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Leão Batista Simões J, Webler Eichler S, Raitz Siqueira ML, de Carvalho Braga G, Bagatini MD. Amyotrophic Lateral Sclerosis in Long-COVID Scenario and the Therapeutic Potential of the Purinergic System in Neuromodulation. Brain Sci 2024; 14:180. [PMID: 38391754 PMCID: PMC10886908 DOI: 10.3390/brainsci14020180] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2024] [Revised: 02/10/2024] [Accepted: 02/13/2024] [Indexed: 02/24/2024] Open
Abstract
Amyotrophic lateral sclerosis (ALS) involves the degeneration of motor neurons and debilitating and possibly fatal symptoms. The COVID-19 pandemic directly affected the quality of life of this group, and the SARS-CoV-2 infection accelerated the present neuroinflammatory process. Furthermore, studies indicate that the infection may have led to the development of the pathology. Thus, the scenario after this pandemic presents "long-lasting COVID" as a disease that affects people who have been infected. From this perspective, studying the pathophysiology behind ALS associated with SARS-CoV-2 infection and possible supporting therapies becomes necessary when we understand the impact on the quality of life of these patients. Thus, the purinergic system was trained to demonstrate how its modulation can add to the treatment, reduce disease progression, and result in better prognoses. From our studies, we highlight the P2X7, P2X4, and A2AR receptors and how their activity can directly influence the ALS pathway.
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Affiliation(s)
| | | | | | | | - Margarete Dulce Bagatini
- Graduate Program in Medical Sciences, Federal University of Fronteira Sul, Chapecó 89815-899, SC, Brazil
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2
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Dumazer A, Gómez-Santacana X, Malhaire F, Jopling C, Maurel D, Lebon G, Llebaria A, Goudet C. Optical Control of Adenosine A 2A Receptor Using Istradefylline Photosensitivity. ACS Chem Neurosci 2024; 15:645-655. [PMID: 38275568 DOI: 10.1021/acschemneuro.3c00721] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2024] Open
Abstract
In recent years, there has been growing interest in the potential therapeutic use of inhibitors of adenosine A2A receptors (A2AR) for the treatment of neurodegenerative diseases and cancer. Nevertheless, the widespread expression of A2AR throughout the body emphasizes the importance of temporally and spatially selective ligands. Photopharmacology is an emerging strategy that utilizes photosensitive ligands to attain high spatiotemporal precision and regulate the function of biomolecules using light. In this study, we combined photochemistry and cellular and in vivo photopharmacology to investigate the light sensitivity of the FDA-approved antagonist istradefylline and its potential use as an A2AR photopharmacological tool. Our findings reveal that istradefylline exhibits rapid trans-to-cis isomerization under near-UV light, and prolonged exposure results in the formation of photocycloaddition products. We demonstrate that exposure to UV light triggers a time-dependent decrease in the antagonistic activity of istradefylline in A2AR-expressing cells and enables real-time optical control of A2AR signaling in living cells and zebrafish. Together, these data demonstrate that istradefylline is a photoinactivatable A2AR antagonist and that this property can be utilized to perform photopharmacological experiments in living cells and animals.
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Affiliation(s)
- Anaëlle Dumazer
- IGF, Université de Montpellier, CNRS, INSERM, 34094 Montpellier, France
- MCS, Laboratory of Medicinal Chemistry and Synthesis, Institute of Advanced Chemistry of Catalonia (IQAC-CSIC), 08034 Barcelona, Spain
| | - Xavier Gómez-Santacana
- MCS, Laboratory of Medicinal Chemistry and Synthesis, Institute of Advanced Chemistry of Catalonia (IQAC-CSIC), 08034 Barcelona, Spain
| | - Fanny Malhaire
- IGF, Université de Montpellier, CNRS, INSERM, 34094 Montpellier, France
| | - Chris Jopling
- IGF, Université de Montpellier, CNRS, INSERM, 34094 Montpellier, France
| | - Damien Maurel
- IGF, Université de Montpellier, CNRS, INSERM, 34094 Montpellier, France
| | - Guillaume Lebon
- IGF, Université de Montpellier, CNRS, INSERM, 34094 Montpellier, France
| | - Amadeu Llebaria
- MCS, Laboratory of Medicinal Chemistry and Synthesis, Institute of Advanced Chemistry of Catalonia (IQAC-CSIC), 08034 Barcelona, Spain
| | - Cyril Goudet
- IGF, Université de Montpellier, CNRS, INSERM, 34094 Montpellier, France
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3
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McDonald F. Releasing the breaks on breathing frequency. Exp Physiol 2023; 108:1370-1371. [PMID: 37720963 PMCID: PMC10988514 DOI: 10.1113/ep091467] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2023] [Accepted: 09/05/2023] [Indexed: 09/19/2023]
Affiliation(s)
- Fiona McDonald
- Department of Physiology, School of Medicine, College of Medicine and HealthUniversity College CorkCorkIreland
- INFANT Research CentreUniversity College CorkCorkIreland
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Ai Y, Wang H, Liu L, Qi Y, Tang S, Tang J, Chen N. Purine and purinergic receptors in health and disease. MedComm (Beijing) 2023; 4:e359. [PMID: 37692109 PMCID: PMC10484181 DOI: 10.1002/mco2.359] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2023] [Revised: 08/07/2023] [Accepted: 08/10/2023] [Indexed: 09/12/2023] Open
Abstract
Purines and purinergic receptors are widely distributed throughout the human body. Purine molecules within cells play crucial roles in regulating energy metabolism and other cellular processes, while extracellular purines transmit signals through specific purinergic receptors. The ubiquitous purinergic signaling maintains normal neural excitability, digestion and absorption, respiratory movement, and other complex physiological activities, and participates in cell proliferation, differentiation, migration, and death. Pathological dysregulation of purinergic signaling can result in the development of various diseases, including neurodegeneration, inflammatory reactions, and malignant tumors. The dysregulation or dysfunction of purines and purinergic receptors has been demonstrated to be closely associated with tumor progression. Compared with other subtypes of purinergic receptors, the P2X7 receptor (P2X7R) exhibits distinct characteristics (i.e., a low affinity for ATP, dual functionality upon activation, the mediation of ion channels, and nonselective pores formation) and is considered a promising target for antitumor therapy, particularly in patients with poor response to immunotherapy This review summarizes the physiological and pathological significance of purinergic signaling and purinergic receptors, analyzes their complex relationship with tumors, and proposes potential antitumor immunotherapy strategies from tumor P2X7R inhibition, tumor P2X7R overactivation, and host P2X7R activation. This review provides a reference for clinical immunotherapy and mechanism investigation.
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Affiliation(s)
- Yanling Ai
- Department of OncologyHospital of Chengdu University of Traditional Chinese MedicineChengduChina
| | - Hengyi Wang
- Department of Infectious DiseasesHospital of Chengdu University of Traditional Chinese MedicineChengduChina
| | - Lu Liu
- School of PharmacyChengdu University of Traditional Chinese MedicineChengduChina
| | - Yulin Qi
- Department of OphthalmologyThe First Affiliated Hospital of Guangzhou University of Chinese MedicineGuangzhou University of Chinese MedicineGuangzhouChina
- Postdoctoral Research Station of Guangzhou University of Chinese MedicineGuangzhouChina
| | - Shiyun Tang
- Hospital of Chengdu University of Traditional Chinese MedicineChengduChina
| | - Jianyuan Tang
- TCM Regulating Metabolic Diseases Key Laboratory of Sichuan ProvinceHospital of Chengdu University of Traditional Chinese MedicineChengduChina
| | - Nianzhi Chen
- State Key Laboratory of Ultrasound in Medicine and EngineeringCollege of Biomedical EngineeringChongqing Medical UniversityChongqingChina
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5
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Townsend EA, Guadarrama A, Shi L, Roti Roti E, Denlinger LC. P2X 7 signaling influences the production of pro-resolving and pro-inflammatory lipid mediators in alveolar macrophages derived from individuals with asthma. Am J Physiol Lung Cell Mol Physiol 2023; 325:L399-L410. [PMID: 37581221 PMCID: PMC10639011 DOI: 10.1152/ajplung.00070.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Revised: 07/26/2023] [Accepted: 07/27/2023] [Indexed: 08/16/2023] Open
Abstract
Few new therapeutics exist to target airway inflammation in mild-to-moderate asthma. Alveolar macrophages regulate airway inflammation by producing proresolving eicosanoids. We hypothesized that stimulation of the purinergic receptor P2X7 in macrophages from individuals with asthma produces eicosanoids associated with airway inflammation and resolution, and that these responses are predicted, in part, by P2X7 pore function. Study subjects were recruited in an Institutional Review Board (IRB)-approved study. Alveolar macrophages were recovered from bronchoalveolar lavage fluid following bronchoscopy. Purinergic receptor classification was performed using flow cytometry and fluorescent cell assay. Macrophages were stimulated in vitro and eicosanoids were measured via ELISA or enzyme immunoassay (EIA) in the presence and absence of P2X7-specific agonist [2'(3')-O-(4-Benzoylbenzoyl)adenosine-5'-triphosphate tri(triethylammonium) salt (Bz-ATP)] and antagonist (AZD9056). Functional P2X7 pore status was confirmed in a live cell assay using P2X7-specific agonists and antagonists. Alveolar macrophages produced increased quantities of the oxylipins lipoxin A4 (LXA4), resolvin D1 (RvD1), and 15(S)-hydroxyeicosatetraenoic acid (15(S)-HETE) following stimulation with Bz-ATP compared with vehicle controls, responses that were attenuated in the presence of the P2X7-selective antagonist, AZD9056. LXA4 and RvD1 production was greatest at 1 h, whereas 15(S)-HETE was maximally produced 24 h. Prostaglandin E-2 and resolvin E1 were minimally produced by P2X7 activation, indicating differential signaling pathways involved in eicosanoid production in alveolar macrophages derived from individuals with asthma. The early production of the proresolving eicosanoids, LXA4 and resolvin D1, is regulated by P2X7, whereas generation of the proinflammatory eicosanoid, 15(S)-HETE, is only partially regulated through P2X7 signaling and reaches maximal production after the peak in proresolving eicosanoids.NEW & NOTEWORTHY Alveolar macrophages obtained from individuals with asthma produce soluble lipid mediators in response to P2X7 purinergic receptor signaling. Proinflammatory mediators may contribute to asthma exacerbations but proresolving mediators may help with resolution of asthma loss of control. These specialized proresolving lipid mediators may serve as future potential therapeutics for asthma exacerbation resolution and recovery.
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Affiliation(s)
- Elizabeth A Townsend
- Department of Anesthesiology, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, United States
| | - Arturo Guadarrama
- Division of Allergy, Pulmonary and Critical Care Medicine, Department of Medicine, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, United States
| | - Lei Shi
- Division of Allergy, Pulmonary and Critical Care Medicine, Department of Medicine, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, United States
| | - Elon Roti Roti
- Division of Allergy, Pulmonary and Critical Care Medicine, Department of Medicine, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, United States
| | - Loren C Denlinger
- Division of Allergy, Pulmonary and Critical Care Medicine, Department of Medicine, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, United States
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Aresta Branco MSL, Gutierrez Cruz A, Borhani Peikani M, Mutafova-Yambolieva VN. Sensory Neurons, PIEZO Channels and PAC1 Receptors Regulate the Mechanosensitive Release of Soluble Ectonucleotidases in the Murine Urinary Bladder Lamina Propria. Int J Mol Sci 2023; 24:ijms24087322. [PMID: 37108490 PMCID: PMC10138949 DOI: 10.3390/ijms24087322] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2023] [Revised: 04/11/2023] [Accepted: 04/13/2023] [Indexed: 04/29/2023] Open
Abstract
The urinary bladder requires adequate concentrations of extracellular adenosine 5'-triphosphate (ATP) and other purines at receptor sites to function properly. Sequential dephosphorylation of ATP to ADP, AMP and adenosine (ADO) by membrane-bound and soluble ectonucleotidases (s-ENTDs) is essential for achieving suitable extracellular levels of purine mediators. S-ENTDs, in particular, are released in the bladder suburothelium/lamina propria (LP) in a mechanosensitive manner. Using 1,N6-etheno-ATP (eATP) as substrate and sensitive HPLC-FLD methodology, we evaluated the degradation of eATP to eADP, eAMP and eADO in solutions that were in contact with the LP of ex vivo mouse detrusor-free bladders during filling prior to substrate addition. The inhibition of neural activity with tetrodotoxin and ω-conotoxin GVIA, of PIEZO channels with GsMTx4 and D-GsMTx4 and of the pituitary adenylate cyclase-activating polypeptide type I receptor (PAC1) with PACAP6-38 all increased the distention-induced but not spontaneous release of s-ENTDs in LP. It is conceivable, therefore, that the activation of these mechanisms in response to distention restricts the further release of s-ENTDs and prevents excessive hydrolysis of ATP. Together, these data suggest that afferent neurons, PIEZO channels, PAC1 receptors and s-ENTDs form a system that operates a highly regulated homeostatic mechanism to maintain proper extracellular purine concentrations in the LP and ensure normal bladder excitability during bladder filling.
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Affiliation(s)
- Mafalda S L Aresta Branco
- Department of Physiology and Cell Biology, School of Medicine, University of Nevada, Reno, NV 89557, USA
| | - Alejandro Gutierrez Cruz
- Department of Physiology and Cell Biology, School of Medicine, University of Nevada, Reno, NV 89557, USA
| | - Mahsa Borhani Peikani
- Department of Physiology and Cell Biology, School of Medicine, University of Nevada, Reno, NV 89557, USA
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Tam SW, Huffer K, Li M, Swartz KJ. Ion permeation pathway within the internal pore of P2X receptor channels. eLife 2023; 12:84796. [PMID: 36940138 PMCID: PMC10027316 DOI: 10.7554/elife.84796] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2022] [Accepted: 03/07/2023] [Indexed: 03/21/2023] Open
Abstract
P2X receptor channels are trimeric ATP-activated ion channels expressed in neuronal and non-neuronal cells that are attractive therapeutic targets for human disorders. Seven subtypes of P2X receptor channels have been identified in mammals that can form both homomeric and heteromeric channels. P2X1-4 and P2X7 receptor channels are cation-selective, whereas P2X5 has been reported to have both cation and anion permeability. P2X receptor channel structures reveal that each subunit is comprised of two transmembrane helices, with both N-and C-termini on the intracellular side of the membrane and a large extracellular domain that contains the ATP binding sites at subunit interfaces. Recent structures of ATP-bound P2X receptors with the activation gate open reveal the unanticipated presence of a cytoplasmic cap over the central ion permeation pathway, leaving lateral fenestrations that may be largely buried within the membrane as potential pathways for ions to permeate the intracellular end of the pore. In the present study, we identify a critical residue within the intracellular lateral fenestrations that is readily accessible to thiol-reactive compounds from both sides of the membrane and where substitutions influence the relative permeability of the channel to cations and anions. Taken together, our results demonstrate that ions can enter or exit the internal pore through lateral fenestrations that play a critical role in determining the ion selectivity of P2X receptor channels.
