1
|
Tajbakhsh A, Gheibihayat SM, Mortazavi D, Medhati P, Rostami B, Savardashtaki A, Momtazi-Borojeni AA. The Effect of Cigarette Smoke Exposure on Efferocytosis in Chronic Obstructive Pulmonary Disease; Molecular Mechanisms and Treatment Opportunities. COPD 2021; 18:723-736. [PMID: 34865568 DOI: 10.1080/15412555.2021.1978419] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Cigarette smoking-related inflammation, cellular stresses, and tissue destruction play a key role in lung disease, such as chronic obstructive pulmonary disease (COPD). Notably, augmented apoptosis and impaired clearance of apoptotic cells, efferocytosis, contribute to the chronic inflammatory response and tissue destruction in patients with COPD. Of note, exposure to cigarette smoke can impair alveolar macrophages efferocytosis activity, which leads to secondary necrosis formation and tissue inflammation. A better understanding of the processes behind the effect of cigarette smoke on efferocytosis concerning lung disorders can help to design more efficient treatment approaches and also delay the development of lung disease, such as COPD. To this end, we aimed to seek mechanisms underlying the impairing effect of cigarette smoke on macrophages-mediated efferocytosis in COPD. Further, available therapeutic opportunities for restoring efferocytosis activity and ameliorating respiratory tract inflammation in smokers with COPD were also discussed.
Collapse
Affiliation(s)
- Amir Tajbakhsh
- Pharmaceutical Sciences Research Center, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Seyed Mohammad Gheibihayat
- Department of Medical Genetics, School of Medicine, Shahid Sadoughi University of Medical Sciences, Yazd, Iran
| | - Deniz Mortazavi
- Department of Genetics and Molecular Biology, School of Medicine, Isfahan University of Medical Science, Isfahan, Iran
| | - Pourya Medhati
- Student research committee, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Behrouz Rostami
- Health & Treatment Center of Rostam, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Amir Savardashtaki
- Epilepsy Research Center, Shiraz University of Medical Sciences, Shiraz, Iran.,Department of Medical Biotechnology, School of Advanced Medical Sciences and Technologies, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Amir Abbas Momtazi-Borojeni
- Department of Medical Biotechnology, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran.,Iran's National Elites Foundation, Tehran, Iran
| |
Collapse
|
2
|
Suarez-Berumen K, Collins-Hooper H, Gromova A, Meech R, Sacco A, Dash PR, Mitchell R, Shestopalov VI, Woolley TE, Vaiyapuri S, Patel K, Makarenkova HP. Pannexin 1 Regulates Skeletal Muscle Regeneration by Promoting Bleb-Based Myoblast Migration and Fusion Through a Novel Lipid Based Signaling Mechanism. Front Cell Dev Biol 2021; 9:736813. [PMID: 34676213 PMCID: PMC8523994 DOI: 10.3389/fcell.2021.736813] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2021] [Accepted: 09/13/2021] [Indexed: 12/12/2022] Open
Abstract
Adult skeletal muscle has robust regenerative capabilities due to the presence of a resident stem cell population called satellite cells. Muscle injury leads to these normally quiescent cells becoming molecularly and metabolically activated and embarking on a program of proliferation, migration, differentiation, and fusion culminating in the repair of damaged tissue. These processes are highly coordinated by paracrine signaling events that drive cytoskeletal rearrangement and cell-cell communication. Pannexins are a family of transmembrane channel proteins that mediate paracrine signaling by ATP release. It is known that Pannexin1 (Panx1) is expressed in skeletal muscle, however, the role of Panx1 during skeletal muscle development and regeneration remains poorly understood. Here we show that Panx1 is expressed on the surface of myoblasts and its expression is rapidly increased upon induction of differentiation and that Panx1-/- mice exhibit impaired muscle regeneration after injury. Panx1-/- myoblasts activate the myogenic differentiation program normally, but display marked deficits in migration and fusion. Mechanistically, we show that Panx1 activates P2 class purinergic receptors, which in turn mediate a lipid signaling cascade in myoblasts. This signaling induces bleb-driven amoeboid movement that in turn supports myoblast migration and fusion. Finally, we show that Panx1 is involved in the regulation of cell-matrix interaction through the induction of ADAMTS (Disintegrin-like and Metalloprotease domain with Thrombospondin-type 5) proteins that help remodel the extracellular matrix. These studies reveal a novel role for lipid-based signaling pathways activated by Panx1 in the coordination of myoblast activities essential for skeletal muscle regeneration.
Collapse
Affiliation(s)
- Katia Suarez-Berumen
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA, United States.,West Anaheim Medical Center, Anaheim, CA, United States
| | | | - Anastasia Gromova
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA, United States.,Development, Aging and Regeneration Program, Center for Genetic Disorders and Aging Research, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, United States
| | - Robyn Meech
- Department of Clinical Pharmacology, Flinders University, Adelaide, SA, Australia
| | - Alessandra Sacco
- Development, Aging and Regeneration Program, Center for Genetic Disorders and Aging Research, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, United States
| | - Phil R Dash
- School of Biological Sciences, University of Reading, Reading, United Kingdom
| | - Robert Mitchell
- School of Biological Sciences, University of Reading, Reading, United Kingdom
| | - Valery I Shestopalov
- Bascom Palmer Eye Institute, University of Miami School of Medicine, Miami, FL, United States.,Institute for Information Transmission Problems, Russian Academy of Sciences, Moscow, Russia
| | - Thomas E Woolley
- Mathematical Institute, University of Oxford, Oxford, United Kingdom
| | | | - Ketan Patel
- School of Biological Sciences, University of Reading, Reading, United Kingdom
| | - Helen P Makarenkova
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA, United States
| |
Collapse
|
3
|
Zahiri D, Burow P, Großmann C, Müller CE, Klapperstück M, Markwardt F. Sphingosine-1-phosphate induces migration of microglial cells via activation of volume-sensitive anion channels, ATP secretion and activation of purinergic receptors. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2020; 1868:118915. [PMID: 33271273 DOI: 10.1016/j.bbamcr.2020.118915] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Revised: 11/20/2020] [Accepted: 11/24/2020] [Indexed: 12/17/2022]
Abstract
Microglia cells are versatile players coordinating inflammatory and regenerative processes in the central nervous system in which sphingosine-1-phosphate (S1P)-mediated migration is essential. We investigated the involved signaling cascade by means of voltage clamp, measurement of ATP secretion, and wound healing assay in murine microglial BV-2 cells. S1P and extracellular hypoosmolar solution evoked an anion conductance of the cell membrane. The corresponding ion currents were inhibited by intracellular hypoosmolar solution and by the anion channel antagonists NPPB, tamoxifen, and carbenoxolone, pointing to the activation of volume-regulated anion channels (VRAC). The knockdown by siRNA indicates the involvement of LRRC8A subunits. The S1PR1-antagonist W123 and pertussis-toxin prevented the S1P-induced currents, showing the involvement of the Gi-protein-coupled S1P receptor 1 (S1PR1). Furthermore, S1P and hypoosmolar extracellular solution induced an increase of ATP levels in the supernatants of BV-2 cells, which was inhibited by NPPB, tamoxifen, and W123. S1P, ATP, and ADP stimulated cell migration into the scratch area. The inhibition of S1PR1 and the downstream Gi proteins hampered cell migration. Antagonists of VRAC were also able to diminish the migration of BV-2 cells. Furthermore, direct inhibition of ATP-gated P2X4 or P2X7 receptors or ADP-stimulated P2Y12 receptors blocked the stimulating effects of S1P on BV-2 cell migration. We conclude that there is an interaction between S1P receptors and purinergic receptors mediated by an S1P-induced ATP release via VRAC and that the amount of released ATP is capable of stimulating cell migration of BV-2 microglia cells via activation of P2X4, P2X7, and P2Y12 receptors.
