this article, benzimidazole-4,7-dione-based derivatives were introduced as a new chemical entity for the development of P2X3R antagonists. Starting from the discovery of a hit compound from the screening of 8364 random library compounds in the Korea Chemical Bank, which had an IC50 value of 1030 nM, studies of structure–activity and structure–property relationships enabled further optimization toward improving the antagonistic activities as well as the drug’s physicochemical properties, including metabolic stability. As for the results, the final optimized compound 14h was developed with an IC50 value of 375 nM at P2X3R with more than 23-fold selectivity versus P2X2/3R, along with properties of metabolic stability and improved solubility. In neuropathic pain animal models evoked by either nerve ligation or chemotherapeutics in male Sprague-Dawley rats, compound 14h showed anti-nociceptive effects through an increase in the mechanical withdrawal threshold as measured by von Frey filament following intravenous administration.
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87
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Torrenegra-Rico JD, Arango-Restrepo A, Rubí JM. Enhancing particle transport in deformable micro-channels. J Chem Phys 2022; 156:054118. [DOI: 10.1063/5.0080125] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- J. D. Torrenegra-Rico
- Departament de Física de la Matèria Condensada, Facultat de Física, Universitat de Barcelona, Avinguda Diagonal 647, 08028 Barcelona, Spain
| | - A. Arango-Restrepo
- Departament de Física de la Matèria Condensada, Facultat de Física, Universitat de Barcelona, Avinguda Diagonal 647, 08028 Barcelona, Spain
| | - J. M. Rubí
- Departament de Física de la Matèria Condensada, Facultat de Física, Universitat de Barcelona, Avinguda Diagonal 647, 08028 Barcelona, Spain
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88
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Sheng D, Hattori M. Recent progress in the structural biology of P2X receptors. Proteins 2022; 90:1779-1785. [PMID: 35023590 DOI: 10.1002/prot.26302] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Revised: 01/04/2022] [Accepted: 01/11/2022] [Indexed: 12/27/2022]
Abstract
P2X receptors are ATP-gated trimeric nonselective cation channels that are important for various physiological and pathological processes, including synaptic transmission, pain perception, immune regulation, and apoptosis. Accordingly, they attract a wide range of interest as drug targets, such as those for chronic cough, neuropathic pain, and depression. After the zebrafish P2X4 receptor structure was reported in 2009, various other P2X receptor structures have been reported, extending our understanding of the molecular mechanisms of P2X receptors. This review article describes the recent progress on understanding the structures and mechanisms of P2X receptors, especially of the mechanisms underlying ATP binding and conformational changes during the gating cycle. In addition, since several antagonists for different P2X subtypes have entered into clinical trials, this review also summarizes the binding sites and regulatory mechanisms of these antagonists, which may contribute to new strategies of targeting P2X receptors for drug discovery.
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Affiliation(s)
- Danqi Sheng
- State Key Laboratory of Genetic Engineering, Collaborative Innovation Center of Genetics and Development, Shanghai Key Laboratory of Bioactive Small Molecules, Department of Physiology and Neurobiology, School of Life Sciences, Fudan University, Shanghai, China
| | - Motoyuki Hattori
- State Key Laboratory of Genetic Engineering, Collaborative Innovation Center of Genetics and Development, Shanghai Key Laboratory of Bioactive Small Molecules, Department of Physiology and Neurobiology, School of Life Sciences, Fudan University, Shanghai, China
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89
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An Q, Yue G, Yang X, Lou J, Shan W, Ding J, Jin Z, Hu Y, Du Q, Liao Q, Xie R, Xu J. Pathophysiological Role of Purinergic P2X Receptors in Digestive System Diseases. Front Physiol 2022; 12:781069. [PMID: 35002763 PMCID: PMC8740087 DOI: 10.3389/fphys.2021.781069] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Accepted: 12/01/2021] [Indexed: 11/16/2022] Open
Abstract
P2X receptors (P2XRs) are trimeric, non-selective cation channels activated by extracellular ATP and widely distributed in the digestive system. P2XRs have an important role in the physiological function of the digestive system, such as neurotransmission, ion transports, proliferation and apoptosis, muscle contraction, and relaxation. P2XRs can be involved in pain mechanisms both centrally and in the periphery and confirmed the association of P2XRs with visceral pain. In the periphery, ATP can be released as a result of tissue injury, visceral distension, or sympathetic activation and can excite nociceptive primary afferents by acting at homomeric P2X(3)R or heteromeric P2X(2/3)R. Thus, peripheral P2XRs, and homomeric P2X(3) and/or heteromeric P2X(2/3)R in particular, constitute attractive targets for analgesic drugs. Recently studies have shown that P2XRs have made significant advances in inflammation and cancer. P2X7R mediates NLRP3 inflammasome activation, cytokine and chemokine release, T lymphocyte survival and differentiation, transcription factor activation, and cell death. The P2X7R is a potent stimulant of inflammation and immunity and a promoter of cancer cell growth. This makes P2X7R an appealing target for anti-inflammatory and anti-cancer therapy. It is believed that with the further study of P2XRs and its subtypes, P2XRs and its specific antagonists will be expected to be widely used in the treatment of human digestive diseases in the future.