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Affiliation(s)
- Stephanie W Tam
- Molecular Physiology and Biophysics Section, Porter Neuroscience Research Center, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, United States
| | - Kate Huffer
- Molecular Physiology and Biophysics Section, Porter Neuroscience Research Center, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, United States
- Department of Biology, Johns Hopkins University, Baltimore, United States
| | - Mufeng Li
- Molecular Physiology and Biophysics Section, Porter Neuroscience Research Center, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, United States
| | - Kenton J Swartz
- Molecular Physiology and Biophysics Section, Porter Neuroscience Research Center, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, United States
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8
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Gutierrez Cruz A, Aresta Branco MSL, Perrino BA, Sanders KM, Mutafova-Yambolieva VN. Urinary ATP Levels Are Controlled by Nucleotidases Released from the Urothelium in a Regulated Manner. Metabolites 2022; 13. [PMID: 36676954 DOI: 10.3390/metabo13010030] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Revised: 12/20/2022] [Accepted: 12/21/2022] [Indexed: 12/28/2022] Open
Abstract
Adenosine 5′-triphosphate (ATP) is released in the bladder lumen during filling. Urothelial ATP is presumed to regulate bladder excitability. Urinary ATP is suggested as a urinary biomarker of bladder dysfunctions since ATP is increased in the urine of patients with overactive bladder, interstitial cystitis or bladder pain syndrome. Altered urinary ATP might also be associated with voiding dysfunctions linked to disease states associated with metabolic syndrome. Extracellular ATP levels are determined by ATP release and ATP hydrolysis by membrane-bound and soluble nucleotidases (s-NTDs). It is currently unknown whether s-NTDs regulate urinary ATP. Using etheno-ATP substrate and HPLC-FLD detection techniques, we found that s-NTDs are released in the lumen of ex vivo mouse detrusor-free bladders. Capillary immunoelectrophoresis by ProteinSimple Wes determined that intraluminal solutions (ILS) collected at the end of filling contain ENTPD3 > ENPP1 > ENPP3 ≥ ENTPD2 = NT5E = ALPL/TNAP. Activation of adenylyl cyclase with forskolin increased luminal s-NTDs release whereas the AC inhibitor SQ22536 had no effect. In contrast, forskolin reduced and SQ22536 increased s-NTDs release in the lamina propria. Adenosine enhanced s-NTDs release and accelerated ATP hydrolysis in ILS and lamina propria. Therefore, there is a regulated release of s-NTDs in the bladder lumen during filling. Aberrant release or functions of urothelial s-NTDs might cause elevated urinary ATP in conditions with abnormal bladder excitability.
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Cserép C, Schwarcz AD, Pósfai B, László ZI, Kellermayer A, Környei Z, Kisfali M, Nyerges M, Lele Z, Katona I, Ádám Dénes. Microglial control of neuronal development via somatic purinergic junctions. Cell Rep 2022; 40:111369. [PMID: 36130488 PMCID: PMC9513806 DOI: 10.1016/j.celrep.2022.111369] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2022] [Revised: 06/28/2022] [Accepted: 08/25/2022] [Indexed: 11/30/2022] Open
Abstract
Microglia, the resident immune cells of the brain, play important roles during development. Although bi-directional communication between microglia and neuronal progenitors or immature neurons has been demonstrated, the main sites of interaction and the underlying mechanisms remain elusive. By using advanced methods, here we provide evidence that microglial processes form specialized contacts with the cell bodies of developing neurons throughout embryonic, early postnatal, and adult neurogenesis. These early developmental contacts are highly reminiscent of somatic purinergic junctions that are instrumental for microglia-neuron communication in the adult brain. The formation and maintenance of these junctions is regulated by functional microglial P2Y12 receptors, and deletion of P2Y12Rs disturbs proliferation of neuronal precursors and leads to aberrant cortical cytoarchitecture during development and in adulthood. We propose that early developmental formation of somatic purinergic junctions represents an important interface for microglia to monitor the status of immature neurons and control neurodevelopment.
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Affiliation(s)
- Csaba Cserép
- "Momentum" Laboratory of Neuroimmunology, Institute of Experimental Medicine, 1083 Budapest, Hungary.
| | - Anett D Schwarcz
- "Momentum" Laboratory of Neuroimmunology, Institute of Experimental Medicine, 1083 Budapest, Hungary
| | - Balázs Pósfai
- "Momentum" Laboratory of Neuroimmunology, Institute of Experimental Medicine, 1083 Budapest, Hungary; Szentágothai János Doctoral School of Neurosciences, Semmelweis University, 1083 Budapest, Hungary
| | - Zsófia I László
- "Momentum" Laboratory of Molecular Neurobiology, Institute of Experimental Medicine, 1083 Budapest, Hungary; University of Dundee, School of Medicine, Dundee DD1 9SY, UK
| | - Anna Kellermayer
- "Momentum" Laboratory of Neuroimmunology, Institute of Experimental Medicine, 1083 Budapest, Hungary
| | - Zsuzsanna Környei
- "Momentum" Laboratory of Neuroimmunology, Institute of Experimental Medicine, 1083 Budapest, Hungary
| | - Máté Kisfali
- "Momentum" Laboratory of Molecular Neurobiology, Institute of Experimental Medicine, 1083 Budapest, Hungary
| | - Miklós Nyerges
- "Momentum" Laboratory of Neuroimmunology, Institute of Experimental Medicine, 1083 Budapest, Hungary
| | - Zsolt Lele
- "Momentum" Laboratory of Molecular Neurobiology, Institute of Experimental Medicine, 1083 Budapest, Hungary
| | - István Katona
- "Momentum" Laboratory of Molecular Neurobiology, Institute of Experimental Medicine, 1083 Budapest, Hungary; Department of Psychological and Brain Sciences, Indiana University, Bloomington, IN 47405, USA
| | - Ádám Dénes
- "Momentum" Laboratory of Neuroimmunology, Institute of Experimental Medicine, 1083 Budapest, Hungary.
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Abstract
Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disease characterized by upper and lower motor neuron loss. The pathomechanisms of ALS are still poorly understood with current hypotheses involving genetic mutations, excitotoxicity, and reactive oxygen species formation. In the absence of a disease-altering clinically approved therapeutic, there is an ever-increasing need to identify new targets to develop drugs that delay disease onset and/or progression. The purinergic P2X7 receptor (P2X7R) has been implicated widely across the ALS realm, providing a potential therapeutic strategy. This review summarizes the current understanding of ALS, the P2X7R and its role in ALS, the current landscape of P2X7R antagonists, and the in vivo potential of these antagonists in preclinical ALS models.
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Affiliation(s)
- André D. J. Mckenzie
- School of Chemistry, Faculty of Science, University of Sydney, Sydney, New South Wales 2006, Australia
| | - Taylor R. Garrett
- School of Chemistry, Faculty of Science, University of Sydney, Sydney, New South Wales 2006, Australia
| | - Eryn L. Werry
- School of Chemistry, Faculty of Science, University of Sydney, Sydney, New South Wales 2006, Australia
- Central Clinical School, Faculty of Medicine and Health, The University of Sydney, Sydney, New South Wales 2006, Australia
| | - Michael Kassiou
- School of Chemistry, Faculty of Science, University of Sydney, Sydney, New South Wales 2006, Australia
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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] [What about the content of this article? (0)] [Affiliation(s)] [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.
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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
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12
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Erdling A, Johansson SE, Radziwon‐Balicka A, Ansar S, Edvinsson L. Changes in P2Y 6 receptor-mediated vasoreactivity following focal and global ischemia. Physiol Rep 2022; 10:e15283. [PMID: 35466569 PMCID: PMC9035753 DOI: 10.14814/phy2.15283] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2022] [Revised: 04/05/2022] [Accepted: 04/07/2022] [Indexed: 06/14/2023] Open
Abstract
Ischemia, both in the form of focal thromboembolic stroke and following subarachnoid hemorrhage (SAH), causes upregulation of vasoconstrictive receptor systems within the cerebral vasculature. Descriptions regarding changes in purinergic signaling following ischemia are lacking, especially when the importance of purinergic signaling in regulating vascular tone is taken into consideration. This prompted us to evaluate changes in P2Y6 -mediated vasomotor reactivity in two different stroke models in rat. We used wire myography to measure changes in cerebral vasoreactivity to the P2Y6 agonist UDP-β-S following either experimental SAH or transient middle cerebral artery occlusion. Changes in receptor localization or receptor expression were evaluated using immunohistochemistry and quantitative flow cytometry. Transient middle cerebral artery occlusion caused an increase in Emax when compared to sham (233.6 [206.1-258.5]% vs. 161.1 [147.1-242.6]%, p = 0.0365). No such change was seen following SAH. Both stroke models were associated with increased levels of P2Y6 receptor expression in the vascular smooth muscle cells (90.94 [86.99-99.15]% and 93.79 [89.96-96.39]% vs. 80.31 [70.80-80.86]%, p = 0.021) and p = 0.039 respectively. There was no change in receptor localization in either of the stroke models. Based on these findings, we conclude that focal ischemic stroke increases vascular sensitivity to UDP-β-S by upregulating P2Y6 receptors on vascular smooth muscle cells while experimental SAH did not induce changes in vasoreactivity in spite of increased P2Y6 receptor expression.
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Affiliation(s)
- André Erdling
- Department of Clinical SciencesDivision of Experimental Vascular ResearchLund UniversityLundSweden
- Department of Cardiothoracic Surgery, Anesthesiology and Intensive CareSkane University HospitalLundSweden
- Applied Neurovascular ResearchDepartment of Clinical SciencesLund UniversityLundSweden
| | - Sara Ellinor Johansson
- Department of Clinical Experimental ResearchGlostrup Research InstituteRigshospitalet‐GlostrupGlostrupDenmark
| | - Aneta Radziwon‐Balicka
- Department of Clinical Experimental ResearchGlostrup Research InstituteRigshospitalet‐GlostrupGlostrupDenmark
| | - Saema Ansar
- Applied Neurovascular ResearchDepartment of Clinical SciencesLund UniversityLundSweden
| | - Lars Edvinsson
- Department of Clinical SciencesDivision of Experimental Vascular ResearchLund UniversityLundSweden
- Department of Clinical Experimental ResearchGlostrup Research InstituteRigshospitalet‐GlostrupGlostrupDenmark
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Domnik NJ, Vincent SG, Fisher JT. Mechanosensitivity of Murine Lung Slowly Adapting Receptors: Minimal Impact of Chemosensory, Serotonergic, and Purinergic Signaling. Front Physiol 2022; 13:833665. [PMID: 35250636 PMCID: PMC8889033 DOI: 10.3389/fphys.2022.833665] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2021] [Accepted: 01/19/2022] [Indexed: 11/13/2022] Open
Abstract
Murine slowly adapting receptors (SARs) within airway smooth muscle provide volume-related feedback; however, their mechanosensitivity and morphology are incompletely characterized. We explored two aspects of SAR physiology: their inherent static mechanosensitivity and a potential link to pulmonary neuroepithelial bodies (NEBs). SAR mechanosensitivity displays a rate sensitivity linked to speed of inflation; however, to what extent static SAR mechanosensitivity is tuned for the very rapid breathing frequency (B f ) of small mammals (e.g., mouse) is unclear. NEB-associated, morphologically described smooth muscle-associated receptors (SMARs) may be a structural analog for functionally characterized SARs, suggesting functional linkages between SARs and NEBs. We addressed the hypotheses that: (1) rapid murine B f is associated with enhanced in vivo SAR static sensitivity; (2) if SARs and NEBs are functionally linked, stimuli reported to impact NEB function would alter SAR mechanosensitivity. We measured SAR action potential discharge frequency (AP f, action potentials/s) during quasi-static inflation [0-20 cmH2O trans-respiratory pressure (PTR)] in NEB-relevant conditions of hypoxia (FIO2 = 0.1), hypercarbia (FICO2 = 0.1), and pharmacologic intervention (serotonergic 5-HT3 receptor antagonist, Tropisetron, 4.5 mg/kg; P2 purinergic receptor antagonist, Suramin, 50 mg/kg). In all protocols, we obtained: (1) AP f vs. PTR; (2) PTR threshold; and (3) AP f onset at PTR threshold. The murine AP f vs. PTR response comprises high AP f (average maximum AP f: 236.1 ± 11.1 AP/s at 20 cmH2O), a low PTR threshold (mean 2.0 ± 0.1 cmH2O), and a plateau in AP f between 15 and 20 cmH2O. Murine SAR mechanosensitivity (AP f vs. PTR) is up to 60% greater than that reported for larger mammals. Even the maximum difference between intervention and control conditions was minimally impacted by NEB-related alterations: Tropisetron -7.6 ± 1.8% (p = 0.005); Suramin -10.6 ± 1.5% (p = 0.01); hypoxia +9.3 ± 1.9% (p < 0.001); and hypercarbia -6.2 ± 0.9% (p < 0.001). We conclude that the high sensitivity of murine SARs to inflation provides enhanced resolution of operating lung volume, which is aligned with the rapid B f of the mouse. We found minimal evidence supporting a functional link between SARs and NEBs and speculate that the <10% change in SAR mechanosensitivity during altered NEB-related stimuli is not consistent with a meaningful physiologic role.
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Affiliation(s)
- Nicolle J. Domnik
- Department of Biomedical and Molecular Sciences, Queen’s University, Kingston, ON, Canada
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, Western University, London, ON, Canada
| | - Sandra G. Vincent
- Department of Biomedical and Molecular Sciences, Queen’s University, Kingston, ON, Canada
| | - John T. Fisher
- Department of Biomedical and Molecular Sciences, Queen’s University, Kingston, ON, Canada
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14
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Saffioti NA, Lauri N, Cané L, Gonzalez-Lebrero R, Alleva K, Mouro-Chanteloup I, Ostuni MA, Herlax V, Schwarzbaum PJ. Interactive Dynamics of Cell Volume and Cell Death in Human Erythrocytes Exposed to α-Hemolysin from Escherichia coli. Int J Mol Sci 2022; 23:872. [PMID: 35055067 DOI: 10.3390/ijms23020872] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2021] [Revised: 01/09/2022] [Accepted: 01/11/2022] [Indexed: 12/16/2022] Open
Abstract
α-hemolysin (HlyA) of E. coli binds irreversibly to human erythrocytes and induces cell swelling, ultimately leading to hemolysis. We characterized the mechanism involved in water transport induced by HlyA and analyzed how swelling and hemolysis might be coupled. Osmotic water permeability (Pf) was assessed by stopped-flow light scattering. Preincubation with HlyA strongly reduced Pf in control- and aquaporin 1-null red blood cells, although the relative Pf decrease was similar in both cell types. The dynamics of cell volume and hemolysis on RBCs was assessed by electrical impedance, light dispersion and hemoglobin release. Results show that HlyA induced erythrocyte swelling, which is enhanced by purinergic signaling, and is coupled to osmotic hemolysis. We propose a mathematical model of HlyA activity where the kinetics of cell volume and hemolysis in human erythrocytes depend on the flux of osmolytes across the membrane, and on the maximum volume that these cells can tolerate. Our results provide new insights for understanding signaling and cytotoxicity mediated by HlyA in erythrocytes.
