1
|
Lagzian A, Askari M, Haeri MS, Sheikhi N, Banihashemi S, Nabi-Afjadi M, Malekzadegan Y. Increased V-ATPase activity can lead to chemo-resistance in oral squamous cell carcinoma via autophagy induction: new insights. Med Oncol 2024; 41:108. [PMID: 38592406 DOI: 10.1007/s12032-024-02313-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2023] [Accepted: 01/23/2024] [Indexed: 04/10/2024]
Abstract
Oral squamous cell carcinoma (OSCC) is a cancer type with a high rate of recurrence and a poor prognosis. Tumor chemo-resistance remains an issue for OSCC patients despite the availability of multimodal therapy options, which causes an increase in tumor invasiveness. Vacuolar ATPase (V-ATPase), appears to be one of the most significant molecules implicated in MDR in tumors like OSCC. It is primarily responsible for controlling the acidity in the solid tumors' microenvironment, which interferes with the absorption of chemotherapeutic medications. However, the exact cellular and molecular mechanisms V-ATPase plays in OSCC chemo-resistance have not been understood. Uncovering these mechanisms can contribute to combating OSCC chemo-resistance and poor prognosis. Hence, in this review, we suggest that one of these underlying mechanisms is autophagy induced by V-ATPase which can potentially contribute to OSCC chemo-resistance. Finally, specialized autophagy and V-ATPase inhibitors may be beneficial as an approach to reduce drug resistance to anticancer therapies in addition to serving as coadjuvants in antitumor treatments. Also, V-ATPase could be a prognostic factor for OSCC patients. However, in the future, more investigations are required to demonstrate these suggestions and hypotheses.
Collapse
Affiliation(s)
- Ahmadreza Lagzian
- Institute of Biochemistry and Biophysics (IBB), University of Tehran, Tehran, Iran
| | - Marziye Askari
- Department of Immunology, School of Medicine, Hamedan University of Medical Sciences, Hamedan, Iran
| | - Melika Sadat Haeri
- Department of Biology, Science and Research Branch, Islamic Azad University, Tehran, Iran
| | - Nastaran Sheikhi
- Biotechnology Department, Biological Sciences Faculty, Alzahra University, Tehran, Iran
| | - Sara Banihashemi
- Department of Bioscience, School of Science and Technology, Nottingham Trend University, Nottingham, UK
| | - Mohsen Nabi-Afjadi
- Department of Biochemistry, Faculty of Biological Sciences, Tarbiat Modares University, Tehran, Iran.
| | - Yalda Malekzadegan
- Department of Microbiology, Saveh University of Medical Sciences, Saveh, Iran.
| |
Collapse
|
2
|
Yee DP, Samo TJ, Abbriano RM, Shimasaki B, Vernet M, Mayali X, Weber PK, Mitchell BG, Hildebrand M, Decelle J, Tresguerres M. The V-type ATPase enhances photosynthesis in marine phytoplankton and further links phagocytosis to symbiogenesis. Curr Biol 2023; 33:2541-2547.e5. [PMID: 37263270 PMCID: PMC10326425 DOI: 10.1016/j.cub.2023.05.020] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2022] [Revised: 03/20/2023] [Accepted: 05/09/2023] [Indexed: 06/03/2023]
Abstract
Diatoms, dinoflagellates, and coccolithophores are dominant groups of marine eukaryotic phytoplankton that are collectively responsible for the majority of primary production in the ocean.1 These phytoplankton contain additional intracellular membranes around their chloroplasts, which are derived from ancestral engulfment of red microalgae by unicellular heterotrophic eukaryotes that led to secondary and tertiary endosymbiosis.2 However, the selectable evolutionary advantage of these membranes and the physiological significance for extant phytoplankton remain poorly understood. Since intracellular digestive vacuoles are ubiquitously acidified by V-type H+-ATPase (VHA),3 proton pumps were proposed to acidify the microenvironment around secondary chloroplasts to promote the dehydration of dissolved inorganic carbon (DIC) into CO2, thus enhancing photosynthesis.4,5 We report that VHA is localized around the chloroplasts of centric diatoms and that VHA significantly contributes to their photosynthesis across a wide range of oceanic irradiances. Similar results in a pennate diatom, dinoflagellate, and coccolithophore, but not green or red microalgae, imply the co-option of phagocytic VHA activity into a carbon-concentrating mechanism (CCM) is common to secondary endosymbiotic phytoplankton. Furthermore, analogous mechanisms in extant photosymbiotic marine invertebrates6,7,8 provide functional evidence for an adaptive advantage throughout the transition from endosymbiosis to symbiogenesis. Based on the contribution of diatoms to ocean biogeochemical cycles, VHA-mediated enhancement of photosynthesis contributes at least 3.5 Gtons of fixed carbon per year (or 7% of primary production in the ocean), providing an example of a symbiosis-derived evolutionary innovation with global environmental implications.
Collapse
Affiliation(s)
- Daniel P Yee
- Scripps Institution of Oceanography, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA; Cell and Plant Physiology Laboratory, University of Grenoble Alpes, CNRS, CEA, INRAE, and IRIG, 17 Avenue des Martyrs, Grenoble 38054, Auvergne-Rhone-Alpes, France.
| | - Ty J Samo
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, CA 94550, USA
| | - Raffaela M Abbriano
- Scripps Institution of Oceanography, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA
| | - Bethany Shimasaki
- Scripps Institution of Oceanography, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA
| | - Maria Vernet
- Scripps Institution of Oceanography, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA
| | - Xavier Mayali
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, CA 94550, USA
| | - Peter K Weber
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, CA 94550, USA
| | - B Greg Mitchell
- Scripps Institution of Oceanography, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA
| | - Mark Hildebrand
- Scripps Institution of Oceanography, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA
| | - Johan Decelle
- Cell and Plant Physiology Laboratory, University of Grenoble Alpes, CNRS, CEA, INRAE, and IRIG, 17 Avenue des Martyrs, Grenoble 38054, Auvergne-Rhone-Alpes, France
| | - Martin Tresguerres
- Scripps Institution of Oceanography, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA.
| |
Collapse
|
3
|
Tolani B, Celli A, Yao Y, Tan YZ, Fetter R, Liem CR, de Smith AJ, Vasanthakumar T, Bisignano P, Cotton AD, Seiple IB, Rubinstein JL, Jost M, Weissman JS. Ras-mutant cancers are sensitive to small molecule inhibition of V-type ATPases in mice. Nat Biotechnol 2022; 40:1834-1844. [PMID: 35879364 PMCID: PMC9750872 DOI: 10.1038/s41587-022-01386-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Accepted: 06/03/2022] [Indexed: 01/14/2023]
Abstract
Mutations in Ras family proteins are implicated in 33% of human cancers, but direct pharmacological inhibition of Ras mutants remains challenging. As an alternative to direct inhibition, we screened for sensitivities in Ras-mutant cells and discovered 249C as a Ras-mutant selective cytotoxic agent with nanomolar potency against a spectrum of Ras-mutant cancers. 249C binds to vacuolar (V)-ATPase with nanomolar affinity and inhibits its activity, preventing lysosomal acidification and inhibiting autophagy and macropinocytosis pathways that several Ras-driven cancers rely on for survival. Unexpectedly, potency of 249C varies with the identity of the Ras driver mutation, with the highest potency for KRASG13D and G12V both in vitro and in vivo, highlighting a mutant-specific dependence on macropinocytosis and lysosomal pH. Indeed, 249C potently inhibits tumor growth without adverse side effects in mouse xenografts of KRAS-driven lung and colon cancers. A comparison of isogenic SW48 xenografts with different KRAS mutations confirmed that KRASG13D/+ (followed by G12V/+) mutations are especially sensitive to 249C treatment. These data establish proof-of-concept for targeting V-ATPase in cancers driven by specific KRAS mutations such as KRASG13D and G12V.
Collapse
Affiliation(s)
- Bhairavi Tolani
- Thoracic Oncology Program, Department of Surgery, Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, CA, USA.
| | - Anna Celli
- Laboratory for Cell Analysis Core Facility, Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, CA, USA
| | - Yanmin Yao
- Department of Pharmaceutical Chemistry and Cardiovascular Research Institute, University of California, San Francisco, CA, USA
| | - Yong Zi Tan
- Molecular Medicine Program, The Hospital for Sick Children, Toronto, ON, Canada
- Department of Biological Sciences, National University of Singapore, Singapore, Singapore
- Disease Intervention Technology Laboratory, Agency for Science, Technology and Research, Singapore, Singapore
| | - Richard Fetter
- Howard Hughes Medical Institute, Department of Biology, Stanford University, Stanford, CA, USA
| | - Christina R Liem
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA, USA
- Division of Biological Sciences, the Section of Cell and Developmental Biology, University of California San Diego, La Jolla, CA, USA
| | - Adam J de Smith
- Center for Genetic Epidemiology, Department of Population and Public Health Sciences, Keck School of Medicine of University of Southern California, Los Angeles, CA, USA
| | - Thamiya Vasanthakumar
- Molecular Medicine Program, The Hospital for Sick Children, Toronto, ON, Canada
- Department of Biochemistry, The University of Toronto, Toronto, ON, Canada
| | - Paola Bisignano
- Department of Pharmaceutical Chemistry and Cardiovascular Research Institute, University of California, San Francisco, CA, USA
| | - Adam D Cotton
- Department of Pharmaceutical Chemistry and Cardiovascular Research Institute, University of California, San Francisco, CA, USA
| | - Ian B Seiple
- Department of Pharmaceutical Chemistry and Cardiovascular Research Institute, University of California, San Francisco, CA, USA
| | - John L Rubinstein
- Molecular Medicine Program, The Hospital for Sick Children, Toronto, ON, Canada
- Department of Biochemistry, The University of Toronto, Toronto, ON, Canada
- Department of Medical Biophysics, The University of Toronto, Toronto, ON, Canada
| | - Marco Jost
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA, USA.
- Department of Microbiology & Immunology, University of California, San Francisco, CA, USA.