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Affiliation(s)
- Qimin An
- Department of Gastroenterology, Affiliated Hospital of Zunyi Medical University, Zunyi, China.,The Collaborative Innovation Center of Tissue Damage Repair and Regeneration Medicine of Zunyi Medical University, Zunyi, China
| | - Gengyu Yue
- Department of Gastroenterology, Affiliated Hospital of Zunyi Medical University, Zunyi, China.,The Collaborative Innovation Center of Tissue Damage Repair and Regeneration Medicine of Zunyi Medical University, Zunyi, China
| | - Xiaoxu Yang
- Department of Gastroenterology, Affiliated Hospital of Zunyi Medical University, Zunyi, China.,The Collaborative Innovation Center of Tissue Damage Repair and Regeneration Medicine of Zunyi Medical University, Zunyi, China
| | - Jun Lou
- Department of Gastroenterology, Affiliated Hospital of Zunyi Medical University, Zunyi, China.,The Collaborative Innovation Center of Tissue Damage Repair and Regeneration Medicine of Zunyi Medical University, Zunyi, China
| | - Weixi Shan
- Department of Gastroenterology, Affiliated Hospital of Zunyi Medical University, Zunyi, China.,The Collaborative Innovation Center of Tissue Damage Repair and Regeneration Medicine of Zunyi Medical University, Zunyi, China
| | - Jianhong Ding
- Department of Gastroenterology, Affiliated Hospital of Zunyi Medical University, Zunyi, China.,The Collaborative Innovation Center of Tissue Damage Repair and Regeneration Medicine of Zunyi Medical University, Zunyi, China
| | - Zhe Jin
- Department of Gastroenterology, Affiliated Hospital of Zunyi Medical University, Zunyi, China.,The Collaborative Innovation Center of Tissue Damage Repair and Regeneration Medicine of Zunyi Medical University, Zunyi, China
| | - Yanxia Hu
- Department of Gastroenterology, Affiliated Hospital of Zunyi Medical University, Zunyi, China.,The Collaborative Innovation Center of Tissue Damage Repair and Regeneration Medicine of Zunyi Medical University, Zunyi, China
| | - Qian Du
- Department of Gastroenterology, Affiliated Hospital of Zunyi Medical University, Zunyi, China.,The Collaborative Innovation Center of Tissue Damage Repair and Regeneration Medicine of Zunyi Medical University, Zunyi, China
| | - Qiushi Liao
- Department of Gastroenterology, Affiliated Hospital of Zunyi Medical University, Zunyi, China.,The Collaborative Innovation Center of Tissue Damage Repair and Regeneration Medicine of Zunyi Medical University, Zunyi, China
| | - Rui Xie
- Department of Gastroenterology, Affiliated Hospital of Zunyi Medical University, Zunyi, China.,The Collaborative Innovation Center of Tissue Damage Repair and Regeneration Medicine of Zunyi Medical University, Zunyi, China
| | - Jingyu Xu
- Department of Gastroenterology, Affiliated Hospital of Zunyi Medical University, Zunyi, China.,The Collaborative Innovation Center of Tissue Damage Repair and Regeneration Medicine of Zunyi Medical University, Zunyi, China
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90
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Shinozaki C, Kohno K, Shiroishi M, Takahashi D, Yoshikawa Y, Abe Y, Hamase K, Nakakido M, Tsumoto K, Inoue K, Tsuda M, Ueda T. Improvement of the affinity of an anti-rat P2X4 receptor antibody by introducing electrostatic interactions. Sci Rep 2022; 12:131. [PMID: 34996944 PMCID: PMC8742113 DOI: 10.1038/s41598-021-03784-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2021] [Accepted: 12/09/2021] [Indexed: 11/30/2022] Open
Abstract