Collapse
Affiliation(s)
- Danyal Zahiri
- Julius-Bernstein-Institute for Physiology, Martin-Luther-University Halle, Magdeburger Straße 6, D-06097 Halle/Saale, Germany
| | - Philipp Burow
- Julius-Bernstein-Institute for Physiology, Martin-Luther-University Halle, Magdeburger Straße 6, D-06097 Halle/Saale, Germany
| | - Claudia Großmann
- Julius-Bernstein-Institute for Physiology, Martin-Luther-University Halle, Magdeburger Straße 6, D-06097 Halle/Saale, Germany
| | - Christa E Müller
- Pharmaceutical Institute, Pharmaceutical & Medicinal Chemistry, University of Bonn, Germany
| | - Manuela Klapperstück
- Julius-Bernstein-Institute for Physiology, Martin-Luther-University Halle, Magdeburger Straße 6, D-06097 Halle/Saale, Germany
| | - Fritz Markwardt
- Julius-Bernstein-Institute for Physiology, Martin-Luther-University Halle, Magdeburger Straße 6, D-06097 Halle/Saale, Germany.
| |
Collapse
|
4
|
Dissection of P2X4 and P2X7 Receptor Current Components in BV-2 Microglia. Int J Mol Sci 2020; 21:ijms21228489. [PMID: 33187309 PMCID: PMC7696836 DOI: 10.3390/ijms21228489] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2020] [Revised: 11/09/2020] [Accepted: 11/09/2020] [Indexed: 12/21/2022] Open
Abstract
Microglia cells represent the immune system of the central nervous system. They become activated by ATP released from damaged and inflamed tissue via purinergic receptors. Ionotropic purinergic P2X4 and P2X7 receptors have been shown to be involved in neurological inflammation and pain sensation. Whether the two receptors assemble exclusively as homotrimers or also as heterotrimers is still a matter of debate. We investigated the expression of P2X receptors in BV-2 microglia cells applying the whole-cell voltage-clamp technique. We dissected P2X4 and P2X7 receptor-mediated current components by using specific P2X4 and P2X7 receptor blockers and by their characteristic current kinetics. We found that P2X4 and P2X7 receptors are activated independently from each other, indicating that P2X4/P2X7 heteromers are not of functional significance in these cells. The pro-inflammatory mediators lipopolysaccharide and interferon γ, if applied in combination, upregulated P2X4, but not P2X7 receptor-dependent current components also arguing against phenotypically relevant heteromerization of P2X4 and P2X7 receptor subunits.
Collapse
|
5
|
Hodge S, Macowan M, Liu H, Hamon R, Chen ACH, Marchant JM, Pizzutto SJ, Upham JW, Chang AB. Sphingosine signaling dysfunction in airway cells as a potential contributor to progression from protracted bacterial bronchitis to bronchiectasis in children. Pediatr Pulmonol 2020; 55:1414-1423. [PMID: 32176839 DOI: 10.1002/ppul.24728] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/28/2019] [Accepted: 01/23/2020] [Indexed: 11/11/2022]
Abstract
AIM Protracted bacterial bronchitis (PBB) is considered a potential precursor to bronchiectasis (BE) in some children. We previously showed that alveolar macrophages (AM) from children with PBB or BE have a similar significant defect in phagocytic capacity, with proinflammatory associations. We hypothesized that the mechanisms responsible for this defect involve dysregulation of the sphingosine-1-phosphate (S1P) signaling pathway, as we have found in adult inflammatory lung diseases. METHOD We employed a Custom TaqMan OpenArray to investigate gene expression of S1P-generating enzymes: sphingosine kinases (SPHK) 1/2, S1P phosphatase 2 (SGPP2), S1P lyase 1 (SGPL1), S1P receptors (S1PR) 1/2/4/5; proinflammatory cytokines TNF-α (TNF) and IFNγ (IFNG), the cytotoxic mediator granzyme B (GZMB), and inflammasomes AIM2 and NLRP3, in bronchoalveolar lavage from 15 children with BE, 15 with PBB and 17 age-matched controls, and determined association with clinical/demographic variables and airway inflammation. RESULT Significantly increased expression of S1PR1, S1PR2, and SPHK1 was noted in PBB and BE AM vs controls with increased SGPP2 only in PBB. TNF, IFNG, AIM2, and NLRP3 were significantly increased in both disease groups with increased GZMB only in PBB. There were no significant differences in the expression of any other S1P-related mediator between groups. There were significant positive associations between Haemophilus influenzae growth and expression of S1PR1 and NLRP3; between S1PR1 and S1PR2, NLRP3 and IFNG; between S1PR2 and AIM2, SPHK1, and SPHK2; and between SPHK1 and GZMB, IFNG, AIM2, and NLRP3. CONCLUSION Children with PBB and BE share similar S1P-associated gene expression profiles. AM phagocytic dysfunction and inflammation in these children may occur due to dysregulated S1P signaling.