- Department of Microbiology, Harvard Medical School, Boston, MA, USA.
| | - Jonathan S Weissman
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA, USA
- Howard Hughes Medical Institute, Massachusetts Institute of Technology, Cambridge, MA, USA
- Whitehead Institute for Biomedical Research, Massachusetts Institute of Technology, Cambridge, MA, USA
- David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA, USA
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, USA
| |
Collapse
|
4
|
Zhou X, Zhao S, Liu T, Yao L, Zhao M, Ye X, Zhang X, Guo Q, Tu P, Zeng K. Schisandrol A protects AGEs-induced neuronal cells death by allosterically targeting ATP6V0d1 subunit of V-ATPase. Acta Pharm Sin B 2022; 12:3843-3860. [PMID: 36213534 PMCID: PMC9532558 DOI: 10.1016/j.apsb.2022.06.013] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2022] [Revised: 04/30/2022] [Accepted: 05/24/2022] [Indexed: 12/26/2022] Open
|
5
|
Butsch TJ, Dubuisson O, Johnson AE, Bohnert KA. A meiotic switch in lysosome activity supports spermatocyte development in young flies but collapses with age. iScience 2022; 25:104382. [PMID: 35620438 PMCID: PMC9126793 DOI: 10.1016/j.isci.2022.104382] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2021] [Revised: 12/01/2021] [Accepted: 05/05/2022] [Indexed: 11/12/2022] Open
Abstract
Gamete development ultimately influences animal fertility. Identifying mechanisms that direct gametogenesis, and how they deteriorate with age, may inform ways to combat infertility. Recently, we found that lysosomes acidify during oocyte maturation in Caenorhabditis elegans, suggesting that a meiotic switch in lysosome activity promotes female germ-cell health. Using Drosophila melanogaster, we report that lysosomes likewise acidify in male germ cells during meiosis. Inhibiting lysosomes in young-male testes causes E-cadherin accumulation and loss of germ-cell partitioning membranes. Notably, analogous changes occur naturally during aging; in older testes, a reduction in lysosome acidity precedes E-cadherin accumulation and membrane dissolution, suggesting one potential cause of age-related spermatocyte abnormalities. Consistent with lysosomes governing the production of mature sperm, germ cells with homozygous-null mutations in lysosome-acidifying machinery fail to survive through meiosis. Thus, lysosome activation is entrained to meiotic progression in developing sperm, as in oocytes, and lysosomal dysfunction may instigate male reproductive aging. Lysosomes acidify at the mitotic-meiotic transition in the testis Acidic lysosomes support germ-cell membrane stability Lysosome acidity naturally declines in the aging male germline Lysosome acidification is required for mature sperm production
Collapse
|
6
|
Ha J, Park SB. Callyspongiolide kills cells by inducing mitochondrial dysfunction via cellular iron depletion. Commun Biol 2021; 4:1123. [PMID: 34556786 PMCID: PMC8460830 DOI: 10.1038/s42003-021-02643-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Accepted: 09/01/2021] [Indexed: 12/15/2022] Open
Abstract
The highly cytotoxic marine natural product callyspongiolide holds great promise as a warhead of antibody-drug conjugate in cancer therapeutics; however, the mechanism underlying its cytotoxicity remains unclear. To elucidate how callyspongiolide kills cells, we employed label-free target identification with thermal stability-shift-based fluorescence difference in two-dimensional (2-D) gel electrophoresis (TS-FITGE), which allowed observation of a unique phenomenon of protein-spot separation on 2-D gels upon treatment with callyspongiolide at increasing temperatures. During our exploration of what proteins were associated with this phenomenon as well as why it happens, we found that callyspongiolide induces mitochondrial/lysosomal dysfunction and autophagy inhibition. Moreover, molecular biology studies revealed that callyspongiolide causes lysosomal dysfunction, which induces cellular iron depletion and leads to mitochondrial dysfunction and subsequent cytotoxicity. Notably, these effects were rescued through iron supplementation. Although our approach was unable to reveal the direct protein targets of callyspongiolide, unique phenomena observed only by TS-FITGE provided critical insight into the mechanism of action of callyspongiolide and specifically its cytotoxic activity via induction of mitochondrial dysfunction through cellular iron depletion caused by lysosomal deacidification, which occurred independent of known programmed cell death pathways. In order to elucidate how callyspongiolide, a potent cytotoxic marine natural product, kills human lung cancer cells, Ha and Park employed TS-FITGE technique, a label-free target identification method with thermal stability-shift-based fluorescence difference in 2-D gel electrophoresis, allowing them to observe protein-spot separation upon treatment in increasing temperatures. They found that callyspongiolide induces lysosomal dysfunction followed by mitochondrial dysfunction as well as iron depletion, which sheds light on the mechanism of action of callyspongiolide.
Collapse
Affiliation(s)
- Jaeyoung Ha
- Department of Biophysics and Chemical Biology, Seoul National University, Seoul, 08826, Korea
| | - Seung Bum Park
- Department of Biophysics and Chemical Biology, Seoul National University, Seoul, 08826, Korea. .,CRI Center for Chemical Proteomics, Department of Chemistry, Seoul National University, Seoul, 08826, Korea. .,SPARK Biopharma, Inc, Seoul, 08791, Korea.
| |
Collapse
|
7
|
Franco-Cano A, Marcos AT, Strauss J, Cánovas D. Evidence for an arginine-dependent route for the synthesis of NO in the model filamentous fungus Aspergillus nidulans. Environ Microbiol 2021; 23:6924-6939. [PMID: 34448331 DOI: 10.1111/1462-2920.15733] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2021] [Revised: 08/16/2021] [Accepted: 08/17/2021] [Indexed: 12/14/2022]
Abstract
Nitric oxide (NO) is a signalling molecule in eukaryotic and prokaryotic organisms. NO levels transiently boost upon induction of conidiation in Aspergillus nidulans. Only one pathway for NO synthesis involving nitrate reductase has been reported in filamentous fungi so far, but this does not satisfy all the NO produced in fungal cells. Here we provide evidence for at least one additional biosynthetic pathway in A. nidulans involving l-arginine or an intermediate metabolite as a substrate. Under certain growth conditions, the addition of l-arginine to liquid media elicited a burst of NO that was not dependent on any of the urea cycle genes. The NO levels were controlled by the metabolically available arginine, which was regulated by mobilization from the vacuoles and during development. In vitro assays with protein extracts and amino acid profiling strongly suggested the existence of an arginine-dependent NO pathway analogous to the mammalian NO synthase. Addition of polyamines induced NO synthesis, and mutations in the polyamine synthesis genes puA and spdA reduced the production of NO. In conclusion, here we report an additional pathway for the synthesis of NO in A. nidulans using urea cycle intermediates.
Collapse
Affiliation(s)
- Antonio Franco-Cano
- Department of Genetics, Faculty of Biology, University of Seville, Seville, Spain
| | - Ana T Marcos
- Department of Genetics, Faculty of Biology, University of Seville, Seville, Spain
| | - Joseph Strauss
- Department of Applied Genetics and Cell Biology, Institute of Microbial Genetics, BOKU University of Natural Resources and Life Science, Campus Tulln, Tulln/Donau, Austria
| | - David Cánovas
- Department of Genetics, Faculty of Biology, University of Seville, Seville, Spain.,Department of Applied Genetics and Cell Biology, Institute of Microbial Genetics, BOKU University of Natural Resources and Life Science, Campus Tulln, Tulln/Donau, Austria
| |
Collapse
|
8
|
Morris C, O'Donnell MJ. Vacuolar H+-ATPase and Na+/K+-ATPase energize Na+ uptake mechanisms in the nuchal organ of the hyperregulating freshwater crustacean Daphnia magna. J Exp Biol 2021; 224:269112. [PMID: 34115859 DOI: 10.1242/jeb.242205] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2020] [Accepted: 05/06/2021] [Indexed: 11/20/2022]
Abstract
The nuchal organ of the embryos and neonates of the cladoceran, Daphnia magna, has been shown to be a site of Na+ influx and H+, NH4+ and Cl- efflux. This study combines the scanning ion-selective electrode technique with application of inhibitors of specific transporters to assess the mechanisms of Na+ transport across the nuchal organ. Na+ influx across the nuchal organ was inhibited both by inhibitors of the Na+/K+-ATPase (ouabain, bufalin) and by inhibitors of the vacuolar H+-ATPase (bafilomycin, N-ethylmaleimde, 7-chloro-4-nitrobenzo-2-oxa-1,3-diazole, KM91104, S-nitrosoglutathione). Na+ influx was unaffected by the epithelial Na+ channel blocker benzamil, but was sensitive to ethylisopropyl amiloride and elevated external ammonium concentrations, consistent with roles for Na+/H+ and Na+/NH4+ exchangers in the apical membrane but not Na+ channels. Transport across the basolateral membrane into the haemolymph is proposed to involve the Na+/K+-ATPase and a thiazide-sensitive Na+/Cl- cotransporter.
Collapse
Affiliation(s)
- Carolyn Morris
- Department of Biology, McMaster University, Hamilton, ON, Canada, L8S 4K1
| | | |
Collapse
|
9
|
Cabodevilla AG, Tang S, Lee S, Mullick AE, Aleman JO, Hussain MM, Sessa WC, Abumrad NA, Goldberg IJ. Eruptive xanthoma model reveals endothelial cells internalize and metabolize chylomicrons, leading to extravascular triglyceride accumulation. J Clin Invest 2021; 131:e145800. [PMID: 34128469 PMCID: PMC8203467 DOI: 10.1172/jci145800] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Accepted: 04/28/2021] [Indexed: 12/13/2022] Open
Abstract
Although tissue uptake of fatty acids from chylomicrons is primarily via lipoprotein lipase (LpL) hydrolysis of triglycerides (TGs), studies of patients with genetic LpL deficiency suggest additional pathways deliver dietary lipids to tissues. Despite an intact endothelial cell (EC) barrier, hyperchylomicronemic patients accumulate chylomicron-derived lipids within skin macrophages, leading to the clinical finding eruptive xanthomas. We explored whether an LpL-independent pathway exists for transfer of circulating lipids across the EC barrier. We found that LpL-deficient mice had a marked increase in aortic EC lipid droplets before and after a fat gavage. Cultured ECs internalized chylomicrons, which were hydrolyzed within lysosomes. The products of this hydrolysis fueled lipid droplet biogenesis in ECs and triggered lipid accumulation in cocultured macrophages. EC chylomicron uptake was inhibited by competition with HDL and knockdown of the scavenger receptor-BI (SR-BI). In vivo, SR-BI knockdown reduced TG accumulation in aortic ECs and skin macrophages of LpL-deficient mice. Thus, ECs internalize chylomicrons, metabolize them in lysosomes, and either store or release their lipids. This latter process may allow accumulation of TGs within skin macrophages and illustrates a pathway that might be responsible for creation of eruptive xanthomas.
Collapse
Affiliation(s)
- Ainara G Cabodevilla
- Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, New York University Grossman School of Medicine, New York, New York, USA
| | - Songtao Tang
- Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, New York University Grossman School of Medicine, New York, New York, USA
| | - Sungwoon Lee
- Vascular Biology and Therapeutics Program, Yale University School of Medicine, New Haven, Connecticut, USA
| | | | - Jose O Aleman
- Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, New York University Grossman School of Medicine, New York, New York, USA
| | - M Mahmood Hussain
- Diabetes and Obesity Center, NYU-Long Island School of Medicine, Mineola, New York, USA
| | - William C Sessa
- Vascular Biology and Therapeutics Program, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Nada A Abumrad
- Nutritional Sciences, Department of Medicine and Department of Cell Biology and Physiology, Washington University School of Medicine, Saint Louis, Missouri, USA
| | - Ira J Goldberg
- Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, New York University Grossman School of Medicine, New York, New York, USA
| |
Collapse
|
10
|
Ravindra S, Irfana Jesin CP, Shabashini A, Nandi GC. Recent Advances in the Preparations and Synthetic Applications of Oxaziridines and Diaziridines. Adv Synth Catal 2021. [DOI: 10.1002/adsc.202001372] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- Sundaresan Ravindra
- Department of Chemistry National Institute of Technology Tiruchirappalli 620015, Tamilnadu India
| | - C. P. Irfana Jesin
- Department of Chemistry National Institute of Technology Tiruchirappalli 620015, Tamilnadu India
| | - Arivalagan Shabashini
- Department of Chemistry National Institute of Technology Tiruchirappalli 620015, Tamilnadu India
| | - Ganesh Chandra Nandi
- Department of Chemistry National Institute of Technology Tiruchirappalli 620015, Tamilnadu India
| |
Collapse
|
11
|
Yee DP, Hildebrand M, Tresguerres M. Dynamic subcellular translocation of V-type H + -ATPase is essential for biomineralization of the diatom silica cell wall. THE NEW PHYTOLOGIST 2020; 225:2411-2422. [PMID: 31746463 DOI: 10.1111/nph.16329] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/11/2019] [Accepted: 11/04/2019] [Indexed: 06/10/2023]
Abstract
Diatom cell walls, called frustules, are main sources of biogenic silica in the ocean and their intricate morphology is an inspiration for nanoengineering. Here we show dynamic aspects of frustule biosynthesis involving acidification of the silica deposition vesicle (SDV) by V-type H+ ATPase (VHA). Transgenic Thalassiosira pseudonana expressing the VHA B subunit tagged with enhanced green fluorescent protein (VHAB -eGFP) enabled subcellular protein localization in live cells. In exponentially growing cultures, VHAB -eGFP was present in various subcellular localizations including the cytoplasm, SDVs and vacuoles. We studied the role of VHA during frustule biosynthesis in synchronized cell cultures of T. pseudonana. During the making of new biosilica components, VHAB -eGFP first localized in the girdle band SDVs, and subsequently in valve SDVs. In single cell time-lapse imaging experiments, VHAB -eGFP localization in SDVs precluded accumulation of the acidotropic silica biomineralization marker PDMPO. Furthermore, pharmacological VHA inhibition prevented PDMPO accumulation in the SDV, frustule biosynthesis and cell division, as well as insertion of the silicalemma-associated protein SAP1 into the SDVs. Finally, partial inhibition of VHA activity affected the nanoscale morphology of the valve. Altogether, these results indicate that VHA is essential for frustule biosynthesis by acidifying the SDVs and regulating the insertion of other structural proteins into the SDV.