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15
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Cliff CL, Williams BM, Chadjichristos CE, Mouritzen U, Squires PE, Hills CE. Connexin 43: A Target for the Treatment of Inflammation in Secondary Complications of the Kidney and Eye in Diabetes. Int J Mol Sci 2022; 23:600. [PMID: 35054783 PMCID: PMC8776095 DOI: 10.3390/ijms23020600] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2021] [Revised: 01/03/2022] [Accepted: 01/04/2022] [Indexed: 02/06/2023] Open
Abstract
Of increasing prevalence, diabetes is characterised by elevated blood glucose and chronic inflammation that precedes the onset of multiple secondary complications, including those of the kidney and the eye. As the leading cause of end stage renal disease and blindness in the working population, more than ever is there a demand to develop clinical interventions which can both delay and prevent disease progression. Connexins are membrane bound proteins that can form pores (hemichannels) in the cell membrane. Gated by cellular stress and injury, they open under pathophysiological conditions and in doing so release 'danger signals' including adenosine triphosphate into the extracellular environment. Linked to sterile inflammation via activation of the nod-like receptor protein 3 inflammasome, targeting aberrant hemichannel activity and the release of these danger signals has met with favourable outcomes in multiple models of disease, including secondary complications of diabetes. In this review, we provide a comprehensive update on those studies which document a role for aberrant connexin hemichannel activity in the pathogenesis of both diabetic eye and kidney disease, ahead of evaluating the efficacy of blocking connexin-43 specific hemichannels in these target tissues on tissue health and function.
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Affiliation(s)
- Chelsy L. Cliff
- Joseph Banks Laboratories, School of Life, Sciences University of Lincoln, Lincoln LN6 7DL, UK; (C.L.C.); (B.M.W.); (P.E.S.)
| | - Bethany M. Williams
- Joseph Banks Laboratories, School of Life, Sciences University of Lincoln, Lincoln LN6 7DL, UK; (C.L.C.); (B.M.W.); (P.E.S.)
| | - Christos E. Chadjichristos
- National Institutes for Health and Medical Research, UMR-S1155, Batiment Recherche, Tenon Hospital, 4 Rue de la Chine, 75020 Paris, France;
| | - Ulrik Mouritzen
- Ciana Therapeutics, Ole Maaloes Vej 3, 2200 Copenhagen N, Denmark;
| | - Paul E. Squires
- Joseph Banks Laboratories, School of Life, Sciences University of Lincoln, Lincoln LN6 7DL, UK; (C.L.C.); (B.M.W.); (P.E.S.)
| | - Claire E. Hills
- Joseph Banks Laboratories, School of Life, Sciences University of Lincoln, Lincoln LN6 7DL, UK; (C.L.C.); (B.M.W.); (P.E.S.)
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16
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Möller S, Laskay T. Purinergic Enhancement of Anti-Leishmanial Effector Functions of Neutrophil Granulocytes. Front Immunol 2021; 12:747049. [PMID: 34733282 PMCID: PMC8558537 DOI: 10.3389/fimmu.2021.747049] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2021] [Accepted: 09/06/2021] [Indexed: 11/22/2022] Open
Abstract
Although macrophages are considered for host cells for the multiplication of Leishmania, recent studies indicate the important role of neutrophil granulocytes as host cells for these intracellular parasites. Neutrophils have been shown to be massively and rapidly recruited to the site of Leishmania infection where they represent the first cells to encounter the parasites. Exposure to ATP and UTP have been shown to enhance anti-Leishmania activity of macrophages and intralesional injection of UTP led to strongly reduced parasite load in vivo. Since the in vivo anti-leishmanial effect of extracellular UTP correlated with enhanced neutrophil recruitment and enhanced ROS production at the site of Leishmania infection we hypothesized that exposure to extracellular nucleotides can directly enhance the killing of Leishmania by neutrophils. Since purinergic signaling is an essential mechanism of neutrophil activation the aim of the present study was to assess whether purinergic exposure results in the activation of anti-leishmanial neutrophil functions and, therefore, represent an essential component of enhanced anti-leishmanial defense in leishmaniasis. We could show that exposure to ATP and UTP led to activation and enhanced CD11b expression of primary human neutrophils in vitro. Leishmania-induced ROS production was strongly enhanced by extracellular ATP and UTP. Importantly, exposure to ATP and UTP resulted in enhanced killing of Leishmania donovani by neutrophils. In addition, ATP strongly enhanced the secretion of IL-8 and IL-1β by Leishmania-exposed neutrophils. Our results suggest that signaling via the P2 receptor and phosphorylation of Erk1/2, Akt and p38 are involved in the purinergic enhancement of anti-leishmanial functions of neutrophils.
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Affiliation(s)
- Sonja Möller
- Department of Infectious Diseases and Microbiology, University of Lübeck, Lübeck, Germany
| | - Tamás Laskay
- Department of Infectious Diseases and Microbiology, University of Lübeck, Lübeck, Germany
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17
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Olabiyi AA, Morsch VM, Oboh G, Schetinger MRC. Cyperus esculentus L. and Tetracarpidium conophorum Müll. Arg. Supplemented Diet Improved Testosterone Levels, Modulated Ectonucleotidases and Adenosine Deaminase Activities in Platelets from L-NAME-Stressed Rats. Nutrients 2021; 13:3529. [PMID: 34684530 DOI: 10.3390/nu13103529] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Revised: 09/22/2021] [Accepted: 09/24/2021] [Indexed: 02/07/2023] Open
Abstract
In hypertensive individuals, platelet morphology and function have been discovered to be altered, and this has been linked to the development of vascular disease, including erectile dysfunction (ED). The impact of nutritional supplementation with Cyperus esculentus (tiger nut, TN) and Tetracarpidium conophorum (walnut, WN) on androgen levels, ectonucleotidases, and adenosine deaminase (ADA) activities in platelets from L-NAME (Nω-nitro-L-arginine methyl ester hydrochloride) challenged rats were investigated. We hypothesized that these nuts may show a protective effect on platelets aggregation and possibly enhance the sex hormones, thereby reverting vasoconstriction. Wistar rats (male; 250-300 g; n = 10) were grouped into seven groups as follows: basal diet control group (I); basal diet/L-NAME/Viagra (5 mg/kg/day) as positive control group (II); ED-induced group (basal diet/L-NAME) (III); diet supplemented processed TN (20%)/L-NAME (IV); diet supplemented raw TN (20%)/L-NAME (V); diet supplemented processed WN (20%)/L-NAME (VI); and diet supplemented raw WN (20%)/L-NAME (VII). The rats were given their regular diet for 2 weeks prior to actually receiving L-NAME (40 mg/kg/day) for ten days to induce hypertension. Platelet androgen levels, ectonucleotidases, and ADA were all measured. L-NAME considerably lowers testosterone levels (54.5 ± 2.2; p < 0.05). Supplementing the TN and WN diets revealed improved testosterone levels as compared to the control (306.7 ± 5.7), but luteinizing hormone levels remained unchanged. Compared to control groups, the L-NAME-treated group showed a rise in ATP (127.5%) hydrolysis and ADA (116.7%) activity, and also a decrease in ADP (76%) and AMP (45%) hydrolysis. Both TN and WN supplemented diets resulted in substantial (p < 0.05) reversal effects. Enhanced testosterone levels and modulation of the purinergic system in platelets by TN and WN could be one of the mechanisms by which they aid in vasoconstriction control.
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18
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Rabbitt RD, Holman HA. ATP and ACh Evoked Calcium Transients in the Neonatal Mouse Cochlear and Vestibular Sensory Epithelia. Front Neurosci 2021; 15:710076. [PMID: 34566562 PMCID: PMC8455828 DOI: 10.3389/fnins.2021.710076] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2021] [Accepted: 08/18/2021] [Indexed: 12/02/2022] Open
Abstract
Hair cells in the mammalian inner ear sensory epithelia are surrounded by supporting cells which are essential for function of cochlear and vestibular systems. In mice, support cells exhibit spontaneous intracellular Ca2+ transients in both auditory and vestibular organs during the first postnatal week before the onset of hearing. We recorded long lasting (>200 ms) Ca2+ transients in cochlear and vestibular support cells in neonatal mice using the genetic calcium indicator GCaMP5. Both cochlear and vestibular support cells exhibited spontaneous intracellular Ca2+ transients (GCaMP5 ΔF/F), in some cases propagating as waves from the apical (endolymph facing) to the basolateral surface with a speed of ∼25 μm per second, consistent with inositol trisphosphate dependent calcium induced calcium release (CICR). Acetylcholine evoked Ca2+ transients were observed in both inner border cells in the cochlea and vestibular support cells, with a larger change in GCaMP5 fluorescence in the vestibular support cells. Adenosine triphosphate evoked robust Ca2+ transients predominantly in the cochlear support cells that included Hensen’s cells, Deiters’ cells, inner hair cells, inner phalangeal cells and inner border cells. A Ca2+ event initiated in one inner border cells propagated in some instances longitudinally to neighboring inner border cells with an intercellular speed of ∼2 μm per second, and decayed after propagating along ∼3 cells. Similar intercellular propagation was not observed in the radial direction from inner border cell to inner sulcus cells, and was not observed between adjacent vestibular support cells.
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Affiliation(s)
- Richard D Rabbitt
- Department of Biomedical Engineering, University of Utah, Salt Lake City, UT, United States.,Graduate Program in Neuroscience, University of Utah, Salt Lake City, UT, United States.,Department of Otolaryngology-Head and Neck Surgery, University of Utah, Salt Lake City, UT, United States
| | - Holly A Holman
- Department of Biomedical Engineering, University of Utah, Salt Lake City, UT, United States
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19
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Gorska AM, Donoso M, Valdebenito S, Prideaux B, Queen S, Scemes E, Clements J, Eugenin E. Human immunodeficiency virus-1/simian immunodeficiency virus infection induces opening of pannexin-1 channels resulting in neuronal synaptic compromise: A novel therapeutic opportunity to prevent NeuroHIV. J Neurochem 2021; 158:500-521. [PMID: 33899944 DOI: 10.1111/jnc.15374] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Revised: 03/27/2021] [Accepted: 04/21/2021] [Indexed: 01/16/2023]
Abstract
In healthy conditions, pannexin-1 (Panx-1) channels are in a close state, but in several pathological conditions, including human immunodeficiency virus-1 (HIV) and NeuroHIV, the channel becomes open. However, the mechanism or contribution of Panx-1 channels to the HIV pathogenesis and NeuroHIV is unknown. To determine the contribution of Panx-1 channels to the pathogenesis of NeuroHIV, we used a well-established model of simian immunodeficiency virus (SIV) infection in macaques (Macaca mulatta) in the presence of and absence of a Panx-1 blocker to later examine the synaptic/axonal compromise induced for the virus. Using Golgi's staining, we demonstrated that SIV infection compromised synaptic and axonal structures, especially in the white matter. Blocking Panx-1 channels after SIV infection prevented the synaptic and axonal compromise induced by the virus, especially by maintaining the more complex synapses. Our data demonstrated that targeting Panx-1 channels can prevent and maybe revert brain synaptic compromise induced by SIV infection.
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Affiliation(s)
- Anna Maria Gorska
- Department of Neuroscience, Cell Biology, and Anatomy, University of Texas Medical Branch (UTMB), Galveston, TX, USA
| | - Maribel Donoso
- Department of Neuroscience, Cell Biology, and Anatomy, University of Texas Medical Branch (UTMB), Galveston, TX, USA
| | - Silvana Valdebenito
- Department of Neuroscience, Cell Biology, and Anatomy, University of Texas Medical Branch (UTMB), Galveston, TX, USA
| | - Brendan Prideaux
- Department of Neuroscience, Cell Biology, and Anatomy, University of Texas Medical Branch (UTMB), Galveston, TX, USA
| | - Suzanne Queen
- Department of Molecular and Comparative Pathobiology, John Hopkins Medical Center, Baltimore, MD, USA
| | - Eliana Scemes
- Department of Cell Biology and Anatomy, New York Medical College, Valhalla, NY, USA
| | - Janice Clements
- Department of Molecular and Comparative Pathobiology, John Hopkins Medical Center, Baltimore, MD, USA
| | - Eliseo Eugenin
- Department of Neuroscience, Cell Biology, and Anatomy, University of Texas Medical Branch (UTMB), Galveston, TX, USA
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20
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Frara N, Giaddui D, Braverman AS, Porreca DS, Brown JM, Mazzei M, Wagner IJ, Pontari MA, Tiwari E, Testa CL, Yu D, Hobson LJ, Barbe MF, Ruggieri MR. Nerve transfer for restoration of lower motor neuron-lesioned bladder function. Part 1: attenuation of purinergic bladder smooth muscle contractions. Am J Physiol Regul Integr Comp Physiol 2021; 320:R885-R896. [PMID: 33759578 PMCID: PMC8285613 DOI: 10.1152/ajpregu.00299.2020] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
This study determined the effect of pelvic organ decentralization and reinnervation 1 yr later on the contribution of muscarinic and purinergic receptors to ex vivo, nerve-evoked, bladder smooth muscle contractions. Nineteen canines underwent decentralization by bilateral transection of all coccygeal and sacral (S) spinal roots, dorsal roots of lumbar (L)7, and hypogastric nerves. After exclusions, 8 were reinnervated 12 mo postdecentralization with obturator-to-pelvic and sciatic-to-pudendal nerve transfers then euthanized 8-12 mo later. Four served as long-term decentralized only animals. Controls included six sham-operated and three unoperated animals. Detrusor muscle was assessed for contractile responses to potassium chloride (KCl) and electric field stimulation (EFS) before and after purinergic receptor desensitization with α, β-methylene adenosine triphosphate (α,β-mATP), muscarinic receptor antagonism with atropine, or sodium channel blockade with tetrodotoxin. Atropine inhibition of EFS-induced contractions increased in decentralized and reinnervated animals compared with controls. Maximal contractile responses to α,β-mATP did not differ between groups. In strips from decentralized and reinnervated animals, the contractile response to EFS was enhanced at lower frequencies compared with normal controls. The observation of increased blockade of nerve-evoked contractions by muscarinic antagonist with no change in responsiveness to purinergic agonist suggests either decreased ATP release or increased ecto-ATPase activity in detrusor muscle as a consequence of the long-term decentralization. The reduction in the frequency required to produce maximum contraction following decentralization may be due to enhanced nerve sensitivity to EFS or a change in the effectiveness of the neurotransmission.