We have recently developed a mouse monoclonal antibody (12-10H) binding to the head domain region in rat P2X4 receptor (rP2X4R, which is crucial for the pathogenesis of neuropathic pain) expressed on the cell with the highest binding affinity (KD = 20 nM). However, the 12-10H antibody failed to detect endogenously expressed P2X4Rs in microglia isolated from the spinal cord of rats whose spinal nerves were injured. Then, we prepared R5 mutant, in which five arginine residues were introduced into variable regions except for the "hot spot" in the 12-10H antibody to increase electrostatic interactions with the head domain, an anionic region, in rP2X4R. The mutation resulted in an increase of 50-fold in the affinity of the R5 mutant for the head domain with respect to the intact 12-10H antibody. As a result, detection of P2X4Rs endogenously expressed on primary cultured microglial cells originated from the neonatal rat brain and spinal cord microglia isolated from a rat model of neuropathic pain was achieved. These findings suggest a strategy to improve the affinity of a monoclonal antibody for an anionic antigen by the introduction of several arginine residues into variable regions other than the "hot spot" in the paratope.
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Grants
- JP26293129 Japan Society for the Promotion of Science
- JP26293129 Japan Society for the Promotion of Science
- JP26293129 Japan Society for the Promotion of Science
- JP16H02420, JP19H05766, and JP20H02531 Japan Society for the Promotion of Science
- JP16H02420, JP19H05766, and JP20H02531 Japan Society for the Promotion of Science
- JP26293129 Japan Society for the Promotion of Science
- JP21am0101091 Japan Agency for Medical Research and Development
- JP21am0101091 Japan Agency for Medical Research and Development
- JP21am0101091 Japan Agency for Medical Research and Development
- JP18am0101094j, JP18dm0107064h, JP18mk0101081h, JP18fm0208030h, JP18fk0108073h, and JP18ak0101100h Japan Agency for Medical Research and Development
- JP18am0101094j, JP18dm0107064h, JP18mk0101081h, JP18fm0208030h, JP18fk0108073h, and JP18ak0101100h Japan Agency for Medical Research and Development
- JP21am0101091 Japan Agency for Medical Research and Development
- JP21am0101091 Japan Agency for Medical Research and Development
- JPMJCR20H8 the JST CREST
- JPMJCR20H8 the JST CREST
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Affiliation(s)
- Chinatsu Shinozaki
- Department of Protein Structure, Function and Design, Graduate School of Pharmaceutical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan
| | - Keita Kohno
- 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
| | - Mitsunori Shiroishi
- Department of Protein Structure, Function and Design, Graduate School of Pharmaceutical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan
- Department of Biological Science and Technology, Tokyo University of Science, 6-3-1 Niijuku Katsushika-ku, Tokyo, 125-8585, Japan
| | - Daisuke Takahashi
- Department of Protein Structure, Function and Design, Graduate School of Pharmaceutical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan
| | - Yu Yoshikawa
- 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
| | - Yoshito Abe
- Department of Protein Structure, Function and Design, Graduate School of Pharmaceutical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan
| | - Kenji Hamase
- Department of Drug Discovery and Evolution, Graduate School of Pharmaceutical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan
| | - Makoto Nakakido
- Department of Bioengineering, School of Engineering, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo, 113-8656, Japan
| | - Kohei Tsumoto
- Department of Bioengineering, School of Engineering, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo, 113-8656, Japan
- Institute of Medical Science, The University of Tokyo, 4-6-1, Shirokanedai, Minato-ku, Tokyo, 108-8639, Japan
| | - Kazuhide Inoue
- 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.
| | - 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.
| | - Tadashi Ueda
- Department of Protein Structure, Function and Design, Graduate School of Pharmaceutical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan.
