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McCauley M, Huston M, Condren AR, Pereira F, Cline J, Yaple-Maresh M, Painter MM, Zimmerman GE, Robertson AW, Carney N, Goodall C, Terry V, Müller R, Sherman DH, Collins KL. Structure-Activity Relationships of Natural and Semisynthetic Plecomacrolides Suggest Distinct Pathways for HIV-1 Immune Evasion and Vacuolar ATPase-Dependent Lysosomal Acidification. J Med Chem 2024. [PMID: 38452116 DOI: 10.1021/acs.jmedchem.3c01574] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/09/2024]
Abstract
The human immunodeficiency virus (HIV)-encoded accessory protein Nef enhances pathogenicity by reducing major histocompatibility complex I (MHC-I) cell surface expression, protecting HIV-infected cells from immune recognition. Nef-dependent downmodulation of MHC-I can be reversed by subnanomolar concentrations of concanamycin A (1), a well-known inhibitor of vacuolar ATPase, at concentrations below those that interfere with lysosomal acidification or degradation. We conducted a structure-activity relationship study that assessed 76 compounds for Nef inhibition, 24 and 72 h viability, and lysosomal neutralization in Nef-expressing primary T cells. This analysis demonstrated that the most potent compounds were natural concanamycins and their derivatives. Comparison against a set of new, semisynthetic concanamycins revealed that substituents at C-8 and acylation of C-9 significantly affected Nef potency, target cell viability, and lysosomal neutralization. These findings provide important progress toward understanding the mechanism of action of these compounds and the identification of an advanced lead anti-HIV Nef inhibitory compound.
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Affiliation(s)
- Morgan McCauley
- University of Michigan, Life Sciences Institute, Ann Arbor, Michigan 48109, United States
| | - Matthew Huston
- University of Michigan, Department of Internal Medicine, Ann Arbor, Michigan 48109, United States
| | - Alanna R Condren
- University of Michigan, Life Sciences Institute, Ann Arbor, Michigan 48109, United States
| | - Filipa Pereira
- University of Michigan, Life Sciences Institute, Ann Arbor, Michigan 48109, United States
| | - Joel Cline
- University of Michigan, Department of Internal Medicine, Ann Arbor, Michigan 48109, United States
| | - Marianne Yaple-Maresh
- University of Michigan, Department of Internal Medicine, Ann Arbor, Michigan 48109, United States
| | - Mark M Painter
- University of Michigan, Graduate Program in Immunology, Ann Arbor, Michigan 48109, United States
| | - Gretchen E Zimmerman
- University of Michigan, Department of Internal Medicine, Ann Arbor, Michigan 48109, United States
| | - Andrew W Robertson
- University of Michigan, Life Sciences Institute, Ann Arbor, Michigan 48109, United States
- University of Michigan Natural Products Discovery Core, Life Sciences Institute, Ann Arbor, Michigan 48109, United States
| | - Nolan Carney
- University of Michigan, Department of Chemistry, Ann Arbor, Michigan 48109, United States
| | - Christopher Goodall
- University of Michigan, Department of Internal Medicine, Ann Arbor, Michigan 48109, United States
| | - Valeri Terry
- University of Michigan, Department of Internal Medicine, Ann Arbor, Michigan 48109, United States
| | - Rolf Müller
- Helmholtz Institute for Pharmaceutical Research Saarland, Saarbrücken 66123, Germany
| | - David H Sherman
- University of Michigan, Department of Microbiology & Immunology, Ann Arbor, Michigan 48109, United States
- University of Michigan, Life Sciences Institute, Ann Arbor, Michigan 48109, United States
- University of Michigan, Department of Medicinal Chemistry, Ann Arbor, Michigan 48109, United States
- University of Michigan, Department of Chemistry, Ann Arbor, Michigan 48109, United States
| | - Kathleen L Collins
- University of Michigan, Graduate Program in Immunology, Ann Arbor, Michigan 48109, United States
- University of Michigan, Department of Internal Medicine, Ann Arbor, Michigan 48109, United States
- University of Michigan, Department of Microbiology & Immunology, Ann Arbor, Michigan 48109, United States
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2