Collapse
Affiliation(s)
- Daniel P Yee
- Scripps Institution of Oceanography, University of California San Diego, 9500 Gilman Drive, La Jolla, CA, 92093, USA
| | - Mark Hildebrand
- Scripps Institution of Oceanography, University of California San Diego, 9500 Gilman Drive, La Jolla, CA, 92093, USA
| | - Martin Tresguerres
- Scripps Institution of Oceanography, University of California San Diego, 9500 Gilman Drive, La Jolla, CA, 92093, USA
| |
Collapse
|
12
|
D'Silva NM, O'Donnell MJ. Mechanisms of transport of H +, Na + and K +, across the distal gastric caecum of larval Aedes aegypti. JOURNAL OF INSECT PHYSIOLOGY 2020; 121:103997. [PMID: 31846613 DOI: 10.1016/j.jinsphys.2019.103997] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2019] [Revised: 12/09/2019] [Accepted: 12/11/2019] [Indexed: 06/10/2023]
Abstract
Measured changes in ion fluxes, transepithelial potential (TEP) and basolateral membrane potential (Vb) in response to ion transporter inhibitors were used to assess the mechanisms of transport of H+, Na+ and K+, across the distal gastric caecum of larval Aedes aegypti, a vector of yellow fever. Preparations were stimulated with 5-hydroxytryptamine (5-HT, 10-6 M) in order to maintain stable rates of H+, Na+, and K+ transport across the distal caecum. Transepithelial potential (TEP), basolateral membrane potential (Vb), and H+, Na+ and K+ fluxes all declined after the addition of a vacuolar-type H+-ATPase (VA) inhibitor, n-ethlymaleimide (NEM), consistent with a primary role for VA in energizing ion transport across the distal gastric caecum. Amiloride also inhibited H+, Na+, and K+ fluxes, consistent with an apically expressed VA that is coupled to a cation:H+ antiporter (AeNHE8), analogous to the coupling of apical VA and cation:nH+ antiporter in Malpighian tubules. A working model of transport of H+, Na+ and K+ across the distal gastric caecum proposes that coupling of VA and AeNHE8 in the apical membrane leads to the removal of intracellular Na+ or K+, thus creating favourable ion gradients to promote the activity of two transporters in the basal membrane, cation:H+ antiporter (AeNHE3) and a bumetanide-sensitive cation chloride cotransporter (CCC).
Collapse
Affiliation(s)
- N M D'Silva
- Department of Biology, McMaster University, Hamilton, ON L8S 4K1, Canada
| | - M J O'Donnell
- Department of Biology, McMaster University, Hamilton, ON L8S 4K1, Canada.
| |
Collapse
|
13
|
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.
Collapse
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
| |
Collapse
|
14
|
A Bacterial Effector Reveals the V-ATPase-ATG16L1 Axis that Initiates Xenophagy. Cell 2019; 178:552-566.e20. [PMID: 31327526 DOI: 10.1016/j.cell.2019.06.007] [Citation(s) in RCA: 192] [Impact Index Per Article: 38.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2018] [Revised: 12/20/2018] [Accepted: 06/03/2019] [Indexed: 12/17/2022]
Abstract
Antibacterial autophagy (xenophagy) is an important host defense, but how it is initiated is unclear. Here, we performed a bacterial transposon screen and identified a T3SS effector SopF that potently blocked Salmonella autophagy. SopF was a general xenophagy inhibitor without affecting canonical autophagy. S. Typhimurium ΔsopF resembled S. flexneri ΔvirAΔicsB with the majority of intracellular bacteria targeted by autophagy, permitting a CRISPR screen that identified host V-ATPase as an essential factor. Upon bacteria-caused vacuolar damage, the V-ATPase recruited ATG16L1 onto bacteria-containing vacuole, which was blocked by SopF. Mammalian ATG16L1 bears a WD40 domain required for interacting with the V-ATPase. Inhibiting autophagy by SopF promoted S. Typhimurium proliferation in vivo. SopF targeted Gln124 of ATP6V0C in the V-ATPase for ADP-ribosylation. Mutation of Gln124 also blocked xenophagy, but not canonical autophagy. Thus, the discovery of SopF reveals the V-ATPase-ATG16L1 axis that critically mediates autophagic recognition of intracellular pathogen.
Collapse
|
15
|
Krah A, Marzinek JK, Bond PJ. Insights into water accessible pathways and the inactivation mechanism of proton translocation by the membrane-embedded domain of V-type ATPases. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2019; 1861:1004-1010. [DOI: 10.1016/j.bbamem.2019.02.010] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2018] [Revised: 01/29/2019] [Accepted: 02/27/2019] [Indexed: 01/25/2023]
|
16
|
Wang L, Han X, Qu G, Su L, Zhao B, Miao J. A pH probe inhibits senescence in mesenchymal stem cells. Stem Cell Res Ther 2018; 9:343. [PMID: 30526663 PMCID: PMC6286523 DOI: 10.1186/s13287-018-1081-0] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2018] [Revised: 11/05/2018] [Accepted: 11/19/2018] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND Bone marrow-derived mesenchymal stem cells (BMSCs) are gradually getting attention because of its multi-directional differentiation potential, hematopoietic support, and promotion of stem cell implantation. However, cultured BMSCs in vitro possess a very limited proliferation potential, and the presence of stem cell aging has substantially restricted the effect together with the efficiency in clinical treatment. Recently, increasing attention has been paid to the connection between cellular aging and lysosomal acidification as new reports indicated that vacuolar H+-ATPase (v-ATPase) activity was altered and lysosomal pH was dysregulated in the process of cellular aging. Therefore, promoting lysosomal acidification might contribute to inhibition of cell senescence. Our previous studies showed that a novel small molecule, 3-butyl-1-chloro imidazo [1, 5-a] pyridine-7-carboxylic acid (SGJ), could selectively and sensitively respond to acidic pH with fast response (within 3 min), but whether SGJ can promote lysosomal acidification and inhibit senescence in BMSCs is unknown. METHODS Rat BMSCs were cultured based on our system that had been already documented. BMSCs were treated with SGJ and/or Bafilomycin-A1 (Baf-A1). The co-localization between SGJ and lysosomes was assessed by a confocal microscope. Acridine orange (AO) staining and the Lysosensor™ Green DND-189 reagents were used for indicating changes in lysosomal concentration of H+. Changes of senescence were detected by immunoblotting of p21 and senescence-associated beta-galactosidase (SA-β-gal) staining as well as immunofluorescence assay of senescence-associated heterochromatin foci (SAHF). Changes of autophagy were detected by immunoblotting of MAP1LC3 (LC3B) and SQSTM1 (p62). Cell proliferation was determined by flow cytometry. Cell viability was calculated by sulforhodamine B assay (SRB). The V0 proton channel of v-ATPase was knocked down by transfecting with its small interfering RNA (si-ATP6V0C). RESULTS Our work showed that SGJ can promote lysosomal acidification and inhibit senescence in BMSCs. Firstly, SGJ and lysosomes were well co-located in senescent BMSCs with the co-localization coefficient of 0.94. Secondly, SGJ increased the concentration of H+ and the protein expression of lysosome-associated membrane protein 1 (LAMP1) and lysosome-associated membrane protein 2 (LAMP2). Thirdly, SGJ suppressed the expression of p21 in the senescent BMSCs and reduced SA-β-gal positive cells. Fourthly, SGJ promoted senescent BMSCs' proliferation and protein level of LC3B but reduced the p62/SQSTM1 protein level. Furthermore, experimental group pretreated with 20 μM SGJ showed a stronger red fluorescent intensity, thinner cell morphology, less SA-β-gal positive cell, and less p21 protein level as well as higher cell viability in the presence of Baf-A1. Notably, ATP6V0C knockdown decreased the activity of v-ATPase and SGJ increased the concentration of H+. CONCLUSION Our work showed that SGJ could inhibit senescence in BMSCs and protect lysosomes by promoting expression of LAMP1 and LAMP2. Meanwhile, SGJ could promote autophagy. Furthermore, our study also suggested that SGJ was a new Baf-A1 antagonist because SGJ could target and occupy the V0 proton channel of v-ATPase.
Collapse
Affiliation(s)
- Lihong Wang
- Shandong Provincial Key Laboratory of Animal Cells and Developmental Biology, School of Life Science, Shandong University, Jinan, 250100, People's Republic of China
| | - Xianjing Han
- Shandong Provincial Key Laboratory of Animal Cells and Developmental Biology, School of Life Science, Shandong University, Jinan, 250100, People's Republic of China
| | - Guojing Qu
- Shandong Provincial Key Laboratory of Animal Cells and Developmental Biology, School of Life Science, Shandong University, Jinan, 250100, People's Republic of China
| | - Le Su
- Shandong Provincial Key Laboratory of Animal Cells and Developmental Biology, School of Life Science, Shandong University, Jinan, 250100, People's Republic of China
| | - Baoxiang Zhao
- Institute of Organic Chemistry, School of Chemistry and Chemical Engineering, Shandong University, Jinan, 250100, People's Republic of China.
| | - Junying Miao
- Shandong Provincial Key Laboratory of Animal Cells and Developmental Biology, School of Life Science, Shandong University, Jinan, 250100, People's Republic of China. .,The Key Laboratory of Cardiovascular Remodeling and Function Research, Chinese Ministry of Education and Chinese Ministry of Health, Shandong University Qilu Hospital, Jinan, 250012, People's Republic of China.
| |
Collapse
|
17
|
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.