Collapse
Affiliation(s)
- Sandra Hodge
- Lung Research Unit, Department of Thoracic Medicine, Royal Adelaide Hospital, Adelaide, South Australia, Australia.,Faculty of Medicine, The University of Adelaide, Adelaide, South Australia, Australia
| | - Matthew Macowan
- Lung Research Unit, Department of Thoracic Medicine, Royal Adelaide Hospital, Adelaide, South Australia, Australia.,Faculty of Medicine, The University of Adelaide, Adelaide, South Australia, Australia
| | - Hong Liu
- Lung Research Unit, Department of Thoracic Medicine, Royal Adelaide Hospital, Adelaide, South Australia, Australia.,Faculty of Medicine, The University of Adelaide, Adelaide, South Australia, Australia
| | - Rhys Hamon
- Lung Research Unit, Department of Thoracic Medicine, Royal Adelaide Hospital, Adelaide, South Australia, Australia
| | - Alice C-H Chen
- Faculty of Medicine, The University of Queensland Diamantina Institute and Princess Alexandra Hospital, Brisbane, Queensland, Australia
| | - Julie M Marchant
- Department of Respiratory Medicine, Queensland Children's Hospital and Queensland University of Technology, Brisbane, Queensland, Australia
| | - Susan J Pizzutto
- Child Health Division, Menzies School of Health Research, Darwin, Northern Territory, Australia
| | - John W Upham
- Faculty of Medicine, The University of Queensland Diamantina Institute and Princess Alexandra Hospital, Brisbane, Queensland, Australia
| | - Anne B Chang
- Department of Respiratory Medicine, Queensland Children's Hospital and Queensland University of Technology, Brisbane, Queensland, Australia.,Child Health Division, Menzies School of Health Research, Darwin, Northern Territory, Australia
| |
Collapse
|
6
|
Xu S, Jiang J, Zhang Y, Chen T, Zhu M, Fang C, Mi Y. Discovery of potential plasma protein biomarkers for acute myocardial infarction via proteomics. J Thorac Dis 2019; 11:3962-3972. [PMID: 31656670 DOI: 10.21037/jtd.2019.08.100] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Background Acute myocardial infarction (AMI) is an acute disease with high mortality and seriously threatens human health. The identification of new effective biological markers for AMI is a prerequisite for treatment. Most proteomic studies have focused on atherosclerotic plaques, vascular cells, monocytes and platelets in the blood; however, the concentration of these factors in plasma is low, making it difficult to measure the complexity of plasma components. Moreover, some studies have examined the plasma protein of patients with acute coronary syndrome with histochemistry; however, the results are not consistent. Therefore, it is necessary to further investigate the differential proteins in the plasma of patients with AMI via proteomics to identify new biomarkers of AMI. Methods In this study, immunodepletion of high-abundance plasma proteins followed by an isobaric tagging for relative and absolute quantitation (iTRAQ)-based quantitative proteomic approach was used to analyze plasma samples from 5 control individuals and 10 AMI patients. Results Four hundred sixty-eight proteins were identified from two samples, and 33 proteins were differentially expressed in AMI patients compared to the controls. Among the 33 proteins, 12 proteins showed a ≥1.5-fold change between AMI and control samples. These proteins included fatty acid binding protein 3 (FABP3, ratio =6.36), creatine kinase-MB (CK-MB ratio =4.89), adenylate kinase1 (AK1 ratio =4.16), pro-platelet basic protein (PPBP ratio =3.29), creatine kinase (CK ratio =2.88), platelet factor 4 (PF4 ratio =2.62), peptidyl prolyl isomerase Cyclophilin A (PPIA ratio =2.05), Cofilin-1 (CFL1 ratio =1.81), coronin1A (CORO1A ratio =1.71), protein kinase M (PKM ratio =1.63), ribonuclease inhibitor (RNH1, ratio =1.67), and triose phosphate isomerase (TPI1 ratio =1.56). By contrast, there was a decrease of 19 proteins, such as adiponectin (ADIPOQ ratio =0.70), insulin-like growth factor binding protein6 (IGFBP6 ratio =0.70), Dickkopf-related protein 3 (DKK3 ratio =0.70) and complement 4B (C4B ratio =0.68). The most over-represented term was regulation of cell proliferation in the cellular component category of Gene Ontology (GO). The top 3 biological process terms were regulation of cell proliferation, response to wounding and wound healing. These proteins included immune proteins, blood coagulation proteins, lipid metabolism proteins, cytoskeleton proteins, energy metabolism proteins, gene regulation proteins, myocutaneous proteins, and myocardial remodeling proteins and were highly connected with each other, which indicates that the functional network of these processes contribute to the pathophysiology of AMI. Conclusions In conclusion, the present quantitative proteomic study identified novel AMI biomarker candidates and might provide fundamental information for the development of an AMI biomarker.
Collapse
Affiliation(s)
- Shasha Xu
- Department of Cardiology, Affiliated Taizhou Hospital of Wenzhou Medical University, Taizhou 317000, China.,Laboratory of Cardiovascular Disease, Affiliated Taizhou Hospital of Wenzhou Medical University, Taizhou 317000, China
| | - Jianjun Jiang
- Department of Cardiology, Affiliated Taizhou Hospital of Wenzhou Medical University, Taizhou 317000, China.,Laboratory of Cardiovascular Disease, Affiliated Taizhou Hospital of Wenzhou Medical University, Taizhou 317000, China
| | - Yang Zhang
- Department of Cardiology, Affiliated Taizhou Hospital of Wenzhou Medical University, Taizhou 317000, China.,Laboratory of Cardiovascular Disease, Affiliated Taizhou Hospital of Wenzhou Medical University, Taizhou 317000, China
| | - Tingting Chen
- Department of Cardiology, Affiliated Taizhou Hospital of Wenzhou Medical University, Taizhou 317000, China.,Laboratory of Cardiovascular Disease, Affiliated Taizhou Hospital of Wenzhou Medical University, Taizhou 317000, China
| | - Min Zhu
- Enze Medical Research Center, Affiliated Taizhou Hospital of Wenzhou Medical University, Taizhou 317000, China
| | - Chongfeng Fang
- Department of Cardiology, Affiliated Taizhou Hospital of Wenzhou Medical University, Taizhou 317000, China.,Laboratory of Cardiovascular Disease, Affiliated Taizhou Hospital of Wenzhou Medical University, Taizhou 317000, China
| | - Yafei Mi
- Department of Cardiology, Affiliated Taizhou Hospital of Wenzhou Medical University, Taizhou 317000, China.,Laboratory of Cardiovascular Disease, Affiliated Taizhou Hospital of Wenzhou Medical University, Taizhou 317000, China.,Enze Medical Research Center, Affiliated Taizhou Hospital of Wenzhou Medical University, Taizhou 317000, China
| |
Collapse
|
7
|
Weigert A, Olesch C, Brüne B. Sphingosine-1-Phosphate and Macrophage Biology-How the Sphinx Tames the Big Eater. Front Immunol 2019; 10:1706. [PMID: 31379883 PMCID: PMC6658986 DOI: 10.3389/fimmu.2019.01706] [Citation(s) in RCA: 76] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2019] [Accepted: 07/08/2019] [Indexed: 12/11/2022] Open
Abstract
The sphingolipid sphingosine-1-phosphate (S1P) is produced by sphingosine kinases to either signal through intracellular targets or to activate a family of specific G-protein-coupled receptors (S1PR). S1P levels are usually low in peripheral tissues compared to the vasculature, forming a gradient that mediates lymphocyte trafficking. However, S1P levels rise during inflammation in peripheral tissues, thereby affecting resident or recruited immune cells, including macrophages. As macrophages orchestrate initiation and resolution of inflammation, the sphingosine kinase/S1P/S1P-receptor axis emerges as an important determinant of macrophage function in the pathogenesis of inflammatory diseases such as cancer, atherosclerosis, and infection. In this review, we therefore summarize the current knowledge how S1P affects macrophage biology.
