1
|
Ma XB, Yue CX, Liu Y, Yang Y, Wang J, Yang XN, Huang LD, Zhu MX, Hattori M, Li CZ, Yu Y, Guo CR. A shared mechanism for TNP-ATP recognition by members of the P2X receptor family. Comput Struct Biotechnol J 2024; 23:295-308. [PMID: 38173879 PMCID: PMC10762375 DOI: 10.1016/j.csbj.2023.12.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2023] [Revised: 11/30/2023] [Accepted: 12/03/2023] [Indexed: 01/05/2024] Open
Abstract
P2X receptors (P2X1-7) are non-selective cation channels involved in many physiological activities such as synaptic transmission, immunological modulation, and cardiovascular function. These receptors share a conserved mechanism to sense extracellular ATP. TNP-ATP is an ATP derivative acting as a nonselective competitive P2X antagonist. Understanding how it occupies the orthosteric site in the absence of agonism may help reveal the key allostery during P2X gating. However, TNP-ATP/P2X complexes (TNP-ATP/human P2X3 (hP2X3) and TNP-ATP/chicken P2X7 (ckP2X7)) with distinct conformations and different mechanisms of action have been proposed. Whether these represent species and subtype variations or experimental differences remains unclear. Here, we show that a common mechanism of TNP-ATP recognition exists for the P2X family members by combining enhanced conformation sampling, engineered disulfide bond analysis, and covalent occupancy. In this model, the polar triphosphate moiety of TNP-ATP interacts with the orthosteric site, while its TNP-moiety is deeply embedded in the head and dorsal fin (DF) interface, creating a restrictive allostery in these two domains that results in a partly enlarged yet ion-impermeable pore. Similar results were obtained from multiple P2X subtypes of different species, including ckP2X7, hP2X3, rat P2X2 (rP2X2), and human P2X1 (hP2X1). Thus, TNP-ATP uses a common mechanism for P2X recognition and modulation by restricting the movements of the head and DF domains which are essential for P2X activation. This knowledge is applicable to the development of new P2X inhibitors.
Collapse
Affiliation(s)
- Xiao-Bo Ma
- Department of Pharmacology and Chemical Biology, Institute of Medical Sciences, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Chen-Xi Yue
- School of Basic Medicine and Clinical Pharmacy, and State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing 210009, China
| | - Yan Liu
- Department of Pharmacology and Chemical Biology, Institute of Medical Sciences, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Yang Yang
- Department of Pharmacology and Chemical Biology, Institute of Medical Sciences, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Jin Wang
- Department of Pharmacology and Chemical Biology, Institute of Medical Sciences, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
- School of Basic Medicine and Clinical Pharmacy, and State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing 210009, China
| | - Xiao-Na Yang
- Department of Pharmacology and Chemical Biology, Institute of Medical Sciences, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
- School of Basic Medicine and Clinical Pharmacy, and State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing 210009, China
| | - Li-Dong Huang
- Department of Pharmacology and Chemical Biology, Institute of Medical Sciences, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Michael X. Zhu
- Department of Integrative Biology and Pharmacology, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, TX 77030, USA
| | - 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 200438, China
| | - Chang-Zhu Li
- State Key Laboratory of Utilization of Woody Oil Resource, Hunan Academy of Forestry, Changsha 410004, China
| | - Ye Yu
- Department of Pharmacology and Chemical Biology, Institute of Medical Sciences, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
- School of Basic Medicine and Clinical Pharmacy, and State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing 210009, China
| | - Chang-Run Guo
- School of Traditional Chinese Pharmacy, and State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing 210009, China
| |
Collapse
|
2
|
Al-Aqtash R, Collier DM. Ionotropic purinergic receptor 7 (P2X7) channel structure and pharmacology provides insight regarding non-nucleotide agonism. Channels (Austin) 2024; 18:2355150. [PMID: 38762911 PMCID: PMC11110710 DOI: 10.1080/19336950.2024.2355150] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2024] [Accepted: 05/10/2024] [Indexed: 05/21/2024] Open
Abstract
P2X7 is a member of the Ionotropic Purinergic Receptor (P2X) family. The P2X family of receptors is composed of seven (P2X1-7), ligand-gated, nonselective cation channels. Changes in P2X expression have been reported in multiple disease models. P2Xs have large complex extracellular domains that function as receptors for a variety of ligands, including endogenous and synthetic agonists and antagonists. ATP is the canonical agonist. ATP affinity ranges from nanomolar to micromolar for most P2XRs, but P2X7 has uniquely poor ATP affinity. In many physiological settings, it may be difficult to achieve the millimolar extracellular ATP concentrations needed for P2X7 channel activation; however, channel function is implicated in pain sensation, immune cell function, cardiovascular disease, cancer, and osteoporosis. Multiple high-resolution P2X7 structures have been solved in apo-, ATP-, and antagonist-bound states. P2X7 structural data reveal distinct allosteric and orthosteric antagonist-binding sites. Both allosteric and orthosteric P2X7 antagonists are well documented to inhibit ATP-evoked channel current. However, a growing body of evidence supports P2X7 activation by non-nucleotide agonists, including extracellular histone proteins and human cathelicidin-derived peptides (LL-37). Interestingly, P2X7 non-nucleotide agonism is not inhibited by allosteric antagonists, but is inhibited by orthosteric antagonists. Herein, we review P2X7 function with a focus on the efficacy of available pharmacology on P2X7 channel current activation by non-nucleotide agonists in effort to understand agonist/antagonist efficacy, and consider the impact of these data on the current understanding of P2X7 in physiology and disease given these limitations of P2X7-selective antagonists and incomplete knockout mouse models.
Collapse
Affiliation(s)
- Rua’a Al-Aqtash
- Department of Pharmaceutical Sciences, University of Tennessee Health Science Center, Memphis, TN, USA
| | - Daniel M. Collier
- Department of Pharmaceutical Sciences, University of Tennessee Health Science Center, Memphis, TN, USA
| |
Collapse
|
3
|
Guilleminault L, Grassin-Delyle S, Mazzone SB. Drugs Targeting Cough Receptors: New Therapeutic Options in Refractory or Unexplained Chronic Cough. Drugs 2024:10.1007/s40265-024-02047-y. [PMID: 38904926 DOI: 10.1007/s40265-024-02047-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/06/2024] [Indexed: 06/22/2024]
Abstract
Refractory chronic cough is a disabling disease with very limited therapeutic options. A better understanding of cough pathophysiology has led to the development of emerging drugs targeting cough receptors. Recent strides have illuminated novel therapeutic avenues, notably centred on modulating transient receptor potential (TRP) channels, purinergic receptors, and neurokinin receptors. By modulating these receptors, the goal is to intervene in the sensory pathways that trigger cough reflexes, thereby providing relief without compromising vital protective mechanisms. These innovative pharmacotherapies hold promise for improvement of refractory chronic cough by offering improved efficacy and potentially mitigating adverse effects associated with current recommended treatments. A deeper comprehension of their precise mechanisms of action and clinical viability is imperative for optimising therapeutic interventions and elevating patient care standards in respiratory health. This review delineates the evolving landscape of drug development in this domain, emphasising the significance of these advancements in reshaping the paradigm of cough management.
Collapse
Affiliation(s)
- Laurent Guilleminault
- Toulouse Institute for Infectious and Inflammatory Diseases (Infinity), INSERM UMR1291, CNRS UMR5051, University Toulouse III, 31024, Toulouse, France.
- Department of Respiratory Medicine, Faculty of Medicine, Hôpital Larrey, Toulouse University Hospital, 24 chemin de Pouvourville, 31059, Toulouse, France.
| | - Stanislas Grassin-Delyle
- Exhalomics®, Hôpital Foch, Suresnes, France
- Département de Biotechnologie de la Santé, Université Paris-Saclay, UVSQ, INSERM, Infection et inflammation (2I), U1173, Montigny le Bretonneux, France
| | - Stuart B Mazzone
- Department of Anatomy and Physiology, University of Melbourne, Melbourne, VIC, Australia
| |
Collapse
|
4
|
Thach T, Dhanabalan K, Nandekar PP, Stauffer S, Heisler I, Alvarado S, Snyder J, Subramanian R. A Second Drug Binding Site in P2X3. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.10.598171. [PMID: 38915546 PMCID: PMC11195084 DOI: 10.1101/2024.06.10.598171] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/26/2024]
Abstract
Purinergic P2X3 receptors form trimeric cation-gated channels, which are activated by extracellular ATP. P2X3 plays a crucial role in chronic cough and affects over 10% of the population. Despite considerable efforts to develop drugs targeting P2X3, the highly conserved structure within the P2X receptor family presents obstacles for achieving selectivity. Camlipixant, a potent and selective P2X3 antagonist, is currently in phase III clinical trials. However, the mechanisms underlying receptor desensitization, ion permeation, principles governing antagonism, and the structure of P2X3 when bound to camlipixant remain elusive. In this study, we established a stable cell line expressing homotrimeric P2X3 and utilized a peptide scaffold to purify the complex and determine its structure using cryo-electron microscopy (cryo-EM). P2X3 binds to camlipixant at a previously unidentified drug-binding site and functions as an allosteric inhibitor. Structure-activity studies combined with modeling and simulations have shed light on the mechanisms underlying the selective targeting and inhibition of P2X3 by camlipixant, distinguishing it from other members of the P2X receptor family.
Collapse
Affiliation(s)
- Trung Thach
- Department of Biological Sciences, Purdue University, West Lafayette, IN-47907, USA
| | | | | | - Seth Stauffer
- Elanco Animal Health, 2500 Innovation Way, Greenfield, IN-46140, USA
| | - Iring Heisler
- Elanco Animal Health, 2500 Innovation Way, Greenfield, IN-46140, USA
| | - Sarah Alvarado
- Elanco Animal Health, 2500 Innovation Way, Greenfield, IN-46140, USA
| | - Jonathan Snyder
- Elanco Animal Health, 2500 Innovation Way, Greenfield, IN-46140, USA
| | - Ramaswamy Subramanian
- Department of Biological Sciences, Purdue University, West Lafayette, IN-47907, USA
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN-47907, USA
| |
Collapse
|
5
|
Nagel J, Törmäkangas O, Kuokkanen K, El-Tayeb A, Messinger J, Abdelrahman A, Bous C, Schiedel AC, Müller CE. Preparation and preliminary evaluation of a tritium-labeled allosteric P2X4 receptor antagonist. Purinergic Signal 2024:10.1007/s11302-024-10005-2. [PMID: 38795223 DOI: 10.1007/s11302-024-10005-2] [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: 01/24/2024] [Accepted: 03/26/2024] [Indexed: 05/27/2024] Open
Abstract
P2X4 receptors are ATP-gated cation channels that were proposed as novel drug targets due to their role in inflammation and neuropathic pain. Only few potent and selective P2X4 receptor antagonists have been described to date. Labeled tool compounds suitable for P2X4 receptor binding studies are lacking. Here, we present a novel allosteric P2X4 receptor antagonist possessing high potency in the low nanomolar range. We describe its tritium-labeling resulting in the P2X4-selective radiotracer [3H]PSB-OR-2020 with high specific activity (45 Ci/mmol; 1.67 TBq/mmol). A radioligand binding assay was developed using human embryonic kidney (HEK293) cell membranes recombinantly expressing the human P2X4 receptor. Competition binding studies with structurally diverse P2X4 receptor antagonists revealed different allosteric binding sites indicating that the new class of P2X4 receptor antagonists, to which PSB-OR-2020 belongs, interacts with an unprecedented allosteric site. [3H]PSB-OR-2020 may become a useful tool for research on P2X4 receptors and for promoting drug development.