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Abstract
The P2X7 receptor has been proposed as a novel drug target for different types of diseases associated with inflammation, including brain diseases, peripheral inflammation, and cancers. Structurally diverse P2X7 receptor antagonists, mainly negative allosteric modulators (NAMs), have been developed in recent years, and several P2X7 receptor antagonists are currently evaluated in clinical trials. The P2X7 receptor requires high micro- to even millimolar ATP concentrations to be activated. Selective agonists for the P2X7 receptor are not available. Positive allosteric modulators (PAMs) have been described, but PAMs with high potency and selectivity are still lacking. This chapter discusses medicinal chemistry approaches toward the development of P2X7 receptor modulators and presents a selection of recommended tool compounds for studying P2X7 receptors in humans and rodents.
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Affiliation(s)
- Christa E Müller
- Pharmaceutical & Medicinal Chemistry, PharmaCenter Bonn, Pharmaceutical Institute, University of Bonn, Bonn, Germany.
| | - Vigneshwaran Namasivayam
- Pharmaceutical & Medicinal Chemistry, PharmaCenter Bonn, Pharmaceutical Institute, University of Bonn, Bonn, Germany
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92
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Mansoor SE. How Structural Biology Has Directly Impacted Our Understanding of P2X Receptor Function and Gating. Methods Mol Biol 2022; 2510:1-29. [PMID: 35776317 DOI: 10.1007/978-1-0716-2384-8_1] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
P2X receptors are ATP-gated ion channels expressed in a wide variety of eukaryotic cells. They play key roles in diverse processes such as platelet activation, smooth muscle contraction, synaptic transmission, nociception, cell proliferation, and inflammation making this receptor family an important pharmacological target. Structures of P2X receptors solved by X-ray crystallography have been instrumental in helping to define mechanisms of molecular P2X receptor function. In 2009, the first X-ray structure of the P2X4 receptor subtype confirmed a trimeric stoichiometry and revealed the overall architecture of the functional ion channel. Subsequent X-ray structures have provided the molecular details to define the orthosteric ATP binding pocket, the orthosteric antagonist binding pocket, an allosteric antagonist binding pocket, and the pore architecture in each of the major conformational states of the receptor gating cycle. Moreover, the unique gating mechanism by which P2X receptor subtypes desensitize at differing rates, referred to as the helical recoil model of receptor desensitization, was discovered directly from X-ray structures of the P2X3 receptor. However, structures of P2X receptors solved by X-ray crystallography have only been able to provide limited information on the cytoplasmic domain of this receptor family, as this domain was always truncated to varying degrees in order to facilitate crystallization. Because the P2X7 receptor subtype has a significantly larger cytoplasmic domain that has been shown to be necessary for its ability to initiate apoptosis, an absence of structural information on the P2X7 receptor cytoplasmic domain has limited our understanding of its complex signaling pathways as well as its unusual ability to remain open without undergoing desensitization. This absence of cytoplasmic structural information for P2X7 receptors was recently overcome when the first full-length P2X7 receptor structures were solved by single-particle cryogenic electron microscopy. These structures finally provide insight into the large and unique P2X7 receptor cytoplasmic domain and revealed two novel structural elements and several surprising findings: first, a cytoplasmic structural element called the cytoplasmic ballast was identified that contains a dinuclear zinc ion complex and a high affinity guanosine nucleotide binding site and second, a palmitoylated membrane proximal structural element called the C-cys anchor was identified which prevents P2X7 receptor desensitization. This chapter will highlight the major structural and functional aspects of P2X receptors discovered through structural biology, with a key emphasis on the most recent cryogenic electron microscopy structures of the full-length, wild-type P2X7 receptor.
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Affiliation(s)
- Steven E Mansoor
- Department of Chemical Physiology and Biochemistry, Oregon Health & Science University, Portland, OR, USA.
- Knight Cardiovascular Institute, Oregon Health & Science University, Portland, OR, USA.
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93
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Schmalzing G, Markwardt F. Established Protocols for cRNA Expression and Voltage-Clamp Characterization of the P2X7 Receptor in Xenopus laevis Oocytes. Methods Mol Biol 2022; 2510:157-192. [PMID: 35776325 DOI: 10.1007/978-1-0716-2384-8_9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
P2X7 receptors (P2X7Rs) are fast ATP4--gated ion channels that, like other members of the P2X receptor family, function as homotrimers. A high-resolution cryo-EM structure of the full-length rat P2X7R is available. Using voltage-clamp experiments in Xenopus laevis oocytes, even the earliest steps of P2X7R activation can be quantitatively recorded in the millisecond range. Site-directed mutagenesis combined with voltage-clamp recordings can reveal residues and domains of the P2X7R involved in ATP4- binding, gating (i.e., opening and closing of the channel pore) and ion selectivity. We present here proven voltage-clamp protocols that take into account requirements that are important at the levels of cDNA and vector sequences, cRNA synthesis, and Xenopus laevis oocyte isolation for reliable results.