Collapse
Affiliation(s)
- Andreas Weigert
- Faculty of Medicine, Institute of Biochemistry I, Goethe-University Frankfurt, Frankfurt, Germany
| | - Catherine Olesch
- Faculty of Medicine, Institute of Biochemistry I, Goethe-University Frankfurt, Frankfurt, Germany
| | - Bernhard Brüne
- Faculty of Medicine, Institute of Biochemistry I, Goethe-University Frankfurt, Frankfurt, Germany.,German Cancer Consortium (DKTK), Partner Site Frankfurt, Frankfurt, Germany.,Project Group Translational Medicine and Pharmacology TMP, Fraunhofer Institute for Molecular Biology and Applied Ecology, Frankfurt, Germany.,Frankfurt Cancer Institute, Goethe-University Frankfurt, Frankfurt, Germany
| |
Collapse
|
8
|
Korbecki J, Gutowska I, Kojder I, Jeżewski D, Goschorska M, Łukomska A, Lubkowska A, Chlubek D, Baranowska-Bosiacka I. New extracellular factors in glioblastoma multiforme development: neurotensin, growth differentiation factor-15, sphingosine-1-phosphate and cytomegalovirus infection. Oncotarget 2018; 9:7219-7270. [PMID: 29467963 PMCID: PMC5805549 DOI: 10.18632/oncotarget.24102] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2017] [Accepted: 01/02/2018] [Indexed: 11/25/2022] Open
Abstract
Recent years have seen considerable progress in understanding the biochemistry of cancer. For example, more significance is now assigned to the tumor microenvironment, especially with regard to intercellular signaling in the tumor niche which depends on many factors secreted by tumor cells. In addition, great progress has been made in understanding the influence of factors such as neurotensin, growth differentiation factor-15 (GDF-15), sphingosine-1-phosphate (S1P), and infection with cytomegalovirus (CMV) on the 'hallmarks of cancer' in glioblastoma multiforme. Therefore, in the present work we describe the influence of these factors on the proliferation and apoptosis of neoplastic cells, cancer stem cells, angiogenesis, migration and invasion, and cancer immune evasion in a glioblastoma multiforme tumor. In particular, we discuss the effect of neurotensin, GDF-15, S1P (including the drug FTY720), and infection with CMV on tumor-associated macrophages (TAM), microglial cells, neutrophil and regulatory T cells (Treg), on the tumor microenvironment. In order to better understand the role of the aforementioned factors in tumoral processes, we outline the latest models of intratumoral heterogeneity in glioblastoma multiforme. Based on the most recent reports, we discuss the problems of multi-drug therapy in treating glioblastoma multiforme.
Collapse
Affiliation(s)
- Jan Korbecki
- Department of Biochemistry and Medical Chemistry, Pomeranian Medical University in Szczecin, 70-111 Szczecin, Poland.,Department of Biochemistry and Molecular Biology, Faculty of Health Sciences, University of Bielsko-Biała, 43-309 Bielsko-Biała, Poland
| | - Izabela Gutowska
- Department of Biochemistry and Human Nutrition, Pomeranian Medical University in Szczecin, 71-460 Szczecin, Poland
| | - Ireneusz Kojder
- Department of Applied Neurocognitivistics, Pomeranian Medical University in Szczecin, 71-252 Szczecin, Poland.,Department of Neurosurgery, Pomeranian Medical University in Szczecin, 71-252 Szczecin, Poland
| | - Dariusz Jeżewski
- Department of Applied Neurocognitivistics, Pomeranian Medical University in Szczecin, 71-252 Szczecin, Poland.,Department of Neurosurgery, Pomeranian Medical University in Szczecin, 71-252 Szczecin, Poland
| | - Marta Goschorska
- Department of Biochemistry and Medical Chemistry, Pomeranian Medical University in Szczecin, 70-111 Szczecin, Poland
| | - Agnieszka Łukomska
- Department of Biochemistry and Human Nutrition, Pomeranian Medical University in Szczecin, 71-460 Szczecin, Poland
| | - Anna Lubkowska
- Department of Functional Diagnostics and Physical Medicine, Pomeranian Medical University in Szczecin, 71-210 Szczecin, Poland
| | - Dariusz Chlubek
- Department of Biochemistry and Medical Chemistry, Pomeranian Medical University in Szczecin, 70-111 Szczecin, Poland
| | - Irena Baranowska-Bosiacka
- Department of Biochemistry and Medical Chemistry, Pomeranian Medical University in Szczecin, 70-111 Szczecin, Poland
| |
Collapse
|
9
|
Abstract
The P2X7 receptor is a trimeric ion channel gated by extracellular adenosine 5'-triphosphate. The receptor is present on an increasing number of different cells types including stem, blood, glial, neural, ocular, bone, dental, exocrine, endothelial, muscle, renal and skin cells. The P2X7 receptor induces various downstream events in a cell-specific manner, including inflammatory molecule release, cell proliferation and death, metabolic events, and phagocytosis. As such this receptor plays important roles in heath and disease. Increasing knowledge about the P2X7 receptor has been gained from studies of, but not limited to, protein chemistry including cloning, site-directed mutagenesis, crystal structures and atomic modeling, as well as from studies of primary tissues and transgenic mice. This chapter focuses on the P2X7 receptor itself. This includes the P2RX7 gene and its products including splice and polymorphic variants. This chapter also reviews modulators of P2X7 receptor activation and inhibition, as well as the transcriptional regulation of the P2RX7 gene via its promoter and enhancer regions, and by microRNA and long-coding RNA. Furthermore, this chapter discusses the post-translational modification of the P2X7 receptor by N-linked glycosylation, adenosine 5'-diphosphate ribosylation and palmitoylation. Finally, this chapter reviews interaction partners of the P2X7 receptor, and its cellular localisation and trafficking within cells.