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Affiliation(s)
- Nagat Frara
- Department of Anatomy and Cell Biology, Lewis Katz School of Medicine, Temple University, Philadelphia, Pennsylvania
| | - Dania Giaddui
- Department of Anatomy and Cell Biology, Lewis Katz School of Medicine, Temple University, Philadelphia, Pennsylvania
| | - Alan S Braverman
- Department of Anatomy and Cell Biology, Lewis Katz School of Medicine, Temple University, Philadelphia, Pennsylvania
| | - Danielle S Porreca
- Department of Anatomy and Cell Biology, Lewis Katz School of Medicine, Temple University, Philadelphia, Pennsylvania
| | - Justin M Brown
- Department of Neurosurgery, Massachusetts General Hospital, Boston, Massachusetts
| | - Michael Mazzei
- Department of Surgery, Lewis Katz School of Medicine, Temple University Hospital, Philadelphia, Pennsylvania
| | - Ida J Wagner
- Department of Surgery, Lewis Katz School of Medicine, Temple University Hospital, Philadelphia, Pennsylvania
| | - Michel A Pontari
- Department of Urology, Lewis Katz School of Medicine, Temple University Hospital, Philadelphia, Pennsylvania
| | - Ekta Tiwari
- Department of Electrical and Computer Engineering, College of Engineering, Temple University, Philadelphia, Pennsylvania
| | - Courtney L Testa
- Department of Anatomy and Cell Biology, Lewis Katz School of Medicine, Temple University, Philadelphia, Pennsylvania
| | - Daohai Yu
- Department of Clinical Sciences, Lewis Katz School of Medicine, Temple University, Philadelphia, Pennsylvania
| | - Lucas J Hobson
- Department of Anatomy and Cell Biology, Lewis Katz School of Medicine, Temple University, Philadelphia, Pennsylvania
| | - Mary F Barbe
- Department of Anatomy and Cell Biology, Lewis Katz School of Medicine, Temple University, Philadelphia, Pennsylvania
| | - Michael R Ruggieri
- Department of Anatomy and Cell Biology, Lewis Katz School of Medicine, Temple University, Philadelphia, Pennsylvania.,Department of Electrical and Computer Engineering, College of Engineering, Temple University, Philadelphia, Pennsylvania
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21
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Prades S, Heard G, Gale JE, Engel T, Kopp R, Nicke A, Smith KE, Jagger DJ. Functional P2X 7 Receptors in the Auditory Nerve of Hearing Rodents Localize Exclusively to Peripheral Glia. J Neurosci 2021; 41:2615-29. [PMID: 33563723 DOI: 10.1523/JNEUROSCI.2240-20.2021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Revised: 12/03/2020] [Accepted: 01/09/2021] [Indexed: 11/21/2022] Open
Abstract
P2X7 receptors (P2X7Rs) are associated with numerous pathophysiological mechanisms, and this promotes them as therapeutic targets for certain neurodegenerative conditions. However, the identity of P2X7R-expressing cells in the nervous system remains contentious. Here, we examined P2X7R functionality in auditory nerve cells from rodents of either sex, and determined their functional and anatomic expression pattern. In whole-cell recordings from rat spiral ganglion cultures, the purinergic agonist 2',3'-O-(4-benzoylbenzoyl)-ATP (BzATP) activated desensitizing currents in spiral ganglion neurons (SGNs) but non-desensitizing currents in glia that were blocked by P2X7R-specific antagonists. In imaging experiments, BzATP gated sustained Ca2+ entry into glial cells. BzATP-gated uptake of the fluorescent dye YO-PRO-1 was reduced and slowed by P2X7R-specific antagonists. In rats, P2X7Rs were immuno-localized predominantly within satellite glial cells (SGCs) and Schwann cells (SCs). P2X7R expression was not detected in the portion of the auditory nerve within the central nervous system. Mouse models allowed further exploration of the distribution of cochlear P2X7Rs. In GENSAT reporter mice, EGFP expression driven via the P2rx7 promoter was evident in SGCs and SCs but was undetectable in SGNs. A second transgenic model showed a comparable cellular distribution of EGFP-tagged P2X7Rs. In wild-type mice the discrete glial expression was confirmed using a P2X7-specific nanobody construct. Our study shows that P2X7Rs are expressed by peripheral glial cells, rather than by afferent neurons. Description of functional signatures and cellular distributions of these enigmatic proteins in the peripheral nervous system (PNS) will help our understanding of ATP-dependent effects contributing to hearing loss and other sensory neuropathies.SIGNIFICANCE STATEMENT P2X7 receptors (P2X7Rs) have been the subject of much scrutiny in recent years. They have been promoted as therapeutic targets in a number of diseases of the nervous system, yet the specific cellular location of these receptors remains the subject of intense debate. In the auditory nerve, connecting the inner ear to the brainstem, we show these multimodal ATP-gated channels localize exclusively to peripheral glial cells rather than the sensory neurons, and are not evident in central glia. Physiologic responses in the peripheral glia display classical hallmarks of P2X7R activation, including the formation of ion-permeable and also macromolecule-permeable pores. These qualities suggest these proteins could contribute to glial-mediated inflammatory processes in the auditory periphery under pathologic disease states.
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22
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Lamb IR, Novielli-Kuntz NM, Murrant CL. Capillaries communicate with the arteriolar microvascular network by a pannexin/ purinergic-dependent pathway in hamster skeletal muscle. Am J Physiol Heart Circ Physiol 2021; 320:H1699-H1711. [PMID: 33606585 DOI: 10.1152/ajpheart.00493.2020] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We sought to determine if a pannexin/purinergic-dependent intravascular communication pathway exists in skeletal muscle microvasculature that facilitates capillary communication with upstream arterioles that control their perfusion. Using the hamster cremaster muscle and intravital microscopy, we locally stimulated capillaries and observed the vasodilatory response in the associated upstream 4A arteriole. We stimulated capillaries with vasodilators relevant to muscle contraction: 10-6 M S-nitroso-N-acetyl-dl-penicillamine (SNAP; nitric oxide donor), 10-6 M adenosine, 10 mM potassium chloride, 10-5 M pinacidil, as well as a known initiator of gap-junction-dependent intravascular communication, acetylcholine (10-5 M), in the absence and the presence of the purinergic membrane receptor blocker suramin (10-5 M), pannexin blocker mefloquine (2 × 10-5 M), or probenecid (5 × 10-6 M) and gap-junction inhibitor halothane (0.07%) applied in the transmission pathway, between the capillary stimulation site and the upstream 4A observation site. Potassium chloride, SNAP, and adenosine-induced upstream vasodilations were significantly inhibited by suramin, mefloquine, and probenecid but not halothane, indicating the involvement of a pannexin/purinergic-dependent signaling pathway. Conversely, SNAP-induced upstream vasodilation was only inhibited by halothane indicating that communication was facilitated by gap junctions. Both pinacidil and acetylcholine were inhibited by suramin but only acetylcholine was inhibited by halothane. These data demonstrate the presence of a pannexin/purinergic-dependent communication pathway between capillaries and upstream arterioles controlling their perfusion. This pathway adds to the gap-junction-dependent pathway that exists at this vascular level as well. Given that vasodilators relevant to muscle contraction can use both of these pathways, our data implicate the involvement of both pathways in the coordination of skeletal muscle blood flow.NEW & NOTEWORTHY Blood flow control during increased metabolic demand in skeletal muscle is not fully understood. Capillaries have been implicated in controlling blood flow to active skeletal muscle, but how capillaries communicate to the arteriolar vascular network is not clear. Our study uncovers a novel pathway through which capillaries can communicate to upstream arterioles to cause vasodilation and therefore control perfusion. This work implicates a new vascular communication pathway in blood flow control in skeletal muscle.
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Affiliation(s)
- Iain R Lamb
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada
| | - Nicole M Novielli-Kuntz
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada
| | - Coral L Murrant
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada
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23
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Abstract
The P2X7 receptor (P2RX7) is an important molecule that functions as a danger sensor, detecting extracellular nucleotides from injured cells and thus signaling an inflammatory program to nearby cells. It is expressed in immune cells and plays important roles in pathogen surveillance and cell-mediated responses to infectious organisms. There is an abundance of literature on the role of P2RX7 in inflammatory diseases and the role of these receptors in host-pathogen interactions. Here, we describe the current knowledge of the role of P2RX7 in the host response to a variety of pathogens, including viruses, bacteria, fungi, protozoa, and helminths. We describe in vitro and in vivo evidence for the critical role these receptors play in mediating and modulating immune responses. Our observations indicate a role for P2X7 signaling in sensing damage-associated molecular patterns released by nearby infected cells to facilitate immunopathology or protection. In this review, we describe how P2RX7 signaling can play critical roles in numerous cells types in response to a diverse array of pathogens in mediating pathogenesis and immunity to infectious agents.
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Affiliation(s)
- Alexandra Y Soare
- Department of Microbiology and Immunology, University of Maryland School of Medicine, Baltimore, Maryland, USA
- Division of Infectious Diseases, Department of Medicine, Immunology Institute, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Tracey L Freeman
- Division of Infectious Diseases, Department of Medicine, Immunology Institute, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Alice K Min
- Department of Microbiology and Immunology, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Hagerah S Malik
- University of Chicago Pritzker School of Medicine, Chicago, Illinois, USA
| | - Elizabeth O Osota
- University of California San Diego, Graduate School of Biomedical Sciences, San Diego, California, USA
| | - Talia H Swartz
- Division of Infectious Diseases, Department of Medicine, Immunology Institute, Icahn School of Medicine at Mount Sinai, New York, New York, USA
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Babola TA, Li S, Wang Z, Kersbergen CJ, Elgoyhen AB, Coate TM, Bergles DE. Purinergic Signaling Controls Spontaneous Activity in the Auditory System throughout Early Development. J Neurosci 2021; 41:594-612. [PMID: 33303678 DOI: 10.1523/JNEUROSCI.2178-20.2020] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2020] [Revised: 10/06/2020] [Accepted: 11/25/2020] [Indexed: 12/23/2022] Open
Abstract
Spontaneous bursts of electrical activity in the developing auditory system arise within the cochlea before hearing onset and propagate through future sound-processing circuits of the brain to promote maturation of auditory neurons. Studies in isolated cochleae revealed that this intrinsically generated activity is initiated by ATP release from inner supporting cells (ISCs), resulting in activation of purinergic autoreceptors, K+ efflux, and subsequent depolarization of inner hair cells. However, it is unknown when this activity emerges or whether different mechanisms induce activity during distinct stages of development. Here we show that spontaneous electrical activity in mouse cochlea from both sexes emerges within ISCs during the late embryonic period, preceding the onset of spontaneous correlated activity in inner hair cells and spiral ganglion neurons, which begins at birth and follows a base to apex developmental gradient. At all developmental ages, pharmacological inhibition of P2Y1 purinergic receptors dramatically reduced spontaneous activity in these three cell types. Moreover, in vivo imaging within the inferior colliculus revealed that auditory neurons within future isofrequency zones exhibit coordinated neural activity at birth. The frequency of these discrete bursts increased progressively during the postnatal prehearing period yet remained dependent on P2RY1. Analysis of mice with disrupted cholinergic signaling in the cochlea indicate that this efferent input modulates, rather than initiates, spontaneous activity before hearing onset. Thus, the auditory system uses a consistent mechanism involving ATP release from ISCs and activation of P2RY1 autoreceptors to elicit coordinated excitation of neurons that will process similar frequencies of sound.SIGNIFICANCE STATEMENT In developing sensory systems, groups of neurons that will process information from similar sensory space exhibit highly correlated electrical activity that is critical for proper maturation and circuit refinement. Defining the period when this activity is present, the mechanisms responsible and the features of this activity are crucial for understanding how spontaneous activity influences circuit development. We show that, from birth to hearing onset, the auditory system relies on a consistent mechanism to elicit correlate firing of neurons that will process similar frequencies of sound. Targeted disruption of this activity will increase our understanding of how these early circuits mature and may provide insight into processes responsible for developmental disorders of the auditory system.
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Abstract
Detection of NaCl by the gustatory system is fundamental for salt intake and tissue homeostasis. Yet, signal transduction mechanisms for salty taste have remained obscure. In this issue of Neuron, Nomura et al. (2020) report that the epithelial sodium channel ENaC, which serves as the salty receptor, is co-expressed with the voltage-activated ATP release channel CALHM1/3 in a subset of taste cells and that these cells mediate amiloride-sensitive salty taste.
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Affiliation(s)
- Emily R Liman
- Department of Biological Sciences, Section of Neurobiology, University of Southern California, 3641 Watt Way, Los Angeles, CA 90089, USA.
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Wang Z, Jung JS, Inbar TC, Rangoussis KM, Faaborg-Andersen C, Coate TM. The Purinergic Receptor P2rx3 is Required for Spiral Ganglion Neuron Branch Refinement during Development. eNeuro 2020; 7:ENEURO. [PMID: 32675174 DOI: 10.1523/ENEURO.0179-20.2020] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Revised: 07/03/2020] [Accepted: 07/08/2020] [Indexed: 12/18/2022] Open
Abstract
The mammalian cochlea undergoes a highly dynamic process of growth and innervation during development. This process includes spiral ganglion neuron (SGN) branch refinement, a process whereby Type I SGNs undergo a phase of “debranching” before forming unramified synaptic contacts with inner hair cells. Using Sox2CreERT2 and R26RtdTomato as a strategy to genetically label individual SGNs in mice of both sexes, we report on both a time course of SGN branch refinement and a role for P2rx3 in this process. P2rx3 is an ionotropic ATP receptor that was recently implicated in outer hair cell spontaneous activity and Type II SGN synapse development (Ceriani et al., 2019), but its function in Type I SGN development is unknown. Here, we demonstrate that P2rx3 is expressed by Type I SGNs and hair cells during developmental periods that coincide with SGN branching refinement. P2rx3 null mice show SGNs with more complex branching patterns on their peripheral synaptic terminals and near their cell bodies around the time of birth. Loss of P2rx3 does not appear to confer general changes in axon outgrowth or hair cell formation, and alterations in branching complexity appear to mostly recover by postnatal day (P)6. However, when we examined the distribution of Type I SGN subtypes using antibodies that bind Calb2, Calb1, and Pou4f1, we found that P2rx3 null mice showed an increased proportion of SGNs that express Calb2. These data suggest P2rx3 may be necessary for normal Type I SGN differentiation in addition to serving a role in branch refinement.