Collapse
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
| |
Collapse
|
18
|
Bi H, Chen X, Gao S, Yu X, Xiao J, Zhang B, Liu X, Dai M. Key Triggers of Osteoclast-Related Diseases and Available Strategies for Targeted Therapies: A Review. Front Med (Lausanne) 2017; 4:234. [PMID: 29326938 PMCID: PMC5742334 DOI: 10.3389/fmed.2017.00234] [Citation(s) in RCA: 90] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2017] [Accepted: 12/04/2017] [Indexed: 01/11/2023] Open
Abstract
Osteoclasts, the only cells with bone resorption functions in vivo, maintain the balance of bone metabolism by cooperating with osteoblasts, which are responsible for bone formation. Excessive activity of osteoclasts causes many diseases such as osteoporosis, periprosthetic osteolysis, bone tumors, and Paget's disease. In contrast, osteopetrosis results from osteoclast deficiency. Available strategies for combating over-activated osteoclasts and the subsequently induced diseases can be categorized into three approaches: facilitating osteoclast apoptosis, inhibiting osteoclastogenesis, and impairing bone resorption. Bisphosphonates are representative molecules that function by triggering osteoclast apoptosis. New drugs, such as tumor necrosis factor and receptor activator of nuclear factor kappa-B ligand (RANKL) inhibitors (e.g., denosumab) have been developed for targeting the receptor activator of nuclear factor kappa-B /RANKL/osteoprotegerin system or CSF-1/CSF-1R axis, which play critical roles in osteoclast formation. Furthermore, vacuolar (H+)-ATPase inhibitors, cathepsin K inhibitors, and glucagon-like peptide 2 impair different stages of the bone resorption process. Recently, significant achievements have been made in this field. The aim of this review is to provide an updated summary of the current progress in research involving osteoclast-related diseases and of the development of targeted inhibitors of osteoclast formation.
Collapse
Affiliation(s)
- Haidi Bi
- Department of Orthopaedics, The First Affiliated Hospital of Nanchang University, Artificial Joints Engineering and Technology Research Center of Jiangxi Province, Nanchang, China
| | - Xing Chen
- Department of Orthopaedics, The People's Hospital of Changxing County, Huzhou, China
| | - Song Gao
- Department of Orthopaedics, The First Affiliated Hospital of Nanchang University, Artificial Joints Engineering and Technology Research Center of Jiangxi Province, Nanchang, China
| | - Xiaolong Yu
- Department of Orthopaedics, The First Affiliated Hospital of Nanchang University, Artificial Joints Engineering and Technology Research Center of Jiangxi Province, Nanchang, China
| | - Jun Xiao
- Department of Orthopaedics, The First Affiliated Hospital of Nanchang University, Artificial Joints Engineering and Technology Research Center of Jiangxi Province, Nanchang, China
| | - Bin Zhang
- Department of Orthopaedics, The First Affiliated Hospital of Nanchang University, Artificial Joints Engineering and Technology Research Center of Jiangxi Province, Nanchang, China
| | - Xuqiang Liu
- Department of Orthopaedics, The First Affiliated Hospital of Nanchang University, Artificial Joints Engineering and Technology Research Center of Jiangxi Province, Nanchang, China
| | - Min Dai
- Department of Orthopaedics, The First Affiliated Hospital of Nanchang University, Artificial Joints Engineering and Technology Research Center of Jiangxi Province, Nanchang, China
| |
Collapse
|
19
|
Chen YC, Backus KM, Merkulova M, Yang C, Brown D, Cravatt BF, Zhang C. Covalent Modulators of the Vacuolar ATPase. J Am Chem Soc 2016; 139:639-642. [PMID: 28010062 DOI: 10.1021/jacs.6b12511] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The vacuolar H+ ATPase (V-ATPase) is a complex multisubunit machine that regulates important cellular processes through controlling acidity of intracellular compartments in eukaryotes. Existing small-molecule modulators of V-ATPase either are restricted to targeting one membranous subunit of V-ATPase or have poorly understood mechanisms of action. Small molecules with novel and defined mechanisms of inhibition are thus needed to functionally characterize V-ATPase and to fully evaluate the therapeutic relevance of V-ATPase in human diseases. We have discovered electrophilic quinazolines that covalently modify a soluble catalytic subunit of V-ATPase with high potency and exquisite proteomic selectivity as revealed by fluorescence imaging and chemical proteomic activity-based profiling. The site of covalent modification was mapped to a cysteine residue located in a region of V-ATPase subunit A that is thought to regulate the dissociation of V-ATPase. We further demonstrate that a previously reported V-ATPase inhibitor, 3-bromopyruvate, also targets the same cysteine residue and that our electrophilic quinazolines modulate the function of V-ATPase in cells. With their well-defined mechanism of action and high proteomic specificity, the described quinazolines offer a powerful set of chemical probes to investigate the physiological and pathological roles of V-ATPase.
Collapse
Affiliation(s)
| | - Keriann M Backus
- Department of Chemical Physiology, The Scripps Research Institute , La Jolla, California 92307, United States
| | - Maria Merkulova
- MGH Center for Systems Biology, Program in Membrane Biology & Division of Nephrology, Richard B. Simches Research Center, Massachusetts General Hospital and Department of Medicine, Harvard Medical School , Boston, Massachusetts 02114, United States
| | | | - Dennis Brown
- MGH Center for Systems Biology, Program in Membrane Biology & Division of Nephrology, Richard B. Simches Research Center, Massachusetts General Hospital and Department of Medicine, Harvard Medical School , Boston, Massachusetts 02114, United States
| | - Benjamin F Cravatt
- Department of Chemical Physiology, The Scripps Research Institute , La Jolla, California 92307, United States
| | | |
Collapse
|
20
|
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]
|
21
|
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.
Collapse
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.
| |
Collapse
|
22
|
Haka AS, Barbosa-Lorenzi VC, Lee HJ, Falcone DJ, Hudis CA, Dannenberg AJ, Maxfield FR. Exocytosis of macrophage lysosomes leads to digestion of apoptotic adipocytes and foam cell formation. J Lipid Res 2016; 57:980-92. [PMID: 27044658 PMCID: PMC4878183 DOI: 10.1194/jlr.m064089] [Citation(s) in RCA: 74] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2015] [Indexed: 12/13/2022] Open
Abstract
Many types of apoptotic cells are phagocytosed and digested by macrophages. Adipocytes can be hundreds of times larger than macrophages, so they are too large to be digested by conventional phagocytic processes. The nature of the interaction between macrophages and apoptotic adipocytes has not been studied in detail. We describe a cellular process, termed exophagy, that is important for macrophage clearance of dead adipocytes and adipose tissue homeostasis. Using mouse models of obesity, human tissue, and a cell culture model, we show that macrophages form hydrolytic extracellular compartments at points of contact with dead adipocytes using local actin polymerization. These compartments are acidic and contain lysosomal enzymes delivered by exocytosis. Uptake and complete degradation of adipocyte fragments, which are released by extracellular hydrolysis, leads to macrophage foam cell formation. Exophagy-mediated foam cell formation is a highly efficient means by which macrophages internalize large amounts of lipid, which may ultimately overwhelm the metabolic capacity of the macrophage. This process provides a mechanism for degradation of objects, such as dead adipocytes, that are too large to be phagocytosed by macrophages.
Collapse
Affiliation(s)
- Abigail S Haka
- Departments of Biochemistry, Weill Cornell Medical College, New York, NY 10065
| | | | - Hyuek Jong Lee
- Medicine, Weill Cornell Medical College, New York, NY 10065
| | - Domenick J Falcone
- Pathology and Laboratory Medicine, Weill Cornell Medical College, New York, NY 10065
| | - Clifford A Hudis
- Medicine, Weill Cornell Medical College, New York, NY 10065 Department of Medicine, Memorial Sloan Kettering Cancer Center, New York, NY 10065
| | | | | |
Collapse
|
23
|
Abstract
Despite diverse and changing extracellular environments, fungi maintain a relatively constant cytosolic pH and numerous organelles of distinct lumenal pH. Key players in fungal pH control are V-ATPases and the P-type proton pump Pma1. These two proton pumps act in concert with a large array of other transporters and are highly regulated. The activities of Pma1 and the V-ATPase are coordinated under some conditions, suggesting that pH in the cytosol and organelles is not controlled independently. Genomic studies, particularly in the highly tractable S. cerevisiae, are beginning to provide a systems-level view of pH control, including transcriptional responses to acid or alkaline ambient pH and definition of the full set of regulators required to maintain pH homeostasis. Genetically encoded pH sensors have provided new insights into localized mechanisms of pH control, as well as highlighting the dynamic nature of pH responses to the extracellular environment. Recent studies indicate that cellular pH plays a genuine signaling role that connects nutrient availability and growth rate through a number of mechanisms. Many of the pH control mechanisms found in S. cerevisiae are shared with other fungi, with adaptations for their individual physiological contexts. Fungi deploy certain proton transport and pH control mechanisms not shared with other eukaryotes; these regulators of cellular pH are potential antifungal targets. This review describes current and emerging knowledge proton transport and pH control mechanisms in S. cerevisiae and briefly discusses how these mechanisms vary among fungi.
Collapse
|
24
|
Mauvezin C, Nagy P, Juhász G, Neufeld TP. Autophagosome-lysosome fusion is independent of V-ATPase-mediated acidification. Nat Commun 2015; 6:7007. [PMID: 25959678 PMCID: PMC4428688 DOI: 10.1038/ncomms8007] [Citation(s) in RCA: 281] [Impact Index Per Article: 31.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2014] [Accepted: 03/23/2015] [Indexed: 12/20/2022] Open
Abstract
The ATP-dependent proton pump V-ATPase ensures low intralysosomal pH, which is essential for lysosomal hydrolase activity. Based on studies with the V-ATPase inhibitor BafilomycinA1, lysosomal acidification is also thought to be required for fusion with incoming vesicles from the autophagic and endocytic pathways. Here we show that loss of V-ATPase subunits in the Drosophila fat body causes an accumulation of non-functional lysosomes, leading to a block in autophagic flux. However, V-ATPase-deficient lysosomes remain competent to fuse with autophagosomes and endosomes, resulting in a time-dependent formation of giant autolysosomes. In contrast, BafilomycinA1 prevents autophagosome–lysosome fusion in these cells, and this defect is phenocopied by depletion of the Ca2+ pump SERCA, a secondary target of this drug. Moreover, activation of SERCA promotes fusion in a BafilomycinA1-sensitive manner. Collectively, our results indicate that lysosomal acidification is not a prerequisite for fusion, and that BafilomycinA1 inhibits fusion independent of its effect on lysosomal pH. BafilomycinA1 is an autophagy inhibitor, presumably owing to its blocking effect on the lysosomal proton pump V-ATPase. Here the authors show that V-ATPase-deficient lysosomes can still fuse with autophagosomes, showing that lysosomal acidification and fusion are two separable, independent events.