Collapse
Affiliation(s)
- Jessica Nagel
- PharmaCenter Bonn, Pharmaceutical Institute, University of Bonn, Pharmaceutical & Medicinal Chemistry, An der Immenburg 4, Bonn, 53121, Germany
| | - Olli Törmäkangas
- Orion Pharma, Orion Corporation, Tengströminkatu 8, FI-20360 Turku, and Orionintie 1A, Espoo, FI- 02200, Finland
| | - Katja Kuokkanen
- Orion Pharma, Orion Corporation, Tengströminkatu 8, FI-20360 Turku, and Orionintie 1A, Espoo, FI- 02200, Finland
| | - Ali El-Tayeb
- PharmaCenter Bonn, Pharmaceutical Institute, University of Bonn, Pharmaceutical & Medicinal Chemistry, An der Immenburg 4, Bonn, 53121, Germany
| | - Josef Messinger
- Orion Pharma, Orion Corporation, Tengströminkatu 8, FI-20360 Turku, and Orionintie 1A, Espoo, FI- 02200, Finland
| | - Aliaa Abdelrahman
- PharmaCenter Bonn, Pharmaceutical Institute, University of Bonn, Pharmaceutical & Medicinal Chemistry, An der Immenburg 4, Bonn, 53121, Germany
| | - Christiane Bous
- PharmaCenter Bonn, Pharmaceutical Institute, University of Bonn, Pharmaceutical & Medicinal Chemistry, An der Immenburg 4, Bonn, 53121, Germany
| | - Anke C Schiedel
- PharmaCenter Bonn, Pharmaceutical Institute, University of Bonn, Pharmaceutical & Medicinal Chemistry, An der Immenburg 4, Bonn, 53121, Germany
| | - Christa E Müller
- PharmaCenter Bonn, Pharmaceutical Institute, University of Bonn, Pharmaceutical & Medicinal Chemistry, An der Immenburg 4, Bonn, 53121, Germany.
| |
Collapse
|
6
|
Purohit R, Couch T, MacLean DM. Proline substitutions in the ASIC1 β11-12 linker slow desensitization. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.09.593312. [PMID: 38798386 PMCID: PMC11118455 DOI: 10.1101/2024.05.09.593312] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2024]
Abstract
Desensitization is a prominent feature of nearly all ligand gated ion channels. Acid-sensing ion channels (ASIC) undergo desensitization within hundreds of milliseconds to seconds upon continual extracellular acidification. The ASIC mechanism of desensitization is primarily due to the isomerization or "flipping" of a short linker joining the 11th and 12th beta sheets in the extracellular domain. In the resting and active states this β11-12 linker adopts an "upward" conformation while in the desensitized conformation the linker assumes a "downward" state. To accommodate this "downward" state, specific peptide bonds within the linker adopt either trans-like or cis-like conformations. Since proline-containing peptide bonds undergo cis-trans isomerization very slowly, we hypothesized that introducing proline residues in the linker may slow or even abolish ASIC desensitization, potentially providing a valuable research tools. Proline substitutions in the chicken ASIC1 β11-12 linker (L414P and Y416P) slowed desensitization decays approximately 100 to 1000-fold as measured in excised patches. Both L414P and Y416P shifted the steady state desensitization curves to more acidic pHs while activation curves and ion selectivity of these slow-desensitizing currents were largely unaffected. To investigate the functional stoichiometry of desensitization in the trimeric ASIC, we created families of L414P and Y416P concatemers with zero, one, two or three proline substitutions in all possible configurations. Introducing one or two L414P or Y416P mutations only slightly attenuated desensitization, suggesting that conformational changes in the remaining faster wild type subunits were sufficient to desensitize the channel. These data highlight the unusual cis-trans isomerization mechanism of ASIC desensitization and support a model where a single subunit is sufficient to desensitize the entire channel.
Collapse
Affiliation(s)
- Rutambhara Purohit
- Department of Pharmacology and Physiology, University of Rochester Medical Center
| | - Tyler Couch
- Department of Pharmacology and Physiology, University of Rochester Medical Center
| | - David M MacLean
- Department of Pharmacology and Physiology, University of Rochester Medical Center
| |
Collapse
|
7
|
Gardner EC, Tramont C, Bachanová P, Wang C, Do H, Boutz DR, Kar S, Zemelman BV, Gollihar JD, Ellington AD. Engineering a human P2X2 receptor with altered ligand selectivity in yeast. J Biol Chem 2024; 300:107248. [PMID: 38556082 PMCID: PMC11063903 DOI: 10.1016/j.jbc.2024.107248] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2023] [Revised: 03/14/2024] [Accepted: 03/23/2024] [Indexed: 04/02/2024] Open
Abstract
P2X receptors are a family of ligand gated ion channels found in a range of eukaryotic species including humans but are not naturally present in the yeast Saccharomyces cerevisiae. We demonstrate the first recombinant expression and functional gating of the P2X2 receptor in baker's yeast. We leverage the yeast host for facile genetic screens of mutant P2X2 by performing site saturation mutagenesis at residues of interest, including SNPs implicated in deafness and at residues involved in native binding. Deep mutational analysis and rounds of genetic engineering yield mutant P2X2 F303Y A304W, which has altered ligand selectivity toward the ATP analog AMP-PNP. The F303Y A304W variant shows over 100-fold increased intracellular calcium amplitudes with AMP-PNP compared to the WT receptor and has a much lower desensitization rate. Since AMP-PNP does not naturally activate P2X receptors, the F303Y A304W P2X2 may be a starting point for downstream applications in chemogenetic cellular control. Interestingly, the A304W mutation selectively destabilizes the desensitized state, which may provide a mechanistic basis for receptor opening with suboptimal agonists. The yeast system represents an inexpensive, scalable platform for ion channel characterization and engineering by circumventing the more expensive and time-consuming methodologies involving mammalian hosts.
Collapse
Affiliation(s)
- Elizabeth C Gardner
- Department of Molecular Biosciences, Center for Systems and Synthetic Biology, The University of Texas at Austin, Austin, Texas, USA
| | - Caitlin Tramont
- Department of Molecular Biosciences, Center for Systems and Synthetic Biology, The University of Texas at Austin, Austin, Texas, USA
| | - Petra Bachanová
- Department of Molecular Biosciences, Center for Systems and Synthetic Biology, The University of Texas at Austin, Austin, Texas, USA
| | - Chad Wang
- Department of Molecular Biosciences, Center for Systems and Synthetic Biology, The University of Texas at Austin, Austin, Texas, USA
| | - Hannah Do
- Department of Molecular Biosciences, Center for Systems and Synthetic Biology, The University of Texas at Austin, Austin, Texas, USA
| | - Daniel R Boutz
- Antibody Discovery and Accelerated Protein Therapeutics, Department of Pathology & Genomic Medicine, Houston Methodist Research Institute, Houston, Texas, USA
| | - Shaunak Kar
- Antibody Discovery and Accelerated Protein Therapeutics, Department of Pathology & Genomic Medicine, Houston Methodist Research Institute, Houston, Texas, USA
| | - Boris V Zemelman
- Department of Neuroscience, Center for Learning and Memory, The University of Texas at Austin, Austin, Texas, USA.
| | - Jimmy D Gollihar
- Antibody Discovery and Accelerated Protein Therapeutics, Department of Pathology & Genomic Medicine, Houston Methodist Research Institute, Houston, Texas, USA.
| | - Andrew D Ellington
- Department of Molecular Biosciences, Center for Systems and Synthetic Biology, The University of Texas at Austin, Austin, Texas, USA.
| |
Collapse
|
8
|
Huffer K, Tan XF, Fernández-Mariño AI, Dhingra S, Swartz KJ. Dilation of ion selectivity filters in cation channels. Trends Biochem Sci 2024; 49:417-430. [PMID: 38514273 PMCID: PMC11069442 DOI: 10.1016/j.tibs.2024.02.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2023] [Revised: 02/19/2024] [Accepted: 02/23/2024] [Indexed: 03/23/2024]
Abstract
Ion channels establish the voltage gradient across cellular membranes by providing aqueous pathways for ions to selectively diffuse down their concentration gradients. The selectivity of any given channel for its favored ions has conventionally been viewed as a stable property, and in many cation channels, it is determined by an ion-selectivity filter within the external end of the ion-permeation pathway. In several instances, including voltage-activated K+ (Kv) channels, ATP-activated P2X receptor channels, and transient receptor potential (TRP) channels, the ion-permeation pathways have been proposed to dilate in response to persistent activation, dynamically altering ion permeation. Here, we discuss evidence for dynamic ion selectivity, examples where ion selectivity filters exhibit structural plasticity, and opportunities to fill gaps in our current understanding.
Collapse
Affiliation(s)
- Kate Huffer
- Molecular Physiology and Biophysics Section, Porter Neuroscience Research Center, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA
| | - Xiao-Feng Tan
- Molecular Physiology and Biophysics Section, Porter Neuroscience Research Center, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA
| | - Ana I Fernández-Mariño
- Molecular Physiology and Biophysics Section, Porter Neuroscience Research Center, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA
| | - Surbhi Dhingra
- Molecular Physiology and Biophysics Section, Porter Neuroscience Research Center, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA
| | - Kenton J Swartz
- Molecular Physiology and Biophysics Section, Porter Neuroscience Research Center, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA.
| |
Collapse
|
9
|
Lu Y, Lin Y, Wang J. Progress on functions of intracellular domain of trimeric ligand-gated ion channels. Zhejiang Da Xue Xue Bao Yi Xue Ban 2024; 53:221-230. [PMID: 38310082 PMCID: PMC11057991 DOI: 10.3724/zdxbyxb-2023-0472] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2023] [Accepted: 11/11/2023] [Indexed: 02/05/2024]
Abstract
Ligand-gated ion channels are a large category of essential ion channels, modulating their state by binding to specific ligands to allow ions to pass through the cell membrane. Purinergic ligand-gated ion channel receptors (P2XRs) and acid-sensitive ion channels (ASICs) are representative members of trimeric ligand-gated ion channel. Recent studies have shown that structural differences in the intracellular domain of P2XRs may determine the desensitization process. The lateral fenestrations of P2XRs potentially serve as a pathway for ion conductance and play a decisive role in ion selectivity. Phosphorylation of numerous amino acid residues in the P2XRs are involved in regulating the activity of ion channels. Additionally, the P2XRs interact with other ligand-gated ion channels including N-methyl-D-aspartate receptors, γ-aminobutyric acid receptors, 5-hydroxytryptamin receptors and nicotinic acetylcholine receptors, mediating physiological processes such as synaptic plasticity. Conformational changes in the intracellular domain of the ASICs expose binding sites of intracellular signal partners, facilitating metabolic signal transduction. Amino acids such as Val16, Ser17, Ile18, Gln19 and Ala20 in the ASICs participate in channel opening and membrane expression. ASICs can also bind to intracellular proteins, such as CIPP and p11, to regulate channel function. Many phosphorylation sites at the C-terminus and N-terminus of ASICs are involved in the regulation of receptors. Furthermore, ASICs are involved in various physiological and pathophysiological processes, which include pain, ischemic stroke, psychiatric disorders, and neurodegenerative disease. In this article, we review the roles of the intracellular domains of these trimeric ligand-gated ion channels in channel gating as well as their physiological and pathological functions, in order to provide new insights into the discovery of related drugs.