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Volonté C, Amadio S, Liguori F, Fabbrizio P. Duality of P2X7 Receptor in Amyotrophic Lateral Sclerosis. Front Pharmacol 2020; 11:1148. [PMID: 32792962 PMCID: PMC7394054 DOI: 10.3389/fphar.2020.01148] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Accepted: 07/15/2020] [Indexed: 12/12/2022] Open
Affiliation(s)
- Cinzia Volonté
- CNR-Institute for Systems Analysis and Computer Science, Rome, Italy.,Fondazione Santa Lucia, IRCCS, Rome, Italy
| | | | | | - Paola Fabbrizio
- Istituto di Ricerche Farmacologiche Mario Negri, IRCCS, Milan, Italy
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Yao D, Li J, Yoshida M, Sessle BJ. NMDA and purinergic processes modulate neck muscle activity evoked by noxious stimulation of dura. J Oral Pathol Med 2020; 49:547-554. [PMID: 32531859 DOI: 10.1111/jop.13072] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2020] [Accepted: 06/04/2020] [Indexed: 02/06/2023]
Abstract
BACKGROUND Adenosine triphosphate (ATP) and glutamate are associated with some headache conditions, and purinergic (P2X) and glutamatergic N-methyl-D-aspartate (NMDA) receptor-related processes in the medulla can modulate the effects of trigeminal nociceptive afferent inputs into the brainstem on craniofacial sensorimotor circuits. This study aimed to test whether neck muscle activity can be induced in rats by noxious stimulation of the frontal dura or superior sagittal sinus that involves P2X or NMDA receptor-dependent mechanisms. METHODS While electromyographic activities of neck and craniofacial muscles were being recorded in anesthetized rats (n = 46), the inflammatory irritant mustard oil (0.2 µL, 20% MO) or vehicle (mineral oil) was topically applied to the dura or sinus, preceded by 10 µL of the ATP antagonist 2',3'-O-(2,4,6- trinitrophenyl) adenosine 5'-triphosphate (TNP-ATP, 0.1 mmol/L; n = 8) or 2-amino-5-phosphonopentanoic acid (APV, 0.05 mmol/L; n = 7) or phosphate-buffered saline (PBS as vehicle control; n = 10). RESULTS Application of MO but not vehicle to the frontal dura significantly increased (P < .05) neck electromyographic activity whereas MO application to the superior sagittal sinus did not significantly increase neck electromyographic activity unless MO had previously been applied to the dura. Pre-treatment (i.t.) with TNP-ATP or APV but not vehicle control significantly reduced neck electromyographic activity evoked by MO application to the dura. CONCLUSIONS These data suggest that noxious stimulation of the frontal dura (but not superior sagittal sinus) may enhance neck muscle activity that is P2X and NMDA receptor-dependent. These effects may contribute to neck muscle stiffness that occurs in some headache conditions.
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Affiliation(s)
- Dongyuan Yao
- Neurological Institute of Jiangxi Province and Department of Neurology, Jiangxi Provincial People's Hospital and School of Pharmaceutical Science, Nanchang University, Nanchang, China.,Faculty of Dentistry and Department of Physiology, Faculty of Medicine, University of Toronto, Toronto, ON, Canada
| | - Jian Li
- Department of Prosthodontics, School and Hospital of Stomatology and National Clinical Research Center for Oral Diseases, Peking University, Beijing, China
| | - Mitsuhiro Yoshida
- Section of Dental Anesthesiology, Department of Oral and Maxillofacial Surgery and Oral Medicine, Hiroshima University Hospital, Hiroshima, Japan
| | - Barry J Sessle
- Faculty of Dentistry and Department of Physiology, Faculty of Medicine, University of Toronto, Toronto, ON, Canada
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DeLalio LJ, Masati E, Mendu S, Ruddiman CA, Yang Y, Johnstone SR, Milstein JA, Keller TCS, Weaver RB, Guagliardo NA, Best AK, Ravichandran KS, Bayliss DA, Sequeira-Lopez MLS, Sonkusare SN, Shu XH, Desai B, Barrett PQ, Le TH, Gomez RA, Isakson BE. Pannexin 1 channels in renin-expressing cells influence renin secretion and blood pressure homeostasis. Kidney Int 2020; 98:630-644. [PMID: 32446934 PMCID: PMC7483468 DOI: 10.1016/j.kint.2020.04.041] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2019] [Revised: 03/29/2020] [Accepted: 04/02/2020] [Indexed: 02/07/2023]
Abstract
Kidney function and blood pressure homeostasis are regulated by purinergic signaling mechanisms. These autocrine/paracrine signaling pathways are initiated by the release of cellular ATP, which influences kidney hemodynamics and steady-state renin secretion from juxtaglomerular cells. However, the mechanism responsible for ATP release that supports tonic inputs to juxtaglomerular cells and regulates renin secretion remains unclear. Pannexin 1 (Panx1) channels localize to both afferent arterioles and juxtaglomerular cells and provide a transmembrane conduit for ATP release and ion permeability in the kidney and the vasculature. We hypothesized that Panx1 channels in renin-expressing cells regulate renin secretion in vivo. Using a renin cell-specific Panx1 knockout model, we found that male Panx1 deficient mice exhibiting a heightened activation of the renin-angiotensin-aldosterone system have markedly increased plasma renin and aldosterone concentrations, and elevated mean arterial pressure with altered peripheral hemodynamics. Following ovariectomy, female mice mirrored the male phenotype. Furthermore, constitutive Panx1 channel activity was observed in As4.1 renin-secreting cells, whereby Panx1 knockdown reduced extracellular ATP accumulation, lowered basal intracellular calcium concentrations and recapitulated a hyper-secretory renin phenotype. Moreover, in response to stress stimuli that lower blood pressure, Panx1-deficient mice exhibited aberrant "renin recruitment" as evidenced by reactivation of renin expression in pre-glomerular arteriolar smooth muscle cells. Thus, renin-cell Panx1 channels suppress renin secretion and influence adaptive renin responses when blood pressure homeostasis is threatened.
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Affiliation(s)
- Leon J DeLalio
- Robert M. Berne Cardiovascular Research Center, University of Virginia School of Medicine, Charlottesville, Virginia, USA; Department of Pharmacology, University of Virginia School of Medicine, Charlottesville, Virginia, USA
| | - Ester Masati
- Robert M. Berne Cardiovascular Research Center, University of Virginia School of Medicine, Charlottesville, Virginia, USA
| | - Suresh Mendu
- Department of Pharmacology, University of Virginia School of Medicine, Charlottesville, Virginia, USA
| | - Claire A Ruddiman
- Robert M. Berne Cardiovascular Research Center, University of Virginia School of Medicine, Charlottesville, Virginia, USA; Department of Pharmacology, University of Virginia School of Medicine, Charlottesville, Virginia, USA
| | - Yang Yang
- Robert M. Berne Cardiovascular Research Center, University of Virginia School of Medicine, Charlottesville, Virginia, USA; Department of Pharmacology, Dalian Medical University, Dalian, China
| | - Scott R Johnstone
- Robert M. Berne Cardiovascular Research Center, University of Virginia School of Medicine, Charlottesville, Virginia, USA
| | - Jenna A Milstein
- Robert M. Berne Cardiovascular Research Center, University of Virginia School of Medicine, Charlottesville, Virginia, USA
| | - T C Stevenson Keller
- Robert M. Berne Cardiovascular Research Center, University of Virginia School of Medicine, Charlottesville, Virginia, USA; Department of Molecular Physiology and Biophysics, University of Virginia School of Medicine, Charlottesville, Virginia, USA
| | - Rachel B Weaver
- Robert M. Berne Cardiovascular Research Center, University of Virginia School of Medicine, Charlottesville, Virginia, USA
| | - Nick A Guagliardo
- Department of Pharmacology, University of Virginia School of Medicine, Charlottesville, Virginia, USA
| | - Angela K Best
- Robert M. Berne Cardiovascular Research Center, University of Virginia School of Medicine, Charlottesville, Virginia, USA
| | - Kodi S Ravichandran
- Department of Microbiology, Immunology, and Cancer, University of Virginia School of Medicine, Charlottesville, Virginia, USA
| | - Douglas A Bayliss
- Department of Pharmacology, University of Virginia School of Medicine, Charlottesville, Virginia, USA
| | - Maria Luisa S Sequeira-Lopez
- Pediatric Center of Excellence in Nephrology, University of Virginia School of Medicine, Charlottesville, Virginia, USA
| | - Swapnil N Sonkusare
- Robert M. Berne Cardiovascular Research Center, University of Virginia School of Medicine, Charlottesville, Virginia, USA; Department of Molecular Physiology and Biophysics, University of Virginia School of Medicine, Charlottesville, Virginia, USA
| | - Xiaohong H Shu
- Department of Pharmacology, Dalian Medical University, Dalian, China
| | - Bimal Desai
- Department of Pharmacology, University of Virginia School of Medicine, Charlottesville, Virginia, USA
| | - Paula Q Barrett
- Department of Pharmacology, University of Virginia School of Medicine, Charlottesville, Virginia, USA
| | - Thu H Le
- Department of Medicine, Division of Nephrology, University of Rochester School of Medicine and Dentistry, Rochester, New York, USA
| | - R Ariel Gomez
- Pediatric Center of Excellence in Nephrology, University of Virginia School of Medicine, Charlottesville, Virginia, USA
| | - Brant E Isakson
- Robert M. Berne Cardiovascular Research Center, University of Virginia School of Medicine, Charlottesville, Virginia, USA; Department of Molecular Physiology and Biophysics, University of Virginia School of Medicine, Charlottesville, Virginia, USA.
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Silberfeld A, Chavez B, Obidike C, Daugherty S, de Groat WC, Beckel JM. LPS-mediated release of ATP from urothelial cells occurs by lysosomal exocytosis. Neurourol Urodyn 2020; 39:1321-1329. [PMID: 32374925 DOI: 10.1002/nau.24377] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2020] [Revised: 04/06/2020] [Accepted: 04/16/2020] [Indexed: 11/11/2022]
Abstract
BACKGROUND While numerous studies have confirmed ATP's importance in bladder physiology/pathophysiology, the literature is still conflicted regarding the mechanism of ATP release from the urothelium. Multiple mechanisms have been identified including non-vesicular release via pannexin channels as well as vesicular release via a mechanism blocked by botulinum toxin. Recently, it has been shown that lysosomes contain significant stores of ATP which can be released extracellularly in response to Toll-like receptor (TLR) stimulation. OBJECTIVE The goal of the current study was to determine if lysosomal exocytosis occurs in urothelial cells in response to TLR4 stimulation by its agonist, bacterial lipopolysaccharide (LPS). MATERIALS AND METHODS Human urothelial cells from an immortalized cell line (TRT-HU1) were treated with bacterial LPS (100 μg/ml) or the nicotinic agoinist cytisine (100 μM) and extracellular release of ATP and lysosomal acid phosphatase were measured. Pannexin-mediated ATP release and lysosomal ATP release were differentiated using Brilliant Blue FCF to inhibit pannexin channels and glycyl-l-phenylalanine-β-naphthylamide (GPN) to destroy lysosomes. The mechanisms controlling lysosomal exocytosis were examined using lysosomal pH measurements using LysoSensor dye and intracellular calcium signaling using Fura-2. RESULTS Stimulation of TRT-HU1 cells with LPS significantly increased ATP release, which was inhibited by GPN, but not by Brilliant Blue FCF. Conversely, stimulation with cytisine induced ATP release that was sensitive to Brilliant Blue FCF but not GPN. LPS stimulation also induced the release of the lysosomal acid phosphatases. LPS increased lysosomal pH and direct alkalization of lysosomal pH using chloroquine or bafilomycin A1 induced ATP and acid phosphatase release, indicating an important role for pH in lysosomal exocytosis. Additionally, stimulation of lysosomal transient receptor potential mucolipin 1 calcium channels evoked intracellular calcium transients as well as ATP release. CONCLUSION These data indicate that LPS-induced ATP release from urothelial cells is mediated by lysosomal exocytosis, a vesicular mechanism distinctly separate from non-vesicular release via pannexin channels.
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Affiliation(s)
- Andrew Silberfeld
- Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | - Brittany Chavez
- Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | - Chinonso Obidike
- Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | - Stephanie Daugherty
- Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | - William C de Groat
- Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | - Jonathan M Beckel
- Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
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Freeman TL, Swartz TH. Purinergic Receptors: Elucidating the Role of these Immune Mediators in HIV-1 Fusion. Viruses 2020; 12:E290. [PMID: 32155980 PMCID: PMC7150916 DOI: 10.3390/v12030290] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2020] [Revised: 03/04/2020] [Accepted: 03/05/2020] [Indexed: 02/07/2023] Open
Abstract
Purinergic receptors are inflammatory mediators activated by extracellular nucleotides released by dying or injured cells. Several studies have described an important role for these receptors in HIV-1 entry, particularly regarding their activity on HIV-1 viral membrane fusion. Several reports identify purinergic receptor antagonists that inhibit HIV-1 membrane fusion; these drugs are suspected to act through antagonizing Env-chemokine receptor interactions. They also appear to abrogate activity of downstream mediators that potentiate activation of the NLRP3 inflammasome pathway. Here we review the literature on purinergic receptors, the drugs that inhibit their function, and the evidence implicating these receptors in HIV-1 entry.