Collapse
Affiliation(s)
- Caroline Mauvezin
- Department of Genetics, Cell Biology and Development, University of Minnesota, 6-160 Jackson Hall, 321 Church Street SE, Minneapolis, Minnesota 55455, USA
| | - Péter Nagy
- Department of Anatomy, Cell and Developmental Biology, Eötvös Loránd University, Pazmany s. 1/C. 6.520, Budapest H-1117, Hungary
| | - Gábor Juhász
- Department of Anatomy, Cell and Developmental Biology, Eötvös Loránd University, Pazmany s. 1/C. 6.520, Budapest H-1117, Hungary
| | - Thomas P Neufeld
- Department of Genetics, Cell Biology and Development, University of Minnesota, 6-160 Jackson Hall, 321 Church Street SE, Minneapolis, Minnesota 55455, USA
| |
Collapse
|
25
|
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]
|
26
|
Cotter K, Capecci J, Sennoune S, Huss M, Maier M, Martinez-Zaguilan R, Forgac M. Activity of plasma membrane V-ATPases is critical for the invasion of MDA-MB231 breast cancer cells. J Biol Chem 2014; 290:3680-92. [PMID: 25505184 DOI: 10.1074/jbc.m114.611210] [Citation(s) in RCA: 73] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
The vacuolar (H(+))-ATPases (V-ATPases) are a family of ATP-driven proton pumps that couple ATP hydrolysis with translocation of protons across membranes. Previous studies have implicated V-ATPases in cancer cell invasion. It has been proposed that V-ATPases participate in invasion by localizing to the plasma membrane and causing acidification of the extracellular space. To test this hypothesis, we utilized two separate approaches to specifically inhibit plasma membrane V-ATPases. First, we stably transfected highly invasive MDA-MB231 cells with a V5-tagged construct of the membrane-embedded c subunit of the V-ATPase, allowing for extracellular expression of the V5 epitope. We evaluated the effect of addition of a monoclonal antibody directed against the V5 epitope on both V-ATPase-mediated proton translocation across the plasma membrane and invasion using an in vitro Matrigel assay. The addition of anti-V5 antibody resulted in acidification of the cytosol and a decrease in V-ATPase-dependent proton flux across the plasma membrane in transfected but not control (untransfected) cells. These results demonstrate that the anti-V5 antibody inhibits activity of plasma membrane V-ATPases in transfected cells. Addition of the anti-V5 antibody also inhibited in vitro invasion of transfected (but not untransfected) cells. Second, we utilized a biotin-conjugated form of the specific V-ATPase inhibitor bafilomycin. When bound to streptavidin, this compound cannot cross the plasma membrane. Addition of this compound to MDA-MB231 cells also inhibited in vitro invasion. These studies suggest that plasma membrane V-ATPases play an important role in invasion of breast cancer cells.
Collapse
Affiliation(s)
- Kristina Cotter
- From the Department of Developmental, Molecular and Chemical Biology, Tufts University School of Medicine and the Program in Cellular and Molecular Physiology, Sackler School of Graduate Biomedical Sciences, Tufts University, Boston, Massachusetts 02111
| | - Joseph Capecci
- From the Department of Developmental, Molecular and Chemical Biology, Tufts University School of Medicine and the Program in Cellular and Molecular Physiology, Sackler School of Graduate Biomedical Sciences, Tufts University, Boston, Massachusetts 02111
| | - Souad Sennoune
- the Department of Cell Physiology and Molecular Biophysics, Texas Tech University, Lubbock, Texas 79430
| | - Markus Huss
- the Department of Biology/Chemistry, Division of Animal Physiology, University of Osnabrück, 49069 Osnabrück, Germany, and
| | - Martin Maier
- the Institute of Organic Chemistry, University of Tuebingen, 72076 Tuebingen, Germany
| | - Raul Martinez-Zaguilan
- the Department of Cell Physiology and Molecular Biophysics, Texas Tech University, Lubbock, Texas 79430
| | - Michael Forgac
- From the Department of Developmental, Molecular and Chemical Biology, Tufts University School of Medicine and the Program in Cellular and Molecular Physiology, Sackler School of Graduate Biomedical Sciences, Tufts University, Boston, Massachusetts 02111,
| |
Collapse
|
27
|
Tian B, Jiang T, Shao Z, Zhai Z, Li H, Fan Q, Liu X, Ouyang Z, Tang T, Jiang Q, Zheng M, Dai K, Qin A, Yu Y, Zhu Z. The prevention of titanium-particle-induced osteolysis by OA-14 through the suppression of the p38 signaling pathway and inhibition of osteoclastogenesis. Biomaterials 2014; 35:8937-50. [PMID: 25086794 DOI: 10.1016/j.biomaterials.2014.06.055] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2014] [Accepted: 06/29/2014] [Indexed: 12/29/2022]
Abstract
Wear-particle-induced osteolysis leads to prosthesis loosening, which is one of the most common causes of joint-implant failure, a problem that must be fixed using revision surgery. Thus, a potential treatment for prosthetic loosening is focused on inhibiting osteoclastic bone resorption, which prevents wear-particle-induced osteolysis. In this study, we synthesized a compound named OA-14 (N-(3- (dodecylcarbamoyl)phenyl)-1H-indole-2-carboxamide) and examined how OA-14 affects titanium (Ti)-particle-induced osteolysis and osteoclastogenesis. We report that OA-14 treatment protected against Ti-particle-induced osteolysis in a mouse calvarial model. Interestingly, the number of tartrate-resistant acid phosphatase-positive osteoclasts decreased after treatment with OA-14 in vivo, which suggested that OA-14 inhibits osteoclast formation. To test this hypothesis, we conducted in vitro studies, and our results revealed that OA-14 markedly diminished osteoclast differentiation and osteoclast-specific gene expression in a dose- and time-dependent manner. Moreover, OA-14 suppressed osteoclastic bone resorption and F-actin ring formation. Furthermore, we determined that OA-14 inhibited osteoclastogenesis by specifically blocking the p38-Mitf-c-fos-NFATc1 signaling cascade induced by RANKL (ligand of receptor activator of nuclear factor κB). Collectively, our results suggest that the compound OA-14 can be safely used for treating particle-induced peri-implant osteolysis and other diseases caused by excessive osteoclast formation and function.
Collapse
Affiliation(s)
- Bo Tian
- Shanghai Key Laboratory of Orthopaedic Implants, Department of Orthopaedics, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, PR China
| | - Tao Jiang
- The Center of Diagnosis and Treatment for Joint Disease, Drum Tower Clinical Medical College of Nanjing Medical University, Jiangsu, PR China
| | - Zhanying Shao
- College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, PR China
| | - Zanjing Zhai
- Shanghai Key Laboratory of Orthopaedic Implants, Department of Orthopaedics, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, PR China
| | - Haowei Li
- Shanghai Key Laboratory of Orthopaedic Implants, Department of Orthopaedics, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, PR China
| | - Qiming Fan
- Shanghai Key Laboratory of Orthopaedic Implants, Department of Orthopaedics, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, PR China
| | - Xuqiang Liu
- Shanghai Key Laboratory of Orthopaedic Implants, Department of Orthopaedics, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, PR China
| | - Zhengxiao Ouyang
- Shanghai Key Laboratory of Orthopaedic Implants, Department of Orthopaedics, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, PR China
| | - Tingting Tang
- Shanghai Key Laboratory of Orthopaedic Implants, Department of Orthopaedics, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, PR China
| | - Qing Jiang
- The Center of Diagnosis and Treatment for Joint Disease, Drum Tower Clinical Medical College of Nanjing Medical University, Jiangsu, PR China
| | - Minghao Zheng
- Centre for Orthopaedic Research, School of Surgery, The University of Western Australia, Perth, Australia
| | - Kerong Dai
- Shanghai Key Laboratory of Orthopaedic Implants, Department of Orthopaedics, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, PR China
| | - An Qin
- Shanghai Key Laboratory of Orthopaedic Implants, Department of Orthopaedics, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, PR China; Centre for Orthopaedic Research, School of Surgery, The University of Western Australia, Perth, Australia.
| | - Yongping Yu
- College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, PR China.
| | - Zhenan Zhu
- Shanghai Key Laboratory of Orthopaedic Implants, Department of Orthopaedics, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, PR China.
| |
Collapse
|
28
|
Nesci S, Ventrella V, Trombetti F, Pirini M, Pagliarani A. Thiol oxidation is crucial in the desensitization of the mitochondrial F1FO-ATPase to oligomycin and other macrolide antibiotics. Biochim Biophys Acta Gen Subj 2014; 1840:1882-91. [DOI: 10.1016/j.bbagen.2014.01.008] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2013] [Revised: 12/12/2013] [Accepted: 01/02/2014] [Indexed: 11/29/2022]
|
29
|
Mangieri LR, Mader BJ, Thomas CE, Taylor CA, Luker AM, Tse TE, Huisingh C, Shacka JJ. ATP6V0C knockdown in neuroblastoma cells alters autophagy-lysosome pathway function and metabolism of proteins that accumulate in neurodegenerative disease. PLoS One 2014; 9:e93257. [PMID: 24695574 PMCID: PMC3973706 DOI: 10.1371/journal.pone.0093257] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2013] [Accepted: 02/22/2014] [Indexed: 02/06/2023] Open
Abstract
ATP6V0C is the bafilomycin A1-binding subunit of vacuolar ATPase, an enzyme complex that critically regulates vesicular acidification. We and others have shown previously that bafilomycin A1 regulates cell viability, autophagic flux and metabolism of proteins that accumulate in neurodegenerative disease. To determine the importance of ATP6V0C for autophagy-lysosome pathway function, SH-SY5Y human neuroblastoma cells differentiated to a neuronal phenotype were nucleofected with non-target or ATP6V0C siRNA and following recovery were treated with either vehicle or bafilomycin A1 (0.3-100 nM) for 48 h. ATP6V0C knockdown was validated by quantitative RT-PCR and by a significant decrease in Lysostracker Red staining. ATP6V0C knockdown significantly increased basal levels of microtubule-associated protein light chain 3-II (LC3-II), α-synuclein high molecular weight species and APP C-terminal fragments, and inhibited autophagic flux. Enhanced LC3 and LAMP-1 co-localization following knockdown suggests that autophagic flux was inhibited in part due to lysosomal degradation and not by a block in vesicular fusion. Knockdown of ATP6V0C also sensitized cells to the accumulation of autophagy substrates and a reduction in neurite length following treatment with 1 nM bafilomycin A1, a concentration that did not produce such alterations in non-target control cells. Reduced neurite length and the percentage of propidium iodide-positive dead cells were also significantly greater following treatment with 3 nM bafilomycin A1. Together these results indicate a role for ATP6V0C in maintaining constitutive and stress-induced ALP function, in particular the metabolism of substrates that accumulate in age-related neurodegenerative disease and may contribute to disease pathogenesis.