Collapse
Affiliation(s)
- Yan Lu
- School of Basic Medicine and Clinical Pharmacy, China Pharmaceutical University, Nanjing 210009, China.
| | - Yiyu Lin
- School of Basic Medicine and Clinical Pharmacy, China Pharmaceutical University, Nanjing 210009, China
| | - Jin Wang
- School of Basic Medicine and Clinical Pharmacy, China Pharmaceutical University, Nanjing 210009, China.
| |
Collapse
|
10
|
Sheng D, Yue CX, Jin F, Wang Y, Ichikawa M, Yu Y, Guo CR, Hattori M. Structural insights into the orthosteric inhibition of P2X receptors by non-ATP analog antagonists. eLife 2024; 12:RP92829. [PMID: 38578670 PMCID: PMC10997329 DOI: 10.7554/elife.92829] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/06/2024] Open
Abstract
P2X receptors are extracellular ATP-gated ion channels that form homo- or heterotrimers and consist of seven subtypes. They are expressed in various tissues, including neuronal and nonneuronal cells, and play critical roles in physiological processes such as neurotransmission, inflammation, pain, and cancer. As a result, P2X receptors have attracted considerable interest as drug targets, and various competitive inhibitors have been developed. However, although several P2X receptor structures from different subtypes have been reported, the limited structural information of P2X receptors in complex with competitive antagonists hampers the understanding of orthosteric inhibition, hindering the further design and optimization of those antagonists for drug discovery. We determined the cryogenic electron microscopy (cryo-EM) structures of the mammalian P2X7 receptor in complex with two classical competitive antagonists of pyridoxal-5'-phosphate derivatives, pyridoxal-5'-phosphate-6-(2'-naphthylazo-6'-nitro-4',8'-disulfonate) (PPNDS) and pyridoxal phosphate-6-azophenyl-2',5'-disulfonic acid (PPADS), and performed structure-based mutational analysis by patch-clamp recording as well as molecular dynamics (MD) simulations. Our structures revealed the orthosteric site for PPADS/PPNDS, and structural comparison with the previously reported apo- and ATP-bound structures showed how PPADS/PPNDS binding inhibits the conformational changes associated with channel activation. In addition, structure-based mutational analysis identified key residues involved in the PPNDS sensitivity of P2X1 and P2X3, which are known to have higher affinity for PPADS/PPNDS than other P2X subtypes.
Collapse
Affiliation(s)
- Danqi Sheng
- State Key Laboratory of Genetic Engineering, Shanghai Key Laboratory of Bioactive Small Molecules, Collaborative Innovation Center of Genetics and Development, Department of Physiology and Neurobiology, School of Life Sciences, Fudan UniversityShanghaiChina
| | - Chen-Xi Yue
- School of Basic Medicine and Clinical Pharmacy, China Pharmaceutical UniversityNanjingChina
| | - Fei Jin
- State Key Laboratory of Genetic Engineering, Shanghai Key Laboratory of Bioactive Small Molecules, Collaborative Innovation Center of Genetics and Development, Department of Physiology and Neurobiology, School of Life Sciences, Fudan UniversityShanghaiChina
| | - Yao Wang
- State Key Laboratory of Genetic Engineering, Shanghai Key Laboratory of Bioactive Small Molecules, Collaborative Innovation Center of Genetics and Development, Department of Physiology and Neurobiology, School of Life Sciences, Fudan UniversityShanghaiChina
| | - Muneyoshi Ichikawa
- State Key Laboratory of Genetic Engineering, Department of Biochemistry and Biophysics, School of Life Sciences, Fudan UniversityShanghaiChina
| | - Ye Yu
- School of Basic Medicine and Clinical Pharmacy, China Pharmaceutical UniversityNanjingChina
| | - Chang-Run Guo
- School of Basic Medicine and Clinical Pharmacy, China Pharmaceutical UniversityNanjingChina
| | - Motoyuki Hattori
- State Key Laboratory of Genetic Engineering, Shanghai Key Laboratory of Bioactive Small Molecules, Collaborative Innovation Center of Genetics and Development, Department of Physiology and Neurobiology, School of Life Sciences, Fudan UniversityShanghaiChina
| |
Collapse
|
11
|
Iqbal J, Bano S, Khan IA, Huang Q. A patent review of P2X7 receptor antagonists to treat inflammatory diseases (2018-present). Expert Opin Ther Pat 2024; 34:263-271. [PMID: 38828613 DOI: 10.1080/13543776.2024.2363885] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2024] [Accepted: 05/31/2024] [Indexed: 06/05/2024]
Abstract
INTRODUCTION The purinergic P2X7 receptor (P2X7R) is expressed on the surface of many different types of cells, including immune cells. Targeting P2X7R with antagonists has been studied for its potential therapeutic effects in a variety of inflammatory illnesses. AREA COVERED Many chemical substances, including carboxamides, benzamides and nitrogen containing heterocyclic derivatives have demonstrated promising inhibitory potential for P2X7 receptor. The chemistry and clinical applications of P2X7R antagonists patented from 2018- present are discussed in this review. EXPERT OPINION Purinergic receptor inhibitor discovery and application has demonstrated the potential for therapeutic intervention, as demonstrated by pharmacological research. Few chemical modalities have been authorized for use in clinical settings, despite the fact that breakthroughs in crystallography and chemical biology have increased the knowledge of purinergic signaling and its consequences in disease. The many research projects and pharmaceutical movements that sustain dynamic P2X receptor programs over decades are evidence of the therapeutic values and academic persistence in purinergic study. P2X7R is an intriguing therapeutic target and possible biomarker for inflammation. Although several companies like Merck and AstraZeneca have published patents on P2X3 antagonists, the search for P2X7R antagonists has not stopped. Numerous pharmaceutical companies have disclosed different scaffolds, and some molecules are presently being studied in clinical studies.
Collapse
Affiliation(s)
- Jamshed Iqbal
- Institute of Intelligent Machines, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei, China
- Centre for Advanced Drug Research, COMSATS University Islamabad, Abbottabad, Pakistan
| | - Sehrish Bano
- Centre for Advanced Drug Research, COMSATS University Islamabad, Abbottabad, Pakistan
| | - Imtiaz Ali Khan
- Centre for Advanced Drug Research, COMSATS University Islamabad, Abbottabad, Pakistan
| | - Qing Huang
- Institute of Intelligent Machines, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei, China
| |
Collapse
|
12
|
Guo Y, Mao T, Fang Y, Wang H, Yu J, Zhu Y, Shen S, Zhou M, Li H, Hu Q. Comprehensive insights into potential roles of purinergic P2 receptors on diseases: Signaling pathways involved and potential therapeutics. J Adv Res 2024:S2090-1232(24)00123-1. [PMID: 38565403 DOI: 10.1016/j.jare.2024.03.027] [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: 01/17/2024] [Revised: 03/03/2024] [Accepted: 03/29/2024] [Indexed: 04/04/2024] Open
Abstract
BACKGROUND Purinergic P2 receptors, which can be divided into ionotropic P2X receptors and metabotropic P2Y receptors, mediate cellular signal transduction of purine or pyrimidine nucleoside triphosphates and diphosphate. Based on the wide expression of purinergic P2 receptors in tissues and organs, their significance in homeostatic maintenance, metabolism, nociceptive transmission, and other physiological processes is becoming increasingly evident, suggesting that targeting purinergic P2 receptors to regulate biological functions and signal transmission holds significant promise for disease treatment. AIM OF REVIEW This review highlights the detailed mechanisms by which purinergic P2 receptors engage in physiological and pathological progress, as well as providing prospective strategies for discovering clinical drug candidates. KEY SCIENTIFIC CONCEPTS OF REVIEW The purinergic P2 receptors regulate complex signaling and molecular mechanisms in nervous system, digestive system, immune system and as a result, controlling physical health states and disease progression. There has been a significant rise in research and development focused on purinergic P2 receptors, contributing to an increased number of drug candidates in clinical trials. A few influential pioneers have laid the foundation for advancements in the evaluation, development, and of novel purinergic P2 receptors modulators, including agonists, antagonists, pharmaceutical compositions and combination strategies, despite the different scaffolds of these drug candidates. These advancements hold great potential for improving therapeutic outcomes by specifically targeting purinergic P2 receptors.
Collapse
Affiliation(s)
- Yanshuo Guo
- School of Pharmacy, China Pharmaceutical University, Nanjing 211198, China
| | - Tianqi Mao
- College of Pharmaceutical Sciences, Soochow University, Suzhou 215006, China
| | - Yafei Fang
- School of Pharmacy, China Pharmaceutical University, Nanjing 211198, China
| | - Hui Wang
- College of Pharmaceutical Sciences, Soochow University, Suzhou 215006, China
| | - Jiayue Yu
- School of Pharmacy, China Pharmaceutical University, Nanjing 211198, China
| | - Yifan Zhu
- College of Pharmaceutical Sciences, Soochow University, Suzhou 215006, China
| | - Shige Shen
- School of Pharmacy, China Pharmaceutical University, Nanjing 211198, China
| | - Mengze Zhou
- School of Pharmacy, China Pharmaceutical University, Nanjing 211198, China.
| | - Huanqiu Li
- College of Pharmaceutical Sciences, Soochow University, Suzhou 215006, China.
| | - Qinghua Hu
- School of Life Science and Technology, China Pharmaceutical University, Nanjing 211198, China.
| |
Collapse
|
13
|
Jojoa-Cruz S, Burendei B, Lee WH, Ward AB. Structure of mechanically activated ion channel OSCA2.3 reveals mobile elements in the transmembrane domain. Structure 2024; 32:157-167.e5. [PMID: 38103547 PMCID: PMC10872982 DOI: 10.1016/j.str.2023.11.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Revised: 09/29/2023] [Accepted: 11/21/2023] [Indexed: 12/19/2023]
Abstract
Members of the OSCA/TMEM63 family are mechanically activated ion channels and structures of some OSCA members have revealed the architecture of these channels and structural features that are potentially involved in mechanosensation. However, these structures are all in a similar state and information about the motion of different elements of the structure is limited, preventing a deeper understanding of how these channels work. Here, we used cryoelectron microscopy to determine high-resolution structures of Arabidopsis thaliana OSCA1.2 and OSCA2.3 in peptidiscs. The structure of OSCA1.2 matches previous structures of the same protein in different environments. Yet, in OSCA2.3, the TM6a-TM7 linker adopts a different conformation that constricts the pore on its cytoplasmic side. Furthermore, coevolutionary sequence analysis uncovered a conserved interaction between the TM6a-TM7 linker and the beam-like domain (BLD). Our results reveal conformational heterogeneity and differences in conserved interactions between the TMD and BLD among members of the OSCA family.