Collapse
Affiliation(s)
- Ronald Sluyter
- School of Biological Sciences, University of Wollongong, Wollongong, NSW, 2522, Australia. .,Centre for Medical and Molecular Bioscience, University of Wollongong, Wollongong, NSW, 2522, Australia. .,Illawarra Health and Medical Research Institute, Wollongong, NSW, 2522, Australia.
| |
Collapse
|
10
|
Custódio R, McLean CJ, Scott AE, Lowther J, Kennedy A, Clarke DJ, Campopiano DJ, Sarkar-Tyson M, Brown AR. Characterization of secreted sphingosine-1-phosphate lyases required for virulence and intracellular survival of Burkholderia pseudomallei. Mol Microbiol 2016; 102:1004-1019. [PMID: 27632710 DOI: 10.1111/mmi.13531] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/13/2016] [Indexed: 01/09/2023]
Abstract
Sphingosine-1-phosphate (S1P), a bioactive sphingolipid metabolite, plays a critical role in the orchestration of immune responses. S1P levels within the mammalian host are tightly regulated, in part through the activity of S1P lyase (S1PL) which catalyses its irreversible degradation. Herein, we describe the identification and characterization of secreted S1PL orthologues encoded by the facultative intracellular bacteria Burkholderia pseudomallei and Burkholderia thailandensis. These bacterial orthologues exhibited S1PL enzymatic activity, functionally complemented an S1PL-deficient yeast strain and conferred resistance to the antimicrobial sphingolipid D-erythro-sphingosine. We report that secretion of these bacterial S1PLs is pH-dependent, and is observed during intracellular infection. S1PL-deficient mutants displayed impaired intracellular replication in murine macrophages (associated with an inability to evade the maturing phagosome) and were significantly attenuated in murine and larval infection models. Furthermore, treatment of Burkholderia-infected macrophages with either S1P or a selective agonist of S1P receptor 1 enhanced bacterial colocalisation with LAMP-1 and reduced their intracellular survival. In summary, our studies confirm bacterial-encoded S1PL as a critical virulence determinant of B. pseudomallei and B. thailandensis, further highlighting the pivotal role of S1P in host-pathogen interactions. In addition, our data suggest that S1P pathway modulators have potential for the treatment of intracellular infection.
Collapse
Affiliation(s)
- Rafael Custódio
- Biosciences, College of Life and Environmental Sciences, University of Exeter, UK
| | | | - Andrew E Scott
- Microbiology, Defence Science and Technology Laboratory, Porton Down, UK
| | | | | | | | | | - Mitali Sarkar-Tyson
- Microbiology, Defence Science and Technology Laboratory, Porton Down, UK.,Marshall Centre for Infectious Diseases and Training, School of Pathology and Laboratory Medicine, University of Western Australia, WA 6009, Australia
| | - Alan R Brown
- Biosciences, College of Life and Environmental Sciences, University of Exeter, UK
| |
Collapse
|
11
|
Tran HB, Barnawi J, Ween M, Hamon R, Roscioli E, Hodge G, Reynolds PN, Pitson SM, Davies LT, Haberberger R, Hodge S. Cigarette smoke inhibits efferocytosis via deregulation of sphingosine kinase signaling: reversal with exogenous S1P and the S1P analogue FTY720. J Leukoc Biol 2016; 100:195-202. [PMID: 26792820 DOI: 10.1189/jlb.3a1015-471r] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2015] [Accepted: 01/04/2016] [Indexed: 12/31/2022] Open
Abstract
Alveolar macrophages from chronic obstructive pulmonary disease patients and cigarette smokers are deficient in their ability to phagocytose apoptotic bronchial epithelial cells (efferocytosis). We hypothesized that the defect is mediated via inhibition of sphingosine kinases and/or their subcellular mislocalization in response to cigarette smoke and can be normalized with exogenous sphingosine-1-phosphate or FTY720 (fingolimod), a modulator of sphingosine-1-phosphate signaling, which has been shown to be clinically useful in multiple sclerosis. Measurement of sphingosine kinase 1/2 activities by [(32)P]-labeled sphingosine-1-phosphate revealed a 30% reduction of sphingosine kinase 1 (P < 0.05) and a nonsignificant decrease of sphingosine kinase 2 in THP-1 macrophages after 1 h cigarette smoke extract exposure. By confocal analysis macrophage sphingosine kinase 1 protein was normally localized to the plasma membrane and cytoplasm and sphingosine kinase 2 to the nucleus and cytoplasm but absent at the cell surface. Cigarette smoke extract exposure (24 h) led to a retraction of sphingosine kinase 1 from the plasma membrane and sphingosine kinase 1/2 clumping in the Golgi domain. Selective inhibition of sphingosine kinase 2 with 25 µM ABC294640 led to 36% inhibition of efferocytosis (P < 0.05); 10 µM sphingosine kinase inhibitor/5C (sphingosine kinase 1-selective inhibitor) induced a nonsignificant inhibition of efferocytosis, but its combination with ABC294640 led to 56% inhibition (P < 0.01 vs. control and < 0.05 vs. single inhibitors). Cigarette smoke-inhibited efferocytosis was significantly (P < 0.05) reversed to near-control levels in the presence of 10-100 nM exogenous sphingosine-1-phosphate or FTY720, and FTY720 reduced cigarette smoke-induced clumping of sphingosine kinase 1/2 in the Golgi domain. These data strongly support a role of sphingosine kinase 1/2 in efferocytosis and as novel therapeutic targets in chronic obstructive pulmonary disease.