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Cashikar AG, Hanson PI. A cell-based assay for CD63-containing extracellular vesicles. PLoS One 2019; 14:e0220007. [PMID: 31339911 PMCID: PMC6655660 DOI: 10.1371/journal.pone.0220007] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2019] [Accepted: 07/05/2019] [Indexed: 02/06/2023] Open
Abstract
Extracellular vesicles (EVs) are thought to be important in cell-cell communication and have elicited extraordinary interest as potential biomarkers of disease. However, quantitative methods to enable elucidation of mechanisms underlying release are few. Here, we describe a cell-based assay for monitoring EV release using the EV-enriched tetraspanin CD63 fused to the small, ATP-independent reporter enzyme, Nanoluciferase. Release of CD63-containing EVs from stably expressing cell lines was monitored by comparing luciferase activity in culture media to that remaining in cells. HEK293, U2OS, U87 and SKMel28 cells released 0.3%-0.6% of total cellular CD63 in the form of EVs over 5 hrs, varying by cell line. To identify cellular machinery important for secretion of CD63-containing EVs, we performed a screen of biologically active chemicals in HEK293 cells. While a majority of compounds did not significantly affect EV release, treating cells with the plecomacrolides bafilomycin or concanamycin, known to inhibit the V-ATPase, dramatically increased EV release. Interestingly, alkalization of the endosomal lumen using weak bases had no effect, suggesting a pH-independent enhancement of EV release by V-ATPase inhibitors. The ability to quantify EVs in small samples will enable future detailed studies of release kinetics as well as further chemical and genetic screening to define pathways involved in EV secretion.
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Affiliation(s)
- Anil G. Cashikar
- Department of Cell Biology & Physiology, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Phyllis I. Hanson
- Department of Cell Biology & Physiology, Washington University School of Medicine, St. Louis, Missouri, United States of America
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3
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Small structural alterations greatly influence the membrane affinity of lipophilic ligands: Membrane interactions of bafilomycin A1 and its desmethyl derivative bearing 19F-labeling. Bioorg Med Chem 2019; 27:1677-1682. [DOI: 10.1016/j.bmc.2019.03.017] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2019] [Revised: 03/06/2019] [Accepted: 03/07/2019] [Indexed: 11/20/2022]
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4
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Duan X, Yang S, Zhang L, Yang T. V-ATPases and osteoclasts: ambiguous future of V-ATPases inhibitors in osteoporosis. Theranostics 2018; 8:5379-5399. [PMID: 30555553 PMCID: PMC6276090 DOI: 10.7150/thno.28391] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2018] [Accepted: 10/10/2018] [Indexed: 12/11/2022] Open
Abstract
Vacuolar ATPases (V-ATPases) play a critical role in regulating extracellular acidification of osteoclasts and bone resorption. The deficiencies of subunit a3 and d2 of V-ATPases result in increased bone density in humans and mice. One of the traditional drug design strategies in treating osteoporosis is the use of subunit a3 inhibitor. Recent findings connect subunits H and G1 with decreased bone density. Given the controversial effects of ATPase subunits on bone density, there is a critical need to review the subunits of V-ATPase in osteoclasts and their functions in regulating osteoclasts and bone remodeling. In this review, we comprehensively address the following areas: information about all V-ATPase subunits and their isoforms; summary of V-ATPase subunits associated with human genetic diseases; V-ATPase subunits and osteopetrosis/osteoporosis; screening of all V-ATPase subunits variants in GEFOS data and in-house data; spectrum of V-ATPase subunits during osteoclastogenesis; direct and indirect roles of subunits of V-ATPases in osteoclasts; V-ATPase-associated signaling pathways in osteoclasts; interactions among V-ATPase subunits in osteoclasts; osteoclast-specific V-ATPase inhibitors; perspective of future inhibitors or activators targeting V-ATPase subunits in the treatment of osteoporosis.