Collapse
Affiliation(s)
- Sebastian Jojoa-Cruz
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Batuujin Burendei
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Wen-Hsin Lee
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Andrew B Ward
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA 92037, USA.
| |
Collapse
|
14
|
Migita K, Oyabu K, Terada K. Rectification of ATP-gated current of rat P2X2 and P2X7 receptors depends on the cytoplasmic N-terminus. Biochem Biophys Res Commun 2023; 688:149213. [PMID: 37976814 DOI: 10.1016/j.bbrc.2023.149213] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2023] [Accepted: 11/02/2023] [Indexed: 11/19/2023]
Abstract
The phenotypes of ATP-gated currents thought ionotropic P2X channels depend on the composition of the oligomeric receptor. We constructed chimeric P2X2/P2X7 receptors to study the effect of cytoplasmic domains on rectification of current flow through the open channel. We found that the identity of the N-terminus determines the pattern of rectification, with chimeric receptors containing the N-terminus of the P2X2 receptor displaying inward rectification, and chimeric receptors containing the N-terminus of the P2X7 receptor displaying slightly outward rectification. In contrast, rectification of current through chimeric receptors with swapped C-termini always mimicked the wild-type receptor. Thus, our findings suggest that the N-terminus of P2X receptors regulate ion flow through the channel pore and are responsible in part for determining current rectification.
Collapse
Affiliation(s)
- Keisuke Migita
- Department of Drug Informatics, Faculty of Pharmaceutical Sciences, Fukuoka University, Fukuoka, 814-0180, Japan.
| | - Kohei Oyabu
- Department of Drug Informatics, Faculty of Pharmaceutical Sciences, Fukuoka University, Fukuoka, 814-0180, Japan
| | - Kazuki Terada
- Division of Pharmacotherapeutics, Faculty of Pharmaceutical Sciences, Himeji Dokkyo University, Himeji, 670-8524, Japan
| |
Collapse
|
15
|
Shen C, Zhang Y, Cui W, Zhao Y, Sheng D, Teng X, Shao M, Ichikawa M, Wang J, Hattori M. Structural insights into the allosteric inhibition of P2X4 receptors. Nat Commun 2023; 14:6437. [PMID: 37833294 PMCID: PMC10575874 DOI: 10.1038/s41467-023-42164-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2023] [Accepted: 10/01/2023] [Indexed: 10/15/2023] Open
Abstract
P2X receptors are ATP-activated cation channels, and the P2X4 subtype plays important roles in the immune system and the central nervous system, particularly in neuropathic pain. Therefore, P2X4 receptors are of increasing interest as potential drug targets. Here, we report the cryo-EM structures of the zebrafish P2X4 receptor in complex with two P2X4 subtype-specific antagonists, BX430 and BAY-1797. Both antagonists bind to the same allosteric site located at the subunit interface at the top of the extracellular domain. Structure-based mutational analysis by electrophysiology identified the important residues for the allosteric inhibition of both zebrafish and human P2X4 receptors. Structural comparison revealed the ligand-dependent structural rearrangement of the binding pocket to stabilize the binding of allosteric modulators, which in turn would prevent the structural changes of the extracellular domain associated with channel activation. Furthermore, comparison with the previously reported P2X structures of other subtypes provided mechanistic insights into subtype-specific allosteric inhibition.
Collapse
Affiliation(s)
- Cheng Shen
- State Key Laboratory of Genetic Engineering, Shanghai Key Laboratory of Bioactive Small Molecules, Collaborative Innovation Center of Genetics and Development, Department of Physiology and Neurobiology, School of Life Sciences, Fudan University, Shanghai, 200438, China
| | - Yuqing Zhang
- School of Basic Medicine and Clinical Pharmacy, China Pharmaceutical University, Nanjing, 211198, China
| | - Wenwen Cui
- School of Basic Medicine and Clinical Pharmacy, China Pharmaceutical University, Nanjing, 211198, China
| | - Yimeng Zhao
- State Key Laboratory of Genetic Engineering, Shanghai Key Laboratory of Bioactive Small Molecules, Collaborative Innovation Center of Genetics and Development, Department of Physiology and Neurobiology, School of Life Sciences, Fudan University, Shanghai, 200438, China
- Human Phenome Institute, Fudan University, Shanghai, 201203, China
| | - Danqi Sheng
- State Key Laboratory of Genetic Engineering, Shanghai Key Laboratory of Bioactive Small Molecules, Collaborative Innovation Center of Genetics and Development, Department of Physiology and Neurobiology, School of Life Sciences, Fudan University, Shanghai, 200438, China
| | - Xinyu Teng
- State Key Laboratory of Genetic Engineering, Shanghai Key Laboratory of Bioactive Small Molecules, Collaborative Innovation Center of Genetics and Development, Department of Physiology and Neurobiology, School of Life Sciences, Fudan University, Shanghai, 200438, China
| | - Miaoqing Shao
- School of Basic Medicine and Clinical Pharmacy, China Pharmaceutical University, Nanjing, 211198, China
| | - Muneyoshi Ichikawa
- State Key Laboratory of Genetic Engineering, Department of Biochemistry and Biophysics, School of Life Sciences, Fudan University, Shanghai, 200438, China
| | - Jin Wang
- School of Basic Medicine and Clinical Pharmacy, China Pharmaceutical University, Nanjing, 211198, China.
| | - Motoyuki Hattori
- State Key Laboratory of Genetic Engineering, Shanghai Key Laboratory of Bioactive Small Molecules, Collaborative Innovation Center of Genetics and Development, Department of Physiology and Neurobiology, School of Life Sciences, Fudan University, Shanghai, 200438, China.
| |
Collapse
|
16
|
Guo CR, Zhang ZZ, Zhou X, Sun MY, Li TT, Lei YT, Gao YH, Li QQ, Yue CX, Gao Y, Lin YY, Hao CY, Li CZ, Cao P, Zhu MX, Rong MQ, Wang WH, Yu Y. Chronic cough relief by allosteric modulation of P2X3 without taste disturbance. Nat Commun 2023; 14:5844. [PMID: 37730705 PMCID: PMC10511716 DOI: 10.1038/s41467-023-41495-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2022] [Accepted: 09/06/2023] [Indexed: 09/22/2023] Open
Abstract
P2X receptors are cation channels that sense extracellular ATP. Many therapeutic candidates targeting P2X receptors have begun clinical trials or acquired approval for the treatment of refractory chronic cough (RCC) and other disorders. However, the present negative allosteric modulation of P2X receptors is primarily limited to the central pocket or the site below the left flipper domain. Here, we uncover a mechanism of allosteric regulation of P2X3 in the inner pocket of the head domain (IP-HD), and show that the antitussive effects of quercetin and PSFL2915 (our nM-affinity P2X3 inhibitor optimized based on quercetin) on male mice and guinea pigs were achieved by preventing allosteric changes of IP-HD in P2X3. While being therapeutically comparable to the newly licensed P2X3 RCC drug gefapixant, quercetin and PSFL2915 do not have an adverse effect on taste as gefapixant does. Thus, allosteric modulation of P2X3 via IP-HD may be a druggable strategy to alleviate RCC.
Collapse
Affiliation(s)
- Chang-Run Guo
- School of Basic Medicine and Clinical Pharmacy, China Pharmaceutical University, Nanjing, 211198, China
- School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing, 211198, China
- State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing, 211198, China
| | - Zhong-Zhe Zhang
- School of Basic Medicine and Clinical Pharmacy, China Pharmaceutical University, Nanjing, 211198, China
| | - Xing Zhou
- School of Basic Medicine and Clinical Pharmacy, China Pharmaceutical University, Nanjing, 211198, China
| | - Meng-Yang Sun
- School of Basic Medicine and Clinical Pharmacy, China Pharmaceutical University, Nanjing, 211198, China
| | - Tian-Tian Li
- School of Basic Medicine and Clinical Pharmacy, China Pharmaceutical University, Nanjing, 211198, China
| | - Yun-Tao Lei
- School of Basic Medicine and Clinical Pharmacy, China Pharmaceutical University, Nanjing, 211198, China
| | - Yu-Hao Gao
- School of Basic Medicine and Clinical Pharmacy, China Pharmaceutical University, Nanjing, 211198, China
| | - Qing-Quan Li
- School of Basic Medicine and Clinical Pharmacy, China Pharmaceutical University, Nanjing, 211198, China
| | - Chen-Xi Yue
- School of Basic Medicine and Clinical Pharmacy, China Pharmaceutical University, Nanjing, 211198, China
| | - Yu Gao
- School of Basic Medicine and Clinical Pharmacy, China Pharmaceutical University, Nanjing, 211198, China
| | - Yi-Yu Lin
- School of Basic Medicine and Clinical Pharmacy, China Pharmaceutical University, Nanjing, 211198, China
| | - Cui-Yun Hao
- School of Basic Medicine and Clinical Pharmacy, China Pharmaceutical University, Nanjing, 211198, China
| | - Chang-Zhu Li
- State Key Laboratory of Utilization of Woody Oil Resource, Hunan Academy of Forestry, Changsha, Hunan, 410004, China
| | - Peng Cao
- Hospital of Integrated Traditional Chinese and Western Medicine, Nanjing University of Chinese Medicine, Nanjing, 210023, China
| | - Michael X Zhu
- Department of Integrative Biology and Pharmacology, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, Texas, 77030, USA
| | - Ming-Qiang Rong
- The National & Local Joint Engineering Laboratory of Animal Peptide Drug Development, College of Life Sciences, Hunan Normal University, Changsha, China.
| | - Wen-Hui Wang
- School of Basic Medicine and Clinical Pharmacy, China Pharmaceutical University, Nanjing, 211198, China.
| | - Ye Yu
- School of Basic Medicine and Clinical Pharmacy, China Pharmaceutical University, Nanjing, 211198, China.
- State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing, 211198, China.
| |
Collapse
|
17
|
Zhao P, Tang C, Yang Y, Xiao Z, Perez-Miller S, Zhang H, Luo G, Liu H, Li Y, Liao Q, Yang F, Dong H, Khanna R, Liu Z. A new polymodal gating model of the proton-activated chloride channel. PLoS Biol 2023; 21:e3002309. [PMID: 37713449 PMCID: PMC10529583 DOI: 10.1371/journal.pbio.3002309] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2023] [Revised: 09/27/2023] [Accepted: 08/23/2023] [Indexed: 09/17/2023] Open
Abstract
The proton-activated chloride (PAC) channel plays critical roles in ischemic neuron death, but its activation mechanisms remain elusive. Here, we investigated the gating of PAC channels using its novel bifunctional modulator C77304. C77304 acted as a weak activator of the PAC channel, causing moderate activation by acting on its proton gating. However, at higher concentrations, C77304 acted as a weak inhibitor, suppressing channel activity. This dual function was achieved by interacting with 2 modulatory sites of the channel, each with different affinities and dependencies on the channel's state. Moreover, we discovered a protonation-independent voltage activation of the PAC channel that appears to operate through an ion-flux gating mechanism. Through scanning-mutagenesis and molecular dynamics simulation, we confirmed that E181, E257, and E261 in the human PAC channel serve as primary proton sensors, as their alanine mutations eliminated the channel's proton gating while sparing the voltage-dependent gating. This proton-sensing mechanism was conserved among orthologous PAC channels from different species. Collectively, our data unveils the polymodal gating and proton-sensing mechanisms in the PAC channel that may inspire potential drug development.