Collapse
Affiliation(s)
- Hai B Tran
- Lung Research Unit, Hanson Institute and Department of Thoracic Medicine, Royal Adelaide Hospital, Adelaide, Australia;
| | - Jameel Barnawi
- Lung Research Unit, Hanson Institute and Department of Thoracic Medicine, Royal Adelaide Hospital, Adelaide, Australia; Department of Medicine, University of Adelaide, Australia; Department of Medical Laboratory Technology, University of Tabuk, Saudi Arabia
| | - Miranda Ween
- Lung Research Unit, Hanson Institute and Department of Thoracic Medicine, Royal Adelaide Hospital, Adelaide, Australia
| | - Rhys Hamon
- Lung Research Unit, Hanson Institute and Department of Thoracic Medicine, Royal Adelaide Hospital, Adelaide, Australia
| | - Eugene Roscioli
- Lung Research Unit, Hanson Institute and Department of Thoracic Medicine, Royal Adelaide Hospital, Adelaide, Australia
| | - Greg Hodge
- Lung Research Unit, Hanson Institute and Department of Thoracic Medicine, Royal Adelaide Hospital, Adelaide, Australia; Department of Medicine, University of Adelaide, Australia
| | - Paul N Reynolds
- Lung Research Unit, Hanson Institute and Department of Thoracic Medicine, Royal Adelaide Hospital, Adelaide, Australia; Department of Medicine, University of Adelaide, Australia
| | - Stuart M Pitson
- Department of Medicine, University of Adelaide, Australia; Centre for Cancer Biology, University of South Australia and SA Pathology, Adelaide, Australia; and
| | - Lorena T Davies
- Centre for Cancer Biology, University of South Australia and SA Pathology, Adelaide, Australia; and
| | - Rainer Haberberger
- Centre for Neuroscience Anatomy and Histology, Flinders University, Adelaide, Australia
| | - Sandra Hodge
- Lung Research Unit, Hanson Institute and Department of Thoracic Medicine, Royal Adelaide Hospital, Adelaide, Australia; Department of Medicine, University of Adelaide, Australia;
| |
Collapse
|
12
|
Affiliation(s)
- Philipp Burow
- a Julius-Bernstein-Institute for Physiology ; Martin-Luther-University Halle ; D-Halle/Saale , Germany
| | | |
Collapse
|
13
|
Fuentes E, Palomo I. Extracellular ATP metabolism on vascular endothelial cells: A pathway with pro-thrombotic and anti-thrombotic molecules. Vascul Pharmacol 2015; 75:1-6. [PMID: 25989108 DOI: 10.1016/j.vph.2015.05.002] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2015] [Revised: 04/16/2015] [Accepted: 05/09/2015] [Indexed: 12/20/2022]
Abstract
Vascular endothelial contributes to the metabolism and interconversion of extracellular adenine nucleotides via ecto-ATPase/ADPase (CD39) and ecto-5'nucleotidase (CD73) activities. These enzymes collectively dephosphorylate ATP, ADP, and AMP with the production of additional adenosine. In the vascular system, adenine nucleotides (ATP and ADP) and nucleoside adenosine represent an important class of extracellular molecules involved in modulating the processes linked to vascular thrombosis exerting various effects in platelets. Yet, the mechanisms by which the extracellular ATP metabolism in the local environment trigger pro-thrombotic and anti-thrombotic states are yet to be fully elucidated. In this article, the relative contribution of extracellular ATP metabolism in platelet regulation is explored.
Collapse
Affiliation(s)
- Eduardo Fuentes
- Department of Clinical Biochemistry and Immunohaematology, Faculty of Health Sciences, Interdisciplinary Excellence Research Program on Healthy Aging (PIEI-ES), Universidad de Talca, Talca, Chile; Centro de Estudios en Alimentos Procesados (CEAP), CONICYT-Regional, Gore Maule, R09I2001 Talca, Chile.
| | - Iván Palomo
- Department of Clinical Biochemistry and Immunohaematology, Faculty of Health Sciences, Interdisciplinary Excellence Research Program on Healthy Aging (PIEI-ES), Universidad de Talca, Talca, Chile; Centro de Estudios en Alimentos Procesados (CEAP), CONICYT-Regional, Gore Maule, R09I2001 Talca, Chile.
| |
Collapse
|
14
|
Burow P, Klapperstück M, Markwardt F. Activation of ATP secretion via volume-regulated anion channels by sphingosine-1-phosphate in RAW macrophages. Pflugers Arch 2014; 467:1215-26. [PMID: 24965069 DOI: 10.1007/s00424-014-1561-8] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2014] [Accepted: 06/17/2014] [Indexed: 12/13/2022]
Abstract
We report the activation of outwardly rectifying anion currents by sphingosine-1-phosphate (S1P) in the murine macrophage cell line RAW 264.7. The S1P-induced current is mainly carried by anions, because the reversal potential of the current was shifted by replacement of extracellular Cl(-) by glutamate(-) but not when extracellular Na(+) was substituted by Tris(+). The inhibition of the current by hypertonic extracellular or hypotonic intracellular solution as well as the inhibitory effects of NPPB, tamoxifen, and glibenclamide indicates that the anion current is mediated by volume-regulated anion channels (VRAC). The S1P effect was blocked by intracellular GDPβS and W123, which points to signaling via the S1P receptor 1 (S1PR1) and G proteins. As cytochalasin D diminished the action of S1P, we conclude that the actin cytoskeleton is involved in the stimulation of VRAC. S1P and hypotonic extracellular solution induced secretion of ATP from the macrophages, which in both cases was blocked in a similar way by typical VRAC blockers. We suppose that the S1P-induced ATP secretion in macrophages via activation of VRAC constitutes a functional link between sphingolipid and purinergic signaling in essential processes such as inflammation and migration of leukocytes as well as phagocytosis and the killing of intracellular bacteria.
Collapse
Affiliation(s)
- Philipp Burow
- Julius Bernstein Institute for Physiology, Martin Luther University Halle, Magdeburger Str. 6, 06097, Halle/Saale, Germany
| | | | | |
Collapse
|
15
|
Adenylate Kinase Isoform Network: A Major Hub in Cell Energetics and Metabolic Signaling. SYSTEMS BIOLOGY OF METABOLIC AND SIGNALING NETWORKS 2014. [DOI: 10.1007/978-3-642-38505-6_6] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
|
16
|
Domercq M, Vázquez-Villoldo N, Matute C. Neurotransmitter signaling in the pathophysiology of microglia. Front Cell Neurosci 2013; 7:49. [PMID: 23626522 PMCID: PMC3630369 DOI: 10.3389/fncel.2013.00049] [Citation(s) in RCA: 77] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2013] [Accepted: 04/05/2013] [Indexed: 01/09/2023] Open
Abstract
Microglial cells are the resident immune cells of the central nervous system. In the resting state, microglia are highly dynamic and control the environment by rapidly extending and retracting motile processes. Microglia are closely associated with astrocytes and neurons, particularly at the synapses, and more recent data indicate that neurotransmission plays a role in regulating the morphology and function of surveying/resting microglia, as they are endowed with receptors for most known neurotransmitters. In particular, microglia express receptors for ATP and glutamate, which regulate microglial motility. After local damage, the release of ATP induces microgliosis and activated microglial cells migrate to the site of injury, proliferate, and phagocytose cells, and cellular compartments. However, excessive activation of microglia could contribute to the progression of chronic neurodegenerative diseases, though the underlying mechanisms are still unclear. Microglia have the capacity to release a large number of substances that can be detrimental to the surrounding neurons, including glutamate, ATP, and reactive oxygen species. However, how altered neurotransmission following acute insults or chronic neurodegenerative conditions modulates microglial functions is still poorly understood. This review summarizes the relevant data regarding the role of neurotransmitter receptors in microglial physiology and pathology.