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Affiliation(s)
| | - Talia H. Swartz
- Division of Infectious Diseases, Department of Medicine, Immunology Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA;
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Soare AY, Malik HS, Durham ND, Freeman TL, Alvarez R, Patel F, Satija N, Upadhyay C, Hioe CE, Chen BK, Swartz TH. P2X1 Selective Antagonists Block HIV-1 Infection through Inhibition of Envelope Conformation-Dependent Fusion. J Virol 2020; 94:e01622-19. [PMID: 31852781 DOI: 10.1128/JVI.01622-19] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2019] [Accepted: 12/08/2019] [Indexed: 01/12/2023] Open
Abstract
Purinergic receptors are well-established modulators of inflammatory processes, primarily through detection of extracellular nucleotides that are released by dying or infected cells. Emerging literature has demonstrated that inhibition of these inflammatory receptors can block HIV-1 productive infection and HIV-1-associated inflammation. The specificity of receptor type and mechanism of interaction has not yet been determined. Here, we characterize the inhibitory activity of P2X1 receptor antagonists, NF279 and NF449, in cell lines, primary cells, and a variety of HIV-1 envelope (Env) clades. NF279 and NF449 blocked productive infection at the level of viral membrane fusion, with a range of inhibitory activities against different HIV-1 Env isolates. A mutant virus carrying a truncation deletion of the C-terminal tail of HIV-1 Env glycoprotein 41 (gp41) showed reduced sensitivity to P2X1 antagonists, indicating that the sensitivity of inhibition by these molecules may be modulated by Env conformation. In contrast, a P2X7 antagonist, A438079, had a limited effect on productive infection and fusion. NF279 and NF449 interfered with the ability of the gp120 variable regions 1 and 2 (V1V2)-targeted broadly neutralizing antibody PG9 to block productive infection, suggesting that these drugs may antagonize HIV-1 Env at gp120 V1V2 to block viral membrane fusion. Our observations indicate that P2X1 antagonism can inhibit HIV-1 replication at the level of viral membrane fusion through interaction with Env. Future studies will probe the nature of these compounds in inhibiting HIV-1 fusion and the development of small molecules to block HIV-1 entry via this mechanism.IMPORTANCE While effective treatment can lower the severe morbidity and mortality associated with HIV-1 infection, patients infected with HIV-1 suffer from significantly higher rates of noncommunicable comorbidities associated with chronic inflammation. Emerging literature suggests a key role for P2X1 receptors in mediating this chronic inflammation, but the mechanism is still unknown. Here, we demonstrate that HIV-1 infection is reduced by P2X1 receptor antagonism. This inhibition is mediated by interference with HIV-1 Env and can impact a variety of viral clades. These observations highlight the importance of P2X1 antagonists as potential novel therapeutics that could serve to block a variety of different viral clades with additional benefits for their anti-inflammatory properties.
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Juneja DS, Nasuto S, Delivopoulos E. Fast and Efficient Differentiation of Mouse Embryonic Stem Cells Into ATP-Responsive Astrocytes. Front Cell Neurosci 2020; 13:579. [PMID: 32038173 PMCID: PMC6985097 DOI: 10.3389/fncel.2019.00579] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2019] [Accepted: 12/16/2019] [Indexed: 12/25/2022] Open
Abstract
Astrocytes are multifunctional cells in the CNS, involved in the regulation of neurovascular coupling, the modulation of electrolytes, and the cycling of neurotransmitters at synapses. Induction of astrocytes from stem cells remains a largely underdeveloped area, as current protocols are time consuming, lack granularity in astrocytic subtype generation, and often are not as efficient as neural induction methods. In this paper we present an efficient method to differentiate astrocytes from mouse embryonic stem cells. Our technique uses a cell suspension protocol to produce embryoid bodies (EBs) that are neurally inducted and seeded onto laminin coated surfaces. Plated EBs attach to the surface and release migrating cells to their surrounding environment, which are further inducted into the astrocytic lineage, through an optimized, heparin-based media. Characterization and functional assessment of the cells consists of immunofluorescent labeling for specific astrocytic proteins and sensitivity to adenosine triphosphate (ATP) stimulation. Our experimental results show that even at the earliest stages of the protocol, cells are positive for astrocytic markers (GFAP, ALDH1L1, S100β, and GLAST) with variant expression patterns and purinergic receptors (P2Y). Generated astrocytes also exhibit differential Ca2+ transients upon stimulation with ATP, which evolve over the differentiation period. Metabotropic purinoceptors P2Y1R are expressed and we offer preliminary evidence that metabotropic purinoceptors contribute to Ca2+ transients. Our protocol is simple, efficient and fast, facilitating its use in multiple investigations, particularly in vitro studies of engineered neural networks.
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34
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Babola TA, Kersbergen CJ, Wang HC, Bergles DE. Purinergic signaling in cochlear supporting cells reduces hair cell excitability by increasing the extracellular space. eLife 2020; 9:e52160. [PMID: 31913121 PMCID: PMC7015667 DOI: 10.7554/elife.52160] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2019] [Accepted: 01/07/2020] [Indexed: 11/13/2022] Open
Abstract
Neurons in developing sensory pathways exhibit spontaneous bursts of electrical activity that are critical for survival, maturation and circuit refinement. In the auditory system, intrinsically generated activity arises within the cochlea, but the molecular mechanisms that initiate this activity remain poorly understood. We show that burst firing of mouse inner hair cells prior to hearing onset requires P2RY1 autoreceptors expressed by inner supporting cells. P2RY1 activation triggers K+ efflux and depolarization of hair cells, as well as osmotic shrinkage of supporting cells that dramatically increased the extracellular space and speed of K+ redistribution. Pharmacological inhibition or genetic disruption of P2RY1 suppressed neuronal burst firing by reducing K+ release, but unexpectedly enhanced their tonic firing, as water resorption by supporting cells reduced the extracellular space, leading to K+ accumulation. These studies indicate that purinergic signaling in supporting cells regulates hair cell excitability by controlling the volume of the extracellular space.
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Affiliation(s)
- Travis A Babola
- The Solomon Snyder Department of NeuroscienceJohns Hopkins UniversityBaltimoreUnited States
| | - Calvin J Kersbergen
- The Solomon Snyder Department of NeuroscienceJohns Hopkins UniversityBaltimoreUnited States
| | - Han Chin Wang
- The Solomon Snyder Department of NeuroscienceJohns Hopkins UniversityBaltimoreUnited States
| | - Dwight E Bergles
- The Solomon Snyder Department of NeuroscienceJohns Hopkins UniversityBaltimoreUnited States
- Department of Otolaryngology Head and Neck SurgeryJohns Hopkins UniversityBaltimoreUnited States
- Kavli Neuroscience Discovery InstituteJohns Hopkins UniversityBaltimoreUnited States
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35
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George B, Swartz KJ, Li M. Hearing loss mutations alter the functional properties of human P2X2 receptor channels through distinct mechanisms. Proc Natl Acad Sci U S A 2019; 116:22862-71. [PMID: 31636190 DOI: 10.1073/pnas.1912156116] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Activation of P2X2 receptor channels by extracellular ATP is thought to play important roles in cochlear adaptation to elevated sound levels and protection from overstimulation. Each subunit of a trimeric P2X2 receptor is composed of intracellular N and C termini, a large extracellular domain containing the ATP binding site and 2 transmembrane helices (TM1 and TM2) that form a cation permeable pore. Whole-exome sequencing and linkage analysis have identified 3 hP2X2 receptor mutations (V60L, D273Y, and G353R) that cause dominantly inherited progressive sensorineural hearing loss (DFNA41). Available structures of related P2X receptors suggest that these 3 mutations localize to TM1 (V60L), TM2 (G353R), or the β-sheet linking the TMs to the extracellular ATP binding sites (D273Y). Previous studies have concluded that the V60L and G353R mutants are nonfunctional, whereas the D273Y mutant has yet to be studied. Here, we demonstrate that both V60L and G353R mutations do form functional channels, whereas the D273Y mutation prevents the expression of functional channels on the cell membrane. Our results show that the V60L mutant forms constitutively active channels that are insensitive to ATP or the antagonist suramin, suggesting uncoupling of the pore and the ligand binding domains. In contrast, the G353R mutant can be activated by ATP but exhibits alterations in sensitivity to ATP, inward rectification, and ion selectivity. Collectively, our results demonstrate that the loss of functional P2X2 receptors or distinct alterations of its functional properties lead to noise-induced hearing loss, highlighting the importance of these channels in preserving hearing.
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Layhadi JA, Fountain SJ. ATP-Evoked Intracellular Ca 2+ Responses in M-CSF Differentiated Human Monocyte-Derived Macrophage are Mediated by P2X4 and P2Y11 Receptor Activation. Int J Mol Sci 2019; 20:E5113. [PMID: 31618941 PMCID: PMC6834299 DOI: 10.3390/ijms20205113] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2019] [Revised: 10/09/2019] [Accepted: 10/10/2019] [Indexed: 12/11/2022] Open
Abstract
Tissues differentially secrete multiple colony stimulating factors under conditions of homeostasis and inflammation, orientating recruited circulating monocytes to differentiate to macrophage with differing functional phenotypes. Here, we investigated ATP-evoked intracellular Ca2+ responses in human macrophage differentiated with macrophage colony-stimulating factor (M-CSF). Extracellular ATP evoked (EC50 13.3 ± 1.4 μM) robust biphasic intracellular Ca2+ responses that showed a dependency on both metabotropic (P2Y) and ionotropic (P2X) receptors. qRT-PCR and immunocytochemistry revealed the expression of P2Y1, P2Y2, P2Y6, P2Y11, P2Y13, P2X1, P2X4, P2X5, and P2X7. Pharmacological analysis revealed contribution of only P2X4 and P2Y11 to the Ca2+ response evoked by maximal ATP concentrations (100 µM). This study reveals the contribution of P2X4 and P2Y11 receptor activation to ATP-evoked intracellular Ca2+ responses, and makes comparison with macrophage differentiated using granulocyte colony-stimulating factor (GM-CSF).
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Affiliation(s)
- Janice A Layhadi
- Biomedical Research Centre, School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, UK.
| | - Samuel J Fountain
- Biomedical Research Centre, School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, UK.
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Abstract
The tooth has an unusual sensory system that converts external stimuli predominantly into pain, yet its sensory afferents in teeth demonstrate cytochemical properties of non-nociceptive neurons. This review summarizes the recent knowledge underlying this paradoxical nociception, with a focus on the ion channels involved in tooth pain. The expression of temperature-sensitive ion channels has been extensively investigated because thermal stimulation often evokes tooth pain. However, temperature-sensitive ion channels cannot explain the sudden intense tooth pain evoked by innocuous temperatures or light air puffs, leading to the hydrodynamic theory emphasizing the microfluidic movement within the dentinal tubules for detection by mechanosensitive ion channels. Several mechanosensitive ion channels expressed in dental sensory systems have been suggested as key players in the hydrodynamic theory, and TRPM7, which is abundant in the odontoblasts, and recently discovered PIEZO receptors are promising candidates. Several ligand-gated ion channels and voltage-gated ion channels expressed in dental primary afferent neurons have been discussed in relation to their potential contribution to tooth pain. In addition, in recent years, there has been growing interest in the potential sensory role of odontoblasts; thus, the expression of ion channels in odontoblasts and their potential relation to tooth pain is also reviewed.
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Affiliation(s)
- Kihwan Lee
- Gachon Pain Center and Department of Physiology, College of Medicine, Gachon University, Incheon 406-799, Korea.
| | - Byeong-Min Lee
- Department of Oral Physiology and Program in Neurobiology, School of Dentistry, Seoul National University, Seoul 08826, Korea.
| | - Chul-Kyu Park
- Gachon Pain Center and Department of Physiology, College of Medicine, Gachon University, Incheon 406-799, Korea.
| | - Yong Ho Kim
- Gachon Pain Center and Department of Physiology, College of Medicine, Gachon University, Incheon 406-799, Korea.
| | - Gehoon Chung
- Department of Oral Physiology and Program in Neurobiology, School of Dentistry, Seoul National University, Seoul 08826, Korea.
- Dental Research Institute, Seoul National University, Seoul 03080, Korea.
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Fong Z, Griffin CS, Hollywood MA, Thornbury KD, Sergeant GP. β 3-Adrenoceptor agonists inhibit purinergic receptor-mediated contractions of the murine detrusor. Am J Physiol Cell Physiol 2019; 317:C131-C142. [PMID: 31042424 DOI: 10.1152/ajpcell.00488.2018] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
β3-Adrenoceptor (β3-AR) agonists are used to treat overactive bladder syndrome; however, their mechanism of action has not been determined. The aims of this study were to compare the effects of β3-AR agonists on cholinergic versus purinergic receptor-mediated contractions of the detrusor and to examine the mechanisms underlying inhibition of the purinergic responses by β3-AR agonists. Isometric tension recordings were made from strips of murine detrusor and whole cell current recordings were made from freshly isolated detrusor myocytes using the patch-clamp technique. Transcriptional expression of exchange protein directly activated by cAMP (EPAC) subtypes in detrusor strips was assessed using RT-PCR and real-time quantitative PCR. The β3-AR agonists BRL37344 and CL316243 (100 nM) inhibited cholinergic nerve-mediated contractions of the detrusor by 19 and 23%, respectively, but did not reduce contractions induced by the cholinergic agonist carbachol (300 nM). In contrast, BRL37344 and CL316243 inhibited purinergic nerve-mediated responses by 55 and 56%, respectively, and decreased the amplitude of contractions induced by the P2X receptor agonist α,β-methylene ATP by 40 and 45%, respectively. The adenylate cyclase activator forskolin inhibited purinergic responses, and these effects were mimicked by a combination of the PKA activator N6-monobutyryl-cAMP and the EPAC activator 8-pCPT-2'-O-methyl-cAMP-AM (007-AM). Application of ATP (1 μM) evoked reproducible P2X currents in isolated detrusor myocytes voltage-clamped at -60 mV. These responses were reduced in amplitude in the presence of BRL37344 and also by 007-AM. This study demonstrates that β3-AR agonists reduce postjunctional purinergic responses in the detrusor via a pathway involving activation of the cAMP effector EPAC.