Collapse
Affiliation(s)
- Piao Zhao
- The National and Local Joint Engineering Laboratory of Animal Peptide Drug Development, College of Life Sciences, Hunan Normal University, Changsha, China
- Peptide and small molecule drug R&D platform, Furong Laboratory, Hunan Normal University, Changsha, China
| | - Cheng Tang
- The National and Local Joint Engineering Laboratory of Animal Peptide Drug Development, College of Life Sciences, Hunan Normal University, Changsha, China
- Peptide and small molecule drug R&D platform, Furong Laboratory, Hunan Normal University, Changsha, China
| | - Yuqin Yang
- Kuang Yaming Honors School, State Key Laboratory of Analytical Chemistry for Life Science, Engineering Research Center of Protein and Peptide Medicine of Ministry of Education, & Institute for Brain Sciences, Nanjing University, Nanjing, Jiangsu, China
| | - Zhen Xiao
- The National and Local Joint Engineering Laboratory of Animal Peptide Drug Development, College of Life Sciences, Hunan Normal University, Changsha, China
| | - Samantha Perez-Miller
- Department of Molecular Pathobiology and NYU Pain Research Center, College of Dentistry, New York University, New York, New York, United States of America
| | - Heng Zhang
- Department of Biophysics and Kidney Disease Center, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Guoqing Luo
- The National and Local Joint Engineering Laboratory of Animal Peptide Drug Development, College of Life Sciences, Hunan Normal University, Changsha, China
| | - Hao Liu
- The National and Local Joint Engineering Laboratory of Animal Peptide Drug Development, College of Life Sciences, Hunan Normal University, Changsha, China
| | - Yaqi Li
- The National and Local Joint Engineering Laboratory of Animal Peptide Drug Development, College of Life Sciences, Hunan Normal University, Changsha, China
| | - Qingyi Liao
- The National and Local Joint Engineering Laboratory of Animal Peptide Drug Development, College of Life Sciences, Hunan Normal University, Changsha, China
| | - Fan Yang
- Department of Biophysics and Kidney Disease Center, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Hao Dong
- Kuang Yaming Honors School, State Key Laboratory of Analytical Chemistry for Life Science, Engineering Research Center of Protein and Peptide Medicine of Ministry of Education, & Institute for Brain Sciences, Nanjing University, Nanjing, Jiangsu, China
| | - Rajesh Khanna
- Department of Molecular Pathobiology and NYU Pain Research Center, College of Dentistry, New York University, New York, New York, United States of America
- Department of Neuroscience and Physiology and Neuroscience Institute, School of Medicine, New York University, New York, New York, United States of America
| | - Zhonghua Liu
- The National and Local Joint Engineering Laboratory of Animal Peptide Drug Development, College of Life Sciences, Hunan Normal University, Changsha, China
- Peptide and small molecule drug R&D platform, Furong Laboratory, Hunan Normal University, Changsha, China
| |
Collapse
|
18
|
Yin Y, Wei L, Caseley EA, Lopez‐Charcas O, Wei Y, Li D, Muench SP, Roger S, Wang L, Jiang L. Leveraging the ATP-P2X7 receptor signalling axis to alleviate traumatic CNS damage and related complications. Med Res Rev 2023; 43:1346-1373. [PMID: 36924449 PMCID: PMC10947395 DOI: 10.1002/med.21952] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2022] [Revised: 11/11/2022] [Accepted: 02/28/2023] [Indexed: 03/18/2023]
Abstract
The P2X7 receptor is an exceptional member of the P2X purinergic receptor family, with its activation requiring high concentrations of extracellular adenosine 5'-triphosphate (ATP) that are often associated with tissue damage and inflammation. In the central nervous system (CNS), it is highly expressed in glial cells, particularly in microglia. In this review, we discuss the role and mechanisms of the P2X7 receptor in mediating neuroinflammation and other pathogenic events in a variety of traumatic CNS damage conditions, which lead to loss of neurological and cognitive functions. We raise the perspective on the steady progress in developing CNS-penetrant P2X7 receptor-specific antagonists that leverage the ATP-P2X7 receptor signaling axis as a potential therapeutic strategy to alleviate traumatic CNS damage and related complications.
Collapse
Affiliation(s)
- Yaling Yin
- Sino‐UK Joint Laboratory of Brain Function and Injury of Henan Province, Department of Physiology and PathophysiologyXinxiang Medical UniversityXinxiangChina
| | - Linyu Wei
- Sino‐UK Joint Laboratory of Brain Function and Injury of Henan Province, Department of Physiology and PathophysiologyXinxiang Medical UniversityXinxiangChina
| | - Emily A. Caseley
- Faculty of Biological Sciences, School of Biomedical SciencesUniversity of LeedsLeedsUK
| | - Osbaldo Lopez‐Charcas
- EA4245, Transplantation, Immunology and Inflammation, Faculty of MedicineUniversity of ToursToursFrance
| | - Yingjuan Wei
- Sino‐UK Joint Laboratory of Brain Function and Injury of Henan Province, Department of Physiology and PathophysiologyXinxiang Medical UniversityXinxiangChina
| | - Dongliang Li
- Sino‐UK Joint Laboratory of Brain Function and Injury of Henan Province, Department of Physiology and PathophysiologyXinxiang Medical UniversityXinxiangChina
- Sanquan College of Xinxiang Medical UniversityXinxiangChina
| | - Steve P. Muench
- Faculty of Biological Sciences, School of Biomedical SciencesUniversity of LeedsLeedsUK
| | - Sebastian Roger
- EA4245, Transplantation, Immunology and Inflammation, Faculty of MedicineUniversity of ToursToursFrance
| | - Lu Wang
- Sino‐UK Joint Laboratory of Brain Function and Injury of Henan Province, Department of Physiology and PathophysiologyXinxiang Medical UniversityXinxiangChina
| | - Lin‐Hua Jiang
- Sino‐UK Joint Laboratory of Brain Function and Injury of Henan Province, Department of Physiology and PathophysiologyXinxiang Medical UniversityXinxiangChina
- Faculty of Biological Sciences, School of Biomedical SciencesUniversity of LeedsLeedsUK
| |
Collapse
|
19
|
Pelleg A, Sirtori E, Rolland JF, Mahadevan A. DT-0111: a novel P2X3 receptor antagonist. Purinergic Signal 2023; 19:467-479. [PMID: 36944825 PMCID: PMC10539268 DOI: 10.1007/s11302-023-09930-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2022] [Accepted: 03/06/2023] [Indexed: 03/23/2023] Open
Abstract
Extracellular adenosine 5'-triphosphate (ATP) acts as an autocrine and paracrine agent, the actions of which on affected cells are mediated by P2 receptors (P2R), which include trans cell-membrane cationic channels (P2XRs), and G protein coupled receptors (P2YRs). The mammalian P2X receptors form homotrimeric or heterotrimeric cationic channels, each of which contains three ATP-binding sites. There are seven homotrimeric P2X receptors (P2X1-7) and three heteromeric (P2X2/P2X3, P2X4/P2X6, P2X1/P2X5). In the lungs and airways, ATP activates P2X3 and P2X2/3 receptors (P2X3R, P2X2/3R, respectively) localized on vagal sensory nerve terminals resulting in bronchoconstriction, and cough, and probably also localized release of pro-inflammatory neuropeptides via the axon reflex. Currently, several P2X3R and P2X2/3R antagonists are being developed as drug-candidates for the treatment of chronic cough. This report presents the receptor affinity data of a novel water-soluble small molecule, DT-0111, that acts as a selective P2X3R antagonist.
Collapse
Affiliation(s)
- Amir Pelleg
- Danmir Therapeutics LLC, 24 Dartmouth Lane, Haverford, PA, 19041-1020, USA.
| | | | | | | |
Collapse
|
20
|
Chawla A, Largajolli A, Hussain A, Kleijn H, Ait‐Oudhia S, Anton J, Krishna Ananthula H, Nussbaum J, La Rosa C, Gheyas F. Population pharmacokinetic analysis of the P2X3-receptor antagonist gefapixant. CPT Pharmacometrics Syst Pharmacol 2023; 12:1107-1118. [PMID: 37147897 PMCID: PMC10431053 DOI: 10.1002/psp4.12978] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2023] [Accepted: 04/14/2023] [Indexed: 05/07/2023] Open
Abstract
Gefapixant, a P2X3-receptor antagonist, demonstrated objective and subjective efficacy in individuals with refractory or unexplained chronic cough. We report a population pharmacokinetic (PopPK) analysis that characterizes gefapixant pharmacokinetics (PKs), quantifies between- and within-participant variability, and evaluates the impact of intrinsic and extrinsic factors on gefapixant exposure. The PopPK model was initially developed using PK data from six phase I studies. Stepwise covariate method was utilized to identify covariates impacting PK parameters; the model was re-estimated and covariate effects were re-assessed after integrating PK data from three phase II and III studies. Simulations were conducted to evaluate the magnitude of covariate effects on gefapixant exposure. Of 1677 participants included in this data set, 1618 had evaluable PK records. Age, body weight, and sex had statistically significant, but not clinically relevant, effects on exposure. Degree of renal impairment (RI) had statistically significant and clinically relevant effects on exposure; exposure was 17% to 89% higher in those with versus without RI. Simulation results indicated that gefapixant 45 mg administered once daily to patients with severe RI has similar exposure to gefapixant 45 mg administered twice daily to patients with normal renal function. There were no significant effects of proton pump inhibitors or food. Of evaluated intrinsic and extrinsic factors, only RI had a clinically relevant effect on gefapixant exposure. Patients with mild or moderate RI do not require dosage adjustments; however, for patients with severe RI who are not on dialysis, gefapixant 45 mg once daily is recommended.
Collapse
Affiliation(s)
| | | | | | - Huub Kleijn
- Certara Strategic ConsultingPrincetonNew JerseyUSA
| | | | | | | | | | | | | |
Collapse
|
21
|
Al-Aqtash R, Ross MS, Collier DM. Extracellular histone proteins activate P2XR7 channel current. J Gen Physiol 2023; 155:e202213317. [PMID: 37199689 PMCID: PMC10200710 DOI: 10.1085/jgp.202213317] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Revised: 03/30/2023] [Accepted: 05/04/2023] [Indexed: 05/19/2023] Open
Abstract
Extracellular histone proteins are elevated in circulation after injury or activation of the innate immune response. In resistance-size arteries, extracellular histone proteins increased endothelial cell (EC) Ca2+ influx and propidium iodide (PI) labeling, but paradoxically decreased vasodilation. These observations could be explained by the activation of an EC resident non-selective cation channel. We tested the hypothesis that the ionotropic purinergic receptor 7 (P2XR7), a non-selective cation channel associated with cationic dye uptake, is activated by histone proteins. We expressed mouse P2XR7 (C57BL/6J variant 451L) in heterologous cells and measured inward cation current using two-electrode voltage clamp (TEVC). Cells expressing mouse P2XR7 had robust ATP- and histone-evoked inward cation currents. ATP- and histone-evoked currents reversed approximately at the same potential. Current decay with agonist removal was slower for histone-evoked than ATP- or BzATP-evoked currents. As with ATP-evoked P2XR7 currents, histone-evoked currents were inhibited by non-selective P2XR7 antagonists (Suramin, PPADS, and TNP-ATP). Selective P2XR7 antagonists, AZ10606120, A438079, GW791343, and AZ11645373, inhibited ATP-evoked P2XR7 currents but did not inhibit histone-evoked P2XR7 currents. As previously reported with ATP-evoked currents, histone-evoked P2XR7 currents were also increased in conditions of low extracellular Ca2+. These data demonstrate that P2XR7 is necessary and sufficient for histone-evoked inward cation currents in a heterologous expression system. These results provide insight into a new allosteric mechanism of P2XR7 activation by histone proteins.