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Affiliation(s)
- Xiaohong Duan
- State Key Laboratory of Military Stomatology, National Clinical Research Center for Oral Diseases, Department of Oral Biology, Clinic of Oral Rare and Genetic Diseases, School of Stomatology, the Fourth Military Medical University, 145 West Changle Road, Xi'an 710032, P. R. China
| | - Shaoqing Yang
- State Key Laboratory of Military Stomatology, National Clinical Research Center for Oral Diseases, Department of Oral Biology, Clinic of Oral Rare and Genetic Diseases, School of Stomatology, the Fourth Military Medical University, 145 West Changle Road, Xi'an 710032, P. R. China
| | - Lei Zhang
- Center for Genetic Epidemiology and Genomics, School of Public Health, Medical College of Soochow University, 199 Renai Road, Suzhou, Jiangsu, P. R. China
| | - Tielin Yang
- Key Laboratory of Biomedical Information Engineering of Ministry of Education, and Institute of Molecular Genetics, School of Life Science and Technology, Xi'an Jiaotong University, 28 West Xianning Road, Xi'an 710049, People's Republic of China
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5
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Harrison MA, Muench SP. The Vacuolar ATPase - A Nano-scale Motor That Drives Cell Biology. Subcell Biochem 2018; 87:409-459. [PMID: 29464568 DOI: 10.1007/978-981-10-7757-9_14] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The vacuolar H+-ATPase (V-ATPase) is a ~1 MDa membrane protein complex that couples the hydrolysis of cytosolic ATP to the transmembrane movement of protons. In essentially all eukaryotic cells, this acid pumping function plays critical roles in the acidification of endosomal/lysosomal compartments and hence in transport, recycling and degradative pathways. It is also important in acid extrusion across the plasma membrane of some cells, contributing to homeostatic control of cytoplasmic pH and maintenance of appropriate extracellular acidity. The complex, assembled from up to 30 individual polypeptides, operates as a molecular motor with rotary mechanics. Historically, structural inferences about the eukaryotic V-ATPase and its subunits have been made by comparison to the structures of bacterial homologues. However, more recently, we have developed a much better understanding of the complete structure of the eukaryotic complex, in particular through advances in cryo-electron microscopy. This chapter explores these recent developments, and examines what they now reveal about the catalytic mechanism of this essential proton pump and how its activity might be regulated in response to cellular signals.
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Affiliation(s)
- Michael A Harrison
- School of Biomedical Sciences, Faculty of Biological Sciences, The University of Leeds, Leeds, UK.
| | - Steven P Muench
- School of Biomedical Sciences, Faculty of Biological Sciences, The University of Leeds, Leeds, UK
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6
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Kissing S, Saftig P, Haas A. Vacuolar ATPase in phago(lyso)some biology. Int J Med Microbiol 2017; 308:58-67. [PMID: 28867521 DOI: 10.1016/j.ijmm.2017.08.007] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2017] [Revised: 07/28/2017] [Accepted: 08/23/2017] [Indexed: 12/23/2022] Open
Abstract
Many eukaryotic cells ingest extracellular particles in a process termed phagocytosis which entails the generation of a new intracellular compartment, the phagosome. Phagosomes change their composition over time and this maturation process culminates in their fusion with acidic, hydrolase-rich lysosomes. During the maturation process, degradation and, when applicable, killing of the cargo may ensue. Many of the events that are pathologically relevant depend on strong acidification of phagosomes by the 'vacuolar' ATPase (V-ATPase). This protein complex acidifies the lumen of some intracellular compartments at the expense of ATP hydrolysis. We discuss here the roles and importance of V-ATPase in intracellular trafficking, its distribution, inhibition and activities, its role in the defense against microorganisms and the counteractivities of pathogens.
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Affiliation(s)
- Sandra Kissing
- Institut für Biochemie, Christian-Albrechts-Universität zu Kiel, Olshausenstrasse 40, D-24098 Kiel, Germany
| | - Paul Saftig
- Institut für Biochemie, Christian-Albrechts-Universität zu Kiel, Olshausenstrasse 40, D-24098 Kiel, Germany.
| | - Albert Haas
- Institut für Zellbiologie, Friedrich-Wilhelms-Universität Bonn, Ulrich-Haberland-Str. 61A, D-53121 Bonn, Germany.
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7
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Masschelein J, Jenner M, Challis GL. Antibiotics from Gram-negative bacteria: a comprehensive overview and selected biosynthetic highlights. Nat Prod Rep 2017. [PMID: 28650032 DOI: 10.1039/c7np00010c] [Citation(s) in RCA: 62] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Covering: up to 2017The overwhelming majority of antibiotics in clinical use originate from Gram-positive Actinobacteria. In recent years, however, Gram-negative bacteria have become increasingly recognised as a rich yet underexplored source of novel antimicrobials, with the potential to combat the looming health threat posed by antibiotic resistance. In this article, we have compiled a comprehensive list of natural products with antimicrobial activity from Gram-negative bacteria, including information on their biosynthetic origin(s) and molecular target(s), where known. We also provide a detailed discussion of several unusual pathways for antibiotic biosynthesis in Gram-negative bacteria, serving to highlight the exceptional biocatalytic repertoire of this group of microorganisms.