Collapse
Affiliation(s)
- Leandra R. Mangieri
- Department Pathology, Neuropathology Division, University of Alabama at Birmingham, Birmingham, Alabama, United States of America
| | - Burton J. Mader
- Department Pathology, Neuropathology Division, University of Alabama at Birmingham, Birmingham, Alabama, United States of America
- Birmingham Veterans Administration Medical Center, Birmingham, Alabama, United States of America
| | - Cailin E. Thomas
- Department Pathology, Neuropathology Division, University of Alabama at Birmingham, Birmingham, Alabama, United States of America
| | - Charles A. Taylor
- Department Pathology, Neuropathology Division, University of Alabama at Birmingham, Birmingham, Alabama, United States of America
| | - Austin M. Luker
- Department Pathology, Neuropathology Division, University of Alabama at Birmingham, Birmingham, Alabama, United States of America
| | - Tonia E. Tse
- Department Pathology, Neuropathology Division, University of Alabama at Birmingham, Birmingham, Alabama, United States of America
| | - Carrie Huisingh
- Department Ophthalmology, University of Alabama at Birmingham, Birmingham, Alabama, United States of America
| | - John J. Shacka
- Department Pathology, Neuropathology Division, University of Alabama at Birmingham, Birmingham, Alabama, United States of America
- Department Ophthalmology, University of Alabama at Birmingham, Birmingham, Alabama, United States of America
| |
Collapse
|
30
|
Petchampai N, Sunyakumthorn P, Guillotte ML, Thepparit C, Kearney MT, Mulenga A, Azad AF, Macaluso KR. Molecular and functional characterization of vacuolar-ATPase from the American dog tick Dermacentor variabilis. INSECT MOLECULAR BIOLOGY 2014; 23:42-51. [PMID: 24164319 PMCID: PMC4237192 DOI: 10.1111/imb.12059] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Vacuolar (V)-ATPase is a proton-translocating enzyme that acidifies cellular compartments for various functions such as receptor-mediated endocytosis, intracellular trafficking and protein degradation. Previous studies in Dermacentor variabilis chronically infected with Rickettsia montanensis have identified V-ATPase as one of the tick-derived molecules transcribed in response to rickettsial infection. To examine the role of the tick V-ATPase in tick-Rickettsia interactions, a full-length 2887-bp cDNA (2532-bp open reading frame) clone corresponding to the transcript of the V0 domain subunit a of D. variabilis V-ATPase (DvVATPaseV0a) gene encoding an 843 amino acid protein with an estimated molecular weight of ~96 kDa was isolated from D. variabilis. Amino acid sequence analysis of DvVATPaseV0a showed the highest similarity to VATPaseV0a from Ixodes scapularis. A potential N-glycosylation site and eight putative transmembrane segments were identified in the sequence. Western blot analysis of tick tissues probed with polyclonal antibody raised against recombinant DvVATPaseV0a revealed the expression of V-ATPase in the tick ovary. Transcriptional profiles of DvVATPaseV0a demonstrated a greater mRNA expression in the tick ovary, compared with the midgut and salivary glands; however, the mRNA level in each of these tick tissues remained unchanged after infection with R. montanensis for 1 h. V-ATPase inhibition bioassays resulted in a significant decrease in the ability of R. montanensis to invade tick cells in vitro, suggesting a role of V-ATPase in rickettsial infection of tick cells. Characterization of tick-derived molecules involved in rickettsial infection is essential for a thorough understanding of rickettsial transmission within tick populations and the ecology of tick-borne rickettsial diseases.
Collapse
Affiliation(s)
- N Petchampai
- Department of Pathobiological Sciences, School of Veterinary Medicine, Louisiana State UniversityBaton Rouge, LA, USA
| | - P Sunyakumthorn
- Department of Pathobiological Sciences, School of Veterinary Medicine, Louisiana State UniversityBaton Rouge, LA, USA
- Mahidol-Oxford Tropical Medicine Research Unit, Mahidol UniversityBangkok, Thailand
| | - M L Guillotte
- Department of Pathobiological Sciences, School of Veterinary Medicine, Louisiana State UniversityBaton Rouge, LA, USA
| | - C Thepparit
- Department of Pathobiological Sciences, School of Veterinary Medicine, Louisiana State UniversityBaton Rouge, LA, USA
- Center for Vaccine Development, Institute of Molecular Biosciences, Mahidol UniversityNakorn Pathom, Thailand
| | - M T Kearney
- Department of Pathobiological Sciences, School of Veterinary Medicine, Louisiana State UniversityBaton Rouge, LA, USA
| | - A Mulenga
- Department of Entomology, 2475 Texas A & M UniversityCollege Station, TX, USA
| | - A F Azad
- Department of Microbiology and Immunology, School of Medicine, University of MarylandBaltimore, MD, USA
| | - K R Macaluso
- Department of Pathobiological Sciences, School of Veterinary Medicine, Louisiana State UniversityBaton Rouge, LA, USA
| |
Collapse
|
31
|
Vacuolar H+-ATPase: An Essential Multitasking Enzyme in Physiology and Pathophysiology. ACTA ACUST UNITED AC 2014. [DOI: 10.1155/2014/675430] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Vacuolar H+-ATPases (V-ATPases) are large multisubunit proton pumps that are required for housekeeping acidification of membrane-bound compartments in eukaryotic cells. Mammalian V-ATPases are composed of 13 different subunits. Their housekeeping functions include acidifying endosomes, lysosomes, phagosomes, compartments for uncoupling receptors and ligands, autophagosomes, and elements of the Golgi apparatus. Specialized cells, including osteoclasts, intercalated cells in the kidney and pancreatic beta cells, contain both the housekeeping V-ATPases and an additional subset of V-ATPases, which plays a cell type specific role. The specialized V-ATPases are typically marked by the inclusion of cell type specific isoforms of one or more of the subunits. Three human diseases caused by mutations of isoforms of subunits have been identified. Cancer cells utilize V-ATPases in unusual ways; characterization of V-ATPases may lead to new therapeutic modalities for the treatment of cancer. Two accessory proteins to the V-ATPase have been identified that regulate the proton pump. One is the (pro)renin receptor and data is emerging that indicates that V-ATPase may be intimately linked to renin/angiotensin signaling both systemically and locally. In summary, V-ATPases play vital housekeeping roles in eukaryotic cells. Specialized versions of the pump are required by specific organ systems and are involved in diseases.
Collapse
|
32
|
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.
Collapse
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.
| |
Collapse
|
33
|
Kubisch R, Fröhlich T, Arnold GJ, Schreiner L, von Schwarzenberg K, Roidl A, Vollmar AM, Wagner E. V-ATPase inhibition by archazolid leads to lysosomal dysfunction resulting in impaired cathepsin B activation in vivo. Int J Cancer 2013; 134:2478-88. [PMID: 24166050 DOI: 10.1002/ijc.28562] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2013] [Revised: 09/02/2013] [Accepted: 10/08/2013] [Indexed: 01/08/2023]
Abstract
The myxobacterial agent archazolid inhibits the vacuolar proton pump V-ATPase. V-ATPases are ubiquitously expressed ATP-dependent proton pumps, which are known to regulate the pH in endomembrane systems and thus play a crucial role in endo- and exocytotic processes of the cell. As cancer cells depend on a highly active secretion of proteolytic proteins in order to invade tissue and form metastases, inhibition of V-ATPase is proposed to affect the secretion profile of cancer cells and thus potentially abrogate their metastatic properties. Archazolid is a novel V-ATPase inhibitor. Here, we show that the secretion pattern of archazolid treated cancer cells includes various prometastatic lysosomal proteins like cathepsin A, B, C, D and Z. In particular, archazolid induced the secretion of the proforms of cathepsin B and D. Archazolid treatment abrogates the cathepsin B maturation process leading to reduced intracellular mature cathepsin B protein abundance and finally decreased cathepsin B activity, by inhibiting mannose-6-phoshate receptor-dependent trafficking. Importantly, in vivo reduced cathepsin B protein as well as a decreased proteolytic cathepsin B activity was detected in tumor tissue of archazolid-treated mice. Our results show that inhibition of V-ATPase by archazolid reduces the activity of prometastatic proteases like cathepsin B in vitro and in vivo.
Collapse
Affiliation(s)
- Rebekka Kubisch
- Pharmaceutical Biotechnology Department of Pharmacy, Ludwig Maximilians University, Munich, Germany
| | | | | | | | | | | | | | | |
Collapse
|
34
|
Candida albicans VMA3 is necessary for V-ATPase assembly and function and contributes to secretion and filamentation. EUKARYOTIC CELL 2013; 12:1369-82. [PMID: 23913543 DOI: 10.1128/ec.00118-13] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The vacuolar membrane ATPase (V-ATPase) is a protein complex that utilizes ATP hydrolysis to drive protons from the cytosol into the vacuolar lumen, acidifying the vacuole and modulating several key cellular response systems in Saccharomyces cerevisiae. To study the contribution of V-ATPase to the biology and virulence attributes of the opportunistic fungal pathogen Candida albicans, we created a conditional mutant in which VMA3 was placed under the control of a tetracycline-regulated promoter (tetR-VMA3 strain). Repression of VMA3 in the tetR-VMA3 strain prevents V-ATPase assembly at the vacuolar membrane and reduces concanamycin A-sensitive ATPase-specific activity and proton transport by more than 90%. Loss of C. albicans V-ATPase activity alkalinizes the vacuolar lumen and has pleiotropic effects, including pH-dependent growth, calcium sensitivity, and cold sensitivity. The tetR-VMA3 strain also displays abnormal vacuolar morphology, indicative of defective vacuolar membrane fission. The tetR-VMA3 strain has impaired aspartyl protease and lipase secretion, as well as attenuated virulence in an in vitro macrophage killing model. Repression of VMA3 suppresses filamentation, and V-ATPase-dependent filamentation defects are not rescued by overexpression of RIM8, MDS3, EFG1, CST20, or UME6, which encode positive regulators of filamentation. Specific chemical inhibition of Vma3p function also results in defective filamentation. These findings suggest either that V-ATPase functions downstream of these transcriptional regulators or that V-ATPase function during filamentation involves independent mechanisms and alternative signaling pathways. Taken together, these data indicate that V-ATPase activity is a fundamental requirement for several key virulence-associated traits in C. albicans.
Collapse
|
35
|
Development and validation of a flow cytometric method to evaluate phagocytosis of pHrodo™ BioParticles® by granulocytes in multiple species. J Immunol Methods 2013; 390:9-17. [DOI: 10.1016/j.jim.2011.06.027] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2011] [Revised: 06/24/2011] [Accepted: 06/24/2011] [Indexed: 12/21/2022]
|
36
|
Bafilomycin A1 activates HIF-dependent signalling in human colon cancer cells via mitochondrial uncoupling. Biosci Rep 2013; 32:587-95. [PMID: 22943412 PMCID: PMC3497721 DOI: 10.1042/bsr20120085] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Mitochondrial uncoupling is implicated in many patho(physiological) states. Using confocal live cell imaging and an optical O2 sensing technique, we show that moderate uncoupling of the mitochondria with plecomacrolide Baf (bafilomycin A1) causes partial depolarization of the mitochondria and deep sustained deoxygenation of human colon cancer HCT116 cells subjected to 6% atmospheric O2. A decrease in iO2 (intracellular O2) to 0–10 μM, induced by Baf, is sufficient for stabilization of HIFs (hypoxia inducible factors) HIF-1α and HIF-2α, coupled with an increased expression of target genes including GLUT1 (glucose transporter 1), HIF PHD2 (prolyl hydroxylase domain 2) and CAIX (carbonic anhydrase IX). Under the same hypoxic conditions, treatment with Baf causes neither decrease in iO2 nor HIF-α stabilization in the low-respiring HCT116 cells deficient in COX (cytochrome c-oxidase). Both cell types display equal capacities for HIF-α stabilization by hypoxia mimetics DMOG (dimethyloxalylglycine) and CoCl2, thus suggesting that the effect of Baf under hypoxia is driven mainly by mitochondrial respiration. Altogether, by activating HIF signalling under moderate hypoxia, mitochondrial uncoupling can play an important regulatory role in colon cancer metabolism and modulate adaptation of cancer cells to natural hypoxic environments.