Collapse
Affiliation(s)
- Rua’a Al-Aqtash
- Department of Pharmaceutical Sciences, University of Tennessee Health Science Center College of Pharmacy, Memphis, TN, USA
| | - Maxwell S. Ross
- Department of Pharmaceutical Sciences, University of Tennessee Health Science Center College of Pharmacy, Memphis, TN, USA
| | - Daniel M. Collier
- Department of Pharmaceutical Sciences, University of Tennessee Health Science Center College of Pharmacy, Memphis, TN, USA
| |
Collapse
|
22
|
Wu YY, Wang Q, Zhang PA, Zhu C, Xu GY. miR-1306-3p directly activates P2X3 receptors in primary sensory neurons to induce visceral pain in rats. Pain 2023; 164:1555-1565. [PMID: 36633528 PMCID: PMC10281022 DOI: 10.1097/j.pain.0000000000002853] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2022] [Revised: 10/23/2022] [Accepted: 11/08/2022] [Indexed: 01/13/2023]
Abstract
ABSTRACT Mounting evidence indicates that microRNAs (miRNAs) play critical roles in various pathophysiological conditions and diseases, but the physiological roles of extracellular miRNAs on the disease-related ion channels remain largely unknown. Here, we showed that miR-1306-3p evoked action potentials and induced inward currents of the acutely isolated rat dorsal root ganglion (DRG) neurons. The miR-1306-3p-induced effects were significantly inhibited by A317491, a potent inhibitor of the P2X3 receptor (P2X3R), or disappeared after the knockdown of P2X3Rs in DRG neurons. We further identified R180, K315, and R52 as the miR-1306-3p interaction sites on the extracellular domain of P2X3Rs, which were distinct from the orthosteric ATP-binding sites. Intrathecal injection of miR-1306-3p produced visceral pain but not somatic pain in normal control rats. Conversely, intrathecal application of a miR-1306-3p antagomir and A317491 significantly alleviated visceral pain in a rat model of chronic visceral pain. Together, our findings suggest that miR-1306-3p might function as an endogenous ligand to activate P2X3Rs, eventually leading to chronic visceral pain.
Collapse
Affiliation(s)
- Yan-Yan Wu
- Jiangsu Key Laboratory of Neuropsychiatric Diseases and Institute of Neuroscience, Soochow University, Suzhou, Jiangsu, P.R. China
- School of Life Sciences and Research Center for Resource Peptide Drugs, Shaanxi Engineering and Technological Research Center for Conversation and Utilization of Regional Biological Resources, Yanan University, Yanan, P. R. China
| | - Qian Wang
- Department of Anesthesiology, Children's Hospital of Soochow University, Suzhou, P.R. China
| | - Ping-An Zhang
- Jiangsu Key Laboratory of Neuropsychiatric Diseases and Institute of Neuroscience, Soochow University, Suzhou, Jiangsu, P.R. China
| | - Cheng Zhu
- Tianjin Key Laboratory of Function and Application of Biological Macromolecular Structures, School of Life Sciences, Tianjin University, Tianjin, P.R. China
| | - Guang-Yin Xu
- Jiangsu Key Laboratory of Neuropsychiatric Diseases and Institute of Neuroscience, Soochow University, Suzhou, Jiangsu, P.R. China
| |
Collapse
|
23
|
Cevoli F, Arnould B, Peralta FA, Grutter T. Untangling Macropore Formation and Current Facilitation in P2X7. Int J Mol Sci 2023; 24:10896. [PMID: 37446075 DOI: 10.3390/ijms241310896] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2023] [Revised: 06/26/2023] [Accepted: 06/28/2023] [Indexed: 07/15/2023] Open
Abstract
Macropore formation and current facilitation are intriguing phenomena associated with ATP-gated P2X7 receptors (P2X7). Macropores are large pores formed in the cell membrane that allow the passage of large molecules. The precise mechanisms underlying macropore formation remain poorly understood, but recent evidence suggests two alternative pathways: a direct entry through the P2X7 pore itself, and an indirect pathway triggered by P2X7 activation involving additional proteins, such as TMEM16F channel/scramblase. On the other hand, current facilitation refers to the progressive increase in current amplitude and activation kinetics observed with prolonged or repetitive exposure to ATP. Various mechanisms, including the activation of chloride channels and intrinsic properties of P2X7, have been proposed to explain this phenomenon. In this comprehensive review, we present an in-depth overview of P2X7 current facilitation and macropore formation, highlighting new findings and proposing mechanistic models that may offer fresh insights into these untangled processes.
Collapse
Affiliation(s)
- Federico Cevoli
- Équipe de Chimie et Neurobiologie Moléculaire, Laboratoire de Conception et Application de Molécules Bioactives (CAMB) UMR 7199, Centre National de la Recherche Scientifique, Faculté de Pharmacie, Université de Strasbourg, 67401 Illkirch, France
| | - Benoit Arnould
- Équipe de Chimie et Neurobiologie Moléculaire, Laboratoire de Conception et Application de Molécules Bioactives (CAMB) UMR 7199, Centre National de la Recherche Scientifique, Faculté de Pharmacie, Université de Strasbourg, 67401 Illkirch, France
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO 63130, USA
| | - Francisco Andrés Peralta
- Équipe de Chimie et Neurobiologie Moléculaire, Laboratoire de Conception et Application de Molécules Bioactives (CAMB) UMR 7199, Centre National de la Recherche Scientifique, Faculté de Pharmacie, Université de Strasbourg, 67401 Illkirch, France
- Instituto de Neurociencias, CSIC-UMH, 03550 San Juan de Alicante, Spain
| | - Thomas Grutter
- Équipe de Chimie et Neurobiologie Moléculaire, Laboratoire de Conception et Application de Molécules Bioactives (CAMB) UMR 7199, Centre National de la Recherche Scientifique, Faculté de Pharmacie, Université de Strasbourg, 67401 Illkirch, France
- University of Strasbourg Institute for Advanced Studies (USIAS), 67000 Strasbourg, France
| |
Collapse
|
24
|
Rupert M, Bhattacharya A, Sivcev S, Knezu M, Cimicka J, Zemkova H. Identification of residues in the first transmembrane domain of the P2X7 that regulates receptor trafficking, sensitization, and dye uptake function. J Neurochem 2023; 165:874-891. [PMID: 36945903 DOI: 10.1111/jnc.15813] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2022] [Revised: 02/24/2023] [Accepted: 03/14/2023] [Indexed: 03/23/2023]
Abstract
P2X receptors (P2X1-7) are trimeric ion channels activated by extracellular ATP. Each P2X subunit contains two transmembrane helices (TM1 and TM2). We substituted all residues in TM1 of rat P2X7 with alanine or leucine one by one, expressed mutants in HEK293T cells, and examined the pore permeability by recording both membrane currents and fluorescent dye uptake in response to agonist application. Alanine substitution of G27, K30, H34, Y40, F43, L45, M46, and D48 inhibited agonist-stimulated membrane current and dye uptake, and all but one substitution, D48A, prevented surface expression. Mutation V41A partially reduced both membrane current and dye uptake, while W31A and A44L showed reduced dye uptake not accompanied by reduced membrane current. Mutations T28A, I29A, and L33A showed small changes in agonist sensitivity, but they had no or small impact on dye uptake function. Replacing charged residues with residues of the same charge (K30R, H34K, and D48E) rescued receptor function, while replacement with residues of opposite charge inhibited (K30E and H34E) or potentiated (D48K) receptor function. Prolonged stimulation with agonist-induced current facilitation and a leftward shift in the dose-response curve in the P2X7 wild-type and most functional mutants, but sensitization was absent in the W31A, L33A, and A44L. Detailed analysis of the decay of responses revealed two kinetically distinct mechanisms of P2X7 deactivation: fast represents agonist unbinding, and slow might represent resetting of the receptor to the resting closed state. These results indicate that conserved and receptor-specific TM1 residues control surface expression of the P2X7 protein, non-polar residues control receptor sensitization, and D48 regulates intrinsic channel properties.
Collapse
Affiliation(s)
- Marian Rupert
- Institute of Physiology, Academy of Sciences of the Czech Republic, Prague, Czech Republic
- 1st Faculty of Medicine, Charles University in Prague, Prague, Czech Republic
| | - Anirban Bhattacharya
- Institute of Physiology, Academy of Sciences of the Czech Republic, Prague, Czech Republic
| | - Sonja Sivcev
- Institute of Physiology, Academy of Sciences of the Czech Republic, Prague, Czech Republic
- Faculty of Sciences, Charles University in Prague, Prague, Czech Republic
| | - Michal Knezu
- Institute of Physiology, Academy of Sciences of the Czech Republic, Prague, Czech Republic
- Faculty of Sciences, Charles University in Prague, Prague, Czech Republic
| | - Jana Cimicka
- Institute of Physiology, Academy of Sciences of the Czech Republic, Prague, Czech Republic
- 1st Faculty of Medicine, Charles University in Prague, Prague, Czech Republic
| | - Hana Zemkova
- Institute of Physiology, Academy of Sciences of the Czech Republic, Prague, Czech Republic
| |
Collapse
|
25
|
Xie W, Patel DJ. Structure-based mechanisms of 2'3'-cGAMP intercellular transport in the cGAS-STING immune pathway. Trends Immunol 2023; 44:450-467. [PMID: 37147228 DOI: 10.1016/j.it.2023.04.006] [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: 02/13/2023] [Revised: 04/03/2023] [Accepted: 04/04/2023] [Indexed: 05/07/2023]
Abstract
Upon activation by double-stranded DNA (dsDNA), the cytosolic dsDNA sensor cyclic GMP-AMP synthase (cGAS) synthesizes the diffusible cyclic dinucleotide 2'3'-cGAMP (cyclic GMP-AMP), which subsequently binds to the adaptor STING, triggering a cascade of events leading to an inflammatory response. Recent studies have highlighted the role of 2'3'-cGAMP as an 'immunotransmitter' between cells, a process facilitated by gap junctions as well as by specialized membrane-spanning importer and exporter channels. This review highlights recent advances from a structural perspective of intercellular trafficking of 2'3'-cGAMP, with particular emphasis on the binding of importer SLC19A1 to 2'3'-cGAMP, as well as the significance of associated folate nutrients and antifolate therapeutics. This provides a path forward for structure-guided understanding of the transport cycle in immunology, as well as for candidate targeting approaches towards therapeutic intervention in inflammation.