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Affiliation(s)
- J Masschelein
- Department of Chemistry, University of Warwick, Gibbet Hill Road, Coventry, UK.
| | - M Jenner
- Department of Chemistry, University of Warwick, Gibbet Hill Road, Coventry, UK.
| | - G L Challis
- Department of Chemistry, University of Warwick, Gibbet Hill Road, Coventry, UK.
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8
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Tsuchikawa H, Hayashi T, Shibata H, Murata M, Nagumo Y, Usui T. Bafilomycin analogue site-specifically fluorinated at the pharmacophore macrolactone ring has potent vacuolar-type ATPase inhibitory activity. Tetrahedron Lett 2016. [DOI: 10.1016/j.tetlet.2016.04.075] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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9
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Cotter K, Stransky L, McGuire C, Forgac M. Recent Insights into the Structure, Regulation, and Function of the V-ATPases. Trends Biochem Sci 2016; 40:611-622. [PMID: 26410601 DOI: 10.1016/j.tibs.2015.08.005] [Citation(s) in RCA: 174] [Impact Index Per Article: 21.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2015] [Revised: 08/06/2015] [Accepted: 08/07/2015] [Indexed: 10/23/2022]
Abstract
The vacuolar (H(+))-ATPases (V-ATPases) are ATP-dependent proton pumps that acidify intracellular compartments and are also present at the plasma membrane. They function in such processes as membrane traffic, protein degradation, virus and toxin entry, bone resorption, pH homeostasis, and tumor cell invasion. V-ATPases are large multisubunit complexes, composed of an ATP-hydrolytic domain (V1) and a proton translocation domain (V0), and operate by a rotary mechanism. This review focuses on recent insights into their structure and mechanism, the mechanisms that regulate V-ATPase activity (particularly regulated assembly and trafficking), and the role of V-ATPases in processes such as cell signaling and cancer. These developments have highlighted the potential of V-ATPases as a therapeutic target in a variety of human diseases.
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Affiliation(s)
- Kristina Cotter
- Program in Cellular and Molecular Physiology, Sackler School of Graduate Biomedical Sciences, Tufts University School of Medicine, 136 Harrison Avenue, Boston, MA 02111, USA
| | - Laura Stransky
- Program in Cellular and Molecular Physiology, Sackler School of Graduate Biomedical Sciences, Tufts University School of Medicine, 136 Harrison Avenue, Boston, MA 02111, USA
| | - Christina McGuire
- Program in Biochemistry, Sackler School of Graduate Biomedical Sciences, Tufts University School of Medicine, 136 Harrison Avenue, Boston, MA 02111, USA
| | - Michael Forgac
- Program in Cellular and Molecular Physiology, Sackler School of Graduate Biomedical Sciences, Tufts University School of Medicine, 136 Harrison Avenue, Boston, MA 02111, USA; Program in Biochemistry, Sackler School of Graduate Biomedical Sciences, Tufts University School of Medicine, 136 Harrison Avenue, Boston, MA 02111, USA; Department of Developmental, Molecular, and Chemical Biology, Tufts University School of Medicine, 136 Harrison Avenue, Boston, MA 02111, USA.