Collapse
|
37
|
Competitive advantage and tolerance of selected shochu yeast in barley shochu mash. J Biosci Bioeng 2013; 116:79-84. [PMID: 23453279 DOI: 10.1016/j.jbiosc.2013.01.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2012] [Revised: 01/14/2013] [Accepted: 01/16/2013] [Indexed: 01/17/2023]
Abstract
A shochu yeast strain, Saccharomyces cerevisiae BAW-6, was previously isolated from Kagoshima yeast strain Ko, and has since been utilized in shochu production. The BAW-6 strain carries pho3/pho3 homozygous genes in contrast to the heterozygous PHO3/pho3 genes in the parental Ko strain. However, absence of the PHO3 gene per se cannot explain the fermentation superiority of BAW-6. Here, we demonstrate the growth advantage of the BAW-6 strain over the Ko strain by competitive cultivation in barley shochu preparation, where alcohol yield and nihonshudo of the former strain were higher than those of the latter strain. In addition, the maximum growth rate of BAW-6 was less affected than that of Ko by high Brix values of barley koji medium, suggesting that BAW-6 is less sensitive to growth inhibitory compounds derived from barley or barley koji. The tolerance of BAW-6 to growth inhibitory compounds, cerulenin and diethylstilbestrol (an H⁺-ATPase inhibitor), was also higher than that of other yeast strains. Consistent with BAW-6's tolerance to diethylstilbestrol in the presence of 8% ethanol (pH 4.5), H⁺-ATPase activity, but not transcription of its gene, was higher in BAW-6 than in Ko. We conclude that the BAW-6 strain is associated with certain gene alterations other than PHO3, such that it can maintain cellular ion homeostasis under conditions of ethanol stress during the latter phase of fermentation.
Collapse
|
38
|
Michel V, Licon-Munoz Y, Trujillo K, Bisoffi M, Parra KJ. Inhibitors of vacuolar ATPase proton pumps inhibit human prostate cancer cell invasion and prostate-specific antigen expression and secretion. Int J Cancer 2013; 132:E1-10. [PMID: 22945374 PMCID: PMC3504192 DOI: 10.1002/ijc.27811] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2012] [Accepted: 08/14/2012] [Indexed: 11/09/2022]
Abstract
Vacuolar ATPases (V-ATPases) comprise specialized and ubiquitously distributed pumps that acidify intracellular compartments and energize membranes. To gain new insights into the roles of V-ATPases in prostate cancer (PCa), we studied the effects of inhibiting V-ATPase pumps in androgen-dependent (LNCaP) and androgen-independent (C4-2B) cells of a human PCa progression model. Treatment with nanomolar concentrations of the V-ATPase inhibitors bafilomycin A or concanamycin A reduced the in vitro invasion in both cell types by 80%, regardless that V-ATPase was prominent at the plasma membrane of C4-2B cells and only traces were detected in the low-metastatic LNCaP parental cells. In both cell types, intracellular V-ATPase was excessive and co-localized with prostate-specific antigen (PSA) in the Golgi compartment. V-ATPase inhibitors reversibly excluded PSA from the Golgi and led to the accumulation of largely dispersed PSA-loaded vesicles of lysosomal composition. Inhibition of acridine orange staining and transferrin receptor recycling suggested defective endosomal and lysosomal acidification. The inhibitors, additionally, interfered with the AR-PSA axis under conditions that reduced invasion. Bafilomycin A significantly reduced steady-state and R1881-induced PSA mRNA expression and secretion in the LNCaP cells which are androgen-dependent, but not in the C4-2B cells which are androgen ablation-resistant. In the C4-2B cells, an increased susceptibility to V-ATPase inhibitors was detected after longer treatments, as proliferation was reduced and reversibility of bafilomycin-induced responses impaired. These findings make V-ATPases attractive targets against early and advanced PCa tumors.
Collapse
Affiliation(s)
- Vera Michel
- Department of Biochemistry and Molecular Biology, School of Medicine, University of New Mexico Health Sciences Center, Albuquerque, New Mexico, USA, 87131
| | - Yamhilette Licon-Munoz
- Department of Biochemistry and Molecular Biology, School of Medicine, University of New Mexico Health Sciences Center, Albuquerque, New Mexico, USA, 87131
| | - Kristina Trujillo
- Department of Biochemistry and Molecular Biology, School of Medicine, University of New Mexico Health Sciences Center, Albuquerque, New Mexico, USA, 87131
| | - Marco Bisoffi
- Department of Biochemistry and Molecular Biology, School of Medicine, University of New Mexico Health Sciences Center, Albuquerque, New Mexico, USA, 87131
| | - Karlett J. Parra
- Department of Biochemistry and Molecular Biology, School of Medicine, University of New Mexico Health Sciences Center, Albuquerque, New Mexico, USA, 87131
| |
Collapse
|
39
|
Persch E, Basile T, Bockelmann S, Huss M, Wieczorek H, Carlomagno T, Menche D. Synthesis and biological evaluation of a water-soluble derivative of the potent V-ATPase inhibitor archazolid. Bioorg Med Chem Lett 2012; 22:7735-8. [DOI: 10.1016/j.bmcl.2012.09.081] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2012] [Revised: 09/19/2012] [Accepted: 09/22/2012] [Indexed: 10/27/2022]
|
40
|
Osteresch C, Bender T, Grond S, von Zezschwitz P, Kunze B, Jansen R, Huss M, Wieczorek H. The binding site of the V-ATPase inhibitor apicularen is in the vicinity of those for bafilomycin and archazolid. J Biol Chem 2012; 287:31866-76. [PMID: 22815478 DOI: 10.1074/jbc.m112.372169] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The investigation of V-ATPases as potential therapeutic drug targets and hence of their specific inhibitors is a promising approach in osteoporosis and cancer treatment because the occurrence of these diseases is interrelated to the function of the V-ATPase. Apicularen belongs to the novel inhibitor family of the benzolactone enamides, which are highly potent but feature the unique characteristic of not inhibiting V-ATPases from fungal sources. In this study we specify, for the first time, the binding site of apicularen within the membrane spanning V(O) complex. By photoaffinity labeling using derivatives of apicularen and of the plecomacrolides bafilomycin and concanamycin, each coupled to (14)C-labeled 4-(3-trifluoromethyldiazirin-3-yl)benzoic acid, we verified that apicularen binds at the interface of the V(O) subunits a and c. The binding site is in the vicinity to those of the plecomacrolides and of the archazolids, a third family of V-ATPase inhibitors. Expression of subunit c homologues from Homo sapiens and Manduca sexta, both species sensitive to benzolactone enamides, in a Saccharomyces cerevisiae strain lacking the corresponding intrinsic gene did not transfer this sensitivity to yeast. Therefore, the binding site of benzolactone enamides cannot be formed exclusively by subunit c. Apparently, subunit a substantially contributes to the binding of the benzolactone enamides.
Collapse
Affiliation(s)
- Christin Osteresch
- Fachbereich Biologie/Chemie, Abteilung Tierphysiologie, Universität Osnabrück, Barbarastrasse 11, 49069 Osnabrück, German
| | | | | | | | | | | | | | | |
Collapse
|
41
|
Qin A, Cheng TS, Pavlos NJ, Lin Z, Dai KR, Zheng MH. V-ATPases in osteoclasts: structure, function and potential inhibitors of bone resorption. Int J Biochem Cell Biol 2012; 44:1422-35. [PMID: 22652318 DOI: 10.1016/j.biocel.2012.05.014] [Citation(s) in RCA: 102] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2012] [Revised: 05/18/2012] [Accepted: 05/18/2012] [Indexed: 01/06/2023]
Abstract
The vacuolar-type H(+)-ATPase (V-ATPase) proton pump is a macromolecular complex composed of at least 14 subunits organized into two functional domains, V(1) and V(0). The complex is located on the ruffled border plasma membrane of bone-resorbing osteoclasts, mediating extracellular acidification for bone demineralization during bone resorption. Genetic studies from mice to man implicate a critical role for V-ATPase subunits in osteoclast-related diseases including osteopetrosis and osteoporosis. Thus, the V-ATPase complex is a potential molecular target for the development of novel anti-resorptive agents useful for the treatment of osteolytic diseases. Here, we review the current structure and function of V-ATPase subunits, emphasizing their exquisite roles in osteoclastic function. In addition, we compare several distinct classes of V-ATPase inhibitors with specific inhibitory effects on osteoclasts. Understanding the structure-function relationship of the osteoclast V-ATPase may lead to the development of osteoclast-specific V-ATPase inhibitors that may serve as alternative therapies for the treatment of osteolytic diseases.
Collapse
Affiliation(s)
- A Qin
- Centre for Orthopaedic Research, School of Surgery, The University of Western Australia, Crawley, Australia.
| | | | | | | | | | | |
Collapse
|
42
|
Müller KH, Kainov DE, El Bakkouri K, Saelens X, De Brabander JK, Kittel C, Samm E, Muller CP. The proton translocation domain of cellular vacuolar ATPase provides a target for the treatment of influenza A virus infections. Br J Pharmacol 2012; 164:344-57. [PMID: 21418188 DOI: 10.1111/j.1476-5381.2011.01346.x] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
BACKGROUND AND PURPOSE Cellular vacuolar ATPases (v-ATPase) play an important role in endosomal acidification, a critical step in influenza A virus (IAV) host cell infection. We investigated the antiviral activity of the v-ATPase inhibitor saliphenylhalamide (SaliPhe) and compared it with several older v-ATPase inhibitors concanamycin A, bafilomycin A1, (BafA) and archazolid B targeting the subunit c of the V(0) sector. EXPERIMENTAL APPROACH An in vitro assay was devised to quantify the anti-influenza effect of v-ATPase inhibitors by measuring green fluorescent protein fluorescence of a reporter IAV. These data were combined with cytotoxicity testing to calculate selectivity indices. Data were validated by testing v-ATPase inhibitors against wild-type IAV in vitro and in vivo in mice. KEY RESULTS In vitro SaliPhe blocked the proliferation of pandemic and multidrug resistant viruses at concentrations up to 51-fold below its cytotoxic concentrations. At essentially non-toxic concentrations, SaliPhe protected 62.5% of mice against a lethal challenge of a mouse-adapted influenza strain, while BafA at cytotoxic concentrations showed essentially no protection against infection with IAV (SaliPhe vs. BafA P < 0.001). CONCLUSIONS AND IMPLICATIONS Our results show that a distinct binding site of the proton translocation domain of cellular v-ATPase can be selectively targeted by a new generation v-ATPase inhibitor with reduced toxicity to treat influenza virus infections, including multi-resistant strains. Treatment strategies against influenza that target host cellular proteins are expected to be more resistant to virus mutations than drugs blocking viral proteins.
Collapse
Affiliation(s)
- Konstantin H Müller
- Institute of Immunology, Centre de Recherche Public-Santé/Laboratoire National de Santé, Luxembourg, Luxembourg.
| | | | | | | | | | | | | | | |
Collapse
|
43
|
Prevention of wear particle-induced osteolysis by a novel V-ATPase inhibitor saliphenylhalamide through inhibition of osteoclast bone resorption. PLoS One 2012; 7:e34132. [PMID: 22509274 PMCID: PMC3324493 DOI: 10.1371/journal.pone.0034132] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2011] [Accepted: 02/22/2012] [Indexed: 11/19/2022] Open
Abstract
Wear particle-induced peri-implant loosening (Aseptic prosthetic loosening) is one of the most common causes of total joint arthroplasty. It is well established that extensive bone destruction (osteolysis) by osteoclasts is responsible for wear particle-induced peri-implant loosening. Thus, inhibition of osteoclastic bone resorption should prevent wear particle induced osteolysis and may serve as a potential therapeutic avenue for prosthetic loosening. Here, we demonstrate for the first time that saliphenylhalamide, a new V-ATPase inhibitor attenuates wear particle-induced osteolysis in a mouse calvarial model. In vitro biochemical and morphological assays revealed that the inhibition of osteolysis is partially attributed to a disruption in osteoclast acidification and polarization, both a prerequisite for osteoclast bone resorption. Interestingly, the V-ATPase inhibitor also impaired osteoclast differentiation via the inhibition of RANKL-induced NF-κB and ERK signaling pathways. In conclusion, we showed that saliphenylhalamide affected multiple physiological processes including osteoclast differentiation, acidification and polarization, leading to inhibition of osteoclast bone resorption in vitro and wear particle-induced osteolysis in vivo. The results of the study provide proof that the new generation V-ATPase inhibitors, such as saliphenylhalamide, are potential anti-resorptive agents for treatment of peri-implant osteolysis.