Collapse
Affiliation(s)
- Wei Xie
- College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, Zhejiang, 311027, China; Department of Infectious Diseases, Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, Zhejiang, 310009, China.
| | - Dinshaw J Patel
- Structural Biology Program, Memorial Sloan-Kettering Cancer Center, New York, NY 10065, USA.
| |
Collapse
|
26
|
Cherninskyi A, Storozhuk M, Maximyuk O, Kulyk V, Krishtal O. Triggering of Major Brain Disorders by Protons and ATP: The Role of ASICs and P2X Receptors. Neurosci Bull 2023; 39:845-862. [PMID: 36445556 PMCID: PMC9707125 DOI: 10.1007/s12264-022-00986-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Accepted: 08/14/2022] [Indexed: 11/30/2022] Open
Abstract
Adenosine triphosphate (ATP) is well-known as a universal source of energy in living cells. Less known is that this molecule has a variety of important signaling functions: it activates a variety of specific metabotropic (P2Y) and ionotropic (P2X) receptors in neuronal and non-neuronal cell membranes. So, a wide variety of signaling functions well fits the ubiquitous presence of ATP in the tissues. Even more ubiquitous are protons. Apart from the unspecific interaction of protons with any protein, many physiological processes are affected by protons acting on specific ionotropic receptors-acid-sensing ion channels (ASICs). Both protons (acidification) and ATP are locally elevated in various pathological states. Using these fundamentally important molecules as agonists, ASICs and P2X receptors signal a variety of major brain pathologies. Here we briefly outline the physiological roles of ASICs and P2X receptors, focusing on the brain pathologies involving these receptors.
Collapse
Affiliation(s)
- Andrii Cherninskyi
- Bogomoletz Institute of Physiology of National Academy of Sciences of Ukraine, Kyiv, 01024, Ukraine.
| | - Maksim Storozhuk
- Bogomoletz Institute of Physiology of National Academy of Sciences of Ukraine, Kyiv, 01024, Ukraine
| | - Oleksandr Maximyuk
- Bogomoletz Institute of Physiology of National Academy of Sciences of Ukraine, Kyiv, 01024, Ukraine
| | - Vyacheslav Kulyk
- Bogomoletz Institute of Physiology of National Academy of Sciences of Ukraine, Kyiv, 01024, Ukraine
| | - Oleg Krishtal
- Bogomoletz Institute of Physiology of National Academy of Sciences of Ukraine, Kyiv, 01024, Ukraine
| |
Collapse
|
27
|
Luo L, Roy S, Li L, Ma M. Polycystic kidney disease: novel insights into polycystin function. Trends Mol Med 2023; 29:268-281. [PMID: 36805211 DOI: 10.1016/j.molmed.2023.01.005] [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: 07/24/2022] [Revised: 01/18/2023] [Accepted: 01/24/2023] [Indexed: 02/17/2023]
Abstract
Autosomal dominant polycystic kidney disease (ADPKD) is a life-threatening monogenic disease caused by mutations in PKD1 and PKD2 that encode polycystin 1 (PC1) and polycystin 2 (PC2). PC1/2 localize to cilia of renal epithelial cells, and their function is believed to embody an inhibitory activity that suppresses the cilia-dependent cyst activation (CDCA) signal. Consequently, PC deficiency results in activation of CDCA and stimulates cyst growth. Recently, re-expression of PCs in established cysts has been shown to reverse PKD. Thus, the mode of action of PCs resembles a 'counterbalance in cruise control' to maintain lumen diameter within a designated range. Herein we review recent studies that point to novel arenas for future PC research with therapeutic potential for ADPKD.
Collapse
Affiliation(s)
- Lingfei Luo
- Institute of Developmental Biology and Regenerative Medicine, Southwest University, Beibei, Chongqing, 400715, China
| | - Sudipto Roy
- Institute of Molecular and Cell Biology, Agency for Science, Technology and Research, Proteos, 61 Biopolis Drive, Singapore, 138673, Singapore; Department of Paediatrics, Yong Loo Lin School of Medicine, National University of Singapore, 1E Kent Ridge Road, Singapore, 119288, Singapore; Department of Biological Sciences, National University of Singapore, 14 Science Drive 4, Singapore, 117543, Singapore
| | - Li Li
- Institute of Developmental Biology and Regenerative Medicine, Southwest University, Beibei, Chongqing, 400715, China; Research Center of Stem cells and Ageing, Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing, 400714, China
| | - Ming Ma
- Institute of Developmental Biology and Regenerative Medicine, Southwest University, Beibei, Chongqing, 400715, China.
| |
Collapse
|
28
|
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: 4.0] [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.
Collapse
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
| |
Collapse
|
29
|
Grohs L, Cheng L, Cönen S, Haddad BG, Bülow A, Toklucu I, Ernst L, Körner J, Schmalzing G, Lampert A, Machtens JP, Hausmann R. Diclofenac and other non-steroidal anti-inflammatory drugs (NSAIDs) are competitive antagonists of the human P2X3 receptor. Front Pharmacol 2023; 14:1120360. [PMID: 37007008 PMCID: PMC10060569 DOI: 10.3389/fphar.2023.1120360] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Accepted: 02/24/2023] [Indexed: 03/18/2023] Open
Abstract
Introduction: The P2X3 receptor (P2X3R), an ATP-gated non-selective cation channel of the P2X receptor family, is expressed in sensory neurons and involved in nociception. P2X3R inhibition was shown to reduce chronic and neuropathic pain. In a previous screening of 2000 approved drugs, natural products, and bioactive substances, various non-steroidal anti-inflammatory drugs (NSAIDs) were found to inhibit P2X3R-mediated currents.Methods: To investigate whether the inhibition of P2X receptors contributes to the analgesic effect of NSAIDs, we characterized the potency and selectivity of various NSAIDs at P2X3R and other P2XR subtypes using two-electrode voltage clamp electrophysiology.Results: We identified diclofenac as a hP2X3R and hP2X2/3R antagonist with micromolar potency (with IC50 values of 138.2 and 76.7 µM, respectively). A weaker inhibition of hP2X1R, hP2X4R, and hP2X7R by diclofenac was determined. Flufenamic acid (FFA) inhibited hP2X3R, rP2X3R, and hP2X7R (IC50 values of 221 µM, 264.1 µM, and ∼900 µM, respectively), calling into question its use as a non-selective ion channel blocker, when P2XR-mediated currents are under study. Inhibition of hP2X3R or hP2X2/3R by diclofenac could be overcome by prolonged ATP application or increasing concentrations of the agonist α,β-meATP, respectively, indicating competition of diclofenac and the agonists. Molecular dynamics simulation showed that diclofenac largely overlaps with ATP bound to the open state of the hP2X3R. Our results suggest a competitive antagonism through which diclofenac, by interacting with residues of the ATP-binding site, left flipper, and dorsal fin domains, inhibits the gating of P2X3R by conformational fixation of the left flipper and dorsal fin domains. In summary, we demonstrate the inhibition of the human P2X3 receptor by various NSAIDs. Diclofenac proved to be the most effective antagonist with a strong inhibition of hP2X3R and hP2X2/3R and a weaker inhibition of hP2X1R, hP2X4R, and hP2X7R.Discussion: Considering their involvement in nociception, inhibition of hP2X3R and hP2X2/3R by micromolar concentrations of diclofenac, which are rarely reached in the therapeutic range, may play a minor role in analgesia compared to the high-potency cyclooxygenase inhibition but may explain the known side effect of taste disturbances caused by diclofenac.
Collapse
Affiliation(s)
- Laura Grohs
- Institute of Clinical Pharmacology, RWTH Aachen University, Aachen, Germany
- Department of Neurology, University Hospital, RWTH Aachen University, Aachen, Germany
| | - Linhan Cheng
- Institute of Clinical Pharmacology, RWTH Aachen University, Aachen, Germany
| | - Saskia Cönen
- Institute of Clinical Pharmacology, RWTH Aachen University, Aachen, Germany
- Molecular and Cellular Physiology (IBI-1), Institute of Biological Information Processing (IBI), Forschungszentrum Jülich, Jülich, Germany
| | - Bassam G. Haddad
- Molecular and Cellular Physiology (IBI-1), Institute of Biological Information Processing (IBI), Forschungszentrum Jülich, Jülich, Germany
| | - Astrid Bülow
- Institute of Clinical Pharmacology, RWTH Aachen University, Aachen, Germany
- Department of Plastic Surgery, Hand Surgery—Burn Center, University Hospital, RWTH Aachen University, Aachen, Germany
| | - Idil Toklucu
- Institute of Physiology (Neurophysiology), RWTH Aachen University, Aachen, Germany
| | - Lisa Ernst
- Institute for Laboratory Animal Science and Experimental Surgery, RWTH Aachen University, Aachen, Germany
| | - Jannis Körner
- Institute of Physiology (Neurophysiology), RWTH Aachen University, Aachen, Germany
- Department of Anesthesiology, University Hospital, RWTH Aachen University, Aachen, Germany
| | - Günther Schmalzing
- Institute of Clinical Pharmacology, RWTH Aachen University, Aachen, Germany
| | - Angelika Lampert
- Institute of Physiology (Neurophysiology), RWTH Aachen University, Aachen, Germany
| | - Jan-Philipp Machtens
- Institute of Clinical Pharmacology, RWTH Aachen University, Aachen, Germany
- Molecular and Cellular Physiology (IBI-1), Institute of Biological Information Processing (IBI), Forschungszentrum Jülich, Jülich, Germany
| | - Ralf Hausmann
- Institute of Clinical Pharmacology, RWTH Aachen University, Aachen, Germany
- *Correspondence: Ralf Hausmann,
| |
Collapse
|
30
|
Optical control of PIEZO1 channels. Nat Commun 2023; 14:1269. [PMID: 36882406 PMCID: PMC9992513 DOI: 10.1038/s41467-023-36931-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Accepted: 02/24/2023] [Indexed: 03/09/2023] Open
Abstract
PIEZO proteins are unusually large, mechanically-activated trimeric ion channels. The central pore features structural similarities with the pore of other trimeric ion channels, including purinergic P2X receptors, for which optical control of channel gating has been previously achieved with photoswitchable azobenzenes. Extension of these chemical optogenetics methods to mechanically-activated ion channels would provide tools for specific manipulation of pore activity alternative to non-specific mechanical stimulations. Here we report a light-gated mouse PIEZO1 channel, in which an azobenzene-based photoswitch covalently tethered to an engineered cysteine, Y2464C, localized at the extracellular apex of the transmembrane helix 38, rapidly triggers channel gating upon 365-nm-light irradiation. We provide evidence that this light-gated channel recapitulates mechanically-activated PIEZO1 functional properties, and show that light-induced molecular motions are similar to those evoked mechanically. These results push the limits of azobenzene-based methods to unusually large ion channels and provide a simple stimulation means to specifically interrogate PIEZO1 function.
Collapse
|
31
|
How the Competition for Cysteine May Promote Infection of SARS-CoV-2 by Triggering Oxidative Stress. Antioxidants (Basel) 2023; 12:antiox12020483. [PMID: 36830041 PMCID: PMC9952211 DOI: 10.3390/antiox12020483] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2022] [Revised: 02/07/2023] [Accepted: 02/10/2023] [Indexed: 02/17/2023] Open
Abstract
SARS-CoV-2 induces a broad range of clinical manifestations. Besides the main receptor, ACE2, other putative receptors and co-receptors have been described and could become genuinely relevant to explain the different tropism manifested by new variants. In this study, we propose a biochemical model envisaging the competition for cysteine as a key mechanism promoting the infection and the selection of host receptors. The SARS-CoV-2 infection produces ROS and triggers a massive biosynthesis of proteins rich in cysteine; if this amino acid becomes limiting, glutathione levels are depleted and cannot control oxidative stress. Hence, infection succeeds. A receptor should be recognized as a marker of suitable intracellular conditions, namely the full availability of amino acids except for low cysteine. First, we carried out a comparative investigation of SARS-CoV-2 proteins and human ACE2. Then, using hierarchical cluster protein analysis, we searched for similarities between all human proteins and spike produced by the latest variant, Omicron BA.1. We found 32 human proteins very close to spike in terms of amino acid content. Most of these potential SARS-CoV-2 receptors have less cysteine than spike. We suggest that these proteins could signal an intracellular shortage of cysteine, predicting a burst of oxidative stress when used as viral entry mediators.