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10
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Shibata H, Tsuchikawa H, Hayashi T, Matsumori N, Murata M, Usui T. Modification of Bafilomycin Structure to Efficiently Synthesize Solid-State NMR Probes that Selectively Bind to Vacuolar-Type ATPase. Chem Asian J 2015; 10:915-24. [DOI: 10.1002/asia.201403299] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2014] [Indexed: 01/05/2023]
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11
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Kartner N, Manolson MF. Novel techniques in the development of osteoporosis drug therapy: the osteoclast ruffled-border vacuolar H(+)-ATPase as an emerging target. Expert Opin Drug Discov 2014; 9:505-22. [PMID: 24749538 DOI: 10.1517/17460441.2014.902155] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
INTRODUCTION Bone loss occurs in many diseases, including osteoporosis, rheumatoid arthritis and periodontal disease. For osteoporosis alone, it is estimated that 75 million people are afflicted worldwide, with high risks of fractures and increased morbidity and mortality. The demand for treatment consumes an ever-increasing share of healthcare resources. Successive generations of antiresorptive bisphosphonate drugs have reduced side effects, minimized frequency of dosing, and increased efficacy in halting osteoporotic bone loss, but their shortcomings have remained significant to the extent that a monoclonal antibody antiresorptive has recently taken a significant market share. Yet this latter, paradigm-shifting approach has its own drawbacks. AREAS COVERED This review summarizes recent literature on bone-remodeling cell and molecular biology and the background for existing approaches and emerging therapeutics and targets for treating osteoporosis. The authors discuss vacuolar H(+)-ATPase (V-ATPase) molecular biology and the recent advances in targeting the osteoclast ruffled-border V-ATPase (ORV) for the development of novel antiresorptive drugs. They also cover examples from the V-ATPase-targeted drug discovery literature, including conventional molecular biology methods, in silico drug discovery, and gene therapy in more detail as proofs of concept. EXPERT OPINION Existing therapeutic options for osteoporosis have limitations and inherent drawbacks. Thus, the search for novel approaches to osteoporosis drug discovery remains relevant. Targeting the ORV may be one of the more selective means of regulating bone resorption. Furthermore, this approach may be effective without removing active osteoclasts from the finely balanced osteoclast-osteoblast coupling required for normal bone remodeling.
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Affiliation(s)
- Norbert Kartner
- University of Toronto , 124 Edward Street, Toronto, Ontario M5G 1G6 , Canada
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12
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Rahioui I, Eyraud V, Karaki L, Sasse F, Carre-Pierrat M, Qin A, Zheng MH, Toepfer S, Sivignon C, Royer C, Da Silva P, Gressent F. Host range of the potential biopesticide Pea Albumin 1b (PA1b) is limited to insects. Toxicon 2014; 89:67-76. [DOI: 10.1016/j.toxicon.2014.07.004] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2014] [Revised: 06/04/2014] [Accepted: 07/15/2014] [Indexed: 01/20/2023]
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13
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Scherer O, Steinmetz H, Kaether C, Weinigel C, Barz D, Kleinert H, Menche D, Müller R, Pergola C, Werz O. Targeting V-ATPase in primary human monocytes by archazolid potently represses the classical secretion of cytokines due to accumulation at the endoplasmic reticulum. Biochem Pharmacol 2014; 91:490-500. [PMID: 25107704 DOI: 10.1016/j.bcp.2014.07.028] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2014] [Revised: 07/25/2014] [Accepted: 07/28/2014] [Indexed: 01/08/2023]
Abstract
The macrolide archazolid inhibits vacuolar-type H(+)-ATPase (V-ATPase), a proton-translocating enzyme involved in protein transport and pH regulation of cell organelles, and potently suppresses cancer cell growth at low nanomolar concentrations. In view of the growing link between inflammation and cancer, we investigated whether inhibition of V-ATPase by archazolid may affect primary human monocytes that can promote cancer by sustaining inflammation through the release of tumor-promoting cytokines. Human primary monocytes express V-ATPase, and archazolid (10-100nM) increases the vesicular pH in these cells. Archazolid (10nM) markedly reduced the release of pro-inflammatory (TNF-α, interleukin-6 and -8) but also of anti-inflammatory (interleukin-10) cytokines in monocytes stimulated with LPS, without affecting cell viability up to 1000nM. Of interest, secretion of interleukin-1β was increased by archazolid. Comparable effects were obtained by the V-ATPase inhibitors bafilomycin and apicularen. The phosphorylation of p38 MAPK and ERK-1/2, Akt, SAPK/JNK or of the inhibitor of NFκB (IκBα) as well as mRNA expression of IL-8 were not altered by archazolid in LPS-stimulated monocytes. Instead, archazolid caused endoplasmic reticulum (ER) stress response visualized by increased BiP expression and accumulation of IL-8 (and TNF-α) at the ER, indicating a perturbation of protein secretion. In conclusion, by interference with V-ATPase, archazolid significantly affects the secretion of cytokines due to accumulation at the ER which might be of relevance when using these agents for cancer therapy.