Collapse
|
44
|
Dyve Lingelem AB, Bergan J, Sandvig K. Inhibitors of intravesicular acidification protect against Shiga toxin in a pH-independent manner. Traffic 2011; 13:443-54. [PMID: 22132807 DOI: 10.1111/j.1600-0854.2011.01319.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2011] [Revised: 11/28/2011] [Accepted: 12/01/2011] [Indexed: 01/01/2023]
Abstract
Shiga toxin inhibits protein synthesis after being transported from the cell surface to endosomes and retrogradely through the Golgi apparatus to the endoplasmic reticulum (ER) and into the cytosol. In this study, we have abolished proton gradients across internal membranes in different ways and investigated the effect on the various transport steps of Shiga toxin. Although inhibitors of the proton pump such as bafilomycin A1 and concanamycin A as well as some ionophores and chloroquine all protect against Shiga toxin, they mediate protection by inhibiting different transport steps. For instance, chloroquine protects the cells, although the toxin is transported to the ER. Importantly, our data indicate that proton pump activity is required for efficient endosome-to-Golgi transport of Shiga toxin, although acidification as such does not seem to be required.
Collapse
Affiliation(s)
- Anne Berit Dyve Lingelem
- Centre for Cancer Biomedicine, Faculty of Medicine, University of Oslo, Montebello, 0379 Oslo, Norway
| | | | | |
Collapse
|
45
|
Abstract
Mammalian target of rapamycin (mTOR) complex 1 (mTORC1) is an important, highly conserved, regulator of cell growth. Ancient among the signals that regulate mTORC1 are nutrients. Amino acids direct mTORC1 to the surface of the late endosome/lysosome, where mTORC1 becomes receptive to other inputs. However, the interplay between endosomes and mTORC1 is poorly understood. Here, we report the discovery of a network that links mTORC1 to a critical component of the late endosome/lysosome, the V-ATPase. In an unbiased screen, we found that mTORC1 regulated the expression of, among other lysosomal genes, the V-ATPases. mTORC1 regulates V-ATPase expression both in cells and in mice. V-ATPase regulation by mTORC1 involves a transcription factor translocated in renal cancer, TFEB. TFEB is required for the expression of a large subset of mTORC1 responsive genes. mTORC1 coordinately regulates TFEB phosphorylation and nuclear localization and in a manner dependent on both TFEB and V-ATPases, mTORC1 promotes endocytosis. These data uncover a regulatory network linking an oncogenic transcription factor that is a master regulator of lysosomal biogenesis, TFEB, to mTORC1 and endocytosis.
Collapse
|
46
|
Huss M, Vitavska O, Albertmelcher A, Bockelmann S, Nardmann C, Tabke K, Tiburcy F, Wieczorek H. Vacuolar H(+)-ATPases: intra- and intermolecular interactions. Eur J Cell Biol 2011; 90:688-95. [PMID: 21640428 DOI: 10.1016/j.ejcb.2011.04.009] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
V-ATPases in eukaryotes are heteromultimeric, H(+)-transporting proteins. They are localized in a multitude of different membranes and energize many different transport processes. Unique features of V-ATPases are, on the one hand, their ability to regulate enzymatic and ion transporting activity by the reversible dissociation of the catalytic V(1) complex from the membrane bound proton translocating V(0) complex and, on the other hand, their high sensitivity to specific macrolides such as bafilomycin and concanamycin from streptomycetes or archazolid and apicularen from myxomycetes. Both features require distinct intramolecular as well as intermolecular interactions. Here we will summarize our own results together with newer developments in both of these research areas.
Collapse
Affiliation(s)
- Markus Huss
- University of Osnabrück, Faculty of Biology and Chemistry, Department of Animal Physiology, Barbarastrasse 11, 49076 Osnabrück, Germany.
| | | | | | | | | | | | | | | |
Collapse
|
47
|
Abstract
AbstractThe rotary ATPase family of membrane protein complexes may have only three members, but each one plays a fundamental role in biological energy conversion. The F1Fo-ATPase (F-ATPase) couples ATP synthesis to the electrochemical membrane potential in bacteria, mitochondria and chloroplasts, while the vacuolar H+-ATPase (V-ATPase) operates as an ATP-driven proton pump in eukaryotic membranes. In different species of archaea and bacteria, the A1Ao-ATPase (A-ATPase) can function as either an ATP synthase or an ion pump. All three of these multi-subunit complexes are rotary molecular motors, sharing a fundamentally similar mechanism in which rotational movement drives the energy conversion process. By analogy to macroscopic systems, individual subunits can be assigned to rotor, axle or stator functions. Recently, three-dimensional reconstructions from electron microscopy and single particle image processing have led to a significant step forward in understanding of the overall architecture of all three forms of these complexes and have allowed the organisation of subunits within the rotor and stator parts of the motors to be more clearly mapped out. This review describes the emerging consensus regarding the organisation of the rotor and stator components of V-, A- and F-ATPases, examining core similarities that point to a common evolutionary origin, and highlighting key differences. In particular, it discusses how newly revealed variation in the complexity of the inter-domain connections may impact on the mechanics and regulation of these molecular machines.
Collapse
|
48
|
Ma B, Xiang Y, An L. Structural bases of physiological functions and roles of the vacuolar H(+)-ATPase. Cell Signal 2011; 23:1244-56. [PMID: 21397012 DOI: 10.1016/j.cellsig.2011.03.003] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2011] [Accepted: 03/03/2011] [Indexed: 12/09/2022]
Abstract
Vacuolar-type H(+)-ATPases (V-ATPases) is a large multi-protein complex containing at least 14 different subunits, in which subunits A, B, C, D, E, F, G, and H compose the peripheral 500-kDa V(1) responsible for ATP hydrolysis, and subunits a, c, c', c″, and d assembly the 250-kDa membrane-integral V(0) harboring the rotary mechanism to transport protons across the membrane. The assembly of V-ATPases requires the presence of all V(1) and V(0) subunits, in which the V(1) must be completely assembled prior to association with the V(0), accordingly the V(0) failing to assemble cannot provide a membrane anchor for the V(1), thereby prohibiting membrane association of the V-ATPase subunits. The V-ATPase mediates acidification of intracellular compartments and regulates diverse critical physiological processes of cell for functions of its numerous functional subunits. The core catalytic mechanism of the V-ATPase is a rotational catalytic mechanism. The V-ATPase holoenzyme activity is regulated by the reversible assembly/disassembly of the V(1) and V(0), the targeting and recycling of V-ATPase-containing vesicles to and from the plasma membrane, the coupling ratio between ATP hydrolysis and proton pumping, ATP, Ca(2+), and its inhibitors and activators.
Collapse
Affiliation(s)
- Binyun Ma
- Key Laboratory of Arid and Grassland Agroecology of Ministry of Education, School of Life Sciences, Lanzhou University, 730000, Lanzhou, China
| | | | | |
Collapse
|
49
|
Marjuki H, Gornitzky A, Marathe BM, Ilyushina NA, Aldridge JR, Desai G, Webby RJ, Webster RG. Influenza A virus-induced early activation of ERK and PI3K mediates V-ATPase-dependent intracellular pH change required for fusion. Cell Microbiol 2010; 13:587-601. [PMID: 21129142 DOI: 10.1111/j.1462-5822.2010.01556.x] [Citation(s) in RCA: 88] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The vacuolar (H+)-ATPases (V-ATPases) facilitate the release of influenza A virus (IAV) genome into the cytoplasm by acidifying the endosomal interior. The regulation of V-ATPases by signalling pathways has been demonstrated in various model systems. However, little is known about signalling-regulated V-ATPase activation during IAV infection. Here we show that V-ATPase activity is elevated during infection of cell monolayers with IAV, as measured by intracellular pH change, via a mechanism mediated by extracellular signal-regulated kinase (ERK) and phosphatidylinositol 3-kinase (PI3K). Inhibition of IAV-induced early activation of these kinases reduced V-ATPase activity and the acidification of intracellular compartments in infected cells. IAV-activated ERK and PI3K appear to interact directly, and they colocalize with the E subunit of V-ATPase V1 domain. Further, siRNAs targeting the E2 subunit isoform significantly reduced virus titres. Interestingly, suppression of PI3K early activation, but not that of ERK or V-ATPase, negatively affected virus internalization, suggesting the involvement of the pathway in earlier, V-ATPase-independent infection-promoting events. Cell treatment with a V-ATPase-specific inhibitor impaired the nuclear localization of incoming viral ribonucleoproteins, inhibiting replication/transcription of viral RNAs. These findings highlight the importance of IAV-induced ERK and PI3K early activation as signalling mediators in V-ATPase-stimulated endosomal acidification required for fusion.
Collapse
Affiliation(s)
- Henju Marjuki
- Division of Virology, Department of Infectious Diseases, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | | | | | | | | | | | | | | |
Collapse
|
50
|
Dawaliby R, Mayer A. Microautophagy of the nucleus coincides with a vacuolar diffusion barrier at nuclear-vacuolar junctions. Mol Biol Cell 2010; 21:4173-83. [PMID: 20943953 PMCID: PMC2993746 DOI: 10.1091/mbc.e09-09-0782] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Nuclei bind yeast vacuoles via nucleus-vacuole (NV) junctions. Under nutrient restriction, NV junctions invaginate and release vesicles filled with nuclear material into vacuoles, resulting in piecemeal microautophagy of the nucleus (PMN). We show that the electrochemical gradient across the vacuolar membrane promotes invagination of NV junctions. Existing invaginations persist independently of the gradient, but final release of PMN vesicles requires again V-ATPase activity. We find that NV junctions form a diffusion barrier on the vacuolar membrane that excludes V-ATPase but is enriched in the VTC complex and accessible to other membrane-integral proteins. V-ATPase exclusion depends on the NV junction proteins Nvj1p,Vac8p, and the electrochemical gradient. It also depends on factors of lipid metabolism, such as the oxysterol binding protein Osh1p and the enoyl-CoA reductase Tsc13p, which are enriched in NV junctions, and on Lag1p and Fen1p. Our observations suggest that NV junctions form in two separable steps: Nvj1p and Vac8p suffice to establish contact between the two membranes. The electrochemical potential and lipid-modifying enzymes are needed to establish the vacuolar diffusion barrier, invaginate NV junctions, and form PMN vesicles.
Collapse
Affiliation(s)
- Rosie Dawaliby
- Département de Biochimie, Université de Lausanne, Chemin des Boveresses 155, 1066 Epalinges, Switzerland
| | | |
Collapse
|