Collapse
|
32
|
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: 3.0] [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.
Collapse
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,
| |
Collapse
|
33
|
Giniatullin R, Nistri A. Role of ATP in migraine mechanisms: focus on P2X3 receptors. J Headache Pain 2023; 24:1. [PMID: 36597043 PMCID: PMC9809127 DOI: 10.1186/s10194-022-01535-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Accepted: 12/16/2022] [Indexed: 01/04/2023] Open
Abstract
Migraine is a major health burden worldwide with complex pathophysiology and multifarious underlying mechanisms. One poorly understood issue concerns the early steps in the generation of migraine pain. To elucidate the basic process of migraine pain further, it seems useful to consider key molecular players that may operate synergistically to evoke headache. While the neuropeptide CGRP is an important contributor, we propose that extracellular ATP (that generally plays a powerful nociceptive role) is also a major component of migraine headache, acting in concert with CGRP to stimulate trigeminal nociceptive neurons. The aim of the present focused review is to highlight the role of ATP activating its P2X3 membrane receptors selectively expressed by sensory neurons including their nerve fiber terminals in the meninges. Specifically, we present data on the homeostasis of ATP and related purines in the trigeminovascular system and in the CNS; the basic properties of ATP signalling at peripheral and central nerve terminals; the characteristics of P2X3 and related receptors in trigeminal neurons; the critical speed and persistence of P2X3 receptor activity; their cohabitation at the so-called meningeal neuro-immune synapse; the identity of certain endogenous agents cooperating with ATP to induce neuronal sensitization in the trigeminal sensory system; the role of P2X3 receptors in familial type migraine; the current state of P2X3 receptor antagonists and their pharmacological perspectives in migraine. It is proposed that the unique kinetic properties of P2X3 receptors activated by ATP offer an interesting translational value to stimulate future studies for innovative treatments of migraine pain.
Collapse
Affiliation(s)
- R. Giniatullin
- grid.9668.10000 0001 0726 2490A.I Virtanen Institute, University of Eastern Finland, 70211 Kuopio, Finland
| | - A. Nistri
- grid.5970.b0000 0004 1762 9868Department of Neuroscience, International School for Advanced Studies (SISSA), 34136 Trieste, Italy
| |
Collapse
|
34
|
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: 0] [Impact Index Per Article: 0] [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.
Collapse
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
| |
Collapse
|
35
|
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.
Collapse
|
36
|
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]
|
37
|
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: 2.0] [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.
Collapse
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
| |
Collapse
|
38
|
Genetzakis E, Gilchrist J, Kassiou M, Figtree GA. Development and clinical translation of P2X7 receptor antagonists: A potential therapeutic target in coronary artery disease? Pharmacol Ther 2022; 237:108228. [DOI: 10.1016/j.pharmthera.2022.108228] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Revised: 05/17/2022] [Accepted: 06/06/2022] [Indexed: 12/12/2022]
|
39
|
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.
Collapse
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
| |
Collapse
|
40
|
AI-based prediction of new binding site and virtual screening for the discovery of novel P2X3 receptor antagonists. Eur J Med Chem 2022; 240:114556. [DOI: 10.1016/j.ejmech.2022.114556] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2022] [Revised: 06/15/2022] [Accepted: 06/18/2022] [Indexed: 11/17/2022]
|
41
|
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: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [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.
Collapse
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
- *Correspondence: Steven E. Mansoor,
| |
Collapse
|
42
|
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: 3.5] [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.
Collapse
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
| |
Collapse
|
43
|
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] [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.
Collapse
Affiliation(s)
- Xue-Fei Ma
- College of Bioscience and Biotechnology, Hunan Agricultural University, Changsha 410128, China; School of Basic Medicine and Clinical Pharmacy and State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing 210009, China
| | - Ting-Ting Wang
- School of Basic Medicine and Clinical Pharmacy and State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing 210009, China
| | - Wen-Hui Wang
- School of Basic Medicine and Clinical Pharmacy and State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing 210009, China
| | - Li Guan
- School of Basic Medicine and Clinical Pharmacy and State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing 210009, China
| | - Chang-Run Guo
- School of Basic Medicine and Clinical Pharmacy and State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing 210009, China
| | - Xing-Hua Li
- School of Basic Medicine and Clinical Pharmacy and State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing 210009, China
| | - Yun-Tao Lei
- School of Basic Medicine and Clinical Pharmacy and State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing 210009, China
| | - Ying-Zhe Fan
- Putuo Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai 200062, China
| | - Xiao-Na Yang
- School of Basic Medicine and Clinical Pharmacy and State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing 210009, 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 200438, China
| | - Osamu Nureki
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, 2-11-16 Yayoi, Bunkyo-ku, Tokyo 113-0032, Japan
| | - Michael X Zhu
- Department of Integrative Biology and Pharmacology, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, TX 77030, USA
| | - Ye Yu
- School of Basic Medicine and Clinical Pharmacy and State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing 210009, China.
| | - Yun Tian
- College of Bioscience and Biotechnology, Hunan Agricultural University, Changsha 410128, China.
| | - Jin Wang
- School of Basic Medicine and Clinical Pharmacy and State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing 210009, China.
| |
Collapse
|
44
|
Dane C, Stokes L, Jorgensen WT. P2X Receptor Antagonists and their Potential as Therapeutics: a patent review (2010 - 2021). Expert Opin Ther Pat 2022; 32:769-790. [PMID: 35443137 DOI: 10.1080/13543776.2022.2069010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
INTRODUCTION : Purinergic receptors play a critical role in neurotransmission, and modulation of complex physiological functions. As such, they have been implicated in numerous disease states including chronic pain, inflammation, autoimmune disease, and cancer. The past decade has seen substantial progress in the design of novel chemical compounds that act on the P2X class of receptors and warrants an updated review of this field. AREAS COVERED : This review provides a summary of the patent literature describing the discovery and clinical uses of P2X receptor antagonists published between 2010 and September 2021. The reader will gain information on structural claims, representative structures, and biological data of recently reported antagonists for seven P2X receptor subtypes. EXPERT OPINION : The potential for therapeutic intervention through the design and use of purinergic receptor inhibitors is pharmacologically well defined. Despite continual advancement in both crystallography and chemical biology strengthening our understanding of purinergic signalling and their roles in pathophysiology, there remains a vast absence of clinically approved chemical modalities. A testament to both the therapeutic potential and academic perseverance in purinergic research is the multitude of research initiatives and pharmaceutical campaigns that maintain active P2X receptor programs that have spanned decades. Very recently, the FDA declined Merck Pharmaceuticals application for Gefapixant, a P2X3 selective inhibitor as a treatment for chronic cough, requesting additional data. This unfortunate setback within the field will ultimately be insignificant considering the long history of P2X investigation and the preclinical and clinical development that would undoubtedly occur over the next decade.
Collapse
Affiliation(s)
- Chianna Dane
- School of Chemistry, The University of Sydney, NSW 2006, Australia
| | - Leanne Stokes
- School of Pharmacy, University of East Anglia, Norwich Research Park, Norwich NR47TJ
| | | |
Collapse
|
45
|
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: 1.0] [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+.
Collapse
|
46
|
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.
Collapse
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
| | | | | |
Collapse
|
47
|
Schiller IC, Jacobson KA, Wen Z, Malisetty A, Schmalzing G, Markwardt F. Dihydropyridines Potentiate ATP-Induced Currents Mediated by the Full-Length Human P2X5 Receptor. Molecules 2022; 27:molecules27061846. [PMID: 35335209 PMCID: PMC8948676 DOI: 10.3390/molecules27061846] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Revised: 03/09/2022] [Accepted: 03/09/2022] [Indexed: 02/06/2023] Open
Abstract
The P2X5 receptor, an ATP-gated cation channel, is believed to be involved in tumor development, inflammatory bone loss and inflammasome activation after bacterial infection. Therefore, it is a worthwhile pharmacological target to treat the corresponding diseases, especially in minority populations that have a gene variant coding for functional homotrimeric P2X5 channels. Here, we investigated the effects of dihydropyridines on the human full-length P2X5 receptor (hP2X5FL) heterologously expressed in Xenopus oocytes using the two-microelectrode voltage clamp method. Agonist dependency, kinetics and permeation behavior, including Cl− permeability, were similar to hP2X5FL expressed in HEK293 or 1321N1 cells. Additionally, 1,4-dihydropyridines have been shown to interact with various other purinergic receptors, and we have examined them as potential hP2X5 modulators. Of seven commercially available and four newly synthesized dihydropyridines tested at hP2X5FL, only amlodipine exerted an inhibitory effect, but only at a high concentration of 300 µM. Isradipine and—even more—nimodipine stimulated ATP-induced currents in the low micromolar range. We conclude that common dihydropyridines or four new derivatives of amlodipine are not suitable as hP2X5 antagonists, but amlodipine might serve as a lead for future synthesis to increase its affinity. Furthermore, a side effect of nimodipine therapy could be a stimulatory effect on inflammatory processes.
Collapse
Affiliation(s)
- Ida C. Schiller
- Julius-Bernstein-Institute for Physiology, Martin-Luther-University Halle-Wittenberg, Magdeburger Str. 6, 06097 Halle, Germany;
| | - Kenneth A. Jacobson
- Laboratory of Bioorganic Chemistry & Molecular Recognition Section, National Institute of Diabetes & Digestive & Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA; (K.A.J.); (Z.W.)
| | - Zhiwei Wen
- Laboratory of Bioorganic Chemistry & Molecular Recognition Section, National Institute of Diabetes & Digestive & Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA; (K.A.J.); (Z.W.)
| | - Aparna Malisetty
- Institute of Clinical Pharmacology, RWTH Aachen University, Wendlingweg 2, 52074 Aachen, Germany; (A.M.); (G.S.)
| | - Günther Schmalzing
- Institute of Clinical Pharmacology, RWTH Aachen University, Wendlingweg 2, 52074 Aachen, Germany; (A.M.); (G.S.)
| | - Fritz Markwardt
- Julius-Bernstein-Institute for Physiology, Martin-Luther-University Halle-Wittenberg, Magdeburger Str. 6, 06097 Halle, Germany;
- Correspondence:
| |
Collapse
|
48
|
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: 6] [Impact Index Per Article: 3.0] [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.
Collapse
|
49
|
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: 3.0] [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.
Collapse
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.
| |
Collapse
|
50
|
The Role of ATP Receptors in Pain Signaling. Neurochem Res 2022; 47:2454-2468. [DOI: 10.1007/s11064-021-03516-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Revised: 12/11/2021] [Accepted: 12/22/2021] [Indexed: 12/21/2022]
|