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Affiliation(s)
- Günther Schmalzing
- Institute of Clinical Pharmacology, RWTH Aachen University, Aachen, Germany
| | - Fritz Markwardt
- Julius-Bernstein-Institute for Physiology, Martin-Luther-University, Halle, Germany.
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94
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The P2X4 purinergic receptor has emerged as a potent regulator of hematopoietic stem/progenitor cell mobilization and homing-a novel view of P2X4 and P2X7 receptor interaction in orchestrating stem cell trafficking. Leukemia 2022; 36:248-256. [PMID: 34285343 DOI: 10.1038/s41375-021-01352-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Revised: 07/07/2021] [Accepted: 07/12/2021] [Indexed: 02/07/2023]
Abstract
Recent evidence indicates that extracellular adenosine triphosphate (eATP), as a major mediator of purinergic signaling, plays an important role in regulating the mobilization and homing of hematopoietic stem progenitor cells (HSPCs). In our previous work we demonstrated that eATP activates the P2X7 ion channel receptor in HSPCs and that its deficiency impairs stem cell trafficking. To learn more about the role of the P2X purinergic receptor family in hematopoiesis, we phenotyped murine and human HSPCs with respect to the seven P2X receptors and observed that, these cells also highly express P2X4 receptors, which shows ~50% sequence similarity to P2X7 subtypes, but that P2X4 cells are more sensitive to eATP and signal much more rapidly. Using the selective P2X4 receptor antagonist PSB12054 as well as P2X4-KO mice, we found that the P2X4 receptor, similar to P2X7 receptor, promotes trafficking of HSPCs in that its deficiency leads to impaired chemotaxis of HSPCs in response to a stromal-derived factor 1 (SDF-1) gradient, less effective pharmacological mobilization, and defective homing and engraftment of HSPCs after transplantation into myeloablated hosts. This correlated with a decrease in SDF-1 expression in the BM microenvironment. Overall, our results confirm the proposed cooperative dependence of both receptors in response to eATP signaling. In G-CSF-induced mobilization, a lack of one receptor is not compensated by the presence of the other one, which supports their mutual dependence in regulating HSPC trafficking.
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95
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Ren W, Rubini P, Tang Y, Engel T, Illes P. Inherent P2X7 Receptors Regulate Macrophage Functions during Inflammatory Diseases. Int J Mol Sci 2021; 23:ijms23010232. [PMID: 35008658 PMCID: PMC8745241 DOI: 10.3390/ijms23010232] [Citation(s) in RCA: 46] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2021] [Revised: 12/21/2021] [Accepted: 12/21/2021] [Indexed: 12/12/2022] Open
Abstract
Macrophages are mononuclear phagocytes which derive either from blood-borne monocytes or reside as resident macrophages in peripheral (Kupffer cells of the liver, marginal zone macrophages of the spleen, alveolar macrophages of the lung) and central tissue (microglia). They occur as M1 (pro-inflammatory; classic) or M2 (anti-inflammatory; alternatively activated) phenotypes. Macrophages possess P2X7 receptors (Rs) which respond to high concentrations of extracellular ATP under pathological conditions by allowing the non-selective fluxes of cations (Na+, Ca2+, K+). Activation of P2X7Rs by still higher concentrations of ATP, especially after repetitive agonist application, leads to the opening of membrane pores permeable to ~900 Da molecules. For this effect an interaction of the P2X7R with a range of other membrane channels (e.g., P2X4R, transient receptor potential A1 [TRPA1], pannexin-1 hemichannel, ANO6 chloride channel) is required. Macrophage-localized P2X7Rs have to be co-activated with the lipopolysaccharide-sensitive toll-like receptor 4 (TLR4) in order to induce the formation of the inflammasome 3 (NLRP3), which then activates the pro-interleukin-1β (pro-IL-1β)-degrading caspase-1 to lead to IL-1β release. Moreover, inflammatory diseases (e.g., rheumatoid arthritis, Crohn’s disease, sepsis, etc.) are generated downstream of the P2X7R-induced upregulation of intracellular second messengers (e.g., phospholipase A2, p38 mitogen-activated kinase, and rho G proteins). In conclusion, P2X7Rs at macrophages appear to be important targets to preserve immune homeostasis with possible therapeutic consequences.