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Affiliation(s)
- Zhihui Fong
- Smooth Muscle Research Centre, Dundalk Institute of Technology , Dundalk , Ireland
| | - Caoimhín S Griffin
- Smooth Muscle Research Centre, Dundalk Institute of Technology , Dundalk , Ireland
| | - Mark A Hollywood
- Smooth Muscle Research Centre, Dundalk Institute of Technology , Dundalk , Ireland
| | - Keith D Thornbury
- Smooth Muscle Research Centre, Dundalk Institute of Technology , Dundalk , Ireland
| | - Gerard P Sergeant
- Smooth Muscle Research Centre, Dundalk Institute of Technology , Dundalk , Ireland
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Soare AY, Durham ND, Gopal R, Tweel B, Hoffman KW, Brown JA, O'Brien M, Bhardwaj N, Lim JK, Chen BK, Swartz TH. P2X Antagonists Inhibit HIV-1 Productive Infection and Inflammatory Cytokines Interleukin-10 (IL-10) and IL-1β in a Human Tonsil Explant Model. J Virol 2019; 93:e01186-18. [PMID: 30305360 PMCID: PMC6288349 DOI: 10.1128/jvi.01186-18] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2018] [Accepted: 09/28/2018] [Indexed: 02/07/2023] Open
Abstract
HIV-1 causes a persistent infection of the immune system that is associated with chronic comorbidities. The mechanisms that underlie this inflammation are poorly understood. Emerging literature has implicated proinflammatory purinergic receptors and downstream signaling mediators in HIV-1 infection. This study probed whether inhibitors of purinergic receptors would reduce HIV-1 infection and HIV-1-stimulated inflammation. An ex vivo human tonsil histoculture infection model was developed to support HIV-1 productive infection and stimulated the inflammatory cytokine interleukin-1 beta (IL-1β) and the immunosuppressive cytokine interleukin-10 (IL-10). This study tests whether inhibitors of purinergic receptors would reduce HIV-1 infection and HIV-1-stimulated inflammation. The purinergic P2X1 receptor antagonist NF449, the purinergic P2X7 receptor antagonist A438079, and azidothymidine (AZT) were tested in HIV-1-infected human tonsil explants to compare levels of inhibition of HIV-1 infection and HIV-stimulated inflammatory cytokine production. All drugs limited HIV-1 productive infection, but P2X-selective antagonists (NF449 and A438079) significantly lowered HIV-stimulated IL-10 and IL-1β. We further observed that P2X1- and P2X7-selective antagonists can act differentially as inhibitors of both HIV-1 infection and HIV-1-stimulated inflammation. Our findings highlight the differential effects of HIV-1 on inflammation in peripheral blood compared to those in lymphoid tissue. For the first time, we demonstrate that P2X-selective antagonists act differentially as inhibitors of both HIV-1 infection and HIV-1-stimulated inflammation. Drugs that block these pathways can have independent inhibitory activities against HIV-1 infection and HIV-induced inflammation.IMPORTANCE Patients who are chronically infected with HIV-1 experience sequelae related to chronic inflammation. The mechanisms of this inflammation have not been elucidated. Here, we describe a class of drugs that target the P2X proinflammatory signaling receptors in a human tonsil explant model. This model highlights differences in HIV-1 stimulation of lymphoid tissue inflammation and peripheral blood. These drugs serve to block both HIV-1 infection and production of IL-10 and IL-1β in lymphoid tissue, suggesting a novel approach to HIV-1 therapeutics in which both HIV-1 replication and inflammatory signaling are simultaneously targeted.
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Affiliation(s)
- Alexandra Y Soare
- Division of Infectious Diseases, Department of Medicine, Immunology Institute, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Natasha D Durham
- Division of Infectious Diseases, Department of Medicine, Immunology Institute, Icahn School of Medicine at Mount Sinai, New York, New York, USA
- Division of Molecular Biology and Microbiology, Sackler School of Graduate Biomedical Sciences, Tufts University School of Medicine, Boston, Massachusetts, USA
| | - Ramya Gopal
- Division of Hematology and Oncology, Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Benjamin Tweel
- Department of Otolaryngology, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Kevin W Hoffman
- Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Julia A Brown
- Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Megan O'Brien
- Division of Infectious Diseases, Department of Medicine, Immunology Institute, Icahn School of Medicine at Mount Sinai, New York, New York, USA
- Division of Hematology and Oncology, Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Nina Bhardwaj
- Division of Hematology and Oncology, Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Jean K Lim
- Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Benjamin K Chen
- Division of Infectious Diseases, Department of Medicine, Immunology Institute, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Talia H Swartz
- Division of Infectious Diseases, Department of Medicine, Immunology Institute, Icahn School of Medicine at Mount Sinai, New York, New York, USA
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Abstract
In the nervous system, ATP is co-stored in vesicles with classical transmitters and released in a regulated manner. ATP from the intracellular compartment can also exit the cell through hemichannels and following shear stress or membrane damage. In the past 30 years, the action of ATP as an extracellular transmitter at cell-surface receptors has evolved from somewhat of a novelty that was treated with skepticism to purinergic transmission being accepted as having widespread important functional roles mediated by ATP-gated ionotropic P2X receptors (P2XRs). This review focuses on work published in the last five years and provides an overview of ( a) structural studies, ( b) the molecular basis of channel properties and regulation of P2XRs, and ( c) the physiological and pathophysiological roles of ATP acting at defined P2XR subtypes.
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Affiliation(s)
- Ralf Schmid
- Department of Molecular and Cell Biology, University of Leicester, Leicester LE1 7RH, United Kingdom; .,Leicester Institute of Structural and Chemical Biology, University of Leicester, Leicester LE1 7RH, United Kingdom
| | - Richard J Evans
- Department of Molecular and Cell Biology, University of Leicester, Leicester LE1 7RH, United Kingdom;
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Craigie E, Menzies RI, Larsen CK, Jacquillet G, Carrel M, Wildman SS, Loffing J, Leipziger J, Shirley DG, Bailey MA, Unwin RJ. The renal and blood pressure response to low sodium diet in P2X4 receptor knockout mice. Physiol Rep 2018; 6:e13899. [PMID: 30350402 PMCID: PMC6198136 DOI: 10.14814/phy2.13899] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2018] [Revised: 09/25/2018] [Accepted: 09/27/2018] [Indexed: 01/02/2023] Open
Abstract
In the kidney, purinergic (P2) receptor-mediated ATP signaling has been shown to be an important local regulator of epithelial sodium transport. Appropriate sodium regulation is crucial for blood pressure (BP) control and disturbances in sodium balance can lead to hypo- or hypertension. Links have already been established between P2 receptor signaling and the development of hypertension, attributed mainly to vascular and/or inflammatory effects. A transgenic mouse model with deletion of the P2X4 receptor (P2X4-/- ) is known to have hypertension, which is thought to reflect endothelial dysfunction and impaired nitric oxide (NO) release. However, renal function in this model has not been characterized; moreover, studies in vitro have shown that the P2X4 receptor can regulate renal epithelial Na+ channel (ENaC) activity. Therefore, in the present study we investigated renal function and sodium handling in P2X4-/- mice, focusing on ENaC-mediated Na+ reabsorption. We confirmed an elevated BP in P2X4-/- mice compared with wild-type mice, but found that ENaC-mediated Na+ reabsorption is no different from wild-type and does not contribute to the raised BP observed in the knockout. However, when P2X4-/- mice were placed on a low sodium diet, BP normalized. Plasma aldosterone concentration tended to increase according to sodium restriction status in both genotypes; in contrast to wild-types, P2X4-/- mice did not show an increase in functional ENaC activity. Thus, although the increased BP in P2X4-/- mice has been attributed to endothelial dysfunction and impaired NO release, there is also a sodium-sensitive component.
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Affiliation(s)
- Eilidh Craigie
- Centre for NephrologyUniversity College London Medical SchoolLondonUnited Kingdom
- Institue for AnatomyUniversity of ZürichZürichSwitzerland
| | - Robert I. Menzies
- British Heart Foundation Centre for Cardiovascular ScienceUniversity of EdinburghEdinburghUnited Kingdom
| | - Casper K. Larsen
- Department of Biomedicine, PhysiologyAarhus UniversityAarhus CDenmark
| | - Grégory Jacquillet
- Centre for NephrologyUniversity College London Medical SchoolLondonUnited Kingdom
| | - Monique Carrel
- Institue for AnatomyUniversity of ZürichZürichSwitzerland
| | - Scott S. Wildman
- Urinary System Physiology UnitMedway School of PharmacyUniversity of KentKentUnited Kingdom
| | | | - Jens Leipziger
- Department of Biomedicine, PhysiologyAarhus UniversityAarhus CDenmark
| | - David G. Shirley
- Centre for NephrologyUniversity College London Medical SchoolLondonUnited Kingdom
| | - Matthew A. Bailey
- British Heart Foundation Centre for Cardiovascular ScienceUniversity of EdinburghEdinburghUnited Kingdom
| | - Robert J. Unwin
- Centre for NephrologyUniversity College London Medical SchoolLondonUnited Kingdom
- CVRM iMEDAstraZeneca GothenburgGothenburgSweden
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42
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Iguchi N, Malykhina AP, Wilcox DT. Early life voiding dysfunction leads to lower urinary tract dysfunction through alteration of muscarinic and purinergic signaling in the bladder. Am J Physiol Renal Physiol 2018; 315:F1320-F1328. [PMID: 30089034 DOI: 10.1152/ajprenal.00154.2018] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Lower urinary tract dysfunction (LUTD) is a common problem in children and constitutes up to 40% of pediatric urology clinic visits. Improved diagnosis and interventions have been leading to better outcomes in many patients, whereas some children are left untreated or do not respond to the treatment successfully. In addition, many of these patients are lost by the pediatric urologists during their teenage years, and the outcome in later life largely remains unidentified. Studies suggest childhood LUTD is associated with subsequent adult urinary tract symptoms. However, whether and how early life LUTD attributes to urinary symptoms in those patients later in life remains to be elucidated. In the current study, we investigated the effects of early life voiding perturbation on bladder function using a neonatal maternal separation (NMS) protocol in mice. The NMS group displayed a delayed development of voluntary voiding behavior, a significant reduction of functional bladder capacity, and bladder overactivity compared with control mice later in life. In vitro evaluation of detrusor smooth muscle and molecular study showed a decrease in muscarinic contribution alongside an increase in purinergic contribution in detrusor contractility in NMS mice compared with control group. These results suggest that early life bladder dysfunction interfered with the normal maturation of the voluntary micturition control and facilitated LUTD in a later stage, which is at least partly attributed to an alteration of muscarinic and purinergic signaling in the urinary bladder.
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Affiliation(s)
- Nao Iguchi
- Division of Urology, Department of Surgery, University of Colorado Denver School of Medicine , Aurora, Colorado
| | - Anna P Malykhina
- Division of Urology, Department of Surgery, University of Colorado Denver School of Medicine , Aurora, Colorado
| | - Duncan T Wilcox
- Division of Urology, Department of Surgery, University of Colorado Denver School of Medicine , Aurora, Colorado.,Children's Hospital Colorado , Aurora, Colorado
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Dreisig K, Sund L, Dommer MW, Kristensen NP, Boddum K, Viste R, Fredholm S, Odum N, Jäättelä M, Skov S, Kornum BR. Human P2Y 11 Expression Level Affects Human P2X7 Receptor-Mediated Cell Death. Front Immunol 2018; 9:1159. [PMID: 29937766 PMCID: PMC6002484 DOI: 10.3389/fimmu.2018.01159] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2017] [Accepted: 05/08/2018] [Indexed: 12/21/2022] Open
Abstract
Adenosine triphosphate (ATP) is known to induce cell death in T lymphocytes at high extracellular concentrations. CD4+ and CD8+ T lymphocytes have a differential response to ATP, which in mice is due to differences in the P2X7 receptor expression levels. By contrast, we observed that the difference in human CD4+ and CD8+ T lymphocyte response toward the synthetic ATP-analog BzATP is not explained by a difference in human P2X7 receptor expression. Rather, the BzATP-induced human P2X7 receptor response in naïve and immune-activated lymphocyte subtypes correlated with the expression of another ATP-binding receptor: the human P2Y11 receptor. In a recombinant expression system, the coexpression of the human P2Y11 receptor counteracted BzATP-induced human P2X7 receptor-driven lactate dehydrogenase release (a marker of cell death) and pore formation independent of calcium signaling. A mutated non-signaling human P2Y11 receptor had a similar human P2X7 receptor-inhibitory effect on pore formation, thus demonstrating that the human P2X7 receptor interference was not caused by human P2Y11 receptor signaling. In conclusion, we demonstrate an important species difference in the ATP-mediated cell death between mice and human cells and show that in human T lymphocytes, the expression of the human P2Y11 receptor correlates with human P2X7 receptor-driven cell death following BzATP stimulation.
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Affiliation(s)
- Karin Dreisig
- Molecular Sleep Laboratory, Department of Clinical Biochemistry, Rigshospitalet, Glostrup Hospital, Glostrup, Denmark
| | - Louise Sund
- Molecular Sleep Laboratory, Department of Clinical Biochemistry, Rigshospitalet, Glostrup Hospital, Glostrup, Denmark
| | - Maja Wallentin Dommer
- Molecular Sleep Laboratory, Department of Clinical Biochemistry, Rigshospitalet, Glostrup Hospital, Glostrup, Denmark
| | - Nikolaj Pagh Kristensen
- Molecular Sleep Laboratory, Department of Clinical Biochemistry, Rigshospitalet, Glostrup Hospital, Glostrup, Denmark
| | - Kim Boddum
- Molecular Sleep Laboratory, Department of Clinical Biochemistry, Rigshospitalet, Glostrup Hospital, Glostrup, Denmark
| | - Rannveig Viste
- Norwegian Centre of Expertise for Neurodevelopmental Disorders and Hypersomnias (NevSom), Oslo University Hospital, Ullevål, Norway
| | - Simon Fredholm
- Department of Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark
| | - Niels Odum
- Department of Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark
| | - Marja Jäättelä
- Cell Death and Metabolism Unit, Center for Autophagy, Recycling and Disease, Danish Cancer Society Research Center, Copenhagen, Denmark
| | - Søren Skov
- Department of Veterinary Disease Biology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Birgitte R Kornum
- Molecular Sleep Laboratory, Department of Clinical Biochemistry, Rigshospitalet, Glostrup Hospital, Glostrup, Denmark.,Danish Center for Sleep Medicine, Department of Neurophysiology, Rigshospitalet, Glostrup Hospital, Glostrup, Denmark
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Martín A, Domercq M, Matute C. Inflammation in stroke: the role of cholinergic, purinergic and glutamatergic signaling. Ther Adv Neurol Disord 2018; 11:1756286418774267. [PMID: 29774059 PMCID: PMC5949933 DOI: 10.1177/1756286418774267] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2018] [Accepted: 03/26/2018] [Indexed: 12/27/2022] Open
Abstract
The inflammatory response is a major factor in stroke pathophysiology and contributes to secondary neuronal damage in both acute and chronic stages of the ischemic injury. Recent work in experimental cerebral ischemia has demonstrated the involvement of neurotransmitter signaling in the modulation of neuroinflammation. The present review discusses recent findings on the therapeutic potential and diagnostic perspectives of cholinergic, purinergic and glutamatergic receptors and transporters in experimental stroke. It provides evidence of the role of neurotransmission signaling as a promising inflammatory biomarker in stroke. Finally, recent molecular imaging studies using positron emission tomography of cholinergic receptors and glutamatergic transporters are outlined along with their potential as novel anti-inflammatory therapy to reduce the outcome of cerebral ischemia.