Collapse
Affiliation(s)
- María Domercq
- Departamento de Neurociencias, Universidad del País Vasco-UPV/EHU 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 Leioa, Spain
| | | | | |
Collapse
|
17
|
Ouro A, Arana L, Gangoiti P, Rivera IG, Ordoñez M, Trueba M, Lankalapalli RS, Bittman R, Gomez-Muñoz A. Ceramide 1-phosphate stimulates glucose uptake in macrophages. Cell Signal 2013; 25:786-95. [PMID: 23333242 DOI: 10.1016/j.cellsig.2013.01.009] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2012] [Revised: 12/28/2012] [Accepted: 01/07/2013] [Indexed: 12/24/2022]
Abstract
It is well established that ceramide 1-phosphate (C1P) is mitogenic and antiapoptotic, and that it is implicated in the regulation of macrophage migration. These activities require high energy levels to be available in cells. Macrophages obtain most of their energy from glucose. In this work, we demonstrate that C1P enhances glucose uptake in RAW264.7 macrophages. The major glucose transporter involved in this action was found to be GLUT 3, as determined by measuring its translocation from the cytosol to the plasma membrane. C1P-stimulated glucose uptake was blocked by selective inhibitors of phosphatidylinositol 3-kinase (PI3K) or Akt, also known as protein kinase B (PKB), and by specific siRNAs to silence the genes encoding for these kinases. C1P-stimulated glucose uptake was also inhibited by pertussis toxin (PTX) and by the siRNA that inhibited GLUT 3 expression. C1P increased the affinity of the glucose transporter for its substrate, and enhanced glucose metabolism to produce ATP. The latter action was also inhibited by PI3K- and Akt-selective inhibitors, PTX, or by specific siRNAs to inhibit GLUT 3 expression.
Collapse
Affiliation(s)
- Alberto Ouro
- Department of Biochemistry and Molecular Biology, Faculty of Science and Technology, University of the Basque Country (UPV/EHU), 48080 Bilbao, Spain
| | | | | | | | | | | | | | | | | |
Collapse
|
18
|
Rached FB, Ndjembo‐Ezougou C, Chandran S, Talabani H, Yera H, Dandavate V, Bourdoncle P, Meissner M, Tatu U, Langsley G. Construction of a
Plasmodium falciparum
Rab‐interactome identifies CK1 and PKA as Rab‐effector kinases in malaria parasites. Biol Cell 2011; 104:34-47. [PMID: 22188458 PMCID: PMC3437490 DOI: 10.1111/boc.201100081] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2011] [Accepted: 10/28/2011] [Indexed: 12/30/2022]
Affiliation(s)
- Fathia Ben Rached
- Institut Cochin, Université Paris Descartes, Sorbonne Paris Cité, CNRS (UMR 8104), 75014 Paris, France
- Inserm U1016, Paris 75014, France
- Université Paris Diderot, Sorbonne Paris Cité, Paris 75013, France
| | - Carinne Ndjembo‐Ezougou
- Institut Cochin, Université Paris Descartes, Sorbonne Paris Cité, CNRS (UMR 8104), 75014 Paris, France
- Inserm U1016, Paris 75014, France
- Université Paris Diderot, Sorbonne Paris Cité, Paris 75013, France
| | - Syama Chandran
- Department of Biochemistry, Indian Institute of Science, Bangalore, 560012 Karnataka, India
| | - Hana Talabani
- Institut Cochin, Université Paris Descartes, Sorbonne Paris Cité, CNRS (UMR 8104), 75014 Paris, France
- Inserm U1016, Paris 75014, France
- Université Paris Diderot, Sorbonne Paris Cité, Paris 75013, France
| | - Hélène Yera
- Institut Cochin, Université Paris Descartes, Sorbonne Paris Cité, CNRS (UMR 8104), 75014 Paris, France
- Inserm U1016, Paris 75014, France
| | - Vrushali Dandavate
- Department of Biochemistry, Indian Institute of Science, Bangalore, 560012 Karnataka, India
| | - Pierre Bourdoncle
- Institut Cochin, Université Paris Descartes, Sorbonne Paris Cité, CNRS (UMR 8104), 75014 Paris, France
- Inserm U1016, Paris 75014, France
- Université Paris Diderot, Sorbonne Paris Cité, Paris 75013, France
| | - Markus Meissner
- Division of Infection and Immunity and Wellcome Centre for Parasitology, Faculty of Biomedical and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Utpal Tatu
- Department of Biochemistry, Indian Institute of Science, Bangalore, 560012 Karnataka, India
| | - Gordon Langsley
- Institut Cochin, Université Paris Descartes, Sorbonne Paris Cité, CNRS (UMR 8104), 75014 Paris, France
- Inserm U1016, Paris 75014, France
- Université Paris Diderot, Sorbonne Paris Cité, Paris 75013, France
| |
Collapse
|
19
|
Kubick C, Schmalzing G, Markwardt F. The effect of anions on the human P2X7 receptor. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2011; 1808:2913-22. [DOI: 10.1016/j.bbamem.2011.08.017] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2011] [Revised: 08/08/2011] [Accepted: 08/12/2011] [Indexed: 10/17/2022]
|
20
|
Flittiger B, Klapperstück M, Schmalzing G, Markwardt F. Effects of protons on macroscopic and single-channel currents mediated by the human P2X7 receptor. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2010; 1798:947-57. [PMID: 20138022 DOI: 10.1016/j.bbamem.2010.01.023] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2009] [Revised: 01/18/2010] [Accepted: 01/28/2010] [Indexed: 01/28/2023]
Abstract
Human P2X7 receptors (hP2X7Rs) belong to the P2X family, which opens an intrinsic cation channel when challenged by extracellular ATP. hP2X7Rs are expressed in cells of the inflammatory and immune system. During inflammation, ATP and protons are secreted into the interstitial fluid. Therefore, we investigated the effect of protons on the activation of hP2X7Rs. hP2X7Rs were expressed in Xenopus laevis oocytes and activated by the agonists ATP or benzoyl-benzoyl-ATP (BzATP) at different pH values. The protons reduced the hP2X7R-dependent cation current amplitude and slowed the current deactivation depending on the type and concentration of the agonist used. These effects can be explained by (i) the protonation of ATP, which reduces the effective concentration of the agonist ATP(4-) at the high- and low-affinity ATP activation site of the hP2XR, and (ii) direct allosteric inhibition of the hP2X7R channel opening that follows ATP(4-) binding to the low-affinity activation site. Due to the hampered activation via the low-affinity activation site, a low pH (as observed in inflamed tissues) leads to a relative increase in the contribution of the high-affinity activation site for hP2X7R channel opening.