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Affiliation(s)
- Wenjing Ren
- International Collaborative Centre on Big Science Plan for Purinergic Signalling, Chengdu University of TCM, Chengdu 610075, China; (W.R.); (P.R.); (Y.T.)
- School of Acupunct3ure and Tuina, Chengdu University of TCM, Chengdu 610075, China
| | - Patrizia Rubini
- International Collaborative Centre on Big Science Plan for Purinergic Signalling, Chengdu University of TCM, Chengdu 610075, China; (W.R.); (P.R.); (Y.T.)
- School of Acupunct3ure and Tuina, Chengdu University of TCM, Chengdu 610075, China
| | - Yong Tang
- International Collaborative Centre on Big Science Plan for Purinergic Signalling, Chengdu University of TCM, Chengdu 610075, China; (W.R.); (P.R.); (Y.T.)
- School of Acupunct3ure and Tuina, Chengdu University of TCM, Chengdu 610075, China
| | - Tobias Engel
- Department of Physiology and Medical Physics, Royal College of Surgeons in Ireland, University of Medicine and Health Sciences, D02 YN77 Dublin, Ireland;
- FutureNeuro, SFI Research Centre for Chronic and Rare Neurological Diseases, RCSI University of Medicine and Health Sciences, D02 YN77 Dublin, Ireland
| | - Peter Illes
- International Collaborative Centre on Big Science Plan for Purinergic Signalling, Chengdu University of TCM, Chengdu 610075, China; (W.R.); (P.R.); (Y.T.)
- School of Acupunct3ure and Tuina, Chengdu University of TCM, Chengdu 610075, China
- Rudolf Boehm Institute for Pharmacology and Toxicology, University of Leipzig, 04107 Leipzig, Germany
- Correspondence:
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96
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Racigh V, Pierdominici-Sottile G, Palma J. Ion Selectivity in P2X Receptors: A Comparison between hP2X3 and zfP2X4. J Phys Chem B 2021; 125:13385-13393. [PMID: 34851131 DOI: 10.1021/acs.jpcb.1c07308] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Charge discrimination in P2X receptors occurs in two stages. The first stage takes place in the extracellular vestibule. The second one happens as the ions travel across the pore. The search of the amino acids required to achieve these goals has focused on negatively charged residues conserved among the family members. This strategy, however, has afforded baffling results since residues that strongly influence ion selectivity in a given member are not present in others. This finding suggests that alternative family members could achieve the same goal using different molecular approaches. We have compared the mechanisms of charge discrimination in the extracellular vestibule of zebrafish P2X4 (zfP2X4) and human P2X3 (hP2X3), employing molecular dynamics simulations. In particular, we have analyzed how the mutation of residues D59 and D61 of zfP2X4 and residues E46, D53, and E57 of hP2X3 influence ion behavior. The results indicate that both D59 and D61 are required to confer the extracellular vestibule of zfP2X4 a preference for cations. In contrast, the presence of D53 suffices to provide that capacity to hP2X3. We also computed the potentials of mean force for the passage of Na+ and Cl- through the pore of hP2X3. These profiles were compared against those already available for zfP2X4. Altogether, the results provide a detailed description of the mechanisms employed by these receptors to discriminate between cations and anions.