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Affiliation(s)
- Abraham Martín
- Experimental Molecular Imaging, Molecular Imaging Unit, CIC biomaGUNE, Pº Miramon 182, San Sebastian, Spain
| | - María Domercq
- Department of Neurosciences, University of the Basque Country, Barrio Sarriena s/n, Leioa, Spain Achucarro Basque Center for Neuroscience-UPV/EHU, Zamudio, Spain Instituto de Salud Carlos III, Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas (CIBERNED), Leioa, Spain
| | - Carlos Matute
- Department of Neurosciences, University of the Basque Country, Barrio Sarriena s/n, Leioa, Spain Achucarro Basque Center for Neuroscience-UPV/EHU, Zamudio, Spain Instituto de Salud Carlos III, Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas (CIBERNED), Leioa, Spain
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45
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Hakim MA, Buchholz JN, Behringer EJ. Electrical dynamics of isolated cerebral and skeletal muscle endothelial tubes: Differential roles of G-protein-coupled receptors and K + channels. Pharmacol Res Perspect 2018; 6:e00391. [PMID: 29636977 PMCID: PMC5889193 DOI: 10.1002/prp2.391] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2017] [Accepted: 02/12/2018] [Indexed: 12/13/2022] Open
Abstract
Electrical dynamics of freshly isolated cerebral endothelium have not been determined independently of perivascular nerves and smooth muscle. We tested the hypothesis that endothelium of cerebral and skeletal muscle arteries differentially utilizes purinergic and muscarinic signaling pathways to activate endothelium‐derived hyperpolarization. Changes in membrane potential (Vm) were recorded in intact endothelial tubes freshly isolated from posterior cerebral and superior epigastric arteries of male and female C57BL/6 mice (age: 3‐8 months). Vm was measured in response to activation of purinergic (P2Y) and muscarinic (M3) receptors in addition to small‐ and intermediate‐conductance Ca2+‐activated K+ (SKCa/IKCa) and inward rectifying K+ (KIR) channels using ATP (100 μmol·L−1), acetylcholine (ACh; 10 μmol·L−1), NS309 (0.01‐10 μmol·L−1), and 15 mmol·L−1 KCl, respectively. Intercellular coupling was demonstrated via transfer of propidium iodide dye and electrical current (±0.5‐3 nA) through gap junctions. With similarities observed across gender, peak hyperpolarization to ATP and ACh in skeletal muscle endothelial tubes was ~twofold and ~sevenfold higher, respectively, vs cerebral endothelial tubes, whereas responses to NS309 were similar (from resting Vm ~−30 mV to maximum ~−80 mV). Hyperpolarization (~8 mV) occurred during 15 mmol·L−1 KCl treatment in cerebral but not skeletal muscle endothelial tubes. Despite weaker hyperpolarization during endothelial GPCR stimulation in cerebral vs skeletal muscle endothelium, the capability for robust SKCa/IKCa activity is preserved across brain and skeletal muscle. As vascular reactivity decreases with aging and cardiovascular disease, endothelial K+ channel activity may be calibrated to restore blood flow to respective organs regardless of gender.
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Affiliation(s)
- Md A Hakim
- Basic Sciences Loma Linda University Loma Linda CA USA
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46
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Rhett JM, Yeh ES. The Potential for Connexin Hemichannels to Drive Breast Cancer Progression through Regulation of the Inflammatory Response. Int J Mol Sci 2018; 19:ijms19041043. [PMID: 29601539 PMCID: PMC5979453 DOI: 10.3390/ijms19041043] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2018] [Revised: 03/27/2018] [Accepted: 03/28/2018] [Indexed: 12/12/2022] Open
Abstract
Over the past few decades, connexin hemichannels have become recognized as major players in modulating the inflammatory response. Chronic inflammation is documented to promote tumorigenesis and is a critical component of tumor progression. Furthermore, inflammation is strongly linked to angiogenesis, immunotolerance, invasiveness, metastasis, and resistance in breast cancers. In this review, the literature on the role of connexin hemichannels in inflammation is summarized, and the potential role for hemichannel-mediated inflammation in driving breast cancer progression is discussed. Lastly, the potential for connexin-based therapeutics to modulate the inflammatory component of the tumor microenvironment as an avenue for the treatment of breast cancer is also discussed.
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Affiliation(s)
- J Matthew Rhett
- Department of Cell and Molecular Pharmacology & Experimental Therapeutics, Medical University of South Carolina, Charleston, SC 29412, USA.
| | - Elizabeth S Yeh
- Department of Cell and Molecular Pharmacology & Experimental Therapeutics, Medical University of South Carolina, Charleston, SC 29412, USA.
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Fernandes V, Sharma D, Vaidya S, P A S, Guan Y, Kalia K, Tiwari V. Cellular and molecular mechanisms driving neuropathic pain: recent advancements and challenges. Expert Opin Ther Targets 2018; 22:131-142. [PMID: 29285962 DOI: 10.1080/14728222.2018.1420781] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
INTRODUCTION Current pharmacotherapeutics for neuropathic pain offer only symptomatic relief without treating the underlying pathophysiology. Additionally, they are associated with various dose-limiting side effects. Pain research in the past few decades has revolved around the role of oxidative-nitrosative stress, protein kinases, glial cell activation, and inflammatory signaling cascades but has failed to produce specific and effective therapies. Areas covered: This review focuses on recent advances in cellular and molecular mechanisms of neuropathic pain that may be translated into future therapies. We discuss emerging targets such as WNT signaling mechanisms, the tetrahydrobiopterin pathway, Mrg receptors, endogenous lipid mediators, micro-RNAs and their roles in pain regulation. Recent evidence is also presented regarding genetic and epigenetic mechanisms of pain modulation. Expert opinion: During chronic neuropathic pain, maladaptation occurs in the peripheral and central nervous systems, including a shift in microglial phenotype from a surveillance state to an activated state. Microglial activation leads to an altered expression of cell surface proteins, growth factors, and intracellular signaling molecules that contribute to development of a neuroinflammatory cascade and chronic pain sensitization. Specific targeting of these cellular and molecular mechanisms may provide the key to development of effective neuropathic pain therapies that have minimal side effects.
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Affiliation(s)
- Valencia Fernandes
- a Department of Pharmacology and Toxicology , National Institute of Pharmaceutical Education and Research (NIPER)-Ahmedabad , Gandhinagar , India
| | - Dilip Sharma
- a Department of Pharmacology and Toxicology , National Institute of Pharmaceutical Education and Research (NIPER)-Ahmedabad , Gandhinagar , India
| | - Shivani Vaidya
- a Department of Pharmacology and Toxicology , National Institute of Pharmaceutical Education and Research (NIPER)-Ahmedabad , Gandhinagar , India
| | - Shantanu P A
- a Department of Pharmacology and Toxicology , National Institute of Pharmaceutical Education and Research (NIPER)-Ahmedabad , Gandhinagar , India
| | - Yun Guan
- b Department of Anesthesiology and Critical Care Medicine , Johns Hopkins University School of Medicine , Baltimore , MD , USA
| | - Kiran Kalia
- a Department of Pharmacology and Toxicology , National Institute of Pharmaceutical Education and Research (NIPER)-Ahmedabad , Gandhinagar , India
| | - Vinod Tiwari
- a Department of Pharmacology and Toxicology , National Institute of Pharmaceutical Education and Research (NIPER)-Ahmedabad , Gandhinagar , India.,b Department of Anesthesiology and Critical Care Medicine , Johns Hopkins University School of Medicine , Baltimore , MD , USA
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Wu D, Lee S, Luo J, Xia H, Gushchina S, Richardson PM, Yeh J, Krügel U, Franke H, Zhang Y, Bo X. Intraneural Injection of ATP Stimulates Regeneration of Primary Sensory Axons in the Spinal Cord. J Neurosci 2018; 38:1351-65. [PMID: 29279307 DOI: 10.1523/JNEUROSCI.1660-17.2017] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2017] [Revised: 11/06/2017] [Accepted: 11/09/2017] [Indexed: 12/17/2022] Open
Abstract
Injury to the peripheral axons of sensory neurons strongly enhances the regeneration of their central axons in the spinal cord. It remains unclear on what molecules that initiate such conditioning effect. Because ATP is released extracellularly by nerve and other tissue injury, we hypothesize that injection of ATP into a peripheral nerve might mimic the stimulatory effect of nerve injury on the regenerative state of the primary sensory neurons. We found that a single injection of 6 μl of 150 μm ATP into female rat sciatic nerve quadrupled the number of axons growing into a lesion epicenter in spinal cord after a concomitant dorsal column transection. A second boost ATP injection 1 week after the first one markedly reinforced the stimulatory effect of a single injection. Single ATP injection increased expression of phospho-STAT3 and GAP43, two markers of regenerative activity, in sensory neurons. Double ATP injections sustained the activation of phospho-STAT3 and GAP43, which may account for the marked axonal growth across the lesion epicenter. Similar studies performed on P2X7 or P2Y2 receptor knock-out mice indicate P2Y2 receptors are involved in the activation of STAT3 after ATP injection or conditioning lesion, whereas P2X7 receptors are not. Injection of ATP at 150 μm caused little Wallerian degeneration and behavioral tests showed no significant long-term adverse effects on sciatic nerve functions. The results in this study reveal possible mechanisms underlying the stimulation of regenerative programs and suggest a practical strategy for stimulating axonal regeneration following spinal cord injury. SIGNIFICANCE STATEMENT Injury of peripheral axons of sensory neurons has been known to strongly enhance the regeneration of their central axons in the spinal cord. In this study, we found that injection of ATP into a peripheral nerve can mimic the effect of peripheral nerve injury and significantly increase the number of sensory axons growing across lesion epicenter in the spinal cord. ATP injection increased expression of several markers for regenerative activity in sensory neurons, including phospho-STAT3 and GAP43. ATP injection did not cause significant long-term adverse effects on the functions of the injected nerve. These results may lead to clinically applicable strategies for enhancing neuronal responses that support regeneration of injured axons.
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Durnin L, Lees A, Manzoor S, Sasse KC, Sanders KM, Mutafova-Yambolieva VN. Loss of nitric oxide-mediated inhibition of purine neurotransmitter release in the colon in the absence of interstitial cells of Cajal. Am J Physiol Gastrointest Liver Physiol 2017; 313:G419-G433. [PMID: 28705804 PMCID: PMC5792210 DOI: 10.1152/ajpgi.00045.2017] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/01/2017] [Revised: 06/26/2017] [Accepted: 07/11/2017] [Indexed: 01/31/2023]
Abstract
Regulation of colonic motility depends on the integrity of enteric inhibitory neurotransmission mediated by nitric oxide (NO), purine neurotransmitters, and neuropeptides. Intramuscular interstitial cells of Cajal (ICC-IM) and platelet-derived growth factor receptor-α-positive (PDGFRα+) cells are involved in generating responses to NO and purine neurotransmitters, respectively. Previous studies have suggested a decreased nitrergic and increased purinergic neurotransmission in KitW/KitW-v (W/Wv ) mice that display lesions in ICC-IM along the gastrointestinal tract. However, contributions of NO to these phenotypes have not been evaluated. We used small-chamber superfusion assays and HPLC to measure the spontaneous and electrical field stimulation (EFS)-evoked release of nicotinamide adenine dinucleotide (NAD+)/ADP-ribose, uridine adenosine tetraphosphate (Up4A), adenosine 5'-triphosphate (ATP), and metabolites from the tunica muscularis of human, monkey, and murine colons and circular muscle of monkey colon, and we tested drugs that modulate NO levels or blocked NO receptors. NO inhibited EFS-evoked release of purines in the colon via presynaptic neuromodulation. Colons from W/Wv, Nos1-/- , and Prkg1-/- mice displayed augmented neural release of purines that was likely due to altered nitrergic neuromodulation. Colons from W/Wv mice demonstrated decreased nitrergic and increased purinergic relaxations in response to nerve stimulation. W/Wv mouse colons demonstrated reduced Nos1 expression and reduced NO release. Our results suggest that enhanced purinergic neurotransmission may compensate for the loss of nitrergic neurotransmission in muscles with partial loss of ICC. The interactions between nitrergic and purinergic neurotransmission in the colon provide novel insight into the role of neurotransmitters and effector cells in the neural regulation of gastrointestinal motility.NEW & NOTEWORTHY This is the first study investigating the role of nitric oxide (NO) and intramuscular interstitial cells of Cajal (ICC-IM) in modulating neural release of purines in colon. We found that NO inhibited release of purines in human, monkey, and murine colons and that colons from KitW/KitW-v (W/Wv ) mice, which present with partial loss of ICC-IM, demonstrated augmented neural release of purines. Interactions between nitrergic and purinergic neurotransmission may affect motility in disease conditions with ICC-IM deficiencies.
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Affiliation(s)
- Leonie Durnin
- 1Department of Physiology and Cell Biology, University of Nevada School of Medicine, Reno, Nevada; and
| | - Andrea Lees
- 1Department of Physiology and Cell Biology, University of Nevada School of Medicine, Reno, Nevada; and
| | - Sheerien Manzoor
- 1Department of Physiology and Cell Biology, University of Nevada School of Medicine, Reno, Nevada; and
| | | | - Kenton M. Sanders
- 1Department of Physiology and Cell Biology, University of Nevada School of Medicine, Reno, Nevada; and
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50
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Duvoor C, Dendi VS, Marco A, Shekhawat NS, Chada A, Ravilla R, Musham CK, Mirza W, Chaudhury A. Commentary: ATP: The crucial component of secretory vesicles: Accelerated ATP/insulin exocytosis and prediabetes. Front Physiol 2017; 8:53. [PMID: 28210227 PMCID: PMC5288386 DOI: 10.3389/fphys.2017.00053] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2016] [Accepted: 01/19/2017] [Indexed: 02/03/2023] Open
Affiliation(s)
- Chitharanjan Duvoor
- Department of Endocrinology and Internal Medicine, University of Arkansas for Medical SciencesLittle Rock, AR, USA; GIM FoundationLittle Rock, AR, USA
| | - Vijaya S Dendi
- GIM FoundationLittle Rock, AR, USA; Department of Internal Medicine and Hospital Medicine, Christus Trinity Mother Frances HospitalTyler, TX, USA
| | - Asween Marco
- GIM FoundationLittle Rock, AR, USA; Department of Policy, University of Arkansas for Little RockLittle Rock, AR, USA
| | - Nawal S Shekhawat
- GIM FoundationLittle Rock, AR, USA; Tutwiler ClinicTutwiler, MS, USA
| | - Aditya Chada
- GIM FoundationLittle Rock, AR, USA; Department of Pulmonary and Critical Care Medicine, University of Arkansas for Medical SciencesLittle Rock, AR, USA
| | - Rahul Ravilla
- GIM FoundationLittle Rock, AR, USA; Winthrop P. Rockefeller Cancer Institute, University of Arkansas for Medical SciencesLittle Rock, AR, USA
| | - Chaitanya K Musham
- GIM FoundationLittle Rock, AR, USA; St. Vincent Infirmary (Catholic Health Initiative)Little Rock, AR, USA
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