Collapse
Affiliation(s)
- B Flittiger
- Julius-Bernstein-Institute for Physiology, Martin-Luther-University Halle, Magdeburger Strasse 6, D-06097 Halle/Saale, Germany
| | | | | | | |
Collapse
|
21
|
Ludlow MJ, Durai L, Ennion SJ. Functional characterization of intracellular Dictyostelium discoideum P2X receptors. J Biol Chem 2009; 284:35227-39. [PMID: 19833731 PMCID: PMC2787382 DOI: 10.1074/jbc.m109.045674] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Indicative of cell surface P2X ion channel activation, extracellular ATP evokes a rapid and transient calcium influx in the model eukaryote Dictyostelium discoideum. Five P2X-like proteins (dP2XA-E) are present in this organism. However, their roles in purinergic signaling are unclear, because dP2XA proved to have an intracellular localization on the contractile vacuole where it is thought to be required for osmoregulation. To determine functional properties of the remaining four dP2X-like proteins and to assess their cellular roles, we recorded membrane currents from expressed cloned receptors and generated a quintuple knock-out Dictyostelium strain devoid of dP2X receptors. ATP evoked inward currents at dP2XB and dP2XE receptors but not at dP2XC or dP2XD. beta,gamma-Imido-ATP was more potent than ATP at dP2XB but a weak partial agonist at dP2XE. Currents in dP2XB and dP2XE were strongly inhibited by Na(+) but insensitive to copper and the P2 receptor antagonists pyridoxal phosphate-6-azophenyl-2',4'-disulfonic acid and suramin. Unusual for P2X channels, dP2XA and dP2XB were also Cl(-)-permeable. The extracellular purinergic response to ATP persisted in p2xA/B/C/D/E quintuple knock-out Dictyostelium demonstrating that dP2X channels are not responsible. dP2XB, -C, -D, and -E were found to be intracellularly localized to the contractile vacuole with the ligand binding domain facing the lumen. However, quintuple p2xA/B/C/D/E null cells were still capable of regulating cell volume in water demonstrating that, contrary to previous findings, dP2X receptors are not required for osmoregulation. Responses to the calmodulin antagonist calmidazolium, however, were reduced in p2xA/B/C/D/E null cells suggesting that dP2X receptors play a role in intracellular calcium signaling.
Collapse
Affiliation(s)
- Melanie J Ludlow
- Department of Cell Physiology and Pharmacology, University of Leicester, Leicester LE1 9HN, United Kingdom
| | | | | |
Collapse
|
22
|
Weigert A, Weis N, Brüne B. Regulation of macrophage function by sphingosine-1-phosphate. Immunobiology 2009; 214:748-60. [PMID: 19625101 DOI: 10.1016/j.imbio.2009.06.003] [Citation(s) in RCA: 88] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
The bioactive lipid sphingosine-1-phosphate (S1P) fulfils manifold tasks in the immune system acting in auto- and/or paracrine fashion. This includes regulation of apoptosis, migration and proliferation. Upon its generation by sphingosine kinases from plasma membrane sphingolipids, S1P can either act as a second messenger within cells or can be released from cells to occupy a family of specific G-protein-coupled receptors (S1P1-5). This diversity is reflected by the impact of S1P on macrophage biology and function. Over the last years it became apparent that the sphingosine kinase/S1P/S1P-receptor signalling axis in macrophages might play a central role in the pathogenesis of inflammatory diseases such as atherosclerosis, asthma, rheumatoid arthritis and cancer. Here, we summarize the current knowledge of the function of S1P in macrophage biology and discuss potential implications for pathology.
Collapse
Affiliation(s)
- Andreas Weigert
- Institute of Biochemistry I/ZAFES, Goethe-University Frankfurt am Main, Germany
| | | | | |
Collapse
|
23
|
Dzeja P, Terzic A. Adenylate kinase and AMP signaling networks: metabolic monitoring, signal communication and body energy sensing. Int J Mol Sci 2009; 10:1729-1772. [PMID: 19468337 PMCID: PMC2680645 DOI: 10.3390/ijms10041729] [Citation(s) in RCA: 278] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2009] [Revised: 03/26/2009] [Accepted: 04/02/2009] [Indexed: 12/20/2022] Open
Abstract
Adenylate kinase and downstream AMP signaling is an integrated metabolic monitoring system which reads the cellular energy state in order to tune and report signals to metabolic sensors. A network of adenylate kinase isoforms (AK1-AK7) are distributed throughout intracellular compartments, interstitial space and body fluids to regulate energetic and metabolic signaling circuits, securing efficient cell energy economy, signal communication and stress response. The dynamics of adenylate kinase-catalyzed phosphotransfer regulates multiple intracellular and extracellular energy-dependent and nucleotide signaling processes, including excitation-contraction coupling, hormone secretion, cell and ciliary motility, nuclear transport, energetics of cell cycle, DNA synthesis and repair, and developmental programming. Metabolomic analyses indicate that cellular, interstitial and blood AMP levels are potential metabolic signals associated with vital functions including body energy sensing, sleep, hibernation and food intake. Either low or excess AMP signaling has been linked to human disease such as diabetes, obesity and hypertrophic cardiomyopathy. Recent studies indicate that derangements in adenylate kinase-mediated energetic signaling due to mutations in AK1, AK2 or AK7 isoforms are associated with hemolytic anemia, reticular dysgenesis and ciliary dyskinesia. Moreover, hormonal, food and antidiabetic drug actions are frequently coupled to alterations of cellular AMP levels and associated signaling. Thus, by monitoring energy state and generating and distributing AMP metabolic signals adenylate kinase represents a unique hub within the cellular homeostatic network.
Collapse
Affiliation(s)
- Petras Dzeja
- Author to whom correspondence should be addressed; E-mail:
(P.D.)
| | | |
Collapse
|
24
|
Kuehnel MP, Rybin V, Anand PK, Anes E, Griffiths G. Lipids regulate P2X7-receptor-dependent actin assembly by phagosomes via ADP translocation and ATP synthesis in the phagosome lumen. J Cell Sci 2009; 122:499-504. [PMID: 19174471 DOI: 10.1242/jcs.034199] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Latex bead phagosomes isolated from J774 macrophages polymerize actin. We show here that five lipids--phosphatidylinositol-4-phosphate, phosphatidylinositol-(4,5)-bisphosphate, sphingosine-1-phosphate (S1P), ceramide-1-phosphate and phosphatidic acid--stimulate both actin assembly and transport of ADP across the phagosomal membrane into the lumen. Once there, this ADP is converted to ATP by adenylate kinase activity. High luminal ATP concentrations correlated well with phagosome actin assembly under different conditions. The ATP-binding P2X7 receptor (P2X7R) was detected in phagosomes. Although S1P stimulated actin assembly by phagosomes from P2X7R-containing bone marrow macrophages, S1P-stimulated actin assembly was inhibited in phagosomes from cells lacking P2X7R. We propose that luminal ATP accumulates in response to selected lipids and activates the P2X7R that signals across the phagosomal membrane to trigger actin assembly on the cytoplasmic membrane surface. In the accompanying paper by Kuehnel et al. (doi:10.1242/jcs.034207), more evidence is provided in support of this model from the analysis of actin assembly at the plasma membrane of intact macrophages.
Collapse
|