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Affiliation(s)
- Vanesa Racigh
- Departamento de Ciencia y Tecnología, Universidad Nacional de Quilmes, Sáenz Peña 352, Bernal B1876BXD, Argentina.,Consejo Nacional de Investigaciones Científicas y Técnicas, Godoy Cruz 2290, C1425FQB CABA, Argentina
| | - Gustavo Pierdominici-Sottile
- Departamento de Ciencia y Tecnología, Universidad Nacional de Quilmes, Sáenz Peña 352, Bernal B1876BXD, Argentina.,Consejo Nacional de Investigaciones Científicas y Técnicas, Godoy Cruz 2290, C1425FQB CABA, Argentina
| | - Juliana Palma
- Departamento de Ciencia y Tecnología, Universidad Nacional de Quilmes, Sáenz Peña 352, Bernal B1876BXD, Argentina.,Consejo Nacional de Investigaciones Científicas y Técnicas, Godoy Cruz 2290, C1425FQB CABA, Argentina
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97
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Nin-Hill A, Mueller NPF, Molteni C, Rovira C, Alfonso-Prieto M. Photopharmacology of Ion Channels through the Light of the Computational Microscope. Int J Mol Sci 2021; 22:12072. [PMID: 34769504 PMCID: PMC8584574 DOI: 10.3390/ijms222112072] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2021] [Revised: 10/31/2021] [Accepted: 11/02/2021] [Indexed: 12/13/2022] Open
Abstract
The optical control and investigation of neuronal activity can be achieved and carried out with photoswitchable ligands. Such compounds are designed in a modular fashion, combining a known ligand of the target protein and a photochromic group, as well as an additional electrophilic group for tethered ligands. Such a design strategy can be optimized by including structural data. In addition to experimental structures, computational methods (such as homology modeling, molecular docking, molecular dynamics and enhanced sampling techniques) can provide structural insights to guide photoswitch design and to understand the observed light-regulated effects. This review discusses the application of such structure-based computational methods to photoswitchable ligands targeting voltage- and ligand-gated ion channels. Structural mapping may help identify residues near the ligand binding pocket amenable for mutagenesis and covalent attachment. Modeling of the target protein in a complex with the photoswitchable ligand can shed light on the different activities of the two photoswitch isomers and the effect of site-directed mutations on photoswitch binding, as well as ion channel subtype selectivity. The examples presented here show how the integration of computational modeling with experimental data can greatly facilitate photoswitchable ligand design and optimization. Recent advances in structural biology, both experimental and computational, are expected to further strengthen this rational photopharmacology approach.
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Affiliation(s)
- Alba Nin-Hill
- Departament de Química Inorgànica i Orgànica (Secció de Química Orgànica) and Institut de Química Teòrica i Computacional (IQTCUB), Universitat de Barcelona, 08028 Barcelona, Spain; (A.N.-H.); (C.R.)
| | - Nicolas Pierre Friedrich Mueller
- Institute for Advanced Simulations IAS-5 and Institute of Neuroscience and Medicine INM-9, Computational Biomedicine, Forschungszentrum Jülich, 52425 Jülich, Germany;
- Faculty of Mathematics and Natural Sciences, Heinrich-Heine-University Düsseldorf, Universitätsstr. 1, 40225 Düsseldorf, Germany
| | - Carla Molteni
- Physics Department, King’s College London, London WC2R 2LS, UK;
| | - Carme Rovira
- Departament de Química Inorgànica i Orgànica (Secció de Química Orgànica) and Institut de Química Teòrica i Computacional (IQTCUB), Universitat de Barcelona, 08028 Barcelona, Spain; (A.N.-H.); (C.R.)
- Institució Catalana de Recerca i Estudis Avançats (ICREA), 08020 Barcelona, Spain
| | - Mercedes Alfonso-Prieto
- Institute for Advanced Simulations IAS-5 and Institute of Neuroscience and Medicine INM-9, Computational Biomedicine, Forschungszentrum Jülich, 52425 Jülich, Germany;
- Cécile and Oskar Vogt Institute for Brain Research, University Hospital Düsseldorf, Medical Faculty, Heinrich Heine University Düsseldorf, 40225 Düsseldorf, Germany
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98
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Prowse N, Hayley S. Microglia and BDNF at the crossroads of stressor related disorders: Towards a unique trophic phenotype. Neurosci Biobehav Rev 2021; 131:135-163. [PMID: 34537262 DOI: 10.1016/j.neubiorev.2021.09.018] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Revised: 09/08/2021] [Accepted: 09/08/2021] [Indexed: 12/16/2022]
Abstract
Stressors ranging from psychogenic/social to neurogenic/injury to systemic/microbial can impact microglial inflammatory processes, but less is known regarding their effects on trophic properties of microglia. Recent studies do suggest that microglia can modulate neuronal plasticity, possibly through brain derived neurotrophic factor (BDNF). This is particularly important given the link between BDNF and neuropsychiatric and neurodegenerative pathology. We posit that certain activated states of microglia play a role in maintaining the delicate balance of BDNF release onto neuronal synapses. This focused review will address how different "activators" influence the expression and release of microglial BDNF and address the question of tropomyosin receptor kinase B (TrkB) expression on microglia. We will then assess sex-based differences in microglial function and BDNF expression, and how microglia are involved in the stress response and related disorders such as depression. Drawing on research from a variety of other disorders, we will highlight challenges and opportunities for modulators that can shift microglia to a "trophic" phenotype with a view to potential therapeutics relevant for stressor-related disorders.