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Affiliation(s)
- Olga Scherer
- Institute of Pharmacy, Friedrich Schiller University Jena, Philosophenweg 14, 07743 Jena, Germany
| | | | - Christoph Kaether
- Leibniz Institute for Age Research - Fritz Lipmann Institute, Jena, Germany
| | - Christina Weinigel
- Institute of Transfusion Medicine, University Hospital Jena, Jena, Germany
| | - Dagmar Barz
- Institute of Transfusion Medicine, University Hospital Jena, Jena, Germany
| | | | - Dirk Menche
- Kekulé-Institut für Organische Chemie und Biochemie der Rheinischen Friedrich-Wilhelms-Universität Bonn, Bonn, Germany
| | - Rolf Müller
- Helmholtz Institute for Pharmaceutical Research Saarland, Helmholtz Centre for Infection Research and Pharmazeutical Biotechnology, Saarland University, Saarbrücken, Germany
| | - Carlo Pergola
- Institute of Pharmacy, Friedrich Schiller University Jena, Philosophenweg 14, 07743 Jena, Germany
| | - Oliver Werz
- Institute of Pharmacy, Friedrich Schiller University Jena, Philosophenweg 14, 07743 Jena, Germany.
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14
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Abstract
Reversible disassembly of their V1 and Vo complexes is a regulatory mechanism of V-ATPases as had been shown by in vitro experiments. Our in vivo results indicate that not the whole V1 complex, but only its subunit C, dissociates into the yeast cytosol.
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15
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Muench SP, Rawson S, Eyraud V, Delmas AF, Da Silva P, Phillips C, Trinick J, Harrison MA, Gressent F, Huss M. PA1b inhibitor binding to subunits c and e of the vacuolar ATPase reveals its insecticidal mechanism. J Biol Chem 2014; 289:16399-408. [PMID: 24795045 PMCID: PMC4047407 DOI: 10.1074/jbc.m113.541250] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2013] [Revised: 04/14/2014] [Indexed: 12/03/2022] Open
Abstract
The vacuolar ATPase (V-ATPase) is a 1MDa transmembrane proton pump that operates via a rotary mechanism fuelled by ATP. Essential for eukaryotic cell homeostasis, it plays central roles in bone remodeling and tumor invasiveness, making it a key therapeutic target. Its importance in arthropod physiology also makes it a promising pesticide target. The major challenge in designing lead compounds against the V-ATPase is its ubiquitous nature, such that any therapeutic must be capable of targeting particular isoforms. Here, we have characterized the binding site on the V-ATPase of pea albumin 1b (PA1b), a small cystine knot protein that shows exquisitely selective inhibition of insect V-ATPases. Electron microscopy shows that PA1b binding occurs across a range of equivalent sites on the c ring of the membrane domain. In the presence of Mg·ATP, PA1b localizes to a single site, distant from subunit a, which is predicted to be the interface for other inhibitors. Photoaffinity labeling studies show radiolabeling of subunits c and e. In addition, weevil resistance to PA1b is correlated with bafilomycin resistance, caused by mutation of subunit c. The data indicate a binding site to which both subunits c and e contribute and inhibition that involves locking the c ring rotor to a static subunit e and not subunit a. This has implications for understanding the V-ATPase mechanism and that of inhibitors with therapeutic or pesticidal potential. It also provides the first evidence for the position of subunit e within the complex.