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Affiliation(s)
- Natalie Prowse
- Department of Neuroscience, Carleton University, Ottawa, ON K1S 5B6, Canada.
| | - Shawn Hayley
- Department of Neuroscience, Carleton University, Ottawa, ON K1S 5B6, Canada.
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Müller CE, Namasivayam V. Recommended tool compounds and drugs for blocking P2X and P2Y receptors. Purinergic Signal 2021; 17:633-648. [PMID: 34476721 PMCID: PMC8677864 DOI: 10.1007/s11302-021-09813-7] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Accepted: 07/15/2021] [Indexed: 12/21/2022] Open
Abstract
This review article presents a collection of tool compounds that selectively block and are recommended for studying P2Y and P2X receptor subtypes, investigating their roles in physiology and validating them as future drug targets. Moreover, drug candidates and approved drugs for P2 receptors will be discussed.
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Affiliation(s)
- Christa E Müller
- PharmaCenter Bonn, Pharmaceutical Institute, Pharmaceutical & Medicinal Chemistry, University of Bonn, An der Immenburg 4, 53121, Bonn, Germany.
| | - Vigneshwaran Namasivayam
- PharmaCenter Bonn, Pharmaceutical Institute, Pharmaceutical & Medicinal Chemistry, University of Bonn, An der Immenburg 4, 53121, Bonn, Germany
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100
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Taidi Z, Zhou T, Moore KH, Mansfield KJ, Liu L. P2X7 Receptor Blockade Protects Against Acrolein-Induced Bladder Damage: A Potential New Therapeutic Approach for the Treatment of Bladder Inflammatory Diseases. Front Pharmacol 2021; 12:682520. [PMID: 34456718 PMCID: PMC8397461 DOI: 10.3389/fphar.2021.682520] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2021] [Accepted: 07/12/2021] [Indexed: 01/28/2023] Open
Abstract
Inflammatory conditions of the urinary bladder have been shown to be associated with urothelial damage and loss of function. The purinergic P2X7 receptor has been implicated in several inflammatory conditions. The aim of this study was to investigate the role of the P2X7 receptor in acrolein-induced inflammatory damage using the porcine urinary bladder. For this purpose, an ex-vivo model of porcine urothelial damage induced by direct instillation of acrolein into the whole bladder lumen was used. To determine the role of the P2X7 receptor, the bladders were pre-incubated with a selective P2X7 receptor antagonist, A804598 (10 μM), for 1 h. The effects of the acrolein-induced urothelial damage on the bladder’s function were assessed by examining the bladder wall contractile response, structure changes, apoptosis, and oxidative stress in the bladder tissues. The acrolein treatment led to significant damage to the urothelium histology, tight junction expression, and contractile responses. Acrolein also induced apoptosis in the mucosa layer. All these acrolein-induced responses were attenuated by pre-treatment with the P2X7 receptor antagonist A804598. Acrolein also significantly induced DNA oxidation in the submucosal layer; however, the P2X7 receptor antagonism did not show any protective effect towards the acrolein-induced oxidative stress. These findings suggested that the P2X7 receptor is involved in the acrolein-induced damage to the urothelium; therefore, the P2X7 receptor antagonists may be a new therapeutic option for the treatment of bladder inflammation.
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Affiliation(s)
- Zhinoos Taidi
- School of Medical Sciences, UNSW Sydney, Sydney, NSW, Australia
| | - Tommy Zhou
- School of Medical Sciences, UNSW Sydney, Sydney, NSW, Australia
| | - Kate H Moore
- St George Hospital, UNSW Sydney, Kogarah, NSW, Australia
| | - Kylie J Mansfield
- School of Medicine, University of Wollongong, Wollongong, NSW, Australia
| | - Lu Liu
- School of Medical Sciences, UNSW Sydney, Sydney, NSW, Australia
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