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Affiliation(s)
- Stephen P Muench
- From the School of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, LS2 9JT Leeds, West Yorkshire, United Kingdom,
| | - Shaun Rawson
- From the School of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, LS2 9JT Leeds, West Yorkshire, United Kingdom
| | - Vanessa Eyraud
- Institut National de la Recherche Agronomique, Institut National des Sciences Appliquées-Lyon, Université de Lyon, IFR 41, UMR203 BF2I, Biologie Fonctionnelle Insectes et Interactions, Batiment Louis-Pasteur 20, avenue Albert Einstein, F-69621 Villeurbanne, France
| | - Agnès F Delmas
- the Centre de Biophysique Moléculaire, Centre National de la Recherche Scientifique Unité Propre de Recherche 4301, Rue Charles Sadron, 45071 Orléans cedex 2, France
| | - Pedro Da Silva
- Institut National de la Recherche Agronomique, Institut National des Sciences Appliquées-Lyon, Université de Lyon, IFR 41, UMR203 BF2I, Biologie Fonctionnelle Insectes et Interactions, Batiment Louis-Pasteur 20, avenue Albert Einstein, F-69621 Villeurbanne, France
| | - Clair Phillips
- From the School of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, LS2 9JT Leeds, West Yorkshire, United Kingdom
| | - John Trinick
- the School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, LS2 9JT Leeds, West Yorkshire, United Kingdom, and
| | - Michael A Harrison
- From the School of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, LS2 9JT Leeds, West Yorkshire, United Kingdom
| | - Frédéric Gressent
- Institut National de la Recherche Agronomique, Institut National des Sciences Appliquées-Lyon, Université de Lyon, IFR 41, UMR203 BF2I, Biologie Fonctionnelle Insectes et Interactions, Batiment Louis-Pasteur 20, avenue Albert Einstein, F-69621 Villeurbanne, France
| | - Markus Huss
- Abteilung Tierphysiologie, Fachbereich Biologie/Chemie Universität Osnabrück, 49069 Osnabrück, Germany
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Kobia F, Duchi S, Deflorian G, Vaccari T. Pharmacologic inhibition of vacuolar H+ ATPase reduces physiologic and oncogenic Notch signaling. Mol Oncol 2013; 8:207-20. [PMID: 24309677 PMCID: PMC5528540 DOI: 10.1016/j.molonc.2013.11.002] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2013] [Revised: 11/06/2013] [Accepted: 11/06/2013] [Indexed: 12/29/2022] Open
Abstract
Notch signaling in prominently involved in growth regulation in metazoan tissues. Because of this, Notch is often upregulated in cancer and current efforts point to developing drugs that block its activation. Notch receptor endocytosis towards acidic compartments is a recently appreciated determinant of signaling activation. Vacuolar H+ ATPase (V‐ATPase) is responsible for acidification of endocytic organelles and mutants in V‐ATPase subunit encoding genes in model organisms have been recently shown to display loss of Notch signaling. Here, we show that administration of BafilomycinA1 (BafA1), a highly specific V‐ATPase inhibitor decreases Notch signaling during Drosophila and Zebrafish development, and in human cells in culture. In normal breast cells, we find that BafA1 treatment leads to accumulation of Notch in the endo‐lysosomal system, and reduces its processing and signaling activity. In Notch‐addicted breast cancer cells, BafA1 treatment reduces growth in cells expressing membrane tethered forms of Notch, while sparing cells expressing cytoplasmic forms. In contrast, we find that V‐ATPase inhibition reduces growth of leukemia cells, without affecting Notch activatory cleavage. However, consistent with the emerging roles of V‐ATPase in controlling multiple signaling pathways, in these cells Akt activation is reduced, as it is also the case in BafA1‐treated breast cancer cells. Our data support V‐ATPase inhibition as a novel therapeutic approach to counteract tumor growth via signaling pathways regulated at the endo‐lysosomal level. V‐ATPase inhibition decreases Notch signaling during fly and fish development. V‐ATPase inhibition reduces Notch signaling in normal and breast cancer cells. V‐ATPase inhibition blocks degradation of membrane‐bound Notch forms. V‐ATPase inhibition prevents Notch cleavage and nuclear translocation. V‐ATPase inhibition reduces Akt signaling in breast cancer and T‐ALL cells.
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Affiliation(s)
- Francis Kobia
- IFOM, Istituto FIRC di Oncologia Molecolare at IFOM-IEO Campus, Via Adamello 16, 20139 Milano, Italy
| | - Serena Duchi
- IFOM, Istituto FIRC di Oncologia Molecolare at IFOM-IEO Campus, Via Adamello 16, 20139 Milano, Italy
| | - Gianluca Deflorian
- IFOM, Istituto FIRC di Oncologia Molecolare at IFOM-IEO Campus, Via Adamello 16, 20139 Milano, Italy
| | - Thomas Vaccari
- IFOM, Istituto FIRC di Oncologia Molecolare at IFOM-IEO Campus, Via Adamello 16, 20139 Milano, Italy.
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